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• Publication Information
• Abstract

Table of Contents

• Publication Information
• Abstract
• Figures
• Executive Summary
• Abbreviations/Acronyms
• 1.0 Introduction
• 1.1 The Proposed Federal Action
• 1.2 Purpose and Need for the Action
• 1.3 Compliance and Consultations
• 1.4 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 Historic and Archaeological Resources
• 2.2.10 Related Federal Project Activities
• 2.3 References
• 3.0 Environmental Impacts of Refurbishment
• 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
• 4.2 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
• 4.5.1 Groundwater Use Conflicts (Potable and Service Water)
• 4.6 Threatened or Endangered Species
• 4.7 Evaluation of Potential New and Significant Information on Impacts of Operations During the Renewal Term
• 4.7.1 Microorganisms That Live in High Radiation, Extreme Heat Conditions
• 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 CCNPP
• 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 Benefit-Cost Comparison
• 5.2.7 Conclusions
• 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 the 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 License Renewal
• A.1.4 Refurbishment
• A.1.5 Ecology
• A.1.6 Human Health
• A.1.7 Socioeconomics
• A.1.8 Archaeology and Historic Resources
• A.1.9 Impacts of Mining, Milling, and Fuel Manufacture
• A.1.10 Severe Accident Mitigation Alternatives
• A.1.11 Operational Safety Issues Associated with Current Operation
• A.1.12 Age-related Safety Issues
• A.1.13 Spent Nuclear Fuel
• A.1.14 Decommissioning
• A.1.15 Alternatives
• A.1.16 Miscellaneous
• A.1.17 Technical Clarifications and Corrections
• A.1.18 Format and Presentation (spelling, grammar, references, clarity, etc.)
• A.2 Public Meeting Transcript Excerpts and Comment Letters
• Letter A (Transcript)
• B. Written Statements Submitted at Public Meetings
• Letter C
• Letter D
• Letter E
• Letter F
• Letter G
• Letter H
• Letter I
• Letter J
• Letter K
• Letter L
• Letter M
• Letter N
• Letter O
• Letter P
• Letter Q
• Letter R
• Letter S
• Letter T
• Appendix B : Contributors to the Supplement
• Appendix C : Chronology of NRC Staff Environmental Review for the Calvert Cliffs Nuclear Power Plant, Unit 1 and 2 License Renewal
• Appendix D : Organizations Contacted
• Appendix E : BGE Compliance Status and Consultations
• Appendix F : GEIS Environmental Issues Not Applicable to the Calvert Cliffs Nuclear Power Plant
• F.1 References

Publication Information

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Supplement 1
Regarding the Calvert Cliffs Nuclear Power Plant
Final Report
Manuscript Completed: October 1999
Date Published: October 1999

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

Availability Notice

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 93 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 Baltimore Gas and Electric Company (BGE) to renew the operating licenses for Calvert Cliffs Nuclear Power Plant (CCNPP) Unit 1 and Unit 2 for an additional 20 years under 10 CFR Part 54. 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.

Neither BGE or the staff have identified significant new information for any of the 69 issues for which the GEIS reached generic conclusions and which apply to the CCNPP. Therefore, the staff concludes that the impacts of renewing the CCNPP operating licenses 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 24 issues that apply to the CCNPP is addressed in this SEIS. For each applicable issue, the staff concludes that the significance of the potential environmental effects of renewal of the operating license is small. The staff also concludes that additional mitigation measures are recommended only for threatened or endangered species and that mitigation measures beyond those recommended by the U.S. Fish and Wildlife Service are not warranted.

The NRC staff recommends that the Commission determine that the adverse environmental impacts of license renewal for Calvert Cliffs Nuclear Power Plant Unit 1 and Unit 2 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 BGE; (3) consultation with Federal, State, and local agencies; (4) its own independent review, and (5) its consideration of public comments.

Figures

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2-1 Calvert Cliffs Nuclear Power Plant Site Area, 50-Mile Region

2-2 Calvert Cliffs Nuclear Power Plant Site Area, Land Uses and Growth Protection Areas

2-3 Calvert Cliffs Nuclear Power Plant Site Layout and Well Locations

2-4 Calvert Cliffs Nuclear Power Plant Station Layout

2-5 Calvert Cliffs Nuclear Power Plant (aerial photo)

2-6 Regional Geologic Section - Coastal Plain

2-7 Intake and Discharge Structures

2-8 Water Supply Systems in Calvert and St. Mary's Counties

2-9 Aquia Aquifer Potentiometric Surface Map

2-10 CCNPP 16-km (10-mi) Population Sectors

2-11 CCNPP 80-km (50-m) Population Sectors

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

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

Executive Summary

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By letter dated April 8, 1998, Baltimore Gas and Electric Company (BGE) submitted an application to the U.S. Nuclear Regulatory Commission (NRC) to renew the operating licenses for Units 1 and 2 of the Calvert Cliffs Nuclear Power Plant (CCNPP) 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 and 2 will be shut down at or before the expiration of the current operating licenses, which are July 31, 2014, and August 13, 2016, respectively.

Under the National Environmental Policy Act (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 BGE application, the NRC began the environmental review process described in 10 CFR Part 51 by publishing a notice of intent to prepare an EIS and conduct scoping. The staff visited the CCNPP site in July 1998 and held public scoping meetings on July 9, 1998, in Solomons, Maryland. The staff reviewed the BGE 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 CCNPP.

This supplemental EIS (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 Commission has provided the criterion to be used in evaluating the environmental impacts, as follows [10 CFR 51.95(c)(4)]:

... 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 CCNPP 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 93 environmental issues using a three-level standard of significance--small, moderate, or large--based on Council on Environmental Quality guidelines. These significance levels are

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 93 issues considered in the GEIS, the analysis in the GEIS shows:

(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 were 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.

Of the 24 issues not meeting the criteria set forth above, 22 were 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, were 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, or at the time this document was prepared.

This SEIS evaluates all 93 environmental issues considered in the GEIS and one new issue-- microorganisms in high-radiation, high-temperature conditions, which was raised during the scoping process. The SEIS considers the environmental impacts associated with alternatives to license renewal and compares 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 CCNPP 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 CCNPP is replaced. These alternatives are evaluated assuming that the replacement power generation plant is located at either the CCNPP site or an unspecified "greenfield" site.

BGE 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 BGE nor the staff is aware of any significant new information related to Category 1 issues that would call into question the conclusions in the GEIS. Similarly, neither BGE or the staff has identified any new issue applicable to the CCNPP 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 BGE 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 CCNPP. Four additional Category 2 issues are not discussed in this SEIS because they are specifically related to refurbishment. BGE has stated in its ER that it "has not identified the need to undertake the major refurbishment activities that the GEIS assumed for license renewal, and no other modifications have been identified that would directly affect the environment or plant effluents."

The remaining 13 Category 2 issues, as well as environmental justice and chronic effects of electromagnetic fields, are discussed in detail in this SEIS. For all issues, the staff concludes that the potential environmental effects are of SMALL significance in the context of the GEIS. For Severe Accident Mitigation Alternatives (SAMAs), the staff concludes that a reasonable, comprehensive effort was made to identify and evaluate SAMAs. Although a limited number of cost-beneficial SAMAs (four) were identified, the SAMAs do not relate to adequately managing the effects of aging during the period of extended operation and, therefore, need not be implemented as part of license renewal pursuant to 10 CFR Part 54.

In addition to considering the 93 issues listed in the GEIS, the staff considered the potential issue associated with microorganisms that live in high-radiation, high-temperature environments and concludes that this issue, while new, is not significant.

Mitigation measures were considered for each Category 2 issue. In general, 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. However, the U.S. Fish and Wildlife Service recommended that BGE amend its conservation agreement with The Nature Conservancy relative to tiger beetles and set constraints on activities in the vicinity of bald eagle nests. No other mitigation measures related to threatened or endangered species are warranted.

In the event that the CCNPP operating licenses are not renewed, and the plants cease operation at 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 CCNPP. 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 Calvert Cliffs Nuclear Power Plant Unit 1 and Unit 2 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 BGE; (3) consultation with other Federal, State and local agencies; (4) its own independent review; and (5) its consideration of public comments.

Abbreviations/Acronyms

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1.0 Introduction

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Baltimore Gas and Electric Company (BGE) operates Calvert Cliffs Nuclear Power Plant (CCNPP) Units 1 and 2 in southern Maryland on the west shore of the Chesapeake Bay under operating licenses (OLs) DPR-53 and DPR-69 issued by the U.S. Nuclear Regulatory Commission (NRC). These OLs will expire in 2014 for Unit 1 and 2016 for Unit 2. By letter dated April 8, 1998, BGE submitted an application to the NRC to renew the CCNPP OLs for an additional 20 years under Title 10 of the Code of Federal Regulations (CFR) Part 54. BGE 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),⁽²⁾ 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), BGE submitted an environmental report (ER) (BGE 1998a) in which BGE 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 (SEIS) for the BGE 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 February 24, 1999. Appendix B lists preparers of this supplement, and Appendix C lists the chronology of correspondence between NRC and BGE with regard to this supplement. The remaining appendices are identified in subsequent sections.

Generic Environmental Impact Statement

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 environmental 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:

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.

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:

(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 characteristic.

(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.

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.

As set forth in the GEIS, the staff assessed 93 environmental issues and determined that 69 are Category 1 issues, 22 are 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. A summary of the findings for all 93 issues is listed in Table 9.1 of the GEIS and is codified in 10 CFR Part 51, Subpart A, Appendix B, Table B-1.

License Renewal Evaluation Process

An applicant seeking a renewal of 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 issues 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. Certain issues, including the need for power, the economic benefits and costs of the proposed action, economic benefits and costs of alternatives to the proposed action, and other issues not related to the environmental effects of the proposed action and associated alternatives need not be considered in the ER in accordance with 10 CFR 51.95(c)(2). In addition, the ER need not discuss any aspect of the storage of spent fuel. Pursuant to 10 CFR 51.53(c)(3)(i) 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, 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 CCNPP operating licenses, BGE implemented a process for identifying and evaluating the potential significance of new information related to environmental impacts that might be associated with the CCNPP license renewal. The process is described in a paper provided to the staff during a staff site visit in July 1998 (BGE 1998b). The process included forming a team of individuals who represent (1) the principal BGE organizations having responsibilities encompassing license renewal environmental issues, (2) the Maryland Department of Natural Resources (MDNR), and (3) BGE's vendor for environmental services. This team conducted site inspections, record and document reviews, interviews, and a CCNPP docket review in search of information that might indicate that any of the findings for Category 1 issues or analyses for Category 2 issues were invalid as applied to CCNPP or that there were potential environmental impacts associated with the CCNPP license renewal that were not addressed in the GEIS.

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 review of an applicant's ER and process for discovering and evaluating the significance of new information; review of records of public meetings and correspondence; review of environmental quality standards and regulations; 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 BGE or the staff has identified any new issue applicable to the CCNPP that has a significant environmental impact; one new issue (extremophiles) was identified, but was determined not to be significant.

The discussion of the environmental issues contained in the GEIS that are applicable to CCNPP 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 paragraphs that state the GEIS conclusion codified in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, followed by the staff's review steps 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 describe 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 BGE's license renewal application began with publication of a notice of acceptance for docketing (63 FR 27601, May 19, 1998). The staff published a notice of intent to prepare an EIS and conduct scoping (63 FR 31813, June 10, 1998). Two public scoping meetings were held on July 9, 1998, in Solomons, Maryland. Comments received during the scoping process were summarized in the Environmental Impact Statement Scoping Process, Calvert Cliffs Nuclear Power Plant, Summary Report, October 1998 (NRC 1998a).

The staff visited the CCNPP site on July 7 through 10, 1998, reviewed the comments received during scoping, and consulted with Federal, State, and local agencies. A list of the organizations consulted is provided in Appendix D of this document. Other documents related to CCNPP 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 BGE application). It issued requests for additional information (RAIs) to BGE by letters dated September 9, and September 28, 1998 (NRC 1998b and 1998c). BGE provided its responses in letters dated November 20, and December 3, 1998 (BGE 1998c and 1998d). The staff reviewed this information, incorporated it into its analysis, and, on February 24, 1999, issued a draft of the SEIS, which contains the preliminary results of its evaluation and recommendation.

With the publication of the EPA notice of filing of the draft SEIS (64 FR 10662, March 5, 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 Maryland on April 6, 1999, in which the staff described the results of the NRC environmental review and answered questions related to it in order to provide members of the public with information to assist them in formulating their comments. The comment period for the CCNPP draft SEIS ended on May 20, 1999.

This report presents the staff's final analysis that considers and weighs the environmental effects of the license renewal, 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, 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 is provided in Chapter 9, "Summary and Conclusions."

1.1 The Proposed Federal Action

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The proposed Federal action is renewal of the operating licenses for CCNPP Units 1 and 2. CCNPP is located in Calvert County, Maryland, approximately 64 km (40 mi) southeast of Washington, D.C., 12 km (7.5 mi) north of Solomons Island, and 96 km (60 mi) south of Baltimore. The plant has two pressurized light-water reactors, each with a design rating of 845 megawatts electric (MWe). Plant cooling is provided by a once-through heat dissipation system into the Chesapeake Bay using shoreline intake and offshore discharge structures. CCNPP provides about 12 million MW-hours of electricity annually to more than one million customers in a 5900-km² (2300-mi²) area. The current operating licenses for Unit 1 and Unit 2 expire July 31, 2014, and August 13, 2016, respectively. By letter dated April 8, 1998, BGE submitted an application to renew these operating licenses for an additional 20 years of operation (i.e., until July 31, 2034, for Unit 1 and August 13, 2036, for Unit 2).

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 operating license 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) decisionmakers.

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 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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BGE is required to hold certain Federal, State, and local environmental permits, as well as meet relevant Federal and State statutory requirements. BGE 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 CCNPP license renewal. Authorizations most relevant to the proposed license renewal action are summarized in Table 1-1. The full list of authorizations provided by BGE is included as Appendix E. MDNR coordinated reviews and interactions with other State agencies.

The staff reviewed the list and 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 compliance or permit issues or significant new environmental issues.

1.4 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 fuel after cessation of reactor operation--generic determination of no significant environmental impact."

10 CFR 51.53, "Postconstruction environmental reports."

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."

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

EPA - U.S. Environmental Protection Agency

MDE - Maryland Department of the Environment

FWS - U.S. Fish and Wildlife Service

NMFS - National Marine Fisheries Service

COMAR - Code of Maryland Regulations

NPDES - National Pollutant Discharge Elimination System

NA - Not applicable

(a) Federal Water Pollution Control Act (FWPCA), also known as the Clean Water Act

(b) Application to extend permit under review

63 FR 27601, "Notice of Acceptance for Docketing," May 19, 1998.

63 FR 31813, "Notice of Intent to Prepare an Environmental Impact Statement and Conduct Scoping Process." June 10, 1998.

64 FR 10662 "Notice of Filing." March 5, 1999.

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

Baltimore Gas and Electric Company (BGE). 1998a. Applicant's Environmental Report - Operating License Renewal Stage Calvert Cliffs Nuclear Power Plant Units 1 and 2. Docket Nos. 50-317 and 50-318. Lusby, Maryland.

Baltimore Gas and Electric Company (BGE). 1998b. Attachment to Memorandum to T. Essig summarizing the site visit. "New and Significant Information Process for License Renewal of Calvert Cliffs Nuclear Power Plant." July 10, 1998.

Baltimore Gas and Electric Company (BGE). 1998c. Letters from Mr. C.H. Cruse (BGE) to NRC Document Control Desk, "Response to Request for Additional Information for the Review of the Calvert Cliffs Nuclear Power Plant Unit Nos. 1 & 2, Environmental Report Associated with License Renewal, and Errata (TAC Nos. MA1524 and M1525)," November 20, and December 3, 1998, Lusby, Maryland.

Coastal Zone Management Act, as amended (CZMA), 16 USC 1455 et seq.

Endangered Species Act (ESA), as amended, 7 USC 136; 16 USC 460 et seq.

Federal Water Pollution Control Act (FWPCA) (also known as the Clean Water Act), as amended, 33 USC 121 et seq.

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. Environmental Impact Statement Scoping Process: Summary Report-Calvert Cliffs Nuclear Power Plant, Lusby, Maryland. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1998b. Letter from Ms. C.M. Craig (NRC) to Mr. C.H.Cruse (BGE), "Request for Additional Information for the Review of the Calvert Cliffs Nuclear Power Plant (CCNPP) Unit Nos. 1 & 2, License Renewal Application, Severe Accident Mitigation Alternatives (TAC Nos. MA 1524 and MA 1525)," September 9, 1998, Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1998c. Letter from Ms. C.M. Craig (NRC) to Mr. C.H. Cruse (BGE), "Request for Additional Information for the Review of the Calvert Cliffs Nuclear Power Plant (CCNPP) Unit Nos. 1 & 2, Environmental Report Associated with License Renewal (TAC Nos. MA 1524 and MA 1524)," September 28, 1998, 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 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.

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

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CCNPP is located near Maryland Highway 2-4 in Calvert County on the west bank of the Chesapeake Bay, approximately halfway between the mouth of the Bay and its headwaters at the Susquehanna River. CCNPP is a two-unit plant. Each unit is equipped with a Combustion Engineering Nuclear Steam Supply System pressurized light-water reactor and uses once-through cooling with water from the Chesapeake Bay. CCNPP supplies more than 12 million megawatt-hours annually to customers in a 5900-km² (2300-mi²) area. The electricity generated is transferred through a power transmission system that consists of two transmission lines to the Waugh Chapel Substation on the Northern Circuit and a single transmission line to the Chalk Point Generating Station on the Southern Circuit. 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.

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

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CCNPP is located on 853 hectares (ha) (2108 acres) in a rural part of southern Maryland on wooded and agricultural lands. It draws its workforce of about 1550 from surrounding communities, and is the major employer in the area. Several small communities are located within a 16-km (10-mi) radius of the site. The population density of the area increases with seasonal summer residents. The population density increases with distance to the northwest and the 80-km (50-mi) radius includes a portion of the Washington, D.C., metropolitan area. Baltimore is 96 km (60 mi) to the north. Figures 2-1 and 2-2 illustrate the plant location with respect to the Chesapeake Bay and the Patuxent River.

The property consists of rolling hills, part of it forested primarily with deciduous trees. There is an understory of grasses, herbs, and shrubs. Part of the land is cultivated under an experimental pest control/fertilization program, and hay, corn, and wheat are routinely cultivated. About 89 ha (220 acres) of the site were altered for plant and auxiliary structures. About 30-40 ha (75-100 acres) of CCNPP borders the Chesapeake Bay. Most of this Bay frontage has near-perpendicular walls. Bay frontage elevation varies from sea level to about 42 m (137 ft) with an average of about 30 m (100 ft).

The topography of the vicinity around the plant defines several small watersheds. The watershed containing the plant and the auxiliary structures drains into the Chesapeake Bay. Part of the upper areas, used primarily during the construction period, drains through the Johns Creek watershed into the St. Leonard Creek, which then drains into the Patuxent River approximately 7 km (4 mi) from the plant. The Patuxent River drains into the Chesapeake Bay approximately 16 km (10 mi) south of the plant.

Figure 2-1. Calvert Cliffs Nuclear Power Plant Site Area, 50 Mile Region

Figure 2-2. Calvert Cliffs Nuclear Power Plant Site Area, Land Uses and Growth Protection Areas

Chesapeake Bay is approximately 313 km (195 mi) long and varies in width from 5 to 56 km (3 to 35 mi) with an average width of 24 km (15 mi) (Figure 2-1). The Bay has an average depth of approximately 9 m (30 ft) and receives the majority of its fresh water, sediment, and nutrients from the Susquehanna River. The Susquehanna watershed encompasses three states, and its flow dominates the circulatory patterns in the upper Bay during the spring months, with the majority of the net flow directed seaward at all depths (K. G. Sellner and B. A. Peters in Heck 1987). Circulation in the Bay is typical of a partially mixed estuary with non-tidal and tidal components producing a net seaward-moving fresh water surface layer and a landward-moving saline layer (Pritchard 1967). The Chesapeake Bay is about 10 km (6 mi) wide at the plant site from its western shore to Taylors Island.

2.1.1 External Appearance and Setting

CCNPP is sited within a forested natural saddle along the Calvert Cliffs, providing a low profile for the plant. The tallest structures do not rise above the top of the surrounding tree line when viewed from the land areas or from the water. The Turbine Building, which houses two turbine generators and ancillary equipment, is the largest structure on the site and parallels the shoreline of the Bay. Twin containment structures and the Auxiliary Building are located to the west of the Turbine Building. The Intake Structure is located east (bayside) of the Turbine Building. The buildings and the switchyard were designed to minimize their visual impact. Disturbed areas are landscaped or otherwise maintained.

Although several additional facilities have been constructed at CCNPP since 1973, the plant, as it appears from the Chesapeake Bay, has changed little. Figures 2-3 and 2-4 show the station in detail, highlighting those permanent facilities constructed since plant operation began. Figure 2-5 is a low-level aerial photograph of CCNPP taken from the Bay looking south-southwest that shows the major plant structures, including the Turbine Building and twin containment structures. The Interim Office Building, Intake Structure, North Service Building, and Sewage Treatment Plant are also visible from the Bay. Most of the other new facilities are visible only from the air due to intervening buildings and wooded hillsides. Except for the Independent Spent Fuel Storage Installation, which has a separate NRC license, all of the additional facilities are located on areas previously disturbed during CCNPP construction.

The onsite Visitors Center is located in a remodeled old working frame tobacco barn, part of which was built in 1818 (Stone 1978). The center displays historic artifacts, dioramas, and animated exhibits that cover the history of the location, and focuses on the site's present use for nuclear power generation. The Visitors Center area also includes the stabilized foundation and chimneys of a small Maryland plantation house of the 18th century, known as "Preston's Cliffs," and a historic log tobacco barn that is reported to be the oldest of its kind still standing in Maryland. The log barn was constructed in 1820. In addition to the Visitors Center, BGE maintains a nature trail that begins at the historic house foundation and includes highlights of the area's historical and natural setting, including the Chesapeake Bay and its shoreline ecology.

Figure 2-3. Calvert Cliffs Nuclear Power Plant Site Layout and Well Locations

Figure 2-4 Calvert Cliffs Nuclear Power Plant Station Layout

Figure 2-5 Calvert Cliffs Nuclear Power Plant (aerial photo)

The site's geologic setting lies within the Coastal Plain Physiographic Province, and is underlain by approximately 760 m (2500 ft) of sedimentary strata. Underlying these sediments are crystalline and metamorphic basement rock.

There is no evidence of faulting in the site vicinity. As shown in Figure 2-6, the strata range from nearly horizontal to gently dipping to the southeast, reflecting the influence of the basement rock slope. Areas above an elevation of 21 m (70 ft) are Pliocene and Pleistocene silt and sand, and are underlain by approximately 82 m (270 ft) (Elevation +70 to -200 feet mean sea level [MSL]) of the relatively impervious sediments of the Chesapeake group of Miocene age; the CCNPP power block area is Elevation +45 feet MSL. The Miocene-age sediments consist of horizontally stratified sandy and clayey silt with occasional interbeds of sands and shells. Approximately 106 m (350 ft) (Elevation -200 to -550 feet MSL) of dense, relatively pervious glauconitic sand and silt of the Eocene and Paleocene age underlie the Miocene sediments.

The site includes a portion of the Calvert Cliffs, noted for scenic and scientific significance. Some of the fossils recovered at the site during an in-depth paleoecological study of the Miocene deposits are displayed at the Visitors Center.

Table 2-1 provides a brief summary of groundwater aquifers beneath CCNPP.

The site water table occurs generally within 9 m (30 ft) (above Elevation +70 feet MSL) of the surface in Pleistocene-age deposits. Groundwater flow within approximately 300 m (1000 ft) of the Chesapeake Bay at CCNPP is toward the Bay; flow west of the divide is toward surface stream valleys. Surficial soil grain size analysis suggests a maximum permeability coefficient of about 6.1×10^-4 m/s (400 gpd/ft²).

Surficial deposits are underlain by approximately 75 m (250 ft) of relatively impermeable deposits, known as the Chesapeake Group, which effectively confine the underlying artesian aquifers. The vertical component of groundwater movement through the Chesapeake Group is upward. Underlying aquifers are composed of glauconitic sand and silt of the Piney Point, Nanjemoy, and Aquia formation. The Piney Point and Nanjemoy Aquifers act as a single unit, but are separated from the underlying Aquia Aquifer by a layer of clay and silt called the Nanjemoy-Marlboro confining unit. The Aquia Aquifer beneath CCNPP is approximately 30 m (100 ft) thick (from Elevation -450 to -550 feet MSL).

2.1.2 Reactor Systems

CCNPP is a two-unit plant. Each unit is equipped with a Combustion Engineering Nuclear Steam Supply System that uses a pressurized light-water reactor and two steam generators. Each unit has a design rating for net electrical power output of 845 MW. The two CCNPP reactors are operated at a maximum core thermal power output level of 2700 MW. The Unit 1 turbine generator is a General Electric Company design, and Unit 2 is a Westinghouse Electric Corporation design. Each turbine is an 1800-rpm tandem compound, six-flow exhaust, indoor unit (BGE 1998a).

Figure 2-6 Regional Geologic Section - Coastal Plain

Table 2-1. A Summary of Groundwater Aquifers Beneath CCNPP^(a)

CCNPP fuel is slightly enriched uranium dioxide in the form of pellets contained in zirconium alloy fuel rods (tubes fitted with welded end caps). CCNPP was originally licensed to use fuel having a uranium-235 enrichment not exceeding 4 percent by weight.⁽³⁾ In 1981, NRC authorized an increase in fuel enrichment up to 4.1 percent uranium-235. In 1989, NRC authorized another increase to 5 percent uranium-235; at the same time, NRC also authorized an increase the in level of CCNPP fuel burnup,⁽⁴⁾ above the original 33,000 megawatt-days per metric tonne uranium (MWd/MTU) to 60,000 MWd/MTU.

Reactor containment structures are designed with engineered safety features to protect the public and plant personnel from 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 (tubes of boron carbide).

2.1.3 Cooling and Auxiliary Water Systems

CCNPP is equipped with a once-through heat dissipation system that withdraws cooling water from and discharges it to the Chesapeake Bay. This circulating water system removes heat from the plant and transfers this energy to the Chesapeake Bay. There are no cooling towers associated with this system.

CCNPP uses water from the Chesapeake Bay for cooling purposes, drawing bottom water through a 15-m (45-ft) deep dredged channel that extends approximately 1380 m (4500 ft) offshore. Water passes through the plant in approximately 4 minutes and is discharged to the north of the plant from an outfall that is approximately 260 m (850 ft) offshore in 3 m (10 ft) of water. A curtain wall that extends to a depth of 9 m (30 ft) over the intake channel limits the intake to mostly bottom water, although there is evidence that mixing of surface and lower depth water occurs before entrance into the plant (Heck 1987). The intake and discharge structures are shown in Figure 2-7.

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 primary coolant system for each unit consists of a reactor, two steam generators, two reactor coolant loops, and four reactor coolant pumps. 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 Chesapeake Bay is used to cool the spent steam in the secondary loop and then is returned to the Bay.

The principal components of the circulating water system are the curtain wall, intake structure, circulating water pumps, condensers, and discharge conduits.

CCNPP has five groundwater production wells that supply process and domestic water in the protected area of the plant (Figure 2-3), and eight wells that supply water for domestic use in outlying areas. The production wells extend into the Aquia Aquifer. Although a gravity drain system was installed during original plant construction to dewater plant areas, CCNPP does not use dewatering pumps for plant operation.

Groundwater wells provide the source of water for domestic, plant service and demineralized make-up water needs, while the Chesapeake Bay is the source of water for the once-through cooling system. All effluents are combined before being discharged through the submerged outfall to the Chesapeake Bay. Both the quantity of water pumped (from both the groundwater wells and the Chesapeake Bay) and quality of the water discharged to the Chesapeake Bay are regulated and permitted by the State of Maryland.

Figure 2-7 Intake and Discharge Structures

2.1.4 Radioactive Waste Management Systems and Effluent Control-Systems

The CCNPP 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 (BGE 1997). Radioactive material in the reactor coolant is the source of gaseous, liquid, and solid radioactive

wastes in light-water reactors (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 discarded reactor components, equipment, and tools as well as contaminated protective clothing, paper, rags, and other trash largely from plant design and operations modifications and routine maintenance activities. Certain dry wastes may be shredded or compacted under high pressure to reduce disposal volume. Spent resins, filters, and evaporator concentrates 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 are removed from the reactor core for disposal are called spent fuel. CCNPP currently operates on a 24-month refueling cycle and stores all its spent nuclear fuel onsite either in a spent fuel pool in the Auxiliary Building or in dry storage at its Independent Spent Fuel Storage Installation (BGE 1992). CCNPP also temporarily stores mixed waste onsite. 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]) and in accordance with an agreement with the Maryland Department of the Environment (MDE).

There are four waste processing systems: the Reactor Coolant Waste Processing System (RCWPS), the Miscellaneous Waste Processing System (MWPS), the Waste Gas Processing System (WGPS), and the Solid Waste Processing System (SWPS).

2.1.4.1 Liquid Waste Processing Systems and Effluent Controls

Radioactive liquid waste generated from the operation of CCNPP can be released to the Chesapeake Bay in accordance with the limits specified in the CCNPP Offsite Dose Calculation Manual (ODCM). There are four outfalls that provide the pathways for all waste water (non-radioactive and radioactive) discharged into the Bay.

CCNPP liquid waste is processed by two systems: (1) the RCWPS, which processes reactor coolant concurrent with the letdown flow from the Chemical and Volume Control System (CVCS), and (2) the MWPS, which processes waste from miscellaneous sources. The liquid waste processing systems are used to reduce the radioactive material in liquid wastes before discharge when the activity in the effluent could exceed the ODCM limits.

The RCWPS provides temporary storage for reactor coolant waste (RCW) to allow for radioactive decay to maintain releases to the environment as low as reasonably achievable (ALARA), as well as maintain the concentration of radioactive isotopes in the effluent below the ODCM limits. Sampling and release of liquid waste is performed on a batch basis, rather than a continuous basis, to provide better control over effluent discharge.

The RCWPS consists of two reactor coolant drain tanks (RCDTs), three cartridge filters, four RCW ion exchangers, two RCW receiver tanks, two evaporators, two RCW monitoring tanks, and various system pumps. The system simultaneously processes reactor coolant and CVCS letdown flow from both Unit 1 and Unit 2.

Before being transferred to the two RCW receiver tanks, the RCW liquid is filtered to remove insoluble corrosion products and then degasified to remove hydrogen, nitrogen, and fission gases. The liquid is pumped to ion exchangers that remove soluble ions, thereby resulting in an effluent that is reduced in total activity. The liquid is then routed to the RCW monitor tank where it is sampled. If the activity level in the monitor tank is within discharge limits, then the liquid may be released in a controlled, monitored fashion to meet the administrative limits in the ODCM.

Controls for limiting the release of radiological liquid effluents are described in the ODCM. Controls are based on (1) concentrations of radioactive materials in liquid effluents and projected dose or (2) dose commitment to a member of the public. Concentrations of radioactive material that may be released in liquid effluents to unrestricted areas are limited to the concentrations specified in 10 CFR Part 20, Appendix B, Table II.⁽⁵⁾ The dose limits are 0.03 millisievert (mSv) (3 mrem) to the whole body and 0.10 mSv (10 mrem) to any organ during any calendar quarter and 0.06 mSv (6 mrem) to the whole body and 0.20 mSv (20 mrem) to any organ during a calendar year. Radioactive liquid wastes are subject to the sampling and analysis program described in the ODCM.

2.1.4.2 Gaseous Waste Processing System and Effluent Controls

Radioactive gaseous waste generated from operation of CCNPP may be released to the atmosphere through the Unit 1 and Unit 2 main vent stacks, the auxiliary boiler deaerator, the steam generator atmospheric steam dump system, the plant nitrogen system, the turbine building ventilation exhaust, the emergency air lock, the plant compressed air system, the main steam line penetrations, the containment equipment hatch, and the auxiliary feedwater pumps.

During normal operation, the WGPS is designed to store the gases removed from liquid waste to allow for radioactive decay before release. The WGPS consists of a surge tank, two compressors, three waste gas decay tanks and a high-efficiency particulate air (HEPA) filter. The WGPS collects, stores, and disposes of gaseous waste from the degasifiers, pressurizer quench tanks, RCDTs, the volume control tanks, and other miscellaneous hydrogenated sources.

There are other potential sources of gaseous releases from the plant that are not collected in the WGPS. Leaks from reactor coolant containment structures, condenser air removal systems, and other potential sources are released through the plant vent. The following are the pathways for gaseous effluents containing or potentially containing radioactive material:

• WGPS
• containment structure purge
• containment hydrogen purge system
• auxiliary building ventilation
• condenser air removal system and gland seal exhauster
• aerated tank vents
• turbine building ventilation.

BGE maintains all gaseous releases within ODCM limits. Potential release pathways are sampled according to approved plant procedures.

The WGPS is used to reduce the radioactive material in gaseous waste before discharge to meet the dose design objectives in 10 CFR Part 50, Appendix I. In addition, the limits in the ODCM are designed to provide reasonable assurance that radioactive material discharged in gaseous effluents would not result in the exposure of a member of the public in an unrestricted area in excess of the limits specified in 10 CFR Part 20, Appendix B.

The quantities of gaseous effluents released from CCNPP are controlled by the administrative limits defined in the ODCM. The controls are specified for dose rate, dose due to noble gases, and dose due to iodine and radionuclides in particulate form. For noble gases, the dose rate limit at or beyond the site boundary is 5 mSv/yr (500 mrem/yr) to the whole body, and 30 mSv/yr (3000 mrem/yr) to the skin. For iodine and particulates with half lives greater than eight days, the limit is 15 mSv/yr (1500 mrem/yr) to any organ. The limit for air dose due to noble gases released in gaseous effluents to areas at or beyond the site boundary during any calendar quarter is 0.1 milligray (mGy) (10 mrad) for gamma radiation and 0.2 mGy (20 mrad) for beta radiation, and, for any calendar year, the limit is 0.2 mGy (20 mrad) for gamma radiation and 0.4 mGy (40 mrad) for beta radiation. The radioactive gaseous waste sampling and analysis program specifications are provided in the ODCM, and address the gaseous release type, sampling frequency, minimum analysis frequency, type of activity analysis, and the lower limit of detection. The WGPS is used to reduce radioactive material in gaseous waste before its discharge when the gaseous effluent air doses due to gaseous effluent releases to the area at and beyond the site boundary are projected to exceed 0.012 mGy (1.2 mrad) for gamma radiation and 0.024 mGy (2.4 mrad) for beta radiation in a 92-day period.

2.1.4.3 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 Parts 61 and Part 71, respectively. The SWPS provides the capability for preparing solid waste for shipment to an offsite disposal facility or processor. The system is designed to minimize radiation exposure to personnel during the handling of solid wastes.

The SWPS equipment is located in the Auxiliary Building. Spent radioactive ion exchanger resin is sluiced to a tank where it is stored and partially dewatered. It is then prepared for shipment. RCWPS evaporator bottoms are normally recycled or otherwise processed in accordance with BGE's Process Control Program. Radioactive filters are transported from each filter housing to the waste disposal area. All solid wastes are packaged in containers suitable for transfer to an offsite processor or disposal.

The Materials Processing Facility (MPF) provides interim storage of dry active waste (DAW) until such waste can be shipped to a permanent disposal facility or a processing facility. The storage capacity of the MPF can accommodate more than five years of expected waste generated at CCNPP, based on normal operation and generation. Provisions are in place for additional expansion, if needed. The design life of the MPF is expected to meet the needs of the license renewal term. The functions of the MPF are interim storage of DAW and low-level processed wastes; decontamination of clothing, respirators, tools, hardware, and radioactive waste material; temporary holding of liquid wastes generated from the laundry; receiving, sorting, compacting, packaging, and offsite return shipment of DAW; office space for radwaste management activities; additional storage of spare plant equipment and components; and processing of liquid waste in the decontamination facility in preparation for offsite shipment.

There are two areas for resin storage: (1) the interim resin storage facility located in the Lake Davies area (waste is limited to spent resins and filters); and (2) the West Road Cage located west of the Auxiliary Building.

All CCNPP radioactive waste shipments are packaged in accordance with NRC and U.S. Department of Transportation requirements. CCNPP currently transports shipments of radioactive material to

• high-level waste examination sites
• low-level waste disposal site (Barnwell, South Carolina)
• offsite processing facility for segregation, recycling, compaction, decontamination, and incineration.

CCNPP also transports material from an offsite processing facility to a disposal site or back to the plant site for reuse or storage.

2.1.5 Nonradioactive Waste Systems

Nonradioactive waste is produced from plant maintenance and cleaning processes. Most of these wastes are from boiler blowdown (as impurities are purged from plant boilers), water treatment sludges and other wastes, boiler metal cleaning wastes, floor and yard drains, and stormwater runoff. Chemical and biocide waste sources are produced from processes to control the pH in the coolant, to control scale, to control corrosion, and to regenerate resins, as well as for cleaning and condenser defouling. Wastes may be discharged as separate point sources or combined with the cooling water discharges. Sewage sludge is transported for offsite disposal. The MDE is responsible for permitting the disposal of nonradioactive liquid and solid wastes.

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 CCNPP 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 of these 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 maintenance, modification, and replacement of major components. Scheduled refueling outages generally last for about two months and occur at 1- to 2-year intervals. Periodic in-service inspections may last 2 to 4 months, while other outages vary, depending on the components being replaced.

BGE performed an aging management review and developed an integrated plant assessment (IPA) for managing the effects of aging on systems, structures, and components in accordance with 10 CFR Part 54. It also reviewed its surveillance, on-line monitoring, inspections, testing, trending, and recordkeeping (SMITTR) program, and identified the need for new and modified programs that could lead to additional periodic monitoring or to eventual modification, replacement, or repair of selected components.

Some of the activities listed in Tables 2-7 and B.2 of the GEIS (NRC 1996) have been or are being conducted at CCNPP. For example, the plant is replacing its steam generators during its current license term and, consequently, this replacement does not meet the definition of a license renewal term refurbishment activity. The CCNPP IPA, conducted under 10 CFR Part 54, did not identify major refurbishment or replacement activities necessary to maintain the functionality of important systems, structures, and components during the CCNPP license renewal term. Therefore, BGE expects to conduct normal refueling and 5- and 10-year inservice inspections, but plans no refurbishment outages specific to license renewal.

2.1.7 Power Transmission System

The CCNPP power transmission system includes the North Circuit, which consists of two separate three-phase 500-kV transmission lines (single right-of-way) from CCNPP to the Waugh Chapel Substation in Anne Arundel County (Figure 2-1), and the single-line South Circuit from CCNPP northwest to the Potomac Electric Power Company (PEPCO) Chalk Point generating station. Approximately 35 km (22 mi) of the lines in the northern circuit are in Calvert County and approximately 40 km (25 mi) are in Anne Arundel County in a 106- to 122-m wide (350- to 400-ft) rights-of-way. These lines were constructed to deliver power generated at CCNPP to the Waugh Chapel Substation, located at a point near BGE's load center. Each line consists of about 182 lattice towers and about 47 stylized poles. The lines cross mostly second-growth hardwood and pine forests, pasture, and farmland.

In 1994, BGE completed the South Circuit 500-kV line, shifting approximately 1.6 km (1 mi) of the original lines to make room for the new South Circuit lines at the point where the North and South Circuit routes diverge (Figure 2-1). The 29 km (18-mi) South Circuit parallels the Waugh Chapel lines from CCNPP north approximately 14 km (9 mi) before diverging in a northwesterly direction to connect with a line at the PEPCO Chalk Point generating station (Figure 2-1). BGE owns the land beneath the North and South Circuit lines.

At the time that BGE constructed CCNPP, the Southern Maryland Electric Cooperative constructed a 69-kV transmission line to CCNPP, connecting to an onsite substation (Figure 2-3) to provide CCNPP with offsite power. The plant is connected to the substation via underground lines. After CCNPP decommissioning, the Southern Maryland Electric Cooperative plans to discontinue the transfer of energy over these lines.

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 and detailed descriptions where needed to support analysis of potential environmental impacts of operation during the renewal term discussed in Chapter 4. Subsection 2.2.9 describes the historic and archaeological resources in the area, and 2.2.10 describes possible cumulative effects of the proposed action and other Federal project activities.

2.2.1 Land Use

CCNPP is located in a sparsely populated area that is undergoing population growth. The major portion of the land surrounding the site is devoted to agricultural and forest uses. While declining, the amount of land being farmed should continue to be substantial. Land devoted to residential and commercial use will increase as the population grows.

The land occupied by the CCNPP is zoned I-1 light industrial by Calvert County. Power generating facilities are a permitted use in I-1 zoning districts (Calvert County 1997a).

The amount of land devoted to various land uses in Calvert County in 1993 is shown in Table 2-2. The region surrounding the CCNPP site is predominately rural in character. However, since 1970, open space in Calvert County has been converted to residential use at an average rate of nearly 400 ha (1000 acres) per year. The amount of farmland in the County declined from approximately 25,000 ha (63,000 acres) in 1970 to approximately 15,000 ha (37,000 acres) in 1992. Commercial, industrial, institutional, and utility development accounts for less than 5 percent of land use in the County.

The Coastal Zone Management Act (CZMA) requires that applicants for a Federal license to conduct an activity in the coastal zone shall provide in the application to the licensing agency a certification that the proposed activity complies with the enforceable policies of the State's approved Coastal Zone Management Program and that the activity will be conducted in a manner consistent with the program [33 USC 1456(c)(3)(A) CZMA].

The MDE determined that renewal of the operating licenses for CCNPP is consistent with the Maryland Coastal Zone Management Program established under the CZMA (MDE 1998).

Table 2-2. Land Use in Calvert County in 1993 (Calvert County 1994a)

2.2.2 Water Use

Cooling water withdrawal from the Chesapeake Bay and groundwater withdrawal for other plant uses, as described previously in Subsection 2.1.3, are regulated by the State of Maryland. CCNPP uses a once-through heat dissipation system that withdraws from and discharges cooling water to the Chesapeake Bay.

Water for plant service, make-up, and domestic uses is withdrawn from five groundwater wells tapping into the Aquia Aquifer. The MDE requires BGE to monitor and report withdrawals from the five production wells. Average daily withdrawal rates for the period of July 1996 to June 1998 was 1.89×10 ² m³/s (392,000 gpd) (BGE 1998b). The current State permit limit for groundwater withdrawals is 2.17×10^-2 m³/s (450,000 gpd).

2.2.3 Water Quality

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 MDE is the State of Maryland agency delegated by the EPA to issue the NPDES discharge permit. The current permit (State Discharge Permit 92-DP-0187) was issued on June 16, 1994, and was scheduled for renewal on June 15, 1999. BGE submitted a timely application for permit renewal and continues to operate within the provisions of the old permit while awaiting issuance of a new permit. The MDE stated that it is unaware of any major issue likely to prevent renewal of this permit. Any new regulations promulgated by EPA or the MDE would be included in future permits and may include development and implementation of Total Maximum Daily Loads.

2.2.4 Air Quality

The Chesapeake Bay and the Atlantic Ocean farther to the east generally give the CCNPP site mild winters and summers. Climatological statistics for Baltimore are generally representative of the climate of the site.

According to the National Oceanic and Atmospheric Administration, typical January daily temperatures range from a minimum of -4.8ºC (23.4ºF) to a maximum of 4.6ºC (40.2ºF). July temperatures typically range from a minimum of 19.3ºC (66.8ºF) to a maximum of 30.7ºC (87.2ºF). The record minimum and maximum temperatures are -22ºC (-7ºF) and 41ºC (105ºF), respectively. Typical morning relative humidities range from a low of about 70 percent in the winter to a high of about 85 percent in the early fall. Afternoon relative humidities are generally about 55 percent. The annual average precipitation is about 104 cm (41 in) and is evenly distributed throughout the year. About one-third of the days have precipitation totaling 0.03 cm (0.01 in) or more. Winter precipitation is generally associated with synoptic weather systems. The average snowfall is about 51 cm/yr (20 in./yr). Summer precipitation tends to be associated with thunderstorms.

During the summer, the region is generally under the influence of the Bermuda high-pressure system. High-pressure systems are typically associated with low winds and increased potential for air quality problems. Air quality in 1997 in Calvert County was generally rated as moderate using the EPA Pollution Standards Index (that is an indicator of community-wide air quality). A moderate rating means that there should be few or no health effects for the general population. The primary pollutant contributing to the moderate rating was ozone. Ozone is not emitted directly; it is the product of chemical reaction that involves volatile organic compounds (VOCs) and nitrogen oxides (NO_x). There appears to have been a gradual decrease in emissions of VOCs and NO_x in Calvert County during the last 10 years (EPA 1999).

Calvert County is within the Washington, D.C., "serious" nonattainment area for ozone (40 CFR 81.321). However, the ozone air quality monitor in Calvert County did not record any exceedences of the National Ambient Air Quality Standard for ozone in 1996, 1997, or 1998. To the west of Calvert County, Prince Georges and Charles counties are also included in the Washington, D.C., nonattainment area. The EPA ozone standard was exceeded at monitors in each of these counties in 1997 and earlier years. To the north of Calvert County, Anne Arundel County is in the Baltimore "severe" nonattainment area for ozone (40 CFR 81.321). The EPA ozone standard has been exceeded in Anne Arundel County each year since 1993. The ozone monitors in Prince Georges and Anne Arundel counties are located generally in the corridor between Washington, D.C., and Baltimore rather than in the portions of the counties nearest the Calvert Cliffs site. St. Mary's County south of Calvert County and the counties across Chesapeake Bay to the east are designated "Unclassifiable/Attainment" areas for ozone (40 CFR 81.321).

The State of Maryland has adopted a State Implementation Plan for that portion of Maryland that is within the boundaries of the Washington, D.C., "serious" nonattainment area for ozone. This plan, which is based upon a plan developed by the Metropolitan Washington Council of Governments, has been approved by the EPA (62 FR 49611). Recent revisions to the plan to achieve an additional 15-percent reduction in emissions of VOCs using reasonably available control technology (RACT) have also been approved by EPA (63 FR 36578). The CCNPP emergency diesel generators (EDGs) are considered major sources of both VOCs and NO_x because of their potential annual release rates (BGE 1998). Permits have been obtained from the MDE for the EDGs.

Calvert County is classified as "Better than National Standards" or "Unclassifiable/Attainment" for the remaining criteria pollutants (40 CFR 81.321). The counties surrounding Calvert County have similar designations for the remaining criteria pollutants except for Anne Arundel County, which does not meet secondary standards for total suspended particulates (40 CFR 81.321). CCNPP is more than 100 km (62 mi) from the nearest Class I area for the Prevention of Significant Deterioration of Air Quality designated in the Clean Air Act (CAA) (42 USC 7401).

2.2.5 Aquatic Resources

The area of the Chesapeake Bay in the vicinity of the CCNPP is used for a variety of purposes, including navigation, recreation, and commercial fisheries. Boating and sportfishing are popular. The Bay supports a variety of aquatic species typical of a warm-water partially mixed estuary, including phytoplankton, zooplankton, epibenthic, intertidal, and subtidal communities, as well as commercially and recreationally important finfish and shellfish. Three representative important species (RIS) identified by the State of Maryland include the eastern oyster, Crassostrea virginica, the soft shell clam, Mya arenaria, and the blue crab, Callinectes sapidus. Oyster breeding and nursery areas occur near the plant, and new beds were created during plant construction to mitigate habitat loss (Abbe 1988, 1992). Softshell clams are also present in the intertidal areas surrounding the plant, but have not occurred in sufficient number for commercial fishery since at least before 1971 (Heck 1987).

Blue crab are often caught by commercial and recreational fishers and represent a sizable proportion of the fishing industry. Although mating occurs in the areas near CCNPP, the females typically migrate down-Bay to a spawning and hatching area approximately 110 km (70 mi) south of CCNPP, where an appropriate salinity of approximately 23 to 28 parts per thousand occurs (Sandoz and Rogers 1944). Other recreationally and commercially important species are presented in Table 2-3, in approximate order of abundance. The finfish presented in this table commonly occur in the vicinity of the CCNPP and spend at least part of their life cycle in these waters.

Two Federally protected species, the shortnose sturgeon and the Atlantic loggerhead turtle, are known to occur in the vicinity of CCNPP. These are also protected under State of Maryland laws. The general location and habitat of these species are shown in Table 2-4. BGE researchers caught one shortnose sturgeon during trawl studies in the vicinity of the CCNPP in 1979 (Heck 1987). However, dam construction has constrained the distribution of most shortnose sturgeon populations to deepwater pools from summer through winter. Adults move upstream to spawn during the spring. The ancestral range of this species is believed to extend from the St. John River in New Brunswick, Canada, to the St. Johns River in Florida. Most populations are considered anadromous, with adults typically living in the ocean and entering freshwater systems to spawn.

Freshwater resources associated with CCNPP include approximately 80 ha (200 acres) of marshlands (AEC 1973), a small man-made wetland created as a mitigation project, several ponds in the vicinity of Camp Conoy, and several small interior streams. The Maryland Natural Heritage Program lists species that are rare-to-uncommon in Maryland (occurrences typically in the range of 21 to 100) as S3 species, although they are not actively tracked by the Heritage & Biodiversity Conservation Programs. A State-ranked S3 aquatic plant species, the humped bladderwort, Utricularia gibba, is found in the littoral zone of a Camp Conoy pond.

2.2.6 Terrestrial Resources

The CCNPP and its associated transmission corridors lie within the oak-pine-hickory association of the eastern deciduous forest (Greller 1988). These mature forested habitat spp. are dominated by oaks, Quercus spp. and hickory, Carya spp., as the successional dominants, along with several species of pine, Pinus spp.

In 1998, BGE conducted a survey of the natural plant communities at the site and within its associated transmission corridors. These habitats include eight plant community types: agricultural land, managed rights-of-way, chestnut oak association, forested wetlands, open water and emergent wetlands, Virginia pine association, tulip poplar/sweetgum association, and old fields. The latter includes all disturbed areas without an actively managed vegetation cover.

Table 2-3. Recreationally or Commercially Important Aquatic Species Near CCNPP in Order of Abundance

Table 2-4. Protected and "Watched" Aquatic Species on and in the Vicinity of the CCNPP Site

Virginia pine, Pinus virginiana, is common on power line rights-of-way. Other trees include chestnut oak, Quercus prinus, black gum, Nyssa sylvatica, sweetgum, Liquidambar styraciflua, tulip poplar, Liriodendron tulipifera, sassafras, Sassafras albidum, and American beech, Fagus grandifolia. The understory includes a variety of herbs and shrubs, including rhododendron, Rhododendron spp.

In 1985 and 1987, BGE foresters developed Forest Resource Management Plans for the CCNPP area in consultation with the Maryland Department of Natural Resources. These plans emphasize preservation and maintenance of mature hardwood stands and removal of Virginia pine for disease and fire control. BGE maintains a system of fire roads and fire-fighting tool caches throughout the CCNPP site.

Non-forested, non-industrial habitats include maintained lawns and agricultural fields (corn, wheat, and hay), and disturbed successional habitat. Agriculture has been practiced on the CCNPP site for over 200 years, and BGE retains a forester/land manager to oversee crop production and forest management. BGE continues to preserve those portions of the forest that were not disturbed by construction.

Mammalian fauna of the site and rights-of-way include white-tailed deer, Odocoileus virginianus, raccoons, Procyon lotor, red and grey fox, Vulpes fulva and Urocyon cinereoargenteus, eastern gray and fox squirrels, Sciurus carolinensis and niger, eastern chipmunk, Tamias striatus, and a variety of mice and voles. White-tailed deer are the most important game mammal, with eastern cottontail rabbits, Sylvilagus floridanus, of secondary importance.

Northern bobwhite, Colinus virginianus, and wild turkey, Meleagris gallopavo, are the most important game birds in the site vicinity. Bobwhites are associated with the agricultural fields and forest edges, while turkeys use the forested habitats, rights-of-way, and old fields. The open water and emergent wetland habitat supports a number of migrant waterfowl, and osprey, Pandion haliaetus, use the forested areas near the Chesapeake Bay shoreline.

As part of its Forest Resource Management Plans, BGE uses late summer mowing to maintain roads and log loading decks as wildlife food plots and wild turkey brooding habitat. In 1987, the State of Maryland developed a Wildlife Management Plan for the CCNPP site, stressing management of woodlands for wild turkey, and management of fields, road edges, and rights-of-way for wild turkey, bobwhite quail, and eastern cottontail rabbits. BGE updated this plan in 1993 to include additional habitat enhancement projects, including a Tiger Beetle Habitat Protection Area operated under a conservation agreement with The Nature Conservancy, an informative nature trail, osprey nesting and monitoring program, bluebird nest box program, and a wild turkey stocking reservoir. This update also provided for a Calvert Cliffs Wildlife Habitat Committee.

Three Federally protected terrestrial animal species are known to occur on the CCNPP site and rights-of-way. The general location and habitat of these species are shown in Table 2-5. These species are also protected under State of Maryland laws. Two species of concern to the Maryland Natural Heritage Program have been identified on the CCNPP site. These are the spurred-butterfly pea, Centrosema virginianum, a State rare species and the pink milkwort, Polygala incarnata, a State watch list species. State rare species are considered to be imperiled in Maryland because of rarity, and watch list species are considered rare to uncommon, but otherwise have no specific protection. Older records suggest that one State endangered species, the blunt-leaved Gerardia, Agalinis obtusifolia, might exist on the CCNPP site in appropriate habitats. In 1997, BGE initiated consultation with the U.S. Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) under Section 7 of the Endangered Species Act. FWS concurred with the listing BGE provided of threatened or endangered species.

2.2.7 Radiological Impacts

Since 1970, BGE has conducted a radiological environmental monitoring program (REMP) around CCNPP. 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 ODCM and the Environmental Radiation Protection standards as stated in 40 CFR Part 190, Environmental Radiation Protection Standards for Nuclear Power Operations

Table 2-5. Protected and "Watched" Terrestrial Species on CCNPP Site and Rights-of-Way

• 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.

These releases are summarized in the annual reports titled "Radiological Environmental Monitoring Program Annual Report" and the annual Effluent Release Reports. The limits for all radiological releases are specified in the ODCM, and these limits are designed to meet Federal standards and requirements. The REMP includes monitoring of the aquatic environment (Bay water, aquatic organisms, shoreline sediment), atmospheric environment (air particulates and iodine), terrestrial environment including vegetation, and direct radiation.

A separate radiological environmental monitoring program is in place for the Independent Spent Fuel Storage Installation, which is covered by a separate license.

Review of historical data on releases and the resultant dose calculations revealed that the doses to maximally exposed individuals in the vicinity of CCNPP 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, dose calculations were performed using the plant effluent release data, onsite meteorological data, and appropriate pathways identified in the ODCM. The summary results for doses to the maximally exposed individual in 1997, which are representative of the doses from the past 5 years, are given below (BGE 1998b).

A review of whole body and organ doses revealed the following results:

• The maximum thyroid dose to a hypothetical child 1.9 km (1.2 mi) WSW of Calvert Cliffs was 0.00005 mSv/yr (0.005 mrem/yr) via liquid and gaseous pathways. This is <0.01 percent of the 0.75 mSv/yr (75 mrem/yr) limit specified in 40 CFR Part 190.
• The maximum whole body gamma dose to a hypothetical child 1.4 km (0.8 mi) WSW of Calvert Cliffs was 0.00009 mSv/yr (0.009 mrem/yr) via liquid and gaseous pathways. This is <0.01 percent of the 0.25 mSv/yr (25 mrem/yr) limit in 40 CFR Part 190.
• The maximum calculated dose to all other organs (GI-tract) was 0.0024 mSv/yr (0.24 mrem/yr) at 1.4 km (.8 mi) WSW of Calvert Cliffs. Compared to the 0.25 mSv/yr (25 mrem/yr) limit in 40 CFR Part 190, this is about 1 percent of the limit.

The applicant does not anticipate any significant changes to the radioactive effluent releases or exposures from CCNPP 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, information available in publications from the State of Maryland, the U.S. Bureau of the Census of the U.S. Department of Commerce (DOC), and planning and economic development bodies in Calvert, St. Mary's, and Charles Counties. Several county staff members, local real estate agents/appraisers, and social services providers were interviewed during a July 1998 site visit. The following information describes the economy, population, and communities near CCNPP.

2.2.8.1 Housing

Between 1970 and 1990, total housing units in Calvert County increased from 7932 to 18,974 (Tri-County Council for Southern Maryland 1993). Growth has continued since 1990 at a rapid rate. Approximately 10 percent of the increase may be attributed to the 909 CCNPP employees who live in Calvert County (as of October 1998). As of July 1998, 256 CCNPP employees live in St. Mary's County and 46 live in Charles County (Table 2-6). Based on the Maryland total employment multiplier⁽⁶⁾ (3.9997) (DOC 1992a), CCNPP may have accounted for 4200 direct and indirect jobs and 40 percent of the housing growth from 1970 to 1990. Between 1980 and 1990, the number of housing units in the Tri-County (Calvert, St. Mary's, and Charles) area increased approximately 43 percent to a total of 81,320 units.

Since 1990, the Calvert County resident population has increased from 51,372 at the 1990 Census to 64,000 in 1995 and about 72,000 in 1998 (Table 2-7). St. Mary's County increased in population from about 76,000 in 1990 to almost 88,000 in 1998. About 6600 housing units were added to the Calvert County housing stock between 1990 and 1996, as the north end of the county became a more popular bedroom community for Washington, D.C., and the Patuxent River Naval Air Station in St. Mary's County added 5200 civilian and military jobs. St. Mary's County added 5100 housing units over the same 1990-1996 period, while Charles County added 6800 units. Housing availability in the Tri-County area is not limited by growth-control measures, although multifamily housing is effectively limited to a handful of town growth centers by water and sewage issues. With a vacancy rate of approximately 7 percent, over 5700 units are available for occupancy (Tri-County Council for Southern Maryland 1993).

2.2.8.2 Public Services

Water Supply

Fresh water used in Calvert County comes from subsurface sources and is used primarily for domestic and agricultural uses. The county has 22 privately owned residential community water systems, 17 municipally owned water systems, and 24 systems owned by corporations or institutions. Some nearby water systems in St. Mary's County draw from and compete with systems in Calvert County. Table 2-8 shows output of selected water supply systems in communities near CCNPP, as well as the estimated population served by each in 1994-1995; Figure 2-8 shows their locations. The normal output of these systems is small, but increases substantially in the summer to accommodate seasonal increases in population.

In Southern Maryland, the majority of the public water supply is drawn from the Aquia Aquifer (Figure 2-9). There are some water supply systems starting to experience supply problems in the southern portion of the Tri-County area, especially in the Solomons Island and Lexington Park areas. These systems both draw water from the Aquia Aquifer with an average daily output of 9.8 L/s (225,000 gpd) and 52.7 L/s (1,203,000 gpd), respectively. As a result of this large demand, the potentiometric surface in this area has dropped more than 9 m (30 ft) in the last 10 years. However, there is 90 m (300 ft) of available drawdown still remaining (MDNR 1993) without exceeding regulatory limits.

Education

In 1990, there were approximately 38,900 students enrolled in schools in the Tri-County area (Tri-County Council for Southern Maryland 1993). By 1997, the enrollment totals for the public schools

Table 2-6. Geographical Distribution of the Residences of CCNPP Employees, October 1998

Table 2-7. Population Growth in the Calvert, St. Mary's, and Charles County, Maryland (1970-1995)

had increased to 14,480 in Calvert County, 21,000 in Charles County, and 14,220 in St. Mary's County, for a total of 49,700. In Charles County, there are 18 public elementary, 6 middle/combined schools, 5 high schools, and 17 private schools. St. Mary's County has 16 public elementary schools, 4 middle schools, 3 high schools, and 8 private schools. Calvert County has 11 public elementary schools, 4 middle schools, 3 high schools, and 10 private schools. Each county has some post-secondary institutions.

A branch of the Charles Community College is located in Calvert County, and the Calvert Career Center is located in Prince Frederick. Off-campus courses from the George Washington University and University of Maryland are offered in Charles County, the Charles Community College (enrollment of 6100) is located in La Plata, and the Career and Technology Center is located in Pomfret. A branch of Charles Community College, and the Southern Maryland Higher Education Center, which provides distance learning through several universities, are located in St. Mary's County; St. Mary's College of Maryland (enrollment of 1650) is also located in St. Mary's County in St. Mary's City.

Calvert County has comparatively low student-teacher ratios, despite having relatively low property taxes. For 1996-1997, student/staff ratios were 15.9 in Calvert County, 13.8 in St. Mary's County, and 15.2 in Charles County. Property tax rates in fiscal year 1998 were $2.23/$1000 in Calvert County, $2.08/$1000 in St. Mary's County, and $2.44/$1000 in Charles County. Given the rapid growth in Calvert County, enrollment is expected to reach 17,000 by the year 2000. Consequently, the fiscal year 1998 capital improvement budget includes several construction projects that are under way, including the construction of two new schools (Windy Hill and South Central) before 2000. St. Mary's County is meeting its needs by renovating and expanding existing schools rather than building new ones. As of July 1998, additions to Chopticon and Leonardtown High Schools, Esperanza Middle School, and Lexington Park, Banneker, and Leonardtown Elementary Schools were underway, with additions to Margaret Brent Middle School in the planning phase.

Table 2-8. Projected Pumpages by Sanitary District/Planning Area from the Aquia and Piney Point-Nanjemoy Aquifers Based on St. Mary's and Calvert Counties' Population Growth Estimates

	1995				2020
		Pumpage (1000 gpd)a				Pumpage (1000 gpd)a
Sanitary District	Population	Total (Aquia and Piney Point)	Aquia	Piney Point-Nanjemo	Population>	Total (Aquia and Piney Point)	Aquia	Piney Point-Nanjemo
ST. MARY'S COUNTY
Luckland Run	8788	607	567	40	12,176	1047	997	50
Dukchart's Creek	6017	277.2	237.2	40	7047	354.2	305.2	49
Leonardtown	10,532	598	558	40	13,589	724.6	674.6	50
Flood Creek	2070	198.5	89.5	109	2835	266.1	113.1	135
Piney Point	4008	369.1	149.1	220	5787	463.3	190.3	273
Lake Conoy	1176	444	0	444	1448	551	0	551
Carroll Pond	3529	722	112	610	4347	923.8	141.8	782
Pine Hill Run	37,639	4398.3	2541.1	1857.2	50,183	5702	3328.5	2373.5
Manor Run	4032	135	95	40	5508	175	125	50
Indian Creek	8235	422.1	382.1	40	12,419	647.9	597.9	50
Total	86,026	8171.2	4731.0	3440.2	115,339	10,854.9 (12,973.2)	6491.4 (8663.9)	4363.5 (4309.3)
CALVERT COUNTY
Planning Area 1	20,870	2256.4	1230	1026.4	39,738	4196.5	2403.7	1792.8
Planning Area 2	15,331	1114.3	808.4	305.9	29,572	1864.6	1357.8	506.5
Planning Area 3	28,197	2325.1	1619.1	706	53,690	3844.5	2662.5	1182
Total	64,598	5695.8	3657.5	2038.3	123,000	9905.3 (11,114)	6424.0 (7655.7)	3481.3 (3458.3)
(a) 1000 gpd 0.044 L/s. Source: Achmed and Hansen (1997).

Figure 2-8. Water Supply Systems in Calvert and St. Mary's Counties

Figure 2-9 Aquia Aquifer Potentiometric Surface Map

Transportation

Calvert County has one main four-lane road (Maryland State Highway 2-4) bisecting the County north to south, with smaller roads running to the water bodies on each side of the peninsula (Figure 2-2.) Very few of the secondary roads connect with each other; therefore, Highway 2-4 services the bulk of the traffic for the length of the County. The highway runs adjacent to the CCNPP site and provides the only access to the site. The highway is considered to meet Service Level D (high density, stable flow in which speed and freedom to maneuver are restricted--see GEIS Section 3.7.4.2); population growth in the county is expected to increase crowded conditions on the road, particularly at selected intersections (Calvert County 1997b).

Splitting from Highway 2 at Solomons Island, Highway 4 connects the southern end of Calvert County via the Thomas Johnson Bridge with Maryland State Highways 5 and 235 in St. Mary's County. Highways 5 and 235 run the length of St. Mary's County from north to south. Highway 235 serves all of the main gates to the Patuxent River Naval Air Station. Highway 2-4 serves as a commuting route from Calvert County to the Patuxent River Naval Air Station. As a consequence of the rapid growth of the station, traffic tie ups at the intersection of Highway 4 and Highway 235 during the morning rush hour can create a backup to the bridge, a distance of about 6 km (4 mi). There are plans to mitigate the bottleneck at this intersection and perform other traffic upgrades in St. Mary's County to accommodate the new population. Several of the secondary highways in Calvert County along Highway 2-4 (such as Highway 760 from Drum Point to Highway 2-4 at the south end of the county) are also becoming crowded due to population growth and may require additional traffic control measures.

The period from 1998 to 2020 has been projected by the State of Maryland to be one of rapid population growth. Calvert County is projected to be the fastest growing county in the State over that period. At the projected growth rate, the County would approximately double its current population by the end of the license renewal period (Calvert County 1994a). Upgrading most arterial links and main highways is likely to be required to accommodate such growth. The Calvert County Planning Commission (Calvert County 1997b) has identified costs of $130 million in improvements to maintain adequate service on Highway 2-4 through the year 2030.

2.2.8.3 Offsite Land Use

Figure 2-2 shows the CCNPP location, general land use, and planned uses for land in Calvert County, respectively. While land use in the Tri-County area would be influenced to some degree by changes at CCNPP, this section concentrates on Calvert County because the bulk of residential and commercial development related to the plant workforce is contained in Calvert County and because the largest share of the CCNPP tax base exists in Calvert County. Spending of CCNPP-related taxes can also affect economic development and land use.

The region around CCNPP remains predominantly rural in character, with 62 percent of Calvert County in farms and forests and only 2 percent commercial or industrial (see Table 2-2). However, with population growth, 8.3 percent of the County's agricultural land was lost to residential and commercial development between 1985 and 1990, as well as 6.8 percent of the County's forested land (Calvert County 1997b). This continued a trend evident since 1970, which has shown a rate of conversion from open space to residential use of about 400 ha (1000 acres) a year. Farmland declined from 25,000 ha (63,000 acres) in 1969 to 15,000 ha (37,000 acres) in 1992 (Calvert County 1988; DOC 1992b).

Since the 1970s, the State of Maryland has allowed Transferable Development Rights (TDRs), where land owners can sell their development rights on the open market. Both the State and the County have been active in purchasing and retiring TDRs to preserve agricultural land and resource preservation areas. The tax base provided by CCNPP was a significant factor in the County's ability to do this.

Calvert County's planning efforts over the last 30 years have been focused on directing growth to suitable locations, promoting selected types of economic growth, and practicing stewardship of the land and Chesapeake Bay. Calvert County has adopted a Comprehensive Plan (Calvert County 1997b) and several land preservation and open space plans to preserve the rural character of the County. These plans include large-lot zoning and the Calvert County Agricultural Preservation Program. The implementation strategy contains four steps:

(1) Reduce total build-out. In 1995, there were 23,500 dwelling units in the County with a theoretical "build-out" capacity of around 50,000 dwellings (Table 2-9). "Build-out" means the total number of dwellings that could be built in the county under current zoning.

(2) Reduce residential growth rate, which has averaged around 5 percent per year for the last 20 years.

(3) Preserve prime farms, forests, historic resources, and sensitive areas. These areas comprise approximately 22,000 ha (54,000 acres). By 1997, about 4900 ha (12,000 acres) of prime farm and forest land had been permanently preserved by the County and an additional 3000 ha (7500 acres) were enrolled in either the State or the County Agricultural Preservation Program (Calvert County 1997b).

(4) Direct growth to appropriate locations. The 1983 Comprehensive Plan called for creation of Town Centers to avoid scattered strip development along Highway 2-4, to promote business growth by encouraging agglomeration economies, to zone and provide infrastructure for multifamily development (including low-income and elderly housing), to reduce dependence on vehicles, and to reduce growth within agricultural areas (Calvert County 1997b).

By 1997, virtually all new commercial development had been directed to Town Centers in Calvert County. General merchandise sales and commercial real property had grown by over 100 percent and both low-income and elderly housing had been built in Town Centers, which also were attracting high and middle-income families. The 1997 Comprehensive Plan (Calvert County 1997b) continues and expands upon these themes. However, new residential development in the County has been in rural areas on large lots (the County requires a minimum lot size of 5 acres in rural areas); approximately 7300 platted, undeveloped lots remain exempt from most current regulations. Approximately 530 ha (1300 acres) of undeveloped land outside of existing residential communities are zoned R-1 (single-family residential) or R-2 (multifamily residential) and need to be reevaluated.

Several other land use controls in the County limit either total development or help steer development toward appropriate locations. In 1988, the County adopted adequate facilities regulations to ensure that roads and schools could accommodate new growth. In the early 1990s, this ordinance effectively stopped the approval of most new subdivisions until schools could be built. Impact fees are also charged for new construction, including a $350/year/unit for landfill impact, $600/unit recreation fee,

Table 2-9. Projected Build-Out in Calvert County Under 1995 Zoning

and a school impact fee of $3000/unit for single-family detached housing or $2000/unit for single-family attached housing. In 1989, the State mandated the establishment of Critical Areas within 305 m (1000 ft) of the County's waterways. Allowable densities in most of this area were reduced to 8.1 ha (20 acres) per dwelling unit. The Maryland Forest Conservation Act, adopted in 1993, helped protect large contiguous forested areas. In 1992, the County adopted mandatory clustering together with the designation of three sub-zoning categories: (1) Farm Communities, (2) Resource Protection Districts, and (3) Rural Communities. The provision required that lots be clustered onto 50 percent of any given parcel within a Rural Community and onto 20 percent of the parcel in the other two types. Design standards were adopted to protect fields, forests, and vistas. Finally, in 1993, a new zoning category called "Employment District" was defined to designate non-retail uses. These uses were required to be adjacent to Town Centers to avoid commercial sprawl.

2.2.8.4 Visual Aesthetics and Noise

From the air, the principal visual features of the CCNPP region are the Chesapeake Bay, the Patuxent River, and the countryside, which is generally wooded. The distance across the Bay in the vicinity of CCNPP is approximately 10 km (6 mi) and the far shore is a dark line on the horizon; the view up- or down-Bay is water to the horizon. From the Bay, the shoreline is wooded with widely spaced small housing developments and marinas. The CCNPP site has a 460-m (1500-ft) wide developed area approximately in the middle of 10 km (6 mi) of undeveloped, wooded shoreline featuring 30-m (100-ft) cliffs. These scenic resources have remained unchanged since CCNPP construction.

Offsite scenic resources inland have changed since CCNPP construction due to population growth. This growth has resulted in housing, commercial, and roadside development supplanting agricultural and wooded areas. However, Maryland Highway 2-4 is a State scenic highway, affording views of gently rolling, wooded countryside with interspersed development and occasional agricultural lands. CCNPP is not visible from Maryland Highway 2-4 due to intervening woods and topography.

Because of setback, woods, and topography, noise from the CCNPP is generally not an issue. The only sounds heard offsite are the plant loudspeakers, which can be heard nearby on the Bay, gunfire from the onsite firing range used by the guards for target practice, and public notification systems for emergencies that are tested periodically. Planting extra trees along the southern boundary of the firing range has mitigated firing range noise and has reduced noise complaints to almost zero.

2.2.8.5 Demography

The Final Environmental Statement (FES), Section II.C (AEC 1973), estimated resident population within 80 km (50 mi) of CCNPP for the years 1970 and 2010. As discussed in Section 3.8.2 of the FES, the projection for the year 2010 was 20 percent higher than the current estimate and is approximately the same as the current estimate for the end of the license renewal period.

Sections 3.8.1 and 3.8.2 of the applicant's ER presented U.S. Census data for 1990 and estimated resident population for each decade through the proposed CCNPP license renewal term (2010, 2020, 2030, and 2040). The 2010 projections represent estimated population near the start of the renewal period for Unit 1 (2014), and the projections for the year 2040 represent populations near the end of the initial renewal term (2036 for Unit 2).

Data for 1990 are based on the 1990 Census of Population (DOC 1991). Projections are based on County population projections provided by State planning agencies in Delaware (Delaware Development Office 1995), Maryland (Maryland Office of Planning 1994), Virginia (Virginia Employment Commission 1993), and Washington, D.C. With the exception of Virginia, agency projections extend through the year 2020 for counties in the 50-mile radius. Agency projections for Virginia extend only to the year 2010. Projections for the remaining years in the renewal term are based on the assumption that the last projected rate of population growth in each county would continue unchanged (i.e., the rate of change from 2010 to 2020 is used as the rate of change from 2020 through 2040 for Delaware, Maryland, and Washington, D.C., and the rate from 2000 to 2010 is used as the rate of change from 2010 to 2040 in Virginia).

Resident Population Within 16 km (10 mi)

The estimated resident population within 16 km (10 mi) of the CCNPP for the years 1990, 2010, 2020, 2030, and 2040 is listed in Tables 2-10 through 2-14. Figure 2-10 illustrates the locations of the sectors identified in these tables.

Between 1970 and 1990, the population within 16 km (10 mi) of CCNPP increased almost 50 percent to approximately 36,000. Current projections indicate that by the year 2010, the population within 16 km (10 mi) will be about 63,000, which is about 5 percent higher than the FES estimate. The higher growth within the 16-km (10-mi) radius is primarily related to rapid population growth in Calvert County, Maryland. Between 1980 and 1990, Calvert County was the fastest growing county in the State. According to agency projections, it is expected to continue to be the fastest growing county in the State through the year 2020 (Calvert County 1994b). Factors stimulating growth in Calvert County include proximity to the Washington, D.C., and Baltimore metropolitan areas (1- to 1.5-hour commute by car), less development and lower taxes than those areas, and less stringent land use, zoning, and development regulations compared with surrounding counties (Calvert County 1994b). Near the end of the initial license renewal term (2040), the population within 16 km (10 mi) of CCNPP is expected to be approximately 124,000.

Resident Population Within 80 km (50 mi)

The estimated resident population distribution within 80 km (50 mi) of CCNPP for the years 1990, 2010, 2020, 2030, and 2040 is shown in Tables 2-15 through 2-19. Figure 2-11 illustrates the locations of the sectors identified in these tables.

Table 2-10. Estimated Population Distribution in 1990 Within 10 mi (16 km) of CCNPP^(a)

Table 2-11. Estimated Population Distribution in 2010 Within 10 mi (16 km) of CCNPP^(a)

Table 2-12. Estimated Population Distribution in 2020 Within 10 mi (16 km) of CCNPP^(a)

Table 2-13. Estimated Population Distribution in 2030 Within 10 mi (16 km) of CCNPP^(a)

Table 2-14. Estimated Population Distribution in 2040 Within 10 mi (16 km) of CCNPP^(a)

Between 1970 and 1990, the population within 80 km (50 mi) of CCNPP increased approximately 30 percent to about 3,086,000 (Table 2-15). Current population projections by Maryland, Virginia, Delaware and the District of Columbia indicate that by the year 2010, the population within 80 km (50 mi) will be approximately 3,718,000 (Table 2-16), which is about 20 percent lower than the FES estimate. This difference may be attributed to the slower than expected growth in the Washington, D.C., metropolitan area. In fact, the FES population estimate of 4,757,810 for the year 2010 is higher than the current population projection of 4,719,000 (Table 2-19) for the year 2040. During the license renewal period, major growth areas within the 80-km (50-mi) radius include Calvert, Charles, and Queen Annes Counties in Maryland, and Stafford County in Virginia.

Table 2-20 lists the age distribution of Calvert County in 1990 and the projected age distribution in 2020 compared to the U.S. population. Given the similarities in percentage distributions in the year 2020, the percentage age distribution for the U.S. population in the year 2030 (approximately the midpoint of the license renewal term) can be used to estimate the age distribution of the population in the region surrounding the plant in the year 2030. Table 2-20 shows the percentage age distribution of the U.S. population, and Table 2-21 shows the estimated age distribution of the population within 16 and 80 km (10 and 50 mi) of CCNPP in 2030. As shown in Table 2-21, the population under the age of 18 is expected to represent approximately 23.7 percent of the total population. The largest group is expected to be composed of individuals aged 18 to 44 years.

Figure 2-10 CCNPP 16-km (10-mi) Population Sectors

Transient Population

The transient population can be classified 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 recreational areas such as parks, museums, and marinas in the area. It is estimated that seasonal transients increase the Calvert County population by approximately 23 percent during the summer months (BGE 1992). The daily and seasonal populations associated with selected industry and recreation within 16 km (10 mi) of the station are listed in Table 2-22.

It should be noted that on most weekdays, a significant portion of the resident population is absent from Calvert County during daytime hours. According to the 1990 Census of Population, 57 percent of employed County residents (about 13,000 people) commuted to jobs outside of Calvert County (Calvert County 1997b). With increased numbers of in-movers to the County, the number of commuters was estimated by the State to have increased to 19,250 in 1996 based on the 1990 Census patterns. However, with the large increase in commuter households since 1990, the percentage of commuters may have increased despite increasing commercial development in the County.

2.2.9 Historic and Archaeological Resources

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

2.2.9.1 Cultural Background

The area around the CCNPP site is rich in both prehistoric and historic period resources. This part of southern Maryland has a cultural sequence that extends back to about 10,000 B.C. Aboriginal occupation of the area lasted until the early 1600s when European encroachment pushed the remaining Native American groups from the area. The prehistoric and proto-historic Native American chronology includes three major cultural periods: (1) Paleo-Indian (10,000-7500 B.C.); (2) Archaic (7500-1000 B.C.); and (3) Woodland (1000 B.C.-1600 A.D.) (Pogue and Smolek 1985). Generally speaking, this sequence includes a semi-nomadic existence emphasizing hunting in the earlier timeframe, followed by a shift to more sedentary settlements, more dependent on maize horticulture, along the larger rivers and Chesapeake Bay coastline in Woodland times. Before contact by Europeans in the early 1600s, the region was occupied for several centuries by two Algonkian tribes known as the Nanticokes and the Piscataway. Another tribe, the Susquehannocks, an Iroquoian group from the area that was to become Pennsylvania, moved into the area just before the European contact.

Table 2-15. Estimated Population Distribution in 1990 Within 50 mi (80 km) of CCNPP^(a)

Table 2-16. Estimated Population Distribution in 2010 Within 50 mi (80 km) of CCNPP^(a)

Table 2-17. Estimated Population Distribution in 2020 Within 50 mi (80 km) of CCNPP^(a)

Table 2-18. Estimated Population Distribution in 2030 Within 50 mi (80 km) of CCNPP^(a)

Table 2-19. Estimated Population Distribution in 2040 Within 50 mi (80 km) of CCNPP^(a)

(a) Sources: Derived from Maryland Office of Planning 1994; Delaware Development Office 1995; Virginia Employment Commission 1993; Washington, D.C. Mayor's Office of Planning 1995.

(b) Figure 2-11 indicates location of sector.

Table 2-20. Estimated Age Distribution of Population in 1990 and 2020

Figure 2-11 CCNPP 80-km (50-m) Population Sectors

Table 2-21. Projected Age Distribution in 2030 Within 10 mi (16 km) and 50 mi (80 km) of CCNPP

Table 2-22. Transient Population Associated with Major Facilities Within 16 km (10 mi) of CCNPP

Historic European intrusion settlement in the area today known as Calvert County began in the 1620s with visits by fur traders, with the first settlement in the county established in the 1640s. During the later parts of the 1600s and continuing into the 1800s, the economy of Calvert County centered on agriculture, primarily the tobacco crop. Small planters, later supplanted by larger plantations, dominated this agrarian context at first. While other sectors of Maryland were undergoing transitions from agricultural to industrial and rural to urban in the late 1800s and early 1900s, Calvert County remained dependent on tobacco farming (McGrath and McGuire 1992). In the early 1900s and continuing until today, shellfish and tourism were added to the important economic pursuits.

The land on which the CCNPP is located is believed to have been part of an original land grant of 1000 acres in 1658 from Cecilius Calvert, the 2nd Lord Baltimore, to Richard Preston. This grant is commonly referred to as "Preston's Cliffs" or "Charles' Gift." In the mid-1700s, the general area was referred to as "Gideon and Cleverlys Right." By 1782, the acreage where the power plant is located was owned by Andrew Wilson, whose heirs owned the land until 1916, at which time it was sold to Goodman Goldstein. The land was purchased from the Goldstein heirs in May 1967 by BGE to be the site of the CCNPP.

2.2.9.2 Historic and Archaeological Resources at CCNPP

Archaeological

There are no known or recorded prehistoric archaeological sites at CCNPP, although no records could be located to indicate that any field surveys have been undertaken to identify such resources at the 2300-acre plant site. Today, 70 percent of this area remains forested and relatively undisturbed by plant activities. Numerous important archaeological sites occur in proximity to CCNPP (Pogue and Smolek 1985), and it is possible that undetected or buried archaeological sites may be present within the plant area boundary.

Away from the plant, several archaeological field surveys and site evaluations have been completed for BGE transmission line activities, beginning in 1980 (Evans 1980) and subsequently in the early 1990s (Hopkins et al. 1992; Davis and Polglase 1992; Davis et al. 1992; Davis and Simons 1993, and Goodwin and Associates 1993).

Historic

Although a systematic cultural resources field survey of the CCNPP tract has not been performed, several historic period sites have either been recorded or are known to exist. These historic properties include the following (site number designations are from either the Maryland Historical Trust State Historic Sites Survey or the Maryland Archaeological Site Survey):

(1) CT-58 (Parran's Park) - This historic farmstead included a Maryland Colonial clapboard house, original construction about 1750, that burned in 1955 and other farm outbuildings. Part of an original tobacco barn, dating to 1840-1860, still exists as part of a reconstructed structure and is used by BGE as a farm and maintenance center as part of the Old Bay Farm operation.

(2) CT-59 (also designated 18-CV-7) (Preston's Cliffs; Wilson Place) - The remnants of this farm are conspicuous today as the location of the CCNPP Visitors Center and Nature Trail. The farm site consists of the foundation and fireplace chimneys of the house (extant by at least 1691), which was destroyed in 1972 because of its deteriorated condition, a standing log barn (CT-59A), indicated as being the oldest of its kind still standing in the State (being built in 1820), and a modified frame tobacco barn (CT59B) (original construction 1820-1840) that currently serves as the permanent Visitors Center and museum.

CT-59 was first recorded in the State listings as a historic site in 1967 and later as an archaeological site in 1973. Although to date it has not been nominated for the National Register of Historic Places, the property has important historic value and is an important visitation location at the CCNPP site. All three of the structures have been described and recorded, including Historic American Building Survey (HABS) level documentation of the house in 1971 before its demolition (Carson 1974a), including measured drawings and photographs. The house foundation and chimneys were stabilized in 1974 (Rose 1974), and limited archaeological testing was conducted along the foundation in conjunction with the stabilization work (Carson 1974b). Nield (1977) described the log barn structure as part of a survey of historical sites along the BGE transmission corridor, and Stone (1978) discussed the frame tobacco barn. The significance of the frame barn that currently serves as the CCNPP Visitors Center has been apparent as it is shown in a 1936 photograph on file at the HABS office in Washington, D.C.

(3) CT-154 (Calvert Cliffs Nuclear Power Plant) - The CCNPP has been recorded as a historical property in the Maryland Historical Trust Survey, including a written statement covering its historical and architectural importance.

(4) Other Sites - Other, as yet unrecorded and unevaluated, historic sites exist on the CCNPP property. Included are standing tobacco barns and Camp Canoy, a currently-used BGE company recreation facility that incorporates an original Boy Scouts of America camp that may have begun to operate as early as the 1930s. Three of about 30 log structures remain from the scout camp era, including two cabins and a larger storage building.

Similar to the situation for prehistoric archaeological sites, archaeological contexts from the historic period have not been fully inventoried nor evaluated. Given the lengthy historic occupation of this area, cultural features such as dumps, privies, and other obscured or buried historic activity areas characteristic of farms may exist on the CCNPP property. Potential impacts to historic sites along the South Circuit transmission corridor were identified and evaluated (Black & Veatch 1992).

National Register of Historic Places and Other Listed Properties

Eight listed historic properties within a 8-km (5-mi) radius of CCNPP are identified in the National Register listing for Calvert County. The closest of these to the plant site are the Middleham Episcopal Chapel (CT-60), located in the Calvert Cliffs State Park south of Lusby, the Cove Point Lighthouse (CT-65), along the Bay coastline southeast of CCNPP, and Morgan Hill Farm, southwest of the plant toward the Patuxent River. The National Register-listed Jefferson Patterson Park and Museum, a Maryland State Museum of History and Archaeology and home to the Maryland Archaeological Conservation Laboratory, is located west of CCNPP, along the Patuxent River.

The Maryland Commission on African American History and Culture maintains an inventory of important sites, structures, and settlements. A review of the listing for Calvert County indicates a number of sites of historic importance to African Americans in the Lusby vicinity, located just southwest of the plant site. Included among these sites are former slave houses and servant's quarters, churches, schools, and settlements. No such properties are indicated as being located within the CCNPP plant site boundary.

2.2.10 Related Federal Project Activities

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

The staff determined that there were no other Federal project activities in the vicinity of CCNPP that could result in cumulative environmental impacts or that would make it desirable for another Federal agency to become a cooperating agency for preparation of the SEIS. No Federal agencies participated in the scoping meetings or submitted written comments during the comment period for the scoping process.

The CCNPP withdraws water from the Aquia Aquifer (see Section 4.5.1). The Patuxent River Naval Air Station located in St. Mary's County is another (and more significant) user of this aquifer. Groundwater withdrawal by the Air Station has environmental effects that are cumulative with the withdrawal for CCNPP. There are numerous other users of the aquifer other than CCNPP and the Naval Air Station. As a result of this large demand, the potentiometric surface in this area has dropped; however, there remains approximately 90 m (300 ft) of drawdown still available. The Maryland Department of Natural Resources (MDNR) monitors the status of the aquifer. The MDE issues permits for groundwater appropriation. BGE holds permits to withdraw groundwater for use at CCNPP and is in compliance with the terms of the permits.

2.3 References

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

National Marine Fisheries Services (NMFS). 1998. Letter from Mr. T.E. Goodger (DOC, NMFS) to Mr. B.W. Doroshuk (BGE) in response to request for consultation with regard to Section 7 of the Endangered Species Act, February 12, 1998, Oxford, Maryland.

The Natural Heritage Network. 1999. "Rare, Threatened, and Endangered Species of Maryland," Maryland Natural Heritage Program. http://www.heritage.tnc.org/nhp/us/md/ftplist.html (accessed July 27, 1999).

Nield, W. L., II. 1977. Historic Sites Survey of Proposed Corridors for the Calvert Cliffs-Chalk Point 500kV transmission Line. Report prepared by the Calvert County Historical District Commission, Prince Frederick, Maryland.

Pogue, D. J. and M. A. Smolek. 1985. An Archaeological Resource Management Plan for the Southern Maryland Region. Maryland Historical Trust Manuscript No. 30. Division of Historical and Cultural Programs, Annapolis, Maryland.

Pritchard, D.W., 1967. "Observations of circulation in coastal plain estuaries." In: Lauff, G. (Editor). Estuaries, American Association for the Advancement of Science: pp 37-44. Washington, D.C.

Resource Conservation and Recovery Act, 42 USC 6901 et seq.

Rose, C. L. 1974. The Conservation of Wooden Foundations of House at Calvert Cliffs. Report on file at Maryland Historical Trust, Crownsville, Maryland.

Sandoz, M., and R. Rogers. 1944. "The effect of environmental factors on hatching, molting, and survival of zoea larvae of the blue crab, Callinectes sapidus Rathburn." Ecology 25: 216-226.

Stone, G. W. 1978. Frame Tobacco Barn on Calvert Cliffs (Visitors Center): Report on a Preliminary Inspection. Report on file at the Maryland Historical Trust, Crownsville, Maryland.

Tri-County Council for Southern Maryland. 1993. 1990 Statistical Profiles for Calvert, Charles, and St. Mary's Counties.

U.S. Atomic Energy Commission (AEC). 1973. Final Environmental Statement Related to Operation of Calvert Cliffs Nuclear Power Plant Units 1 and 2, Docket Nos. 50-317 and 50-318, (April 1973). Washington, D.C.

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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. Department of Commerce (DOC). 1992a. Regional Multipliers: A User Handbook for the Regional Input-Output Modeling system (RIMS II). Economics and Statistics Administration, DOC, Washington, D.C.

U.S. Department of Commerce (DOC). 1992b. 1992 Census of Agriculture, Maryland Summary and State Data, Volume I, Part 20, Bureau of the Census. Washington, D.C.

U.S. Department of Commerce (DOC). 1995. Statistical Abstract of the United States. Economics and Statistics Administration, Washington, D.C.

U.S. Department of Commerce (DOC). 1996. Current Population Reports: Population Projections of the United States by Age, Sex, Race, and Hispanic Origin: 1995-2050. P25-1130. Economics and Statistics Administration, Washington, D.C.

U.S. Environmental Protection Agency (EPA). 1999. "Environmental Profile for: Calvert County, Maryland." http://tree 2.epa.gov/CEIS/CEIS.NSF/$$All/2442009AIR (accessed June 21, 1999).

U.S. Fish and Wildlife Services (FWS). 1998. U.S. Department of the Interior. Letter from John P. Welflin, Supervisor, Chesapeake Bay Field Office, to Barth W. Doroshuk, BGE, CCNPP (November 3, 1998).

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3.0 Environmental Impacts of Refurbishment

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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.

Table 3-1. Category 1 Issues for Refurbishment Evaluation

Environmental issues related to refurbishment considered in the GEIS for which generic 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.

Table 3-2. Category 2 Issues for Refurbishment Evaluation

The potential environmental effects of refurbishment actions would be identified, and the analysis would be summarized within this section, if such actions were planned. BGE stated that it "has not identified the need to undertake the major refurbishment activities that the GEIS assumed for license renewal, and no other modifications have been identified that would directly affect the environment or plant effluents (BGE 1998 and 1999)." Therefore, refurbishment is not considered in this SEIS.

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). 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 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.

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 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 CCNPP. Section 4.1 addresses the Category 1 issues applicable to the CCNPP once-through cooling system, while Category 2 issues applicable to the CCNPP cooling system are discussed at greater length in Sections 4.1.1 through 4.1.3. 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 Section 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 Section 4.5.1. Section 4.6 discusses the impacts of renewal-term operations on threatened and endangered species, a Category 2 issue. Section 4.7 addresses an issue, extremophiles, that was raised by the public during scoping. This issue was determined to be new, but not significant. 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 CCNPP cooling system operation during the renewal term are listed in Table 4-1. BGE stated in its Environmental Report (ER) that it is unaware of any new and significant information related to these Category 1 issues. 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 BGE 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 the Chesapeake Bay performed for the Maryland Department of Natural Resources (MDNR). Therefore, the staff concludes that there are no impacts of altered current patterns during the renewal term beyond those discussed in the GEIS.
• Altered salinity gradients: Based on information in the GEIS, the Commission found that "Salinity gradients 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 BGE 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 the Chesapeake Bay performed for the MDNR. Therefore, the staff concludes that there are no impacts of altered salinity gradients during the renewal term beyond those discussed in the GEIS.
• 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 BGE 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 the Chesapeake Bay performed for the Maryland Department of National Resources (MDNR). 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.

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

• 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 BGE 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 caused by discharged cooling water 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 BGE 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 BGE ER and the site visit, the scoping process, its review of public comments on the draft SEIS, and independent evaluation of available information including the CCNPP National Pollutant Discharge Elimination System (NPDES) permit. 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 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 BGE ER, the NPDES permit for CCNPP, the site visit, 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 discharges of sanitary wastes or 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 BGE ER, the NPDES permit for CCNPP, the site visit, 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 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 dissipation systems." The staff has not identified any significant new information during its independent review of the BGE 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 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 BGE 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 monitoring reports and technical reports. 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 BGE 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 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 BGE 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 monitoring reports developed by Academy of Natural Sciences of Philadelphia (ANSP 1980, 1981). 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 BGE 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 monitoring reports developed by ANSP (1980, 1981). 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 effect the larger geographical distribution of aquatic organisms." The staff has not identified any significant new information during its independent review of the BGE 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 monitoring reports developed by ANSP (Heck 1987) and Martin-Marietta (Holland 1985). 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 BGE 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 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 is 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 BGE 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 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 BGE 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 monitoring studies conducted by ANSP (Heck 1987). 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 BGE 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 sublethal stresses during the renewal term beyond those discussed in the GEIS.
• Stimulation of nuisance organisms (e.g., shipworms): 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 BGE 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. Staff review of available literature (Heck 1987) and information in the GEIS suggests that the occurrences of periodic episodes of algal blooms, and the recent appearance of the dinoflagellate Pfisteria piscidida in the Chesapeake Bay are not attributable to the activities of CCNPP. Therefore, the staff concludes that there are no impacts of stimulation of nuisance organisms during the renewal term beyond those discussed in the GEIS.
• Microbial 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 BGE 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 microbial 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 BGE 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 CCNPP are discussed in the sections that follow. These issues are listed Table 4-2.

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

4.1.1 Entrainment of Fish and Shellfish in Early Life Stages

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 No. 92-DP-0187 along with a letter from the Maryland Department of the Environment (MDE) stating that the permit holder is currently in compliance with all conditions of the permit (MDE 1998). The staff also evaluated a compilation of BGE and contractor studies of entrainment associated with the cooling water intake. BGE submitted a formal report in 1981 (ANSP 1981) to satisfy the requirements of Section 316 of the Federal Water Pollution Control Act (FWPCA), also known as the Clean Water Act. This report, along with continuing studies and regulatory evaluations of plant impacts, has supported subsequent renewals of the facility's discharge permit.

The staff's investigation of entrainment issues centered around the following activities: (1) review of the susceptibility of "important" fish and shellfish species to entrainment, (2) the economic value of the species for local or regional commercial fisheries, (3) regional standing stocks of "important" fish and shellfish species potentially affected by plant operation, and (4) transit time from the intake structure to the point of discharge to the Chesapeake Bay. "Important" refers to species that may be commercially or recreationally important, protected by Federal or State law, or may reside in critical habitats. The staff reviewed these issues to determine the environmental impact of plant license renewal on entrainment of fish and shellfish in early life stages.

Plant-specific studies conducted by BGE personnel and studies conducted by the ANSP provided evidence of how entrainment of fish and shellfish affects the standing populations of the Chesapeake Bay in the vicinity of the CCNPP. Entrainment studies conducted by ANSP and summarized by Horowitz in Heck (1987) led to the following conclusions:

• The species composition of the zooplankton community in the vicinity of Calvert Cliffs is typical of estuaries along the Atlantic and southeastern coast, and the planktonic species were typically entrained in the plant cooling water in densities similar to those of the surrounding waters.
• The five species of zooplankton sufficiently abundant in entrained water to permit statistical study were Neomysis americana, Corophium lacustre, Gammarus mucronatus, Neanthes (Nereis) succinea, and Scolecolepides viridis. None of these species represent larval or early life stage forms of the representative important species (RIS) identified by the State of Maryland, or commercially or recreationally important species summarized in Table 2-3.
• Transitory exposure of estuarine zooplankton to the elevated temperatures of CCNPP entrainment and discharge plumes was generally non-lethal. Transit time was estimated to be 4 minutes.
• Entrainment survival of the above species was generally high, ranging from 65 to 100 percent.

The conclusions were supported by the results of a study by Newman and Sage (1981), who concluded that the principal effect of entrainment appears to be "cropping," which is defined as a reduction in species density from intake to discharge. Cropping mortality was described as "minimal." Entrained organisms either maintained their structural integrity and survived passage through the plant, or were fragmented from the mechanical and hydraulic shear forces and were lost. Zooplankton survival, defined as the percent of organisms surviving plant passage (number alive at discharge/number alive at intake) were similar to the study described above, with survival ranging from 12 to 100 percent, with a median survival of 55 percent for all species studied.

Anecdotal evidence suggests that mortality is probably due in large part to the mechanical action of passing through the cooling system rather than to short-term exposure to heated water, as laboratory experiments conducted by ANSP suggest a tolerance range for most species above the upper limit set for cooling water. This information also suggests that survival rates were not consistent, but fluctuated hourly, daily, and seasonally.

The results of these studies suggest that the planktonic species entrained did not represent biologically, commercially, or recreationally important species. Entrainment of fish and shellfish in early life stages does not commonly occur, cropping rates are generally low, and survival, while variable, is generally high. The larvae of the three species that are considered RIS by the State of Maryland: the blue crab, Callinectes sapidus; the soft shell clam, Mya arenaria; and the eastern oyster, Crassostrea virginica; are not susceptible to entrainment by the CCNPP cooling system because the intake is below the zone in which these zooplankton generally occur. It is unlikely that there are management control procedures that would decrease the likelihood of entrainment of zooplankton based on plant design and ecological and hydrodynamic features of this portion of Chesapeake Bay.

The staff has reviewed the available information relative to potential impacts of the cooling water intake system on the site'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

Impingement of fish and shellfish 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 the NPDES Permit, No. 92-DP-0187, along with a letter from the MDE stating that the permit holder is currently in compliance with all conditions of the permit (MDE 1998b). A Federal Water Pollution Control Act (FWPCA) 316(b) demonstration was conducted by the ANSP (1981) using the annual studies conducted in 1977 through 1979. A 316(b) demonstration ensures the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impacts. This information, and subsequent studies and regulatory evaluations of plant operations have supported subsequent renewals of the NPDES permit. Full, annual impingement investigations were conducted during the first 21 years of plant operation

An early impingement study conducted by ANSP (ANSP 1981) determined the number of blue crabs and finfish impinged on the traveling screens at CCNPP, and estimated the value of the loss caused by the impingement based on data from 1977, 1978, and 1979. Impingement studies conducted by ANSP for the years between 1975 to 1983 are compiled and summarized by Horowitz in Heck (1987). The results of these studies form the basis of the decision concerning the effects of impingement on important fish and shellfish populations surrounding the CCNPP. The importance of impingement is determined relative to the recreationally or commercially important species listed in Table 2-3.

During the ANSP (1981) 316(b) demonstration (and for a total of 21 years of continuous impingement monitoring), a collecting net was placed in the screenwash discharge trough through which the impinged individuals travel back to Chesapeake Bay. The sampling schedule was based on repeating 6-day cycles to sample each hour of the day with equal frequency over a 365-day period. On each sampling day, one-hour collections were made at each unit. Since data from earlier impingement survival studies at the CCNPP (see ANSP 1981) had demonstrated greater than 99 percent survival of blue crabs and hogchokers (Trinectes maculatus), these species were not included in this study. Survival data from Burton (1976) were also used to assess potential survival of impinged species and to extrapolate the yearly death toll and subsequent economic loss.

The conclusions of the study for the 3 study years were as follows:

Thus for the 1977 through 1979 time frame, an annual average of 1,600,000 finfish and blue crabs were collected on the traveling screens, of which 260,000 did not survive. The expected monetary loss attributed to the death of finfish and blue crabs due to impingement was $24,000 per year.

In response to the draft SEIS (February 1999), the MDNR Power Plant Assessment Division provided additional data on the economic evaluation of monetary loss due to impingement at CCNPP (MDNR 1999). In an attachment to the comment letter, MDNR provided summary tables estimating economic losses due to impingement for the years 1993, 1994, and 1995. Table 4.3 is derived from these MDNR tables and summarizes the number of fish and other aquatic species impinged, their survival rate, the total number killed, and the value of the losses. The estimated number of fish impinged as well as the estimated weights were obtained from the ANSP annual impingement studies (Hixon and Breitburg 1993, 1994, 1995). A summary of the information contained in the letter from MDNR to NRC dated May 19, 1999 follows.

Following the methods described above, no value was estimated for species with survival rates greater than 99 percent after impingement (Callinectes sapidus and Trinectes maculatus). Because there were no known survival estimates for three species (Morone americana, Morone saxitilis, and Cynoscion regalis), the percent survival data presented in Table 4-3 was estimated to be the mean survival for other species impinged for that year (78 percent for M. americana and M. saxatillis, 82 percent for C. regalis.

The value column identified as being from MDNR expresses a valuation of individual species using the AFS valuation factors (AFS 1992). The last column uses factors established in the Code of Maryland Regulations (COMAR Title 08, COMAR Title 26) and an inflated dollar value (1993-1995) based on the Consumer Price Index (CPI). When the COMAR value varied with the size of the fish, an estimate of likely mean size was developed by comparing the approximate weight per fish (from estimated weight and number of fish of each species per unit per year) to known size-weight relationships. The MD NR believes that the assumptions in this valuation are conservative, thereby potentially overestimating the value of fish killed each year.

Comparison of the 1993-1995 valuation with the 1977-1979 estimates contained in the draft SEIS suggest that the draft SEIS may have overestimated the monetary value of impingement losses. The average monetary loss for the years 1977-1979 was $24,289; average losses presented in Table 4-3 (1993-1995) were $5746 and $8599, respectively. It is probable that management actions to decrease impingement (described in later portions of this SEIS) contributed to the decrease in monetary losses associated with this phenomena.

Additional impingement studies conducted by ANSP and summarized by Horowitz in Heck (1987) were performed by collecting fish and shellfish in a nylon net placed in the screen wash discharge troughs of the CCNPP. One-hour collections were made on randomly selected days during three 8-hour periods in 1975. The format became more structured after that and continued for 21 years. Experimental designs changed periodically in response to plant expansion to two online reactors, changes to the curtain wall surrounding the intake, and alterations to the traveling screens. During each study, numbers, species, weight, size, and physical condition of impinged individuals were noted. Sublethal effects, such as loss of equilibrium, were also noted, where appropriate. Estimates of variance in survival rate were calculated for species in which greater than 300 individuals were collected. The number of potential episodes of impingement was estimated based on the number of fish or shellfish impinged per screen per hour. Impingement episodes at the species level were also compared to trawl data to determine if the species impinged on the traveling screens were indicative of the local population distribution, or whether CCNPP was selectively removing certain susceptible species.

The results of the studies indicated that the impinged subset did not show the same degree of dominance and consistency in rank abundance as the trawl samples. This probably was reflective of a high variation in the rate of impingement. Much of the total impingement in a month or year occurred in occasional large impingement episodes of schools of one or only a few species. This suggests an episodic nature to impingement, not a constant removal of individuals over time. The particular schooling species varied with the season, environmental conditions, etc., leading to a greater variation

Table 4-3. Summary of 1993-1995 Fish Losses Through Impingement

in the overall catch. The most common species in the impingement samples are listed as follows:

Anchoa mitchilli, the bay anchovy

Leiostomus xanthurus, the spot

Trinectes maculatus, the hogchoker

Brevoortia tyrannus, the Atlantic menhaden

Micropogonias undulatus, the croaker

Although several of the same species were dominant in both impingement and trawl samples, the impingement samples contained greater numbers of hogchokers, menhaden, and other species. Survival studies showed high survival rates for flounders, cyprinodontids, gobies, and blennies. Herring, anchovies, and silversides typically showed intermediate rates of survival, and perciforms showed variable, but generally low survival after coming in contact with the traveling screens.

The blue crab was often impinged on the traveling screens of CCNPP. ANSP has estimated that a total of 5.25 million crabs were impinged on the traveling screens of CCNPP from 1975 to 1982, with annual estimates ranging from 293,000 to over 1.6 million. This correlated well with the annual number of crabs ANSP caught in pots at various locations in the Bay. Experiments showed that impingement survival of blue crabs exceeded 99 percent (Burton 1976), suggesting that impingement probably has little effect on the total population density of crabs in the area of CCNPP.

BGE provided a comprehensive summary of impingement investigations at the CCNPP from 1975-1995 (BGE 1998b). In this report, detailed information is presented that summarizes the number of species and individuals impinged on the traveling screens each year, and estimates mortality based on previous study results. In addition to 21 annual impingement surveys, three studies are discussed: The FWPCA Section 316 Study (ANSP 1981), Ecological Studies in the Middle Reach of the Chesapeake Bay (Horowitz in Heck 1987), and a 1989 Trends reports developed by ANSP. The results of the BGE report suggest that some impingement episodes may occur due to stressful environmental conditions in the Bay caused by natural phenomena. During these stressful conditions, large numbers of finfish may become debilitated and subsequently impinged on the traveling screens. Plant modifications, including curtain wall panel removal at critical times, have enabled fish to escape the intake area and follow an oxygen gradient out of the area. BGE presents the following quote from the 1982-1986 ANSP report that summarizes one of their conclusions concerning impingement:

Most abundant species were impinged in significantly larger numbers during some years than during others. However, peak years of commercial catches and peak years of impingement did not coincide for any of the abundant species for which commercial catch data are available. Instead, large impingements often resulted from fish kills associated with low dissolved oxygen concentrations.

The results of these studies suggest the following:

• Mortality due to impingement is species-dependent: blue crabs, flounders, cyprinodontids, gobies and blennies exhibit high survival after impingement; herring, anchovies, and silversides exhibit intermediate survival; and perciform fish generally do not survive impingement.
• Losses of finfish and blue crabs to impingement represent only about 0.1 percent of commercial landings. If recreational landings of fish and shellfish are included, the impingement losses associated with the CCNPP represent approximately 0.05 percent of the total take from this area of the Chesapeake Bay.
• Management actions to reduce impingement have been ongoing since plant construction and have included modification of the intake curtains (including panel removal during episodes of low dissolved oxygen in intake water), traveling screen configuration, and discharge trough design.
• Yearly economic losses due to impingement, even after conversion to 1998 dollars, appear to be only a very small fraction of the total value of the resource to commercial and recreational entities.
• Excessive impingement events appear to be correlated with stressful environmental conditions that are not attributable to CCNPP operations. Warm weather, a thermally stratified bay, and prolonged west or southwest winds may create low dissolved-oxygen conditions near the plant that debilitate finfish and make impingement more likely.

As described above, 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

The effects of heat shock are listed as a Category 2 issue and require plant-specific evaluation before license renewal.

A copy of the NPDES permit, No. 92-DP-0187, along with a letter from the MDE, affirms that the permit holder is currently in compliance with all conditions of the permit. A 316(a) demonstration (FWPCA) was conducted by the ANSP (1981). This information, and subsequent studies and regulatory evaluations of plant operations, have supported subsequent renewals of the NPDES permit. The staff evaluated the following information:

• a description of the condenser cooling system; its configuration determines which permits must be acquired, and the potential severity of impacts on particular aquatic organisms or systems
• a temperature-duration-mortality relationship and susceptibility of "important" local species to heat shock
• estimates of the regional standing stocks for those "important" species potentially affected by cooling system discharge operation
• a description of applicable State and Federal (40 CFR Part 423) effluent guidelines and the thermal standards or limitations applicable to the water body to which the discharge is made (including maximum permissible temperature, maximum permissible temperature increase, mixing zones, and maximum rates of increase and decrease), and whether and to what extent these standards or limitations have been approved by the Administrator of the EPA in accordance with the Federal Water Pollution Control Act, as amended.

The potential effects of heat shock associated with the cooling water discharge from the CCNPP can best be determined by understanding the behavior of the thermal plume as it leaves the discharge and enters the Chesapeake Bay. Bay water enters the CCNPP through the intake channel, and transits through the plant in approximately 4 min, with a resulting maximum allowed temperature change (T) of 6.7ºC (12ºF). After passing through the condensers, the warm effluent is discharged through four 4 × 4 m (12.5 × 12.5 ft), concrete conduits (two for each unit) which rest on the bay bottom. Water is discharged along the 3-m (10-ft) depth contour at 2.7 m/s (700 gal/s) from the conduit system, which is located 260 m (850 ft) offshore (Holland et al. 1984).

A number of studies have been conducted to determine plume dimensions and compare the results to the State of Maryland Water Quality Standards (Martin Marietta 1976a, b; ANSP 1980). An overall compilation of studies of plume characteristics may also be found in Ecological Studies in the Middle Reach of Chesapeake Bay, Lecture Notes on Coastal and Estuarine Studies (Heck 1987). These studies represent the most complete analyses of the thermal plume associated with the CCNPP activities to date.

Early studies were conducted to determine plume characteristics during one- and two-unit operation, determine relative current speed and direction during tidal cycles via current meters, and determine both near- and far-field effects under varying plant loads. Dye studies were also employed to better understand the dispersive characteristics of the plume. Extensive studies were performed on plume characteristics in 1979, concluding that for a condenser temperature rise of 6.7ºC (12ºF), the CCNPP full-load plume would comply with all mixing zone requirements for discharges to tidal waters. Further, these studies estimated the area in which the temperature rise exceeded 2ºC (3.6ºF) at 0.15 km² (0.06 mi²) based on a condenser temperature rise of 6.7ºC (12ºF). These data suggest that under most conditions, thermal shock is not expected to occur, based on a target organism's ability to withstand episodic temperature changes of 2ºC (3.6ºF) or less.

Summary information provided in Heck (1987) suggested the following findings concerning the relative effects of the thermal plume associated with cooling water from the CCNPP discharge:

• With a maximum temperature increase of 6.7ºC (12ºF), 9100 m³ (2.4 million gallons) of water pass through the condensers each minute and transfer a tremendous amount of waste heat into the Bay. However, dilution is great, mixing is rapid, and the thermal plume is confined to a relatively small area.
• The area in which the temperature rise exceeds 2ºC (3.6ºF) is estimated to be 0.34 km² (0.13 mi²); the area in which the temperature rise exceeds 1ºC (1.3ºF) is estimated to be 1.00 km² (0.4 mi²).
• Three RIS have been identified that may be influenced by the thermal plume created by the CCNPP: the eastern oyster, the soft-shell clam, and the blue crab.
• The eastern oyster is the most important resource that uses the area near the CCNPP for breeding and as a nursery. Entrainment studies by Olson and Sage (1979) and Newman and Sage (1981) showed no entrainment of oyster larvae in the plume. Once oysters have set, they show increased growth from the elevated temperature near the CCNPP, based on data from planting efforts conducted by MDNR (Abbe 1988, 1992).
• The soft shell clam has not occurred in sufficient numbers near the CCNPP to support commercial harvesting. The low population densities occurred long before plant operation began in 1975 and appear to be related to the physical and hydrodynamic characteristics of the Chesapeake Bay, predation, and other factors.
• There is little thermal impact on juvenile and adult crabs, and essentially no effect on larvae, since they are not found in the area.
• Many finfish are found in the area on a seasonal basis or move through the area during spawning runs, but the commercially and recreationally valuable species such as striped bass, weakfish, bluefish, spot, croaker, flounder, or herring do not spawn in the area. Their larvae, therefore, are not susceptible to thermal effects. Since the area of increased temperature is small, it does not block established migratory fish routes.
• The thermal plume does not support large numbers of overwintering species; therefore, abrupt changes in plant operation are not expected to create adverse conditions for endemic species.

The results of these studies suggest that heat shock and other adverse effects associated with cooling water discharge from the CCNPP present little risk of long-term environmental damage. Pursuant to 10 CFR 51.53(c)(3)(ii)(B), no further assessment of heat shock is required. Therefore, the staff concludes that potential heat shock impacts resulting from operation of the plant's cooling water discharge system to the aquatic environment or in the vicinity of the site are SMALL, and mitigation is not warranted.

4.2 Transmission Lines

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The CCNPP power transmission system is divided into a North and a South Circuit. The land beneath the lines, about 105 km (65 mi) of 100 to 125-m (350- to 400-ft) wide rights-of-way, is owned by BGE. The lines cross mostly second-growth hardwood and pine forests, pasture, and farmland. The plant is connected to the Southern Maryland Electric Cooperative's substation via a 69-kV underground transmission line.

Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B-1, that are applicable to CCNPP transmission lines are listed in Table 4-4. BGE stated in its ER that it is unaware of any new and significant information related to these Category 1 issues. 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.

A brief description of the staff's review and the 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 BGE ER, the staff's site visit, the scoping process, consultation with MDNR, 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 collision 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 BGE 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 BGE monitoring program, BGE efforts to document collisions, and BGE 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 BGE 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 BGE ER, the staff's site visit, the scoping process, consultation with MDNR, 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 power line right-of-way during the renewal term beyond those discussed in the GEIS.

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

• 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 BGE 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 BGE 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 and land use: Based on information in the GEIS, the Commission found that "Ongoing use of power line right of ways 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 BGE 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 that is being treated as a Category 2 issue. These issues are listed in Table 4-5. They are discussed n Sections 4.2.1 and 4.2.2.

4.2.1 Electromagnetic Fields--Acute Effects

The GEIS analysis for electric shock from transmission lines was unable to reach a conclusion on the significance of the electric shock potential because for earlier licensed plants, electric shock was not addressed, some plants may have chosen to upgrade the voltage line, and land use may have 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, BGE stated that the South Circuit was designed to be in compliance with the NESC for electrical shock potential. Calculations of steady-state current for the largest vehicle anticipated under the lines result in less than the 5-milliampere (mA) code limit. The North Circuit lines were installed before the NESC was adopted. However, calculations of steady-state current for the largest vehicle anticipated under the northern lines results in less than the 5-mA code limit. BGE, therefore, concludes (BGE 1998a) that the North Circuit also meets the NESC recommendations for preventing electric shock from induced currents.

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

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 51, Subpart A, Appendix B, Table B-1, that are applicable to CCNPP with regard to radiological impacts are listed in Table 4-6. BGE stated in its ER that it is unaware of any new and significant information related to these Category 1 issues. 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 BGE 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 BGE 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 51, Subpart A, Appendix B, Table B-1, that are applicable to socioeconomic impacts during the renewal term are listed in Table 4-7. BGE stated in its ER that it is unaware of any new and significant information related to these Category 1 issues. 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 BGE ER, the staff's site visit, the scoping process or public comments on the draft SEIS , 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 in its review of the BGE ER or through the site visit, the scoping process or public comments on the draft SEIS, and independent evaluation of 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 BGE 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 BGE 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.⁽⁷⁾

4.4.1 Housing Impacts During Operations

In determining housing impacts, BGE chose to follow Appendix C of the GEIS, which presents a population characterization method that is based on two factors, "sparseness" and "proximity" (GEIS Section C.1.4). Sparseness measures population density and city size within 32 km (20 mi) of the site, while proximity measures population density and city size within 80 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). CCNPP 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 CCNPP population as "high" (GEIS Table C.2). Using the demographic data given in Section 2.2.8, the population density within a 32-km (20-mi) radius of CCNPP is 42 persons/km² 109 persons/mi²), giving a sparseness Category of 3. The population density within an 80-km (50-mi) radius is 152 persons/km² (393 persons/mi²), giving the site a proximity Category 4. These values combine to give the CCNPP population a category measure of 4.3, within the "high" category, consistent with the GEIS characterization. Moreover, forecasted growth in the region from 1998 to 2040 due to causes other than CCNPP is likely to make the population rating continue to increase.

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

As described in Section 2.2.8, the Tri-County (Calvert, St. Mary's, and Charles) area around CCNPP is not subject to growth control measures that effectively limit housing development, although Calvert County is attempting to steer the growth toward particular locations to preserve the County's rural character. The County is also buying development rights to some lands to preserve open space. In 10 CFR Part 51, Subpart A, Appendix B, Table B-1, NRC found that impacts to housing are expected to be of small significance at plants located in a "high" population area where growth control measures are not in effect. The applicant states that because CCNPP is located in a high population area and is not located in an area where growth control measures limit housing development, housing impacts are expected to be SMALL.

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 of the additional population that would move to the area as a result of CCNPP operations during the license renewal period. BGE does not expect to hire additional employees for license renewal, but used the bounding estimate in the GEIS of 60 new employees as the basis for analyzing a bounding case scenario. The maximum impact to area housing was calculated by BGE using the following assumptions: (1) all direct and indirect jobs would be filled by in-migrating residents; (2) the residential distribution of new residents would be similar to the current worker distribution; (3) each new job (direct and indirect) represents one housing unit. As described in Section 2.2.8 of this report, the counties that have the most CCNPP workers are Calvert, St. Mary's, and Charles, which, together, account for approximately 93 percent of CCNPP employees. Were the applicant's maximum impact assumptions to hold true, BGE's bounding estimate of 60 license renewal employees could generate demand for as many as 223 housing units (60 employees Maryland employment multiplier of 3.997 x 93%). However, the 81,000 housing units in the three counties and a vacancy rate of 7 percent (Tri-County Council for Southern Maryland 1993) together give about 5700 units currently available for occupancy. Although it would add a small amount to any future cumulative impact on housing from general population change, a decrease in availability of 4 percent (223 units) is not expected on its own to have a discernable effect on housing availability, rental rates, or housing prices, or to spur housing construction or conversion. The staff reviewed the available information relative to housing impacts. Based on this review, 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 little or no change occurs 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 capacity occurs during periods of peak demand. Impacts are considered large if existing levels of service (e.g., such as water or sewer services) are substantially degraded and additional capacity is needed to meet ongoing demands for services. The GEIS indicates that, absent any new and significant information to the contrary, the only impacts on public utilities that could be significant are impacts on public water supplies. BGE's analysis of new and existing information on public services showed no reason to expect impacts on public services other than water supply. In view of the expected population increase in the three counties, especially Calvert County, there may be reason to add significant public services and infrastructure other than water supply during the next 40 years. However, only a very small fraction of the increase would be due to the impact of a maximum of 60 additional CCNPP workers on the area's population.

Analysis of impacts to the public water supply system considered both plant demand and plant-related population growth on local groundwater resources. Section 2.2.2 describes the plant's permitted withdrawal rate and the plant's actual use of groundwater from the Aquia Aquifer for process and domestic uses. Section 4.5.1 presents an analysis of groundwater use conflicts.

As described in Section 2.2.8 of this report, the Solomons Island and Lexington Park areas are starting to experience water supply problems. Therefore, BGE focused its water supply analysis on these two areas. The estimate of a maximum of 60 additional plant employees could generate a population increase of up to 643 people in Calvert and St. Mary's Counties (based on 89% the population increase locating in these two counties, a Maryland employment multiplier of 3.997, and an average household size in Maryland of 3.01). To analyze the impact on the water supply situation in Solomons Island/Lexington Park, only the portion of the population increase expected in those two communities should be considered. The current population distribution of the two counties indicates that about 9 percent of the total population lives in Solomons or Lexington Park communities. (Mitchell and Papenfuse 1994; Calvert County Department of Economic Development 1994). Assuming that the same percentage of plant-related population growth would live in this area, a population increase of about 58 people could be expected in Solomons/Lexington Park as a result of the renewal of the CCNPP operating licenses (9 percent of 643).

The incremental impact to the local water supply systems can be determined by calculating the amount of water that would be needed by these additional residents. The average American uses between 200-300 liters per day (L/d) (50 and 80 gallons per day [gpd]) of water for personal use (Fetter 1988). At this consumption rate, the plant-related population increase would use between 11,000 and 17,600 additional L/d (2900 to 4640 gpd) of water. The Solomons Water Supply system has an average output of 850,000 L/d (225,000 gpd) of water, and the Lexington Park Water Supply system an average output of 4,500,000 L (1,203,000 gal), for a total of approximately 5,300,000 L (1,400,000 gal). An additional 58 residents, drawing an additional 17,600 L/d (4640 gpd), represents less than 1 percent of current daily output. While expected additional population growth in the next 40 years may double the current population of Calvert and St. Mary's Counties and place significantly greater demands on the groundwater resources (perhaps as much as doubling those demands as well), the impact of plant-related population, while contributing a small portion of this cumulative impact, would be an even smaller portion of the future withdrawal rate, requiring no additional capacity. The staff concludes that the impact on water supply is SMALL, and that 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. 10 CFR Part 51, Subpart A, Appendix B, Table B-1 notes 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, then new tax-driven land-use changes during the plant's license renewal term would be small, especially where 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. New population-driven changes in land use during the license renewal term would be small because the projected plant-related population increase is expected to be far less than 1 percent of the current population and is not even a significant portion of the projected population increase for the study area. Calvert County, which is expected to experience a plant-related population increase of 502 (based on 69% of the increase in Calvert County alone), would see a less than 1 percent increase in population as a result of license renewal. Because Calvert County continues to experience high population growth, conversion of agricultural land to residential and commercial uses is likely to continue. However, only a very small fraction (less than 1 percent) of this conversion would be attributable to plant-related population growth.

Calvert County is the principal jurisdiction that receives direct tax revenue as a result CCNPP's presence. Because there are no major refurbishment activities and no new construction as a result of license renewal, no new tax payments are expected that could significantly influence land use in Calvert County. However, continued operation of the plant would provide a significant continuing source of tax revenues to Calvert County. The Final Environmental Statement (FES) related to operations of CCNPP, Section XI.C.1, written by the U.S. Atomic Energy Commission (AEC 1973), estimated that CCNPP would generate $6.5 million annually in county tax revenues, which in 1973 would have represented more than 50 percent of county tax revenue. Using the gross national product implicit price deflators, this would be equivalent to about $20.7 million in 1998 dollars. As shown in Table 4-9, BGE actually paid about $17 million in property taxes to Calvert County in 1994-95, and over $20 million in 1997-98. This payment represented about 21 percent of the county budget and has a substantial, positive impact on the fiscal condition of Calvert County. The applicant estimates that property tax payments will continue to rise over the license renewal term, reaching approximately $33 million per year by 2036.

Table 4-9. Calvert County Property Taxes Paid on CCNPP, Selected Years, 1972-1998

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). 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 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.

Using these criteria, CCNPP tax payments, representing around 21 percent of the total Calvert County budget, are of moderate to large significance. The County also has experienced significant population growth and moderate to large land-use changes. The growth is not directly related to the presence of the CCNPP. Other factors such as proximity to Washington, D.C., and Baltimore, Maryland; less development and lower taxes than those areas; and less stringent land-use, zoning, and development regulations, compared to surrounding counties, clearly play a role. The County has well-established patterns of development due to an established comprehensive plan, including actions by the County to protect open space, and has public services in place to support development, which is being directed toward town centers. In combination, these two factors would be expected to result in SMALL land-use impacts from CCNPP-related taxes.

Continuation of Calvert County's tax receipts from CCNPP as a result of license renewal has two offsetting effects on offsite land use. On the one hand, the presence of this major industrial taxpayer 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 availability of CCNPP taxes makes it possible for the County to conduct an aggressive program to preserve open space by buying open-land development rights, which are then retired.

Calvert County also obtains an indirect monetary benefit from the CCNPP tax base, which helps keep property tax rates low and may add slightly to land conversion due to population growth. Due, in part, to the presence of such a large, stable source of tax income, Calvert County enjoys an AAA bond rating, one of the highest ratings of any jurisdiction in the state (League of Women Voters of Calvert County 1994). This bond rating indicates that there is minimal risk that Calvert County will default in its timely payment of interest and principal, and it affords the county lower interest rates on borrowed funds. License renewal would continue this indirect benefit. Conversely, plant shutdown and the resulting loss of the property tax base could lower the county bond rating.

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, Calvert County has a well-developed plan for land use that will minimize land conversion in the future. In addition, while the relatively low taxes, good bond rating, and high levels of public service afforded by CCNPP-related tax receipts tend to draw population growth to the County, these same receipts make possible programs that favor open space. 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 (64 FR 68496). This issue is treated as such in this final SEIS.

There is significant population growth expected in all three counties in the study area by 2036, as was discussed in Section 2.2.8 of this report. However, at most, less than 1 percent of this expected growth will be due directly to increases in employment at CCNPP. It may be argued that the industrial tax base afforded by CCNPP makes the county a more affordable and pleasant place to live and indirectly increases population, but even this indirect impact is likely to be small and difficult to predict. The additional 60 employees that the plant may require during the renewal period are unlikely to add noticeably to the highway burden. Future general population increase likely will degrade highway level of service at some choke points, but the magnitude of impact of CCNPP on this service degradation is likely to be SMALL and does not require mitigation.

4.4.5 Historical and Archaeological Resources

Because the BGE license renewal application (BGE 1998a) covering an additional 20 years of operation of the CCNPP 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 historic and archaeological resources. 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 known or undiscovered resources would receive de facto protection for the term of the license renewal period, being located within an undisturbed area with secured access. Similarly, historic resources and buildings would continue to be preserved and interpreted for the public at the CCNPP Visitors Center and Nature Trail area.

Notwithstanding that BGE does not plan future land disturbances or structural modifications beyond routine maintenance at the plant, there is a possibility that undiscovered or unrecorded prehistoric or historic period archaeological sites remain on the 2300-acre plant site. Accordingly, care should be taken during normal operations or maintenance 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 farming, recreation, wildlife habitat enhancement, or maintaining/upgrading access roads throughout the plant site.

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 under which Federal actions should not result in disproportionately high and adverse environmental 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 Maryland by 10 percent, or if the percentage of minorities within the census block is at least 50 percent. For census blocks within the District of Columbia and States of Virginia and Delaware, 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 (Office of 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 should include an analysis of impacts on low-income and minority populations, the location and significance of any environmental impacts during operations on those 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 CCNPP were examined. Within that area, there are a few potential environmental impacts that 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 low-income and minority populations recorded during the 1990 Census (DOC 1991), supplemented by field inquiries to the local planning departments in Calvert, St. Mary's, and Charles 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 with the 80 km (50 mi) radius. Figure 4-1 generally shows that minority populations are concentrated in northern Virginia, near Richmond and near Washington, D.C. However, there are three census block groups with higher percentages of minority residents, one in a generally south south-westerly direction from CCNPP, near Lusby, and the other two slightly to the west-northwest, near Broomes Island, Maryland. Generally, however, minority populations are either 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. There is a small low-income, mainly Hispanic, population concentration at Broome's Island in Calvert County and a small concentration of a mixed-race (Piscataway-African American-white) minority group (locally called "Wesorts") near Benedict in St. Mary's County. Low-income populations are well-scattered throughout the three-county area. Some of these individuals are known to be watermen or ex-sharecroppers effectively engaged in subsistence agriculture. Figure 4-2 shows concentrations of low-income population in the Washington, D.C. area, with other, mainly scattered pockets throughout the 50-mile region (DOC 1991). 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 Maryland for those census blocks within the State of Maryland. It also includes census blocks where the percentage of households below the poverty level exceeds 50 percent. For census blocks within the District of Columbia and the States of Virginia or Delaware, the percentage of households below the poverty level is compared to the percentage of households below the poverty level in the corresponding state. Low-income housing tends to be concentrated in the Prince Frederick area. St. Mary's County shows concentrations of low-income population in the vicinity of Hillville-Hollywood-Lexington Park area and at Leonardtown. These are also the locations of low-income housing.

The low-income populations in the Lexington Park area might be adversely affected by groundwater conflicts due to population growth; however, the marginal effect of CCNPP on this problem is at most SMALL. 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 fisheries or subsistence agriculture were significantly affected. Therefore, the impact is SMALL, and no special mitigation actions are warranted.

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

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

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 CCNPP groundwater use and quality and is listed in Table 4-10. BGE stated in its ER that it is unaware of any new and significant information related to this Category 1 issue. 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 4-10. Category 1 Issues Applicable to Groundwater Use and Quality During the Renewal Term

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

• Ground-water quality degradation (saltwater intrusion): Based on information in the GEIS, the Commission found that "Nuclear power plants do not contribute significantly to saltwater intrusion." The staff has not identified any significant new information during its independent review of the BGE 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 groundwater quality from saltwater intrusion during the renewal term beyond those discussed in the GEIS.

There is one Category 2 issue related to groundwater use and quality. That issue is listed in Table 4-11 and discussed in Section 4.5.1.

Table 4-11. Category 2 Issues Applicable to Groundwater Use and Quality During the Renewal Term

4.5.1 Groundwater Use Conflicts (Potable and Service Water)

With both units operating, CCNPP withdraws an average of 0.018 m³/s (284 gpm or 409,000 gpd) (BGE 1998b). This is a Category 2 issue because this flow exceeds the 0.006 m³/s (100 gpm) limit in the GEIS for a Category 1 issue. The groundwater withdrawal is in compliance with a groundwater appropriation permit issued by MDE.

CCNPP withdraws water from the Aquia Aquifer. The drawdown of the water in the Aquia Aquifer in the vicinity of CCNPP is a result of the combined withdrawals of CCNPP and other users. Average withdrawals from the Aquia Aquifer in 1995 were about 0.16 m³/s (3.7 million gpd) in Calvert County and 0.21 m³/s (4.7 million gpd) in St. Mary's County (see Table 2-8).

The U.S. Geological Survey and the MDNR maintain a joint monitoring program of the Aquia Aquifer. The program has tracked and reported on water levels in the Aquia Aquifer since 1975 (Achmad and Hansen 1997). Water levels at a monitoring well located at the CCNPP site have dropped from 4.6 m (15 ft) below mean sea level (MSL) in 1978 to 18 m (60 ft) below MSL in 1994.

In Maryland, water level declines are permitted up to 80 percent of the available drawdown, a distance measured from the estimated prepumping water level to the top of the aquifer. This regulation permits the water level to drop to 109 m (358 ft) below MSL, a far greater depth than has been observed or calculated based on regional growth projections.

The incremental drawdown, based on the maximum permitted withdrawal, resulting from pumpage continuing for the renewal period was estimated to be less than 2 m (5 ft) at 5000 ft from the withdrawal wells. Although continued operation of CCNPP will continue the existing drawdowns caused by the site's groundwater withdrawal wells, and these drawdowns will be further exacerbated by the superimposition of drawdowns associated with the impact of growing regional groundwater use, the impact is considered SMALL, and does not require mitigation.

4.6 Threatened or Endangered Species

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Threatened or endangered species is listed as a Category 2 issue in Table B-1 of Appendix B of 10 CFR 51, Subpart A. The issue is listed in Table 4-12.

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 on October 23, 1997, with the U.S. Fish and Wildlife Service (FWS), and on October 9, 1997, with the National Marine Fisheries Service (NMFS). FWS identified three Federally protected species under their jurisdiction as occurring on the CCNPP

Table 4-12. Category 2 Issues Applicable to Threatened or Endangered Species During the Renewal Term

site (see Section 2.2.6). In addition, the NMFS identified the shortnose sturgeon and the loggerhead turtle as potentially occurring in the vicinity of the CCNPP site (see Section 2.2.5). The response letters from FWS and NMFS are included in Appendix E.

FWS concluded that no adverse impacts to listed species would be likely under conditions of license renewal. FWS also recommended a number of conservation measures that have been implemented by BGE. The Nature Conservancy is allowed escorted foot access to the beach below the CCNPP so that censuses of tiger beetles can be conducted. BGE has placed constraints on activities in the vicinity of active bald eagle nests: no nonroutine human activities (e.g., construction, timber harvest, or heavy machinery operation) are allowed within 0.4 km (1/4 mile) of active bald eagle nests during the nesting season (December 15 to June 15) without coordination and approval from MDNR and FWS. BGE has also agreed to initiate consultation with the FWS whenever activities are planned that would result in significant habitat changes within the 0.4 km (1/4 mile) radius of active bald eagle nests, regardless of time of the year.

An additional potential impact on threatened or endangered species is the regulation control and related disturbances associated with routine maintenance of transmission line corridors. The staff has examined the potential impacts on the species listed in Section 2.2.6 and concludes that there is little likelihood that adverse impacts on endangered or threatened species will occur as a result of routine transmission line corridor maintenance activities during the 20-year period of license renewal.

The NMFS concluded that CCNPP license renewal would not adversely affect either the shortnose sturgeon or the loggerhead turtles because the CCNPP discharge/intake does not lie within the areas normally used by either species. There is no evidence that the thermal effects of the CCNPP cooling water discharge would influence periodic migration of the shortnose sturgeon to and from river systems, nor have either the shortnose sturgeon or the loggerhead turtles been found impinged on the intake screen during the 21 years of monitoring data summarized in the BGE impingement study. Thus, operating license renewal should not affect the viability of either of these species or result in further decline.

The staff has completed consultation with NMFS and FWS relative to potential impacts to listed and proposed threatened or endangered species or critical habitats from operations during the renewal term. Based on this consultation, the staff concludes that the impact is SMALL, and mitigation beyond the measures recommended by the FWS and implemented by BGE is not needed.

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 related to operation during the renewal term listed in 10 CFR Part 51, Subpart A, Appendix B, Table B-1. 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. During the CCNPP site visit in July 1998, BGE staff stated that measurements of channel intake depths indicated that siltation has occurred since the channel was constructed. BGE indicated that it has no plans to dredge the channel. If conditions changed and maintenance dredging became necessary, an application for a dredging permit, including environmental review of methods of redredging and spoil disposal, would be submitted to the applicable permitting agencies at the appropriate time. This new information is not considered a significant ecological concern relative to CCNPP operation during the renewal term.

The review process also would identify environmental issues that have not been evaluated. During a scoping meeting, a member of the public raised an issue regarding the release to the Chesapeake Bay of microorganisms that may live in extreme heat in spent fuel pools, and the potential threat posed by such a release. This issue is discussed in the following section.

4.7.1 Microorganisms That Live in High Radiation, Extreme Heat Conditions

During the July 1998 scoping meeting, one member of the public referred to an article that had been published in the May 23, 1998, issue of Science News (Volume 153, "Something's Bugging Nuclear Fuel") and expressed concerns regarding the potential for microorganisms that can live under extreme heat conditions and be exposed to nuclear radiation (such as within the spent fuel pool) within nuclear power plants. The commenter asked that this issue be considered as part of the scoping process, and specifically that consideration be given to the types of organisms that could live under these conditions, the possibility for mutation, and the consequences of these microorganisms escaping from the plant into the Chesapeake Bay.

In response, the staff investigated and talked with microbiologists that specialized in research on microorganisms that live in extreme heat conditions. The following is a summary of the information that was obtained from the specialists:

Many types of organisms can live quite comfortably in the temperature range of the pools (100 to 150°F or 38 to 65ºC). Some organisms (hyperthermophiles) can thrive at temperatures as high as 110°C (230ºF) near ocean vents. Thermophilic bacteria have been extensively studied (Alfredsson and Kristjannson 1995). Bacteria in the genus Thermus are common inhabitants of hot water tanks, piping, and hot springs, such as those in Yellowstone National Park. Some bacteria are also fairly radiation resistant; Deinococcus radiodurans can recover from doses of ionizing radiation as great as 20 kGy. Although most microbes would not be able to exist in the radiation fields near the fuel assemblies, they would be able to survive in the lower radiation fields found at the surface and against the walls of the spent fuel pool.

There is a potential for mutation in all living organisms, but microbes that have high levels of radiation resistance also have developed extremely efficient repair systems. These repair systems have a remarkably high degree of fidelity and would reduce the potential for mutation. Bacteria already thrive in many extreme environments, and while mutations do occur, it is difficult to detect changes in the morphology or physiology of such mutated organisms.

Organisms that are associated with thermal waters of the spent fuel pool are likely to die if they are transferred into much colder waters, such as those of the Chesapeake Bay. If the organisms are truly adapted to thermal conditions, they would not likely be able to survive and compete with the indigenous microbiota of the relatively cold waters of the Chesapeake Bay. Although some bacteria can survive in a dormant state for long periods of time, bacteria in a microbially-active system such as the Chesapeake Bay likely will have a much shorter lifespan due to factors such as predation and competition.

Based on this information, the staff concludes that microorganisms that may inhabit high-radiation, high-temperature environments (such as the spent fuel pool) have little potential for a significant increase in number in the environment, and would not have a deleterious effect on public health as a result of the continued operation of CCNPP during a 20-year license renewal term.

4.8 Summary of Impacts of Operations During the Renewal Term

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Neither BGE or the staff is aware of significant new information related to any of the applicable Category 1 issues associated with the CCNPP 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 13 Category 2 issues applicable to CCNPP operation during the renewal term and for environmental justice. For 12 issues and environmental justice, the staff concluded that the potential environmental impact of renewal term operations of CCNPP would be of SMALL significance in the context of the standards set forth in the GEIS and that mitigation would not be warranted. The staff also concluded that the potential impacts of CCNPP operating license renewal would be of SMALL significance on threatened or endangered species. Mitigation measures beyond those identified by the FWS and implemented by BGE are not warranted.

In addition, the staff determined that a consensus has not been reached by appropriate Federal health agencies that there are adverse health effects from electromagnetic fields.

4.9 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."

40 CFR Part 423, "Steam Electric Power Generating Point Source Category."

Abbe, G. R. 1988. "Population structure of the American oyster, Crassostrea virginica, on an oyster bar in central Chesapeake Bay: Changes associated with shell planting and increased recruitment." Journal of Shellfish Research, Vol. 7, No. 1, 33-40.

Abbe, G. R. 1992. "Population structure of the eastern oyster, Crassostrea virginica (Gmelin, 1791) on two oyster bars in central Chesapeake Bay: Further changes associated with shell planting, recruitment, and disease." Journal of Shellfish Research, Vol. 11, No. 2, 421-430.

Academy of Natural Sciences of Philadelphia (ANSP) and Edinger JW Associates Inc. 1980. Calvert Cliffs Nuclear Power Plant Thermal Plume Dye Studies: April and August 1979, and Analysis of Plume Sites. Report No. 80-10. Academy of National Sciences, Philadelphia. 122 pp.

Academy of Natural Sciences of Philadelphia (ANSP). 1981. Assessment of Thermal, Entrainment, and Impingement Impacts on the Chesapeake Bay in the Vicinity of the Calvert Cliffs Nuclear Power Plant. Report No. 81-10. Prepared for Baltimore Gas and Electric Company. 298 pp.

Achmad, G. and H. J. Hansen. 1997. Hydrogeology, Model Simulation, and Water-Supply Potential of the Aquia and Piney Point-Najemoy Aquifers in Calvert and St. Mary's Counties, Maryland. Report of Investigations No. 64. Maryland Geological Survey, Baltimore, Maryland.

American Fisheries Society. 1992. Investigation and Valuation of Fish Kills. American Fisheries Society Special Publication 24. Bethesda, Maryland.

Baltimore Gas and Electric Company (BGE). 1998a. Applicant's Environmental Report--Operating License Renewal Stage Calvert Cliffs Nuclear Power Plant Units 1 and 2, Docket Nos. 50-317 and 50-318. Lusby, Maryland.

Baltimore Gas and Electric Company (BGE). 1998b. Letter from Mr. C.H. Cruse (BGE) to NRC Documents Control Desk, "Investigations of Impingement of Aquatic Organisms at the Calvert Cliffs Nuclear Power Plant, 1975-1995. Response to Question Number 23 of the Request for Additional Information for the Review of the Calvert Cliffs Nuclear Power Plant, Unit Nos. 1&2, Environmental Report Associated with License Renewal (TAC Nos. MA1524 and MA1525)," December 3, 1998. Lusby, Maryland.

Burton, D. T. 1976. "Impingement studies: II: Qualitative and quantitative survival estimates of impinged fish and crabs." In: Semi-annual environmental monitoring report for the Calvert Cliffs Nuclear Power Plant, March 1976. Baltimore, Maryland

Calvert County Department of Economic Development. 1994. Demographic Information for Solomons, Maryland and the Surrounding Area, Calvert County Department of Economic Development, Prince Frederick, Maryland, March 26, 1994.

COMAR (Code of Maryland Regulations) Title 08, Subtitle 02, Chapter 09, Section 01 - Monetary Value of Tidal Water and Non-Tidal Water Aquatic Animals.

COMAR (Code of Maryland Regulations) Title 26, Subtitle 08, Chapter 03, Section 05 - Cooling Water Intake Structures.

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.

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 the Clean Water Act [CWA]).

Fetter, C. W. 1988. Applied Hydrology, Second edition, Macmillan Publishing Company.

Heck, K. L., Jr. (Ed.). 1987. Ecological Studies in the Middle Reach of Chesapeake Bay, Lecture Notes on Coastal and Marine Studies. Springer-Verlag - Berlin, Heidelberg, New York.

Hixon, J. H. III, and D. L. Breitburg. 1993. 1993 Impingement Studies at Calvert Cliffs Nuclear Power Plant for Baltimore Gas and Electric Company. Estuarine Research Center, St. Leonard, Maryland, of The Academy of Natural Sciences, Philadelphia, Pennsylvania. Report No. 94-28.

Hixon, J. H. III, and D. L. Breitburg. 1994. 1994 Impingement Studies at Calvert Cliffs Nuclear Power Plant for Baltimore Gas and Electric Company. Estuarine Research Center, St. Leonard, Maryland, of The Academy of Natural Sciences, Philadelphia, Pennsylvania. Report No. 95-13.

Hixon, J. H. III, and D. L. Breitburg. 1993. 1995 Impingement Studies at Calvert Cliffs Nuclear Power Plant for Baltimore Gas and Electric Company. Estuarine Research Center, St. Leonard, Maryland, of The Academy of Natural Sciences, Philadelphia, Pennsylvania. Report No. 96-12.

Holland, A. F. 1985. "Long-term variation of macrobenthos in a mesohaline region of Chesapeake Bay." Estuaries 8:98-113.

League of Women Voters of Calvert County. 1994. Know Your County-Living in Calvert County, Maryland.

Martin Marietta Corporation. 1976a. Calvert Cliffs Chemical Thermometer Thermal Plume Study. PPMP Technical Note 76-1. Prepared for Maryland Department of Natural Resources Power Plant Siting Program, Baltimore, Maryland.

Martin Marietta Corporation. 1976b. Calvert Cliffs Thermal Plume Survey, September and November 1975. PPMP Technical Note 76-2. Prepared for Maryland Department of Natural Resources Power Plant Siting Program, Baltimore, Maryland.

Maryland Department of the Environment (MDE). 1998. Letter from Edwal Stone, Chief, Industrial Discharge Permits Division to Claudia Craig, U.S. Nuclear Regulatory Commission (October 13, 1998).

Maryland Department of Natural Resources (MDNR). 1999. Letter from Richard McLean, Manager, Nuclear Programs to Chief, Rules Review and Directives Branch, U.S. Nuclear Regulatory Commission (May 19, 1999).

Mitchell, R. D. and E. C. Papenfuse. 1994. "Maryland -The Old Line State," contributed by World Book Encyclopedia, World Book, Inc.

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

Newman, E. M. and L. E. Sage. 1981. "Entrainment Studies: Zooplankton." In: Assessment of Thermal, Entrainment and Impingement Impacts on the Chesapeake Bay in the Vicinity of the Calvert Cliffs Nuclear Power Plant. Academy of Natural Sciences, Philadelphia, Pennsylvania. Report No. 81-10. April 8, 1981.

Olson, M. and L. E. Sage. 1979. "Zooplankton entrainment." In: Non-radiological environmental monitoring report, Calvert Cliffs Nuclear Power Plant, January-December 1978. Baltimore, Maryland. Baltimore Gas and Electric Company: pp 12.2-1 to 12.2-57.

Science News. 1998. "Something's Bugging Nuclear Fuel." Volume 153, May 23, 1998.

Tri-County Council for Southern Maryland. 1993. 1990 Statistical Profiles for Calvert, Charles, and St. Mary's Counties, Tri-County Council for Southern Maryland, February 1993.

U.S. Atomic Energy Commission (AEC). 1973. Final Environmental Statement Related to Operation of Calvert Nuclear Power Plant Units 1 and 2, Docket Nos. 50-317 and 50-318. (April 1973), Washington, D.C.

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

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). 1999. 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, Volume 1, Addendum 1. 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 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.

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. The generic potential impacts from postulated accidents have been described in the Generic Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437 (NRC 1996a).

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 CCNPP postulated accidents and is listed in Table 5-1. BGE stated in its Environmental Report (ER) (BGE 1998a) that it is unaware of any new and significant information related to this Category 1 issue. 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.

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

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

Design Basis Accidents: Based on information in the GEIS, the Commission found: that "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 BGE 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 CCNPP is discussed in Table 5-2.

Table 5-2. Category 2 Issues Applicable to Postulated Accidents

Severe Accidents: Based on information in the GEIS, the Commission found the following: that "The probability weighted consequences of atmospheric releases fallout onto open bodies of water, releases to ground water, 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 in its review of the BGE ER (BGE 1998a), the BGE Final Safety Analysis Report (FSAR) (BGE 1998b), the site visit, the scoping process, its consideration of public comments, or in its independent evaluation of the 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 CCNPP. 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 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 previously been considered for CCNPP; therefore, the remainder of Chapter 5 addresses those alternatives.

5.2.1 Introduction

BGE submitted an initial assessment of SAMAs for CCNPP in the ER. This assessment was based on an updated version of the CCNPP Individual Plant Examination (IPE) for internal events (BGE 1993), an updated version of the CCNPP Individual Plant Examination for External Events (IPEEE) (BGE 1997), and supplementary analyses of offsite consequences and economic impacts. BGE concluded that none of the candidate SAMAs identified and evaluated were cost-effective for CCNPP. However, BGE was still evaluating three proposed changes at the time the license renewal application was submitted.

Based on a review of the SAMA submittal, the staff issued an RAI to BGE by letter dated September 9, 1998 (NRC 1998b). Major issues concerned the inclusion of averted onsite costs (AOSCs) in BGE's value impact analysis, the effects of uncertainties in risk and cost estimates on the identification of cost-beneficial SAMAs, and the results of BGE's evaluation of the three remaining SAMAs.

BGE submitted additional information by letter dated December 3, 1998 (BGE 1998c). One SAMA, which involves installing a watertight door between the service water pump room and the adjacent fan room to reduce risk from internal flooding, is being considered under BGE's modification process. Several additional SAMAs were also shown to have a positive net value when evaluated in accordance with NRC's regulatory analysis handbook (i.e., when AOSCs are included as benefits). However, BGE concluded that none of these additional SAMAs warrant implementation.

The staff's assessment of SAMAs for CCNPP, which included review of the BGE process and independent staff analysis, follows.

5.2.2 Estimate of Risk for CCNPP

A description of BGE's estimates of the offsite risk at CCNPP is summarized below. The summary is followed by the staff's review of BGE's risk estimates.

5.2.2.1 BGE Risk Estimates

The Calvert Cliffs Probabilistic Risk Assessment (CCPRA) model, which forms the basis for the SAMA analysis, is a Level 3 risk analysis (i.e., it includes treatment of core damage frequency, containment performance, and offsite consequences). The model, which BGE refers to as Update 2, consists of an internal events portion, based on an updated version of the IPE, and an external events portion, based on an updated version of the IPEEE. Major changes in the analysis since the IPE submittal are described in BGE's December 3, 1998, RAI response (BGE 1998c).

Changes in the Level 1 (core damage frequency [CDF]) portion of the analysis following the IPE submittal include improved treatment of success criteria for anticipated transient without scram events, reactor coolant pump (RCP) seal loss of coolant accidents (LOCAs), and low pressure feed; common cause failure of inverters and transformers; and human action dependencies and recovery actions. Some changes resulted in risk reduction and others in risk increase. The net impact of the changes on CDF is small despite the significance of some of these changes due to the offsetting effect of the risk increase and decrease. The BGE SAMA analysis is based on the Unit 1 model, but the impact of the differences between units was considered in the screening and value/impact analysis.

The Level 2 (also called containment performance) portion of the CCPRA model, including the plant damage state descriptors, the Containment Performance 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 Melcor Accident Consequence Code System (MACCS), Version 1.5.11.1 (Chanin et al. 1990), and site-specific data for meteorology, population, and evacuation modeling.

BGE estimated the total CDF for internally and externally initiated events to be 3.3×10^-4 per reactor-year, and the offsite risk to the population within 80 km (50 mi) of the CCNPP site to be about 0.68 person-sievert (person-Sv) (68 person-rem) per reactor-year. The breakdown of the Unit 1 CDF is provided in Table 5-3. It shows that transients are a dominant contributor to CDF, followed by fire and LOCAs.

The breakdown of containment release frequency and population dose by release category is given in Table 5-4. Among the CCNPP conditional containment failure probabilities, early containment failure is about 7 percent, with isolation failure the primary contributor; late containment failure is about 49 percent, with containment over-pressure the primary contributor; and containment bypass is about 2 percent, with steam generator tube rupture the primary contributor. The containment remains intact

Table 5-3. Calvert Cliffs CDF Profile

42 percent of the time. These results differ from the values reported in the original IPE due to the Level 1 model updates described later. Early containment failure accounts for approximately 94 percent of the population dose, with containment bypass and late containment failures contributing about 3 percent and 2 percent, respectively.

Table 5-4. Contribution of Containment Release Category to Release Frequency and Population Dose

5.2.2.2 Review of BGE Risk Estimates

BGE's estimate of offsite risk at CCNPP is based on the following three major elements of analysis:

(1) the Level 1 and 2 risk models for CCNPP that form the bases for the December 1993 IPE submittal (BGE 1993) and the August 1997 IPEEE submittal (BGE 1997)

(2) the major modifications to the IPE model subsequent to December 1993 (BGE 1998c)

(3) the extension of the Level 2 Probabilistic Risk Assessment (PRA) model to a Level 3 assessment.

The staff reviewed each of these analyses/processes to determine the acceptability of BGE's risk estimates for the SAMA analysis. The results of this analyses follow.

The staff's review of the CCNPP IPE is described in an evaluation report dated April 16, 1996 (NRC 1996b). 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 BGE's analysis met the intent of Generic Letter 88-20 (NRC 1988); that is, the IPE results are reasonable considering the design, operation, and experience of the plant, together with the contributions from initiators and the failure of frontline safety and support systems. The staff also found that the CCNPP IPE compares reasonably with other Combustion Engineering plants, but is highest in CDF. The staff did not identify major shortcomings associated with the licensee's IPE, and further enhancements have since been made to the IPE. The CCNPP IPE identified seven vulnerabilities in the following areas:

(1) loss of electrical switchgear room cooling

(2) loss of main feedwater following a plant trip

(3) loss of auxiliary feedwater (AFW) if valves are inoperable

(4) loss of pressurizer spray during a steam generator tube rupture because of proceduralized trip of RCPs

(5) significant challenges to operators following an inadvertent engineered safeguards feature, reactor protection system, and AFW system actuation resulting from failure of two 120V AC buses

(6) RCP seal LOCA resulting from loss of component cooling water seal cooling

(7) common cause or maintenance failure of both turbine-driven AFW pumps.

Corrective actions have been implemented that address these vulnerabilities except for the RCP seal LOCA, for which BGE determined no actions are required. The staff notes that the BGE SAMA analysis considered potential modifications in RCP seal LOCAs. Therefore, the staff concludes that the internal events portion of CCPRA provides an acceptable platform for assessing the risk reduction potential of SAMAs.

The staff's review of the licensee's IPEEE is currently underway. The preliminary results did not identify any significant shortcomings or deficiencies. A cursory review of the BGE submittal finds that the overall method, scope, and level of detail are generally comprehensive. The staff also notes that the BGE IPEEE has been subjected to both internal and external peer reviews. In the IPEEE, BGE identified several plant improvements from external events, and these have been implemented or are planned and being tracked for resolution. These improvements address/include switchgear room ventilation recovery during a hurricane, smoke infiltration into the control room via ventilation intake, inadvertent isolation of switchgear room and cable spreading room ventilation, fire barrier inspections, and control of transient ignition sources in the cable chases. The BGE SAMA analysis is based on the updated version of the IPEEE. The applicant stated (BGE 1998c) that the updated version, CCPRA, is slightly different from the IPEEE (BGE 1997). Based on these findings, the staff concludes that the external events portion of CCPRA provides an acceptable platform for assessing the risk reduction potential of SAMAs.

The changes to the IPE resulting from incorporating the PRA modifications previously discussed were not extensively evaluated as part of the present review. However, the staff notes that BGE made an extensive effort to update and maintain the CCPRA to reflect the as-built and as-operated condition of the plant, and that the CDF and risk estimates are the results of a detailed PRA model, which has been subjected to both staff and peer reviews. Furthermore, because the principal role of the CCPRA is to screen potential SAMAs, precise CDF and risk estimates are not critical to the analysis. Therefore, the staff concludes that the results of the CCPRA are adequate for purposes of meeting the SAMA evaluation requirement.

The staff reviewed the process used by BGE 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 MACCS analyses. This information is provided in Section F.1 of the ER and in BGE's responses to requests for additional information.

BGE used the Modular Accident Analysis Program code to analyze postulated accidents and develop radiological source terms for each of six containment release categories: intact containment, late containment failure, early containment failure (which is also further divided into large and small), and containment bypass (which is also further divided into large and small). These source terms were incorporated within the MACCS analysis as either a single puff release or split into two plume segments with different release times to represent the time variation in the releases. The staff reviewed BGE'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 MACCS input used site-specific meteorological data processed from measurements taken during 1993. Data from 1993 were used because they were the most readily available data in 1995 when the offsite consequence (Level 3) analysis was performed. BGE indicates that a review of the 1993 data show that they are well within the normal trend for meteorology at the CCNPP site. Therefore, the staff considers this data representative of the climate for the site.

The population distribution around the CCNPP site was based on the projected permanent resident population for the year 2030. This projection was based on 1990 census data, based on county population projections provided by various State planning agencies. These were the most current population projections at the time the consequence analysis was performed. More recent population projections indicate slight (less than 10 percent) increases in some counties and decreases in other counties relative to the projections on which the SAMA evaluation was based (NRC 1999). The net change is a 0.2 percent decrease in the projected total population within a 80-km (50-mi) radius of the plant. Thus, the population projections used in the SAMA analysis remain valid.

Site-specific economic data were used in the MACCS code. Land-use statistics, including farmland values, farm product values, and other factors were provided on a County-wide and State-wide basis for distances out to 80 km (50 mi). The majority of these data were taken from the MACCS Users Manual or NUREG-1150 and are considered by the staff to provide a reasonable representation of the estimated offsite costs of a severe accident.

Evacuation modeling is based on site-specific evacuation studies carried out by BGE. It was assumed that only 95 percent of the people within the plume exposure pathway emergency planning zone would participate in the evacuation. The remaining 5 percent are assumed to be unable or unwilling to evacuate, and are assumed to go about their normal activities for 24 hours. This assumption is conservative relative to the NUREG-1150 study, which assumed evacuation of 99.5 percent of the population within the emergency planning zone.

The staff concludes that the methodology used by BGE to estimate the CDF and offsite consequences for CCNPP 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 BGE.

5.2.3 Potential Design Improvements

The process for identifying potential design improvements, the staff's evaluation of this process, and the design improvements evaluated in detail by BGE are discussed in this section.

5.2.3.1 Process for Identifying Potential Design Improvements

BGE identified an initial list of 158 potential design improvements through a process consisting of the following steps:

(1) consideration of significant plant issues that contributed to large numbers of sequences, and of issues that indicated a higher likelihood of being risk-beneficial. This is based mainly on the risk insights from the extensive PRA knowledge and experience of the BGE personnel.

(2) review of insights from other plant-specific risk studies and from generic containment improvement studies. This included insights from the IPE program presented during a public workshop on the IPE and documented in NUREG-1560 (NRC 1997a), and design improvements for large dry pressurized water reactor containments identified through the NRC Containment Performance Improvement Program (NRC 1990b).

(3) review of plant improvements evaluated in previous severe accident mitigation design alternative analyses for other operating nuclear plants (Watts Bar [NRC 1995a], Comanche Peak [NRC 1989a], and Limerick [NRC 1989b]), and for advanced light water reactor designs (ABB-CE System80+ [NRC 1994] and Westinghouse AP600 [NRC 1998c]).

As a preliminary screening, BGE eliminated any SAMAs that are not applicable to CCNPP (e.g., enhancements applicable only to boiling water reactors), already implemented at CCNPP (e.g., automatic transfer to containment sump recirculation), or related to RCP seal injection. Improvements to RCP injection were eliminated because CCNPP, like other Combustion Engineering plants, does not have an RCP seal injection system. However, SAMAs to reduce the frequency of sequences involving RCP seal LOCA and a SAMA to replace the existing RCP seal system with a seal injection system were retained in the evaluation. Based on the preliminary screening, BGE designated 97 of the original SAMAs for further study. Several SAMAs are multiple-part and effectively add 8 more SAMAs, bringing the total number of SAMAs identified for further study to 105. These SAMAs address the spectrum of contributors to containment release for CCNPP.

As a final screening, BGE eliminated additional SAMAs, based on a preliminary value-impact analysis. As a first step, BGE redefined the conceptual SAMAs in terms of CCNPP-specific design improvements. Based on the more specific SAMA description, a number of potential SAMAs were screened out because they are already addressed in the current design. The benefits and costs associated with the remaining SAMAs were estimated as described later. BGE then eliminated those SAMAs whose cost was expected to exceed the maximum attainable benefit (estimated by BGE to be $2.3 million) and those hardware items having an estimated monetized benefit of less than $40,000. On the basis of this screening, BGE identified 26 SAMAs for further analysis. This includes three SAMAs that were still under review by BGE at the time the ER was submitted.

BGE did not include several factors in the treatment of onsite economic costs. Specifically, the onsite property damage costs associated with cleanup and decontamination were not included on the basis that such costs are covered by property damage insurance. Also, BGE did not include replacement power costs as an onsite economic cost on the basis that such costs are unlikely to be incurred by the utility in a deregulated energy market. In view of the significant impact of AOSCs on both the estimated benefit for each SAMA and the maximum attainable benefit (i.e., the benefit associated with eliminating all core damage events), the staff requested that BGE include AOSCs in the estimation of benefits for each affected SAMA, update the value for the maximum attainable benefit based on inclusion of AOSCs, and update the SAMA screening accordingly.

In the response to the RAI, BGE updated the benefit estimates for all SAMAs and updated the maximum attainable benefit (from $2.4 million to $8.6 million) to account for inclusion of AOSCs. BGE re-screened the SAMAs using these revised benefit estimates. BGE compiled a list of the 10 SAMAs with the highest calculated net values and compared these SAMAs with a similar list based on their original screening (which did not include AOSCs). The revised list includes 9 of the 26 SAMAs identified by BGE in its ER and the following SAMA that was previously excluded because of a high cost of enhancement: "Install high capacity power operated relief valves (PORVs) such that a single PORV is capable of providing adequate decay heat removal (SAMA 77)." BGE included this additional improvement along with the 9 other SAMAs identified for further analysis.

5.2.3.2 Staff Evaluation

BGE's effort to identify an initial list of potential SAMAs focused primarily on areas associated with internal initiating events. The initial 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 CCNPP. Though BGE did not fully take advantage of the CCPRA and the capabilities of the detailed model, it made a reasonable effort to search for potential SAMA candidates, using the knowledge and experience of its PRA personnel, reviewing insights from other plant-specific studies, and reviewing plant improvements in previous SAMA analyses. The staff also finds that the CCNPP IPEEE has identified several plant improvements. These have been implemented or are planned and being tracked for resolution. It is also noted that none of the previous SAMA analyses for operating plants included an explicit search for SAMAs associated with external initiating events. Additionally, BGE uses both its internal and external event PRA model for estimating risk benefit of SAMAs that are screened in for further evaluation. Therefore, the staff concludes that BGE's effort to search for potential SAMAs is reasonable.

The staff reviewed the set of potential enhancements resulting from BGE's preliminary screening process (listed in Appendix F.2 of BGE's ER). The SAMAs include improvements oriented toward reducing the CDF and risk from major contributors specific to CCNPP; improvements identified as part of the NRC containment performance improvement program; several accident management strategies identified by NRC in Generic Letter 88-20, Supplement 2 (NRC 1990c); and improvements identified in previous severe accident mitigation design alternatives (SAMDA) reviews for Watts Bar, Comanche Peak, and Limerick that would be applicable to CCNPP. The staff notes that while many of the SAMAs involve major modifications and significant costs, less expensive design improvements and procedure changes that provide similar levels of risk reduction are also included. The SAMAs also include a filtered containment vent and flooded rubble bed core retention device, 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 concludes that the set of potential SAMAs considered by BGE is reasonably complete and comprehensive.

As mentioned previously, BGE performed a final screening by eliminating those SAMAs whose cost exceeded the maximum attainable benefit (estimated by BGE to be $2.3 million), and those hardware items having an estimated monetized benefit less than $40,000. AOSC were omitted in the original screening process (documented in the ER), but the impact of AOSCs was subsequently evaluated by BGE in response to a staff request. The screening process and criteria appears reasonable.

The staff confirmed BGE's SAMA identification process by performing an independent screening of those SAMAs remaining following BGE's preliminary screening, as described in Section 5.2.6. The staff's screening did not identify any hardware changes that were not already included within the 27 SAMAs identified by BGE. This includes the original 23 SAMAs identified by BGE, the three additional SAMAs still under review by BGE at the time the ER was submitted, and the previously excluded SAMA related to the installation of the PORVs (SAMA 77). Several SAMAs involving procedure improvements were indicated to be cost-beneficial through the staff's screening. These SAMAs had been separately considered by BGE and eliminated in the final screening because (1) the improvement beyond the current plant procedures assumed in the analysis is not realistically achievable, or (2) in the case of flood mitigation procedures, the procedure change would need to be re-evaluated following disposition of SAMA 66b (implement hardware modifications to prevent flood propagation). Elimination of these SAMAs for the reasons provided by BGE appears reasonable.

The staff concludes that BGE has used a systematic and comprehensive process for identifying potential design improvements for CCNPP, and that the set of potential design improvements identified by BGE and supplemented based on inclusion of AOSCs, is reasonably comprehensive and, therefore, acceptable.

5.2.3.3 Design Improvements Evaluated in Detail by BGE

A brief summary of the 27 improvements evaluated further by BGE and the anticipated benefits of each is provided in the discussion below. The numbers in parentheses correspond to the SAMA number in BGE's submittal.

Improvements Related to RCP Seal LOCAs (Loss of Component Cooling Water or Saltwater)

• Modify the plant such that, during emergency conditions, the saltwater, service water, and component cooling water pumps automatically start when the operating pump fails (1a) - This would increase the time before the loss of component cooling in the loss of essential raw cooling water sequences and reduce the potential for RCP seal failure.
• Modify the plant such that, during normal operating conditions, the saltwater, service water, and component cooling water pumps automatically start when the operating pump fails (1b) - This would increase the time before the loss of component cooling water in the loss of essential raw cooling water sequences and reduce the potential for RCP seal failure.
• Modify fire protection system piping to the component cooling water system to provide alternate cooling for the shutdown cooling heat exchangers, the safety injection pump, and RCP seals (5) - This would reduce the impact of a loss of component cooling by providing a means to maintain the reactor coolant pump seals after a loss of component cooling water.
• Implement procedures to stagger high-pressure safety injection pump use after a loss of saltwater (96) - This would allow extended use of high-pressure safety injection after the Saltwater System loss, which causes the emergency core cooling system (ECCS) pump room coolers to be lost.

Improvements Related to Heating, Ventilation, and Air Conditioning

• Install a redundant and diverse AFW pump room ventilation system that automatically starts on high temperature (7) - This would improve the reliability of AFW when room cooling is lost.

Improvements Related to Ex-Vessel Accident Mitigation/Containment Phenomena

• Install containment spray pump header automatic throttle valves (8) - This would extend the time over which water remains in the refueling water storage tank, when full spray flow is not needed.
• Install a passive hydrogen ignition system (15) - This would reduce the potential for hydrogen detonations without requiring electric power.
• Upgrade the fire protection system and hard-pipe a connection to the containment spray system, such that the fire protection system can serve as a back-up source for containment spray (23) - This would provide a redundant source of water for containment spray, at a lower cost than a dedicated system.

Improvements in Alternating Current (AC)/Direct Current (DC) Power Reliability and Availability

• Provide additional DC battery capability (31) - This would extend the availability of DC power when battery charging is lost, thereby reducing the frequency of long-term station blackout core melt sequences and other losses of 125V DC power core melt sequences.
• Use fuel cells instead of lead-acid batteries (32) - This would extend the availability of DC when battery charging is lost, thereby reducing the frequency of long-term station blackout core melt sequences and other losses of 125V DC power core melt sequences.
• Implement automatic cross-tie capability between 4kV buses 11 and 14 (33a). This would ensure that either bus experiencing an under-voltage condition would be fed automatically from the other bus, thereby improving AC power reliability.
• Implement automatic cross-tie capability between 4kV buses 21 and 14 (33b). This would ensure that either bus experiencing an under-voltage condition would be fed automatically from the other bus, thereby improving AC power reliability.
• Modify the plant such that a portable generator could be used to directly feed each of the four 125V DC buses (34) - This would reduce the likelihood of battery depletion, thereby reducing the frequency of long-term station blackout core melt sequences and other losses of 125V DC power core melt sequences.
• Replace batteries with a more reliable model (36) - This would improve DC power reliability, thereby reducing the frequency of station blackout core melt sequences and other losses of 125V DC power core melt sequences.
• Double the capacity of the fuel oil day tanks (38b) - This would extend the operability of the diesel generators, thereby reducing the frequency of long-term station blackout core melt sequences.
• Make the service water-cooled emergency diesel generators air-cooled (44) - This would eliminate the dependency of diesel generators on cooling water support systems, thereby reducing the frequency of station blackout core melt sequences.
• Use the fire protection system as a back-up source for diesel cooling (45) - This would provide a redundant source for diesel generator cooling, thereby reducing the frequency of station blackout core melt sequences.
• Convert under-voltage, auxiliary feedwater actuation signal (AFAS), and reactor protective system high pressurizer pressure actuation signals to 3-out-of-4 logic (48a) - This would reduce the risk associated with 2/4 inverter failure, which was found to be a significant contributor to core damage frequency in the CCPRA.
• Operate with the power-operated relief valve block valves shut (48b) - This modification would increase the demands on the safety relief valves; however, the PORVs would be less likely to spuriously open and would still be available for feed-and-bleed.
• Add an automatic bus transfer feature that would automatically transfer the 120V vital AC bus from the online unit to the standby unit upon failure of the operating inverter (49) - This would eliminate the manual action currently required to place the standby unit online, thereby reducing the frequency of spurious safety system actuation sequences (SSSAs).

Improvements in Identifying/Coping with Containment Bypass

• Install additional instrumentation for detecting intersystem LOCAs (59) - Installing pressure or leak monitoring instruments between the first two pressure isolation valves on low-pressure injection lines, residual heat removal suction lines, and high-pressure safety injection lines, would reduce the potential for interfacing system LOCA events.

Improvements to Reduce Internal Flooding Frequency

• Implement internal flood prevention and mitigation enhancements (e.g., watertight doors) to prevent flood propagation (66b) - Installing a watertight door between the service water pump room and the adjacent fan room would prevent floods from propagating out of the service water pump room, as well as floods from passing into this room, and would eliminate a significant portion of the risk from plant flooding.

Improvements in Feedwater/Feed-and-Bleed Reliability and Availability

• Install separate accumulators for the AFW cross-connect and block valves to separate this equipment from the constant bleed equipment (e.g., AFW flow control valves) (68) - This would enhance the operator's ability to operate the AFW cross-connect and block valves following a loss of air support.
• Increase the capacity of Condensate Storage Tank (CST) 12 to contain 24 hours of AFW inventory for both units (69) - This would permit the operation of secondary side cooling for an extended period, thereby reducing the frequency of long-term loss of feedwater core damage sequence, and other core damage sequences.
• Provide a means to cool the turbine-driven AFW pumps in a station blackout event (70) - This would permit the operation of AFW for an extended period, thereby reducing the frequency of long-term station blackout core melt sequences.
• Automate demineralized water make-up to CST12 (74) - Automating this function and providing a dedicated diesel generator for this purpose would permit continued inventory make-up to the CST during a loss of offsite power, thereby reducing the frequency of long-term loss of feedwater core melt sequences, as well as enhancing Service Water and Component Cooling Water System make-up capabilities.
• Install high-capacity PORVs such that a single PORV is capable of providing adequate decay heat removal (77) - This would permit successful feed-and-bleed with operation of just one of the two PORVs, thereby improving the availability of feed-and-bleed.

5.2.4 Risk Reduction Potential of Design Improvements

The process used by BGE to determine the risk reduction potential for each enhancement is described in Section 4.1.17.4 of the ER. This process involved determining the approximate effect that the design change would have on top events on the related event tree, reflecting that impact by modifying the saved sequences, and calculating a new value of CDF and total risk (expressed in terms of offsite population dose, offsite economic costs, onsite dose, and onsite economic costs). A spreadsheet was used to total the plant damage states resulting from the various sequences, transfer the plant damage state frequency to the appropriate release categories, and translate the release category frequencies into each of the four risk impacts (offsite population dose, offsite economic costs, onsite dose, and onsite economic costs). The resulting risk impacts were subtracted from the base case risk impacts to calculate the "averted" risk.

BGE 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. A bounding approach was taken to reflect the generic nature of the initial SAMA concepts and to allow each SAMA benefit to be calculated using "saved sequences" rather than requantifying the CCPRA. As a result of these bounding approximations, the benefits are generally overestimated. A more detailed evaluation of a specific enhancement may result in a significant reduction in the estimated benefit. BGE's basis for estimating the risk reduction for each design improvement is given in BGE (1998a). The corresponding risk reduction estimates (core damage frequency reduction and offsite dose reduction) are listed in Table 5-5.

The staff has reviewed BGE's bases for calculating the maximum risk reduction for the various design improvements. The staff notes that BGE used judgment in assessing the impact of each design change with regard to estimating averted offsite risk on the CCNPP risk profile. However, the rationale and assumptions on which the risk reduction estimates are based are reasonable and generally conservative. Accordingly, the staff based its estimates of averted risk for the various SAMAs on BGE's risk reduction estimates.

5.2.5 Cost Impacts of Candidate Design Improvements

BGE's method for determining costs for each potential design enhancement is described in Section 4.1.17.3 of the ER. The cost analyses for specific SAMAs are documented in Appendix F.4 of the ER. Revised cost estimates for several SAMAs are provided in the response to the NRC request for additional information (RAI), and in the presentation materials provided during a January 7, 1999, meeting with BGE (NRC 1999).

BGE developed cost estimates for each implementation option from either a site-specific cost estimate, estimates from other licensee submittals, or through application of engineering judgement. The site-specific estimates consider seven major cost categories (BGE labor, labor burden, material,

Table 5-5. Value-Impact Results for Potentially Cost Beneficial SAMAs

material handling, equipment maintenance, indirect supervision and engineering, and allowance for funds used during construction) with subcategories defined by the requirements of the proposed enhancement (e.g., development of training, nuclear regulatory matters, equipment qualification). To provide common grounds for comparison with the monetized benefits values, implementation cost estimates were calculated based on a single-unit implementation basis. The costs did not include the cost of replacement power during extended outages required to implement the modifications and did not generally include contingency costs associated with unforeseen implementation obstacles. Estimates based on modifications that were implemented or estimated in the past were presented in terms of dollar values at the time of implementation (or estimation) and were not adjusted to present-day dollars.

The staff notes that a number of simplifying assumptions appear to have been employed in developing the cost estimates. On balance, however, the staff detected no systematic bias in the resulting cost estimates due to reliance on these assumptions. For example, failure to include replacement energy costs, contingencies, and present-day dollars would tend to understate costs, whereas, calculations based on a single-unit implementation basis are likely to overstate the actual per-unit cost.

The costs for several SAMAs were singled out for review based on the estimated net value, and the potential for significant risk reduction for these SAMAs, specifically SAMAs 45, 48a, 49, and 77. For certain improvements, the staff also compared BGE's cost estimates with estimates developed elsewhere for similar improvements, even though the bases for some of these cost estimates were different. The staff considered the cost estimates developed as part of the evaluation of design improvements for operating reactors (Watts Bar, Comanche Peak, and Limerick) and for the evolutionary advanced light-water reactors.

In general, BGE's cost estimates are judged to reflect valid bases and assumptions, and their accuracy is considered sufficient to provide a reasonable and appropriate basis for the SAMAs analyses, given the uncertainties surrounding the underlying cost estimates and the level of precision necessary considering the greater uncertainty inherent on the benefit side, with which these costs were compared. Accordingly, the staff adopted BGE's cost estimates for the various candidate improvements.

5.2.6 Benefit-Cost Comparison

The benefit-cost comparison as evaluated by BGE and the staff's evaluation of the benefit-cost analysis are described in the following sections.

5.2.6.1 BGE Evaluation

The methodology used by BGE to perform the CCNPP SAMA analysis was based primarily on NRC's guidance for performing benefit-cost analysis, i.e., NUREG/BR-0184, Regulatory Analysis Technical Evaluation Handbook. In accordance with the guidance, BGE estimated the "net value" added by each SAMA to determine whether any of the SAMAs would be cost-beneficial. The net value is the sum of the dollar equivalents for each severe accident impact (offsite population exposure, offsite economic costs, onsite dose, and onsite economic costs) minus the cost of implementing the SAMA. 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 cost-beneficial.

BGE calculated the net value for each SAMA using the following formula:

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

The derivation of each of these factors is discussed below.

Averted Public Exposure

APE costs were calculated using the following formula:

BGE estimated the annual reduction in public exposure risk for each SAMA. 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 for the base case.

As stated in NUREG/BR-0184, it is important to note that the monetary value of 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

AOCs were calculated using the following formula:

AOC =	{ [Release category frequency with SAMA - release category frequency without SAMA]
	x offsite economic costs associated with release category}
	x present value conversion factor

BGE determined the offsite economic costs for each containment release category using the MACCS code. AOCs are the product of the change in the release category frequency and the offsite economic costs for each release class, summed over all release categories. Calculated values for offsite economic costs were discounted to present value in the same manner as for public exposure.

Averted Occupational Exposure

AOE was calculated using the following formula:

BGE derived the values for averted occupational exposure based on information provided in Section 5.7.3 of NUREG/BR-0184. Immediate occupational dose (3300 person-rem) and long-term occupational dose (20,000 person-rem over a 10-year cleanup period) were used for best estimate values. 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

AOSCs include averted cleanup and decontamination costs, and averted power replacement costs. BGE derived the values for AOSCs based on information provided in Section 5.7.6 of the regulatory analysis handbook. Averted cleanup costs (ACC) are calculated using the following formula:

The net present value for cleanup and decontamination of a severe accident is given as $1.1 billion in NUREG/BR-0184 (discounted over 10 years). 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 AOSCs.

Long-term replacement power costs (U_RP) are calculated using the following formula:

In accordance with guidance provided in Section 5.7.6.2 of NUREG/BR-0184, BGE estimated the net present value of replacement power for a single event to be $9.73×10⁸, based on 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. After applying a correction factor to account for CCNPP's size relative to that of the generic reactor described in NUREG/BR-0184, the U_RP were determined to be $7.3 billion. This value was multiplied by the annual reduction in core damage frequency to obtain the averted replacement costs portion of the AOSCs.

Although BGE calculated AOSCs, they chose to omit AOSCs as a benefit in the original screening and value-impact analysis submitted in the ER. Onsite property damage costs associated with cleanup and decontamination were not included on the basis that such costs are covered by property damage insurance. Replacement power costs were not included as an onsite economic cost on the basis that such costs are unlikely to be incurred by the utility in a deregulated energy market. None of the SAMAs were found to have a positive net value when AOSCs are omitted. To explore the sensitivity of the results to changes in the discount rate, BGE also recalculated the net value of the 10 most promising SAMAs (those having the highest net values) using a 3-percent discount rate in place of the 7-percent discount rate used in the base case analysis. Reducing the discount rate increases the net value of potential SAMAs and reorders their ranking, but the net value for each of the top 10 SAMAs remained negative even at the lower discount rate.

In response to a staff request, BGE provided a subsequent reassessment in which AOSCs were included as benefits. This information is described in the response to the RAI, and supplemented in the presentation materials from the January 7, 1999, meeting with BGE (NRC 1999a). BGE reviewed each of the 23 SAMAs identified in Table 4-3 of the ER to determine the revised net values when AOSCs are included as benefits. Additionally, BGE revisited the benefit estimates for all SAMAs that were screened out from consideration because the cost of enhancement exceeded the maximum possible benefit. Revised cost estimates were also developed for several SAMAs. An updated list of the 10 SAMAs with highest net values was developed. The updated list includes 9 of the 23 SAMAs identified in Table 4-3 of the ER, plus 1 SAMA originally excluded because of a high implementation cost.

Five of the top 10 SAMAs have a positive net value when AOSC are included and bounding risk reduction benefits are assumed. The remaining 5 SAMAs have a negative net value, even after including these conservative factors. Consequently, BGE performed a more-detailed evaluation of the benefits associated with these SAMAs. This evaluation attempted to (1) remove some of the conservatism in the bounding analysis by establishing a best-estimate benefit; (2) account for the impact of several changes to the CCNPP plant model that were recommended based on a contractor review of the model, but not implemented in the CCPRA used for the SAMA analysis; and (3) account for design differences between Unit 1 and Unit 2 with regard to emergency diesel generator support systems. For each SAMA, a lower bound CDF estimate, representing the minimum benefit that could be expected, was established quantitatively using the saved sequences. (The upper bound CDF estimate was based on the bounding estimate used in the original SAMA analysis.) The best-estimate risk reduction value was qualitatively established based on consideration of the degree of conservatism built into the lower-bound and upper-bound estimates. The best-estimate benefits were also adjusted to account for possible changes in the economic and evacuation time assumptions used in the MACCS analysis. Specifically, the estimates of averted offsite costs were doubled to bound possible changes to the economic input data due to inflation, and the estimates of averted public exposure were doubled to bound increased evacuation times resulting from increased population.

The three SAMAs that were still being reviewed by BGE at the time the ER was submitted were not included within the set of SAMAs discussed above. The results of BGE's further evaluation of the three SAMAs was provided in BGE (1998c). BGE has determined that one of these SAMAs may be cost-beneficial when evaluated under the assumptions used in the ER, i.e., neglecting AOSCs. This SAMA (66b), which involves installing a watertight door between the service water pump room and the adjacent fan room to reduce risk from internal flooding, is being considered under CCNPP's modification process. A second SAMA (49), which involves adding an automatic bus transfer feature, was found to be cost-beneficial when AOSCs are included, and was further evaluated under best-estimate assumptions. BGE concluded that based on the small positive net value and the fact that the estimated benefits are conservative when applied to this SAMA, this SAMA is not risk-beneficial. The remaining SAMA (96), which involves a procedure change to stagger high-pressure safety injection pump operation after a loss of saltwater cooling, was eliminated based on adverse safety impacts.

BGE's estimates of the net values for the top 10 SAMAs are presented in Table 5-5 for both bounding and best-estimate risk reduction values, and with and without AOSCs. Information related to the three additional SAMAs evaluated by BGE is also included. All SAMAs have a negative net value when AOSCs are not included. When AOSCs are included, SAMAs 34, 36, 48a, 49, 74, and 77 were found to be cost-beneficial under bounding risk reduction assumptions. Under best-estimate assumptions, the net value remains positive for only SAMAs 36, 48a, and 74, but SAMA 68 also becomes cost-beneficial. The net value for certain SAMAs (including SAMA 68) is greater under best-estimate assumptions than under bounding assumptions due to the combined effect of doubling APE and AOC benefits and accounting for modeling changes and Unit1/Unit2 differences in the best-estimate case.

BGE dispositioned certain SAMAs based on their net values under the best-estimate assumptions. BGE concluded that implementation of SAMAs 7, 34, 38b, 45, 48b, 49, and 77 is not justified under best-estimate assumptions since these SAMAs have a negative net value irrespective of whether AOSCs are included. SAMAs 36, 48a, 68, and 74, which were found to have a positive net value when AOSCs were included, were dispositioned on the basis of other considerations.

• SAMA 36, "Replace batteries with a more reliable model," was judged to be not feasible, based on the reliability record of modern lead-acid batteries, and the unproven reliability of other battery designs.
• SAMA 48a, "Convert under-voltage, AFAS block, and high pressurizer pressure logic to 3-out-of-4 logic," was judged to have a negative net value when all of the costs of the regulatory aspects of the modification are taken into account. (Some, but not all regulatory costs were included in BGE's cost estimate.)
• SAMA 68, "Install separate accumulators for the AFW cross-connect and AFW block valves," has a positive net value only when AOSCs are included in the analysis. BGE's position is that replacement power costs and insured onsite property costs are not appropriate considerations for a NEPA analysis, such as the SAMA analysis.
• SAMA 74, "Automate demineralized water (DW) make-up to condensate storage tank," has a positive net value only when AOSCs are included in the analysis. BGE's position is that replacement power costs and insured onsite property costs are not appropriate considerations for a NEPA analysis, such as the SAMA analysis.

Based on the above factors, BGE has decided not to pursue any of these SAMAs further. The staff independently considered these SAMAs further as discussed in the next section.

5.2.6.2 Staff Evaluation

The methodology used by BGE to perform the CCNPP value-impact analysis was based primarily on NUREG/BR-0184 (NRC 1997b). The only noted difference in BGE's analysis concerned omission of AOSCs in the SAMA analysis contained in the ER. The NRC's regulatory analysis guidelines in NUREG/BR-0184 consider a societal perspective in the performance of regulatory analyses and state that AOSCs, including cleanup and decontamination costs and replacement power costs, should be treated as benefits in the value impact analysis. The Commission reaffirmed the NRC staff treatment of AOSCs in regulating analyses by an SRM to SECY-99-169 (NRC 1999b). According to the regulatory analysis guidelines, insurance payments are transfer payments that do not involve consumptive use of real resources, and therefore are not a relevant basis for excluding AOSC. Similarly, NUREG/BR-0184 states that replacement power costs should be included as impacts. This handbook also states that where consideration of AOSCs is expected to alter or significantly affect results, the results should be calculated with and without AOSCs, so that the decisionmaker is fully aware of its overall effect on the benefit and cost considerations of the alternatives. In view of the significant impacts of AOSCs, the staff has chosen to display SAMA results both with and without AOSCs.

The staff confirmed BGE's SAMA identification process by performing an independent screening of those SAMAs remaining following BGE's preliminary screening. The staff estimated the net value for each SAMA with and without AOSCs. In accordance with the regulatory analysis guidance, the staff assumed a present worth discount rate of 7 percent for the base case, and performed a sensitivity case assuming a 3 percent discount rate. The staff relied on BGE's bounding estimates of core damage frequency and offsite consequence reduction (provided in BGE 1998a), BGE's cost estimates for each SAMA (provided in BGE 1998a and 1998c), and the handouts from the January 7, 1999 (NRC 1999a), public meeting with BGE. The staff used bounding risk reduction estimates to account for uncertainties in the analysis because BGE did not submit documentation on the process and assumptions used to develop best-estimate values. The staff included adjustment factors provided by BGE to account for differences in risk contributors between Unit 1 and Unit 2 because these factors led to significantly greater benefits for Unit 2 for certain SAMAs (i.e., those involving improvements to the emergency diesel generators (EDGs) and their support systems). The staff determined these values based on the cost information provided by the applicant (BGE 1998a and 1998c). The staff did not double the benefits associated with APE and AOC, as assumed in BGE's analysis, since these benefits were found to be small relative to other benefits, particularly AOSCs. Procedure improvements were included in the screening and conservatively assigned a zero cost of implementation. The staff identified those SAMAs having a positive net value greater than $100,000 and compared them to the 13 SAMAs identified by BGE (the 10 having greatest net benefit, plus the three that were still under evaluation at the time the ER was submitted).

The staff's screening identified the same six SAMAs that BGE found cost-beneficial under bounding risk reduction assumptions, and did not identify any hardware changes that were not already included within the set of SAMAs identified by BGE. However, several SAMAs involving procedure improvements were indicated to be cost-beneficial through the staff's screening. These were

SAMA 35 - Increase/improve DC bus load shedding.

SAMA 41 - Develop a severe weather conditions procedure.

SAMA 66a - Enhance procedures to improve flood mitigation guidance.

SAMA 71 - Enhance procedures for local-manual operation of AFW.

SAMA 80 - Implement a refueling water storage tank make-up procedure.

SAMA 82 - Ensure that the plant air compressors are diesel generator backed.

These SAMAs had been separately considered by BGE and eliminated in the final screening because (1) the intent of the SAMA is already addressed by current plant procedures, (2) the improvement assumed in the bounding analysis is not realistically achievable, (3) changes to some of these procedures could increase risk from other contributors, or (4) in the case of flood mitigation procedures, the procedure change would need to be re-evaluated following disposition of SAMA 66b (implement hardware modifications to prevent flood propagation).

The staff notes that the risk reduction values assumed for these SAMAs in the bounding evaluation were extremely conservative and that the risk reduction that can realistically be achieved is minimal, given that plant procedures are already in place at CCNPP in each of the above areas. The material provided during the January 7, 1999, meeting with BGE (NRC 1999a) documents additional information regarding the current procedures that address these areas. BGE has indicated that the need to modify flood mitigation procedures will be re-evaluated following disposition of SAMA 66-b and revision of the FLOOD module of the CCPRA. Elimination of the other procedure-related SAMAs for the reasons provided by BGE appears reasonable.

Based on review of the screening results, the staff notes the following:

• AOSCs are the single most important factor in the analysis. No SAMAs are cost-beneficial when AOSCs are not included, but several SAMAs are cost-beneficial when AOSCs are included in the analysis in accordance with NUREG/BR-0184.
• Onsite cleanup and decontamination costs typically account for about two-thirds of the total AOSCs, with replacement power costs accounting for the balance. Although replacement power costs represent only one-third of the AOSCs, these costs are still substantial (typically, several hundred thousand dollars after adjustment for frequency for possible cost-beneficial SAMAs). As mentioned above, six SAMAs become cost beneficial when AOSCs (both onsite cleanup and decontamination costs and replacement power costs) are included in the analysis. If only the onsite cleanup and decontamination component of AOSCs is included in the analysis, and replacement power costs are neglected, the net value for several of these SAMAs would remain negative. However, several SAMAs would continue to be cost beneficial under bounding assumptions (SAMA 34, 36, 48a, 49) and best estimate assumptions (SAMA 36, 48a).
• Use of a 3 percent discount rate increases net values, but does not lead to identification of any cost-beneficial SAMAs beyond those already identified by BGE.
• 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 that assumed a 3-percent discount rate.

The staff assessed in more detail the six potentially cost-beneficial SAMAs, recognizing the uncertainties inherent in the benefit/cost analysis and the screening nature of the analysis. A summary of this assessment, which was based on both probabilistic and deterministic considerations, follows.

Incorporate an Alternate Battery Charging Capability (34)

This proposed enhancement involves providing a portable diesel-driven generator that could be used to provide battery charging during station blackout conditions. The generator would be connected using the existing plant switchgear for the battery charger via temporary cables; a breaker would be racked out, the power feed to the battery charger would be disconnected, and the diesel generator connected in its place. With implementation of this enhancement, all long-term battery functions would be enhanced if the short-term functions are successful.

Based on the bounding risk-reduction estimate, BGE estimated that this enhancement would result in a 4 percent (1.5×10^-5/reactor-year) reduction in total CDF, and a 3 percent (2 person-rem/reactor-year) reduction in offsite dose. This assumes that the 125V bus will be available for 24 hours, given that the 125VDC batteries operate in the short term; loss of offsite power events in excess of 4 hours are eliminated; the likelihood of the 480 VAC buses experiencing common cause failure is significantly reduced; and the benefit is reduced by 20 percent to account for the possible failure of operators to recognize the failure of the installed battery chargers and to manually connect the portable chargers to the affected bus. The licensee's best-estimate risk reduction is approximately half of the bounding value.

The staff agrees that a portable diesel-driven battery charger would significantly enhance the availability of DC power for a longer time. However, batteries alone do not ensure the ability to cope with a long-term station blackout. The continued availability of condensate inventory, compressed air, heating, ventilation, and air conditioning and reactor inventory would also need to be ensured. These aspects would not generally be accounted for in the approach used by BGE to estimate risk reduction, i.e., use of saved sequences. The actual risk reduction would be significantly less than the bounding estimate, and the net value for this SAMA becomes negative when these factors are considered. The staff concludes that this improvement is not warranted because of the practical limitations on the effectiveness of this design improvement, and the relatively small estimated risk reduction that would be achieved under more realistic modeling assumptions.

Replace Batteries with a More Reliable Model (36)

This proposed enhancement involves replacing the existing batteries at CCNPP with new batteries, which are more reliable. With more reliable 125 VDC batteries, the frequency of station blackout and overall plant risk can be reduced.

Based on the bounding risk-reduction estimate, BGE estimated that this enhancement would result in a 9 percent (2.8×10^-5/reactor-year) reduction in total CDF, and a 5 percent, 0.036 person-Sv (3.6 person-rem)/reactor-year reduction in offsite dose. This assumes that all short-term battery failures and all 125 VDC bus failures at power are eliminated. The applicant's best-estimate risk reduction is approximately 75 percent of the bounding value. BGE noted that lead-acid batteries have been proven to be one of the most reliable large storage cell designs available; high specific gravity round cells installed at some plants have not proven to be more reliable than lead-acid batteries; and BGE's current requirements for weekly, quarterly, and biennial surveillance ensure an acceptable level of battery reliability.

The staff acknowledges that BGE's risk reduction estimates for this SAMA are appreciable, and that the SAMA has a positive net value under both bounding and best-estimate risk reduction assumptions when AOSCs are included. However, the level of risk reduction assumed in the analysis does not appear to be achievable, given that there are no obvious options that have proven to be more reliable than the currently installed lead-acid batteries. The actual risk reduction may be significantly less than the bounding estimate when these factors are taken into consideration. The staff concurs with BGE's arguments concerning this enhancement, and concludes that implementation of the improvement for license renewal is not warranted because of the practical limitations on its effectiveness and the relatively small estimated risk reduction that would be achieved under more realistic modeling assumptions.

Change Under-voltage, AFAS Block, and High Pressurizer Pressure Actuation Signals to 3-out-of-4 Logic (48a)

This proposed enhancement involves modifying the logic of the Under-Voltage, AFAS block, and High Pressurizer Pressure Actuation signals. The existing engineered safety features actuation system, AFAS, and Pressurizer Pressure logic modules, which are based on 2-out-of-4 logic, would be replaced with new modules based on 3-out-of-4 logic. This modification would prevent an SSSA, which is one of the most risk-significant contributors in the CCPRA model. The change to a 3-out-of-4 logic offers an advantage of preventing a spurious actuation upon failure of 2 channels in the tripped condition, but has the disadvantage of preventing actuation if 2 channels fail in the untripped condition. In either case, the system will perform correctly with a single failure.

The staff notes that the current CCNPP design meets the single failure criteria and that licensed operators at CCNPP have received training (including simulator training) in the appropriate response to an SSSA event. However, based on the bounding risk-reduction estimate, BGE estimated that this enhancement would result in a 30 percent (9.1E-5/reactor-year) reduction in total CDF, and a 17 percent, 0.11 person-Sv (11 person-rem)/reactor-year reduction in offsite dose. This estimate conservatively assumes that all failures of 120V vital AC panels, 125 VDC buses, and operator actions to align inverters to back-up power are eliminated. The licensee's best-estimate risk reduction is approximately one-third of the bounding value. The SAMA has a positive net value under both bounding and best-estimate risk reduction assumptions when AOSCs are included.

Although predicted to offer a significant risk reduction, the implementation of the SAMA may reduce the ability of the trip system to respond correctly with two failures, or a bypass and a failure. BGE appears to have considered this concern, as indicated by their statement that the risk benefit to be achieved by preventing this event from occurring exceeds the risk benefit to be expected from modifying the actuation logic, but further review would be required. The NRC would require additional justification and regulatory review to ensure that this change in logic will not unacceptably reduce the ability of the trip system to respond correctly. BGE notes that implementation of this change is expected to involve a 10 CFR 50.59 evaluation, an Unreviewed Safety Question submittal (USQ), and a revision to the CCNPP technical specifications. An estimate of the regulatory costs ($100,000) was included in the estimated cost of this SAMA, but the actual costs could vary significantly.

Although this SAMA appears to be cost beneficial, it does not relate to adequately managing the effects of aging during the period of extended operation and therefore, will not need to be implemented as part of license renewal pursuant to 10 CFR Part 54.

Add Automatic Bus Transfer Feature to Transfer Between Either the Back-up Bus or the Standby Inverter on the Failure of the Operating Inverter (49)

Upon failure of two 120 VAC vital panels, all engineered safety features actuation system, AFAS, and reactor protection system actuation modules trip. Tripping of these modules could lead to the risk-significant SSSA scenario discussed above. This SAMA involves the addition of an automatic transfer switch (ATS) feature that would automatically transfer between either the back-up bus or the standby inverter upon the failure of the operating inverter. This would minimize the potential for loss of power from a 120 VAC vital panel, and thereby reduce the frequency of the SSSA scenario.

While an ATS feature minimizes the loss of power to two 120 VAC vital panels, thereby reducing the CDF from SSSA scenarios, it also has some disadvantages. One disadvantage of an ATS feature is if failure of the operating inverter is caused by a fault on the bus or on the bus load side circuitry, placing the back-up inverter on the same bus could result in damage or failure of the back-up inverter. Another disadvantage is the potential for a failure of the ATS feature that could result in loss of both inverters. Measures must be taken for the circuitry and hardware designs along with the installation of an ATS feature to ensure that these disadvantages are adequately addressed.

The staff notes that the current CCNPP design meets the single-failure criteria and applicable regulations regarding loss of vital AC, and that loss of power from two 120 VAC vital panels is beyond the design and licensing bases for the plant. Furthermore, the licensed operators at CCNPP have received training in the appropriate response to an SSSA event.

BGE estimated the risk reduction potential for SAMA 49 using the same assumptions used for evaluating SAMA 48a, since both SAMAs address the same scenario (i.e., an SSSA scenario). Use of benefit estimates for SAMA 48a is conservative since these benefit estimates do not account for potential failure mechanisms for the ATS. Under bounding assumptions, this enhancement would result in a 30 percent (9.1×10^-5/reactor-year) reduction in total CDF, and a 17 percent, 0.11 person-Sv (11 person-rem)/reactor-year reduction in offsite dose. Under best-estimate assumptions, the risk reduction is approximately one-third of the bounding value. When AOSCs are included, the SAMA has a positive net value under bounding risk reduction assumptions, but a negative net value under best-estimate risk reduction assumptions. (In the latter case, the net value for Unit 2 is slightly positive, but is offset by a larger negative net value for Unit 1.) Based on the above, implementation is not warranted.

Automate Demineralized Water Make-Up to Condensate Storage Tank (74)

This proposed enhancement involves modifying the DW make-up to CST 12 such that it automatically makes up on the low water level in the tank, and providing a dedicated non-safety related electric diesel generator, which would automatically start and supply power to the make-up pump and associated control valves. This enhancement will improve the reliability of make-up to the service water and component cooling water head tanks (by making the demineralized water transfer pumps diesel-backed), and eliminate operator actions to align a long-term AFW supply (by designing the demineralized water make-up to automatically open on low water level in CST 12).

Based on the bounding risk-reduction estimate, BGE estimated that this enhancement would result in a 5 percent (1.7×10^-5/reactor-year) reduction in total CDF, and a 3 percent, 0.02 person-Sv (2 person-rem)/reactor-year reduction in offsite dose. This conservatively assumes that long-term AFW water supply, as well as service water and component cooling water head tank make-up, are always successful. The licensee's best-estimate risk reduction is approximately 60 percent of the bounding value. This SAMA has a positive net value under both bounding and best-estimate risk reduction assumptions when AOSCs are included.

The staff acknowledges that this enhancement has a positive net value; however, it does not relate to adequately managing the effects of aging during the period of extended operation and therefore, will not need to be implemented as part of license renewal pursuant to 10 CFR Part 54.

Increase PORV Size So That Only One PORV is Required for Successful Feed-and-Bleed (77)

This proposed enhancement involves replacing the existing PORVs, block valves, and associated discharge piping, such that only a single PORV is required to provide adequate decay heat removal. This would substantially improve the reliability of feed-and-bleed cooling since only 1-of-2 rather than 2-of-2 PORVs would be required for success. A similar modification was made to the Palisades plant in 1989, at a cost of $2.7 million, and was used as the basis for BGE's cost estimates for this SAMA.

Based on the bounding risk-reduction estimate, BGE estimated that this enhancement would result in a 46 percent (1.5×10^-4/reactor-year) reduction in total CDF, and a 45 percent, 0.31 person-Sv (31 person-rem)/ reactor-year reduction in offsite dose. This benefit is based on the conservative assumption that all AFW hardware and human-action-related failures are eliminated. The licensee's best-estimate risk reduction is approximately half of the bounding value.

The SAMA has a positive net value under bounding risk reduction assumptions when AOSCs are included. However, the level of risk reduction assumed in the bounding case does not appear to be achievable, given that all AFW hardware and human-action-related failures would not realistically be eliminated through this change. In this regard, BGE's best estimate of risk reduction appears more representative of the level of risk reduction that might be achieved. Under best-estimate risk reduction assumptions, the SAMA has a negative net value, even when AOSCs are included.

5.2.7 Conclusions

BGE completed a comprehensive effort to identify and evaluate potential cost-beneficial plant enhancements to reduce the risk associated with severe accidents at CCNPP. As a result of this assessment, BGE identified and committed to pursue one enhancement in accordance with the CCNPP modification process. This involves the installation of a watertight door between the service water pump room and the adjacent fan room to reduce the likelihood of core damage from internal flooding events. BGE also committed to further evaluate the adequacy of CCNPP procedures regarding response to internal floods following resolution of the hardware flooding enhancement. BGE concluded that no additional mitigation alternatives are cost-beneficial and warrant implementation at CCNPP.

Based on the staff's review of SAMAs for CCNPP, several SAMAs appear to be cost-beneficial when evaluated using the guidance in NUREG/BR-0184 (NRC 1997b). Three SAMAs (36, 48a, and 74) have a positive net value under both bounding and best-estimate risk reduction assumptions when AOSCs are included. The most risk-significant enhancement, SAMA 48a, has a CDF reduction of approximately 30 percent under bounding assumptions, and 10 percent under best-estimate assumptions. All remaining SAMAs have either a very small negative net value, or offer minimal risk reduction (i.e., a reduction of only a few percent) under best estimate risk reduction assumptions.

Although a limited number of SAMAs (four) appear to be cost beneficial and to offer a level of risk reduction, those SAMAs do not relate to adequately managing the effects of aging during the period of extended operation. Therefore, they need not be implemented as part of license renewal pursuant to 10 CFR Part 54.

5.3 References

10 CFR 50.59, "Changes, tests, and experiments."

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

10 CFR 51.53, "Postconstruction environmental reports."

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."

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Baltimore Gas and Electric (BGE). 1971. Supplement to Environmental Report; Calvert Cliffs Nuclear Power Plant, (November 8, 1971) Baltimore, Maryland.

Baltimore Gas and Electric (BGE). 1993. Letter from R.E. Denton, BGE, to U.S. NRC. Summary Report of Individual Plant Examination (IPE) Results (Generic Letter 88-20).

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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). 1989a. Supplement Final Environmental Statement Related to the Operation of Comanche Peak Steam Electric Station, Units I and 2, NUREG-0775. Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1989b. Letter from S. A. Varga, U.S. NRC, to G. A. Hunger, Jr., Philadelphia Electric Company. August 16, 1989. Subject: Supplement to the Final Environmental Statement - Limerick Generating Station, Units 1 and 2.

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

U.S. Nuclear Regulatory Commission (NRC). 1990b. Generic Letter 88-20, Supplement 3. "Completion of Containment Performance Improvement Program and Forwarding Insights for Use in the Individual Plant Examination for Severe Accident Vulnerabilities." Washington, D.C.

U.S. Nuclear Regulatory Commission (NRC). 1990c. 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 8