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Safety Evaluation Report Related to the License Renewal of Oconee Nuclear Station, Units 1, 2 and 3 (NUREG-1723) |
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Docket Nos. 50-269, 50-270, and 50-287
Duke Energy Corporation
Manuscript Completed: March 2000
Date Published: March 2000
Division of Regulatory Improvement Program
Office of Nuclear Reactor Regulation
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001
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This safety evaluation report (SER) documents the technical review of the Oconee Nuclear Station (ONS), Unit Nos. 1, 2, and 3 license renewal application (LRA) by the U.S. Nuclear Regulatory Commission (NRC) staff. By letter dated July 6, 1998, Duke Energy Corporation (Duke) submitted the license renewal application for the ONS in accordance with Title 10 of the Code of Federal Regulations Part 54 (10 CFR Part 54). Duke is requesting renewal of the operating licenses issued under Section 104 of the Atomic Energy Act of 1954, as amended, for the ONS, Unit Nos. 1, 2, and 3 (license numbers DPR-38, DPR-47, and DPR-55, respectively) for a period of 20 years beyond the current expiration dates: midnight, February 6, 2013, for Unit 1; midnight, October 6, 2013, for Unit 2; and midnight, July 19, 2014, for Unit 3.
The ONS is located in Oconee County in northwestern South Carolina on the shores of Lake Keowee. The three-unit nuclear station was constructed during the period from 1967 to 1974. Each unit consists of a Babcock and Wilcox (B&W) pressurized-water reactor nuclear steam supply system designed to generate 2568 MW thermal, or approximately 860 MW electric.
On the basis of its evaluation of the LRA, the staff concludes that: (1) actions have been identified and have been or will be taken with respect to managing the effects of aging during the period of extended operation on the functionality of structures and components that have been identified to require an aging management review under 10 CFR 54.21(a)(1), and (2) actions have been identified and have been or will be taken with respect to time-limited aging analyses that have been identified to require review under 10 CFR 54.21(c). Accordingly, the staff finds that there is reasonable assurance that the activities authorized by a renewed license will continue to be conducted in accordance with the current licensing basis for the ONS, Unit Nos. 1, 2, and 3 during the period of extended operation.
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This report describes the results of a review by the Nuclear Regulatory Commission (NRC) staff of an application to renew the licenses for the three units of the Oconee Nuclear Station (ONS). Under the Atomic Energy Act (AEA), the NRC issues licenses for commercial power reactors to operate for up to 40 years. The AEA also permits the licenses to be renewed. The NRC established license renewal requirements in the regulations. When those requirements are satisfied, a license can be renewed for up to 20 additional years.
Plant owners are interested in license renewal because they need to know what requirements must be satisfied to permit long-term plant operation. This knowledge helps them to predict the cost of plant operation for long-term energy planning.
The requirements for license renewal are presented in Part 54 of Title 10 to the Code of Federal Regulations (10 CFR Part 54). When those requirements were developed, the NRC concluded that the existing licensing basis and the regulatory process are adequate to maintain safe plant operation, except for the possible effects of aging on passive systems, structures, and components. Therefore, the requirements in 10 CFR Part 54 focus on managing the effects of aging for such passive structures and components as buildings, tanks, and pipes.
The NRC also established requirements for a license renewal environmental report in 10 CFR Part 51. Those requirements establish the scope of a review of environmental impacts, which is one part of the NRC's responsibilities under the National Environmental Policy Act (NEPA). The results of that review are described in Supplement 2 of NUREG-1437, "Generic Environmental Impact Statement for License Renewal of Nuclear Plants Regarding the Oconee Nuclear Station."
In a letter dated July 6, 1998, Duke Energy Corporation (Duke) filed an application to renew the licenses for its three-unit Oconee Nuclear Station. Duke requested a 20-year extension in the license term for the three units. The existing licenses expire on midnight, February 6, 2013 (for Unit 1), midnight, October 6, 2013 for (Unit 2), and midnight, July 19, 2014, for (Unit 3). If granted, the renewed licenses would extend to February 6, 2033; October 6, 2033; and July 19, 2034, respectively.
The ONS is located in Oconee County in northwestern South Carolina on the shores of Lake Keowee. The three-unit nuclear station was constructed during the period from 1967 to 1974. Each unit consists of a Babcock and Wilcox (B&W) pressurized-water reactor nuclear steam supply system designed to generate 2568 MW thermal, or approximately 860 MW electric.
In accordance with 10 CFR Part 54, Duke submitted information in its renewal application that identifies all plant systems, structures, and components (SSCs): (1) that are safety-related, (2) whose failure could affect safety-related functions, and (3) that are relied on to demonstrate compliance with the NRC's regulations for fire protection, environmental qualification, pressurized thermal shock, anticipated transients without scram, and station blackout. Duke's application also describes how the effects of aging will be managed in such a way that the intended functions of those structures and components will be maintained for the 20-year period of extended operation. These structures and components include, but are not limited to, the containment building, other safety-related structures, the reactor vessel, the reactor cooling system pressure boundary, steam generators, the pressurizer, piping, pump casings, and valve bodies. The surveillance and maintenance programs for active equipment (for example, motors, diesel generators, air compressors, control rod drives, instruments, cooling fans, and batteries), as well as other aspects of the plant design and licensing basis, are required to be maintained throughout the period of extended operation.
For some passive structures and components within the scope of the renewal evaluation, no additional action was required if Duke demonstrated that the existing programs provide adequate aging management. In other cases, Duke described changes to existing programs and new programs to ensure that applicable aging effects would be adequately managed. These activities include, for example, adding new monitoring programs, increasing inspections, or revising inspection criteria.
Another requirement for license renewal is the identification and updating of time-limited aging analyses. During the design phase for a plant, certain assumptions are made about the length of time the plant will be operated and are incorporated into design calculations for several of the plant's SSCs. These calculations must be shown to be valid for the period of extended operation or be projected to the end of the period of extended operation, or the applicant must demonstrate that the effects of aging on these SSCs will be adequately managed for the period of extended operation.
This report describes the results of the NRC staff's review of the Duke programs to manage aging effects. In this report, we conclude that Duke has demonstrated that aging effects applicable to the required scope of SSCs will be adequately managed for the 20-year period of extended operation. Our evaluation describes the features of the maintenance and inspection programs that we relied on to develop this conclusion. Our evaluation also describes how Duke has resolved our questions about specific aging management concerns. In some cases, our conclusion is based on changes in procedures or actions that will be taken. Duke will update its final safety analysis report, associated with the existing license, to include the changes to the licensing basis reflected in this report, which we relied on to grant a renewed license.
During meetings to gather public comments about the environmental impacts of extending the ONS licenses, we heard several concerns related to plant safety because of aging effects. Interested individuals and groups expressed specific concerns regarding embrittlement of the reactor vessel and other aging effects on plant safety systems and fuel storage facilities. In applicable sections of this report, we describe the particular programs, maintenance activities, and inspection procedures that we have relied on to conclude that those concerns have been adequately addressed.
NRC verified the conclusions in this report by conducting inspections. The scope of the inspections consisted of selected information in the renewal application and information in this report. The inspection results form the basis for a separate recommendation by the administrator of the regional office responsible for the plant.
The bases for the conclusions in this report are also reviewed by the NRC's Advisory Committee on Reactor Safeguards (ACRS). ACRS independently reviews the application and submits its recommendation directly to the Commission; that recommendation is included in the published version of this report (Chapter 5).
In our recommendation for granting a renewed license for the ONS, we have described the programs, maintenance activities, and inspection procedures that we rely on to conclude that there is reasonable assurance that Duke has taken or will take such actions to manage the effects of aging for a 20-year period of extended operation, such that the plant can continue to operate safely.
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This document is a safety evaluation report (SER) on the application for license renewal for the Oconee Nuclear Station (ONS), Unit Nos. 1, 2, and 3, as filed by the applicant, Duke Energy Corporation (Duke or applicant). By a letter dated July 6, 1998, Duke submitted its application to the United States Nuclear Regulatory Commission (NRC) for renewal of the ONS operating licenses for an additional 20 years. The NRC staff prepared this report and reviewed the renewal application for compliance with the requirements of 10 CFR Part 54, "Requirements for Renewal of Operating Licenses for Nuclear Power Plants." The NRC license renewal project manager for the ONS is Joseph M. Sebrosky. Mr. Sebrosky may be contacted by calling him at 301-415-1132, or by writing to him at the License Renewal and Standardization Branch, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555-0001.
In its July 6, 1998, submittal, Duke requested renewal of the operating licenses issued under Section 104 of the Atomic Energy Act of 1954, as amended, for ONS, Unit Nos. 1, 2, and 3 (license numbers DPR-38, DPR-47, and DPR-55, respectively) for a period of 20 years beyond the current license expirations of February 6, 2013; October 6, 2013; and July 19, 2014, respectively. The ONS is located in Oconee County in northwestern South Carolina on the shores of Lake Keowee. Each unit consists of a Babcock and Wilcox (B&W) pressurized-water reactor nuclear steam supply system designed to generate 2568 MW thermal, or approximately 860 MW electric. Details concerning the plant and the site are found in the updated Final Safety Analysis Report (UFSAR) for ONS, Unit Nos. 1, 2, and 3.
The license renewal process proceeds along two tracks: a technical review of safety issues and an environmental review. The requirements for these two reviews are stated in NRC regulations 10 CFR Parts 54 and 51, respectively. The safety review for the ONS license renewal is based on Duke's application for license renewal and on the applicant's answers to requests for additional information (RAIs) from the NRC staff. In meetings and docketed correspondence, Duke has also supplemented its answers to the RAIs and submitted answers to the open items identified in the June 16, 1999, version of this SER. The public can review the license renewal application (LRA) and all pertinent information and materials, including the UFSAR mentioned above, at the NRC Public Document Room, 2120 L Street, NW., Washington, D.C. In addition, the application and significant information and material related to the renewal review are available on the NRC Web page at www.nrc.gov.
This SER summarizes the findings of the staff's safety review of the ONS LRA and delineates the scope of the technical details considered in evaluating the safety aspects of its proposed operation for an additional 20 years beyond the term of the current operating license. The staff reviewed the LRA in accordance with the NRC regulations and the guidance presented in the NRC draft "Standard Review Plan (SRP) for the Review of License Renewal Applications for Nuclear Power Plants," dated September 1997.
Chapters 2 through 4 of the SER address the staff's review and evaluation of license renewal issues that have been considered during the review of the application. Chapter 5 contains the report of the Advisory Committee on Reactor Safeguards (ACRS). The conclusions of this report are in Chapter 6.
Appendix A is a chronology of NRC's and Duke's principal correspondence related to the review of the application. Appendix B is a bibliography of the documents used during the course of the review. Appendix C is a list of abbreviations used throughout the report. The NRC staff's principal reviewers and its contractors for this project are listed in Appendix D. Appendix E presents an index of the staff's RAIs and Duke's responses.
In accordance with 10 CFR Part 51, the staff prepared draft and final plant-specific supplements to the generic environmental impact statement (GEIS) that discuss the environmental considerations related to renewing the license for the ONS, Unit Nos. 1, 2, and 3. The draft and final plant-specific supplements to the GEIS were issued separately from this report. Specifically, NUREG-1437 Supplement 2, "Generic Environmental Impact Statement for License Renewal of Nuclear Plants Regarding the Oconee Nuclear Station" dated December 1999, is the final environmental report for ONS.
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Pursuant to the Atomic Energy Act of 1954, as amended, and NRC regulations, licenses for commercial power reactors to operate are issued for 40 years. These licenses can be renewed for up to 20 additional years. The original 40-year license term was selected on the basis of economic and antitrust considerations--not by technical limitations. However, some individual plant and equipment designs may have been engineered on the basis of an expected 40-year service life.
In 1982, the NRC held a workshop on nuclear power plant aging, in anticipation of the interest in license renewal. That led the NRC to establish a comprehensive program plan for nuclear plant aging research (NPAR). Based on the results of that research, a technical review group concluded that many aging phenomena are readily manageable and do not pose technical issues that would preclude life extension for nuclear power plants.
In 1986, the NRC published a request for comment on a policy statement that would address major policy, technical, and procedural issues related to life extension for nuclear power plants.
In 1991, the NRC published the license renewal rule in 10 CFR Part 54. The NRC participated in industry sponsored demonstration programs to apply the rule to pilot plants and develop experience to establish implementation guidance. To establish a scope of review for license renewal, the rule defined age-related degradation unique to license renewal. However, during the demonstration program, the NRC found that many aging mechanisms occur and are managed during the period of the initial license. In addition, the NRC found that the scope of the review did not allow sufficient credit for existing programs, particularly for the implementation of the maintenance rule, which also manages plant aging phenomena.
As a result, in 1995 the NRC amended the license renewal rule. The amended 10 CFR Part 54 established a regulatory process that is expected to be simpler, more stable, and more predictable than the previous license renewal rule. In particular, 10 CFR Part 54 was clarified to focus on managing the adverse effects of aging rather than on identifying all aging mechanisms. The rule changes were intended to ensure that important systems, structures, and components (SSCs) will continue to perform their intended function in the period of extended operation. In addition, the integrated plant assessment (IPA) process was clarified and simplified to be consistent with the revised focus on passive, long-lived structures and components.
In parallel with these efforts, the NRC pursued a separate rulemaking effort, 10 CFR Part 51, to focus the scope of the review of environmental impacts of license renewal, in fulfilling NRC's responsibilities under the National Environmental Policy Act of 1969 (NEPA).
License renewal requirements for power reactors are based on two key principles:
| (1) | The regulatory process is adequate to ensure that the licensing bases of all currently operating plants provide and maintain an acceptable level of safety, with the possible exception of the detrimental effects of aging on the functionality of certain plant SSCs in the period of extended operation and possibly a few other issues related to safety only during the period of extended operation. |
| (2) | The plant-specific licensing basis must be maintained during the renewal term in the same manner and to the same extent as during the original licensing term. |
In implementing these two principles, the rule in 10 CFR 54.4, defines the scope of license renewal as those plant SSCs (a) that are safety-related, (b) whose failure could affect safety-related functions, and (c) that are relied on to demonstrate compliance with the NRC's regulations for fire protection, environmental qualification, pressurized thermal shock, anticipated transients without scram, and station blackout.
Pursuant to 10 CFR 54.21(a), the applicant must review all SSCs within the scope of the rule to identify structures and components subject to an aging management review (AMR). Structures and components subject to an AMR are those that perform an intended function without a change in configuration or properties and that are not subject to replacement based on qualified life or specified time period. As required by 10 CFR 54.21(a), it must be demonstrated that the effects of aging will be managed in such a way that the intended function or functions of those structures and components will be maintained, consistent with the current licensing basis, for the period of extended operation. Active equipment, however, is considered to be adequately monitored and maintained by existing programs. In other words, the detrimental aging effects that may occur for active equipment are more readily detectable and will be identified and corrected through routine surveillance, performance indicators, and maintenance. The surveillance and maintenance programs for active equipment, as well as other aspects of maintaining the plant design and licensing basis, are required throughout the period of extended operation. 10 CFR 54.21(d) requires that a supplement to the FSAR contain a summary description of the programs and activities for managing the effects of aging.
Another requirement for license renewal is the identification and updating of time-limited aging analyses. During the design phase for a plant, certain assumptions are made about the length of time the plant will be operated and these assumptions are incorporated into design calculations for several of the plant's SSCs. In accordance with 10 CFR 54.21(c)(1), these calculations must be shown to be valid for the period of extended operation or must be projected to the end of the period of extended operation, or the applicant must demonstrate that the effects of aging on these SSCs will be adequately managed for the period of extended operation.
In 1996, the NRC developed and issued draft regulatory guide DG-1047, "Standard Format and Content for Applications To Renew Nuclear Power Plant Operating Licenses." This guide proposes to endorse an implementation guideline prepared by the Nuclear Energy Institute (NEI) as an acceptable method of implementing the license renewal rule. The NEI guideline is NEI 95-10, "Industry Guideline for Implementing the Requirements of 10 CFR Part 54--The License Renewal Rule," which was issued in March 1996. The NRC prepared a draft standard review plan (SRP) for the safety review, which was placed in the Public Document Room in September 1997. The draft regulatory guide will be used, along with the draft SRP, to review applications and to assess technical issue reports involved in license renewal as submitted by industry groups. As experience is gained, NRC will improve the SRP and clarify regulatory guidance.
The staff revised the environmental protection regulations in 10 CFR Part 51 in December 1996 to facilitate the environmental review for license renewal. The staff prepared a "Generic Environmental Impact Statement (GEIS) for License Renewal of Nuclear Plants," NUREG-1437(1), in which it examined the possible environmental impacts associated with renewing licenses of nuclear power plants. For certain types of environmental impacts, the GEIS establishes generic findings that are applicable to all nuclear power plants. These generic findings are identified as Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B. Pursuant to 10 CFR 51.53(c)(3)(i), an applicant for license renewal may incorporate these generic findings in its environmental report. Analyses of those environmental impacts that must be evaluated on a plant-specific basis, Category 2 issues, must be included in the environmental report in accordance with 10 CFR 51.53(c)(3)(ii).
In accordance with NEPA and the requirements of 10 CFR Part 51, the NRC performed a plant-specific review of the environmental impacts of license renewal, including whether there was new and significant information not considered in the GEIS. A public meeting was held on October 19, 1998, near the ONS as part of the NRC's scoping process to identify environmental issues specific to the plant. Results of the environmental review and a preliminary recommendation with respect to the license renewal action were documented in NRC's draft plant-specific Supplement 2 to the GEIS, which NRC issued on May 20, 1999. During the 75-day comment period that followed, another public meeting was held near the site on July 8, 1999, at which the staff described the results of the NRC environmental review and answered questions related to it in order to provide members of the public with information to assist them in formulating any comments they might have regarding the review. On December 9, 1999, the staff issued the final version of Supplement 2 to the GEIS on the ONS, in which it presented its final environmental analysis that considers and weighs the environmental effects of the license renewal, and alternatives available for avoiding adverse environmental effects. The staff considered and addressed the comments that were received during the comment period.
Based on (1) the analysis and findings in the "Generic Environmental Impact Statement for License Renewal of Nuclear Power Plants," NUREG-1437; (2) the Environmental Report submitted by Duke; (3) consultation with other Federal, State, and local agencies; (4) its own independent review; and (5) its consideration of public comments, the staff recommended, in Supplement 2 to NUREG-1437 that the Commission determine that the adverse environmental impacts of license renewal for the ONS Units Nos. 1, 2, and 3 are not so great that preserving the option of license renewal for energy planning decisionmakers would be unreasonable.
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The requirements for renewing operating licenses for nuclear power plants are described in 10 CFR Part 54. The staff performed its technical review of the ONS application for license renewal in accordance with Commission guidance and the requirements of 10 CFR 54.19, 54.21, 54.22, 54.23, and 54.25. The standards for renewing a license are contained in 10 CFR 54.29. This SER describes the results of the staff's technical review.
In 10 CFR 54.19(a), the Commission requires a license renewal applicant to submit general information. Duke submitted this general information in Enclosure 1 to its July 6, 1998, submittal letter regarding the application for renewed operating licenses for the ONS, Unit Nos. 1, 2, and 3. In that enclosure the staff finds that Duke submitted the information required by 10 CFR 54.19(a).
In 10 CFR 54.19(b), the Commission requires that LRAs include "conforming changes to the standard indemnity agreement, 10 CFR 140.92, Appendix B, to account for the expiration term of the proposed renewed license." Duke stated the following in its renewal application regarding this issue:
The current indemnity agreement for Oconee states in Article VII that the agreement shall terminate at the time of expiration of that license specified in Item 3 of the Attachment to the agreement. Item 3 of the Attachment to the indemnity agreement, as revised by Amendment No. 9, lists six license numbers. Duke requested that conforming changes be made to Article VII of the indemnity agreement, and/or Item 3 of the Attachment to that agreement, specifying the extension of agreement until the expiration dates of the renewed Oconee operating licenses as set forth in this Application. Thus, license number DPR-38 would be extended to expire at midnight, February 6, 2033; DPR-47 would be extended to expire at midnight, October 6, 2033; and DPR-55 would be extended to expire at midnight, July 19, 2034. In addition, should the license numbers be changed upon issuance of the renewed licenses, Duke requests that conforming changes be made to Item 3 of the Attachment, and any other section of the indemnity agreement as appropriate.
The staff intends to maintain the license numbers on issuance of the renewed license. Therefore, there is no need to make conforming changes to the indemnity agreement, and the requirements of 10 CFR 54.19(b) have been met.
In 10 CFR 54.21, the Commission requires that each application for a renewal license for a nuclear facility must contain the following information: (a) an integrated plant assessment (IPA), (b) current licensing basis (CLB) changes during NRC review of the application, (c) an evaluation of time-limited aging analyses (TLAAs), and (d) a final safety analysis report (FSAR) supplement. Duke submitted the information to address the license renewal requirements of 10 CFR 54.21(a) and (c) in Exhibit A to the LRA of July 6, 1998. Exhibit A is titled "Oconee Nuclear Station, License Renewal--Technical Information, OLRP-1001." Duke submitted the information to address the license renewal requirements of 10 CFR 54.21(b) in a letter dated September 30, 1999. Duke submitted the information to address the license renewal requirements of 10 CFR 54.21(d) in Exhibit B of its LRA.
In 10 CFR 54.22, the Commission states requirements regarding technical specifications. Duke addressed the requirements of 10 CFR 54.22 in Exhibit C of its LRA.
The staff evaluated the technical information required by 10 CFR 54.21 and 10 CFR 54.22 in accordance with the NRC's regulations and the guidance presented the draft SRP titled "Review of License Renewal Applications for Nuclear Power Plants," which was published in September 1997. The staff's evaluation of the LRA in accordance with 10 CFR 54.21 and 54.22 appears in Chapters 2, 3, and 4 of this SER.
The staff's evaluation of the environmental information required by 10 CFR 54.23 can be found in the draft and final plant-specific supplements to the GEIS (NUREG-1437, Supplement 2), that state the considerations related to renewing the license for ONS, Unit Nos. 1, 2, and 3.
The report by the Advisory Committee on Reactor Safeguards required by 10 CFR 54.25 is in Chapter 5 of this SER. The findings required by 10 CFR 54.29 are in Chapter 6 of this report.
In accordance with 10 CFR 54.17(e), Duke also incorporated by reference several Babcock and Wilcox Owners Group topical reports into the ONS LRA. The topical reports demonstrate generically that the aging effects for reactor coolant system components are adequately managed for the period of extended operation under a renewed license. Specifically, Duke incorporated the following topical reports into its application:
The staff has issued separate safety evaluations for these topical reports. Specifically, the staff issued the final safety evaluations for the following topical reports: BAW-2243 on March 21, 1996; BAW-2244 on August 18, 1997; BAW-2241P on February 18, 1999; BAW-2251 on April 26, 1999; and BAW-2248 on December 9, 1999. In accordance with procedures established in NUREG-0390, "Topical Report Review Status," the staff requested that the Babcock and Wilcox Owners Group publish accepted versions of the reports. The accepted version incorporates the transmittal letter and the staff's safety evaluation between the title page and the abstract. The accepted versions includes an -A (designating accepted) following the report identification symbol.
Each safety evaluation for the topical reports is intended to be a standalone document. An applicant incorporating the topical reports by reference into its LRA must ensure that the conditions of approval contained in the safety evaluations are met. The staff's evaluation of how the topical reports were incorporated into the application is found in Section 3.4 of this SER.
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As a result of its initial review of the LRA for the ONS, including the additional information submitted to the NRC, the staff identified a number of open issues and confirmatory items when this report was issued in June 1999. That report was revised to describe in each applicable section the manner by which those matters have been resolved.
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10 CFR 54.21, "Contents of application -- technical information," requires, in part, that each application for license renewal contains an integrated plant assessment (IPA) that identifies and lists those systems, structures, and components (SSCs) satisfying the criteria in 10 CFR 54.4(a)(1), (a)(2), and (a)(3) that are subject to an aging management review (AMR). 10 CFR 54.4, "Scope," defines the criteria for inclusion of SSCs within the scope of 10 CFR Part 54, "Requirements for Renewal of Operating Licenses for Nuclear Power Plants."
The Oconee Nuclear Station (ONS) IPA was developed along traditional engineering disciplines, that is, mechanical, civil/structural, and electrical. The methodology used by the applicant to identify structures and mechanical systems at the ONS subject to an AMR is generally consistent with the industry guidance in an Nuclear Energy Institute (NEI) document NEI 95-10, "Industry Guideline for Implementing the Requirements of 10 CFR Part 54 -- The License Renewal Rule." However, the applicant developed a process specific to the ONS for identifying electrical components.
Exhibit A, "License Renewal -- Technical Information (OLRP-1001)," to the ONS license renewal application (LRA) contains the technical information required by 10 CFR 54.21(a) and (c), including the methodology used to identify the SSCs at the ONS that are within the scope of license renewal. Exhibit A, Section 2.2, "Identification of Systems, Structures, and Components Within the Scope of License Renewal," describes the process used by the applicant to satisfy the criteria contained in 10 CFR 54.4(a)(1), (a)(2), and (a)(3) for structures and mechanical systems at the ONS. The methodology used to identify electrical components within the scope of license renewal is described in Section 2.6, "Electrical Components," of Exhibit A.
Additionally, Section 2.3.1, "Description of the Process to Identify Reactor Building (Containment) Structural Components"; Section 2.4.1, "Description of the Process to Identify Reactor Coolant System Components and Class 1 Component Supports Subject to Aging Management Review"; Section 2.5.1, "Process Used to Identify Mechanical Components Subject to Aging Management Review"; Section 2.5.2, "Detailed Process Descriptions"; Section 2.6.1, "Description of the Process to Identify Electrical Components Subject to Aging Management Review"; and Section 2.7.1, "Description of the Process to Identify Structural Components Subject to Aging Management Review," contain amplifying information on the process used by the applicant to satisfy the requirements of 10 CFR 54.21(a)(1) and (a)(2) for the ONS structural, mechanical, and electrical components that are subject to an AMR for license renewal.
2.1.2.1 Technical Information for Identifying Systems, Structures, and Components Within the Scope of License Renewal
In OLRP-1001, Subsection 2.2, "Identification of Systems, Structures, and Components Within the Scope of License Renewal" of Exhibit A of the LRA the applicant states the following:
| Because the ONS was licensed before terms such as 'safety-related' were more precisely defined by the NRC, a list of the ONS safety-related SSCs, in and of itself, will not meet the intent of 10 CFR 54.4(a)(1). Because the criteria in 10 CFR 54.4(a)(1) are the scoping criteria of many modern-day, regulatory-required programs, ONS conducted a design study that validated all functions required for the successful mitigation of ONS design-basis events and identified the systems and components relied upon to complete those functions. The individual design-basis event mitigation calculations produced as a result of the study contain a list of the system functions required to successfully mitigate each event. The applicant determined that the systems that perform these functions are within the scope of license renewal. |
During an audit of the ONS license renewal scoping and screening process conducted by the NRC staff on October 27 through 30, 1998, at Duke Energy Corporation's offices in Charlotte, N.C., the audit team learned that the "design study" identified in Subsection 2.2.1.1 and the Oconee Safety-Related Designation Clarification (OSRDC) project developed in response to GL 83-28, "Required Actions Based on Generic Implications of Salem ATWS Events" (July 1983) was one and the same. Specifically, in its November 4, 1983, response to GL 83-28, as supplemented by letters dated January 17, 1984, and June 9, 1987, the applicant described the scope of the ONS operational QA program for safety-related equipment classification. The NRC staff approved the scope of the ONS operational QA program in a safety evaluation dated November 4, 1987.
In a supplemental response to GL 83-28, dated April 12, 1995, the applicant submitted amplifying information on the ONS QA-1 licensing basis, and on information given to the NRC Region II staff during a February 6, 1995, meeting. The QA-1 designation originally applied to ONS SSCs that were relied upon to mitigate a large-break loss-of-coolant accident (LBLOCA) coincident with a loss of offsite power (LOOP) event; the QA-1 designation did not encompass all SSCs which are relied upon to remain functional during and following design-basis events (DBEs) as defined under 10 CFR 54.4(a)(1).
In Attachment 3 to the April 12, 1995, letter, "Supplemental Response to Subpart 1 of Section 2.2.1 of GL 83-28 General Criteria for Classifying QA-1 SSCs," the applicant stated that the list of additional QA-1 SSCs would be developed through the OSRDC project by July 10, 1995. Also, in Attachment 4, "Oconee Licensing Position on Non QA-1 SSCs Which Are Used to Mitigate Accidents," the applicant committed to developing a new QA classification (QA-5) so that these SSCs can be identified for testing and maintenance under selected Appendix B [to 10 CFR Part 50] criteria without procuring the SSCs per Appendix B.
On this basis, and by letter dated December 1, 1998, the staff requested that the applicant do the following:
In its February 17, 1999, response to the staff's request for additional information (RAI 2.2-6), the applicant clarified the role of the OSRDC project in the ONS license renewal process. Subsequent to the applicant's response to the staff's RAI, the staff met with the applicant on March 11, 1999, to obtain clarification and additional insights into the methodology used by the applicant to meet the requirements of 10 CFR 54.4 for identifying the SSCs within the scope of the rule. As a result of the meeting on March 11, 1999, the applicant submitted additional information and clarifications in a letter dated March 18, 1999. In a May 11, 1999, meeting, which is documented in a meeting summary dated May 19, 1999, Duke met with the staff to further discuss the DBEs used by the applicant to determine the safety-related SSCs required by the scoping criteria under 10 CFR 54.4(a)(1). During this meeting Duke agreed to supplement its response to the staff's RAI 2.2-6, to include a description of the process used to identify events for Oconee license renewal scoping consistent with the presentation that was given to the staff.
2.1.2.2 Technical Information for the Structures and Components Subject to an Aging Management Review
During the audit of October 27 through 30, 1998, members of the NRC staff visited the Duke Energy Corporate Office in Charlotte, NC, to review the license renewal scoping and screening methodology and justification for the ONS LRA. The audit team reviewed the site-specific specifications used to identify the structures and components (SCs) subject to an AMR from those identified as being within the scope of the rule. The staff also reviewed other supporting documentation and interviewed applicant staff members as part of its evaluation of the applicant's process for identifying those SCs subject to an AMR. The staff also performed an inspection of the applicant's scoping process from April 26, 1999, to April 30, 1999, and performed another audit of the applicant's scoping methodology during the week of August 16, 1999. In addition, there were numerous public meetings, telecommunications, and docketed correspondence, including RAIs and RAI responses between the staff and the applicant to address specific scoping concerns as discussed below.
Mechanical Components Review
During the week of October 27, 1998, the site-visit team reviewed the methodology used by the applicant to identify and list the mechanical components subject to an AMR, as well as the applicant's technical justification for this methodology. The team also examined the applicant's results from the implementation of this methodology by reviewing an overview of the mechanical systems identified as being within the scope of license renewal, a sample of evaluation boundaries drawn within those systems, the resulting components determined to be within the scope of the rule, the corresponding component-level intended functions, and the resulting list of mechanical components subject to an AMR.
The site-visit team reviewed the methodology described in the LRA, Subsection 2.4 and 2.5, entitled "Reactor Coolant System Mechanical Components and Class 1 Component Supports," and "Mechanical System Components." The site-visit team also reviewed a number of on-site engineering documents not docketed, including Oconee site specification OSS-0274.00-00-0001, "Oconee Mechanical System Scoping for License Renewal"; OSS-274.00-00-0002, "Oconee Mechanical Component Screening for License Renewal"; appropriate portions of the ONS updated final safety analysis report (UFSAR); the ONS flow diagrams that contain the color-coded evaluation boundaries for the systems identified as being within the scope of license renewal; and the mechanical component commodity-type menus developed by the applicant to identify the SCs that are required to be subject to an AMR under 10 CFR 54.21(a)(1)(i) and (a)(1)(ii). The site-visit team found the applicant's process consistent with the scoping process described in the "Industry Guideline for Implementing the Requirements of 10 CFR Part 54 - The License Renewal Rule" (NEI 95-10, Revision 0), and adequate for the purpose of determining the mechanical components requiring an AMR. However, the staff needed to better understand the OSRDC process, which was used to determine the applicable design-basis events defined in the applicant's current licensing basis (CLB), to ensure that all the mechanical systems, as required by 10 CFR 54.4(a)(1) and (a)(2), were identified as being within the scope of license renewal.
As a result of the information reviewed, the staff issued RAI 2.2-6 relating to the design-basis events used to determine the mechanical systems within the scope of the rule and the resulting components requiring an AMR. Duke provided an initial response to the staff's request for additional information in a letter dated February 17, 1999. The RAI response was followed by a technical meeting on March 11, 1999, and a supplemental response from Duke dated March 18, 1999.
During the week of April 26, 1999, the staff performed an inspection of the results of the applicant's scoping activities including the scoping of mechanical SSCs. The results of this inspection were documented in NRC inspection report number IR99-011. On May 11, 1999, the applicant met with NRC staff to further discuss concerns with its list of design-basis events that were used to scope mechanical SSCs for the purpose of license renewal. That meeting led to additional information provided by the applicant in a letter dated June 22, 1999. The staff performed a third site visit during the week of August 16, 1999, to audit additional design documentation relative to the scoping methodology and the design-basis events used in the applicant's scoping process. As a result of a number of additional meetings and docketed correspondence between the staff and the applicant, Duke submitted its final response on November 30, 1999. The response discussed specific events and their inclusion as scoping events for the purpose of license renewal.
Structures and Structural Component Review
The site-visit team reviewed the methodology used by Duke to identify and list the structural components subject to an AMR, as well as the applicant's technical justification for this methodology. The team also examined the applicant's results from the implementation of this methodology by reviewing the structural components identified as being within the scope of license renewal, the corresponding structural-level intended functions, and the resulting list of structural components subject to an AMR.
The site-visit team reviewed the methodology described in the LRA, Subsection 2.3 and 2.7, entitled "Reactor Building Structural (Containment) Components," and "Structures and Structural Components." The site-visit team also reviewed a number of on-site engineering documents including Oconee site specification OSS-0274.00-00-0007, "Oconee Structures and Structural Component Aging Management Review," a number of other ONS specifications relating to structural classifications, appropriate portions of the ONS UFSAR, ONS General Arrangement Drawings, ONS Commodities and Facilities Drawings, and Quality Standards Manual NSD 307. As a result of the information reviewed, the staff issued RAI 2.6.7-1 requesting additional information relating to the validations of the structures determined not to be within the scope of license renewal. Duke provided a response to the staff's request for additional information in a letter dated February 17, 1999. The RAI response was followed by a technical meeting on March 11, 1999. During the week of April 26, 1999, the staff also performed an inspection of the results of the applicant's overall scoping activities including the scoping of structural SSCs.
Electrical Components Review
The site-visit team reviewed the methodology used by Duke to identify and list the electrical components subject to an AMR, as well as the applicant's technical justification for the identification process. The team examined the applicant's results from the implementation of this methodology by reviewing the list of electrical components subject to an AMR.
The site-visit team reviewed the methodology described in the LRA, Subsection 2.6, entitled "Electrical Components." The site-visit team also reviewed a number of on-site engineering documents including Oconee site specification OSS-0274.00-00-0006, "Oconee Electrical Component Aging Management Review for License Renewal," appropriate portions of the ONS UFSAR, ONS Electrical Drawings, and NEI 95-10, Revision 0. The site-visit team found the applicant's process to be significantly different from the scoping process described in the industry guideline, NEI 95-10, and determined that additional information was needed for the staff to adequately assess the applicant's process for scoping electrical SSCs.
As a result of the information reviewed, the staff issued RAI 2.6-1 requesting additional clarification of the applicant's scoping process. Duke provided an initial response to the staff's request for additional information in a letter dated February 17, 1999. The RAI response was followed by a technical meeting on March 11, 1999, and a supplemental response from Duke dated March 18, 1999. As previously noted, during the week of April 26, 1999, the staff also performed an inspection of the results of the applicant's overall scoping activities including the scoping of electrical SSCs.
In Section 2.2, "Identification of Systems, Structures, and Components Within the Scope of License Renewal," of Exhibit A of the LRA, the applicant described the methodology used to identify the mechanical components that are within the scope of license renewal and subject to an AMR. The mechanical components included within the scope of license renewal and subject to an aging management review are described in Section 2.4, "Reactor Coolant System Mechanical Components and Class 1 Component Supports," and Section 2.5, "Mechanical System Components" of Exhibit A of the LRA. The structures included within the scope of license renewal and subject to an aging management review are described in Section 2.3, "Reactor Building (Containment) Structural Components," and Section 2.7, "Structures and Structural Components," of Exhibit A of the LRA. The electrical components included within the scope of license renewal and subject to an aging management review are described in Section 2.6, "Electrical Components," of Exhibit A of the LRA.
2.1.3.1 Evaluation of the Methodology for Identifying Systems, Structures and Components Within the Scope of License Renewal
As indicated above, the applicant stated in its LRA that ONS conducted a design study that was used to validate all the functions required for the successful mitigation of ONS design-basis events and identified the SCs relied upon to complete those functions. On October 27 through 30, 1998, members of the NRC staff visited the Duke Energy Corporate Office in Charlotte, NC, to review the license renewal scoping and screening methodology and justification presented in the ONS LRA. As a result of that review, the staff confirmed that the applicant relied on a design study to identify the SSCs that are needed to satisfy the requirements of 10 CFR 54.4(a).
The site-visit team discussed this design study and the process used to identify the SSCs within the scope of the rule. The basic process, as described by the applicant, involved identifying all the SSCs that met the "safety-related criteria" under 10 CFR 54.4(a)(1). Evaluation boundaries were established for the portions of those systems and structures required to perform the system functions that satisfied the specified criteria. In addition, the applicant stated that it had reviewed the non safety-related SSCs whose failure could prevent the successful completion of the safety functions identified from the review of the safety-related criteria under 10 CFR 54.4(a)(2). Again, evaluation boundaries were established for the portions of those non safety-related systems and structures. The components within those evaluation boundaries that were not already identified were added to the scope of license renewal.
The team found the results of the applicant's design study and subsequent scoping activities to be a reasonable approach for identifying a supplemental list of SSCs to complement the applicant's list of QA-1 SSCs required by the scoping criteria under 10 CFR 54.4 (a)(1) and (a)(2). However, the team concluded that the design study used by the applicant to meet the scoping requirements for license renewal was not fully described in the LRA. Therefore, the staff submitted a request for additional information to obtain the necessary information.
In its February 17, 1999, response to the staff's request for additional information (RAI 2.2-6), the applicant clarified the role of the OSRDC study in the Oconee license renewal scoping process. Specifically, the applicant stated that the "design study" in Exhibit A of the LRA refers only to the second initiative of the OSRDC project. The purpose of the first initiative of the project, identified as a commitment associated with the applicant's response to GL 83-28, was to clarify the ONS QA-1 licensing basis by developing a list of all QA-1 SSCs at ONS.
The purpose of the second initiative of the OSRDC study was to clarify ONS's licensing basis with respect to design-basis-event mitigation requirements, that is, to identify non-QA-1 SSCs credited with accident mitigation functions at ONS and those SSCs whose failure could prevent satisfactory accomplishment of any of the applicable accident mitigation functions. The third and fourth initiatives of the OSRDC project involved identifying and implementing an "augmented" QA (QA-5) program for those SSCs identified as a result of the second initiative and were not relevant to the license renewal scoping process.
Subsequent to the applicant's response to the staff's RAI, the staff met with the applicant on March 11, 1999, to obtain clarification and additional insights into the methodology used by the applicant to justify the scoping results. Specifically, the staff requested that the applicant describe its methodology for identifying the SSCs within the scope of 10 CFR 54.4(a)(1) and (a)(2) as it applies to design-basis events defined under 10 CFR 50.49(b)(1).
During the March 11, 1999, meeting, the discussion focused on which ONS design-basis events (DBEs) were considered in the ONS license renewal scoping process. Specifically, the staff was interested in how the applicant complied with the requirements of 10 CFR 54.4(a)(1) and with the definition of DBEs in 50.49(b)(1). The applicant stated its position that the set of DBEs contained in Chapter 15 of the ONS Updated Final Safety Analysis Report (UFSAR) complies with the requirements of 10 CFR 54.4(a)(1) and meets the definition in 10 CFR 50.49(b)(1). The applicant also stated that in order to be conservative, it considered an additional set of events based on plant-specific insights.
In a letter dated March 18, 1999, the applicant submitted additional information and clarifications as a result of the meeting on March 11, 1999. Specifically, the applicant: (1) amended its original response to RAI 2.2-6 to provide additional clarification in accordance with discussions held during the meeting, (2) amended its response to RAI 2.6-1 to clarify the electrical scoping description and to indicate how the results were validated, and (3) amended its response to RAI 2.6.7-1 to indicate how the validation of structural results was performed.
In a May 11, 1999, meeting, which is documented in a summary dated May 19, 1999, Duke stated that the license renewal "scoping events" included UFSAR Chapter 15 events, natural phenomena criteria, post-Three Mile Island emergency feedwater design basis scenarios, and turbine building floods mitigated by the standby shutdown facility. Duke considered a total of 26 events when initially scoping to comply with 10 CFR 54.4(a)(1) and 10 CFR 54.4(a)(2). Duke also stated that it reviewed an additional 32 events for possible inclusion into the set of scoping events. Duke determined that none of the additional 32 events needed to be considered for purposes of scoping in accordance with 10 CFR 54.4 (a)(1) and 10 CFR 54.4(a)(2). Because of the narrow definition of DBEs used by the applicant, the staff was concerned that the applicant may have overlooked some SCs needed to prevent or mitigate any of the additional 32 events that might have been identified if the applicant used the broader 10 CFR 50.49(b)(1) view of a DBE. Therefore, the applicant was then asked to take the following actions:
The staff reviewed the applicant's response to Open Item 2.1.3.1-1 provided in a letter dated June 22, 1999, and performed an audit of on-site information during August 16-18, 1999. The staff then performed a review of the 32 events, that were originally considered by the applicant but determined not to be DBEs, against the applicant's UFSAR, license conditions, the applicable regulations, Commission orders, and exemptions that are in effect and that define the applicant's design requirements. As a results of these activities, the staff identified 10 events that the staff believed needed additional consideration under the license renewal scoping criteria, 10 CFR 54.4(a) of the rule. The applicant was asked to reevaluate these 10 events for potential SCs that needed to be included within the scope of license renewal. In response to this request the applicant identified seven additional events that needed to be considered for scoping under 10 CFR 54.4(a)(1) and (a)(2). The results of the applicant's review were as follows:
As a result of this review, the applicant did not identify any additional SSCs associated with these ten events, that needed to be added to the scope of license renewal, and therefore, did not add any addition SCs to the list of SCs subject to an AMR.
On the basis of the staff's reviews and the applicant's actions described above, the staff found that there is reasonable assurance that the applicant has considered the necessary DBEs in the implementation of its scoping methodology used to identify the SSCs required by the scoping criteria under 10 CFR 54.4(a)(1) and (a)(2). Open Item 2.1.3.1-1 is closed.
2.1.3.2 Evaluation of Methodology for Identifying Structures and Components Subject to an Aging Management Review
Mechanical Components
The methodology used by the applicant for identifying mechanical component within the scope of the rule included the following steps: identifying all systems and their intended functions that are relied upon to remain functional during and following the design-basis events for which the plant must be designed; identifying all the systems and intended functions whose failure could prevent satisfactory accomplishment of any of the functions identified under 10 CFR 54.4(a)(1); identifying all those systems and intended functions necessary to demonstrate compliance with the regulated events identified under 10 CFR 54.4(a)(3); and identifying all other mechanical systems or portions of systems that contain safety-related and seismically designed components.
The process used by the applicant to identify the mechanical components requiring an AMR included a set of highlighted ONS flow diagrams that were used to define the evaluation boundaries of the license renewal-related equipment. These highlighted drawings identified the flow paths required to be functional during and following design-basis events, and the components necessary for each system to accomplish its intended function(s). Interfacing flow paths, which share a common pressure boundary with the principal path, or non safety-related flow paths whose failure could prevent satisfactory accomplishment of any of the safety-related functions under 10 CFR 54.4(a) were included. The highlighted flow diagrams were color-coded to distinguish between Class 1 and non-Class 1 seismic piping.
In Exhibit A, Section 2.5.2, "Detailed Process Description," the applicant described the process to scope and screen mechanical components within the scope of the rule and subject to an AMR. However, details regarding this methodology that would give the staff an understanding about how the requirements of 10 CFR 54.21 are being met were not provided. In RAI 2.5.2-1, the staff asked the applicant to provide a brief narrative that explained how the screening of mechanical components within the scope of license renewal was performed. In its response to this RAI, Duke stated the following:
| The mechanical component screening is consistent with the guidance provided in NEI 95-10, Rev. 0. Components subject to an AMR are those that are "passive" and "long-lived." A menu of every mechanical component type installed at ONS was developed, going beyond the list of components in NEI 95-10. Using the "passive" and "long-lived" guidance, a determination was made for each of those mechanical component types. The components within the evaluation boundaries shown on the license renewal flow diagrams were "driven" through the menu to determine if they were subject to an AMR. From this exercise, a list of components subject to an AMR was developed. |
The staff notes that the mechanical components subject to an AMR resulting from the applicant's process described in Section 2.5.2 of the LRA, and the mechanical screening process discussed in the response to RAI 2.5.2-1, are provided in Sections 2.5.3 through 2.5.14 of the LRA.
After the evaluation boundaries were established, the process is designed to identify those components within the evaluation boundaries that require an AMR primarily by eliminating those components excluded under 10 CFR 54.21(a)(1)(i). The applicant also identified the component-level intended functions that are required to fulfill the system-level intended functions during the scoping process. The resulting list of components, and groups of component types subject to an AMR was presented in the LRA, Subsections 2.5.3 through 2.5.14 and associated tables. These tables also contained the intended functions and the materials of construction for each of the mechanical components.
On the basis of the above review, the staff finds that the methodology used by the applicant to identify mechanical components that require an AMR is consistent with the requirements of the rule. The evaluation for the specific implementation of this methodology for ONS mechanical components can be found in Section 2.2 of this safety evaluation.
Structures
The screening process for structures began with the development of a list of structural component types from the structures determined to be within the scope of the rule using the requirements of 10 CFR 54.21, and the guidance contained in NEI 95-10, and the "NUMARC Containment and Class I Structures Industry Report." Other structural components were added from the review of the commitments made by the applicant with respect to the "regulated events" identified under 10 CFR 54.4(a)(3). The applicant also reviewed design basis specifications and structural drawings to complete its list of structural components within the scope of the rule. To verify that the list was complete, an independent review was performed by ONS structural experts.
The applicant then identified structural component-level intended functions from information in the UFSAR, ONS site specifications, commitments associated with design-basis events, regulated events, or input from Duke structural experts. This resulted in a list of component-level functions that supported the structural-level intended function plus some additional intended functions unique to individual components. For example, the spent fuel storage racks have a component specific intended function to provide separation to prevent criticality which does not match the Auxiliary building intended functions. The applicant then removed those structural components identified as performing their intended function with moving parts or a change in configuration or properties in the rule and in NEI 95-10, Appendix B. The applicant also removed all structural components that are replaced based on qualified life or specified time period. The remaining components were listed as structural components requiring an AMR.
On the basis of the above review, the staff finds that the methodology used by the applicant to identify the structures and structural components that require an AMR is consistent with the requirements of the rule. The implementation of this methodology and the listing of the structures and structural components for Reactor Building and other structures is evaluated in Section 2.2 of this safety evaluation.
Electrical Component
The methodology used to identify the electrical component requiring an AMR was different from the methodology used for mechanical and structural components. The applicant opted to develop a different process from the industry guidance. During the staff initial review, and the October 27 through 30, 1998 site-visit, the staff found the applicant's methodology unclear. The staff expressed its concern and documented its need for additional information in a letter dated December 1, 1998. In its February 17, 1999, response to the staff's request for additional information (RAI 2.2-6), the applicant provided a written description of its methodology.
The process for determining the electrical components subject to an AMR began with a complete list of all electrical component-types used at ONS. For this list of component types, the applicant identified the intended function(s) and eliminated those component types that required moving parts, or a change in configuration or properties to perform its intended function(s) as allowed by 10 CFR 54.21(a)(1)(i) and staff agreed-upon guidance in NEI 95-10. For those components remaining, the applicant eliminated a selected group of component types that did not meet the scoping criteria under 10 CFR 54.4(a). Finally, the applicant eliminated those components that are replaced based on a qualified life or specified time period. All remaining components are subject to an AMR. The above process describes the basic steps used in the identification of electrical components. Although this process is not consistent with the industry guidance provided in NEI 95-10, it is permitted by the rule and the staff finds it acceptable.
On the basis of the above review, the staff finds that the methodology used by the applicant to identify electrical components that require an AMR is consistent with the requirements of the rule. The evaluation for the specific implementation of this methodology for ONS electrical components can be found in Section 2.2.3.7 of this safety evaluation.
On the basis of the above review, the staff finds that there is reasonable assurance that the applicant's methodology for identifying the SSCs within the scope of license renewal and requiring an AMR is consistent with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
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In Sections 2.3 through 2.7 of Exhibit A, "License Renewal--Technical Information," of the LRA, the applicant described the SCs that are subject to an AMR for license renewal. The staff reviewed these sections of the LRA to determine if there is reasonable assurance that the applicant has listed those SCs subject to an AMR to meet the requirements stated in 10 CFR 54.21(a)(1).
The staff reviewed Sections 2.3 through 2.7 of Exhibit A to the LRA to determine if there is reasonable assurance that the applicant has appropriately identified and listed those SCs subject to an AMR to meet the requirements stated in 10 CFR 54.21(a)(1). The statement of considerations (SOC) for the license renewal rule (60 FR 22478) indicates that an applicant has the flexibility to determine the set of SCs for which an AMR is performed, provided that this set encompasses the SCs for which the Commission has determined an AMR is required. Accordingly, the staff focused its review on verifying that the implementation of the applicant's methodology discussed in Section 2.1 of this safety evaluation report (SER) did not result in the omission of SCs subject to an AMR in accordance with 10 CFR 54.21(a)(1). The staff performed the following two-step evaluation:
The staff used the ONS Updated Final Safety Analysis Report (UFSAR) in performing its review. Pursuant to 10 CFR 50.34(b), the FSAR contains " [a] description and analysis of the SSCs of the facility, with emphasis upon performance requirements, the bases, with technical justification therefore, upon which such requirements have been established, and the evaluations required to show that safety functions will be accomplished." The FSAR is required to be updated periodically pursuant to 10 CFR 50.71(e). Thus, the UFSAR contains updated plant-specific licensing-basis information regarding the SSCs and their functions.
The applicant presented its methodology (i.e., the integrated plant assessment (IPA)) to identify the SSCs within the scope of license renewal in Sections 2.1 and 2.2 of Exhibit A of the LRA. This IPA methodology consists of a review of all plant systems and structures to determine those that are within the scope of license renewal in accordance with the requirements of 10 CFR 54.4. The staff reviewed the IPA methodology and presented its evaluation in Section 2.1 of this SER. The applicant documented the implementation of that methodology in Sections 2.3 through 2.7 of Exhibit A of the LRA.
To ensure that the IPA methodology described in Sections 2.1 and 2.2 of Exhibit A of the LRA was implemented properly and identified the systems and structures within the scope of license renewal, the staff performed the following additional review: the staff sampled the contents of the UFSAR to identify systems or structures that may have intended functions meeting the scoping requirements of 10 CFR 54.4 that the applicant did not include within the scope of license renewal; the staff selected several systems, such as the radiation monitors and spent fuel building ventilation; and in a letter to the applicant dated December 2, 1998, the staff requested additional information about these systems.
In their January 25, 1999, response to NRC RAI 2.2-7 on whether radiation monitors were within the scope of license renewal, the applicant stated that the radiation monitors do not support any system intended functions as defined in 10 CFR 54.4(a). The staff agrees that while some radiation monitors do not support system intended functions. However, the staff believed that radiation monitors that detect activity in the control room air supply are credited for initiating certain operator actions. This continuous radiation monitoring was thought to be a safety-related function that cautions the control room operators to manually activate the filtration train of the control room pressurization and filtration system for Units 1, 2, and 3 control rooms under given accident conditions to meet TMI Action Plan Item III.D.3.4, for control room habitability.
The continuous radiation monitoring is described in ONS UFSAR Section 9.4.1.3, which states that "[r]eturn air from the control room is continuously monitored by a radiation monitor before recirculating back to the control room. A high radiation level will alert the operators to energize the outside air filter trains." On April 8, 1999, the staff requested that the applicant clarify its justification for excluding the radiation monitors from within the scope of license renewal. On May 10, 1999, the applicant responded to the staff's April 8, 1999, request for clarification of RAI 2.2-7. In its response, the applicant stated that although radiation monitors RIA-39 for Units 1, 2, and 3 will prompt operators to energize outside filter trains, operation of the monitors is not relied upon for the successful mitigation of any design-basis event and failure of the monitors will not prevent the successful mitigation of any design-basis event. In addition, the applicant stated that the radiation monitors are not relied upon to meet the requirements of any of the regulated events identified in 10 CFR 54.4(a)(3). The staff also requested that the applicant review the functions of the radiation monitors on OLRP-1002 drawings OLRFD-116C-1.1, 124B-1.5, and 133A-1.5 to ensure that these monitors did not have any intended functions that would require the monitors be included within the scope of license renewal. In its May 10, 1999, response, the applicant stated that the radiation monitors identified on the referenced drawing are all non-safety-related and not relied upon for the successful mitigation of a design-basis event. The staff has reviewed the applicant's responses and agrees that the radiation monitors are not within the scope of license renewal.
In NRC RAI 2.2-8, the staff asked the applicant to justify the omission of the spent fuel pool (SFP) ventilation system from within the scope of license renewal. SFP area ventilation is often credited in mitigating fuel handling accidents as well as performing other safety functions. The applicant responded in a letter dated February 17, 1999, that its analyses show that the system is not required to remain functional during or following any design-basis event to ensure any of the functions required by 10 CFR 54.4(a)(1) and does not meet the criteria of 10 CFR 54.4(a)(2) or (3) and is, therefore, not within the scope of license renewal. The staff reviewed the applicant's response and Chapter 15 of the UFSAR, and agreed with the applicant's decision to not include the system in the scope of license renewal.
In a letter to the applicant dated April 16, 1999, the staff requested additional information (RAI 2.5-1) concerning the identification and listing of components associated with instrumentation lines within the scope of license renewal. Rules for highlighting the OLRFD drawings in the front of each OLRP-1002 volume of flow diagrams contain the statement, "[a]ll instrumentation lines normally open to the process flow through, but not including the instrument, are included in license renewal. These lines are not highlighted except for containment penetrations." Section 2.5 of Exhibit A of the LRA lists the mechanical systems within the scope of license renewal and presents a table for each system at the end of the section identifying the components that are subject to an AMR. The staff review of these tables generally found the component "tubing" on the table of components subject to an AMR. However, several systems did not list tubing as a component, even though some instrument lines originated from points of the system that were within the scope of license renewal. In the letter dated April 16, 1999, the staff requested that the applicant clarify the status of the instrumentation lines for the following systems:
On May 10, 1999, the applicant responded to the staff's RAI. The applicant stated that for three systems, reactor building spray, component cooling, and feedwater, stainless steel tubing is included within the scope of license renewal and was inadvertently omitted from Tables 2.5-2 and 3.5-2 of the LRA. For three systems, reactor building cooling system, auxiliary building ventilation system, and the SSF HVAC System, no tubing exists within the license renewal boundaries of the systems. For the Condenser Circulating Water (CCW) System, the applicant stated that this system does have instrumentation lines within the license renewal boundaries, but they do not perform any intended function and are, therefore, not subject to an AMR. Therefore, this tubing was not included on Table 2.5-9 for the CCW System. The staff reviewed the applicant's response and found it acceptable.
In Section 9.2.2.2.4 of the ONS UFSAR, the applicant described the design and operation of the Recirculation Cooling Water (RCW) System. One function of the RCW System is to remove decay heat from the stored fuel in the spent fuel pool by transferring the heat from the spent fuel pool coolers to the CCW System. In the UFSAR, the applicant also stated that the SFP Cooling System is designed to keep the pool bulk temperature below 150°F under a variety of postulated normal and upset conditions, and under 205°F when considering abnormally high heat loads and certain equipment failure. The UFSAR further stated that 205°F represents the actual operating limit, because calculations show that the seismic and structural integrity of the pool is not compromised below this temperature. In addition, Chapter 15 Section 11.2.1 of the UFSAR stated the assumptions for a fuel handling accident in the SFP, which include a fuel assembly gap pressure based on a bulk SFP coolant temperature of 150°F.
Since the RCW System is relied upon to supply cooling water to the SFP Cooling System coolers to maintain the bulk SFP coolant temperature below the SFP design limits and below assumptions for the fuel handling accident analysis described in Section 15.11.2.1 of the UFSAR, the staff requested that the applicant clarify the basis for excluding the RCW System from the scope of license renewal. This issue was identified as Open Item 2.2.3-1.
In letters dated October 15, and November 30, 1999, the applicant responded to Open Item 2.2.3-1. The applicant clarified the basis of the SFP Cooling System design and the reason for omitting the RCW System from the scope of license renewal. In its response, the applicant stated that the fuel handling accident analysis for ONS assumes that spent fuel pool cooling, and thus the RCW System, is not functional during or following such an event. The applicant stated that the results of the safety analysis for the fuel handling accident demonstrates that the consequences of such an accident are within the 10 CFR Part 100 guidelines. The normal operating temperature for the spent fuel storage pool established by the ONS operating procedures ensure that the results of a fuel handling accident analysis remain valid even if all forced cooling to the spent fuel pool is lost at the commencement of the accident. 10 CFR 54.4(a)(1) states that safety-related SSCs, which are those relied upon to remain functional during and following design-basis events to ensure the capability to mitigate or prevent the consequences of an event (such as a fuel handling accident), that could result in potential offsite exposure comparable to 10 CFR Part 100 guidelines shall be included within the scope. Since the applicant's analysis demonstrated that spent fuel pool cooling is not required to remain functional during or following a fuel handling accident or to prevent or mitigate the consequences that could result in potential offsite exposure comparable to 10 CFR Part 100 guidelines, the SSCs required to fulfill the function of decay heat removal from the spent fuel pool, including the RCW System, are not within the scope of license renewal. The staff reviewed the reasons for excluding the RCW System from the scope of license renewal and found the applicants justification acceptable. On the basis of this review and the staff's findings, Open Item 2.2.3-1 is closed.
The staff reviewed the information submitted by the applicant in the LRA, information in the ONS UFSAR, and additional information in the applicant's January 25, February 17, and May 10, 1999, responses to the NRC's December 2, 1998, and April 16, and October 15, 1999, letter and did not identify any systems or structures with intended functions that were not already evaluated in the LRA. Therefore, the staff has reasonable assurance that the applicant has appropriately identified the systems and structures within the scope of license renewal in accordance with 10 CFR 54.4.
2.2.3.1 Containment Structures
2.2.3.1.1 Concrete Components, Steel Components, and Post-Tensioning System
In Section 2.3, "Reactor Building (Containment) Structural Components," of Exhibit A of the LRA, the applicant identified the SCs that are within the scope of license renewal and which of those within-scope SCs are subject to an AMR.
Component (equipment and piping) supports for the SCs described below are covered separately in Section 2.7 of Exhibit A of the ONS LRA. Electrical components that support the operation of the systems are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant included instrument line components with the system to which they are attached.
2.2.3.1.1.1 Summary of Technical Information in the Application
The reactor buildings are Class 1 structures which prevent uncontrolled release of radioactivity. The applicant has determined that Class 1 structures meet the intent of 10 CFR 54.4(a)(1) and are within the scope of license renewal. A part of the reactor building, the containment, includes the concrete containment structure, liner, and all penetrations. The containment has been divided into three groups according to material of construction and component-level function. These component groups are described in Section 2.3.2, "Concrete Components"; Section 2.3.3, "Steel Components"; and Section 2.3.4, "Post-Tensioning System." The three containment component groups within the scope of 10 CFR Part 54 and their intended functions are given in Table 2.3-2 of Exhibit A of the LRA.
The concrete component group consists of the cylinder wall, dome, floor, and foundation slab. The applicant identified the following intended functions for the concrete component group:
One additional intended function identified for the cylinder wall, was the need for the wall to provide a rated fire barrier to confine or retard a fire from spreading to or from adjacent areas of the plant.
The steel component group includes anchorages, embedments, attachments, electrical penetrations, emergency personnel hatch, equipment hatch, fuel transfer tubes, liner plate, mechanical penetrations, and personnel hatch. All the components of the steel component group have the intended function of providing an essentially leak-tight barrier to prevent uncontrolled release of radioactivity. For anchorages, embedments, and attachments, the applicant also identified the intended function of providing a structural and/or functional support to safety-related SSCs and non-safety-related SSCs where failure of the structural component could directly prevent satisfactory accomplishment of any of the required safety-related functions. Mechanical penetrations also provide structural and/or functional support to safety-related SSCs and this was identified as an intended function. Finally, the ability of the liner plate to provide a heat sink during design-basis accidents or station blackout was identified as an intended function.
The post-tensioning group comprises two component types, tendon anchorage and tendon wires. Providing structural and/or functional support to safety-related SSCs was identified as the intended function for the post-tensioning group. More specifically, this function involves imposing compressive forces on the concrete containment structure to resist the internal pressure resulting from a design-basis accident with no loss of structural integrity.
2.2.3.1.1.2 Staff Evaluation
The staff reviewed Section 2.3 of Exhibit A of the LRA to determine whether there is reasonable assurance that the applicant has identified the containment SCs subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.1.1.2.1 Containment Structures, Systems, and Components Within the scope of License Renewal and Subject to an Aging Management Review
The staff reviewed Section 6.2.1, "Containment Functional Design," of the UFSAR and compared the description of the structures, systems, and other components in the UFSAR to the description in the application to determine if there were any additional portions of the system that the applicant should have identified as within the scope of license renewal. As described in Sections 2.3 and 2.7 of Exhibit A of the LRA, essentially all portions of the containment were determined to be within the scope of license renewal and subject to an AMR. The staff reviewed the few remaining components of the containment to verify that they do not perform any intended functions. The staff also reviewed Section 6.2.1 of the UFSAR to determine if there were any additional functions that were not identified as intended functions in the LRA. The staff found no omissions. Therefore, there is reasonable assurance that the applicant adequately identified all portions of the containment structures which fall within the scope of license renewal and are subject to an AMR in accordance with 10 CFR Part 54.
In RAI 2.3-8, the staff asked the applicant why the tendon gallery, which provides access to the bottom anchorages of the vertical tendons as part of the post-tensioning system, had not been included within the scope of license renewal under 10 CFR 54.4(a)(2). In response to the RAI the applicant stated that the function of the tendon access gallery is to provide access to the bottom of the vertical tendons so that they can be tested and that its failure would not prevent satisfactory accomplishment of any of the functions identified by 10 CFR 54.4(a)(1)(i), (ii) or (iii). The staff agrees that the tendon gallery itself is not within the scope of license renewal. However, operational experience, as documented in NUREG-1522, has shown that water infiltration and high humidity in the tendon gallery can be a significant aging effect on the vertical tendons that could potentially result in loss of the ability of the post-tensioning system to perform its intended function. This is reflected in Open Item 3.3.3.1-1.
In RAI 2.3-11, the staff asked the applicant why the function(s) of the containment sump was not identified as an intended function(s) of the containment. The applicant responded to the RAI by stating that the sumps were not included in Section 2.3 of Exhibit A of the LRA because they do not perform the function of providing an essentially leak-tight barrier to prevent uncontrolled release of radioactivity, which is the function of the containment building. However, the emergency and normal sumps are included in Section 2.7 with reactor building internal structures as components requiring an AMR.
2.2.3.1.1.3 Review Findings for Concrete Components, Steel Components, and Post-Tensioning System
As described above, the staff has reviewed the information provided in Section 2.3 of Exhibit A of the LRA and the additional information provided by the applicant in response to the staff's RAIs. The staff has reasonable assurance that the applicant has appropriately identified those portions of the containment, and the associated SCs thereof, that are within the scope of license renewal and subject to an AMR in accordance with the requirements of 10 CFR 54.4.
2.2.3.2 Reactor Coolant System
2.2.3.2.1 Reactor Coolant System
In Section 2.4, "Reactor Coolant System Mechanical Components and Class 1 Component Supports," of the LRA, the applicant described the SCs of the Reactor Coolant System (RCS) that are subject to an AMR for license renewal.
2.2.3.2.1.1 Summary of Technical Information in the Application
As described in the application, the following SCs of the RCS are within the scope of license renewal and are subject to an AMR: RCS piping (Class 1; non-Class 1 portions are addressed in Section 2.5 of the application), pressurizer, reactor vessel, reactor vessel internals, once-through steam generator, reactor coolant pumps, control rod drive motor tube housings, letdown coolers, Class 1 component supports, reactor coolant piping supports, pressurizer supports, reactor vessel support skirt, control rod drive service structure, once-through steam generator supports, and reactor coolant pump supports. The rest of this section lists the intended functions of these SCs according to 10 CFR 54.4(a) and briefly describes these SCs.
Reactor Coolant System Piping (Class 1)
Intended Function:
For the ONS, the following components are within the reactor coolant pressure boundary: reactor vessel, once-through steam generators (primary side), pressurizer, reactor coolant pump, main coolant piping and portions of systems attached to these components. The attached systems that contain Class 1 components include the Core Flood System, High-Pressure Injection System, Low-Pressure Injection System, and Chemical Addition System. In addition, vents, drains, and instrumentation lines contain Class 1 components. RCS piping includes piping (including fittings, branch connections, safe ends, and thermal sleeves), valve bodies (pressure retaining parts of RCS isolation/boundary valves), and bolted closures and connections.
Pressurizer
Intended Functions:
The pressurizer is a vertical cylindrical vessel with a bottom surge line penetration connected to the hot leg piping by the surge line piping. The pressurizer contains electric heaters in its lower section and a water spray nozzle in its upper section. Since all sources of heat in the RCS are interconnected by piping with no intervening isolation valves, relief protection is provided on the pressurizer. Overpressure protection consists of two code safety valves and one power- operated relief valve. Piping attached to the pressurizer is Class 1 up to and including the first isolation valve.
Reactor Vessel
Intended Functions:
The reactor vessel consists of the cylindrical vessel shell, lower vessel head, closure head, nozzles, interior attachments and all associated pressure-retaining bolting. Coolant enters the reactor through the inlet nozzles, passes down through the annulus between the thermal shield and vessel inside wall, reverses at the lower head, passes up through the core, turns around through the plenum assembly, and leaves the reactor vessel through the outlet nozzles.
The reactor vessel has two outlet nozzles, through which the coolant is transported to the steam generators, and four inlet nozzles, through which coolant enters the reactor vessel from the discharge of the reactor coolant pumps. Two smaller nozzles between the inlet nozzles serve as inlets for decay heat removal and emergency core cooling water injection. The reactor vessel is vented through the control rod drives. Instrumentation nozzles penetrate the lower vessel head.
Control rod drive mechanisms are attached to flanged nozzles, which penetrate the closure head, and are not within the scope of license renewal. However, the control rod drive motor tube housings are within the scope of license renewal and subject to an AMR.
Reactor Vessel Internals (RVI)
Intended functions:
The RVI consist of two structural subassemblies that are normally located within the reactor vessel. The RVI can be removed during refueling outages when necessary. The two subassemblies of the internals are the plenum assembly and the core support assembly. The RVI for the ONS are described in the B&WOG topical report, BAW-2248. The applicant states that it has reviewed the current design and operation of the ONS RVI, and has determined that they are bounded by the description in BAW-2248, with the exception of thermal shield and thermal shield upper restraint. The thermal shield and thermal shield upper restraint were omitted from the generic report; however, these items support an ONS RVI intended function and are subject to an AMR. The thermal shield surrounds the core barrel and is constructed of austenitic stainless steel. The thermal shield upper restraint is also constructed of austenitic stainless steel.
Once-Through Steam Generator (OTSG)
Intended Functions:
Each ONS unit has two OTSGs. Each is a vertical, straight-tube, once-through, counterflow, shell-and-tube heat exchanger with shell-side boiling. The steam generator consists of upper and lower hemispherical heads welded to tubesheets that are separated by a seven-course shell assembly. Over 15,000 straight Alloy 600 tubes are held in alignment by 15 tube support plates. Primary coolant from the reactor enters the steam generator through a single inlet nozzle in the top of the upper head. Coolant flows downward through the straight parallel tubes, is cooled by the secondary coolant on the shell side, and then exits through two outlet nozzles in the lower head. Secondary coolant enters through a ring of ports that penetrate the shell approximately midway up the shell assembly. The feedwater travels downward through an annulus between the lower baffle and the shell. Near the lower tubesheet the feedwater turns inward, and then flows upward around the tubes and through the tube support plates. As the feedwater absorbs heat from the primary coolant, it boils and then becomes superheated. The dry steam exits the steam generator through two steam outlet nozzles just above the feedwater inlet ports. The OTSG items that are subject to an AMR are the hemispherical heads, secondary shell, tubes, plugs, mechanical sleeves, tubesheets, primary nozzles, main and auxiliary feedwater nozzles, steam outlet nozzles, instrumentation nozzles, drain nozzles, all associated pressure retaining bolting, and integral attachments inspected in accordance with ASME Section XI, Subsections IWB and IWC.
Reactor Coolant Pumps (RCPs)
Intended Function:
The reactor coolant pumps provide the head required to transport the reactor coolant through the reactor core, piping, and steam generators. All four reactor coolant pumps of each ONS unit are required during normal operation. The four reactor coolant pumps installed on ONS Unit 1 are Westinghouse Model 93A, while those installed on ONS Units 2 and 3 are Sultzer-Bingham.
The reactor coolant pump items that are subject to an AMR are the casing, cover, and associated pressure-retaining bolting. The portion of the reactor coolant pump rotating element above the pump coupling, the electric motor, and the flywheel are not subject to an AMR in accordance with 10 CFR 54.21(a)(1).
The pump cover is a generic term used to describe the pressure-retaining closure of the pump casing. The cast austenitic stainless steel cover (stuffing box for Sultzer-Bingham pumps) serves as a housing for the mechanical seals, radial bearing, thermal barrier, and recirculating impeller for the Sultzer-Bingham pumps. The cover is clamped between the carbon steel driver mount (motor stand for Sultzer-Bingham pumps) and the stainless steel pump casing. The main flange serves as the cover for the Westinghouse design. The Westinghouse cover closure consists of the main flange, thermal barrier, and pump casing.
Each reactor coolant pump is supported by the cold leg piping during all modes of operation; the weight of each reactor coolant pump motor is supported by two vertical constant load supports.
Control Rod Drive Motor Tube Housing
Intended Function:
Control rod drive mechanism motor tube housings provide the reactor coolant pressure boundary around the control rod drive mechanisms. During normal operation, the control rod drive mechanism motor tube housings are filled with borated reactor coolant at the system operating pressure. Thermal barriers in the lower-motor tube mechanism, the control rod drive mechanism cooling system, and vessel head cooling fans maintain the temperature in the housings below RCS temperature.
Two different designs of control rod drive mechanisms are currently in use at ONS: Type A at ONS Units 1 and 2, and Type C at ONS Unit 3. The control rod drive mechanisms themselves are active and not considered to be subject to an AMR for license renewal.
Letdown Coolers
Intended Function:
The letdown coolers are used during normal operation to cool the letdown flow from the RCS to prevent damage to the purification system ion exchange resins. The coolers are of the shell and spiral tube design. Borated water from the RCS is on the tube side and treated water from the Component Cooling System is on the shell side. The tubes, tubesheets, and channel heads in the coolers are stainless steel and are within the scope of license renewal for the RCS. The cooler shell is carbon steel and is considered part of the Component Cooling System. Each unit has two letdown coolers.
Class 1 Component Supports
The following component supports are within the RCS evaluation boundary:
RCS Class 1 Piping Supports
Intended Function:
Supports associated with the RCS piping include standard unit pipe supports, LOCA restraints, and snubbers. Snubbers are active and are not subject to an AMR in accordance with 10 CFR 54.21(a)(1).
RCS piping supports provide structural and functional support of the Class 1 piping during seismic events in accordance with design basis loads. LOCA restraints provide structural support during seismic events and prevent pipe whip in the event of a postulated rupture of a pipe.
Class1 piping greater than 14-inch nominal pipe size (NPS) includes the 36-inch and 28-inch hot and cold leg piping. The hot and cold leg piping is supported by the once-through steam generator and the reactor vessel. Two LOCA restraints surround each hot leg: one at the 90-degree elbow that directs coolant flow to the vertical riser section, and the second that envelops the vertical riser. Each cold leg contains a LOCA restraint at the reactor coolant pump inlet. All LOCA restraints are shimmed so that a gap exists between the restraint and the piping during all modes of operation.
Class 1 piping less than or equal to 14-inch NPS includes the decay heat drop line, core flood/decay heat injection lines, pressurizer surge line, pressurizer spray and auxiliary spray lines, high-pressure injection/makeup lines, letdown lines, vent and drain lines, instrumentation lines, and In-core Monitoring System piping. Piping supports associated with these lines (with the exception of the pressurizer surge line, which is supported by the hot leg and the pressurizer) include the following standard support units: variable spring hangers, constant load supports, threaded rods with fasteners, pipe clamps, U-bolts, and swing sway braces. Items that support the intended function include the standard support units and the exposed portion of the connection to the building structure.
Pressurizer Supports
Intended Function:
The pressurizer supports consist of the support plate assemblies, support frame assembly, and a LOCA restraint. The pressurizer support plate assemblies and the support frame assembly provide structural support for the pressurizer. The LOCA restraint minimizes the movement of the pressurizer following a postulated break of the surge line.
Eight support plate assemblies are welded to the exterior shell of the pressurizer and each support plate assembly is bolted to the support frame assembly. The support frame assembly is attached to and supported by the secondary shield wall. In addition, a LOCA restraint surrounds the pressurizer surge nozzle to limit motion of the vessel following a postulated rupture of the pressurizer surge line. The LOCA restraint is hung from the support frame assembly. One end of the LOCA restraint is clamped around the pressurizer surge nozzle and the other end is suspended with its end very close to the secondary shield wall.
The support plate assemblies are fabricated from carbon steel. Structural members that support the intended functions of the support frame assembly and LOCA restraint include beams, bracket, stiffeners, plates, hanger rods, and structural bolting. Support frame and LOCA restraint structural members are fabricated from carbon steel and alloy steel. In addition, the exposed portion of the connection to the building structure is within the scope and subject to an AMR.
Reactor Vessel Support Skirt
Intended Function:
The reactor vessel supports consists of a support skirt and support flange. The reactor vessel support skirt is a cylindrical structure that supports each reactor vessel. The support skirt rests on a sole plate, which is supported by a reinforced concrete pedestal and is fixed to the pedestal by a steel flange that is bolted to the pedestal by prestressed bolts. The evaluation boundary of the reactor vessel support skirt begins at the weld of the skirt to the reactor vessel transition forging and terminates at the bottom of the skirt flange. The evaluation boundary also includes the exposed surface of the anchor bolts and shear pins. The support skirt consists of two carbon steel semicircular rings welded together longitudinally to form a cylinder. This cylinder is welded to the bottom of the reactor vessel transition forging. The cylinder has holes for ventilation of the reactor vessel cavity. The anchor bolts are prestressed to accommodate the loads of a design basis seismic event.
Control Rod Drive Service Structure
Intended Function:
The control rod drive service structure is located on top of the reactor vessel and prevents excessive lateral motion of the control rod drive mechanisms to ensure that the control rods can drop into the core under design-basis loading conditions. The control rod drive service structure consists of five major assemblies:
OTSG Supports
Intended Function:
OTSG supports that are subject to an AMR include the support skirt and upper lateral support structure. The intended function of the steam generator support skirt is to transfer lateral and vertical loads from the OTSG to the reinforced steam generator foundation. The intended function of the upper lateral support structure is to provide support during seismic events (i.e., to transmit pipe rupture forces and dynamic forces to the secondary concrete shield wall).
The OTSG support skirt consists of a perforated alloy steel cylinder that is welded to a carbon steel support plate. Reinforcement of the joint that connects the cylinder to the support plate is provided through equally spaced carbon steel gusset plates that are welded to the inside of the cylinder and the support plate. The support plate has holes equally spaced around it. These holes match up with the anchor bolts embedded in the steam generator foundation which supplies the vertical support of the steam generator.
The steam generator support skirt is attached to the lower steam generator head by a rolled low-alloy steel plate transition ring, which is welded to the exterior of the lower head. For ONS Units 1 and 2, the support skirt is welded to the transition forging with full penetration welds. The transition ring at ONS Unit 3 is a low-alloy steel ring forging that is part of the lower head pressure boundary assembly and has a shaped transition that projects out to accept the support skirt attachment weld.
The upper lateral support structure surrounds each steam generator at the elevation of the upper tube sheet. The structure consists of five lateral support subassemblies that are attached to the secondary shield wall at five azimuthal locations surrounding the steam generator. Each subassembly extends from the secondary shield wall to the steam generator, and each subassembly is connected to an adjacent subassembly with tie plates. Attached to the end of each subassembly is a spring head that consists of a carbon steel backing plate, carbon steel shims, and a machined lubrite pad fabricated from bridge bearing bronze. The external face of each lubrite pad is concave and faces a convex carbon steel bearing plate that is bolted to the exterior shell of the steam generator. The bearing plates are machined to dimensions for the cold position and the lubrite pads are machined to dimensions for the hot position. The lubrite pads are shimmed in the field to ensure proper fit-up with the bearing plates during cold and hot conditions. The lateral support subassemblies and tie plates are fabricated from carbon steel and alloy steel fasteners.
All structural members used to construct the upper lateral support structure, including the exposed portion of the anchor bolts and nuts that connect the upper lateral support subassemblies to the secondary shield wall, are subject to an AMR.
Reactor Coolant Pump Supports
Intended Function:
Reactor coolant pump supports consist of vertical support assemblies and lateral support assemblies. Two vertical support assemblies are provided for each reactor coolant pump motor. Each vertical assembly consists of: two coated constant load supports, two galvanized rods manufactured from alloy steel, and galvanized washers and nuts that connect the rods to the motor and the constant load support to the rods. The constant load supports are designed to accept the weight of the reactor coolant pump motor at normal operating temperature.
The reactor coolant pump lateral support assemblies include snubbers and turnbuckles. Snubbers are not subject to an AMR in accordance with 10 CFR 54.21(a)(1). However, the pins that connect the snubbers to the pumps and the secondary shield wall are within the scope and subject to an AMR. Turnbuckles (two per pump) limit lateral displacement of the pump and motor following a postulated LOCA. The RCP lateral support assemblies are subject to an AMR as shown in Table 3.4-1 of Exhibit A of the LRA.
2.2.3.2.1.2 Staff Evaluation
The NRC staff reviewed this section of the application to determine whether there is reasonable assurance that the RCS components and supporting structures subject to an AMR have been identified in accordance with the requirements of 10 CFR 54.21(a)(1). The staff's review is discussed below.
2.2.3.2.1.2.1 RCS Within the Scope of License Renewal and Subject to an AMR
As part of the evaluation, the staff determined whether the applicant had properly identified the SSCs within the scope of license renewal and subject to an AMR, pursuant to 10 CFR 54.4(a) and 10 CFR 54.21(a)(1). The staff reviewed portions of the UFSAR for the RCS, and compared the information in the UFSAR with the information in the application to identify portions that the applicant did not identify as within the scope of license renewal and subject to an AMR. The staff then reviewed SCs that the applicant did not identify, and as described below, requested the applicant provide additional information and/or clarifications for certain SSCs to verify that (1) they do not have any intended functions as delineated in 10 CFR 54.4(a), and if they do, that (2) they are either active components or are subject to replacement either at the end of qualified life or at specified intervals, as described in 10 CFR 54.21(a)(1). The staff also reviewed the UFSAR for any safety-related system functions that were not identified as intended functions in the application, to verify that no SCs having intended functions were omitted from consideration as being within the scope of the rule.
After completing the initial review, by letter dated November 30, 1998, the staff issued requests for additional information (RAIs) regarding the RCS, and by letters dated January 25, February 8, and February 17, 1999 the applicant provided responses to those RAIs. In RAI 2.4-1, the staff stated that drawings nos. OLRFD-107A-1.1, 2.1 and 3.1 of the LRA show the pressurizer quench tank with the sparger; but it was not clear from the drawings if the sparger nozzles are within the scope of license renewal. Therefore, the staff requested the applicant provide clarification. In response, the applicant clarified that sparger nozzles within the Coolant Storage System are within the scope of license renewal and subject to an AMR.
In RAI 2.4-2, the staff referenced page 4-51, Section 4.5.1.3.1, of the ONS UFSAR, which states that lifting lugs are provided for remote handling of the plenum assembly (reactor vessel internals), and that these lugs are welded to the cover grid. However, it was not clear from the LRA (Fig. 2.4-5) if these lifting lugs and attachment welds are within the scope of license renewal. The RAI requested the applicant discuss whether these items are within the scope or provide a basis for their exclusion. The applicant responded by stating that these lifting lugs are within the scope of license renewal and subject to an AMR.
In RAI 2.4-3, the staff referred to page 5-44, Section 5.3.1 of the UFSAR, which states that guide lugs are welded inside the reactor vessel lower head to limit a vertical drop of the reactor internals and core to ½-inch or less and prevent rotation about the vertical axis in the unlikely event of a major internals component failure. It was not clear from the LRA (Figs. 2.4-2, 3 and 4) if these lugs and attachment welds are within the scope of license renewal; therefore, the RAI sought clarification as to whether these items are within the scope of license renewal. The applicant stated in its response that the core guide lugs and their attachment welds are within the scope of license renewal and subject to an AMR.
In RAI 2.4-4, the staff referred to page 4-10, Section 4.2.2.1.5 of the UFSAR, which states that attached to the upper end fitting (reactor vessel internals) is a holddown spring, which provides a positive holddown margin to oppose hydraulic forces resulting from the flow of the primary coolant. It was not clear from the LRA (Fig. 2.4-5) if this spring is within the scope of license renewal; therefore, the RAI requested the applicant discuss whether this item is within the scope of license renewal or provide a basis for its exclusion. The applicant's response explained that the holddown spring is attached to the upper end fitting of the fuel assembly and is not attached to the reactor vessel internals, and that the end fittings are retired from service when the fuel assembly is replaced for refueling. The fuel assemblies and associated upper end fittings, including the holddown springs, are periodically replaced during refueling outages and are not subject to an AMR in accordance with 54.21(a)(1)(ii).
In RAI 2.4-5, the staff referred to page 5-43, Section 5.3.1, of the UFSAR, where it is stated that test taps are provided in the annulus between the two O-rings to afford a means to leak test the reactor vessel closure seal. It was not clear from the LRA (Figs. 2.4-2, 3, and 4) if these test taps are within the scope of license renewal. Therefore, the RAI requested the applicant discuss whether these test taps are within the scope of license renewal or provide a basis for their exclusion. The applicant responded that the test taps (also referred to as monitoring pipes) do not support a reactor vessel intended function and are not subject to an AMR.
In RAI 2.4-6, the staff pointed out that Figs. 2.4-2, 3, and 4 of the LRA show the reactor vessel; however, these figures do not show the closure head of the vessel. As a result, the RAI requested the applicant discuss if the following two device types are subject to an AMR: (1) lifting lugs and (2) vents that were added to the reactor vessel and to the pressurizer head in response to NUREG-0737, Item II.B.I. In response, the applicant stated that the reactor vessel lifting lugs do not support a reactor vessel intended function, and are not subject to an AMR; however, the reactor vessel head and the pressurizer vent lines are within the scope of license renewal and subject to an AMR.
Finally, in RAI 2.4-7, the staff requested the applicant explain Table 2.4-4 of the LRA, which lists RCS components and their intended functions. The staff asked the applicant to discuss why the following intended functions, for the specified components, were not considered as intended functions to be maintained for license renewal, and to provide bases. The components and their intended functions are given below:
| Component | Intended Function(s) |
|---|---|
| Reactor Vessel Internals | Capability to shutdown the reactor and maintain it in a safe-shutdown condition. |
| OTSG | Provide heat removal under abnormal operating conditions. |
In addition, the staff requested that the applicant verify that reactor coolant pumps do not have any intended functions, credited for design-basis events, that meet the requirements of 10 CFR 54.4, other than the intended function cited for license renewal, i.e., pressure boundary function of the pump casing and flow-related coastdown function associated with the RCP flywheel, and are therefore not considered within the scope. The applicant's response to the RAI was as follows:
Reactor Vessel Internals Intended Function -- capability to shut down the reactor. The subject intended function has been defined by the applicant as a system level scoping function, and is not a component intended function, and therefore, not included as an intended function for the RVI. Furthermore, the addition of this function as an intended function would not subject any additional RVI items to an AMR.
OTSG Intended Function -- provide heat removal under abnormal operating conditions. The OTSG intended functions as listed in the application are (1) maintaining the primary pressure boundary so the RCS can perform its system function, and (2) providing decay heat removal under design basis conditions. The second ONS OTSG intended function encompasses the NRC-specified function to provide heat removal under abnormal operating conditions. Design-basis calculations cover all modes of operation: i.e., normal, upset, emergency, and faulted.
Reactor Coolant Pump Intended Function. The applicant reviewed the ONS UFSAR and the RCS design-basis document and concluded that the only intended function of the RCP is the pressure boundary function as listed in the application, and that no additional intended functions were identified for the RCPs. The coastdown function of the RCP is required to mitigate selected design-basis events (e.g., loss-of-coolant flow accident in Chapter 15 of the UFSAR); however, the applicant determined that flow coastdown, which is a function of system resistance and flywheel inertia, is a system level function and not a component function. The time-limited aging analysis of the RCP flywheel is addressed in Section 5.4.4 of the application.
GSI-23 Reactor Coolant Pump Seal Failures
In Section 1.5.2 of Exhibit A of the LRA, Duke discusses GSI-23. GSI-23 deals with the high rate of reactor coolant pump seal failures that challenge the makeup capacity of the Emergency Core Cooling Systems in pressurized water reactors. The license renewal rule states that the application must identify and list those SCs subject to an AMR. The rule goes on to state that SCs subject to an AMR shall encompass those SCs that, among other things, are "not subject to replacement based on a qualified life or specified time period." The applicant stated, in Section 1.5.2 of Exhibit A of the LRA, that a license renewal AMR is not required for the RCP seals because they are routinely replaced. In subsequent documentation, dated February 17, 1999, the applicant stated that the RCPs are replaced in accordance with the "Engineering Support Program." Additionally, the seals "are replaced on an interval not to exceed every four operating cycles," for Units 2 and 3, which use Bingham manufactured RCPs, and for the first (of three) stage of the Unit 1 seals, which uses Westinghouse manufactured RCPs. The applicant went on to state that the second and third stages for the Unit 1 seals "are replaced on an interval not to exceed every two operating cycles." As a result, in accordance with 10 CFR 54.21(a)(1(ii) because the RCP seals are subject to replacement based on a qualified life or specified time period, the staff agrees that these seals are not subject to an AMR.
2.2.3.2.1.3 Review Findings for RCS
On the basis of the staff's review of the information provided in Sections 2.4.3 through 2.4.3.11 of the application, the supporting information in the ONS UFSAR, and the applicant's response to the staff's RAIs as discussed in the preceding section, the staff did not find any omissions by the applicant and, therefore, concludes that there is reasonable assurance that the applicant adequately identified those portions of the RCS and its supporting SCs that fall within the scope of license renewal and are subject to an AMR, in accordance with 10 CFR 54.4(a) and 10 CFR 54.21(a)(1).
2.2.3.3 Engineered Safety Features Systems
2.2.3.3.1 Containment Heat Removal Systems
In Section 2.5.3, "Containment Heat Removal Systems," of Exhibit A of the LRA, the applicant identified the systems and components that are within the scope of license renewal and that are subject to an AMR. The Containment Heat Removal Systems include the Reactor Building Cooling System and the Reactor Building Spray System.
Component (equipment and piping) supports for the systems are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant evaluated instrument line components with the system to which they are attached.
2.2.3.3.1.1 Summary of Technical Information in the Application
Reactor Building Cooling System (RBCS)
The RBCS is designed to provide cooling to the reactor building following a loss-of-coolant accident. The steam-air mixture within the reactor building passes over the cooling coils in one of three reactor building cooling units to transfer heat from the containment atmosphere to the Low-Pressure Service Water System.
The applicant described their process for identifying the mechanical components subject to an AMR in Section 2.5.2 of Exhibit A of the LRA. The applicant identified the portions of the RBCS that are within the scope of license renewal on flow diagrams listed on Table 2.5-2 of Exhibit A of the LRA. Using the methodology described in Section 2.5.2.2 of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant provided that list in Table 2.5-3 of Exhibit A of the LRA. Four component types were identified as subject to an AMR, including three types of ductwork (aluminum, stainless steel, and galvanized steel) and reactor building cooling units. For these component types, maintaining the pressure boundary was identified as an intended function. Heat transfer was identified as an additional intended function for the reactor building cooling units.
Reactor Building Spray System (RBSS)
The RBSS is designed to remove heat from the containment atmosphere after a design-basis accident. The system also removes fission product iodine from the post-accident containment atmosphere. The RBSS consists of two redundant trains capable of taking suction from the header in the Low-Pressure Injection System and delivering borated water through the spray nozzles to the containment atmosphere during an accident. The borated water sprayed through the spray nozzles is collected in the reactor building sump and is recirculated for long-term cooling of the containment atmosphere.
The applicant described their process for identifying the mechanical components subject to an AMR in Section 2.5.2 of Exhibit A of the LRA. The applicant identified the portions of the RBSS that are within the scope of license renewal on flow diagrams listed in Table 2.5-2 of Exhibit A of the LRA. Using the methodology described in Section 2.5.2.2 of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant provided that list on Table 2.5-3 of Exhibit A of the LRA. Six component types were identified as subject to an AMR: mechanical expansion joint, orifice, pipe, pump casing, spray nozzle, and valve bodies. For these component types, maintaining the pressure boundary was identified as an intended function. Two other intended functions, throttling and spraying, were identified for the orifice and spray nozzle.
2.2.3.3.1.2 Staff Evaluation
The staff reviewed Section 2.5.3, "Containment Heat Removal Systems," of Exhibit A of the LRA to determine whether there is reasonable assurance that the applicant has identified the Containment Heat Removal System components subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.3.1.2.1 Containment Heat Removal Systems Within the Scope of License Renewal and Subject to an Aging Management Review
The staff reviewed Section 6.2.2, "Containment Heat Removal Systems," of the UFSAR and compared the description of the systems and other components in the UFSAR to the description in the application to determine if the applicant should have identified any additional portions of the system as within the scope of license renewal. As described in Sections 2.5.3 of Exhibit A of the LRA, essentially all portions of the Containment Heat Removal Systems were determined to be within the scope of license renewal and subject to an AMR. Two exceptions, as addressed below, are RBCS ductwork downstream of the dropout plates and the RBCS piping that directs condensate to the reactor building sump. The staff reviewed the remaining components of the containment heat removal systems to verify that they do not perform any intended functions. The staff also reviewed Section 6.2.2 of the UFSAR to determine whether the applicant failed to identify any additional functions as intended functions in the LRA. The staff found no omissions. Therefore, there is reasonable assurance that the applicant adequately identified all portions of the Containment Heat Removal System that fall within the scope of license renewal and are subject to an AMR in accordance with 10 CFR Part 54.
In RAI 2.5.3-1, the staff questioned why the RBCS piping and ductwork that supply cooling air to the steam generator cavity and reactor vessel annulus and direct condensate to the reactor building sump were not included within the scope of license renewal. The piping and ductwork in question are shown on Flow Diagrams OLRFD-116E-1.1, 2.1, and 3.1. The staff requested the applicant verify that the above functions were not credited in any safety analyses. Specifically, the applicant was asked to discuss its assumptions as to (1) initial or normal operating temperature assumed in the steam generator cavity and reactor vessel annulus for the purpose of equipment qualification, (2) normal operating temperature assumed to support the integrated exposure before a 10% reduction in sensitivity for the out-of-core neutron detectors, and (3) reactor building sump inventory.
In response to RAI 2.5.3-1, the applicant reaffirmed that the RBCS piping and ductwork that supply air to the steam generator cavity and reactor vessel annulus and direct condensate to the reactor building sump are not credited with supporting any system function as defined in 10 CFR 54.4(a). The applicant then addressed the three assumptions the staff requested information about. Temperature measurements in the steam generator and reactor vessel cavities are recorded and trended on an ongoing basis. If temperatures rise substantially above normal operating ranges for a period of time, that period of time at high temperatures is evaluated for impact on the established average ambient temperatures used in the qualified life calculations. The 10% reduction in sensitivity for the out-of-core neutron detectors is primarily a function of neutron flux intensity and not temperature. Calibration of the nuclear instrumentation system would detect any change in sensitivity and/or inability to meet performance requirements and the detector would be replaced per established procedures. Finally, reactor building sump inventory analyses do not rely on the water supplied by the RBCS condensate drain to the reactor building normal sump. Because the RBCS ductwork and piping are not credited with supporting a function defined in 10 CFR 54.4 (a) or (b), the applicant has justified not including this ductwork and piping within the scope of license renewal.
Section 9.4.6.2 of the ONS UFSAR states that in the event of a LOCA the RBCS fusible links melt, which assures a positive path for recirculation of the reactor building atmosphere. In RAI 2.5.3-2, the staff questioned why the fusible links were not included as one of the RBCS components subject to an AMR in Table 2.5-3 of Exhibit A of the LRA. In response to RAI 2.5.3-2, the applicant stated that the fusible links are considered within the scope of license renewal but are not subject to an AMR, in accordance with 10 CFR 54.21, because they change state (melt) to perform their intended function. The staff reviewed the information provided by the applicant and found it acceptable.
Section 15.15.1 of the ONS UFSAR states that the RBSS is credited with removal of a portion of the remaining iodine from the building atmosphere. In RAI 2.5.3-6, the staff questioned whether this intended function had been addressed by Exhibit A of the LRA. In response to RAI 2.5.3-6, the applicant stated that sodium hydroxide is credited with the removal of iodine following a postulated design-basis event. A portion of the chemical addition system is used to inject the sodium hydroxide and is within the scope of license renewal and subject to an AMR. The portion of the chemical addition system responsible is found on flow diagrams OLRFD-110A-1.8, 2.8, and 3.8. The applicant further stated that these flow diagrams were inadvertently omitted from Table 2.5-10 of Exhibit A of the LRA. The AMR for these components is found in Section 3.5.7.1of Exhibit A of the LRA. Based on the applicant's response to RAI 2.5.3-6, the staff finds the above intended function of the RBSS adequately addressed by Exhibit A of the LRA.
2.2.3.3.1.3 Review Findings for Containment Heat Removal Systems
As described above, the staff has reviewed the information provided in Section 2.5.3 of Exhibit A of the LRA and the additional information provided by the applicant in response to the staff's RAIs. Based on this review, the staff has reasonable assurance that the applicant has appropriately identified those portions of the Containment Heat Removal Systems, and components thereof, that are within the scope of license renewal and subject to an AMR in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21.
2.2.3.3.2 Containment Isolation System
In Section 2.5.4, "Containment Isolation System," of Exhibit A of the LRA, the applicant identified portions of the system and the components therein that are within the scope of license renewal, and identified which of those within-scope components are subject to an AMR.
Component (equipment and piping)supports for the system are presented separately in Section 2.6 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.7 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant included instrument line components with the system to which they are attached.
2.2.3.3.2.1 Summary of Technical Information in the Application
The Containment Isolation System is an engineered safety feature that provides for the closure of all fluid penetrations not required for operation of the engineered safeguards system to prevent the leakage of uncontrolled or unmonitored radioactive materials to the environment.
The applicant described its process for identifying the mechanical components subject to an AMR in Section 2.5.2 of Exhibit A of the LRA. On the basis of this methodology, the applicant identified the portions of the Containment Isolation System that are within the scope of license renewal on flow diagrams listed on Table 2.5-4 of Exhibit A of the LRA. Using the methodology described in Section 2.5.2.2 of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant provided that list in Table 2.5-5 of Exhibit A of the LRA. Ten component types were identified as subject to an AMR: pipe, valve bodies, orifice, hose connection, tubing, air flow monitor, annubar, ductwork, filter, and grill. For these component types, maintaining the pressure boundary was identified as the intended function. Two other intended functions, throttling and filtration, were identified for the orifice and filter.
2.2.3.3.2.2 Staff Evaluation
The staff reviewed Section 2.5.4 of Exhibit A of the LRA to determine whether there is reasonable assurance that the applicant has identified the Containment Isolation System components subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.3.2.2.1 Containment Isolation System Within the Scope of License Renewal and Subject to an Aging Management Review
The staff reviewed Section 6.2.3, "Containment Isolation System," of the UFSAR and compared the description of the system and components in the UFSAR to the description in the application to determine if the applicant should have identified any additional portions of the system as within the scope of license renewal and subject to an AMR. The plant's containment isolation valves are listed in Figure 6-9 of the UFSAR. In RAI 2.5.4-1, forwarded by a letter dated December 1, 1998, the staff asked the applicant to clarify whether all the containment isolation valves listed in Figure 6-9 of the UFSAR are subject to an AMR. In a letter dated February 8, 1999, the applicant responded to the RAI and stated that all the containment isolation valves listed in Figure 6-9 are within the scope of license renewal and subject to an AMR.
The staff also reviewed Section 6.2.3 of the UFSAR for any safety-related
functions that may not have been identified as an intended function by
the applicant in Exhibit A of the LRA. The staff performed this review to identify any structure or component having a safety
related function (that is performed without moving parts, or without a change in
configuration or propertied, and that is not subject to replacement) that may not have been
correctly determined to be subject to an AMR. The staff found no omissions in the SCs
selected by the applicant as requiring an AMR.
2.2.3.3.2.3 Review Findings for Containment Isolation System
As described above, the staff has reviewed the information provided in Section 2.5.4 of Exhibit A of the LRA and the additional information provided by the applicant in response to the staff's RAI. Based on this review, the staff has reasonable assurance that the applicant has appropriately identified those portions of the Containment Isolation System, and the associated components thereof, that are within the scope of license renewal and subject to an AMR in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.3.3 Emergency Core Cooling Systems
In Section 2.5.5, "Emergency Core Cooling Systems," of Exhibit A of the LRA, the applicant identified the SCs of the Emergency Core Cooling Systems (ECCSs) that are within the scope and subject to an AMR for license renewal.
Component (equipment and piping) supports for the systems are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant evaluated instrument line components with the system to which they are attached.
2.2.3.3.3.1 Summary of Technical Information in the Application
As described in the LRA, ECCSs are designed to cool the reactor core and provide shutdown capability following design-basis accidents. The following systems of the ECCS are included by the applicant as within the evaluation boundary for license renewal:
Core Flood (CF) System
The following components of the CF System are within the scope of license renewal, and are subject to an AMR: tank, pipe, tank nozzle, tubing, and valve bodies. The intended function for these components, based on the requirements of 10 CFR 54.4(a) is listed as pressure boundary.
The CF System is designed to inject water directly into the reactor vessel when the RCS pressure drops below a certain level following an accident. The CF System is self-contained, self-actuating, and passive in nature. During power operation, when the RCS pressure is higher than the CF System pressure, check valves (bodies only) located between the reactor vessel CF nozzles and the CF tanks prevent high-pressure reactor coolant from entering the CF tanks. The driving force to inject the stored borated water into the reactor vessel is supplied by a pressurized nitrogen cover in the CF tanks. After an accident, when the RCS pressure decreases below the nitrogen cover pressure, the contents of the CF tanks will be injected directly into the reactor vessel.
High-pressure Injection (HPI) System
The following components of the HPI System are within the scope of license renewal, and are subject to an AMR: demineralizer, filter, flexible hose, flow meter, flow nozzle, mechanical expansion joint, orifice, pipe, pump casing, tank, tubing, valve bodies, reactor coolant pump (RCP) coolers (Units 2 and 3), and RCP seal return coolers.
The intended functions for these components based on the requirements of 10 CFR 54.4(a) are listed as pressure boundary and throttle.
The HPI System operates during normal reactor operation to recirculate reactor coolant for purification and to supply seal water to the RCPs (casings). Letdown flow is directed to the letdown storage tank, which provides suction flow to the operating HPI pump. The letdown storage tank is normally supplied with a hydrogen overpressure. The HPI pump supplies water directly to the RCS by way of the normal charging header and also supplies seal injection water to the RCPs (casings).
During emergency operation, the HPI System automatically supplies borated water directly to the reactor vessel injection nozzles on low RCS pressure or high reactor building pressure. The HPI System also supplies borated water to the RCP seals. The water added directly to the system makes up for water lost from a primary-side leak or from a "shrink" in reactor coolant volume due to cooling caused by a secondary-side break.
Low-Pressure Injection (LPI) System
The following components of the LPI System are within the scope of license renewal, and are subject to an AMR: annubar, decay heat removal coolers, orifice, pipe, pump casing, tank (borated water storage), tubing, and valve bodies. The intended functions for these components, based on the requirements of 10 CFR 54.4(a), are listed as pressure boundary, throttle, and heat transfer.
The LPI System is used during cold shutdown and refueling operations to remove decay heat. During power operation, the system is idle. This system is also part of the ECCS and supplies cooling water to the reactor after intermediate and large loss-of-coolant accidents.
During unit cooldown, the reactor coolant temperature and pressure are reduced by way of the steam generators. At approximately 250 °F and 300 psig, the LPI System is placed in service. Reactor coolant is drawn from the RCS through the decay heat drop line and is cooled by the decay heat removal coolers and returned to the RCS. The decay heat removal coolers have pressure boundary and heat transfer functions.
Upon initiation of an accident, the LPI System takes suction from the borated water storage tank and injects the tank contents into the reactor vessel. When the borated water storage tank level becomes low, system suction is manually transferred to the reactor building emergency sump.
Water from the sump is cooled by the decay heat removal coolers and reinjected into the reactor vessel.
2.2.3.3.3.2 Staff Evaluation
The staff reviewed Section 2.5.5 of the application to determine whether there is reasonable assurance that the ECCS components and supporting structures within the scope of license renewal in accordance with 10 CFR 54.4 and subject to an AMR have been identified in accordance with the requirements of 10 CFR 54.21(a)(1). This was accomplished as discussed below.
2.2.3.3.3.2.1 ECCS Within the Scope of License Renewal and Subject to an AMR
As part of the evaluation, the staff determined whether the applicant had properly identified the SSCs within the scope of license renewal and subject to an AMR, pursuant to 10 CFR 54.4(a) and 10 CFR 54.21(a)(1). The staff reviewed portions of the UFSAR for the ECCS, and compared the information in the UFSAR with the information in the application to identify portions that the applicant did not identify as within the scope of license renewal and subject to an AMR. The staff then reviewed SCs outside the applicant-identified portion, and as described below, requested that the applicant submit additional information or clarifications or both for a selected number of SCs to verify that (1) they do not have any intended functions as delineated in 10 CFR 54.4(a) and, if they did, to verify that (2) they are either active components or they are subject to replacement based on a qualified life or specified time period, as described in 10 CFR 54.21(a)(1). The staff also reviewed the UFSAR for any safety-related system functions that were not identified as intended functions in the application to verify that all SCs having intended functions were not omitted from consideration within the scope of the rule.
After completing the initial review, by letter dated November 30, 1998, the staff issued requests for additional information (RAIs) regarding the ECCS, and by letters dated January 25, February 8, and February 17, 1999, the applicant provided responses to those RAIs. In RAI 2.5.5-1, the staff made reference to page 6-38, Section 6.3.2.5 of the UFSAR, where it is indicated that all components with surfaces in contact with water containing boric acid are protected from corrosion and deterioration. With the exception of the borated water storage tank (BWST), the major components in the LPI System are constructed of stainless steel. The BWST is made of carbon steel with an interior phenolic coating to protect it from corrosion and deterioration. In the RAI, the staff requested that the applicant clarify whether the coating is relied upon to ensure the intended function of the BWST for the period of extended operation. If it is, then the applicant was asked to describe the program to maintain the coating; and if not, then to present the basis for its exclusion. The applicant responded that the internal coating of the BWST is a physical design feature of the tank. Loss of material from the carbon steel shell was determined to be an applicable aging effect for the tank given a carbon steel and borated water material/environment combination. The aging effect is managed by inspecting the BWST internal coatings during preventive maintenance activities. This inspection will manage the effect of loss of material from the tank by monitoring the condition of the inside of the tank, including the coating. The staff's review of the applicant's program is discussed in Section 3.2.10 of this SER.
In RAI 2.7-5, the staff indicated that during the ONS license renewal scoping and screening process overview meeting held on October 1, 1998, the staff was informed that tanks (including the vertical tanks erected in the field) are considered to be mechanical components. However, the tank foundation and anchorage systems are considered structural components. With regard to the scoping process for the vertical tanks, the staff requested that the applicant address the following concerns:
| a. | a basis for not including tank supports in the discussion of Section 2.7.2, "Structural Components," in the application |
| b. | the definition of the boundary (or interface) between tanks (mechanical components) and tank supports (structural components), which are usually welded to the tanks |
In a response to RAI 2.7-5, the applicant stated the following:
| c. | Tank supports are not uniquely identified as components but are included in the category of equipment component supports listed in Section 2.7.2 of the application. |
| d. | The boundary (or interface) between the tanks and the tank supports is at the weld of the support to the tank. The weld is included with the tank in the AMR. |
Regarding Duke's February 8, 1999, response to RAI 2.7-5(a), the staff agreed with the applicant's categorization of the anchorage systems of the field-erected vertical tanks as steel equipment component supports (as stated on page 2.7-5 of the application). However, vertical tanks can have tank foundations that are made of concrete rather than steel (e.g., BWST). The staff questioned if these tank foundations were considered to be within the scope of license renewal.
As documented in a June 2, 1999, phone call summary Duke responded that vertical tanks such as the BWST are included in mechanical scope. The tanks' foundations or pads are included in Oconee license renewal scope in Section 2.7.2.1. The BWST foundation is located in the Yard and included within the category of equipment pads in Table 2.7-8. The staff also notes that the BWST foundation was identified in the license renewal basis document (OSS-0274.00-00-0007), which was reviewed on-site by the NRC during the scoping and screening inspection that occurred from April 26 through April 30, 1999.
In RAI 2.5.5-2, the staff indicated that boric acid solution is stored in heated and insulated tanks and is piped in heat-traced and insulated lines to preclude precipitation of the boric acid. In the RAI, the staff requested that the applicant clarify whether the insulation material is within the scope of license renewal, and if it is not, to identify the basis for its exclusion. The applicant responded that the tanks within the scope of license renewal in the ECCS are the letdown storage tank (LST), the core flood tank (CFT), and the BWST. The LST stores RCS letdown and provides suction to the HPI System, which is normally in service. Thus, temperatures are high enough that it is not necessary to heat and insulate the tank to prevent boron precipitation. The CFTs store borated water for use during an accident. These tanks are located in the reactor building so that temperatures are high enough that it is not necessary to heat and insulate the tank to prevent boron precipitation. The BWST stores borated water for emergency systems for accident conditions. These tanks are located in the yard and are heated and insulated in order to preclude boron precipitation. Additionally, the associated piping that is located in the yard is heat traced and insulated for the same purpose. The heaters, heat tracing, and insulation are designed to maintain the BWST inventory above the minimum technical specification (TS) temperature during normal operation. As a result of monitoring and maintaining the TS temperature limits, any heater failure or excessive heat loss from these tanks and pipes can be detected in time, and corrective actions can be taken to maintain the required boron concentration. The insulation, therefore, need not be within the scope of license renewal, and is not subject to an AMR.
As a follow up question, the staff requested the applicant, by letter dated December 14, 1999, to clarify why insulation need not be within the scope of license renewal; particularly, to clarify the basis on which the applicant concluded that the insulation is not relied on to ensure that the emergency systems will maintain a safe-shutdown condition or mitigate the consequences of design-basis events. In response, the applicant provided the following technical justifications:
| a) | Failure of the insulation during and following a design-basis event would not prevent the ECCS suction piping from performing its function during and following a design-basis event. Although, no quantitative calculation exists to support this statement, a review of boron solubility curves from Chemistry procedures (the Chemistry procedures are associated with Duke's Chemistry Control Program which is discussed in Section 4.6 of Exhibit A of the LRA) indicate that the temperature at which the boron precipitation may occur is well below the minimum temperature allowed by TS. The relative short period of time that the ECCS suction piping is in use post-accident is not long enough to allow boron precipitation, even at winter ambient temperatures. |
| b) | A review of the design and operational aspects of the ECCS suction piping and BWST was performed by the applicant to provide additional information regarding boron precipitation in the event the insulation were to fail before an event. The design of the 14" diameter ECCS suction piping includes heat tracing that is thermostatically controlled at 50 F. The 20 to 30 feet of piping between the tank and the auxiliary building is routed in a covered yard trench and is insulated. The BWST heaters are controlled at approximately 60 F. The BWST boron concentration requirement varies based on core operating limits, but a 3000 ppm limit is used as a bounding, worst-case value. Boron concentration limits are required to be verified every 7 days according to TS. According to boron solubility curves in Chemistry procedures, for a concentration of 3000 ppm, boron will not precipitate from solution until water temperatures falls below 22 F. It is not considered plausible for the water temperature in the tank or the ECCS suction piping to reach 22 F, primarily because TS require that the BWST borated water temperature be maintained between 45 F and 115 F. When the ambient temperature is less than 45 F or greater than 115 F, the tank temperature is required to be verified every 24 hours using a temperature monitor near the bottom of the tank. If borated water temperature inside the BWST falls outside the limit, it must be returned to an acceptable temperature within 8 hours in order to continue unit operation. |
| c) | Notwithstanding the TS limit, it is considered physically impractical that the water in the ECCS suction piping would ever reach 22 F. The ambient outside air temperature rarely gets below 22 F, and the tank heaters and heat tracing are thermostatically controlled at 60 F and 50 F, respectively. Even if the heat tracing were to fail and all of the insulation were to fail in a manner that rendered it completely useless, simple heat transfer equations reveal that it would take several days for the water in a 14" diameter pipe to reach 22 F, assuming the piping is completely exposed to a constant ambient temperature of 20 F. This assumption is conservative because ECCS suction piping is routed below ground level in a covered yard trench that serves as insulation to the ambient temperature and wind. The temperature of the piping in the trench should be approximately ground temperature, which stays well above 20 F. |
| d) | An additional operational aspect to consider is that water flows from the BWST through the ECCS suction piping approximately twice per week for purification purposes, quarterly for low pressure injection pump testing, and every refueling outage to empty the contents of the tank. Therefore, neither the water in the tank nor the water in the ECCS suction piping remains stagnant for long periods of time. |
The justifications provided above clarifies the applicant's basis for concluding that the insulation at Oconee is not relied upon to ensure that the emergency systems will maintain a safe-shutdown condition or mitigate the consequences of design-basis events. Based on the above information, the applicant reaffirms the accuracy and validity of its response to RAI 2.5.5-2 previously provided in its letter dated February 17, 1999. The staff considers the applicant's assessment and the conclusion acceptable.
In RAI 2.5.5-3, because the containment sump suctions to the ECCS pumps are enclosed by particulate screens, whose intended function is to prevent debris from entering the pumps, the staff requested that the applicant clarify whether these screens are within the scope of license renewal; and if they are not, to identify the basis for their exclusion. The staff also requested a discussion of the intended functions these items might perform for license renewal. The applicant responded by stating that the containment sump screens are within the scope of license renewal and are subject to an AMR. The intended function of the sump screens, which has been listed in Table 2.7-5 of the application, is to provide structural or functional support or both to safety-related equipment. The applicant further clarified that providing functional support encompasses preventing debris from entering the pumps.
In RAI 2.5.5-4, the staff requested that the applicant clarify if the flow restriction orifices are within the scope of license renewal; and if they are not, to identify the basis for their exclusion. The RAI also requested a discussion of the intended functions these items might perform for license renewal. The applicant's response was that Section 2.5.5 of the application, "Emergency Core Cooling System," covers the HPI System, the LPI System, and the CF System. No orifices are within the license renewal portions of the CF System. The orifices within the license renewal portions of the HPI System and the LPI System are within the scope of license renewal and are subject to an AMR. All orifices in the HPI and LPI Systems have a component-intended function of pressure boundary. Some orifices have the component-intended function of throttling to limit mass flow rate. Some orifices are required to throttle flow for flow rate measurement.
Finally, the staff issued RAI 2.5.5-5 to obtain clarification of flow diagrams OLRFD-103A-1.1, 2.1, and 3.1 that are referenced in the LRA, which shows the LPI System that supplies water to the Reactor Building (containment) Spray System. The RAI asked whether the nozzles in this spray system are within the scope of license renewal; and if not, to identify the basis for their exclusion. The response from the applicant was that the reactor building spray nozzles are within the scope of license renewal and are subject to an AMR.
2.2.3.3.3.2.2 Review Findings for the ECCS
On the basis of the staff's review of the information contained in Sections 2.5.5 of the application, the supporting information in the ONS UFSAR, and the applicant's response to the staff's RAI as discussed in the preceding section, the staff did not find any omissions by the applicant, and therefore, concludes that there is reasonable assurance that the applicant adequately identified those portions of the ECCS and its associated components that fall within the scope of license renewal and are subject to an AMR, in accordance with 10 CFR 54.4(a) and 10 CFR 54.21(a)(1).
2.2.3.4 Auxiliary Systems
2.2.3.4.1 Auxiliary Systems
In Section 2.5.6, "Auxiliary Systems," of Exhibit A of the LRA, the applicant described the auxiliary systems and identified the SSCs that are within the scope of license renewal. Auxiliary systems are generally located in the auxiliary building and they included the following systems: Spent Fuel Cooling System (SFCS), Auxiliary Service Water (ASW) System, Condenser Circulating Water (CCW) System, High-Pressure Service Water (HPSW) System, and Low Pressure Service Water (LPSW) System. From these systems, the applicant also identified those within-scope SCs that are subject to an AMR.
In a letter to the staff dated September 30, 1999, the applicant amended the SSCs included within the scope of license renewal as a result of revising the Steam Generator Tube Rupture Accident (SGTRA) analysis to include portions of the Component Cooling System (CC). The revised SGTRA analysis adds the additional system function of transferring heat from the reactor coolant pump thermal barriers, but does not affect other portions of the LRA.
Component (equipment and piping) supports for the systems listed above are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the systems are presented in Section 2.6, "Electrical Components," of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of the SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, rules for identifying components within the scope of license renewal in OLRP-1002 specifically state that instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow. The applicant included instrument line components with the system to which they are attached.
2.2.3.4.1.1 Summary of Technical Information in the Application
Spent Fuel Cooling (SFCS) System
The primary functions of the SFCS are to remove decay heat from the spent fuel stored in the spent fuel pool (SFP), to maintain clarity and chemistry of the water in the pool at acceptable levels, and to transfer water within the systems. The Oconee Nuclear Station has two SFPs; one pool stores spent fuel from Units 1 and 2, and the second pool stores spent fuel from Unit 3. Each pool has an independent SFCS. Each SFCS consists of three coolant pumps, three parallel coolers, bypass flow through a demineralizer, and filters that remove soluble ions and insoluble particulates, and various piping, valves, and instrumentation. The Recirculating Cooling Water (RCW) System supplies cooling water flow to the spent fuel coolers.
The applicant described its process for identifying the mechanical components subject to an AMR in Section 2.5.2, "Detailed Process Description," of Exhibit A of the LRA. The applicant determined that the cooling and purification functions of the SFCS do not provide any design-basis-event mitigation functions that warrant including the system within the scope of license renewal. However, there are other plant functions that interface with the SFCS that perform design-basis-event mitigation, fire protection functions, and station blackout functions. These portions of the SFCS are within the scope of license renewal. In addition, because the cooling and purification portions of the SFCS are seismically designed Class B and C piping and provide design margin against loss of inventory of the system and the spent fuel pool, the applicant considers this piping within the scope of license renewal. As a result, essentially all piping and components in the SFCS are within the scope of license renewal.
On the basis of its methodology described above, the applicant identified the portions of the SFCS that are within the scope of license renewal on flow diagrams listed in Table 2.5-8 of Exhibit A of the LRA. Using the methodology described in Section 2.5.2.2, "Identification of Mechanical Components Subject to an Aging Management Review," of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant listed these in Table 2.5-9 of Exhibit A of the LRA. The applicant identified the following 11 component types as subject to an AMR: pipe, pump casing, demineralizer, filter, flexible hose, orifice, spent fuel transfer tube, tank, tubing, valve bodies, and spent fuel coolers. The applicant identified maintaining the pressure boundary as the only intended function for these components.
Auxiliary Service Water (ASW) System
The ASW System is designed to remove decay heat from all three units simultaneously, assuming the concurrent loss of each unit's main feedwater, emergency feedwater, and LPI Systems. Loss of these systems can be postulated as a result of a tornado. The system also serves as a backup source of cooling water for the high-pressure injection pump motor coolers. Lake water is supplied to the ASW System through the Unit 2 CCW System's intake pipes. During normal plant operation, the ASW System is not operating, and manual isolation valves on the suction discharge and minimum flow piping are closed. The discharge header supplies all three units and is isolated from the six steam generators by several closed check valves and closed, manually operated gate valves. The ASW System piping is designed and constructed to the requirements of Oconee System Piping Class F. The system is designed to withstand a design-basis earthquake without a loss of function.
The applicant described its process for identifying the mechanical components within the scope of license renewal and subject to an AMR in Section 2.5.2 of Exhibit A of the LRA. On the basis of this methodology, the applicant identified the portions of the ASW System that are within the scope of license renewal on flow diagrams listed in Table 2.5-8 of Exhibit A of the LRA. The applicant identified essentially all of the components in the ASW System as being within the scope of license renewal. Using the methodology described in Section 2.5.2.2 of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant listed the components and their intended functions in Table 2.5-9 of Exhibit A of the LRA. The following 7 component types were identified as subject to an AMR: two types of piping, pump casing, tubing, annubar tube, and two types of valve bodies. The applicant identified maintaining the pressure boundary, and for the annubar tube, throttling, as the intended functions for these components.
Condenser Circulating Water (CCW) System
The CCW System utilizes lake water that serves as the ultimate heat sink during normal operation and for decay heat removal during plant cooldown. This system also supplies cooling water to various pieces of plant equipment and is the suction source for other cooling water systems, including the Low-Pressure Service Water System. Each unit has four CCW pumps that supply water through two 11 foot-diameter conduits into a common condenser intake header. The CCW System is also designed to operate using a siphon lineup to the Keowee hydro tailrace, should a loss-of-power occur.
In a letter to the staff dated October 15, 1999, as a result of adding portions of the Chilled Water System to the scope of license renewal, the applicant amended the LRA to include those portions of the CCW System that remove heat from the Chilled Water System. The Chilled Water System that provides cooling water to the Control Room Ventilation System is evaluated in Section 2.2.3.4.10 of this SER. Prior to this amendment, removing heat from the Chilled Water System was not an intended function of the CCW System, therefore, this portion of the CCW System was not within the scope of license renewal.
The portions of the CCW System within the scope of license renewal are Oconee System Piping Class D, F, and G. The CCW pumps and intake piping to the low-pressure service water pumps, through the condenser and emergency CCW discharge piping, are Class D or F. The Class F portions of the system are designed to withstand a design-basis earthquake without loss of function. The Class D portions of the system are designed to maintain pressure boundary and structural integrity based on the potential for interaction with other systems during a design-basis earthquake. Portions of the CCW within the scope of license renewal and constructed of Oconee Piping Class G are designed to USAS B31.1.0 and are not designed for seismic loading.
The applicant described its process for identifying the mechanical components within the scope of license renewal and subject to an AMR in Section 2.5.2 of Exhibit A of the LRA. On the basis of this methodology, the applicant identified the portions of the CCW System that are within the scope of license renewal on flow diagrams listed in Table 2.5-8 of Exhibit A of the LRA and in Section 2 of Attachment 2 of the letter dated October 15, 1999. Using the methodology described in Section 2.5.2.2 of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant provided that list in Table 2.5-9 of Exhibit A of the LRA and in Table 2 of Attachment 2 of the letter dated October 15, 1999. The following 14 component types were identified as subject to AMR: four types of tubing, annubar tube, flexible hose, and two each of the following component types - strainers, piping, pump casings, and valve bodies. The applicant identified maintaining the pressure boundary, and for the annubar tube, throttling, as the intended functions for these components.
High-Pressure Service Water (HPSW) System
The HPSW System supplies water to fire protection sprinkler systems, hose stations, fire hydrants, and deluge systems throughout the plant and plant site (excluding the reactor building and the Keowee station). The system also supplies sealing or cooling water to many plant components. Two motor-driven large-capacity pumps and one motor-driven small-capacity pump, together with the elevated water storage tank, deliver a reliable supply of water for the system. The pumps and elevated water storage tank discharge into a common header that distributes the water supply throughout the plant.
The HPSW System piping inside any structures or buildings and the piping at the CCW intake structure are typically Oconee System Piping Class G. Only portions of the HPSW System designated as Class F piping are capable of withstanding a design-basis earthquake without loss of function.
The applicant described its process for identifying the mechanical components within the scope of license renewal and subject to an AMR in Section 2.5.2 of Exhibit A of the LRA. On the basis of this methodology, the applicant identified the portions of the HPSW System that are within the scope of license renewal on flow diagrams listed in Table 2.5-8 of Exhibit A of the LRA. The applicant identified essentially all of the components in the HPSW System as being within the scope of license renewal. Using the methodology described in Section 2.5.2.2 of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant provided that list in Table 2.5-9 of Exhibit A of the LRA. The following 21 component types were identified as subject to an AMR: three types of piping, pump casings, four tubing types, filters, four types of valve bodies, fire hydrants, two hose rack types, two types of mechanical expansion joints, mulsifiers, sprinklers and strainers. The applicant identified maintaining the pressure boundary, and for the sprinklers, spray, as the intended functions for these components.
Low-Pressure Service Water (LPSW) System
The LPSW System supplies cooling water for normal and emergency services throughout the ONS. The LPSW System distributes cooling water to the following safety-related equipment: the reactor building cooling units, low-pressure injection coolers, high-pressure injection pump motor bearing coolers, turbine-driven emergency feedwater pump bearing cooling jackets, and the motor-driven emergency feedwater pump motor air coolers. In addition, the LPSW System supplies various non-safety-related systems and components with cooling, sealing, makeup, fire protection, flush, and backwash capabilities. The system shares two pumps for Units 1 and 2, and has two pumps for Unit 3, plus the necessary piping, valves, instrumentation, and other components. Water is supplied to the LPSW System by gravity or siphon flow following a design-basis event in which CCW pumps are not assumed to be operating. Safety-related portions of the LPSW System identified in the flow diagrams listed in Table 2.5-8 of Exhibit A of the LRA are designated as Oconee System Piping Class F.
The applicant described its process for identifying the mechanical components within the scope of license renewal and subject to an AMR in Section 2.5.2 of Exhibit A of the LRA. On the basis of this methodology, the applicant identified the portions of the LPSW System that are within the scope of license renewal on flow diagrams listed in Table 2.5-8 of Exhibit A of the LRA. The applicant identified essentially all of the components in the LPSW System as being within the scope of license renewal. Using the methodology described in Section 2.5.2.2 of the LRA, the applicant compiled a list (Table 2.5-9 of Exhibit A) of mechanical components and component types, and the associated intended functions that are within the evaluation boundaries and subject to an AMR. The following 24 component types were identified as subject to an AMR: two types of piping, pump casing, four tubing types, annubar tube, two filter types, three types of valve bodies, component coolers, two strainer types, two site glass types, orifice, two types of mechanical expansion joints, two hose rack types, and flex hose. The applicant identified maintaining the pressure boundary, and for the annubar tube, throttling, as the intended functions for these components. Filtering and throttling were also identified as intended functions for filters and orifices.
In a letter dated September 30, 1999, the applicant added the Reactor Building Auxiliary Coolers to the list of components subject to AMR. These coolers had been omitted from the original application because they were isolated from LPSW System flow due to operability issues and, therefore, did not perform an intended function under 10 CFR Part 54. The applicant resolved the operability issues regarding the coolers, returned the coolers to service, and have included the coolers within the scope of license renewal and subject to AMR. The applicant identified maintaining the pressure boundary as the intended function for these components.
Component Cooling (CC) System
The CC System provides cooling water to various components in the Reactor Building, including the control rod drives, letdown heat exchangers, quench tank coolers, and the reactor coolant pump coolers and jackets. Initially, only those portions of the CC System associated with the containment isolation function were included within the scope of license renewal. In a letter dated September 30, 1999, the applicant revised the application to include those portions of the CC System that provide cooling water to the reactor coolant pump coolers and jacket. This revision was made because of modifications made to the SGTRA analysis.
The applicant described its process for identifying the mechanical components within the scope of license renewal and subject to AMR in Section 2.5.2 of Exhibit A of the LRA. On the basis of this methodology, the applicant identified the portions of the CC System that are within the scope of license renewal in a letter dated September 30, 1999. The staff requested and the applicant provided additional clarification regarding the portions of the CC System within the scope of license renewal, including highlighted flow diagrams of the CC System. The applicant identified essentially all of the components in the CC System as being within the scope of license renewal. The applicant compiled a list of the mechanical components within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant presented the list in Table 2-1 of Attachment 1, to the September 30, 1999, letter. The following 19 component types were identified as subject to AMR: filters, two types of flexible hose, orifices, two types of piping, pump casings, tanks, three types of tubing, two types of valve bodies, heat exchanger channel head, heat exchanger shell, two types of heat exchanger tubes, and two types of heat exchanger tubesheets. The applicant identified maintaining the pressure boundary, and for the heat exchanger tubes, heat transfer, as the intended functions for these components.
2.2.3.4.1.2 Staff Evaluation
The staff reviewed Section 2.5.6 of Exhibit A of the LRA and the letters dated September 30, and October 15, 1999, to determine whether there is reasonable assurance that the applicant appropriately identified the auxiliary system components within the scope of license renewal in accordance with 10 CFR 54.4 and subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1). After completing the initial review of the LRA, the staff issued RAIs regarding the information submitted by the applicant for the auxiliary systems in a letter dated December 2, 1998. The applicant responded to those RAIs by letters dated January 25, February 8, and February 17, 1999. The staff did not issue RAIs after reviewing the September 30 and October 15, 1999, letters from the applicant, but did request clarifying information from the applicant, as documented in the staff memorandum dated November 18, 1999.
2.2.3.4.1.2.1 Auxiliary System Components Subject to an Aging Management Review
The staff reviewed the text and diagrams submitted by the applicant in Section 2.5.6 of Exhibit A of the LRA, the applicant's letter dated September 30, and October 15, 1999, and the ONS UFSAR to identify if there were portions of the system piping and other components that the applicant did not identify as within the scope of license renewal that performed intended functions. Essentially all portions of the auxiliary systems perform at least one intended function and, therefore, essentially all portions and components of the auxiliary systems are within the scope of license renewal and are identified as such by the applicant in Section 2.5.6 of Exhibit A of the LRA. For scoping systems and structures, the staff focused its review on those SCs of the auxiliary systems that were not identified as being within the scope of license renewal to verify that they do not have any intended functions that meet the scoping requirements of
10 CFR 54.4. The staff also reviewed the UFSAR to determine if there were any additional system functions that were not identified as intended functions in the LRA and verified that those additional functions did not meet the scoping requirements of 10 CFR 54.4. As described in detail below, with respect to each system, the staff found no omissions by the applicant. Therefore, there is reasonable assurance that the applicant adequately identified all portions of the auxiliary systems that fall within the scope of license renewal in accordance with 10 CFR 54.4.
The staff then determined whether the applicant had properly identified the components subject to an AMR from among those identified as within the scope of license renewal. The applicant listed the SCs subject to an AMR for the auxiliary systems in Table 2.5-9 of Exhibit A of the LRA using the screening methodology described in Section 2.5.2 of Exhibit A of the LRA. The staff evaluated the scoping and screening methodology and documented its findings in Section 2.1 of this SER. As described in more detail in the following subsections, the staff sampled from the list of SCs for each auxiliary system identified by the applicant as subject to an AMR, to get reasonable assurance that all components subject to an AMR were appropriately identified. The staff also sampled SCs that were within the scope of license renewal but not subject to an AMR to verify that these SCs performed their intended functions with moving parts or a configuration change or were subject to replacement on the basis of a qualified life or a specified time period (i.e., active or short-lived).
Spent Fuel Cooling System
In the LRA, the applicant listed seven detailed flow diagrams OLRFD-102A1.1, 2.1, 3.1, 104A-1.1, 1.2, 3.1, and 3.2 of the SFCS in Table 2.5.8 of Exhibit A of the LRA and listed the mechanical components subject to an AMR and their intended functions in Table 2.5-9 of Exhibit A. The applicant highlighted the detailed flow diagrams to identify those portions of the system within the scope of license renewal. The applicant highlighted those components which, they believe, perform at least one intended function meeting the scoping requirements of 10 CFR 54.4. The staff compared the LRA flow diagrams to the system drawings and descriptions in the UFSAR to ensure they were representative of the SFCS. The staff sampled portions of the flow diagrams that were not highlighted to ensure that these components did not perform any intended functions defined in 10 CFR 54.4. Based on this review, the staff issued RAIs regarding several components in the SFCS (NRC letter dated December 2, 1998), and by letters dated January 25 and February 8, 1999, the applicant responded to those RAIs. Specifically, the staff asked in RAIs 2.5.6-1 and 2.5.6-2 whether the SFP transfer tube isolation valve and blank flange closure plate were in the scope for license renewal. Neither were indicated as being within the scope on the system flow diagrams. The applicant responded that the diagrams were wrong and that the components were within the scope for license renewal and were identified in Table 2.5-9 of Exhibit A of the LRA as valves and piping.
The staff also asked in RAI 2.5.6-14 about the intended functions of the following components: filter, orifice, and spent fuel cooler. Pressure boundary was the only intended function listed in the LRA; however, these components perform other functions, such as filtering, throttling, and heat exchange. The applicant responded that only those intended functions of the listed components that support the system intended function as required by 10 CFR 54.4(a), are listed in Table 2.5-9. The staff reviewed the system intended functions for the SFCS and agreed with the applicant that, maintaining the pressure boundary is the only intended function of the orifice and filter that meet the requirements of 10 CFR 54.4, and that should be listed for those components on Table 2.5-9.
However, in Section 2.2 of this SER, the staff identified an open item regarding the omission of the RCW System from within the scope of license renewal. The RCW System supplies cooling water to the spent fuel coolers, which were identified by the applicant as being within the scope of license renewal. The staff reviewed this issue and documented its closure in Section 2.2.3 of this SER. On the basis of this review, the staff determined that the SFCS performs only a pressure boundary function, and that heat transfer was not an intended function of the spent fuel coolers required by 10 CFR 54.4.
On the basis of a review of the LRA, supporting information in the UFSAR, and the applicant's responses to the staff's RAI concerning those components not within the scope of license renewal, the staff has reasonable assurance that the applicant has identified all portions of the SFCS on the flow diagrams listed in Table 2.5-8 of Exhibit A of the LRA with intended functions meeting the criteria in 10 CFR 54.4 as being within the scope of license renewal.
Using the information presented on the flow diagrams for the SFCS in Table 2.5-8 of Exhibit A, the staff sampled several components to determine whether the applicant properly identified the passive, long-lived components on the list of components as subject to an AMR in Table 2.5-9 of Exhibit A from among those identified as within the scope of license renewal. The staff verified that the passive, long-lived components highlighted on the system flow diagrams appeared in the list of components subject to an AMR for the SFCS in Table 2.5-9 of Exhibit A. No omissions were identified. On the basis of this review, the staff has reasonable assurance that the applicant has identified the components of the SFCS subject to an AMR.
Auxiliary Service Water System
The applicant listed the detailed flow diagram OLRFD-121D1.2 for the ASW System in Table 2.5-8 of Exhibit A of the LRA and identified the mechanical components subject to an AMR and their intended functions in Table 2.5-9. The applicant highlighted the detailed flow diagram to identify those portions of the system within the scope of license renewal. The applicant highlighted those components which, they believe, perform at least one intended function meeting the scoping requirements of 10 CFR 54.4. The staff compared the LRA flow diagrams to the system drawings and descriptions in the UFSAR to ensure they were representative of the ASW System.
Essentially all of the ASW System was highlighted, indicating it was within the scope of license renewal. The staff verified that the components not highlighted did not perform any intended functions meeting the requirements of 10 CFR 54.4.
On the basis of a review of the LRA and supporting information in the UFSAR, the staff has reasonable assurance that all portions of the ASW System with intended functions meeting the criteria in 10 CFR 54.4 are identified as being the within the scope of license renewal on the flow diagrams listed in Table 2.5-8 of Exhibit A of the LRA.
Using the information on the flow diagrams for the ASW in Table 2.5-8 of Exhibit A, the staff sampled several components to determine whether the applicant properly identified the passive, long-lived components on the list of components as subject to an AMR in Table 2.5-9 of Exhibit A from among those identified as within the scope of license renewal. The staff verified that the passive, long-lived components highlighted on the system flow diagrams appeared on the list of components subject to an AMR for the ASW System in Table 2.5-9 of Exhibit A. No omissions were identified. On the basis of this review, the staff has reasonable assurance that the applicant has identified the components of the ASW System subject to an AMR.
Condenser Circulating Water System
The applicant listed 15 detailed flow diagrams OLRFD-124B1.1, 2.1, 3.1, 133A-1.1, 1.2, 1.3, 1.4, 1.5, 2.1, 2.2, 2.3, 3.1, 3.2, 3.3, and 3.4 of the CCW System in Table 2.5-8 of Exhibit A of the LRA and identified the mechanical components subject to an AMR and their intended functions in Table 2.5-9. The applicant highlighted the detailed flow diagrams to identify those portions of the system within the scope of license renewal. The applicant highlighted those components which, they believe, perform at least one intended function meeting the scoping requirements of 10 CFR 54.4. The staff compared the LRA flow diagrams to the system drawings and descriptions in the UFSAR to ensure they were representative of the CCW System. The staff sampled portions of the flow diagrams that were not highlighted to ensure that these components did not perform any intended functions defined in 10 CFR 54.4. Based on this review, the staff issued RAIs regarding several components in the CCW System (NRC letter dated December 2, 1998), and by letters dated January 25 and February 8, 1999, the applicant responded to those RAIs. Specifically, the staff asked in RAI 2.5.6-3 whether valves 2CCW-438 and -246 were within the scope of license renewal, since neither valve was indicated as being within the scope of license renewal on the detailed system flow diagrams. The applicant responded that the diagrams were wrong and that the components were within the scope for license renewal and were listed in Table 2.5-9 of Exhibit A of the LRA under the "valves" category. The staff also asked in RAI 2.5.6-14 about the intended functions of the following components: orifice and RCW heat exchanger. Pressure boundary was the only intended function listed in the LRA; however, these components perform other functions, such as throttling and heat exchange. The applicant responded that only those intended functions of the listed components that support the system intended function required by 10 CFR 54.4 are listed in Table 2.5-9. The staff reviewed the system intended function for the CCW System and agreed with the applicant that the orifice only performs a pressure boundary function.
However, in Section 2.2 of this SER, the staff identified an open item regarding the omission of the RCW System from within the scope of license renewal. The applicant identified the RCW coolers, which transfer spent fuel decay heat to the CCW System, as being within the scope of license renewal because they are part of the within-scope CCW System. However, maintaining the pressure boundary was the only intended function identified for this component. Because the RCW System removes decay heat from the SFP coolant and transfers it to the CCW System, which maintains SFP temperature below 150°F to support the UFSAR Chapter 15 fuel handling accident analysis assumptions, the staff considered heat transfer as an intended function for the RCW coolers during its evaluation of this system. This issue was identified as Open Item 2.2.3-1. The applicant responded to the open item in letters dated October 15, and November 30, 1999. The staff reviewed and accepted the applicant's justification for omitting the RCW system from the scope of license renewal and documented their decision in Section 2.2.3 of this report.
In a letter dated October 15, 1999, the applicant amended the initial LRA to include portions of the CCW System that provide heat removal from the Chill Water System chillers that support the Control Room Ventilation System. The applicant listed the additional CCW components subject to an AMR on Table 2 of Attachment 2 to the October 15, 1999, letter. The staff reviewed flow diagrams OFD-133A-1.1 and 124A-1.2 to identify those portions of the CCW System that performed the revised intended function of transferring heat from the Chilled Water System. The staff sampled components from the flow diagrams that were considered not within the scope of license renewal to ensure the components did not perform any intended functions defined in 10 CFR 54.4. Based on this review, the staff did not identify any components outside the license renewal boundary that performed intended functions within the scope of license renewal. However, the staff asked the applicant to clarify the system designations associated with the components that provide cooling water to the Chilled Water System chillers. On diagram OFD-124A-1.2, the applicant highlighted portions of the LPSW System that provide cooling to the chillers. Since the applicant indicated in their October 15, 1999, letter that the piping and components that provide cooling to the chillers were part of the CCW System, the staff asked the applicant to clarify the boundaries and system designations of this support system. In addition, the staff asked the applicant to verify that flooding would not be a concern for a section of the LPSW System in the process flow that was not designated as being within the scope of license renewal. This piping performed no intended function as defined by 10 CFR 54.4, but could cause flooding if severe leakage occurred. As documented in an NRC memorandum dated November 18, 1999, the applicant stated that even though the components have LPSW designations, they are considered part of the CCW System because they support a CCW System function (providing cooling water to the Chilled Water System chillers). The applicant also addressed the flooding concern stating that the piping is located in the Turbine Building, away from safety-related equipment, and would have been classified Oconee Piping Class D had failure of the pressure boundary affected the function of safety-related equipment. The staff reviewed the applicant's responses and concluded that classifying portions of the LPSW in this manner was acceptable for license renewal because the SCs subject to an AMR were identified and listed in accordance with 10 CFR 54.21. In addition, based on the applicant's assessment that failure of the subject piping will not affect the function of safety-related equipment, the staff concluded that the CCW System scoping boundary is acceptable.
On the basis of a review of the LRA, the applicant's letter dated October 15, 1999, supporting information in the UFSAR, and the applicant's responses to the staff's RAI concerning components outside the scope of license renewal, the staff has reasonable assurance that all portions of the CCW System with intended functions meeting the criteria in 10 CFR 54.4 are identified as being within the scope of license renewal on the flow diagrams listed in Table 2.5-8 of Exhibit A of the LRA and described in Attachment 2 of the applicant's letter dated October 15, 1999.
Using the information on the flow diagrams for the CCW System (Table 2.5-8 of Exhibit A, flow diagrams OPD-124A-1.2 and 133A-1.1), the staff sampled several components to determine whether the applicant properly identified the passive, long-lived components in the list of components as subject to an AMR (Table 2.5-9 of Exhibit A, and Table 2 of Attachment 2 of the applicant's letter dated October 15, 1999) from among those identified as within the scope of license renewal. The staff verified that the passive, long-lived components highlighted on the system flow diagrams were in the list of components subject to an AMR for the CCW System in Table 2.5-9, and Table 2 of Attachment 2 of the applicant's letter dated October 15, 1999. No omissions were identified. On the basis of this review, the staff has reasonable assurance that the applicant has identified the components of the CCW System subject to an AMR.
High-Pressure Service Water System
The applicant listed 14 detailed flow diagrams OLRFD-124C-1.1, 1.2, 1.3, 1.4, 1.6, 2.2, 2.3, 2.6, 3.2, 3.3, 3.6, 133A-1.1, 2.1, and 3.1 of the HPSW System in Table 2.5-8 of Exhibit A of the LRA and identified the mechanical components subject to an AMR and their intended functions in Table 2.5-9. The detailed flow diagrams were highlighted to identify those portions of the system within the scope of license renewal. The applicant highlighted those components that perform at least one intended function meeting the scoping requirements of 10 CFR 54.4. The staff compared the LRA flow diagrams to the system drawings and descriptions in the UFSAR to ensure they were representative of the HPSW System. The staff sampled portions of the flow diagrams that were not highlighted to ensure that these components did not perform any intended functions defined in 10 CFR 54.4.
Based on this review, the staff issued RAIs regarding several components in the HPSW System (NRC letter dated December 2, 1998), and by letters dated February 8 and 17, 1999, the applicant responded to these RAIs. Specifically, the staff asked in RAI 2.5.6-9 whether the following components identified on the system flow diagrams but not listed in Table 2.5-9 for the HPSW System were within the scope of license renewal: the HPSW pump motor air coolers, flow restricting orifices, annubar tubes, the elevated storage tank, and quick disconnects. In its response to RAI 2.5.6-9, the applicant stated that two components (orifices and annubar tubes) had been inadvertently left off the list and that a revised Table 2.5-9 listing the two components was submitted in response to RAI 4.16-11. The staff reviewed the revised Table 2.5-9 and found that it contained the components and was, therefore, acceptable. The applicant also clarified that the elevated water tank is considered a structure, is within the scope of license renewal and subject to an AMR, and is described in Section 2.7.10.3 of Exhibit A of the LRA and listed on Table 2.7-8. Similarly, quick disconnects are encompassed by the commodity group "pipe" and are included with this group on Table 2.5-9. The staff reviewed Tables 2.7-8 and 2.5-9 and found the components listed appropriately. The applicant stated in their response to RAI 2.5.6-9 that the HPSW motor air coolers are within the scope of license renewal, however, the coolers are not subject to an AMR because they are considered to be sub-components of the motor. The staff does not agree that these components can be excluded from an AMR. A similar condition exists for skid mounted components on the SSF diesel described in Section 2.2.3.4.8.2.1 of this SER. The staff reviewed the methodology which the applicant used in its IPA to exclude these components (i.e., the motor air coolers) from an AMR, and found that it was not consistent with Section 4.1.1, "Establishing Evaluation Boundaries," of the Nuclear Energy Institute's 95-10, "Industry Guide for Implementing the Requirements of 10 CFR 54 - The License Renewal Rule," or Example 5 of Appendix C of 95-10. This issue was being tracked by open item 2.2.3.4.8.2.1-1 in the June 1999, version of this report. See Section 2.2.3.4.8.2.1 of this report for the discussion regarding the resolution of this item.
The staff also asked in RAI 2.5.6-14 about the intended functions of the following components: filter, mulsifier, and strainer. Pressure boundary was the only intended function listed in the LRA; however, these components perform other functions, such as filtering. The applicant responded that only those intended functions of the listed components that support the system intended function required by 10 CFR 54.4 are listed in Table 2.5-9. The staff reviewed the applicant's response and the information contained in the LRA and the UFSAR concerning the components' intended functions and agrees with the applicant that maintaining the pressure boundary is the only intended function of the filter, mulsifier, and strainer that meets the requirements of 10 CFR 54.4. Therefore, the staff finds the omission of these intended functions from Table 2.5-9 acceptable.
On the basis of a review of the LRA, the supporting information in the UFSAR, and the applicant's responses to the staff's RAI the staff has reasonable assurance that all portions of the HPSW System with intended functions meeting the criteria in 10 CFR 54.4 are identified as being within the scope of license renewal on the flow diagrams listed in Table 2.5-8 of Exhibit A.
Using the information on the flow diagrams for the HPSW System in Table 2.5-8 of Exhibit A, the staff sampled several components to determine whether the applicant properly identified the passive, long-lived components on the list of components as subject to an AMR in Table 2.5-9 of Exhibit A from among those identified as within the scope of license renewal. The staff verified that the passive, long-lived components highlighted on the system flow diagrams were included on the list of components subject to an AMR for the HPSW System in Table 2.5-9. No omissions were identified. On the basis of this review the staff has reasonable assurance that the applicant has identified the components of the HPSW System subject to an AMR.
Low-Pressure Service Water System
The applicant listed 25 detailed flow diagrams OLRFD-100A-1.3, 2.3, 3.3, 121C-1.1, 124A-1.1, 1.2, 1.3, 2.3, 3.1, 3.3, 124B-1.1, 1.2, 1.4, 1.5, 1.6, 2.1, 2.2, 2.4, 3.1, 3.2, 3.4, 3.6, 133A-1.1, 2.1, and 3.1 of the LPSW System in Table 2.5-8 of Exhibit A of the LRA and identified the mechanical components subject to an AMR and their intended functions in Table 2.5-9. The applicant highlighted detailed flow diagrams to identify those portions of the system within the scope of license renewal. The applicant highlighted on each flow diagram those components that perform at least one intended function meeting the scoping requirements of 10 CFR 54.4. The staff compared the LRA flow diagrams to the system drawings and descriptions in the UFSAR to ensure they were representative of the LPSW System. The staff sampled components on the flow diagrams that were not highlighted to ensure that these components did not perform any intended functions defined in 10 CFR 54.4. Based on this review, the staff issued RAIs regarding several components in the LPSW System (NRC letter dated December 2, 1998), and by letters dated January 25 and February 8, 1999, the applicant responded to those RAIs. Specifically, the staff asked in RAI 2.5.6-12 whether certain piping identified on the system flow diagrams but not highlighted as within the scope of license renewal had any intended functions. In the response to RAI 2.5.6-12, the applicant stated that the piping (LPSW cooling water return from the high-pressure injection pump motor cooler) is not required. Analysis indicated that only the cooling water supply to the pump motor coolers was required for the pump to perform its intended function. The staff reviewed the applicant's response and agreed that, based on the applicant's analysis, the LPSW cooling water return from the high pressure injection pump motor cooler does not perform an intended function as defined in 10 CFR 54.4 and is, therefore, not within the scope of license renewal.
The staff also asked in RAI 2.5.6-14 about the intended functions of the following components: filter, annubar tube, component coolers, and strainer. Pressure boundary was the only intended function listed in the LRA; however, these components perform other functions, such as filtering and heat exchange. The applicant responded that only those intended functions of the listed components that support the system intended function required by 10 CFR 54.4 are listed in Table 2.5-9. The applicant did identify that for the component filter, the filter intended function was listed in Table 2.5-9. The staff reviewed the applicant's response and the information contained in the LRA and the UFSAR and agreed that the annubar tube, component coolers, and strainers do not perform an intended function, other than maintaining pressure boundary, that meets the requirements of 10 CFR 54.4. Therefore, the staff finds the omission of these intended functions from Table 2.5-9 acceptable.
In response to the applicant's September 30,1999, letter adding the Reactor Building Auxiliary Coolers to the list of components subject to an AMR, the staff reviewed flow diagrams OLRFD 124B-1.3, 2.3, and 3.3, to ensure the applicant included all of the components supporting the Reactor Building Auxiliary Cooler pressure boundary for each unit. No omissions were identified.
On the basis of a review of the LRA, supporting information in the UFSAR, the applicant's letter dated September 30, 1999, and the applicant's responses to the staff's RAIs, the staff has reasonable assurance that all portions of the LPSW System with intended functions meeting the criteria in 10 CFR 54.4 are identified as being within the scope of license renewal on the flow diagrams listed in Table 2.5-8 of Exhibit A.
Using the information on the flow diagrams for the LPSW in Table 2.5-8 of Exhibit A, the staff sampled several components to determine whether the applicant properly identified the passive, long-lived components on the list of components as subject to an AMR in Table 2.5-9 of Exhibit A, from among those identified as within the scope of license renewal. The staff verified that the passive, long-lived components highlighted on the system flow diagrams were on the list of components subject to an AMR for the LPSW System in Table 2.5-9 or Table 3-1 of the applicant's letter dated September 30, 1999. No omissions were identified. On the basis of this review, the staff has reasonable assurance that the applicant has identified the components of the LPSW System subject to an AMR.
Component Cooling System
In their letter dated September 30, 1999, the applicant incorporated a revision to the Steam Generator Tube Rupture Accident analysis that assumes operation of the reactor coolant pumps will be available for a period of time after the accident occurs. Operation of the reactor coolant pumps requires component cooling water to the pump's thermal barriers. The applicant revised the intended functions of the CC System and identified the mechanical components subject to an AMR and their intended functions in Table 2-1 of the September 30, 1999, letter to the NRC. The list of components in Table 2-1 expanded the original list of components subject to an AMR identified in Section 2.5.4.2 of the LRA.
The staff reviewed system flow diagrams OFD-144A-1.1, 1.4, 2.1, 3.1, OLRFD-144A-1.3,2.3, and 3.3 and compared the components listed in Table 2-1 of the letter dated September 30, 1999, to the system flow diagrams to ensure those CC System components required to remove heat from the reactor coolant pumps were identified on the list of components within the scope of license renewal and subject to an AMR. The staff asked the applicant to clarify the status of the following component types not found on Table 2-1: heat exchangers (the Quench Tank Heat Exchanger and the Letdown Coolers) and stator water jackets.
As documented in NRC memorandum dated November 18, 1999, the applicant responded that the stator water jackets should have been identified as a component within the scope of license renewal, but not subject to an AMR because the stator water jackets are subcomponents of the control rod drive mechanisms which are not subject to AMR in accordance with 10 CFR 54.21(a)(1)(i). The staff reviewed this conclusion and agreed with the applicant that the stator water jackets are not subject to AMR. After further review, the applicant concluded in a letter dated December 17, 1999, that the Quench Tank Heat Exchanger, and the Letdown Coolers were also within the scope of license renewal and subject to an AMR.
On the basis of a review of the applicant's letter of September 30, 1999, the system flow diagrams, and the applicant's responses to staff questions regarding the components within the scope of license renewal documented in the staff's memorandum dated November 18, 1999, and the applicant's response dated December 17, 1999, the staff has reasonable assurance that all portions of the CC System with intended functions meeting the criteria of 10 CFR 54.4 are identified as being within the scope of license renewal.
Using the information on the flow diagrams of the CC System OFD-144A-1.1, 1.4, 2.1, 3.1, OLRFD-144A-1.3, and 2.3, the staff sampled several components from Table 2-1 to determine whether the applicant properly identified the passive, long-lived components on the list of components subject to an AMR from among those identified as within the scope of license renewal. The staff verified that the passive, long-lived components on the system flow diagrams were on the list of components subject to an AMR for the CC System in Table 2-1 of the applicant's September 30, 1999, letter. No omissions were identified. On the basis of this review, the staff has reasonable assurance that the applicant has identified the SCs of the CC System subject to an AMR.
2.2.3.4.1.2.2 Review Findings for Auxiliary Systems
On the basis of the staff's review of the information in Section 2.5.6 of the application, the supporting information in the ONS FSAR, and the applicant's responses to the staff's RAIs as discussed in the preceding section, the staff did not find any omissions by the applicant and, therefore, concludes that there is reasonable assurance that the applicant adequately identified those portions of the auxiliary systems and their associated (supporting) SCs that fall within the scope of license renewal and are subject to an AMR, in accordance with 10 CFR 54.4(a) and 10 CFR 54.21(a)(1).
2.2.3.4.2 Process Auxiliaries
In Section 2.5.7, "Process Auxiliaries," of the LRA, the applicant described the SCs of the process auxiliaries that are within the scope and subject to an AMR for license renewal.
Component (equipment and piping) supports for the systems are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant evaluated instrument line components with the system to which they are attached.
2.2.3.4.2.1 Summary of Technical Information in the Application
As described in the LRA, the process auxiliary systems are required to support the reactor during normal operation. These systems are generally located within the auxiliary building. The following systems of the Process Auxiliaries are included by the applicant as within the evaluation boundary for license renewal:
Chemical Addition System
The following components of the Chemical Addition System are within the scope of license renewal, and are subject to an AMR: accumulator, expansion coil, flexible hose, orifice, pipe, pump casing, tubing, and valve bodies. The intended function for these components, based on the requirements of 10 CFR 54.4(a), are listed as pressure boundary.
The Chemical Addition System is designed to mix, store, and inject chemicals into the RCS and auxiliary systems. The system also functions as a central location for sampling various fluids throughout the plant to ensure chemical concentrations are maintained within the prescribed limits.
The portion of the Chemical Addition System used to draw samples from the secondary side of the steam generators is exposed to a treated water internal environment. The portion of the system used to draw samples from the primary side of the steam generators and the pressurizer steam and water spaces is exposed to a borated water internal environment. The Chemical Addition System external surfaces are exposed to the reactor building and auxiliary building environments.
Coolant Storage System
The following components of the Coolant Storage System are within the scope of license renewal, and are subject to an AMR: pipe, spray nozzles, tubing, and valve bodies. The intended function for these components, based on the requirements of 10 CFR 54.4(a), is listed as pressure boundary.
The Coolant Storage System is used for the collection and storage of reactor coolant liquid. The liquid is received from the high-pressure injection system as a result of reactor coolant expansion during startup and for boric acid concentration reduction during startup and normal operation. Coolant is stored in coolant bleed holdup tanks or is processed through deborating demineralizers for boric acid removal and returned to the High-Pressure Injection System as unborated makeup. Liquid from the coolant bleed holdup tanks is pumped to the coolant treatment system for processing. The quench tank, located inside the reactor building, condenses and contains effluent from the pressurizer safety valves (bodies only), power-operated relief valves (bodies only), and various vents and drains.
2.2.3.4.2.2 Staff Evaluation
The staff reviewed this section of the application to determine whether there is reasonable assurance that the process auxiliaries components subject to an AMR have been identified in accordance with the requirements of 10 CFR 54.21(a)(1). This was accomplished as discussed below.
2.2.3.4.2.2.1 Process Auxiliaries Within the Scope of License Renewal and Subject to an AMR
As part of the evaluation, the staff determined whether the applicant had properly identified the SSCs within the scope of license renewal and subject to an AMR, pursuant to 10 CFR 54.4(a) and 10 CFR 54.21(a)(1). The staff reviewed portions of the UFSAR for the process auxiliaries, and compared the information in the UFSAR with the information in the application to identify portions that the applicant did not identify as within the scope of license renewal and subject to an AMR. The staff then reviewed SCs outside the applicant identified portion, and as described below, requested that the applicant submit additional information or clarifications or both for a selected number of SCs to verify that (1) they do not have any intended functions as delineated in 10 CFR 54.4(a) and, if they did, verify that (2) they are either active components or they are subject to replacement based on a qualified life or specified time period, as described in 10 CFR 54.21(a)(1). The staff also reviewed the UFSAR for any safety-related system functions that were not identified as intended functions in the application to verify that all SCs having intended functions were not omitted from consideration within the scope of the rule.
After completing the initial review, by letter dated November 30, 1998, the staff issued requests for additional information (RAIs) regarding the process auxiliaries, and by letters dated January 25 and February 8, 1999, the applicant responded to those RAIs. In RAI 2.5.7-1, the staff made reference to Table 2.5-11 of the application, which lists the components in the process auxiliaries and their intended functions. In the RAI, the staff requested that the applicant explain why the intended function "ability to spray water as designed" was not considered as an intended function to be maintained for license renewal. The applicant responded that the spray nozzles under consideration here are in the Coolant Storage System. This portion of the Coolant Storage System is within the scope of license renewal because it meets the criteria of 10 CFR 54.4(a)(3). This system is relied upon to meet the requirements of 10 CFR 50.48. During certain fire events, the Coolant Storage System routes releases from the RCS relief valves (used to control RCS pressure) to the quench tank where the spray nozzles are located. The releases from the relief valves flash to steam due to the high temperature of the RCS. The component function to spray the steam into the quench tank is not required in support of the system function to route this release to the quench tank. Therefore, "ability to spray water as designed" is not an intended function for the purpose of license renewal, and the staff agrees with the applicant's conclusion.
In RAI 2.5.7-2, the staff indicated that flow restriction orifices are installed in several pipes within the evaluation boundary for process auxiliaries in order to limit the mass flow rate during an accident. The RAI requested that the applicant clarify which of these orifices are within the scope of license renewal, and also to discuss the intended functions these items might perform for license renewal. In response, the applicant mentioned that the process auxiliaries include the chemical addition and Coolant Storage Systems. No orifices are within the license renewal portion of the Coolant Storage System. The orifices within the license renewal portions of the Chemical Addition System are within the scope and subject to an AMR. These orifices provide pressure boundary and throttle flow for flow measurement. Flow measurement is not required in support of the system-intended functions within the scope of license renewal. Therefore, the only component-intended function of the orifices that the applicant listed is pressure boundary.
2.2.3.4.2.2.2 Review Findings for Process Auxiliaries
On the basis of the staff's review of the information contained in Section 2.5.7 of the application, the supporting information in the ONS UFSAR, and the applicant's response to the staff's RAIs as discussed in the preceding section, the staff did not find any omissions by the applicant and, therefore, concludes that there is reasonable assurance that the applicant adequately identified those portions of the process auxiliaries and the associated (supporting) components that fall within the scope of license renewal and are subject to an AMR, in accordance with 10 CFR 54.4(a) and 10 CFR 54.21(a)(1).
2.2.3.4.3 Heating, Ventilation, and Air Conditioning Systems (HVAC)
In Section 2.5.8, "Air Conditioning, Heating, Cooling and Ventilation Systems," of Exhibit A of the LRA, the applicant identified portions of the auxiliary building ventilation system, the control room pressurization and filtration system, and the penetration room ventilation system, and the components that are within the scope of license renewal and identified which of those "within-scope" components are subject to an AMR. The applicant stated In Section 2.5.8 of Exhibit A of the LRA that HVACS are further described within Section 9.4 of the UFSAR. The HVACS consist of the following systems that are within the scope of the license renewal:
Component (equipment and piping) supports for the systems are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant evaluated instrument line components with the system to which they are attached.
2.2.3.4.3.1 Summary of Technical Information in the Application
Auxiliary Building Ventilation System (ABVS)
The ABVS consists of the ABVS proper and the hot machine shop. Air is supplied to the auxiliary building by a low-pressure fan duct system. Air is taken in through outside air intake louvers by supply units consisting of roughing filters, steam coil, and cooling coil supplied by low-pressure service water. Six main supply fans are required for normal plant operation. Temperatures are maintained in the auxiliary building by throttling steam to the steam coils or low-pressure service water to the cooling coils as required. Exhaust fans exhaust air from the auxiliary building through the exhaust duct and through three unit vent stacks, where it is monitored before being released to the atmosphere. Under normal operating conditions, the ABVS supply fans and exhaust fans are balanced so that the exhaust air flow exceeds the supply air flow in order to minimize outleakage.
Air is supplied to the hot machine shop by two recirculating local cooling units. Each unit consists of roughing filters, a compressor, evaporator and condenser coils, and a centrifugal fan. These units supply recirculated air with a small amount of makeup air throughout the hot machine shop via a low-pressure duct system. Temperatures are maintained in the hot machine shop by electric unit heaters in the supply ductwork. The hot machine shop uses direct expansion cooling. Air is exhausted from the hot machine shop via an exhaust duct and a filter train and is discharged to the atmosphere through an independent vent stack.
Remote recirculating fan-coil-type units provide standby spot cooling in the pump rooms and other high heat load areas. The fan coil units are also served by the LPSW System.
The ONS Units 1 and 2 purge fan to remove smoke from the cable rooms and equipment rooms is located in the ONS Unit 2 equipment room wall to purge smoke to the auxiliary building corridor where it can be monitored and exhausted to the unit vent through ABVS equipment. The ONS Unit 3 purge fan is located on auxiliary building elevation 838'-0" with HVAC equipment, and would exhaust to that area enabling the ABVS to pick up, monitor, and discharge products of combustion through the plant vent.
In Section 2.5.8 of Exhibit A of the LRA and Section 9.4 of the UFSAR, the applicant identified the following intended functions for the ABVS based on 10 CFR 54.4(a)(1) and (2):
Section 2.5.8 of Exhibit A of the LRA -
Section 9.4 of the UFSAR -
The applicant also determined that the following were intended functions of the ABVS based on the requirements of 10 CFR 54.4(a)(3):
Section 2.5.8 of Exhibit A of the LRA -
Section 9.4 of the UFSAR -
Control Room Pressurization and Filtration System (CRPFS)
The CRPFS is designed to maintain the environment in the control areas of ONS Units 1, 2, and 3 which consists of the control room (common control room for ONS Units 1 and 2), cable rooms, and electrical equipment rooms within acceptable limits for the operation of unit controls as necessary for equipment and operating personnel. The control room envelope consists of the control room, offices, computer rooms, operators' break area, and operators' toilet room. Redundant air conditioning and ventilation equipment is provided to assure that no single active failure within these systems will prevent proper environmental control in the control area.
The ONS Units 1 and 2 control areas are served by four air handling units (AHUs). The control room is primarily served by two AHUs. Each unit has 100 percent capacity and only one unit is required to operate at a time. Cooling is provided to the Unit 1 cable room, Unit 2 cable room, Unit 1 equipment room, and Unit 2 equipment room by a total of four AHUs.
The ONS Unit 3 control areas are served by six AHUs. Two 100 percent AHUs serve the control room, two 100 percent AHUs serve the cable room, and two 100 percent AHUs serve the electrical equipment room.
The chilled water for the AHUs is supplied from the plant Chilled Water System, which is capable of supplying sufficient chilled water for all necessary systems with one of two chillers in service.
For pressurization purposes, outside air is supplied to the common control room for Units 1 and 2, and the control room for Unit 3 from an intake on the roof of the auxiliary building to offset the exfiltration from the control room zone. This minimizes uncontrolled infiltration into the control room zone by creating a positive pressure with respect to adjacent zones. Air passes through filter trains, which consist of pre-filters, 99.5 percent efficient high-efficiency particulate air (HEPA) filters, 90 percent efficient charcoal filter beds, and a centrifugal fan. Units 1, 2, and 3 control room filter systems are served by two 50 percent filter trains, and the system is capable of operating with one or both trains. The filter trains are manually started by the plant operators. When a radiation monitor in the return air intake of the AHUs alerts the operators in the control room to a high radiation reading, the operators start the outside-air filter trains.
The applicant stated that no potential sources of toxic gas releases were identified off-site. The NRC staff previously found that the applicant's evaluation of protection of control room operators against potential toxic gas release accidents was adequate. Self-contained-type breathing apparatuses are available to operator personnel. The ONS Units 1 and 2 control room has six apparatuses with 12 refill bottles and the ONS Unit 3 control room has three apparatuses with 6 refill bottles.
A purge fan in the wall of the Unit 2 equipment room purges air to the auxiliary building corridor where it can be transported by the auxiliary building HVAC equipment, monitored, and exhausted through the unit vent. The Units 1 and 2 control room is purged with portable equipment. In Unit 3, two purge and exhaust ducts are furnished for the equipment room and kitchen area of the control room. These exhaust ducts enable the equipment room, cable room, and control room to be purged in the event of a fire. The fan for purging Unit 3, which is designed to remove smoke from the control room through the kitchen and from the equipment room, is located on elevation 838'-0" with HVAC equipment and would exhaust to the area that would enable the auxiliary building system to pick up, monitor, and discharge products of combustion through the plant vent. Neither a single failure nor an inadvertent operation of the purge systems would affect plant operations. A single failure would require that portable equipment be used to purge individual areas. The control room is isolated from other areas of the plant by 3-hour fire barriers, except for the wall adjacent to the lobby around the entrance door, where a steel plate was installed to satisfy the concerns other than fire protection. Ionization smoke detection is provided in the control room and cable rooms.
In a letter dated October 15, 1999, the applicant stated that certain mechanical components associated with portions of the CRPFS have been added to the scope of license renewal due to the addition of the Chilled Water (WC) System in response to Open Item 2.2.3.4.3.2.1-1. The components were identified in Attachment 2, Table 3, to the letter. No new components types were identified as a result of this effort. The WC System is discussed in Section 2.2.3.4.10 of this report. The applicant identified maintaining a suitable environment (within acceptable limits) in the control room after postulated design-basis events as the intended function for the portions of the CRPFS that have been added to the scope of license renewal. In response to Open Item 2.2.3.4.3.2.1-2, the applicant stated that it will manage the effects of aging of the CRPFS sealant materials as part of its control room ventilation system examination required by the ONS Technical Specifications Surveillance Requirement 3.7.9.1. The staff's evaluation of the AMR for sealant materials is discussed in Section 3.6.1 of this report.
In Section 2.5.8 of Exhibit A of the LRA and the UFSAR, the applicant identified the following intended functions for the CRPFS based on 10 CFR 54.4(a)(1) and (2):
Section 2.5.8 of Exhibit A of the LRA
Sections 6.4 and 9.4 of the UFSAR
The applicant also determined that the following were intended functions of the CRPFS based on the requirements of 10 CFR 54.4(a)(3):
Section 2.5.8 of Exhibit A of the LRA
Section 9.4 of the UFSAR
Penetration Room Ventilation System (PRVS)
The PRVS has two fans and two filter assemblies. Both fans discharge through a single line to the unit vent. The fans and filter trains for the system are redundant and only one fan and one filter train is required for emergency operation. During normal operation, this system is held on standby and each fan is aligned with a filter assembly. The engineered safeguards signal from the reactor building pressure will actuate the fans. The control room, as well as remote instrumentation, monitors operation.
The three valves in each purge-line penetration will be closed by a reactor building isolation signal. The reactor building purge equipment, if running, will be shut down from an interlock on the reactor building purge isolation valves. After the external valves close, a small, normally open valve vents any leakage from the two outermost valves into the penetration room. The reactor building purge equipment is not activated when the reactor is above cold-shutdown conditions.
Following a loss-of-coolant accident, a reactor building isolation signal will place the system in operation by starting both full-size fans. Two power-operated butterfly valves, which open when the fans start, are installed downstream of each fan. These valves will be closed to prevent recirculation if one fan fails. A check valve is also installed downstream of each fan to prevent recirculation if a fan fails. In the event of a fan failure, the normally closed tie valve can be opened from its remote manual station to maintain adequate cooling air through the idle filter train.
The system utilizes remote manual control valves in conjunction with constant-speed fans to provide the proper negative pressure in the penetration room. If the leakage increases during operation, causing a decrease in negative pressure below 0.06 inches water gauge with respect to the outside atmosphere, the remote manual control valve will be adjusted or leaks will be repaired to bring the negative pressure to 0.06 inches water gauge or more.
The remote manual control valve is also used to compensate for filter loading. Initially, it will be partially closed; and as the filter loads up causing a decrease in flow and negative penetration room pressure, the valve will gradually be opened so that the pressure drop across the filter-valve combination remains constant. By periodically adjusting the remote manual control valve to offset the effect of increased leakage and filter loading, the system characteristic remains constant.
The communicative paths between various parts of the penetration room are very large in comparison with the minute leakage that might exist because of imperfect seals. Therefore, it can be assumed that no pressure differentials exist in the room so that an instrument string sensing pressure at a single point can be used. Penetration room pressure is displayed in the control room and excessive and insufficient vacuums are annunciated. During normal operation, an operator can actuate the system to test it. Particulate filtration is achieved by a medium efficiency pre-filter and a HEPA filter. Adsorption filtration is accomplished by an activated charcoal filter. The filter consists of three horizontal, removable-type, double-tray, carbon cells. Flow through the trays is essentially vertical. At rated flow, the average face velocity is 40 ft/min and the residence time is 0.25 seconds. Each tray contains 40 lb. of carbon. The carbon is impregnated so that it will adsorb methyl iodide as well as elemental iodine. In Section 2.5.8 of Exhibit A of the LRA and Section 9.4 of the UFSAR, the applicant identified the following intended functions for the PRVS based on 10 CFR 54.4(a)(1) and (2):
Section 2.5.8 of Exhibit A of the LRA
Section 9.4 of the UFSAR
On the basis of the intended functions identified above for the ABVS, CRPFS, and PRVS, the portions of these systems that were identified by the applicant as within the scope of license renewal include all safety-related components in the system (electrical, mechanical, and instrument). The applicant described their process for identifying the mechanical components subject to an AMR in Section 2.5.2 of Exhibit of the LRA. Based on this methodology, the applicant identified the portions of the ABVS, CRPFS and PRVS that are within the scope of license renewal on flow diagrams listed in Table 2.5-12 of Exhibit A of the LRA. Using the methodology described in Section 2.5.2.2. of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant provided this list in Table 2.5-13 of Exhibit A of the LRA.
Auxiliary Building Ventilation System (ABVS) - The following five device types are identified as within the scope of license renewal and subject to an AMR: air flow monitors (aluminum, carbon steel, and galvanized steel), AHUs (aluminum, stainless steel, and galvanized steel), ductwork (aluminum, stainless steel, and galvanized steel), filters (aluminum, stainless steel, and galvanized steel), and grills (aluminum, stainless steel, and galvanized steel).
Control Room Pressurization and Filtration System (CRPFS) - The following eight device types are identified as within the scope of license renewal and subject to an AMR: air flow monitors (aluminum, carbon steel, and galvanized steel), AHUs (aluminum, stainless steel, and galvanized steel), ductwork (aluminum, stainless steel, and galvanized steel), filters (aluminum, stainless steel, and galvanized steel), grills (aluminum, stainless steel, and galvanized steel), heaters (aluminum, galvanized steel and stainless steel), tubing (brass, carbon steel, copper, and stainless steel) and sealants.
Penetration Room Ventilation System (PRVS) - The following six device types are identified as within the scope of license renewal and subject to an AMR: filters (carbon steel), grills (aluminum, stainless steel, and galvanized steel), orifices (stainless steel), pipes (carbon steel), tubing (brass, carbon steel, copper, and stainless steel), and valve bodies (carbon steel).
The applicant further indicated in Table 2.5-13 that the ABVS, CRPFS, and PRVS pressure boundary is the only applicable intended function associated with the components of the ABVS, CRPFS, and PRVS that are subject to an AMR.
2.2.3.4.3.2 Staff Evaluation
The staff reviewed Section 2.5.8 of Exhibit A of the LRA to determine whether there is reasonable assurance that the ABVS, CRPFS, and PRVS components within the scope of license renewal (10 CFR 54.4) and subject to an AMR have been identified in accordance with the requirements of 10 CFR 54.21(a)(1). After completing the initial review, the staff issued a request for additional information (RAI), by letter dated November 24, 1998, regarding the ABVS, CRPFS, and PRVS. The applicant responded to the RAI in letters dated January 25, February 8, and February 17, 1999.
2.2.3.4.3.2.1 HVAC Systems Within the Scope of License Renewal and Subject to an Aging Management Review
In Section 2.5.2.2, "Identification of Mechanical Components Subject to an Aging Management Review" of Exhibit A of the LRA, the applicant discussed the process of identifying mechanical components subject to an AMR, which is evaluated in Section 2.1 of this SER, "Methodology for Identifying Structures and Components Subject to Aging Management Review." The applicant stated in Section 2.5.8 of the LRA that the flow diagrams listed in Table 2.5-12 show the evaluation boundaries for the (highlighted) portions of the HVACS that are within the scope of license renewal and Table 2.5-13 lists those mechanical components and their intended functions.
The staff reviewed portions of the UFSAR, including Sections 6.4 and 9.4, to determine if there were any portions of the system that the applicant did not identify as within the scope of license renewal that should have been so identified. The staff also reviewed Sections 6.4 and 9.4 of the UFSAR to determine if there were any safety-related system functions that were not identified as intended functions in the LRA, and to determine if there were SCs having intended functions that might have been omitted from consideration within the scope of the license renewal. The staff also reviewed the system flow diagrams of OLRP-1002 to determine if any structures or components not identified in the LRA as within the scope of the rule should have been so identified under 10 CFR 54.4(a)(2) or (3). The staff compared the functions described in the UFSAR to those identified in the LRA. The staff then determined whether the applicant had properly identified SCs subject to an AMR from among those identified as within the scope of license renewal. The applicant identified and listed the SCs subject to an AMR for the HVACs in Table 2.5-13 of Exhibit A of the LRA using the screening methodology described in section 2.5.2 of Exhibit A of the LRA. The staff evaluated the scoping and screening methodology and documented its findings in Section 2.1 of this SER. As described in more detail in the following subsections, the staff sampled from the list of SCs for each auxiliary system identified by the applicant as subject to an AMR to get reasonable assurance that all components subject to an AMR were appropriately identified. The staff also sampled the SCs that were within the scope of license renewal but not subject to an AMR to verify that these SCs performed their intended functions with moving parts or a configuration change or were subject to replacement on the basis of a qualified life or specified time period (i.e., active or short-lived). As discussed below, the staff found no omissions and, therefore, concluded that there was reasonable assurance that the applicant adequately identified those portions of the ABVS, CRPFS, and PRVS and the associated components that fall within the scope of license renewal and subject to an AMR in accordance with 10 CFR Part 54.4 and 54.21.
To help ensure that those portions of the ABVS, CRPFS, and PRVS identified as not within the scope of license renewal did not perform any intended functions, the staff issued an RAI based on the information in the UFSAR and the LRA. The staff noted that Section 2.5.8 of Exhibit A of the LRA presents a summary description of the system functions, highlighted boundaries in flow diagrams of OLRP-1002, "License Renewal Flow Diagrams, Oconee Nuclear Station, Units 1, 2, and 3," and tabulates components within the scope of license renewal for the ABVS, CRPFS, and PRVS subject to an AMR. The corresponding drawings for these systems in the UFSAR, however, show additional components that were not listed in Table 2.5-13 of Exhibit A of the LRA. The staff's RAI and the applicant's response are discussed below:
Auxiliary Building Ventilation System
The staff requested clarifications or justifications or both in RAI 2.5.8-1 concerning the exclusion from the scope of license renewal or an AMR or both of (1) the damper, damper operator, gravity damper, bird screen, exhaust/supply fans and enclosures, heating/cooling coils, compressors, valves, and air dryers; (2) exhaust filtration function for the ABVS served areas for the hot machine shop and spent fuel pool areas; and (3) several supply or return/exhaust from the various components or both, including exhaust fan, condenser steam air ejectors, and sample hood, as shown in flow diagram OLRP-1002 for the ABVS.
In a letter dated February 8, 1999, the applicant responded to RAI 2.5.8-1 and stated that the dampers, damper operators, gravity dampers, fans, compressors, and air dryers are excluded from an AMR in accordance with 10 CFR 54.21(a), and that fan enclosures (identified as "air handling unit") and bird screens (identified as "grills") are subject to an AMR as identified in Table 2.5-13 of Exhibit A of the LRA. From a pressure boundary standpoint, the cooling and heating coils are considered as subcomponents of the AHUs that are subject to an AMR, and AHUs are listed in Table 2.5-13 of Exhibit A of the LRA. Pursuant to10 CFR 54.4, the compressors, valves, and air dryers are not components of the ABVS and are not necessary for the ABVS to perform its intended function, therefore, they are excluded from the license renewal scope. The applicant further clarified in a letter dated May 10, 1999, in response to RAI 2.5.8-1, that the ABVS is constructed of ductwork and dampers, not pipes and valves. The ductwork is subject to an AMR and is listed in Table 2.5-13 of Exhibit A of the LRA. The dampers are within the scope of license renewal, but are not subject to an AMR in accordance with 10 CFR 54.21(a)(1)(i). On the basis of the additional information provided by the applicant, the staff finds the exclusion of valve bodies and piping from the scope of ABVS components requiring an AMRs, acceptable.
In a letter dated February 8, 1999, the applicant responded to RAI 2.5.8-2 concerning the exclusion of the hot machine shop exhaust from the scope of license renewal. The applicant stated that the license renewal scoping criterion of §54.4 does not contain any requirement related to 10 CFR Part 20 and, therefore, it did not use 10 CFR Part 20 as a criterion to determine which systems were within the scope of license renewal. Additionally, no design-basis events occur in the hot machine shop areas and no portions of the ABVS supporting the hot machine shop are relied upon to perform the smoke removal function and, therefore, hot machine shop areas are not within the scope of license renewal. The staff agrees with the applicant's rationale for excluding the hot machine shop exhaust from the scope of license renewal. In its response concerning the exclusion of the spent fuel pool areas exhaust from the scope of license renewal, the applicant stated that (1) the environment in the spent fuel pool area is controlled by the SFP ventilation system, (2) exhaust from the spent fuel pool areas is not filtered before release to the plant vents, (3) the exhaust from the spent fuel pool areas is filtered by the reactor building purge system filter package before release to the plant vents as required by ONS Technical Specifications, and (4) a review of fuel handling design-basis events determined that no system or component functions are credited in support of accident mitigation. The NRC staff has previously concluded in Section 11.0 of the "Safety Evaluation by the Directorate of Licensing, U.S. Atomic Energy Commission, in the matter of Duke Power Company, Oconee Nuclear Station, Units 2 and 3," dated July 6, 1973, that the offsite dose for a fuel handling accident is less than the guideline values of 10 CFR Part 100 for Oconee Nuclear Station, Units 2 and 3. On this basis, the staff agrees with the applicant's assessment that even though the exhaust air filtration from the spent fuel pool areas conforms with 10 CFR Part 100 guidelines, it is not credited in support of accident mitigation (fuel handling accident) and, therefore, SFP exhaust is outside the scope of license renewal.
In a letter dated January 25, 1999, the applicant responded to RAI 2.5.8-3. The applicant stated that (1) the highlighted portions of the supply or return/exhaust ductwork or both, shown on flow diagrams OLRFD-116G-1.1, OLRFD-116G-1.2, OLRFD-116G-2.1, OLRFD-116G-3.1, and OLRFD-116G-3.2, are required for fire protection as they support a system-intended function of smoke removal for the auxiliary building and non-highlighted portions do not support any ABVS-intended function as defined in §54.4(a); (2) OLRFD-116G-1.3 will be revised to correct editorial comment for "LR" scoping arrows; and (3) the exhaust from the condenser steam air ejectors and the sample hood to the specific vent stack of Units 1, 2, and 3 and the filter discharges to specific vent stacks of Units 1 and 3 shown on OLRFD-116G-1.4 do not support any ABVS-intended function as defined in §54.4(a)(1), (2), (3), or (b). The staff agrees with the applicant's approach for excluding the non-highlighted portions of the ABVS, which do not support the intended functions as defined in §54.4(a)(1), (2), (3), or (b).
Control Room Pressurization and Filtration System
The staff requested clarifications or justifications or both concerning the exclusion from the scope of license renewal or an AMR or both of (1) the dampers, damper operators, gravity dampers, bird screens, exhaust/supply fans and enclosures, heating/cooling coils, compressors, valves, and air dryers and (2) sealant materials to control the unfiltered in-leakage for the pressurization function of CRPFS.
In a letter dated February 8, 1999, the applicant responded to RAI 2.5.8-1. In its response, the applicant stated that the dampers, gravity dampers, and fans are excluded from an AMR in accordance with 10 CFR 54.21(a)(1)(i), while heating coils, fan enclosures (identified as "air handling units"), and bird screens (identified as "grills") are subject to an AMR as identified in Table 2.5-13 of Exhibit A of the LRA. The staff finds the applicant's rationale for listing these components in Table 2.5-13 of Exhibit A of the LRA as subject to an AMR acceptable. From a pressure boundary standpoint, the cooling and heating coils are considered as subcomponents of the AHUs that are subject to an AMR, and AHUs are listed in Table 2.5-13 of Exhibit A of the LRA. Pursuant to 10 CFR 54.4, the compressors, valves, and air dryers are not components of the CRPFS and are not necessary for the CRPFS to perform its intended function, therefore, they are excluded from the license renewal scope. The applicant further clarified in a letter dated May 10, 1999, in response to RAI 2.5.8-1, that the CRPFS is constructed of ductwork and dampers, but not pipes and valves. The ductwork is subject to an AMR and is listed in Table 2.5-13 of Exhibit A of the LRA. The dampers are within the scope of license renewal, but are not subject to an AMR in accordance with 10 CFR 54.21(a)(1)(i).
Also in the May 10,1999, letter, the applicant provided reasons why the chilled water (WC) System (which supports the cooling function for the CRPFS) is not included within the scope of license renewal. The applicant stated that for certain design-basis events, the CRPFS maintains a positive pressure in the control room and that air conditioning is not required. The applicant stated that failure of the WC System does not prevent the CRFPS from maintaining a positive pressure in the control room for accident conditions and is not classified ONS Piping Class D for seismic II/I concerns. Further, the applicant stated that the CRFPS is credited with maintaining a suitable environment in the control room during a fire event and providing for smoke removal from the control room, neither of which require air conditioning supported by the WC System. The applicant also noted that the CRPFS and the supporting WC System do not perform an intended function in support of any other regulated event listed in 10 CFR 54.4(a)(3). The applicant concluded from this evaluation that the WC System is not within the scope of license renewal. The staff did not agree with this conclusion. It appeared to the staff that the WC System was needed at ONS in order to assure the capability to shutdown the reactor and maintain it in a shutdown condition. The staff requested that the applicant identify where in the CLB the loss of the WC System has been addressed, and clarify why the WC System is not within the scope of license renewal and subject to an AMR. This was Open Item 2.2.3.4.3.2.1-1.
The applicant reviewed the open item and by letter dated October 15, 1999, the applicant stated that the WC System is within the scope of license renewal and is subject to an AMR. The applicant also stated that a new TS for the WC System has been added to the ONS CLB under Section 3.7.16, "Control Room Area Cooling Systems (CRACS)."
On the basis of the above review, that includes the WC System as being within the scope of LR and subject to an AMR, Open Item 2.2.3.4.3.2.1-1 is closed. The staff's evaluation of the SCs of the WC System that are within the scope of license renewal and subject to an AMR is addressed in Section 2.2.3.4.10 of this report.
In a letter dated February 17, 1999, the applicant responded to RAI 2.5.8-4 concerning the use of sealant materials in CRPFS. In its response the applicant stated the following:
The condition of these sealant materials is determined during the Control Room Pressure Test conducted in accordance with technical specifications (Oconee Improved Technical Specification ITS 3.7.9, Surveillance Requirement SR 3.7.9.3). The test acceptance criterion requires prompt action to correct the leaking seal by either repair or replacement. In addition, the requirement to maintain a positive pressure within the control room area is a function that is maintained under the Maintenance Rule (§50.65) program. For the sealant materials, the programmatic action is not to "manage" sealant life, but rather to replace the sealant when its condition indicates it is no longer acceptable for service. Therefore, sealant materials used to control unfiltered in-leakage are repaired or replaced based upon performance or condition and, thus, are not subject to an AMR.
The staff notes that the SOC for 10 CFR Part 54 (60 FR 22478) states the following:
| . . . the Commission has decided not to generically exclude passive structures and components that are replaced based on performance or condition monitoring from an AMR. . . . However, the Commission does not intend to preclude a license renewal applicant from providing site-specific justification in a license renewal application that a replacement program on the basis of performance or condition for a passive structure or component provides reasonable assurance that the intended function of the passive structure or component will be maintained . . . |
Accordingly, the staff concluded that the condition monitoring provided by the referenced ONS ITS surveillance did not, by itself, provide a plant-specific basis for excluding the sealant materials in the CRPFS from an AMR. However, the staff believes that the ITS surveillance, in conjunction with related system inspections and the corrective action process, can provide an adequate aging management program for the sealant materials in the CRPFS System. This was Open Item 2.2.3.4.3.2.1-2.
The applicant reviewed the open item and by letter dated October 15, 1999, stated that the aging of the CRPFS sealant materials will be managed by the control room ventilation system examination using the program attributes discussed in LRA Section 4.2 of Exhibit A, that is required by ONS Technical Specification (TS) Surveillance Requirement (SR) 3.7.9.1. The applicant further stated that the examinations that serve to manage the aging of the sealants, rubber boots, seals, and flexible collars of the CRPFS include the following attributes: purpose, scope, aging effects, method, sample size, industry codes and standards, frequency, acceptance criteria, corrective action, timing of new program initiation, administrative controls, and regulatory basis. The applicant also stated that the sealants (caulking, sealants, and water stops) associated with the control room pressure boundary which includes the walls, ceiling, floor, access doors, and penetrations for electrical and mechanical equipment are addressed in response to Open Item 2.2.3.6.1.2.1-1 in the October 15, 1999 letter. The aging of the control room pressure boundary fire barriers (access doors and penetrations) is managed by the fire protection program which is discussed in LRA Section 4.19 of Exhibit A.
As stated in the letter dated October 15, 1999, in response to SER Open Item 2.2.3.4.3.2.1-2, the CRPFS sealant materials will be managed by the control room ventilation system examination which is required by ONS Technical Specification Surveillance Requirement 3.7.9.1. The staff's evaluation of the AMR for sealants can be found in Section 3.6.1 of this report. The staff agrees with the applicant that the CRPFS sealant material is within the scope of LR and subject to AMR. Therefore, Open Item 2.2.3.4.3.2.1-2 is closed.
Penetration Room Ventilation System
The staff requested clarifications or justifications or both concerning the exclusion from the scope of license renewal or an AMR or both of (1) the dampers, damper operators, gravity dampers, bird screens, exhaust/supply fans and enclosures, heating/cooling coils, compressors, valves, and air dryers. In a letter dated February 8, 1999, the applicant responded to RAI 2.5.8-1. The applicant stated that the dampers, gravity dampers, and fans are excluded from an AMR in accordance with 10 CFR 54.21(a). The valve bodies and pipes are subject to an AMR, as identified in Table 2.5-13 of Exhibit A of the LRA. The staff finds the applicant's rationale acceptable concerning the valve bodies and pipes for listing them in Table 2.5-13 of Exhibit A of the LRA as subject to an AMR. Since PRVS is primarily an exhaust filtration system, the bird screens, heating coils, cooling coils, compressors, fan enclosures, and air dryers are not components of the PRVS and, therefore, are not within the scope of license renewal.
Some components that are common to many systems, including ABVS, CRPFS, and PRVS, have been included in separate sections of Exhibit A to the LRA which address those components for the entire plant. As indicated below, the following components were not included in the individual system sections:
Based on a review of Exhibit A of the LRA, supporting information in the UFSAR, and the applicant's responses to the staff's RAI, the staff has reasonable assurance that all portions of the HVAC systems (ABVS, CRPFS, and PRVS) with intended functions meeting the criteria in 10 CFR 54.4 are identified as being within the scope of license renewal on the flow diagrams listed in Table 2.5-8 of Exhibit A.
Using the information provided on the flow diagrams for the HVAC system (ABVS, CRPFS, and PRVS) (Table 2.5-13 of Exhibit A), the staff sampled several components to determine whether the applicant properly identified the passive, long-lived components in the list of components as subject to an AMR (Table 2.5-13 of Exhibit A) from among those identified as within the scope of license renewal. The staff verified that the passive, long-lived components highlighted on the system flow diagrams were included in the list of components that are subject to an AMR for the HVAC systems (ABVS, CRPFS, and PRVS) in Table 2.5-13. No omissions were identified. Based on this review the staff has reasonable assurance that the applicant has identified the components of HVAC systems (ABVS, CRPFS, and PRVS) subject to an AMR.
2.2.3.4.3.2.2 Review Findings for HVAC
The staff has reviewed the information in Section 2.5.8, "Air Conditioning, Heating, Cooling and Ventilation Systems," of Exhibit A of the LRA. On the basis of this review, the staff has reasonable assurance that the applicant has identified and listed the portions of the ABVS, CRPFS, and PRVS, and the associated components thereof, that are within the scope of license renewal and subject to an AMR in accordance with the requirements of 10 CFR 54.4, and 10 CFR 54.21.
2.2.3.4.4 Post-Accident Hydrogen Control
In Section 2.5.10, "Post-Accident Hydrogen Control," of Exhibit A of the LRA, the applicant identified the systems and components that are within the scope of license renewal and which of those within-scope components are subject to an AMR. The Post-Accident Hydrogen Control Systems include the containment hydrogen control system and the Post-Accident Monitoring System.
Component (equipment and piping) supports for the system are presented separately in Section 2.7of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant included instrument line components with the system to which they are attached.
2.2.3.4.4.1 Summary of Technical Information in the Application
Containment Hydrogen Control System (CHCS)
The CHCS maintains the reactor building hydrogen concentration below flammable limits following a LOCA. During normal operation, the CHCS piping is used as a flowpath for radiation monitoring and atmosphere sampling of the reactor building. The CHCS also includes a portable hydrogen recombiner that is shared among all three units. Hydrogen concentration is controlled by circulating containment atmosphere through the hydrogen recombiner. This system also contains containment isolation valves.
The applicant described its process for identifying the mechanical components subject to an AMR in Section 2.5.2 of Exhibit A of the LRA. The applicant identified the portions of the CHCS that are within the scope of license renewal on flow diagrams listed on Table 2.5-16 of Exhibit A of the LRA. Using the methodology described in Section 2.5.2.2 of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR and identified their intended functions. The applicant provided that list on Table 2.5-17 of Exhibit A of the LRA. Four component types were identified as subject to an AMR: flex hose, pipe, hydrogen recombiner, and valve bodies. For these component types, maintaining the pressure boundary was identified as the intended function.
Post-Accident Monitoring System (PAMS)
The PAMS is designed to draw air samples from various locations inside containment following an accident to determine the concentration of hydrogen.
The applicant described its process for identifying the mechanical components subject to an AMR in Section 2.5.2 of Exhibit A of the LRA. The applicant identified the portions of the PAMS that are within the scope of license renewal on flow diagrams listed on Table 2.5-16 of Exhibit A of the LRA. Using the methodology described in Section 2.5.2.2 of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types that are within the license renewal boundaries and are subject to an AMR and identified their intended functions. The applicant provided that list on Table 2.5-17 of Exhibit A of the LRA. Three component types were identified as subject to an AMR: pipe, tubing, and valve bodies. For these component types, maintaining the pressure boundary was identified as the intended function.
2.2.3.4.4.2 Staff Evaluation
The staff reviewed Section 2.5.10, "Post-Accident Hydrogen Control," of Exhibit A of the LRA to determine whether there is reasonable assurance that the applicant has identified the post-accident hydrogen control systems and components subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.4.4.2.1 Post-Accident Hydrogen Control Systems Within the Scope of License Renewal and Subject to an Aging Management Review
The staff reviewed Section 15.16, "Post-Accident Hydrogen Control," of the UFSAR and compared the description of the systems and other components in the UFSAR to the description in the application to determine whether the applicant should have identified any additional portions of the system as within the scope of license renewal. As described in Sections 2.5.10 of Exhibit A of the LRA, essentially all portions of the post-accident hydrogen control systems were determined to be within the scope of license renewal and subject to an AMR. The hydrogen analyzers are within the scope of license renewal but perform their intended function with a change in properties, and pursuant to 10 CFR 54.21(a)(1)(i), are not subject to an AMR. The staff reviewed the remaining components of the post-accident hydrogen control systems to verify that they do not perform any intended functions. The staff also reviewed Section 15.16 of the UFSAR to determine whether the applicant had failed to identify any additional functions that were not identified as intended functions in the LRA. The staff found no omissions by the applicant. Therefore, there is reasonable assurance that the applicant adequately identified all portions of the post-accident hydrogen control systems that fall within the scope of license renewal and are subject to an AMR in accordance with 10 CFR Part 54.
2.2.3.4.4.2.2 Review Findings for Post-Accident Hydrogen Control
The staff has reviewed the information provided in Section 2.5.10 of Exhibit A of the LRA and the additional information provided by the applicant in response to the staff's RAIs. Based on this review, the staff has reasonable assurance that the applicant has appropriately identified those portions of the post-accident hydrogen control systems, and components thereof, that are within the scope of license renewal and subject to an AMR in accordance with the requirements of 10 CFR 54.4.
2.2.3.4.5 Reactor Coolant Pump Motor Oil Collection System
In Section 2.5.11, "Reactor Coolant Pump Motor Oil Collection System," of the LRA, the applicant described the components that utilize or process lubricating oil for the reactor coolant pumps (RCPs), including the oil lift system, oil coolers, and the upper and lower pots. The applicant identified that the RCP motor oil collection system is within the scope of license renewal and also identified the components that are subject to an AMR. By letter dated February 8, 1999, the applicant responded to requests for additional information (RAIs) regarding the fire protection (FP) systems and components. On April 1, 1999, the staff participated in a telephone conference with the applicant to discuss questions that the staff had regarding fire protection. A summary of that discussion is documented in a phone call summary dated April 13, 1999.
Component (equipment and piping) supports for the systems are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant evaluated instrument line components with the system to which they are attached.
2.2.3.4.5.1 Summary of Technical Information in the Application
Structures and mechanical systems that are relied upon to perform or support performance of a function that demonstrates compliance with the Commission's regulations described in 10 CFR 54.4(a)(3) are within the scope of license renewal. In 10 CFR 54.4(a)(3), the Commission requires that all SSCs relied upon in safety analyses or plant evaluation to demonstrate compliance with the Commission's regulations in 10 CFR 50.48, be included within the scope of license renewal. The applicant's FP program meets the requirements of 10 CFR 50.48 by complying with Appendix A to Branch Technical Position (Auxiliary Power Conversion System Branch) 9.5-1 (BTP APCSB) 9.5-1, "Guidelines for Fire Protection for Nuclear Plants Docketed Prior to July 1, 1976," and Sections III.G, III.J, and III.O of Appendix R, "Fire Protection Program for Nuclear Power Facilities Operating Prior to January 1, 1979," to 10 CFR Part 50. The RCP motor oil collection system is relied upon to meet the requirements of Appendix R, Section III.O, "Oil Collection System for Reactor Coolant Pump."
In 10 CFR 50.48, the Commission requires that the applicant implement and maintain an FP program. The FP program is incorporated into various plant documents to ensure that it remains updated. Furthermore, flow diagrams are updated any time plant or licensing changes warrant a revision. As described in the LRA, the applicant used flow diagrams to indicate the evaluation boundaries for mechanical systems that were within the scope of license renewal. Mechanical components are considered to be those installed in components that contain a fluid, including air or gas. In a two-step process, the applicant identified the mechanical components subject to an AMR. First the applicant reviewed the flow diagrams and developed a menu of mechanical component types at ONS. Secondly, the applicant identified mechanical components and component types within the evaluation boundaries that are subject to an AMR, along with their intended functions. In Section 2.5.11 of the LRA, the applicant described the components of the RCP motor oil collection system that are subject to an AMR and listed their intended functions.
Each RCP has several components that utilize or process lubricating oil, including the oil lift system, oil coolers, and the upper and lower pots. Each RCP is equipped with an oil collection system in accordance with the requirements of Appendix R, Section III.O. The underlying purpose of the lube oil collection system is to ensure that leaking oil will not lead to a fire that could damage safety-related equipment during normal conditions or design-basis accident conditions.
The portions of the system piping that are within the scope of license renewal are designed and constructed to the requirements of Oconee System Piping Class D. These portions are designed to remain intact following a design-basis earthquake. License renewal flow diagrams OLRFD-100A-1.4, OLRFD-100A-2.4, and OLRFD-100A-3.4 show the evaluation boundaries for the portion of the RCP motor oil collection system that is within the scope of license renewal. In Table 2.5-19 of the LRA, the applicant identified mechanical components of the RCP motor oil collection system that are subject to an AMR and also identified their intended functions.
2.2.3.4.5.2 Staff Evaluation
In 10 CFR 54.21(a)(1), the Commission's regulations state that for those SSCs within the scope of 10 CFR 54.4, the integrated plant assessment (IPA) must identify and list those SCs subject to an AMR. The staff reviewed Section 2.5.11 of the LRA, as supplemented by a letter dated February 8, 1999, and the other documentation discussed below, to determine whether there was reasonable assurance that the applicant has appropriately identified the components and supporting systems that serve FP-intended functions, and are within the scope of license renewal in accordance with 10 CFR 54.4, and are subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.4.5.2.1 Reactor Coolant Pump Motor Oil Collection System Within the Scope of License Renewal and Subject to an Aging Management Review
This evaluation determines whether the applicant has properly identified, for the RCP motor oil collection system, the components that are within the scope of license renewal. The staff will then determine if the components that are within the scope of license renewal were properly identified by the applicant as being subject to an AMR.
The applicant searched its licensing documents for commitments made to comply with 10 CFR 50.48 and stated that any structures or components that are relied upon for meeting the commitments are included within the scope of license renewal. The applicant also reviewed flow diagrams, design-basis documents and drawings to identify portions of the RCP motor oil collection system within the scope of license renewal.
The staff sampled portions of the FP safety evaluations (SEs) dated August 11, 1978, April 28, 1983, and August 21, 1989, and UFSAR Section 9.5, "Other Auxiliary Systems." The staff then compared the RCP motor oil collection components identified within the SEs to the RCP motor oil collection flow diagrams OLRFD-100A-1.4, OLRFD-100A-2.4, and OLRFD-100A-3.4 to verify that required components were identified within the evaluation boundaries of the flow diagram and were not excluded from the scope of license renewal. As part of the evaluation, the staff also reviewed the same flow diagrams for the RCP motor oil collection system to determine if there were any additional portions of the system piping or components located outside of the evaluation boundary, with intended functions that should have been identified as within the scope of license renewal. The staff determined that all components and equipment that the applicant identified for the RCP motor oil collection system are within the scope of license renewal. In addition, these components are passive and long-lived and are, therefore, subject to an AMR. These components are enclosures, flex hoses, pipes, tubing, and valve bodies.
Flow diagram OLRFD-100A-1.4 for the RCP motor oil collection system, identifies portions of piping connected to the RCP motor oil collection tank that were not included within the highlighted evaluation boundaries. As documented in a phone call summary dated April 13, 1999, the staff asked the applicant if it omitted these portions of piping from the scope of license renewal because of their maintenance functions. The applicant stated that these piping lines were only used to drain oil during maintenance and, therefore, are not required under Appendix R, Section III.O. The staff agrees and, therefore, is reasonably assured that the applicant did not exclude system piping or components with intended functions from the scope of license renewal.
On the basis of its review, the staff concludes that there is reasonable assurance that the applicant has appropriately identified the portions of the system piping and the components that are within the scope of license renewal in accordance with the requirements of 10 CFR 54.4.
After the staff determined which components were within the scope of license renewal, it determined whether the applicant properly identified the components subject to an AMR from among those identified as being within the scope of license renewal. The staff reviewed selected components that the applicant identified as being within the scope of license renewal to verify that the applicant had identified these components as subject to an AMR, and to determine if they perform intended functions without moving parts or without a change in configuration or properties, and are not subject to replacement on the basis of a qualified life or specified time period.
The staff reviewed mechanical components from flow diagrams OLRFD-100A-1.4, OLRFD-100A-2.4, and OLRFD-100A-3.4, and compared them to the list of components with intended functions that the applicant presented in Table 2.5-19, to verify that there were no omissions of passive, long-lived components that were subject to an AMR. The staff did not find any omissions of long-lived, passive components with intended functions. Table 1, below, categorizes the types of mechanical components for the RCP motor oil collection system that have passive, long-lived components that are subject to an AMR.
Table 1 Components of the RCP Motor Oil Collection System and Their Intended Functions
| Mechanical Component | Intended Function (s) |
|---|---|
| Enclosures (Carbon Steel) | Pressure Boundary |
| Flex Hose (Carbon Steel) | Pressure Boundary |
| Pipe (Carbon Steel) | Pressure Boundary |
| Tubing (Brass, Carbon Steel, Copper, Stainless Steel) | Pressure Boundary |
| Valve Bodies (Carbon Steel, Stainless Steel) | Pressure Boundary |
On the basis of its review, the staff concludes that there is reasonable assurance that the applicant has appropriately identified the components for the RCP motor oil collection system that are subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.4.6 Reactor Coolant System Vents, Drains, and Instrument Lines
In Section 2.5.12, "Reactor Coolant System Vents, Drains, and Instrument Lines," of the LRA, Duke (the applicant) described the SCs of the reactor coolant system (RCS) vents, drains, and instrument lines that are subject to an AMR for license renewal.
Component (equipment and piping) supports for the systems are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant evaluated instrument line components with the system to which they are attached.
2.2.3.4.6.1 Summary of Technical Information in the Application
As described in the LRA, the RCS vents, drains, and instrument lines, as well as the Duke Inservice Inspection Class A piping are discussed in Section 2.4 of the application. With the exception of the pressurizer relief valve piping, all piping that is not Duke Inservice Inspection Class A in the RCS is 2-inch nominal pipe diameter or smaller.
The portions of the RCS, other than the Duke Inservice Inspection Class A piping, within the scope of license renewal are Oconee System Piping Class B or C. These piping classes are seismically designed to withstand a design-basis earthquake without a loss of function. This system is constructed of stainless steel. The internal environment of the portions of the RCS applicable to license renewal is borated water. The RCS external surfaces are exposed to the reactor building and auxiliary building environments.
The following components of the RCS vents, drains, and instrument lines are within the scope of license renewal, and are subject to an AMR: mechanical expansion joint, pipe, pressure breakdown coil, tubing, and valve bodies. The intended function for these components, based on the requirements of 10 CFR 54.4(a), is listed as pressure boundary.
2.2.3.4.6.2 Staff Evaluation
The staff reviewed this section of the application to determine whether there is reasonable assurance that the RCS vents, drains, and instrument line components and supporting structures subject to an AMR have been identified in accordance with the requirements of 10 CFR 54.21(a)(1). This was accomplished as described below.
2.2.3.4.6.2.1 RCS Vents, Drains, and Instrument Lines Within the Scope of License Renewal and Subject to an AMR
As part of the evaluation, the staff determined whether the applicant had properly identified the SSCs within the scope of license renewal and subject to an AMR, pursuant to 10 CFR 54.4(a) and 10 CFR 54.21(a)(1). The staff reviewed portions of the UFSAR for the RCS vents, drains, and instrument lines, and compared the information in the UFSAR with the information in the application to identify portions that the applicant did not identify as within the scope of license renewal and subject to an AMR. The staff then reviewed SCs outside the applicant-identified portion to verify that (1) they do not have any intended functions as delineated in 10 CFR 54.4(a) and, if they did, to verify that (2) they are either active components or they are subject to replacement based on a qualified life or specified time period, as described in 10 CFR 54.21(a)(1). The staff also reviewed the UFSAR for any safety-related system functions that were not identified as intended functions in the application to verify that all SCs having intended functions were not omitted from consideration within the scope of the rule.
2.2.3.4.6.2.2 Review Findings for RCS Vents, Drains, and Instrument Lines
On the basis of the staff's review of the information contained in Section 2.5.12 of the application, and the supporting information in the ONS UFSAR, as discussed in the preceding section, the staff did not find any omissions by the applicant and, therefore, concludes that there is reasonable assurance that the applicant adequately identified those portions of the RCS vents, drains, instrument lines and associated components that fall within the scope of license renewal and are subject to an AMR, in accordance with 10 CFR 54.4(a) and 10 CFR 54.21(a)(1).
2.2.3.4.7 Keowee Hydroelectric Station
In Section 1.2.2, "License Renewal Technical Information," of Exhibit A of the LRA, the applicant described Keowee Hydroelectric Station, which is the on-site emergency power source for ONS. The station consists of two hydroelectric units, which provide two separate and independent power paths.
Component supports for the systems are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant evaluated instrument line components with the system to which they are attached.
2.2.3.4.7.1 Summary of Technical Information in the Application
In Section 2.5.13 of the LRA, the applicant identified the following nine systems of the Keowee and their components that are within the scope of license renewal:
In Table 2.5-22 of the LRA, the applicant identified flow diagrams for these nine systems, and highlighted the evaluation boundaries for these portions of the Keowee Systems that are within the scope of license renewal. The applicant used the screening process described in Section 2.5.2 of the LRA to determine which components are subject to an AMR, and listed those components and their intended functions in Table 2.5-23 of the LRA.
The carbon dioxide system provides fire protection to the Keowee generators. The components of the carbon dioxide system that were identified for license renewal are highlighted in flow diagram KLRFD-108A-1.1. The components subject to an AMR are flexible hose, nozzle, pipe tubing, and valve bodies. The intended function for all these components is maintaining the pressure boundary.
The depressing air system forces water from the turbine space to reduce turbine rolling resistance. The AMR for this system only considers the need for the components in the system to maintain pressure boundary and structural integrity. The components of the depressing air system that were identified for license renewal are highlighted in flow diagram KLRFD-111A-1.1. The components subject to an AMR are pipe and valve bodies. The intended function for all these components is maintaining the pressure boundary.
The generator high-pressure oil system provides two functions. During unit startup and shutdown, system pumps provide a film of oil between the thrust-bearing shoes to keep them apart to reduce wear. When the generator reaches a certain speed, the system pumps stop, and the system provides only pressure boundary for lubrication and cooling of the generator thrust and guide bearings. The components of the generator high-pressure oil system that were identified for license renewal are highlighted in flow diagrams KLRFD-103A-1.1 and 103A-2.1. The components subject to an AMR are filter, pipe, pump casing, tank, tubing, and valve bodies. The intended function for all these components is maintaining the pressure boundary.
The governor air system maintains a cover pressure in the governor oil pressure tank to supply hydraulic oil to operate the turbine wicket gates. The components of the governor air system that were identified for license renewal are highlighted in flow diagrams KLRFD-104A-1.1, 104A-2.1, 105A-1.1, and 105A-2.1. The components subject to an AMR are pipe, tank, and valve bodies. The intended function for all these components is maintaining the pressure boundary.
The governor oil system supplies hydraulic oil to operate the turbine wicket gates. The components of the governor oil system that were identified for license renewal are highlighted in flow diagrams KLRFD-105A-1.1, and 105A-2.1. The components subject to an AMR are pipe, pump casing, tank, tubing, and valve bodies. The intended function for all these components is maintaining the pressure boundary.
The Service Water System supplies cooling water to various plant equipment and supplies water for fire protection services at Keowee. The system is within the scope of license renewal for fire protection. The components of the Service Water System that were identified for license renewal are highlighted in flow diagrams KLRFD-109A-1.1 and OLRFD-117B-1.5. The components subject to an AMR are annubar, filter, fire hydrant, hose rack, mulsifier, pipe, pump casing, strainer, tubing, and valve bodies. The intended functions for the annubar are maintaining the pressure boundary and throttling, and for all the other components the intended function is maintaining the pressure boundary.
The turbine generator cooling water system supplies cooling water to the turbine packing box, generator thrust bearing coolers, generator air coolers, and turbine guide bearing oil coolers as well as backup cooling to other unit loads. The components of the turbine generator cooling water system that were identified for license renewal are highlighted in flow diagrams KLRFD-100A-1.1 and 100A-2.1. The components subject to an AMR are filter, orifice, pipe, tubing, and valve bodies. The intended functions for the filter are maintaining the pressure boundary and filtering, for the turbine guide bearing oil coolers are maintaining the pressure boundary and heat transfer, and for all the other components, the intended function is maintaining the pressure boundary.
The turbine guide bearing oil system provides lubrication and cooling for the turbine guide bearings. The components of the turbine guide bearing oil system that were identified for license renewal are highlighted in flow diagrams KLRFD-101A-1.1 and 101A-2.1. The components subject to an AMR are orifice, pipe, pump casing, strainer, tank, tubing, turbine guide bearing oil coolers, and valve bodies. The intended functions for the turbine guide bearing oil coolers are maintaining the pressure boundary and heat transfer, and the intended function for all the other components is maintaining the pressure boundary.
The Turbine Sump Pump System is provided with two ac-motor-driven pumps and a dc-motor-driven pump to move water from the turbine wheel pit to the Keowee tailrace. This function is safety-related because flooding in the turbine wheel pit would jeopardize the ability of a Keowee unit to produce emergency power. The components of the Turbine Sump Pump System that were identified for license renewal are highlighted in flow diagrams KLRFD-102A-1.1 and 102A-2.1. The components subject to an AMR are filter, pipe, pump casing, and valve bodies. The intended function for all these components is maintaining the pressure boundary.
2.2.3.4.7.2 Staff Evaluation
The staff reviewed these sections of the LRA to determine whether there is reasonable assurance that the components of the Keowee Hydroelectric Station within the scope of license renewal and subject to an AMR have been identified in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1). After completing the initial review, the staff issued requests for additional information by letter dated November 20, 1998, regarding the Keowee Hydroelectric Stations. The applicant responded to the RAIs in letters dated January 25 and February 17, 1999.
2.2.3.4.7.2.1 Keowee Hydroelectric Station Within the Scope of License Renewal and Subject to an Aging Management Review
As part of its evaluation, the staff reviewed the LRA and Section 8.3.1.1.1, "Keowee Hydro Station," of the UFSAR, to determine if there were any additional portions of the system and other components that the applicant should have identified in the LRA as within the scope of license renewal in accordance with 10 CFR 54.4 and subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
In Section 2.5.13 of Exhibit A of the LRA, the applicant discussed the Keowee station as if it had only nine subsystems. The staff found that these nine supporting subsystems by themselves were not able to perform the intended function of emergency power generation. Based on the information about Keowee in the LRA and UFSAR it was not apparent whether all the major systems that are used for emergency power generation are within the scope of license renewal in accordance with 10 CFR 54.4. In RAI 2.5.13-2, the staff requested that the applicant identify the missing systems/components that are required for the intended function of emergency power generation.
In Attachment 2A of a letter, dated February 17, 1999, the applicant provided a description and figures of the major systems/components relied upon for the generation of emergency power from Keowee. The components are turbine, governor, excitation/voltage regulation, generator output breakers, Keowee emergency start and control, protective relaying, and auxiliary power. Furthermore, the applicant stated that all of the SSCs relied upon for the generation of emergency power from Keowee are within the scope of license renewal in accordance with 10 CFR 54.4. Those systems and components, that are within the scope of license renewal but not discussed in the LRA, were screened out in accordance with 10 CFR 54.21. For mechanical components, the screening process described in Section 2.5.2 of Exhibit A of the LRA was performed to identify the components that are subject to an AMR. The results of the screening process are listed in Table 2.5-23 of the LRA. The screening process for structures is described in Section 2.2.1.2 of the LRA and for structure components in Section 2.7.1. The screening process for electrical components is described in Section 2.6 of the LRA and in the response to RAI 2.6-1. The staff reviewed this response and found it acceptable in establishing all systems/components of Keowee being within the scope of license renewal in accordance with 10 CFR 54.4.
Some components that are common to many systems, including Keowee systems, have been evaluated in the separate sections of the LRA that address those components for the entire plant. Therefore, the following components were not evaluated in the sections that discuss individual systems:
In a response to RAI 2.5.9-2, the applicant stated that all instrumentation lines off the highlighted lines on the OLRFD drawings, through the instrument, are within the scope of license renewal. Instrumentation lines within the scope of license renewal were not highlighted on the OLRFD drawings to improve readability of the OLRFD drawings. Instrumentation lines are listed in Table 2.5-23 of the LRA as tubing. Instruments that are within the scope of license renewal but not subject to an AMR, are excluded from Table 2.5-23. On the basis of its review of Table 2.5-23 and drawings, the staff agrees with the applicant on its determination of all the instruments subject to an AMR.
In Section 2.5.2.2, "Identification of Mechanical Components Subject to an Aging Management Review," of Exhibit A of the LRA the applicant discussed the process of identifying mechanical components subject to an AMR, which is evaluated in Section 2.1 of this SER, "Methodology for Identifying Structures and Components Subject to Aging Management Review." The description of the screening process in Section 2.5.2.2 of the LRA was not clear to the staff. In RAI 2.5.2-1, the staff asked the applicant to clarify its screening process. The applicant's response to the RAI was found to be acceptable as discussed in Section 2.1.3 of this report.
In conjunction with the review of the methodology as discussed in Section 2.1 of this report, the staff proceeded with its review of the list of components in the Keowee systems that are subject to an AMR. In Section 2.5.13 of the LRA, the applicant stated that the mechanical components and their intended functions for the systems in this section are identified in Table 2.5-23, "Components of Keowee Hydroelectric Station Systems and Their Intended Functions." Neither the LRA statement nor the title of Table 2.5-23 indicates that the list in Table 2.5-23 is the one that presents "all the components subject to an AMR." The staff determined that Table 2.5-23 specifically listed the mechanical components identified by the applicant as being within the scope of license renewal and subject to an AMR. This was confirmed in a conference call with the applicant on November 3, 1998, and is documented in a response to RAI 2.5.13-1. On the basis of its review of the components listed in Table 2.5-23 and highlighted in the drawings in accordance with the requirements stated in 10 CFR 54.21 (a)(1) and the additional information, as discussed below, the staff agrees with the applicant that all the components subject to an AMR are properly identified.
In RAI 2.5.13-2, the staff asked why the Keowee turbine was not identified in the LRA as being within the scope of license renewal nor being subject to an AMR. In the response, the applicant stated that the Keowee turbine was within the scope of license renewal because it was required for emergency power generation. However, the turbine is not like a conventional steam turbine with a steel casing, which may be subject to an AMR. The turbine in Keowee is more like a water wheel encased in the concrete structure. The rotating turbine is within the scope of license renewal in accordance with 10 CFR 54.4, but is not subject to an AMR in accordance with 10 CFR 50.21 because it performs its function with moving parts. The "turbine casing" in this case, is actually the concrete substructure of the Keowee powerhouse that is within the scope of license renewal and is subject to an AMR. The results of the AMR for this structure are presented in Section 3.7.6 of Exhibit A of the LRA. The staff concurs with the applicant on its determination of the turbine being within the scope of license renewal and the portion being subject to an AMR.
In RAI 2.5.13-3, the staff requested that the applicant justify the exclusion of the governor in the governor oil system (flow diagram KLRFD-105A-1.1) from an AMR. In a response, the applicant stated that the governor performs its function with moving parts, and thus, in accordance with 10 CFR 54.21, is not subject to an AMR. The staff concurs with the applicant on its exclusion of the governor from an AMR.
2.2.3.4.7.3 Review Findings for Keowee Hydroelectric Station
As described above, the staff has reviewed the information in the LRA and the additional information sent by the applicant in response to the staff's RAIs. On the basis of that review, the staff concludes that the applicant has appropriately identified the portions of Keowee station that are within the scope of license renewal in accordance with 10 CFR 54.4 and that are subject to an AMR in accordance with 10 CFR 54.21(a)(1).
2.2.3.4.8 Standby Shutdown Facility (SSF)
In Section 2.5.14, "Standby Shutdown Facility," of Exhibit A of the LRA, the applicant identified the systems and the components credited with performing fire protection (FP) functions that are within the scope of license renewal. It also identified which of those systems and its components within the scope are subject to an AMR. The SSF will be used when the existing plant systems or facilities of any of the three units are unavailable due to a fire. By letter dated February 8, 1999, the applicant responded to RAIs regarding the FP systems and components. On April 1, 1999, the staff participated in a telephone conference with the applicant to discuss some of the staff's questions about fire protection. A summary of the discussion that occurred is documented in a phone call summary dated April 13, 1999.
Component supports for the systems are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant evaluated instrument line components with the system to which they are attached.
2.2.3.4.8.1 Summary of Technical Information in the Application
As described in the LRA, structures and mechanical systems that are relied upon to perform or support performance of a function that demonstrates compliance with the Commission's regulations described in 10 CFR 54.4(a)(3) are within the scope of license renewal. As required under 10 CFR 54.4(a)(3), all SSCs relied upon in safety analyses or plant evaluations to demonstrate compliance with the Commission's regulations in 10 CFR 50.48 must be included within the scope of license renewal. The applicant's FP program meets the requirements of 10 CFR 50.48 by complying with Appendix A to Branch Technical Position (Auxiliary Power Conversion System Branch) 9.5-1 (BTP (APCSB) 9.5-1)), "Guidelines for Fire Protection for Nuclear Plants Docketed Prior to July 1, 1976," and Sections III.G, III.J, and III.O of Appendix R, "Fire Protection Program For Nuclear Power Facilities Operating Prior to January 1, 1979," to 10 CFR Part 50. To satisfy Appendix A to BTP (APCSB) 9.5-1, the applicant proposed a dedicated SSF to provide an alternate means to achieve and maintain hot-shutdown conditions following a fire, sabotage, turbine building flood, station blackout, or tornado missile event.
10 CFR 50.48 requires that the applicant implement and maintain an FP program. The FP program is incorporated into various plant documents to ensure that it remains updated. Furthermore, flow diagrams are updated any time plant or licensing changes warrant a revision. As described in the LRA, the applicant used flow diagrams to indicate the evaluation boundaries for mechanical systems that were within the scope of license renewal. Mechanical components are considered to be those installed in components that contain a fluid, including air or gas. In a two-step process, the applicant identified the mechanical components subject to an AMR. First, the applicant reviewed the flow diagrams and developed a menu of mechanical component types at ONS. Secondly, the applicant identified mechanical components and component types within the evaluation boundaries that are subject to an AMR, along with their intended functions. In Section 2.5.14 of Exhibit A of the LRA, the applicant described the systems and components of the SSF that are subject to an AMR and listed their intended functions.
The SSF is designed to achieve and maintain the reactor in a safe-shutdown condition within 72 hours in accordance with criteria of its design-basis events. Safe shutdown is accomplished by:
The SSF is primarily comprised of the structure and several systems. The structure was addressed in Section 2.7.8 of Exhibit A of the LRA. The SSF mechanical systems and components were addressed in Section 2.5.14 of the LRA and reviewed by the staff in this section of the SER. Separate from the application, the applicant submitted flow diagrams whose numbers are listed in Table 2.5-24, which show the evaluation boundaries for the portions of the SSF systems that are within the scope of license renewal. The mechanical components and their intended functions for the systems in this section that are subject to an AMR are identified by the applicant in Table 2.5-25. A brief description of each system within the SSF is presented in the following paragraphs.
The Air Intake and Exhaust System was discussed in Section 2.5.14.1 of Exhibit A of the LRA. It supplies combustion air for the SSF diesel engines and removes exhaust gases from the engines. The air intake portion of the system contains a filter, a silencer assembly, and a turbocharger assembly. The filter and silencer assembly removes particulates from the air supply and reduce noise. The turbocharger assembly increases the engine horsepower and produces better fuel economy through the utilization of exhaust gases to pressurize the intake air. The exhaust portion of the system contains an exhaust silencer to reduce exhaust gas noise. Flow diagram OLRFD-137D-1.3 shows the evaluation boundaries for the portion of the air intake and exhaust system that is within the scope of license renewal. The mechanical components that perform intended functions and are subject to an AMR include a mechanical expansion joint, muffler/silencer, pipes, screens, and tubing. Each component performs a pressure boundary function and also performs, for the screen and the muffler, an additional function for filtration and noise reduction.
The Diesel Generator Fuel Oil System was described in Section 2.5.14.2 of Exhibit A of the LRA. It supplies fuel oil to each diesel engine injector for combustion and fuel injector cooling. The system operates when the diesel engine is operating and, is otherwise, normally stagnant and at ambient conditions in the SSF. Flow diagram OLRFD-135A-1.2 shows the evaluation boundaries for the portion of the diesel generator fuel oil system that is within the scope of license renewal. The mechanical components that perform intended functions and that are subject to an AMR include orifices, pipes, pump casings, strainers, tanks, tubing, and valve bodies. Each component performs a pressure boundary function and also performs for the screen, an additional function as a filter.
The Starting Air System, which was described in Section 2.5.14.8 of Exhibit A of the LRA, supplies compressed air to start the diesel engines in the SSF. The portions of the starting air system that are within the scope of license renewal are shown on flow diagrams OLRFD-137D-1.1 and OLRFD-137D-1.2. The mechanical components with intended functions subject to an AMR perform a pressure boundary function and consist of pipes, tanks, valves, and tubing.
The Drinking Water System, which was described in Section 2.5.14.3 of Exhibit A of the LRA, distributes potable water throughout the SSF. The portions of the drinking water system that are within the scope of license renewal are shown on flow diagram OLRFD-126B-1.1. The mechanical components with intended functions subject to an AMR, perform a pressure boundary function and consist of pipes, valve bodies, and hose connections.
The Sanitary Lift System, which was described in Section 2.5.14.6 of Exhibit A of the LRA, includes a network of piping that collects sanitary wastewater from drains within the SSF. The portions of the sanitary lift system that are within the scope of license renewal are shown on flow diagram OLRFD-126B-1.1. Pipes, that perform a pressure boundary function are the only mechanical components subject to an AMR.
In Section 2.5.14.7 of Exhibit A of the LRA, the applicant described the Auxiliary Service Water System (ASWS). It is a high-head, high-volume system that supplies sufficient steam generator inventory to ensure adequate decay heat removal for all three units during a station blackout, in conjunction with the loss of normal and Emergency Feedwater System flow. The SSF ASWS consists of the SSF heating, ventilation, and air conditioning (HVAC) service water subsystem and the SSF diesel engine service water subsystem. The SSF ASWS also contains the HVAC water-cooled condensers. Included in the ASWS is a submersible pump, which is a low-head, high-volume pump capable of providing adequate makeup flow from Lake Keowee to the Unit 2 CCW System piping that serves as a supply reservoir for several plant systems. This pump is only used if both the CCW flow and siphon flow are lost during an event that requires operation of the SSF. The portions of the ASWS that are within the scope of license renewal are shown on flow diagram OLRFD-133A-2.5. The mechanical components with intended functions that are subject to an AMR, perform a pressure boundary function and consist of air ejectors, annubar tubes, orifices, pipes, pump casings, SSF HVAC water-cooled condensers, strainers, tubing, and valve bodies. In addition to performing the pressure boundary function, the air ejectors perform a gas-removal function, the annubar tubes perform a throttling function, and the strainers perform a filtration function.
The Reactor Coolant Makeup System, which is described in Section 2.5.14.5 of Exhibit A of the LRA, is designed to supply reactor coolant pump seal injection flow to any of the three ONS units in the event that the normal makeup system becomes inoperable while RCS temperature is greater than or equal to 250 F. The portions of the Reactor Coolant Makeup System that are within the scope of license renewal are shown on flow diagrams OLRFD-101A-1.5,
OLRFD-101A-2.5, and OLRFD-101A-3.5. The mechanical components, with intended functions that are subject to an AMR, perform a pressure boundary function and include the following component types: accumulators, filters, orifices, pipes, pulsation dampers, pump casings, tubing, and valve bodies. In addition to the pressure boundary function, the filters perform a filtering function and the orifices perform a throttling function.
Finally, the HVAC system is discussed in Section 2.5.14.4 of Exhibit A of the LRA. This system maintains the SSF environment within a predetermined temperature range to support equipment operability. A cooling coil in the HVAC system performs a heat transfer and pressure boundary function. The portions of the HVAC system that are within the scope of license renewal are shown on flow diagram OLRFD-116N-1.1. The mechanical components with intended functions that are subject to an AMR, perform a pressure boundary function and include the grills and the pressure boundary portion of the heaters.
2.2.3.4.8.2 Staff Evaluation
10 CFR 54.21(a)(1), requires that for those SSCs within the scope of this part, as delineated in 10 CFR 54.4, the integrated plant assessment (IPA) must identify and list those SCs that are subject to an AMR. The staff reviewed Section 2.5.14 of Exhibit A of the LRA, as supplemented by a letter dated February 8, 1999, and the other documentation discussed below, to determine whether there was reasonable assurance that the applicant has appropriately identified the components and supporting systems that serve any applicable intended functions, and that have been identified as being within the scope of license renewal in accordance with 10 CFR 54.4 and subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.4.8.2.1 Standby Shutdown Facility Within the Scope of License Renewal and Subject to an Aging Management Review
This evaluation determines whether the applicant has properly identified, for the SSF, the systems and components that are within the scope of license renewal. The staff then determines if the applicant properly identified the systems and components that are within the scope of license renewal as being subject to an AMR.
The applicant searched its licensing documents for commitments made to meet 10 CFR 50.48, and stated that any structures or components that are relied upon for meeting the commitments are included within the scope of license renewal. The applicant also reviewed flow diagrams, design-basis documents and drawings to identify portions of the SSF systems within the scope of license renewal.
The staff sampled portions of the FP safety evaluations (SEs) dated August 11, 1978, August 21, 1989, and April 28, 1983, and Section 9.5, "Other Auxiliary Systems," of the FSAR. The staff then compared the systems and components identified from the SEs to the applicable SSF system flow diagrams to verify that required systems and components were identified within the evaluation boundaries of the flow diagrams and were not excluded from the scope of license renewal. As part of its evaluation, the staff also reviewed flow diagrams for the SSF systems to determine if there were any additional portions of the SSF systems or components located outside of the evaluation boundaries, with intended functions, that should have been identified as within the scope of license renewal.
The staff was concerned that the applicant excluded SSF components with intended functions, from within the scope of license renewal. In particular, the SSF HVAC system contains (1) a water-cooled condenser, (2) an air-cooled condenser, and (3) air-cooling coils. The applicant stated in Section 3.5.14 of Exhibit A of the LRA that the air conditioning units that contains air cooling coils and air-cooled condensers are not within the scope of license renewal, but the units with air cooling coils and water-cooled condensers are within the scope of license renewal. In a letter dated April 6, 1999, the applicant's response to RAI 3.2.1-5 stated that the SSF HVAC system is composed of the safety-related SSF air conditioning subsystem and the non-safety-related central alarm station (CAS) HVAC subsystem. The safety-related SSF air conditioning subsystem, which contains the water-cooled condenser, is within the scope of license renewal and was originally installed to supply conditioned air to the control room, computer room, response room, and battery room in the SSF. The non-safety-related CAS HVAC subsystem contains the air-cooled condensers, and was installed to maintain acceptable temperatures for equipment not within the scope of license renewal. The staff is reasonably assured, that the air conditioning units which contain air cooling coils and air-cooled condensers are not within the scope of license renewal and, that a failure of the non-safety-related CAS HVAC will not adversely affect any safety-related component or piece of equipment.
Table 1 lists the flow diagrams reviewed by the staff for the SSF systems, which show the evaluation boundaries for the portions of the SSF that are identified as within the scope of license renewal.
Table 1 Flow Diagrams Indicating Evaluation Boundaries of SSF Systems
| SSF Systems | Flow Diagram |
|---|---|
| Air Intake and Exhaust System | OLRFD-137D-1.3 |
| Diesel Generator Fuel Oil System | OLRFD-135A-1.2 |
| Drinking Water System | OLRFD-126B-1.1 |
| Heating, Ventilation, and Air Conditioning System | OLRFD-116N-1.1 |
| Reactor Coolant Makeup System | OLRFD-101A-1.5 OLRFD-101A-2.5 OLRFD-101A-3.5 |
| Sanitary Lift System | OLRFD-126B-1.1 |
| SSF Auxiliary Service Water System | OLRFD-133A-2.5 |
| Starting Air System | OLRFD-137D-1.1 OLRFD-137D-1.2 |
On the basis of its review, the staff concludes that there is reasonable assurance that the applicant has appropriately identified the portions of the SSF systems and components that are within the scope of license renewal in accordance with the requirements of 10 CFR 54.4.
After the staff determined which systems and components of the SSF were within the scope of license renewal, the staff determined whether the applicant properly identified the components subject to an AMR from among those identified as being within the scope of license renewal. The staff reviewed selected components that the applicant identified as being within the scope of license renewal to verify that the applicant had identified these components as subject to an AMR, if they perform intended functions without moving parts or without a change in configuration or properties, and are not subject to replacement on the basis of a qualified life or specified time period.
Using the SSF flow diagrams, the staff sampled mechanical components from the flow diagrams and compared them to the list of components with intended functions presented by the applicant in Table 2.5-19, of the LRA to verify that there were no omissions of passive, long-lived components that were subject to an AMR. The staff found examples of potential omissions of long-lived, passive components with intended functions and discusses them in the following paragraphs.
During an April 1, 1999, phone conference, the applicant was asked to clarify why portions of the Diesel Fuel Oil System and starting air system were not within the highlighted evaluation boundaries. As documented in a phone call summary dated April 13, 1999, the applicant stated that the Diesel Fuel Oil System piping, which leads directly to the diesel oil injectors from the oil day tank, are within the scope of license renewal and, therefore, should have been highlighted on flow diagram OLRFD-135A-1.2. However, the applicant considers the portion of the Diesel Fuel Oil System and starting air system supplied by the vendor to be excluded from an AMR on the basis of 10 CFR 54.21(a)(1)(i). Further evaluation by the staff revealed that this methodology also excludes the diesel engine jacket water heat exchangers from an AMR because it is part of the vendor-supplied diesel generator skid-mounted equipment. Because they are passive and long-lived, the staff does not agree that these mechanical components can be excluded from an AMR.
10 CFR 54(a)(1)(i) does not provide justification for exclusion taken by the applicant. A review of the SOCs did not identify any guidance that would allow the exclusion taken by the applicant. However, guidance was provided in NEI 95-10, "Industry Guide for Implementing the Requirements of 10 CFR Part 54 -- The License Renewal Rule." In Section 2.5.1 of Exhibit A of the LRA, Duke states that "the methodology used to identify the mechanical components subject to AMR at Oconee is consistent with the guidance provided in NEI 95-10." The exclusion of the diesel engine jacket water heat exchanger, and portions of the Diesel Fuel Oil System and Starting Air System from an AMR was determined by the staff not to be consistent with NEI 95-10, Section 4.1.1, "Establishing Evaluation Boundaries," or Appendix C, Example 5. This issue was identified as Open Item 2.2.3.4.8.2.1-1.
Duke addressed this issue in a letter dated October 15, 1999. The letter stated that they reassessed their methodology to establish the diesel generator evaluation boundary at the vendor-supplied skid boundary. The original methodology consisted of the applicant drawing an enclosure around the diesel generator skid. Duke defined the active diesel generator component listed in 10 CFR 54.21(a) to include the components, within this enclosure, on the skid supplied by the vendor. As a result, the original methodology excluded passive and long-lived components that were part of the vendor-supplied diesel generator package from an AMR.
Duke concluded that drawing an enclosure around the diesel generator skid to determine the active component boundaries excludes some passive and long-lived components. As a result, Duke revised the methodology and redefined the evaluation boundaries of the diesel generator components to be at the connections of the engine, turbocharger, air motors, and generator. As a result of the revised methodology, the staff's review has expanded to include the following additional SSF subsystems and components with intended functions, that are subject to an AMR. The additional components discussed below are found in systems that support the diesel generator.
Air Intake and Exhaust System
The air intake and exhaust system provides combustion air for the SSF diesel engines and removes exhaust gases from the engines. Flow diagram OLRFD-137D-1.3 identifies the mechanical components of the air intake and exhaust system with intended functions. The original methodology identified that the entire system was subject to an AMR. Therefore, when Duke revised the component boundary from the skid connection to the engine connection, no additional mechanical components with intended functions that are subject to an AMR were identified.
Diesel Jacket Water Cooling System
The Diesel Jacket Water Cooling System removes heat from the SSF diesel engines when the engines are operating. The system also maintains the engines at standby temperatures when the engines are shutdown. The original methodology excluded the diesel engine jacket water heat exchangers from an AMR on the basis that these components were part of the vendor-supplied diesel generator package. The revised methodology includes the Diesel Jacket Water Cooling System and components with intended functions that are subject to an AMR. Table 4 in Attachment 2 of the October 15, 1999 letter, lists the mechanical components with a pressure boundary intended function. These components are flexible hoses, heat exchanger channels, heat exchanger shells, heat exchanger tubing, heat exchanger tube sheets, immersion heaters, piping, pump casing, sight glass, tanks, tubing, and valve bodies. The heat exchanger tubing also performs a heat transfer intended function.
SSF Diesel Generator Fuel Oil System
The SSF fuel oil system supplies fuel oil to each diesel engine fuel injector for combustion and provides cooling of the fuel injector. For the original methodology, flow diagram OLRFD-135A-1.2 shows the evaluation boundaries of the fuel oil system which identified the mechanical components with intended functions. When Duke revised the component boundary from the skid connection to the engine connection, additional mechanical components with intended functions that are subject to an AMR were identified. Table 5 in Attachment 2 of the October 15, 1999 letter, lists the mechanical components that perform pressure boundary intended functions. These components are flexible hoses, pipes, pump casing, sight glass, strainers, tubing, and valve bodies. The strainers also provide a filtration intended function.
SSF Diesel Generator Lube Oil System
The diesel lube oil system provides lubrication and cooling to the SSF diesel engine bearings, gears, turbocharger bearings, and cooling of the diesel engine pistons while the diesels are operating. The original methodology excluded the diesel lube oil system from an AMR on the basis that these components were part of the vendor-supplied diesel generator package. Using the revised methodology, Duke identified this system and its mechanical components with intended functions that are subject to an AMR. Table 6 in Attachment 2 of the October 15, 1999 letter, lists the mechanical components that perform pressure boundary intended functions, and include the following component types: filters, flexible hoses, heat exchanger channels, heat exchanger shells, heat exchanger tubing, heat exchanger tube sheets, orifices, pipes, pump casings, sight glass, strainers, tubing, and valve bodies. In addition, the heat exchanger tubing provides a heat transfer intended function, the orifices provide a throttle intended function, and the strainers provide a filtration intended function.
Starting Air System
The starting air system provides dry compressed air to start the SSF diesel engines. The original methodology identified the mechanical components with intended functions in flow diagrams OLRFD -137D-1.1 and OLRFD-137D-1.2. When Duke revised the component boundary from the skid connection to the engine connection, additional mechanical components were identified with intended functions that were subject to an AMR. Attachment 2, Table 7 of the October 15, 1999 letter, lists the following component types that perform pressure boundary intended functions: flexible hoses, lubricators, pipes, strainers, tubing, and valve bodies. In addition, the strainers provide a filtration intended function.
Staff Evaluation of the Revised Evaluation Boundary Methodology
This evaluation determines whether the applicant has properly identified, for the expanded review of the SSF, the additional systems and components that are within the scope of license renewal. The staff then determines if the applicant properly identified those additional systems and components that are within the scope of license renewal as being subject to an AMR.
As previously stated, Duke revised their evaluation boundary methodology to include the components located on the diesel generator skid. The applicant's LRA flow diagrams used for the staff's review and preparation of the June 16, 1999, SER, were still appropriate for the review of the additional systems and components.
The staff reviewed portions of Section 9.5, "Other Auxiliary Systems," of the FSAR. For each system noted above, the staff compared the additional components included within the scope of license renewal due to the revised evaluation boundary, to the FSAR and applicable SSF flow diagrams. As part of its evaluation, the staff also reviewed portions of flow diagrams and FSAR Figure 9-37, "SSF HVAC SWS & SSF Diesel Cooling Water System," and Figure 9-38, "SSF Diesel Air Starting System," to verify that there were not any additional portions of the SSF systems or components located outside of the evaluation boundaries, with intended functions, that should have been identified as within the scope of license renewal. The staff found no omissions of portions of systems that should have been identified within the scope of license renewal. On the basis of this review, the staff has reasonable assurance that the additional components with intended functions were identified and that none were excluded from the scope of license renewal. Therefore, Open Item 2.2.3.4.8.2.1-1 is closed.
Finally, the staff sampled SCs from the flow diagrams and compared them to the list of components with intended functions presented by Duke in Tables 4, 5, 6, and 7 of Attachment 2 of the letter dated October 15, 1999. The purpose of this review was to verify that there were no omissions of passive, long-lived components that are subject to an AMR.
The staff was concerned that Duke's application of the revised methodology incorrectly excluded the motor air coolers and oil coolers, from an AMR. 10 CFR 54.21(a) lists motors as active components which do not require an AMR. However, some large motors may contain motor air coolers or oil coolers, or both. Air coolers provide cooling to the air surrounding the stator and oil coolers provide cooling to the lubricating oil which removes heat from the motor bearing. They are both located inside the motor enclosure with connections at the motor surface for cooling water system connection. The performance of these items connected to the motor are measured by the performance of the motor. Since the motor air coolers and oil coolers integral to large motors are part of the motor enclosure, the staff concludes that these components are not subject to an AMR in accordance with 10 CFR 54.21(a).
As a result of Duke's revised methodology, the staff concludes that there is reasonable assurance that the applicant has appropriately identified those portions of the SSF systems and its components with intended functions, that are within the scope of license renewal. The staff is also reasonably assured that there were no omissions of passive, long lived components that were subject to an AMR.
Table 2 categorizes the types of mechanical components that the applicant identified for the SSF systems that have passive, long-lived components and are subject to an AMR.
Table 2 Components of the SSF Systems and Their Intended Functions
| Mechanical Component | Intended Function (s) |
|---|---|
| Air Intake and Exhaust System | |
| Muffler/Silencer (Carbon Steel) | Pressure Boundary, Noise Reduction |
| Mechanical Expansion Joint (Chrome-Molybdenum) | Pressure Boundary |
| Pipe (Carbon Steel, Chrome-Molybdenum) | Pressure Boundary |
| Screen (Carbon Steel, Chrome-Molybdenum) | Pressure Boundary, Filtration |
| Tubing (Carbon Steel) | Pressure Boundary |
| Diesel Generator Fuel Oil System | |
| Orifice (Stainless Steel) | Pressure Boundary |
| Pipe (Stainless Steel) | Pressure Boundary |
| Pump Casing (Carbon Steel) | Pressure Boundary |
| Strainer (Stainless Steel) | Pressure Boundary, Filter |
| Tank | Pressure Boundary |
| Tubing (Carbon Steel, Brass, Copper, Stainless Steel) | Pressure Boundary |
| Valve Bodies (Stainless Steel) | Pressure Boundary |
| Sight Glass (Glass) | Pressure Boundary |
| Flexible Hose (Stainless Steel) | Pressure Boundary |
| Drinking Water System | |
| Hose Connection (Stainless Steel) | Pressure Boundary |
| Pipe (Stainless Steel) | Pressure Boundary |
| Valve Bodies (Stainless Steel) | Pressure Boundary |
| Heating, Ventilation and Air Conditioning | |
| Air Flow Monitor (Aluminum, Galvanized Steel, Stainless Steel) | Pressure Boundary |
| Air Handling Unit (Aluminum, Galvanized Steel) | Pressure Boundary |
| Cooling Coil (except the SSF HVAC Condensers) (Aluminum, Copper) | Pressure Boundary |
| Ductwork (Aluminum, Galvanized Steel, Stainless Steel) | Pressure Boundary |
| Filter (Aluminum, Galvanized Steel, Stainless Steel) | Pressure Boundary |
| Grill (Aluminum, Galvanized Steel, Stainless Steel) | Pressure Boundary |
| Heater (PB only) (Aluminum, Galvanized Steel, Stainless Steel) | Pressure Boundary |
| Reactor Coolant Makeup System | |
| Accumulator (Stainless Steel) | Pressure Boundary |
| Filter (Stainless Steel) | Pressure Boundary, Filter |
| Orifice (Stainless Steel) | Pressure Boundary, Throttling |
| Pipe (Stainless Steel) | Pressure Boundary |
| Pulsation Damper (Stainless Steel) | Pressure Boundary |
| Pump Casing (Stainless Steel) | Pressure Boundary |
| Tubing (Stainless Steel) | Pressure Boundary |
| Valve Bodies (Stainless Steel) | Pressure Boundary |
| Sanitary Lift System | |
| Pipe (Stainless Steel) | Pressure Boundary |
| SSF Auxiliary Service Water System | |
| Air Ejector (Stainless Steel) | Pressure Boundary, Gas Removal |
| Annubar Tube (Stainless Steel) | Pressure Boundary, Throttling |
| Orifice (Stainless Steel) | Pressure Boundary, Throttling |
| Pipe (Carbon Steel, Stainless Steel) | Pressure Boundary |
| Pump Casing (Carbon Steel, Cast Iron) | Pressure Boundary |
| SSF HVAC water-cooled condensers (90-10 Copper/Nickel, Carbon Steel) | Pressure Boundary |
| Strainer (Carbon Steel, Stainless Steel) | Pressure Boundary, Filtration |
| Tubing (Stainless Steel) | Pressure Boundary |
| Valve Bodies (Carbon Steel, Stainless Steel) | Pressure Boundary |
| Diesel Jacket Water Cooling System | |
| Flexible Hose (Carbon Steel) | Pressure Boundary |
| Heat Exchanger Channel (Carbon Steel) | Pressure Boundary |
| Heat Exchanger Shell (Carbon Steel) | Pressure Boundary |
| Heat Exchanger Tubing (Admiralty Brass) | Pressure Boundary, Heat Transfer |
| Heat Exchanger Tube Sheets (Carbon Steel) | Pressure Boundary |
| Immersion Heater (Carbon Steel) | Pressure Boundary |
| Piping (Carbon Steel) | Pressure Boundary |
| Pump Casing (Carbon Steel, Stainless Steel)) | Pressure Boundary |
| Sight Glass (Glass) | Pressure Boundary |
| Tank (Carbon Steel) | Pressure Boundary |
| Tubing (Carbon Steel, Stainless Steel) | Pressure Boundary |
| Valve Bodies (Carbon Steel, Stainless Steel) | Pressure Boundary |
| Diesel Lube Oil System | |
| Filter (Carbon Steel) | Pressure Boundary, Filtration |
| Flexible Hose (Carbon Steel) | Pressure Boundary |
| Heat Exchanger Channel (Carbon Steel) | Pressure Boundary |
| Heat Exchanger Shell (Carbon Steel) | Pressure Boundary |
| Heat Exchanger Tubing (Admiralty Brass) | Pressure Boundary, Heat Transfer |
| Heat Exchanger Tube Sheets (Carbon Steel) | Pressure Boundary |
| Orifice (Stainless Steel) | Pressure Boundary, Throttle |
| Pipe (Carbon Steel, Stainless Steel) | Pressure Boundary |
| Pump Casing (Carbon Steel) | Pressure Boundary |
| Sight Glass (Glass) | Pressure Boundary |
| Strainers (Carbon Steel, Stainless Steel) | Pressure Boundary, Filtration |
| Tubing (Carbon Steel, Stainless Steel) | Pressure Boundary |
| Valve Bodies (Carbon Steel, Stainless Steel) | Pressure Boundary |
| Starting Air System | |
| Flexible Hose (Stainless Steel) | Pressure Boundary |
| Lubricator (Carbon Steel) | Pressure Boundary |
| Pipe (Carbon Steel) | Pressure Boundary |
| Strainers (Cast Iron, Monel) | Pressure Boundary, Filtration |
| Tubing (Carbon Steel, Stainless Steel) | Pressure Boundary |
| Valve Bodies (Carbon Steel, Stainless Steel) | Pressure Boundary |
Consumable Issue and the Fire Detection Cables and Connections
The staff's review of the LRA led to the finding of two other FP issues, unrelated to the evaluation of the SSF structure, for which the applicant excluded certain fire protection components from an AMR.
The first example is contained in Section 2.6.6.1.2 of Exhibit A of the LRA. The applicant identified insulated cables and connections used for fire detectors as part of the fire detection system, and excluded them from an AMR because they are replaced on the basis of performance or condition programs. The staff does not agree that these cables can be excluded from an AMR. This issue was being tracked by open item 2.2.3.7-1 in the June 1999, version of this report. Further discussion of this issue is presented in Section 2.2.3.7 of this SER.
Also, the staff expressed concern in RAI 2.2-5 that hoses, scott air packs, and fire extinguishers were not considered to be subject to an AMR. In its response to this question, the applicant stated that these components are considered to be consumables. Consumables are materials and supplies expended during normal operation or maintenance of SSCs. In a letter to NEI dated April 10, 1999, the staff provided a position on consumables. The staff's position, which is documented in this letter and consistent with the SOC, allows the applicant to exclude hoses, scott air packs, and fire extinguishers based on the site specific justifications provided. Specifically, the applicant's FP program complies with applicable National Fire Protection Association (NFPA) standards, which specify performance and condition monitoring programs for these specific components. The FP program determines the replacement of the fire hoses, scott air packs, and fire extinguishers and these consumables are routinely checked by inspections performed under the FP program. Fire hoses are inspected and pressure tested periodically and must be replaced if they do not pass the test or inspection. Scott air packs are periodically tested and must be replaced if they do not pass the test. Each fire extinguisher has a qualified life and must be replaced at the end of the qualified life. The staff is satisfied that the applicant is consistent with the staff's consumable position dated April 10, 1999, and that these components are not subject to an AMR.
2.2.3.4.8.3 Review Findings for Standby Shutdown Facility
On the basis of its review, the staff concludes that there is reasonable assurance that the applicant has appropriately identified the systems and components from the SSF that are subject to an AMR, in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.4.9 Essential Siphon Vacuum System and Siphon Seal Water System
By letter dated September 30, 1999, the applicant submitted an amendment to the LRA to identify the changes to the CLB in accordance with the requirements of 10 CFR 54.21(b). As part of the CLB change, the applicant added the Essential Siphon Vacuum (ESV) System and the Siphon Seal Water (SSW) System to the LRA. The ESV and SSW Systems are newly installed as a result of the plant modifications under the Oconee service water (OSW) project. The applicant indicated that the ESV and SSW Systems and their associated components are within the scope, and subject to an AMR for license renewal.
2.2.3.4.9.1 Summary of Technical Information in the Application
The function of the ESV System is to remove any trapped air and gases from the emergency condenser circulating water (ECCW) siphon headers during normal operation and following an event involving loss of offsite power (LOOP). The ECCW System is a siphon system that is a subsystem of the CCW System. Since the CCW pumps are load shed during a LOOP, the ECCW System has a safety function of providing cooling water to the low pressure service water (LPSW) pumps, following a LOOP, using a siphon or gravity as the motive force. Siphon flow to the LPSW pumps is controlled by the lake water level and the CCW System alignment. Therefore, the ESV System is designed to increase the reliability and duration of the ECCW System first siphon supply to the LPSW System. A minimum flow line to the ESV pump is provided on the ESV receiver tank to ensure that a minimum amount of air can pass through the ESV pump. Without this minimum air, the vacuum created in the ESV pump will cause cavitation that will degrade the pump over a long period of operation. During emergency operation, the ESV pump minimum flow line is isolated and the ESV pumps remove any air that possibly accumulated in the ECCW siphon headers. This will allow ESV pumps to be directed at full capacity toward the ECCW siphon headers until the event is mitigated.
The ESV System consists of three liquid-ring vacuum pumps per unit. The liquid-ring vacuum pump requires a continuous supply of seal water in order to create a vacuum. This sealing water is provided by the SSW System. Two pumps connect to the two ESV receiver tanks and the third pump in between is a spare. The two receiver tanks are connected to the CCW intake headers (one tank per header). The ESV pumps are controlled from the control room where the pump operation status and vacuum tank pressure indication are shown. The applicant stated in its submittal that the portions of the ESV System that fall within the scope of license renewal are
Oconee system piping Class F. The Class F components are designed to remain intact following a design-basis earthquake without a loss of function. The materials for the components are stainless steel with glass installed in a level glass. The mechanical components of the ESV System and their intended functions are listed in Table 1-1 of the LRA Amendment.
The function of the SSW System is to provide a seal water supply to the liquid-ring vacuum pumps of the ESV System. It also provides sealing and cooling water to the CCW pump shaft seal and motor bearing cooler. The SSW System consists of two SSW headers that are routed from the LPSW System in the turbine building to the CCW intake structure. Both the SSW headers are normally in service, but only one header is required to supply all loads. The piping of the SSW System falling within the scope of license renewal are also Oconee system piping Class F. The mechanical components of the SSW System and their intended functions are listed in Table 1-2 of the LRA Amendment.
2.2.3.4.9.2 Staff Evaluation
The staff reviewed the applicant's submittal for the LRA amendment and supporting information to determine whether there is reasonable assurance that the applicant has appropriately identified the components of the ESV and SSW Systems that are within the scope of license renewal, pursuant to10 CFR 54.4, and identified the components within the scope of license renewal, and subject to an AMR, in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.4.9.2.1 Essential Siphon Vacuum System and Siphon Seal Water System Within the Scope of License Renewal and Subject to Aging Management Review
As part of its evaluation, the staff reviewed Section 1.1, "Mechanical Integrated Plant Assessment," of the LRA Amendment and the supporting information in Section 9.2.2.2.5 of the ONS UFSAR, flow diagrams, and the previous technical specification change (#96-09) submittal for the upgraded ECCW System (dated August 28, 1999) to determine if there were any other components within the systems that the applicant should have identified in the LRA Amendment as within the scope and subject to an AMR for license renewal. The staff reviewed the mechanical components and their intended functions listed in Table 1-1 (for the ESV System) and Table 1-2 ( for the SSW System) of the LRA Amendment. The staff compared the information in the tables with the cited supporting information to verify that all the components having intended functions were not omitted from consideration within the scope of the rule.
In Table 1-1, the mechanical components of the ESV System identified as subject to an AMR include the following component types: pumps, tanks, level glass, valves, orifices, pipes, and tubing. In Table 1-2, the mechanical components of the SSW System identified as subject to an AMR include the following component types: annubar, orifices, pipes, strainers, valves, and tubing. The applicant indicated in the tables that maintaining pressure boundary is the only passive function associated with these mechanical components except the strainer. The intended functions of the strainers are pressure boundary and filtration. The staff asked the applicant why it did not list other components that perform additional functions. For example, the orifice and annubar have the throttling function in addition to maintaining a pressure boundary. The applicant responded to the staff's questions via an e-mail, which was documented in a RAI response summary, dated November 18, 1999. The applicant stated that only the component's intended functions required in support of the system intended functions within the scope of license renewal are listed. Throttling of the orifice and annubar is to create a differential pressure for flow measurement which is not required to support the system's intended function. The staff agrees with the applicant's rationale because the additional function does not support the system's intended function required by 10 CFR 54.4.
The applicant also submitted flow diagrams OFD-130A-1.1, 2.1, and 3.1 for the ESV System, and OFD-129A-1.1, -1.2, -2.2, and -3.2 for the SSW System on October 28, 1999 (without cover letter) for the staff to verify the applicant's scoping results. The applicant highlighted the boundaries of the flow diagrams to identify the components within the scope of license renewal. The staff compared the flow diagrams with the information in the LRA Amendment and identified an open item regarding the omission of the air/water separators from the scope. The air/water separators connected to the pumps are neither highlighted on the drawings nor listed in
Table 1-1 of the LRA Amendment. The staff questioned the applicant whether the air/water separators are within the scope and subject to AMR for license renewal. In its response by an e-mail (which was documented in the RAI summary of November 18, 1999), the applicant stated that the air/water separators are part of the pump casings and do not have a unique equipment number. They are evaluated with the pump casing and are not listed separately. The staff finds that the air/water separators are within the scope and subject to an AMR for license renewal as part of the ESV pumps. Therefore, no omissions by the applicant were found. On the basis of this review, the staff has reasonable assurance that the applicant has properly identified the components of the ESV and SSW Systems that are subject to an AMR.
2.2.3.4.9.3 Review Finding for Essential Siphon Vacuum System and Siphon Seal Water System
The staff has reviewed the information provided in Section 1.1 of the LRA Amendment and the additional information provided by the applicant in response to the staff's questions and did not find any omissions by the applicant. Therefore, the staff concludes that there is a reasonable assurance that the applicant has adequately identified those portions of the ESV and SSW Systems and associated components that fall within the scope of license renewal, pursuant to 10 CFR 54.4(a), and that are subject to an AMR, in accordance with the requirements of 10 CFR 54.21(a)(1).
2.2.3.4.10 Chilled Water System
In a letter dated October 15, 1999, the applicant responded to SER Open Item 2.2.3.4.3.2.1-1, concerning the Chilled Water (WC) System. The applicant committed to include the WC System within the scope of license renewal and identified all SCs that are within the scope of license renewal. The WC System is located in the auxiliary and turbine buildings. The applicant also identified SCs that are within the scope and subject to an AMR.
Component (equipment and piping) supports for the systems listed above are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the systems are presented in Section 2.6, "Electrical Components," of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6.9 and 2.2.3.7 of this report. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, rules for identifying components within the scope of license renewal in OLRP-1002 specifically state that instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow. The applicant included instrument line components with the system to which they are attached.
2.2.3.4.10.1 Chilled Water System Summary of Technical Information in the Application
The primary function of the WC System is for the Control Room Area Ventilation and Air Conditioning System (CRACS) to maintain control room and control area temperatures within the prescribed limits. The system ensures cooling of vital equipment by providing chilled water to various cooling coils in the CRPFS. ONS has two redundant trains of CRACS and WC Systems to ensure that one train of each system is available, assuming a single active failure disables the other train in one or both systems. The requirement that the WC System withstand a single active failure is addressed in UFSAR Section 3.11.4, "Loss of Ventilation." The requirement to have two trains of WC System operable is addressed in Section 3.7.16, "Control Room Area Cooling Systems (CRACS)" of the ONS Improved Technical Specifications. While the WC System is addressed in the ONS CLB, a loss of WC System event is not.
Each WC System train consists of a chiller with associated evaporator coil, condensing coil, refrigerant piping, and compressor, and associated system piping and instrumentation. The CCW System provides cooling water to the control room ventilation chillers and is discussed in Section 2.2.3.4 of this report. The license renewal portions of the WC System are designed and constructed to the requirements of ONS Piping Class G. Class G piping and components are not designed to remain operable during and following a seismic event (see Table 2.5-1 of Exhibit A of the Application). The materials of construction of this system are brass, carbon steel, cast iron, copper, galvanized steel and stainless steel. The tubes of the heat exchanger in the evaporator and condenser are constructed of copper.
The applicant described its process for identifying the mechanical components subject to an AMR in Section 2.5.2, "Detailed Process Description," of Exhibit A of the LRA. As stated above, the applicant committed to include the WC System within the scope of license renewal. As a consequence of adding the WC System, the applicant stated that an integrated plant assessment has been performed on the WC System. The WC System is capable of providing the cooling function in control rooms and control areas during design-basis-events without a loss of off-site power. In the letter dated October 15, 1999, the applicant stated in response to SER Open Item 2.2.3.4.3.2-1 that the WC System is non-safety-related and engineering analysis showed that its loss of function during a design-basis event can be withstood for 24 hours, upon which time several options of compensatory actions exist.
The applicant conforms with the requirements of 10 CFR 50.63, "Station Blackout," by having a four hour coping capability for ONS Units 1, 2, and 3. The WC System is capable of providing the cooling function to maintain the control rooms and control areas at the operating temperature limits of the equipment required to operate during a station blackout scenario. These portions of the WC System are within the scope of license renewal.
On the basis of its methodology described above, the applicant identified the portions of the WC System that are within the scope of license renewal on flow diagrams OFD-133A-1.1, OFD-136J-1.5, OFD-136J-1.6, and OFD-136J-3.3. Using the methodology described in Section 2.5.2.2, "Identification of Mechanical Components Subject to an Aging Management Review," of Exhibit A of the LRA, the applicant compiled a list of the mechanical components and component types within the license renewal boundaries that are subject to an AMR; and identified their intended functions. In Table 1 of Section 4 of the letter dated October 15, 1999, the applicant listed the WC System SCs subject to an AMR in response to SER Open Item 2.2.3.4.3.2.1-1. The applicant identified the following 19 component types as subject to an AMR: compressor, cooling coil tube, cooling coil header, condensing heat exchanger channel, condensing heat exchanger shell, condensing heat exchanger tube, condensing heat exchanger tube sheet, evaporator heat exchanger channel, evaporator heat exchanger shell, evaporator heat exchanger tube, evaporator heat exchanger tube sheet, orifice, pipe, pump casing, sight glass, strainers, tank, tubing, and valve bodies. The applicant identified maintaining pressure boundary as the intended function for each component. Additionally, the applicant identified maintaining heat transfer as the intended function for the cooling coil tube, condensing heat exchanger tube, and evaporator heat exchanger tube and components.
2.2.3.4.10.2 Staff Evaluation
The staff reviewed Section 2.5.6 of Exhibit A of the LRA to determine whether there is reasonable assurance that the applicant appropriately identified the chilled water system components and supporting structures within the scope of license renewal in accordance with 10 CFR 54.4; and subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1). After completing the initial review, the staff issued questions concerning the WC System scoping. The staff's questions and the applicant's responses are documented in a summary dated November 5, 1999.
2.2.3.4.10.2.1 Chilled Water System Structures and Components Subject to an Aging Management Review
The staff reviewed the text and diagrams submitted by the applicant in the letter dated October 15, 1999 and the ONS UFSAR to determine if there are portions of the system piping and other components that the applicant did not identify as being within the scope of license renewal that are required to perform intended functions. Essentially, all WC System components perform at least one intended function and, therefore, are within the scope of license renewal and are identified as such by the applicant in the letter dated October 15, 1999. For scoping review, the staff focused on those SCs of the WC System that were not identified as being within the scope of license renewal to verify that they do not have any intended functions that meet the scoping requirements of 10 CFR 54.4. The staff also reviewed the UFSAR to determine if there were any additional system functions that were not identified as intended functions and verified that those additional functions did not meet the scoping requirements of 10 CFR 54.4.
The staff then determined whether the applicant had properly identified the SCs subject to an AMR from among those identified as within the scope of license renewal. In Table 1 of Section 4 of the letter dated October 15, 1999, the applicant listed the WC System SCs subject to an AMR in response to SER Open Item 2.2.3.4.3.2.1-1. The staff evaluated the applicant's scoping and screening methodology and documented its findings in Section 2.1 of this SER. The staff sampled from the list of SCs identified by the applicant as subject to an AMR for the WC System to obtain reasonable assurance that all components subject to an AMR were appropriately identified. The staff also sampled SCs that were within the scope of license renewal, but not subject to an AMR, to verify that these SCs performed their intended functions with moving parts or a configuration change or were subject to replacement on the basis of a qualified life or a specified time period (i.e., active or short-lived).
In Table 1 of Section 4 to the letter dated October 15, 1999, the applicant listed the mechanical components subject to an AMR and their intended functions. The applicant also provided four detailed flow diagrams OFD-133A-1.1, 116J-1.5, 116J-1.6, and 116J-3.3 of the WC System. The applicant highlighted the flow diagrams to identify those portions of the system within the scope of license renewal. The applicant highlighted those components which, they believe, perform at least one intended function meeting the scoping requirements of 10 CFR 54.4. The staff compared the flow diagrams to the system drawings and descriptions in the UFSAR to ensure they were representative of the WC System. The staff sampled portions of the flow diagrams that were not highlighted to ensure that these components did not perform any intended functions defined in 10 CFR 54.4. Based on this review, the staff issued questions concerning the WC System scoping based on the information submitted by the applicant for the WC System in the letter dated October 15, 1999. The staff's questions and Duke's responses are documented in the letter dated November 5, 1999. Specifically, the staff questioned whether the scoping boundary ended at the end of valve "WC-40" on drawing OFD-116J-1.6. The applicant responded that the valve WC-40 is the supply side isolation valve for chilled water supply to the administrative building. This portion of the WC System (from the end of valve "WC-40" and beyond to the administrative building) is not within the scope of license renewal. In the event isolation of the chilled water system is necessary, WC-40 can be closed by manual action and does not result in the loss of cooling function to the control room. The staff agrees with the applicant's conclusion that valve WC-40 can be closed by manual action as part of the boundary isolation function and that the chilled water supply to the administrative building is not in the scope of license renewal.
The staff compared Table 3 of Attachment 2 of the letter dated October 15, 1999, to Table 2.5-13 of the LRA, and questioned which portions of the CRPFS have been added to the scope of license renewal as a result of the addition of the WC System. The applicant responded that portions of CRPFS ducting, previously considered outside the scope license renewal, now have intended functions and are included within the scope. The applicant noted that although new portions of the CRPFS have been added to the scope of license renewal due to the inclusion of the WC System and its intended functions, the new component types are already included in Table 2.5-13 of the LRA. Therefore, no new component types have been added to the list of components within the scope of license renewal. The staff sampled components within the revised boundary of the CRPFS, expanded as a result of inclusion of the WC System, and agrees that it includes the SCs that are within the scope of license renewal in accordance with 10 CFR 54.4. The staff also agrees that the SCs within the scope of license renewal for the CRPFS are already included on Table 2.5-13 of the LRA.
On the basis of a review of the letter dated October 15, 1999, supporting information in the UFSAR, and the applicant's responses to the staff's question concerning those WC System components serving the administrative building (high lighted in flow diagram OLRFD-116J-1.1 at the end of valve WC-40) that are not within the scope of license renewal, the staff has reasonable assurance that the applicant has identified all portions of the WC System on the flow diagrams provided, that are within the scope of license renewal and meets the criteria of 10 CFR 54.4.
Using the information presented on the flow diagrams for the WC System, the staff sampled several components to determine whether the applicant properly identified the passive, long-lived components on the list of components as subject to an AMR (Table 1 of Attachment 2 to the letter dated October 15, 1999) from among those identified as within the scope of license renewal. The staff verified that the passive, long-lived components highlighted on the system flow diagrams appeared on the list of components subject to an AMR for the WC System in Table 1 Attachment 2 to the letter dated October 15, 1999. No omissions were identified. On the basis of this review, the staff has reasonable assurance that the applicant has identified the SCs of the WC System subject to an AMR.
2.2.3.4.10.2.2 Review Findings for WC System
On the basis of its evaluation, the staff concludes that there is reasonable assurance that the applicant has identified and listed the portions of the WC System, and the associated SCs thereof, that are within the scope of license renewal and subject to an AMR in accordance with the requirements of 10 CFR 54.4, and 10 CFR 54.21.
2.2.3.5 Steam and Power Conversion Systems
2.2.3.5.1 Steam and Power Conversion Systems
In Section 2.5.9, of Exhibit A of the LRA the applicant described steam and power conversion systems. These systems were designed to remove heat from the RCS, and include the following: Main Steam System, Condensate System, Emergency Feedwater System, and Feedwater System.
Component supports for the systems are presented separately in Section 2.7 of Exhibit A of the LRA. Electrical components that support the operation of the system are presented in Section 2.6 of Exhibit A of the LRA. The staff evaluated component supports and electrical components in Sections 2.2.3.6 and 2.2.3.7 of this SER. Although instrument lines are not individually highlighted as being within the scope of license renewal on the flow diagrams in OLRP-1002, instrumentation line components (e.g., tubing, valves) are within the scope if the lines are normally open to process flow, as stated in the rules for the identification of components within the scope of license renewal in OLRP-1002. The applicant evaluated instrument line components with the system to which they are attached.
2.2.3.5.1.1 Summary of Technical Information in the Application
The steam and power conversion systems are described in Chapter 10 of the ONS UFSAR. In Section 2.5.9, of Exhibit A of the LRA, the applicant identified the following four portions of the steam and power conversion systems and their components that are within the scope of license renewal:
Table 2.5-14 of Exhibit A of the LRA identified flow diagrams for these four systems, highlighting the evaluation boundaries for those portions of the steam and power conversion systems that are within the scope of license renewal. The applicant used the screening process described in Section 2.5.2 of Exhibit A of the LRA to determine which components are subject to an AMR, and listed those components and their intended functions in Table 2.5-15.
The Main Steam System transports dry, superheated steam from the steam generators to the main turbine and main feedwater pump turbines. The system supplies steam to drive the emergency feedwater pump (EFWP) turbine during emergency operation and various other components during normal operation. The system is relied upon to dissipate heat from the RCS following a load rejection, a turbine trip, or a reactor trip by dumping steam to the condenser or atmosphere, or both. The system is also used to achieve normal cooldown to Low-Pressure Injection System initiations. The components of the Main Steam System that were identified by the applicant for license renewal are highlighted in the flow diagrams of OLRFD-122A-1.1 through 122A-1.5, OLRFD-122A-2.1 through 122A-2.5, OLRFD-122A-3.1 through 122A-3.5, OLRFD-122B-1.1, 122B-2.1, and 122B-3.1. Listed in Table 2.5-15 of Exhibit A of the LRA as components subject to an AMR include the following: EFWP turbine casing, filter, orifice, pipe, tubing, and valve bodies. The intended function for all the components is maintaining the pressure boundary.
The Condensate System delivers condensate from the condenser hotwells to the suction of the main feedwater pumps, purifies the condensate, removes non-condensable gases from the condensate, and heats the condensate to improve overall plant efficiency. The Condensate System supplies water to the emergency feedwater pumps during emergency operation. The Condensate System is comprised of the main condenser, condensate coolers, and generator water coolers. The components of the Condensate System that were identified by the applicant for license renewal, are highlighted in the flow diagrams of OLRFD-121A-1.1 through 121A-1.8, OLRFD-121A-2.1 through 121A-2.8, and OLRFD-121A-3.1 through 121A-3.8. Listed in Table 2.5-15 of Exhibit A of the LRA, as the components subject to an AMR include the following: demineralizer, filter, mechanical expansion joint, orifice, pipe, pump casing, strainer, tanks, tubing, valve bodies, main condenser, condensate coolers, and generator water coolers. The intended function for all of these components is maintaining the pressure boundary.
The Emergency Feedwater System is designed to supply water to the steam generator in the event of a loss of both main feedwater pumps or a low steam generator level. The system ensures that a sufficient water level is maintained in the steam generator, allowing time to restore the flow of main feedwater to cool down the RCS to the point at which decay heat can be removed by the Low-pressure Injection System. The components of the Emergency Feedwater System that were identified by the applicant for license renewal are highlighted in the flow diagrams of OLRFD-121D-1.1 through 121D-1.2, OLRFD-121D-2.1, and 121D-3.1. Listed in Table 2.5-15 of Exhibit A of the LRA, as the components subject to an AMR include the following: flow nozzle, flow sensor, orifice, pipe, pump casing, tubing, and valve bodies. The intended function(s) for the flow sensor and orifice are maintaining the pressure boundary and throttle, and for all the other components is maintaining the pressure boundary.
The Feedwater System receives water from the Condensate System, increases the water pressure and temperature, and delivers the water to the steam generators at a controlled rate of flow. The system operates during accidents to provide steam generator level indication, isolates feedwater flow to a faulted steam generator to prevent containment overpressurization, and provides the feedwater pump operating status to the Reactor Protection System and the SCRAM System. The Feedwater System also provides containment isolation during accidents that require containment integrity to be maintained. The components of the Feedwater System that were identified by the applicant for license renewal are highlighted in the flow diagrams of OLRFD-121B-1.3, 121B-1.5, 121B-2.3, 121B-2.5, 121B-3.3, and 121B-3.5. Listed in Table 2.5-15 of Exhibit A of the LRA, as the components subject to an AMR include the following: the emergency feedwater header, low nozzle, main feedwater header, pipe, pump casing, and valve bodies. The intended function for all of these components is maintaining the pressure boundary.
2.2.3.5.1.2 Staff Evaluation
The staff reviewed Section 2.5.9 of Exhibit A of the LRA to determine whether there is reasonable assurance that the components of the steam and power conversion systems within the scope of license renewal and subject to an AMR, have been identified in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1). After completing the initial review, the staff issued RAIs by letter dated November 21, 1998, regarding the steam and power conversion systems. The applicant responded to the RAIs in a letter dated January 25, 1999.
2.2.3.5.1.2.1 Steam and Power Conversion Systems Within the Scope of License Renewal and Subject to an Aging Management Review
As part of its evaluation, the staff reviewed Section 2.5.9 of the LRA and Chapter 10, "Steam and Power Conversion Systems," of the UFSAR, to determine if there were any additional portions of the system and other components that the applicant should have identified in the LRA as within the scope of license renewal in accordance with 10 CFR 54.4, and subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
In Section 2.5.9.1 of Exhibit A of the LRA, the applicant stated that the portions of the Main Steam System piping within the scope of license renewal are designed and constructed to the requirements of Oconee System Piping Class F and G. In reviewing the Main Steam System drawings identified in Table 2.5-14 of Exhibit A of the LRA, the staff found that Class F piping was within the scope of license renewal, but most of Class G piping was outside the scope of license renewal. In RAI 2.5.9-1, the staff requested a clarification from the applicant to explain how the applicant made its determination for Class G piping. In a letter dated January 25, 1999, the applicant responded that the portions of Class G piping that are within the scope of license renewal were determined by their intended functions, as defined in 10 CFR 54.4, and were highlighted in the system drawings. The remaining Class G piping was determined not to support any intended functions as specified in 10 CFR 54.4. On the basis of its review, the staff has determined that all of the piping that was within the scope of license renewal (highlighted in the drawings) was considered to be subject to an AMR in accordance with the requirements of 10 CFR 54.21(a)(1).
In RAIs 2.5.9-3 and 2.5.9-4, the staff requested that the applicant submit the basis for excluding the main feedwater pump turbine, upper surge tank dome (located between upper surge tanks 1A and 1B), and condensate storage tank from the scope of license renewal. The applicant responded that because these components do not support any intended functions as defined in 10 CFR 54.4, they are excluded from the scope of license renewal.
In RAIs 2.5.9-5, 2.5.9-6, and 2.5.9-7, the staff requested the basis for excluding certain portions of the piping identified in flow diagrams OLRFD-121A-1.4 "Condensate System," 121A-1.6 "Condensate System," and 121B-1.3 "Feedwater System" from the scope of license renewal. The applicant responded that the piping and components highlighted in the first two drawings are important, as related to 10 CFR 54.4, in maintaining the hotwell water supply inventory for Emergency Feedwater System supply. Failure of the piping and components that were not highlighted would not affect hotwell supply inventory since the piping and components in question do not support any system-intended functions as defined in 10 CFR 54.4. Further, in the third drawing, the applicant stated that these portions of the piping in question (upstream of valves 1FDW-41 and 32) do not support any system-intended functions as defined in 10 CFR 54.4. Therefore, the applicant determined that those portions of piping and components are excluded from the scope of license renewal.
On the basis of all the above applicant's responses, the staff agrees that the diagrams identify the system level scoping boundaries, and that those boundaries correctly separate system components within the scope of license renewal from those that are outside.
Some components that are common to many systems, including steam and power conversion systems, have been evaluated in the separate sections of the LRA that address those components for the entire plant. Therefore, the following components were not evaluated in the sections that discuss individual systems:
In LRA Section 2.5.2.2, "Identification of Mechanical Components Subject to an Aging Management Review," the applicant discussed the process of identifying mechanical components subject to an AMR, which is evaluated in Section 2.1 of this SER, "Methodology for Identifying Structures and Components Subject to Aging Management Review." The description of the screening process in Section 2.5.2.2 of Exhibit A of the LRA was not clear to the staff. In RAI 2.5.2-1, the staff asked the applicant to clarify its screening process. The applicant's response to the RAI was found to be acceptable as discussed in Section 2.1.3 of this report.
The staff reviewed the list of components in the steam and power conversion systems that are subject to an AMR. The staff finds that the list was not clearly identified in the LRA. In Section 2.5.9 of Exhibit A of the LRA, the applicant stated that "the mechanical components and their intended functions for the systems in this section are identified in Table 2.5-15." The title of Table 2.5-15 is "Components of Steam and Power Conversion Systems and Their Intended Functions." Neither the LRA statement nor the title of Table 2.5-15 indicates that the list in Table 2.5-15 is the one that presents all the components subject to an AMR. It is unclear whether the listed components in Table 2.5-15 are "all the important components of the system," or "all the components within the scope of license renewal," or "the specific components subject to an AMR." After its review, the staff determined that Table 2.5-15 listed specifically all the mechanical components identified by the applicant as being within the scope of license renewal and subject to an AMR. This was confirmed in a conference call with the applicant on November 3, 1998, and is documented in a response to RAI 2.5.13-1. By comparing the components listed in Table 2.5-15 and the components highlighted in the drawings for each subsystem and using the requirements stated in 10 CFR 54.21 (a)(1), the staff agrees with the applicant that all the components subject to an AMR are properly identified.
In RAI 2.5.9-2, the staff asked the applicant to explain why certain instruments, which appeared to be within the scope of license renewal, were not highlighted in the diagrams. The applicant responded that all instrumentation lines off highlighted lines on the OLRFD diagrams, through the instrument, are within the scope of license renewal. Instrumentation lines within the scope of license renewal were not highlighted on the OLRFD diagrams to improve readability of the OLRFD diagrams. Instrumentation lines are listed in Tables 2.5-15 of Exhibit A of the LRA as "tubing." Instruments that are within the scope of license renewal but not subject to an AMR, are excluded from Table 2.5-15. On the basis of the applicant's response, the staff finds that the tubing is listed in Table 2.5-15 for the Main Steam System, Condensate System, and Emergency Feedwater System. In flow diagrams OLRFD-121B-1.5 and 121B-1.3 for the Feedwater System, there are many instrumentation lines off highlighted lines, such as FDWFE-0156, FDWPG-0244, FDWLT-0008, and FDWLT-0080. However, the staff found that Table 2.5-15, as related to Feedwater System, did not list any tubing, which means that the applicant has determined that all the instruments for the Feedwater System are excluded from an AMR. The staff could not find any basis for this exclusion. In RAI 2.5-1, the staff asked the applicant why the instrumentation tubing for several systems (including the Feedwater System) was excluded from an AMR. This issue is addressed in Section 2.2.3 of this report as related to the identification and listing of components associated with instrumentation lines within the scope of license renewal (RAI 2.5-1).
2.2.3.5.1.3 Review Findings for Steam and Power Conversion Systems
As described above, the staff has reviewed the information in the LRA and the additional information sent by the applicant in response to the staff's RAIs. On the basis of that review, the staff concludes that the applicant has appropriately identified the portions of steam and power conversion systems that are within the scope of license renewal in accordance with 10 CFR 54.4, and that are subject to an AMR in accordance with 10 CFR 54.21(a)(1).
2.2.3.6 Structures and Structural Components
In Section 2.7, "Structures & Structural Components," of Exhibit A of the LRA - Technical Information (OLRP-1001), the applicant identified the structures and structural components that are within the scope of license renewal in accordance with the requirements of 10 CFR 54.4 and subject to an AMR. The applicant identified the following structures as being within the scope of license renewal and subject to AMR:
The staff reviewed Section 2.7 of Exhibit A of the LRA to determine whether the applicant has properly identified the structures and their associated components with its methodology, which is discussed in Section 2.1, "Methodology for Identifying Structures and Components Subject to Aging Management Review," of this report such that there is reasonable assurance that the applicant has identified and listed the SCs subject to an AMR that have met the requirements stated in 10 CFR 54.21(a)(1). The staff also used the ONS's UFSAR, the site plan, and applicable design drawings to verify the information provided in Section 2.7 of Exhibit A of the LRA. The staff's review of each of the above structures is presented in the following sections.
2.2.3.6.1 Auxiliary Buildings
In Section 2.7.3, "Auxiliary Buildings," of Exhibit A of the LRA, the applicant identified the SSCs of the auxiliary buildings that are within the scope of license renewal as required under 10 CFR 54.4. The applicant also identified and listed the auxiliary building SCs that are subject to an AMR as required under 10 CFR 54.21 (a)(1).
2.2.3.6.1.1 Summary of Technical Information in the Application
The applicant determined that the auxiliary buildings were within the scope of license renewal and identified the following structures as being part of the auxiliary buildings: the auxiliary buildings, spent fuel pool, hot machine shop, and the tunnel between the auxiliary buildings and hot machine shop. As described in Exhibit A of the LRA, ONS has two auxiliary buildings; one building is shared by Units 1 and 2 and the other building is for Unit 3. The auxiliary buildings, which are free-standing reinforced concrete structures sitting on reinforced concrete mat foundations, serve as enclosures to protect the auxiliary systems, control rooms, and other systems required for the safe operation of the plant. The portions of the auxiliary buildings that house engineered safeguard systems, control rooms, fuel storage facilities, and radioactive materials are Class 1 structures. Class 1 structures are those structures which prevent uncontrolled release of radioactivity and are designed to withstand all loadings without loss of function. The applicant has determined that Class 1 structures meet the intent of 10 CFR 54.4(a)(1). Other portions of the auxiliary buildings are Class 2 structures. Class 2 structures are those structures whose limited damage would not result in a release of radioactivity and would permit a controlled plant shutdown but could interrupt power generation. The applicant has determined that Class 2 structures meet the intent of 10 CFR 54.4(a)(2).
The hot machine shop and its extension are located between the Unit 1 and 2 reactor buildings and shares the reinforced concrete walls on the east and north sides with the Unit 1 and 2 spent fuel pool and fuel loading area. The hot machine shop is a reinforced concrete structure and its extension is a steel frame structure. A reinforced concrete tunnel, which runs under the Units 1 and 2 spent fuel pool, connects the auxiliary building and the hot machine shop. The tunnel provides a sheltered and shielded passage for equipment between the auxiliary building areas and the hot machine shop work area. The hot machine shop is a Class 2 structure and its extension is a QA 4 structure whose continued functions are not required during and after a seismic event.
In Table 2.7-1 of Exhibit A of the LRA, the applicant identified the structural components that are within the scope of license renewal, as well as the intended functions of each structural component. The methodology used to identify generic component types is evaluated in Section 2.1 of this report. The applicant identified a total of 35 component types within the auxiliary building as being within the scope of license renewal because they perform one or more of the following intended functions, as noted in the table:
The applicant determined the intended functions for these structures and structural components based on ONS's UFSAR, technical specifications, and regulated events documentation. These structural components are subject to an AMR because the intended function(s) are performed without moving parts or without a change in configuration or properties and because they are not replaced based on qualified life or specified time period .
To facilitate the structures and structural components AMRs, the applicant grouped the 35 component types into four general categories according to their operating environment and material as follows:
2.2.3.6.1.2 Staff Evaluation
The staff reviewed Section 2.7.3 of Exhibit A of the LRA and the ONS UFSAR to determine if the applicant has adequately implemented its methodologies such that there is reasonable assurance that the auxiliary buildings structures and structural components (as discussed in Subsection 2.2.3.6.1.1 of this report) have been properly identified as being within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.1.2.1 Auxiliary Buildings Within the Scope of License Renewal and Subject to an Aging Management Review
The staff reviewed the information presented in Exhibit A, Section 2.7, of the LRA, portions of the UFSAR, Chapter 3, "Design of Structures, Components, Equipment, and Systems," and applicable drawings in the UFSAR, Chapter 1, to determine if there were any structures, or associated structural components within the auxiliary buildings that the applicant did not properly identify as being within the scope of license renewal or did not properly identify as being subject to an AMR. On the basis of its review, the staff identified the finding described below.
In Section 2.7.1, "Description of Process to Identify Structural Components Subject to AMR," of Exhibit A of the LRA, the applicant included the spent fuel pool in the boundary of the auxiliary buildings. However, the spent fuel pool was not described in Section 2.7.3, "Auxiliary Buildings," of Exhibit A of the LRA, while some of its components are listed in Table 2.7-1 of Exhibit A of the LRA. It was not clear whether all the components that constitute the spent fuel pool are included in the table.
In its May 10, 1999, response to the staff RAI 2.7-11 regarding the major structural components that comprise the spent fuel pool, the applicant stated that specific aspects of structures within the auxiliary buildings, such as the spent fuel pools, were not described in the application. The spent fuel pools are described in the UFSAR, Section 9.1.2. The staff compared Table 2.7-1 of Exhibit A of the LRA with the UFSAR, Section 9.1.2.1.1 and found that the components within the spent fuel pool were included in the table.
In Section 2.7.2, "Structural Components," of Exhibit A of the LRA, the applicant did not identify water stops, expansion joints, and structural sealants or caulking as structural components that require an AMR. Section 2.7.3 of Exhibit A of the LRA states that all the below grade construction joints in the exterior walls are protected by cast-in-place water stops. In RAI 2.7-3, the staff asked the applicant why the water stops were not included within the scope of license renewal. In its response to the staff's question, the applicant stated that the water stops do not support any component intended function, and therefore, need not be subject to an AMR. The staff did not agree with the applicant's response because ground water in-leakage into the auxiliary building could occur as a result of degradation to the water stops. This leakage may cause flooding of equipment within the scope of license renewal (UFSAR Section 3.4.1, "Flood Protection," discusses the effect of flooding). Water stops perform its function without any moving parts, or change in configuration or properties. The auxiliary building water stops are built into the concrete at the expansion joints that are not replaceable after construction. Therefore, water stops should be subject to an AMR. Water stops are also subject to age related degradation, and should require aging management during the period of extended operation.
As discussed in Section 3.8.3.1 of this report, expansion joints, structural sealants or caulking are nonmetallic components that play important roles in maintaining the integrity of the components to which they are connected. As stated in the staff's position regarding consumables (see License Renewal Issue No. 98-0012, "Consumables," dated April 20, 1999), structural sealants that are within the scope of license renewal typically meet the requirements under 10 CFR 54.21(a)(1)(i) and (a)(1)(ii). Structural sealants are often required for the structural integrity of containment and other safety-related structures. Expansion joints and structural sealants perform its intended function(s) without any moving parts, or change in configuration or properties and are not typically subject to periodic replacement based on qualified life or specified time period. They are relied upon for decades of service and material aging degradation may occur. Therefore, water stops, expansion joints, and structural sealants should be subject to an AMR. This was identified as Open Item 2.2.3.6.1.2.1-1.
In its response of October 15, 1999 to Open Item 2.2.3.6.1.2.1-1, the applicant stated that the caulking, sealants, and water-stops were not considered as structures or components. However, these materials are important in maintaining the integrity of the components to which they are connected. The intended functions of the structure or component supported by these materials are to (1) maintain pressure boundary for the control room, (2) provide fire barrier penetration seal, and (3) provide a flood barrier. Aging of the control room boundary walls, ceiling, and floor is managed by the Inspection Program of Civil Engineering Structures and Components (the Inspection Program) which is addressed in Section 4.19 of Exhibit A of the LRA. Reinforced concrete walls located below grade and flood curbs in the auxiliary building are sealed with caulk, sealant, and water-stops at the seal joints of the walls and flood curbs. Degradation of the caulking, sealants, and water-stops in the auxiliary buildings is also managed by the Inspection Program. Inspection findings are evaluated to determine the appropriate corrective action that may include monitoring, repair, or replacement of caulk or sealant. The fire retardant sealant in the fire barriers are discussed in the fire protection program in Section 4.16 of Exhibit A of the LRA, and are evaluated in Section 3.2.4 of this report. The applicant stated that continued implementation of the inspection program provides reasonable assurance that caulking, sealants, and water-stops will be maintained to support the intended functions of the control room and auxiliary buildings for the period of extended operation.
The staff reviewed the applicant's response and found that caulking, sealants, and water-stops are included as parts of structural components that are within the scope of license renewal, and subject to an AMR under the inspection program or fire protection program. As a result of this review, the staff found the applicant's inclusion of caulking, sealants, and water stops as subcomponents acceptable. Therefore, Open Item 2.2.3.6.1.2.1-1 is closed.
2.2.3.6.1.2.2 Review Findings for Auxiliary Building
The staff has reviewed the information presented in Section 2.7.3 of Exhibit A of the LRA, the ONS UFSAR, and additional information submitted by the applicant in response to the staff's RAIs. On the basis of this review, the staff finds no omissions by the applicant in scoping the SCs for license renewal. The staff's review also found that all the structures and structural components identified as being within the scope of license renewal were subject to an AMR. Therefore, the staff concludes that there is reasonable assurance that the applicant has properly identified those structures and structural components associated with the auxiliary building group that are within the scope and subject to an AMR for license renewal, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.2 Earthen Embankments
In Section 2.7.4, "Earthen Embankments," of Exhibit A of the LRA, the applicant identified the SSCs of the earth embankments that are within the scope of license renewal as required under 10 CFR 54.4. The applicant also identified and listed the earth embankment SCs that are subject to an AMR as required under 10 CFR 54.21 (a)(1).
2.2.3.6.2.1 Summary of Technical Information in the Application
As described in Section 2.7.4 of Exhibit A of the LRA, the earthen embankments consist of the intake canal dike, Keowee River dam, Little River dam and dikes A, B, C, and D that are partially or totally submerged in Lake Keowee. The intake canal dike is a homogenous embankment construction with rolled earth-fill. The dike has zoned filter drainage blankets under the downstream slope to collect and control seepage. The up-stream face is rip-rapped with dumped rip-rap and quarry run stone to accommodate all reservoir water levels. The intake canal dike is a Class 2 structure that is designed to withstand seismic loads and control erosion.
The Keowee River dam is a homogenous embankment construction with rolled earth-fill. The dam embankment has seepage monitoring weirs and pipes, observation wells, and piezometers that monitor the dam performance. Slope protection from wind-generated waves was provided on the upstream slope of the dam and stone rip-rap was provided to accommodate all reservoir levels, including maximum draw-down and maximum flood. Ground cover is provided to control erosion. The Keowee River dam is a Class 2 structure and its design was approved by the Federal Energy Regulatory Commission (FERC) in accordance with the license issued by that agency.
The Little River dam and dikes A, B, C, and D, which impound the Little River watershed of the Keowee reservoir, are of a homogeneous embankment construction with rolled earth-fill. The dam and dikes are Class 2 structures and their designs were approved by the FERC in accordance with the license issued by that agency. The design and construction of the dam and dikes are similar to that of Keowee River Dam as described above.
2.2.3.6.2.2 Staff Evaluation
The staff reviewed Section 2.7.4 of Exhibit A of the LRA and the ONS UFSAR to determine if the applicant has adequately implemented its methodologies such that there is reasonable assurance that the structures and structural components comprising the earthen embankments have been properly identified as being within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.2.2.1 Earthen Embankment Within the Scope of License Renewal and Subject to an Aging Management Review
The basic earthen embankment is a mass earth work of soil fill designed to retain water. As shown in Table 2.7-2 of Exhibit A of the LRA, the intake canal dike, Keowee River dam, and Little River dam and dikes A, B, C and D are listed as the structures of the earthen embankments. These structures are within the scope of license renewal because they perform both of the following intended functions, as noted in the table:
The staff reviewed the information presented in Section 2.7.4 of Exhibit A of the LRA and reviewed the discussion of the structures in UFSAR Sections 2.5.6 and 3.8.5 and the ONS Site Plan (flow diagram No. OLR-1), to determine if the listed structures are part of the earthen embankments or whether other similar structures having the earthen embankments' intended functions are not included in the scope of license renewal. As a result of this review, the staff found no omissions of structures by the applicant. However, the applicant listed the earthen embankment structures in Table 2.7-2 but did not list their associated components, such as weirs, pipes, observation wells, and piezometers. Upon further review, the staff finds the applicant's decision not to include components such as weirs, pipes, observation wells, and piezometers in Table 2.7-2 of Exhibit A of the LRA acceptable because these components monitor the dams' and dikes' performance and do not support the intended functions of the earthen embankments. The structures within the earthen embankments are subject to an AMR because its intended functions are performed without moving parts, or without a change in configuration or properties, and are not subject to replacement based on qualified life or specified time period. Therefore, the staff has reasonable assurance that the applicant has properly identified the earthen embankment structures that are within the scope of license renewal and subject to an AMR.
2.2.3.6.2.2.2 Review Findings for Earthen Embankments
The staff has reviewed the information in Section 2.7.4 of Exhibit A of the LRA, the ONS UFSAR, and the applicant's response to the staff's RAIs. On the basis of this review, the staff has reasonable assurance that the applicant (1) has properly identified those SCs within the scope of license renewal, as required by 10 CFR 54.4, and (2) has properly identified those SCs within the scope of license renewal which require an AMR, as required by 10 CFR 54.21(a)(1).
2.2.3.6.3 Intake Structure
In Section 2.7.5, "Intake Structure," of Exhibit A of the LRA, the applicant identified the SSCs of the intake structure that are within the scope of license renewal as required under 10 CFR 54.4. The applicant also identified and listed the intake structure SCs that are subject to an AMR as required under 10 CFR 54.21 (a)(1).
2.2.3.6.3.1 Summary of Technical Information in the Application
The intake structure, located at the north end of the intake canal, houses the CCW pumps and supports the pump motors and portions of the condenser cooling water piping. The intake structure is constructed primarily of reinforced concrete without a steel superstructure. The steel trash racks and screens at the entrance of the intake structure protect the condensers from foreign material present in the lake water. The reinforced concrete utility trench attached to the back of the intake structure protects the electrical cables to the intake structure. The intake structure and the utility trench are Class 2 structures that are designed to withstand a safe-shutdown earthquake.
In Table 2.7-3 of Exhibit A to the LRA, the applicant identified 17 structural components, such as foundation, slab, wall, cable tray, equipment supports, trash rack and screens. These components are within the scope of license renewal because they contribute to at least one of the following intake structure intended functions, as noted in the table:
During the process to determine which components within the scope of license renewal are subject to an AMR, the applicant combined the 17 structural components into three general categories based on their design and materials: (1) concrete, (2) steel in air environment, and (3) steel in fluid environment. The steel components within the intake structure are either exposed to the external atmospheric environment or to lake water. The carbon steel trash racks, screens, and equipment component supports are the structural steel components that are exposed to lake water.
2.2.3.6.3.2 Staff Evaluation
The staff reviewed Section 2.7.5 of Exhibit A of the LRA and the ONS UFSAR to determine if the applicant has adequately implemented its methodologies such that there is reasonable assurance that the structures and structural components comprising the intake structure have been properly identified as being within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.3.2.1 Intake Structure within the Scope of License Renewal and Subject to an Aging Management Review
The staff reviewed the information provided in Section 2.7.5 and Table 2.7-3 of Exhibit A of the LRA and found that certain items for the intake structure were not clearly addressed. Specifically, components such as steel beams, columns, and trusses, indicated to the staff that the intake had a steel superstructure, when in reality it does not. The staff questioned the applicant about this approach in a May 27, 1999, conference call. The applicant's response, which is documented in a phone call summary dated June 2, 1999, was that the intake structure has no steel superstructure. The applicant stated that for the purposes of Table 2.7-3, miscellaneous steel components were included under the commodity group "steel beams, columns, plates, and trusses." In addition, the applicant stated that the components within the intake structure that fall within this commodity group are miscellaneous steel plates and other steel sections for guides for the trash racks and screens. Based on how the applicant categorized the items in Table 2.7-3, the staff agrees that this issue is resolved.
The ONS intake underwater weir is not described in Section 2.7.5 of Exhibit A of the LRA and was found not to be within the scope of license renewal. This submerged weir at the CCW pump suction has the intended function of retaining an emergency water supply in the event of a failure of the dam or dike that results in loss of the normal water supply. The staff discussed this issue with the applicant during the scoping inspection that occurred from April 26 through April 30, 199. The staff asked why the underwater weir was excluded from the scope of license renewal. The applicant provided the staff with documentation that provides the basis for not including the weir within the scope of license renewal. Specifically, the applicant referred the staff to Section 3.3.4 of the "Safety Evaluation by the Directorate of Licensing, USAEC, In the Matter of Oconee Nuclear Power Station, Units 2 and 3," dated July 6, 1973. The applicant also referred the staff to an inspection report dated May 31, 1995, and UFSAR Section 9.2.2.2.1. The applicant concluded that the underwater weir is not within the scope of license renewal based on the analysis performed in 1995 for a postulated loss of Lake Keowee event. The analysis indicated that the licensing basis does not rely on the underwater weir nor recirculation of the intake canal water for decay heat removal after a loss of Lake Keowee event. Based on the above documentation, the staff agrees with the applicant's determination that the underwater weir is not within the scope of license renewal.
As a result of the above review, the staff found no omissions in the SSCs of the intake structure that were included within the scope of license renewal as defined in 10 CFR 54.4(a). The staff also found no omissions in the structures and components of the intake structure included in the applicant's AMR that perform its intended function(s) without moving parts or without a change in configuration or properties, or that are not replaced based on a qualified life or specified time period, as required under 10 CFR 54.21(a)(1).
2.2.3.6.3.2.2 Review Findings for Intake Structure
The staff has reviewed the information presented in Section 2.7.5 of Exhibit A of the LRA, the ONS UFSAR, and the applicant's response to the staff's RAIs. On the basis of this review, the staff has reasonable assurance that the applicant (1) has properly identified those SSCs within the scope of license renewal, as required by 10 CFR 54.4, and (2) has properly identified those SCs within the scope of license renewal which require an AMR, as required by 10 CFR 54.21(a)(1).
2.2.3.6.4 Keowee Structures
In Section 2.7.6, "Keowee Structures," of Exhibit A of the LRA, the applicant identified the SSCs of the Keowee structures that are within the scope of license renewal as required under 10 CFR 54.4. The applicant also identified and listed the Keowee structure SCs that are subject to an AMR as required under 10 CFR 54.21 (a)(1).
2.2.3.6.4.1 Summary of Technical Information in the Application
As described in Section 2.7.6 of Exhibit A to the LRA, the Keowee structures consist of a breaker vault, intake structure, power and penstock tunnels, powerhouse, service bay structure, and spillway. These Keowee structures are Class 2 structures. The Keowee breaker vault houses generator output breakers and protects the electrical equipment used to route power for plant emergency power needs. The vault structure is located on the operating floor of the powerhouse and its structural components, such as walls, roof, and access openings, are designed to withstand tornado and missile forces.
The Keowee intake structure controls flow from Lake Keowee to the Keowee hydroelectric station turbines via the power and penstock tunnels. The Keowee intake structure is a reinforced concrete structure with eight sides. Each side has a pier connected to a reinforced concrete compression ring girder at the base to support a concrete silo type structure on top. The concrete silo structure supports a structural steel frame, which in turn provides support for the gate hoisting machinery. The water intakes between the eight piers can be closed individually by closing a steel buck-head gate between two piers. Alternatively, all eight intake openings can be closed by a large cylindrical gate inside the structure. The cylindrical gate is normally lowered inside the structure to a closed position and can be rigidly fastened to the steel superstructure with wire cables to an open position when the Keowee generating units are in operation for emergency power.
The Keowee power and penstock tunnels convey water from the intake structure in Lake Keowee to the Keowee hydroelectric station turbines in the Keowee powerhouse. The power tunnel connects the intake structure and the two penstocks that are branched from the power tunnel to each unit. The power tunnel and one-half of the penstock downstream of the power house are reinforced concrete structures. The downstream part of the penstock is steel lined with a concrete envelope around the steel lining. The power and penstock tunnels are built on excavated rock.
The Keowee powerhouse provides support and protection for the equipment and components used to generate emergency electrical power for ONS. The substructure of the powerhouse is a monolithic mass concrete construction on rock up to the operating floor level which supports a steel frame superstructure. The concrete substructure supports two vertical Francis-type turbines and contains a draft tube gallery, a scroll case access gallery, and a mechanical equipment gallery. The steel frame superstructure, which is covered with insulated steel panels, provides protection for the generator, a 270-ton bridge crane, and the associated electrical and mechanical equipment. A bay adjacent to the power house provides protection for the electrical switchgear and bus.
The Keowee service bay structure, located adjacent to the powerhouse structure, has two floor levels; one floor supports the station batteries and the other supports the Keowee control room, cable room, and equipment room. The service bay structure is a reinforced concrete structure built on rock.
The Keowee spillway controls the discharge of storm inflow from rainfall on the Lake Keowee drainage basin and prevents overtopping of the Keowee River dam, the Little River dam and dikes, and the ONS intake canal dike during periods of high rainfall on the drainage basin. The spillway is a mass concrete ogee-shaped structure with four taintor gates. Below the ogee section is a tapered concrete chute section with mass concrete side walls and a concrete flip bucket. The spillway is built on rock and the mass concrete wing-walls form an approach channel to the spillway. The taintor gates are constructed of a steel plate over a system of structural shapes that are supported on concrete piers between the gates. The piers also provide support for a bridge across the top of the structure that is used for inspection and maintenance of the structure and hoisting equipment.
Within these Keowee structures, the applicant identified 29 structural components and grouped them into three general categories; (1) concrete, (2) steel in air environment, and (3) steel in fluid environment. The 29 structural components, which are listed in Table 2.7-4 of Exhibit A to the LRA, are within the scope of license renewal because they perform one or more of the following intended functions, as noted in the table:
The 29 structural components identified as being within the scope of license renewal were determined to be passive and not periodically replaced, and therefore, subject to an AMR.
2.2.3.6.4.2 Staff Evaluation
The staff reviewed Section 2.7.6 of Exhibit A of the LRA and the ONS UFSAR to determine if the applicant has adequately implemented its methodologies such that there is reasonable assurance that the structures and structural components comprising the Keowee structures have been properly identified as being within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.4.2.1 Keowee Structures Within the scope of License Renewal and Subject to an Aging Management Review
The staff reviewed the information in Section 2.7.6 of Exhibit A of the LRA to determine if the applicant properly identified all the structures and structural components of the Keowee facility as being within the scope of license renewal that meet the scoping criteria under 10 CFR 54.4(a). In Exhibit A of the LRA, the applicant has identified that the breaker vault, intake structure, power and penstock tunnels, powerhouse, service bay structure, and spillway at the Keowee site were within the scope of license renewal. The staff reviewed the information presented in Section 2.7.6 of Exhibit A of the LRA, the site plan (drawing OLR-1), and the UFSAR, Section 3.8.5, to determine if all the structures and structural components of the Keowee facility have been included within the scope of the rule and subject to an AMR, consistent with 10 CFR 54.4 and 54.21(a)(1). Based on that review, the staff questioned two areas associated with its review of Section 2.7.6 of Exhibit A of the LRA.
In RAI 3.7.6-3, the staff asked the applicant to explain why the roof slabs, listed in Table 2.7-4 of Exhibit A of the LRA, were identified as concrete components. In its response to this RAI, the applicant stated that the Keowee structures do not have any concrete roof slabs. The Keowee structures have a built-up roofing system. However, a reference to roof slabs in Table 2.7-4 needed additional clarification. The staff asked the applicant about the roof slabs in a May 27, 1999, phone call, and documented the discussions in a June 2, 1999, summary.
The applicant stated that the Keowee structures use both reinforced concrete roof slabs and built-up roofing systems. The Keowee breaker vault that is located within the powerhouse has a reinforced concrete roof slab. The main structures, such as the Keowee powerhouse and the service bay structure, have built-up roofing systems. The built-up roof systems are comprised of a metal roof deck, covered with rigid insulation and rubberized material. The applicant stated that this roof system is a short-lived component and is subject to periodic replacement based on its service condition. Therefore, the applicant did not include the built-up roof system in Table 2.7-4, and did not consider it subject to an AMR. However, neither the rule nor the Commission guidance provided in the Statements of Consideration (SOC), allows the generic exclusion of SCs based on performance or condition monitoring. An applicant may exclude SCs that are replaced on the basis of specific performance or condition monitoring activities from an AMR only if the following two conditions are met: 1) that the applicant identifies those SCs in the LRA that are being excluded based on performance and condition monitoring, and 2) that the applicant submit a site-specific justification for the exclusion of these components. This issue was identified as Open Item 2.2.3.6.4.2.1-1.
In its response of October 15, 1999 to Open Item 2.2.3.6.4.2.1-1, the applicant stated that rather than generally excluding the roof based on performance or condition monitoring, the built-up roof system has been re-evaluated based on function to determine whether an AMR is required. Upon further investigation, the applicant has determined that the roof system of the Keowee powerhouse is not subject to AMR because it does not perform an intended function required by 10 CFR 54.4. The powerhouse is within the scope of license renewal in accordance with the requirements of 10 CFR 54.4(a). The roof is a component of the powerhouse, but it is not needed for the powerhouse to perform its intended function. Degradation or loss of the powerhouse roof will not result in loss of any structural, mechanical, or electrical system or component intended functions.
Table 2.7-4 of Exhibit A of the LRA identifies those components that perform the intended function of shelter or protection of safety-related equipment. The breaker vault is constructed of reinforced concrete walls, floor and roof slabs that protect the breakers. The electrical equipment is protected by the switchgear cabinets. The switchgear cabinets are included within the electrical panels and enclosures. The applicant stated that degradation of the powerhouse roof would not result in the loss of any component intended function. As a result, the roof of the powerhouse does not require an AMR, and is not listed in Table 2.7-4 of the LRA. The staff has reviewed the applicant's response and concludes that the applicant's justification for not including the powerhouse roof in the scope of license renewal is acceptable because it does not perform any function required by 10 CFR 54.4(a). In addition, because the roof system is not subject to an AMR, a site-specific justification for its exclusion is not required. Therefore, Open Item 2.2.3.6.4.2.1-1 is closed.
Section 2.7.6.4 described the function of the electrical switchgear bay but did not describe its structure and components or whether they are subject to an AMR. The staff asked the applicant about the switchgear structures in a May 27, 1999, phone call, and documented the phone call in a June 2, 1999, summary.
The applicant stated that the switchgear bay is part of the Keowee powerhouse located on the operating floor. The switchgear bay is the adjacent area where the switchgear are located. As part of the powerhouse, the applicant considers this area to be subject to an AMR. The staff finds the applicant's response acceptable.
The staff has reasonable assurance that the applicant has properly identified those SCs associated with the Keowee structure which perform the intended functions as defined in 10 CFR 54.4, and has properly identified these SCs as being within the scope of license renewal.
As a result of the above review, the staff found no omissions in the SSCs of the Keowee structures that were included within the scope of license renewal as defined under 10 CFR 54.4(a). The staff also found no omissions in the structures and components of the Keowee structures included in the applicant's AMR that perform its intended function(s) without moving parts or without a change in configuration or properties, or that are not replaced based on a qualified life or specified time period, as required under 10 CFR 54.21(a)(1).
2.2.3.6.4.2.2 Review Findings for Keowee Structures
The staff has reviewed the information presented in Section 2.7.6 of Exhibit A of the LRA, the ONS UFSAR, and the applicant's response to the staff's RAIs. On the basis of this review, the staff has reasonable assurance that the applicant (1) has properly identified those SSCs within the scope of license renewal, as required by 10 CFR 54.4, and (2) has properly identified those SCs within the scope of license renewal which require an AMR, as required by 10 CFR 54.21(a)(1).
2.2.3.6.5 Reactor Buildings Internal Structure and the Unit Vent Stacks
In Section 2.7.7, "Reactor Buildings Internal Structure and the Unit Vent Stacks," of Exhibit A of the LRA, the applicant identified the SSCs of the reactor buildings internal structure and unit vent stacks that are within the scope of license renewal as required under 10 CFR 54.4. The applicant also identified and listed the reactor building internal structure and unit vent stack SCs that are subject to an AMR as required under 10 CFR 54.21 (a)(1).
2.2.3.6.5.1 Summary of Technical Information in the Application
As described in Section 2.7.7 of Exhibit A to the LRA, the reactor building internal structures consist of: (1) the reactor cavity, (2) two steam generator compartments, and (3) a refueling canal which is located between the steam generator compartments and above the reactor cavity in each of the reactor buildings. The reactor cavity, which serves as the primary shield wall, houses the reactor vessel and was designed for core flooding water pressure up to the level of the reactor nozzle. Each of the two steam generator compartments serves as a secondary shield wall which house the steam generator, reactor coolant pump, and associated RCS piping. The pressurizer and quench tank are located in one of the steam generator compartments. The unit vent stack is a vertical steel cylindrical stack used to release gaseous discharge. The reactor cavity has six openings that are missile protected and used for venting purposes. The steam generator compartments are designed so that the secondary shield walls can be removed. The removable sections of the secondary shield walls are post-tensioning reinforced concrete structures which are designed as horizontal post-tensioned prestressed and vertical steel reinforced concrete structures. The remaining portions of the secondary shield walls are reinforced concrete structures. The post-tensioning reinforced concrete components that are subject to an AMR are grouped as the post-tensioning system. Lateral supports are provided for the steam generator that are attached to the secondary shield wall. There are structural steel platforms, ladders and grating in each of the compartments for access to various elevations of the compartment for inspection and maintenance. The reactor building internal steel structures are also designed to support the safety related components, such as the core flood tanks, reactor building cooling units, Emergency Core Cooling System piping, and electrical instrumentation, control, and power. The reactor building internal structures are Class 1 structures that are designed to withstand all loadings without loss of function and prevent uncontrolled release of radioactivity, and therefore, meet 10 CFR 54.4(a)(1).
The applicant identified and listed 28 structural component types in Table 2.7-5 of Exhibit A to the LRA. These components are further grouped into four categories based on their materials and function: (1) concrete, (2) steel in air environment, (3) steel in fluid environment, and (4) miscellaneous. The miscellaneous category includes the post-tensioning system which is unique to the steam generator compartments. These 28 structural components are within the scope of license renewal because they perform one or more of the following intended functions, as noted in the table:
The 28 structural components identified above were determined by the applicant to be subject to an AMR because its intended functions are performed without moving parts or without a change in configuration or properties and these SCs are not subject to replacement based on qualified life or specified time period as specified under 10 CFR 54.21(a)(1).
2.2.3.6.5.2 Staff Evaluation
The staff reviewed Section 2.7.7 of Exhibit A of the LRA and the ONS UFSAR to determine if the applicant has adequately implemented its methodologies such that there is reasonable assurance that the structures and structural components comprising the reactor building internal structure and unit vent stacks have been properly identified as being within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.5.2.1 Reactor Building Internal Structure and Unit Vent Stacks Within the Scope of License Renewal and Subject to an Aging Management Review
The staff reviewed the information presented in Section 2.7.7 of Exhibit A of the LRA, a portion of UFSAR Chapter 3.8, and the floor plan drawings in UFSAR Chapter 1, to determine if there were any structures, portions of structures, and components associated with the reactor building internal structure and unit vent stacks that the applicant did not properly identify as being within the scope of license renewal or did not properly identify as being subject to an AMR. The staff reviewed each of the 28 components listed in Table 2.7-5 of Exhibit A of the LRA to determine if they are part of the components within the reactor buildings. The staff also verified, with the UFSAR and applicable drawings, that there were no other reactor building components that were not included within the scope of license renewal that perform the reactor building intended functions.
As a result of the above review, the staff found no omissions in the SSCs included within the scope of license renewal as defined under 10 CFR 54.4(a). The staff also found no omissions in the SCs of the Reactor Building internal structure and unit vent stacks identified by the applicant as requiring an AMR.
2.2.3.6.5.2.2 Review Findings for Reactor Buildings Internal Structure and Unit Vent Stacks
The staff has reviewed the information presented in Section 2.7.7of Exhibit A of the LRA, and the ONS UFSAR. On the basis of this review, the staff has reasonable assurance that the applicant (1) has properly identified those SSCs within the scope of license renewal, as required by 10 CFR 54.4, and (2) has properly identified those SCs within the scope of license renewal which require an AMR, as required by 10 CFR 54.21(a)(1).
2.2.3.6.6 Standby Shutdown Facility
In Section 2.7.8, "Standby Shutdown Facility," of Exhibit A of the LRA, the applicant identified the SSCs of the standby shutdown facility (SSF) that are within the scope of license renewal as required under 10 CFR 54.4. The applicant also identified and listed the SSF SCs that are subject to an AMR as required under 10 CFR 54.21 (a)(1).
2.2.3.6.6.1 Summary of Technical Information in the Application
The SSF is a reinforced concrete structure that houses the standby shutdown systems used to achieve and maintain safe-shutdown conditions from outside of the control room in the event of a postulated fire, sabotage, or flooding event. The SSF is a Class 1 structure that must remain functional after a safe-shutdown earthquake. The applicant identified and listed 25 structural components in Table 2.7-6 of Exhibit A of the LRA and grouped them into two generic categories: (1) the concrete components, including reinforced concrete beams, columns, walls, floor and roof slabs, foundation, hatches, equipment pad, flood curbs and anchorage, and (2) the steel components, including battery racks, cable tray and conduits and their supports, control room ceiling, control boards, instrument panels and enclosures, flood and pressure doors, equipment component supports, HVAC ducts, instrument lines, pipe supports, crane rails and girders, and stairs, platforms and gratings supports. These 25 structural components are within the scope of license renewal because they perform at least one of the following intended functions, as noted in the table:
These 25 structural components within the scope of license renewal, are subject to an AMR because the intended functions are performed without moving parts or without a change in configuration or properties, and are not subject replacement based on qualified life or specified time period.
2.2.3.6.6.2 Staff Evaluation
The staff reviewed Section 2.7.8 of Exhibit A of the LRA and the ONS UFSAR to determine if the applicant has adequately implemented its methodologies such that there is reasonable assurance that the structures and structural components comprising the SSF have been properly identified as being within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.6.2.1 Standby Shutdown Facility Within the Scope of License Renewal and Subject to an Aging Management Review
The staff reviewed the information presented in Section 2.7.8 and Table 2.7-6 of Exhibit A of the LRA, supporting information in the UFSAR, and the applicant's response to the staff's question concerning water stops and structural sealants for the Standby Shutdown Facility (SSF) water-tight building to determine if all the structures and structural components have been included within the scope of the rule and subject to an AMR consistent with the requirements of 10 CFR 54.4 and 54.21(a)(1). The staff reviewed the 25 structures and structural components and their intended functions listed in Table 2.7-6.
In Section 2.2.3.6.1 of this report, the staff discusses the inclusion of expansion joints, caulking, structural sealants, and water stops within the scope of license renewal and subject to an AMR. This discussion also applies to expansion joints, caulking, structural sealants, and water stops associated with the SSF because this structure was designed to be water tight under all design-basis events. Section 2.2.3.6.1 identifies and addresses the generic need for the applicant to include expansion joints, caulking, structural sealants, and water stops within the scope of license renewal and subject to an AMR when applicable under 10 CFR 54.4 and 54.21(a)(1). As discussed in Section 2.2.3.6.1, the applicant did include expansion joints, caulking, structural sealants, and water stops as subcomponents for all applicable structures and structural components including the SSF.
In its response to Open Item 2.2.3.6.1.2.1-1, dated October 15, 1999, the applicant stated that materials, such as caulking, sealants, and water stops, are not considered as individual structures or components. However, these materials are important in maintaining the integrity of the components to which they are connected. The applicant has identified the inspection program for Civil Engineering Structures and Components as the program used to manage the aging of these subcomponents. The implementation of this program has identified instances where degradation of these materials have resulted in discoloration of the concrete and leaching in the SSF building, and have resulted in the implementation of corrective actions. Discoloration and leaching along the expansion joints with water stops also have been identified. The expansion joint has been sealed on the inside surface of the concrete. The applicant stated that continued implementation of the inspection program for Civil Engineering Structures and Components provides reasonable assurance that the caulking, sealants, and water stops can support the intended functions of the SSF building. The staff has previously reviewed the applicant's rationale for Open Item 2.2.3.6.1.2.1-1 and found it acceptable for the auxiliary building, as addressed in Section 2.2.3.6.1.2.1 of this report. Based on the same rationale, the staff finds that including caulking, sealants, and water stops within the scope of the rule and subject to an AMR as subcomponents is acceptable for the SSF.
2.2.3.6.6.2.2 Review Finding for Standby Shutdown Facility
The staff has reviewed the information presented in Section 2.7.8 of Exhibit A of the LRA, the ONS UFSAR, and the applicant's response to the staff's RAIs. On the basis of this review, the staff has reasonable assurance that the applicant (1) has properly identified those SSCs within the scope of license renewal, as required by 10 CFR 54.4, and (2) has properly identified those SCs within the scope of license renewal which require an AMR, as required by 10 CFR 54.21(a)(1).
2.2.3.6.7 Turbine Building
In Section 2.7.9, "Turbine Building," of Exhibit A of the LRA, the applicant identified the SSCs of the turbine building that are within the scope of license renewal as required under 10 CFR 54.4. The applicant also identified and listed the turbine building SCs that are subject to an AMR as required under 10 CFR 54.21 (a)(1).
2.2.3.6.7.1 Summary of Technical Information in the Application
In Section 2.7.9 of Exhibit A of the LRA, the applicant identified the turbine building as being within the scope of license renewal. For the purpose of license renewal, the applicant defined the following structures as being part of the turbine buildings: the turbine buildings, Units 1 and 2 transformer and switchgear enclosure, and Unit 3 switchgear enclosure. The turbine building is a large steel frame structure which houses the turbine generators and its associated components and equipment for all three units without partitions between each unit. The turbine buildings are constructed with a reinforced concrete substructure and a steel frame superstructure. The substructure consists of a reinforced concrete mat foundation and walls that are below grade. The superstructure, which is above grade, is a structural steel building with metal sidings. The turbine building is a Class 2 structure. Class 2 structures are those whose limited damage would not result in a release of radioactivity and would permit a controlled plant shutdown, but could interrupt power generation. Duke determined Class 2 structures meet the intent of 10 CFR 54.4(a)(2).
The Units 1 and 2 transformer (CT4) and switchgear (4kV) enclosure and the Unit 3 switchgear (4kV) enclosure are Class 1 structures that must remain functional after a safe-shutdown earthquake. The Units 1 and 2 transformer and switchgear enclosure is a reinforced concrete structure with penetrations on the walls for the electrical bus, ventilation, and personnel access. The enclosure is divided into two separate rooms by a masonry block firewall. Ventilation for transformer CT4 and its enclosure is provided by fans on the east wall and 12 penetrations
through the North and South walls. The Unit 3 switchgear enclosure is a reinforced concrete structure supported by battered-pipe piles filled with concrete. Ventilation for this enclosure is provided by fans on the West wall. The ventilation penetrations and personnel access doors for all these enclosures are missile protected. The transformers and electrical buses are seismically braced with structural steel.
The applicant listed 29 generic structural components within the turbine building, and identified their intended functions in Table 2.7-7 of Exhibit A to the LRA. The 29 structural components are grouped into three categories based on their materials and function: (1) concrete, (2) steel in air environment, and (3) fire barriers. These 29 components are within the scope of license renewal because they perform one or more of the following intended functions, as noted in the table:
These 29 structural components within the scope of license renewal, are subject to an AMR because the intended functions are performed without moving parts or without a change in configuration or properties, and are not subject replacement based on qualified life or specified time period.
2.2.3.6.7.2 Staff Evaluation
The staff reviewed Section 2.7.9 of Exhibit A of the LRA and the ONS UFSAR to determine if the applicant has adequately implemented its methodologies such that there is reasonable assurance that the turbine building structures and structural components have been properly identified as being within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.7.2.1 Turbine Building Within the Scope of License Renewal and Subject to an Aging Management Review
The staff reviewed the information submitted in Section 2.7.9 of Exhibit A of the LRA, the structural components listed in Table 2.7-7 of Exhibit A of the LRA, and portions of Chapter 3 of the UFSAR to determine if there were any portions of the structures and associated components that the applicant did not identify as within the scope of license renewal or subject to an AMR.
In Exhibit A of the LRA, Table 2.7-7, the applicant lists roof slabs as concrete components. The staff's review found that the turbine building has a steel frame superstructure with a composite roof system (not concrete roof slabs) built on top of roof trusses. Furthermore, the turbine building roof supports the pull-off structures of the transmission lines. These special devices were not described and the applicable components were not listed in Exhibit A, Table 2.7-7. The staff asked the applicant about the roof slabs and the pull-off structures of the transmission lines in a May 27, 1999, phone call, and documented these discussions in a June 2, 1999, summary.
The applicant stated in the May 27, 1999, phone call that the switchgear enclosures adjacent to the turbine building are reinforced concrete structures with reinforced concrete roof slabs that were listed in Table 2.7-7 of Exhibit A of the LRA. The turbine building has a composite roof system, which is comprised of a metal roof deck, covered with rigid insulation, bitumen, inorganic felts and a cover layer of aggregate. This composite roof system is a short-lived component and is subject to periodic replacement based on performance and condition. Therefore, the applicant determined that the composite roof system was within the scope of license renewal but not subject to an AMR and did not listed the applicable components in Table 2.7-7.
However, as discussed in Subsection 2.2.3.6.4.2.1 of this report, neither the rule nor the Commission guidance provided in the SOC, allows for the generic exclusion of SCs based on performance or condition monitoring. An applicant may exclude a structure and component from an AMR on the basis of performance or condition monitoring activities only if the following two conditions are met: 1) the applicant identifies those SCs in the LRA that are being excluded based on performance and condition monitoring, and 2) the applicant submit a site-specific justification for the exclusion of these components. This item was addressed in Open Item 2.2.3.6.4.2.1-1.
In its October 15, 1999, response to Open Item 2.2.3.6.4.2.1-1, the applicant re-evaluated the roof systems for the Keowee powerhouse and turbine building to determine whether they are subject to an AMR. On the basis of its evaluation, the applicant determined that the turbine building roof system was not subject to AMR because it does not meet the scoping criteria under 10 CFR 54.4, and should not have been included within the scope of license renewal. The applicant stated that degradation or loss of the turbine building roof will not result in the loss of any structural, mechanical, or electrical system or component function. The turbine building contains safety-related SSCs in the basement, which would remain sheltered and protected by several reinforced concrete floors if the turbine building roof was to degrade. Since the roof does not perform an intended function within the scope of license renewal, the roof system is not listed in Table 2.7-7 of Exhibit A of the LRA and is not within the scope of license renewal.
The staff reviewed the applicant's response for excluding the roof system of the turbine building from within the scope of license renewal and found it's rationale acceptable. The roof system of the turbine building does not meet any of the scoping criteria of 10 CFR 54.4(a) and is not within the scope of license renewal. Because the roof system is not within the scope of the rule, it need not be considered under 10 CFR 54.21(a)(1) for an AMR.
The applicant also stated in the May 27, 1999, phone call that the shield wire pull-off structures, which are described in Section 2.7.10.6 of Exhibit A of the LRA, are A-frame towers similar to the strain structures in the 230 kV switchyard. These structures are constructed of hot-dipped galvanized steel with welded and bolted connections. The shield wire pull-off structures are included in the yard structures in Subsection 2.7.10.6 of Exhibit A of the LRA under transmission towers because of its similar function and construction materials. The transmission towers were listed in Table 2.7-8 and 3.7-8 of Exhibit A of the LRA. The shield wire pull-off structures are subject to an AMR. The staff found the applicant's response for the roof slabs and the shield wire pull-off structure to be acceptable.
As a result of the above review, the staff found no omissions in the SSCs of the Turbine Building that were included within the scope of license renewal as defined under 10 CFR 54.4(a). The staff also found no omissions in the structures and components of the Turbine Building included in the applicant's AMR that perform its intended function(s) without moving parts or without a change in configuration or properties, or that are not replaced based on a qualified life or specified time period, as required under 10 CFR 54.21(a)(1).
2.2.3.6.7.2.2 Review Findings for Turbine Building
The staff has reviewed the information presented in Section 2.7.9 of Exhibit A of the LRA, the ONS UFSAR, and the applicant's response to the staff's RAIs. On the basis of this review, the staff has reasonable assurance that the applicant (1) has properly identified those SSCs within the scope of license renewal, as required by 10 CFR 54.4, and (2) has properly identified those SCs within the scope of license renewal which require an AMR, as required by 10 CFR 54.21(a)(1).
2.2.3.6.8 Yard Structures
In Section 2.7.10, "Yard Structures," of Exhibit A of the LRA, the applicant identified the SSCs of the yard structures that are within the scope of license renewal as required under 10 CFR 54.4. The applicant also identified and listed the yard structure SCs that are subject to an AMR as required under 10 CFR 54.21 (a)(1).
2.2.3.6.8.1 Summary of Technical Information in the Application
As described in Section 2.7.10 of Exhibit A of the LRA, the yard structures consist of a 230 kV relay house, 230 kV switchyard structures, trenches, 230 kV towers from Keowee to the ONS, an elevated water storage tank, transformer pads for transformers CT1, CT2, CT3, and Keowee transformer 1, and the foundations and pipe supports located in the yard.
The 230 kV switchyard relay house is a rectangular steel frame structure that houses and protects the 230 kV switchyard relay. It is erected on a reinforced concrete slab on grade. This relay house is a Class 2 structure that is designed to withstand design basis seismic loads.
The 230 kV switchyard structures are Class 2 structures that are designed to support or protect the electrical equipment and transmission lines in the 230 kV switchyard and the overhead power path. The applicant identified the following switchyard structures to be within the scope of license renewal and subject to an AMR:
The bus support bases are cylindrical reinforced concrete footings embedded in earth that support the electrical buswork support steels. The coupling capacitor potential device support bases, disconnect switch supports, lightning arrestor supports, and the wave trap supports are steel post supports built in a reinforced concrete base. The power circuit breaker bases that support certain power circuit breakers for the Keowee overhead power path are reinforced concrete footings embedded in the ground. The steel strain structures and their reinforced concrete foundations in the 230 kV switchyard and at the Keowee site are an integral part of the Keowee overhead power path.
The elevated water storage tank is a 100,000 gallon circular atmospheric tank that stores water for the High Pressure Service Water System. The circular shaft and conical bell of the tank are constructed of structural steel. The bell is attached to the foundation by anchors. Both the interior and exterior of the tank are coated for corrosion protection.
The Keowee main step-up transformer base is located southwest of the Keowee powerhouse. The transformer is supported on piers which are on top of a reinforced concrete base on soil. A structural steel frame attached to each pier is provided as the seismic restraint for the transformer. The ONS CT1, CT2, and CT3 startup transformer bases are located in the ONS transformer yard to the east of the turbine building. Reinforced concrete bases on soil are provided for each of the unit's startup transformers. The transformers are supported on top of the reinforced concrete base with piers. These bases are Class 2 structures.
There are external reinforced concrete trenches throughout the ONS yard to route underground cables and piping. Only the trenches that provide shelter and protection for the safety-related equipment are within the scope of license renewal. The applicant identified the following trenches that are subject to an AMR:
The standby shutdown facility cable trench carries electrical cables from the standby shutdown facility to each unit's auxiliary building. This cable trench is a Class 2 structure that is designed for missile, seismic, and truck loads. The emergency power path cable trench is a precast, reinforced concrete structure that is laid out on a grid pattern to cover the entire 230 kV switchyard. This cable trench is a Class 2 structure. The intake structure cable trench is a reinforced concrete trench with a checkered plate cover. The cable trench to the intake structure is a Class 2 structure. The borated water storage tank pipe trench is a reinforced concrete structure located between the auxiliary building and the borated water storage tank foundation such that the foundation of the auxiliary building forms the east side trench wall. The borated water storage tank pipe trench is a Class 1 structure. All of the trenches are covered with reinforced concrete panels except the intake structure cable trench.
The 230 kV Keowee transmission line, which provides the overhead power path from the 230 kV switchyard in the Keowee site to the ONS site, is supported by two dead-end type lattice towers and one suspension lattice tower. These three lattice towers are Class 2 steel structures that meet the requirements of the National Electric Code (NEC) for heavy loading Grade B construction and their components are seismically designed. The shield wire pull-off structures located on the roof of the turbine building support the loads of the transmission lines. The transmission towers are constructed of hot-dipped galvanized steel with welded and bolted connections. The applicant identified these structures as within the scope of license renewal and subject to an AMR.
2.2.3.6.8.2 Staff Evaluation
The staff reviewed Section 2.7.10 of Exhibit A of the LRA and the ONS UFSAR to determine if the applicant has adequately implemented its methodologies such that there is reasonable assurance that the structures and structural components comprising the yard structures have been properly identified as being within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.8.2.1 Yard Structures Within the scope of License Renewal and Subject to an Aging Management Review
The applicant identified the 230 kV relay house, 230 kV switchyard structures, certain cable and pipe trenches, transmission towers, elevated water storage tank, transformer pads, and pipe supports for transformers CT1, CT2, CT3, and the Keowee transformer, as being within the scope of license renewal. The staff agrees that these structural components are within the scope of license renewal because they perform either or both of the two yard structures intended functions: (1) provide structural and/or functional support to safety-related or non-safety related equipment, and (2) provide shelter/protection to safety-related equipment. Within the yard structures, the applicant listed 22 structural components and identified their intended functions in Table 2.7-8 of Exhibit A of the LRA. These 22 components are grouped into three categories: (1) concrete, (2) steel in air environment, and (3) steel in fluid environment. Other structural components that are part of the yard structures, but do not contribute to any of the intended functions of the yard structures are not included in the table. The components listed on Table 2.7-8 of Exhibit A of the LRA are subject to an AMR because the intended functions are performed without moving parts and without a change in configuration or properties, and are not subject to replacement based on qualified life or specified time period.
As a result of the above review, the staff found no omissions in the SSCs of the yard structures that were included within the scope of license renewal as defined under 10 CFR 54.4(a). The staff also found no omissions in the structures and components of the yard structure identified by the applicant as requiring an AMR.
2.2.3.6.8.2.2 Review Findings for Yard Structure
The staff has reviewed the information presented in Section 2.7.10 of Exhibit A of the LRA, the ONS UFSAR, and the applicant's response to the staff's RAIs. On the basis of this review, the staff has reasonable assurance that the applicant (1) has properly identified those SSCs within the scope of license renewal, as required by 10 CFR 54.4, and (2) has properly identified those SCs within the scope of license renewal which require an AMR, as required by 10 CFR 54.21(a)(1).
2.2.3.6.9 Pipe Supports
In Section 2.7.2, "Structural Components," of Exhibit A to the LRA, the applicant listed the concrete and steel structural components, including pipe supports, subject to an AMR. The applicant provided further details about which pipe supports are within the scope of license renewal and subject to an AMR in Section 2.7.2.2.1, "Pipe Supports," of Exhibit A of the LRA.
2.2.3.6.9.1 Summary of Technical Information Regarding Pipe Supports in the Application
At the ONS, piping is supported by different types of hangers and supports to satisfy the United States of America Standard (USAS) B31.1.0 and B31.7 code requirements. Piping supports are constructed of a standard support, a structural frame, or some combination of the two. Pipe supports are coated to prevent corrosion and loss of material.
The types of piping supports used at the ONS include:
The applicant noted in Section 2.7.2.2.1 of Exhibit A of the LRA, that although snubbers themselves are excluded from an AMR by 10 CFR 54.21, the components that mount the snubber to the pipe and structure are subject to an AMR.
The applicant identified the pipe supports that are within the scope of license renewal using the system flow diagrams in OLRP-1002. Piping within the scope of license renewal is identified on these flow diagrams. The flow diagrams can be used to identify the associated math model that contains the pipe supports. All pipe supports within the license renewal evaluation boundary defined by the Oconee flow diagrams, including any overlap supports required by the seismic analysis math modeling, are within the scope of license renewal. The applicant identified the following groups of pipe supports within the scope of license renewal:
The applicant inadvertently noted in the original application that pipe supports associated with Oconee Piping Class E are not within the scope of license renewal. The applicant corrected the list of piping classes within the scope of license renewal in a letter to the staff dated October 15, 1999, to include those Class E piping supports that are required for seismic structural integrity.
2.2.3.6.9.2 Staff Evaluation
The staff reviewed this section of the LRA to determine whether there is reasonable assurance that the pipe supports within the scope of license renewal and subject to an AMR have been identified by the applicant in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.9.2.1 Pipe Supports Subject to Aging Management Review
As part of the first step of its evaluation, the staff reviewed the information submitted by the applicant in the LRA to determine whether the applicant failed to identify systems, or portions of systems, that have pipe supports and that perform intended functions within the scope of license renewal. In Section 2.7.2.2.1 of Exhibit A of the LRA, the applicant stated that all pipe supports within the license renewal boundary, as defined by the flow diagrams in OLRP-1002, are within the scope of license renewal for Oconee Class A, B, C, D, and F piping. In addition, pipe supports associated with Oconee Class G and H piping assigned a QA Condition 4 and any piping required to meet any of the regulatory events defined in 10 CFR 54.4(a)(3) are also within the scope of license renewal, and identified as such on the flow diagrams in OLRP-1002. In a letter dated October 15, 1999, the applicant clarified the fact that pipe supports associated with Oconee Class E piping assigned a QA Condition 4, which had been inadvertently omitted from the LRA, were also included within the scope of license renewal.
In Section 2.2.3 of this SER, the staff reviewed the applicant's identification of those systems and structures at the ONS that were within the scope of license renewal and determined that there was reasonable assurance that the applicant had identified all of the systems and structures within the scope of license renewal. Sections 2.2.3.1 through 2.2.3.7 of this SER document the staff's review of the individual system and structure boundary evaluations to determine whether the applicant identified those portions of systems and structures within the scope of license renewal. Since the applicant includes all pipe supports within the license renewal boundary defined by the flow diagrams in OLRP-1002, and since the staff has reviewed and accepted the license renewal boundaries for the systems within the scope of license renewal, the staff has reasonable assurance that the applicant has identified all the pipe supports within the scope of license renewal.
Inasmuch as pipe supports are passive components and not subject to replacement on a periodic basis, they are subject to an AMR. Snubbers are specifically excluded from this group of components by 10 CFR 54.21(a)(1)(i) and have been appropriately identified by the applicant as not subject to an AMR. The staff reviewed Tables 2.7-1 through 2.7-8 and found pipe supports appropriately listed as components subject to an AMR, pursuant to 10 CFR 54.21, for each structure except earthen embankments (Table 2.7-2). Earthen embankments, which are reviewed in Section 2.2.3.6.2 of this SER, are dikes and dams made from rolled earthfill and do not have pipe supports performing intended functions as defined in 10 CFR 54.4.
Piping Segments that Provide Structural Support
Systems which have safety-related/non-safety-related (SR/NSR) transition points include a boundary valve or other flow controlling component (e.g., orifice) at the transition point. The structural integrity of the boundary point, which functions as system pressure boundary, must not be compromised. To ensure proper seismic structural support if the boundary component itself is not anchored, the system's structural boundary must be extended beyond the boundary component to the first seismic anchor (or equivalent) and include the pipe segment connecting the boundary component to the pipe support. The pipe segment and seismic anchor together act as a single support system ensuring the integrity of the SR/NSR functional boundary under all design basis conditions. Providing structural support under all CLB design loading conditions for safety-related components (within the scope of license renewal) is the only intended function for these piping segments and anchors.
Since all fluid systems containing safety-related piping are within the scope of license renewal, these systems potentially have SR/NSR functional boundaries where piping segments beyond the functional boundary could be credited with structural support of the boundary point. The applicant states in Section 2.7.2.2.1, that the flow diagrams in OLRP-1002 can be used to identify the associated math model that contains the pipe supports. However, the highlighted flow diagrams in OLRP-1002 do not show which pipe segments and pipe supports are credited with supporting the functional boundary components, and as such, the staff could not verify that the applicant had identified all pipe segments that are within the scope of license renewal and subject to AMR. This concern was documented as Confirmatory Item 2.2.3.6.9-1.
On June 2, 1999, the staff and the applicant held two conference calls to clarify the applicant's position on documenting pipe segments that provide structural support. In a memorandum dated June 2, 1999, the staff documented the conclusion from the conference calls. As documented in the June 2, 1999, memorandum, the applicant stated that all SR/NSR interface valves for Oconee piping classes B, C, and F included piping segments and anchorages beyond the SR/NSR interface boundary valve that ensured the integrity of the boundary valve under all design basis loadings. The applicant stated that these components were included within the scope of license renewal and subject to AMR. The applicant further clarified that Oconee piping class A does not interface with non-safety-related piping and, therefore, does not have any piping segments or anchorages that support SR/NSR boundary valves. Likewise, Oconee class D piping is NSR and is included within the scope of license renewal only to ensure its failure during a design-basis event does not affect the capability of adjacent safety-related equipment to perform its intended function. Therefore, class D piping included in the scope of license renewal for this reason will not have any SR/NSR interfaces requiring piping segments that provide structural support to boundary points. Likewise, Oconee piping Classes E, G, and H, which were included within the scope of license renewal, are not safety-related or seismically qualified, and therefore, will not have SR/NSR interfaces requiring piping segments that provide structural support to boundary points.
The applicant committed to document the information from the two conference calls regarding the status of piping segments that provide structural support to boundary points. In a letter dated October 15, 1999, the applicant provided the information necessary to close Confirmatory Item 2.2.3.6.9-1.
2.2.3.6.9.2.2 Review Findings for Pipe Supports
On the basis of this review the staff concludes that there is reasonable assurance that the applicant has identified and listed the pipe supports within the scope of license renewal and subject to an AMR, in accordance with 10 CFR 54.4 and 10 CFR 54.21.
2.2.3.6.10 Essential Siphon Vacuum Building and Trenches
In its LRA Amendment submittal of September 30, 1999, the applicant added essential siphon vacuum (ESV) building and trenches to its application for license renewal as a result of the plant modification (which was discussed in Section 2.2.3.4.9 of this report). This plant modification constitutes a change to the contents of the LRA, which was submitted in July 1998. In Section 1.2, "Structural Integrated Plant Assessment," of the LRA Amendment, the applicant described the ESV building and trench structures and listed their structural components that are within the scope, and subject to an AMR for license renewal.
2.2.3.6.10.1 Summary of Technical Information in the Application
The ESV building encloses the pumps, motors and associated equipment of the ESV System and provides a suitable environment (protected from weather) for maintenance activities. The ESV building is a single story, single span, pre-engineered rigid frame steel structure with metal sidings built on a reinforced concrete slab foundation. This pre-engineered ESV building and its foundation are Class 2 structures. Class 2 structures are those structures whose limited damage would not result in a release of radioactivity and would permit a controlled plant shutdown but could interrupt power generation. The applicant has determined that Class 2 structures meet the intent of 10 CFR 54.4(a)(2).
The essential siphon vacuum trenches, which include ESV System cable trench and ESV System intake dike trench, are designed for underground routing of cables and piping. The piping and cables associated with the ESV and SSW Systems are routed from the turbine building to the ESV building via the existing radwaste trench and the newly constructed ESV System cable trench. Routing of the ESV and SSW Systems piping, electrical heat trace cables, and electrical instrumentation cables from the ESV building to the intake structure is by way of embedded conduits and the newly constructed intake dike trench. The intake dike trench is constructed of reinforced concrete (bottom slab and walls) and covered with steel plate except at the roadway crossing. The covers at the roadway are the removable reinforced concrete slabs. The design and construction of the cable trench are similar to that of the intake dike trench. The ESV System cable and dike trenches are Class 2 structures.
The structural components of the ESV building and their intended functions are listed in Table 1-3 of the LRA Amendment. The applicant listed the anchorage and embedment in concrete, equipment pads, flood curbs, and foundation as the concrete components. The anchorage and embedment at exposed surfaces, expansion anchors, cable tray and conduit and their supports, checkered plate, electrical and instrument panels and their enclosures, instrument line and pipe supports, instrument racks and frames, louvers and vents, as well as the structural steel beams, columns, plates, and trusses are listed as the steel components in air environment. The applicant identified a total of 17 component types in the table that are within the scope of license renewal because they perform one or more of the following intended functions, as noted in the table:
These components are subject to an AMR because the intended function(s) are performed without moving parts, or without a change in configuration or properties, and are not replaced based on qualified life or specified time period. The table does not list the components of the ESV trenches. However, because these trenches are similar in design and construction, the applicant determined that the ESV trenches are part of the trenches in the yard structures of Section 2.7.9 of Exhibit A of the LRA. Therefore, the ESV trenches are within the scope of license renewal, and are subject to an AMR. The staff's review of the group of trenches is provided in Section 2.2.3.6.8 of this report.
2.2.3.6.10.2 Staff Evaluation
The staff reviewed Section 1.2 of the LRA Amendment and the ONS UFSAR to determine if there is reasonable assurance that the SCs comprising the ESV building and trenches have been properly identified as being within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21(a)(1).
2.2.3.6.10.2.1 Essential Siphon Vacuum Building and Trenches Within the Scope of License Renewal and Subject to Aging Management Review
The staff has reviewed Section 1.2 of the LRA Amendment and the supporting information in Section 3.8.5.1 of the ONS UFSAR, design drawings Nos. 0-347-J-001 and -002 (for the ESV building), and the partial site plan (for the trenches) to determine if there were any structures or associated components within the ESV building and trenches that the applicant did not identify as being within the scope of license renewal or did not identify as being subject to an AMR. On the basis of this review, the staff requested additional information regarding the ESV building roof and siding. The drawings submitted by the applicant did not include the roof of the ESV building. In addition, the roof and siding were not listed in Table 3-1 of the LRA Amendment as being within the scope of license renewal. The staff asked the applicant whether the roof and siding are within the scope of license renewal and also asked the applicant to describe the roof system. In its response by an e-mail (which was documented in the RAI response summary of November 18, 1999), the applicant stated that the roof and siding are structural components of the ESV building but they are not within the scope of license renewal because they do not meet any of the scoping criteria under 10 CFR 54.4(a). The roof and siding are not required to provide shelter/protection to safety-related equipment, or structural and/or functional support to safety-related and non safety-related equipment within the scope of license renewal. The applicant stated that degradation or loss of the roof or siding would not result in loss of intended functions for any structure, system, mechanical component, or electrical component. Because these components are not within the scope of license renewal, the roof and siding are not subject to AMR and, therefore, are not listed in Table 3-1 of the LRA Amendment.
As a result of the above review, the staff found no omissions by the applicant on scoping the structural components. The staff also found that all the within the scope structural components are subject to an AMR. Therefore, the staff has reasonable assurance that the applicant has properly identified those SCs associated with the ESV building and trenches as being within the scope of license renewal.
2.2.3.6.10.2.2 Review Findings for Essential Siphon Vacuum Building and Trenches
On the basis of the above review, the staff concludes that there is reasonable assurance that the applicant has properly identified the structural components of the ESV building and trenches within the scope of license renewal and subject to an AMR, in accordance with the requirements of 10 CFR 54.4 and 10 CFR 54.21.
2.2.3.7 Electrical Components
In Section 2.6, "Electrical Components," of Exhibit A of the LRA, the applicant described the technical information related to electrical components at the ONS site that are within the scope for license renewal and identified which of those electrical components are subject to an AMR.
2.2.3.7.1 Summary of Technical Information in the Application
For scoping purposes, the applicant grouped all plant electrical components into one of three categories:
| Category 1: | Electrical components that are designated as QA Condition 1 and are scoped in because they meet the criteria of 10 CFR 54.4(a) and are subject to an AMR. |
| Category 2: | Four selected groups of electrical components that do not meet the 10 CFR 54.4(a) criteria and are scoped out (these are electrical components associated with (1) the 525-kV switchyard, (2) the Jocassee, Calhoun, Oconee, and Dacus 230-kV transmission lines, (3) the radwaste facility, and (4) the Oconee retail substation. These electrical components are not included in the AMR. |
| Category 3: | All remaining electrical components that are not in Category 1 or Category 2 and are included in the scope of the review. |
On the basis of this scoping methodology, all electrical components at the ONS are within the scope of license renewal, except for the four groups of components identified in Category 2 above. In accordance with this scoping methodology, the applicant provided a list of all of the electrical device types and determined which of the ONS electrical device types perform their intended function without moving parts, without a change in configuration or properties, or are not subject to replacement based on a qualified life or specified time period. As a result of the applicant's scoping methodology, the following electrical device types were identified as subject to an AMR for license renewal:
In the LRA, the applicant has identified the following intended functions for the listed electrical components:
| Bus, insulated cables & connections, and transmission conductors | Provide electrical connection between two sections of an electrical circuit. |
| Insulators (high-voltage equipment) | Insulate and support an electrical conductor. |
Subsequent to completing the electrical scoping process for the ONS, the applicant reviewed the results of the Oconee Safety-Related Designation Clarification (OSRDC) project to verify that the four selected groups of electrical components referenced in scoping Category 2 are not required to meet the criteria in 10 CFR 54.4(a)(1) or (a)(2). The OSRDC project generated a list of all ONS electrical components required to meet the criteria of 10 CFR 54.4(a)(1) or (a)(2). For electrical scoping verification, the location of each component on the OSRDC list was identified and verified to confirm that none of the components was associated with the four selected groups of electrical components identified in scoping Category 2. The applicant stated that the results of the OSRDC study verified that the four selected groups of electrical components in scoping Category 2 are not required to meet the criteria in 10 CFR 54.4(a)(1) or (a)(2).
2.2.3.7.2 Staff Evaluation
The staff reviewed Section 2.6 of Exhibit A of the LRA to determine whether there is reasonable assurance that the applicant has identified the