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• Publication Information
• Abstract

Table of Contents

• Publication Information
• Abstract
• Figures
• Executive Summary
• Abbreviations/Acronyms
• 1.0 Introduction
• Generic Environmental Impact Statement
• License Renewal Evaluation Process
• 1.1 The Proposed Federal Action
• 1.2 Purpose and Need for the Action
• 1.3 Compliance and Consultations
• References
• 2.0 Description of Nuclear Power Plant and Site and Plant Interaction with the Environment
• 2.1 Plant and Site Description and Proposed Plant Operation During the Renewal Term
• 2.1.1 External Appearance and Setting
• 2.1.2 Reactor Systems
• 2.1.3 Cooling and Auxiliary Water Systems
• 2.1.4 Radioactive Waste Management Systems and Effluent Control Systems
• 2.1.5 Nonradioactive Waste Systems
• 2.1.6 Plant Operation and Maintenance
• 2.1.7 Power Transmission System
• 2.2 Plant Interaction with the Environment
• 2.2.1 Land Use
• 2.2.2 Water Use
• 2.2.3 Water Quality
• 2.2.4 Air Quality
• 2.2.5 Aquatic Resources
• 2.2.6 Terrestrial Resources
• 2.2.7 Radiological Impacts
• 2.2.8 Socioeconomic Factors
• 2.2.9 Historical and Archaeological Resources
• 2.2.10 Related Federal Project Activities
• 2.3 References
• 3.0 Environmental Impacts of Refurbishment
• 3.1 References
• 4.0 Environmental Impacts of Operation
• 4.1 Cooling System
• 4.1.1 Entrainment of Fish and Shellfish in Early Life Stages
• 4.1.2 Impingement of Fish and Shellfish
• 4.1.3 Heat Shock
• 4.1.4 Microbiological Organisms (Human Health)
• 4.2 Transmission Lines
• 4.2.1 Electromagnetic Fields - Acute Effects
• 4.2.2 Electromagnetic Fields - Chronic Effects
• 4.3 Radiological Impacts of Normal Operations
• 4.4 Socioeconomic Impacts of Plant Operations During the License Renewal Period
• 4.4.1 Housing Impacts During Operations
• 4.4.2 Public Services: Public Utility Impacts During Operations
• 4.4.3 Offsite Land Use During Operations
• 4.4.4 Public Services: Transportation Impacts During Operations
• 4.4.5 Historical and Archaeological Resources
• 4.4.6 Environmental Justice
• 4.5 Groundwater Use and Quality
• 4.6 Threatened or Endangered Species
• 4.7 Evaluation of Potential New and Significant Information on Impacts of Operations During the Renewal Term
• 4.8 Summary of Impacts of Operations During the Renewal Term
• 4.9 References
• 5.0 Environmental Impacts of Postulated Accidents
• 5.1 Postulated Plant Accidents
• 5.2 Severe Accident Mitigation Alternatives
• 5.2.1 Introduction
• 5.2.2 Estimate of Risk for ONS
• 5.2.3 Potential Design Improvements
• 5.2.4 Risk Reduction Potential of Design Improvements
• 5.2.5 Cost Impacts of Candidate Design Improvements
• 5.2.6 Cost-Benefit Comparison
• 5.2.7 Conclusions
• 5.3 References
• 6.0 Environmental Impacts of the Uranium Fuel Cycle and Solid Waste Management
• 6.1 The Uranium Fuel Cycle
• 6.2 References
• 7.0 Environmental Impacts of Decommissioning
• 7.1 References
• 8.0 Environmental Impacts of Alternatives to License Renewal
• 8.1 No-Action Alternative
• 8.2 Alternative Energy Sources
• 8.2.1 Coal-Fired Generation
• 8.2.2 Gas-Fired Generation
• 8.2.3. Imported Electrical Power
• 8.2.4 Other Alternatives
• 8.3 References
• 9.0 Summary and Conclusions
• 9.1 Environmental Impacts of the Proposed Action - License Renewal
• 9.1.1 Unavoidable Adverse Impacts
• 9.1.2 Irreversible or Irretrievable Resource Commitments
• 9.1.3 Short-Term Use Versus Long-Term Productivity
• 9.2 Relative Significance of the Environmental Impacts of License Renewal and Alternatives
• 9.3 Staff Conclusions and Recommendations
• 9.4 References
• Appendix A : Discussion of Comments on the Draft Supplement
• A.1 Comments and Responses
• A.1.1 General Comments in Support of Nuclear Energy and License Renewal
• A.1.2 General Comments in Opposition to License Renewal
• A.1.3 General Comments on Adequacy of the Review and Analysis
• A.1.4 License Renewal Review Process
• A.1.5 Refurbishment
• A.1.6 Ecology
• A.1.7 Transmission Lines
• A.1.8 Water Quality and Use
• A.1.9 Human Health
• A.1.10 Socioeconomics
• A.1.11 Archaeology and Human Resources
• A.1.12 Severe Accident Mitigation Alternatives
• A.1.13 Operational Safety Issues
• A.1.14 Age-Related Safety Issues
• A.1.15 Spent Nuclear Fuel
• A.1.16 Alternatives
• A.1.17 Miscellaneous
• A.1.18 Technical Clarifications and Corrections
• A.1.19 Format and Presentation (Spelling, Grammar, References, Clarity, etc.)
• A.2 Public Meeting Transcript Excerpts and Comment Letters
• Letter A (Transcript)
• Letter B
• Letter C
• Letter D
• Letter E
• Letter F
• Letter G
• Letter H
• Letter I
• Letter J

• ---

  Letter K
• Attachment 1
• Appendix B : Contributors to the Supplement
• Appendix C : Chronology of NRC Staff Environmental Review Correspondence Related to the Duke Application for License Renewal of Oconee Nuclear Station, Units 1, 2, and 3
• C.1 Reference
• Appendix D : Organizations Contacted
• Appendix E : Duke Compliance Status and Consultations
• E.1 References
• Appendix F : GEIS Environmental Issues Not Applicable to the Oconee Nuclear Station
• F.1 References

Publication Information

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Supplement 2
Regarding the Oconee Nuclear Station
Final Report
Manuscript Completed: December 1999
Date Published: December 1999

Division of Regulatory Improvement Programs
U.S. Nuclear Regulatory Commission
Office of Nuclear Reactor Regulation
Washington, DC 20555-0001

Abstract

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The U.S. Nuclear Regulatory Commission (NRC) considered the environmental effects of renewing nuclear power plant operating licenses for a 20-year period in the Generic Environmental Impact Statement for Renewal of Nuclear Plants (GEIS), NUREG-1437, and codified the results in 10 CFR Part 51. The GEIS (and its Addendum 1) identifies 92 environmental issues and reaches generic conclusions related to environmental impacts for 69 of these issues that apply to all plants or to plants with specific design or site characteristics. Additional plant-specific review is required for the remaining issues. These plant-specific reviews are to be included in a supplement to the GEIS.

This supplemental environmental impact statement (SEIS) has been prepared in response to an application submitted to the NRC by Duke Energy Corporation (Duke) to renew the operating licenses (OLs) for Oconee Nuclear Station (ONS) Units 1, 2, and 3 for an additional 20 years under 10 CFR Part 54. This SEIS includes the staff's analysis that considers and weighs the environmental effects of the proposed action, the environmental impacts of alternatives to the proposed action, and alternatives available for reducing or avoiding adverse effects. It also includes the staff's recommendation regarding the proposed action.

Neither Duke nor the staff has identified significant new information for any of the 69 issues for which the GEIS reached generic conclusions and which apply to ONS. Therefore, the staff concludes for these issues that the impacts of renewing the ONS OLs will not be greater than impacts identified in the GEIS for these issues. For each of these issues, the GEIS conclusion is that the impact is of SMALL significance (except for collective offsite radiological impacts from the fuel cycle and from high-level waste and from spent fuel, which were not assigned a single significance level) and that additional mitigation measures are likely not to be sufficiently beneficial to be warranted.

Each of the remaining 23 issues that applies to ONS is addressed in this SEIS. For each applicable issue, the staff concludes that the significance of the potential environmental effects of renewal of the OL is small. The staff also concludes that additional mitigation measures are likely not to be sufficiently beneficial as to be warranted.

The NRC staff recommends that the Commission determine that the adverse environmental impacts of license renewal for ONS Units 1, 2, and 3 are not so great that preserving the option of license renewal for energy-planning decisionmakers would be unreasonable. This recommendation is based on (1) the analysis and findings in the GEIS; (2) the Environmental Report submitted by Duke; (3) consultation with Federal, State, and local agencies; (4) the staff's own independent review, and (5) the staff's consideration of public comments.

Figures

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2-1 Location of Oconee Nuclear Station

2-2 Oconee Nuclear Station - One-Mile Exclusion Area

2-3 Location of Oconee Nuclear Station Relative to Other Parts of Keowee-Toxaway Project

2-4 Oconee Nuclear Station Layout

2-5 Oconee Nuclear Station (aerial photo)

2-6 Transmission Lines Attributable to the Oconee Nuclear Station in the Final Environmental Statement

2-7 Oconee Nuclear Station - Water Flow Diagram

2-8 Oconee Nuclear Station - 16-km (10-mi) Radius

2-9 Oconee Nuclear Station - 80-km (50-mi) Radius

4-1 Geographic Distribution of Minority Populations Within 80 km (50 mi) of ONS

4-2 Geographic Distribution of Low-Income Populations Within 80 km (50 mi) of ONS

Executive Summary

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By letter dated July 7, 1998, Duke Energy Corporation (Duke) submitted an application to the U.S. Nuclear Regulatory Commission (NRC) to renew the operating licenses for Units 1, 2, and 3 of the Oconee Nuclear Station (ONS) for an additional 20-year period. If the operating licenses are renewed, Federal (other than NRC) agencies, State regulatory agencies, and the owners of the plant will ultimately decide whether the plant will continue to operate. This decision will be based on factors such as the need for power or other matters within the State's jurisdiction or the purview of the owners. If the operating licenses are not renewed, Units 1, 2, and 3 will be shut down on or before the expiration of the current operating licenses, which are February 6, 2013, October 6, 2013, and July 19, 2014, respectively.

Under the National Environmental Policy Act of 1969 (NEPA), an environmental impact statement (EIS) is required for major Federal actions significantly affecting the quality of the human environment. The NRC has implemented Section 102 of NEPA in 10 CFR Part 51. In 10 CFR 51.20(b)(2), the Commission requires preparation of an EIS or a supplement to an EIS for renewal of a reactor operating license; 10 CFR 51.95(c) states that the EIS prepared at the operating license renewal stage will be a supplement to the Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437.⁽¹⁾

Upon acceptance of the Duke application, the NRC staff began the environmental review process described in 10 CFR Part 51 by publishing a notice of intent to prepare an EIS and to conduct scoping. The staff visited the ONS site in October 1998 and held public scoping meetings on October 19, 1998, in Clemson, South Carolina. The staff reviewed the Duke environmental report (ER) and compared it to the GEIS, consulted with Federal, State, and local agencies, conducted an independent review of the issues following the guidance set forth in the draft Standard Review Plans for Environmental Reviews for Nuclear Power Plants, Supplement 1: Operating License Renewal, NUREG-1555, Supplement 1, and considered the public comments from the scoping process and the comment period for the draft Supplemental Environmental Impact Statement (SEIS) for ONS (that was issued on May 20, 1999). Two public meetings were held in Clemson, South Carolina, on July 8, 1999, during which the staff described the preliminary 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 their comments. This SEIS includes the NRC staff's analysis that considers and weighs the environmental effects of the proposed action, the environmental impacts of alternatives to the proposed action, and alternatives available for reducing or avoiding adverse effects. It also includes the staff's recommendation regarding the proposed action.

The Commission has adopted the following definition of purpose and need for license renewal from the GEIS:

The purpose and need for the proposed action (renewal of an operating license) is to provide an option that allows for power generation capability beyond the term of a current nuclear power plant operating license to meet future system generating needs, as such needs may be determined by State, utility, and, where authorized, Federal (other than NRC) decisionmakers.

The goal of the staff's environmental review, as defined in 10 CFR 51.95(c)(4) and the GEIS, is to determine:

... whether or not the adverse environmental impacts of license renewal are so great that preserving the option of license renewal for energy planning decisionmakers would be unreasonable.

Both the statement of purpose and need and the evaluation criterion implicitly acknowledge that there are factors, in addition to license renewal, that will ultimately determine whether ONS continues to operate beyond the period of the current operating licenses.

The GEIS contains the results of a systematic evaluation of the consequences of renewing an operating license and operating a nuclear power plant for an additional 20 years. It evaluates 92 environmental issues using a three-level standard of significance--SMALL, MODERATE, or LARGE--based on Council on Environmental Quality guidelines. These significance levels are as follows:

SMALL: Environmental effects are not detectable or are so minor that they will neither destabilize nor noticeably alter any important attribute of the resource.

MODERATE: Environmental effects are sufficient to alter noticeably, but not to destabilize, important attributes of the resource.

LARGE: Environmental effects are clearly noticeable and are sufficient to destabilize important attributes of the resource.

For 69 of the 92 issues considered in the GEIS, the analysis in the GEIS shows that

(1) the environmental impacts associated with the issue have been determined to apply either to all plants or, for some issues, to plants having a specific type of cooling system or other plant or site characteristics

(2) a single significance level (i.e., SMALL, MODERATE, or LARGE) has been assigned to the impacts (except for collective offsite radiological impacts from the fuel cycle and from high-level waste and spent fuel disposal)

(3) mitigation of adverse impacts associated with the issue has been considered in the analysis, and it has been determined that additional plant-specific mitigation measures are likely not to be sufficiently beneficial to warrant implementation.

These 69 issues are identified in the GEIS as Category 1 issues. In the absence of significant new information, the staff relied on conclusions as amplified by supporting information in the GEIS for issues designated Category 1 in 10 CFR Part 51, Subpart A, Appendix B, Table B-1.

Of the 23 issues not meeting the criteria set forth above, 21 are classified as Category 2 issues requiring analysis in a plant-specific supplement to the GEIS. The remaining two issues, environmental justice and chronic effects of electromagnetic fields, are not categorized. Environmental justice was not evaluated on a generic basis and must also be addressed in a plant-specific supplement to the GEIS. Information on the chronic effects of electromagnetic fields was not conclusive at the time the GEIS was prepared.

This SEIS documents the staff's evaluation of all 92 environmental issues considered in the GEIS. The staff considered the environmental impacts associated with alternatives to license renewal and compared the environmental impacts of license renewal and the alternatives. The alternatives to license renewal that are considered include the no-action alternative (not renewing the ONS operating licenses) and alternative methods of power generation. Among the alternative methods of power generation, coal-fired and gas-fired generation appear the most likely if the power from ONS is replaced. These alternatives are evaluated assuming that the replacement power generation plant is located at either the ONS site or an unspecified "greenfield" site.

Duke and the staff have established independent processes for identifying and evaluating the significance of any new information on the environmental impacts of license renewal. Neither Duke nor the staff has identified any significant new information related to Category 1 issues that would call into question the conclusions in the GEIS. Similarly, neither Duke nor the staff has identified any new issue applicable to the ONS that has a significant environmental impact. Therefore, the staff relies upon the conclusions of the GEIS for all 69 Category 1 issues.

The staff has reviewed the Duke analysis for each Category 2 issue and has conducted an independent review of each issue. Five Category 2 issues are not applicable because they are related to plant design features or site characteristics not found at ONS. Four Category 2 issues are not discussed in this SEIS because they are specifically related to refurbishment. Four additional Category 2 issues that apply to both refurbishment and to operation during the renewal term are only discussed in relation to operation during the renewal term. Duke has stated that their evaluation of structures and components, as required by 10 CFR 54.21, did not identify any major plant refurbishment activities or modifications necessary to support the continued operation of ONS beyond the end of the existing operating licenses. In addition, routine replacement of components or additional inspection activities are within the bounds of normal plant component replacement and therefore are not expected to affect the environment outside of the bounds of the plant operations evaluated in the Final Environmental Statement (FES) for ONS.

Twelve Category 2 issues, as well as environmental justice and chronic effects of electromagnetic fields, are discussed in detail in this SEIS. For all 12 Category 2 issues and environmental justice, the staff concludes that the potential environmental effects are of SMALL significance in the context of the standards set forth in the GEIS. In addition, the staff determined that a consensus has not been reached by appropriate Federal health agencies that there are adverse effects from electromagnetic fields. Therefore, no further evaluation of this issue is required. For severe accident mitigation alternatives (SAMAs), the staff concludes that a reasonable, comprehensive effort was made to identify and evaluate SAMAs. Based on its review of the SAMAs for ONS, the staff concludes that none of the candidate SAMAs are cost beneficial.

Mitigation measures were considered for each Category 2 issue. Current measures to mitigate environmental impacts of plant operation were found to be adequate, and no additional mitigation measures were deemed sufficiently beneficial to be warranted.

In the event that the ONS operating licenses are not renewed and the units cease operation on or before the expiration of their current operating licenses, the adverse impacts of likely alternatives will not be smaller than those associated with continued operation of ONS. The impacts may, in fact, be greater in some areas.

The NRC staff recommends that the Commission determine that the adverse environmental impacts of license renewal for Oconee Nuclear Station Units 1, 2, and 3 are not so great that preserving the option of license renewal for energy planning decisionmakers would be unreasonable. This recommendation is based on (1) the analysis and findings in the GEIS; (2) the ER submitted by Duke; (3) consultation with other Federal, State, and local agencies; (4) the staff's own independent review, and (5) the staff's consideration of public comments.

Abbreviations/Acronyms

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1.0 Introduction

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Duke Energy Corporation (Duke)⁽²⁾ operates Oconee Nuclear Station (ONS) Units 1, 2, and 3 in northwestern South Carolina under operating licenses (OLs) DPR-38, DPR-47, and DPR-55 issued by the U.S. Nuclear Regulatory Commission (NRC). These OLs will expire in 2013 for Units 1 and 2 and in 2014 for Unit 3. By letter dated July 7, 1998, Duke submitted an application to the NRC to renew the ONS OLs for an additional 20 years under Title 10 of the Code of Federal Regulations (CFR) Part 54. Duke is a licensee for the purposes of its current OLs and an applicant for the renewal of the OLs.

The National Environmental Policy Act of 1969 (NEPA) requires an environmental impact statement (EIS) for major Federal actions significantly affecting the quality of the human environment. As provided in the Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437 (NRC 1996; 1999a),⁽³⁾ under NRC's environmental protection regulations in 10 CFR Part 51 implementing NEPA, renewal of a nuclear power plant operating license is identified as a major Federal action significantly affecting the quality of the human environment. Therefore, an EIS is required for a plant license renewal review. The EIS requirements for a plant-specific license renewal review are specified in 10 CFR Part 51. Pursuant to 10 CFR 54.23 and 51.53(c), Duke submitted an environmental report (ER) (Duke 1998) in which Duke analyzed the environmental impacts associated with the proposed action, considered alternatives to the proposed action, and evaluated any alternatives for reducing adverse environmental effects.

As part of NRC's evaluation of the application for license renewal, the NRC staff is required under 10 CFR Part 51 to prepare an EIS for the proposed action, issue the statement in draft form for public comment, and issue a final statement after considering public comments on the draft. This report is the final plant-specific supplement to the GEIS (supplemental environmental impact statement [SEIS]) for the Duke license renewal application. The staff will also prepare a separate safety evaluation report in accordance with 10 CFR Part 54.

The following sections in this introduction describe the background and the process used by the staff to assess the environmental impacts associated with license renewal, describe the proposed Federal action, discuss the purpose and need for the proposed action, and present the status of compliance with environmental quality standards and requirements that have been imposed by Federal, State, regional, and local agencies having responsibility for environmental protection. Chapter 2 describes the site, power plant, and interactions of the plant with the environment. Chapters 3 and 4 discuss the potential environmental impacts of plant refurbishment and plant operation during the renewal term, respectively. Chapter 5 contains an evaluation of potential environmental impacts of plant accidents and includes consideration of severe accident mitigation alternatives (SAMAs). Chapter 6 discusses the uranium fuel cycle and solid waste management, and Chapter 7 discusses decommissioning. The alternatives to license renewal are considered in Chapter 8. Finally, Chapter 9 summarizes the findings of the prior chapters, draws conclusions related to the adverse impacts that cannot be avoided (the relationship between short-term uses of man's environment and the maintenance and enhancement of long-term productivity, and the irreversible or irretrievable commitments of resources), and presents the recommendation of the staff with respect to the proposed action. Additional information is included in Appendices. Appendix A contains a discussion of comments on the draft SEIS issued on May 20, 1999. Appendix B lists preparers of this supplement, and Appendix C lists the chronology of correspondence between NRC and Duke with regard to this supplement. The remaining appendices are identified in subsequent sections.

Generic Environmental Impact Statement

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The NRC initiated a generic assessment of the environmental impacts associated with the license renewal term to improve the efficiency of the license renewal process by documenting the assessment results and codifying the results in the Commission's regulations. This assessment is provided in the GEIS. The GEIS serves as the principal reference for all nuclear power plant license renewal EISs.

The GEIS documents the results of the systematic approach that was taken to evaluate the environ-mental consequences of renewing the licenses of individual nuclear power plants and operating them for an additional 20 years. For each potential environmental issue, the GEIS (1) described the activity that affects the environment, (2) identified the population or resource that is affected, (3) assessed the nature and magnitude of the impact on the affected population or resource, (4) characterized the significance of the effect for both beneficial and adverse effects, (5) determined whether the results of the analysis applied to all plants, and (6) considered whether additional mitigation measures would be warranted for impacts that would have the same significance level for all plants.

The standard of significance was established using the Council on Environmental Quality (CEQ) terminology for "significantly" (40 CFR 1508.27) for assessing environmental issues as SMALL, MODERATE, or LARGE. Using the CEQ terminology, the NRC established three significance levels as follows:

The GEIS assigned a significance level to each environmental issue. In assigning these levels, it was assumed that ongoing mitigation measures would continue.

The GEIS included a determination of whether the analysis of the environmental issue could be applied to all plants, and whether additional mitigation measures would be warranted. Issues were then assigned a Category 1 or a Category 2 designation. As set forth in the GEIS, Category 1 issues are those that meet all of the following criteria:

For issues that meet the three Category 1 criteria, no additional plant-specific analysis is required unless new and significant information is identified.

Category 2 issues are those that do not meet one or more of the criteria of Category 1, and therefore, additional plant-specific review for these issues is required.

In the GEIS, the staff assessed 92 environmental issues and determined that 69 qualified as Category 1 issues, 21 qualified as Category 2 issues, and two issues were not categorized. The latter two issues, environmental justice and chronic effects of electromagnetic fields, are to be addressed in a plant-specific analysis. Of the 92 issues, 10 are related to refurbishment, 74 are related to operations during the renewal term, and 8 apply to both refurbishment and operation during the renewal term. A summary of the findings for all 92 issues of the GEIS is codified in 10 CFR Part 51, Subpart A, Appendix B, Table B-1.

License Renewal Evaluation Process

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An applicant seeking to renew its operating license is required to submit an ER as part of its application. This ER must provide an analysis of the issues listed as Category 2 in 10 CFR Part 51, Subpart A, Appendix B, Table B-1 in accordance with 10 CFR 51.53(c)(3)(ii). The ER must include a discussion of actions to mitigate adverse impacts associated with the proposed action and environmental impacts of alternatives to the proposed action. In accordance with 10 CFR 51.53(c)(2), the ER need not consider the economic benefits and costs of the proposed action and alternatives to the proposed action except insofar as such benefits and costs are either essential for determination regarding the inclusion of an alternative in the range of alternatives considered or relevant to mitigation. Section 51.53(c)(2) also provides that certain other issues, including the need for power and other issues not related to the environmental effects of the proposed action need not be considered in the ER. In addition, the ER need not discuss any aspect of the storage of spent fuel within the scope of the generic determination in 10 CFR 51.23(a) in accordance with 10 CFR 51.23(b). Pursuant to 10 CFR 51.53(c)(3)(I)(iii) and (iv), the ER is not required to contain an analysis of any Category 1 issues unless there is significant new information on a specific issue. New and significant information is (1) information that identifies a significant environmental issue not covered in the GEIS and codified in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, or (2) information that was not considered in the analyses summarized in the GEIS and which leads to an impact finding different from that codified in 10 CFR Part 51.

In preparing to submit its application to renew the ONS operating licenses, Duke developed a process to ensure that new and significant information regarding the environmental impacts of license renewal for ONS would be properly reviewed before submitting the ER and to ensure that new and significant information related to renewal of the ONS licenses would be identified, reviewed, and addressed during the period of NRC review. Duke reviewed the Category 1 issues appearing in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, to verify that the conclusions of the GEIS remained valid with respect to ONS. This review was performed by personnel from Duke's Group Environmental Health and Safety and the Oconee station personnel. Duke has committed to repeating this review process at 1-year intervals until a determination on the Oconee license renewal application is made. Duke also committed to include the South Carolina Department of Health and Environmental Control (SCDHEC), the South Carolina Department of Natural Resources (SCDNR), and the U.S. Fish and Wildlife Service (FWS) as part of the review process and making revisions to the ER if new issues were identified that had not been included in the GEIS or if changes to conclusions made in the ER were required.

The NRC staff also has a process for identifying new and significant information. That process is described in detail in a draft of the Standard Review Plans for Environmental Reviews for Nuclear Power Plants, Supplement 1: Operating License Renewal (ESRP), NUREG-1555, Supplement 1 (February 1999 pre-publication copy) (NRC 1999b). The search for new information includes a review of an applicant's ER and the process for discovering and evaluating the significance of new information; review of records of public meetings and correspondence; review of environmental quality standards and regulation coordination with Federal, State, and local environmental protection and resource agencies; and review of the technical literature. Any new information discovered by the staff is evaluated for significance using the criteria set forth in the GEIS. For Category 1 issues where new and significant information is identified, reconsideration of the conclusions for those issues is limited in scope to the assessment of the relevant new and significant information; the scope of the assessment does not include other facets of the issue that are not affected by the new information. Neither Duke nor the staff has identified any new issue applicable to ONS that has a significant environmental impact.

The discussion of the environmental issues considered in the GEIS that are applicable to ONS is found in Chapters 3 through 7. At the beginning of the discussion of each set of issues, there is a table that identifies the issues to be addressed and lists the sections in the GEIS where the issue is discussed. Category 1 and Category 2 issues are listed in separate tables. For Category 1 issues for which there is no new and significant information, the table is followed by a set of short paragraphs that state the GEIS conclusion codified in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, followed by the staff's analysis and conclusion. For Category 2 issues, in addition to the list of GEIS sections where the issue is discussed, the tables list the subparagraph of 10 CFR 51.53(c)(3)(ii) that describes the analysis required and the SEIS sections where the analysis is presented. The SEIS sections discussing the Category 2 issues are listed immediately following the table.

The NRC prepares an independent analysis of the environmental impacts of license renewal as well as a comparison of these impacts to the environmental impacts of alternatives. The evaluation of Duke's license renewal application began with publication of a notice of acceptance for docketing (63 FR 42885, August 11, 1998). The staff published a notice of intent to prepare an EIS and conduct scoping (63 FR 50257, September 21, 1998). Two public scoping meetings were held on October 19, 1998, in Clemson, South Carolina. Comments received during the scoping meeting were summarized in the Environmental Impact Statement Scoping Process, Oconee Nuclear Station, Summary Report, January 1999 (NRC 1999c).

The staff visited the ONS Site on October 19 through 22, 1998, reviewed the comments received during scoping, and consulted with Federal, State, regional, and local agencies. A list of the organizations consulted is provided in Appendix D of this document. Other documents related to ONS were also reviewed and are referenced.

The staff followed the review guidance contained in the February 1999 prepublication version of the ESRP (which was under development at the time of the Duke application). It issued requests for additional information (RAIs) to Duke by letters dated December 29, 1998 (NRC 1998a and 1998b). Duke provided its responses in a letter dated March 4, 1999 (Duke 1999). The staff reviewed this information, incorporated it into its analysis, and, on May 20, 1999, issued a draft of the SEIS, which contained the preliminary results of its evaluation and recommendation.

With the publication of the EPA Notice of Filing of the draft SEIS (64 FR 28843, May 28, 1999), a 75-day comment period began to allow members of the public to comment on the preliminary results of the NRC staff's review. During this comment period, two public meetings were held in Clemson, South Carolina, on July 8, 1999, during which the staff described the preliminary 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 their comments. The comment period for the ONS draft SEIS ended on August 16, 1999.

This report presents the staff's final analysis that considers and weighs the environmental effects of the proposed renewal of the ONS licenses, the environmental impacts of alternatives to license renewal, and alternatives available for avoiding adverse environmental effects. The staff considered the comments that were received during the comment period. The disposition of these comments is addressed in Appendix A of this SEIS. The staff modified the analysis set forth in the draft SEIS to address certain comments, where appropriate. A vertical bar in the margin indicates where the staff made changes to the draft SEIS. In addition, Chapter 9, "Summary and Conclusions," provides the NRC staff's final recommendation to the Commission on whether the adverse environmental impacts of license renewal are so great that preserving the option of license renewal for energy planning decisionmakers would be unreasonable.

1.1 The Proposed Federal Action

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The proposed Federal action is renewal of the operating licenses for ONS Units 1, 2, and 3. ONS is located in Oconee County, South Carolina, approximately 13 km (8 mi) northeast of Seneca, South Carolina. The plant has three pressurized light-water reactors, each with a design rating for net electrical power output of 887 megawatts (MW(e)). Plant cooling is provided by a once-through heat dissipation system into Lake Keowee. Keowee Hydroelectric Station, was constructed at approximately the same time as ONS. ONS produces electricity to supply the needs of more than 730,000 homes. The current operating license for Unit 1 expires on February 6, 2013, for Unit 2 on October 6, 2013, and for Unit 3 on July 19, 2014. By letter dated July 7, 1998, Duke submitted an application to renew these operating licenses for an additional 20 years of operation (i.e., until February 6, 2033, for Unit 1, October 6, 2033, for Unit 2, and July 19, 2034, for Unit 3).

1.2 Purpose and Need for the Action

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Although a licensee must have a renewed license to operate a plant beyond the term of the existing operating license, the possession of that license is just one of a number of conditions that must be met for the licensee to continue plant operation during the term of the renewed license. Once an OL is renewed, State regulatory agencies and the owners of the plant will ultimately decide whether the plant will continue to operate based on factors such as the need for power or other matters within the State's jurisdiction or the purview of the owners.

Thus, for license renewal reviews, the Commission has adopted the following definition of purpose and need (GEIS, Section 1.3):

The purpose and need for the proposed action (renewal of an operating license) is to provide an option that allows for power generation capability beyond the term of a current nuclear power plant operating license to meet future system generating needs, as such needs may be determined by State, utility, and where authorized, Federal (other than NRC) decision makers.

This definition of purpose and need reflects the Commission's recognition that, unless there are findings in the safety review required by the Atomic Energy Act (AEA) of 1954, as amended, or findings in the NEPA environmental analysis that would lead the NRC to reject a license renewal application, the NRC does not have a role in the energy planning decisions of State regulators and utility officials as to whether a particular nuclear power plant should continue to operate. From the perspective of the licensee and the State regulatory authority, the purpose of renewing an operating license is to maintain the availability of the nuclear plant to meet system energy requirements beyond the current term of the plant's license.

1.3 Compliance and Consultations

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Duke is required to hold certain Federal, State, and local environmental permits, as well as meet relevant Federal and State statutory requirements. Duke provided a list in its ER of the status of authorizations from Federal, State, and local authorities for current operations as well as environmental approvals and consultations associated with ONS license renewal. Authorizations most relevant to the proposed license renewal action are summarized in Table 1-1. The full list of authorizations provided by Duke is included as Appendix E.

The staff reviewed the list and has consulted with the appropriate Federal, State, and local agencies to identify any compliance or permit issues or significant environmental issues of concern to the reviewing agencies. Agency interactions identified no new and significant environmental issues. The staff has also not identified any new and significant environmental issues.

Table 1-1. Federal, State, and Local Authorizations

References

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10 CFR Part 51, "Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions."

10 CFR 51.53, "Postconstruction environmental reports."

10 CFR 51.95, "Postconstruction environmental impact statements."

10 CFR Part 51, Subpart A, Appendix B, Table B-1, "Environmental effect of renewing the operating license of a nuclear power plant."

10 CFR Part 54, "Requirements for renewal of operating licenses for nuclear power plants."

10 CFR 54.23, "Contents of application - environmental information."

40 CFR 1508.27, "Terminology and Index - Significantly."

63 FR 42885, "Notice of Acceptance for Docketing of the Application and Notice of Opportunity for a Hearing Regarding Renewal of Licenses Nos. DPR-38, DPR-47 and DRP-55." August 11, 1998.

63 FR 50257, "Notice of Intent to Prepare an Environmental Impact Statement and Conduct Scoping Process." September 21, 1998

64 FR 28843, "Duke Energy Corporation, Oconee Nuclear Station, Units 1, 2, and 3; Notice of Availability of the Draft Supplement to the Generic Environmental Impact Statement and Public Meeting for the License Renewal of Oconee Nuclear Station, Units 1, 2, and 3." May 27, 1999.

Atomic Energy Act of 1954, as amended, 42 USC 2011, et seq.

Duke Energy Corporation. 1998. Application for Renewed Operating Licenses - Oconee Nuclear Station, Units 1, 2, and 3. Volume IV, Environmental Report.

Duke Energy Corporation. 1999. Letter from M.S. Tuckman, Duke Energy Corporation to U.S. Nuclear Regulatory Commission. Subject: License Renewal-Response to Requests for Additional Information, Oconee Nuclear Station. Dated March 4, 1999.

Endangered Species Act, as amended, 16 USC 1531, et seq.

Federal Water Pollution Control Act (FWPCA), as amended, 33 USC 1251, et seq. (also known as the Clean Water Act).

National Environmental Policy Act of 1969, as amended, 42 USC 4321, et seq.

National Historic Preservation Act, as amended, 16 USC 470, et seq.

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1998a. Letter from U.S. NRC to William R. McCollum, Duke Energy Corporation. Subject: Request for Additional Information for the Review of the Oconee Nuclear Station Units 1, 2, and 3. Environmental Report Associated with License Renewal-Environmental. Dated December 29, 1998.

U.S. Nuclear Regulatory Commission (NRC). 1998b. Letter from U.S. NRC to William R. McCollum, Duke Energy Corporation. Subject: Request for Additional Information for the Review of the Oconee Nuclear Station Unit Nos. 1, 2 & 3 Environmental Report Associated with License Renewal - SAMA. Dated December 29, 1998.

U.S. Nuclear Regulatory Commission (NRC). 1999a. Generic Environmental Impact Statement for License Renewal of Nuclear Plants, Main Report, Section 6.3 - Transportation, Table 9.1, Summary of findings on NEPA issues for license renewal of nuclear power plants, NUREG-1437 Vol. 1, Addendum 1. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1999b. Standard Review Plans for Environmental Reviews for Nuclear Power Plants, Supplement 1: Operating License Renewal, NUREG-1555, Supplement 1. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1999c. Environmental Impact Statement Scoping Process: Summary Report - Oconee Nuclear Station Units 1, 2 and 3, Oconee County, South Carolina. Washington, D.C.

2.0 Description of Nuclear Power Plant and Site and Plant Interaction with the Environment

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The Oconee Nuclear Station (ONS) is located near State Highways 130 and 183 on Lake Keowee in eastern Oconee County, South Carolina, approximately 13 km (8 mi) northeast of Seneca, South Carolina. The site is within 40 km (25 mi) of the boundaries of the States of North Carolina and Georgia, as shown in Figure 2-1. ONS is a three-unit plant. Each unit is equipped with a nuclear steam supply system manufactured by Babcock & Wilcox that uses a pressurized light-water reactor (LWR) and once-through cooling with water from Lake Keowee. The electricity generated is transferred to the switchyards located at the ONS site. Each unit has a design rating for net electrical power output of 887 megawatts electric [MW(e)]. Each unit is rated at 846 MW(e) net power. This provides a combined station total of 2538 MW(e) net power. The amount of electricity produced by ONS can supply the needs of more than 730,000 homes. Descriptions of the plant and its environs follow in Section 2.1, and the plant's interaction with the environment is presented in Section 2.2.

Figure 2-1. Location of Oconee Nuclear Station

2.1 Plant and Site Description and Proposed Plant Operation During the Renewal Term

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ONS is located on 210 ha (510 acres) in a rural part of northwestern South Carolina. Figure 2-1 shows the location of ONS in relationship to the tri-state area (northwest South Carolina, northeast Georgia, and southwest North Carolina). The site is surrounded by an exclusion area of 1.6-km (1-mi) radius as shown in Figure 2-2. All land is owned by Duke in full except for a small rural church lot, a highway right-of-way, and approximately 4 ha (9.9 acres) included in the Hartwell Reservoir project.

The region surrounding ONS was identified by the Generic Environmental Impact Statement (GEIS) as having a medium population density. Approximately 1700 persons comprise the non-outage work force at ONS. There are 1350 Duke employees normally onsite. The remainder of the 1700 persons are contract or vendor workers. The plant is located near the cities of Seneca, Walhalla, and Clemson, South Carolina. The nearest town is Six Mile, located 6 km (4 mi) east northeast. The majority of the land area is forest, with pasture, cropland, and residential development each contributing significant proportions of land use. The land within 8 km (5 mi) of the plant is primarily forest.

The property consists of rolling hills, with surface elevations ranging from about 210 m to 273 m (700 ft to 900 ft) within the region. The area is well drained by several intermittent streams flowing away from the center of the site in a radial pattern. The site lies within the drainage area of the Little and Keowee Rivers, which flow southerly into the Seneca River and subsequently discharge into the main drainage course of the Savannah River. The average annual rainfall at the site area is approximately 135 cm (53 in).

ONS is part of Duke's integrated energy producing area called the Keowee-Toxaway complex. ONS was constructed as a part of the Keowee-Toxaway Project (FERC Project #2503). This project also included the construction of Lake Keowee, Lake Jocassee, and the associated hydroelectric stations. Construction of the project occurred between 1968 and 1974. The Keowee-Toxaway Complex is located in the upper Savannah River drainage basin. It consists of the three-unit ONS, the Keowee Hydroelectric Station (a two-unit conventional hydroelectric facility), the Jocassee Hydroelectric Station (a four-unit pumped storage hydroelectric facility) and the Bad Creek Pumped Storage Project (a four-unit pumped storage hydroelectric facility). A pumped storage hydroelectric facility can operate in a generating mode or in a pumping mode to store water for later generation of electric power. In the generating mode, electricity is generated by allowing water to flow from Lake Jocassee (upper pond) into Lake Keowee (lower pond). In the pumping mode, water is pumped into Lake Jocassee from Lake Keowee for generation of electricity at a later time. The Bad Creek Pumped Storage Facility uses Lake Jocassee as the lower pond, and the Bad Creek Reservoir serves as the upper pond. Figure 2-3 illustrates the location of ONS in relationship to the rest of the Keowee Toxaway project and the Bad Creek project.

Figure 2-2. Oconee Nuclear Station - One-Mile Exclusion Area

Figure 2-3. Location of Oconee Nuclear Station Relative to Other Parts of Keowee-Toxaway Project

ONS is on the shores of Lake Keowee. The main bodies of the lake lie to the north and southwest of the site. Lake Keowee was formed by damming the water of the Little River and the Keowee River above the Hartwell Reservoir. Hartwell Reservoir, an Army Corps of Engineers' reservoir, is located south and downstream of the site. Lake Jocassee is approximately 17.5 km (11 mi) to the north. Keowee Lake covers about 7490 ha (18,500 acres) and has 480 km (300 mi) of shoreline, which is developed with both permanent and vacation residences, along with campgrounds, boat launch areas, marinas, golf courses, and some small retail establishments. The volume of Lake Keowee is 1.18x10⁹ m³ (952,300 acre ft). The mean depth is 16 m (52 ft) with a maximum depth of 43 m (141 ft). In addition to uses for the needs of the nuclear and hydroelectric power plants, Lake Keowee is used as a source of municipal drinking water by Greenville and Seneca and is extensively used for recreation by fishermen, swimmers, skiers, and boaters.

2.1.1 External Appearance and Setting

The station is sited within a forested valley and is only visible from the neighboring highways in a few locations. The most obvious view is that of the water tower. ONS consists of three cylindrical concrete reactor building structures, approximately 38 m (125 ft) in diameter and about 61 m (200 ft) high. A turbine building and an auxiliary building are shared among the three units. Switchyards are located near the turbine building. Various other office buildings and facilities are located at ONS to support the station. Figure 2-4 shows the general features of the ONS site. Figure 2-5 presents an aerial view of the facility showing the three cylindrical reactor buildings.

Duke has an independent spent fuel storage installation (ISFSI) located on the site that has a license separate from the operating license. Duke was issued a Materials License (No. SNM-2503) for the ISFSI on January 29, 1990, with an expiration date of January 31, 2010. The ISFSI is outside the scope of this review.

The Old Pickens Presbyterian Church and Cemetery are located to the southeast of ONS on a small parcel of land that is not owned by Duke. The church is the only building remaining from the original Pickens town site. A Visitor's Center on a hill just above the site displays "The Story of Energy," which describes how sources of energy are found in nature and converted into electricity by Duke's generating facilities. There is also a lakeside picnic area, a nature trail, and landscaped grounds.

The site's geological setting is in the southeastern Piedmont physiographic province, and the site is underlain by crystalline rocks (AEC 1972). This northeastward-trending belt of ancient metamorphic rocks extends northward from Alabama east of the Appalachians, and in South Carolina, it crosses the state from the fall line on the east to the Blue Ridge and Appalachian Mountains on the west. These rocks are generally recognized as being divided into four parallel northeast-southwest-trending belts in the Carolinas. From southeast to northwest, these are the Carolina Slate Belt, the Charlotte Belt, the Kings Mountain Belt, and the Inner Piedmont Belt. The site is in the northwestern Inner Piedmont Belt.

Figure 2-4. Oconee Nuclear Station Layout

Figure 2-5. Oconee Nuclear Station (aerial photo)

The rocks are geologically ancient and complex. These rocks were folded and metamorphosed when the Appalachian Mountains were formed during the Appalachian Revolution, some 270 million years ago. Faults and other lines of weakness dating from this Revolution may serve to locate present-day minor crustal movements that produce small earthquakes, and their location is of some importance. The most important is the Brevard fault zone that passes 17.5 km (11 mi) northwest of the site. The design criteria for the Station took this fault zone into account. Small earthquakes have been detected along this zone with intensities of IV to VI. Using this scale of intensities, V and VI represent disturbances that can dislodge plaster, etc.; X, XI, and XII represent disturbances that are severely damaging (AEC 1972).

In addition to the Brevard fault, there are fault zones 48 km (30 mi) to 320 km (200 mi) southeast where quake intensities of VII or VIII have been recorded. But because of their distance from the site, these zones are of slight importance for ONS (AEC 1972).

ONS is in the drainage basins of the Little and Keowee Rivers, which receive the runoff of surface water and groundwater from the site. The residual soil in the area is comparatively impermeable, particularly in late winter and early spring when the soil is saturated, and much of the precipitation goes into direct surface runoff. The residual soils do accept some water, and the area is underlain by a water table that is a subdued replica of the topography. Groundwater is not an important source of water supply in the area; all neighboring towns obtain their municipal supplies from above-ground sources.

The rate of movement of the groundwater was calculated to be 45 m to 76 m (150 ft to 250 ft) per year (AEC 1972). The residual soil has excellent ion exchange properties.

2.1.2 Reactor Systems

ONS is a three-unit plant. Each unit is a pressurized LWR, with a nuclear steam supply system manufactured by Babcock & Wilcox. Each unit has a design rating for net electrical power output of 887 MW(e) and is operated at a maximum core thermal power output level of 2568 MW(t). The turbines are manufactured by General Electric Company. Each turbine is a tandem, compound, six-flow exhaust, indoor unit.

ONS fuel is low-enriched (up to 5 percent by weight)⁽⁴⁾ uranium dioxide in the form of pellets contained in zirconium alloy fuel rods (tubes fitted with welded end caps).

Duke can operate ONS in accordance with the methodology presented in B&W topical report BAW-10186P-A, which was approved by the staff in its letter dated April 29, 1997 (NRC 1997). Based on this methodology, cycle length, and fuel enrichment, the ONS fuel burnup⁽⁵⁾ rate does not exceed 62,000 megawatt-days per metric ton uranium (MWd/MTU).

Reactor containment structures are designed with engineered safety features to protect the public and plant personnel from an accidental release of radioactive fission products, particularly in the unlikely event of a loss-of-coolant accident (LOCA). These safety features function to localize, control, mitigate, and terminate such events to limit exposure levels below applicable dose guidelines. The reactor is controlled using a combination of chemical controls (boric acid dissolved in coolant water) and solid absorber material.

2.1.3 Cooling and Auxiliary Water Systems

ONS is equipped with a once-through heat dissipation system that withdraws cooling water from the Little River arm of Lake Keowee, from underneath a skimmer wall. The discharge for the cooling water is located on the Keowee River arm of the lake just above the Lake Keowee dam. The Keowee River and the Little River basins are connected by a canal, approximately 31 m (100 ft) wide and 12 m (40 ft) deep (illustrated in Figure 2.2). It is nearly 3.2 km (2 mi) by lake from the point of discharge to the mouth of the intake canal. A natural cove was deepened and extended to within a few hundred feet of the power plant as part of the project when initially licensed. Across the mouth of the cove, a skimmer wall was constructed extending from above the surface of the lake (normally 244 m [800 ft] above mean sea level) down to an elevation of 223 m (735 ft). This wall ensures that cooler water from near the bottom of the lake enters the intake canal. Further into the intake cove is a submerged dam, or weir, with its crest at 233 m (770 ft) above mean sea level. The distance from the weir to the intake structures is nearly 1.2 km (0.75 mi). Figure 2-4 shows the water flow for the plant and illustrates the location of the skimmer wall, intake structure, and the outfall for the once-through cooling system.

Each generating unit has three separate water loops. The primary coolant loop is a closed piping system: pressurized water in the system is circulated through the reactor and transfers heat from the reactor to the steam generator. The secondary loop is also a closed system: water from this system is converted into steam (in the steam generators) that is used to drive the turbine. The third loop is an open system: water from the Little River arm of Lake Keowee is used to cool the spent steam in the secondary loop, and then it is returned to the Keowee River arm of Lake Keowee. The principal components of the third cooling loop are the skimmer wall, intake structure, circulating water pumps, condensers, and discharge conduits.

2.1.4 Radioactive Waste Management Systems and Effluent Control Systems

ONS uses liquid, gaseous, and solid radioactive waste management systems to collect and process the liquid, gaseous, and solid wastes that are the by-products of the ONS operation. These systems reduce radioactive liquid, gaseous, and solid effluents before they are released to the environment. The ONS waste processing systems meet the design objectives of 10 CFR Part 50, Appendix I, and control the processing, disposal, and release of radioactive liquid, gaseous, and solid wastes. Radioactive material in the reactor coolant is the source of gaseous, liquid, and solid radioactive wastes in LWRs. Radioactive fission products build up within the fuel as a consequence of the fission process. These fission products are contained in the sealed fuel rods, but small quantities escape the fuel rods and contaminate the reactor coolant. Neutron activation of the primary coolant system also is responsible for coolant contamination.

Non-fuel solid wastes result from treating and separating radionuclides from gases and liquids and from removing contaminated material from various reactor areas. Solid wastes also consist of reactor components, equipment, and tools removed from service as well as contaminated protective clothing, paper, rags, and other trash generated from plant design and operations modifications and routine maintenance activities. Solid wastes may be shipped to a waste processor for volume reduction before disposal or may be sent directly to the licensed burial site. Spent resins and filters are dewatered and stored or packaged for shipment to an offsite processing or disposal facility.

Fuel rods that have exhausted a certain percentage of their fuel and that are removed from the reactor core for disposal are called spent fuel. ONS currently operates on an 58-month refueling cycle for all three units. Spent fuel is stored onsite either in a spent fuel pool in the Auxiliary Building or in dry storage at the ONS ISFSI. ONS also temporarily stores mixed waste onsite (mixed wastes are composed of radioactive material and hazardous waste). This storage is governed by the Atomic Energy Act (AEA) for radioactive material and the Resource Conservation and Recovery Act (RCRA) for hazardous waste, consistent with NRC and EPA requirements (42 USC 2011-2259 [AEA]; 42 USC 6901 [RCRA]).

The systems used for processing--liquid waste processing, gaseous waste processing, solid waste processing, and nonradioactive waste systems--are discussed in the subsequent sections.

The Offsite Dose Calculation Manual (ODCM) specifies the following methodology and parameters used to calculate potential offsite doses due to radioactive liquid and gaseous effluents and to ensure compliance with the dose limitations of the Selected Licensee Commitments (Section 16.11, "Radiological Effluents Control," of the Updated Final Safety Analysis Report [UFSAR]):

• The concentration of radioactive liquid effluents released from the site to the unrestricted area will be limited to ten times the effluent concentration (EC) levels of 10 CFR Part 20, Appendix B, Table 2.
• The exposures to any individual member of the public from radioactive liquid effluents will not result in doses greater than the design objectives of 10 CFR Part 50, Appendix I.
• The dose rate at any time at the site boundary from radioactive gaseous effluents will be limited to (a) less than or equal to 5 mSv/yr (500 mrem/yr) to the whole body and less than or equal to 30 mSv/yr (3000 mrem/yr) to the skin for noble gases and (b) less than or equal to 15 mSv/yr (1500 mrem/yr) to any organ for iodine-131 and 133, tritium, and for all radioactive materials in particulate form with half-lives greater than 8 days.
• The exposure to any individual member of the public from radioactive gaseous effluents will not result in doses greater than the design objectives of 10 CFR Part 50, Appendix I.
• The dose to any individual member of the public from the nuclear fuel cycle will not exceed the limits of 40 CFR Part 190 and 10 CFR Part 20.

2.1.4.1 Liquid Waste Processing Systems and Effluent Controls

Based on the water source and process train, radioactive liquid wastes from the operation of ONS are accumulated in storage tanks. These wastes are collected in the Auxiliary Building and transferred to the Radwaste Facility for processing by filtration or demineralization or both. The Radwaste Facility processes high-activity wastes, low-activity wastes, and miscellaneous wastes from the Auxiliary Building. There is also an Interim Radwaste Building that can process liquid wastes, but it is not currently in use.

ONS liquid wastes are disposed of by one of the following three methods based on the concentration of radioactive material in the waste:

• Collected, sampled, and analyzed and then discharged directly to the tailrace of the Keowee Hydroelectric plant.
• Processed by filtration or demineralization or both, collected, sampled, and analyzed with the filters and/or resins and then packaged and shipped to an approved licensed burial ground.
• Processed by filtration or demineralization or both, collected, sampled, and analyzed with the filters and/or resins and then packaged and shipped to an offsite vendor waste processor.

The potential waste generation rate for the three units is 28,343 m³ (944,773 ft³) per year. The liquid waste holdup capacity is approximately 303,200 liters (80,000 gal). The actual liquid waste generated is reported in the Oconee Annual Effluent Report.

The ODCM prescribes the effluent release rate that will ensure that the concentration of radioactive liquid effluents released from the site to the unrestricted area is less than ten times the effluent concentrations of 10 CFR Part 20, Appendix B, Table 2. In addition, the ODCM provides calculations for the radiation monitor alarm/trip set points that define the relationship between the measured effluent activity, the maximum allowable effluent activity, and the effluent flowrate needed to ensure that the instantaneous release rate is not exceeded and thereby that the Selected Licensee Commitments are met.

2.1.4.2 Gaseous Waste Processing Systems and Effluent Controls

Radioactive gaseous wastes at ONS are created by the evolution of gases in liquid contained in tanks and piping. The wastes are monitored and released at a permissible rate prescribed by the ODCM. Units 1 and 2 share a Gaseous Waste Disposal System, and Unit 3 has a separate system that can be interconnected to the Unit 1 and 2 system. The purposes of the Gaseous Waste Disposal Systems are to (1) maintain a non-oxidizing cover gas of nitrogen in tanks and equipment that may contain radioactive gas, (2) holdup gas for decay, and (3) release the gases under controlled conditions.

The gaseous wastes are to be released in the following ways depending on the source, quantities, and concentration of radioactive material: (1) release of Auxiliary Building ventilation air and Reactor Building purges into the unit vents, (2) release of Reactor Building purges through high-efficiency particulate and charcoal iodine filters to the unit vents, (3) release of waste gas directly or through high efficiency particulate and charcoal iodine filters to the unit vents, (4) diversion of gaseous radioactive waste to waste gas tanks followed by a controlled release to the unit vents via high-efficiency particulate and charcoal iodine filters after sampling and analysis, and (5) release of Radwaste Facility heating, ventilation, and air conditioning (HVAC) and process exhaust.

The ODCM prescribes the effluent release rate to ensure that releases are less than the Selected Licensee Commitments. In addition, the ODCM provides the calculational methodology for the radiation monitor alarm/trip set points, which defines the relationship between the measured effluent activity, the maximum allowable effluent activity, and the effluent flowrate needed to ensure that the instantaneous release rate limit is not exceeded and thereby that the Selected Licensee Commitments are met.

2.1.4.1 Solid Waste Processing and Handling

Solid waste is packaged in containers to meet the applicable requirements of 49 CFR Parts 171 through 177. Disposal and transportation are performed in accordance with the applicable requirements of 10 CFR Part 61 and Part 71, respectively. There are no releases to the environmentfrom radioactive solid wastes created at ONS. NRC and the state of South Carolina have approved the disposal of slightly contaminated materials within the Owner Controlled Area. For each onsite disposal, the waste is analyzed and confirmed to have acceptably low radionuclide concentrations, following the approval process described in 10 CFR 20.2002.

Approximately 150 shipments are made from ONS each year. About 120 are radioactive material shipments (contaminated parts, tools, equipment, sources, etc.) and 30 radwaste shipments (dry active waste, dewatered resins, irradiated hardware, etc.). The radwaste shipments may be shipped to a waste processor to reduce the volume before disposal or may be sent directly to a licensed burial site.

From year to year, the volume of radioactive contaminated waste generated will vary, but averages are about 750 m³ (25,000 ft³) per year. ONS has been aggressively reducing volume and minimizing waste for several years and plans to continue to do so in the future.

2.1.5 Nonradioactive Waste Systems

The primary nonradioactive chemical wastes produced by ONS are from reactor coolant system make-up water, steam generator make-up water, water treatment demineralizers, and deborating demineralizers. Non-sanitary, nonradioactive wastes are neutralized and sent to the holding ponds, eventually being discharged to the Keowee River, downstream from the Keowee Hydroelectric Station. Sanitary wastes are routed to an aerated sewage lagoon. The effluents are treated by chlorination. The treated effluents from the sanitary waste treatment system are dechlorinated before being discharged.

2.1.6 Plant Operation and Maintenance

Routine maintenance performed on plant systems and components is necessary for safe and reliable operation of a nuclear power plant. Some of the maintenance activities conducted at ONS include inspection, testing, and surveillance to maintain the current licensing basis of the plant and to ensure compliance with environmental and public safety requirements. Certain activities can be performed while the reactor is operating. Others require that the plant be shut down. Long-term outages are scheduled for refueling and for certain types of repairs or maintenance, such as replacement of a major component. Scheduled refueling outages commonly have a duration of 35 to 55 days for a single unit. An additional 800 to 900 workers are onsite during a typical outage. Scheduled refueling outages for ONS occur on 18-month intervals for all three units.

Duke performed an aging management review and developed an integrated plant assessment for managing the effects of aging on systems, structures, and components in accordance with 10 CFR Part 54. The integrated plant assessment identified several activities that must necessarily be conducted during the period of extended operation. These activities include inspections and replacement of certain components. The applicant indicated that replacing these components and conducting additional inspections are within the bounds of normal plant operations. Therefore, Duke expects to conduct these activities during plant operation or normal refueling and other outages, but plans no outages specifically for the purpose of refurbishment. Duke has no plans to add additional full-time persons (non-outage workers) at the plant during the period of the extended license.

2.1.7 Power Transmission System

The ONS FES (AEC 1972) lists the transmission lines shown in Table 2-1 as being "attributable to the (Oconee) nuclear station." These lines account for 528 km (330 mi) of lines and about 3120 ha (7800 acres) of land in the rights-of-way. Figure 2-6 illustrates the location of these transmission lines.

Table 2-1. Transmission Lines from Oconee Nuclear Station

These transmission lines were constructed concurrently with the construction of Oconee and the Keowee-Toxaway project and at a time that the Duke transmission system was being expanded in the Piedmont area. These lines are owned and operated by Duke Electric Transmission, a division of Duke Energy separate from Duke Power (Duke 1998a). The applicant indicated that the transmission lines will remain in service following the termination of operation and the decommissioning of Oconee, unless business needs require otherwise. The applicant stated that the 525 kV and the 230 kV lines from the Oconee substation provide an outlet for the 1675 MW of electrical power at the Jocassee and Bad Creek Pumped Storage Hydro plants. They are a source of power when these units are in pump mode.

Figure 2-6. Transmission Lines Attributable to the Oconee Nuclear Station in the Final Environmental Statement (AEC 1972)

In addition, Duke stated that three of the lines were energized before initial ONS startup. These lines are also used for tie-ins to the Virginia-Carolinas subregion of the Southeastern Electric Reliability Council as well as for connections to Georgia and Florida. In its license renewal application, uke (1998a) proposed that the transmission lines that should be considered to connect the plant to the transmission system are only those lines from the Oconee Turbine Building to the 230 kV and the 525 kV switchyards. However, as provided in 10 CFR 51.53(c)(3)(ii)(H), the scope of the review of transmission lines for the Category 2 issue concerning electric shock is the set of transmission lines that were constructed for the specific urpose of connecting the plant to the transmission system. The NRC staff has determined that the scope of the review of transmission lines for the Category 2 issue concerning threatened or endangered species should be identical to the scope of review for electric shock (NRC 1999b). As stated above, the ONS FES indicates that all the transmission lines listed in Table 2-1 were "attributable to [ONS]." Accordingly, the staff has determined that all these lines were

constructed for the specific purpose of connecting ONS to the transmission system and determined that all of the transmission lines discussed in the FES should be evaluated.

2.2 Plant Interaction with the Environment

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Subsections 2.2.1 through 2.2.8 provide general descriptions of the environment as background information. They also provide detailed descriptions where needed to support the analysis of potential environmental impacts of refurbishment and operation during the renewal term as discussed in Chapters 3 and 4. Subsection 2.2.9 describes the historical and archaeological resources in the area, and 2.2.10 describes possible impacts on other Federal project activities.

2.2.1 Land Use

ONS is located in the northwest corner of South Carolina. The station is in the eastern portion of Oconee County. It is approximately 13 km (8 mi) northeast of the city of Seneca, the largest city in Oconee County. Lake Keowee occupies the area immediately north and west of the station. Lake Keowee covers approximately 7500 ha (18,500 acres) and was created by dams on the Lower Keowee and Little River.

The total area occupied by the station is 210 ha (510 acres). Forests cover the majority of the land area in the region surrounding ONS. The topography of the immediate area is undulating to rolling. Surface elevations range from approximately 210 m (700 ft) to 275 m (900 ft).

Oconee County is predominantly rural. The county's major population centers and developed areas are concentrated in the east central portion of the county around the municipalities of Walhalla, Westminster, and Seneca. Walhalla is the county seat for Oconee County. Table 2-2 shows a breakdown of land use in Oconee County in 1994. The amount of developed land is increasing with time.

Table 2-2. Land Use in Oconee County in 1994 (Talbert & Bright 1996)

The land occupied by the station is in an unincorporated portion of Oconee County. Oconee County has not imposed any zoning or land-use restrictions in the unincorporated portions of the county.

2.2.2 Water Use

Water from Lake Keowee (8.3 x 10⁶ m³/d [2200 million gpd]) provides once-through condenser circulating water (CCW) for ONS (see Section 2.1.3). Lake Keowee serves as the lower pond for the Jocassee Pumped Storage Station and furnishes energy to drive the Keowee Hydroelectric Station. Water from the Seneca water treatment plant (120 m³/d [0.03 million gpd]) is used for potable water. Treated waste water (51 m³/d [0.01 million gpd]) from the plant's liquid rad-waste system is diluted and returned to the Keowee dam tailrace. Treated water (5300 m³/d [1.4 million gpd]) from the sewage treatment system, the chemical treatment system, the landfill leachate collection system, chemical treatment ponds, storm water runoff, and the turbine building sump are returned to the Keowee River at a location below the tailrace. Figure 2.7 illustrates the water flow for the plant.

In addition to serving the needs of the nuclear and hydroelectric power plants, Lake Keowee is used as a source of municipal drinking water for the cities of Greenville and Seneca. Lake Keowee experiences extensive recreational use by fishermen, boaters, skiers, and swimmers.

Seven groundwater wells are located at the Oconee site. One of these wells is used to supply the site baseball field with drinking water and with water for a restroom facility. This well is also used for seasonal irrigation at the site baseball field and has a pumping capacity of 0.0019 m³/s (30 gpm). The well at the baseball field is the only onsite groundwater well permitted to supply drinking water. There are two groundwater wells used to supply seasonal irrigation for landscaping at a training building and office complex. The other four wells are used infrequently as low volume, non-potable water sources.

The estimated combined pumping rate for all groundwater wells at the Oconee site is less than 0.068 m³/s (100 gpm).

2.2.3 Water Quality

The concentrations of all minerals in Lake Keowee are very low, with total dissolved solids of less than 25 mg/L (0.00021 lb/gal). Water clarity is generally very high. Dissolved oxygen concentrations in the surface waters are adequate, and algae are never present in nuisance concentrations. Due to low nutrient content of its waters, Lake Keowee has a relatively low standing crop (pounds per acre) of fish.

Figure 2-7. Oconee Nuclear Station - Water Flow Diagram

SCDHEC, as part of the Clean Lakes program, monitors the water quality and use of lakes in the State. These results are published in Watershed Water Quality Assessment, Savannah and Salkehatchie Basins, Technical Report No. 003-97 (SCDHEC 1997). In this document, SCDHEC reported that

Eutrophication assessments indicate that Lake Keowee is the least eutrophic large lake in South Carolina, characterized by very low nutrient concentrations. Preservation of this lake's desirable trophic condition is recommended. Aquatic life uses are not supported in Lake Keowee due to occurrences of copper in excess of the aquatic life acute standards, including a high concentration of copper measured in 1995, compounded by a significant increasing trend in pH. A significant increasing trend in dissolved oxygen concentration and a significant decreasing trend in five-day biochemical oxygen demand suggest improving conditions for these parameters. Recreational uses are fully supported at this site.

Pursuant to the Federal Water Pollution Control Act (FWPCA) (33 USC 1251), also known as the Clean Water Act (CWA), the water quality of plant effluent discharges is regulated through the National Pollutant Discharge Elimination System (NPDES). The SCDHEC is the state agency delegated by the EPA to issue the NPDES permit. The current permit (SC0000515) was issued on September 29, 1999, and expires on September 30, 2003. Any new regulations promulgated by EPA or the SCDHEC would be included in future permits.

2.2.4 Air Quality

ONS is located on the eastern slope of the Appalachian Mountains at an elevation of about 240 m (800 ft) mean sea level. The climate of the region is generally mild. Climatological records for Greenville-Spartanburg, South Carolina (NOAA 1998), which should be representative of the site, show normal daily maximum temperatures ranging from about 10C (50F) in January to about 31C (88F) in July; normal daily minimum temperatures range from about -1C (30F) in January to about 20C (68F) in July. Precipitation, which averages about 130 cm (51 inches) per year, is spread rather uniformly through the year. Monthly average wind speeds range from 2.7 m/s (6.1 mph) to 3.75 m/s (8.4 mph), with the highest speeds during the winter and lowest speeds during the summer. The influence of the Appalachian Mountains is seen in the prevailing wind directions, which are west-southwest and northeast. Section 2.3 of the ONS updated final safety analysis report (UFSAR) (Duke 1998b) contains a more detailed description of the climate of the region and site.

Climatological records also show that the area is subject to occasional storms, including destructive winds. In most years, one or more tropical storms affect the site; however, ONS is sufficiently far inland that the winds associated with these storms are below hurricane force. Tornadoes are infrequent in this region and are generally small when they occur.

For about two-thirds of the year, the region is under the influence of the Bermuda high pressure system. High pressure systems are typically associated with low winds and increased potential for air pollution problems. As indicated in 40 CFR 81.334, 40 CFR 81.341, and the 1997 South Carolina Air Quality Annual Report (SCDHEC 1998), South Carolina and North Carolina are in attainment of the National Air Quality Standards. The only non-attainment area in Georgia is an ozone non-attainment area in the Atlanta region (40 CFR 81.311). The Pollutant Standards Index (PSI) is an air quality index developed by the EPA in cooperation with the Council on Environmental Quality. For 1997, the average PSI for the Spartanburg, Greenville, Anderson metropolitan area was 48, which is associated with Good air quality (SCDHEC 1998). The daily PSIs for 211 days were in the Good range, and the remaining daily PSIs were in the Moderate range. The days with Moderate PSIs resulted from ozone formation.

The Oconee site is within 100 km (62 mi) of the Great Smoky Mountains National Park and Shining Rock Wilderness Area. These areas are designated in 40 CFR, Part 81, Subpart D, as mandatory Class I Federal areas in which visibility is an important value. As a result of the proximity of the Oconee Site to these Class I areas, future industrial development at the site will be subject to strict Federal standards for pollution control (SCDHEC 1998).

2.2.5 Aquatic Resources

Lake Keowee serves the needs of the local nuclear and hydroelectric power plants and is also used as a source of municipal drinking water by the cities of Greenville and Seneca, South Carolina. It is used extensively by fishermen, boaters, skiers, and swimmers, and its banks are developed with vacation and permanent residences, campgrounds, boat launch areas, marinas, golf courses, and small retail establishments.

Algae have never been present in nuisance concentrations, and, because of the low nutrient content of the water, Lake Keowee has a relatively low standing crop of fish. A creel census conducted in 1973 indicated that largemouth bass (Micropterus salmoides), bluegill (Lepomis macrochirus), and crappie (Pomoxis, spp.) were the most important recreational species in Lake Keowee (Edwards et al. 1976). Data on angler effort and harvest rates collected over a period from 1974 to 1993 (Barwick et al. 1995) confirmed that largemouth bass remained the most important sportfish in the reservoir and that sunfish (Lepomis spp., including bluegill) and crappie were the only other species that contributed in a significant way to the reservoir's sport fishery.

The U.S. Fish and Wildlife Service (FWS), in a letter dated April 17, 1998, provided a list of the Federally endangered and threatened species that potentially occur in Oconee County, South Carolina. No Federally listed aquatic species were identified for Oconee County. However, the bog turtle (Clemmys muhlenbergii) occurs in neighboring Pickens County and was listed as a threatened species due to similarity of appearance to the northern population of the same species. A survey conducted during June 1998 by Dr. L.L. Gaddy (Duke 1998a) found no Federal- or State-listed threatened or endangered species present within a 1.6-km (1-mi) radius Unit 2's reactor building at ONS. This includes the owner-controlled areas as well as additional lands along the Keowee River and along Lake Keowee. No State-ranked aquatic species listed as occurring in Oconee or Pickens Counties have been identified as occurring on or in the immediate vicinity of ONS.

The importance of fishery resources to the local community has promoted a partnership between Duke and SCDNR. Recently, SCDNR and Duke Power Company signed a Memorandum of Understanding (Keowee-Toxaway Fisheries Resources 1996) and developed a 10-year work plan to enhance communication between the two groups and provide for continued research, management, and enhancement of the fisheries resources in the watershed.

2.2.6 Terrestrial Resources

The vegetation in the vicinity of ONS has been variously described as part of the oak-pine-hickory biome of the eastern deciduous forest (Greller 1988) or as part of the southern mixed forest province (Bailey 1976, 1980). Much of the Piedmont region near ONS was cleared and converted to cotton production during the late 1800s and then abandoned in the 1930s. Most of the existing forested areas in the vicinity of ONS consequently represent second growth forests. The various pine species, such as loblolly (Pinus taeda), shortleaf (P. echinata), and Virginia (P. virginiana) pines, are the dominant conifers. Common hardwoods include red and white oaks (Quercus rubra, Q. alba), hickory (Carya sp.), and tulip poplar (Liriodendron tulipifera), among others. The understory is dominated by shrubs such as dogwood (Cornus florida), mountain laurel (Kalmia latifolia), and redbud (Cercis canadensis), as well as many species of herbs and grasses.

White-tailed deer (Odocoileus virginianus), black bear (Ursus americanus), raccoon (Procyon lotor), rabbits (Sylvilagus floridanus), squirrels (Sciurus carolinensis and Tamiasciurus hudsonicus), beavers (Castor canadensis), muskrats (Ondatra zibethica), foxes (Urocyon cinereoargenteus and Vulpes vulpes), opossums (Didelphis marsupialis), skunks (Mephitus mephitus and Spilogale putorius), river otters (Lutra canadensis), mink (Mustela vison), and various mice, voles, and shrews are wildlife species found in the project area. The white-tailed deer is the most popular game species, and black bear are hunted in the areas to the west of ONS.

The turkey (Meleagris gallopavo), bobwhite quail (Colinus virginianus), and mourning dove (Zenaida macroura), are the most common game birds. Many species of songbirds inhabit the area, including the eastern bluebird (Sialia sialis), red-eyed vireo (Vireo olivaceus), cardinal (Cardinalis cardinalis), tufted titmouse (Parus bicolor), woodthrush (Hylocichla mustelina), summer tanager (Piranga rubra), blue-gray gnatcatcher (Polioptila caerulea), hooded warbler (Wilsonia citrina), and Carolina wren (Thryothorus ludovicianus). The box turtle (Terrapene carolina), common garter snake (Thamnophis sirtalis), timber rattlesnake (Crotalus horridus), and assorted frogs, toads, and salamanders comprise the herpetofauna.

Extensive areas of ONS are protected or managed as upland natural areas, wetlands, or wildlife areas. In support of the environmental report, Duke funded a survey of all lands within a 1.6-km (1-mi) radius of the plant site. This survey, which was conducted in May and June 1998, identified several areas that retain characteristics of mature upland forests that the applicant has designated as protected natural areas. Wetlands were also identified during this survey, and these are managed as sensitive environmental areas. The applicant has a program of wildlife enhancement in unused portions of the plant site. The program was designed in partnership with the South Carolina Wildlife Federation, the SCDNR, and the National Wild Turkey Federation. This program has established semi-natural meadows, enhanced wetland native plants, placed wood duck and bluebird nesting boxes, and developed a butterfly garden.

The field survey also included an inventory of endangered, threatened, and otherwise noteworthy plant and animal species within a 1.6 km (1 mi) radius of ONS. No Federally listed, proposed, or candidate threatened or endangered species were identified during the onsite survey. However, three State-listed plant species and one plant species not previously known in South Carolina (Table 2-3) were identified. The populations of these four species were all confined to "natural areas" located toward the periphery of the survey area, well away from areas used for normal plant operations. Three additional state-listed plant and one animal species have been reported from the general area in the past, but were not located within the 1.6-km (1-mi) radius of ONS during this survey (Table 2-3).

Table 2-3. Endangered, Threatened, and South Carolina State Listed Plant and Animal Species Found on or Historically Occurring in the Vicinity of the Oconee Nuclear Station

During the spring of 1998, Duke contacted the FWS and the SCDNR to request information about threatened or endangered species that potentially could occur in the vicinity of the ONS. The staff contacted the FWS during the spring of 1999 to request similar information concerning the ONS related transmission lines. The FWS identified (FWS 1998) nine species that have been reported to occur within either Pickens or Oconee counties, South Carolina, and eight additional species reported from the other counties crossed by the transmission lines (Table 2-4). None of the species listed in Table 2-4 are known to inhabit the immediate vicinity of the ONS.

Federally listed species that have been occasionally sighted near ONS include the threatened bald eagle (Haliaeetus leucocephalus) and the endangered peregrine falcon (Falco peregrinus). Bald eagles are occasional visitors near the ONS site, but are not known to nest or to reside near the site for significant time periods. Bald eagles are known to be more numerous and spend more time in the vicinity of the Jocassee and Bad Creek Reservoirs. Peregrine falcons are occasional transients near ONS. Attempts have been made to introduce individuals near the Jocassee dam, but they are not known to reside near ONS.

Transmission lines associated with the ONS extend through a number of additional counties in both South Carolina and North Carolina. The FWS provided the staff information about threatened and endangered species that may occur in these counties. This list is summarized in Table 2-4.

Table 2-4. Federally Listed Threatened or Endangered Species Known or Potentially Occurring Near the ONS or in Counties Crossed by Transmission Lines Associated with the ONS

Examination of the National Heritage Databases from South Carolina and North Carolina indicates that three plant species listed in Table 2-4 may occur within or near the transmission line rights-of-way. The bunched arrowhead occurs in the corridors located northwest of Greenville, South Carolina, and in the corridors located northeast of Traveler's Rest, South Carolina. The dwarf-flowered heartleaf occurs near corridors northeast of Traveler's Rest and also between Landrum, South Carolina, and the McGuire substation. Schweinitz's sunflower is known to occur near the Newport and McGuire substation at the far eastern end of the ONS related transmission system.

2.2.7 Radiological Impacts

Duke has conducted a radiological environmental monitoring program (REMP) around ONS since 1969. The radiological impacts to workers, the public, and the environment have been carefully monitored, documented, and compared to the appropriate standards. The purposes of the REMP are to

• verify that radioactive materials and ambient radiation levels attributable to plant operation are within the limits contained in the Selected Licensee Commitments and the Environmental Radiation Protection standards as stated in 40 CFR Part 190, Environmental Radiation Protection Standards for Nuclear Power Operations
• detect any measurable buildup of long-lived radionuclides in the environment
• monitor and evaluate ambient radiation levels
• determine whether any statistically significant increase occurs in the concentration of radionuclides in important pathways.

Radiological releases are summarized in the annual reports titled "Oconee Nuclear Station Units 1, 2, and 3 Annual Radiological Environmental Operating Report" and the annual effluent release reports and includes the results of the monitoring for the ISFSI. The limits for all radiological releases are specified in the Selected Licensee Commitments, and these limits are designed to meet Federal standards and requirements. The REMP includes monitoring of the aquatic environment (aquatic organisms and shoreline sediment in Lake Keowee and Hartwell Reservoir), atmospheric environment (air particulates and iodine), and terrestrial environment (vegetation and direct radiation).

Review of historical data on releases and the resultant dose calculations revealed that the doses to maximally exposed individuals in the vicinity of ONS were fractions of the limits specified in the Environmental Protection Agency's environmental radiation standards 40 CFR Part 190 as required by 10 CFR 20.1301(d). For 1997 (the most recent year that data were available), dose estimates were calculated based on actual 1997 liquid and gaseous effluent release data (Duke Power 1997). Calculations were performed using the plant effluent release data, onsite meteorological data, and appropriate pathways identified in the ODCM.

A review of whole body and organ doses (Duke Power 1997) revealed the following results: the total body dose estimate to an adult from environmental measurements was 0.0014 mSv/yr (0.14 mrem/yr) and the total body dose estimate from all effluent release pathways was 0.00615 mSv/yr (0.615 mrem/yr). The critical pathway for both of these estimates was from fish consumption. Cesium-137 was the major contributing radionuclide. These doses, which are representative of the doses from the past 5 years, are provided to demonstrate that the impact to the environment from releases from ONS is small.

The applicant does not anticipate any significant changes to the radioactive effluent releases or exposures from ONS operations during the renewal period and, therefore, the impacts to the environment are not expected to change.

2.2.8 Socioeconomic Factors

The staff reviewed the applicant's environmental report and information obtained from several county staff members, local real estate agents/appraisers, and social services providers during the October 1998 site visit. The following information describes the economy, population, and communities near ONS.

2.2.8.1 Housing

Between 1970 and 1990, total housing units in Oconee County increased from 14,032 to 25,983 (DOC 1991; U.S. Bureau of the Census 1988). Approximately 146 new households, or one percent of the growth in households, may be attributed to ONS employment (NRC 1996). A total of 891 ONS employees currently live in Oconee County (as of January 1999). As of January 1999, 515 ONS employees live in Pickens County and 161 live in Anderson (see Table 2-5). County growth has continued since 1990. Based on the estimates in the GEIS (NRC 1996) of 2,300 direct employment in 1990, immigrant ratio of 16.4 percent, and indirect employment multiplier of 0.41, ONS may have accounted for 3,243 direct and indirect jobs in Oconee, Pickens, and Anderson Counties. This accounted for 378 households and less than 2 percent of the housing growth from 1970 to 1990. Between 1980 and 1990, the number of housing units in the Tri-County (Oconee, Pickens, and Anderson) area increased approximately 22.5 percent to a total of 122,602 units (Knight 1998a). Table 2-6 provides the number of housing units and housing unit vacancies by county in the Tri-County area for the years 1970 to 1996.

Since 1990, Oconee County population has continued to increase from 57,494 at the 1990 Census to 64,059 in 1998 (Table 2-7). Pickens County increased in population from about 93,894 in 1990 to 104,618 in 1998 (Table 2-7). About 4,000 units were added to the Oconee County housing stock between 1990 and 1996, as the county became a more popular bedroom community, recreation area, and second home and retirement community and as manufacturing jobs were added (Table 2-6). The east end of Pickens County increasingly became a bedroom community for Greenville. At the time of the 1990 Census, about 10,700 Pickens County residents per day commuted to Greenville County (Knight 1997) and this number likely has increased. Clemson University is a major employer in Pickens County, with 7,156 jobs in 1997 (Knight 1997). Anderson County increased in population from 145,177 at the 1990 Census to 160,791 in 1998 (South Carolina Statistical Abstract [South Carolina Office of

Table 2-5. Employee Residence Information, Oconee Nuclear Station, January 1999

Table 2-6. Housing Units and Housing Units Vacant (Available) by County 1970-1996

Table 2-7. Population Growth in Oconee, Pickens, and Anderson Counties, South Carolina (1970-1998)

Research and Statistical Services 1998]), due largely to growth in branch plant manufacturing. In 1997, Anderson County employed 15,800 in major manufacturing facilities, compared with 8,400 in Oconee County and 6,800 in Pickens County (Knight 1997). Oconee County added 4,017 housing units between 1990 and 1996; Pickens County added 4,835 housing units over the same period; while Anderson County added 6,947 units (Table 2-6). Housing availability in the Tri-County area is not limited by growth-control measures. With a 1996 vacancy rate of approximately 10 percent, over 14,300 units are available for occupancy in the three closest counties (Bureau of Census 1996).

2.2.8.2 Public Services

• Water Supply

Potable water used in Oconee County is from both subsurface and surface sources and is used primarily for domestic and industrial uses. The county has four privately owned water systems, five municipal water systems, and a single sewer commission that serves the incorporated towns in the county and some selected rural areas. Table 2.8 shows source and capacity information on selected water supply systems in communities near ONS, as well as the area served by each. Both Seneca and Greenville are served with surface water from Lake Keowee, which is very high quality and has low concentrations of minerals and nutrients. Large areas of Oconee County are not served by public water supplies. According to the Oconee Community Facilities Plan, some supplies are threatened by incompatible development, including septic tanks around lakes and sedimentation and erosion from land-clearing activities. Both Seneca and Walhalla (which draws water from Coneross Creek, above Lake Keowee) have identified current plant capacity as inadequate for meeting future water demand. Seneca is searching for a location for a new treatment plant to meet future demand, while Walhalla is considering construction of a new treatment plant in the next 5 years, drawing on Lake Jocassee (reducing its need to depend on the limited capacity of Coneross Creek).

Availability of adequate wastewater collection is considered to be a current constraint on development in both Oconee and Pickens Counties. Public wastewater collection is provided in Oconee County by the municipalities of Seneca, Walhalla, and Westminster, while water treatment is provided by the Oconee County Sewer Authority (Oconee County Planning Commission 1997). Private treatment operators serve Chickasaw Point, Keowee Key, and Newry. The Authority operates the Coneross Waste Treatment Plant, which was expanded in capacity to 0.4 m³/s (7.8 million gpd). Average daily volume is only 0.14 m³/s (3 million gpd). While the difference allows considerable excess capacity for economic development within the area served by the system, there are large portions of the county not served, and there are institutional constraints that make serving the I-85 corridor a problem in Oconee County. Pickens County has limited excess capacity, and this constrains the county's ability to absorb or recruit manufacturing. Current excess capacity has been only about 0.02 m³/s (500,000 gpd), and a current $12 million upgrade is expected to primarily replace older, environmentally unacceptable capacity, expanding excess capacity to 0.04 m³/s (800,000 gpd).

Table 2-8. Major Public Water Supply Systems in Oconee County in 1997

• Education

In 1996, there were approximately 49,600 students enrolled in schools in the Oconee-Pickens-Anderson County area (Knight 1997). Enrollment totals for the public schools were 10,056 in Oconee County, 26,187 in Anderson County, and 13,353 in Pickens County. Oconee County has 11 public elementary schools, four middle schools, four high schools, and four private schools. In Anderson County, there are 27 public elementary, 11 middle/junior high schools, 9 high schools, and 5 private schools. Pickens County has 15 public elementary schools, 5 middle schools, 5 high schools, and 8 private schools. Pickens and Anderson Counties have some post-secondary capability. Anderson County has Tri-County Technical College (enrollment 3,250), Forrest Junior College (enrollment 899), and Anderson College (a private, 4-year university with an enrollment of 245). Pickens County has Clemson University, with 16,526 enrollment, and Southern Wesleyan University, with an enrollment of 1,298. Economic development also benefits from the presence of technical college and university education in nearby Greenville, especially Greenville Tech.

The area has comparatively low student/teacher ratios, despite also having relatively low property taxes. For 1996, student/teacher ratios were 14.8/1 in Oconee County, 16.9/1 in Pickens County, and varied from 15.4/1 to 18.5/1 among the five school districts in Anderson County (Knight 1997). Property tax rates in 1997 were $1.99/$1000 in Oconee County (Knight 1998b), $2.04/$1000 in Pickens County, and $2.24/$1000 in Anderson County (an average of the range among 31 districts of $1.95 to $2.64).⁽⁶⁾ Reflecting population growth, during the 1996-97 school year, the Oconee School District opened two new elementary schools, Fair Oak and Orchard Park, with a combined enrollment of over 1,100 students (Oconee County Planning Commission 1997). Fair Play Elementary School was closed and replaced by Fair Oak. All schools in the county except West Oak and Seneca High Schools received some expansion or upgrade. These two schools had received upgrades in recent years.

• Transportation

Oconee County is served by I-85 at its southeast corner, plus U.S. highways 76 and 123 and State highways 28 and Scenic 11. ONS is on a two-lane highway with service to the site being convenient from four main directions. Highway access remains adequate for the time being, but population growth in the county may create crowded conditions in the future, particularly at selected intersections.

Pickens County is not served by the Interstate Highway system, but has ready access to the I-85 corridor via U.S. 76 , 123, and 178. State Highways 8, 96, 135, 137, 124, and Scenic 11 complete the major road net. Highway 123 runs the length of Pickens County from east to west with four-lane service to Greenville. State Highway 133 (which runs north-south on the east side of Lake Keowee) and State Highway 183 from Pickens serve as commuting highways from Pickens County to ONS. Although several of the residential communities on both sides of Lake Keowee have long, narrow access roads, none of these roads has been identified as seriously congested.

The period from 1995 to 2015 has been projected by the State of South Carolina to be one of moderate population growth (1.1 percent per year). Oconee County is projected to grow at about the same rate as the state during that period, while Pickens and Anderson Counties are expected to grow at about 0.9 percent per year. At these rates, Oconee County would increase its current population by about 50 percent at the end of the license renewal period (see Section 2.2.8.1 and Knight 1998a). Significant upgrading of most arterial links and main highways is likely to be required to accommodate such growth. The population of the other two counties would grow by about 40 percent and also likely would require highway upgrades.

2.2.8.3 Offsite Land Use

Oconee and Pickens Counties both have land-use plans, but neither has zoning regulations (Talbert & Bright, Inc. 1996; interview with Pickens County Director of Planning, October 22, 1998). Industrial development is concentrated in the I-85, S.C. Route 123, Route 28, and Route 76 corridors in the two counties and in Anderson County. There are some restrictions on building practices, but these are not extensive. Industrial development has been limited in Pickens County by lack of sewer and water infrastructure. Oconee County has been relatively selective about the industry they target. Oconee County also has a sanitary landfill that is nearly at capacity and may constrain growth if it is not replaced (Oconee County Planning Commission 1997).

The continued availability of ONS and the associated tax base is an important feature in Oconee County's ability to continue to invest in infrastructure and to draw industry and new residents. In 1998-1999, the Oconee County Operational Budget was $26.2 million and the school operating budget $41.1 million, for a total of $67.4 million. Duke will pay $22.3 million in taxes on ONS in 1998-1999, or roughly a third of the county combined operational and school budget.⁽⁷⁾ In Pickens County, continued presence of the plant will have less influence on development or land use, since the plant does not directly contribute to the tax base of the county. There is relatively little impact on land use in Anderson County from Oconee-related population. Duke helps with industrial recruiting in all three counties.

2.2.8.4 Visual Aesthetics and Noise

From the air, the principal visual features of the ONS region are Lakes Keowee, Jocasee, and Hartwell and the countryside, which is generally wooded or in small farms. The position of the plant relative to Lake Keowee is such that the ONS is only visible from the water within the first 1.6 km (1 mi) to the north. Further north, islands and the topography of the shoreline render the plant invisible. From the lake, the shoreline appears mostly wooded with upscale housing developments and boat launches.

Scenic resources inland from the lake have changed since ONS construction because of population growth. This growth has resulted in housing and some roadside development supplanting agricultural and wooded areas. However, South Carolina Highway 130, which follows the east side of Lake Keowee south of the plant and follows the west side of the lake to the north of the plant, mainly affords attractive views of the lake and surrounding hilly, wooded countryside with interspersed development and occasional agricultural lands. This is the main access route to the plant from either north or south. The view on South Carolina Highway 183 coming from either the east or west shows mainly woods and fields and does not reveal ONS until the traveler is within a hundred yards of the plant gate.

Because of woods and topography, noise from the ONS is generally not an issue. The only sounds heard offsite are the plant loudspeakers, which can be heard nearby on the lake.

2.2.8.5 Demography

The update to Duke's Final Safety Analysis Report (Duke 1998b) refers to Duke's emergency response plan, which had an estimated resident population as 65,423 within 16 km (10 mi) of ONS for 1990. This is only slightly different than Duke's current estimate of 64,405 (Duke 1999a). Seasonal resident population adds another 6,694, transient summer weekend visitors add 8,636 more, and on Clemson football weekends, there may be over 75,000 visitors to the area.

Tables 24.1 through 24.5 in Duke (1999a) estimated resident population for 1990 and each decade through the proposed ONS license renewal term (2010, 2020, 2030). The 2010 projections represent estimated population near the first year of license renewal for Unit 1 (2013), and the projections for the year 2030 represent populations after the end of the renewal term (2034 for Unit 3). Near the end of the license renewal term (2030), the population within 80 km (50 mi) of ONS is expected to be approximately 1.3 million, as compared with 990,000 in 1990 (Duke 1998b).

Data for 1990 are based on the 1990 Census of Population. Future population estimates were developed by combining information that was available from the 1990 Census⁽⁸⁾ and resident population projections found in the GEIS, Vol. 2, page A-46.

The 1990 resident population distribution (by distance and directions) is found in Table 24.1 of Duke (1999a). Populations for the sectors⁽⁹⁾ were calculated using population values at the census block level, the smallest enumeration level used by the Census Bureau. Census blocks whose geographic centroid was located within a sector were considered to lie within that sector. For each sector that is located within 80 km (50 mi) of the plant, the population numbers for the blocks within each sector were summed to give a total for that sector.

The projected population within the sectors for the years 2000, 2010, 2020, and 2030 was calculated by increasing the 1990 population for each sector by the percentage increases between the respective periods.

The projected 1990 population within 80 km (50 mi) of the Oconee Nuclear Station from the GEIS is 990,000 persons. The 1990 Census Bureau data for the year 1990 indicated 1,021,226 people living within 80 km (50 mi) of the plant. This difference (3.2 percent) was considered to be small. Therefore, Duke (1999a) used the predicted total population values found in the GEIS for the 80-km (50-mi) radius around the plant to extrapolate the 1990 population distribution data forward in time for the years 2010 and 2030. The total resident population within the 80-km (50-mi) radius for the year 2020 (not listed in the GEIS) was determined by using linear interpolation between the population totals for the years 2010 and 2030. This same procedure was applied by the staff to Duke's estimates to obtain the population by sector within 16 km (10 mi).

• Resident Population Within 16 km (10 mi)

The estimated resident population within 16 km (10 mi) of ONS for the years 1990, 2010, 2020, and 2030 is listed in Tables 2-9 through 2-12. Figure 2-8 illustrates the 10-mile radius from ONS.

Between 1970 and 1990, the population within 16 km (10 mi) of ONS increased about 70 percent, from 37,831 (AEC 1972) to 64,405 (Duke 1999a). Current projections indicate that by the year 2010, the population within 16 km (10 mi) will be 73,789 (obtained from the FSAR [Duke 1998b]), which is about

39 percent higher than projected in the original FES (AEC 1972). The higher growth within the 16-km (10-mi) radius is primarily related to rapid population growth in Oconee County. Between 1980 and 1990, Oconee County grew half again as fast as the State (1.7 percent per year vs. 1.1 percent per year). According to agency projections, it is expected to grow at about the same rate as the state through the year 2015 (Knight 1998a). Factors stimulating growth in Oconee County include proximity to high-quality recreation and to Greenville. To these factors one could add relatively easy commutes to metropolitan areas (45-min to 1-hr commute by car), less development and lower taxes than those areas, and less stringent land use, zoning, and development regulations compared with some surrounding counties.

• Resident Population Within 80 km (50 mi)

The estimated resident population distribution within 80 km (50 mi) of ONS for the years 1990, 2010, 2020, and 2030 is shown in Tables 2-13 through 2-16. Figure 2-9 illustrates the 80-km (50-mi) radius from ONS.

Between 1970 and 1990, the population within 80 km (50 mi) of ONS increased approximately 36 percent, from about 730,000 (AEC 1972) to about 1,020,000 (Table 2-14). Current population projections in the environmental report (ER) (Duke 1998a) indicate that by the year 2010, the population within 80 km (50 mi) will be approximately 1,170,000.

Table 2-17 lists the age distribution of Oconee County in 1990 compared to the U.S. population.

• Transient Population

The transient population in the vicinity of ONS can be identified as daily or seasonal. Daily transients are associated with places where a large number of people gather regularly, such as local businesses, industrial facilities, and schools. Seasonal transients result from the use of weekend recreational areas such as Lakes Keowee, Jocasee, and Hartwell. It is estimated that seasonal transients increase the population within 16 km (10 mi) of ONS by approximately 10 percent during the summer months (Oconee Nuclear Station Emergency Response Plan, Duke 1999b). The daily and seasonal population associated with selected industry and recreation within 16 km (10 mi) of the station is listed in Table 2-18.

Table 2-9. Estimated Population Distribution in 1990 Within 16 km (10 mi) of ONS

Table 2-10. Estimated Population Distribution in 2010 Within 16 km (10 mi) of ONS

Table 2-11. Estimated Population Distribution in 2020 Within 16 km (10 mi) of ONS

Table 2-12. Estimated Population Distribution in 2030 Within 16 km (10 mi) of ONS

Figure 2-8. Oconee Nuclear Station - 16-km (10-mi) Radius

Table 2-13. Estimated Population Distribution in 1990 Within 80 km (50 mi) of ONS

Table 2-14. Estimated Population Distribution in 2010 Within 80 km (50 mi) of ONS

Table 2-15. Estimated Population Distribution in 2020 Within 80 km (50 mi) of ONS

Table 2-16. Estimated Population Distribution in 2030 Within 80 km (50 mi) of ONS

Table 2-17. Estimated Age Distribution of Population in 1990^(a)

Figure 2-9. Oconee Nuclear Station - 80-km (50-mi) Radius

It should be noted that on most weekdays, a significant portion of the resident population is absent from Oconee County during daytime hours. According to the 1990 Census of Population, 25 percent of employed County residents (about 6700 people) commuted to jobs outside of Oconee County while over 4200 commuted into the county (Talbert & Bright 1996). With increased numbers of in-movers to Oconee County, the number of commuters likely has increased, although no post-1990 numbers are available.

Table 2-18. Transient Population Within 16 km (10 mi) of ONS^(a)

2.2.9 Historical and Archaeological Resources

This section discusses the cultural background and the known historical and archaeological resources at the ONS site and in the surrounding area.

2.2.9.1 Cultural Background

The area around ONS is rich in prehistoric and historic Native American and historic Euroamerican cultural resources. This part of northwestern South Carolina has an archaeological sequence that extends back to about 10,000 B.C., although human use of the area was probably limited until about 4,000 to 5,000 B.C. when numerous small campsites are evident in the archaeological record. By 1000 B.C., archaeological data suggest a shift from scattered campsites to a more sedentary settlement and a subsistence system that was concentrated on ravine settings. By A.D. 1000, the archeological evidence for ancestral Cherokee culture is present, beginning with the regional Pisgah Phase (A.D. 1000 to 1500) and the following contact period Qualla Phase (A.D. 1500 to 1850) (Dickens 1976; Keel 1976). Pisgah villages included upright wooden post houses encircled by a palisade. These villages were commonly located in the larger alluvial valleys where soils were suitable for horticulture. This general village pattern continued into the Early Qualla Phase with the Late Qualla Phase being characterized by the Europeanization of Native American technology, economy, and settlement patterns after A.D. 1820.

The Cherokee were first noted in the written record by Spanish explorers in 1540. During the Qualla historic period, the Cherokee Indian cultural group has been divided into three subgroups, based on cultural, linguistic, and environmental distinctions (Dickens 1979). Of these subgroups, the Lower Cherokee grouping occupied the foothills of the Appalachian Mountains near the upper reaches of the Savannah River system. The Keowee River valley, which includes ONS and the associated reservoir, was one of the principal riverine settings for Lower Cherokee settlements of this period. Other Lower Cherokee villages are documented from historical written references in this part of South Carolina (Sheriff 1994; Ross 1980). During the 18^th century, Keowee was the most important of these villages (Harmon 1986). The Cherokee village of Keowee, which is today located beneath the waters of Lake Keowee about 8 km (5 mi) north of ONS, was partially excavated during a preimpoundment archaeological project sponsored by Duke from 1966 to 1968. Also investigated by this project was Fort Prince George, a garrison constructed across the river from Keowee Village by the British Government in 1753 to protect the Lower Cherokee from French intrusions into the area and to secure trade relations between the British and the Cherokees (Hembree and Jackson 1998; Williams 1998).

The Cherokee Indian presence throughout their former extensive homelands came to a close in the late 1700s through a series of treaties with the Colonies and the United States, culminating with the well-documented removal of the Cherokee and other southeastern tribes to Indian Territory in the West (Perdue and Green 1995). The part of South Carolina, including the Oconee project area, was included in a land cession treaty completed in May of 1777 (Royce 1884). A small number of Cherokee in North Carolina avoided the removal actions and today are recognized as the Eastern Band of Cherokee Indians, with their tribal headquarters at Cherokee, North Carolina, some 80 km (50 mi) north of ONS. Cherokees removed to the West are today known as the Cherokee Nation of Oklahoma.

Following the 1777 treaty, northwestern South Carolina was immediately occupied by land-hungry white settlers. The first deeds in the Keowee River valley date to 1784; by the turn of the century, most of the land along the Keowee and adjacent valleys had been deeded. Hembree and Jackson (1998) document the historical development of the Keowee River valley from initial settlement through construction of Duke's Keowee-Toxaway Project that transformed the entire river valley.

2.2.9.2 Historical and Archaeological Resources at ONS

Archaeological

As noted above, archaeological investigations were conducted throughout the Keowee-Toxaway Project area, basically the Keowee River valley from the present Keowee Dam and ONS north to include the inundated portion of Lake Keowee. This effort was conducted by personnel from the South Carolina State Department of Archaeology during which 39 archaeological sites were recorded. Of this total, 9 of the sites were archaeologically tested, and significant excavations were completed at 6 sites, including Keowee Indian village and Fort Prince George (Beuschel, no date). Although final reports of these activities were not issued following the fieldwork, recent documents have provided some detail (Harmon 1986; Williams 1998). Information gained about both the Cherokee occupation and the British operation of Fort Prince George is also presented in the interpretive displays at the Keowee-Toxaway State Park.

Archaeological site file searches at the South Carolina Department of Archives and History and the Institute of Archaeology and Anthropology, University of South Carolina, revealed the presence of four recorded Native American sites within a 1.6-km (1-mi) radius of ONS. Two of these sites were recorded during a field survey of the Oconee-Bad Creek 500 kV transmission line (Brockington 1978). Both of these archaeological sites, located northwest of the ONS, are low-density lithic tool scatter sites and were evaluated as not possessing characteristics that would make them eligible for the National Register of Historic Places. The other two archaeological sites are located southwest of the plant. Each of these sites is also categorized as a nondescript lithic scatter.

Historical

The preinundation archaeological project focused solely on the prehistoric and early historic Cherokee sites and Fort Prince George. The architecture and archaeology of historic Euroamerican period settlements in the overall project area were not documented and evaluated, including the Old Pickens townsite at the location of ONS. A number of cemeteries in the valley were relocated before inundation. Additionally, many historic structures were relocated by Duke, including residences, a girl's camp, two sawmills, and a covered wooden bridge.

The original town of Pickens on the west bank of the Keowee River was active between 1828 and 1868 as the courthouse town of Pickens District, which then included present-day Oconee and Pickens Counties (Hembree and Jackson 1998; Holder 1991). In 1868, the Keowee River was designated as the boundary line between the two newly formed counties. In response to this division, a new town, also called Pickens, was established about 24 km (15 mi) northeast to be the seat of Pickens County. Most of the buildings in the original town of Pickens were torn down or dismantled and moved to the new town of Pickens or to Walhalla, the new county seat of Oconee County.

The original townsite apparently included much of what became ONS. According to Hembree and Jackson (1998), "The Pickens townsite stretched from the bank of the Keowee, along what is now the Pickens-Walhalla Highway [Highway 183], west across the Duke construction and maintenance shops, and north over the site of the nuclear plant."

Today, the only standing structure at the Old Pickens townsite is a one-story brick building built between 1849 and 1851, commonly known as the "Old Pickens Presbyterian Church." A cemetery with over 200 marked graves surrounds the church, including the original cemetery associated with the church and relocated graves from 14 family or other cemeteries that were moved to Old Pickens in the late 1960s before Lake Keowee was filled. A complete listing of tombstone inscriptions from the original and relocated cemeteries is found in the Pendleton Chapter of South Carolina Genealogical Society (1983-84). The Old Pickens Presbyterian Church was nominated for inclusion in the National Register of Historic Places in 1994 and listed in 1996 (Sherard 1994).

No other historic period sites are currently recorded at ONS. While no historic structures are present, there is potential for either surface or buried historic archaeological remains (e.g., artifact scatters, privies, and refuse dumps) that could exist in areas that have not received substantial soil disturbance.

Any such remains could have been associated either with the Old Pickens townsite, with nearby homesteads along the river, or along Highways 183 and 130. According to the Keowee-Toxaway Project description, 17 houses were relocated in connection with development of ONS (Duke 1971).

For example, Hembree and Jackson (1998) illustrate a historic two-story home, known in the 1800s as the Pleasant Alexander House that once stood in the Oconee project area on the west bank of the Keowee River. During dam construction in the 1960s, Duke used the house as an office, after which it was moved to High Falls County Park where it continues to serve as park offices. In a 1968 aerial photograph of the ONS construction site, the house is clearly evident on the west bank, just below the damsite (Hembree and Jackson 1998). In the same view, two other then-extant historic houses can be seen along the north side of Highway 183, along the southern edge of the plant site. At the same location near the current access road into the plant from Highway 183, there is a small fenced cemetery on the knoll above the road. This cemetery has not been recorded and is not included in the listing of Oconee County historic cemeteries (Pendleton Chapter of South Carolina Genealogical Society 1983-84). Household artifacts in the vicinity of this cemetery indicate that a house was probably at one time associated with the graves.

2.2.10 Related Federal Project Activities

The Federal Power Commission, now the Federal Energy Regulatory Commission (FERC), issued a license (FERC Project No. 2503) to Duke Power on September 1, 1966, for the construction of the Keowee hydroelectric station and the Jocassee pumped storage project. Lake Keowee, from which the ONS draws cooling water, is formed by dams on the Keowee River and Little River. The Keowee hydroelectric station is located at the dam on the Keowee River. The station serves as the onsite emergency electric power source for ONS. The license for the Keowee and Jocassee hydroelectric projects will expire in 2016. Under current FERC rules, Duke will need to file a notice of intent with FERC by 2011 declaring whether it intends to seek a new license for the Keowee and Jocassee hydroelectric projects. At least 2 years before the license expires, Duke will need to file an application for a new license (relicense). FERC procedures for processing a new license are similar to those for an original license.

The staff reviewed the possibility that activities of other Federal agencies (including FERC) might impact the renewal of the operating license for the ONS. Any such activities could result in cumulative environmental impacts and the possible need for such a Federal agency to become a cooperating agency for preparation of the SEIS.

The staff determined that there were no Federal project activities in the vicinity of ONS that could result in cumulative environmental impacts or that would make it desirable for another Federal agency to become a cooperating agency for preparing the SEIS. The Natural Resources Conservation Service (NRCS), a division of the U.S. Department of Agriculture, was the only Federal agency to participate in the scoping process. NRCS submitted a letter stating that it has partnered with Duke in planning, implementing, and promoting environmental stewardship, such as the cooperative work to prevent and control soil erosion at work sites in the South Carolina mountains and foothills.

2.3 References

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10 CFR Part 20, "Standards for Protection Against Radiation."

10 CFR 20.1301(d), "Dose limits for individual members of the public."

10 CFR 20.2002, "Method for obtaining approval of proposed disposal procedures."

10 CFR Part 20, Appendix B, Table 2, "Annual limits on intake (ALIs) and derived air concentrations (DACs) of radionuclides for occupational exposure; effluent concentrations; concentrations for Release to Sewerage."

10 CFR Part 50, Appendix I, "Numerical guides for design objectives and limiting conditions for operation to meet the criterion 'as low as is reasonably achievable' for radioactive material in light-water-cooled nuclear power reactor effluents."

10 CFR 51.53, "Postconstruction environmental reports."

10 CFR 54, "Requirements for Renewal of Operating Licenses for Nuclear Power Plants."

10 CFR Part 61, "Licensing requirements for land disposal of radioactive waste."

10 CFR Part 71, "Packaging and transportation of radioactive material."

40 CFR 81.311, "Georgia."

40 CFR 81.334, "North Carolina."

40 CFR 81.341, "South Carolina."

40 CFR Part 81, Subpart D, "Identification of Mandatory Class I Federal Areas where Visibility is an Important Factor."

40 CFR Part 190, "Environmental radiation protection standards for nuclear power operations."

49 CFR Parts 171 through 177.

Atomic Energy Act of 1954, as amended, 42 USC 2011-2259, et seq.

Bailey, R.G. 1976. Ecoregions of the United States (map). Ogden, Utah: USDA Forest Service, Intermountain Region. 1:7,500,000.

Bailey, R.G. 1980. Descriptions of the Ecoregions of the United States. USDA Forest Service, Misc. Publication No. 1391.

Barwick, D.H., L.E. Miller, W.R. Geddings, and D.M. Rankin. 1995. Fish biomass and angler harvest from a South Carolina cooling reservoir. Proceedings of the Annual Conference of the Southeastern Association of Fish and Wildlife Agencies 49: 129-139.

Beuschel, L.L. No Date. Keowee Toxaway Reservoir Project: A Partial Account of the Archaeology. Draft report prepared for Duke Power Company, Charlotte, NC. Copy on file at the South Carolina Institute of Archaeology and Anthropology, University of South Carolina, Columbia, South Carolina.

Brockington, P.E. 1978. An Archaeological Survey of Duke Power's Oconee-Bad Creek 500 kV and Jocassee-Bad Creek 100 kV Transmission Lines, Oconee County, south Carolina. South Carolina Institute of Archaeology and Anthropology, Research Manuscript Series 130, Columbia, South Carolina.

Clean Air Act (CAA), as amended, 42 USC 7401, et seq.

Coastal Zone Management Act (CZMA), as amended, 33 USC 1455, et seq.

Dickens, R.S., Jr. 1976. Cherokee Prehistory. University of Tennessee Press, Knoxville, Tennessee.

Dickens, R.S., Jr. 1979. The Origins and Development of Cherokee Culture. In The Cherokee Indian Nation: A Troubled History, edited by Duane H. King, pp. 3-32. University of Tennessee Press, Knoxville, Tennessee.

Duke Energy Corporation. 1998a. Application for Renewed Operating Licenses Oconee Nuclear Station - Units 1, 2 and 3. Volume IV - Environmental Report.

Duke Energy Corporation. 1998b. Oconee Updated Final Safety Analysis Report (UFSAR). Charlotte, North Carolina.

Duke Energy Corporation. 1999a. Letter from M.S. Tuckman, Duke Energy Corporation to U.S. Nuclear Regulatory Commission. Subject: License Renewal - Response to Requests for Additional Information, Oconee Nuclear Station. Dated March 4, 1999.

Duke Energy Corporation. 1999b. Oconee Nuclear Station Emergency Plan, Rev. 99-01. Charlotte, North Carolina.

Duke Power Company. 1971. Supplement to Environmental Quality Features of Keowee-Toxaway Project. Charlotte, North Carolina.

Duke Power Company. 1977. Oconee Nuclear Station Environmental Summary Report 1971-1976, Volumes 1 and 2. Duke Power Company Steam Production Department.

Duke Power Company. 1997. Oconee Nuclear Station Units 1 and 3, Annual Radiological Environmental Operating Report.

Edwards, T.J., W.H. Hunt, L.E. Miller, and J.J. Sevic. 1976. An evaluation of the impingement of fishes at four Duke Power Company steam-generating facilities. Pages 373-380 in Esch, G.W. and R.W. McFarlane (eds.). Thermal Ecology II. National Technical Information Service, U.S. Department of Commerce, Springfield, Virginia.

Federal Water Pollution Control Act (FWPCA), as amended, 33 USC 1251 et seq. (Also know as the Clean Water Act).

Greller, A.M. 1988. "Deciduous Forest." Pp. 287-316, In North American Terrestrial Vegetation, M.G. Barbour and W.D. Billings, eds., Cambridge University Press, New York.

Harmon, M.A. 1986. Eighteenth Century Lower Cherokee Adaptation and Uses of European Material Culture. South Carolina Institute of Archaeology and Anthropology, Volumes in Historical Archaeology 2, Columbia, South Carolina.

Hembree, M. and D. Jackson. 1998. Keowee: The Story of the Keowee River Valley in Upstate South Carolina. Fourth Printing, Revised. No publisher given.

Holder, F.C., Compiler. 1991. Historic Sites of Oconee County, SC: Part of the History of Oconee County Told Through Historic Preservation. Second Edition. Oconee County Historical Society.

Keel, B.C. 1976. Cherokee Archaeology. University of Tennessee Press, Knoxville, Tennessee.

Keowee-Toxaway Fishery Resources. 1996. Ten-Year Work Plan: January 1996-December 2005. South Carolina Department of Natural Resources and Duke Power Company.

Knight, H.T. (Ed.) 1997. 1997 Upstate Profile. Quality of Life of the S.C. Upstate. Part Three: Upstate Living, Upstate Leisure, Business Travel, and Tourism. South Carolina Appalachian Council of Governments, Greenville, South Carolina.

Knight, H.T. (Ed.) 1998a. 1998 Upstate Profile. Development of the SC Upstate. Part 1: Population, Income, and Housing. South Carolina Appalachian Council of Governments, Greenville, South Carolina.

Knight, H.T. (Ed.) 1998b. 1998 Oconee County Economic Profile. Comprehensive Overview of South Carolina's Golden Corner. South Carolina Appalachian Council of Governments, Greenvilee, South Carolina.

National Oceanic and Atmospheric Administration (NOAA). 1998. "1997 Local Climatological Data Annual Summary with Comparative Data, Greenville-Spartanburg (Greer), South Carolina." Asheville, North Carolina.

Oconee County Planning Commission. 1997. Oconee County Community Facilities Plan. Prepared by the Oconee County Planning Commission and the Appalachian Council of Governments, Walhalla, South Carolina., August 1997.

Pendleton Chapter of South Carolina Genealogical Society. 1983, 1984. Oconee County, South Carolina Cemetery Survey. 2 Vols. A Press, Greenville, South Carolina.

Perdue, T. and M.D. Green, Editors. 1995. The Cherokee Removal: A Brief History with Documents. Bedford Books, Boston, Massachusetts.

Resource Conservation and Recovery Act of 1976, 42 USC 6901.

Ross, L.W. 1980. A Short History of the Cherokee Indians in Oconee County, SC. No publisher given. Pamphlet, 8 pp.

Royce, C.C. 1884. Map of the Former Territorial Limits of the Cherokee "Nation of" Indians Exhibiting the Boundaries of the various Cessions of Land Made by them to the Colonies and to the United States by Treaty Stipulations, from the Beginnings of their Relations with the Whites to the Date of their Removal West of the Mississippi River. 1977 Reprint by the Museum of the Cherokee Indians, Cherokee, North Carolina.

Sherard, G.W., Compiler. 1994. National Register of Historic Places Registration Form: Old Pickens Presbyterian Church. Copy of file at South Carolina Department of Archives and History, Columbia, South Carolina.

Sheriff, A., Editor. 1994. Cherokee Villages in South Carolina, Including Information on Fort Prince George and Fort Rutledge. Second Edition. Forest Acres/McKissick Quest Program, Easley, South Carolina.

South Carolina Department of Health and Environmental Control (SCDHEC). 1997. Watershed Water Quality Assessment: Savannah and Salkehstchie River Basins, Technical Report No. 003-97. Columbia, South Carolina.

South Carolina Department of Health and Environmental Control (SCDHEC). 1998. South Carolina Air Quality Annual Report, Volume XVII 1997. Columbia, South Carolina.

South Carolina Office of Research and Statistical Services. 1998. South Carolina Statistical Abstract. South Carolina State Budget and Control Board. Published by the Office of Research and Statistics, Columbia, South Carolina.

Talbert & Bright, Inc. and Holland Consulting Planners, Inc. 1996. Oconee County, South Carolina 1996 Land Use Plan.

U.S. Atomic Energy Commission (AEC). 1972. Final Environmental Statement related to operation of Oconee Nuclear Station Units 1, 2 and 3. March 1972. Washington, D.C.

U.S. Bureau of the Census. 1988. County and City Data Book. Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

U.S. Bureau of the Census. 1996. Population Estimates Branch, Estimates of Housing Units and Households of Counties 1990-1996. U.S. Government Printing Office, Washington, D.C.

U.S. Bureau of the Census. 1999. County Population Estimates for July 1, 1998, and Population Change for July 1, 1997, to July 1, 1999, Population Estimates Program Population Division.

U.S. Department of Commerce (DOC). 1991. 1990 Census - Population and Housing; Public Law 94-171 Data. Bureau of the Census, Washington, D.C.

U.S. Fish and Wildlife Service. 1998. Letter from R.L. Banks (FWS, Charleston, South Carolina) to J. Huff (Duke Power, Charlotte, North Carolina) dated April 17, 1998. Letter provides a list of 9 species in Oconee and Pickens Counties.

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1997. Letter from NRC to Framatome Technologies, Inc. Subject: Acceptance for Referencing of FCF Topical Report BAW-10186P "Extended Burnup Evaluation." Dated April 29, 1997.

U.S. Nuclear Regulatory Commission (NRC). 1998. Letter from NRC to Duke Energy Corporation. Subject: Request for Additional Information for the Review of the Oconee Nuclear Station Unit Nos. 1, 2, & 3 Environmental Report Associated with License Renewal - Environmental. Dated December 29, 1998.

U.S. Nuclear Regulatory Commission (NRC). 1999a. Letter from NRC to Duke Energy Corporation. Subject: Use of Framatome Cogema Fuels Topical Report on High Burnup - Oconee Nuclear Station, Units 1, 2, and 3. Dated March 1, 1999.

U.S. Nuclear Regulatory Commission (NRC). 1999b. Letter from NRC to Duke Energy Corporation. Subject: Determination of the Scope of Transmission Lines Impact Assessment for Oconee License Renewal. Dated May 10, 1999.

Williams, M.W. 1998. A Memoir of the Archaeological Excavation of Fort Prince George, Pickens County, South Carolina. South Carolina Institute of Archaeology and Anthropology Research, Research Manuscript Series 226, Columbia, South Carolina.

3.0 Environmental Impacts of Refurbishment

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Environmental issues associated with refurbishment activities were discussed in the Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437 (NRC 1996). The GEIS included a determination of whether the analysis of the environmental issues could be applied to all plants and whether additional mitigation measures would be warranted. Issues were then assigned a Category 1 or a Category 2 designation. As set forth in the GEIS, Category 1 issues are those that meet all of the following criteria:

(1) the environmental impacts associated with the issue have been determined to apply either to all plants or, for some issues, to plants having a specific type of cooling system or other specified plant or site characteristics

(2) a single significance level (i.e., SMALL, MODERATE, or LARGE) has been assigned to the impacts (except for collective offsite radiological impacts from the fuel cycle and from HLW and spent fuel disposal)

(3) mitigation of adverse impacts associated with the issue has been considered in the analysis, and it has been determined that additional plant-specific mitigation measures are likely not to be sufficiently beneficial to warrant implementation.

For issues that meet the three Category 1 criteria, no additional plant-specific analysis is required unless new and significant information is identified.

Category 2 issues are those that did not meet one or more of the criteria of Category 1, and therefore, additional plant-specific review for these issues is required.

License renewal actions may require refurbishment activities for the extended plant life. These actions may have an impact on the environment that requires evaluation, depending on the type of action and the plant-specific design. Environmental issues associated with refurbishment that were determined to be Category 1 issues are listed in Table 3-1.

Environmental issues related to refurbishment considered in the GEIS for which these conclusions could not be reached for all plants, or for specific classes of plants, are Category 2 issues. These are listed in Table 3-2.

The potential environmental effects of refurbishment actions would be identified, and the analysis would be summarized within this section, if such actions were planned. Duke indicated that it has performed an evaluation of structures and components pursuant to 10 CFR 54.21 to identify activities that are necessary to continue operation of ONS during the requested 20-year period of extended

Table 3-1. Category 1 Issues for Refurbishment Evaluation

operation. These activities include replacement of certain components as well as new inspection activities and are described in Exhibit A of the Oconee Application for Renewed Operating Licenses (Duke 1998).

However, Duke stated that the replacement of these components and the additional inspection activities are within the bounds of normal plant component replacement and inspections; therefore, they are not expected to affect the environment outside the bounds of plant operations as evaluated in the final environmental statement (FES) (AEC 1972). In addition, Duke's evaluation of structures and components as required by 10 CFR 54.21 did not identify any major plant refurbishment activities or modifications necessary to support the continued operation of ONS beyond the end of the existing operating licenses. Therefore, refurbishment is not considered in this SEIS.

Table 3-2. Category 2 Issues for Refurbishment Evaluation

3.1 References

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10 CFR Part 51, Subpart A, Appendix B, "Environmental effect of renewing the operating license of a nuclear power plant."

10 CFR 54.21, "Contents of application - technical information."

Duke Energy Corporation 1998. Application for Renewed Operating Licenses, Oconee Nuclear Station Units 1, 2, and 3. Volume IV - Environmental Report.

U.S. Atomic Energy Commission (AEC). 1972. Final Environmental Statement related to Operation of Oconee Nuclear Station Units 1, 2, and 3. March 1972. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC) 1996. Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437. Washington, D.C.

4.0 Environmental Impacts of Operation

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Environmental issues associated with operation during the renewal term were discussed in the Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437 (NRC 1996a; 1999a). The GEIS included a determination of whether the analysis of the environmental issues could be applied to all plants and whether additional mitigation measures would be warranted. Issues were then assigned a Category 1 or a Category 2 designation. As set forth in the GEIS, Category 1 issues are those that meet all of the following criteria:

(1) the environmental impacts associated with the issue have been determined to apply either to all plants or, for some issues, to plants having a specific type of cooling system or other specified plant or site characteristics

(2) a single significance level (i.e., SMALL, MODERATE, or LARGE) has been assigned to the impacts (except for collective offsite radiological impacts from the fuel cycle and from HLW and spent fuel disposal)

(3) mitigation of adverse impacts associated with the issue has been considered in the analysis, and it has been determined that additional plant-specific mitigation measures are likely not to be sufficiently beneficial to warrant implementation.

For issues that meet the three Category 1 criteria, no additional plant-specific analysis is required unless new and significant information is identified.

Category 2 issues are those that did not meet one or more of the criteria of Category 1, and therefore, additional plant-specific review for these issues is required.

This chapter addresses those issues related to operation during the renewal term that are listed in 10 CFR Part 51, Subpart A, Appendix B, Table B-1 that are applicable to ONS. Section 4.1 addresses the Category 1 issues applicable to the ONS once-through cooling system, while Category 2 issues applicable to the ONS cooling system are discussed at greater length in Sections 4.1.1 through 4.1.4. Section 4.2 addresses Category 1 issues related to transmission lines and land use, while Category 2 issues are discussed in Sections 4.2.1 and 4.2.2. Section 4.3 addresses the radiological impacts of normal operation. There are no Category 2 issues related to radiological impacts of normal operation. Section 4.4 addresses the Category 1 issues related to the socioeconomic impacts of normal operation during the renewal term. Category 2 socioeconomic issues are discussed in Sections 4.4.1 through 4.4.6. Section 4.5 addresses the Category 1 issues related to groundwater use and quality. Category 2 groundwater use and quality issues are discussed in Sections 4.5.1 and 4.5.2. Section 4.6 discusses the impacts of renewal-term operations on threatened and endangered species, a Category 2 issue. Section 4.7 addresses new information that was raised during the scoping period. The results of the evaluation of environmental issues related to operation during the renewal term are summarized in Section 4.8. Finally, Section 4.9 lists the references for Chapter 4.

4.1 Cooling System

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Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to ONS cooling system operation during the renewal term are listed in Table 4-1. Duke stated in its environmental report (ER) (Duke 1998a) that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of the issues, the GEIS concluded that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, for each of these issues follows:

• Altered current patterns at intake and discharge structures: Based on information in the GEIS, the Commission found that "Altered current patterns have not been found to be a problem at operating nuclear power plants and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information, including reports of studies of Lake Keowee performed for the South Carolina Department of Health and Environmental Control (SDCHEC). Therefore, the staff concludes that there are no impacts of altered current patterns during the renewal term beyond those discussed in the GEIS.
• Altered thermal stratification of lakes: Based on information in the GEIS, the Commission found that "Generally, lake stratification has not been found to be a problem at operating nuclear power plants and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including reports of studies of Lake Keowee performed for the SCDHEC. Therefore, the staff concludes that there are no impacts of altered thermal stratification of Lake Keowee during the renewal term beyond those discussed in the GEIS.

Table 4-1. Category 1 Issues Applicable to the Operation of the ONS Cooling System During the Renewal Term

• Temperature effects on sediment transport capacity: Based on information in the GEIS, the Commission found that "These effects have not been found to be a problem at operating nuclear power plants and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of temperature effects on sediment transport capacity during the renewal term beyond those discussed in the GEIS.
• Scouring caused by discharged cooling water: Based on information in the GEIS, the Commission found that "Scouring has not been found to be a problem at most operating nuclear power plants and has caused only localized effects at a few plants. It is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of scouring during the renewal term beyond those discussed in the GEIS.
• Eutrophication: Based on information in the GEIS, the Commission found that "Eutrophication has not been found to be a problem at operating nuclear power plants and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including plant monitoring data and technical reports. Therefore, the staff concludes that there are no impacts of eutrophication during the renewal term beyond those discussed in the GEIS.
• Discharge of chlorine or other biocides: Based on information in the GEIS, the Commission found that "Effects are not a concern among regulatory and resource agencies, and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including the NPDES permit for ONS. Therefore, the staff concludes that there are no impacts of discharge of chlorine or other biocides during the renewal term beyond those discussed in the GEIS.
• Discharge of sanitary wastes and minor chemical spills: Based on information in the GEIS, the Commission found that "Effects are readily controlled through the NPDES permit and periodic modifications, if needed, and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including the NPDES permit for ONS. Therefore, the staff concludes that there are no impacts of discharges of sanitary wastes and minor chemical spills during the renewal term beyond those discussed in the GEIS.
• Discharge of other metals in waste water: Based on information in the GEIS, the Commission found that "These discharges have not been found to be a problem at operating nuclear power plants with cooling-tower-based heat dissipation systems and have been satisfactorily mitigated at other plants. They are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including the NPDES permit for ONS. Therefore, the staff concludes that there are no impacts of discharges of other metals in waste water during the renewal term beyond those discussed in the GEIS.
• Water-use conflicts (plants with once-through cooling systems): Based on information in the GEIS, the Commission found that "These conflicts have not been found to be a problem at operating nuclear power plants with once-through heat dissipating systems." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of available information. Therefore, the staff concludes that there are no water-use conflicts during the renewal term beyond those discussed in the GEIS.
• Accumulation of contaminants in sediments or biota: Based on information in the GEIS, the Commission found that "Accumulation of contaminants has been a concern at a few nuclear power plants but has been satisfactorily mitigated by replacing copper alloy condenser tubes with those of another metal. It is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of available information. Therefore, the staff concludes that there are no impacts of accumulation of contaminants in sediments or biota during the renewal term beyond those discussed in the GEIS.
• Entrainment of phytoplankton and zooplankton: Based on information in the GEIS, the Commission found that "Entrainment of phytoplankton and zooplankton has not been found to be a problem at operating nuclear power plants and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including reports by Hudson and Nichols (1978) and Duke (1977). Therefore, the staff concludes that there are no impacts of entrainment of phytoplankton and zooplankton during the renewal term beyond those discussed in the GEIS.
• Cold shock: Based on information in the GEIS, the Commission found that "Cold shock has been satisfactorily mitigated at operating nuclear plants with once-through cooling systems, has not endangered fish populations or been found to be a problem at operating nuclear power plants with cooling towers or cooling ponds, and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including Barwick et al. (1995). Therefore, the staff concludes that there are no impacts of cold shock during the renewal term beyond those discussed in the GEIS.
• Thermal plume barrier to migrating fish: Based on information in the GEIS, the Commission found that "Thermal plumes have not been found to be a problem at operating nuclear power plants and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including information from Oliver and Hudson (1987). Therefore, the staff concludes that there are no impacts of thermal plumes during the renewal term beyond those discussed in the GEIS.
• Distribution of aquatic organisms: Based on information in the GEIS, the Commission found that "Thermal discharge may have localized effects but is not expected to affect the larger geographical distribution of aquatic organisms." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including pre- and post-operational reports by Oliver and Hudson (1987), Barwick (1984), and Barwick et al. (1995). Therefore, the staff concludes that there are no impacts on the distribution of aquatic organisms during the renewal term beyond those discussed in the GEIS.
• Premature emergence of aquatic insects: Based on information in the GEIS, the Commission found that "Premature emergence has been found to be a localized effect at some operating nuclear power plants but has not been a problem and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including pre- and post-operational studies reported by Oliver and Hudson (1987). Therefore, the staff concludes that there are no impacts of premature emergence of aquatic insects during the renewal term beyond those discussed in the GEIS.
• Gas supersaturation (gas bubble disease): Based on information in the GEIS, the Commission found that "Gas supersaturation was a concern at a small number of operating nuclear power plants with once-through cooling systems but has been satisfactorily mitigated. It has not been found to be a problem at operating nuclear power plants with cooling towers or cooling ponds and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of gas supersaturation during the renewal term beyond those discussed in the GEIS.
• Low dissolved oxygen (DO) in the discharge: Based on information in the GEIS, the Commission found that "Low dissolved oxygen has been a concern at one nuclear power plant with a once-through cooling system but has been effectively mitigated. It has not been found to be a problem at operating nuclear power plants with cooling towers or cooling ponds and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including pre- and post-operational studies conducted by Oliver and Hudson (1987) and the 316(a) demonstration report (Duke 1995). Therefore, the staff concludes that there are no impacts of low dissolved oxygen during the renewal term beyond those discussed in the GEIS.
• Losses from predation, parasitism, and disease among organisms exposed to sublethal stresses: Based on information in the GEIS, the Commission found that "These types of losses have not been found to be a problem at operating nuclear power plants and are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of losses from predation, parasitism, and disease among organisms exposed to sub-lethal stresses during the renewal term beyond those discussed in the GEIS.
• Stimulation of nuisance organisms: Based on information in the GEIS, the Commission found that "Stimulation of nuisance organisms has been satisfactorily mitigated at the single nuclear power plant with a once-through cooling system where previously it was a problem. It has not been found to be a problem at operating nuclear power plants with cooling towers or cooling ponds and is not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information including the 316(a) demonstration report (Duke 1995). Therefore, the staff concludes that there are no impacts of stimulation of nuisance organisms during the renewal term beyond those discussed in the GEIS.
• Microbiological organisms (occupational health): Based on information in the GEIS, the Commission found that "Occupational health impacts are expected to be controlled by continued application of accepted industrial hygiene practices to minimize worker exposures." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of microbiological organisms during the renewal term beyond those discussed in the GEIS.
• Noise: Based on information in the GEIS, the Commission found that "Noise has not been found to be a problem at operating plants and is not expected to be a problem at any plant during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of noise during the renewal term beyond those discussed in the GEIS.

Category 2 issues related to cooling system operation during the renewal term that are applicable to ONS are discussed in the sections that follow. These issues are listed in Table 4-2.

Table 4-2. Category 2 Issues Applicable to the Operation of the ONS Cooling System During the Renewal Term

4.1.1 Entrainment of Fish and Shellfish in Early Life Stages

For plants with once-through cooling systems, entrainment of fish and shellfish in early life stages into cooling water systems associated with nuclear power plants is considered a Category 2 issue, requiring a site-specific assessment before license renewal.

The staff reviewed NPDES Permit #SC0000515 (that governs the release of effluents by Oconee Nuclear Power Station into the receiving waters of Lake Keowee and to the Keowee Hydro Station's tailrace). The current permit was issued on September 29, 1999, and expires on September 30, 2003.

The EPA-issued NPDES permit effective February 18, 1975, required Oconee to implement a program to monitor entrainment through plant intake structures in accordance with Section 316(b) of the Federal Water Pollution Control Act (FWPCA), also known as the Clean Water Act. Rates of entrainment were studied and summarized in a letter report to the EPA on March 24, 1976 (letter from W.D. Adair, 1976, in Duke 1999a). The summary report, which Duke considers its 316(b) demonstration, indicated that no fish eggs or larvae were collected after extensive sampling that began in May 1973.

While no formal record of acceptance by the EPA of this 316(b) demonstration has been identified, the EPA did issue a modified NPDES permit on August 30, 1976, that deleted requirements to monitor entrainment through plant intake structures (Duke 1998a). No further studies or analyses were required in subsequent NPDES permits.

However, while the EPA was reviewing the 316(b) demonstration report, Duke was conducting additional larval entrainment studies weekly from March through August 1976 to document the efficiency of the skimmer wall to reduce entrainment of larval fish (Olmsted and Adair 1981). Standing crops of fish larvae in the intake canal and in Lake Keowee were compared to numbers of fish larvae entrained under the skimmer wall and through the condensers. Overall, the density of fish larvae entrained was always less than 1 percent of that noted in concurrent lake sampling at ONS. The difference in larvae densities between the lake and intake canal was attributed to the skimmer wall's depth being below the thermocline during the spawning season. Thus, this study served to reinforce the results of the 316(b) demonstration.

On March 2, 1979, the staff issued Amendments to the Licenses for Oconee Units 1, 2, and 3 that deleted the aquatic surveillance and special studies programs because the Environmental Impact Appraisal performed for this amendment concluded the impact of Oconee on the aquatic environment was within the bounds of the final environmental statement (FES) and that the special study programs were no longer necessary (letter from R.W. Reid, March 1979 in Duke 1999a).

The staff has reviewed the available information relative to potential impacts of the cooling water intake system's entrainment of fish and shellfish in early life stages. Based on this review, the staff has concluded that the potential impacts are SMALL, and mitigation is not warranted.

4.1.2 Impingement of Fish and Shellfish

For plants with once-through cooling systems, impingement of fish and shellfish on debris screens of cooling water systems associated with nuclear power plants is considered a Category 2 issue, requiring a site-specific assessment before license renewal. Impingement of shellfish is not an issue because there is no significant population of endemic shellfish species in the vicinity of ONS (Duke 1999b).

The staff reviewed NPDES Permit #SC0000515, which was issued on September 29, 1999, and expires on September 30, 2003. This permit governs the release of effluents by Oconee Nuclear Power Station into the receiving waters of Lake Keowee and to the Keowee River (at the location of the Keowee Hydro Station's tailrace).

An early EPA-issued NPDES permit effective February 18, 1975, required Oconee to implement a program to monitor impingement of fish on plant intake structures in accordance with Section 316(b) of the Clean Water Act. Rates of impingement were studied and summarized in a letter report to the EPA on March 24, 1976 (letter from W.D. Adair 1976 in Duke 1999a). The summary report indicated that

These findings on impingement were drawn largely from a study conducted by Duke (Edwards et al. 1976) that determined the number of finfish impinged on stationary screens at Oconee Nuclear Station between July 1974 and May 1975. Six screens (two screens per unit and 25 percent of total screen area) were removed and inspected at 2-week intervals. Over the entire study period, 241,697 fish were collected on representative screens.

Overall, species composition found impinged during the study included threadfin shad, Dorosoma petenense (49.3 percent), yellow perch, Perca flavescens (2.5 percent), and bluegill, Lepomis macrochirus (1.4 percent), even though threadfin shad were only introduced to Lake Keowee in February 1974 and did not show up in impingement samples until November 1974. Many fish collected during the study were unidentifiable (46.8 percent), but were suspected to be almost entirely threadfin shad (Duke 1998a, Attachment B), and the remainder were miscellaneous species that comprised an insignificant portion of the impingement samples.

SCUBA divers inspected all 24 screens at ONS between September 16 and 19, 1974, to ensure that impingement rates were similar for all screens and that subsampling at representative screens from each unit was realistic for estimating total impingement. Significant differences among screens was not apparent (Duke 1998a, Attachment B). Electrofishing, gill-net, and rotenone data were used to compare species composition throughout the lake to species found on intake screens. All species collected on the intake screens were represented in field collection samples, but 33 species collected in the field were not observed on intake screens. This suggests that susceptibility to impingement was, in part, species specific.

Impacts from impingement are determined relative to recreationally or commercially important species. A creel census conducted in 1973 indicated that largemouth bass (Micropterus salmoides), bluegill, and crappie (Pomoxis spp.) were the most important sport fish taken from Lake Keowee. Data on angler effort and harvest rates collected over a period from 1974 to 1993 (Barwick et al. 1995) confirmed that largemouth bass remained the most important sportfish in the reservoir and that sunfish (Lepomis spp., including bluegill) and crappie were the only other species that contributed in a significant way to the reservoir's sport fishery. Sampling conducted from 1972 to 1993 indicated that these species were also the most common sportfish in the reservoir (Duke 1995). Occasional impingement of these species is not expected to produce population-level effects. Again, only 1.4 percent of fish impinged in the 1974-75 study (Edwards et al. 1976) were bluegill. Other sunfish species, largemouth bass, and crappie were included in the "miscellaneous" category that made up less than 0.3 percent of the total fish impinged. Threadfin shad were the most frequently impinged species (49.3 percent). They are a forage fish species and are not considered important by either recreational or commercial standards.

Over the years, NPDES permits issued to Duke for ONS gradually reduced requirements for evaluating impingement because research indicated that important aquatic species were not being adversely impacted. No correspondence could be located indicating EPA's formal approval of the study. However, the EPA issued a modified NPDES permit on August 30, 1976, that deleted requirements to monitor impingement through plant intake structures (Duke 1998a). No further studies or analyses were required in subsequent NPDES permits. On March 2, 1979, the staff issued Amendments to the Licenses for Oconee Units 1, 2, and 3 that deleted the aquatic surveillance and special studies programs because the Environmental Impact Appraisal performed for this amendment concluded that the impact of Oconee on the aquatic environment was within the bounds of the FES and that the special study programs were no longer necessary (letter from R.W. Reid, March 1979 in Duke 1999a).

Although special studies were no longer required, additional impingement studies were performed from January through March 1990 (Barwick 1990). During this period of weekly sampling, only three fish species were found in impingement samples, none of which are considered important sportfish species. Threadfin shad comprised 91.5 percent of the total fish impinged, blueback herring (Alosa aestivalis) comprised 8.4 percent, and yellow perch comprised 0.1 percent. The numbers of fish impinged were 2.6 times the number of impinged fish that were reported by Edwards et al. (1976) and were estimated to represent 11.1 percent of the pelagic fish population in the Keowee Reservoir. Although threadfin shad are not commercially or recreationally important, the high rate of impingement merits some discussion. Mobile hydroacoustic surveys conducted during spring and fall 1989, 1990, 1996, and fall 1997 show a pattern in threadfin shad population dynamics that helps explain the high percentage of impinged fish (Duke 1999a).

Table 4-3 (Duke 1999a) shows the fluctuation in pelagic fish populations (approximately 51 percent threadfin shad and 49 percent blueback herring) between spring and fall surveys.

Table 4-3. Fluctuation in Pelagic Fish Populations Between Spring and Fall Surveys

The estimated numbers of small pelagic fish are always lower in spring than fall, following a period of high winter mortality. Blueback herring are not overly susceptible to cold temperatures, but threadfin shad become stressed at temperatures less than 10C (50F) and exhibit complete mortality at 4C (39F) (Griffith 1978). Areas of Keowee Reservoir often drop below 10C (50F) during the winter, severely weakening large numbers of threadfin shad that die or become stressed and unable to resist intake currents. According to the seasonal study conducted by Edwards et al. (1976), 88 percent of all threadfin shad impingement at Oconee occurred between January and March. However, as indicated by the hydroacoustic survey results showing seasonal population fluctuations, threadfin shad have a high fecundity and generally expand their population considerably by fall so long as an adequate number of spawners survived the winter. Edwards et al. (1976) concluded that "the impingement of threadfin shad at (Oconee) does not appear to be a major cause of mortality but is rather an indication of natural mortality of the species."

Based on these data, the staff has reviewed the available information relative to potential impacts of the cooling water intake system on the impingement of fish and shellfish, and concludes that the potential impacts are SMALL, and mitigation is not warranted.

4.1.3 Heat Shock

For plants with once-through cooling systems, the effects of heat shock are listed as a Category 2 issue and require plant-specific evaluation before license renewal.

The staff reviewed NPDES Permit #SC0000515, which was issued on September 29, 1999, and expires on September 30, 2003 (as discussed in Section 4.1.1). This permit governs the release of effluents by Oconee Nuclear Power Station into the receiving waters of Lake Keowee and to the Keowee River at the location of the tailrace to the Keowee Hydro Station.

The staff also reviewed the results of a 316(a) demonstration that Duke submitted in January 1995 (Duke 1999a). Based on the study, the SCDHEC granted a 316(a) variance. Duke submitted a reapplication in March 1998 and supporting documentation in May 1998 to the SCDHEC requesting a continuation of the variance.

ONS complies with State standards and has an approved NPDES permit and 316(a) variance. Under such circumstances, pursuant to 10 CFR 51.53(c)(3)(ii)(B), no further assessment of heat shock is required. Thus, the staff concludes that potential heat shock impacts resulting from operation of the plant's cooling water discharge system to the aquatic environment on or in the vicinity of the site are SMALL, and mitigation is not warranted.

4.1.4 Microbiological Organisms (Human Health)

For plants discharging cooling water to cooling ponds, lakes, canals, or small rivers, the effects of microbiological organisms on human health are listed as a Category 2 issue and require plant-specific evaluation before license renewal.

ONS has a once-through cooling system that uses Lake Keowee as the cooling source. The Keowee and Little Rivers were impounded to form Lake Keowee. The combined flow rate for the Keowee and Little Rivers is lower than the 9 × 10¹⁰ m³ per year (3.15 × 10¹² ft³ per year) specified in 10 CFR 51.53(c)(3)(ii)(G). This low flow rate raises a concern from the standpoint of the potential for enhancement of thermophylic microorganisms such as Naegleria fowleri. This type of organisms could be a potential health concern for members of the public swimming in the cooling source (Duke 1998a).

Although Lake Keowee is a popular site for water-based recreational activities, including swimming and water skiing, these activities are dispersed throughout the lake, rather than being concentrated in specific areas such as near the plant. In addition, the nearest private pier located on the Keowee River arm of the lake is 1300 m (4200 ft) from the discharge structure.

In a letter included with the ER (Duke 1998a), the State toxicologist at the SCDHEC indicated that there "seems to be no significant threat to off-site persons near such heated recreational waters [from operation of ONS] ."

Although there is a potential for deleterious thermophylic microorganisms to be associated with the cooling system, the actual hazard to public health has not been documented or substantiated. The results of analyses and evaluations, including the results of consultation with the State Public Health Department, indicate that the impact of deleterious microbiological organisms during continued operation of the plant during the renewal term are expected to be SMALL, and mitigation is not warranted.

4.2 Transmission Lines

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The FES discussed five transmission lines with a total length of 528 km (330 mi) that connect the plant to the Duke Energy Transmission System. They were constructed concurrently with the construction of Oconee and the Keowee-Toxaway Project and connect both Oconee and the Keowee-Toxaway Project hydro plants to the Duke Energy Transmission System.

Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to the ONS transmission lines are listed in Table 4-4. Duke stated in its ER that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of those issues, the GEIS concluded that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

Table 4-4. Category 1 Issues Applicable to the ONS Transmission Lines During the Renewal Term

A brief description of the staff's review and GEIS conclusions, as codified in Table B-1, for each of these issues follows:

• Power line right-of-way management (cutting and herbicide application): Based on information in the GEIS, the Commission found that "The impacts of right-of-way maintenance on wildlife are expected to be of small significance at all sites." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, consultation with the FWS and SCDNR, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of power line right-of-way management during the renewal term beyond those discussed in the GEIS.
• Bird collisions with power lines: Based on information in the GEIS, the Commission found that "Impacts [of bird collisions with power lines] are expected to be of small significance at all sites." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information, including the status of the Duke monitoring program, Duke efforts to document collisions, and Duke efforts to protect species nesting on the power lines. Therefore, the staff concludes that there are no impacts of bird collisions with power lines during the renewal term beyond those discussed in the GEIS.
• Impacts of electromagnetic fields on flora and fauna (plants, agricultural crops, honeybees, wildlife, livestock): Based on information in the GEIS, the Commission found that "No significant impacts of electromagnetic fields on terrestrial flora and fauna have been identified. Such effects are not expected to be a problem during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of electromagnetic fields on flora and fauna during the renewal term beyond those discussed in the GEIS.
• Floodplains and wetland on power line right-of-way: Based on information in the GEIS, the Commission found that "Periodic vegetation control is necessary in forested wetlands underneath power lines and can be achieved with minimal damage to the wetland. No significant impact is expected at any nuclear power plant during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, consultation with the FWS, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts on floodplains and wetland on the power line right-of-way during the renewal term beyond those discussed in the GEIS.
• Air quality effects of transmission lines: Based on information in the GEIS, the Commission found that "Production of ozone and oxides of nitrogen is insignificant and does not contribute measurably to ambient levels of these gases." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no air quality impacts of transmission lines during the renewal term beyond those discussed in the GEIS.
• Onsite land use: Based on information in the GEIS, the Commission found that "Projected onsite land use changes required during ... the renewal period would be a small fraction of any nuclear power plant site and would involve land that is controlled by the applicant." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no onsite land-use impacts during the renewal term beyond those discussed in the GEIS.
• Power line right-of-way (land use): Based on information in the GEIS, the Commission found that "Ongoing use of power line rights-of-way would continue with no change in restrictions. The effects of these restrictions are of small significance." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of restriction on use of power line rights-of-way during the renewal term beyond those discussed in the GEIS.

There is one Category 2 issue related to transmission lines, and another issue related to transmission lines is being treated as a Category 2 issue. These issues are listed in Table 4-5. They are discussed in Sections 4.2.1 and 4.2.2.

Table 4-5. Category 2 Issues Applicable to the ONS Transmission Lines During the Renewal Term

4.2.1 Electromagnetic Fields - Acute Effects

In the GEIS, the Commission found that without a review of the conformance of each nuclear plant transmission line with NESC criteria, it is not possible to determine the significance of the electric shock potential. Evaluation of individual plant transmission lines is necessary because the issue of electric shock safety was not addressed in the licensing process for some plants. For the other plants, some may have chosen to upgrade line voltage or land use in the vicinity of transmission lines that may have been changed. To comply with 10 CFR 51.53(c)(3)(ii)(H), the applicant must provide an assessment of the potential shock hazard if the transmission lines that were constructed for the specific purpose of connecting the plant to the transmission system do not meet the recommendations of the National Electric Safety Code (NESC) for preventing electric shock from induced currents.

In the ER, Duke stated that the transmission lines that connect Units 1 and 2 to the 230 kV switching station and the lines that connect Unit 3 to the 525 kV switching station meet the vertical clearance requirement specified in the 1997 edition of NESC (1997). Duke states further that the transmission lines constructed concurrently with the Oconee and the Keowee-Toxaway Project are part of the Duke Energy Transmission System. These transmission lines were constructed to the standards of NESC, 6^th edition, published in November 1961. According to the ER, there have been no upgrades in line voltage on these transmission lines since they were constructed. Duke reviewed the vertical clearances of the 528 km (330 mi) of transmission lines attributed to Oconee in the FES (AEC 1972) using the 1997 edition of NESC and determined that all clearances exceeded the minimum requirements of the 1997 NESC (Duke 1999a).

Based on the above, the staff concludes that the impact of the potential for electrical shock is SMALL, and mitigation is not warranted.

4.2.2 Electromagnetic Fields - Chronic Effects

In the GEIS, the chronic effects of electromagnetic fields from power lines were given a finding of "not applicable" rather than a Category 1 or 2 designation until a scientific consensus is reached on the health implications of these fields.

The potential for chronic effects from these fields continues to be studied and is not known at this time. The National Institute of Environmental Health Sciences (NIEHS) directs related research through the U.S. Department of Energy (DOE). A recent report (NIEHS 1999) includes the following paragraph:

The NIEHS concludes that ELF-EMF [extremely low frequency-electromagnetic field] exposure cannot be recognized as entirely safe because of weak scientific evidence that exposure may pose a leukemia hazard. In our opinion, this finding is insufficient to warrant aggressive regulatory concern. However, because virtually everyone in the United States uses electricity and therefore is routinely exposed to ELF-EMF, passive regulatory action is warranted such as a continued emphasis on educating both the public and the regulated community on means aimed at reducing exposures. The NIEHS does not believe that other cancers or non-cancer health outcomes provide sufficient evidence of a risk to currently warrant concern.

This statement is not sufficient to cause the staff to change its position with respect to the chronic effects of electromagnetic fields. The staff considers the GEIS finding of "not applicable" still appropriate and will continue to follow developments on this issue.

4.3 Radiological Impacts of Normal Operations

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Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to ONS with regard to radiological impacts are listed in Table 4-6. Duke stated in its ER that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of those issues, the GEIS concluded that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

Table 4-6. Category 1 Issues Applicable to Radiological Impacts of Normal Operations During the Renewal Term

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, for each of these issues follows:

• Radiation exposures to public (license renewal term): Based on information in the GEIS, the Commission found that "Radiation doses to the public will continue at current levels associated with normal operations." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of radiation exposures to the public during the renewal term beyond those discussed in the GEIS.
• Occupational radiation exposures (license renewal term): Based on information in the GEIS, the Commission found that "Projected maximum occupational doses during the license renewal term are within the range of doses experienced during normal operations and normal maintenance outages, and would be well below regulatory limits." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of occupational radiation exposures during the renewal term beyond those discussed in the GEIS.

4.4 Socioeconomic Impacts of Plant Operations During the License Renewal Period

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Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to socioeconomic impacts during the renewal term are listed in Table 4-7. Duke stated in its ER (Duke 1998a) that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of those issues, the GEIS concluded that the impacts are small, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

Table 4-7. Category 1 Issues Applicable to Socioeconomics During the Renewal Term

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, for each of these issues follows:

• Public services: public safety, social services, and tourism and recreation: Based on information in the GEIS, the Commission found that "Impacts to public safety, social services, and tourism and recreation are expected to be of small significance at all sites." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts on public safety, social services, and tourism and recreation during the renewal term beyond those discussed in the GEIS.
• Public services: education (license renewal term): Based on information in the GEIS, the Commission found that "Only impacts of small significance are expected." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts on education during the renewal term beyond those discussed in the GEIS.
• Aesthetic impacts (license renewal term): Based on information in the GEIS, the Commission found that "No significant impacts are expected during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no aesthetic impacts during the renewal term beyond those discussed in the GEIS.
• Aesthetic impacts of transmission lines (license renewal term): Based on information in the GEIS, the Commission found that "No significant impacts are expected during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no aesthetic impacts of transmission lines during the renewal term beyond those discussed in the GEIS.

Table 4-8 lists the Category 2 socioeconomic issues, which require plant-specific analysis and environmental justice, which was not addressed in the GEIS.

4.4.1 Housing Impacts During Operations

In determining housing impacts, the applicant chose to follow Appendix C of the GEIS (NUREG-1437), which presents a population characterization method that is based on two factors, "sparseness" and "proximity" (GEIS Section C.1.4). Sparseness measures population density within 32 km (20 mi) of the site, and proximity measures population density and city size within 80.5 km (50 mi). Each factor has categories of density and size (GEIS Table C.1), and a matrix is used to rank the population category as low, medium, or high (GEIS, Figure C.1). ONS was selected by the NRC to be evaluated as a potential socioeconomic case study site. The results of this evaluation, published in the GEIS, classifies the current ONS population as "medium" (GEIS Table C.2).

Table 4-8. Category 2 Issues Applicable to Socioeconomics During the Renewal Term

As described in Section 2.2.8, the Tri-County (Oconee, Pickens, and Anderson) area around ONS is not subject to growth control measures that effectively limit housing development, although Oconee County in particular is attempting to steer the growth toward the center of the county, where the infrastructure is most completely developed. In 10 CFR Part 51, Subpart A, Appendix B, Table B-1, NRC concluded that impacts on housing availability are expected to be of small significance at plants located in a "medium" population area where growth control measures are not in effect. ONS is located in a medium population area and is not located in an area where growth control measures limit housing development, so housing impacts would be expected to be small, even if there were plant-related increases in population.

Small impacts result when no discernable change in housing availability occurs, changes in rental rates and housing values are similar to those occurring statewide, and no housing construction or conversion occurs. Although significant housing impacts are expected in all three counties as a result of population growth, it will be difficult to discern the impact from license renewal activities. Although the GEIS assumed an additional staff of 180 permanent workers during the license renewal period, Duke, in the ER, indicated that they "have not identified any increases in staffing related to license renewal-related programs." The staff has reviewed the available information relative to housing impacts. Because Duke expects no increase in staffing levels, there should be no discernable change in housing availability. Therefore, there will be no impact on economic development from license renewal and the staff has concluded that the impact on housing during the license renewal period is SMALL, and mitigation is not warranted.

4.4.2 Public Services: Public Utility Impacts During Operations

Impacts on public utility services are considered small if there is little or no change in the ability of the system to respond to the level of demand, and thus there is no need to add capital facilities. Impacts are considered moderate if overtaxing of service capabilities occurs during periods of peak demand. Impacts are considered large if existing levels of service (e.g., water or sewer services) are substantially degraded, and additional capacity is needed to meet ongoing demands for services. The GEIS indicates that, absent new significant information to the contrary, the only impacts on public utilities that could be significant are impacts on public water supplies. The staff believes that, in view of the expected population increase in the three counties, there may be reason to add significant public services and infrastructure other than water supply during the next 40 years. None of the increase would be due to the impact of additional ONS workers because no need for additional workers has been identified.

Analysis of impacts to the public water supply system considered both plant demand and plant-related population growth. Section 2.2.2 describes the plant's permitted withdrawal rate and the plant's actual use of water. The applicant does not expect plant demand to have a direct effect on water resources.

As described in Section 2.2.8, Walhalla and Seneca in eastern Oconee County have some water plant capacity problems, but only Walhalla is actually limited by the water source (Coneross Creek). Walhalla is considering construction of a new water treatment plant. Seneca draws drinking water from Lake Keowee, which is considered adequate. Because ONS obtains its water from an adequate renewable surface water source, and no increase in population is expected as a result of the renewal of the ONS operating license, no impact is expected from license renewal on water supplies. The staff concludes that the impact on water supply is SMALL, and mitigation is not warranted.

4.4.3 Offsite Land Use During Operations

Land use in the vicinity of a nuclear power plant may change as a result of plant-related population growth. It is noted in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that significant changes in land use may be associated with population and tax revenue changes resulting from license renewal. However, Section 3.7.5 of the GEIS notes that if the plant-related increase in population is less than 5 percent of the study area's total population and if plant total tax payments are small relative to the community's total revenue, new population-driven and tax-driven land-use changes during the plant's license renewal term would be small, especially if the community has pre-established patterns of development and has provided adequate public services to support and guide development.

The analysis of offsite land use during the renewal term has two components, population-driven changes in offsite land use and tax-driven changes in offsite land use. No plant-related, population-driven changes in land use are expected during the license renewal term because no increase in employment is expected.

Oconee County is the only jurisdiction that taxes ONS directly, and it is the principal jurisdiction that receives direct tax revenue as a result of ONS's presence. Because there are no major refurbishment activities and no new construction as a result of the license renewal, no new sources of plant-related tax payments are expected that could significantly influence land use in Oconee County. However, continued operation of the plant would provide a significant continuing source of tax revenues to Oconee County. As discussed in Section 2.8, the applicant is expected to pay $22.3 million in property taxes to Oconee County in 1998-99. This payment represented about one-third of the county budget and has a substantial, positive impact on the fiscal condition of Oconee County.

The staff has determined that the significance of project-related tax payments are moderate if the payments to a jurisdiction are between 10 and 20 percent of the total tax revenue of the jurisdiction, and large if the percentage is greater than 20 percent (GEIS). Using these criteria, ONS tax payments, representing around 33 percent of the total Oconee County budget, are of large significance. If the tax-related revenues are medium to large relative to the jurisdiction's total revenue, tax-driven land-use changes would most likely be moderate if the community has no pre-established patterns of development (i.e., land-use plans or controls), or has not provided adequate public services to guide land-use changes in the past (GEIS). The staff defined the magnitude of land-use changes as follows:

• SMALL - Very little new development and minimal changes to the area's land-use pattern.
• MODERATE - Considerable new development and some changes to land-use patterns.
• LARGE - Large-scale new development and many changes to land-use patterns.

Oconee County has experienced significant population growth and moderate land-use changes. The growth is not directly related to the presence of the ONS. Other factors, such as development of Lake Keowee recreational property, industrial growth, proximity to Greenville and Anderson, and less stringent land-use, zoning, and development regulations compared to surrounding counties clearly play a role. Oconee County has not adopted land codes or ordinances nor does it enforce a minimum housing code (Talbert & Bright 1996). However, Oconee County has well established patterns of development and has public services in place to support development, which is being directed toward the center of the county. In combination, these two factors would be expected to result in SMALL land-use impacts from ONS-related taxes.

Continuation of Oconee County's tax receipts from ONS keeps tax rates below what they otherwise would have to be to fund the county's government and also provides for a higher level of public infrastructure and services than otherwise would be possible. This enhances the county's attractiveness as a place to live and tends to accelerate the conversion of open space to residential and commercial uses. On the other hand, the presence of Duke's real estate arm as a major landowner has provided a considerable degree of discipline on development in the county.

Based on this review of the issues, the staff concludes that the net impact of plant-related population increases and tax receipts is likely to be SMALL. While the tax receipts are large enough to result in moderate impacts on land use, Oconee County has a conservative approach to providing water and sewer that limits upgrades and could slow future economic development except in areas already served. In addition, while the relatively low taxes and high levels of public service afforded by ONS-related tax receipts tend to draw population growth to the County, these same receipts make possible formal tax relief programs that favor open space or land-use control programs if such programs are deemed necessary in the future. Additional mitigation does not appear to be warranted.

4.4.4 Public Services: Transportation Impacts During Operations

On October 4, 1999, 10 CFR 51.53(c)(3)(ii)(J) and 10 CFR Part 51, Subpart A, Appendix B, Table B-1 were revised to clearly state that "Public Services: Transportation Impacts During Operations" is a Category 2 issue (see NRC 1999a for more discussion of this clarification). This issue is treated as such in this final SEIS.

Significant population growth is expected in all three counties in the study area by 2034, as was discussed in Section 2.2.8 of this report. However, none of this expected growth will be due directly to increases in employment at ONS. It may be argued that the industrial tax base afforded by ONS makes the county a more affordable and pleasant place to live and indirectly increases population, but even this indirect impact is likely to be fairly small and difficult to predict. Future general population increase likely will increase highway congestion at specific locations, but the expected magnitude of impact of ONS on this service degradation is SMALL and, thus, no mitigation is warranted.

4.4.5 Historical and Archaeological Resources

Because the Duke license renewal application (Duke 1998a) covering an additional 20 years of operation of the ONS does not include plans for future land disturbances or structural modifications beyond routine maintenance activities at the plant, there would be no identifiable adverse effects to known historical and archaeological resources. Consultation between the license renewal applicant and the South Carolina State Historic Preservation Office resulted in a determination by the State office that no known historical properties included in or eligible for inclusion in the National Register of Historic Places would be affected by the proposed action.

Continued operation of the power plant and protection of the natural landscape and vegetation within the site boundaries would have a beneficial effect in that either known or undiscovered resources would receive de facto protection for the term of the license renewal period, being located in an undisturbed area with secured access. Duke has assisted in conservation and security of the adjacent National Register property, the Old Pickens Church and cemetery. This assistance will continue to enhance long-term preservation of that property.

Notwithstanding that Duke does not plan future land disturbances or structural modifications beyond routine maintenance at the plant, there is a possibility that undiscovered and/or unrecorded prehistoric and historic period archaeological sites remain on the 210-ha (510-acre) plant site. Accordingly, additional care should be taken during normal operational or maintenance conditions to ensure that cultural resources are not inadvertently impacted. These activities may include not only operation of the plant itself, but also land management-related actions such as recreation, wildlife habitat enhancement, or maintaining/upgrading access roads throughout the plant site. To ensure that care is taken to protect cultural resources that may be encountered during construction or other land-disturbing activities, the ONS site environmental work practices have been revised. If archeological sites are identified during land-disturbing activities, land-disturbing activities will stop, and the State Historic Preservation Office will be contacted to determine the appropriate steps to be taken before resuming the activities.

The staff concludes that impacts on historical and archaeological resources is SMALL, and mitigation is not needed.

4.4.6 Environmental Justice

Environmental justice refers to a Federal policy in which Federal actions should not result in disproportionately high and adverse impacts on low-income or minority populations. A minority population is defined to exist if the percentage of minorities within the census blocks exceeds the percentage of minorities in the entire state of South Carolina by 10 percent, or if the percentage of minorities within the census block is at least 50 percent. For census blocks within the states of Georgia or North Carolina, the percentage of minorities is compared to the percentage of minorities in the respective state. Executive Order 12898 (59 FR 7629) directs Federal executive agencies to consider environmental justice under NEPA, and the Council on Environmental Quality (CEQ) has provided guidance for addressing environmental justice under NEPA (CEQ 1997). Although it is not subject to the executive order, the Commission has voluntarily committed to undertake environmental justice reviews. Specific guidance is provided in Attachment 4 to NRR (Nuclear Reactor Regulation) Office Letter No. 906, Revision 1: Procedural Guidance for Preparing Environmental Assessments and Considering Environmental Issues (NRC 1996b).

The scope of the review as defined in NRR Office Letter No. 906, Rev. 1 (NRC 1996b) should include an analysis of impacts on low-income and minority populations, the location and significance of any environmental impacts during operations on populations that are particularly sensitive, and any additional information pertaining to mitigation. The descriptions to be provided by this review should be of sufficient detail to permit subsequent staff assessment and evaluation of specific impacts, in particular whether these impacts are likely to be disproportionately high and adverse, and to evaluate the significance of such impacts.

Air, land, and water resources within about 80 km (50 mi) of ONS were examined. Within that area, a few potential environmental impacts could affect human populations; all of these were considered small. These include

• groundwater use conflicts
• electric shock
• microbial organisms
• accident scenarios.

To decide whether any of these impacts could be disproportionate, the staff examined the geographic distribution of minority and low-income populations recorded during the 1990 Census (DOC 1991), supplemented by field inquiries to the local planning departments in Oconee, Pickens, and Anderson Counties, and to social service agencies in the three counties. The staff focused this portion of the review on the geographic areas most likely to experience the impacts discussed above, i.e., the three closest surrounding counties. This area is referred to as the study area.

Generally speaking, minority populations are a small, dispersed, and declining proportion of the study area's population. Figure 4-1, taken from the 1990 Census (DOC 1991) shows the geographic distribution of minority populations within the 80-km (50-mi) radius of the plant. Minority populations are located primarily in Greenville and Anderson. However, a few scattered census block groups showed a significant concentration of minority individuals in the Seneca and Clemson areas. Figure 4-1 indicates that minority populations in general are either relatively well-mixed into the majority population, or concentrations of minority individuals are too small to be caught in the census detail. This is consistent with the results of field interviews.

Figure 4-2, also taken from the 1990 Census (DOC 1991) shows the geographic distribution of low-income populations within the 80-km (50-mi) radius of the plant. The cross-hatched census blocks show areas where the percentage of households below the poverty level is 10 percent or more greater than the percentage of households below the poverty level in the entire state of South Carolina for those census blocks within the state of South Carolina. It also includes census blocks where the percentage of households below the poverty level exceeds 50 percent. For census blocks within the states of Georgia or North Carolina, the percentage of households below the poverty level is compared to the percentage of households below the poverty level in the corresponding state. The largest concentrations of low-income populations within the 80-km (50-mi) radius are located in North Carolina. Some small groups are scattered throughout the three-county area, although none is within 16 km (10 mi) of ONS. Some of these individuals are known to be ex-sharecroppers effectively engaged in subsistence agriculture. The 1990 Census (DOC 1991) shows concentrations of low-income population at Seneca, Easley, and Clemson, the latter partly due to a large university student population. Low-income housing tends to be concentrated in the Seneca and Clemson area.

Figure 4-1. Geographic Distribution of Minority Populations (shown in shaded areas) Within 80 km (50 mi) of ONS

Examination of the various environmental pathways by which low-income and minority populations could be disproportionately affected reveals no unusual resource dependencies or practices through which these populations could be disproportionately affected. Specifically, no pathways were found through which subsistence agriculture was significantly affected. In general, the prevailing atmospheric transport direction from the ONS site is toward the northeast, thus missing most census blocks showing minority and low-income populations. Therefore, the impact is SMALL, and no special mitigation actions are warranted.

Figure 4-2. Geographic Distribution of Low-Income Populations (shown in shaded areas) Within 80 km (50 mi) of ONS

4.5 Groundwater Use and Quality

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A Category 1 issue in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, is applicable to ONS groundwater use and quality and is listed in Table 4-9. Duke stated in its ER that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review.

Table 4-9. Category 1 Issue Applicable to Groundwater Use and Quality During the Renewal Term

Therefore, the staff concludes that there are no impacts related to this issue beyond those discussed in the GEIS. For this issue, the GEIS concluded that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, follows.

• Groundwater use conflicts (potable and service water; plants that use <100 gpm): Based on information in the GEIS, the Commission found that "Plants using less than 100 gpm are not expected to cause any groundwater use conflicts." As discussed in Section 2.2.2, ONS's groundwater use is less than 0.068 m³/s (100 gpm). The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no groundwater use conflicts during the renewal term beyond those discussed in the GEIS.

There are no Category 2 issues related to groundwater use and quality.

4.6 Threatened or Endangered Species

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Threatened or endangered species is listed as a Category 2 issue in 10 CFR Part 51, Subpart A, Appendix B, Table B-1. The issue is listed in Table 4-10.

This issue requires consultation with appropriate agencies to determine whether threatened or endangered species are present and whether they would be adversely affected. Consultation under Section 7 of the Endangered Species Act was initiated by Duke during April 1998 with a request for information to FWS concerning species potentially occurring near ONS. The FWS identified (FWS 1998a) nine listed species known to occur in either Oconee or Pickens Counties and one species that could possibly occur in those counties (see Section 2.2.6). Subsequent to that letter, Duke performed a survey of all of the land within 1.6 km (1 mi) of ONS during May and June of 1998. No Federally listed, proposed, or candidate threatened or endangered species were identified during that survey. The results of the survey were documented for the FWS and the South Carolina Department of Natural Resources (SCDNR) (Duke 1998b; Duke 1998c).

Table 4-10. Category 2 Issue Applicable to Threatened or Endangered Species During the Renewal Term

The FWS concurred with Duke's determination that the proposed action will have no effect on listed or proposed endangered or threatened species (FWS 1998b). The SCDNR also concurred with the findings presented in the report submitted by Duke (SCDNR 1998).

Four plant species of concern to the SCDNR were identified within the surveyed area (see Section 2.2.6, Table 2-3). These species were all confined to "natural areas" located toward the periphery of ONS, well away from areas used for normal plant operations.

Based on its review of the applicant's report and their independent analysis, the FWS⁽¹⁰⁾ and the SCDNR concluded that continued operation of the plant under license renewal will have no effect on listed or proposed endangered or threatened species within the immediate vicinity of the ONS.

Federally-listed species are known to occur near the transmission line rights-of-way attributable to the ONS (see Section 2.2.6). Of these, the dwarf-flowered heartleaf and the bunched arrowhead occur within or very near the rights-of-way of the McGuire 525 kV line and the Tiger 230 kV lines, respectively.

The staff submitted a biological assessment to the FWS in a letter dated June 30, 1999 (NRC 1999b). The FWS reviewed the biological assessment and requested more information related to Duke's maintenance practices for the transmission lines and the location of five species: bunched arrowhead, dwarf-flowered heartleaf, smooth coneflower, Schwenitz's sunflower, and mountain sweet pitcher plant. The FWS was concerned about the potential effects from the proposed maintenance of the right-of-way. The FWS conducted field visits to portions of the project area and reviewed the supplemental information provided by Duke. Subsequently, in a letter dated November 4, 1999 (FWS 1999), the FWS concurred with the staff's determination that the renewal of the ONS licenses for a period of 20 years would likely not adversely affect listed species or critical habitat based on the practices and procedures Duke uses to maintain the transmission line rights-of-way. Therefore, it is the staff's determination that the impact on threatened or endangered species of an additional 20 years of maintenance activities for the transmission lines would be SMALL, and further mitigation is not warranted.

4.7 Evaluation of Potential New and Significant Information on Impacts of Operations During the Renewal Term

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The staff has not identified new and significant information on environmental issues listed in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, related to operation during the renewal term. The staff reviewed the discussion of environmental impacts associated with operation during the renewal term in the GEIS and has conducted its own independent review, including the public scoping meetings, to identify issues with significant new information. Processes for identification and evaluation of new information are described in Section 1.0 under License Renewal Evaluation Process.

4.8 Summary of Impacts of Operations During the Renewal Term

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Neither Duke nor the staff is aware of significant new information related to any of the applicable Category 1 issues associated with the ONS operation during the renewal term. Consequently, the staff concludes that the environmental impacts associated with these issues are bounded by the impacts described in the GEIS. For each of these issues, the GEIS concluded that the impacts would be SMALL and that "plant-specific mitigation measures are not likely to be sufficiently beneficial to warrant implementation."

Plant-specific environmental evaluations were conducted for 12 Category 2 issues applicable to ONS operation during the renewal term and for environmental justice. For all 12 issues and environmental justice, the staff concluded that the potential environmental impact of renewal term operations of ONS would be of SMALL significance in the context of the standards set forth in the GEIS and that mitigation would not be warranted.

In addition, the staff determined that a consensus has not been reached by appropriate Federal health agencies that there are adverse effects from electromagnetic fields. Therefore, no evaluation of this issue is required.

4.9 References

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10 CFR 50.51, "Continuation of license."

10 CFR 51.53, "Postconstruction environmental reports."

10 CFR Part 51, Subpart A, Appendix B, "Environmental effect of renewing the operating license of a nuclear power plant."

Barwick, D.H. 1984. Role of fish distribution on estimates of standing crop in a cooling reservoir. North American Journal of Fishery Management 4:308-313.

Barwick, H. 1990. Fish impingement at Oconee Nuclear Station - 1990. Scientific Services, Duke Power Company, Huntersville, North Carolina.

Barwick, D.H., L.E. Miller, W.R. Geddings, and D.M. Rankin. 1995. Fish biomass and angler harvest from a South Carolina cooling reservoir. Proceedings of the Annual Conference of the Southeastern Association of Fish and Wildlife Agencies 49:129-139.

Council on Environmental Quality (CEQ). 1997. Environmental Justice: Guidance Under the National Environmental Policy Act. Council on Environmental Quality, Executive Office of the President, Washington, D.C.

Duke Power Company. 1977. Oconee Nuclear Station Environmental Summary Report 1971-1976, Volumes 1 and 2. Duke Power Company Steam Production Department.

Duke Power Company. 1995. Oconee Nuclear Station 316(a) Demonstration Report.

Duke Energy Corporation. 1998a. Application for Renewed Operating Licenses, Oconee Nuclear Station, Units 1, 2, & 3. Volume IV - Environmental Report.

Duke Power Company. 1998b. Letter from J. Huff, Duke Power, Charlotte, North Carolina, to Mr. R. L. Banks (FWS, Charleston, South Carolina) June 23, 1998, Conveys the Gaddy Report to FWS.

Duke Power Company. 1998c. Letter from J. Huff, Duke Power, Charlotte, North Carolina to R.E. Duncan, SCDNR. Dated June 23, 1998. Conveys the Gaddy Report to SCDNR.

Duke Energy Corporation. 1999a. Letter from M.S. Tuckman, Duke Energy Corporation to US Nuclear Regulatory Commission. Subject: License Renewal. Response to Requests for Additional Information, Oconee Nuclear Station. Dated March 4, 1999.

Duke Energy Corporation. 1999b. Letter from M.S. Tuckman, Duke Energy Corporation to U.S. Nuclear Regulatory Commission. Subject: Followup to Staff's Request for Additional Information. Dated December 29, 1998, Related to the Environmental Position of the Review of the License Renewal Application for Oconee Units 1, 2, and 3. Dated May 13, 1999.

Edwards, T.J., W.H. Hunt, L.E. Miller, and J.J. Sevic. 1976. "An evaluation of the impingement of fishes at four Duke Power Company steam-generating facilities." Pages 373-380 in Esch, G.W. and R.W. McFarlane (eds.). Thermal Ecology II. National Technical Information Service, U.S. Department of Commerce, Springfield, Virginia.

Executive Order 12898, "Federal Actions to Address Environmental Justice in Minority and Low-Income Populations." 59 Federal Register 7629-7633 (1994).

Federal Water Pollution Control Act (FWPCA), as amended, 33 USC 1251-1387 (also known as Clean Water Act).

Griffith, J.S. 1978. Effects of low temperature on the survival and behavior of threadfin shad, Dorosoma petenense. Transactions of the American Fisheries Society. 107:63-70.

Hudson and Nichols. 1978. Relation between zooplankton migration and entrainment in a South Carolina cooling reservoir. Waste Heat Management and Utilization Conference, Miami Beach, Florida, December 4-6, 1978.

National Electrical Safety Code (NESC). 1997. Institute of Electrical and Electric Engineers, Inc., New York.

National Institute of Environmental Health Sciences (NIESH). 1999. NIESH Report on Health Effects from Exposure to Power Line Frequency and Electric and Magnetic Fields. NIH Publication No. 99-4493. National Institutes of Health, Research Triangle Park, North Carolina.

Oliver and Hudson. 1987. Thermal and dissolved oxygen characteristics of a South Carolina cooling reservoir. Water Resources Bulletin, American Water Resources Association, 23(2):257-269.

Olmsted, L.L. and W.D. Adair. 1981. Protection of fish larvae at two southeastern power plants using skimmer walls. Research Report PES/81-30. Duke Power Company, Huntersville, North Carolina.

South Carolina Department of Health and Environmental Control (SCDHEC). 1997. Watershed Water Quality Assessment, Savannah and Salkehatchie River Basins. Technical Report No. 003-97, SCDHEC, Columbia, South Carolina.

South Carolina Department of Health and Environmental Control (SCDHEC). 1999. Letter from R. Michael, Gandy, South Carolina. Department of Health and Environmental Control to U.S. Nuclear Regulatory Commission. Subject: status of NPDES and land disposal permits for Oconee Nuclear Station. Dated April 21, 1999.

South Carolina Department of Natural Resources (SCDNR). 1998. Letter from Robert E. Duncan (SCDNR) to Ms. Jennifer Huff (Duke Power). September 24, 1998.

Talbert, S. J. & Bright, Inc., and Holland Consulting Planners, Inc. 1996. Oconee County, South Carolina 1996 Land Use Plan.

U.S. Atomic Energy Commission (AEC). 1972. Final Environmental Statement Related to Operation of Oconee Nuclear Station units 1, 2, and 3. March 1972. Washington, D.C.

U.S. Department of Commerce (DOC). 1991. 1990 Census-Population and Housing; Public Law 94-171 Data, Bureau of the Census. Washington, D.C.

U.S. Fish and Wildlife Service. 1998a. Letter from R. L. Banks (FWS, Charleston, South Carolina) to J. Huff (Duke Power, Charlotte, North Carolina) dated April 17, 1998. Letter provides a list of 9 species in Oconee and Pickens Counties.

U.S. Fish and Wildlife Service. 1998b. Letter dated August 4, 1998 from the Acting Field Supervisor for the Charleston Field Office to Duke Power indicating that continued operation or refurbishment of the Oconee Nuclear Station will have no effect on listed or proposed endangered or threatened species.

U.S. Fish and Wildlife Service. 1999. Letter dated November 4, 1999, from Brian P. Cole to U.S. Nuclear Regulatory Commission. Subject: Biological Assessment for License Renewal at Oconee Nuclear Station.

U.S. Nuclear Regulatory Commission (NRC). 1996a. Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1996b. Procedural Guidance for Preparing Environmental Assessments and Considering Environmental Issues, Attachment 4 to NRR Office Letter No. 906, Revision 1. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1999a. Generic Environmental Impact Statement for License Renewal of Nuclear Plants, Main Report, Section 6.3--Transportation, Table 9.1, Summary of Findings in NEPA issues for license renewal of nuclear power plants. NUREG-1437, Volume 1, Addendum 1. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1999b. Letter from NRC to the U.S. Fish and Wildlife Service. Subject: Biological Assessment. Dated June 30, 1999, Washington, D.C.

5.0 Environmental Impacts of Postulated Accidents

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Environmental issues associated with postulated accidents were discussed in the Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437 (NRC 1996). The GEIS included a determination of whether the analysis of the environmental issue could be applied to all plants and whether additional mitigation measures would be warranted. Issues were then assigned a Category 1 or a Category 2 designation. As set forth in the GEIS, Category 1 issues are those that meet all of the following criteria:

(1) the environmental impacts associated with the issue have been determined to apply either to all plants or, for some issues, to plants having a specific type of cooling system or other specified plant or site characteristics

(2) a single significance level (i.e., SMALL, MODERATE, or LARGE) has been assigned to the impacts (except for collective offsite radiological impacts from the fuel cycle and from HLW and spent fuel disposal)

(3) mitigation of adverse impacts associated with the issue has been considered in the analysis, and it has been determined that additional plant-specific mitigation measures are likely not to be sufficiently beneficial to warrant implementation.

For issues that meet the three Category 1 criteria, no additional plant-specific analysis is required unless new and significant information is identified.

Category 2 issues are those that do not meet one or more of the criteria of Category 1, and therefore, additional plant-specific review for these issues is required.

This chapter describes the environmental impacts from postulated accidents that might occur during the license renewal term.

5.1 Postulated Plant Accidents

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A Category 1 issue in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, is applicable to ONS postulated accidents and is listed in Table 5-1. Duke stated in its Environmental Report (ER) (Duke 1998a) that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to this issue beyond those discussed in the GEIS. For this issue, the GEIS concluded that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

Table 5-1. Category 1 Issue Applicable to Postulated Accidents During the Renewal Term

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, follows.

Design-Basis Accidents (DBAs): Based on information in the GEIS, the Commission found "The NRC staff has concluded that the environmental impacts of design basis accidents are of small significance for all plants." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of DBAs beyond those discussed in the GEIS.

A Category 2 issue related to postulated accidents that is applicable to ONS is discussed in Table 5-2.

Severe Accidents: Based on information in the GEIS, the Commission found that "The probability weighted consequences of atmospheric releases fallout onto open bodies of water, releases to groundwater, and societal and economic impacts from severe accidents are small for all plants. However, alternatives to mitigate severe accidents must be considered for all plants that have not considered such alternatives."

The staff has not identified any significant new information with regard to the consequences from severe accidents during its independent review of the Duke ER, the Duke Final Safety Analysis Report (FSAR) (Duke 1998b), the staff's site visit, the scoping process, the review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of severe accidents beyond those discussed in the GEIS. However, in accordance with 10 CFR 51.53(c)(3)(ii)(L), the staff has reviewed severe accident mitigation alternatives (SAMAs) for ONS. The results of its review are discussed in Section 5.2.

5.2 Severe Accident Mitigation Alternatives

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It is required in 10 CFR 51.53(c)(3)(ii)(L) that license renewal applicants provide a consideration of alternatives to mitigate severe accidents if the staff has not previously considered SAMAs for the applicant's plant in an EIS or related supplement or in an environmental assessment. The purpose of

Table 5-2. Category 2 Issue Applicable to Postulated Accidents During the Renewal Term

this consideration is to ensure that plant design changes with the potential for improving severe accident safety performance are identified and evaluated. SAMAs have not been previously considered for ONS; therefore, the remainder of Chapter 5 addresses those alternatives.

5.2.1 Introduction

Duke submitted an assessment of SAMAs for ONS as part of the ER (Duke 1998a). This assessment was based on Revision 2 of the ONS Probabilistic Risk Assessment (Duke 1997a). Revision 2 constitutes a full-scope Level 3 Probabilistic Risk Assessment (PRA) with the analysis of both internal and external events; the internal events analysis is an updated version of the Individual Plant Examination (IPE) model (Duke 1990), whereas the external events analysis is the same as the Individual Plant Examination for External Events (IPEEE) model (Duke 1995). In identifying and evaluating potential SAMAs, Duke took into consideration the insights and recommendations from earlier risk studies as well as several more recent risk studies. Duke concluded that none of the candidate SAMAs evaluated were cost effective for ONS.

Based on a review of the SAMA assessment, NRC issued a request for additional information (RAI) to Duke by letter dated December 29, 1998 (NRC 1998). Major issues concerned the process used by the license renewal applicant to identify potential SAMAs, the implementation status of numerous enhancements identified in previous studies, and the inclusion of averted onsite costs (AOSC) in Duke's value impact analysis. Duke submitted additional information by letter dated March 4, 1999 (Duke 1999), clarifying the SAMA identification process, the disposition of previously identified design enhancements, and the impact of AOSC on the cost-benefit analysis. This response provided additional clarification regarding the staff's concerns and reaffirmed that none of the SAMAs would be cost-beneficial even when averted onsite costs are included.

The staff's assessment of SAMAs for ONS is provided in Section 5.2.3.2.

5.2.2 Estimate of Risk for ONS

Duke's estimates of the offsite risk at ONS are summarized below. The summary is followed by the staff's review of Duke's risk estimates.

5.2.2.1 Duke Risk Estimates

The ONS PRA model, which forms the basis for the SAMA analysis, is a Level 3 risk analysis; i.e., it includes the treatment of core damage frequency, containment performance, and offsite consequences. The model, which Duke refers to as PRA, Revision 2, consists of an internal events portion, based on an updated version of the IPE (Duke 1990) and an external events portion, based on the current version of the IPEEE (Duke 1995). The calculated total core damage frequency for internal and external events in Revision 2 is 8.9E-5 per year.

Since the ONS PRA is a "living" PRA, the original version of the IPE is being continuously updated to reflect various design and procedural changes, such as those related to the improvements identified in the IPE, to incorporate comments from the "peer review certification" and to reflect up-to-date operational experience. A comparison of risk profiles between the original IPE PRA (which was reviewed by the staff) and the current version (internal events portion of PRA, Revision 2) indicated that there are no significant differences that could change the results of the SAMA analysis by impacting the approach used to identify potential SAMAs or the assessed risk reductions.

Since the issuance of the ONS PRA, Revision 2, report, the total core damage frequency has been recalculated. An IPEEE supplemental report (Duke 1997b) further evaluated the relay chatter issue and updated the seismic core damage frequency (CDF) to be 3.5E-5 per year. A high pressure injection (HPI) reliability study performed in response to an operational event (Duke 1997c) resulted in an updated core damage frequency of 4.3E-5 per year for all events, excluding seismic. Thus, by removing conservative assumptions related to the original seismic analysis and the HPI system, the net effect of these two studies would be to reduce the total CDF for ONS from 8.9E-5 per year to 7.8E-5 per year. Despite the availability of these later studies, the results of the ONS PRA, Revision 2, were used as the basis for the SAMA analysis since the later studies did not include Level 2 and Level 3 calculations and because the net impact of the changes was a small decrease in CDF.

Since Duke's PRA is based on ONS Unit 3, the licensee performed an analysis to determine the applicability of the PRA results to Units 1 and 2 and submitted the analysis as part of the IPE. This analysis concluded that inter-unit differences do not have a significant impact on the PRA results. Most mechanical and electrical systems of Units 1 and 2 are redundant and diverse from those of Unit 3. Those systems and structures that are shared affect all three units in a similar fashion during a severe accident scenario. Because civil structures of Units 1 and 2 are similar to those of Unit 3, external events impact structures and components similarly for each unit. Therefore, the results and insights of the ONS PRA are applicable to all three units.

The Level 2 (also called containment performance) portion of the ONS PRA model, Revision 2, including the plant damage state descriptors, the Containment Event Tree, and the source term binning and containment release categories, is essentially the same as the IPE Level 2 analysis. The offsite (or Level 3) consequence analyses were carried out using the NRC-developed Calculations of Reactor Accident Consequences Version 2 (CRAC2) code, and site-specific data for meteorology, population, and evacuation modeling.

Duke estimated the total CDF for internally and externally initiated events to be 8.9E-5 per year based on Revision 2 of the ONS PRA. The breakdown of the CDF is provided in Table 5-3. External event initiators represent about 71 percent of the total CDF and are dominated by seismic (44 percent of total CDF) and tornado initiators (16 percent of total CDF). External flood and fire initiators together account for about 11 percent of the total CDF. Internal event initiators represent about 29 percent of the total CDF and are dominated by internal flood (11 percent of total CDF), transient (9 percent of total CDF), and loss of coolant accident initiators (8 percent of total CDF). Remaining contributors together account for less than 2 percent of total CDF.

Duke estimated the dose to the population within 80 km (50 mi) of the ONS site from all initiators (internal and external) to be 0.0492 person-sievert (person-Sv) (4.92 person-rem) per year (Duke 1999). The breakdown of the total population dose by containment end-state is summarized in Table 5-4. Of the total risk from all initiators, about 80 percent is due to external events. Interfacing system loss-of-coolant accident (LOCA), containment isolation failure, and late containment failure dominate external event risk (Column 3 of Table 5-4) and total risk from all initiators (Column 4 of Table 5-4) with nearly equal contributions from each. Early containment failure accounts for approximately 10 percent of the total risk from all initiators, with the majority of this contribution coming from external events. Only about 20 percent of the total risk from all initiators is due to internal events, with the majority of this risk from late containment failure (Column 2 of Table 5-4). All other internal event contributors combined account for less than 10 percent of the total risk from all initiators.

5.2.2.2 Review of Duke's Risk Estimates

Duke's estimate of offsite risk at ONS is based on Revision 2 of the ONS PRA. For purposes of this review, the staff considered the ONS study in terms of the following major elements:

• the Level 1 and 2 risk models that form the bases for the November 1990 IPE submittal (Duke 1990)
• the major modifications to the IPE model that have been incorporated in Revision 2 of the PRA (Duke 1997b)

Table 5-3. ONS Core Damage Frequencies

• the external event models that form the basis for the December 1995 IPEEE submittal (Duke 1995)
• the analyses performed to translate fission product release frequencies from the Level 2 PRA model into offsite consequence measures.

The staff reviewed each of these analyses to determine the acceptability of Duke's risk estimates for the SAMA analysis, as summarized below.

The staff's review of the ONS IPE is described in an evaluation report dated April 1, 1993 (NRC 1993). In that review, the staff evaluated the methodology, models, data, and assumptions used to estimate CDF and characterize containment performance and fission product releases. The staff concluded that Duke's analysis met the intent of Generic Letter 88-20 (NRC 1988); that is, the IPE was of adequate quality to be used to look for design or operational vulnerabilities. Although the staff reviewed certain aspects of the IPE in more detail than others, the review primarily focused on the licensee's ability to examine ONS for severe accident vulnerabilities and not specifically on the detailed findings or

Table 5-4. Breakdown of Population Dose by Containment End-State

(Total Dose = 4.92 person-rem per year)

quantification estimates. However, ONS's risk profile and important IPE findings compare well to those of other Babcock & Wilcox plants (NUREG-1560) (NRC 1997a), and any differences are well understood. Overall, the staff believes that the ONS PRA is of adequate quality to be used as a tool in searching for areas with high potential for risk reduction and to assess such risk reductions, especially when the PRA models are used in conjunction with insights, such as those from risk importance, sensitivity, and uncertainty analyses.

The staff's review of the applicant's IPEEE is currently underway. The preliminary results did not identify any significant shortcomings or deficiencies. A limited review of the Duke submittal finds that the overall method, scope, and level of detail are generally comprehensive. The staff also notes that the Duke IPEEE has been subjected to both internal and external peer reviews. Based on these findings, the staff concludes that the external events portion of the ONS PRA provides an acceptable platform for identifying potential SAMAs and for assessing risk reductions.

The staff reviewed the process used by Duke to extend the containment performance (Level 2) portion of the IPE to the offsite consequence (Level 3) assessment. This included consideration of the source terms used to characterize fission product releases for each containment release category and the major input assumptions used in the offsite consequence analyses. This information is provided in Section 6.3 of Duke's IPE submittal. Duke used the Modular Accident Analysis Program code to analyze postulated accidents and develop radiological source terms for each of 35 containment release categories used to represent the containment end-states identified in Table 5-4. These source terms were incorporated as input to the CRAC2 analysis. The staff reviewed Duke's source term estimates for the major release categories and found these predictions to be in reasonable agreement with estimates of NUREG-1150 (NRC 1990a) for the closest corresponding release scenarios. The staff concludes that the assignment of source terms is acceptable.

The CRAC2 code has been superceded by the Melcor Accident Consequence Code System (MACCS), which, among other advancements, incorporates more recent models for calculating health effects (e.g., latent cancers). Although MACCS represents a significant improvement over CRAC2, both codes use a straight line Gaussian plume dispersion and transport model and, for the same input assumptions, provide comparable estimates of population dose (person-rem). Thus, the CRAC2 code is considered acceptable for purposes of estimating population dose for a severe accident.

The CRAC2 input in PRA, Revision 2, used site-specific meteorological data processed from measurements taken during the mid-1970s. To assess the impact that data from two different time periods may have on offsite dose, Duke obtained more recent data from the ONS site for the period January 1, 1997, through December 31, 1997. Re-analysis of the Level 3 portion of the PRA using the 1997 meteorological data (Duke 1999) shows that the risk results are only slightly impacted (reduced by about 2 percent). The staff therefore considers the meteorological data in PRA, Revision 2, to be representative of the climate for the site.

The population distribution used in Revision 2 of the PRA is based on 1990 census data. The impact of population increases was not included in Revision 2 since the purpose of the PRA was to understand the risk associated with current operation of the plant. Based on information contained in NUREG-1437 (NRC 1996), the population within an 80-km (50-mi) radius of the ONS site is projected to increase by about 33 percent between the years 1990 and 2030. Since the population dose is roughly proportional to the total population, use of the increased population value would result in an increase in the total risk from all initiators of approximately 1.6 person-rem per year. This increase is small in absolute terms and does not have a significant impact on the conclusions of the SAMA analysis, as discussed later.

Evacuation modeling is based on site-specific evacuation studies carried out by Duke. It was assumed that only 95 percent of the people within the emergency planning zone (determined by the plume exposure pathway) would participate in the evacuation. The remaining 5 percent would delay evacuation for 24 hours. This assumption is conservative relative to the NUREG-1150 (NRC 1990a) study, which assumed evacuation of 99.5 percent of the population within the emergency planning zone.

Site-specific economic data were used in the CRAC2 code. However, as discussed later, the applicant based their assessment of offsite costs on generic cost estimates rather than CRAC2 code calculations.

The staff concludes that the methodology used by Duke to estimate the CDF and offsite consequences for ONS provides an acceptable basis from which to proceed with an assessment of risk reduction potential for candidate SAMAs. Accordingly, the staff based its assessment of offsite risk on the CDF and offsite doses reported by Duke.

5.2.3 Potential Design Improvements

This section discusses the process for identifying potential design improvements, the staff's evaluation of this process, and the design improvements evaluated in detail by Duke.

5.2.3.1 Process for Identifying Potential Design Improvements

Duke's process for identifying potential plant improvements consisted of the following three elements:

• The core damage cutsets from Revision 2 of the ONS PRA were reviewed to identify potential SAMAs that could reduce CDF.
• The Fussell-Vesely (F-V) importance measures were evaluated for the basic events (including initiating events, random failure events, human error events, and maintenance/testing unavailabilities), and the importance ranking was examined to identify any events of significant F-V importance.
• Potential enhancements to reduce containment failure modes of concern for ONS (including early containment failure, containment isolation failure, and containment bypass), were reviewed for possible implementation.

This included a review of recommendations from the ONS IPE and IPEEE (those that had not been implemented), results of other plant-specific SAMA analyses, and insights from the staff's report on the individual plant examination (NRC 1997a) for possible inclusion of these concepts as additional SAMAs.

As a starting point for the core damage cutset review, Duke developed a listing of the top 100 cutsets (severe accident sequences) based on internal initiators and the top 100 cutsets for external initiators. These 200 sequences include all potential core damage sequences with at least a 0.06-percent contribution to the total CDF. Duke reviewed the cutsets to identify potential SAMAs that could reduce CDF. Cutoff values of 4.5E-7 per year and 8.5E-7 per year were used to screen internal and external events, respectively. To account for the cumulative effect of cutsets below these cutoff values, the basic events importance measure was also used to identify potential enhancements, as discussed below.

For each seismic initiator cutset, Duke calculated the associated offsite risk based on the person-rem risk and CDF for the plant damage states (PDSs) attributable to the seismic initiator. Duke conservatively assumed that the implementation of plant enhancements for seismic events would completely eliminate the seismic risk and calculated the present worth of the averted risk based on a $2000 per person-rem conversion factor, a discount factor of 7 percent, and a 20-year license renewal period. This process was repeated for each of the remaining seismic initiator cutsets above the cutoff frequency. The present worth of averted risk for all of the seismic cutsets combined was estimated to be about $51,000. Duke cited sensitivity studies performed previously as part of the IPEEE analysis, which show that most of the seismic upgrades to plant components would result in only a small reduction in CDF (less than 5E-6 per year). On the basis of the small risk reduction achievable and the large costs associated with substantial seismic upgrades, Duke eliminated seismic SAMAs from further consideration.

Duke reviewed the F-V Basic Event Importance Ranking presented in the ONS PRA report, Revision 2, and identified the top 30 basic events for further consideration. These included seismic-related events, initiating events, equipment failures, and human-error events. Seismic-related events were not evaluated further for reasons discussed above. Duke judged that all but one of the initiating events, such as tornado, dam failure, and fire events, could not be significantly impacted by SAMAs and that the remaining initiator (reactor trip initiator) is adequately addressed by their current ORAM-SENTINEL configuration management system. Based on a review of the remainder, Duke identified nine events/sequences and a potential plant enhancement to address each event. The list of the potential enhancements to reduce CDF are presented in Table 5-5.

Duke also considered potential alternatives to reduce containment failure modes of concern for ONS. These alternatives included nine containment-related improvements evaluated as part of the staff's assessment of severe accident mitigation design alternatives for Watts Bar (NRC 1995a) and five containment-related improvements derived from the staff's report on the individual plant examination program (NRC 1997a). Duke eliminated those alternatives that are either (1) not applicable to ONS (e.g., containment air return fans used only in ice condenser containments), (2) related to control of hydrogen combustion (since the Level 2 PRA shows the ONS containment is capable of withstanding large hydrogen burns), or (3) already implemented at ONS, e.g., by inclusion either in emergency operating procedures, severe accident management guidelines, or the operator training program. Based on the screening, Duke designated seven of the containment related SAMAs for further study. The list of the potential enhancements to improve containment performance is presented in Table 5-6.

5.2.3.2 Staff Evaluation

Duke's effort to identify potential SAMAs focused on areas found to be risk-significant in the ONS PRA. The list of SAMAs generally coincide with accident categories that are dominant CDF contributors or with issues that tend to have a large impact on a number of accident sequences at ONS. Duke made

Table 5-5. Value-Impact Results for Potentially Cost-Beneficial SAMAs that Prevent Core Damage

Table 5-6. Value-Impact Results for Potentially Cost-Beneficial SAMAs that Improve Containment Performance

a reasonable effort to use the ONS PRA to search for potential SAMAs and to review insights from other plant-specific risk studies and previous SAMA analyses for potential applicability to ONS. The staff notes that Duke identified a number of recommendations for reducing risk as a result of the ONS IPE and IPEEE, and that many of these plant improvements have been implemented or are planned and being tracked for resolution (Duke 1998c; Duke 1999). For those recommendations that were not implemented, Duke provided justification as to why these improvements are not warranted.

The staff reviewed the set of potential enhancements considered in Duke's SAMA identification process. These include improvements oriented toward reducing the CDF and risk from major contributors specific to ONS, improvements identified as part of the NRC containment performance improvement program, accident management strategies identified by NRC in Generic Letter 88-20, Supplement 2 (NRC 1990b), and improvements identified in the previous severe accident mitigation design alternative review for Watts Bar (NRC 1995a) that would be applicable to ONS. The SAMAs also include a filtered containment vent and a bed-core retention device for flooded rubble, which are cited specifically in NUREG-0660 (NRC 1980) for evaluation as part of Three Mile Island Task Action Plan Item II.B.8.

The staff notes that most of the SAMAs involve major modifications and significant costs and that less expensive design improvements and procedure changes could conceivably provide similar levels of risk reduction. However, lower cost improvements are not expected to offer significant risk reduction, given that external events account for the majority (80 percent) of the risk. Much of this risk is due to postulated earthquakes with ground accelerations significantly greater than the ONS design-basis earthquake. As such, SAMAs that would significantly reduce overall risk would involve substantial upgrades in the seismic ruggedness of the plant and would be very costly.

It should be noted that Duke has made extensive use of PRA methods to gain insights regarding severe accidents at ONS. Risk insights from various ONS risk assessments, such as the ONS IPE, the ONS IPEEE, the Keowee PRA, and ONS HPI reliability study, have been identified and implemented to improve both the design and operation of the plant. For example, using the IPE process, Duke identified and implemented modifications to procedures to (1) isolate the high pressure service water (HPSW) to the condenser circulating water (CCW) pumps during a turbine building flooding event to extend the time the elevated water storage tank (EWST) inventory would last, (2) power the SSF from the Unit 2 main feeder bus, (3) terminate containment sprays to conserve the BWST inventory to enhance long-term HPI cooling following a flooding event in the turbine building, and (4) cope with common cause failure of both HPI suction valves. Examples of plant improvements that resulted from IPEEE findings and whose implementation is being planned by Duke are (1) the mounting of the combustible storage locker near the SSF diesel to prevent combustible materials from being spilled around the diesel during a seismic event or knocked over by personnel, and (2) the replacement of the deluge (open head) sprinklers in the Cable and Equipment Rooms with closed head sprinklers to reduce water damage to equipment important to safety during a fire. The implementation

of such improvements reduced the risk associated with the major contributors identified by the ONS PRA and contributed to the reduced number of candidate SAMAs identified as part of Duke's application for license renewal.

The staff concludes that Duke has used a systematic process for identifying potential design improvements for ONS and that the set of potential design improvements identified by Duke is reasonably comprehensive and, therefore, acceptable.

5.2.4 Risk Reduction Potential of Design Improvements

Section 4.3 of the ER describes the process used by Duke to determine the risk reduction potential for each enhancement.

For each seismic initiator cutset, Duke calculated the associated offsite risk based on the person-rem risk and CDF for the PDSs attributable to the seismic initiator. Implementation of the plant enhancement was assumed to completely eliminate the seismic risk associated with the cutset. For each (non-seismic) sequence/enhancement, Duke assigned a PDS based on the type of plant damage and potential containment release characteristics. In general, where an alternative impacted more than one PDS, Duke used the PDS with the highest conditional person-rem risk to characterize the associated risk and assumed that implementation of the alternative would completely eliminate the risk. For each containment-related improvement, Duke assumed that all of the person-rem risk associated with the release categories impacted by the SAMA would be eliminated. For those alternatives that benefit more than one containment failure mode (i.e., independent containment spray system, reactor depressurization system, and filtered containment vent), the total person-rem dose for all affected failure modes was assumed to be completely eliminated by implementing the alternative.

The staff notes that Duke evaluated the risk reduction potential for each SAMA in a bounding fashion; i.e., each SAMA was assumed to completely eliminate all sequences that the specific enhancement was intended to address. As a result, the benefits are generally over estimated and conservative. Accordingly, the staff based its estimates of averted risk for the various SAMAs on Duke's risk reduction estimates.

5.2.5 Cost Impacts of Candidate Design Improvements

Duke's estimated costs for each potential design enhancement are provided in Tables 4-2 and 5-1 of Attachment K to the ER. For most of the SAMAs, Duke estimated the cost of implementation to be greater than $1 million based on cost estimates developed in previous industry studies. For three SAMAs, Duke developed plant-specific cost estimates because there was no readily available information on the estimated cost to implement similar alternatives and because the basic events associated with these alternatives were found to have a high importance in the ONS PRA. These SAMAs involve (1) increasing the height of the SSF flood barrier, (2) manning the SSF 24 hours a day with trained operators, and (3) installing a protective barrier for the upper surge tanks or upgrading the 4160 volt switchgear to withstand tornado winds. The costs to implement these SAMAs were estimated to be on the order of $500,000, $5 million, and $1 million, respectively. Because the safety benefits of the potential SAMAs were significantly less than their estimated implementation costs (by about a factor of five), none of the cost estimates were further refined.

The staff compared Duke's cost estimates with estimates developed elsewhere for similar improvements, including estimates developed as part of the evaluation of severe accident mitigation design alternatives for operating reactors and advanced LWRs. The staff notes that Duke's estimated implementation costs of $1 million dollars or greater are consistent with the values reported in previous analyses for changes of similar scope and are not unreasonable for the SAMAs under consideration, given that these enhancements involve major hardware changes and impact safety-related systems.

Although the applicant did not provide the underlying bases for its cost estimates, the staff views their cost estimates as reasonable for evaluating the SAMAs because the estimates are consistent with those developed by others and because the spread between the estimated costs and benefits is significant. Accordingly, the staff adopted Duke's cost estimates for the various candidate improvements.

5.2.6 Cost-Benefit Comparison

The following sections describe Duke's cost-benefit comparison and the staff's evaluation of the cost-benefit analysis.

5.2.6.1 Duke Evaluation

In the analysis provided in the ER, Duke did not include the following factors in its cost-benefit evaluation: averted onsite cleanup and decontamination cost, replacement power cost, and averted offsite property damage cost. In view of the significant impact of these averted costs on the estimated benefit for a SAMA, the staff requested that Duke include these factors in their cost-benefit analysis for each affected SAMA. In their response to the request for additional information, Duke updated the benefit estimates to include these factors for all SAMAs that reduce CDF. The methodology used by Duke was based primarily on NRC's guidance for performing cost-benefit analysis, i.e., NUREG/BR-0184, Regulatory Analysis Technical Evaluation Handbook (NRC 1997b), and NUREG/BR-0058, Regulatory Analysis Guidelines of the U.S. Nuclear Regulatory Commission (NRC 1995b). The guidance involves determining the net value for each SAMA according to the following formula:

Net Value = (APE + AOC + AOE + AOSC) - COE

If the net value of a SAMA is negative, the cost of implementing the SAMA is larger than the benefit associated with the SAMA and is not considered beneficial. Duke's derivation of each of the associated costs is summarized below.

Averted Public Exposure (APE)

Averted public exposure costs were calculated using the following formula:

APE =	Annual reduction in public exposure (person-rem/reactor-year)
	x monetary equivalent of unit dose
	x present value conversion factor

Duke estimated the annual reduction in public exposure for each SAMA as discussed previously. The reduction in public exposure (person-rem per year) was converted to a monetary equivalent by applying NRC's conversion factor of $2000 per person-rem and then discounting the monetary equivalent to present value. A 20-year period for the license renewal period and a 7-percent real discount rate was assumed, resulting in a present value conversion factor of 10.76.

As stated in NUREG/BR-0184 (NRC 1997b), it is important to note that the monetary value of the public health risk after discounting does not represent the expected reduction in public health risk due to a single accident. Rather, it is the present value of a stream of potential losses extending over the remaining lifetime (in this case, the renewal period) of the facility. Thus, it reflects the expected annual loss due to a single accident, the possibility that such an accident could occur at any time over the renewal period, and the effect of discounting these potential future losses to present value.

Averted Offsite Property Damage Costs

Averted offsite property damage costs were calculated using the following formula:

Duke determined the offsite economic costs for a severe accident based on the weighted costs for offsite property damage for the five NUREG-1150 plants (reported in Table 5.6 of NUREG/BR-0184). These costs were inflated to year 2000 dollars based on a 4-percent inflation rate, yielding a value of $364 million. Calculated values for offsite economic costs were discounted to present value in the same manner as for averted public exposure.

Averted Occupational Exposure

Averted occupational exposure was calculated using the following formula:

Duke derived the values for averted occupational exposure based on information provided in Section 5.7.3 of the regulatory analysis handbook (NRC 1997b). Best estimate values provided for immediate occupational dose (3,300 person-rem) and long-term occupational dose (20,000 person-rem over a 10-year cleanup period) were used. The present value of these doses was calculated using equations provided in the handbook in conjunction with a monetary equivalent of unit dose of $2000 per person-rem, a real discount rate of 7 percent, and a time period of 20 years to represent the license renewal period.

Averted Onsite Costs

AOSC includes averted cleanup and decontamination costs and averted power replacement costs. Duke derived the values for AOSC based on information provided in Section 5.7.6 of the regulatory analysis handbook (NRC 1997b).

Averted cleanup costs are calculated using the following formula:

The net present value for cleanup and decontamination of a severe accident (discounted over 10 years) is given as $1.1 billion in the handbook (NRC 1997b). Use of a discount factor of 10.76 to account for the 20-year license renewal period yields an integrated cleanup cost of $12 billion. This value was multiplied by the annual reduction in core damage frequency to obtain the averted cleanup costs portion of the AOSC.

Long-term replacement power costs (U_RP) are calculated as

In accordance with guidance provided in Section 5.7.6.2 of the handbook (NRC 1997b), Duke estimated the net present value of replacement power for a single event to be $1.23 billion, based on a replacement power cost for each ONS unit of $152 million (year 2000 dollars), a real discount rate of 7 percent, and a 20-year license renewal period. This value was multiplied by a factor of 8.1 to obtain a summation of the single-event costs over the entire license renewal period, yielding a replacement power cost of $10.0 billion. This value was multiplied by the annual reduction in core damage frequency to obtain the averted replacement costs portion of the AOSC.

The value-impact results for the 16 SAMAs are presented in Tables 5-5 and 5-6. All of the SAMAs have a negative net value, even when bounding risk reduction benefits are assumed, and AOSC is included. Duke concluded that implementation of SAMAs is not justified since the cost of implementation far exceeds the benefit of these SAMAs. As such, Duke has decided not to pursue any of these SAMAs further.

5.2.6.2 Staff Evaluation

The updated cost-benefit analysis provided by Duke (Duke 1999) was based primarily on NRC's Regulatory Analysis Technical Evaluation Handbook (NRC 1997b). The only noted deviation from the regulatory guidance was the omission of the averted offsite property damage cost component for those SAMAs that impact only containment performance. (A reduction in offsite consequences results in both averted public exposure and averted offsite property damage. Duke appropriately considered averted offsite property damage costs for the SAMAs that prevent core damage, but failed to include these averted costs for the SAMAs that improve containment performance.) The staff has evaluated the averted offsite property damage cost component for these SAMAs and found it to be small (less than $100,000 for the most effective mitigative SAMA identified) and well below the cost of the enhancements. Thus, the total present worth benefit for any of the containment-related SAMAs would be less than $150,000.

The staff concludes that the cost of implementing any of the 16 SAMAs would far exceed the estimated benefit, with a margin of about a factor of five. Based on its review, the staff notes the following:

• Averted onsite costs are the single most important factor in the cost-benefit analysis. However, no SAMAs are cost-beneficial when these costs are included in the analysis in accordance with NRC's regulatory analysis guidance.
• Use of a 3-percent discount rate in place of the 7-percent discount rate used in the base case analysis increases net values, but does not lead to identification of any cost-beneficial SAMAs.
• The effect of implementing the SAMA in the near term rather than delaying implementation until the start of the license renewal period (i.e., use of a 35-year rather than a 20-year period in the value impact analysis) is bounded by the sensitivity study, which assumed a 3-percent discount rate, and does not lead to identification of any cost-beneficial SAMAs.

5.2.7 Conclusions

Duke completed a comprehensive effort to identify and evaluate potential cost-beneficial plant enhancements to reduce the risk associated with severe accidents at ONS. As a result of this assessment, Duke concluded that no additional mitigation alternatives are cost-beneficial and warrant implementation at ONS.

Based on its review of SAMAs for ONS, the staff concurs that none of the candidate SAMAs are cost beneficial. This conclusion is consistent with the low residual level of risk indicated in the ONS PRA and the fact that Duke has already implemented many plant improvements identified from previous plant-specific risk studies. Both the conditional probability of an early release of fission products and the total offsite risk at ONS are already quite small (less than 4 percent and 5 person-rem per year, respectively). External events account for the majority (80 percent) of the risk, with much of this from postulated earthquakes with ground accelerations significantly greater than the ONS design-basis earthquake. Given the low level of residual risk and the large cost of seismic-related enhancements necessary to substantially reduce risk, cost-beneficial enhancements that can significantly reduce risk are unlikely and have not been identified. The margins in the analysis are considered ample to cover uncertainties in risk and cost estimates given that, in general, estimates for these factors were conservatively evaluated.

5.3 References

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10 CFR 51.53, "Postconstruction environmental reports."

10 CFR Part 51, Subpart A, Appendix B, "Environmental effect of renewing the operating license of a nuclear power plant."

Duke Energy Corporation. 1990. Letter from Tuckman, Duke Energy Corporation. Subject: Transmitting Individual Plant Examination. Dated November 30, 1990.

Duke Energy Corporation. 1995. Letter from Hampton, Duke Energy Corporation. Subject: Transmitting Individual Plant Examination for External Events. Dated December 28, 1995.

Duke Energy Corporation. 1997a. Letter from Hampton, Duke Energy Corporation. Subject: Transmitting Oconee Probabilistic Risk Assessment. Dated February 13, 1997.

Duke Energy Corporation. 1997b. Letter from McCollum, Duke Energy Corporation. Subject: Transmitting Oconee Supplemental Individual Plant Examination for External Events Submittal Report. Dated December 18, 1997.

Duke Energy Corporation. 1997c. Letter from McCollum, Duke Energy Corporation. Subject: Transmitting High Pressure Injection Reliability Study. Dated December 18, 1997.

Duke Energy Corporation. 1998a. Application for Renewed Operating Licenses, Oconee Nuclear Station-Units 1, 2, and 3. Volume IV-Environmental Report.

Duke Energy Corporation. 1998b. Final Safety Analysis Report (Oconee Updated FSAR). Charlotte, North Carolina.

Duke Energy Corporation. 1998c. Letter from McCollum, Duke Energy Corporation, Subject: SQUG Resolution of USI A-46 (Generic Letter 87-02) Expected Completion of SQUG Outliers. Oconee Supplemental IPEEE Submittal Report. Dated June 30, 1998.

Duke Energy Corporation. 1999. Letter from M. S. Tuckman, Duke Energy Corporation to U.S. Nuclear Regulatory Commission. Subject: License Renewal - Response to Requests for Additional Information, Oconee Nuclear Station. Dated March 4, 1999.

U.S. Nuclear Regulatory Commission (NRC). 1980. NRC Action Plan Developed As a Result of TMI-2 Accident. NUREG-0660. U.S. Nuclear Regulatory Commission, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1988. Generic Letter 88-20, "Individual Plant Examination for Severe Accident Vulnerabilities." November 23, 1988.

U.S. Nuclear Regulatory Commission (NRC). 1990a. Severe Accident Risks - An Assessment for Five U.S. Nuclear Power Plants. NUREG-1150. U.S. Nuclear Regulatory Commission, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1990b. Letter from J. G. Partlow, U.S. NRC, to All Holders of Operating Licenses and Construction Permits for Nuclear Power Reactor Facilities. April 4, 1990. Subject: Accident Management Strategies for Consideration in the Individual Plant Examination Process - Generic Letter 88-20, Supplement No. 2.

U.S. Nuclear Regulatory Commission (NRC). 1993. Weins (NRC) letter dated 4/1/93 transmitting Evaluation of the Oconee 1, 2, and 3 Individual Plant Examination (IPE) - Internal Events.

U.S. Nuclear Regulatory Commission (NRC). 1995a. Final Environmental Statement Related to the Operation of Watts Bar Nuclear Plant Units 1 and 2. NUREG-0498, Supplement 1. U.S. Nuclear Regulatory Commission, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1995b. Regulatory Analysis Guidelines of the U.S. Nuclear Regulatory Commission. NUREG/BR-0058, Revision 2. U.S. Nuclear Regulatory Commission, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement for License Renewal of Nuclear Power Plants (GEIS), NUREG-1437. U.S. Nuclear Regulatory Commission, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1997a. Individual Plant Examination Program: Perspectives on Reactor Safety and Plant Performance. NUREG-1560. U.S. Nuclear Regulatory Commission, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1997b. Regulatory Analysis Technical Evaluation Handbook. NUREG/BR-0184. U.S. Nuclear Regulatory Commission, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1998. Letter from NRC to Duke Energy Corporation. Subject: Request for Additional information for the Review of the Oconee Nuclear Station Unit Nos. 1, 2, & 3 Environmental Report Associated with License Renewal - Environmental. Dated December 29, 1998.

6.0 Environmental Impacts of the Uranium Fuel Cycle and Solid Waste Management

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Environmental issues associated with the uranium fuel cycle and solid waste management were discussed in the Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437 (NRC 1996; NRC 1999⁽¹¹⁾). The GEIS included a determination of whether the analysis of the environmental issue could be applied to all plants and whether additional mitigation measures would be warranted. Issues were then assigned a Category 1 or a Category 2 designation. As set forth in the GEIS, Category 1 issues are those that meet all of the following criteria:

For issues that meet the three Category 1 criteria, no additional plant-specific analysis is required unless new and significant information is identified.

Category 2 issues are those that do not meet one or more of the criteria of Category 1, and therefore, additional plant-specific review for these issues is required.

This chapter addresses those issues that are related to the uranium fuel cycle and solid waste management during the license renewal term that are listed in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to ONS. The generic potential impacts of the radiological and non-radiological environmental impacts of the uranium fuel cycle and transportation of nuclear fuel and wastes are described in detail in the GEIS based on the generic impacts provided in 10 CFR 51.51(b), Table S-3, "Table of Uranium Fuel Cycle Environmental Data," and in 10 CFR 51.52(c), Table S-4, "Environmental Impact of Transportation of Fuel and Waste to and from One Light-Water-Cooled Nuclear Power Reactor." The GEIS also addresses the impacts from radon and technetium. There are no Category 2 issues for the uranium fuel cycle and solid waste management.

6.1 The Uranium Fuel Cycle

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Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to ONS from the uranium fuel cycle and solid waste management are listed in Table 6-1. Duke stated in its environmental report (ER) (Duke 1998) that it is not aware of any new and significant information

Table 6-1. Category 1 Issues Applicable to the Uranium Fuel Cycle and Solid Waste Management During the Renewal Term

associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of those issues, the staff concluded in the GEIS that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

A brief description of the staff review and the GEIS conclusions, as codified in Table B-1, for each of these issues follows:

6.2 References

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10 CFR Part 51, "Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions."

10 CFR 51.23, "Temporary storage of spent fuels after cessation of reactor operation--generic determination of no significant environmental impact."

10 CFR 51.51(b), Table S-3, "Uranium fuel cycle environmental data."

10 CFR 51.52(c), Table S-4, "Environmental effects of transportation of fuel and waste.

10 CFR Part 51, Subpart A, Appendix B, "Environmental effects of renewing the operating license of a nuclear power plant."

10 CFR Part 54, "Requirements for Renewal of Operating Licenses for Nuclear Power Plants."

40 CFR Part 191, "Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Waste."

Duke Energy Corporation. 1998. Application for Renewed Operating Licenses. Oconee Nuclear Station Units 1, 2, and 3. Volume IV Environmental Report.

National Academy of Sciences (NAS). 1995. Technical Bases for Yucca Mountain Standards, Washington, D.C.

U.S. Department of Energy (DOE). 1980. Final Environmental Impact Statement: Management of Commercially Generated Radioactive Waste, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement for License Renewal of Nuclear Plant (GEIS), NUREG-1437, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1999. Generic Environmental Impact Statement to License Renewal of Nuclear Plants Main Report, Section 6.3--Transportation, Table 9.1, Summary of findings on NEPA issues for license renewal of nuclear power plants. NUREG-1437, Volume 1, Addendum 1. Washington, D.C.

7.0 Environmental Impacts of Decommissioning

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Environmental issues associated with decommissioning resulting from continued plant operation during the renewal term were discussed in the Generic Environmental Impact Statement for License Renewal of Nuclear Power Plants, NUREG-1437 (NRC 1996). The GEIS included a determination of whether the analysis of the environmental issue could be applied to all plants and whether additional mitigation measures would be warranted. Issues were then assigned a Category 1 or a Category 2 designation. As set forth in the GEIS, Category 1 issues are those that meet all of the following criteria:

For issues that meet the three Category 1 criteria, no additional plant-specific analysis is required unless new and significant information is identified.

Category 2 issues are those that do not meet one or more of the criteria of Category 1, and therefore, additional plant-specific review for these issues is required. There are no Category 2 issues related to decommissioning at ONS.

Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to ONS decommissioning following the renewal term are listed in Table 7-1. Duke stated in its Environmental Report (ER) (Duke 1998) that it is not aware of any new and significant information associated with the renewal of the Oconee operating licenses. No significant new information has been identified by the staff in the review process and in the staff's independent review. Therefore, the staff concludes that there are no impacts related to these issues beyond those discussed in the GEIS. For all of those issues, the staff concluded in the GEIS that the impacts are SMALL, and plant-specific mitigation measures are not likely to be sufficiently beneficial to be warranted.

Table 7-1. Category 1 Issues Applicable to the Decommissioning of the ONS Following the Renewal Term

A brief description of the staff's review and the GEIS conclusions, as codified in Table B-1, for each of the issues follows:

• Radiation doses: Based on information in the GEIS, the Commission found that "Doses to the public will be well below applicable regulatory standards regardless of which decommissioning method is used. Occupational doses would increase no more than 1 man-rem (0.01 person-SV) caused by buildup of long-lived radionuclides during the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no radiation doses associated with decommissioning following license renewal beyond those discussed in the GEIS.
• Waste management: Based on information in the GEIS, the Commission found that "Decommissioning at the end of a 20-year license renewal period would generate no more solid wastes than at the end of the current license term. No increase in the quantities of Class C or greater than Class C wastes would be expected." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comment on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of solid waste associated with decommissioning following the license renewal term beyond those discussed in the GEIS.
• Air quality: Based on information in the GEIS, the Commission found that "Air quality impacts of decommissioning are expected to be negligible either at the end of the current operating term or at the end of the license renewal term." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of license renewal on air quality during decommissioning beyond those discussed in the GEIS.
• Water quality: Based on information in the GEIS, the Commission found that "The potential for significant water quality impacts from erosion or spills is no greater whether decommissioning occurs after a 20-year license renewal period or after the original 40-year operation period, and measures are readily available to avoid such impacts." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of the license renewal term on water quality during decommissioning beyond those discussed in the GEIS.
• Ecological resources: Based on information in the GEIS, the Commission found that "Decommissioning after either the initial operating period or after a 20-year license renewal period is not expected to have any direct ecological impacts." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of the license renewal term on ecological resources during decommissioning beyond those discussed in the GEIS.
• Socioeconomic Impacts: Based on information in the GEIS, the Commission found that "Decommissioning would have some short-term socioeconomic impacts. The impacts would not be increased by delaying decommissioning until the end of a 20-year relicense period, but they might be decreased by population and economic growth." The staff has not identified any significant new information during its independent review of the Duke ER, the staff's site visit, the scoping process, its review of public comments on the draft SEIS, or its evaluation of other available information. Therefore, the staff concludes that there are no impacts of license renewal on the socioeconomic impacts of decommissioning beyond those discussed in the GEIS.

7.1 References

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10 CFR Part 51, Subpart A, Appendix B, "Environmental effect of renewing the operating license of a nuclear power plant."

Duke Energy Corporation. 1998. Application for Renewed Operating Licenses--Oconee Nuclear Station, Units 1, 2 and 3. Volume IV-Environmental Report.

U.S. Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement for License Renewal of Nuclear Plant (GEIS), NUREG-1437. Washington, D.C.

8.0 Environmental Impacts of Alternatives to License Renewal

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This chapter examines the potential environmental impacts associated with denying a renewed operating license (i.e., the no-action alternative); the potential environmental impacts from electric generating sources other than renewal of the ONS operating licenses; the potential impacts from instituting additional conservation measures to reduce the total demand for power; and the potential impacts from power imports. The impacts are evaluated using a three-level standard of significance--SMALL, MODERATE, or LARGE--based on Council on Environmental Quality (CEQ) guidelines. These significance levels are as follows:

8.1 No-Action Alternative

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For license renewal, the no-action alternative refers to a scenario in which NRC would not renew the ONS operating licenses, and the applicant would then decommission ONS when plant operations cease. Replacement of ONS electricity generation capacity would be met either by demand-side management and energy conservation (perhaps supplied by an energy service company), imported power, some generating alternative other than ONS, or some combination of these. However, due to the influence of the ongoing deregulation of the retail market, Duke might not be the ultimate power supplier.

Duke will be required to comply with NRC decommissioning requirements whether or not the operating licenses are renewed. If the ONS operating licenses are renewed, decommissioning activities may be postponed for up to an additional 20 years. If the licenses are not renewed, then Duke would begin decommissioning activities when plant operations cease, beginning in 2013 or perhaps sooner. The impacts of decommissioning would occur concurrently with the impacts of supplying replacement power. The GEIS (NRC 1996) and the Final Generic Impact Statement on Decommissioning of Nuclear Facilities, NUREG-0586 (NRC 1988) provide a description of decommissioning activities.

The environmental impacts associated with decommissioning under the no-action alternative would be bounded by the discussion of impacts in Chapter 7 of the GEIS, Chapter 7 of the SEIS, and NUREG-0586 (NRC 1988). The impacts of decommissioning after 60 years of operation generally would not be significantly different from those occurring after 40 years of operation.

Table 8-1. Summary of Environmental Impacts from No-Action Alternative

8.2 Alternative Energy Sources

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Nuclear power plants are commonly used for base-load generation; the GEIS indicates that coal-fired and gas-fired generation capacity are the feasible alternatives to nuclear power generating capacity, based on current (and expected) technological and cost factors. The alternatives of coal-fired generation and gas-fired generation are presented (Sections 8.2.1 and 8.2.2, respectively) as if such plants were constructed at the ONS site, using the existing water intake and discharge structures, switchyard, and transmission lines, or at an alternate location that could be either a current industrial site or an undisturbed, pristine site requiring a new generating building and facilities, new switchyard, and at least some new transmission lines. For purposes of this SEIS, a "greenfield" site is assumed to be an undisturbed, pristine site.

Depending on the location of an alternative site, it might also be necessary to provide a connection to the nearest gas pipeline (in the case of natural gas) or rail connection (in the case of coal). The requirement for these additional facilities also likely would increase the environmental impacts relative to those that would be experienced at the ONS site, although this is less certain.

The cooling water needs of a fossil-fired plant of equal capacity to the ONS facility would require the use of either a once-through cooling system located on a large body of water such as Lake Keowee or a closed cycle system using cooling towers.

The potential for using imported power is discussed in Section 8.2.3. Imported power is considered feasible, but would result in the transfer of environmental impacts from the current region in South Carolina to some other location in South Carolina, another state, or a Canadian province. Several other technologies were considered, but were determined not to be reasonable replacements for a nuclear power plant. These options included wind, solar, hydropower, geothermal, wood energy, municipal solid waste, oil, advanced nuclear, fuel cells, delayed retirement of other generating units, and utility-sponsored conservation as discussed in Section 8.2.4.

Some of the alternatives in this section are not inherently infeasible, but could not provide enough power on their own to replace the power from ONS. The final subsection considers the environmental consequences of a mix of alternatives. These impacts are the same or larger than the environmental consequences of relicensing.

8.2.1 Coal-Fired Generation

It was assumed that it would take 2500 MW(e) of coal-fired generation capacity to replace the approximately 2500-MW(e) ONS. The typical size [MW(e)] and configuration used by the electrical power industry in the application of coal-fired generation technology varies.

8.2.1.1 Once-Through Cooling System

Section 8.2.1.1 sets forth the environmental impacts of converting the current ONS site to a coal-fired generation facility with once-through cooling and building a similar facility on a greenfield site. Differences in impacts with closed-cycle cooling are covered in Section 8.2.1.2. Land use in the discussion that follows was based on two of Duke's current coal-fired generating plants: the four-unit, 2090-MW(e) Marshall Steam Station in Catawba County, North Carolina, which occupies 650 ha (1600 acres), and the 2-unit, 2370-MW(e) Belews Creek Steam Station in Stokes County, North Carolina, which occupies 280 ha (700 acres) (Duke 1999a). Environmental impacts were based on data in EPA (1995). The impacts are summarized in Table 8-2.

Construction of the coal-fired alternative would take approximately 5 years. The workforce during the construction period would be expected to average 1500, with a peak of 2500 (GEIS, adjusted for the larger scale of the ONS replacement plant) and during operations to average 500 (Duke 1998).

Additional water would be needed for controlling wet-scrubber sulfur dioxide emissions and for boiler makeup.

Table 8-2. Summary of Environmental Impacts from Coal Alternative--Once-Through Cooling