Generic Environmental 

Impact Statement for License 

Renewal of Nuclear Plants

Supplement 50

Regarding Grand Gulf

Nuclear Station, Unit 1 

Draft Report for Comment

Office of Nuclear Reactor Regulation

NUREG-1437

Supplement 50
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Generic Environmental

Impact Statement for License 

Renewal of Nuclear Plants

Supplement 50

Regarding Grand Gulf

Nuclear Station, Unit 1 

Draft Report for Comment

Manuscript Completed: October 2013

Date Published: November 2013

Office of Nuclear Reactor Regulation

NUREG-1437

Supplement 50
COMMENTS ON DRAFT REPORT

Any interested party may submit comments on this report for consideration by the NRC staff. 

Comments may be accompanied by additional relevant information or supporting data. Please 

specify the report number NUREG-1437, Supplement 50, in your comments, and send them by 

the end of the comment period specified in the Federal Register notice announcing the 

availability of this report. 

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Gallagher at 301-287-3422 or by e-mail at Carol.Gallagher@nrc.gov. 

Mail comments to: Cindy Bladey, Chief, Rules, Announcements, and Directives Branch

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(ADAMS). Do not provide information you would not want to be publicly available.
iii

1 ABSTRACT

2 This supplemental environmental impact statement (SEIS) has been prepared in response to an 

3 application submitted by Entergy Operations, Inc. (Entergy) to renew the operating license for 

4 Grand Gulf Nuclear Station, Unit 1 (GGNS), for an additional 20 years.

5 This SEIS includes the preliminary analysis that evaluates the environmental impacts of the 

6 proposed action and alternatives to the proposed action. Alternatives considered include: new 

7 nuclear generation, natural gas-fired combined-cycle generation, supercritical coal-fired 

8 generation, combination alternative, and no renewal of the license (the no-action alternative).

9 The U.S. Nuclear Regulatory Commission’s (NRC’s) preliminary recommendation is that the 

10 adverse environmental impacts of license renewal for GGNS are not great enough to deny the 

11 option of license renewal for energy-planning decisionmakers. This recommendation is based 

12 on the following:

13 • the analysis and findings in NUREG–1437, Volumes 1 and 2, Generic 

14 Environmental Impact Statement for License Renewal of Nuclear Plants, 

15 • the Environmental Report submitted by Entergy,

16 • consultation with Federal, State, local, and Tribal government agencies,

17 • the NRC’s environmental review, and

18 • consideration of public comments received during the scoping process.

v 

1 TABLE OF CONTENTS

2 ABSTRACT.............................................................................................................................. iii

3 TABLE OF CONTENTS ............................................................................................................ v

4 FIGURES.................................................................................................................................. xi

5 TABLES ................................................................................................................................. xiii

6 EXECUTIVE SUMMARY ......................................................................................................... xv

7 ABBREVIATIONS AND ACRONYMS .................................................................................... xxi

8 1.0 PURPOSE AND NEED FOR ACTION.......................................................................... 1-1

9 1.1 Proposed Federal Action..................................................................................... 1-1

10 1.2 Purpose and Need for the Proposed Federal Action ........................................... 1-1

11 1.3 Major Environmental Review Milestones............................................................. 1-2

12 1.4 Generic Environmental Impact Statement........................................................... 1-3

13 1.5 Supplemental Environmental Impact Statement.................................................. 1-6

14 1.6 Cooperating Agencies......................................................................................... 1-6

15 1.7 Consultations ...................................................................................................... 1-6

16 1.8 Correspondence ................................................................................................. 1-7

17 1.9 Status of Compliance.......................................................................................... 1-7

18 1.10 References ......................................................................................................... 1-7

19 2.0 AFFECTED ENVIRONMENT........................................................................................ 2-1

20 2.1 Facility Description.............................................................................................. 2-1

21 2.1.1 Reactor and Containment Systems ........................................................ 2-1

22 2.1.2 Radioactive Waste Management............................................................ 2-5

23 2.1.3 Nonradiological Waste Management...................................................... 2-6

24 2.1.4 Plant Operation and Maintenance .......................................................... 2-8

25 2.1.5 Power Transmission System.................................................................. 2-9

26 2.1.6 Cooling and Auxiliary Water Systems..................................................... 2-9

27 2.1.7 Facility Water Use and Quality ............................................................. 2-10

28 2.2 Surrounding Environment ................................................................................. 2-14

29 2.2.1 Land Use.............................................................................................. 2-16

30 2.2.2 Air Quality and Meteorology ................................................................. 2-17

31 2.2.3 Geologic Environment.......................................................................... 2-25

32 2.2.4 Surface Water Resources .................................................................... 2-30

33 2.2.5 Groundwater Resources ...................................................................... 2-32

34 2.2.6 Aquatic Resources ............................................................................... 2-37

35 2.2.7 Terrestrial Resources........................................................................... 2-45

36 2.2.8 Protected Species and Habitats ........................................................... 2-52

37 2.2.9 Socioeconomics ................................................................................... 2-63

38 2.2.10 Historic and Archaeological Resources ................................................ 2-76
Table of Contents

vi

1 2.3 Related Federal and State Activities ................................................................. 2-80

2 2.4 References ....................................................................................................... 2-81

3 3.0 ENVIRONMENTAL IMPACTS OF REFURBISHMENT ................................................ 3-1

4 3.1 References ......................................................................................................... 3-2

5 4.0 ENVIRONMENTAL IMPACTS OF OPERATION .......................................................... 4-1

6 4.1 Land Use ............................................................................................................ 4-1

7 4.2 Air Quality ........................................................................................................... 4-2

8 4.3 Geologic Environment......................................................................................... 4-2

9 4.3.1 Geology and Soils .................................................................................. 4-2

10 4.4 Surface Water Resources ................................................................................... 4-3

11 4.5 Groundwater Resources ..................................................................................... 4-3

12 4.5.1 Generic Groundwater Issues.................................................................. 4-3

13 4.5.2 Groundwater Use Conflicts (Ranney Wells) ........................................... 4-4

14 4.5.3 Radionuclides Released to Groundwater ............................................... 4-4

15 4.6 Aquatic Resources.............................................................................................. 4-5

16 4.6.1 Exposure of Aquatic Organisms to Radionuclides .................................. 4-6

17 4.7 Terrestrial Resources.......................................................................................... 4-6

18 4.7.1 Generic Terrestrial Resource Issues ...................................................... 4-7

19 4.7.2 Exposure of Terrestrial Organisms to Radionuclides.............................. 4-7

20 4.7.3 Effects on Terrestrial Resources (Non-cooling System Impacts)............ 4-8

21 4.8 Protected Species and Habitats.......................................................................... 4-8

22 4.8.1 Correspondence with Federal and State Agencies................................. 4-9

23 4.8.2 Species and Habitats Protected Under the Endangered Species 

24 Act.......................................................................................................... 4-9

25 4.8.3 Species Protected by the State of Mississippi ...................................... 4-12

26 4.8.4 Species Protected Under the Bald and Golden Eagle Protection 

27 Act........................................................................................................ 4-13

28 4.8.5 Species Protected Under the Migratory Bird Treaty Act........................ 4-13

29 4.9 Human Health................................................................................................... 4-13

30 4.9.1 Generic Human Health Issues.............................................................. 4-13

31 4.9.2 Radiological Impacts of Normal Operations.......................................... 4-14

32 4.9.3 Electromagnetic Fields—Acute Effects................................................. 4-17

33 4.9.4 Electromagnetic Fields—Chronic Effects.............................................. 4-18

34 4.10 Socioeconomics................................................................................................ 4-18

35 4.10.1 Generic Socioeconomic Issues ............................................................ 4-19

36 4.10.2 Housing................................................................................................ 4-19

37 4.10.3 Public Services—Public Utilities ........................................................... 4-20

38 4.10.4 Public Services—Transportation .......................................................... 4-20

39 4.10.5 Offsite Land Use .................................................................................. 4-21

40 4.10.6 Historic and Archaeological Resources ................................................ 4-22

41 4.10.7 Environmental Justice .......................................................................... 4-23
Table of Contents

vii

1 4.11 Evaluation of New and Potentially Significant Information................................. 4-29

2 4.12 Cumulative Impacts .......................................................................................... 4-30

3 4.12.1 Air Quality ............................................................................................ 4-31

4 4.12.2 Water Resources ................................................................................. 4-33

5 4.12.3 Aquatic Resources ............................................................................... 4-35

6 4.12.4 Terrestrial Resources........................................................................... 4-38

7 4.12.5 Human Health ...................................................................................... 4-40

8 4.12.6 Socioeconomics ................................................................................... 4-41

9 4.12.7 Historic and Archaeological Resources ................................................ 4-42

10 4.12.8 Summary of Cumulative Impacts.......................................................... 4-42

11 4.13 References ....................................................................................................... 4-44

12 5.0 ENVIRONMENTAL IMPACTS OF POSTULATED ACCIDENTS.................................. 5-1

13 5.1 Design-Basis Accidents ...................................................................................... 5-1

14 5.2 Severe Accidents................................................................................................ 5-2

15 5.3 Severe Accident Mitigation Alternatives .............................................................. 5-3

16 5.3.1 Overview of SAMA Process ................................................................... 5-3

17 5.3.2 Estimate of Risk ..................................................................................... 5-3

18 5.3.3 Potential Plant Improvements................................................................. 5-5

19 5.3.4 Evaluation of Risk Reduction and Costs of Improvements...................... 5-7

20 5.3.5 Cost-Benefit Comparison ..................................................................... 5-10

21 5.3.6 Conclusions ......................................................................................... 5-11

22 5.4 References ....................................................................................................... 5-12

23 6.0 ENVIRONMENTAL IMPACTS OF THE URANIUM FUEL CYCLE, 

24 SOLID WASTE MANAGEMENT, AND GREENHOUSE GAS EMISSIONS.................. 6-1

25 6.1 The Uranium Fuel Cycle ..................................................................................... 6-1

26 6.2 Greenhouse Gas Emissions ............................................................................... 6-3

27 6.2.1 Existing Studies...................................................................................... 6-3

28 6.2.2 Conclusions: Relative Greenhouse Gas Emissions............................... 6-8

29 6.3 References ....................................................................................................... 6-10

30 7.0 ENVIRONMENTAL IMPACTS OF DECOMMISSIONING............................................. 7-1

31 7.1 Decommissioning................................................................................................ 7-1

32 7.2 References ......................................................................................................... 7-2

33 8.0 ENVIRONMENTAL IMPACTS OF ALTERNATIVES.................................................... 8-1

34 8.1 New Nuclear Generation..................................................................................... 8-4

35 8.1.1 Air Quality .............................................................................................. 8-5

36 8.1.2 Groundwater Resources ........................................................................ 8-6

37 8.1.3 Surface Water Resources ...................................................................... 8-7

38 8.1.4 Aquatic Ecology ..................................................................................... 8-7

39 8.1.5 Terrestrial Ecology ................................................................................. 8-8

40 8.1.6 Human Health ........................................................................................ 8-8
Table of Contents

viii

1 8.1.7 Land Use................................................................................................ 8-8

2 8.1.8 Socioeconomics ..................................................................................... 8-9

3 8.1.9 Transportation........................................................................................ 8-9

4 8.1.10 Aesthetics ............................................................................................ 8-10

5 8.1.11 Historic and Archaeological Resources ................................................ 8-10

6 8.1.12 Environmental Justice .......................................................................... 8-11

7 8.1.13 Waste Management ............................................................................. 8-11

8 8.1.14 Summary of Impacts of New Nuclear Generation................................. 8-12

9 8.2 Natural Gas-Fired Combined-Cycle Generation................................................ 8-12

10 8.2.1 Air Quality ............................................................................................ 8-13

11 8.2.2 Groundwater Resources ...................................................................... 8-15

12 8.2.3 Surface Water Resources .................................................................... 8-16

13 8.2.4 Aquatic Ecology ................................................................................... 8-16

14 8.2.5 Terrestrial Ecology ............................................................................... 8-17

15 8.2.6 Human Health ...................................................................................... 8-17

16 8.2.7 Land Use.............................................................................................. 8-18

17 8.2.8 Socioeconomics ................................................................................... 8-18

18 8.2.9 Transportation...................................................................................... 8-19

19 8.2.10 Aesthetics ............................................................................................ 8-19

20 8.2.11 Historic and Archaeological Resources ................................................ 8-19

21 8.2.12 Environmental Justice .......................................................................... 8-20

22 8.2.13 Waste Management ............................................................................. 8-21

23 8.2.14 Summary of Impacts of NGCC Alternative ........................................... 8-21

24 8.3 Supercritical Pulverized Coal-Fired Generation................................................. 8-21

25 8.3.1 Air Quality ............................................................................................ 8-23

26 8.3.2 Groundwater Resources ...................................................................... 8-25

27 8.3.3 Surface Water Resources .................................................................... 8-26

28 8.3.4 Aquatic Ecology ................................................................................... 8-26

29 8.3.5 Terrestrial Ecology ............................................................................... 8-27

30 8.3.6 Human Health ...................................................................................... 8-28

31 8.3.7 Land Use.............................................................................................. 8-28

32 8.3.8 Socioeconomics ................................................................................... 8-29

33 8.3.9 Transportation...................................................................................... 8-29

34 8.3.10 Aesthetics ............................................................................................ 8-30

35 8.3.11 Historic and Archaeological Resources ................................................ 8-30

36 8.3.12 Environmental Justice .......................................................................... 8-31

37 8.3.13 Waste Management ............................................................................. 8-31

38 8.3.14 Summary of Impacts of SCPC Alternative ............................................ 8-32
Table of Contents

ix

1 8.4 Combination Alternative.................................................................................... 8-32

2 8.4.1 Air Quality ............................................................................................ 8-34

3 8.4.2 Groundwater Resources ...................................................................... 8-36

4 8.4.3 Surface Water Resources .................................................................... 8-37

5 8.4.4 Aquatic Ecology ................................................................................... 8-37

6 8.4.5 Terrestrial Ecology ............................................................................... 8-38

7 8.4.6 Human Health ...................................................................................... 8-39

8 8.4.7 Land Use.............................................................................................. 8-40

9 8.4.8 Socioeconomics ................................................................................... 8-41

10 8.4.9 Transportation...................................................................................... 8-42

11 8.4.10 Aesthetics ............................................................................................ 8-42

12 8.4.11 Historic and Archaeological Resources ................................................ 8-43

13 8.4.12 Environmental Justice .......................................................................... 8-44

14 8.4.13 Waste Management ............................................................................. 8-45

15 8.4.14 Summary of Impacts of Combination Alternative .................................. 8-45

16 8.5 Alternatives Considered But Dismissed ............................................................ 8-46

17 8.5.1 Demand-Side Management.................................................................. 8-46

18 8.5.2 Wind Power.......................................................................................... 8-47

19 8.5.3 Solar Power ......................................................................................... 8-48

20 8.5.4 Hydroelectric Power ............................................................................. 8-48

21 8.5.5 Wave and Ocean Energy ..................................................................... 8-49

22 8.5.6 Geothermal Power ............................................................................... 8-49

23 8.5.7 Municipal Solid Waste.......................................................................... 8-49

24 8.5.8 Biomass ............................................................................................... 8-50

25 8.5.9 Oil-Fired Power .................................................................................... 8-51

26 8.5.10 Fuel Cells ............................................................................................. 8-51

27 8.5.11 Purchased Power................................................................................. 8-51

28 8.5.12 Delayed Retirement.............................................................................. 8-52

29 8.6 No-Action Alternative ........................................................................................ 8-52

30 8.6.1 Air Quality ............................................................................................ 8-52

31 8.6.2 Groundwater Resources ...................................................................... 8-52

32 8.6.3 Surface Water Resources .................................................................... 8-53

33 8.6.4 Aquatic Ecology ................................................................................... 8-53

34 8.6.5 Terrestrial Ecology ............................................................................... 8-53

35 8.6.6 Human Health ...................................................................................... 8-53

36 8.6.7 Land Use.............................................................................................. 8-53

37 8.6.8 Socioeconomics ................................................................................... 8-53

38 8.6.9 Transportation...................................................................................... 8-54

39 8.6.10 Aesthetics ............................................................................................ 8-54

40 8.6.11 Historic and Archaeological Resources ................................................ 8-54
Table of Contents

x 

1 8.6.12 Environmental Justice .......................................................................... 8-54

2 8.6.13 Waste Management ............................................................................. 8-54

3 8.6.14 Summary of Impacts of Combination Alternative .................................. 8-54

4 8.7 Alternatives Summary....................................................................................... 8-55

5 8.8 References ....................................................................................................... 8-58

6 9.0 CONCLUSION.............................................................................................................. 9-1

7 9.1 Environmental Impacts of License Renewal........................................................ 9-1

8 9.2 Comparison of Alternatives ................................................................................. 9-1

9 9.3 Resource Commitments...................................................................................... 9-2

10 9.3.1 Unavoidable Adverse Environmental Impacts ........................................ 9-2

11 9.3.2 Short-Term Versus Long-Term Productivity ........................................... 9-2

12 9.3.3 Irreversible and Irretrievable Commitments of Resources ...................... 9-3

13 9.4 Recommendations.............................................................................................. 9-3

14 10.0 LIST OF PREPARERS ............................................................................................... 10-1

15 11.0 LIST OF AGENCIES, ORGANIZATIONS, AND PERSONS TO WHOM 

16 COPIES OF THIS SEIS ARE SENT ........................................................................... 11-1

17 12.0 INDEX......................................................................................................................... 12-1

18 APPENDIX A COMMENTS RECEIVED ON THE GGNS ENVIRONMENTAL 

19 REVIEW ......................................................................................................... A-1 

20 APPENDIX B NATIONAL ENVIRONMENTAL POLICY ACT ISSUES FOR 

21 LICENSE RENEWAL OF NUCLEAR POWER PLANTS................................ B-1 

22 APPENDIX C APPLICABLE REGULATIONS, LAWS, AND AGREEMENTS ...................... C-1 

23 APPENDIX D CONSULTANT CORRESPONDENCE........................................................... D-1 

24 APPENDIX E CHRONOLOGY OF ENVIRONMENTAL REVIEW 

25 CORRESPONDENCE .................................................................................... E-1 

26 APPENDIX F U.S. NUCLEAR REGULATORY COMMISSION STAFF 

27 EVALUATION OF SEVERE ACCIDENT MITIGATION 

28 ALTERNATIVES FOR GRAND GULF NUCLEAR STATION IN 

29 SUPPORT OF LICENSE RENEWAL APPLICATION REVIEW ..................... F-1 
Table of Contents

xi

1 FIGURES

2 Figure 1–1. Environmental Review Process ........................................................................ 1-2

3 Figure 1–2. Environmental Issues Evaluated During License Renewal ............................... 1-5

4 Figure 2–1. Location of GGNS, 50-mi (80-km) Vicinity ........................................................ 2-2

5 Figure 2–2. Location of GGNS, 6-mi (10-km) Vicinity .......................................................... 2-3

6 Figure 2–3. GGNS, General Site Layout ............................................................................. 2-4

7 Figure 2–4. Plan (Map) View and Cross Section View of Ranney Well at GGNS .............. 2-12

8 Figure 2–5. GGNS Ranney Well Locations ....................................................................... 2-13

9 Figure 2–6. GGNS Upland Complex Aquifer Permitted Wells............................................ 2-15

10 Figure 2–7. Topographic Map of GGNS Facility ................................................................ 2-16

11 Figure 2–8. GGNS Wind at 33-ft (10-m) and 162-ft (50-m), 2006–2011 ............................ 2-19

12 Figure 2–9. Location Map for Geologic Cross-Sections A-A' and B-B' ............................... 2-27

13 Figure 2–10. Geologic Cross Section A-A' .......................................................................... 2-28

14 Figure 2–11. Geologic Cross Section B-B' .......................................................................... 2-29

15 Figure 2–12. GGNS Surface Water Features ...................................................................... 2-31

16 Figure 2–13. Most Recent GGNS Tritium Contaminated Well Data from 

17 February 2012................................................................................................ 2-36

18 Figure 2–14. GGNS Property Habitat Types ....................................................................... 2-47

19 Figure 4–1. 2010 Census Minority Block Groups Within a 50-mi Radius of GGNS............ 4-26

20 Figure 4–2. 2010 Census Low-Income Block Groups Within a 50-mi Radius of 

21 GGNS ............................................................................................................ 4-27

Table of Contents

xiii

1 TABLES

2 Table ES–1. NRC Conclusions Relating to Site-Specific Impacts of License 

3 Renewal ........................................................................................................... xvii

4 Table 2–1. Permitted Maximum Allowable Emission Limits for Criteria Air 

5 Pollutants and Volatile Organic Compounds (VOCs) and Estimated 

6 Annual CO2e Emission Rate at GGNS ............................................................ 2-22

7 Table 2–2. National Ambient Air Quality Standards (NAAQS) .......................................... 2-23

8 Table 2–3. Dominant Vegetation by Habitat Type ............................................................ 2-48

9 Table 2–4. Most Common or Abundant Wildlife Documented on GGNS .......................... 2-50

10 Table 2–5. Transmission Line Corridor Land Use by Area................................................ 2-52

11 Table 2–6. Federally and State-Listed Species ................................................................ 2-55

12 Table 2–7. 2009 GGNS Employee Residence by County................................................. 2-64

13 Table 2–8. Housing in GGNS ROI.................................................................................... 2-64

14 Table 2–9. Claiborne County Public Water Supply Systems............................................. 2-65

15 Table 2–10. Major Commuting Routes Near GGNS 2011 Average Annual Daily 

16 Traffic ............................................................................................................. 2-66

17 Table 2–11. Population and Percent Growth in GGNS ROI Counties from 

18 1970–2009 and Projected for 2010–2050....................................................... 2-68

19 Table 2–12. Demographic Profile of the Population in the GGNS ROI in 2010................... 2-69

20 Table 2–13. 2010 Seasonal Housing in Counties within 50 miles of GGNS........................ 2-70

21 Table 2–14. Migrant Farm Workers and Temporary Farm Labor in Counties 

22 Located within 50 Miles of GGNS................................................................... 2-72

23 Table 2–15. Major Employers of the GGNS ROI in 2012.................................................... 2-74

24 Table 2–16. Estimated Income Information for the GGNS ROI in 2010 .............................. 2-75

25 Table 2–17. 2007–2012 Unemployment Rates in the GGNS ROI ...................................... 2-75

26 Table 3–1. Category 1 Issues Related to Refurbishment.................................................... 3-1

27 Table 3–2. Category 2 Issues Related to Refurbishment.................................................... 3-2

28 Table 4–1. Land Use Issues............................................................................................... 4-1

29 Table 4–2. Air Quality Issues.............................................................................................. 4-2

30 Table 4–3. Surface Water Issues ....................................................................................... 4-3

31 Table 4–4. Groundwater Issues.......................................................................................... 4-3

32 Table 4–5. Aquatic Resource Issues .................................................................................. 4-6

33 Table 4–6. Terrestrial Resource Issues.............................................................................. 4-7

34 Table 4–7. Threatened or Endangered Species ................................................................. 4-8

35 Table 4–8. Human Health Issues ..................................................................................... 4-13

36 Table 4–9. Socioeconomics Issues .................................................................................. 4-19

37 Table 4–10. Summary of Cumulative Impacts on Resource Areas ..................................... 4-43

38 Table 5–1. Issues Related to Postulated Accidents............................................................ 5-2

39 Table 5–2. GGNS Core Damage Frequency (CDF) for Internal Events.............................. 5-4

40 Table 5–3. Base Case Mean Population Dose Risk and Offsite Economic Cost 

41 Risk for Internal Events..................................................................................... 5-6

42 Table 5–4. Severe Accident Mitigation Alternatives Cost-Benefit Analysis for 

43 GGNS............................................................................................................... 5-8
Table of Contents

xiv

1 Table 5–5. Estimated Cost Ranges for SAMA Applications .............................................. 5-10

2 Table 6–1. Issues Related to the Uranium Fuel Cycle and Solid Waste 

3 Management. ................................................................................................... 6-1

4 Table 6–2. Nuclear Greenhouse Gas Emissions Compared to Coal .................................. 6-6

5 Table 6–3. Nuclear Greenhouse Gas Emissions Compared to Natural Gas....................... 6-7

6 Table 6–4. Nuclear Greenhouse Gas Emissions Compared to Renewable Energy 

7 Sources ............................................................................................................ 6-8

8 Table 7–1. Issues Related to Decommissioning ................................................................. 7-1

9 Table 8–1. Summary of Alternatives Considered In Depth ................................................. 8-4

10 Table 8–2. Summary of Environmental Impacts of the New Nuclear Alternative 

11 Compared to Continued Operation of GGNS.................................................. 8-12

12 Table 8–3. Summary of Environmental Impacts of the NGCC Alternative 

13 Compared to Continued Operation of GGNS.................................................. 8-21

14 Table 8–4. Summary of Environmental Impacts of the SCPC Alternative 

15 Compared to Continued Operation of GGNS.................................................. 8-32

16 Table 8–5. Summary of Environmental Impacts of the Combination Alternative 

17 Compared to Continued Operation of GGNS.................................................. 8-46

18 Table 8–6. Summary of Environmental Impacts of the No-action Alternative 

19 Compared to Continued Operation of GGNS.................................................. 8-55

20 Table 8–7. Summary of Environmental Impacts of Proposed Action and 

21 Alternatives..................................................................................................... 8-57

22 Table 10–1. List of Preparers ............................................................................................. 10-1

23 Table A–1. Individuals Who Provided Comments During the Scoping Comment 

24 Period.................................................................................................................. 1

25 Table B–1. Summary of Issues and Findings......................................................................... 1

26 Table C–1. Federal and State Environmental Requirements............................................... C-1

27 Table C–2. Licenses and Permits ....................................................................................... C-4

28 Table D-1. Consultation Correspondence .......................................................................... D-1

29 Table E–1. Environmental Review Correspondence.............................................................. 1

30 Table F–1. Grand Gulf Nuclear Station Core Damage Frequency (CDF) for 

31 Internal Events.................................................................................................. F-4

32 Table F–2. Base Case Mean Population Dose Risk and Offsite Economic Cost 

33 Risk for Internal Events..................................................................................... F-5

34 Table F–3. Major GGNS Probabilistic Safety Assessment (PSA) Models ........................... F-7

35 Table F–4. GGNS Fire IPEEE Core Damage Frequency (CDF) Results for 

36 Unscreened Compartments............................................................................ F-13

37 Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for 

38 Grand Gulf Nuclear Station............................................................................. F-24

39 Table F–6. Estimated Cost Ranges for SAMA Applications .............................................. F-36
xv 

1 EXECUTIVE SUMMARY

2 BACKGROUND

3 By letter dated October 28, 2011, Entergy Operations, Inc. (Entergy) submitted an application to 

4 the U.S. Nuclear Regulatory Commission (NRC) to issue a renewed operating license for Grand 

5 Gulf Nuclear Station, Unit 1 (GGNS), for an additional 20-year period.

6 Pursuant to Title 10, Part 51.20(b)(2) of the Code of Federal Regulations (10 CFR 51.20(b)(2)), 

7 the renewal of a power reactor operating license requires preparation of an environmental 

8 impact statement (EIS) or a supplement to an existing EIS. In addition, 10 CFR 51.95(c) states 

9 that the NRC shall prepare an EIS, which is a supplement to the Commission’s NUREG-1437, 

10 Generic Environmental Impact Statement (GEIS) for License Renewal of Nuclear Plants. 

11 Upon acceptance of Entergy’s application, the NRC staff began the environmental review 

12 process described in 10 CFR Part 51 by publishing a notice of intent to prepare a supplemental 

13 EIS (SEIS) and conduct scoping. In preparation of this SEIS for GGNS, the NRC staff 

14 performed the following:

15 • conducted public scoping meetings on January 31, 2012, in 

16 Port Gibson, Mississippi;

17 • conducted a site audit at the plant in March 2012;

18 • reviewed Entergy’s environmental report (ER) and compared it to the GEIS; 

19 • consulted with other agencies;

20 • conducted a review of the issues following the guidance set forth in 

21 NUREG-1555, “Standard Review Plans for Environmental Reviews for 

22 Nuclear Power Plants, Supplement 1: Operating License Renewal”; and 

23 • considered public comments received during the scoping process.

24 PROPOSED ACTION

25 Entergy initiated the proposed Federal action—issuing a renewed power reactor operating 

26 license—by submitting an application for license renewal of GGNS, for which the existing 

27 license (NPF-29) for GGNS, will expire on November 1, 2024. The NRC’s Federal action is the 

28 decision whether or not to renew the license for an additional 20 years.

29 PURPOSE AND NEED FOR ACTION

30 The purpose and need for the proposed action (issuance of a renewed license) is to provide an 

31 option that allows for power generation capability beyond the term of the current nuclear power 

32 plant operating license to meet future system generating needs. Such needs may be 

33 determined by other energy-planning decisionmakers, such as state, utility, and—where 

34 authorized, Federal (other than NRC). This definition of purpose and need reflects the NRC’s 

35 recognition that, unless there are findings in the safety review required by the Atomic Energy 

36 Act or findings in the National Environmental Policy Act (NEPA) environmental analysis that 

37 would lead the NRC to reject a license renewal application, the NRC does not have a role in the 

38 energy planning decisions of whether a particular nuclear power plant should continue to 

39 operate.
Executive Summary

xvi

1 If the renewed license is issued, the appropriate energy-planning decisionmakers, along with 

2 Entergy, will ultimately decide if the reactor unit will continue to operate based on factors such 

3 as the need for power. If the operating license is not renewed, then the facility must be shut 

4 down on or before the expiration date of the current operating license—November 1, 2024.

5 ENVIRONMENTAL IMPACTS OF LICENSE RENEWAL

6 The SEIS evaluates the potential environmental impacts of the proposed action. The 

7 environmental impacts from the proposed action are designated as SMALL, MODERATE, or 

8 LARGE. As set forth in the GEIS, Category 1 issues are those that meet all of the following 

9 criteria:

10 • The environmental impacts associated with the issue 

11 is determined to apply either to all plants or, for some 

12 issues, to plants having a specific type of cooling 

13 system or other specified plant or site characteristics.

14 • A single significance level (i.e., SMALL, MODERATE, 

15 or LARGE) has been assigned to the impacts, except 

16 for collective offsite radiological impacts from the fuel 

17 cycle and from high-level waste and spent fuel

18 disposal.

19 • Mitigation of adverse impacts associated with the 

20 issue is considered in the analysis, and it has been 

21 determined that additional plant-specific mitigation

22 measures are likely not to be sufficiently beneficial to 

23 warrant implementation.

24 For Category 1 issues, no additional site-specific analysis is required in this SEIS unless new 

25 and significant information is identified. Chapter 4 of this report presents the process for 

26 identifying new and significant information. Site-specific issues (Category 2) are those that do 

27 not meet one or more of the criterion for Category 1 issues; therefore, an additional site-specific 

28 review for these non-generic issues is required, and the results are documented in the SEIS.

29 On June 20, 2013, the NRC published a final rule (78 FR 37282) revising its environmental 

30 protection regulation, 10 CFR Part 51, “Environmental Protection Regulations for Domestic 

31 Licensing and Related Regulatory Functions.” The final rule updates the potential 

32 environmental impacts associated with the renewal of an operating license for a nuclear power 

33 reactor for an additional 20 years. A revised GEIS, which updates the 1996 GEIS, provides the 

34 technical basis for the final rule. The revised GEIS specifically supports the revised list of NEPA

35 issues and associated environmental impact findings for license renewal contained in Table B–1 

36 in Appendix B to Subpart A of the revised 10 CFR Part 51. The final rule consolidates similar 

37 Category 1 and 2 issues, changes some Category 2 issues into Category 1 issues, and 

38 consolidates some of those issues with existing Category 1 issues. The final rule also adds new 

39 Category 1 and 2 issues.

40 The final rule became effective 30 days after publication in the Federal Register. Compliance 

41 by license renewal applicants is not required until 1 year from the date of publication 

42 (i.e., license renewal environmental reports submitted later than 1 year after publication must be 

43 compliant with the new rule). Nevertheless, under NEPA, the NRC must now consider and 

44 analyze, in its license renewal SEISs, the potential significant impacts described by the revised 

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.
Executive Summary

xvii

1 rule’s new Category 2 issues, and to the extent there is any new and significant information, the 

2 potential significant impacts described by the revised rule’s new Category 1 issues.

3 The NRC staff has reviewed Entergy’s established process for identifying and evaluating the 

4 significance of any new and significant information (including the consideration and analysis of 

5 new issues associated with the recently approved revision to 10 CFR Part 51) on the 

6 environmental impacts of license renewal of GGNS. Neither Entergy nor NRC identified 

7 information that is both new and significant related to Category 1 issues that would call into 

8 question the conclusions in the GEIS. This conclusion is supported by NRC’s review of the 

9 applicant’s ER, other documentation relevant to the applicant’s activities, the public scoping

10 process and substantive comments raised, and the findings from the environmental site audit 

11 conducted by NRC staff. Further, the NRC staff did not identify any new issues applicable to 

12 GGNS that have a significant environmental impact. The NRC staff, therefore, relies upon the 

13 conclusions of the GEIS for all Category 1 issues applicable to GGNS.

14 Table ES-1 summarizes the Category 2 issues applicable to GGNS, if any, as well as the NRC 

15 staff’s findings related to those issues. If the NRC staff determined that there were no 

16 Category 2 issues applicable for a particular resource area, the findings of the GEIS, as 

17 documented in Appendix B to Subpart A of 10 CFR Part 51, stand.

18 Table ES–1. NRC Conclusions Relating to Site-Specific Impacts of License Renewal

Resource Area Relevant Category 2 Issues Adverse Impacts

Land Use None SMALL

Air Quality None SMALL

Geology and Soils None SMALL

Surface Water Resources None SMALL

Groundwater Resources

Groundwater use conflicts

Radionuclides released to groundwater

SMALL

SMALL

Aquatic Resources None SMALL

Terrestrial Resources Non-cooling system impacts SMALL

Protected Species Threatened or endangered species

No effect/ may affect, but 

is not likely to adversely 

affect(a)

Human Health Issues Electromagnetic fields—acute effects SMALL

Socioeconomics

Housing Impacts

Public services (public utilities)

Offsite land use

Public services (public transportation)

Historic & archaeological resources

SMALL

Cumulative Impacts

Aquatic Resources

Terrestrial Resources

Protected Species & Habitats

All other evaluated resources

MODERATE

MODERATE

May affect, but is not 

likely to adversely affect(a)

SMALL

(a): For Federally protected species, the GEIS and the final rule state that, in complying with the Endangered 

Species Act (ESA), the NRC will report the effects of continued operations and refurbishment in terms of its ESA 

findings, which varies by species for GGNS.

19 With respect to environmental justice, the NRC staff has determined that there would be no 

20 disproportionately high and adverse impacts to these populations from the continued operation 

21 of GGNS during the license renewal period. Additionally, the NRC staff has determined that no 
Executive Summary

xviii

1 disproportionately high and adverse human health impacts would be expected in special 

2 pathway receptor populations in the region as a result of subsistence consumption of water, 

3 local food, fish, and wildlife. 

4 SEVERE ACCIDENT MITIGATION ALTERNATIVES

5 Since GGNS had not previously considered alternatives to reduce the likelihood or potential 

6 consequences of a variety of highly uncommon, but potentially serious, accidents at GGNS, 

7 10 CFR 51.53(c)(3)(ii)(L) requires that Entergy evaluate severe accident mitigation alternatives 

8 (SAMAs) in the course of the license renewal review. SAMAs are potential ways to reduce the 

9 risk or potential impacts of uncommon, but potentially severe accidents, and they may include 

10 changes to plant components, systems, procedures, and training.

11 The NRC staff reviewed the ER’s evaluation of potential SAMAs. Based on the staff’s review, 

12 the NRC staff concluded that none of the potentially cost beneficial SAMAs relate to adequately 

13 managing the effects of aging during the period of extended operation. Therefore, they need 

14 not be implemented as part of the license renewal, pursuant to 10 CFR Part 54.

15 ALTERNATIVES

16 The NRC staff considered the environmental impacts associated with alternatives to license 

17 renewal. These alternatives include other methods of power generation and not renewing the 

18 GGNS operating license (the no-action alternative). Replacement power options considered 

19 were as follows:

20 • new nuclear generation,

21 • natural gas-fired combined-cycle generation,

22 • supercritical pulverized coal-fired generation, and

23 • combination alternative. 

24 The NRC staff initially considered a number of additional alternatives for analysis as alternatives 

25 to license renewal of GGNS; these were later dismissed due to technical, resource availability, 

26 or commercial limitations that currently exist and that the NRC staff believes are likely to 

27 continue to exist when the existing GGNS license expire. The no-action alternative by the NRC 

28 staff, and the effects it would have, were also considered. Where possible, the NRC staff 

29 evaluated potential environmental impacts for these alternatives located both at the GGNS site 

30 and at some other unspecified alternate location. Alternatives considered, but dismissed, were 

31 as follows:

32 • energy conservation and energy efficiency,

33 • wind power,

34 • solar power,

35 • hydroelectric power,

36 • wave and ocean energy,

37 • geothermal power,

38 • municipal solid waste, 

39 • biomass,

40 • oil-fired power,

41 • fuel cells,

42 • purchased power, and

43 • delayed retirement.
Executive Summary

xix

1 The NRC staff evaluated each alternative using the same impact areas that were used in 

2 evaluating impacts from license renewal.

3 RECOMMENDATION

4 The NRC’s preliminary recommendation is that the adverse environmental impacts of license 

5 renewal for GGNS are not great enough to deny the option of license renewal for 

6 energy-planning decisionmakers. This recommendation is based on the following:

7 • analysis and findings in the GEIS, 

8 • ER submitted by Entergy,

9 • consultation with Federal, State, local, and Tribal government agencies,

10 • NRC staff’s own independent review, and

11 • consideration of public comments received during the scoping process.

xxi

1 ABBREVIATIONS AND ACRONYMS

2 °C degree(s) Celsius

3 °F degree(s) Fahrenheit

4 AADT average annual daily traffic 

5 AAI American Aquatics, Inc.

6 ac acre(s)

7 ACAA American Coal Ash Association

8 ACC averted cleanup and decontamination costs

9 ACHP Advisory Council on Historic Preservation

10 ADAMS Agencywide Documents Access and Management System

11 AEA Atomic Energy Authority

12 AEC U.S. Atomic Energy Commission

13 ALARA as low as is reasonably achievable

14 ANL Argonne National Laboratory

15 ANS American Nuclear Society

16 AOC averted offsite property damage costs

17 AOE averted occupation exposure

18 AOSC averted onsite costs

19 APE averted public exposure

20 AQCR air quality control region 

21 AQRV air quality related values

22 ARI Alternative Resources, Inc.

23 ASME American Society of Mechanical Engineering

24 BACT Best Available Control Technology

25 BEA U.S. Bureau of Economic Analysis

26 BLM Bureau of Land Management

27 BLS U.S. Bureau of Labor Statistics

28 BMPs best management practices

29 BP before present

30 Btu British thermal unit(s)

31 Btu/kWh British thermal units per kilowatt-hour

32 Btu/lb British thermal units per pound

33 BWR boiling water reactor

34 BWROG BWR Owners Group
Abbreviations and Acronyms

xxii

1 CAA Clean Air Act

2 CAES compressed air energy storage

3 CAPS Circular Area Profiling System

4 CCDPs conditional core damage probabilities

5 CCP coal combustion products

6 CDF core damage frequency

7 CDM Clean Development Mechanism

8 Ceq/kWh carbon equivalent per kilowatt-hour

9 CEQ Council on Environmental Quality

10 CET containment event tree

11 CFR Code of Federal Regulations

12 cfs cubic feet per second

13 CH4 methane

14 cm centimeter(s)

15 CNWRA Center for Nuclear Waste Regulatory Analyses

16 CO carbon monoxide 

17 CO2 carbon dioxide

18 CO2e carbon dioxide equivalent

19 COE cost of enhancement

20 COL combined license

21 CP construction permit

22 CS&I Crossroads, Shiloh & Ingleside

23 CWA Clean Water Act

24 CZMA Coastal Zone Management Act

25 dBA decibels adjusted

26 DBA design-basis accident

27 DC direct current

28 DOE U.S. Department of Energy

29 DOT Department of Transportation

30 DSEIS draft Supplemental Environmental Impact Statement

31 DSM demand-side management 

32 EA Environmental Assessment

33 EAC Electricity Advisory Committee

34 EDG emergency diesel generator

35 EHV Extra High Voltage
Abbreviations and Acronyms

xxiii

1 EIA Energy Information Administration

2 EIS environmental impact statement

3 ELF-EMF extremely low frequency-electromagnetic field

4 EMI Entergy Mississippi, Inc

5 EMS environmental management systems

6 Entergy Entergy Operations, Inc.

7 EO Executive Order

8 EPA U.S. Environmental Protection Agency 

9 EPCRA Emergency Planning and Community Right-to-Know Act

10 EPRI Electric Power Research Institute

11 EPU extended power uprate

12 ER Environmental Report 

13 ESA Endangered Species Act of 1973, as amended

14 ESBWR Economic Simplified Boiling Water Reactor

15 ESP early site permit

16 FEIS final environmental impact statement

17 FEMA U.S. Federal Emergency Management Agency

18 FERC Federal Energy Regulatory Commission

19 FES final environmental statement

20 FIVE Fire-Induced Vulnerability Evaluation

21 FLMs Federal Land Managers

22 FONSI Finding of No Significant Impact

23 FR Federal Register

24 ft foot (feet)

25 ft/s feet per second

ft3 26 cubic feet

27 FWS U.S. Fish and Wildlife Service

28 gal gallon(s)

29 gal/yr gallons per year

30 GE General Electric 

31 GEA Geothermal Energy Association

32 GEIS Generic Environmental Impact Statement for License Renewal of 

33 Nuclear Power Plants, NUREG–1437

34 GGNS Grand Gulf Nuclear Station

35 GHG greenhouse gas
Abbreviations and Acronyms

xxiv

1 GI Generic Issue

2 gpd gallons per day

3 gpm gallons per minute

4 GSI Generic Safety Issue

5 GW gigawatt(s)

6 GWh gigawatthour(s)

7 ha hectare(s)

8 HAPs hazardous air pollutants

9 H/E high early

10 HFCs hydrofluorocarbons

11 HMR Hydro Meteorological Reports

12 HPCS high-pressure core spray

13 HVAC heating, ventilation, and air conditioning

14 IAEA International Atomic Energy Agency

15 IEEE Institute of Electrical and Electronics Engineers

16 IGCC integrated gasification combined-cycle 

17 in. inch(es)

18 INEEL Idaho National Engineering and Environmental Laboratory

19 IPCC Intergovernmental Panel on Climate Change

20 IPE individual plant examination

21 IPEEE individual plant examination of external events

22 ISFSI Independent Spent Fuel Storage Installation

23 kg kilogram(s)

24 km kilometer(s)

km2 25 square kilometers

26 kV kilovolt(s)

27 kWh kilowatthour(s)

28 lb pound(s)

29 lb/MWh pounds per megawatthour

30 LERF large early release frequency

31 LOCA Loss of Coolant Accident

32 LOSP loss of offsite power

33 LRA license renewal application

34 m meter(s)

35 m/s meters per second
Abbreviations and Acronyms

xxv 

m2 1 square meters

m3 2 cubic meters

m3 3 /s cubic meters per second 

m3 4 /yr cubic meters per year

5 mA milliampere(s)

6 MAAP Modular Accident Analysis Program

7 MACCS2 MELCOR Accident Consequence Code System 2 

8 MBTA Migratory Bird Treaty Act of 1918, as amended

9 MCEQ Mississippi Commission on Environmental Quality

10 MCR model change request

11 MDAH Mississippi Department of Archives and History

12 MDEQ Mississippi Department of Environmental Quality

13 MDES Mississippi Department of Employment Security

14 MDH Mississippi Department of Health

15 MDEQ Mississippi Department of Environmental Quality

16 MDOT Mississippi Department of Transportation

17 MDWFP Mississippi Department of Wildlife, Fisheries, and Parks

18 mg/L milligrams per liter

19 mGy milligray

20 mi mile(s)

mi2 21 square miles

22 MIHL Mississippi Institutions of Higher Learning

23 millirem milliroentgen equivalent man

24 mm millimeter(s)

25 MMBtu/MWh one million Btu per megawatthour

26 MMNS Mississippi Museum of Natural Science

27 MNHP Mississippi Natural Heritage Program

28 MMPA Marine Mammal Protection Act

29 MP&L Mississippi Power & Light Company

30 mph miles per hour

31 mrad milliradiation absorbed dose

32 mrem milliroentgen equivalent man

33 MSA Magnuson–Stevens Fishery Conservation and Management Act, 

34 as amended through January 12, 2007

35 MSCEQ Mississippi Commission of Environmental Quality
Abbreviations and Acronyms

xxvi 

1 MSL mean sea level

2 mSv millisievert

3 MT metric ton(s)

4 MTHM metric ton of heavy metal

5 MWd/MTU megawatt-days per metric ton of uranium

6 MWe megawatt(s) electrical 

7 MWt megawatt(s) thermal

8 N2O nitrous oxide

9 NAAQS National Ambient Air Quality Standards

10 NAS National Academy of Sciences

11 NASS National Agricultural Statistics Service

12 NCDC National Climatic Data Center

13 NCES National Center for Education Statistics

14 NCF no containment failure

15 NEA Nuclear Energy Agency

16 NEI Nuclear Energy Institute

17 NEPA National Environmental Policy Act

18 NESC National Electrical Safety Code

19 NETL National Energy Technology Laboratory

20 NGCC natural-gas-fired combined-cycle 

21 NHPA National Historic Preservation Act

22 NIEHS National Institute of Environmental Health Sciences

23 NMFS National Marine Fisheries Service

24 NOAA National Oceanic and Atmospheric Administration 

25 NOx nitrogen oxide(s)

26 NPDES National Pollution Discharge Elimination System 

27 NRC U.S. Nuclear Regulatory Commission 

28 NRCS National Resources Conservation Service

29 NREL National Renewable Energy Laboratory

30 NRHP National Register of Historic Places

31 NRR Office of Nuclear Reactor Regulation

32 NS Nuclear Station

33 NUREG NRC technical report designation (Nuclear Regulatory 

34 Commission)

35 O3 ozone
Abbreviations and Acronyms

xxvii 

1 ODCM Offsite Dose Calculation Manual

2 OECD Organization for Economic Co-operation and Development

3 OECR offsite economic cost risk

4 PAH polycyclic aromatic hydrocarbon

5 Pb lead

6 pCi/L picocuries per liter

7 PDR population dose risk

8 PDS plant damage state

9 PFCs perfluorocarbons

10 pH hydrogen-ion concentration

11 PM10 particulate matter >2.5 microns and ≤10 microns in diameter

12 PM2.5 particulate matter ≤2.5 microns in diameter

13 PMP probably maximum precipitation

14 PNNL Pacific Northwest National Laboratory

15 POST Parliamentary Office of Science and Technology

16 ppb parts per billion

17 ppm parts per million

18 PRA probabilistic risk assessment

19 PSA probabilistic safety assessment

20 PSD Prevention of Significant Deterioration

21 RAI request for additional information

22 RC release category

23 RCRA Resource Conservation and Recovery Act of 1976

24 REMP radiological environmental monitoring program

25 RES Nuclear Regulatory Research, Office of

26 RLE review level earthquake

27 RM river mile(s) 

28 ROI region of influence

29 ROW(s) right(s)-of-way

30 RPC replacement power cost

31 RPSEA Research Partnership to Secure Energy for America

32 RPV reactor pressure vessel

33 RRW risk reduction worth

34 SAAQS State Ambient Air Quality Standards

35 SAMA Severe Accident Mitigation Alternative
Abbreviations and Acronyms

xxviii 

1 SAR safety analysis report

2 SCPC supercritical pulverized coal

3 SDWA Safe Drinking Water Act

4 SEIS supplemental environmental impact statement 

5 SERI System Energy Resources, Inc.

6 SF6 sulfur hexafluoride

7 SHPO State Historic Preservation Office

8 SMA seismic margins assessment

9 SNL Sandia National Laboratory

10 SO2 sulfur dioxide

11 SOx sulfur oxide(s)

12 SRP Standard Review Plan

13 SSCs systems, structures, and components

14 SSE safe shutdown earthquake

15 SSW standby service water

16 State State of Mississippi

17 Sv sievert(s) 

18 TCPA Texas Comptroller of Public Accounts

19 TEEIC Tribal Energy and Environmental Information Center

20 TPWD Texas Parks and Wildlife Department

21 TSS total suspended solids

22 U.S. United States

23 U.S.C. United States Code

24 USACE U.S. Army Corps of Engineers 

25 USCB U.S. Census Bureau

26 USDA U.S. Department of Agriculture

27 USFS U.S. Forest Service

28 USFWS U.S. Fish & Wildlife Service

29 USGCRP U.S. Global Change Research Program

30 USGS U.S. Geological Survey

31 USOWC U.S. Offshore Wind Collaborative

32 VOCs volatile organic compounds

33 WCD Waste Confidence Decision Rule
1-1 

1 1.0 PURPOSE AND NEED FOR ACTION

2 Under the U.S. Nuclear Regulatory Commission’s (NRC’s) environmental protection regulations 

3 in Title 10 of the Code of Federal Regulations Part 51 (10 CFR Part 51)—which carry out the 

4 National Environmental Policy Act (NEPA)—renewal of a nuclear power plant operating license 

5 requires the preparation of an environmental impact statement (EIS).

6 The Atomic Energy Act of 1954 originally specified that licenses for commercial power reactors 

7 be granted for up to 40 years. The 40-year licensing period was based on economic and 

8 antitrust considerations rather than on technical limitations of the nuclear facility.

9 The decision to seek a license renewal rests entirely with nuclear power facility owners and, 

10 typically, is based on the facility’s economic viability and the investment necessary to continue 

11 to meet NRC safety and environmental requirements. The NRC makes the decision to grant or 

12 deny license renewal based on whether the applicant has demonstrated that the environmental 

13 and safety requirements in the agency’s regulations can be met during the period of extended 

14 operation.

15 1.1 Proposed Federal Action

16 Entergy Operations, Inc. (Entergy) initiated the proposed Federal action by submitting an 

17 application for license renewal of Grand Gulf Nuclear Station, Unit 1 (GGNS), for which the 

18 existing license (NPF-29) expires on November 1, 2024. The NRC’s Federal action is the 

19 decision whether to renew the license for an additional 20 years.

20 1.2 Purpose and Need for the Proposed Federal Action

21 The purpose and need for the proposed action (decision whether to renew the license) is to 

22 provide an option that allows for power generation capability beyond the term of a current 

23 nuclear power plant operating license to meet future system generating needs, as such needs 

24 may be determined by other energy-planning decision-makers. This definition of purpose and 

25 need reflects the Commission’s recognition that, unless there are findings in the safety review 

26 required by the Atomic Energy Act or findings in the NEPA environmental analysis that would 

27 lead the NRC to reject a license renewal application, the NRC does not have a role in the 

28 energy-planning decisions of State regulators and utility officials as to whether a particular 

29 nuclear power plant should continue to operate.

30 If a renewed license is issued, State regulatory agencies and Entergy will ultimately decide 

31 whether the plant will continue to operate based on factors such as the need for power or other 

32 matters within the State’s jurisdiction or the purview of the owners. If a renewed license is 

33 denied, then the facility must be shut down on or before the expiration date of the current 

34 operating license—November 1, 2024. 
Purpose and Need for Action

1-2 

1 Figure 1–1. Environmental Review Process

2 1.3 Major Environmental Review Milestones

3 Entergy submitted an Environmental Report (ER) (Entergy 2011a) as part of its License 

4 Renewal Application (Entergy 2011b) on November 1, 2011. After reviewing the application and 

5 ER for sufficiency, the staff published a Federal Register Notice of Acceptability and Opportunity 

6 for Hearing (76 FR 80980) on December 27, 2011. Then, on December 29, 2011, the NRC 

7 published another notice in the Federal Register (76 FR 81996) on the intent to conduct 

8 scoping, thereby beginning the 60-day scoping period.

9 Two public scoping meetings were held on January 31, 2012, in Port Gibson, Mississippi 

10 (NRC 2012a). The comments received during the scoping process are presented in 

NRC staff 

reviews 

application

Staff conducts

environmental 

site audit

NRC issues 

draft SEIS

Company submits

an application

to NRC

*Scoping 

Process

*Draft 

SEIS 

Process

NRC issues 

final SEIS

NRC decision

on whether to 

renew license

* Opportunity

for Public

Involvement
Purpose and Need for Action

1-3 

1 “Environmental Impact Statement, Scoping Process, Summary Report,” published in April 2013 

2 (NRC 2013a). The scoping process summary report presents NRC responses to comments 

3 that the NRC staff considered to be out-of-scope of the environmental license renewal review. 

4 The comments considered within the scope of the environmental license renewal review and the 

5 NRC responses are presented in Appendix A of this supplemental environmental impact 

6 statement (SEIS).

7 In order to independently verify information provided in the ER, NRC staff conducted a site audit 

8 at GGNS in March 2012. During the site audit, NRC staff met with plant personnel, reviewed 

9 specific documentation, toured the facility, and met with interested Federal, State, and local 

10 agencies. A summary of that site audit is contained in “Summary of Site Audit Related to the 

11 Environmental Review of the License Renewal Application for Grand Gulf Nuclear Station,

12 Unit 1,” published in May 2012 (NRC 2012b).

13 Upon completion of the scoping period and site audit, NRC staff compiled its findings in a draft 

14 SEIS (Figure 1–1). This document is made available for public comment for 45 days. During 

15 this time, NRC staff will host public meetings and collect public comments. Based on the 

16 information gathered, the NRC staff will amend the draft SEIS findings as necessary, and 

17 publish the final SEIS.

18 The NRC has established a license renewal process that can be completed in a reasonable 

19 period of time with clear requirements to assure safe plant operation for up to an additional 

20 20 years of plant life. The safety review, which documents its finding in a Safety Evaluation 

21 Report, is conducted simultaneously with the environmental review. The findings in both the 

22 SEIS and the Safety Evaluation Report are factors in the Commission’s decision to either grant 

23 or deny the issuance of a renewed license.

24 1.4 Generic Environmental Impact Statement

25 The NRC performed a generic assessment of the environmental impacts associated with 

26 license renewal to improve the efficiency of the license renewal process. The Generic 

27 Environmental Impact Statement for License Renewal of Nuclear Power Plants, NUREG-1437 

28 (GEIS) (NRC 1996, 1999) documented the results of the NRC staff’s systematic approach to 

29 evaluate the environmental consequences of renewing the licenses of individual nuclear power 

30 plants and operating them for an additional 20 years. NRC staff analyzed in detail and resolved 

31 those environmental issues that could be resolved generically in the GEIS.

32 The GEIS established 92 separate issues for NRC staff to independently verify. Of these 

33 issues, NRC staff determined that 69 are generic to all plants (Category 1) while 21 issues do 

34 not lend themselves to generic consideration (Category 2). Two other issues remained 

35 uncategorized; environmental justice and chronic effects of electromagnetic fields, and must be 

36 evaluated on a site-specific basis. A list of all 92 issues can be found in Appendix B.

37 For each potential environmental issue, the GEIS: 

38 (1) describes the activity that affects the environment,

39 (2) identifies the population or resource that is affected,

40 (3) assesses the nature and magnitude of the impact on the affected population or 

41 resource,

42 (4) characterizes the significance of the effect for both beneficial and adverse effects,

43 (5) determines whether the results of the analysis apply to all plants, and
Purpose and Need for Action

1-4 

1 (6) considers whether additional mitigation measures would be warranted for impacts 

2 that would have the same significance level for all plants.

3 The NRC’s standard of significance for impacts was established using the Council on 

4 Environmental Quality (CEQ) terminology for “significant.” The NRC established three levels of 

5 significance for potential impacts: SMALL, MODERATE, and LARGE, as defined below.

6 SMALL: Environmental effects are not detectable 

7 or are so minor that they will neither destabilize nor 

8 noticeably alter any important attribute of the 

9 resource.

10 MODERATE: Environmental effects are sufficient 

11 to alter noticeably, but not to destabilize, important

12 attributes of the resource.

13 LARGE: Environmental effects are clearly 

14 noticeable and are sufficient to destabilize important 

15 attributes of the resource.

16 The GEIS includes a determination of whether the analysis of the environmental issue could be 

17 applied to all plants and whether additional mitigation measures would be warranted 

18 (Figure 1–2). Issues are assigned a Category 1 or a Category 2 designation. As set forth in the 

19 GEIS, Category 1 issues are those that meet the following criteria:

20 (1) The environmental impacts associated with the issue have been determined 

21 to apply either to all plants or, for some issues, to plants having a specific 

22 type of cooling system or other specified plant or site characteristics.

23 (2) A single significance level (i.e., SMALL, MODERATE, or LARGE) has been 

24 assigned to the impacts (except for collective offsite radiological impacts from 

25 the fuel cycle and from high-level waste and spent fuel disposal).

26 (3) Mitigation of adverse impacts associated with the issue has been considered 

27 in the analysis, and it has been determined that additional plant-specific 

28 mitigation measures are likely not to be sufficiently beneficial to warrant 

29 implementation.

30 For generic issues (Category 1), no additional site-specific analysis is required in this SEIS 

31 unless new and significant information is identified. The process for identifying new and 

32 significant information is presented in Chapter 4. Site-specific issues (Category 2) are those 

33 that do not meet one or more of the criteria of Category 1 issues, and therefore, additional 

34 site-specific review for these issues is required. The results of that site-specific review are 

35 documented in the SEIS.

Significance indicates the importance of 

likely environmental impacts and is 

determined by considering two variables: 

context and intensity. 

Context is the geographic, biophysical, 

and social context in which the effects will 

occur. 

Intensity refers to the severity of the 

impact, in whatever context it occurs.
Purpose and Need for Action

1-5 

1 Figure 1–2. Environmental Issues Evaluated During License Renewal

2 The NRC staff initially evaluated 92 issues in the GEIS. Based on the findings of the GEIS, a 

3 site-specific analysis is required for 23 of those 92 issues.

4 On June 20, 2013, the NRC published a final rule (78 FR 37282) revising its environmental 

5 protection regulation, Title 10 of the Code of Federal Regulations (10 CFR) Part 51, 

6 “Environmental Protection Regulations for Domestic Licensing and Related Regulatory 

7 Functions.” Specifically, the final rule updates the potential environmental impacts associated 

8 with the renewal of an operating license for a nuclear power reactor for an additional 20 years. 

9 A revised GEIS (NRC 2013b), which updates the 1996 GEIS, provides the technical basis for 

10 the final rule. The revised GEIS specifically supports the revised list of NEPA issues and 

11 associated environmental impact findings for license renewal contained in Table B–1 in 

12 Appendix B to Subpart A of the revised 10 CFR Part 51. The revised GEIS and final rule reflect 

13 lessons learned and knowledge gained during previous license renewal environmental reviews. 

14 In addition, public comments received on the draft revised GEIS and rule and during previous 

15 license renewal environmental reviews were re-examined to validate existing environmental 

16 issues and identify new ones. 

17 The final rule identifies 78 environmental impact issues, of which 17 will require plant-specific 

18 analysis. The final rule consolidates similar Category 1 and 2 issues, changes some 

19 Category 2 issues into Category 1 issues, and consolidates some of those issues with existing 

20 Category 1 issues. The final rule also adds new Category 1 and 2 issues. The new Category 1 
Purpose and Need for Action

1-6 

New and significant information either:

(1) identifies a significant environmental 

issue not covered in the GEIS, or

(2) was not considered in the analysis in the 

GEIS and leads to an impact finding that 

is different from the finding presented in 

the GEIS.

1 issues include geology and soils, exposure of terrestrial organisms to radionuclides, exposure of 

2 aquatic organisms to radionuclides, human health impact from chemicals, and physical 

3 occupational hazards. Radionuclides released to groundwater, effects on terrestrial resources 

4 (non-cooling system impacts), minority and low-income populations (i.e., environmental justice), 

5 and cumulative impacts were added as new Category 2 issues.

6 The final rule became effective 30 days after publication in the Federal Register. Compliance 

7 by license renewal applicants is not required until 1 year from the date of publication 

8 (i.e., license renewal environmental reports submitted later than 1 year after publication must be 

9 compliant with the new rule). Nevertheless, under NEPA, the NRC must now consider and 

10 analyze, in its license renewal SEISs, the potential significant impacts described by the final 

11 rule’s new Category 2 issues and, to the extent there is any new and significant information, the 

12 potential significant impacts described by the final rule’s new Category 1 issues.

13 1.5 Supplemental Environmental Impact Statement

14 The SEIS presents an analysis that considers the environmental effects of the continued 

15 operation of GGNS, alternatives to license renewal, and mitigation measures for minimizing 

16 adverse environmental impacts. Chapter 8 contains analysis and comparison of the potential 

17 environmental impacts from alternatives while Chapter 9 presents the staff’s preliminary

18 recommendation to the Commission on whether or not the environmental impacts of license 

19 renewal are so great that preserving the option of license renewal would be unreasonable. The 

20 recommendation includes consideration of comments received during the public scoping period. 

21 In the preparation of this SEIS for GGNS, the staff:

22  reviewed the information provided in Entergy’s ER, 

23  consulted with other Federal, State, and local agencies, 

24  conducted an independent review of the issues during a site audit, and

25  considered the public comments received during the scoping process.

26 New information can be identified from a 

27 number of sources, including the applicant, 

28 NRC, other agencies, or public comments. If a 

29 new issue is revealed, then it is first analyzed to 

30 determine whether it is within the scope of the 

31 license renewal evaluation. If it is not 

32 addressed in the GEIS then the NRC 

33 determines its significance and documents its 

34 analysis in the SEIS.

35 1.6 Cooperating Agencies

36 During the scoping process, no Federal, State, or local agencies were identified as cooperating 

37 agencies in the preparation of this SEIS.

38 1.7 Consultations

39 The Endangered Species Act of 1973, as amended; the Magnuson–Stevens Fisheries 

40 Management Act of 1996, as amended; and the National Historic Preservation Act of 1966

41 require that Federal agencies consult with applicable State and Federal agencies and groups 
Purpose and Need for Action

1-7 

1 prior to taking action that may affect endangered species, fisheries, or historic and 

2 archaeological resources, respectively. Below are the agencies and groups with whom the 

3 NRC consulted; Appendix D to this report includes copies of consultation documents.

4  Advisory Council on Historic Preservation

5  National Marine Fisheries Service

6  U.S. Fish and Wildlife Service, Mississippi Field Office

7  U.S. Fish and Wildlife Service, Louisiana Field Office

8  Mississippi Band of Choctaw Indians

9  Jena Band of Choctaw Indians

10  Choctaw Nation of Oklahoma

11  Tunica-Biloxi Tribe of Louisiana

12 1.8 Correspondence

13 During the course of the environmental review, the NRC staff contacted the Federal, State, 

14 regional, local, and tribal agencies listed in Section 1.7, as well as the following:

15  Mississippi Department of Archives and History

16  Louisiana Division of Historic Preservation

17  Mississippi Natural Heritage Program

18  Louisiana Natural Heritage Program

19 Appendix E contains a chronological list of all the documents sent and received during the 

20 environmental review. 

21 A list of persons who received a copy of this SEIS is provided in Chapter 11.

22 1.9 Status of Compliance

23 Entergy is responsible for complying with all NRC regulations and other applicable Federal, 

24 State, and local requirements. A description of some of the major Federal statutes can be found 

25 in Appendix H of the GEIS. Appendix C to this SEIS includes a list of the permits and licenses 

26 issued by Federal, State, and local authorities for activities at GGNS.

27 1.10 References

28 10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

29 Protection Regulations for Domestic Licensing and Related Regulator Activities.”

30 76 FR 80980. U.S. Nuclear Regulatory Commission, Washington DC, “Notice of Acceptance for 

31 Docketing of the Application and Notice of Opportunity for Hearing Regarding Renewal of 

32 Facility Operating License No. NPF-29 for an Additional 20-Year Period, Entergy Operations, 

33 Inc., Grand Gulf Nuclear Station.” Federal Register 76(248): 80980-80982, December 27, 2011. 

34 76 FR 81996. U.S. Nuclear Regulatory Commission, Washington DC, “Entergy Operations, Inc.; 

35 Notice of Intent To Prepare an Environmental Impact Statement and Conduct Scoping Process 

36 for Grand Gulf Nuclear Station, Unit 1.” Federal Register 76(250): 81996–81998, December 29, 

37 2011.

38 78 FR 37282. U.S. Nuclear Regulatory Commission. "Revisions to Environmental Review for 

39 Renewal of Nuclear Power Plant Operating Licenses." Federal Register 78(119): 37282-37324. 

40 June 20, 2013. 

41 Atomic Energy Act of 1954. 42 U.S.C. §2011, et seq.
Purpose and Need for Action

1-8 

1 Endangered Species Act of 1973, as amended. 16 U.S.C. §1531, et seq.

2 [Entergy] Entergy Operations, Inc. 2011a. Grand Gulf Nuclear Station, Unit 1, License Renewal 

3 Application, Appendix E, Applicant’s Environmental Report, Operating License Renewal Stage. 

4 Agencywide Documents Access and Management System (ADAMS) Accession 

5 No. ML11308A234.

6 [Entergy] Entergy Operations, Inc. 2011b. Grand Gulf Nuclear Station, Unit 1—License Renewal 

7 Application. October 2011. ADAMS Accession No. ML11308A101. 

8 Magnuson–Stevens Fishery Conservation and Management Act, as amended by the 

9 Sustainable Fisheries Act of 1996. 16 U.S.C. §1855, et seq.

10 National Environmental Policy Act of 1969, as amended. 42 U.S.C. §4321, et seq.

11 National Historic Preservation Act of 1966. 16 U.S.C. §470, et seq.

12 [NRC] U.S. Nuclear Regulatory Commission. 1996. Generic Environmental Impact Statement

13 for License Renewal of Nuclear Plants, NUREG-1437, Volumes 1 and 2. Washington DC. 

14 May 1996. ADAMS Accession Nos. ML040690705 and ML040690738. 

15 [NRC] U.S. Nuclear Regulatory Commission. 1999. Generic Environmental Impact Statement

16 for License Renewal of Nuclear Plants, Main Report, “Section 6.3–Transportation, Table 9.1, 

17 Summary of Findings on NEPA Issues for License Renewal of Nuclear Power Plants, Final 

18 Report, NUREG-1437, Volume 1, Addendum 1. Washington DC. August 1999. ADAMS 

19 Accession No. ML040690720.

20 [NRC] U.S. Nuclear Regulatory Commission. 2012a. “Summary of Public Scoping Meetings 

21 Conducted on January 31, 2012, Related to the Review of the Grand Gulf Nuclear Station, 

22 Unit 1, License Renewal Application.” February 2012. ADAMS Accession No. ML12044A151.

23 [NRC] U.S. Nuclear Regulatory Commission. 2012b. “Summary of Site Audit Related to the 

24 Environmental Review of the License Renewal Application for Grand Gulf Nuclear Station, 

25 Unit 1.” May 21, 2012. ADAMS Accession No. ML12116A060. 

26 [NRC] U.S. Nuclear Regulatory Commission. 2012c. Staff Requirements, SECY-12-0063 – Final 

27 Rule: Revisions to Environmental Review for Renewal of Nuclear Power Plant Operating 

28 Licenses (10 CFR Part 51; RIN 3150–AI42). December 6, 2012. ADAMS Accession 

29 No. ML12341A134. 

30 [NRC] U.S. Nuclear Regulatory Commission. 2013a. “Environmental Impact Statement, Scoping 

31 Process, Summary Report,” April 2013. ADAMS Accession No. ML12201A623. 

32 [NRC] U.S. Nuclear Regulatory Commission. 2013b. Generic Environmental Impact Statement

33 for License Renewal of Nuclear Plants. Washington, DC: Office of Nuclear Reactor Regulation. 

34 NUREG-1437, Revision 1, Volumes 1, 2, and 3. June 2013. ADAMS Accession Nos. 

35 ML13106A241, ML13106A242, and ML13106A244. 
2-1 

1 2.0 AFFECTED ENVIRONMENT 

2 Grand Gulf Nuclear Station (GGNS) is located in Claiborne County, Mississippi, on the east 

3 bank of the Mississippi River, approximately 25 miles (mi) (39 kilometers (km)) south-southwest 

4 of Vicksburg, Mississippi. Figure 2–1 and Figure 2–2 present the 50-mi (80-km) and 6-mi 

5 (10-km) vicinity maps, respectively. In this supplemental environmental impact statement 

6 (SEIS), the “affected environment” is the environment that currently exists at and around GGNS. 

7 Because existing conditions are at least partially the result of past construction and operation at 

8 the plant, the impacts of these past and ongoing actions, and how they have shaped the 

9 environment, are presented here. Section 2.1 of this SEIS describes the facility and its 

10 operation, and Section 2.2 discusses the affected environment.

11 2.1 Facility Description

12 GGNS is a single-unit nuclear power plant that began commercial operation in July 1985. 

13 The property boundary shown in Figure 2–3 encloses approximately 2,100 acres (ac), or 

14 850 hectares (ha). Currently, the property is approximately 2,015 ac (816 ha) because of the 

15 loss of approximately 85 ac (34 ha) from erosion by the Mississippi River (Entergy 2011a). The 

16 original application submitted in 1972 for GGNS was for a two-unit nuclear power facility. 

17 Construction on Unit 2 was halted before completion in 1979. The majority of the Unit 2 power 

18 block buildings were completed, along with the outer cylindrical concrete wall of the reactor

19 containment building. The switchyard was designed and constructed for two units 

20 (NRC 2006a).

21 The most conspicuous structures on the GGNS site include the natural draft cooling tower, the 

22 turbine building, the Unit 1 reactor containment building, the Unit 2 (cancelled) reactor 

23 containment outer cylindrical concrete wall, the auxiliary cooling tower, and various other 

24 buildings.

25 2.1.1 Reactor and Containment Systems

26 The GGNS nuclear reactor system is a single-cycle, forced-circulation, General Electric Mark III 

27 boiling water reactor (BWR). The reactor core heats water to make steam that is dried by steam 

28 separators and dryers located in the upper portion of the reactor vessel. The steam is then 

29 directed to the main turbine through the main steam lines where it turns the turbine generator to 

30 produce electricity. 

31 Fuel for GGNS is made of low-enrichment (less than 5 percent by weight) high-density ceramic 

32 uranium dioxide fuel pellets, with a maximum average burnup level of less than 

33 62,000 megawatt-days/metric ton of uranium. GGNS operates on an 18-month refueling cycle 

34 and plans to switch to a 24-month refueling cycle in the future. 

35 The functional design basis of the containment, including its penetrations and isolation valves, is 

36 to contain, with adequate design margin, the energy released from a design basis 

37 loss-of-coolant accident. It also provides a leak-tight barrier against the uncontrolled release of 

38 radioactivity to the environment, even assuming a partial loss of engineered safety features.

39 The reactor and related systems are enclosed in containment and enclosure structures. The 

40 containment structure encloses the reactor coolant system, drywell, suppression pool, upper 

41 pool, and some of the engineered safety feature systems and supporting systems. The 

42 enclosure building and auxiliary building are combined to form a secondary containment which 
Affected Environment

2-2 

1 Figure 2–1. Location of GGNS, 50-mi (80-km) Vicinity

2 Source: Entergy 2011a ••CII•CII-11::==:::.- Miles 0 5 10 15 2 0 Cl Airports ......... Existing Transmission Corridor - Interstate -- U.S. H1ghway 

- State Highway/Road 

-- Natchez Trace Parkway 

_,_Rail 

() 6-Mile Radius 0 50-Mile Radius 

D Surface Water 

c:J GGNS Property [, , J State Wildlife Mgmt Areas ffiJEJ State Pa1 ks 

r National Forest 

National 

Wildlife Refuge D Urban Areas 
Affected Environment

2-3 

1 Figure 2–2. Location of GGNS, 6-mi (10-km) Vicinity

2 Source: Entergy 2011a

Legend 

Ill! Helicopter Pad -- Highways --+-- Abandoned Ra ilroads t:::J GGNS Property 

B.] 

[!J Principal H istorical Site 4 0 2 3 

--Other Princ 111al RnariR -+-- Ar.11VA -

County/Local Roads ._...... Existing Transmission Corridor Urban Areas 

Stale Boundary c:::::I:::I::::Natura l Gas Line 
Affected Environment

2-4 

1 Figure 2–3. GGNS, General Site Layout

2 Source: Modified from Entergy 2011a

.•·· . . . 

. ·· ·· .. . . . · ·. . . 

. . .· · ..Grand Gulf 

Barge Slip~ 

Q) 

~ \ 

~ \ 0 ........ 

~ •.. ~ 

.. wastewater 

Treatment Plant 

·. ~. 

• . .... ·. . 

. Sediment Basin A\ 

Energy ~ 

· .. ·. 

I 

.. · ... ·· 

. 

. ·· . 

. 

. 

. . . . 

. 

. . 

•" .......... ··: '~·<t········ .. ··· . 

) 

/ . 

. ,._ 

. 

Services 

Center 

Sediment Basin B 

.J\;:·· .. .. ... .A 

.. ..• ··"' . . . 

·· ... · 

,... B ndary Security Barrier 

• I Boundary (2,500 teet radlusl Exclusion Area •. 1 • · ; 

. ····· ; 

.· .. .. .. 

, 

, 

, 

, 

, 

,' ~ Bat , ~<:~ d Hilt ROad , ; "T 

, 

, 

, 

; 

, 

, 

, 

, 

, 

; , 

N 

: •• ,..:Property ou .-1 Security Fenceline DExclusionArea Boundary (EAB) l_, Roads 

State Boundary 0 Site Layout 

1.000 2.000 4.000 

eet 

0 375 

s 

750 

Meters 

, 

500 kV Switchyard 

1.500 
Affected Environment

2-5 

1 maintains a negative pressure in the volume between the containment and enclosure/auxiliary

2 building. These two containment systems and associated engineered safety features are

3 designed and maintained to minimize the release of airborne radioactive materials under 

4 accident conditions.

5 2.1.2 Radioactive Waste Management

6 GGNS radioactive waste systems collect, treat, and dispose of radioactive wastes that are 

7 byproducts of plant operations. These byproducts are activation products associated with 

8 nuclear fission, reactor coolant activation, and non-coolant material activation.

9 Release of liquid and gaseous effluents are controlled to meet the limits specified in Title 

10 10, Code of Federal Regulations (CFR) Part 20 and 10 CFR Part 50, Appendix I, through the 

11 Radioactive Effluent Controls Program defined in the GGNS technical specifications. Operation 

12 procedures for the radioactive waste systems ensure that radioactive wastes are safely 

13 processed and discharged from GGNS. The systems are designed and operated to ensure that 

14 the quantities of radioactive materials released from GGNS are as low as is reasonably 

15 achievable (ALARA) and within the dose standards set forth in 10 CFR Part 20, “Standards for 

16 protection against radiation,” and Appendix I to 10 CFR Part 50, “Domestic licensing of 

17 production and utilization facilities.” The GGNS Offsite Dose Calculation Manual (ODCM) 

18 contains the methods and parameters used to calculate offsite doses resulting from radioactive 

19 effluents. These methods are used to ensure that radioactive material discharges from GGNS 

20 meet regulatory dose standards. 

21 Radioactive wastes resulting from GGNS plant operations are classified as liquid, gaseous, or 

22 solid. Liquid radioactive wastes are generated from liquids received directly from portions of the 

23 reactor coolant system or were contaminated by contact with liquids from the reactor coolant 

24 system. Gaseous radioactive wastes are generated from gases or airborne particulates vented 

25 from reactor and turbine equipment containing radioactive material. Solid radioactive wastes 

26 are solids from the reactor coolant system, solids that came into contact with reactor coolant 

27 system liquids or gases, or solids used in the steam and power conversion system. 

28 Reactor fuel that has exhausted a certain percentage of its fissile uranium content is referred to 

29 as spent fuel. Spent fuel assemblies that are removed from the reactor core are replaced with 

30 fresh fuel assemblies during routine refueling outages. Spent nuclear fuel from the GGNS 

31 reactor is stored on site in a spent fuel pool and an independent spent fuel storage installation

32 (ISFSI) (Entergy 2011a).

33 2.1.2.1 Radioactive Liquid Waste

34 The GGNS liquid radwaste system collects, processes, recycles, and disposes of potentially 

35 radioactive wastes produced during operation of the plant. The liquid effluents from the liquid 

36 radwaste system are monitored continuously, and the discharges are terminated if the effluents 

37 exceed preset radioactivity levels, which are specified in the GGNS ODCM. The liquid radwaste 

38 system is comprised of a group of subsystems designed to collect and treat different types of 

39 liquid waste, designated as the equipment drain processing subsystem (clean radwaste), floor 

40 drain processing subsystem (dirty radwaste), chemical waste subsystem, and miscellaneous 

41 supporting subsystems. 

42 Liquid wastes that accumulate in radwaste drain tanks or in sumps are transferred to collection 

43 and sample tanks in the radwaste building. The liquid wastes are processed through filters and 

44 demineralizers and returned to the condensate system or released from the plant.

45 Control of discharges from the radwaste system includes a radiation monitor, an effluent flow 

46 control valve, and dilution water flow rate monitoring equipment. Radioactive liquid wastes are 
Affected Environment

2-6 

1 subject to the sampling and analysis program described in the ODCM. This enables GGNS to 

2 handle radioactive liquid releases in accordance with applicable regulations and impacts to 

3 offsite areas will be consistent with ALARA concepts (Entergy 2011a). 

4 2.1.2.2 Radioactive Gaseous Waste

5 The gaseous radwaste system processes and controls the release of gaseous radioactive 

6 effluents to the atmosphere. Gaseous effluents are released from the radwaste building vent, 

7 the turbine building vent, the containment vent, the auxiliary vent, and standby gas treatment 

8 system. 

9 Radioactive gas is continuously removed from the main condenser by the air ejector during 

10 plant operation. It is then filtered, cooled, and discharged to the environment. GGNS uses

11 continuous radiation monitors to ensure radioactive gaseous effluent discharges are within 

12 specifications in the ODCM (Entergy 2011a).

13 2.1.2.3 Radioactive Solid Waste

14 The solid waste management system collects, processes, and packages solid radioactive 

15 wastes for storage and offsite shipment and permanent disposal. GGNS has developed 

16 long-term plans that would ensure radwaste generated during the license renewal term would 

17 either be stored on site in existing structures or shipped to an offsite licensed facility for 

18 processing and disposal. 

19 Wet wastes are collected, dewatered, packaged in containers and stored before offsite 

20 shipment. 

21 Dry wastes usually consist of small tools, air filters, miscellaneous paper, rags, equipment parts 

22 that cannot be effectively decontaminated, wood, and solid laboratory waste. Compressible 

23 wastes can be shipped off site and compacted to reduce their volume. Noncompressible 

24 wastes are packaged in appropriate containers. Because of its low radiation levels, this waste 

25 can be stored until enough is accumulated to permit economic transportation off site for final 

26 disposal or further processing. 

27 GGNS currently transports radioactive waste to licensed processing facilities in Tennessee, 

28 such as the Studsvik, Duratek (owned by EnergySolutions), or Race (owned by Studsvik) 

29 facilities, where wastes are further processed before they are sent to a facility such as 

30 EnergySolutions in Clive, Utah, for disposal. GGNS also may transport material from an offsite 

31 processing facility to a disposal site or back to the plant site for reuse or storage. GGNS 

32 radioactive waste shipments are packaged in accordance with both NRC and Department of 

33 Transportation (DOT) requirements (Entergy 2011a). 

34 2.1.2.4 Low-Level Mixed Wastes

35 Currently, no mixed wastes are generated or stored on the GGNS site. If they were, they would 

36 be managed and transported to an offsite facility licensed to accept and manage the wastes in 

37 accordance with appropriate GGNS and Entergy procedures (Entergy 2011a). 

38 2.1.3 Nonradiological Waste Management

39 The Resource Conservation and Recovery Act of 1976 (RCRA) governs nonradioactive 

40 hazardous and nonhazardous wastes produced at GGNS. The U.S. Environmental Protection 

41 Agency (EPA) is ultimately responsible for implementing RCRA and regulations governing the 

42 disposal of solid and hazardous waste are contained in 40 CFR Parts 239–299. Specifically, 

43 RCRA Subtitle D regulations for solid (nonhazardous) waste are contained in 

44 40 CFR Parts 239–259. RCRA Subtitle C regulations for hazardous waste are contained in 
Affected Environment

2-7 

1 40 CFR Parts 260–279. RCRA Subtitle C establishes a system for controlling hazardous waste 

2 from “cradle to grave.” RCRA Subtitle D encourages states to develop comprehensive plans to 

3 manage nonhazardous solid waste and mandates minimum technological standards for 

4 municipal solid waste landfills. EPA authorizes states to implement the RCRA hazardous waste 

5 program through their rulemaking process. 

6 EPA granted initial authorization to Mississippi to operate its hazardous waste program on 

7 June 13, 1984. The Mississippi Department of Environmental Quality (MDEQ) administers the 

8 State’s hazardous waste regulations and addresses the identification, generation, minimization, 

9 transportation, and final treatment, storage, or disposal of hazardous and nonhazardous waste. 

10 Mississippi’s hazardous waste regulations can be found in MDEQ, Office of Pollution Control, 

11 Hazardous Waste Management Regulations, HW-1. Mississippi’s solid waste law is contained 

12 in Chapter 17, “Solid Wastes Disposal Law of 1974,” of Title 17, “Local Government; Provisions 

13 Common to Counties and Municipalities.” As EPA amends its RCRA regulations, Mississippi 

14 has amended its program to maintain consistency with the national standards. 

15 2.1.3.1 Nonradioactive Waste Streams 

16 GGNS generates nonradioactive waste as part of routine maintenance of equipment, cleaning 

17 activities, and plant operations. Nonradioactive waste generated at GGNS includes batteries, 

18 fluorescent lamps, scrap metals, used oil, used oil filters, used tires, electronics for 

19 reconditioning, and equipment containing mercury. Nonhazardous waste generated at GGNS 

20 consists of materials such as blasting media, oil contaminated wastes, wastewater, and 

21 wastewater sludges. Hazardous waste generated at GGNS is usually a small percentage of the 

22 total waste generated at the plant. Hazardous waste generated at GGNS includes aerosols, oils 

23 and solvents, paint, and out-of-date or off-specification chemicals. 

24 EPA recognizes the following main types of hazardous waste generators (40 CFR 260.10) 

25 based on the quantity of the hazardous waste produced:

26  large quantity generators that generate 2,200 pounds (lb) (1,000 kilograms 

27 (kg)) per month or more of hazardous waste, more than 2.2 lb (1 kg) per 

28 month of acutely hazardous waste, or more than 220 lb (100 kg) per month of 

29 acute spill residue or soil; 

30  small quantity generators that generate more than 220 lb (100 kg) but less 

31 than 2,200 lb (1,000 kg) of hazardous waste per month; and,

32  conditionally exempt small quantity generators that generate 220 lb (100 kg) 

33 or less per month of hazardous waste, 2.2 lb (1 kg) or less per month of 

34 acutely hazardous waste, or less than 220 lb (100 kg) per month of acute spill 

35 residue or soil. 

36 Mississippi has adopted EPA’s regulations relating to RCRA Subpart C and Subpart D wastes 

37 and MDEQ recognizes GGNS as a small quantity generator of hazardous wastes. The NRC 

38 staff reviewed Waste Minimization Certified Reports that GGNS submitted to MDEQ, 

39 Environmental Permits Division, for the years 2006 through 2010. These reports document the 

40 types and quantities of nonradioactive waste generated at GGNS and verify the status of GGNS 

41 as a small quantity generator of hazardous waste.

42 Conditions and limitations for wastewater discharge by GGNS are specified in National Pollution 

43 Discharge Elimination System (NPDES) Permit No. MS0029521. Radioactive liquid waste is 

44 addressed in Section 2.1.2 of this SEIS. Section 2.2.4 provides more information about the 

45 GGNS NPDES permit and permitted discharges.
Affected Environment

2-8 

1 The Emergency Planning and Community Right-to-Know Act (EPCRA) requires applicable 

2 facilities to supply information about hazardous and toxic chemicals to local emergency planning 

3 authorities and the EPA (42 USC 11001). GGNS is subject to Federal EPCRA reporting 

4 requirements. As such, GGNS submits an annual Section 312 (Tier II) report on hazardous 

5 substances to the Claiborne County Emergency Planning Committee and to the Mississippi 

6 Emergency Management Agency. 

7 2.1.3.2 Pollution Prevention and Waste Minimization

8 EPA encourages the use of environmental management systems (EMS) for organizations to 

9 assess and manage the environmental impacts associated with their activities, products, and 

10 services in an efficient and cost-effective manner. The EPA defines an EMS as “a set of 

11 processes and practices that enable an organization to reduce its environmental impacts and 

12 increase its operating efficiency.” EMSs help organizations fully integrate a wide range of 

13 environmental initiatives, establish environmental goals, and create a continuous monitoring 

14 process to help meet those goals. The EPA Office of Solid Waste especially advocates the use 

15 of EMSs at RCRA-regulated facilities to improve environmental performance, compliance, and 

16 pollution prevention (EPA 2010).

17 Related to the use of EMSs, Entergy, the parent company for GGNS, has established a Waste 

18 Minimization Plan for its fleet of nuclear power plants. The plan describes the activities plant 

19 personnel must take to reduce, to the extent feasible, the hazardous, hazardous/radioactive, 

20 and nonhazardous wastes generated, treated, stored, or disposed. The Waste Minimization 

21 Plan is used in conjunction with Entergy’s fleet procedures and the individual plant’s procedures 

22 to minimize, to the maximum extent possible, the generation of all types of waste.

23 Pollution-prevention and waste-minimization efforts that GGNS uses are summarized in annual 

24 Waste Minimization Certified Reports submitted to MDEQ. Entergy’s Waste Minimization 

25 procedure (EN-EV-104) lists the practices used to minimize waste generation. The hierarchy for 

26 minimizing or managing waste is:

27  source reduction – reduce or eliminate potential waste material, 

28  recycle – reuse or reclaim material instead of throwing it in the trash, 

29  treatment – neutralize acids or bases, and

30  disposal – last resort when no other action can be taken.

31 2.1.4 Plant Operation and Maintenance

32 Maintenance activities conducted at GGNS include inspection, testing, and surveillance to 

33 maintain the current licensing basis of the facility and to ensure compliance with environmental 

34 and safety requirements. These maintenance activities include inspection requirements for 

35 reactor vessel materials, boiler and pressure vessel inservice inspection and testing, the 

36 monitoring program for maintaining structures, and maintenance of water chemistry.

37 Additional programs include those carried out to meet technical specification surveillance 

38 requirements, those implemented in response to the NRC generic communications, and various 

39 periodic maintenance, testing, and inspection procedures. Certain program activities are carried 

40 out during the operation of the unit, while others are carried out during scheduled refueling 

41 outages. Nuclear power plants must periodically discontinue the production of electricity for 

42 refueling, periodic inservice inspection, and scheduled maintenance. GGNS operates on an 

43 18-month refueling cycle.
Affected Environment

2-9 

1 2.1.5 Power Transmission System

2 Three 500-kilovolt (kV) transmission lines were constructed to connect GGNS to the regional 

3 power grid: the Baxter-Wilson line, the Franklin line, and a short, unnamed tie-in line that 

4 connects the Unit 1 turbine building to the GGNS station switchyard. Entergy Mississippi, Inc. 

5 (EMI) owns and operates these lines. This section summarizes each line and discusses 

6 vegetative maintenance procedures. Figures 2–1 and 2–2 depict the transmission line 

7 corridors. 

8 The Baxter-Wilson line is a 22-mi (35-km) single-circuit 500-kV line that extends north from the 

9 GGNS switchyard to the Baxter-Wilson Steam Electric Station Extra High Voltage (EHV) 

10 switchyard in Claiborne County, Mississippi. Its corridor is 200 feet (ft) (60 meters (m)) wide 

11 and traverses rural, sparsely populated agricultural and forested land.

12 The Franklin line is a 43.6-mi (70.2-km) single-circuit 500-kV line that extends southeast from 

13 the GGNS switchyard to the Franklin EHV Switching Station in Franklin County, Mississippi. 

14 Its corridor is 200 ft (60 m) wide and traverses four major highways, the Bayou Pierre and 

15 Homochitto Rivers, and a portion of the Homochitto National Forest.

16 The third transmission line extends 300 ft (90 m) from the Unit 1 turbine building to the GGNS 

17 switchyard.

18 EMI inspects each transmission line right-of-way

19 by air or ground at least three times per year to 

20 identify encroaching vegetation or other required 

21 maintenance. EMI follows an integrated 

22 vegetative plan that includes mechanical and 

23 manual clearing and herbicide application. The 

24 degree and type of clearance varies by line 

25 voltage and the type, growth rate, and branching 

26 characteristics of trees and vegetation. Large 

27 trees generally are trimmed or pruned to allow for 

28 adequate line clearance; smaller trees and woody 

29 vegetation may be mowed to prepare the area for followup herbicide treatments. In sensitive 

30 areas, such as streams, ponds, or other water features, EMI chooses maintenance techniques 

31 that minimize erosion. In wetlands and aquatic habitat, EMI personnel selectively apply 

32 herbicides that are EPA-approved for aquatic environments. These herbicides are applied on 

33 foot with backpack sprayers to minimize impacts. All EMI maintenance crew personnel have a 

34 U.S. Department of Agriculture (USDA) state-approved herbicide license.

35 Along the Franklin line, 38.6 ac (15.6 ha) of the transmission line corridor pass through the Bude 

36 Range District of the Homochitto National Forest. For this portion of the line, EMI holds a USDA

37 Forest Service Special Use Permit for construction, operation, and maintenance of the line. EMI 

38 also uses a low-toxicity herbicide program for this portion of the transmission line corridor to 

39 promote open, grassy habitat as part of a partnership established in 2003 with the National Wild 

40 Turkey Federation (Entergy 2011a). 

41 2.1.6 Cooling and Auxiliary Water Systems

42 A surface water structure to obtain cooling water from the Mississippi River does not exist at 

43 GGNS. Instead, water is pumped from Ranney wells located in an aquifer along the Mississippi 

44 River. The Ranney well system design and hydrogeology is discussed in greater detail in 

45 Section 2.1.7. 

A transmission line right-of-way (ROW) is a 

strip of land used to construct, operate, 

maintain, and repair transmission line 

facilities. The transmission line is usually 

centered in the ROW. The width of a ROW 

depends on the voltage of the line and the 

height of the structures. ROWs must 

typically be clear of tall-growing trees and 

structures that could interfere with a 

powerline.
Affected Environment

2-10

1 Entergy’s Environmental Report (ER) (Entergy 2011a) provides information on the circulating 

2 water system that removes excess heat from the reactor. The circulating water system cools 

3 the main condenser. Heat is removed from the circulating water system by cooling towers, 

4 which dissipate the heat to the atmosphere. The main cooling tower is a natural draft cooling 

5 tower. It does not require the use of fans to operate. It may operate alone or it may operate in 

6 tandem with a forced draft auxiliary cooling tower, which use fans. When both tower systems 

7 are in service, the maximum temperature of the cooling water delivered to the main condenser 

8 by the circulating water system is 32.2 °C (90 °F). 

9 Five Ranney wells provide makeup water to replace water lost from the cooling towers by drift, 

10 evaporation, and blowdown. During normal operation, as many wells and pumps as required 

11 are operated to meet the plant demand. Blowdown (water intentionally removed from the 

12 cooling water system to avoid concentration of impurities) is returned to the Mississippi River 

13 through a 54-inch (in.) (137-centimeter (cm)) diameter pipeline (Entergy 2011a). 

14 The temperature of the water exiting the 54-in (137-cm) discharge pipeline is monitored 

15 throughout the year as required by MDEQ NPDES Permit MS0029521. GGNS has not violated 

16 the thermal conditions of the permit. Therefore, water temperatures in the Mississippi River as 

17 a result of this discharge have not exceeded a water temperature change of 2.8 °C (5.0 °F) 

18 relative to the upriver temperature, outside a mixing zone not exceeding a maximum width of 

19 60 ft (18.5 m) from the river edge and a maximum length of 6,000 ft (1,829 m) downstream from 

20 the point of discharge, as measured at a depth of 5 ft (1.5 m). Further, the maximum water 

21 temperatures outside the mixing zone have not exceeded 32.2 °C (90 °F), except when ambient 

22 river temperatures approach or exceed this value (GGNS 2010a). 

23 Should an emergency plant shutdown occur, a standby service water system would supply 

24 auxiliary cooling to the reactor. Makeup water is provided automatically by the Ranney wells to 

25 the standby service water system basins. However, if the Ranney wells were not operable, the 

26 plant service water basins contain enough water to ensure cooling for the shutdown reactor for 

27 30 days (GGNS 2003a).

28 2.1.7 Facility Water Use and Quality

29 Cooling water for GGNS is supplied from Ranney wells located next to the Mississippi River. 

30 A Ranney well is a radial well used to extract water from an aquifer with direct connection to a 

31 river or lake. It consists of a vertical caisson constructed into sand or gravel below the surface 

32 level of an adjacent river or lake. Screened conduits are extended horizontally from ports in the 

33 caisson. The radial arrangement of the screened conduits extending outward from the central 

34 vertical caisson forms a large infiltration gallery (Figure 2–4). Groundwater flows into the 

35 horizontal screened conduits that make up the infiltration gallery. From there, the water flows to 

36 the central caisson, where it is pumped to the surface. One advantage of using a Ranney well 

37 to extract water from a river or lake is that less water treatment may be required than if the 

38 water is directly extracted from the river or lake. 

39 At GGNS, Ranney wells supply water from the Mississippi River by pumping water from the 

40 aquifer, which underlies the Mississippi River (NRC 2006a). Pumping from the aquifer removes 

41 suspended sediment from Mississippi River water. With the exception of suspended sediment, 

42 the water quality obtained from these wells is nearly identical to that of the Mississippi River. 

43 Fresh (potable) water for the plant is obtained from three wells located within the site boundary

44 and from the Crossroads, Shiloh & Ingleside (CS&I) Water Association #1 located 6 mi away 

45 from GGNS (Entergy 2011a). 

46 The following sections describe water use and relevant quality issues at GGNS. 
Affected Environment

2-11

1 2.1.7.1 Surface Water Use 

2 Mississippi River water quality is generally hard to very hard, requiring softening to avoid scale 

3 formation when heated in a cooling system (NRC 2006). In March 2012, four Ranney wells 

4 supplied water from the Mississippi River by pumping water from the Mississippi River Alluvial 

5 Aquifer. Most of this water cooled the reactor, but some supplied makeup water to the standby 

6 service water cooling towers, administration building, and fire protection system. Each of the 

7 Ranney wells is permitted by MDEQ to operate at a maximum production rate of 10,000 gallons 

per minute (gpm) (0.63 cubic meters per second (m3 8 /s)) (Entergy 2011a). This would produce a 

total maximum production rate from the Mississippi River of 40,000 gpm (2.5 m3 9 /s). However, 

10 from 2005 through 2010, the four Ranney wells generated a combined annual water production 

11 rate that was much less than permitted amounts. This is because infiltration rates have 

12 declined over time due to sediment buildup in the screened conduits. Over this time period, the 

production rate from all four wells averaged approximately 22,396 gpm (1.4 m3 13 /s). 

14 A new Ranney well (well number PSW-6 on Figure 2–5) was installed and became operational 

15 in August 2012. Its purpose is to ensure that adequate plant cooling water is maintained. As 

16 with the other Ranney wells, this well is located next to the Mississippi River. The estimated 

17 average combined production rate of Mississippi River water is approximately 27,860 gpm 

(1,758 m3

/s). Of this volume, 7,170 gpm (0.45 m3 18 /s) of blowdown is estimated to be returned to 

19 the Mississippi River through a 54-in. (137-cm) diameter discharge pipeline. An estimated 

20,690 gpm (1.31 m3 20 /s) of water is lost to the atmosphere, mainly through evaporation and drift 

21 from the cooling towers (Entergy 2011a).
Affected Environment

2-12

1 Figure 2–4. Plan (Map) View and Cross Section View of Ranney Well at GGNS

2 Source: Modified from Entergy 2011a
Affected Environment

2-13

1 Figure 2–5. GGNS Ranney Well Locations

2 Source: Modified from Entergy 2011a
Affected Environment

2-14

1 2.1.7.2 Groundwater Use 

2 As discussed in Section 2.1.7.1, the GGNS reactor cooling system relies on induced infiltration 

3 from the Mississippi River obtained by a system of Ranney collector wells (Entergy 2012a). 

4 The total annual pumping from these four wells amounts to 10,800–13,100 million gallons (gal)

(40.9–49.6 million m3 5 ) per year (Entergy 2006, 2010b, 2011c).

6 Three wells (North Construction Well and the North and South Drinking Water Wells), located 

7 within the site boundary and northeast of the main plant buildings, produce water used for 

8 domestic purposes, once-through cooling for plant air conditioners, and for regenerating the 

9 water softeners (Figure 2–6). After it has been used, this water flows to the Mississippi River 

10 through a 54-in. (137-cm) diameter pipeline, either after it has been processed by the onsite 

11 sewage treatment facility or as other permitted surface water discharges. Total annual pumping 

from these three wells amounts to 32–39 million gal/yr (0.12–0.15 million m3 12 /yr) 

13 (Entergy 2006, 2010b, 2011c). The average rate of water these wells produce from the 

groundwater in the Upland Terrace Deposits is estimated to be 67 gpm (0.3 m3 14 /s).

15 GGNS also obtains potable water from the CS&I Water Association #1. This public water 

16 system supplies potable water needs for the GGNS recreational vehicle trailer park, firing range, 

17 health physics calibration laboratory, and environmental garden areas. The water association 

18 obtains its water from three wells completed in the Catahoula Formation at a location 6 mi 

19 (10 km) to the east-northeast of GGNS. The amount of water supplied to GGNS by the water 

association is estimated to be 286,740 gal/yr (108.5 m3 20 /yr) (Entergy 2011a). 

21 2.2 Surrounding Environment

22 GGNS is located in Claiborne County, Mississippi, on the east bank of the Mississippi River, 

23 approximately 25 mi (39 km) south-southwest of Vicksburg, Mississippi. The site is bounded by 

24 the Mississippi River on the west. The western half of the site lies in the Mississippi River 

25 floodplain. This portion of GGNS has generally level topography, with elevations varying from 

26 55 to 75 ft (16.7 to 22.8 m) above mean sea level (MSL) (Figure 2–7). This area also contains 

27 Hamilton and Gin Lakes. These oxbow lakes were once a channel of the Mississippi River. 

28 They have an average depth of approximately 8 to 10 ft (2.4 to 3 m). The reactor building and 

29 most of the associated facilities are located in the eastern half of the site. This portion of GGNS 

30 is separated from the lowland plain by steep bluffs that trend north-south through the middle 

31 portion of the site. The topography in the upland area rises from the floodplain as rough, 

32 irregular bluffs, with steep slopes and deep-cut stream valleys and drainage courses. 

33 The surface topography in the upland area ranges from 80 to 200 ft (24 to 61 m) above MSL. 

34 A 6-mile radius from the center of the power block location (Figure 2–2) includes a portion of 

35 Claiborne County, Mississippi, on the east side of the Mississippi River and Tensas Parish, 

36 Louisiana, on the west side of the Mississippi River. The nearest incorporated community is the 

37 City of Port Gibson, which has an estimated population of less than 1,600 people located about 

38 6 mi (9 km) southeast of the site. The Grand Gulf Military Park, a Mississippi State park, 

39 borders part of the north side of the property. The region surrounding GGNS consists mainly of 

40 forest and agricultural lands (Entergy 2011a). 
Affected Environment

2-15

1 Figure 2–6. GGNS Upland Complex Aquifer Permitted Wells

2 Source: Modified from Entergy 2011a

Sedimentation 

Basin B 

r: ~e:t _terin_g Wells 

mUse) 

1 

2 

3 

4 

5 

6 

7 

8 

~ 

Structures Key 

Energy Se . Unit 2 W rvlces Center 

Ad . . arehouse 

U ministration Buildin 

n~t 2 (cancelled) g 

5 n1t 1 ( . operational) 

U OOkv Switch yard 

Wnlt 1 Cooling Tower 

astewater T Auxiliary Cool" reatment Plant 

mg Tower 

I> 

o'" ~ 

~ 

8' ..:' 

<: Q.-!t 

Stream A 
Affected Environment

2-16

1 Figure 2–7. Topographic Map of GGNS Facility

2 Source: Modified from GGNS 2003

3 2.2.1 Land Use

4 The GGNS site is comprised of 2,015 ac (815 ha). The western half of the site lies in the 

5 Mississippi River floodplain and is mostly undeveloped. The eastern half of the site contains the 

6 power block and support facilities (buildings, parking lots, and roads). A 2 ac (1 ha) 
Affected Environment

2-17

1 privately-owned residential property is located in the southwest sector of the site and is totally 

2 surrounded by the GGNS site property boundary. No other industrial, commercial, institutional, 

3 or residential structures are on the site other than a private hunting lodge in the extreme 

4 southwest corner. Public access is allowed to parts of the site for recreational purposes 

5 (NRC 2006).

6 The immediate area surrounding GGNS is enclosed by a security fence shown in Figure 2–3. 

7 Road access to GGNS is through a security gate by a two-lane road connecting to Grand Gulf 

8 Road, north of the plant, and from Bald Hill Road on the east and south. The site also can be 

9 accessed to the west from a barge slip on the Mississippi River. No active railways traverse the 

10 site. Railways constructed for GGNS construction have been abandoned. One 

11 county-maintained road runs through the GGNS site. Bald Hill Road cuts through the 

12 south-southeast, south, south-southwest, and southwest sectors of the site. Another road 

13 (unpaved) traverses the GGNS site property in the north, north-northwest, northwest, 

14 west-northwest, and west sectors, providing access to the two lakes on the property. Two 

15 transmission lines traverse the eastern edge of the site. 

16 The immediate area of GGNS is rural and largely undeveloped or agricultural. Nearby land 

17 across the Mississippi River in Louisiana is almost entirely agricultural land. Notable manmade 

18 features within a 6-mi (10-km) radius of GGNS (see Figure 2–2) include several Civil War 

19 monuments and historic plantations around the town of Port Gibson. The Port of Claiborne is 

20 located 2.2 mi (3.5 km) southwest of GGNS at river mile (RM) 404.8 of the Mississippi.

21 Nearby communities include the small community of Grand Gulf, about 1.6 mi (2.7 km) north, 

22 the town of Port Gibson, approximately 6 mi (10 km) southeast; the city of Vicksburg, 25 mi 

23 (40 km) north; and the city of Natchez, 37 mi (60 km) southwest. Several other small towns are 

24 located in the surrounding area in Mississippi and Louisiana. Alcorn State University 

25 (enrollment 3,252, fall 2011) is located 10.5 mi (17 km) southwest of GGNS. The nearest 

26 occupied residence is 0.83 mi (1.3 km) east of GGNS. Prominent features of the surrounding 

27 area, out to 50 mi (80 km), are shown in Figure 2–1 (Entergy 2011a). 

28 2.2.2 Air Quality and Meteorology

29 GGNS is located on the east bank of the Mississippi River in Claiborne County in southwestern 

30 Mississippi (NRC 2006a). The site is located approximately 150 mi (240 km) from the coast of 

31 the Gulf of Mexico, which has a moderating effect on the climate. During most of the year, the 

32 dominant air mass in the region is maritime tropical. As a result, the climate of the region is 

33 significantly humid during most of the year, with long, warm summers and short, mild winters. 

34 Occasional cold spells are associated with outbreaks of continental polar air but are usually of 

35 short duration. In summer, temperatures above 100 °F (38 °C) are infrequent and extended 

36 periods of very hot temperatures in the summers are rare. The location and seasonal intensity 

37 of the Bermuda High, which is a semi-permanent area of high pressure, can dominate an entire 

38 season in Mississippi (NCDC 2012a). 

39 The nearby terrain consists mainly of forest and agricultural lands. The Louisiana side of the 

40 Mississippi River is typically a flat alluvial plain, while the Mississippi side is typically upland and 

41 rolling, forested hill country. These terrain features do not appreciably influence the local 

42 climate around the GGNS site (NRC 2006a). 

43 The area around the site is characterized by light winds. Based on 2006–2011 wind 

44 measurements taken at two levels at GGNS, average wind speeds are about 4.3 mph (1.9 m/s) 

45 at the lower level (a height of 33 ft (10 m)) and 8.3 mph (3.7 m/s) at the higher level (a height of 

46 162 ft [50 m]) (GGNS 2012a, GGNS 2012c), as shown in Figure 2–8. During the same period, 

47 highest wind speeds of 22.7 mph (10.1 m/s) and 34.1 mph (15.2 m/s) were recorded at the 
Affected Environment

2-18

1 lower and higher levels, respectively. Seasonal average wind speeds at both levels are highest 

2 in winter and about 50 percent higher than the lowest in summer. Although not prominent, 

3 prevailing wind directions are from the northeast (about 9.2 percent of the time) at the lower 

4 level and from the southeast (about 11.6 percent of the time) at the higher level. At the lower 

5 level, winds from the northeast and southeast quadrants are far more frequent than winds from 

6 the northwest and southwest quadrants. However, at the higher level, winds from the southeast 

7 are far more frequent than winds from the three other quadrants, which are equally distributed. 

8 By season, prevailing wind directions at the lower level are south in spring, northeast in summer 

9 and fall, and north in winter. In contrast, prevailing wind directions at the higher level swing from 

10 southeast to south-southwest throughout the year. The wind patterns at the higher level reflect 

11 the regional wind patterns, while those at the lower level seem to be influenced by local 

12 topography and nearby vegetation.

13 The long-term (48 years) annual average temperature at Jackson International Airport, which is 

14 located about 60 mi (96.5 km) east-northeast of GGNS, was 64.7 °F (18.2 °C) (NCDC 2012b). 

15 During these years, monthly average temperatures ranged from 45.7 °F (7.6 °C) in January to 

16 81.8 °F (27.7 °C) in July. From 1971–2000, the average number of days with maximum 

17 temperatures greater than or equal to 90 °F (32.2 °C) was about 84. In contrast, about 46 days 

18 had minimum temperatures at or below freezing, and none of the days had minimum 

19 temperatures below 0 °F (-17.8 °C). During the last 47-year period, the highest temperature, 

20 107 °F (41.7 °C), was reached in August 2000, and the lowest, 2 °F (-16.7 °C), in January 1985.

21 Based on 2006–2011 measurements at GGNS, average temperature with an annual average of 

22 64.9 °F (18.3 °C) and monthly averages ranging from 47.0 °F (8.3 °C) in January and 80.3 °F 

23 (26.8 °C) in August are similar to those at the Jackson International Airport. For the 2006–2011 

24 period, the lowest and highest temperatures recorded at GGNS were 17.4 °F (-8.1 °C) and 99.7 

25 °F (37.6 °C), respectively (GGNS 2012a, GGNS 2012c).

26 Mississippi, along with other coastal states along the Gulf of Mexico, is situated in one of the 

27 wettest regions in the United States. Based on data from 1971–2000, the annual average 

28 precipitation at Jackson International Airport was about 55.95 in. (142 cm) (NCDC 2012b). 

29 Annually, about one third of the days (about 110 days) experienced a measurable precipitation 

30 (0.01 in. [0.025 cm] or higher). Precipitation is fairly well-distributed throughout the year, with 

31 monthly precipitation ranging from 3.23–5.98 in. (8.20–15.19 cm). In general, monthly 

32 precipitation is lower from May through October, and higher from November through April (with 

33 the exception of February). At GGNS, the annual average precipitation for 2006–2011 was 

34 about 49.63 in. (126.1 cm) and ranged from 38.43–58.50 in. (97.6–148.6 cm). For the same 

35 period, the annual average precipitation and monthly precipitation patterns at the site are similar 

36 to those in Jackson, Mississippi (GGNS 2012a, GGNS 2012c). Snow in this area starts as early 

37 as November and continues as late as April. Most of the snow falls from December through 

38 March, with a peak in January that accounts for about 60 percent of snowfalls. The annual 

39 average snowfall at the Jackson International Airport is about 0.9 in. (2.3 cm) (NCDC 2012b).
Affected Environment

2-19

1 Figure 2–8. GGNS Wind at 33-ft (10-m) and 162-ft (50-m), 2006–2011 (GGNS 2012)

2 The 30-year (1971–2000) relative humidity has an annual average of about 75 percent and 

3 diurnal variation from 58 percent at 12 p.m. to 91 percent at 6:00 a.m. Hourly average relative 

4 humidity ranges from 53 percent at 12 p.m. in April to 95 percent at 6:00 a.m. in August. For 

5 each hour, monthly variations in relative humidity are relatively small. When the relative 

6 humidity is near 100 percent, small water droplets (fog) form in the atmosphere and degrade 

7 visibility. At Jackson, heavy fog, defined as visibility of 1/4 mile (0.4 km) or less, occurs about 
Affected Environment

2-20

1 20 days per year based on the last 48 years of data. Heavy fog is more frequent in winter 

2 months than in summer months, with the lowest of 0.8 days in June and the highest of about 

3 2.9 days in December (NCDC 2012b). 

4 Severe weather events, such as floods, hail, high winds and thunderstorm winds, snow and ice 

5 storms, tornadoes, and hurricanes have been reported for Claiborne County (NCDC 2012c). 

6 Other significant weather can be associated with these events. For example, lightning, hail, and 

7 high winds frequently occur with thunderstorms, and tornadoes can occur with both 

8 thunderstorms and hurricanes (NRC 2006a). 

9 Based on the data for the last 48-year period, thunderstorms occur about 67.3 days per year at 

10 Jackson (NCDC 2012b). Thunderstorms are least frequent in winter (the lowest of 2.3 days in 

11 December) and most frequent in summer (the highest of 12.7 days in July). In the warmer 

12 season, prevailing southerly winds provide humid, semitropical conditions often conducive to 

13 creating afternoon thunderstorms. Thunderstorms sometimes are accompanied by high winds, 

14 mostly occurring from March through June. The highest recorded thunderstorm wind speed of 

15 about 100 mph (45 m/s) occurred in April 1956 (NCDC 2012c).

16 Since 1999, 13 floods were reported in Claiborne County, 11 of which were classified as flash 

17 floods (NCDC 2012c). In Mississippi, the flood season is from November through June 

18 (coincident with the period of greatest rainfall), with peaks in March and April, but flooding is 

19 also associated with persistent thunderstorms in summer and tropical cyclones in late summer 

20 or early fall (NCDC 2012a).

21 Tornadoes occur frequently in Mississippi, many of which are violent. Based on 1991–2010 

22 data, Mississippi is in the higher range among the U.S. states in terms of average number of 

23 tornadoes per unit area and average number of strong-violent (on the enhanced Fujita scale of 

24 EF3 to EF5) tornadoes per unit area (NCDC 2012d). From 1957 to March 2012, a total of 

25 29 tornadoes were reported in Claiborne County, mostly occurring in non-summer months with 

26 a peak of 6 tornadoes in November (NCDC 2012c). Magnitudes of tornadoes for 

27 pre-2006 years are not available but, since 2006, the worst tornado in Claiborne County was an 

28 EF2 reported in March 2012. Historically, a tornado struck the GGNS site shortly after 

29 11:00 p.m. on April 17, 1978, when two GGNS units were under construction (NRC 2006b). 

30 The damage path at the plant site was approximately 1,500–1,800 ft (457–549 m) wide, and the 

31 highest onsite wind speeds were estimated to be in the 125–150 mph (56–67 m/s) range. The 

32 collapse of construction cranes caused major damage to the power plant facility; high winds 

33 also extensively damaged the switchyard installation (NRC 2006a).

34 Tropical cyclones strike the Gulf Coast along the Louisiana and Mississippi coastlines with 

35 expected return periods of 7 to 14 years for any hurricane and 20 to 34 years for a major 

36 hurricane (Category 3 or higher) passing within 50 nautical miles (57.5 mi or 92.6 km) 

37 (Blake et al. 2011). In general, impacts due to high winds from hurricanes include loss of life 

38 and property damage but are limited mainly to the coastal areas. Most of these high winds are 

39 weakened by passage over land and could cause rain damage to crops and considerable 

40 flooding of inland areas (NCDC 2012a). Since 1851, 64 tropical cyclones have passed within 

41 100 mi (161 km) of the GGNS site, 14 of which were classified as hurricanes (CSC 2012). 

42 Among the 14 hurricanes, the strongest ever recorded were 3 Category 3 hurricanes: 1 not 

43 named (1909), Camille (1969), and Elena (1985). 

44 2.2.2.1 Air Quality

45 The Air Division of MDEQ is the regulatory agency whose primary responsibility is to ensure that 

46 air quality within Mississippi is protective of public health and welfare. MDEQ is charged with 

47 controlling, preventing, and abating air pollution to achieve compliance with air emission 
Affected Environment

2-21

1 regulations pursuant to the Mississippi Air and Water Pollution Control Act, applicable 

2 regulations promulgated by the EPA, and the Federal Clean Air Act (MDEQ 2012a). 

3 A facility is defined as a “major” source if it has the potential to emit 100 tons (90.7 metric tons) 

4 or more per year of one or more of the criteria pollutants, or 10 tons (9.07 metric tons) or more 

5 per year of any of the listed hazardous air pollutants (HAPs), or 25 tons (22.7 metric tons) or 

6 more per year of an aggregate total of HAPs. Major sources are subject to Title V of the Clean 

7 Air Act (CAA) (42 U.S.C. 7401 et seq.), which standardizes air quality permits and the permitting 

8 process across the United States. Permit stipulations include source-specific emission limits, 

9 monitoring, operational requirements, recordkeeping, and reporting. A “synthetic minor” (or 

10 “conditional major”) source has the potential to exceed major source emission thresholds but 

11 avoids major source requirements by accepting Federally enforceable permit conditions limiting 

12 emissions below major source thresholds. The “small” (or “minor”) source has no potential for 

13 exceeding major source emission thresholds. 

14 GGNS has the following sources of criteria pollutants and HAPs (Entergy 2011a; GGNS 2008): 

15 (1) combustion sources: standby emergency diesel generators, fire water pump diesel engines, 

16 the Energy Services Center diesel generator, the Operations Support Center diesel generator, 

17 diesel start engines, water well diesel engine, outage equipment, and a telecommunications 

18 emergency diesel generator; (2) bulk material storage tanks: diesel, gasoline, lube oil, hydraulic 

19 oil, and used oil tanks; (3) other sources, such as: natural draft and auxiliary cooling towers, 

20 standby service water cooling towers, and sand blasting/painting; and (4) miscellaneous 

21 sources, such as: small diesel generators, welding, hand-held equipment, and laboratory hoods. 

22 GGNS is classified as a “synthetic minor” source (air permit number 0420-00023) (GGNS 2008). 

23 Although GGNS may periodically use a portable auxiliary boiler or generator(s) during power 

24 outages, nonradioactive combustion-related gaseous effluents result primarily from testing and 

25 preventive maintenance of emergency generators and diesel pumps operating on an 

26 intermittent basis. To comply with the National Ambient Air Quality Standards (NAAQS) and to 

27 ensure that potential air quality impacts are maintained at minimal levels, the MDEQ governs 

28 the discharge of regulated pollutants by limiting operational run times and sulfur limits stipulated 

29 in the operating permit. GGNS reports operating hours for selected equipment to show 

30 compliance with permit limitations, but it has no requirements to report annual emissions 

31 inventory data to the MDEQ. Continuous emission sources at the GGNS site include cooling 

32 towers, which emit particulate matter as drift. The GGNS air permit does not require reporting 

33 of cooling tower operating hours.

34 Air emission sources at GGNS emit criteria pollutants, volatile organic compounds (VOCs), and 

35 HAPs into the atmosphere. Maximum allowable emissions from the entire facility, in 

36 accordance with operating permit requirements, are presented in Table 2–1, which includes air 

37 emissions from all stationary combustion and cooling tower sources at the site (GGNS 2008). 

38 Because emission sources are operating well below the maximum operating hours specified in 

39 the permit, actual emissions of criteria pollutants, VOCs, and HAPs are typically well below the 

40 maximum allowable emissions for a “synthetic minor” source. From 2006–2011, there have 

41 been no regulatory notices of violation issued to GGNS, based on a review of records 

42 associated with the air permit (Entergy 2011a).

43 As shown in Table 2–1, annual emissions for greenhouse gases (GHGs), which include those 

44 from stationary and mobile sources, are presented in terms of carbon dioxide equivalent (CO2e). 

45 “Carbon dioxide equivalent” adjusts for different global warming potentials for different GHGs. 

46 Total annual GHG emissions from GGNS were estimated to be about 5,980 tons CO2e

47 (5,425 metric tons CO2e) in 2011 (EPA 2011; GGNS 2012b), which is well below EPA’s 

48 mandatory reporting threshold of 25,000 metric tons CO2e per year (74 FR 56264). GGNS 
Affected Environment

2-22

1 emits GHGs such as CO2, methane (CH4), and nitrous oxide (N2O) from combustion sources. 

2 Additionally, GGNS uses GHGs such as hydrofluorocarbons (HFCs) in the two plant cooling 

3 water chillers as refrigerants and sulfur hexafluoride (SF6) in three electrical disconnect 

4 switches. GGNS does not use perfluorocarbons (PFCs).

5 Table 2–1. Permitted Maximum Allowable Emission Limits for 

Criteria Air Pollutants and Volatile Organic Compounds (VOCs)(a) 6 

7 and Estimated Annual CO2e Emission Rate at GGNS

Pollutant(b)

Emission Limits and CO2e Emission Rate

(lb/hr) (tons/yr)

CO 225.03 25.17

NOx 850.41 98.18

PM10 42.07 68.73

SO2 264.13 26.44

VOCs 24.80 12.94

CO2e -

(c) 5,980

(5,425)(d)

(a) Estimated based on maximum operating hours specified for permitted sources, including stationary combustion 

sources and cooling towers.

(b) CO = carbon monoxide; CO2e = carbon dioxide equivalent; NOx = nitrogen oxides; PM10 = particulate matter with 

an aerodynamic diameter of ≤10 μm; SO2 = sulfur dioxide; and VOCs = volatile organic compounds.

(c) A hyphen denotes that the data are not available.

(d) Values in parentheses are in metric tons carbon dioxide equivalent. 

Source: EPA (2011); GGNS (2008); GGNS (2012b).

8 Under the CAA, EPA has set NAAQS for pollutants considered harmful to public health and the 

9 environment (40 CFR Part 50). NAAQS are established for criteria pollutants: carbon

10 monoxide (CO); lead (Pb); nitrogen oxides (NOx); particulate matter with an aerodynamic

11 diameter of 10 microns or less and 2.5 microns or less (PM10 and PM2.5, respectively);

12 ozone (O3); and sulfur dioxide (SO2) (EPA 2012a). The CAA established two types of NAAQS: 

13 primary standards to protect public health, including sensitive populations, such as asthmatics, 

14 children, and the elderly; and secondary standards to protect public welfare, including protection 

15 against decreased visibility and damage to animals, crops, vegetation, and buildings. Individual 

16 states can have their own State Ambient Air Quality Standards (SAAQS), but SAAQS must be 

17 at least as stringent as the NAAQS. If a state has no standard corresponding to one of the 

18 NAAQS, or the SAAQS is not as stringent as the NAAQS, then the NAAQS apply. Except for 

19 odor, Mississippi has adopted the NAAQS (MDEQ 2012b), as presented in Table 2–2.
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Table 2–2. National Ambient Air Quality Standards (NAAQS)(a),(b) 1 

Pollutant(c) Averaging Time NAAQS

Value Type(d)

CO 1-hour 35 ppm P

8-hour 9 ppm P

Pb Rolling 3-month 

average 0.15 μg/m3 P, S

NO2

1-hour 100 ppb P 

Annual

(arithmetic average) 53 ppb P, S

O3 8-hour 0.075 ppm P, S

PM10 24-hour 150 μg/m3 P, S

PM2.5

24-hour 35 μg/m3 P, S

Annual

(arithmetic average) 15 μg/m3 P, S

SO2

1-hour 75 ppb P 

3-hour 0.5 ppm S

(a) Except for odor, the ambient air quality standards for Mississippi are the primary and secondary NAAQS as duly 

promulgated by EPA. (b) Refer to 40 CFR Part 50 for detailed information on attainment determination and reference method for 

monitoring.

(c) CO = carbon monoxide; NO2 = nitrogen dioxide; O3 = ozone; Pb = lead; PM2.5 = particulate matter with an 

aerodynamic diameter of ≤2.5 μm; PM10 = particulate matter with an aerodynamic diameter of ≤10 μm; and 

SO2 = sulfur dioxide.

(d) P = primary standards, which set limits to protect public health, including the health of “sensitive” populations 

such as asthmatics, children, and the elderly; S = secondary standards, which set limits to protect public welfare 

including protection against decreased visibility, damage to animals, crops, vegetation, and buildings.

Sources: EPA (2012c); MDEQ (2012b).

2 EPA designates areas that meet NAAQS as “attainment areas.” Areas that exceed NAAQS are 

3 designated as “nonattainment areas.” Areas that previously were nonattainment areas but 

4 where air quality has improved to meet the NAAQS are redesignated “maintenance areas,” 

5 subject to an air quality maintenance plan. Claiborne County, Mississippi, where GGNS is 

6 located, is part of the Mobile (Alabama)-Pensacola-Panama City (Florida)-Southern Mississippi 

7 Interstate Air Quality Control Region (AQCR) (40 CFR 81.68), which includes 3 southwestern 

8 counties in Alabama, 10 northwestern panhandle counties in Florida, and 37 southern counties 

9 in Mississippi. The area across the Mississippi River from the site is in the Monroe 

10 (Louisiana)-El Dorado (Arkansas) Interstate AQCR (40 CFR 81.92). The EPA has designated 

11 all of the counties in these AQCRs adjacent to the GGNS site as in compliance with the NAAQS 

12 (40 CFR 81.301, 81.304, 81.310, 81.319, and 81.325). Mississippi is in attainment with primary 

13 and secondary NAAQS for all criteria pollutants, except De Soto County which is located about 

14 200 miles (322 km) north-northeast of GGNS and part of which was recently designated as a 

15 marginal nonattainment area for the 2008 8-hour ozone standard. Outside of Mississippi, the 

16 nearest nonattainment areas include the Birmingham area in Alabama for PM2.5 and the 

17 Houston-Galveston-Brazoria area in Texas for 8-hour ozone (O3), both of which are located 

18 about 240 mi (386 km) east-northeast and west-southwest, respectively, of GGNS. The nearest 

19 maintenance area is the Baton Rouge area in Louisiana for 8-hour O3, which is located about 

20 90 mi (145 km) south of GGNS.
Affected Environment

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1 In recent years, three revisions to NAAQS have been announced. Effective January 12, 2009, 

EPA revised the Pb standard from a calendar-quarter average of 1.5 μg/m3 2 to a rolling 3-month 

average of 0.15 μg/m3 3 (73 FR 66964). Effective April 12, 2010, EPA established a new 1-hour 

4 primary NAAQS for NO2 at 100 ppb (75 FR 6474) and effective August 23, 2010, EPA 

5 established a new 1-hour primary NAAQS for SO2 at 75 ppb (75 FR 35520). Notwithstanding 

6 these revisions to the NAAQS, the attainment status for Claiborne County will not be affected 

7 because concentration levels at nearby monitoring stations are relatively low compared to the 

8 NAAQS and generally are trending downward as discussed below.

9 Through operation of a network of air monitoring stations, MDEQ evaluates compliance with

10 NAAQS. The MDEQ monitors all criteria air pollutants, except CO and Pb. Monitoring for CO 

11 and Pb was discontinued because the measured concentrations were much lower than the 

12 NAAQS limits. Currently, no air monitoring data are available in Claiborne County 

13 (MDEQ 2011c), but air monitoring stations exist in nearby Adams County where the city of 

14 Natchez is located, and Hinds County where Jackson is located. Eight-hour O3 and PM2.5 data 

15 collected in these counties indicated a general downward trend for these pollutants from 

16 2001–2010. Only Jackson County, which is located in the southeastern corner of the State and 

17 abuts the Gulf of Mexico, monitors NO2 and SO2 in Mississippi and also exhibits a general 

18 downward trend during the same period. As a result, Mississippi meets all NAAQS based on air 

19 monitoring data scattered around the State.

20 While the NAAQS place upper limits on the levels of air pollution, Prevention of Significant 

21 Deterioration (PSD) regulations (40 CFR 52.21) place limits on the total increase in ambient 

22 pollution levels above established baseline levels for SO2, NO2, PM10, and PM2.5, thus 

23 preventing “polluting up to the NAAQS.” These allowable increments are smallest in Class I 

24 areas, such as national parks and wilderness areas, and less limiting in other areas. A major 

25 new source or modification of an existing major source located in an attainment or unclassified 

26 area must meet stringent control technology requirements. As a matter of policy, EPA

27 recommends that the permitting authority notify the Federal Land Managers (FLMs) when a 

28 proposed PSD source will be located within 62 mi (100 km) of a Class I area. If the source’s 

29 emissions are large, EPA recommends that sources beyond 62 mi (100 km) be brought to the 

30 attention of the FLMs. The FLMs then become responsible for determining whether the 

31 source’s emissions could have an adverse effect on air quality related values (AQRVs), such as 

32 scenic, cultural, biological, and recreational resources. There are no Class I areas in 

33 Mississippi and none of the Class I areas in other nearby states are located within the 

34 aforementioned 62-mi (100-km) range. The nearest Class I area is Breton Wilderness Area in 

35 Louisiana managed by the U.S. Fish and Wildlife Service (40 CFR 81.412), which is located 

36 about 186 mi (300 km) southeast of GGNS. Considering the locations of and intervening terrain 

37 features to any nearby Class I areas around GGNS, prevailing wind directions, distances from 

38 GGNS, and the minor nature of air emissions from GGNS, there is little likelihood that activities 

39 at GGNS would adversely impact air quality and AQRVs in this Class I area.

40 GGNS has a primary and backup tower for monitoring and collecting meteorological data. The 

41 primary tower is 162 ft (50 m) high. It has instrumentation at heights of 162 ft (50 m) and 33 ft 

42 (10 m). The backup tower is 33 ft (10 m) high. Along with an instrument shack, these towers 

43 are located in an open area surrounded by tall vegetation about 0.9 mi (1.4 km) north-northwest 

44 of the reactor control building. The backup tower and instrument shack are located about 300 

45 and 430 ft (91 and 131 m), respectively, north-northeast of the primary tower. Onsite 

46 meteorological monitoring began in March 1972. The original meteorological monitoring system 

47 was replaced in December 2000. This current monitoring system will continue to serve for the 

48 period of extended operation, with no major changes or upgrades anticipated (GGNS 2010b). 
Affected Environment

2-25

1 The primary tower monitors wind speed, wind direction, and ambient temperature along with 

2 differential temperature and data used to determine atmospheric stability collected at both 162 ft 

3 (50 m) and 33 ft (10 m). Relative humidity data is collected only at 33 ft (10 m), while 

4 precipitation data using a tipping bucket rain gauge is collected at the ground level. 

5 Meteorological data from the primary tower is supplemented with those from the backup tower. 

6 The backup tower monitors wind speed, wind direction, ambient temperature, and atmospheric 

7 stability data. GGNS uses data processing procedures for analyzing meteorological data. 

8 Observations are averaged to 15-minute and hourly values and are made available to the 

9 GGNS plant computer and then this information is transmitted to the control room. Information 

10 from both towers is provided to the reactor control room (GGNS 2010b). 

11 The data processing procedures for GGNS meteorological data involve three basic steps: 

12 (1) data collection (recorded in digital form); (2) data editing and consolidation; and (3) data 

13 analysis. For steps (2) and (3), computer software has been developed to process the collected 

14 data. The plant data computer receives data measurements at least every 10 seconds. Data is

15 recorded each time a value varies by a preset amount. Each piece of data is checked to assure 

16 it is between the minimum and maximum instrument limits. This quality indication and the time 

17 are recorded with each value. An average is calculated every 15 minutes and each hour. The 

18 quality of the samples is reflected in the quality of the average. This quality indication and the 

19 time the average was calculated are recorded with each value. The meteorological data, for 

20 which readings are available every 10 seconds or less, a 15-minute average, and an hourly 

21 average, are relayed to the main control room by the plant computer (GGNS 2010b). 

22 Based on the NRC’s Regulatory Guide 1.23, “Meteorological Monitoring Programs for Nuclear 

23 Power Plants,” meteorological instruments should be inspected and serviced at a frequency that 

24 will ensure data recovery of at least 90 percent annually. GGNS has established procedures for 

25 the inspection and maintenance of the onsite meteorological system. Routine inspections are 

26 made to ensure proper operation of equipment and that no damage to the towers, instrument 

27 shack, or any other structure or equipment has occurred. Semi-annual visual inspections of the 

28 tower and equipment are made to determine the conditions of sensors, cabinets, wiring, 

29 structures, and individual components. Semi-annual checks for proper instrumentation readings 

30 are performed. All calibrations at the site are performed in compliance with the 

31 recommendations of Regulatory Guide 1.23. Based on the 2006–2011 onsite meteorological 

32 data, the data recovery rates for all meteorological parameters from the meteorological 

33 monitoring system at GGNS were over 90 percent.

34 2.2.3 Geologic Environment

35 This section describes the current geologic environment of GGNS and vicinity, including 

36 topography, geology, soils, and seismic conditions. 

37 2.2.3.1 Topography and Geology 

38 GGNS is bounded by the Mississippi River on the west. The western half of the site is called 

39 the lowland plain and lies in the floodplain of the Mississippi River. This portion of GGNS has a 

40 generally level topography, with elevations that vary from 55–75 ft (16.7–22.8 m) above MSL 

41 (Figure 2–7). This area also contains Hamilton and Gin Lakes. These oxbow lakes were once 

42 a channel of the Mississippi River. They have an average depth of approximately 8–10 ft (2.4–

43 3 m).

44 The reactor building and most of the associated facilities are located in the eastern half of the 

45 site, which is called the upland area. The upland area is separated from the lowland plain by 

46 steep bluffs that trend north-south through the middle portion of the site. The topography in the 

47 upland area rises from the floodplain as rough, irregular bluffs, with steep slopes and deep-cut 
Affected Environment

2-26

1 stream valleys and drainage courses. The surface topography in the upland area ranges from 

2 80–200 ft (24–61 m) above MSL. Most of the facilities are located about 132.5 ft (40.3 m) 

3 above MSL. The upland area has two drainage channels that trend east-west. One drainage 

4 channel (Stream A) is north of the reactor and site facilities and the other (Stream B) is south of 

5 the main plant complex.

6 The lowland plain is underlain by the Mississippi River Alluvium. At the land surface, it consists 

7 of a layer of clay and silt that overlies interbedded layers of stream-deposited sand, gravel, silt, 

8 and clay. The alluvium generally ranges from 95–182 ft (29–55 m) thick. On GGNS, the 

9 lowland plain extends from the Mississippi River to the bluffs of the upland area.

10 The upland area is underlain by loess deposits. The loess deposits are made up of about 

11 75 ft (23 m) of fine-grained silt deposited by wind and comprise the bluffs that rise above the 

12 floodplain of the Mississippi River. The loess deposits are underlain by the Upland Complex, 

13 which is comprised of two stream-deposited terraces, the Upland Complex Alluvium and the 

14 Upland Complex Old Alluvium. These terrace deposits are thickest near the bluffs (up to 

15 150 ft (46 m) thick) and thinnest near the power block area (about 40 ft (12 m) thick) 

16 (GZA GeoEnvironmental Inc. 2009). The Upland Complex Alluvium is typically comprised of 

17 sands and clayey, silty sands, while the Upland Complex Old Alluvium is comprised of clayey, 

18 silty sands with coarse grained sands and gravels. Neither upland complex unit is found west of 

19 the bluffs of the upland area, as they have been removed by the erosive activity of the 

20 Mississippi River and replaced by Mississippi River Alluvium. 

21 The Upland Complex Alluvium, the Upland Complex Old Alluvium, and the Mississippi Alluvium 

22 are all underlain by the Catahoula Formation. The Catahoula Formation underlies the entire 

23 GGNS property. It consists of lenticular deposits of sand, clayey silt, and sandy-silty clay. The 

24 sand layers are predominantly fine-grained and range in thickness from a few inches to more 

25 than 100 ft (30 m) thick. 

26 At the site, the Catahoula Formation is underlain by the Bucatunna Formation (Entergy 2011a). 

27 It is composed of clay and is about 100-ft (30-m) thick at the site. Underneath the Bucatunna 

28 Formation is the Glendon Formation, which is made up of beds of limestone. Figures 2–9, 

29 2–10, and 2–11 contain generalized geologic cross-sections that illustrate the stratigraphy 

30 across the site from east to west.

31 2.2.3.2 Soils 

32 U.S. Department of Agriculture (USDA 2012) soil unit mapping identifies the area of the site on 

33 the Mississippi River alluvial valley (mostly Bowdre soil) as being made up of soils that are 

34 somewhat poorly drained, frequently flooded, and in locations where the water table is near the 

35 land surface. The soil is comprised of clayey alluvium over loamy alluvium. In areas that 

36 underlie surface drainage areas (Adler silt loam), soils are moderately well drained and 

37 occasionally flooded. These soils are made up of silt loam. The upland area of the site is 

38 largely made up of soils that developed in loess (mostly Memphis and Natchez silt loams). The 

39 depth to the water table for these soils generally is in excess of 6 ft (1.8 m). They are well 

40 drained and not prone to flooding. Their typical texture is silty loam to silty clay loam.

41 2.2.3.3 Seismic Setting 

42 The region is characterized by extremely low rates of earthquake activity. The rate of 

43 earthquake activity in the Gulf Coastal Plain is among the lowest in the United States (Entergy 

44 2011a). 

45 The earliest recorded and strongest earthquake (magnitude 4.6) within Mississippi occurred at 

46 Charleston, Mississippi, on December 16, 1931. In the area of maximum intensity, the walls 
Affected Environment

2-27

1 and foundation of an agricultural high school cracked and several chimneys were thrown down. 

2 The shock was perceptible over a 65,000 square mile area, including the northern two-thirds of 

3 Mississippi and adjacent portions of Alabama, Arkansas, and Tennessee. Two earthquakes 

4 greater than a magnitude 3.5 occurred within Mississippi (USGS 2012a, 2012b) between 1976 

5 and 2003. During that same time period, neighboring Louisiana had one earthquake greater 

6 than a magnitude 3.5.

7 Figure 2–9. Location Map for Geologic Cross-Sections A-A' and B-B' 

8 Source: Modified from Entergy 2011a
Affected Environment

2-28

1 Figure 2–10. Geologic Cross Section A-A' 

2 Source: Modified from Entergy 2011a
Affected Environment

2-29

1 Figure 2–11. Geologic Cross Section B-B' 

2 Source: Modified from Entergy 2011a B 150 i 0 Mississippi River Alluvium 0 z / i·50 J 0 g . -1oo Catahoula Fm. ·150 

·200 

ApproXimate boundary between 

fine-and coarse-grained alluvium 

Bl 

I 

150 

All 100 

50 

0 i 

0 

z 

-50 i 

8 

., 

·100 

Iii 

150 

·200 

·250 
Affected Environment

2-30

1 Although the number of earthquakes reported within Mississippi’s boundaries is small, the State 

2 has been affected by numerous shocks located in neighboring states. In 1811 and 1812, a 

3 series of earthquakes (maximum magnitude 7.7) occurred, near New Madrid, in southeast 

4 Missouri and was felt as far south as the Gulf Coast. This series of earthquakes caused the 

5 banks of the Mississippi River to cave in as far south as Vicksburg, more than 300 mi (483 km) 

6 from the epicentral region. While earthquakes still occur in the New Madrid area, it is far 

7 enough away that only a very small probability exists of experiencing damaging earthquake 

8 effects in the area of GGNS (FEMA 2012).

9 The geologic setting and modern tectonic framework suggest that the earthquake hazard for the 

10 region will remain low for the foreseeable future. There have been no active faults found within 

11 a 5 mi (8 km) radius of the site (Entergy 2011a).

12 2.2.4 Surface Water Resources

With an average discharge of 593,000 cfs (16,792 m3 13 /s), the Mississippi River is the largest river 

14 in the United States. The western boundary of the site begins at the river’s eastern bank. At 

15 the site, the Mississippi River is about 0.5 mi (0.8 km) wide at low flow and about 1.4 mi 

16 (2.3 km) wide during a typical annual high-flow period. The lowland plain between the river and 

17 the upland area is subject to nearly annual flooding by the Mississippi River. The plain contains 

18 Hamilton and Gin Lakes, which are two shallow oxbow lakes (created in a now abandoned 

19 former river channel) and a small borrow pit (created during plant construction). Under 

20 non-flooding conditions, watersheds that drain the upland area discharge water into Hamilton or 

21 Gin Lakes. Gin Lake discharges water into Hamilton Lake through a culvert. Hamilton Lake 

22 discharges into the Mississippi River (Entergy 2011a). 

23 The upland area is drained by two watersheds. Watershed A is north of Watershed B. The 

24 watersheds are drained by Stream A and Stream B, respectively. The estimated areas of 

Watershed A and Watershed B are 2.94 mi2 (7.6 km2

) and 0.68 mi2 (1.7 km2 25 ), respectively. 

26 Water from each watershed flows through sedimentation basins before flowing into either 

27 Hamilton or Gin Lakes (Figure 2–12).

28 Surface water discharges that flow to the Mississippi River from the site are permitted by the 

29 MDEQ NPDES program. The current permit authorizes discharges at 11 outfalls (locations). 

30 Three of the outfalls monitor discharges to surface water outside the site boundary (external 

31 outfalls); eight of the outfall locations monitor discharges within the site boundary (internal 

32 outfalls). 

33 The three external outfalls (Outfalls 001, 013, and 014) monitor all releases to surface water

34 from GGNS. Outfall 001 is a 54-in. (137-cm) diameter pipe that discharges in the barge slip 

35 along the Mississippi River. It receives water from internal outfalls, including cooling tower 

36 blowdown, standby service water leakage, the low volume waste basin, liquid radwaste, and 

37 storm water. Outfall 013 is the discharge from the northwest end of Sedimentation Basin A to 

38 Hamilton Lake; it includes sanitary wastewater effluent from the onsite wastewater treatment 

39 plant and storm water. Outfall 014 is at the northwest end of Sedimentation Basin B. This basin 

40 receives various effluents at Outfall 007 through a large concrete structure at its southeast end 

41 with an approximately 20-ft (6-m) diameter corrugated metal pipe discharging water from 

42 Stream B (designed to convey storm water from the site from a 100-year storm event). 

43 Outfall 007 also receives miscellaneous wastewaters; such as heating, ventilation, and air 

44 conditioning (HVAC) blowdown; air conditioner cooling water; oily waste sumps; ionic reject 

45 water; and turbine building cooling water blowdown.
Affected Environment

2-31

1 Figure 2–12. GGNS Surface Water Features

2 Source: Modified from Entergy 2011a

3 Permit conditions require flow reporting at all outfalls and value reporting or monthly average 

4 and/or maximum of various other parameters. Depending on the outfall, these parameters may 

5 include water temperature, free available chlorine, zinc, oil and grease, total suspended solids, 
Affected Environment

2-32

1 total residual chlorine, biochemical oxygen demand, and fecal coliform. Iron, arsenic, and 

2 copper must be reported at some outfalls, and a range of pH (6.0–9.0 standard units) is required 

3 at several outfalls. Details are provided in GGNS’s Certificate of Permit Coverage under 

4 Mississippi’s Baseline Storm Water General NPDES Permit (MDEQ 2010a). The permit also 

5 specifies a maximum Mississippi River water temperature increase of 5 °F (2.8 °C) beyond a 

6 mixing zone. Thermal monitoring is required during certain low-flow river conditions. 

7 The Ranney wells each have their own service water system for motor cooling. Permitted 

8 discharge from each is back to the Mississippi River through an underground pipe

9 (MDEQ 2011b). 

10 In March 2011, GGNS had one EPA violation in its effluent monitoring at Outfall 007 for total 

11 suspended solids (TSS) (EPA 2012a). The violation was because of an average TSS of 

12 31 mg/L, when the average limit is 30 mg/L. This was not considered a significant 

13 noncompliance effluent violation. The ER (Entergy 2011a) lists several other noncompliances 

14 from 2006–2010. These included three pH exceedances, a zinc exceedance, a free residual 

15 chlorine exceedance, and an unauthorized discharge. 

16 As described above, GGNS has an NPDES permit (MDEQ 2011a) to discharge wastewater in 

17 accordance with effluent limits, monitoring requirements, and other permit conditions. Under 

18 Section 401 of the Clean Water Act (CWA), an entity requiring a Federal permit for any activity 

19 that may result in a discharge to navigable waters of the United States must obtain a 401 Water 

20 Quality Certification from the state in which the discharge will occur to ensure that the discharge 

21 complies with state water quality standards. Mississippi issued a water quality certification for 

22 GGNS in 1974. In a letter dated October 17, 2011, MDEQ stated that the water quality 

23 certification remains in effect as long as GGNS does not expand its footprint, increase its water 

24 discharge, engage in any new activity that would trigger the need for a new certification from the 

25 State, and remains in compliance with State and Federal regulations to refrain from violating the 

26 State’s water quality standards (MDEQ 2011b).

27 A storm water pollution prevention plan (GGNS 2006) and a permit to discharge storm water 

28 (MDEQ 2010a) are also maintained for the site. The plan documents best management 

29 practices (BMPs), potential pollutant sources, and other aspects related to storm water quality. 

30 According to GGNS staff at the environmental site audit, no dredging takes place at the 

31 Mississippi River barge slip or at the sedimentation basins. 

32 2.2.5 Groundwater Resources

33 2.2.5.1 Mississippi River Alluvium 

34 The Mississippi River Alluvium forms an aquifer underlying both the river and the lowland plain. 

35 The water table in the lowland plain is at most a few feet beneath the ground surface 

36 (NRC 2006a). The Mississippi River Alluvial Aquifer is in close hydraulic connection with the 

37 river. Increases or decreases in Mississippi River water levels cause changes in the direction of 

38 flow in the Mississippi River Alluvial Aquifer and corresponding increases or decreases in 

39 groundwater level. Usually, the alluvium discharges to the river. However, during floods, the 

40 river may discharge to the aquifer.

41 This close hydraulic connection between the Mississippi River and the Mississippi River Alluvial 

42 Aquifer means that the Mississippi River forms a large, effective hydraulic boundary along the 

43 western boundary of the site. As a result, groundwater use, flow, and water quality west of the 

44 Mississippi River are unlikely to be influenced by groundwater use, flow, and water quality east 

45 of the Mississippi River (the plant side of the river).
Affected Environment

2-33

1 The GGNS cooling system uses Ranney wells to pump water from the Mississippi River Alluvial 

2 Aquifer (see Section 2.1.7). Pumping from these wells induces river water to flow through the 

3 alluvial aquifer to the wells. The connection between the alluvium and the river means that 

4 GGNS is essentially using river water from which river water sediment has been removed 

5 (filtered out by the pore spaces of the aquifer) (NRC 2006a). 

6 2.2.5.2 Perched Groundwater and the Upland Complex Aquifer 

7 Some perched groundwater occurs in the loess deposits of the upland area (Entergy 2011a). 

8 Because of their small area extent, size, and low production rates, the perched groundwater is 

9 not considered a groundwater resource. 

10 The water table occurs in the sand and gravel deposits of the Upland Complex Aquifer, which 

11 underlies the loess deposits. The Upland Complex Alluvium and the Upland Complex Old 

12 Alluvium form the Upland Complex Aquifer. West of the bluffs of the upland area, the Upland 

13 Complex Aquifer has been removed by the erosive activity of the Mississippi River and replaced 

14 by Mississippi River Alluvium. As a result, in the lowland plain, where the two aquifers are in 

15 contact, the Upland Complex Aquifer is hydraulically connected to the Mississippi River Alluvial 

16 Aquifer.

17 The Upland Complex Aquifer is recharged by local precipitation and the lateral movement of 

18 groundwater within the Upland Complex Aquifer. Groundwater flows laterally into the southeast 

19 corner of the plant property and moves in a northwest direction. From the west side of Unit 1 

20 and Unit 2 power blocks, groundwater in the Upland Complex Aquifer flows west until it reaches 

21 the bluffs. At that point, groundwater in the Upland Complex Aquifer flows into the Mississippi 

22 River Alluvial Aquifer. From the east side of the power blocks, groundwater in the Upland 

23 Complex Aquifer flows towards the northeast, until it exits the site boundary. Downward vertical 

24 flow in the Upland Complex Aquifer is prevented by a thick clay layer at the top of the Catahoula 

25 Formation. This clay layer has a very low permeability and is approximately 50 ft (15 m). 

26 2.2.5.3 Catahoula Aquifer 

27 The Catahoula Formation underlies the Mississippi River Alluvial Aquifer in the lowland plain 

28 and underlies the Upland Complex Aquifer in the upland area. Sandstone layers, separated by 

29 layers of siltstone or clay, transmit water in the Catahoula Formation and make up the 

30 Catahoula Aquifer. The top of the Catahoula Formation contains approximately 50 ft (15 m) of 

31 clay that forms an effective flow barrier, preventing the downward movement of water from the 

32 Upland Complex Aquifer (NRC 2006a) into the sands of the Catahoula Aquifer. Hydraulic 

33 interconnection between the Upland Complex Aquifer and the Catahoula Aquifer has not been 

34 identified in pumping well tests, monitor well water levels, or by the collection of drill-hole data. 

35 The Catahoula Aquifer is fully saturated and a confined aquifer (water in a well would rise above 

36 the top of the Catahoula Aquifer sands). Water in the Catahoula Aquifer is not of local origin. 

37 Aquifer recharge occurs north of the site in Warren and Hinds Counties (Entergy 2011a).

38 The substructures (basements) of the plant power blocks penetrate through the loess deposits 

39 and the Upland Complex Aquifer and rest on top of the Catahoula Formation. The top of the 

40 Catahoula Formation is elevated in the area of the power block, forming a ridge beneath the 

41 power block that is oriented northwest-southeast. The elevation of the top of the Catahoula 

42 Formation generally decreases in elevation in all directions from the power block area 

43 (GZA GeoEnvironmental, Inc. 2009). The thick vertical flow barrier and change in elevation of 

44 the top of the Catahoula Formation and the excavation of the power block through the Upland 

45 Complex Aquifer is interpreted as causing two directions of lateral groundwater flow in the 

46 Upland Complex Aquifer in the power block area.
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1 At the site, the Catahoula Aquifer is underlain by the Bucatunna Formation (Entergy 2011a). It 

2 is composed of clay and is about 100 ft (30 m) thick, forming a barrier to the downward 

3 movement of water in the Catahoula Aquifer. Of the three aquifers at the site, the Catahoula 

4 Aquifer is the least productive. Not only is it deeper, but the ability of the aquifer to transmit 

5 water to a well is much less that the other two aquifers. No wells at the site produce water from 

6 the Catahoula Aquifer or from any deeper aquifers.

7 On the lowland plain, the ancient Mississippi River eroded (cut into) the top of the Catahoula 

8 Aquifer and then deposited the Mississippi River Alluvial Aquifer on top of that surface 

9 (Entergy 2011a). Data from holes drilled on the lowland plain have not detected any hydraulic 

10 interconnection between the Catahoula Aquifer and the Mississippi River Alluvial Aquifer. 

11 However, it cannot be completely ruled out that some upper sands of the Catahoula Aquifer 

12 may be hydraulically connected to the Mississippi River Alluvial Aquifer, either under the river 

13 itself or under the lowland areas on either side of the river. This is because it is difficult to 

14 determine how deep the Mississippi River has eroded into the top of the Catahoula in the 

15 lowland plain or under the river.

16 Transmissivity is a measure of the ability of an aquifer to transmit water. It is more difficult to 

17 extract water from aquifers with low transmissivity than from aquifers with high transmissivity. 

18 At the site, the transmissivity of the Mississippi River Alluvium ranges from 21,500 to 

163,500 gpd/ft (267 to 2,031 m2 19 /day), while the transmissivity of the Catahoula Aquifer sands 

has an estimated transmissivity of 300 gpd/ft (3.7 m2 20 /day) (Entergy 2011a). The transmissivity 

21 of the Catahoula Aquifer sands is so much less than the Mississippi River Alluvial Aquifer that if 

22 an interconnection between the two aquifers exists, wells pumping water from the Mississippi 

23 River Alluvial Aquifer would obtain their water as induced infiltration from the Mississippi River 

24 rather than from upward discharge of groundwater from the Catahoula Aquifer. Furthermore, 

25 should groundwater contamination enter the Mississippi River Alluvial Aquifer, it would be likely 

26 to remain in the Mississippi River Alluvial Aquifer or discharge into the Mississippi River.

27 The groundwater quality in Claiborne County is generally good. Onsite groundwater quality is 

28 adequate for a variety of uses. Except for less suspended sediment, the induced infiltration 

29 from the operation of the GGNS Ranney wells produces water nearly identical to the water 

30 quality of the Mississippi River (Entergy 2011a). Onsite Upland Complex Aquifer water quality 

31 is suitable for use as potable water. Water from the GGNS Upland Complex Aquifer wells is 

32 sampled as required by the Mississippi Department of Health (MDH), pursuant to the Safe 

33 Drinking Water Act. County residents obtain their water from the Catahoula Aquifer. 

34 Groundwater from the Catahoula Aquifer, although very hard, is suitable for potable uses. 

35 Water quality generally decreases for aquifers underlying the Catahoula Formation 

36 (NRC 2006a; Entergy 2011a).

37 EPA designated the Southern Hills Aquifer, which includes the Catahoula Aquifer that underlies 

38 GGNS, to be a sole-source aquifer (EPA 2012c). The designation protects an area’s 

39 groundwater resource by requiring EPA to review all proposed projects within the designated 

40 area that will receive Federal financial assistance. All proposed projects receiving Federal 

41 funds are subject to review to ensure they do not endanger the groundwater source. As such, 

42 the MDEQ’s Wellhead Protection Program is working to identify and manage potential sources 

43 of contamination located near public water supply wells. The Port Gibson and CS&I Water 

44 Association #1 well fields are the only wellhead protection areas identified within a 6-mi (10-km) 

45 radius of the site (Entergy 2011a; MDEQ 2010b).

46 2.2.5.4 Groundwater with elevated tritium

47 Groundwater with elevated tritium activities (above background levels) was recently found in 

48 backfill material and in the Upland Complex Aquifer near the northeast side of the Unit 2 power 
Affected Environment

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1 block. This power block does not contain a nuclear reactor. No other radionuclides have been 

2 detected above background levels in the Upland Complex Aquifer. Based on a review of 

3 available data, tritium contaminated groundwater has not migrated off site (GGNS 2012a). 

4 Contamination appears to be restricted to the area near the power block. No radionuclides 

5 above background levels have been detected in the Catahoula Aquifer or the Mississippi River 

6 Alluvial Aquifer (Entergy 2011a). Elevated tritium levels have not been detected in the GGNS 

7 potable water supply wells, or in any radiological environmental monitoring program monitoring 

8 wells (GGNS 2012a).

9 With the exception of dewatering well DW-01 and monitor well MW-07, all wells with tritium

10 activities above background levels have levels significantly below the EPA primary drinking 

11 water standard for tritium (20,000 pCi/L) (40 CFR 141). Recent tritium values for DW-01 ranged 

12 from 8,407 to 21,100 pCi/L and for MW-07 ranged from 7,135 to 17,404 pCi/L. DW-01 

13 exceeded the EPA drinking water standard in September 2011. These wells are located close 

14 together near the outer wall of the Unit 2 power block (Figure 2–13). These wells are located in 

15 backfill material between the power block and the tie-back wall. The backfill material was used 

16 to fill the excavation created to build the power blocks. The tie-back wall is a structure built to 

17 hold up the sides of the open excavation during construction. After the power blocks were built, 

18 this structure was left in place and the excavation was filled in. Outside of the tie-back wall, 

19 groundwater near the Unit 2 power block is moving away from the power block toward the 

20 northeast (GGNS 2012a). 

21 Elevated tritium values have not been detected in any wells located outside the site. The 

22 nearest wells outside GGNS that provide water from the Upland Complex Aquifer are located 

23 approximately 1 mi (1.6 km) south-southeast from the Unit 1 power block. One well provides 

24 water to two residences; the other well is not being used for human consumption. These wells 

25 are located in the opposite direction (i.e., upgradient), from the direction of contamination 

26 migration in the Upland Complex Aquifer. CS&I Water Association #1 provides water to the 

27 majority of the rural population in the area. The closest area of concentrated groundwater

28 withdrawal is the Port Gibson municipal water system, which obtains water from the Catahoula 

29 Aquifer about 5 mi (8 km) southeast of the site (Entergy 2011a). Hydraulic interconnection 

30 between the Upland Complex Aquifer and the Catahoula Aquifer has not been identified.

31 Elevated tritium levels above background have not been detected in the three onsite Upland 

32 Complex Aquifer wells that supply potable water to GGNS. The wells, located near the bluffs 

33 between the Mississippi River and the power blocks, are in the opposite direction from any 

34 contamination moving northeast from the Unit 2 power block. These are the only drinking water 

35 wells that could be affected if groundwater contamination moved westward from the power block 

36 towards the Mississippi River Alluvial Aquifer. These wells are sampled annually for tritium and 

37 the results are reported to the NRC.

38 In 2007, the nuclear power industry began implementing its “Industry Ground Water Protection 

39 Initiative” (NEI 2007). Since 2008, the NRC has been monitoring implementation of this 

40 initiative at licensed nuclear reactor sites. The initiative identifies actions to improve utilities’ 

41 management and response to instances in which the inadvertent release of radioactive 

42 substances may result in low but detectible levels of plant-related materials in subsurface soils 

43 and water. It also seeks to identify those actions necessary for implementation of a timely and 

44 effective groundwater protection program. The areas of contamination were discovered as part 

45 of GGNS participation in this initiative. At this time, monitoring wells have been drilled on all 

46 sides of the power blocks and GGNS is monitoring them. Monitoring results from these wells 

47 are reported annually to the NRC.
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1 Figure 2–13. Most Recent GGNS Tritium Contaminated Well Data from February 2012*

2 (*Most recent data for MW-07 is August 2011)

3 Source: Modified from GGNS 2012a N MW-1148 {2,340 pCi!L) {17,800 pCi/L) '\ •• DW-01 OW-2098 {5,980 pCi!L) s 
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1 2.2.6 Aquatic Resources

2 GGNS is located adjacent to the Mississippi River, which is part of the largest river basin in 

3 North America and the third largest river basin in the world (Brown et al. 2005). GGNS lies 

4 within the Lower Mississippi River, which is defined as the portion of the Mississippi River that 

5 extends from the confluence with the Ohio River in Illinois to the Gulf of Mexico in Louisiana 

6 (Brown et al. 2005). The site occurs within the Gulf Coastal Plain physiographic province.

7 The Lower Mississippi River has relatively high number of species, especially for fish. The high 

8 species richness is in part due to the variety of habitats within the Mississippi River, as well as 

9 nearby floodplain habitats hydraulically connected to the Mississippi River during flooding 

10 events. Other factors that contribute to the high species diversity include the length of the river, 

11 the unique habitats that the river’s tributaries provide, and the connection with the Gulf of 

12 Mexico, which brings marine and anadromous species into the lower reaches of the Mississippi 

13 River (Brown et al. 2005). 

14 2.2.6.1 Environmental Changes in the Lower Mississippi River

15 Human activities have had a large influence on the relative abundance of many species and 

16 their habitat within the Mississippi River. The major activities that altered aquatic resources 

17 near GGNS include: (1) efforts to control flooding and increase navigation; (2) chemical 

18 contamination from runoff as a result of industrial, urban, and agricultural activities; and 

19 (3) introduction of nonnative species (Brown et al. 2005). 

20 To allow for ship traffic along the Mississippi River, several projects have changed the relative 

21 abundance and types of habitats within the river. Beginning in 1824, the U.S. government has 

22 removed snags, such as trees or tree roots, from the river. Snags provide natural habitat for 

23 invertebrates that require a firm attachment site. On the other hand, revetments, which are built 

24 to prevent erosion and river meandering, have increased availability of hard-surface habitats, 

25 but decreased the availability of soft-surface river bank habitats. Revetments such as timber, 

26 wooden or wire fences, rocks, and tires cover approximately 50 percent of the banks of the 

27 Lower Mississippi River (Baker et al. 1991; Brown et al. 2005). At GGNS, articulated concrete 

28 was installed on the river bank downstream of the discharge structure and barge slip to stabilize 

29 the river bank (NRC 1981).

30 In addition, the U.S. Army Corps of Engineers (USACE) has artificially created cutoffs that 

31 shortened the length of the river by cutting across a point bar or neck of a meander. 

32 Baker et al. (1991) estimate that artificially created cutoffs have shortened the length of the 

33 Lower Mississippi River by 25 to 30 percent, or approximately 500 km (310 mi). Cutoffs also 

34 can increase the river speed and erosion of river banks (Baker et al. 1991). 

35 Levees have been built along the Mississippi River for more than 300 years to control flooding. 

36 By 1973, 29 km (18 mi) of levees lined the river near New Orleans. By 1844, levees were 

37 nearly continuous up to the confluence with the Arkansas River (Baker et al. 1991). As of 2005, 

38 nearly 3,000 km (1,864 mi) of levees lined the Lower Mississippi River and an additional 

39 1,000 km (621 mi) of levees lined its tributaries (Brown et al. 2005). The levees decrease the 

40 frequency of flooding events, during which aquatic biota can move between the Mississippi and 

41 floodplain habitats. The movement of aquatic resources from floodplain habitats into the river is 

42 one reason that the Lower Mississippi is so rich in species diversity. USACE continues to 

43 dredge, install river bank revetments and levees, and regulate upstream reservoirs to minimize 

44 the historical movements of the river and create a relatively stable channel.

45 In addition to physical changes, runoff from over 40 percent of the conterminous 48 states 

46 drains into the Mississippi River. Land use changes over time have increased the concentration 

47 of industrial, chemical, and sediment inputs into the river. For example, forests have been 
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1 cleared to farm cotton, soybeans, rice, and corn near GGNS. Farming practices currently 

2 include the use of fertilizers, pesticides, and herbicides, which wash into the Mississippi River, 

3 especially after large rain events (Brown et al. 2005). Plowed fields, as compared to forested 

4 areas, increase the amount of sediments entering the Mississippi River. 

5 From 1963 through 1965, a catastrophic fish kill occurred from Memphis to the Mississippi River 

6 mouth as a result of industrial releases of endrin, a pesticide made from a chlorinated 

7 hydrocarbon. Mississippi Power & Light Company (MP&L) suggests that the endrin release 

8 may have reduced species diversity near GGNS by extirpating some species that were highly 

9 sensitive to the chlorinated hydrocarbon pesticide (MP&L 1981). As of 2002, testing has 

10 indicated that several of the older “first generation” chlorinated insecticides can be detected in 

11 low concentrations in bed sediments, although none of the chemical were detected in the water 

12 column.

13 2.2.6.2 Description of the Aquatic Resources Associated With GGNS 

14 Aquatic resources in the vicinity of GGNS include the following:

15 • the Mississippi River,

16 • Hamilton and Gin Lakes, 

17 • a flooded borrow pit,

18 • three small upland ponds,

19 • Stream “A” and Stream “B,” and

20 • ephemeral drainages. 

21 In 1972, MP&L conducted aquatic studies on the GGNS site to determine baseline conditions of 

22 the aquatic environment before construction. MP&L conducted aquatic ecology surveys from 

23 June 1972 to August 1973 and documented 86 fish species, more than 100 plankton taxa, and 

24 more than 50 macroinvertebrate taxa (MP&L 1981). System Energy Resources, Inc. (SERI) 

25 conducted reconnaissance-level surveys from August 19 to 24, 2002, and October 29 to 

26 November 1, 2002, in support of the early site permit (ESP) for GGNS (SERI 2005). These 

27 surveys primarily resulted in qualitative data and general observations. In November 2006, 

28 Entergy hired a consultant to conduct a mussel survey along the Mississippi River in support of 

29 the COL application. Entergy is not aware of any other aquatic studies that have been 

30 conducted at GGNS (GGNS 2012a).

31 SERI (2005) concluded that similar aquatic resources were present in 2002 as in 1972 and 

32 1973 at GGNS. SERI (2005) based this finding primarily upon the results of the 2002 

33 reconnaissance-level surveys. SERI (2005) also noted that the only major change that could 

34 have substantial impacts on aquatic biota was the installation of the articulated concrete mats 

35 along the river bank in 1979. The staff notes the operation of GGNS and its discharge of 

36 effluent into the Mississippi River is another change that has occurred since 1973.

37 The staff notes that the current aquatic resources may vary from that recorded in 1972 and 

38 1973. As described above, the relative abundance of human-made habitats in the 

39 Mississippi River, such as deep channels and hard substrates, have increased, while 

40 meandering portions of the river and soft substrates have decreased. Therefore, species that 

41 prefer human-made habitats have likely increased in relative abundance. Similarly, the relative 

42 abundance of pollution-sensitive species has likely increased because of the improved water 

43 quality in the Mississippi River since the implementation of the CWA and other environmental 

44 regulations (Caffey et al. 2002).

45 The staff compared aquatic surveys from 1972 through 1974 with more recent surveys from 

46 2006 through 2008. The surveys were recorded on FishNet (2012), which is a collaborative 

47 effort by the Mississippi Natural History Museum and other natural history museums and 
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1 biodiversity institutions to compile a database of fish survey data. Aquatic surveys from the 

2 Mississippi River near GGNS from 1972 through 1974 captured a total of 215 fish, representing 

3 25 different species belonging to 12 families. Aquatic surveys from the Mississippi River near 

4 GGNS from 2006 through 2008 captured a total of 205 fish, representing 20 different species 

5 belonging to 9 families. Of the 25 species recorded from 1972 through 1974, 8 species 

6 (32 percent) were collected and 17 species (68 percent) were not collected in the more recent 

7 surveys. In addition, 12 species were collected from 2006 through 2008 that were not collected 

8 during the earlier surveys. Of the 12 families recorded from 1972 through 1974, 8 families 

9 (67 percent) were collected and 4 families (37 percent) were not collected in the more recent 

10 surveys. In addition, one family was collected from 2006 through 2008 that was not collected 

11 during the earlier surveys. These results suggest that the aquatic resources from 1972 through 

12 1974 have changed, although some of the same species and many of the same families likely 

13 still inhabit the aquatic environments near GGNS. In addition, some new species have likely 

14 been introduced into the Mississippi River near GGNS. The staff also notes that degree of 

15 species overlap reported above is likely lower than what occurs in nature given that the studies 

16 likely used different capture methods, occurred at different seasons, and sampled in different 

17 areas or habitats in the river. 

18 Mississippi River

19 The Mississippi River’s eastern bank defines the western boundary of the GGNS site. The 

20 width of the river ranges from approximately 0.5 mi (0.8 km) at low flow to 1.4 mi (2.3 km) at 

21 high flow. The deepest part of the channel is about 16 ft (4.9 m). Three predominate habitat 

22 types occur within the Mississippi River near GGNS: backwater habitat, river bank habitat, and 

23 the main channel (Entergy 2011a). GGNS-related aquatic surveys within these habitats are 

24 described below. 

25 Sampling Methods for Preconstruction Studies

26 MP&L (1981) sampled aquatic biota in the Mississippi River from September 1972 through 

27 August 1973. MP&L sampled areas within each of the three main habitats between RM 400 

28 and RM 410.

29 For fish, MP&L (1981) collected monthly samples for 3 to 15 consecutive days using various 

30 mesh sizes of gill, trammel, and hoop nets in backwater and river bank habitats. MP&L set nets 

31 for 24 hours, or for as long as conditions permitted. Along the channel, MP&L sampled fish 

32 once in September 1972 and monthly from June through September 1973, using an otter trawl 

33 and fish-locating echo sounder. MP&L collected larval fish monthly or semi-monthly from 

34 January through July 1973. 

35 For macroinvertebrates, which are invertebrates that are visible without a microscope, MP&L 

36 sampled monthly using a Shipek sediment sampler from September 1972 through August 1973. 

37 Starting in January 1973, drifting benthic macroinvertebrate samples were collected near the 

38 water surface at two stations in the Mississippi River using a 1-m (3-ft) diameter plankton net 

39 (505-micron mesh). MP&L collected shrimp monthly using 4 x 2 x 1 ft (1.2 x 0.6 x 0.3 m) box 

40 traps (MP&L 1981). 

41 MP&L sampled plankton monthly to semi-monthly from September 1972 through August 1973. 

42 Sample stations were similar to that described for fish.

43 The results of this sampling are discussed in the following sections.

44 Biological Communities in Backwater Habitat 

45 Backwater habitat occurs in the slow, relatively shallow waters created by the large bend in the 

46 Mississippi River near the site. The substrate is generally loosely consolidated, silty clay 
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1 sediment of low plasticity. MP&L documented an abundant assemblage of fish, 

2 macroinvertebrates, and plankton in this habitat. The relatively high number of 

3 macroinvertebrates provides food and shelter for spawning fish, eggs, and larvae. 

4 Fish. MP&L collected 35 fish species within the backwater habitat. Ten fish species comprised 

5 85 percent of the fish captured. The most common species included gizzard shad (Dorosoma 

6 cepedianum), blue catfish (Ictalurus furcatus), river carpsucker (Carpiodes carpio), freshwater 

7 drum (Aplodinotus grunniens), and shovelnose sturgeon (Scaphirhynchus platorynchus). 

8 Catch-per-unit-effort (CPUE) was highest in the fall (MP&L 1981). 

9 Invertebrates. Benthic invertebrates, which inhabit the bottom of the river, were the most 

10 abundant and dense within backwater habitats as compared to river bank and river channel 

11 habitats. The most common taxa included tubificid worms, chironomid larvae (dipteran), 

12 burrowing mayfly (Hexagenia) larvae, leeches, and bivalves (mussels and clams) 

13 (MP&L 1981; NRC 2006a). The abundance of benthic invertebrates in backwaters increased 

14 from September 1972 through June 1973 and then decreased through August. MP&L 

15 determined that backwaters provide an important feeding ground for fish based on the dry 

16 weight standing stock of benthic macroinvertebrates (MP&L 1981).

17 Biological Communities in River Bank Habitat

18 The river bank provides habitat with moderate to swift currents passing by steep banks. The 

19 substrate is generally consolidated, high-plastic clay (SERI 2005). In 1979, the river bank 

20 downstream of the discharge structure and barge slip was stabilized with articulated concrete 

21 mats (NRC 1981). 

22 Juvenile and Adult Fish. MP&L collected 34 fish species within river bank habitat. The most 

23 commonly collected fish were gizzard shad, freshwater drum, silver chub (Macrhybopsis 

24 storeriana), flathead catfish (Pylodictis olivaris), and blue catfish. Gizzard shad comprised 

25 52 percent of the relative abundance of fish. CPUE was highest in late winter, right before larval 

26 fish were observed. Therefore, MP&L conjectured that these fish were likely moving toward 

27 spawning habitat in late winter (MP&L 1981). 

28 Ichthyoplankton. MP&L first observed larval fish in March 1973 and observed seven species 

29 during this time. The most abundant early-spawning species included shad, Mississippi 

30 silverside (Menidia audens), and mosquitofish (Gambusia affinis) larvae. The density of larval 

31 fish increased throughout the spring with peak spawning activity occurring in April and May. 

32 MP&L observed lower densities of larvae through July, although spawning activity likely occurs 

33 through the fall (MP&L 1981).

34 The spawning periods and number of spawning peaks varied for different species. For 

35 example, shad spawning began in early April, peaked in May and June, and extended through 

36 July. Drum, on the other hand, spawned during a shorter period of time with two spawning 

37 peaks: once in June and again in mid-July. MP&L observed a relatively long spawning period 

38 for minnow as larvae were collected throughout the entire sampling period. While MP&L 

39 commonly observed adult catfish and suckers, their larvae were not collected near the river 

40 bank probably because adults spawn in backwaters where larvae mature until they enter the 

41 riverine environment as juveniles (MP&L 1981).

42 Most fish eggs near GGNS are demersal (sinking), adhesive, and small (between 0.02 and 

43 0.03 in. (0.5 mm) diameter. As such, eggs spawned in backwaters typically adhere to 

44 vegetation or logs and eggs spawned over gravelbars and sandbars typically adhere to the 

45 bottom substrate during development. Therefore, MP&L caught relatively few fish eggs in its 

46 0.02 in. (0.5 mm)-mesh plankton net. Specifically, MP&L caught 20 fish eggs compared to 

47 16,596 larvae (MP&L 1981).
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1 Invertebrates. MP&L collected benthic invertebrates on stable river banks, but did not observe 

2 benthic invertebrates on unstable river banks because these river banks likely eroded before 

3 invertebrates could establish in sufficient numbers. Highly erosive clay and sand river banks 

4 make for a highly dynamic benthic invertebrate community. In some locations, MP&L observed 

5 benthic invertebrates during one sampling period, but not during the following month, because 

6 of recently eroded clay river banks. The most common taxa included tubificids, the midges 

7 Cryptochironomus and Chaoborus, the mayflies Pentagenia and Tortopus, chironomids, and 

8 amphipods (MP&L 1981). 

9 MP&L also collected river shrimp (Macrobrachium ohione) in the nearshore habitat along the 

10 river bank. River shrimp abundance was highest from August through October and close to 

11 zero from November 1972 through April 1973. MP&L attributed the decline in river shrimp to the 

12 river temperature dropping below 7.5 °C (46 °F) in November 1972 and not rising above 20 °C 

13 (68 °F) until April 1973 (MP&L 1981).

14 In November 2006, American Aquatics, Inc. (AAI) conducted a mussel survey in support of 

15 Entergy’s COL application. The purpose of the survey was to determine whether any mussels 

16 occurred along the east Mississippi River bank near RM 406 (Entergy 2008c). Survey methods 

17 included visual surveys of dead mussel shells along four shoreline sites and visual underwater 

18 surveys for live mussels along six transects. One of the four shoreline sampling sites was in the 

19 area of the discharge structure. AAI did not observe any live mussels. AAI found dead mussel 

20 shells of two non-native species, zebra mussels (Dresissena polymorpha) and Asiatic Clam 

21 (Corbicula fluminea). River currents likely transported the dead shells from upriver locations. 

22 As a result of these surveys, AAI concluded that mussel colonization near GGNS was not likely 

23 (Entergy 2008b).

24 Biological Communities in Main Channel Habitat

25 The most prominent aquatic habitat in the vicinity of GGNS is the main channel. This area 

26 provides deep water habitat with strong and turbulent currents. The coarse grained river bottom 

27 typically consists of gravelly sand sediments (MP&L 1981; SERI 2005). MP&L documented 

28 relatively low productivity within the main channel as few benthic invertebrates inhabited the 

29 river bottom and the water column contained less fish compared to other river habitats. 

30 However, difficult conditions during sampling techniques, such as rapid currents, irregular bed 

31 configurations, and bottom associated debris, also may have contributed to the relatively low 

32 numbers of fish captured (MP&L 1981). 

33 Fish. Commonly observed species included gizzard shad and drum. During June and July 

34 trawls, all captured fish were young-of-the-year. Commonly collected species during trawl 

35 sampling in August and September included blue and channel catfish (Ictalurus punctatus), 

36 shovelnose sturgeon, and four chub species, most of which were juveniles. Adult fish also were 

37 likely present in the main channel, but they may have avoided capture more easily because of 

38 faster swim speeds (MP&L 1981). 

39 Invertebrates. MP&L collected 36 benthic samples from the bottom of the main channel in 

40 September and October 1972, and March, June, July, and August 1973. MP&L did not observe 

41 any macroinvertebrates.

42 Overall Biological Community in Mississippi River 

43 Fish. MP&L captured a total of 69 fish species (MP&L 1981). A similar study conducted at the 

44 same time period captured the same number of species at the River Bend Nuclear Station, 

45 232 km (144 mi) downstream from GGNS (MP&L 1981; NRC 2006). Gizzard shad was the 

46 most abundant species, and the relative numerical abundance varied from 3 to 76 percent 

47 (MP&L 1981). The relative abundances of other dominant species captured were freshwater 
Affected Environment

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1 drum (10 percent), blue catfish (8 percent), flathead catfish, and river carpsucker (5 percent) 

2 (MP&L 1981). 

3 Plankton. MP&L (1981) characterized plankton in the Mississippi River as either zooplankton 

4 or phytoplankton. Zooplankton are small animals that float, drift, or weakly swim in the water 

5 column of any body of water, whereas phytoplankton are plants. Zooplankton density ranged 

6 over two orders of magnitude during the study period. MP&L identified 46 taxa and dominant 

7 zooplankton that included a stalked protozoan (Carchesium sp.), various cladocerans, and a 

8 colonial rotifer. Carchesium sp. can be an indicator of pollution, especially where sewage is not 

9 treated properly. MP&L identified a total of 49 phytoplankton genera and the most dominant 

10 were centric diatoms (MP&L 1981).

11 Hamilton and Gin Lakes

12 Hamilton and Gin Lakes are remnants of a former Mississippi River channel after the river 

13 moved west. The lakes are relatively shallow, approximately 2 to 3 m (8 to 10 ft deep 

14 (Energy 2011a). SERI (2005) examined aerial photography from 2001 and estimated the 

15 surface area of Hamilton Lake to be 26 ha (64 ac) and Gin Lake to be 22 ha (55 ac). The lakes 

16 have decreased in size since 1973.

17 Water enters and leaves Hamilton and Gin Lakes when the Mississippi River floods. Hamilton 

18 Lake also receives water from Streams “A” and “B,” which transport storm water from GGNS. 

19 Gin Lake is connected to Hamilton Lake through a culvert beneath the Heavy Haul Road 

20 (MP&L 1981; SERI 2005).

21 MP&L characterized the oxbow lakes as similar to backwater habitat in physical characteristics. 

22 The lakes are relatively shallow with no current and the bottom habitat is loosely consolidated, 

23 highly plastic clay sediments. Relatively productive biotic assemblages inhabit the lakes 

24 (MP&L 1981). 

25 Biological Communities in Hamilton and Gin Lakes

26 Fish. MP&L sampled for fish in Hamilton and Gin Lakes bimonthly from June 1972 through 

27 August 1973 using electrofishing gear or gill and trammel nets (MP&L 1981). MP&L set nets for 

28 24 hours, or for as long as conditions permitted.

29 Although both lakes have similar habitats, MP&L collected 46 fish species in Hamilton Lake and 

30 36 species from Gin Lake. The greater number of species in Hamilton Lake likely is due to the 

31 more frequent connection with the Mississippi River (MP&L 1981). For example, eight of the 

32 species observed in Hamilton Lake, but not in Gin Lake, were species that typically inhabit the 

33 Mississippi River.

34 Despite the difference in species diversity, the most common species in both lakes were the 

35 same: Eighty percent of the fish were gizzard shad, bluegill (Lepomis macrochirus), threadfin 

36 shad (Dorosoma petenense), or largemouth bass (Micropterus salmoides). In both lakes, 

37 gizzard shad was the most common species within open-water habitats, whereas bluegill was 

38 the most common species within shoreline-covered habitats. 

39 Fish communities within oxbow lakes are relatively dynamic. When the Mississippi River floods, 

40 aquatic biota can enter and leave the lakes. For example, in April and May 1973, the 

41 Mississippi River flooded to Hamilton Lake and the silvery minnow (a river species) comprised 

42 17 and 2 percent of the lake, respectively. In June, after the flood subsided, MP&L did not 

43 observe silvery minnow in the lakes. Therefore, MP&L’s one-year study provides a basic 

44 characterization of the lakes that may vary considerably both on a short-term and long-term 

45 basis.
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1 Invertebrates. MP&L sampled benthic invertebrates in Hamilton and Gin Lakes using a Ponar 

2 bottom grab starting in October 1972 through August 1973. Benthic macroinvertebrates in 

3 Hamilton and Gin Lakes resembled the macroinvertebrate community MP&L observed in 

4 backwater habitats of the Mississippi River. Grab samples during the fall and winter indicated 

5 that the most common taxa included larvae of the phantom midge Chaoborus and various 

6 genera of chironomid midges (e.g., Coelotanypus, Procladius, Cryptochironomus, Pentaneura

7 and Tanypus). During the spring, common taxa included tubificid worms and bivalves 

8 (MP&L 1981). MP&L also observed several species not included in grab samples, such as 

9 large unionid mussels (Carunculinus, Anodonta, and Lampsilus), large snails (Campeloma and 

10 Viviparus), whirligig beetles (Gyrinus), water striders (Notonectidae), crayfish (Procambarus), 

11 and the grass shrimp Palaemonetes kadiakensis.

12 Benthic invertebrate density in Hamilton Lake was relatively stable, whereas MP&L observed 

13 several peaks of benthic invertebrate density in Gin Lake (MP&L 1981). 

14 Plankton. During the 1972 and 1973 studies, MP&L observed that the frequency and duration 

15 of Mississippi River flooding, which allowed the plankton to enter or leave the lakes, had a 

16 strong influence on the plankton composition and abundance. When the lakes were not 

17 flooded, plankton developed into distinct populations that differed from the river communities. 

18 However, during flood events, the plankton community more closely resembled plankton 

19 communities within the Mississippi River (MP&L 1981).

20 Flooded Borrow Pit

21 MP&L created a borrow pit north of the barge slip in the 1970s to obtain fill for use in GGNS 

22 construction. Water enters and leaves the borrow pit when the Mississippi River floods. The 

23 depth of the pit is not known. SERI (2005) examined aerial photography from 2001 and 

24 estimated the surface area to be 6.5 ha (16 ac) in size. The pit does not appear to be 

25 hydrologically connected to the lakes, except when the Mississippi River floods and the flood 

26 water flows between the lakes and burrow pit. The bottom habitat within the burrow pit is likely 

27 similar to that of the oxbow lakes (SERI 2005). 

28 Three Small Upland Ponds

29 Three small upland ponds exist on the GGNS site. Each pond is approximately 0.25–0.50 ac 

30 (0.1–0.2 ha). MP&L (1981) concluded that previous land owners stocked the ponds with bluegill 

31 and channel catfish. 

32 Biological Communities in Upland Ponds

33 MP&L sampled the upland ponds using electrofishing and mark-recapture methods 

34 (MP&L 1981). The most common species include bluegill and mosquitofish. One pond also 

35 contained a few channel catfish.

36 Streams A and B

37 Streams A and B are perennial streams that run through the GGNS site. Stream A flows west 

38 from the GGNS sanitary waste water treatment facility. Stream A receives continual flow from 

39 facility storm water and processed discharge from the waste water treatment facility 

40 (NRC 2006a). Stream B flows west from the cooling towers on the south side of Heavy Haul 

41 Road. Flow in Stream B is intermittent, consisting mostly of storm runoff, and runs into Hamilton 

42 Lake. MP&L constructed sedimentation basins on both Stream A and B, referred to as 

43 Outfall 13 and 14, respectively (MP&L 1981; SERI 2005).
Affected Environment

2-44

1 Biological Communities in Stream A and B

2 MP&L sampled Stream A twice between 1972 and 1973 (MP&L 1981). MP&L observed a total 

3 of 21 fish species, including bluntnose minnow, green sunfish (Lepomis cyanellus), longear 

4 sunfish (Lepomis megalotis), silvery minnow (Hybognathus nuchalis, a river species), and 

5 blackspotted top minnow (Fundulus olivaceus). Aquatic biota likely entered the stream during 

6 spring floods (SERI 2005). For example, several species, such as largemouth bass, river shiner 

7 (Notropus blennius), and warmouth (Lepomis gulosus), also inhabit Hamilton and Gin Lakes 

8 and the Mississippi River (MP&L 1981). In addition to the small number of fish, MP&L observed 

9 unidentified bivalves and snails in Stream A. As a result of the preconstruction studies, 

10 SERI (2005) concluded that Stream A is relatively unproductive. For example, species diversity 

11 in Stream A was lower than similar streams near Vicksburg, Mississippi (MP&L 1981).

12 NRC is not aware of any aquatic surveys in Stream B. Stream A and B likely provide similar 

13 habitat for aquatic resources (SERI 2005), and therefore contain similar species. However, the 

14 aquatic community within Stream B may be smaller than the community in Stream A due to the 

15 intermittent flow of water. In addition, the species in Stream B would need to be able to survive 

16 in a wide-range of environmental conditions due to the intermittent flow of water. 

17 Ephemeral Drainages

18 SERI (2005) calculated 24,140 linear ft (7.4 km) of ephemeral drainage channels throughout the 

19 GGNS site. These ephemeral drainage channels occur on the upland bluffs primarily on the 

20 eastern portion of the GGNS site. Several drainages support small wetlands (SERI 2005).

21 Commercially and Recreationally Important Fish

22 Limited commercial fishing occurs in the area. Most commercial fishing occurs on the 

23 Mississippi River near GGNS and on the Big Black and Bayou Pierre Rivers (NRC 2006a). 

24 Predominate harvest species include bigmouth (Ictiobus cyprinellus) and smallmouth buffalo 

25 (Ictiobus bubalus) (SERI 2005). 

26 In 1973, MP&L estimated that there may have been 10–15 full-time and 30–40 part-time 

27 commercial fishermen operating between Grand Gulf and Natchez. Commonly collected 

28 species from a creel study in January through February 1973 included bigmouth and 

29 smallmouth buffalo (MP&L 1981).

30 Recreational fishing occurs on the Mississippi River and Hamilton and Gin Lakes (SERI 2005; 

31 NRC 2006a). Recreational fisherman generally fish from boats and the bank as well as use 

32 trotlines in the lakes. The most common fish caught include catfish, bluegill, and bass 

33 (MP&L 1981; SERI 2005).

34 Nuisance Species

35 The ERs associated with the Operating Permit (MP&L 1981), ESP (SERI 2005), COL 

36 (Entergy 2008c), and LRA (Entergy 2011a) did not identify aquatic nuisance species in the 

37 waters associated with GGNS. As described above, in November 2006, AAI observed dead 

38 mussel shells of two exotic species, zebra mussels (Dresissena polymorpha) and Asiatic Clam 

39 (Corbicula fluminea), while conducting mussel surveys in support of the COL application 

40 (Entergy 2008c). River currents likely transported the dead shells from an unknown upriver 

41 location. Zebra mussels also have been observed 35 river miles upriver of GGNS, near 

42 Vicksburg and throughout the Lower Mississippi River (Benson 2011). The Asiatic clam has 

43 been observed in the Big Black River north of GGNS and throughout the Lower Mississippi 

44 River (USGS 2012c). 
Affected Environment

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1 Aquatic Resources Associated with Transmission Line Rights-of-Way

2 Transmission line rights-of-way for GGNS cross waterways in Claiborne County. The

3 Baxter-Wilson right-of-way crosses the Big Black River approximately 12 km (7.5 mi) to the 

4 northeast of the GGNS site. In addition, the Baxter-Wilson substation in Warren County is less 

5 than 0.75 km (0.47 mi) from the shores of the Mississippi River. The Franklin right-of-way 

6 crosses the Bayou Pierre approximately 5.5 km (3.4 mi) to the south of GGNS (NRC 2006a). 

7 The Franklin right-of-way also crosses the Homochitto River (Entergy 2011a). 

8 Neither the ER for the ESP (SERI 2005), the ER for the COL (Entergy 2008c), nor the ER for 

9 license renewal (Entergy 2011a) provide a description of the aquatic resources along the 

10 transmission lines. NRC (2006a) determined that information on aquatic resources was not 

11 available from the transmission and distribution system owner and operator, EMI.

12 2.2.7 Terrestrial Resources

13 2.2.7.1 GGNS Ecoregion

14 GGNS lies where the Mississippi Valley Alluvial Plain and Mississippi Valley Loess Plain meet. 

15 The Mississippi Valley Alluvial Plain ecoregion consists of a broad, flat alluvial plain. River 

16 terraces, swales, and levees provide the main elements of relief. Soils are typically 

17 finer-textured and poorly drained compared to the upland soils of the adjacent Mississippi Valley 

18 Loess Plains ecoregion. The Mississippi Valley Loess Plains consist of a thin strip of land that 

19 extends from western Kentucky southward to Louisiana. It is about 750 km (470 mi) long, 

110 km (70 mi) wide, and covers about 43,775 km2 (16,901 mi2 20 ) of land (USGS 2011). This 

21 ecoregion consists of irregular plains with a thick layer of highly erodible loess deposits, 

22 oak-hickory and oak-hickory-pine forests, and streams with low gradients and silty substrates.

23 2.2.7.2 Summary of Past GGNS Site Surveys and Reports

24 In 1972, MP&L conducted vegetation and wildlife studies on the GGNS site to determine 

25 baseline conditions of the terrestrial environment before construction. As part of these studies, 

26 MP&L mapped overstory and understory vegetation and conducted wildlife surveys to determine 

27 the occurrence and relative abundance of mammals, birds, reptiles, and amphibians on the site. 

28 The U.S. Atomic Energy Commission (NRC’s predecessor agency) summarized the results of 

29 these studies and described the terrestrial environment in its Final Environmental Statement 

30 Related to Construction of Grand Gulf Nuclear Station, Units 1 and 2 (FES) (AEC 1973). 

31 In 2003, SERI submitted an application to the NRC for an ESP on the GGNS site. As part of its 

32 ESP application, SERI prepared an ER (SERI 2005). In its preparation of the ESP ER, SERI 

33 conducted qualitative reconnaissance site visits to compare the ecological conditions with those 

34 described in the 1973 FES. The ESP ER identified little change in undeveloped portions of the 

35 site; the report largely summarized the findings in AEC’s 1973 FES. The NRC developed an 

36 environmental impact statement (EIS) (NRC 2006a) during its review of the ESP application, 

37 which it published in 2006.

38 In 2008, Entergy submitted an application for a combined license (COL) to the NRC for the 

39 proposed Grand Gulf, Unit 3. Entergy requested that the NRC suspend its review of this 

40 application in January 2009 until further notice. Nevertheless, the application contained an ER

41 (Entergy 2008c) that included an assessment of the terrestrial environment. Entergy conducted 

42 several new surveys during the preparation of its ER for the COL specific to protected species. 

43 Section 2.2.8 discusses these surveys in more detail. In 2011, Entergy submitted an application 

44 for license renewal to the NRC. The associated ER (Entergy 2011a) also described the 

45 terrestrial environment. Entergy did not conduct any new surveys for the license renewal 

46 application. Entergy does not conduct any ongoing terrestrial monitoring on the site beyond that 
Affected Environment

2-46

1 associated with the site’s radiological environmental monitoring program (REMP) 

2 (Entergy 2011a). Section 4.8 of this SEIS describes the REMP.

3 Since multiple, previously published reports describe the GGNS site in detail, the following 

4 section provides a brief overview of the site habitats and wildlife. Refer to the reports 

5 referenced above for a more detailed description of the GGNS site.
Affected Environment

2-47

1 Figure 2–14. GGNS Property Habitat Types (Source: Entergy 2011a)

2 2.2.7.3 GGNS Site

3 The GGNS site lies along the east bank of the Mississippi River. North-south bluffs run parallel 

4 to the river and divide seasonally inundated bottomlands from upland habitat atop the bluffs. 

Legend 

- • • Property Line 

Exbtlng Bu~ctngs BononV.nd P-..ttmt: Emerg~n~, S.atoMtj Flooded. 30 ecrn - Upl1nd FOI'ttltd. • OO acrn 

- /lcfeJ9tlosttoRiY«·85Kfft 8onoml~ndPatu1triM Sc:Nb-SI'INb S.ason~ lyfloodeod-IOacn UpllfldFJtklNOf'I-Fort*d-ISSK~M 

~ Wetland - Botaomland Pllustme Scnlti-.SNub. S.asot~~ ly AGoded. Syc.imofto • 70 aues - Upldand Dweklpedk• • 270 aues. 8octomland Devtil(l9eCIAin ·55 ktH 

Soort:e: tuSACE 1910) Wetllnd Boundlry-A~ed to march SUIFigtnlA·l 

CSERI 2002) F9Jre 2.4-l.ll:n C-AM aae.s.. habhat types and h abit•t bounc&.ils 

•-==-•:::J-----=====-----•Miles 0 0.25 0.5 0. 75 1 

1:25,000 
Affected Environment

2-48

1 Roughly half of the site consists of upland habitats and half the site consists of bottomland 

2 habitats. Two small lakes—Hamilton and Gin Lakes—lie within the bottomlands. During 

3 construction, about 270 ac (109 ha) of upland habitat was cleared for GGNS buildings and 

4 related infrastructure. Upland areas are more diverse than bottomland areas because they do 

5 not experience prolonged periods of river inundation as do the bottomland habitats 

6 (Entergy 2011a). The South Woods, which lies to the south and west of the cooling tower, is an 

7 especially diverse area because of its complex topography of narrow ridges with steep slopes, 

8 ravines, and bluffs. Figure 2–14 shows the GGNS property by habitat type. This figure outlines 

9 the historical property boundary, which encompasses 2,100 ac (850 ha), although the actual 

10 property size today is 2,015 ac (815 ha) because of erosional loss from the Mississippi River.

11 Table 2–3 summarizes the GGNS site habitats. Since the only terrestrial site surveys were 

12 conducted before construction, the table primarily relies on information from these surveys as 

13 they were presented in the AEC’s 1973 FES. However, the table includes updated or more 

14 specific habitat information, as available in the ESP ER (SERI 2005), the COL ER 

15 (Entergy 2008c), and the license renewal ER (Entergy 2011a). Two primary habitat changes 

16 between preconstruction and present day are in the bottomland scrub-shrub wetlands (east of 

17 Gin Lake) and the upland open fields and clearings, in which Entergy has planted American 

18 sycamore (Platanus occidentali) and loblolly pine (Pinus taeda), respectively.

19 Table 2–3. Dominant Vegetation by Habitat Type

Bottomland Hardwood Forest

Community types: bottomland deciduous forest

Area: 985 ac (398 ha)(a)

Dominant vegetation: Overstory

box elder (Acer negundo) 

pecan (Carya illinoiensis) 

sugarberry (Celtis laevigata) 

swamp privet (Forestiera acuminate) 

green ash (Fraxinus pennsylvanica) 

black willow (Salix nigra) 

Understory

aster (Aster spp.)

buckvine [or ambervine] (Ampelopsis arborea) 

false nettle (Boehmeria cylindrica) 

trumpet creeper (Campsis radicans) 

sugarberry (Celtis laevigata) 

ladies’-eardrops (Fuchsia megellanica) 

dewberry (Rubus spp.)

Johnson grass (Sorghum halepense) 

poison ivy (Toxicodendron radicans)

Bottomland Emergent Wetlands

Community types: palustrine, emergent seasonally flooded

Area: 30 ac (12 ha)

Dominant vegetation: redtop panicgrass (Panicum rigidulum)

sedges (Carex spp.)

Bottomland Scrub-Shrub Wetlands

(east of Gin Lake)

Community types: palustrine, seasonally flooded

Area: 70 ac (28 ha)

Dominant vegetation: American sycamore (Platanus occidentali)
Affected Environment

2-49

Bottomland Scrub-Shrub Wetlands

(north, northwest, and south of Gin Lake)

Community types: palustrine, seasonally flooded

Area: 10 ac (4 ha)

Dominant vegetation: black willow (Salix nigra)

swamp privet (Forestiera acuminate) 

common button bush (Cephalanthus occidentalis)

Upland Loessial Bluff Hardwood Forest

Community types: oak forests

American elm forests

oak-sweetgum forests

Area: 400 ac (162 ha)

Dominant vegetation: Overstory

bitternut hickory (Carya cordiformis) 

pecan (C. illinoiensis) 

sweetgum (Liquidambar styraciflua) 

cherrybark oak (Quercus pagoda) 

southern red oak (Q. falcata) 

Texas oak (Q. texana) 

water oak (Q. nigra) 

American elm (Ulmus americana) 

Understory

aster (Aster spp.)

switchcane (Arundinaria gigantean) 

sedges (Carex spp.)

Japanese honeysuckle (Lonicera japonica) 

poison ivy (Toxicodendron radicans) 

oaks (Quercus spp.)

greenbriers (Similax spp.)

winged elm (Ulmus alata) 

grasses

Upland Open Fields and Clearings

Community types: upland early successional field

Area: 155 ac (63 ha)

Dominant vegetation: loblolly pine (Pinus taeda) 

goldenrod (family Asteraceae)

sida (Sida spp.)

goatweed (Ageratum conyzoides) 

mare’s-tail (Hippuris spp.)

common ragweed (Ambrosia artemisiifolia) 

dog fennel (Anthemis spp.)

(a) Habitat acreage in each of the references varies because of the loss of riparian habitat along the Mississippi 

River to erosion over time. This table uses those areas that appear in the most recent reference, the license 

renewal ER (Entergy 2011a). However, the FES (AEC 1973) is the only reference that specifies acreage for 

the bottomland hardwood forest area. Therefore, for this habitat type, the staff used the acreage estimate 

from the FES. 

Sources: AEC 1973; Entergy 2008c; Entergy 2011a; SERI 2005

1 The 1972 pre-operational wildlife surveys documented 96 species of birds on the site out of an 

2 estimated 141 species likely to occur in the area (AEC 1973). Additionally, the AEC (1973) 

3 notes that 45 mammalian species, 67 reptiles, and 25 amphibians are likely to occupy the 

4 GGNS site. Tables D–1 through D–5 in the AEC’s 1973 FES list these species. Table 2–4 

5 below lists the most common or abundant species on the site. Common or abundant birds and 

6 mammals are those identified in the ESP EIS (NRC 2006a). The ESP EIS, however, does not 
Affected Environment

2-50

1 include information on reptiles or amphibians. Thus, reptile and amphibian species listed in 

2 Table 2–4 are those identified as being abundant in the license renewal ER (Entergy 2011a) or 

3 in the FES (AEC 1973).

4 Table 2–4. Most Common or Abundant Wildlife Documented on GGNS

Birds(a)

Passerines and Near Passerines

Acadian flycatcher S

(Empidonax virescens) 

mourning dove Y

(Zenaida macroura)

American robin W

(Turdus migratorius) 

northern cardinal Y

(Cardinalis cardinalis)

belted kingfisher Y

(Ceryle alcyon)

northern rough-winged swallow S

(Stelgidopteryx serripennis) 

blue jay Y

(Cyanocitta cristata)

orchard oriole S

(Icterus spurius) 

field sparrow W

(Spizella pusilla) 

red-winged blackbird Y

(Agelaius phoeniceus)

lark sparrow W

(Chondestes grammacus) 

ruby-crowned kinglet W

(Regulus calendula) 

Herons, Egrets, and Storks

American coot W

(Fulica americana)

tricolored heron S

(Egretta tricolor)

cattle egret S

(Bubulcus ibis)

white ibis S

(Eudocimus albus)

great blue heron Y

(Ardea Herodias)

wood stork S

(Mycteria americana)

great egret S

(Ardea alba)

yellow-billed cuckoo S

(Coccyzus americanus)

Waterfowl and Grebes

pied-billed grebe W

(Podilymbus podiceps) 

northern pintail S

(Anas acuta) 

mallard S

(Anas platyrhynchos) 

wood duck Y

(Aix sponsa)

Birds of Prey

black vulture Y

(Coragyps atratus)

American kestrel M

(Falco sparverius)

turkey vulture Y

(Cathartes aura)

Mississippi kite S

(Ictinia mississippiensis)

broad-winged hawk S

(Buteo lineatus)

great horned owl Y

(Bubo virginianus)

red-tailed hawk Y

(Buteo jamaicensis)

northern harrier M

(Circus cyaneus)

red-shouldered hawk Y

(Buteo lineatus)

eastern screech owl Y

(Otus asio)

sharp-shinned hawk M

(Accipiter striatus)
Affected Environment

2-51

Mammals

beaver

(Castor canadensis)

least shrew

(Cryptotis parva)

bobcat

(Lynx rufus)

marsh rice rat

(Oryzomys palustris)

cotton mouse

(Peromyscus gossypinus)

nine-banded armadillo

(Dasypus novemcinctus)

eastern chipmunk

(Tamias striatus)

opossum

(Didelphis marsupialis)

eastern cottontail

(Sylvilagus floridanus)

raccoon

(Procyon lotor)

eastern fox squirrel

(Sciurus niger)

shorttail shrew

(Blarina brevicauda)

eastern gray squirrel

(Sciurus carolinensis)

striped skunk

(Mephitis mephitis)

fulvous harvest mouse

(Reithrodontomys fulvescens)

swamp rabbit

(Sylvilagus aquaticus)

golden mouse

(Ochrotomys nuttalli)

white-footed mouse

(Peromyscus leucopus)

gray fox

(Urocyon cinereoargenteus)

whitetail deer

(Odocoileus virginianus)

hispid cotton rat

(Sigmodon hispidus)

woodland vole

(Microtus pinetorum)

house mouse

(Mus musculus)

Reptiles(b)

American alligator AQ, TR

(Alligator mississippiensis)

ground skinkTR

(Lygosoma laterale)

American toad TR

(Bufo americanus)

red-eared turtle AQ

(Pseudemys scripta)

black racer TR

(Coluber constrictor)

southern black racer TR

(Coluber constrictor priapus)

broad-banded water snake AQ, TR

(Natrix sipedon)

southern copperhead TR

(Agkistrodon contortrix contortrix)

diamond-backed water snake AQ, TR

(Natrix rhombifera)

spade foot toad LB

(Scaphiopus holbrookii)

eastern hognose TR

(Heterodon platyrhinos)

speckled kingsnake TR

(Lampropeltis getulus)

Fowler’s toad TR

(Bufo woodhousel fowleri)

stinkpot AQ

(Sternotherus odoratus)

gray rat snake TR

(Elaphe obsolete)

three-toed box turtle TR

(Terrapene carolina triunguis)

green anole TR

(Anolis carolinensis carolinensis)

western cottonmouth AQ, TR

(Agkistrodon piscivorus leucostoma)
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2-52

Amphibians(b)

amphiuma salamander BL

(Amphiuma spp.)

lesser siren BL

(Siren intermedia)

bronze frog AQ, TR

(Rana clamitans)

mole salamander LB

(Ambystoma talpoideum)

bullfrog AQ, TR

(Rana catesbeiana)

slimy salamander LB

(Plethodon glutinosus)

(a)Codes following bird names signify seasonal use of the GGNS site; S = summer; 

M = migratory stopover; W = fall and winter; Y = year-round.

(b)Codes following amphibian names signify habitat use; AQ = aquatic habitat; 

BL = bottomlands; LB = loessial bluffs; TR = terrestrial habitat (general).

Sources: AEC 1973; Entergy 2011a; NRC 2006a

1 2.2.7.4 Transmission Line Corridors

2 Section 2.1.5 of this SEIS describes the three transmission lines (two full-length lines and one 

3 short tie that terminates on the site) associated with GGNS construction. The majority of the 

4 land (77.7 percent) that the transmission lines traverse is undeveloped. About 15 percent of the 

5 transmission line corridors is agricultural lands. Table 2–5 provides the land use by acreage 

6 and percent along the transmission line corridors.

7 Table 2–5. Transmission Line Corridor Land Use by Area

Land Use Acres (Hectares) Percent

Agricultural 246 (100) 14.7

Developed (Residential) 28 (11) 1.6

Developed (Non-residential) 3 (1) 0.2

Undeveloped 1,296 (525) 77.7

Water or Wetlands 96 (39) 5.8

Source: Entergy 2011a; NRC 2006a 

8 The Baxter-Wilson line runs through hardwood forest, loessial bluffs, hardwood-forested Big 

9 Black River bottomland, farmland, and sparsely populated rural areas. The Franklin line runs 

10 through loessial bluff hardwood forest and fields, pine and hardwood forest, and farmland 

11 (Entergy 2011a). The Franklin line also runs through Homochitto National Forest to the 

12 southeast of the GGNS site. Homochitto National Forest is an 189,000 ac (76,500 ha) National 

13 Forest that spans seven Mississippi counties.

14 2.2.8 Protected Species and Habitats

15 The U.S. Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) 

16 jointly administer the Endangered Species Act (ESA) of 1973, as amended. The FWS manages 

17 the protection of and recovery effort for listed terrestrial and freshwater species, while the NMFS 

18 manages the protection of and recovery effort for listed marine and anadromous species. 

19 Within Mississippi, the Mississippi Department of Wildlife, Fisheries, and Parks (MDWFP) lists 

20 species as State endangered under the Mississippi Nongame and Endangered Species 

21 Conservation Act of 1974 (MNHP 2011).

22 The NMFS has not designated any essential fish habitat under the Magnuson–Stevens Fishery 

23 Conservation and Management Act, as amended, within affected waterbodies within the vicinity 
Affected Environment

2-53

1 of GGNS (NMFS 2012a); therefore, this section does not discuss species with essential fish 

2 habitat.

3 This section also discusses those species protected under the Bald and Golden Eagle 

4 Protection Act of 1940, as amended, and the Migratory Bird Treaty Act of 1918, as amended. 

5 The FWS and NMFS have not designated any critical habitat under the ESA within the action 

6 area, nor has either agency proposed the listing or designation of any new species or critical 

7 habitat within the action area.

8 2.2.8.1 Action Area

9 For purposes of its protected species and habitat discussion and analysis, the NRC considers 

10 the action area, as defined by the ESA regulations at 50 CFR 402.02, to include the lands and 

11 waterbodies described below. The following sections only consider terrestrial and aquatic 

12 species that occur or have the potential to occur within this action area.

13 Terrestrial, wetland, and riparian habitat on the GGNS site and surrounding area within a 

14 2-mi (10-km) radius. The 2,015-ac (815-ha) GGNS site lies within Claiborne County, 

15 Mississippi. The site includes hardwood forest, open fields and clearings, and several areas of 

16 emergent wetlands and riparian habitat bordering the Mississippi River. Section 2.2.7 describes 

17 the site terrestrial ecology.

18 Mississippi River 6 river miles (10 river kilometers) upstream and downstream of GGNS 

19 and site aquatic features. This area includes the extent of the maximum thermal plume from 

20 GGNS discharge into the Mississippi River. The action area also includes the aquatic features 

21 at GGNS, including Hamilton and Gin Lakes, the borrow pit, streams “A” and “B,” three small 

22 upland ponds, and ephemeral drainages. Section 2.2.6 describes the site aquatic ecology.

23 Transmission line corridors and 1-mi (1.6-km) buffer on either side of the lines. The 

24 transmission lines associated with GGNS travel through Claiborne, Franklin, Jefferson, and 

25 Warren Counties. The transmission line corridors traverse pine and hardwood forest, loessial 

26 bluffs, farmland, and sparsely populated rural areas and cross several rivers, including the 

27 Mississippi, Bayou Pierre, and Big Black Rivers. One of the lines (the Franklin line) also runs 

28 through Homochitto National Forest to the southeast of the GGNS site.

29 2.2.8.2 Overview of Protected Aquatic and Terrestrial Species

30 Sections 2.2.6 and 2.2.7 summarize past aquatic and terrestrial surveys that have been 

31 conducted on the GGNS site. MP&L captured pallid sturgeon (Scaphirhynchus albus), chestnut 

32 lamprey (Ichthyomyzon castaneus), black buffalo (Ictiobus niger), blue sucker (Cycleptus 

33 elongates), and paddlefish (Polyodon spathula) during the 1972 through 1973 preconstruction 

34 surveys (AEC 1973). However, neither the preconstruction surveys, the recent reconnaissance 

35 surveys associated with the ESP application, nor the surveys associated with the COL 

36 application identified any other Federally or State-listed species on the GGNS site. Several of 

37 these Federally listed species (see Table 2–6) have the potential to occur in the action area.

38 Table 2–6 identifies Federally and State-listed species that occur in Claiborne County, in which

39 GGNS is located, or within one of the four counties through which the transmission line corridors

40 traverse. The NRC compiled this table from FWS’s online search by county (FWS 2012b); the 

41 Mississippi Natural Heritage Program’s online database (MNHP 2011); and correspondence 

42 from the FWS (2012c, 2012d), MDWFP (2012), and NMFS (2012b). The MNHP online 

43 database lists about 30 additional State-listed animal species and about 30 additional plant 

44 species that do not appear in Table 2–6; however, the MDWFP (2012) did not identify any of 

45 these additional species as occurring within 2 mi (3.2 km) of the GGNS site or transmission line 

46 corridors. Therefore, this section does not include these species in its discussion.
Affected Environment

2-54

1 In response to the NRC’s request for endangered and threatened species that could be affected 

2 by the proposed license renewal, NMFS (2012b) stated that no species under its jurisdiction 

3 occur within the action area, but that gulf sturgeon (Acipenser oxyrinchus desotoi) are known to 

4 occur in the Mississippi River and have been collected upstream of the project site in the region 

5 of Vicksburg, Mississippi. NMFS (2012b) suggested that the NRC contact the FWS Panama 

6 City Office about the gulf sturgeon. In response to the NRC’s inquiry, the FWS Panama City 

7 Office stated that it defers to the letters written by the Louisiana FWS Office (FWS 2012c) and 

8 Mississippi FWS Office (FWS 2012d) regarding Section 7 consultation. FWS (2012c, 2012d) 

9 did not identify any concerns related to the proposed project on gulf sturgeon. Furthermore, 

10 FWS, which has jurisdiction over the gulf sturgeon in the Mississippi River, did not identify the 

11 species as occurring within the action area or within Claiborne, Franklin, Jefferson, or Warren 

12 Counties (FWS 2012b, 2012c, 2012d). Therefore, the NRC will not consider this species in any 

13 further detail in this SEIS.
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1 Table 2–6. Federally and State-Listed Species

County(ies) 

of 

Occurrence(c)

Scientific Name Common Name

Federal 

Status(a)

State 

Status(a)

State 

Rank(b) 

Claiborne

Franklin

Jefferson

Warren

Amphibians

Plethodon websteri Webster’s 

salamander - - S3 x x 

Birds

Eudocimus albus white ibis - - S2B, S3N x x x x

Haliaeetus leucocephalus bald eagle - E S1B, S2N x x x x 

Mycteria americana wood stork E E S2N x x x x 

Picoides borealis red-cockaded 

woodpecker E E S1 x x 

Sterna antillarum least tern (interior 

pop.) E E S3B x x x 

Fish

Crystallaria asprella crystal darter - E S1 x x

Cycleptus elongatus blue sucker - - S3 x 

Etheostoma rubrum bayou darter T T S1 x

Ichthyomyzon castaneus chestnut lamprey - - S3 x

Ictiobus niger black buffalo - - S3 x x

Macrhybopsis meeki sicklefin chub - - SA x 

Polyodon spathula paddlefish - - S3 x x

Scaphirhynchus albus pallid sturgeon E E S1 x x x

Mammals

Ursus americanus 

luteolus

Louisiana black 

bear T E S1 x x x x 

Ursus americanus American black 

bear T(SA) E S1 x x x x 

Mussels

Potamilus capax fat pocketbook E E S1 x x x

Quadrula cylindrica ssp. 

cylindrica rabbitsfoot PT - - x x 

(a) E = endangered; T = threatened; T(SA) – threatened due to similarity of appearance to another listed 

species; PT = proposed threatened.

(b) S1 = critically imperiled in MS because of extreme rarity; S2 = imperiled in MS because of rarity; S3 = rare or 

uncommon in MS; SA = accidental or casual in MS (i.e., infrequent and far outside usual range); B = applies 

to breeding populations; N = applies to migratory or non-breeding populations.

(c) GGNS is located in Claiborne County, Mississippi. The transmission lines associated with GGNS traverse 

Claiborne, Franklin, Jefferson, and Warren Counties.

Sources: FWS 2012b, 2012c, 2012d; Mann et al. 2011; MDWFP 2012
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1 2.2.8.3 Species and Habitats Protected Under the Endangered Species Act

2 Wood Stork (U. S. Breeding Population)

3 The U.S. Fish and Wildlife Service (FWS) listed the U.S. breeding population of wood stork 

4 (Mycteria americana) as endangered in 1984 (49 FR 7332). The wood stork is a large, white 

5 wading bird with black flight and tail feathers. Its head is not feathered, and both the head and 

6 bill are grey to brownish-grey in color. Wood storks’ historic breeding range extends from South 

7 Carolina to Florida, west to Texas, and throughout most of South America. Today, the species 

8 breeds in South Carolina, Florida, and Georgia, though it still migrates west and south. Within 

9 Mississippi, the wood stork occurs along the western edge of the State along the Mississippi 

10 River in late summer and fall near freshwater wetlands, ponds, bayheads, oxbow lakes, and 

11 ditches (MMNS 2001). 

12 The AEC’s 1973 FES notes that pre-construction surveys recorded the wood stork as occurring 

13 in the summer on or near Hamilton and Gin Lakes. The license renewal ER (Entergy 2011a) 

14 does not provide any updated information on the species’ occurrence but notes that the wood 

15 stork is a possible non-breeding transient to the GGNS site and surrounding area. Thus, the 

16 staff assumes that the wood stork occurs in the action area. However, individuals in Mississippi 

17 represent migrants from Mexican breeding colonies (49 FR 7332), and thus, would not be part 

18 of the U.S. breeding population. Therefore, the NRC will not analyze this species in any further 

19 detail in this SEIS.

20 The FWS has not designated critical habitat for this species.

21 Red-cockaded Woodpecker

22 In 1970, under the Endangered Species Preservation Act of 1966, the predecessor regulation to 

23 the Endangered Species Act (ESA) (35 FR 16047), the FWS listed the red-cockaded 

24 woodpecker (Picoides borealis) as endangered wherever found. The red-cockaded 

25 woodpecker is a medium-sized woodpecker that is distinguishable by barred black and white 

26 horizontal stripes on its back and black cap and nape encircling white cheek patches. Males 

27 have a small red streak along the back portion of their heads.

28 Red-cockaded woodpeckers live in family groups with one breeding pair and several 

29 non-breeding birds that help raise young (FWS 2003). Males more often are helpers, but 

30 females also may take on the helper role. If a breeder dies, a helper can replace the breeder. 

31 Helpers also may increase fledgling success and reduce the workload of breeders, which 

32 increases breeder survivorship (Khan and Walters 2002). Therefore, the effective population 

33 size depends more on the number of breeding groups instead of the number of young 

34 successfully raised in a given year. This cooperative breeding system makes the red-cockaded 

35 woodpecker resistant to many environmental and demographic changes, but highly sensitive to 

36 habitat spatial characteristics (FWS 2003).

37 Red-cockaded woodpeckers inhabit open pine woodlands and savannahs with large old pines 

38 that serve as cavity trees for nesting and roosting. The species uses mature pine stands with 

39 open canopies, little to no midstory, and native bunchgrass and forbs for foraging. Cavity tree 

40 availability is often the limiting factor for growth in most populations (FWS 2003).

41 The red-cockaded woodpecker does not occur in Claiborne County; therefore, it does not occur 

42 on the GGNS site. The Homochitto National Forest, which spans seven Mississippi counties, 

43 including Franklin and Jefferson Counties, contains a secondary core population of the species 

44 (FWS 2003). As of 2000, this national forest contained 51 active breeding clusters (FWS 2003). 

45 The recovery plan sets forth a goal of 254 active breeding clusters for this population. The 

46 Franklin transmission line (discussed in Section 2.1.5) travels through the northern section of 
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1 Homochitto National Forest in Jefferson and Franklin Counties before its termination point at the 

2 Franklin EHV Switching Station in Franklin County. Thus, the species is likely to occur within 

3 the action area in the vicinity of the Franklin transmission line corridor within the Homochitto 

4 National Forest.

5 The FWS has not designated critical habitat for this species.

6 Least Tern (Interior Population)

7 The FWS listed the interior population of the least tern (Sterna antillarum) as endangered in 

8 1985 (50 CFR 21784). The least tern is an 8- to 9-in. bird that has a white body, gray back and 

9 wings, a black crown on its head, orange legs, and a yellow bill.

10 Least terns arrive in the United States from early April to early June and spend 3 to 5 months in 

11 breeding grounds (TPWD 2012). The species inhabits barren to sparsely vegetated sandbars 

12 along the Missouri, Mississippi, Ohio, Red, and Rio Grande Rivers; sand and gravel pits; and 

13 lake and reservoir shorelines (Sidle and Harrison 1990). Least terns nest in small colonies in 

14 such areas, and females create nests by scraping shallow holes in sandy areas or exposed 

15 flats. Females lay two to three eggs over a period of several days in late May. Chicks hatch 

16 within 20 to 22 days and are capable of flight within 3 weeks. Because least terns nest on 

17 sandbars and shorelines, annual nesting success in a given location varies greatly due to water 

18 level fluctuations. Least terns generally stay close to their breeding colony and limit their activity 

19 to that portion of the river near the colony. The species is territorial and individuals communally 

20 will defend the colony against invaders. Least terns are opportunistic feeders and prey on a

21 variety of small fish, crustaceans, and insects. Least terns migrate south to fall and winter 

22 habitats beginning in late August. (TPWD 2012)

23 Since 1986, biologists from the U.S. Army Corps of Engineers and Dyersburg State Community 

24 College have conducted least tern surveys along the Mississippi River from Cape Girardeau, 

25 Missouri, to Baton Rouge, Louisiana. The least tern occurs along this entire stretch of the 

26 Mississippi River. During the most recent survey conducted in July 2011, Jones (2011) 

27 recorded a total of 12,247 least terns and 45 nesting colonies. Two nesting colonies occur 

28 within the action area: the Yukatan Dikes (RM 410; 4 RM upriver of GGNS) colony and the 

29 Bondurant Towhead Dikes (RM 393; 13 RM downriver of GGNS) colony. The Baxter-Wilson 

30 transmission line lies 0.46 mi (0.74 km) from the Mississippi River at its closest point, and the 

31 nearest least tern colonies are at least 2 mi (3.2 km) away from the transmission line corridor; 

32 thus, these colonies are outside the action area.

33 The FWS has not designated critical habitat for this species.

34 Bayou Darter

35 The FWS listed the bayou darter (Etheostoma rubrum) as threatened in 1975 (40 FR 17590). 

36 Bayou darter are small fish; adults range from 1.0–1.8 in. (2.5–4.6 cm) in length. These fish are 

37 the smallest representative of the subgenus Nothonotus. Bayou darters are endemic to the 

38 Bayou Pierre and also occur in the lower reaches of its tributaries, including White Oak Creek, 

39 Foster Creek, and Turkey Creek. Bayou darter habitat includes meandering stream with stable 

40 gravel riffles or sandstone exposures (FWS 2012d). Such habitat is often found downstream of 

41 a headcutting area. In these areas, the stream becomes shallow (less than 6-in. (15-mm) 

42 depth), the flow is moderate to swift, and riffles become numerous. Primary prey includes 

43 midges, blackflies, water mites, caddisflies, and mayflies (FWS 2012d). Bayou darter spawn 

44 when water temperatures rise to between 72 and 84 °F (22 and 29 °C), which generally occurs 

45 from April to early June (FWS 2012d). Past and current threats to the Bayou darter include 

46 human-induced habitat alteration, such as floodplain or channel modification, petroleum 

47 exploration and transportation, and farming and forestry (FWS 2012d).
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1 At GGNS, MP&L did not observe bayou darter during preconstruction studies from 1972 through 

2 1973 (Entergy 2011a). However, bayou darter is endemic to Bayou Pierre, which flows within 

3 2 mi (3.2 km) of the GGNS site and is crossed by the Franklin transmission line. Therefore, the 

4 bayou darter is likely to occur within the action area.

5 The FWS has not designated critical habitat for this species.

6 Pallid Sturgeon

7 In 1990, the FWS listed the pallid sturgeon (Scaphirhynchus albus) as endangered wherever 

8 found (55 FR 36641). Pallid sturgeon have a long, uniformly grayish-white body and a flattened, 

9 shovel-shaped snout. Pallid sturgeon inhabit the Mississippi and Missouri Rivers from Montana 

10 to Louisiana. Within the Mississippi River, primary habitat includes the main channel, especially 

11 near the river bottom. Primary prey include fish and aquatic insects (FWS 2007a). Although 

12 information on reproduction is limited, pallid sturgeon likely spawn between June and August 

13 (FWS 2007a). Larval fish drift downstream from the hatching site (Kynard et al. 2002). Eleven 

14 to 17 days after hatching, larvae settle from the lower portion of the water column (FWS 2007a). 

15 Current threats include commercial and recreational harvest because of misidentification by 

16 fishermen, habitat modification (e.g., channelization of the Mississippi River), and curtailment of 

17 the species’ habitat range due to the operation of dams along the Missouri River (FWS 2009).

18 During the 1972–1973 preconstruction studies, a specimen was collected offshore of the future 

19 GGNS site (Entergy 2011a). Spawning habitat may exist within 10 mi (16 km) of the site. 

20 In 2001, FWS, the Mississippi Museum of Natural Science, and the Lower Mississippi River 

21 Conservation Committee conducted trawl surveys for pallid sturgeon approximately 

22 38 mi (61 km) upstream of GGNS (Hartfield et al. 2001 in SERI 2005). The team observed nine

23 adult pallid sturgeon and seven intermediates (sub-adults) within a variety of channel habitats 

24 that included moderate to strong currents, sand or gravel substrates, 20–40 ft (6.1–12.2 m) 

25 depths, and usually some type of habitat structure. From 2000–2005, USACE sampled the 

26 lower Mississippi River from river miles (RMs)145 to 954. USACE collected 162 pallid sturgeon 

27 from more than 130 locations (FWS 2005). FWS (2012c) stated that pallid sturgeon may occur 

28 within 50 mi (80 km) of GGNS. Similarly, MDFWP (2012) stated that pallid sturgeon may occur 

29 within 2 mi (3.2 km) of GGNS. Therefore, the pallid sturgeon may occur within the action area.

30 The FWS has not designated critical habitat for this species.

31 Louisiana and American Black Bears

32 The Louisiana black bear (Ursus americanus luteolus) is one of 16 recognized subspecies of 

33 American black bear (U. americanus). In 1992, the FWS published a final rule listing the 

34 Louisiana black bear as threatened (57 FR 588). This final rule also listed the American black

35 bear as threatened because of its similarity in appearance to the Louisiana black bear. The 

36 American black bear is listed as threatened within all Louisiana counties and those Mississippi 

37 and Texas counties within the historic range of the Louisiana black bear.

38 The Louisiana black bear is distinguished from the American black bear by its longer and 

39 narrower skull and larger molar teeth. The species has a brown muzzle and generally uniformly 

40 black fur, although its fur can range from shades of brown to red. Adult males weigh between 

41 200 and 400 lbs (90 to 180 kg), and females weigh between 120 and 200 lbs (55 to 90 kg) 

42 (FWS undated a).

43 The Louisiana black bear is an opportunistic omnivore whose diet varies with food availability 

44 and season. From 2002 through 2004, Benson and Chamberlain (2006) studied the diets of two 

45 subpopulations in the Tensas River Basin, which lies west of the GGNS site and runs parallel to 

46 the Mississippi River. The study identified corn; pokeberry (Phytolacca americana), muscadine 
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1 (Vitis rotundifolia), and other shrubs or vine fruit; and invertebrates as the primary sources of 

2 food in spring. In the fall, acorns made up a significant portion of the Louisiana black bear’s 

3 diet. In the winter, the species relied on acorns, grasses, sedges, and invertebrates. Louisiana 

4 black bears also consume small mammals and carrion opportunistically. In areas where bears 

5 are in close proximity to agricultural fields, they often consume large amounts of wheat, oats, 

6 and other cereal grains (Benson 2005).

7 Louisiana black bears prefer bottomland hardwood forest habitat with relatively inaccessible 

8 terrain, thick understory vegetation, and abundant hard (acorns and nuts) and soft (leaf buds, 

9 berries, drupes) mast (74 FR 10350). Studies indicate that individual home ranges of Louisiana 

10 black bears are rather large and habitat use varies widely by gender, season, food availability, 

11 and reproductive status. In a movement ecology study, Marchinton (1995) found that males 

have a mean home range of about 52 km2 (20 mi2 12 ), while females have a mean home range of 

about 13 km2 (5 mi2 13 ), and that ranges for both sexes were largest in fall. The Louisiana Black 

14 Bear Recovery Plan (FWS 1995) indicates that in the Tensas River Basin, males and females 

may have a home range of up to 162 km2 (63 mi2

) and 73 km2 (28 mi2 15 ), respectively. The 

16 smaller mean range of females could correlate with reproduction. Females may restrict their 

17 ranges while rearing cubs because of the limited mobility of young in the first few months of life 

18 (Lindzey and Meslow 1977). Availability of covered corridors between fragmented forest 

19 habitats also affects individual ranges.

20 Females breed at three to four years of age and give birth to one to three cubs in late January to 

21 early February while hibernating. Females and their cubs emerge from dens in late March to 

22 late May, and females continue to care for cubs until their second summer. Thus, females 

23 reproduce at most every other year.

24 Historically, the species occurred across North America as far north as Alaska and south to 

25 Mexico. The species now occurs in two core populations within the Tensas and Atchafalaya 

26 River Basins in Louisiana and in small, scattered populations in Mississippi. Continued habitat 

27 fragmentation from transportation development, agricultural activities, and urban sprawl as well 

28 as human-induced mortality from poaching and vehicle strikes threaten the continued existence 

29 of the Louisiana black bear (74 FR 10350).

30 The FES for construction of GGNS (AEC 1973) did not identify either the Louisiana or American 

31 black bears as likely to occur on the GGNS site. However, the Final ER for operation of GGNS 

32 (MP&L 1981) indicates that black bears (subspecies unidentified) were observed on the GGNS 

33 site four times in 1977, and several bear tracks and other signs of inhabitance were observed in 

34 the bottomlands south of the GGNS property line. MP&L (1981) did not indicate that these 

35 observations were part of any formal surveys; they appear to have been causal sightings 

36 recorded by construction or site staff. 

37 Entergy commissioned a field survey for suitable Louisiana black bear habitat on GGNS in 

38 December 2006 (Wenstrom 2007a). The survey identified 30 trees that met the FWS’s criteria 

39 of candidate trees for black bear den habitat. The trees included water oak (Quercus nigra), 

40 chinquapin oak (Quercus muehlembergii), and other oaks, pecans (Carya spp.), and elms 

41 (Ulmus spp.) of 36 in. (91 cm) diameter at breast height or larger. Only one tree had a cavity, 

42 which was open and exposed. None of the trees had enclosed cavities, claw marks, or other 

43 evidence of black bear use. The survey also identified one potential ground den about 400 ft 

44 (121 m) north of the heavy haul road and 3,800 ft (1,200 m) east of the Mississippi River. The 

45 survey noted numerous foraging areas containing blackberry (Rubus trivialis) thickets or shallow 

46 water in bottomlands scattered throughout the GGNS site. Wenstrom (2007a) concluded that 

47 the site contains suitable habitat for black bear foraging and denning, but the survey did not 

48 reveal any evidence of current use by bears.
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1 Based on historic occurrence and recent habitat surveys of the GGNS site, the NRC assumes 

2 that the Louisiana and American black bears occur in the action area.

3 Designated critical habitat for the Louisiana black bear is discussed below. The FWS has not 

4 designated critical habitat for the American black bear.

5 Louisiana Black Bear Critical Habitat

6 The FWS published a final rule to designate Louisiana black bear critical habitat in 2009 

7 (74 FR 10350). The FWS did not designate any land within Mississippi as critical habitat; the 

8 closest critical habitat lies along the Tensas River Basin about 16 mi (26 km) west of the GGNS 

9 site at its closest point (Entergy 2011a; NRC 2006a). The FWS has designated a total of 

10 628,505 ac (254,347 ha) of habitat as critical within this basin, of which about a third is owned 

11 by the Federal or State government (74 FR 10350). However, because no critical habitat 

12 occurs within the action area, the NRC will not analyze designated Louisiana black bear habitat 

13 in any further detail in this SEIS.

14 Fat Pocketbook Mussel

15 In 1976, the FWS listed the fat pocketbook mussel (Potamilus capax) as endangered wherever 

16 found (41 FR 24062). Fat pocketbook mussels are large freshwater mussels that grow up to 

17 130 mm (5.1 in) in length (FWS 2012e). The shells are shiny and tan or light brown without 

18 rays. Fat pocketbook mussels inhabit sand, mud, and silt substrates (FWS 2007b). Similar to 

19 other freshwater mussels, fat pocketbook mussels filter feed by siphoning phytoplankton, 

20 zooplankton, detritus, and diatoms from the water. 

21 During the reproductive cycle, males release sperm into the water column that are sucked in by 

22 females through their siphons during feeding and respiration. Fertilized eggs develop into 

23 larvae (glochidia) within the gills of females. After releasing the mussel glochidia into the water, 

24 the glochidia must attach to the appropriate species of fish, which they parasitize until they 

25 develop into juvenile mussels (FWS 2012e).

26 Historically, fat pocketbook mussels inhabited a significant portion of the Mississippi River, from 

27 the confluence of the Minnesota and St. Croix rivers, in Minnesota, downstream to the White 

28 River system in Arkansas (FWS 2007b). While most historical records are from the upper

29 Mississippi River, FWS (2007b) was not aware of any records of occurrence within the upper 

30 Mississippi River within the past two decades. Within the Lower Mississippi River, these 

31 mussels currently inhabit some secondary channels and side channels along a 300-mi (480-km) 

32 stretch of the Mississippi River that includes the GGNS area (FWS 2007b). In 2003, Mississippi 

33 Museum of Natural Science biologists collected 16 dead shells and 1 live fat pocketbook in the 

34 Ben Lomond Dike Field near Vicksburg in the Mississippi River channel (FWS 2004). These 

35 mussels also occur downstream of GGNS in St. Catherine Creek Wildlife Refuge on the 

36 Mississippi River near Natchez (FWS 2006).

37 At GGNS, MP&L did not observe fat pocketbook mussels during preconstruction studies from 

38 1972–1973 (Entergy 2011a). In November 2006, AAI conducted a mussel survey in support of 

39 Entergy’s COL application. The purpose of the survey was to determine whether any mussels 

40 occurred along the east Mississippi River bank near RM 406, which is near the discharge

41 structure (Entergy 2008b). Survey methods included visual surveys of dead mussel shells 

42 along four shoreline sites and visual underwater surveys for live mussels along six transects. 

43 AAI did not observe any dead or live fat pocketbook mussels. As a result of these surveys, AAI 

44 concluded that mussel colonization near GGNS was not likely (Entergy 2008b).

45 In correspondence with the NRC, FWS Louisiana Ecological Services Office stated that the fat 

46 pocketbook occurs within 50 mi (80 km) of GGNS (FWS 2012c). However, MDWFP (2012) did 
Affected Environment

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1 not identify the fat pocketbook as occurring within 2 mi (3.2 km) of GGNS. Given that MP&L 

2 and AAI did not observe any dead or live fat pocketbook mussels at GGNS and MDFWP (2012) 

3 did not identify fat pocketbook mussels within 2 mi (3.2 km) of GGNS, the NRC staff concludes 

4 that this species is not likely to occur within the action area. The FWS has not designated 

5 critical habitat for this species.

6 Rabbitsfoot Mussel

7 The FWS issued a proposed rule to list the rabbitsfoot mussel (Quadrula cylindrica ssp.

8 cylindrica) as threatened under the ESA in October 2012 (77 FR 63439). The ESA allows the 

9 FWS one year from the publication of its proposed rule to make a final determination as to 

10 whether to list the rabbitsfoot mussel as threatened.

11 Rabbitsfoot mussels are freshwater, medium to large-sized mussels that grow to about 

12 6 in. (15 cm) in length (FWS 2010). Rabbitsfoot mussels filter feed by siphoning phytoplankton, 

13 zooplankton, detritus, and diatoms from the water. Similar to fat pocketbook and other 

14 freshwater mussels, male rabbitsfoot mussels release sperm into the water column that are 

15 sucked in by females and develop into glochidia (FWS 2010).

16 At GGNS, MP&L did not observe rabbitsfoot mussels during preconstruction studies from 

17 1972–1973 (Entergy 2011a). As described above, in November 2006, AAI conducted a mussel 

18 survey in support of Entergy’s COL application (Entergy 2008b). AAI did not observe any dead 

19 or live rabbitsfoot mussels. As a result of these surveys, AAI concluded that mussel 

20 colonization near GGNS was not likely (Entergy 2008b).

21 In correspondence with natural resource agencies, FWS Louisiana Ecological Services Office, 

22 FWS Mississippi Field Office, and MDWFP did not include rabbitsfoot mussel as a species that 

23 occurs within the action area (FWS 2012d, 2012c; MDWFP 2012). Therefore, the NRC staff 

24 concludes that this species is not likely to occur within the action area. 

25 Rabbitsfoot Mussel Proposed Critical Habitat

26 The FWS proposed critical habitat for the rabbitsfoot mussel with its October 2012 Federal 

27 Register notice issuing a proposed rule to list the species as threatened under the ESA

28 (77 FR 63439). The rule proposes critical habitat within 10 states in the midwest and 

29 southeastern U.S. Within Mississippi, proposed critical habitat occurs within Hinds, Sunflower, 

30 Tishomingo, and Warren Counties. The only county applicable to the proposed GGNS license 

31 renewal action area is Warren County, in which one proposed critical habitat unit occurs: RF17 

32 (Big Black River). RF17 includes 43.3 river kilometers (26.9 river miles) of the Big Black River 

33 from the Porter Creek confluence west of Lynchburg, Hinds County, Mississippi, downstream to 

34 Mississippi Highway 27 west of Newman, Warren County, Mississippi (77 FR 63439).

35 Within the action area, the Baxter-Franklin transmission line corridor traverses the Big Black 

36 River in Claiborne County. However, the corridor does not traverse this river within Warren 

37 County where the proposed critical habitat unit RF17 is located. The portion of the 

38 Baxter-Franklin transmission line in Warren County is a 2.2-mi (3.5-km) stretch in the western 

39 portion of the county. RF17 occurs in the eastern portion of the county. Thus, the NRC will not 

40 analyze proposed rabbitsfoot mussel critical habitat in any further detail in this SEIS.

41 2.2.8.4 Species Protected by the State of Mississippi 

42 Aquatic Species

43 Crystal Darter The State of Mississippi considers crystal darters (Crystallaria asprella) 

44 endangered. These fish are elongated, cigar-shaped fish that grow to a maximum length of 

45 approximately 150 mm (6 in.). The body is light-olive with dark lateral bands and dark blotches 

46 along each side (MDWFP 2001). Crystal darters inhabit larger creeks and rivers with sand and 
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1 gravel bottoms and a depth of 60 cm (2 ft) or more. These fish prefer moderate to strong 

2 currents. The historical range of crystal darters included Wisconsin east to Ohio and south to 

3 Oklahoma, Louisiana and Florida, although they currently are absent from all of Ohio, Indiana, 

4 and Illinois (MDWFP 2001). Crystal darters inhabit the Bayou Pierre River and tributaries, 

5 which flow as close as 2 mi (3.2 km) east of GGNS (MDWFP 2001; Entergy 2011a). The FES 

6 for construction of GGNS (AEC 1973) and the ESP EIS (NRC 2006a) did not identify crystal 

7 darter as occurring on the GGNS site.

8 Crystal darters may occur in suitable habitat along the transmission line corridors. For example, 

9 crystal darters inhabit the Bayou Pierre, which is crossed by the Franklin transmission line. 

10 However, no GGNS-related aquatic surveys have been conducted along the transmission lines. 

11 Species of Special Concern In the State of Mississippi, a species of special concern includes 

12 “any species that is uncommon in Mississippi, or has unique or highly specific habitat 

13 requirements or scientific value and therefore requires careful monitoring of its status” 

14 (MDWFP 2011). In its correspondence with the NRC, the MDWFP (2012) identified five fish 

15 species considered species of special concern by the State of Mississippi: blue sucker 

16 (Cycleptus elongates), chestnut lamprey (Ichthyomyzon castaneus), black buffalo 

17 (Ictiobus niger), sicklefin chub (Macrhybopsis meeki), and paddlefish (Polyodon spathula). 

18 These species inhabit portions of the Mississippi River (NatureServe 2010). MP&L observed 

19 paddlefish, black buffalo, blue sucker, and chestnut lamprey during preconstruction surveys in 

20 1972 and 1973 (AEC 1973). The FES for construction of GGNS (AEC 1973) and the ESP EIS 

21 (NRC 2006a) did not identify sicklefin chub as occurring on the GGNS site.

22 Chestnut lamprey, blue sucker, black buffalo sicklefin chub, and paddlefish may occur in 

23 suitable habitat along the transmission line corridors. For example, crystal darter, chestnut 

24 lamprey, blue sucker, and chestnut lamprey inhabit the Bayou Pierre, which is crossed by the 

25 Franklin transmission line. However, no GGNS-related aquatic surveys have been conducted 

26 along the transmission lines. 

27 Terrestrial Species 

28 In its correspondence with the NRC, the MDWFP (2012) identified two State-listed species that 

29 may occur in the action area: Webster’s salamander (Plethodon websteri) and the white ibis 

30 (Eudocimus albus). Webster’s salamander is a small salamander with several color morphs 

31 that occurs in mesophytic forest bordering rocky streams. It generally seeks shelter under logs, 

32 bark, or leaf litter on the forest floor or on rocky stream beds. The white ibis is a large white bird 

33 that nests in large groups in coastal marshes along the Atlantic and Gulf coasts. The FES for 

34 construction of GGNS (AEC 1973) and the ESP EIS (NRC 2006a) identify the white ibis as 

35 occurring on the GGNS site. The species is also likely to occur in suitable habitat along the 

36 transmission line corridors. Because the MDWFP (2012) did not identify any impacts of the 

37 proposed license renewal that would affect these species, neither the Webster’s salamander nor 

38 the white ibis will be considered in further detail in this SEIS.

39 2.2.8.5 Species Protected Under the Bald and Golden Eagle Protection Act

40 The Bald and Golden Eagle Protection Act prohibits anyone from taking bald eagles 

41 (Haliaeetus leucocephalus) or golden eagles (Aquila chrysaetos), including their nests or eggs, 

42 without an FWS-issued permit. The term “take” in the Act is defined as to “pursue, shoot, shoot 

43 at, poison, wound, kill, capture, trap, collect, molest, or disturb” (50 CFR 22.3). “Disturb” means 

44 to take action that (1) causes injury to an eagle, (2) decreases its productivity by interfering with 

45 breeding, feeding, or sheltering behavior, or (3) results in nest abandonment (50 CFR 22.3).

46 Bald eagles live and nest along the Mississippi River, but no studies are available on nesting 

47 or population status in the action area. However, Entergy commissioned a one-day 
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1 reconnaissance field survey to identify bald eagle nests along the Mississippi River in the 

2 vicinity of GGNS in December 2006 (Wenstrom 2007b). The survey did not identify any bald 

3 eagle nests or any eagles scavenging or perched in the survey area that would indicate bald 

4 eagles may nest along this portion of the river (Wenstrom 2007b).

5 2.2.8.6 Species Protected Under the Migratory Bird Treaty Act

6 The FWS administers the Migratory Bird Treaty Act (MBTA), which prohibits anyone from taking 

7 native migratory birds or their eggs, feathers, or nests. The MBTA definition of a “take” differs 

8 from that of the ESA and is defined as “to pursue, hunt, shoot, wound, kill, trap, capture, or 

9 collect, or any attempt to carry out these activities” (50 CFR 10.12). Unlike a take under the 

10 ESA, a take under the MBTA does not include habitat alteration or destruction. The MBTA 

11 protects a total of 1,007 migratory bird species (75 FR 9282). Of these 1,007, the FWS allows 

12 for the legal hunting of 58 species as game birds (FWS undated b). Within Mississippi, the 

13 MDWFP manages migratory bird hunting seasons and associated licenses for turkeys, 

14 waterfowl, quail, and doves. The Federally and State-listed bird species that appear in 

15 Table 2–6 are protected under the MBTA. Table 2–4 lists other bird species that commonly 

16 occur on or near the GGNS site, all of which are protected by the MBTA. Additionally, all U.S.

17 native bird species that belong to the families, groups, or species listed at 10 CFR 10.13 are 

18 protected under the MBTA.

19 Entergy holds a depredation permit from the FWS that authorizes Entergy to take 200 cliff 

20 swallows (Petrochelidon spp.), 200 cliff swallow nests (including eggs), 200 barn swallows 

21 (Hirundo rustica), and 200 barn swallow nests (including eggs) per year to mitigate the 

22 safety-related concern that the birds pose when nesting on certain plant structures 

23 (FWS 2012a). The permit directs Entergy to favor the use of hazing, harassment, or other 

24 non-lethal techniques over lethal techniques. From 2006 through 2010, Entergy took 13 cliff 

25 swallows and 7 eggs in 2006 and 4 barn swallows in 2009 (Entergy 2007, 2008a, 2009, 2010a, 

26 2011b). 

27 2.2.9 Socioeconomics

28 This section describes current socioeconomic factors that have the potential to be directly or 

29 indirectly affected by changes in operations at GGNS. GGNS, and the communities that 

30 support it, can be described as a dynamic socioeconomic system. The communities supply the 

31 people, goods, and services required to operate the nuclear power plant. Power plant 

32 operations, in turn, supply wages and benefits for people and dollar expenditures for goods and 

33 services. The measure of a community’s ability to support GGNS operations depends on its

34 ability to respond to changing environmental, social, economic, and demographic conditions.

35 The socioeconomics region of influence (ROI) is defined by the areas where GGNS employees 

36 and their families reside, spend their income, and use their benefits, thus affecting the economic 

37 conditions of the region. GGNS employs a permanent workforce of approximately 

38 690 employees (Entergy 2011a). Approximately 81 percent live in Claiborne, Hinds, Jefferson, 

39 and Warren counties (see Table 2–7). Most of the remaining 19 percent of the workforce are 

40 spread among 13 counties in Mississippi, with numbers ranging from one to 31 employees per 

41 county. Given the residential locations of GGNS employees, the most significant effects of plant 

42 operations are likely to occur in Claiborne, Hinds, Jefferson, and Warren counties; therefore, 

43 these four counties are the GGNS ROI. The focus of the socioeconomic impact analysis in this 

44 document is, therefore, on the impacts of continued GGNS operation on these four counties.
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1 Table 2–7. 2009 GGNS Employee Residence by County

County Number of Employees Percentage of Total

Mississippi

Warren 240 35

Claiborne 142 21

Hinds 94 14

Jefferson 82 12

Copiah 31 4 

Adams 30 4 

Lincoln 23 3 

Other 37 5 

Other states 11 2 

Total 690 100

Source: Entergy 2011a

2 Refueling outages at the GGNS typically have occurred at 18-month intervals. During refueling 

3 outages, site employment increases by as many as 700–900 temporary workers for 

4 approximately 25–30 days (Entergy 2011a). Outage workers are drawn from all regions of the 

5 country; however, the majority would be expected to come from Mississippi, Louisiana, and 

6 other southeastern states. The following sections describe the housing, public services, offsite 

7 land use, visual aesthetics and noise, population demography, and the economy in the ROI 

8 surrounding GGNS.

9 2.2.9.1 Housing

10 The socioeconomic ROI is dominated by Hinds County, which is part of the Jackson 

11 metropolitan area. The size of the Jackson area weighs heavily on the housing statistics, as the 

12 rural counties of Claiborne and Jefferson are considerably different than the ROI averages 

13 would indicate. Table 2–8 lists the total number of occupied and vacant housing units, vacancy 

14 rates, and median home value in the four-county ROI. According to the 2010 Census, there 

15 were approximately 133,096 housing units in the socioeconomic region, of which approximately 

16 113,607 were occupied. The median values of owner-occupied housing units in the ROI range 

17 from $53,500 in Claiborne County to $105,000 in Hinds County. The vacancy rate also ranged 

18 considerably, from 11.5 percent in Warren County to 23.8 percent in Jefferson County 

19 (USCB 2012).

20 Table 2–8. Housing in GGNS ROI

2006–2010, 5-year Estimate

Claiborne Hinds Jefferson Warren ROI

Total 4,255 103,351 3,717 21,773 133,096

Occupied housing units 3,308 88,201 2,831 19,267 113,607

Vacant units 947 15,150 886 2,506 19,489

Vacancy rate (percent) 22.3 14.7 23.8 11.5 14.6

Median value (dollars) 53,500 105,000 67,000 99,700 101,400

Source: USCB 2012
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1 2.2.9.2 Public Services

2 This section presents information on public services that include water supply, education, and 

3 transportation.

4 Water Supply 

5 Information about municipal water suppliers in close proximity to GGNS and maximum design 

6 yields, reported annual peak usage, and population served are presented in Table 2–9. The 

7 source of potable water at GGNS is Entergy’s private water system accessing groundwater. 

8 Table 2–9. Claiborne County Public Water Supply Systems 

Water System

Capacity 

(GPM)

Usage 

(GPM) Population Served

Alcorn State University 1,136 646 3,824

CS&I Water Association #1 288 185 1,100

Hermanville Water Association 552 160 1,230

Pattison Water Association–West 982 389 2,994

Reedtown Water Association 243 35 504

Romola Water Association 556 155 650

Town of Port Gibson 850 587 4,308

Entergy Operations Inc. (private) 1,335 223 1,000

Sources: Entergy 2011a; EPA 2012e

9 Beyond the water systems near GGNS, larger systems supply water to Vicksburg, Clinton, and 

10 Jackson, Mississippi. These systems use groundwater wells with the exception of the City of 

11 Jackson, which relies on Lake Jackson to provide water to a population of approximately 

12 176,000 (EPA 2012e).

13 Education 

14 The Claiborne County School District has one elementary school, one middle school, and one 

15 high school. During the 2009–2010 school year, enrollment was 1,723 students (NCES 2012a).

16 Hinds County has four public school districts and 42 elementary schools, 17 middle schools, 

17 11 high schools, and 16 alternative or special needs schools. The enrollment in 2009 was over 

18 42,200 students (NCES 2012a).

19 The Jefferson County School District has two elementary schools, one middle school, one high 

20 school, and two alternative or vocational schools. The enrollment during the 2009–2010 school 

21 year was 1,465 students (NCES 2012a).

22 The Vicksburg-Warren School District serves all of Warren County and includes eight 

23 elementary schools, four middle schools, two high schools, and two alternative or vocational 

24 schools. During the 2009–2010 school year, enrollment was 8,871 students (NCES 2012a).

25 Transportation 

26 The area surrounding GGNS is largely rural. Highway access to Claiborne County and GGNS 

27 from population centers is via US-61, a principal arterial paralleling the Mississippi River along 

28 much of its course. Interstate 20 is a four-lane divided highway that runs east and west, 
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1 connecting Dallas, TX with Jackson, MS, and passes through 

2 Vicksburg—about 25 mi north of GGNS. US-84 is also a four-lane divided highway that lies 

3 about 30 mi south of GGNS, and runs east-west, connecting Interstate 49 in Louisiana with 

4 Interstate 55 in central Mississippi. The Natchez Trace Parkway, administered by the National 

5 Park Service, preserves a transportation route of Civil War historical significance and provides 

6 tourist access to Jefferson and Claiborne counties as it traverses a route between Natchez and 

7 Clinton.

8 Table 2–10 lists commuting routes to GGNS and average annual daily traffic (AADT) volume 

9 values. The AADT values represent traffic volume during the average 24-hour period 

10 during 2011.

11 Table 2–10. Major Commuting Routes Near GGNS 2011 Average Annual Daily Traffic

Roadway and Location Average Annual Daily Traffic

Grand Gulf Road at GGNS main gate 1,600

Old Mill Road between Grand Gulf Road and Bald Hill Road 860

Grand Gulf Road between Lake Claiborne Road and Old Mill Road 980

Grand Gulf Road between US Hwy 61 and Lake Claiborne Road 1,200

US Hwy 61 between Shiloh Road and Willow Road 7,500

US Hwy 61 between Natchez Trace Pkwy and McComb Avenue 6,600

Source: MDOT 2012 

12 2.2.9.3 Offsite Land Use

13 Land use in the GGNS ROI primarily consists of agricultural lands, with small urban areas and 

14 undeveloped forested land.

Claiborne County occupies approximately 487 mi2 (1,247 square kilometers (km2 15 )) 

16 (USCB 2012). Agricultural and forested lands make up the majority of the land used, with urban 

17 lands making up about 4 percent of the total county land area (USDA NASS 2012). The 

18 principal agriculture land use is pasture and hay crops and livestock products, with the market 

19 value of crops (mostly cotton and soybeans) being about double that of livestock, poultry, and 

20 their products. The number of farms in Claiborne County decreased about 12 percent from 

21 2002–2007. Farmland acreage in the county decreased 7 percent during the same period, and 

22 the average size of a farm increased 6 percent to 360 ac (146 ha) (USDA NASS 2009).

Hinds County occupies approximately 869 mi2 (2,251 km2 23 ) (USCB 2012). Hinds County is 

24 home to part of Jackson, the State capital and largest city in Mississippi, along with Clinton, a 

25 principal suburb of Jackson. Nearly 14 percent of the county is urbanized (USDA NASS 2012). 

26 The majority of the county land area is either forested (40 percent) or agricultural land 

27 (30 percent). The principal crop is livestock forage (i.e., hay and grass silage), followed by 

28 cotton and nursery and greenhouse products. Livestock (mostly cattle and calves) is about 

29 23 percent the market value for all agriculture products. The number of farms in Hinds County 

30 decreased from 2002–2007 by 14 percent. Farmland acreage in the county decreased 

31 seven percent during the same period, and the average size of a farm increased 9 percent to 

32 24 ac (98 ha) (USDA NASS 2009).

Jefferson County covers approximately 519 mi2 (1,344 km2 33 ) (USCB 2012). Jefferson County is 

34 mainly rural, with just 4 percent of the county urbanized (USDA NASS 2012). Undeveloped 

35 forest, grassland, and wetlands make up over 87 percent of the county’s land area. The 
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1 principal crop is livestock forage (i.e., hay and grass silage), followed by cotton and nursery and 

2 greenhouse products. Livestock (mostly poultry and cattle) is about 70 percent the market 

3 value for all agriculture products. The number of farms in Jefferson County increased from 

4 2002–2007 by 13 percent. Farmland acreage in the county also increased 10 percent during 

5 the same period, and the average size of a farm increased 2 percent to 282 ac (114 ha) 

6 (USDA NASS 2009).

Warren County occupies approximately 587 mi2 (1,520 km2 7 ) (USCB 2012). Nearly 

8 seven percent of the county is urbanized (USDA NASS 2012), with Vicksburg being the 

9 principal city. The majority of the county land area is either forested (about 40 percent) or 

10 wetlands (about 30 percent). The principal crops are soybeans and cotton, making up over 

11 85 percent of the value of all agricultural products. The number of farms in Warren County 

12 remained stable over the 2002–2007 period, as has farmland acreage. The average size of a 

13 farm is 403 ac (163 ha) (USDA NASS 2009).

14 2.2.9.4 Visual Aesthetics and Noise

15 GGNS is situated on a relatively flat bluff above the shore of the Mississippi River. Predominant 

16 features include the containment structure, turbine building, auxiliary building, control building, 

17 diesel generator building, standby service water cooling towers and basins, enclosure building, 

18 radwaste building, independent spent fuel storage installation (ISFSI), auxiliary cooling tower, 

19 and the natural draft cooling tower (Entergy 2011a).

20 There is often a visible plume of condensation rising up from the cooling towers. Its height and 

21 visibility depend on weather conditions such as temperature, humidity, and wind speed. It is 

22 typically several hundred feet tall and can be seen from several miles away. Because of the 

23 open and flat terrain on the Louisiana side of the Mississippi River, the plume and the cooling 

24 tower are clearly seen from US-65 in Louisiana for many miles in all directions. The rolling and 

25 forested terrain of Claiborne County provides significant visual screening in the immediate 

26 vicinity of GGNS.

27 Noise from nuclear plant operations can be detected off site. There are no local noise 

28 ordinances that limit allowable sound levels at GGNS. The staff determined background noise 

29 levels at GGNS are expected to range from 45 to 55 dBA at the nearest site boundary 

30 (NRC 2006a). Noise levels may sometimes exceed the 55-decibel adjusted level that the EPA

31 uses as a threshold level to protect against excess noise during outdoor activities. However, 

32 according to the EPA this threshold does “not constitute a standard, specification, or regulation,” 

33 but was intended to give a basis for state and local governments establishing noise standards 

34 (EPA 1974).

35 2.2.9.5 Demography

36 According to the 2010 Census, an estimated 23,406 people live within 20 mi (32 km) of GGNS, 

which equates to a population density of 19 persons per mi2 37 (Entergy 2011a). This translates to 

38 a Category 1, “most sparse” population density using the GEIS measure of sparseness (less 

than 40 persons per mi2 39 and no community with 25,000 or more persons within 20 mi). An 

40 estimated 329,043 people live within 50 mi (80 km) of GGNS with a population density of 

42 persons per mi2 41 (Entergy 2011a). Since Jackson is located beyond 50 mi from GGNS, this 

42 translates to a Category 1 density, using the GEIS measure of proximity (no cities with 

100,000 or more persons and less than 50 persons per mi2 43 within 50 mi). Therefore, GGNS is 

44 located in a low population area based on the GEIS sparseness and proximity matrix.

45 Table 2–11 shows population projections and growth rates from 1970–2050 in the four-county 

46 GGNS ROI. The net population growth rate in the ROI has been negative over the last two 

47 decades. Based on State forecasts, rural counties are expected to continue to decline in 
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1 population through 2025, while more developed urban counties are expected to continue 

2 modest growth through 2025 (MIHL 2012). Beyond 2025, the staff applied the 50-year trend in 

3 population, observed between 1970 and 2020 projections, to approximate long-term trends.

4 Table 2–11. Population and Percent Growth in GGNS ROI Counties 

5 from 1970–2009 and Projected for 2010–2050

Year

Claiborne Hinds Jefferson Warren

PopulationPercent 

growth(a)

PopulationPercent 

growth(a)

PopulationPercent 

growth(a)

PopulationPercent 

growth(a)

1970 10,086 – 214,973 – 9,295 – 44,981 – 

1980 12,279 21.7% 250,998 16.8% 9,181 -1.2% 51,627 14.8%

1990 11,370 -7.4% 254,441 1.4% 8,653 -5.8% 47,880 -7.3%

2000 11,831 4.1% 250,800 -1.4% 9,740 12.6% 49,644 3.7%

2010 9,604 -18.8% 245,285 -2.2% 7,726 -20.7% 48,773 -1.8%

2020 8,700 -9.4% 250,264 2.0% 7,074 -8.4% 48,030 -1.5%

2030 8,676 -0.3% 251,086 0.3% 7,040 -0.5% 48,095 0.1%

2040 8,652 -0.3% 251,910 0.3% 7,006 -0.5% 48,160 0.1%

2050 8,628 -0.3% 252,737 0.3% 6,973 -0.5% 48,225 0.1%

– = No data available.

(a) Percent growth rate is calculated over the previous decade.

Sources: Population data for 1970 through estimated population data for 2009 (USCB 2012); population projections 

for 2020 by Mississippi Institutions of Higher Learning (MIHL2012); 2030-2050 calculated.

6 Demographic Profile 

7 According to the 2010 Census, minority populations were estimated to have increased by over 

8 17,100 persons and comprised 69.4 percent of the ROI population (see Table 2–12). Most of 

9 this increase was due to an estimated influx of African Americans to urban centers such as 

10 Jackson and Vicksburg, while minority populations in rural counties declined over the same 

11 period. 
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1 Table 2–12. Demographic Profile of the Population in the GGNS ROI in 2010

Claiborne Hinds Jefferson Warren ROI

Total Population 9,604 245,285 7,726 48,773 311,388

Race (percent of total population, Not-Hispanic or Latino)

White 14.1 28.0 13.7 49.5 30.6

Black or African American 84.0 68.8 85.4 46.8 66.3

American Indian and Alaska Native 0.1 0.1 0.2 0.2 0.2

Asian 0.4 0.8 0.0 0.8 0.7

Native Hawaiian Other Pacific 

Islander

0.0 0.0 0.0 0.0 0.0

Some other race 0.1 0.1 0.0 0.0 0.1

Two or more races 0.5 0.7 0.3 0.7 0.7

Ethnicity

Hispanic or Latino 74 3,630 28 896 4,628

Percent of total population 0.8 1.5 0.4 1.8 1.5

Minority population (including Hispanic or Latino ethnicity)

Total minority population 8,251 176,676 6,670 24,630 216,227

Percent minority 85.9 72.0 86.3 50.5 69.4

Source: USCB 2012.

2 Transient Population 

3 Within 50 mi (80 km) of GGNS, colleges and recreational opportunities attract daily and 

4 seasonal visitors who create demand for temporary housing and services. In 2010, there were 

5 approximately 21,859 students attending colleges and universities within 50 mi (80 km) of 

6 GGNS (NCES 2012b).

7 Based on the 2010 Census, approximately 10,471 seasonal housing units are located within 

8 50 mi of GGNS. Of those, 1,536 are located in the GGNS four-county ROI. Table–13 supplies 

9 information on seasonal housing for the counties located all or partly within 50 mi of GGNS.
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1 Table 2–13. 2010 Seasonal Housing in Counties within 50 miles of GGNS

County(a) Housing Units

Vacant Housing Units: 

for Seasonal, 

Recreational, or 

Occasional Use Percent

Mississippi

Adams 14,771 649 4.4

Amite 6,638 553 8.3

Claiborne 4,255 388 9.1

Copiah 12,056 323 2.7

Franklin 4,170 482 11.6

Hinds 103,351 458 0.4

Issaquena 712 46 0.4

Jefferson 3,717 350 6.5

Lincoln 15,101 411 9.4

Madison 37,349 375 2.7

Rankin 55,200 544 1.0

Sharkey 2,065 167 1.0

Simpson 11,837 94 8.1

Warren 21,773 340 0.8

Wilkinson 5,085 928 1.6

Yazoo 10,094 374 18.2

County Subtotal 308,174 6,482 2.1

Louisiana

Caldwell 5,014 622 12.4

Catahoula 4,987 779 15.6

Concordia 9,369 931 9.9

East Carroll 2,813 65 2.3

Franklin 8,987 295 3.3

Madison 4,827 235 4.9

Richland 8,557 442 5.2

Tensas 3,357 620 18.5

County Subtotal 47,911 3,989 8.3

Total 356,085 10,471 2.9

(a) Counties within 50 mi (80 km) of GGNS with at least one block group located within the 50-mi (80-km) 

radius.

Source: USCB 2012. 

2 Migrant Farm Workers 

3 Migrant farm workers are individuals whose employment requires travel to harvest agricultural 

4 crops. These workers may or may not have a permanent residence. Some migrant workers 

5 follow the harvesting of crops, particularly fruit, throughout rural areas of the United States. 

6 Others may be permanent residents near GGNS and travel from farm to farm harvesting crops.
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1 Migrant workers may be members of minority or low-income populations. Because they travel 

2 and can spend a significant amount of time in an area without being actual residents, migrant 

3 workers may be unavailable for counting by census takers. If uncounted, these workers would 

4 be “underrepresented” in U.S. Census Bureau (USCB) minority and low-income population 

5 counts.

6 Information on migrant farm and temporary labor was collected in the 2007 Census of 

7 Agriculture. Table 2–14 supplies information on migrant farm workers and temporary farm labor 

8 (less than 150 days) within 50 mi of GGNS. According to the 2007 Census of Agriculture, 

9 approximately 6,440 farm workers were hired to work for less than 150 days and were 

10 employed on 1,419 farms within 50 mi of GGNS. The county with the largest number of 

11 temporary farm workers (1,152) on 185 farms was Franklin County, Louisiana 

12 (USDA NASS 2009).
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1 Table 2–14. Migrant Farm Workers and Temporary Farm Labor in Counties Located 

2 within 50 Miles of GGNS

County(a)

Number of Farms 

with Hired Farm 

Labor

Number of Farms 

Hiring Workers for 

Less than 150 days 

Number of Farm 

Workers Working 

for Less than 150 

days

Number of 

Farms 

Reporting 

Migrant Farm 

Labor

Mississippi

Adams 30 24 (b) 3 

Amite 91 72 339 7 

Claiborne 49 47 176 3 

Copiah 108 86 438 2 

Franklin 22 20 64 2 

Hinds 142 108 344 9 

Issaquena 28 15 76 3 

Jefferson 56 38 143 0 

Lincoln 125 100 401 6 

Madison 134 95 280 9 

Rankin 138 108 364 5 

Sharkey 38 7 171 4 

Simpson 114 95 300 5 

Warren 50 40 157 2 

Wilkinson 49 38 155 0 

Yazoo 121 77 508 7 

Subtotal 1,295 970 3,916 67

Louisiana

Caldwell 65 58 139 4

Catahoula 61 36 218 4

Concordia 61 33 198 1

East Carroll 75 25 178 2

Franklin 250 185 1152 6

Madison 67 28 156 4

Richland 112 74 250 13

Tensas 59 10 233 5

Subtotal 750 449 2,524 39

Total 2,045 1,419 6,440 106

(a) Counties within 50 miles of GGNS with at least one block group located within the 50-mi radius.

(b)

Data not disclosed by USDA.

Source: 2007 Census of Agriculture—County Data (USDA NASS 2009).

3 In the 2002 Census of Agriculture, farm operators were asked for the first time whether or not 

4 they hired migrant workers—defined as a farm worker whose employment required travel—to 

5 do work that prevented the migrant worker from returning to their permanent place of residence 

6 the same day. A total of 106 farms, in the 50-mi radius of GGNS, reported hiring migrant 
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1 workers in the 2007 Census of Agriculture. Richland County, Louisiana, reports the most farms 

2 with migrant farm labor (13 farms) (USDA NASS 2009).

3 2.2.9.6 Economy

4 This section contains a discussion of the economy, including employment and income, 

5 unemployment, and taxes. 

6 Employment and Income 

7 From 2000 to 2012, the civilian labor force in the GGNS ROI declined by about 5 percent to just 

8 over 147,000. The number of employed persons declined by about 7 percent over the same 

9 period, to about 135,000. Consequently, the number of unemployed people in the ROI has 

10 increased over 36 percent in the same period, to over 12,200, or about 8.3 percent of the 

11 current workforce (BLS 2012).

12 In 2010, state and local government made up the largest sector of the economy in terms of 

13 employment (19.6 percent), followed by health care and social assistance (13.9 percent), retail 

14 trade (8.2 percent), administrative services (6.4 percent) and accommodations and food 

15 services (6.2 percent) (BEA 2012). A list of selected major employers in the ROI is given in 

16 Table 2–15. As shown in the table, GGNS is the 22nd largest employer in the ROI and the 

17 second largest in Claiborne County.
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1 Table 2–15. Major Employers of the GGNS ROI in 2012

Employer

Number of 

Employees County

State of Mississippi 31,556 Hinds

University Medical Center 8,000 Hinds

U.S. Government 5,500 Hinds

Jackson Public Schools 4,814 Hinds

Baptist Health Systems 2,875 Hinds

St. Dominic Health Services 2,600 Hinds

City of Jackson 2,323 Hinds

Jackson State University 1,667 Hinds

USACE Engineer Research & Development 

Center

1,600 Warren

River Region Health Systems 1,500 Warren

AT&T Mississippi 1,300 Hinds

Vicksburg-Warren School District 1,300 Warren

Central MS Medical Center 1,200 Hinds

USACE, Division/District 1,100 Warren

Trustmark National Bank 1,075 Hinds

Delphi Mississippi 1,075 Hinds

Ameristar Casino 900 Warren

Saks Incorporated 800 Hinds

Entergy Mississippi 765 Hinds

Alcorn State University 750 Claiborne

LeTourneau Technologies 750 Warren

Grand Gulf Nuclear Station 691 Claiborne

Tyson Foods 680 Warren

Eaton Aerospace 625 Hinds

DiamondJacks Casino Hotel 588 Warren

City of Vicksburg 586 Warren

Walmart Supercenter 550 Warren

Jefferson Co School District 100 Jefferson

Southern Lumber Co., Inc. 80 Claiborne

MMC Materials, Inc. 32 Claiborne

Source: Port Gibson Chamber (2012), Warren Co. Port Commission (2012), Hinds Co. Economic Development 

Authority (2008). Smaller Jefferson and Claiborne County employers are shown to be representative.

2 Estimated income information for the GGNS ROI is presented in Table 2–16. According to the 

3 USCB’s 2006–2010 American Community Survey 5-Year Estimates, people living in Claiborne 

4 and Jefferson Counties had median household and per capita incomes below the State 

5 average, while Hinds and Warren counties had median incomes higher than the State average. 

6 The same trend is evident for families and individuals living below the official poverty level. The 

7 relative lack of economic development in Claiborne and Jefferson counties contributes to higher 
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1 than average poverty and lower than average median incomes compared to the more 

2 economically developed counties of Hinds and Warren. The State of Mississippi, as a whole, is 

3 positioned between the economically developed and the economically undeveloped county 

4 groupings of the GGNS ROI for both median income and living below poverty level.

5 Table 2–16. Estimated Income Information for the GGNS ROI in 2010

Claiborne Hinds Jefferson Warren Mississippi

Median household income (dollars)(a) 24,150 39,215 24,304 40,404 37,881

Per capita income (dollars)(a) 12,571 20,676 12,534 22,079 19,977

Individuals living below the poverty level 

(percent)

35.0 22.5 39.0 21.4 16.7

Families living below the poverty level 

(percent)

27.6 17.7 29.3 16.5 21.2

(a) In 2010 inflation adjusted dollars.

Source: USCB 2012.

6 Unemployment 

7 Unemployment rates in the GGNS ROI have mirrored State and national trends from 2007 to 

8 2012. Table 2–17 illustrates the not-seasonally-adjusted unemployment rates for the GGNS 

9 ROI counties compared to State and national rates. 

10 The effects of the recent economic recession on employment are visible in all counties. 

11 Claiborne and Jefferson Counties have had consistently higher unemployment rates than their 

12 urban neighboring counties through this period.

13 Table 2–17. 2007–2012 Unemployment Rates in the GGNS ROI

ROI Counties 2007 2008 2009 2010 2011 2012

Claiborne 9.8 9.1 14.3 12.8 14.3 11.8

Hinds 5.4 5.0 7.1 8.9 8.8 7.6

Jefferson 11.2 10.7 14.7 14.4 14.5 13.0

Warren 6.0 5.3 8.7 10.5 11.3 9.3

Mississippi 5.9 5.5 8.3 9.9 10.0 8.3

United States 4.3 4.8 8.6 9.5 8.7 7.7

Source: MDES (2012); for consistency all values not seasonally adjusted.

14 Taxes 

15 Mississippi Code Title 27 addresses taxation of nuclear generating plants and the distribution of 

16 tax revenues from nuclear plants. This code states that any nuclear generating plant located in 

17 the State, which is owned or operated by a public utility, is exempt from county, municipal, and 

18 district ad valorem taxes. In lieu of the payment of county, municipal, and district ad valorem 

19 taxes, the nuclear power plant pays the Mississippi State Tax Commission a sum based on the 

20 assessed value of the nuclear generating plant.

21 GGNS is taxed by the State for a sum equal to 2 percent of the assessed value but not less 

22 than $20 million annually, $7.8 million of which is provided to Claiborne County. Of this amount, 

23 $3 million is contingent upon Claiborne County upholding its commitment to the GGNS offsite 
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1 emergency plan. The $7.8 million provided by the State represents roughly 83 percent of all 

2 Claiborne County revenues.

3 The Mississippi State Tax Commission transfers $160,000 annually to the city of Port Gibson, 

4 provided the city maintains its commitment to the GGNS offsite emergency plan. Ten percent of 

5 the remainder of the payments are transferred from the Mississippi Tax Commission to the 

6 General Fund of the State. The balance of the tax revenue from the GGNS site is transferred to 

7 the counties and municipalities in the State of Mississippi where electric service is provided. 

8 The tax revenues are distributed in proportion to the amount of electric energy consumed by the 

9 retail customers in each county, with no county receiving an excess of 20 percent of the funds. 

10 This distribution, based on energy consumed, also includes Claiborne County.

11 (Mississippi Code Title 27) 

12 2.2.10 Historic and Archaeological Resources

13 This section discusses the cultural background and known historic and archaeological 

14 resources in and around GGNS.

15 2.2.10.1 Cultural Background

16 The area in and around GGNS has a high potential for significant prehistoric and historic 

17 resources. Human occupation in the Mississippi Valley area is generally characterized based 

18 on the following chronological sequence (Peacock 2005): 

19  Paleoindian Period (14,000+ to 9,000 years before present (BP))

20  Archaic Period (9,000 to 3,000 BP) 

21  Woodland Period (3,000 to 1,000 BP) 

22  Mississippian Period (1,000 to 300 BP) 

23  Protohistoric/Historic Period (300 BP to present) 

24 Paleoindian Period (14,000 to 9,000 BP)

25 The Paleoindian Period is generally characterized by highly mobile bands of hunters and 

26 gatherers. Little information is known about Paleoindian methods of subsistence, but it is 

27 assumed that they would have hunted now-extinct megafauna (e.g., mammoth, ground sloth, 

28 and saber-tooth tiger), in addition to hunting smaller game and gathering wild plants. No 

29 Paleoindian sites are currently known in the GGNS vicinity; however, Paleoindian sites in the 

30 Southeastern U.S. generally consist of isolated projectile points or other tools such as flaked 

31 stone end scrapers or bone tools (Peacock 2005). 

32 Archaic Period (9,000 to 3,000 BP) 

33 The Archaic Period is generally distinguished from the preceding Paleoindian Period by 

34 changes in the environment, technology, and population. The warmer and dryer part of the 

35 Early Archaic Period facilitated groups’ ability to exploit more diverse resources, and 

36 consequently their tool kit also became more diversified. Technological changes are evidenced 

37 by the manufacture of notched projectile points, which were smaller than Paleoindian points, 

38 likely reflecting a reliance on smaller game (Neusius and Gross 2007). Groups became 

39 sedentary as the climate became wetter and warmer as the Archaic Period progressed, and 

40 ceremonialism (e.g., mounds, effigies) is evident in the archaeological record during this time. 

41 Archaic sites have been documented on GGNS property (Entergy 2011a; MDAH 2012). 
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1 Woodland Period (3,000 to 1,000 BP) 

2 The Woodland Period is often divided into early, middle, and late periods. One of the most 

3 notable aspects in the archaeological record of the Woodland Period is widespread pottery use; 

4 the period is sometimes referred to as the Early Ceramic Period. Groups living permanently in 

5 one place dominated the settlement pattern during the Woodland Period, an aspect that may 

6 have facilitated the widespread development of pottery (Peacock 2005). Mounds were 

7 frequently built in the Middle Woodland Period, but this practice dissipated by the end of the 

8 period. Sites dating to the Late Woodland Period are the most common sites found in 

9 Mississippi. These sites are found in various types of landforms; valleys, hills, deltas, and 

10 prairies (Peacock 2005). Another important development during the latter portion of the 

11 Woodland Period is the bow-and-arrow, which is evidenced by smaller projectile points and 

12 likely involved significant changes in the way warfare and hunting were conducted (Lee 2010). 

13 The GGNS property contains an example of a Middle Woodland mound. The Grand Gulf 

14 Mound Site (22Cb522) is located on a loess bluff 220 ft above sea level, overlooking the 

15 Mississippi River. Clarence Moore identified the mound in 1911. Members of Harvard’s 

16 Peabody Museum visited the site in the 1940s, and it was excavated in 1973 by the Mississippi 

17 Department of Archives and History (MDAH) (Brookes 1976). Unfortunately, two-thirds of the 

18 mound was bulldozed before its excavation and the portion that was not destroyed was 

19 vandalized by looters. Human remains (mandible with teeth, several ribs, and a humerus) were 

20 found in the dirt from the bulldozed section of the mound (Stone 1972). Artifacts found during 

21 excavation of the mound include copper pieces (of non-local origin), ceramics, and a platform 

22 pipe (found by a collector) (Brookes 1976). These artifacts suggest that those living at the 

23 Grand Gulf Mound Site likely participated in an extensive trading network, the Hopewell 

24 Interaction Sphere, with groups throughout the Eastern Woodlands. Potentially significant 

25 deposits in the vicinity of the mound are still possible.

26 Two other mounds were documented at GGNS. They were located close to each other and 

27 likely were farther back on the bluff than the Grand Gulf Mound Site; however, they have since 

28 been destroyed (Brookes 1976). Additionally, Brookes (1976) noted that the area just north of 

29 the Grand Gulf Mound Site had many surface finds and suggested that the area may have been 

30 an Archaic Site or Woodland work area. Woodland sites also have been documented on the 

31 western side of the Mississippi River across from the town of Grand Gulf located just north of 

32 GGNS (Brookes 1976).

33 Mississippian Period (1,000 to 300 BP) 

34 The Mississippian Period is arguably the most intensely studied period in the American 

35 Southeast. With sites as far north as Wisconsin and extending to the Gulf Coast, Mississippian 

36 peoples maintained a vast cultural and trading network. In the vicinity of GGNS, the 

37 Mississippian Period was preceded by an Emergent Mississippian Period, referred to as the 

38 Coles Creek Culture, beginning around A.D. 700 and lasting until about A.D. 1200 (Roe and 

39 Schilling 2010). This period is characterized by changes in settlement patterns, mortuary 

40 practices, and ceramic technology and decoration, as well as distinctive ceremonial centers 

41 (Roe and Schilling 2010). Subsistence during the Emergent Mississippian Period in this area 

42 continued to rely on hunting and gathering, with small amounts of maize and domesticated 

43 crops beginning to appear (Roe and Schilling 2010). Around A.D. 1200, the Mississippian 

44 Culture took hold in the region and is expressed locally as the Plaquemine Culture. The type 

45 site of the culture is the Medora Site in West Baton Rouge Parish, Louisiana (Rees 2010). 

46 Characterized by ceremonial mound centers, shell-tempered pottery, ceramic and stone 

47 smoking pipes, stone axes, game stones and small stemmed projectile points, it is commonly 
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1 accepted that the Mississippian Period saw more social stratification than previous periods, and 

2 these high-status individuals likely lived on top of the platform mounds constructed (Rees 2010). 

3 In other parts of the Southeast, the Mississippian Period is seen to decline around A.D. 1500, 

4 but in the Lower Mississippi Valley the Mississippian Period appears to have continued into the 

5 Protohistoric Period, with historically known groups such as the Natchez and Chitimacha 

6 persisting in the Mississippian culture until contact with Europeans changed their way of life. 

7 Protohistoric/Historic Period (300 BP to Present)

8 Hernando de Soto undertook the earliest European expedition into the Southeast United States 

9 that passed by the GGNS study area. While he did not stop near GGNS, the impact of this 

10 expedition was felt by Native American tribes throughout the Southeast United States, which

11 were decimated by the diseases that the Europeans brought. Until fall 1543, de Soto and his 

12 expedition attacked and enslaved the Native populations throughout the Southeast United 

13 States, often exhausting Native food supplies (Neusius and Gross 2007). 

14 An early historic reference to Grand Gulf comes from French explorer René Robert Cavelier, 

15 Sieur de La Salle’s 1862 voyage down the Mississippi River to find water passages into Spanish 

16 territory. He traveled passed the GGNS vicinity and his subsequent maps referred to the locale 

17 as “Grand Gouffre,” designating a large whirlpool (Wright 1982). The whirlpool was formed by 

18 the Black River entering the Mississippi River, and the eddy was made more treacherous with a 

19 large rock outcropping known as “Point of Rock,” which is located within the Grand Gulf Military 

20 Monument Park near GGNS.

21 Significant political and social reorganization took place among most of the Southeastern tribes 

22 after European contact. Many of the historically known tribes were formed from refugee 

23 populations or around the remnants of once great chiefdoms (Saunt 2004); however, in the 

24 vicinity of GGNS little is known about the period between the end of the Mississippian Period 

25 and European settlement. It has been suggested that early historic period groups moved 

26 frequently based on the location of Europeans on the landscape (Kidder 2004). There are no 

27 historical records of the tribal affiliation of groups in the GGNS vicinity; however, the Natchez 

28 had significant settlements south of the property and the Taensa were located on the other side 

29 of the Mississippi River in Louisiana. 

30 An established European presence in the region came in 1699, when the French formed a 

31 colony at Biloxi Bay near D’Iberville, Mississippi, about 170 mi southeast of GGNS. At this time, 

32 the Mississippi River was one of the most important transportation and trade routes in the 

33 country, and Europeans set up temporary camps along the river to float their cargo downriver to 

34 the commercial center of New Orleans. The location of Grand Gulf on the Mississippi River, 

35 along with the construction of a railroad connecting Grand Gulf and Port Gibson in 1830, 

36 provided the opportunity for Grand Gulf’s citizens to flourish as cotton shippers (Wright 1982). 

37 Unfortunately, the prosperity would not last, when, after several floods, a tornado hit the town in 

38 1853 and the town was unable to recover. 

39 During the Civil War, Union General William Sherman’s “total war” campaign decimated several 

40 parts of the State of Mississippi. Union forces destroyed homes, factories, and infrastructure as 

41 they battled throughout the State. After the fall of New Orleans in April 1862, Grand Gulf began 

42 to play an increasingly important role in the Confederate defense of Vicksburg. Leading up to 

43 the eventual 1863 Union victory at Vicksburg, Confederate installations at Grand Gulf 

44 successfully defended Vicksburg and surrounding towns against several Union maneuvers 

45 (Wright 1982). However, in April 1863, Union forces made the largest amphibious landing in 

46 American History (before World War II) at Grand Gulf. The outnumbered Confederates held 

47 onto their positions for 18 hours before abandoning the fortifications and retreating to Bayou 
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1 Pierre. The Union forces moved into the town and used Grand Gulf as a base until early June. 

2 This was by far the largest battle fought at Grand Gulf, but an additional skirmish occurred 

3 between a Union patrol and Confederate partisans on July 16, 1864, and a Union boat was 

4 destroyed by Confederate forces in December 1864 (Wright 1982). The 1863 Union capture of 

5 Vicksburg is viewed as one of the critical turning points in the war that helped to ensure a Union 

6 victory (Smith 2010).

7 At the end of the war, a main feature of Reconstruction was the introduction of the sharecropper 

8 system to the area surrounding GGNS. In this system, land owners rented parcels of their land 

9 to those who farmed it in exchange for a percentage of the crop. Many newly freed slaves 

10 participated in this system and potential sharecropper sites were documented at GGNS during a 

11 survey in 2006 (22Cb824 and 22Cb827). Most of the African-American sharecroppers began 

12 resettling at the end of the 19th century in nearby towns, and the area around GGNS remained 

13 rural farmland until GGNS acquired it in the 1970s (Entergy 2011a). GGNS began commercial 

14 operations in July 1985, as the first and only nuclear power plant in Mississippi. 

15 2.2.10.2 Historic and Archaeological Resources

16 Before the construction of the approximately 2,015-ac (816-ha) GGNS site, the area was used 

17 as farmland. The Mississippi River bounds the property on the west, with other land owners to 

18 the north, south, and east. Both historic and prehistoric resources have been documented on 

19 the GGNS property; however, any extant cultural resources are most likely subsurface remains 

20 and would not be discovered unless land-disturbing operations took place. 

21 The GGNS property has been subject to several archaeological surveys and consultations with 

22 the Mississippi State Historic Preservation Office. In June 1972, Mississippi Power & Light 

23 Company (MP&L), a precursor of Entergy, contracted the MDAH to perform archaeological, 

24 architectural, and historical surveys of the property and transmission routes in Claiborne 

25 County. Eight sites were recorded as a result of this survey, only one of which (the Grand Gulf 

26 Mound) was considered potentially eligible for inclusion in the National Register of Historic 

27 Places (NRHP). 

28 The architectural survey of Claiborne County identified one additional resource, the Callendar 

29 house. This was a mid-19th century Greek Revival style house, located on the eastern portion 

30 of the GGNS property. The house was in poor condition during the 1970s and is no longer 

31 extant. The 164 acres of land GGNS donated to the Grand Gulf Military Monument Park 

32 contained vestiges of the town of Grand Gulf that has been preserved with the protection the 

33 park provides (Entergy 2011a). 

34 Two transmission lines, which leave GGNS property, were constructed to connect GGNS to the 

35 regional power grid: the Baxter-Wilson line and the Franklin line. Neither of these transmission 

36 lines are documented as having been formally surveyed before construction. Other surveys 

37 conducted in the vicinity of the transmission lines have identified at least seven cultural resource

38 sites that are present either in the path of the Baxter-Wilson and Franklin transmission lines or 

39 in very close proximity to them. One of the sites along the Baxter-Wilson right-of-way is the 

40 Loosa Yokena site (22Wr691), which is a Middle- to Late-Archaic stone and gem working 

41 workshop and occupation site that is listed on the NRHP. The Yokena Mound Group 

42 (Site 22Wr500/544) consists of three pyramid mounds damaged by a railroad cut, and 

43 Site 22Wr530 is a small occupational area on the Mississippi River floodplain. The current 

44 eligibility status of these two sites is undetermined and would require further investigation to 

45 assess their eligibility. Site 22Li558 is a Woodland site very near to the Franklin right-of-way 

46 with lithics (stone tools and other chipped stone artifacts) and ceramics that requires further 

47 testing before an NRHP eligibility determination can be made. Site 22Cb642 is also a 
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1 Woodland period site with undetermined eligibility status. Sites 22Je581 and 22Je584 are not 

2 eligible for listing in the NRHP (MDAH 2012). 

3 The Archaeological Research Laboratory of the University of Tennessee conducted a Phase I 

4 survey of areas of potential construction for a proposed new reactor at GGNS. The survey 

5 identified two previously recorded sites (22Cb524 and 22Cb528), as well as nine newly 

6 discovered sites (22Cb820, 22Cb821, 22Cb822, 22Cb823, 22Cb824, 22Cb825, 22Cb826, 

7 22Cb827, and 22Cb828). Site 22Cb528 is an Archaic Period village consisting of ceramics and 

8 lithics at various stages of production. It was determined that the site should be avoided or 

9 tested further to determine eligibility (Entergy 2011a; MDAH 2012). A portion of the Grand Gulf 

10 to Port Gibson railroad passes through the site boundary and was inspected by NRC staff on 

11 April 13, 2004. It was determined that because the only extant remnants of the railroad are the 

12 bed and berm, this section of the railroad does not retain enough integrity to warrant 

13 preservation (Stapp 2004). 

14 Overall, 17 archaeological sites have been documented on GGNS property; only one (22Cb528) 

15 is considered potentially eligible for listing in the NRHP. Fifteen of these sites are prehistoric, 

16 and two of them have both prehistoric and historic components. Even though the Grand Gulf 

17 Mound (22Cb522) has been excavated, mound sites were typically part of larger village sites, 

18 and it is possible that significant subsurface deposits exist in the vicinity of the mound complex. 

19 Within 10 mi of GGNS, 219 archaeological sites have been documented, 9 of which are listed 

20 on the NRHP, 2 are eligible, 40 are potentially eligible, 138 are of unknown potential, and 30 are 

21 not eligible. Claiborne County maintains 38 properties in the NRHP; the closest listed properties 

22 to GGNS are the Grand Gulf Military Park and historic sites in the town of Port Gibson 

23 (Entergy 2011a; MDAH 2012). 

24 2.3 Related Federal and State Activities

25 The staff reviewed the possibility that activities of other Federal agencies might affect the 

26 renewal of the operating license for GGNS. Any such activity could result in cumulative 

27 environmental impacts and the possible need for a Federal agency to become a cooperating 

28 agency in the preparation of NRC’s SEIS for GGNS. 

29 There are no Federal projects that would make it necessary for another Federal agency to 

30 become a cooperating agency in the preparation of this document. There are no known 

31 American Indian lands within 50 mi (80 km) of GGNS. Federally owned facilities within 50 mi 

32 (80 km) of GGNS are listed below:

33  Tensas River National Wildlife Refuge

34  Bayou Cocodrie National Wildlife Refuge

35  Poverty Point National Monument

36  Natchez Trace Parkway and National Scenic Trail

37  Vicksburg National Military Park

38  Natchez National Historical Park

39  Homochitto National Forest

40  Saint Catherine Creek National Wildlife Refuge

41  Delta National Forest

42 The NRC is required, under Section 102(2)(c) of the National Environmental Policy Act, to 

43 consult with and obtain the comments of any Federal agency that has jurisdiction by law or 

44 special expertise with respect to any environmental impact involved. For example, during the 

45 course of preparing this DSEIS, the NRC consulted with the FWS and the NMFS. Federal 

46 agency consultation correspondence is presented in Appendix D.
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1 2.4 References

2 10 CFR Part 20. Code of Federal Regulations, Title 10, Energy, Part 20, “Standards for 

3 protection against radiation.”

4 10 CFR Part 50. Code of Federal Regulations, Title 10, Energy, Part 50, “Domestic licensing of 

5 production and utilization facilities.”

6 10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

7 protection regulations for domestic licensing and related regulatory functions.”

8 10 CFR Part 54. Code of Federal Regulations, Title 10, Energy, Part 54, “Requirements for 

9 renewal of operating licenses for nuclear power plants.”

10 10 CFR Part 61. Code of Federal Regulations, Title 10, Energy, Part 61, “Licensing 

11 requirements for land disposal of radioactive waste.”

12 10 CFR Part 71. Code of Federal Regulations, Title 10, Energy, Part 71, “Packaging and 

13 transportation of radioactive material.”

14 40 CFR Part 50. Code of Federal Regulations, Title 40, Protection of Environment, Part 50, 

15 “National primary and secondary ambient air quality standards.”

16 40 CFR Part 52. Code of Federal Regulations, Title 40, Protection of Environment, Part 52, 

17 “Approval and promulgation of implementation plans.”

18 40 CFR Part 81. Code of Federal Regulations, Title 40, Protection of Environment, Part 81, 

19 “Designation of areas for air quality planning purposes.”

20 40 CFR Part 141. Code of Federal Regulations, Title 40, Protection of Environment, Part 141, 

21 “National primary drinking water regulations.”

22 40 CFR Part 190. Code of Federal Regulations, Title 40, Protection of Environment, Part 190, 

23 “Environmental radiation protection standards for nuclear power operations.”

24 50 CFR Part 10. Code of Federal Regulations, Title 50, Wildlife and Fisheries, Part 10, “General 

25 provisions.”

26 50 CFR Part 22. Code of Federal Regulations, Title 50, Wildlife and Fisheries, Part 22, “Eagle 

27 permits.”

28 35 FR 16047. U.S. Fish and Wildlife Service. “Conservation of endangered species and other 

29 fish or wildlife; Appendix D—United States list of endangered native fish and wildlife.” Federal 

30 Register 35(199):16047-16048. October 13, 1970. 

31 49 FR 7332. U.S. Fish and Wildlife Service. “Endangered and threatened wildlife and plants; 

32 U.S. breeding population of the wood stork determined to be endangered.” Federal Register

33 49(40):7332-7335. February 28, 1984. Available at 

34 <http://ecos.fws.gov/docs/federal_register/fr800.pdf> (accessed 11 June 2012).

35 50 FR 21784. U.S. Fish and Wildlife Service. “Endangered and threatened wildlife and plants; 

36 interior population of the least tern determined to be endangered.” Federal Register

37 50(102):21784-21792. May 28, 1985. Available at 

38 <http://ecos.fws.gov/docs/federal_register/fr957.pdf> (accessed 12 June 2012).

39 57 FR 588. U.S. Fish and Wildlife Service. “Endangered and threatened wildlife and plants; 

40 threatened status for the Louisiana black bear and related rules.” Federal Register

41 57(4):588-595. January 7, 1992. Available at 

42 <http://ecos.fws.gov/docs/federal_register/fr2000.pdf> (accessed 11 June 2012).
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1 73 FR 66964. U.S. Environmental Protection Agency. “National ambient air quality standards for 

2 lead; final rule.” Federal Register 73(219):66964-67062. November 12, 2008.

3 74 FR 10350. U.S. Fish and Wildlife Service.” Endangered and threatened wildlife and plants; 

4 designation of critical habitat for the Louisiana black bear (Ursus americanus luteolus): final 

5 rule.” Federal Register 74(45):10350-10409. March 10, 2009. Available at 

6 <http://www.gpo.gov/fdsys/pkg/FR-2009-03-10/pdf/E9-4536.pdf#page=1> (accessed 

7 11 June 2012).

8 74 FR 56264. U.S. Environmental Protection Agency. “Mandatory reporting of greenhouse

9 gases; final rule.” Federal Register 74(209):56260-56519. October 30, 2009.

10 75 FR 6474. U.S. Environmental Protection Agency. “Primary national ambient air quality 

11 standards for nitrogen dioxide; final rule.” Federal Register 75(26):6474-6537. February 9, 2010.

12 75 FR 9282. U.S. Fish and Wildlife Service. “General provisions; revised list of migratory birds.” 

13 Federal Register 75(39):9282-9314. March 1, 2010.

14 75 FR 35520. U.S. Environmental Protection Agency. “Primary national ambient air quality 

15 standard for sulfur dioxide; final rule.” Federal Register 75(119):35520-35603. June 22, 2010.

16 77 FR 63439. U.S. Fish and Wildlife Service. Endangered and threatened wildlife and plants; 

17 Proposed endangered status for the Neosho mucket, threatened status for the rabbitsfoot, and 

18 designation of critical habitat for both species; proposed rule.” Federal Register

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21 Construction of Grand Gulf Nuclear Station, Units 1 and 2. Washington, DC: AEC. August 1973. 

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29 Benson JF. 2005. “Ecology and Conservation of Louisiana Black Bears in the Tensas River 

30 Basin and Reintroduced Populations.” M.S. thesis. Louisiana State University, Baton Rouge, 

31 LA. May 2005. 126 p. Available at <http://etd.lsu.edu/docs/available/etd-04112005-125206/

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33 Benson JF, Chamberlain MJ. 2006. Food habitats of Louisiana black bears (Ursus americanus 

34 luteolus) in two subpopulations of the Tensas River Basin. The American Midland Naturalist, 

35 156(1):118-127.

36 Benson, A. J. 2011. Zebra mussel sightings distribution. Available at:

37 http://nas.er.usgs.gov/taxgroup/mollusks/zebramussel/zebramusseldistribution.aspx (accessed 

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39 Blake ES, Landsea CW, Gibney EJ. 2011. The Deadliest, Costliest, and Most Intense United 

40 States Tropical Cyclones from 1851 to 2010 (and Other Frequently Requested Hurricane 

41 Facts). NOAA Technical Memorandum NWS NHC-6. August. Available at 

42 http://www.nhc.noaa.gov/pdf/nws-nhc-6.pdf (accessed 21 June 2012).

43 [BLS] U.S. Bureau of Labor Statistics. 2012. Local Area Unemployment Statistics. Available at

44 http://www.bls.gov/data/ (accessed June 2012).
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1 Brookes SO. 1976. The Grand Gulf Mound Salvage Excavation of an Early Marksville Burial 

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7 Caffey, R. H. , P. Coreil, and D. Demcheck. 2002. Mississippi River Water Quality: Implications 

8 for Coastal Restoration, Interpretive Topic Series on Coastal Wetland Restoration in Louisiana, 

9 Coastal Wetland Planning, Protection, and Restoration Act (eds.), National Sea Grant Library 

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14 Clean Air Act of 1963, as amended. 42 U.S.C. §7401 et seq.

15 Endangered Species Act of 1973, as amended. 16 U.S.C. §1531 et seq.

16 [Entergy] Entergy Operations, Inc. 2004. Telephone call to M. Snow (Entergy Services, Inc.) 

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40 [Entergy] Entergy Operations, Inc. 2011a. Grand Gulf Nuclear Station, Unit 1, License Renewal 

41 Application. Appendix E, Applicant’s Environmental Report. Port Gibson, MS: Entergy. 

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13 [EPA] U.S. Environmental Protection Agency. 1974. Information on Levels of Environmental 

14 Noise Requisite to Protect Health and Welfare with an Adequate Margin of Safety. 

15 Washington, D.C., Report 550/9-74-004.. Available at 

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28 ADAMS No. ML12157A412.

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34 ADAMS No. ML11350A190.

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7 Available at

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11 of Mississippi.” Crystal Darter. Available at 

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15 (accessed May 2012).

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17 A. Sanderson, Ecologist, Mississippi Natural Heritage Program, MDWFP, to D. Wrona, RPB2 

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21 2015, 2020, 2025. Available at http://www.ihl.state.ms.us/urc/downloads

22 /PopulationProjections.pdf (accessed May 2012).

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24 97 p. Available at <http://museum.mdwfp.com/downloads/

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32 National Historic Preservation Act of 1966. 16 U.S.C. §470 et seq.

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35 June 25, 2012).

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9 Atmospheric Administration, Satellite and Information Service. Available at 

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11 21 June 2012).

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13 Department of Education, National Center for Education Statistics, Common Core of Data 

14 (CCD), “Public Elementary/Secondary School Universe Survey,” 2010-11 School Year.”

15 Available at http://nces.ed.gov/ccd/districtsearch/ (accessed April 2012).

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17 Navigator Web Application. Available at http://nces.ed.gov/collegenavigator/default.aspx 

18 (accessed May 2012).

19 [NEI] Nuclear Energy Institute. 2007. Industry Ground Water Protection Initiative – Final 

20 Guidance Document. Washington, DC: Nuclear Energy Institute. NEI 07-07 (Final). 

21 August 2007. ADAMS No. ML091170588. 

22 Neusius SW, Gross GT. 2007. Seeking Our Past: An Introduction to North American 

23 Archaeology. New York, NY: Oxford University Press.

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25 Available at http://sharpfin.nmfs.noaa.gov/website/EFH_Mapper/map.aspx (Accessed on 

26 June 13, 2012).

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28 Regional Administrator for Protected Resources, to D. Wrona, RPB2 Branch Chief, NRC. 

29 Subject: Reply to request for list of species at Grand Gulf Nuclear Station, Unit 1. 

30 March 1, 2012. ADAMS Accession No. ML12065A167.

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32 the Operation of Grand Gulf Nuclear Station, Units 1 and 2, Docket Nos. 50-416 and 50-417. 

33 NUREG–0777. September 1981. ADAMS Legacy Library No. 8110220161. 

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35 for License Renewal of Nuclear Plants. Washington, DC: NRC. NUREG–1437. May 1996. 

36 ADAMS Nos. ML040690705 and ML040690738.

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38 Summary of findings on NEPA issues for license renewal of nuclear power plants. In: Generic 

39 Environmental Impact Statement for License Renewal of Nuclear Plants. Washington, DC: 

40 NRC. NUREG–1437, Volume 1, Addendum 1. August 1999. ADAMS No. ML04069720.

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42 Early Site Permit (ESP) at the Grand Gulf ESP Site, Final Report. NUREG–1817. April 2006. 

43 876 p. ADAMS No. ML060900037.

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45 Permit (ESP) at the Grand Gulf Site. NUREG–1840. April 2006. 
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6 Available at http://portgibsononthemississippi.com/Employers.html (accessed May 2012).

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8 Mark A. Rees. Baton Rouge, LA: Louisiana State University Press.

9 Roe LM, Schilling TM. 2010. “Coles Creek.” In Archaeology of Louisiana, edited by 

10 Mark A. Rees. Baton Rouge, LA: Louisiana State University Press.

11 Saunt C. 2004. “History until 1776.” In Handbook of North American Indians: Southeast, edited 

12 by Raymond D. Fogelson. Washington, DC: Smithsonian Institution.

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14 Revision 2. Available at <http://www.nrc.gov/reading-rm/adams.html>. ADAMS No. 

15 ML052780449.

16 Sidle JG, Harrison WF. 1990. Interior population of the least tern (Sterna antillarum) recovery 

17 plan. Bloomington, MN: U.S. Fish and Wildlife Service, Midwest Region. 95 p. Available at 

18 <http://ecos.fws.gov/docs/recovery_plan/900919a.pdf> (accessed 11 April 2013).

19 Smith TB. 2010. Mississippi in the Civil War. Jackson, MI: University Press of Mississippi.

20 Stapp DC. 2004. “Historic and Cultural Resources Contribution to Grand Gulf Trip 

21 Report 4-13-04 to 4-15-04.” ADAMS No. ML050350472. 

22 Stone JH. 1972. “Grand Gulf Mound Statement of Significance and National Register of Historic 

23 Places Nomination Form.” U.S. Department of the Interior, National Park Service. Available at 

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27 (accessed 14 June 2012).

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29 2010, 5-Year Estimate, American Community Survey, State and County QuickFacts on 

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31 http://factfinder.census.gov and http://quickfacts.census.gov (accessed May 2012).

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33 County, Mississippi. National Resources Conservation Service, Available at 

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20 p. 7. ADAMS No. ML12157A493.

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23 Military Monument. Archaeological Report No. 8.

3-1 

1 3.0 ENVIRONMENTAL IMPACTS OF REFURBISHMENT

2 Facility owners or operators may need to undertake or, for economic or safety reasons, may 

3 choose to perform refurbishment activities in anticipation of license renewal or during the license 

4 renewal term. The major refurbishment class of activities characterized in the Generic 

5 Environmental Impact Statement (GEIS) for License Renewal of Nuclear Plants (NRC 1996) is 

6 intended to encompass actions that typically take place only once in the life of a nuclear plant, if 

7 at all. Examples of these activities include, but are not limited to, replacement of boiling water 

8 reactor recirculation piping and pressurized water reactor steam generators. These actions may 

9 have an impact on the environment beyond those that occur during normal operations and that 

10 require evaluation, depending on the type of action and the plant-specific design. Table 3–1 

11 lists the environmental issues associated with refurbishment that the U.S. Nuclear Regulatory 

12 Commission (NRC) staff (the staff) determined to be Category 1 issues in the GEIS.

13 Table 3–1. Category 1 Issues Related to Refurbishment

Issue GEIS section(s)

Surface water quality, hydrology, and use (for all plants)

Impacts of refurbishment on surface water quality 3.4.1

Impacts of refurbishment on surface water use 3.4.1

Aquatic ecology (for all plants)

Refurbishment 3.5

Groundwater use and quality

Impacts of refurbishment on groundwater use and quality 3.4.2

Land use

Onsite land use 3.2

Human health

Radiation exposures to the public during refurbishment 3.8.1

Occupational radiation exposures during refurbishment 3.8.2

Socioeconomics

Public services: public safety, social services, and tourism and recreation 3.7.4; 3.7.4.3; 

3.7.4.4; 3.7.4.6

Aesthetic impacts (refurbishment) 3.7.8

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

14 Table 3–2 lists environmental issues related to refurbishment that the NRC staff determined to 

15 be plant-specific or inconclusive in the GEIS. These issues are Category 2 issues. The 

16 definitions of Category 1 and 2 issues can be found in Section 1.4.
Environmental Impacts of Refurbishment

3-2 

1 Table 3–2. Category 2 Issues Related to Refurbishment

Issue GEIS section(s) 10 CFR 51.53 (c)(3)(ii) 

Subparagraph

Terrestrial resources

Refurbishment impacts 3.6 E 

Threatened or endangered species (for all plants)

Threatened or endangered species 3.9 E 

Air quality

Air quality during refurbishment

(nonattainment and maintenance areas) 3.3 F 

Socioeconomics

Housing impacts 3.7.2 I 

Public services: public utilities 3.7.4.5 I 

Public services: education (refurbishment) 3.7.4.1 I 

Offsite land use (refurbishment) 3.7.5 I 

Public services, transportation 3.7.4.2 J 

Historic and archaeological resources 3.7.7 K 

Environmental justice

Environmental justice(a) Not addressed Not addressed

(a) Guidance related to environmental justice was not in place at the time the U.S. Nuclear Regulatory Commission 

(NRC) prepared the GEIS and the associated revision to 10 CFR Part 51. If an applicant plans to undertake 

refurbishment activities for license renewal, the applicant’s environmental report (ER) and the staff’s environmental 

impact statement must address environmental justice.

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

2 Table B.2 of the GEIS identifies systems, structures, and components (SSCs) that are subject to 

3 aging and might require refurbishment to support continued operation during the license 

4 renewal period of a nuclear facility. In preparation for its license renewal application, Entergy 

5 Operations, Inc. (Entergy) performed an evaluation of these SSCs pursuant to Section 54.21 of 

6 Title 10 of the Code of Federal Regulation (10 CFR 54.21) in order to identify the need to 

7 undertake any major refurbishment activities that would be necessary to support the continued 

8 operation of Grand Gulf Nuclear Station (GGNS) during the proposed 20-year period of 

9 extended operation.

10 In its SSC evaluation, Entergy did not identify the need to undertake any major refurbishment or 

11 replacement actions associated with license renewal to support the continued operation of 

12 GGNS beyond the end of the existing operating license (Entergy 2011). Therefore, the staff will 

13 not assess refurbishment activities in this SEIS.

14 3.1 References

15 10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

16 protection regulations for domestic licensing and related regulatory functions.”
Environmental Impacts of Refurbishment

3-3 

1 10 CFR Part 54. Code of Federal Regulations, Title 10, Energy, Part 54, “Requirements for 

2 renewal of operating licenses for nuclear power plants.”

3 [Entergy] Entergy Operations, Inc. 2011. Grand Gulf Nuclear Station, Unit 1, License Renewal 

4 Application. Port Gibson, MS: Entergy. Appendix E, Applicant’s Environmental Report. 

5 October 2011. 425 p. Agencywide Documents Access and Management System (ADAMS) 

6 Accession No. ML11308A234.

7 [NRC] U.S. Nuclear Regulatory Commission. 1996. Generic Environmental Impact Statement

8 for License Renewal of Nuclear Plants. Washington, DC: NRC. NUREG–1437. May 1996. 

9 ADAMS Accession Nos. ML040690705 and ML040690738.

10 [NRC] U.S. Nuclear Regulatory Commission. 1999. Section 6.3 – Transportation, Table 9.1, 

11 Summary of findings on NEPA issues for license renewal of nuclear power plants. In: Generic 

12 Environmental Impact Statement for License Renewal of Nuclear Plants. Washington, DC: 

13 NRC. NUREG–1437, Volume 1, Addendum 1. August 1999. ADAMS Accession 

14 No. ML04069720.

4-1 

1 4.0 ENVIRONMENTAL IMPACTS OF OPERATION

2 This chapter addresses potential environmental impacts related to the license renewal term of 

3 Grand Gulf Nuclear Station (GGNS). These impacts are grouped and presented according to 

4 resource. Generic issues (Category 1) rely on the analysis presented in the Generic 

5 Environmental Impact Statement (GEIS) for License Renewal of Nuclear Plants

6 (NRC 1996, 1999a, 2013a), unless otherwise noted. Most site-specific issues (Category 2) 

7 have been analyzed for GGNS and assigned a significance level of SMALL, MODERATE, or 

8 LARGE. For Protected Species and Habitats and Historic and Archaeological Resources the 

9 impact significance determination language is specific to the authorizing legislation (e.g., 

10 Endangered Species Act, National Historic Preservation Act). Also, environmental justice and 

11 chronic effects of electromagnetic fields were considered. Some issues are not applicable to 

12 GGNS because of site characteristics or plant features. Section 1.4 of this supplemental 

13 environmental impact statement (SEIS) provides an explanation of the criteria for Category 1 

14 and Category 2 issues, as well as the definitions of SMALL, MODERATE, and LARGE. As also 

15 described in Section 1.4, the U.S. Nuclear Regulatory Commission (NRC) has published a final 

16 rule (78 FR 37282, June 20, 2013) revising its environmental protection regulation, Title 10 of 

17 the Code of Federal Regulations (10 CFR) Part 51, “Environmental Protection Regulations for 

18 Domestic Licensing and Related Regulatory Functions.” The final rule consolidates similar 

19 Category 1 and 2 issues, changes some issues from Category 2 to Category 1 issues, and 

20 consolidates some of those issues with existing Category 1 issues. The final rule also adds new 

21 Category 1 and 2 issues. 

22 The NRC staff also considers new and significant information on environmental issues related to 

23 operation during the renewal term. New and significant information is information that identifies 

24 a significant environmental issue not covered in the GEIS and codified in Table B–1 of 

25 Appendix B to Subpart A of 10 CFR Part 51 or information that was not considered in the 

26 analyses summarized in the GEIS and that leads to an impact finding that is different from the 

27 finding presented in the GEIS and codified in 10 CFR Part 51. Section 4.11 of this SEIS 

28 describes the process used to identify and evaluate new and significant information.

29 4.1 Land Use

30 Table 4–1 identifies the two land use issues applicable to GGNS during the renewal term. 

31 Section 2.2.1 of this SEIS describes the land use conditions near GGNS.

32 Table 4–1. Land Use Issues

Issue GEIS section Category

Onsite land use 4.5.3 1 

Power line right-of-way (ROW) 4.5.3 1 

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

33 The NRC staff did not find any new and significant information during the review of the 

34 applicant’s Environmental Report (ER) (Entergy 2011a), the site audit, the scoping process, or 

35 the evaluation of other available information. Therefore, the staff concludes that there are no 

36 impacts related to these issues beyond those discussed in the GEIS. Consistent with the GEIS, 

37 the staff concludes that the impacts are SMALL.
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1 4.2 Air Quality

2 Table 4–2 identifies the air quality issue applicable to GGNS during the renewal term. Section 

3 2.2.2 of this SEIS describes the meteorology and air quality in the vicinity of GGNS. 

4 Table 4–2. Air Quality Issues

Issue GEIS Section Category

Air quality effects of transmission lines 4.5.2 1 

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

5 The NRC staff did not find any new and significant information during the review of the 

6 applicant’s ER (Entergy 2011a), the site audit, the scoping process, or the evaluation of other 

7 available information. Therefore, the staff concludes that there are no impacts related to this

8 issue beyond those discussed in the GEIS. Consistent with the GEIS, the staff concludes that 

9 the impacts are SMALL.

10 4.3 Geologic Environment

11 4.3.1 Geology and Soils

12 As described in Section 1.4 of this SEIS, the NRC has approved a revision to its environmental 

13 protection regulation, 10 CFR Part 51, “Environmental protection regulations for domestic 

14 licensing and related regulatory functions.” With respect to the geologic environment of a plant 

15 site, the final rule amends Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51, by adding a 

16 new Category 1 issue, “Geology and soils.” This new issue has an impact level of SMALL. This 

17 new Category 1 issue considers geology and soils from the perspective of those resource 

18 conditions or attributes that can be affected by continued operations during the renewal term. 

19 An understanding of geologic and soil conditions has been well established at all nuclear power 

20 plants and associated transmission lines during the current licensing term, and these conditions 

21 are expected to remain unchanged during the 20-year license renewal term for each plant. The 

22 impact of these conditions on plant operations and the impact of continued power plant 

23 operations and refurbishment activities on geology and soils are SMALL for all nuclear power 

24 plants and not expected to change appreciably during the license renewal term. Operating 

25 experience shows that any impacts to geologic and soil strata would be limited to soil 

26 disturbance from construction activities associated with routine infrastructure renovation and 

27 maintenance projects during continued plant operations. Implementing best management 

28 practices would reduce soil erosion and subsequent impacts on surface water quality. 

29 Information in plant-specific SEISs prepared to date and reference documents has not identified 

30 these impacts as being significant.

31 Section 2.2.3 of this SEIS describes the local and regional geologic environment relevant to 

32 GGNS. The NRC staff did not identify any new and significant information with regard to this

33 Category 1 (generic) issue based on review of the ER (Entergy 2011a), the public scoping

34 process, or as a result of the environmental site audit. As discussed in Chapter 3 of this SEIS 

35 and as identified in the ER (Entergy 2011a), Entergy has no plans to conduct refurbishment or 

36 replacement actions associated with license renewal to support the continued operation of 

37 GGNS. Further, Entergy anticipates no new construction or other ground-disturbing activities or 

38 changes in operations and that operation and maintenance activities would be confined to 

39 previously disturbed areas or existing ROWs. Based on this information, it is expected that any 

40 incremental impacts on geology and soils during the license renewal term would be SMALL. 
Environmental Impacts of Operation

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1 4.4 Surface Water Resources

2 Table 4–3 identifies the surface water issues applicable to GGNS during the renewal term. 

3 Section 2.2.4 of this SEIS describes surface water at GGNS.

4 Table 4–3. Surface Water Issues

Issue GEIS Section Category

Impact of refurbishment on surface water quality 3.4.1 1 

Impacts of refurbishment on surface water use 3.4.1 1 

Altered salinity gradients 4.2.1.2.1 1 

Temperature effects on sediment transport capacity 4.2.1.2.3 1 

Scouring caused by discharged cooling water 4.2.1.2.3 1 

Eutrophication 4.2.1.2.3 1 

Discharge of chlorine or other biocides 4.2.1.2.4 1 

Discharge of sanitary wastes and minor chemical spills 4.2.1.2.4 1 

Discharge of other metals in wastewater 4.2.1.2.4 1 

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

5 The NRC staff did not find any new and significant information during the review of the 

6 applicant’s ER (Entergy 2011a), the site audit, the scoping process, or the evaluation of other 

7 available information. Therefore, the staff concludes that there are no impacts related to these

8 issues beyond those discussed in the GEIS. For these issues, the GEIS concludes that the 

9 impacts are SMALL. 

10 4.5 Groundwater Resources

11 Table 4–4 identifies the issues related to groundwater that are applicable to GGNS during the 

12 renewal term. Section 2.2.5 of this SEIS describes groundwater at GGNS. 

13 Table 4–4. Groundwater Issues

Issue GEIS Section Category

Groundwater use conflicts (potable and service water; plants that use 

<100 gpm) 4.8.1.1 1 

Groundwater use conflicts (Ranney wells) 4.8.1.4 2 

Groundwater quality degradation (Ranney wells) 4.8.2.2 1 

Radionuclides released to groundwater 4.5.1.2(a) 2 

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51; (a) NRC 2013a 

14 4.5.1 Generic Groundwater Issues

15 The NRC staff did not identify any new and significant information associated with the 

16 Category 1 groundwater issues during the review of the applicant’s ER (Entergy 2011a), the site 

17 audit, the scoping process, or the evaluation of other available information. Therefore, the staff 

18 concludes that there are no impacts related to these issues beyond those discussed in the 

19 GEIS. Consistent with the GEIS, the staff concludes that the impacts are SMALL. 
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1 4.5.2 Groundwater Use Conflicts (Ranney Wells)

For nuclear power plants using Ranney wells or pumping more than 100 gpm (0.006 m3 2 /s) of 

3 groundwater (total on site), the potential impact on groundwater is considered a Category 2 

4 issue, therefore requiring a plant-specific assessment. The requirement for this assessment is 

5 specified by 10 CFR 51.53(c)(3)(ii)(C). This groundwater aspect was classified as a site6 specific (Category 2) issue because groundwater levels might be lowered beyond the site 

7 boundary. The staff previously concluded in the GEIS that “[t]he impact of cooling water intake 

8 on groundwater at the Grand Gulf plant (the only plant employing Ranney wells) does not 

9 conflict with other groundwater uses in the area” (NRC 1996). In evaluating the potential 

10 impacts resulting from groundwater use conflicts associated with license renewal, the NRC staff 

11 uses as its baseline the existing groundwater resource conditions described in Sections 2.1.7 

12 and 2.2.5 of this SEIS. These baseline conditions encompass the existing hydrogeologic 

13 framework and conditions (including aquifers) potentially affected by continued operations as 

14 well as the nature and magnitude of groundwater withdrawals for cooling and other purposes 

15 (as compared to relevant appropriation and permitting standards). The baseline also considers 

16 other downgradient or in-aquifer uses and users of groundwater. 

17 Future activities at the GGNS site are not expected to lower groundwater levels beyond the 

18 plant boundary. The original evaluation of groundwater withdrawal impacts in the GGNS final 

environmental statement (FES) was for an estimated 42,636 gpm (2.69 m3 19 /s) for makeup 

20 cooling water needs. This evaluation was for two nuclear reactors (NRC 1973). However, only 

21 one reactor was constructed. Groundwater withdrawals during the license renewal term are 

expected to be approximately 27,860 gpm (1.76 m3 22 /s), which is about 65 percent of the 

23 withdrawal rate previously evaluated and found to be acceptable (Entergy 2011a). Groundwater 

24 level changes are not detected far from the Ranney wells (Entergy 2011a) because water from 

25 the Mississippi River continuously flows into the Mississippi River Alluvial Aquifer, which 

26 supplies the Ranney wells, and the aquifer is a thick water table aquifer. Consistent with the 

27 GEIS, the staff concludes that the impact for this issue is SMALL.

28 4.5.3 Radionuclides Released to Groundwater

29 As described in Section 1.4 of this SEIS, the NRC has approved a revision to its environmental 

30 protection regulation, 10 CFR Part 51. With respect to groundwater quality, the final rule 

31 amends Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51 by adding a new 

32 Category 2 issue, “Radionuclides released to groundwater,” with an impact level range of 

33 SMALL to MODERATE, to evaluate the potential impact of discharges of radionuclides from 

34 plant systems into groundwater. This new Category 2 issue has been added to evaluate the 

35 potential impact to groundwater quality from the discharge of radionuclides from plant systems, 

36 piping, and tanks. This issue was added because, within the past several years, there have 

37 been events at nuclear power reactor sites that involved unknown, uncontrolled, and 

38 unmonitored releases of radioactive liquids into the groundwater. In evaluating the potential 

39 impacts on groundwater quality associated with license renewal, the NRC staff uses as its 

40 baseline the existing groundwater conditions described in Section 2.2.5 of this SEIS. These 

41 baseline conditions encompass the existing quality of groundwater potentially affected by 

42 continued operations (as compared to relevant state or EPA primary drinking water standards) 

43 as well as the current and potential onsite and offsite uses and users of groundwater for drinking 

44 and other purposes. The baseline also considers other downgradient or in-aquifer uses and 

45 users of groundwater. 

46 Section 2.2.5.4 of this SEIS contains a description of tritium contamination on the northeast side 

47 of the Unit 2 power block. The groundwater contamination appears to be restricted to the 
Environmental Impacts of Operation

4-5 

1 backfill material and the Upland Complex Aquifer near the power block. This power block does 

2 not contain a nuclear reactor. No other radionuclides have been detected above background 

3 levels in the Upland Complex Aquifer. Tritium-contaminated groundwater has not migrated off 

4 site. No radionuclide concentrations above background levels have been detected in the 

5 Catahoula Aquifer or the Mississippi River Alluvial Aquifer or in any other areas in the Upland 

6 Complex Aquifer.

7 GGNS is actively involved in defining the extent of contamination and determining its cause 

8 (Entergy 2011a). Should the contamination continue unchecked, it is very unlikely to move 

9 downward into the Catahoula Aquifer because of the thick clay bed on top of the aquifer. 

10 Rather, the areas of contamination should move laterally with the direction of groundwater flow 

11 (northeast) within the Upland Complex Aquifer. 

12 At this time, it is unknown if the plume will continue in that direction or if it will eventually flow 

13 into the Mississippi River Alluvial Aquifer and from there to the Mississippi River. In any case, 

14 dispersion, radioactive decay, and dilution would decrease the tritium activity concentration in 

15 the plume.

16 In 2007, the nuclear power industry began implementing its “Industry Ground Water Protection 

17 Initiative” (NEI 2007). Since 2008, the staff has been monitoring implementation of this initiative 

18 at licensed nuclear reactor sites. The initiative identifies actions to improve utilities’ 

19 management and response to instances in which the inadvertent release of radioactive 

20 substances may result in low but detectible levels of plant-related materials in subsurface soils 

21 and water. It also seeks to identify those actions necessary for implementation of a timely and 

22 effective groundwater protection program. The areas of contamination were discovered as part 

23 of GGNS participation in this initiative. At this time, monitoring wells have been drilled on all 

24 sides of the power blocks and GGNS is monitoring them. Monitoring results from these wells 

25 are reported annually to the NRC.

26 The NRC staff’s analysis of groundwater monitoring results and the site’s hydrogeologic regime 

27 indicates there is no immediate threat to groundwater resources. Water use in the area should 

28 not be affected even if tritium-contaminated groundwater were ever to move off site. Therefore, 

29 the NRC staff concludes that inadvertent releases of tritium have not substantially impaired site 

30 groundwater quality or affected groundwater use. With continued NRC attention and GGNS 

31 action, the NRC staff further concludes that groundwater quality impacts would remain SMALL 

32 during the license renewal term. 

33 4.6 Aquatic Resources

34 Sections 2.1.6 and 2.2.6 of this SEIS describe the GGNS cooling system and aquatic 

35 environment, respectively. Table 4–5 identifies the Category 1 issues related to aquatic 

36 resources that are applicable to GGNS during the renewal term. There are no Category 2 

37 issues that apply to aquatic resources at GGNS. The staff did not find any new and significant 

38 information during the review of the applicant’s ER (Entergy 2011a), the site audit, the scoping

39 process, or the evaluation of other available information; therefore, the staff concludes that there 

40 are no impacts related to aquatic resource issues beyond those discussed in the GEIS. For 

41 these issues, the GEIS concludes that the impacts are SMALL. 
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4-6 

1 Table 4–5. Aquatic Resource Issues

Issues GEIS Section Category

For All Plants

Accumulation of contaminants in sediments or biota 4.1.1.2.4 1

Entrainment of phytoplankton & zooplankton 4.2.2.1.1 1

Cold shock 4.2.2.1.5 1

Thermal plume barrier to migrating fish 4.2.2.1.6 1

Distribution of aquatic organisms 4.2.2.1.6 1

Premature emergence of aquatic insects 4.2.2.1.7 1

Gas supersaturation (gas bubble disease) 4.2.2.1.8 1

Low dissolved oxygen in the discharge 4.2.2.1.9 1

Losses from predation, parasitism, and disease among organisms 

exposed to sublethal stresses 4.2.2.1.10 1 

Stimulation of nuisance organisms 4.2.2.1.11 1

Exposure of aquatic organisms to radionuclides 4.6.1.2(a) 1

For Plants with Cooling Tower-Based Heat Dissipation Systems

Entrainment of fish and shellfish in early life stages 4.3.3 1

Impingement of fish and shellfish 4.3.3 1

Heat shock 4.3.3 1

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51; (a) NRC 2013a 

2 4.6.1 Exposure of Aquatic Organisms to Radionuclides

3 As described in Section 1.4 of this SEIS, the NRC has approved a revision to its environmental 

4 protection regulation, 10 CFR Part 51. With respect to the aquatic organisms, the revision 

5 amends Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51 by adding a new Category 1 

6 issue, “Exposure of aquatic organisms to radionuclides,” among other changes. This new 

7 Category 1 issue considers the impacts to aquatic organisms from exposure to radioactive 

8 effluents discharged from a nuclear power plant during the license renewal term. An 

9 understanding of the radiological conditions in the aquatic environment from the discharge of 

10 radioactive effluents within NRC regulations has been well established at nuclear power plants 

11 during their current licensing term. Based on this information, the NRC concluded that the 

12 doses to aquatic organisms are expected to be well below exposure guidelines developed to 

13 protect these organisms and assigned an impact level of SMALL.

14 The NRC staff has not identified any new and significant information related to the exposure of 

15 aquatic organisms to radionuclides during its independent review of the applicant’s ER, the site 

16 audit, and the scoping process. Section 2.1.2 of this SEIS describes the applicant’s radioactive 

17 waste management program to control radioactive effluent discharges to ensure that they 

18 comply with NRC regulations in 10 CFR Part 20. Section 4.9.2 of this SEIS contains the NRC 

19 staff’s evaluation of GGNS’s radioactive effluent and radiological environmental monitoring 

20 programs. GGNS’s radioactive effluent and radiological environmental monitoring programs 

21 provide further support for the conclusion that the impacts to aquatic organisms from 

22 radionuclides are SMALL. The NRC staff concludes that there would be no impacts to aquatic 

23 organisms from radionuclides beyond those impacts contained in the GEIS (NRC 2013a) and 

24 therefore, the impacts to aquatic organisms from radionuclides are SMALL.

25 4.7 Terrestrial Resources

26 The Category 1 (generic) and Category 2 (site-specific) terrestrial resources issues applicable to 

27 GGNS are discussed in the following sections and listed in Table 4–6. Terrestrial resources 

28 issues that apply to GGNS are described in Sections 2.2.7 and 2.2.8. 
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4-7 

1 Table 4–6. Terrestrial Resource Issues

Issue GEIS Section Category

Cooling tower impacts on crops and ornamental vegetation 4.3.4 1 

Cooling tower impacts on native plants 4.3.5.1 1 

Bird collisions with cooling towers 4.3.5.2 1 

Power line right-of-way management (cutting, herbicide application) 4.5.6.1 1 

Bird collisions with power lines 4.5.6.1 1 

Impacts of electromagnetic fields on flora and fauna (plants, agricultural 

crops, honeybees, wildlife, livestock) 4.5.6.3 1 

Floodplains and wetland on power line right-of-way 4.5.7 1 

Exposure of terrestrial organisms to radionuclides 4.6.1.1(a) 1 

Effects on terrestrial resources (non-cooling system impacts) 4.6.1.1(a) 2 

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51; (a) NRC 2013a 

2 4.7.1 Generic Terrestrial Resource Issues

3 For the Category 1 terrestrial resources issues listed in Table 4–6, the NRC staff did not identify 

4 any new and significant information during the review of the ER (Entergy 2011a), the NRC 

5 staff’s site audit, the scoping process, or the evaluation of other available information. 

6 Therefore, there are no impacts related to these issues beyond those discussed in the GEIS. 

7 For these issues, the GEIS concludes that the impacts are SMALL. 

8 4.7.2 Exposure of Terrestrial Organisms to Radionuclides

9 As described in Section 1.4 of this SEIS, the NRC has approved a revision to its environmental 

10 protection regulation, 10 CFR Part 51. With respect to the terrestrial organisms, the revision

11 amends Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51 by adding a new Category 1 

12 issue, “Exposure of terrestrial organisms to radionuclides,” among other changes. This new 

13 issue has an impact level of SMALL. This new Category 1 issue considers the impacts to 

14 terrestrial organisms from exposure to radioactive effluents discharged from a nuclear power 

15 plant during the license renewal term. An understanding of the radiological conditions in the 

16 terrestrial environment from the discharge of radioactive effluents within NRC regulations has 

17 been well established at nuclear power plants during their current licensing term. Based on this 

18 information, the NRC concluded that the doses to terrestrial organisms are expected to be well 

19 below exposure guidelines developed to protect these organisms and assigned an impact level 

20 of SMALL.

21 The NRC staff has not identified any new and significant information related to the exposure of 

22 terrestrial organisms to radionuclides during its independent review of the applicant’s ER, the 

23 site audit, and the scoping process. Section 2.1.2 of this SEIS describes the applicant’s 

24 radioactive waste management program to control radioactive effluent discharges to ensure that 

25 they comply with NRC regulations in 10 CFR Part 20. Section 4.9.2 of this SEIS contains the 

26 NRC staff’s evaluation of GGNS’s radioactive effluent and radiological environmental monitoring 

27 programs. GGNS’s radioactive effluent and radiological environmental monitoring programs 

28 provide further support for the conclusion that the impacts from radioactive effluents are SMALL.
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4-8 

1 Therefore, the NRC staff concludes that there would be no impact to terrestrial organisms from

2 radionuclides beyond those impacts contained in the GEIS (NRC 2013a). For this issue, the 

3 GEIS concludes that the impacts are SMALL. 

4 4.7.3 Effects on Terrestrial Resources (Non-cooling System Impacts)

5 As described in Section 1.4 of this SEIS, the NRC has approved a revision to its environmental 

6 protection regulation, 10 CFR Part 51. With respect to the terrestrial organisms, the revision 

7 amends Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51 by expanding the Category 2 

8 issue, “Refurbishment impacts,” among others, to include normal operations, refurbishment, and 

9 other supporting activities during the license renewal term. This issue remains a Category 2 

10 issue with an impact level range of SMALL to LARGE; however, the GEIS (NRC 2013a) 

11 renames this issue “Effects on terrestrial resources (non-cooling system impacts).”

12 The geographic scope for the assessment of this issue is the GGNS site and area near the site, 

13 and the baseline is the condition of the terrestrial resources under the no-action alternative. 

14 Section 2.2.7 describes the terrestrial resources on and in the vicinity of the GGNS site, and 

15 Section 2.2.8 describes protected species and habitats. During construction of GGNS, 

16 approximately 14 percent of the plant site (270 ac [109 ha]) was cleared for buildings, parking 

17 lots, roads, and other infrastructure. The remaining terrestrial and associated wetland habitats 

18 have not changed significantly since construction, except for reforestation activities performed 

19 by Entergy (see Section 2.2.7). As discussed in Chapter 3 of this SEIS and according to the 

20 applicant’s ER (Entergy 2011a), Entergy has no plans to conduct refurbishment or replacement 

21 actions associated with license renewal to support the continued operation of GGNS. Further, 

22 Entergy (2011a) anticipates no new construction or other ground-disturbing activities, changes 

23 in operations, or changes in existing land use conditions due to license renewal. Entergy 

24 (2011a) reports that operation and maintenance activities would be confined to previously 

25 disturbed areas or existing ROWs. As a result, Entergy (2011a) anticipates no new impacts on 

26 the terrestrial environment on the GGNS site or along the in-scope transmission line corridors

27 during the license renewal term. Based on the staff’s independent review, the staff concludes 

28 that operation and maintenance activities that Entergy might undertake during the renewal term, 

29 such as maintenance and repair of plant infrastructure (e.g., roadways, piping installations, 

30 onsite transmission lines, fencing and other security infrastructure), would likely be confined to 

31 previously-disturbed areas of the GGNS site. Therefore, the staff expects non-cooling system

32 impacts on terrestrial resources during the license renewal term to be SMALL.

33 4.8 Protected Species and Habitats

34 Section 2.2.8 of this SEIS describes the action area, as defined by the Endangered Species Act

35 of 1973, as amended (ESA), regulations at 50 CFR 402.02, and describes the protected species 

36 and habitats within the action area associated with the GGNS license renewal.

37 Table 4–7 identifies the one Category 2 issue related to protected species and habitats that is 

38 applicable to GGNS. 

39 Table 4–7. Threatened or Endangered Species

Issue GEIS Section Category

Threatened or endangered species 4.1 2 

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51
Environmental Impacts of Operation

4-9 

1 4.8.1 Correspondence with Federal and State Agencies

2 As part of its National Environmental Policy Act (NEPA) and ESA reviews, the NRC staff

3 contacted the Louisiana and Mississippi Field Offices of the U.S. Fish and Wildlife Service

4 (FWS), the National Marine Fisheries Service (NMFS), the Louisiana Department of Wildlife and 

5 Fisheries (LDWF) and the Mississippi Department of Wildlife, Fisheries, and Parks (MDWFP) to 

6 gather information on protected species and habitats that may occur in the action area.

7 The NRC staff sent letters to the Louisiana and Mississippi FWS Field Offices and the NMFS on 

8 January 19, 2012 (NRC 2012a, 2012b, 2012c), requesting concurrence with the NRC’s list of 

9 Federally protected species in the vicinity of GGNS. The Mississippi FWS Field Office replied in 

10 a letter dated February 3, 2012 (FWS 2012a). In that letter, the FWS did not address the list of 

11 Federally protected species, but it stated that no Federally listed species or their habitats are 

12 likely to be affected from the proposed GGNS license renewal and that no further consultation 

13 under the ESA would be necessary with that office. The Louisiana FWS Field Office concurred 

14 with the NRC’s list of Federally protected species in the vicinity of GGNS in a letter dated 

15 February 29, 2012 (FWS 2012b). The NMFS replied to the NRC on March 1, 2012, as 

16 described in Section 2.2.8 (NMFS 2012). 

17 The NRC sent a letter to the MDWFP on January 20, 2012 (NRC 2012d), requesting information 

18 on both Federally and State-listed species. The MDWFP replied in a letter dated 

19 February 13, 2012 (MDWFP 2012), that provided the NRC with a list of species that occur within 

20 2 mi (3.2 km) of the GGNS site and transmission line corridors. 

21 The NRC (2012e) sent a letter to the LDWF on February 6, 2012, requesting information on 

22 both Federally and State-listed species. The LDWF (2012) replied in a letter dated 

23 February 16, 2012, that stated, “After careful review of our database, no impacts to rare, 

24 threatened or endangered species or critical habitats are anticipated from the proposed project.”

25 Pursuant to the ESA, the NRC intends to submit this draft SEIS to the FWS with a request for 

26 concurrence on the NRC’s effect determinations for Federally listed species and designated 

27 critical habitat. The results of this consultation will be documented in the final SEIS.

28 4.8.2 Species and Habitats Protected Under the Endangered Species Act

29 4.8.2.1 Wood Stork

30 Section 2.2.8 concludes that the wood stork (Mycteria americana) occurs in the action area, but 

31 that the individuals within Mississippi do not represent members of the endangered 

32 U.S. breeding populations. Thus, the staff concludes that the proposed GGNS license renewal 

33 would have no effect on the wood stork.

34 4.8.2.2 Red-cockaded Woodpecker

35 Section 2.2.8 concludes that the red-cockaded woodpecker occurs in the action area along the 

36 portion of the Franklin transmission line corridor that travels through the Homochitto National 

37 Forest and the corresponding 1-mi (0.6-km) buffer.

38 Because the red-cockaded woodpecker does not occur on the GGNS site, ongoing operations 

39 and maintenance activities associated with the proposed license renewal would have no effect 

40 on the species.

41 In 2003, the U.S. Forest Service (USFS) completed an environmental assessment that 

42 considered the environmental effects of managing utility corridors with practices intended to 

43 enhance wildlife habitat within the Homochitto National Forest (USFS 2003). The environmental 

44 assessment included a biological evaluation of the effects of transmission line maintenance on 
Environmental Impacts of Operation

4-10

1 the red-cockaded woodpecker. The biological evaluation concluded that herbicide application 

2 and other activities associated with transmission line maintenance would have no direct or 

3 indirect effects on the species (USFS 2003). Since EMI’s transmission line maintenance 

4 procedures have not changed since 2003, the NRC adopts the USFS’s conclusion of “no effect.” 

5 Additionally, in correspondence with the NRC, the FWS (2012a) indicated that no Federally 

6 listed species would be affected by the proposed license renewal.

7 The staff concludes that the proposed license renewal would have no effect on the 

8 red-cockaded woodpecker.

9 4.8.2.3 Least Tern (Interior Population)

10 Section 2.2.8 concludes that the least tern occurs within the action area along the Mississippi 

11 River upstream and downstream of the GGNS site. The proposed GGNS license renewal 

12 would not include new construction, refurbishment, ground-disturbing activities, or changes to 

13 existing land use conditions that would affect any of the natural habitats on the site or any offsite 

14 areas. Additionally, in its correspondence with the NRC, the FWS (2012b) indicated that no 

15 Federally listed species would be affected by the proposed license renewal.

16 The staff concludes that the proposed action would have no effect on the least tern.

17 4.8.2.4 Bayou Darter 

18 Section 2.2.8 concludes that bayou darters occur in the action area along the portion of the 

19 Franklin transmission line corridor that crosses Bayou Pierre. Although highly unlikely,

20 transmission line and vegetation maintenance requiring in-stream work could adversely affect 

21 bayou darters directly or indirectly. Potential indirect effects could include a temporary decline 

22 in habitat quality from increased sedimentation and turbidity during maintenance activities. 

23 Entergy Mississippi, Inc. (EMI), takes a number of precautions to avoid impacts to bayou darters 

24 and their habitat when performing maintenance in or near water bodies. As described in 

25 Section 2.1.5, EMI chooses maintenance techniques that minimize impacts in streams and 

26 other water features. In wetlands and aquatic habitats, EMI personnel selectively apply 

27 Environmental Protection Agency (EPA) approved herbicides for wetlands and aquatic area 

28 applications. Personnel spray areas on foot with backpack sprayers to minimize impacts. All 

29 EMI maintenance crew personnel hold U.S. Department of Agriculture (USDA) State-approved 

30 herbicide licenses. Therefore, the continued operation and maintenance of the Franklin 

31 transmission line would have discountable or insignificant effects on bayou darters.

32 Bayou darters do not occur on the GGNS site because the species is endemic to the Bayou 

33 Pierre, which does not flow through GGNS, as described in Section 2.2.8. Because bayou 

34 darters do not occur on the GGNS site, ongoing operations and maintenance activities 

35 associated with the proposed license renewal would have no effect on the species. 

36 In correspondence with the NRC, the FWS Mississippi Field Office concluded that neither bayou 

37 darters nor their habitat would likely be affected from the proposed GGNS operating license 

38 renewal (FWS 2012a). Similarly, MDFWP (2012) stated that the proposed project likely poses 

39 no threat to listed species or their habitat if best management practices are properly 

40 implemented. Based on FWS (2012a), MDWFP (2012), and the NRC staff’s assessment that 

41 the continued operation and maintenance of the Franklin transmission line would have 

42 discountable or insignificant effects on bayou darters, the NRC staff concludes that the 

43 proposed GGNS license renewal may affect, but is not likely to adversely affect bayou darters.

44 4.8.2.5 Pallid Sturgeon 

45 Section 2.2.8 concludes that pallid sturgeon could occur in the action area in the Mississippi 

46 River. Increased water temperature and other conditions near GGNS’s discharge could affect 
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1 pallid sturgeon. Direct effects to pallid sturgeon from heat shock would be highly unlikely 

2 because the thermal plume does not create a barrier across the Mississippi River; therefore, the 

3 fish could avoid the warmer temperature water (NRC 1972). Indirect effects could include a 

4 decrease in habitat quality from thermal discharge in the Mississippi River. GGNS’s NPDES

5 permit limits the flow, temperature, and other conditions of GGNS’s discharge into the 

6 Mississippi River. Therefore, the continued discharge from GGNS would have discountable or 

7 insignificant effects on pallid sturgeon.

8 In correspondence with the NRC, the FWS Mississippi Field Office concluded that neither pallid 

9 sturgeon nor their habitat would likely be affected from the proposed GGNS operating license 

10 renewal (FWS 2012a). Similarly, MDFWP (2012) stated that the proposed project likely poses 

11 no threat to listed species or their habitat if best management practices are implemented

12 properly. Based on FWS (2012a), MDWFP (2012), and the staff’s assessment that the 

13 continued discharge from GGNS would have discountable or insignificant effects on pallid 

14 sturgeon, the NRC staff concludes that the proposed GGNS license renewal may affect, but is 

15 not likely to adversely affect the pallid sturgeon.

16 4.8.2.6 Louisiana and American Black Bears

17 Section 2.2.8 concludes that the Louisiana (Ursus americanus luteolus) and American 

18 (U. americanus) black bears occur in the action area in bottomland hardwood forest habitat or 

19 other suitable habitat. Black bears would be expected to avoid areas of human activity and 

20 would be unlikely to occur on the developed portion of the GGNS site. Within the GGNS site, 

21 the proposed license renewal would include maintenance and operation activities within 

22 developed or previously disturbed areas and would not involve new construction, refurbishment, 

23 ground-disturbing activities, or changes to existing land use conditions in either natural or 

24 developed areas. The continued operation of GGNS during the license renewal term would 

25 preserve the existing natural habitats on the site. The large tracts of bottomland and upland 

26 hardwood forests on the site are relatively remote, restricted from public access, and provide 

27 contiguous habitat with offsite areas of hardwood forest. Therefore, continued operation of the 

28 GGNS site could result in beneficial effects to the species.

29 The continued operation and maintenance of the Baxter-Wilson and Franklin transmission lines

30 would have discountable or insignificant effects on black bears. Within the transmission line 

31 corridors, black bears could take in herbicides that have been sprayed on berries or shrubs. 

32 Noise from machinery and human activity could temporarily alter the behavior of black bears 

33 during transmission line maintenance activities. However, none of these effects would be 

34 measurable or detectable or reach the scale in which a take would occur. Transmission line 

35 maintenance could require removal of mature trees if they pose a threat to the transmission 

36 lines; however, black bears are unlikely to den at the edge of forest habitat, so tree removal 

37 should not affect denning habitat. 

38 Based on the staff’s assessment that the continued operation and maintenance of the

39 Baxter-Wilson and Franklin transmission lines would have discountable or insignificant effects 

40 on bears, the NRC staff concludes that the proposed GGNS license renewal may affect, but is 

41 not likely to adversely affect the Louisiana and American black bears.

42 4.8.2.7 Louisiana Black Bear Critical Habitat

43 Section 2.2.8 concludes that no designated Louisiana black bear critical habitat occurs within 

44 the action area, but notes that the closest designated critical habitat lies about 16 mi (26 km) 

45 west of the GGNS site at its closest point. Because no designated critical habitat lies within the 

46 action area, the staff concludes that the proposed GGNS license renewal would have no effect

47 on designated Louisiana black bear critical habitat.
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1 4.8.2.8 Fat Pocketbook Mussel 

2 Section 2.2.8 concluded that fat pocketbook mussels are not likely to occur within the action 

3 area. In correspondence with the NRC, the FWS Mississippi Field Office concluded that neither 

4 fat pocketbook mussels nor their habitat would likely be affected from the proposed license 

5 renewal (FWS 2012a). Similarly, MDFWP (2012) stated that the proposed project likely poses 

6 no threat to listed species or their habitat if best management practices are implemented

7 properly. Therefore, the staff concludes that the proposed GGNS license renewal would have 

8 no effect on fat pocketbook mussels.

9 4.8.2.9 Rabbitsfoot Mussel 

10 Section 2.2.8 concluded that rabbitsfoot mussels are not likely to occur within the action area. 

11 In correspondence with natural resource agencies, FWS Mississippi Field Office, FWS 

12 Louisiana Field Office, and MDWFP did not include rabbitsfoot mussel as a species that would 

13 be affected by the proposed license renewal (FWS 2012a, 2012b; MDFWP 2012). Therefore, 

14 the staff concludes that the proposed GGNS license renewal would have no effect on 

15 rabbitsfoot mussels.

16 4.8.2.10 Rabbitsfoot Mussel Proposed Critical Habitat

17 Section 2.2.8 concludes that no proposed rabbitsfoot mussel critical habitat occurs within the 

18 action area. Thus, the staff concludes that the proposed GGNS license renewal would have no 

19 effect on proposed rabbitsfoot mussel critical habitat.

20 4.8.3 Species Protected by the State of Mississippi 

21 4.8.3.1 Aquatic Species

22 Section 2.2.8 concluded that the chestnut lamprey, black buffalo, paddlefish, blue sucker, and 

23 sicklefin chub inhabit portions of the Mississippi River (NatureServe 2010). Section 2.2.8 also 

24 concluded that crystal darter, chestnut lamprey, blue sucker, black buffalo sicklefin chub, and 

25 paddlefish may occur in suitable habitat along the transmission line corridors, such as the 

26 transmission line crossings along the Mississippi, Big Black, and Bayou Pierre rivers. No 

27 GGNS-related aquatic surveys have been conducted along the transmission lines. 

28 In the Mississippi River, increased water temperature and other conditions near GGNS’s 

29 discharge could affect State-protected fish. As described above, GGNS’s NPDES permit limits 

30 the flow, temperature, and other conditions of GGNS’s discharge into the Mississippi River. In 

31 addition, the thermal plume would not extend the width of the Mississippi River; therefore, fish 

32 could swim away to avoid the plume (NRC 1972). 

33 The continued operation and maintenance of the transmission lines would have discountable or 

34 insignificant effects on State-protected fish. Although highly unlikely, line and vegetation 

35 maintenance requiring in-stream work could adversely affect fish directly and indirectly. 

36 Potential adverse effects include a temporary decline in habitat quality from increased 

37 sedimentation and turbidity during maintenance activities. As described in Section 2.1.5, EMI 

38 takes a number of precautions to avoid impacts to State-protected fish and their habitat when 

39 performing transmission line maintenance in or near water bodies. As described in Section 

40 2.1.5, EMI chooses maintenance techniques that minimize erosion in streams and other water 

41 features. In wetlands and aquatic habitats, EMI personnel selectively apply EPA-approved 

42 herbicides on foot with backpack sprayers to minimize impacts. All EMI maintenance crew 

43 personnel hold USDA state-approved herbicide licenses. 
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1 In correspondence with the NRC, MDWFP (2012) did not identify any impacts of the proposed 

2 license renewal that would affect State-protected species, assuming that best management 

3 practices are implemented properly 

4 4.8.3.2 Terrestrial Species

5 Section 2.2.8 discusses two species protected under the Mississippi Nongame and Endangered 

6 Species Conservation Act of 1974: Webster’s salamander (Plethodon websteri) and the white 

7 ibis (Eudocimus albus). In its correspondence with the NRC, the MDWFP (2012) concluded 

8 that “the proposed project likely poses no threat to listed species or their habitats.” 

9 4.8.4 Species Protected Under the Bald and Golden Eagle Protection Act

10 Though bald eagles occur throughout the action area, no known nests are in close proximity to 

11 the GGNS site or along the transmission line corridors that could be disturbed by operations or 

12 maintenance activities associated with the proposed license renewal. Since the proposed 

13 license renewal does not involve construction or land disturbances, the proposed license 

14 renewal would not affect any bald eagle habitat. 

15 4.8.5 Species Protected Under the Migratory Bird Treaty Act

16 Section 2.2.7 discusses a variety of migratory birds that inhabit the GGNS site and surrounding 

17 region. Section 2.2.8 describes Entergy’s depredation permit for cliff swallows 

18 (Petrochelidon spp.) and barn swallows (Hirundo rustica). In the past 5 years of available 

19 depredation reports, Entergy has taken a small number of birds to ensure the safety and 

20 integrity of plant structures. This small number of takes would not be expected to destabilize or 

21 noticeably alter either species’ populations. Also, the FWS reviews Entergy’s depredation 

22 reports and renews the depredation permit annually to ensure that impacts to migratory birds 

23 are minimal. The proposed license renewal does not involve construction or other land

24 disturbances that might adversely affect migratory birds. 

25 4.9 Human Health

26 Table 4–8 lists the issues related to human health that are applicable to GGNS.

27 Table 4–8. Human Health Issues

Issue GEIS Section Category

Microbiological organisms (occupational health) 4.3.6 1

Noise 4.3.7 1

Radiation exposures to public (license renewal term) 4.6.2 1

Occupational radiation exposures (license renewal term) 4.6.3 1

Electromagnetic fields—acute effects (electric shock) 4.5.4.1 2

Electromagnetic fields—chronic effects 4.5.4.2 Uncategorized

Human health impact from chemicals 4.9.1.1.2(a) 1

Physical occupational hazards 4.9.1.1.5(a) 1

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51; (a) NRC 2013a

28 4.9.1 Generic Human Health Issues

29 Category 1 issues in 10 CFR Part 51, Subpart A, Appendix B, Table B–1, applicable to GGNS in 

30 regard to human health are listed in Table 4–9. Entergy stated in its ER (Entergy 2011a) that it 
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1 was not aware of any new and significant human health issues associated with the renewal of 

2 the GGNS operating license. The NRC staff did not identify any new and significant information 

3 during its independent review of the applicant’s ER, the staff’s site audit, the scoping process, or 

4 the evaluation of other available information. Therefore, there are no impacts related to 

5 Category 1 human health issues beyond those discussed in the GEIS. For these issues, the 

6 GEIS concluded that the impacts are SMALL, and additional site-specific mitigation measures 

7 are not likely to be sufficiently beneficial to warrant implementation. These impacts are 

8 expected to remain SMALL through the license renewal term.

9 4.9.1.1 New Category 1 Human Health issues

10 As described in Section 1.4 of this SEIS, the NRC has approved a revision to its environmental 

11 protection regulation, 10 CFR Part 51. With respect to the human health, the revision amends 

12 Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51 by adding two new Category 1 issues, 

13 “Human health impact from chemicals” and “Physical occupational hazards.” The first issue 

14 considers the impacts from chemicals to plant workers and members of the public. The second 

15 issue only considers the non-radiological occupational hazards of working at a nuclear power 

16 plant. An understanding of these non-radiological hazards to nuclear power plant workers and 

17 members of the public have been well established at nuclear power plants during those plants’ 

18 current licensing terms. The impacts from chemical hazards are expected to be minimized 

19 through the licensee’s use of good industrial hygiene practices as required by permits and 

20 Federal and State regulations. Also, the impacts from physical hazards to plant workers will be 

21 of small significance if workers adhere to safety standards and use protective equipment as 

22 required by Federal and State regulations. The impacts to human health for each of these new 

23 issues from continued plant operations are SMALL.

24 The NRC staff has not identified any new and significant information related to these non25 radiological issues during its independent review of the applicant’s ER, the site audit, and the 

26 scoping process. Therefore, the NRC staff concludes that there would be no impact to human 

27 health from chemicals or physical hazards beyond those impacts described in the GEIS

28 (NRC 2013a) and, therefore, the impacts are SMALL. 

29 4.9.2 Radiological Impacts of Normal Operations

30 Entergy stated in its ER that it was not aware of any new and significant radiological impacts 

31 related to human health issues associated with the renewal of the GGNS operating license. 

32 The NRC staff has not identified any new and significant information radiological impacts related 

33 to human health issues during its independent review of the applicant’s ER, the site audit, the 

34 scoping process, or its evaluation of other available information. Therefore, the NRC staff 

35 concludes that there would be no impact from radiation exposures to the public or to workers 

36 during the renewal term beyond those discussed in the GEIS. 

37 The findings in the GEIS are as follows:

38  Radiation exposures to public (license renewal term)—Based on information 

39 in the GEIS, the NRC found that radiation doses to the public will continue at 

40 current levels associated with normal operations.

41  Occupational exposures (license renewal term)—Based on information in the 

42 GEIS, the NRC found that projected maximum occupational doses during the 

43 license renewal term are within the range of doses experienced during 

44 normal operations and normal maintenance outages, and would be well 

45 below regulatory limits. 

46 There are no Category 2 issues related to radiological impacts of routine operations.
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1 The information presented below is a discussion of selected radiological programs conducted at 

2 GGNS.

3 4.9.2.1 GGNS Radiological Environmental Monitoring Program 

4 GGNS conducts a radiological environmental monitoring program (REMP) to assess the 

5 radiological impact, if any, to its employees, the public, and the environment from operations. 

6 The REMP measures aquatic, terrestrial, and atmospheric radioactivity, as well as ambient 

7 radiation. 

8 The REMP also measures background radiation (i.e., cosmic sources, global fallout, and 

9 naturally occurring radioactive material, including radon). The REMP supplements the 

10 radioactive effluent monitoring program, discussed later in this section, by verifying that any 

11 measurable concentrations of radioactive materials and levels of radiation in the environment 

12 are not higher than those calculated using the radioactive effluent release measurements and 

13 transport models.

14 An annual radiological environmental operating report is issued, which contains a discussion of 

15 the results of the monitoring program performed for the previous year. The REMP collects 

16 samples of environmental media to measure the radioactivity levels that may be present. The 

17 media samples are representative of the radiation exposure pathways that may have an impact 

18 on the public. 

19 The GGNS radiological environmental monitoring program consists of four categories based on 

20 exposure pathways to the public. These categories are: airborne, waterborne, ingestion, and 

21 direct radiation. The airborne samples taken around GGNS are airborne particulate and 

22 airborne iodine. The waterborne pathway samples are taken from surface water and 

23 groundwater sources. Sediment samples also are included in this pathway. The ingestion 

24 pathway samples include fish and broadleaf vegetation. GGNS will also sample milk for this 

25 pathway if it is available commercially within 8 km (5 mi) of the site. For 2012, there was no 

26 commercial milk available to sample. The direct radiation pathway measures direct exposure 

27 from environmental radiation doses using thermoluminescent dosimeters. 

28 In addition to the REMP, GGNS has an onsite groundwater protection program designed to 

29 monitor the onsite environment for detection of leaks from plant systems and pipes containing 

30 radioactive liquid (Entergy 2011a). Additional information on the groundwater protection 

31 program is contained later in this section and in the groundwater quality section in Chapter 2 of 

32 this document.

33 The NRC staff reviewed the GGNS annual radiological environmental operating reports for 2008 

34 through 2012 for significant impacts to the environment or unusual trends in the data 

35 (Entergy 2009a, 2010a, 2011b, 2012a, 2013a). Five years provides a data set that covers a 

36 broad range of activities that occur at a nuclear power plant, including refueling outages, 

37 non-refueling outage years, routine operation, and years where there may be significant 

38 maintenance activities. Based on the staff’s review, no adverse trends (i.e., steadily increasing 

39 build-up of radioactivity levels) were observed and the data showed no measurable impact to 

40 the environment from operations at GGNS.

41 4.9.2.2 Ground Water Protection Program 

42 In 2007, the Nuclear Energy Institute (NEI) established a standard for monitoring and reporting 

43 radioactive isotopes in groundwater: NEI 07-07, “Industry Ground Water Protection Initiative – 

44 Final Guidance Document” (NEI 2007). GGNS implemented the recommendations of this 

45 industry standard after initial sampling efforts in 2007. Results of Entergy’s groundwater 
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1 protection program are contained in the annual radioactive effluent release report submitted 

2 annually to the NRC. 

3 Information on the GGNS groundwater protection program is located in Sections 2.2.5 and 4.5.3 

4 in this SEIS. 

5 4.9.2.3 GGNS Radioactive Effluent Release Program 

6 All nuclear plants were licensed with the expectation that they would release radioactive 

7 material to both the air and water during normal operation. However, NRC regulations require 

8 that radioactive gaseous and liquid releases from nuclear power plants must meet radiation 

9 dose-based limits specified in 10 CFR Part 20, and the as low as is reasonably achievable 

10 (ALARA) criteria in Appendix I to 10 CFR Part 50. Regulatory limits are placed on the radiation 

11 dose that members of the public can receive from radioactive effluents that a nuclear power 

12 plant releases. In addition, 10 CFR 50.36(a) requires nuclear power plants to submit an annual 

13 report to the NRC that lists the types and quantities of radioactive effluents released into the 

14 environment. 

15 The NRC staff reviewed the annual radioactive effluent release reports for 2008 through 2012 

16 (Entergy 2009b, 2010b, 2011c, 2012b, 2013b). The review focused on the calculated doses to 

17 a member of the public from radioactive effluents released from GGNS. The doses were 

18 compared to the radiation protection standards in 10 CFR 20.1301 and the ALARA dose design 

19 objectives in Appendix I to 10 CFR Part 50 and EPA’s 40 CFR Part 190. 

20 Dose estimates for members of the public are calculated based on radioactive gaseous and 

21 liquid effluent release data and atmospheric and aquatic transport models. The 2012 annual 

22 radioactive effluent release report (Entergy 2013b) contains a detailed presentation of the 

23 radioactive discharges and the resultant calculated doses. The following summarizes the 

24 calculated dose to a member of the public located outside the GGNS site boundary from 

25 radioactive gaseous and liquid effluents released during 2012: 

26  The total-body dose to an offsite member of the public from GGNS 

radioactive liquid effluents was 3.02x10-01 mrem (3.02x10-03 27 mSv), which is 

28 well below the 3 mrem (0.03 mSv) dose criterion in Appendix I to 

29 10 CFR Part 50.

30  The organ (liver) dose to an offsite member of the public from GGNS 

radioactive liquid effluents was 5.64x10-01 mrem (5.64x10-03 31 mSv), which is 

32 well below the 10 mrem (0.10 mSv) dose criterion in Appendix I to 

33 10 CFR Part 50.

34  The air dose at the site boundary from gamma radiation in gaseous effluents 

from GGNS was 4.23x10-01 mrad (4.23x10-03 35 mGy), which is well below the 

36 10 mrad (0.1 mGy) dose criterion in Appendix I to 10 CFR Part 50.

37  The air dose at the site boundary from beta radiation in gaseous effluents 

from GGNS was 2.16x10-01 mrad (2.16x10-03 38 mGy), which is well below the 

39 20 mrad (0.2 mGy) dose criterion in Appendix I to 10 CFR Part 50.

40  The dose to an organ (bone) from radioactive iodine, radioactive particulates, 

and carbon-14 from GGNS was 7.06 mrem (7.06x10-02 41 mSv), which is below 

42 the 15 mrem (0.15 mSv) dose criterion in Appendix I to 10 CFR Part 50.

43 4.9.2.4 Summary 

44 The NRC staff’s review of the GGNS radioactive effluent control program showed that radiation 

45 doses to members of the public for the years 2008–2012 comply with Federal radiation 
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1 protection standards contained in Appendix I to 10 CFR Part 50, 10 CFR Part 20, and 

2 40 CFR Part 190.

3 The applicant has no plans to conduct refurbishment activities during the license renewal term; 

4 however, routine plant refueling and maintenance activities currently performed will continue 

5 during the license renewal term. Based on the past performance of the radioactive waste 

6 system to maintain the dose from radioactive effluents to be ALARA, similar performance is 

7 expected during the license renewal term. Continued compliance with regulatory requirements 

8 is expected during the license renewal term; therefore, the staff concludes that the impacts from 

9 radioactive effluents would be SMALL.

10 4.9.3 Electromagnetic Fields—Acute Effects

11 Based on the GEIS, the NRC found that electric shock resulting from direct access to energized 

12 conductors or from induced charges in metallic structures has not been a problem at most 

13 operating nuclear power plants and generally is not expected to be a problem during the license 

14 renewal term. However, site-specific review is required to determine the significance of the 

15 electric shock potential along portions of the transmission lines within the scope of this 

16 document.

17 In the GEIS (NRC 1996), the NRC found that without a review of the conformance of each 

18 nuclear plant transmission line with National Electrical Safety Code (NESC) criteria, it was not 

19 possible to determine the significance of the electric shock potential (IEEE 2002). Evaluation of 

20 individual plant transmission lines is necessary because electric shock safety was not 

21 addressed in the licensing process for some plants. For other plants, land use in the vicinity of 

22 transmission lines may have changed, or power distribution companies may have upgraded line 

23 voltage. The NRC uses the NESC criteria as its baseline to assess the potential human health 

24 impact of the induced current from an applicant’s transmission lines. As discussed in the GEIS, 

25 the issue of electric shock is of small significance for transmission lines that are operated in 

26 adherence with the NESC criteria. To comply with 10 CFR 51.53(c)(3)(ii)(H), Entergy provided 

27 an assessment of the impact of the proposed action on the potential shock hazard from the 

28 transmission lines. 

29 GGNS electrical output is delivered to the Baxter-Wilson Steam Electric Station Extra High 

30 Voltage (EHV) switchyard and the Franklin EHV Switching Station through two 500-kilovolt (kV) 

31 transmission lines. The Baxter-Wilson transmission line is a 22-mi (35-km) single-circuit line 

32 that spans from the 500-kV switchyard located at GGNS to the Baxter-Wilson Steam Electric 

33 Station EHV switchyard. The Franklin transmission line is a 43.6-mi (70.2-km) single-circuit line 

34 that spans from the 500-kV switchyard located at GGNS to the Franklin EHV Switching Station. 

35 There is also a 500-kV line that spans approximately 300 ft (90 m) from the GGNS Turbine 

36 Building to the 500-kV switchyard located on site. Entergy Mississippi, Inc. (EMI) owns and 

37 operates the transmission lines constructed to connect GGNS to the electric grid. 

38 Entergy completed an acute shock analysis for the transmission lines using the software 

39 “EMF-10 Electric Field Induction” developed by the Electric Power Research Institute (EPRI). 

40 The input parameters included the design features of the Franklin and Baxter-Wilson 

41 transmission lines and a large tractor-trailer was assumed to be the maximum vehicle size 

42 under the lines. The minimum clearance on the Franklin line above any of the travel ways 

43 mentioned was 35.4 ft (10.8 m). The minimum clearance above any of the travel ways 

44 mentioned on the Baxter-Wilson line was 44.5 ft (13.6 m). The maximum induced current 

45 calculated for those power lines was 2.03 mA on the Franklin transmission line. The minimum 

46 clearance at any point on the 500-kV line that spans approximately 300 ft (90 m) from the 

47 GGNS Turbine Building to the 500-kV switchyard located on site was 70 ft (21.3 m). Since that 
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1 clearance is almost twice the clearance used in the acute shock analyses for the Baxter-Wilson 

2 and Franklin transmission lines, this span would not induce a current greater than the 

3 NESC 5 mA criterion. Therefore, the lines meet the NESC 5 mA criterion (Entergy 2011a).

4 The GGNS transmission line corridor crosses over mostly rural agricultural and forest land, with 

5 the exception of the Franklin transmission line, which crosses over portions of highways and 

6 rivers in the area. EMI inspects all transmission lines 230-kV and above at least three times 

7 each year. Any problems or hazards related to vegetation are recorded in an electronic 

8 database and assigned to crews for mitigation. Also, transmission lines 230-kV and above are 

9 presently scheduled to receive herbicide every 2 years to maintain proper clearances from 

10 conductors. EMI also uses aerial patrols to inspect their transmission lines and works with 

11 internal and external customers to investigate and resolve potential problems, such as building 

12 or roadway construction projects and pipeline installation or maintenance. EMI’s current 

13 maintenance practices associated with maintaining transmission line clearances will continue 

14 during the license renewal term (Entergy 2011a). 

15 The NRC staff reviewed the information Entergy provided to document the results of its acute 

16 shock evaluation of its transmission lines. The staff notes that Entergy used appropriate 

17 assumptions in its calculations: identification of the transmission lines covered by 

18 10 CFR 51.53(c)(3)(ii)(H), the use of the maximum vehicle size to be located below the 

19 transmission lines, and software developed by EPRI—the nationally recognized expert in this 

20 area. Based on this information, the NRC staff concludes that the potential impacts from 

21 electric shock during the renewal period would be SMALL.

22 4.9.4 Electromagnetic Fields—Chronic Effects

23 In the GEIS, the effects of chronic exposure to 60-Hz electromagnetic fields from power lines 

24 were not designated as Category 1 or 2, and will not be until a scientific consensus is reached 

25 on the health implications of these fields.

26 The potential effects of chronic exposure from these fields continue to be studied and are not 

27 known at this time. The National Institute of Environmental Health Sciences (NIEHS) directs 

28 related research through the U.S. Department of Energy (DOE). 

29 The report by NIEHS (NIEHS 1999) contains the following conclusion:

30 The NIEHS concludes that ELF-EMF (extremely low frequency-electromagnetic 

31 field) exposure cannot be recognized as entirely safe because of weak scientific 

32 evidence that exposure may pose a leukemia hazard. In our opinion, this finding 

33 is insufficient to warrant aggressive regulatory concern. However, because 

34 virtually everyone in the United States uses electricity and therefore is routinely 

35 exposed to ELF-EMF, passive regulatory action is warranted such as continued 

36 emphasis on educating both the public and the regulated community on means 

37 aimed at reducing exposures. The NIEHS does not believe that other cancers or 

38 non-cancer health outcomes provide sufficient evidence of a risk to currently 

39 warrant concern.

40 This statement is not sufficient to cause the NRC staff to change its position with respect to the 

41 chronic effects of electromagnetic fields. The NRC staff considers the GEIS finding of 

42 “UNCERTAIN” still appropriate and will continue to follow developments on this issue. 

43 4.10 Socioeconomics

44 The socioeconomic issues applicable to GGNS are shown in Table 4–9. Section 2.2.9 of this SEIS 

45 describes the socioeconomic conditions near GGNS. 
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1 Table 4–9. Socioeconomics Issues

Issues GEIS Section Category

Housing impacts 4.7.1 2 

Public services: public safety, social services, tourism & 

recreation

4.7.3, 4.7.3.3, 4.7.3.4, 

4.7.3.6 1 

Public services: public utilities 4.7.3.5 2 

Public services: education (license renewal) 4.7.3.1 1 

Offsite land use (license renewal term) 4.7.4 2 

Public Services: transportation 4.7.3.2 2 

Historic & archaeological resources 4.7.7 2 

Aesthetic impacts (license renewal term) 4.7.6 1 

Aesthetic impacts of transmission lines (license renewal term) 4.5.8 1 

Environmental justice: minority and low-income populations 4.10.1(a) 2 

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51; (a)NRC 2013a

2 4.10.1 Generic Socioeconomic Issues

3 The applicant’s ER, scoping comments, and other available data records on GGNS, were 

4 reviewed and evaluated for new and significant information. The review included a data 

5 gathering site visit to GGNS. No new and significant information was identified during this 

6 review that would change the conclusions presented in the GEIS. Therefore, for these 

7 Category 1 issues, impacts during the renewal term are not expected to exceed those 

8 discussed in the GEIS. For GGNS, the staff incorporates the GEIS conclusions by reference. 

9 Impacts for Category 2 issues and the uncategorized issue (environmental justice) are 

10 discussed in Sections 4.10.2 through 4.10.7. In evaluating the potential socioeconomic impacts 

11 resulting from license renewal, the NRC uses as its baseline the existing socioeconomic 

12 conditions described in Section 2.2.9 of this SEIS. These baseline socioeconomic conditions 

13 include existing housing, transportation, offsite land use, demographic, public services, and 

14 economic conditions affected by ongoing operations at the nuclear power plant.

15 4.10.2 Housing

16 Appendix C of the GEIS presents a population characterization method based on two factors, 

17 sparseness and proximity (GEIS, Section C.1.4). Sparseness measures population density 

18 within 20 miles (32 kilometers) of the site, and proximity measures population density and city 

19 size within 50 miles (80 kilometers). Each factor has categories of density and size 

20 (GEIS, Table C.1). A matrix is used to rank the population category as low, medium, or high 

21 (GEIS, Figure C.1).

22 According to the 2010 Census, an estimated 23,406 people lived within 20 mi (32 km) of GGNS, 

which equates to a population density of 19 persons per mi2 23 (Entergy 2011a). This translates to 

24 a Category 1, “most sparse” population density using the GEIS measure of sparseness (less 

than 40 persons per mi2 25 and no community with 25,000 or more persons within 20 mi). An 

26 estimated 329,043 people live within 50 mi (80 km) of GGNS with a population density of 

42 persons per mi2 27 (Entergy 2011a). This translates to a Category 1 density, using the GEIS 

measure of proximity (no cities with 100,000 or more persons and less than 50 persons per mi2 28
Environmental Impacts of Operation

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1 within 50 mi). Therefore, GGNS is located in a low population area based on the GEIS 

2 sparseness and proximity matrix.

3 Table B–1 of 10 CFR Part 51, Subpart A, Appendix B, states that impacts on housing availability 

4 may be SMALL, MODERATE, or LARGE. MODERATE or LARGE housing impacts of the 

5 workforce associated with refurbishment may be associated with plants located in sparsely 

6 populated areas or in areas with growth control measures that limit housing development. 

7 Since Entergy has no planned refurbishment activities at GGNS and Claiborne, Hinds, 

8 Jefferson, and Warren counties are not subject to growth-control measures that would limit 

9 housing development; any changes in employment at GGNS would have little noticeable effect 

10 on housing availability in these counties. Since Entergy has no plans to add non-outage 

11 employees during the license renewal period, employment levels at GGNS would remain 

12 relatively constant with no additional demand for permanent housing during the license renewal 

13 term. Based on this information, there would be no impact on housing during the license 

14 renewal term beyond what already has been experienced. Therefore, the NRC staff concludes 

15 that the impacts would be SMALL.

16 4.10.3 Public Services—Public Utilities

17 Impacts on public utility services (e.g., water, sewer) are considered SMALL if the public utility 

18 has the ability to respond to changes in demand and would have no need to add or modify 

19 facilities. Impacts are considered MODERATE if service capabilities are overtaxed during 

20 periods of peak demand. Impacts are considered LARGE if additional system capacity is 

21 needed to meet ongoing demand.

22 Analysis of impacts on the public water systems considered both plant demand and 

23 plant-related population growth. Section 2.1.7 describes the permitted withdrawal rate and 

24 actual use of water for reactor cooling at GGNS.

25 Since Entergy has no plans to add non-outage employees during the license renewal period, 

26 employment levels at GGNS would remain relatively unchanged with no additional demand for 

27 public water services. Public water systems in the region are adequate to meet the demands of 

28 residential and industrial customers in the area. Therefore, there would be no impact to public 

29 water services during the license renewal term beyond what is already being experienced. 

30 Therefore, the NRC staff concludes that the impacts would be SMALL.

31 4.10.4 Public Services—Transportation

32 Table B–1 of Appendix B to Subpart A of 10 CFR Part 51 states the following:

33 Transportation impacts (level of service) of highway traffic generated...during the 

34 term of the renewed license are generally expected to be of SMALL significance. 

35 However, the increase in traffic associated with additional workers and the local 

36 road and traffic control conditions may lead to impacts of MODERATE or LARGE 

37 significance at some sites.

38 The regulation in 10 CFR 51.53(c)(3)(ii)(J) requires all applicants to assess the impacts of 

39 highway traffic generated by the proposed project on the level of service of local highways 

40 during the term of the renewed license. Since Entergy has no plans to add non-outage 

41 employees during the license renewal period, traffic volume and levels of service on roadways 

42 in the vicinity of GGNS would not change. Therefore, there would be no transportation impacts 

43 during the license renewal term beyond what is already being experienced. Therefore, the NRC 

44 staff concludes that the impacts would be SMALL.
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1 4.10.5 Offsite Land Use

2 Offsite land use during the license renewal term is a Category 2 issue (10 CFR Part 51, Subpart 

3 A, Appendix B, Table B–1). Table B–1 notes that; "significant changes in land use may be 

4 associated with population and tax revenue changes resulting from license renewal." Section 

5 4.7.4 of the GEIS defines the magnitude of land-use changes as a result of plant operation 

6 during the license renewal term as SMALL when there will be little new development and 

7 minimal changes to an area's land use pattern, as MODERATE when there will be considerable 

8 new development and some changes to the land use pattern, and LARGE when there will be 

9 large-scale new development and major changes in the land use pattern.

10 Tax revenue can affect land use because it enables local jurisdictions to provide the public 

11 services (e.g., transportation and utilities) necessary to support development. Section 4.7.4.1 of 

12 the GEIS states that the assessment of tax-driven land use impacts during the license renewal 

13 term should consider the size of the plant's tax payments relative to the community's total 

14 revenues, the nature of the community's existing land use pattern, and the extent to which the 

15 community already has public services in place to support and guide development. If the plant's 

16 tax payments are projected to be small relative to the community's total revenue, tax driven land 

17 use changes during the plant's license renewal term would be SMALL, especially where the 

18 community has pre-established patterns of development and has provided public services to 

19 support and guide development. Section 4.7.2.1 of the GEIS states that if tax payments by the 

20 plant owner are less than 10 percent of the taxing jurisdiction's revenue, the significance level 

21 would be SMALL. If tax payments are 10 to 20 percent of the community's total revenue, new 

22 tax-driven land use changes would be MODERATE. If tax payments are greater than 

23 20 percent of the community's total revenue, new tax-driven land use changes would be 

24 LARGE. This would be especially true where the community has no pre-established pattern of 

25 development or has not provided adequate public services to support and guide development. 

26 As discussed in Sections 4.10.2, 4.10.3, and 4.10.4, it is not expected that there would be any 

27 change in the staffing levels at GGNS or increased demand for additional housing, public 

28 services related to public utilities, and transportation during the license renewal period. 

29 Therefore, the NRC staff concludes that the impacts would be SMALL.

30 4.10.5.1 Population-Related Impacts

31 Since Entergy has no plans to add non-outage employees during the license renewal period, 

32 there would be no plant operations-driven population increase in the vicinity of GGNS. 

33 Therefore, there would be no population-related offsite land use impacts during the license 

34 renewal term beyond what has already been experienced. Therefore, the NRC staff concludes 

35 that the impacts would be SMALL.

36 4.10.5.2 Tax Revenue-Related Impacts

37 As discussed in Chapter 2, Entergy pays property taxes for GGNS to the State of Mississippi. 

38 Part of these taxes are distributed to counties near GGNS. Since Entergy started making 

39 property tax payments, local county populations have been in decline and land use conditions 

40 have generally remained unchanged. Therefore, tax revenue from GGNS as a proportion of 

41 total tax revenue in the ROI has had little or no effect on land use conditions within these 

42 counties. Since employment levels would remain relatively unchanged with no increase in the 

43 assessed value of GGNS, annual property tax payments also would be expected to remain 

44 relatively unchanged throughout the license renewal period. Based on this information, there 

45 would be no tax-revenue-related offsite land use impacts during the license renewal term 

46 beyond those already being experienced. Therefore, the NRC staff concludes that the impacts 

47 would be SMALL.
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1 4.10.6 Historic and Archaeological Resources

2 The National Historic Preservation Act (NHPA) requires Federal agencies to consider the effects 

3 of their undertakings on historic properties. Historic properties are defined as resources eligible 

4 for listing on the National Register of Historic Places (NRHP). The criteria for eligibility are listed 

5 in 36 CFR 60.4 and include association with significant events in history; association with the 

6 lives of persons significant in the past; embodiment of distinctive characteristics of type, period, 

7 or construction; and sites or places that have yielded or are likely to yield important information. 

8 The historic preservation review process (Section 106 of the National Historic Preservation Act 

9 of 1966, as amended [NHPA]) is outlined in regulations issued by the Advisory Council on 

10 Historic Preservation (ACHP) in 36 CFR Part 800. In accordance with 36 CFR 800.8(c), the 

11 NRC has elected to use the NEPA process to comply with the obligations found under 

12 Section 106 of the NHPA.

13 In accordance with 36 CFR 800.8(c), the NRC initiated Section 106 consultation with the ACHP

14 and the Mississippi and Louisiana State Historic Preservation Offices (SHPOs) in January 2012, 

15 by notifying them of the agency’s intent to review a request from Entergy to renew the GGNS 

16 operating license (NRC 2012f, 2012g, 2012h). On February 28, 2012, the Mississippi SHPO 

17 responded to the NRC’s letter stating its opinion that the proposed license renewal will have no 

18 adverse effect on historic properties (MDAH 2012a). No comments were received from the 

19 ACHP or the Louisiana SHPO as a result of these consultation letters. 

20 The NRC also initiated consultation on the proposed GGNS license renewal with four Federally 

21 recognized tribes: the Jena Band of Choctaw Indians, the Mississippi Band of Choctaw Indians, 

22 the Choctaw Nation of Oklahoma, and the Tunica-Biloxi Tribe of Louisiana (NRC 2012i). In 

23 letters to the tribes, the NRC supplied information about the proposed action (license renewal) 

24 and the definition of the area of potential effect, and stated that the NHPA review would be 

25 integrated with the NEPA process, according to 35 CFR 800.8. The NRC invited the Tribes to 

26 participate in the identification of potentially affected historic properties near GGNS and the 

27 scoping process. The Choctaw Nation of Oklahoma, Jena Band of Choctaw Indians, and the 

28 Mississippi Band of Choctaw Indians responded. The Tribes did not raise any concerns through 

29 scoping comments and requested updates throughout the review process (see Appendix D).

30 The staff reviewed information on historic and archaeological resources provided in the 

31 applicant’s ER. It also conducted a review at the Mississippi Department of Archives and 

32 History (MDAH) and identified 17 previously recorded archaeological resources on GGNS 

33 property; surveys conducted in 1972 and 2006 of the archaeological, architectural, and historic 

34 resources on and around GGNS property; and multiple surveys that intersected the 

35 transmission lines (MDAH 2012b). One site identified in these surveys, 22Cb528, is located on 

36 GGNS property and is considered potentially eligible for listing in the NRHP. Site 22Cb528 is 

37 an Archaic Period village consisting of ceramics and lithics at various stages of production, and 

38 it has been determined that the site should be avoided or tested further to determine eligibility 

39 (Entergy 2011a; MDAH 2012b). Along the transmission lines, seven sites were identified as 

40 being within or very near to the transmission line rights-of-way; one is listed in the NRHP; four 

41 others would require further evaluation to determine eligibility status and are considered 

42 potentially eligible until a determination is made; and the remaining two are ineligible. 

43 Background research also identified nine NRHP-listed resources within a 10-mi (16km) radius of 

44 the facility; however, none are located within the boundaries of the GGNS property.

45 As noted in Section 2.2.10.1, the area near where the Grand Gulf Mound was located has high 

46 potential for subsurface archaeological deposits. Additionally, areas on the property could have 

47 historic resources related to the Grand Gulf town site or the Civil War battles that took place on 

48 and near the GGNS property. Because the GGNS property has been surveyed for historic and 
Environmental Impacts of Operation

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1 archaeological resources, it is likely that the undiscovered resources would be subsurface 

2 deposits. 

3 Entergy currently has no planned changes or ground-disturbing activities associated with 

4 license renewal at GGNS. However, given the high potential for the discovery of additional 

5 historic and archaeological resources at GGNS, Entergy has formal guidelines in its 

6 Environmental Reviews and Evaluations Nuclear Management Manual (EN-EV-115) for 

7 protecting archaeological resources. The procedure advises Entergy staff on consulting with 

8 the appropriate SHPO, and the NRC, as applicable, before ground-disturbing activities take 

9 place at GGNS. An additional procedure (EN-EV-121) requires work to be stopped if evidence 

10 of a historical or archaeological artifact is found during ground disturbance. The vegetation 

11 management plan for transmission lines, however, does not specifically mention vegetation 

12 maintenance near cultural resources (AM-ERS-FAC-001). Entergy could minimize any possible 

13 effects to cultural resources found within transmission line corridors by adding procedures for 

14 maintenance near cultural resources. GGNS also is governed by Mississippi State burial law, 

15 which requires a work stoppage if human remains are unexpectedly uncovered. 

16 Based on the review of Mississippi SHPO files for the region, published literature, and 

17 information Entergy and consulting parties provided, the staff concludes that the potential 

18 impact from license renewal of GGNS on historic or archaeological resources is SMALL, and 

19 there would be no adverse effect on historic properties as specified in 36 CFR 800.4(d)(1). 

20 Entergy could further reduce any potential effect to historic and archaeological resources at the 

21 GGNS site by referencing its formal guidelines for protecting historic and archaeological 

22 resources in its vegetation management plan.

23 4.10.7 Environmental Justice

24 As described in Section 1.4 of this SEIS, the NRC has approved a revision to its environmental 

25 protection regulation, 10 CFR Part 51. With respect to environmental justice concerns, the 

26 revision amends Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51 by adding a new 

27 Category 2 issue, “Minority and low-income populations,” to evaluate the impacts of continued 

28 operations and any refurbishment activities during the license renewal term on minority

29 populations and low-income populations living in the vicinity of the plant. Environmental justice 

30 was listed in Table B–1 as a concern but was not evaluated in the 1996 GEIS and therefore, is 

31 addressed in each SEIS. 

32 Under Executive Order (EO) 12898 (59 FR 7629, February 16, 1994), Federal agencies are 

33 responsible for identifying and addressing, as appropriate, disproportionately high and adverse 

34 human health and environmental impacts on minority and low-income populations. In 2004, the 

35 Commission issued a Policy Statement on the Treatment of Environmental Justice Matters in 

36 NRC Regulatory and Licensing Actions (69 FR 52040, August 24, 2004), which states, “The 

37 Commission is committed to the general goals set forth in EO 12898, and strives to meet those 

38 goals as part of its NEPA review process.”

39 The Council of Environmental Quality (CEQ) provides the following information in Environmental 

40 Justice: Guidance Under the National Environmental Policy Act (CEQ 1997):

41 Disproportionately High and Adverse Human Health Effects. Adverse health 

42 effects are measured in risks and rates that could result in latent cancer fatalities, 

43 as well as other fatal or nonfatal adverse impacts on human health. Adverse 

44 health effects may include bodily impairment, infirmity, illness, or death. 

45 Disproportionately high and adverse human health effects occur when the risk or 

46 rate of exposure to an environmental hazard for a minority or low-income 

47 population is significant (as employed by NEPA) and appreciably exceeds the 
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1 risk or exposure rate for the general population or for another appropriate 

2 comparison group.

3 Disproportionately High and Adverse Environmental Effects. A 

4 disproportionately high environmental impact that is significant (as defined by 

5 NEPA) refers to an impact or risk of an impact on the natural or physical 

6 environment in a low-income or minority community that appreciably exceeds the 

7 environmental impact on the larger community. Such effects may include 

8 ecological, cultural, human health, economic, or social impacts. An adverse 

9 environmental impact is an impact that is determined to be both harmful and 

10 significant (as employed by NEPA). In assessing cultural and aesthetic

11 environmental impacts, impacts that uniquely affect geographically dislocated or 

12 dispersed minority or low-income populations or American Indian tribes are 

13 considered.

14 The environmental justice analysis assesses the potential for disproportionately high and 

15 adverse human health or environmental effects on minority populations and low-income 

16 populations that could result from the operation of GGNS during the renewal term. In assessing 

17 the impacts, the following definitions of minority individuals and populations and low-income 

18 population were used (CEQ 1997):

19  Minority individuals. Individuals who identify themselves as members of the 

20 following population groups: Hispanic or Latino, American Indian or Alaska Native, 

21 Asian, Black or African American, Native Hawaiian or Other Pacific Islander, or two or 

22 more races, meaning individuals who identified themselves on a Census form as 

23 being a member of two or more races (e.g., Hispanic and Asian).

24  Minority populations. Minority populations are identified when (1) the minority 

25 population of an affected area exceeds 50 percent or (2) the minority population 

26 percentage of the affected area is meaningfully greater than the minority population 

27 percentage in the general population or other appropriate unit of geographic analysis.

28  Low-income population. Low-income populations in an affected area are identified 

29 with the annual statistical poverty thresholds from the Census Bureau's Current 

30 Population Reports, Series P60, on Income and Poverty.

31 4.10.7.1 Minority Population

32 According to 2010 Census data, 53.2 percent of the population residing within a 50-mi (80-km) 

33 radius of GGNS identified themselves as minority individuals. The largest minority group was 

34 Black or African American (51.3 percent), followed by Hispanic or Latino (of any race) 

35 (2.0 percent) (CAPS 2012).

36 According to 2010 Census data, minority populations in the socioeconomic region of influence 

37 (ROI) (Claiborne, Hinds, Jefferson, and Warren Counties) comprised 69.4 percent of the total 

38 four-county population (see Table 2–12). Figure 4–1 shows minority population block groups, 

39 using 2010 Census data for race and ethnicity, within a 50-mi (80-km) radius of GGNS.

40 Census block groups were considered minority population block groups if the percentage of the 

41 minority population within any block group exceeded 53.2 percent (the percent of the minority 

42 population within the 50-mi [80-km] radius of GGNS). A minority population exists if the 

43 percentage of the minority population within the block group is meaningfully greater than the 

44 minority population percentage in the 50-mi (80-km) radius. Approximately 144 of the 294 

45 census block groups located within the 50-mi (80-km) radius of GGNS were determined to have 

46 meaningfully greater minority populations.
Environmental Impacts of Operation

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1 Minority population block groups are concentrated on the east side of the Mississippi River and 

2 include the census block group containing GGNS. According to the 2010 Census, 

3 approximately 85.4 percent of the Port Gibson population identified themselves as minority.

4 4.10.7.2 Low-Income Population

5 According to 2010 American Community Survey Census data, an average of 16.3 percent of 

6 families and 21.1 percent of individuals residing in the 24 counties within a 50-mi (80-km) radius 

7 of GGNS were identified as living below the Federal poverty threshold in 2010. The 

8 2010 Federal poverty threshold was $22,314 for a family of four (USCB 2012).

9 According to the 2010 Census, 16.7 percent of families and 21.2 percent of individuals in 

10 Mississippi were living below the Federal poverty threshold in 2010, and the median household 

11 income for Mississippi was $37,881 (USCB 2012). Claiborne and Jefferson Counties had lower 

12 median household incomes and higher percentages of families and individuals living in poverty 

13 compared to State averages. Hinds and Warren Counties had higher median incomes when 

14 compared to the State average. Claiborne County had a median household income average of 

15 $24,150 and 35.0 percent of individuals and 27.6 percent of families living below the poverty 

16 level. Hinds County had a median household income average of $39,215 and 22.5 percent of 

17 individuals and 17.7 percent of families living below the poverty level. Jefferson County had a 

18 median household income of $24,304 and 39.0 percent of individuals and 29.3 percent of 

19 families living below the poverty level. Warren County had a median household income 

20 average of $40,404 and 21.4 percent of individuals and 16.5 percent of families living below the 

21 poverty level (USCB 2012).

22 Figure 4–2 shows low-income census block groups within a 50-mi (80-km) radius of GGNS. 

23 Census block groups were considered low-income population block groups if the percentage of 

24 individuals living below the Federal poverty threshold within any block group exceeded the 

25 percent of the individuals living below the Federal poverty threshold within the 50-mi (80-km) 

26 radius of GGNS. Approximately 120 of the 294 census block groups located within the 50-mi 

27 (80-km) radius of GGNS were determined to have meaningfully greater low-income populations.
Environmental Impacts of Operation

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1 Figure 4–1. 2010 Census Minority Block Groups Within a 50-mi Radius of GGNS

2 Source: USCB 2012

Cities • Aggregate Minority Population W+E 

s 

0 3 6 12 18 24 ••CJ•-=---===::::::J·-·Miles 

* Grand Gulf Site D County Boundaries 

CJ 50 Mile Buffer 
Environmental Impacts of Operation

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1 Figure 4–2. 2010 Census Low-Income Block Groups Within a 50-mi Radius of GGNS

2 Source: USCB 2012

Cities - Low Income Population 

N w+ 

s 

0 3 6 12 18 24 

•-=:~•-= .. --====---Miles 

* Grand Gulf Site D County Boundaries 

D 50 Mile Buffer 
Environmental Impacts of Operation

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1 Low-income block groups are distributed across the 50-mi (80-km) radius area around GGNS, 

2 with no particular concentrations. The nearest low-income population to GGNS is located in 

3 Port Gibson, Mississippi, and several other low-income block groups are in close proximity to 

4 GGNS.

5 4.10.7.3 Analysis of Impacts 

6 The NRC addresses environmental justice matters for license renewal through (1) identifying 

7 the location of minority and low-income populations that the continued operation of the nuclear 

8 power plant may affect during the license renewal term, and (2) determining whether there 

9 would be any potential human health or environmental effects to these populations and special 

10 pathway receptors, and (3) determining if any of the effects may be disproportionately high and 

11 adverse.

12 Figures 4–1 and 4–2 identify the location of minority and low-income block group populations 

13 residing within a 50-mi (80-km) radius of GGNS. This area of impact is consistent with the 

14 impact analysis for public and occupational health and safety, which also focuses on 

15 populations within a 50-mi (80-km) radius of the plant. Chapter 4 presents the assessment of 

16 environmental and human health impacts for each resource area. The analyses of impacts for 

17 all environmental resource areas indicated that the impact from license renewal would be 

18 SMALL.

19 Potential impacts to minority and low-income populations (including migrant workers or Native 

20 Americans) mostly would consist of socioeconomic and radiological effects; however, radiation 

21 doses from continued operations during the license renewal term are expected to continue at 

22 current levels and would remain within regulatory limits. Chapter 5 of this SEIS discusses the 

23 environmental impacts from postulated accidents that might occur during the license renewal 

24 term, which include both design-basis and severe accidents. In both cases, the staff has 

25 generically determined that impacts associated with design-basis accidents are SMALL 

26 because nuclear plants are designed and operated to successfully withstand such accidents, 

27 and the probability weighted impact risks associated with severe accidents also were SMALL. 

28 Therefore, based on this information and the analysis of human health and environmental 

29 impacts presented in Chapters 4 and 5 of this SEIS, there would be no disproportionately high 

30 and adverse impacts to minority and low-income populations from the continued operation of 

31 GGNS during the license renewal term.

32 4.10.7.4 Subsistence Consumption of Fish and Wildlife

33 As part of addressing environmental justice concerns associated with license renewal, the staff

34 also assessed the potential radiological risk to special population groups (such as migrant 

35 workers or Native Americans) from exposure to radioactive material received through their 

36 unique consumption and interaction with the environment. These include subsistence 

37 consumption of fish, native vegetation, surface waters, sediments, and local produce; 

38 absorption of contaminants in sediments through the skin; and inhalation of airborne radioactive 

39 material released from the plant during routine operation. This analysis is presented below.

40 The special pathway receptors analysis is an important part of the environmental justice

41 analysis because consumption patterns may reflect the traditional or cultural practices of 

42 minority and low-income populations in the area, such as migrant workers or Native Americans. 

43 Section 4–4 of Executive Order 12898 (1994) directs Federal agencies, whenever practical and 

44 appropriate, to collect and analyze information on the consumption patterns of populations that 

45 rely principally on fish and/or wildlife for subsistence and to communicate the risks of these 

46 consumption patterns to the public. In this SEIS, the NRC considered whether there were any 
Environmental Impacts of Operation

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1 means for minority or low-income populations to be disproportionately affected by examining 

2 impacts to African American, American Indian, Hispanics, migrant workers, and other traditional 

3 lifestyle special pathway receptors. The assessment of special pathways took into account the 

4 levels of radiological and nonradiological contaminants in native vegetation, crops, soils and 

5 sediments, groundwater, surface water, fish, and game animals on or near GGNS.

6 The following is a summary discussion of the staff’s evaluation from Section 4.9.2 of the 

7 radiological environmental monitoring programs that assess the potential impacts for 

8 subsistence consumption of fish and wildlife near the GGNS site.

9 Entergy has an ongoing comprehensive REMP to assess the impact of GGNS operations on the 

10 environment. To assess the impact of nuclear power plant operations, samples are collected 

11 annually from the environment and analyzed for radioactivity. A plant effect would be indicated 

12 if the radioactive material detected in a sample was significantly larger than background levels. 

13 Two types of samples are collected. The first type, control samples, are collected from areas 

14 beyond the measurable influence of the nuclear power plant or any other nuclear facility. These 

15 samples are used as reference data to determine normal background levels of radiation in the 

16 environment. These samples are then compared with the second type of samples, indicator 

17 samples, collected near the nuclear power plant. Indicator samples are collected from areas 

18 where any contribution from the nuclear power plant will be at its highest concentration. These 

19 samples are then used to evaluate the contribution of nuclear power plant operations to 

20 radiation or radioactivity levels in the environment. An effect would be indicated if the 

21 radioactivity levels detected in an indicator sample were significantly larger than the control 

22 sample or background levels.

23 Samples of environmental media are collected from the aquatic and terrestrial pathways in the 

24 vicinity of GGNS. The aquatic pathways include groundwater, surface water, drinking water, 

25 fish, and shoreline sediment. The terrestrial pathways include airborne particulates and food 

26 products (i.e., broad leaf vegetation). During 2011, analyses performed on samples of 

27 environmental media at GGNS showed no significant or measurable radiological impact above 

28 background levels from site operations (Entergy 2012a).

29 Based on the radiological environmental monitoring data from GGNS, the staff finds that no 

30 disproportionately high and adverse human health impacts would be expected in special 

31 pathway receptor populations in the region as a result of subsistence consumption of water, 

32 local food, fish, and wildlife. 

33 4.11 Evaluation of New and Potentially Significant Information

34 The staff has not identified new and significant information on environmental issues related to 

35 operation during the renewal term. The staff also determined that information provided during 

36 the public comment period did not identify any new issue that requires site-specific assessment. 

37 The staff reviewed the discussion of environmental impacts associated with operation during the 

38 renewal term in the GElS and has conducted its own independent review, including a public 

39 involvement process (e.g., public meetings) to identify issues with new and significant 

40 information.

41 New and significant information is information that identifies a significant environmental issue 

42 not covered in the GEIS and codified in Table B–1 of 10 CFR Part 51, Subpart A, Appendix B, 

43 or information that was not considered in the analyses summarized in the GEIS and that leads 

44 to an impact finding that is different from the finding presented in the GEIS and codified in 

45 10 CFR Part 51.
Environmental Impacts of Operation

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1 In accordance with 10 CFR 51.53(c), the ER that the applicant submits must provide an analysis 

2 of the Category 2 issues in Table B–1 of 10 CFR Part 51, Subpart A, Appendix B. Additionally, 

3 it must discuss actions to mitigate any adverse impacts associated with the proposed action and 

4 environmental impacts of alternatives to the proposed action. In accordance with 

5 10 CFR 51.53(c)(3), the ER does not need to contain an analysis of any Category 1 issue 

6 unless there is new and significant information on a specific issue.

7 The NRC also has a process for identifying new and significant information. That process is 

8 described in NUREG–1555, Supplement 1, Standard Review Plans for Environmental Reviews 

9 for Nuclear Power Plants, Supplement 1: Operating License Renewal (NRC 1999b, 2013b). 

10 The search for new information includes: 

11  review of an applicant’s ER and the process for discovering and evaluating 

12 the significance of new information, 

13  review of public comments,

14  review of environmental quality standards and regulations, 

15  coordination with Federal, State, and local environmental protection and 

16 resource agencies, and 

17  review of the technical literature. 

18 New information that the staff discovered is evaluated for significance using the criteria set forth 

19 in the GEIS. For Category 1 issues in which new and significant information is identified, 

20 reconsideration of the conclusions for those issues is limited in scope to assessment of the 

21 relevant new and significant information; the scope of the assessment does not include other 

22 facets of an issue that the new information does not affect. 

23 4.12 Cumulative Impacts

24 As described in Section 1.4 of this SEIS, the NRC has approved a revision to its environmental 

25 protection regulation, 10 CFR Part 51. With respect to cumulative impacts, the revision amends 

26 Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51 by adding a new Category 2 issue, 

27 “Cumulative impacts,” to evaluate the potential cumulative impacts of license renewal.

28 The staff considered potential cumulative impacts in the environmental analysis of continued 

29 operation of GGNS during the renewed license term. Cumulative impacts may result when the 

30 environmental effects associated with the proposed action are overlaid or added to temporary or 

31 permanent effects associated with other past, present, and reasonably foreseeable actions. 

32 Cumulative impacts can result from individually minor, but collectively significant, actions taking 

33 place over a period of time. It is possible that an impact that may be SMALL by itself could 

34 result in a MODERATE or LARGE cumulative impact when considered in combination with the 

35 impacts of other actions on the affected resource. Likewise, if a resource is regionally declining 

36 or imperiled, even a SMALL individual impact could be important if it contributes to or 

37 accelerates the overall resource decline.

38 For the purposes of this cumulative analysis, past actions are those before the receipt of the

39 license renewal application. Present actions are those related to the resources at the time of 

40 current operation of the power plant, and future actions are those that are reasonably 

41 foreseeable through the end of plant operation including the period of extended operation. 

42 Therefore, the analysis considers potential impacts through the end of the current license terms 

43 as well as the 20-year license renewal term. The geographic area over which past, present, 
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1 and reasonably foreseeable actions would occur is dependent on the type of action considered 

2 and is described below for each resource area.

3 To evaluate cumulative impacts, the incremental impacts of the proposed action, as described 

4 in Sections 4.1–4.10, are combined with other past, present, and reasonably foreseeable future 

5 actions regardless of what agency (Federal or non-Federal) or person undertakes such actions. 

6 The staff used the information provided in the ER, responses to requests for additional 

7 information; information from other Federal, State, and local agencies; scoping comments, and 

8 information gathered during the audit at the GGNS site to identify other past, present, and 

9 reasonably foreseeable actions. 

10 To be considered in the cumulative analysis, the staff determined if the project would occur 

11 within the noted geographic areas of interest and within the period of extended operation, if it 

12 was reasonably foreseeable, and if there would be potential overlapping effect with the 

13 proposed project. For past actions, consideration within the cumulative impacts assessment is 

14 resource and project specific. In general, the effects of past actions are included in the 

15 description of the affected environment in Chapter 2, which serves as the baseline for the 

16 cumulative impacts analysis. However, past actions that continue to have an overlapping effect 

17 on a resource potentially affected by the proposed action are considered in the cumulative 

18 analysis. Other actions and projects that were noted during this review and considered in the 

19 cumulative impact analysis are described below: 

20 • modification and management of the Mississippi River basin

21 • construction of fossil-fuel power plant(s) to meet regional electricity demands

22 • climate change

23 • increased agricultural activities

24 • maintenance of transmission line crossings through the Homochitto National Forest

25 • continued operation of independent spent fuel storage installation (ISFSI) at GGNS

26 Additionally, NRC prepared an FEIS in 2006 in response to an application for an early site 

27 permit (ESP) for the construction and operation of a new nuclear power plant at GGNS 

28 (NRC 2006). On April 5, 2007, the NRC issued an ESP for the GGNS site. In 2008, Entergy 

29 submitted an application for a combined license for a new boiling-water reactor at GGNS, 

30 designated as Unit 3. However, in January 2009, Entergy informed the NRC that it was 

31 considering alternate reactor design technologies and requested the NRC suspend its review 

32 effort until further notice. Accordingly, the construction of Unit 3 at GGNS is considered a 

33 reasonably foreseeable future action and is included in the cumulative impacts assessment 

34 (NRC 2006).

35 4.12.1 Air Quality

36 This section addresses the direct and indirect effects of license renewal on air quality when 

37 added to the aggregate effects of other past, present, and reasonably foreseeable future 

38 actions. In evaluating the potential impacts on air quality associated with license renewal, the 

39 NRC staff uses as its baseline the existing air quality conditions described in Section 2.2.2.1 of 

40 this SEIS. These baseline conditions encompass the existing air quality conditions (EPA’s 

41 National Ambient Air Quality Standard (NAAQS) county designations) potentially affected by air 

42 emissions from continued operations. As described in Section 2.2.2.1, the Mobile (Alabama)-

43 Pensacola-Panama City (Florida)-Southern Mississippi Interstate Air Quality Control Region 

44 (AQCR) (40 CFR 81.68), which encompasses GGNS, is designated as an attainment area for 

45 all criteria pollutants except for part of De Soto County, Mississippi, which is designated as a 

46 marginal nonattainment area for the 2008 8-hour ozone standard and is located about 200 miles 

47 (322 km) north-northeast of GGNS. Other nearby nonattainment areas include the Birmingham 
Environmental Impacts of Operation

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1 area in Alabama for PM2.5 and the Houston-Galveston-Brazoria area in Texas for 8-hour ozone, 

2 located about 240 mi (386 km) east-northeast and west-southwest of GGNS, respectively. The 

3 nearest maintenance area for 8-hour ozone is located about 90 mi (145 km) south of GGNS.

4 Currently, GGNS is operating under a “synthetic minor” permit, which covers site-wide 

5 combustion emission sources, such as diesel generators, fire water pump engines, and cooling 

6 towers (GGNS 2008a). GGNS operations are in compliance with its air permit and Entergy has 

7 no plans for refurbishments or other license renewal-related construction activities that would 

8 affect permitted operations for the license renewal term (Entergy 2011a). Annual emissions of 

9 criteria pollutants, volatile organic compounds (VOCs), and hazardous air pollutants (HAPs) at 

10 GGNS vary from year to year but are well below the plant’s permitted “synthetic minor” 

11 emissions limits (see Table 2–1), based on actual operating hours reported to MDEQ. 

12 Considering the distances to the nearest nonattainment and maintenance areas around GGNS, 

13 prevailing wind directions, and the minor nature of air emissions from GGNS, emissions from 

14 GGNS operations are not anticipated to affect current attainment or maintenance area status. 

15 Accordingly, air emissions from continued operation of the plant and associated effects on 

16 ambient air quality would not be expected to change during the license renewal term.

17 As discussed in Section 2.2.2.1, operations at GGNS release greenhouse gas (GHG) emissions 

18 as follows: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) from fuel combustion; 

19 hydrofluorocarbons (HFCs) in the two plant cooling water chillers; and sulfur hexafluoride (SF6) 

20 in three electric disconnect switches. Perfluorocarbons (PFCs) currently are not used at GGNS. 

21 Combustion-related GHG emissions (such as CO2, CH4, and N2O) at GGNS are minor. The 

22 permitted combustion sources are designed for efficiency and operated intermittently throughout 

23 the year (i.e., often only for testing and preventive maintenance). Other combustion-related 

24 GHG emission sources at GGNS include commuter, visitor, support, and delivery vehicle traffic 

25 within, to, and from the plant. In addition, small amounts of HFCs and SF6 are released into the 

26 atmosphere during normal operations or at various stages of the equipment’s life cycle. Total 

27 annual GHG emissions from the GGNS site were estimated to be about 5,980 tons CO2e

28 (5,425metric tons CO2e) in 2011 (GGNS 2012a; EPA 2011b), which is well below the EPA’s 

29 mandatory reporting threshold of 25,000 metric tons CO2e per year (74 FR 56264).

30 To estimate the amount of GHG releases potentially avoided by continued GGNS operation, its 

31 electricity generation can be compared to an equivalent amount of electricity generation in 

32 fossil-fuel power plant(s). For 2009, the composite CO2e emission factor (representing an 

33 average of all operating fossil-fuel power plants) is approximately 1,107 lb/MWh for the 

34 Mississippi Valley subregion (EPA 2012a). GGNS generates approximately 11,500 GWh per 

35 year, at 1,475 MWe and a capacity factor of 89 percent based on a 2007–2009 average 

36 (Entergy 2011a). Thus, GGNS’s generating capacity avoids the release of approximately 

37 6.4 million tons (5.8 million metric tons) of CO2e. This is approximately 23.5 percent of the 

38 27.0 million tons (24.5 million metric tons) CO2e emitted by fossil fuel electricity generation in 

39 Mississippi in 2009 (EPA 2012a). This also equals about 0.08 percent of total U.S. GHG 

40 emissions of 7,520 million tons (6,822 million metric tons) CO2e, in 2010 (EPA 2012b).

41 The Intergovernmental Panel on Climate Change (IPCC 2011) also estimated GHG emission 

42 factors during the life cycle of nuclear power plants along with other renewable and conventional 

43 power generation technologies. Estimated median GHG emission factors of 16 g CO2e/kWh for 

44 nuclear energy are comparable to those for renewable energy (ranging from 4 g CO2e/kWh for 

45 hydropower to 46 g CO2e/kWh for photovoltaic solar energy) but far lower than those for fossil 

46 fuel energy (ranging from 469 g CO2e/kWh for natural gas to 1,001 g CO2e/kWh for coal).

47 Entergy did not report any foreseeable projects that could contribute to cumulative impacts to air 

48 quality (Entergy 2011a). If a project with the potential to affect air quality did occur, permitting 
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1 and licensing requirements would limit its impact. The review of the GGNS Unit 3 combined 

2 license (COL) application is currently on hold. However, if the facility were to be built in the 

3 future, impacts on air quality that may result from construction will be temporary. The impacts of 

4 construction on air quality would be from ground-clearing, grading and excavation activities that 

5 raise dust, emissions from construction equipment, and emissions resulting from construction 

6 workforce transportation. The impacts of operation on air quality would be from releases to the 

7 environment of heat and moisture from the cooling towers, emissions from operation of auxiliary 

8 equipment, and emissions from the workforce. The operation of Unit 3 would have air 

9 emissions similar to those of the existing GGNS plant. NRC (2006) concluded that the impacts 

10 of construction and operation of a proposed unit would be SMALL. 

11 As discussed in Section 2.2.2, patterns of ambient temperature and precipitation at Jackson 

12 International Airport generally are increasing slowly based on data from 1960 to 2011 

13 (NCDC 1990, 2012). Recent research on climate change effects in the United States done by 

14 the U.S. Global Change Research Program (USGCRP), a Federal Advisory Committee 

15 (USGCRP 2009), was considered in preparation of this document. In the near term (2010–2029

16 projected average change), which includes the first 5 years of the period of extended operation, 

17 the temperatures around GGNS are projected to rise an additional 2–3 °F (1.1–1.7 °C), 

18 compared to the recent past (1961–1979). In 2040–2059, which includes the last 5 years of the 

19 period of extended operation, the temperatures around GGNS are projected to rise an additional 

20 3–4 °F (1.7–2.2 °C) compared to the recent past. Over the past 50 years, average precipitation 

21 around GGNS has increased about 5–10 percent. Future changes in total precipitation are 

22 more difficult to project than those in temperatures, but models generally predict that in the 

23 Southeast region of the United States, encompassing GGNS, precipitation rates will decrease in 

24 winter, spring, and summer relative to current precipitation rates (USGCRP 2009). During the 

25 past 50 years, more severe weather, such as tornadoes and severe thunderstorms, has been 

26 reported. This increase is widely believed to be due to improvements in monitoring 

27 technologies such as Doppler radars combined with changes in population and increasing 

28 public awareness. Considering these factors, there is no clear trend in the frequency or 

29 strength of tornadoes since the 1950s in the United States as a whole. The power and 

30 frequency of Atlantic hurricanes has increased in recent decades, and the intensity of these 

31 storms is likely to increase in this century. However, an increase in the frequency of hurricanes 

32 making landfall has not been observed in recent decades; therefore, there may not necessarily 

33 be an increase in the number of these storms that make landfall in the future (USGCRP 2009). 

34 Changes in hurricanes are difficult to project because many countervailing forces are involved.

35 Given that there is no planned site refurbishment associated with the GGNS license renewal 

36 and, therefore, no additional air emissions beyond those noted in Section 2.2.2.1 from continued 

37 operations of GGNS, the incremental impacts to cumulative air quality impacts near GGNS 

38 would be SMALL. Although not identified, other reasonably foreseeable projects could result in 

39 cumulative impacts to air quality. However, permitting and licensing requirements and various 

40 mitigation measures likely would limit air quality impacts such that air quality continues to meet 

41 applicable air quality standards.

42 Based on the above discussion, the staff concludes that combined with the emissions from 

43 other past, present, and reasonably foreseeable future actions, cumulative impacts on ambient 

44 air quality and global climate change from operations at GGNS would be SMALL. 

45 4.12.2 Water Resources

46 This section addresses the direct and indirect effects of license renewal on water resources 

47 when added to the aggregate effects of other past, present, and reasonably foreseeable future 

48 actions. The geographic area considered in the cumulative aquatic resources analysis includes
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1 the vicinity of GGNS, including the Mississippi River basin near GGNS. As described in 

2 Sections 4.4 and 4.5, the incremental impacts on water resources from continued operation of 

3 GGNS during the license renewal term would be SMALL. 

4 4.12.2.1 Cumulative Impacts on Surface Water Resources

5 The review of the GGNS Unit 3 COL application is currently on hold. However, this facility, if 

6 built in the future, has the potential to influence surface water use and availability within the 

7 geographic area. NRC (2006) determined that the normal makeup flow rate of the new nuclear 

8 facility would be approximately 3,175 L/s (50,320 gpm), and the maximum expected makeup 

9 flow would be 5,400 L/s (85,000 gpm). In addition, approximately 25 percent of this water would 

10 be returned to the Mississippi River as blowdown. NRC (2006) concluded that a new nuclear 

11 unit would withdraw only a small amount of water relative to the total river flow (about 0.2 

12 percent) at even the lowest minimum river discharge conditions recorded for the area. Climate 

13 patterns and increased water demands upstream of GGNS, also may increase the number of 

14 water users and rate of withdrawal from the Mississippi River (Caffey et al. 2002). Continued

15 regulation of the flow by the U.S. Army Corps of Engineers is expected to preserve the course 

16 and flow of the Mississippi River. Building and operating a new nuclear unit and other activities 

17 beyond GGNS would not be expected to noticeably alter water resources within the Mississippi 

18 River because the Mississippi River is an abundant source of surface water. 

19 Similar to surface water use and availability, the proposed new nuclear unit at GGNS has 

20 potential to influence surface water quality within the geographic area considered because the 

21 proposed new unit would discharge into the Mississippi River. However, the flow of water in the 

22 Mississippi River is so large that a new reactor is unlikely to change the river’s basic water 

23 quality. As discussed in Section 4.12.3.2, historically the Mississippi River has experienced 

24 decreased water quality from other land-use activities such as agriculture, industrial 

25 development, and urban sprawl. However, with the implementation of the Clean Water Act, the 

26 water quality of the past few decades has progressively improved. In addition, the proposed 

27 new units and other water discharges in the area would obtain and comply with its NPDES

28 permit, which would define the limits of certain chemical and thermal properties of the 

29 discharge. 

30 Therefore, the staff concludes that the cumulative impact on the site’s surface water use and 

31 quality are SMALL. 

32 4.12.2.2 Cumulative Impacts on Groundwater Resources

33 Activities that could potentially impact groundwater use in the area of interest include public 

34 water supply companies, the construction and operating of the proposed new nuclear reactor, 

35 and continued operations of GGNS. Most groundwater users outside of the GGNS site obtain 

36 their water from public water supply companies that get their water from deep aquifers 

37 (Catahoula Aquifer and deeper aquifer). The public water supply companies distribute the water 

38 to customers via buried pipes and this operation is expected to continue for the reasonably 

39 foreseeable future. The existing unit and the new nuclear unit proposed in the COL application 

40 (review currently on hold) at GGNS have the potential to influence groundwater use within the 

41 geographic area considered. However, it is expected the future reactor would not consume 

42 groundwater from the deep underlying aquifers (GGNS 2008a) used by the public water supply 

43 companies, similar to the existing unit at GGNS. Instead, makeup water and potable water for

44 the new reactor would be drawn from groundwater near surface aquifers that either have a 

45 direct or indirect hydraulic connection to the Mississippi River. These aquifers near GGNS are 

46 not connected to the deep aquifers. In addition, abundant water supplies exist from the deeper 

47 aquifer accessed by the water supply companies to supply the needs of other future land-use 

48 activities in the area. 
Environmental Impacts of Operation

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1 Activities that could potentially impact groundwater quality in the area of interest include the 

2 construction and operation of the proposed new nuclear reactor, continued operations of GGNS, 

3 and other land use actions that could result in contaminants reaching groundwater. However, 

4 the groundwater quality of aquifers used as a source of public water is not likely to be noticeably 

5 altered by present and future activities at GGNS or in the region. This is due to the large 

6 thickness of low permeability geologic deposits that overly (i.e. protect) these aquifers from 

7 surface contaminants. In addition, as discussed in Section 2.2.5, the EPA has identified the 

8 Catahoula Aquifer as a sole source aquifer and will work to protect the deep groundwater 

9 resources from contamination from projects that receive federal financial assistance. As such, 

10 the MDEQ’s Wellhead Protection Program will manage potential present and future sources of 

11 contamination that are located near public water supply wells that obtain water from the 

12 Catahoula Aquifer. No activities have been identified at or near GGNS that could impact the 

13 quality of the Catahoula and deeper aquifers. These regulatory programs are expected to 

14 continue to protect groundwater quality from future land-use activities. 

15 Therefore, the staff concludes that the cumulative impact on the site’s ground water use and 

16 quality are SMALL. 

17 4.12.3 Aquatic Resources

18 This section addresses the direct and indirect effects of license renewal on aquatic resources, 

19 including protected aquatic species, when added to the aggregate effects of other past, present, 

20 and reasonably foreseeable future actions. The cumulative impact is the total effect on the 

21 aquatic resources of all actions taken, no matter who has taken the actions. The geographic 

22 area considered in the cumulative aquatic resources analysis includes the vicinity of GGNS, 

23 including the Mississippi River basin near GGNS and on site aquatic features such as Hamilton 

24 and Gin Lakes, the borrow pit, three small ponds, streams “A” and “B,” and ephemeral 

25 drainages. Consistent with other agencies use of the term “baseline” and CEQ’s NEPA

26 guidance, the term “baseline” pertains to the condition of the resource without the action, i.e., 

27 under the no-action alternative. Under the no action alternative, the plant would shut down and 

28 the resource would conceptually return to its condition without the plant (which is not necessarily 

29 the same as the condition before the plant was constructed). The baseline, or benchmark, for 

30 assessing cumulative impacts on aquatic resources takes into account the pre-operational 

31 environment as recommended by the EPA (1999) for its review of NEPA documents:

32 Designating existing environmental conditions as a benchmark may focus the 

33 environmental impact assessment too narrowly, overlooking cumulative impacts 

34 of past and present actions or limiting assessment to the proposed action and 

35 future actions. For example, if the current environmental condition were to serve 

36 as the condition for assessing the impacts of relicensing a dam, the analysis 

37 would only identify the marginal environmental changes between the continued 

38 operation of the dam and the existing degraded state of the environment. In this 

39 hypothetical case, the affected environment has been seriously degraded for 

40 more than 50 years with accompanying declines in flows, reductions in fish 

41 stocks, habitat loss, and disruption of hydrologic functions. If the assessment 

42 took into account the full extent of continued impacts, the significance of the 

43 continued operation would more accurately express the state of the environment 

44 and thereby better predict the consequences of relicensing the dam. 

45 Sections 2.2.6 and 2.2.8 present an overview of the conditions of the Mississippi River basin 

46 near GGNS and the history and factors that led to its current condition. Since the 1700s, efforts 

47 to control flooding and increase navigation along the Mississippi River have changed the 

48 relative abundance of various habitats within the river. In addition, levees have decreased the 

49 connectivity of aquatic life within floodplain habitats and the Mississippi River because of the 
Environmental Impacts of Operation

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1 decrease in flooding events when biota can move in between floodplain habitats and the river. 

2 In addition to physical changes to aquatic habitat, runoff has led to habitat degradation and 

3 decreased water quality. Land use changes within the Mississippi River basin have introduced 

4 new industrial and chemical inputs into the river (Brown et al. 2005). The introduction of 

5 non-native species also has threatened many protected, native species near GGNS. As 

6 described in Section 2.2.6.2, the staff compared aquatic surveys from 1972 through 1974 with 

7 surveys from 2006 through 2008 (FishNet 2012). Of the 25 species recorded in the earlier 

8 surveys, 8 species (32 percent) were collected and 17 species (68 percent) were not collected 

9 in the later surveys (FishNet 2012). These results indicate that many species that once 

10 inhabitated the Mississippi River may no longer exist near GGNS. 

11 Many natural and human activities can influence the current and future aquatic life in the area 

12 surrounding GGNS. Potential biological stressors include continued potential thermal stress 

13 from GGNS as described in Section 4.8.2.5; modifications to the Mississippi River; runoff from 

14 industrial, agricultural, and urban areas; other water users and dischargers; and, climate 

15 change, as described in Section 4.12.3.4. 

16 4.12.3.1 Modifications to the Mississippi River 

17 The relative abundance of hard substrate, deep channel, and river bank habitat has been 

18 largely influenced by human activities to decrease flooding events and increase navigability. 

19 The U.S. Army Corps of Engineers (USACE) and Mississippi River Commission continue to 

20 oversee a comprehensive river management program that includes: 

21 • levees for containing flood flows; 

22 • floodways for the passage of excess flows past critical reaches of the 

23 Mississippi River; 

24 • channel improvement and stabilization to provide an efficient and reliable 

25 navigation channel, increase the flood-carrying capacity of the river, and 

26 protect the levee system; and, 

27 • tributary basin improvements for major drainage basins to include dams and 

28 reservoirs, pumping plants, auxiliary channels and pumping stations 

29 (MRC 2012).

30 Implementing this management program will continue to affect the relative availability of aquatic 

31 habitats, resulting in, for example, a decrease in the amount of soft sediment river bank habitat 

32 and an increase in the amount of hard substrates (e.g., riprap or other materials used to line the 

33 river bank). Consequently, invertebrates that depend on a hard surface for attachment, and can 

34 colonize human-made materials, such as tires, concrete, or riprap used to line river banks, likely 

35 will continue to increase in relative abundance as compared to species that require soft 

36 sediments along the river bank. 

37 The Mississippi River Commission also implements various programs to support the 

38 sustainability of aquatic life within the Mississippi River. For example, the Davis Pond and 

Caernarvon freshwater diversion structures divert more than 18,000 ft3

/s (510 m3 39 /s) of fresh 

40 water to coastal marshlands. The input of freshwater helps to preserve the marsh habitat and 

41 reduce coastal land loss (MRC 2012). In addition, the Mississippi River Commission conducted 

42 research and determined that using grooved articulated concrete mattresses to line river banks 

43 can help support benthic invertebrate and fish populations. For example, using grooved 

44 articulated concrete mattresses increases larval insect production, which is an important source 

45 of prey for many fish (MRC 2012). 
Environmental Impacts of Operation

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1 4.12.3.2 Runoff from Industrial, Agricultural, and Urban Areas 

2 Nearly 40 percent of the land within the contiguous United States drains into the Mississippi 

3 River. Land use changes and industrial activities within this area have had a substantial impact 

4 on aquatic habitat and water quality within the Mississippi River. For example, historically, the 

5 Mississippi River has experienced decreased water quality as a result of industrial discharges, 

6 agricultural runoff, municipal sewage discharges, surface runoff from mining activity, and 

7 surface runoff from municipalities. However, over the past few decades, water quality within the 

8 Mississippi River has improved because of the implementation of the Clean Water Act and other 

9 environmental regulations (Caffey et al. 2002). For example, most of the older, first-generation 

10 chlorinated insecticides have been banned since the late 1970s. Similarly, the addition and 

11 upgrading of numerous municipal sewage treatment facilities, rural septic systems, and animal 

12 waste management systems have helped to significantly decrease the concentration of median 

13 fecal coliform bacteria in the Mississippi River (Caffey et al. 2002). Despite the trend of 

14 improving water quality within the Mississippi River, trace levels of some contaminants and 

15 increased nutrients from agricultural lands remain a source of concern for aquatic life (Caffey et 

16 al. 2002; Rabalais et al. 2009).

17 4.12.3.3 Other Water Users and Discharges 

18 Several other currently existing and proposed facilities withdraw water from the Mississippi 

19 River. For example, Entergy previously proposed to build a new nuclear reactor at the GGNS 

20 site, which would withdraw water from the Mississippi River as a source of cooling water 

21 (NRC 2006). In addition, climate patterns and increased water demands upstream of GGNS 

22 also may increase the number of water users and rate of withdrawal from the Mississippi River 

23 (Caffey et al. 2002). Aquatic life, especially threatened and endangered species, rely on 

24 sufficient flow within streams and rivers to survive. Also, fish and other aquatic life could be 

25 impinged and entrained within the new nuclear unit and other facility water intake systems. 

26 Entergy proposed to use a closed-cycle cooling system, which would minimize impingement

27 and entrainment (NRC 2006). In addition, as described in Section 4.12.3.1, continued 

28 regulation of the flow by the U.S. Army Corps of Engineers is expected to preserve the course 

29 and flow of the Mississippi River. Building and operating a new nuclear unit and other activities 

30 beyond GGNS would not be expected to noticeably alter aquatic resources within the 

31 Mississippi River. 

32 A new reactor at GGNS and other water users along the Mississippi River also would discharge

33 cooling water and other effluents into the Mississippi River. NRC (2006) considered the impacts 

34 to aquatic resources from discharge of heated effluent (e.g., water temperature, dissolved 

35 oxygen, thermal stratification, impact to fauna), cold shock, and chemical treatment of the 

36 cooling water and determined that the effluent would not noticeably alter aquatic resources. 

37 Additionally, Entergy and other water dischargers would be required to comply with NPDES

38 permits that must be renewed every 5 years, allowing MDEQ to ensure the permit limits provide 

39 the appropriate level of environmental protection. 

40 4.12.3.4 Climate change 

41 Climate change could noticeably alter aquatic resources near GGNS. In the southeastern 

42 United States, precipitation during the fall has increased 30 percent from 1901 to 2007 and the 

43 overall amount of heavy downpours also has increased (USGCRP 2009). Heavy downpours 

44 can increase the rate of runoff and pollutants reaching the Mississippi River because the 

45 heavier precipitation, and the pollutants washed away in the runoff, have less time to be 

46 absorbed in the soil before reaching the river and other surface waterbodies. Climate change 

47 models predict continued increases in heavy downpours in the southeastern United States. 
Environmental Impacts of Operation

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1 Climate models also predict increasing temperatures in the southeast, especially during spring 

2 and summer (USGCRP 2009). Increased temperatures and nutrients in runoff could lead to a 

3 decline in oxygen within small streams, lakes, and shallow aquatic habitats. During periods of 

4 low oxygen, many fish and other aquatic life may not be able to survive. Increased 

5 temperatures also may increase the frequency of shellfish-borne illness, alter the distribution of 

6 native fish, increase the local loss of threatened and endangered species, and increase the 

7 displacement of native species by non-native species (USGCRP 2009).

8 Since the 1970s, there has been an increase in the amount of moderate to severe drought, 

9 especially during spring and summer. Climate models predict a continued increase in the 

10 amount and severity of droughts, which can lead to water use conflicts (USGCRP 2009). 

11 Regulatory programs will be required to ensure sufficient water and flow is available within 

12 surface waterbodies to provide habitat for aquatic life, especially threatened and endangered 

13 species. 

14 4.12.3.5 Conclusion 

15 The direct and indirect impacts to aquatic resources from historical Mississippi River 

16 modifications and pollutants and sediments introduced into the river have had a substantial 

17 effect on aquatic life and their habitat. The incremental impacts from GGNS are SMALL for 

18 aquatic resources because GGNS operation would have minimal impacts on aquatic life due to

19 use of a closed-cycle cooling system and Ranney wells. The cumulative stress from the 

20 activities described above, spread across the geographic area of interest depends on many 

21 factors that the NRC staff cannot quantify. This stress may noticeably alter some aquatic 

22 resources. For example, climate change may increase the temperature of the Mississippi River 

23 and rate of runoff into the river. This may noticeably alter the habitat for species most sensitive 

24 to nutrient loading, high levels of contaminants, and higher temperatures. In addition, a 

25 comparison of fish surveys from 1972 through 1974 and from 2006 through 2008 suggests that 

26 some species no longer inhabitate the Mississippi River near GGNS (FishNet 2012). Therefore, 

27 the staff concludes that the cumulative impacts from the proposed license renewal and other 

28 past, present, and reasonably foreseeable projects would be MODERATE. 

29 4.12.4 Terrestrial Resources

30 This section addresses past, present, and future actions that could result in cumulative impacts 

31 on the terrestrial species and habitats described in Section 2.2.7, including protected terrestrial 

32 species. For purposes of this analysis, the geographic area considered in the evaluation 

33 includes the GGNS site and the in-scope transmission line corridors. As explained for aquatic 

34 resources, the baseline for this assessment is the condition of the resource without the action, 

35 i.e., under the no-action alternative. 

36 4.12.4.1 Historic Conditions 

37 Section 2.2.7 discusses the ecoregions in which the GGNS site lies—the Mississippi Valley 

38 Alluvial Plain and Mississippi Valley Loess Plain. This region consists of irregular plains with a 

39 thick layer of highly erodible loess deposits, oak-hickory and oak-hickory-pine forests, and 

40 streams with low gradients and silty substrates. When GGNS was built, forests and agriculture 

41 were the dominant land types. Between 1973 and 2000, agricultural lands decreased by 

42 6.8 percent, while developed land increased by 4.0 percent (USGS 2001). Forested land 

43 remained relatively constant and accounted for 43 to 44 percent of land cover over the time 

44 period (USGS 2001).

45 On the immediate site, Mississippi Power & Light Company cleared about 270 ac (109 ha) of 

46 upland habitat for GGNS buildings and related infrastructure. The terrestrial habitats on the 
Environmental Impacts of Operation

4-39

1 undeveloped portions of the site have not changed significantly since GGNS’s construction 

2 (Entergy 2011a). The two primary habitat changes between preconstruction and present day 

3 are in the bottomland scrub-shrub wetlands (east of Gin Lake) and the upland open fields and 

4 clearings, in which Entergy has planted American sycamore (Platanus occidentali) and loblolly 

5 pine (Pinus taeda), respectively.

6 4.12.4.2 GGNS Unit 3 

7 The review of the GGNS Unit 3 COL application is currently on hold. However, if the facility 

8 were to be built in the future, Entergy (2011a) anticipates that onsite land disturbance would be 

9 primarily limited to previously disturbed areas of the site. GGNS Unit 3 may require the 

10 construction of new transmission lines. The impacts from such construction would vary 

11 depending on the types of habitat the lines would cross and whether such transmission lines are 

12 routed along existing transmission line corridors. Terrestrial resource impacts resulting from 

13 operation of GGNS Unit 3 would be similar to impacts of operation of GGNS and would be 

14 SMALL.

15 4.12.4.3 Agricultural Runoff 

16 Within Claiborne County, 531 ac (126,073 ha) of land were used for cultivation of major crops 

17 as of 2006 (NRC 2006). The 2000 National Water Quality Inventory reported that agricultural 

18 nonpoint source pollution accounted for the second largest source of impairments to wetlands 

19 (EPA 2012a). Fertilizers and pesticides can affect wetlands and bottomlands in a variety of 

20 ways. Because wetlands and bottomlands are often at lower elevation than surrounding land, 

21 these habitats receive much of the runoff first, and that runoff persists because it is unable to 

22 drain to lower ground. This can result in bioaccumulation of pollutants and changes to species 

23 composition and abundance. Species that rely on wetlands, such as birds and amphibians, are 

24 more sensitive to these environmental stressors than other animal groups.

25 4.12.4.4 National Forests 

26 The Franklin transmission line crosses through the Homochitto National Forest to the southeast 

27 of the GGNS site. This national forest will continue to provide valuable habitat to native wildlife 

28 and migratory birds during the proposed license renewal period. As habitat fragmentation 

29 resulting from various types of development increases, these areas will become ecologically 

30 more important because they will provide large areas of natural habitat.

31 4.12.4.5 Climate Change 

32 Since 1970, the average annual temperature in the southeastern United States has risen by 

33 about 2 °F (1.1 °C) and the number of freezing days has declined by 4 to 7 days per year 

34 (USGCRP 2009). Over the next several decades, the U.S. Global Change Research Program 

35 (USGCRP 2009) estimates that the average temperatures in the region will rise by an additional 

36 4.5 °F (2.5 °C). The Gulf Coast states, including Mississippi, will have less rainfall in winter and 

37 spring, and higher temperatures will increase the frequency, duration, and intensity of drought. 

38 Hurricane intensity also will likely increase (USGCRP 2009). Changes in the climate will shift 

39 many wildlife population ranges and alter migratory patterns. Such changes could favor 

40 non-native invasive species and promote population increases of insect pests and plant 

41 pathogens. Climate change will likely alter the severity or frequency of precipitation, flooding, 

42 and fire. Climate change may also exacerbate the effects of existing stresses in the natural 

43 environment, such as those caused by habitat fragmentation, invasive species, nitrogen 

44 deposition and runoff from agriculture, and air emissions.
Environmental Impacts of Operation

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1 4.12.4.6 Conclusion 

2 Section 4.7 of this SEIS concludes that the impact from the proposed license renewal would not 

3 noticeably alter the terrestrial environment, and, thus, would be SMALL. However, as 

4 environmental stressors such as agricultural runoff and climate change continue over the 

5 proposed license renewal term, certain attributes of the terrestrial environment (such as species 

6 diversity and distribution) are likely to noticeably change. The staff does not expect these 

7 impacts to destabilize any important attributes of the terrestrial environment because such 

8 impacts will cause gradual change, which should allow the terrestrial environment to 

9 appropriately adapt. The staff concludes that the cumulative impacts of the proposed license 

10 renewal of GGNS plus other past, present, and reasonably foreseeable future projects or 

11 actions would result in MODERATE impacts to terrestrial resources. 

12 4.12.5 Human Health 

13 The NRC and EPA have developed radiological dose limits for protection of the public and 

14 workers to address the cumulative impact of acute and long-term exposure to radiation and 

15 radioactive material. These dose limits are codified in 10 CFR Part 20 and 40 CFR Part 190. 

16 For the purpose of this analysis, the area within a 50-mi (80-km) radius of GGNS was included. 

17 The radiological environmental monitoring program Entergy conducted in the vicinity of the 

18 GGNS site measures radiation and radioactive materials from all sources (i.e., hospitals and 

19 other licensed users of radioactive material); therefore, the monitoring program measures 

20 cumulative radiological impacts. There currently are no other nuclear power reactors or 

21 uranium fuel cycle facilities within the 50-mi (80-km) radius of the GGNS site. 

22 Radioactive effluent and environmental monitoring data for the 5-year period from 2008 to 2012 

23 were reviewed as part of the cumulative impacts assessment. In Section 4.9.1 of this SEIS, the 

24 staff concluded that impacts of radiation exposure to the public and workers (occupational) from 

25 operation of GGNS during the renewal term are SMALL. The NRC and the State of Mississippi 

26 would regulate any future actions in the vicinity of the GGNS site that could contribute to 

27 cumulative radiological impacts.

28 Entergy constructed an independent spent fuel storage installation (ISFSI) on the GGNS site in 

29 2000 for the storage of its spent fuel. The installation and monitoring of this facility is governed 

30 by NRC requirements in 10 CFR Part 72, “Licensing Requirements for the Independent Storage 

31 of Spent Nuclear Fuel, High-Level Radioactive Waste, and Reactor–Related Greater Than 

32 Class C Waste.” Radiation from this facility, as well as from the operation of GGNS, is required 

33 to be within the radiation dose limits in 10 CFR Part 20, 40 CFR Part 190, and 10 CFR Part 72. 

34 The NRC carries out periodic inspections of the ISFSI to verify its compliance with its licensing 

35 and regulatory requirements.

36 In September 2010, Entergy applied to the NRC for an extended power uprate (EPU). In 

37 July 2012, the NRC issued an amendment approving the power increase (NRC 2012j). The 

38 staff considered the environmental impacts of the EPU in this evaluation.

39 As discussed in Section 4.12, review of the application for the proposed new nuclear reactor

40 designated as GGNS Unit 3 is on hold. However, GGNS Unit 3 is considered in the cumulative 

41 impacts section since it is a reasonable and foreseeable future action.

42 The cumulative radiological impacts from GGNS Unit 1, the ISFSI, and the proposed GGNS 

43 Unit 3, would be required to meet the radiation dose limits in 10 CFR Part 20 and 

44 40 CFR Part 190. For these reasons, the staff concludes that cumulative radiological impacts 

45 would be SMALL.
Environmental Impacts of Operation

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1 4.12.6 Socioeconomics 

2 This section addresses socioeconomic factors that have the potential to be affected directly or 

3 indirectly by changes in operations at GGNS in addition to the aggregate effects of other past, 

4 present, and reasonably foreseeable future actions. The primary geographic area of interest 

5 considered in this cumulative analysis is Claiborne, Hinds, Jefferson, and Warren Counties

6 where approximately 81 percent of GGNS employees reside (see Table 2–7). This is where the 

7 economy, tax base, and infrastructure most likely would be affected since GGNS workers and 

8 their families reside, spend their income, and use their benefits within these counties.

9 As discussed in Section 4.10 of this SEIS, continued operation of GGNS would have no impact 

10 on socioeconomic conditions in the region during the license renewal term beyond what is 

11 already being experienced. Since Entergy has no plans to hire additional non-outage workers 

12 during the license renewal term, overall expenditures and employment levels at GGNS are 

13 expected to remain relatively unchanged with no additional or increased demand for permanent 

14 housing and public services. In addition, since employment levels and tax payments would not 

15 change, there would be no population or tax revenue-related land use impacts. Based on this 

16 and other information presented in Chapter 4 of this SEIS, there would be no contributory effect 

17 from the continued operation of GGNS on socioeconomic conditions in the region beyond what 

18 is currently being experienced. The only cumulative contributory effects would come from the 

19 other planned activities in the region independent of GGNS operations. Therefore, the staff 

20 concludes that the cumulative socioeconomic impacts would be SMALL.

21 4.12.6.1 Environmental Justice 

22 The environmental justice cumulative impact analysis assesses the potential for 

23 disproportionately high and adverse human health and environmental effects on minority and 

24 low-income populations that could result from past, present, and reasonably foreseeable future 

25 actions including GGNS operations during the renewal term. Adverse health effects are 

26 measured in terms of the risk and rate of fatal or nonfatal adverse impacts on human health. 

27 Disproportionately high and adverse human health effects occur when the risk or rate of 

28 exposure to an environmental hazard for a minority or low-income population is significant and 

29 exceeds the risk or exposure rate for the general population or for another appropriate 

30 comparison group. Disproportionately high environmental effects refer to impacts or risk of 

31 impact on the natural or physical environment in a minority or low-income community that are 

32 significant and appreciably exceed the environmental impact on the larger community. Such 

33 effects may include biological, cultural, economic, or social impacts. Some of these potential 

34 effects have been identified in resource areas presented in Chapter 4 of this SEIS. Minority and 

35 low-income populations are subsets of the general public residing in the area and all would be 

36 exposed to the same hazards generated from GGNS operations. As previously discussed in 

37 this chapter, the impact from license renewal for all resource areas (e.g., land, air, water, 

38 ecology, and human health) would be SMALL.

39 As discussed in Section 4.10.7 of this SEIS, there would be no disproportionately high and 

40 adverse impacts to minority and low-income populations from the continued operation of GGNS 

41 during the license renewal term. Since Entergy has no plans to hire additional non-outage 

42 workers during the license renewal term, employment levels at GGNS are expected to remain 

43 relatively unchanged with no additional or increased demand for housing or increased traffic. 

44 Based on this information and the analysis of human health and environmental impacts 

45 presented in Chapters 4 and 5, it is not likely there would be any disproportionately high and 

46 adverse contributory effect on minority and low-income populations from the continued 

47 operation of GGNS during the license renewal term.
Environmental Impacts of Operation

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1 4.12.7 Historic and Archaeological Resources

2 This section addresses the direct and indirect effects of license renewal on historic and cultural 

3 resources, in and around GGNS, when added to the aggregate effects of other past, present, 

4 and reasonably foreseeable actions. Section 2.2.10 discusses the cultural background and 

5 known historic and archaeological resources in and around GGNS. 

6 As described in Section 4.10.6, the NRC staff concluded that license renewal would have a 

7 SMALL impact on historic and cultural resources at GGNS. However, any future 

8 ground-disturbing maintenance and operations activities during the license renewal term could 

9 affect undiscovered historic and archaeological resources. In addition, future construction and 

10 operation of a new nuclear power plant site at GGNS would have the potential to result in 

11 impacts on cultural resources through inadvertent discovery during ground-disturbing activities. 

12 Future urbanization near GGNS could also affect historic and archaeological resources.

13 Given the high potential for historic and archaeological resources to be present at GGNS, as 

14 well as the existing historic and archaeological resources presented in Section 2.2.10.2, GGNS 

15 has procedures regarding protection of cultural resources. Any ground-disturbing maintenance 

16 and operations activities during the GGNS license renewal term or construction of a new 

17 nuclear power plant would be reviewed in accordance with these procedures. These 

18 procedures are designed to ensure that investigations and consultations are conducted as 

19 needed and that existing or potentially existing cultural resources are adequately protected. 

20 Should historic or archaeological resources be encountered during construction, work would 

21 cease until Entergy environmental personnel would perform an evaluation and consider possible 

22 mitigation measures through consultation with the Mississippi SHPO. Any future urbanization

23 that might directly or indirectly affect historic or archaeological resources (i.e. inadvertent 

24 discovery, viewshed impacts) would be required to comply with applicable State and Federal 

25 laws regarding protection of cultural and archaeological resources, and any impacts would be 

26 mitigated accordingly.

27 Based on this information, the NRC staff finds that the continued operation of GGNS during the 

28 license renewal term would not incrementally contribute to cumulative impacts on historic and 

29 archaeological resources within GGNS and in the surrounding area. Therefore, the cumulative 

30 impact on historic and archaeological resources during the license renewal term would be 

31 SMALL.

32 4.12.8 Summary of Cumulative Impacts

33 The staff considered the potential impacts resulting from the operation of GGNS during the 

34 period of extended operation and other past, present, and reasonably foreseeable future actions 

35 near GGNS. The preliminary determination is that the potential cumulative impacts would range 

36 from SMALL to LARGE, depending on the resource. Table 4–10 summarizes the cumulative 

37 impacts on resources areas.
Environmental Impacts of Operation

4-43

1 Table 4–10. Summary of Cumulative Impacts on Resource Areas

Resource area Cumulative impact

Air Quality

Considering the distances to the nearest nonattainment and maintenance areas around 

GGNS, prevailing wind directions, and the minor nature of air emissions from GGNS, 

emissions from GGNS operations are not anticipated to affect current attainment or 

maintenance area status. Accordingly, air emissions from continued operation of the 

plant and associated impacts on ambient air quality would not be expected to change 

during the license renewal term.

Based on the above discussion, the NRC staff concludes that combined with the 

emissions from other past, present, and reasonably foreseeable future actions, 

cumulative impacts on ambient air quality and global climate change from operations at 

GGNS would be SMALL. 

Water Resources

The watersheds contributing flow to the two streams on the GGNS site are nearly 

contained within the site, and the remaining drainage area outside the site area would 

not be expected to change significantly. Therefore, changes in surface water supply 

outside the site would not alter the surface water conditions of the site’s two streams. 

No activity at the GGNS site by itself, nor other activities outside the site, would be 

expected to alter fundamentally the character of the Mississippi River. The cumulative 

impacts from past, present, and reasonably foreseeable future actions on surface water 

resources during the license renewal term would be SMALL. 

In the region around GGNS, public water is obtained from deep underlying aquifers. 

Past, present and future activities at the GGNS site have not and will not use these 

aquifers as a source of water. Throughout the region, the groundwater quality of the 

deep underlying aquifers is protected from land-use activities by thick layers of low 

permeability geologic deposits and by government regulatory programs. The 

cumulative impact on groundwater use will be SMALL because abundant good water 

quality groundwater is and will continue to be readily available for public use.

Based on the above considerations, the cumulative impacts from past, present, and 

reasonably foreseeable future actions on groundwater resources during the license 

renewal term would be SMALL.

Aquatic Ecology

The direct and indirect impacts to aquatic resources from historical Mississippi River 

modifications and pollutants and sediments introduced into the river have had a 

substantial effect on aquatic life and their habitat. The incremental impacts from GGNS 

are SMALL for aquatic resources because GGNS uses a closed-cycle cooling system

and Ranney wells. The cumulative stress from the activities described in 

Section 4.12.3, spread across the geographic area of interest depends on many factors 

that NRC staff cannot quantify. This stress may noticeably alter some aquatic 

resources. The cumulative impacts from the proposed license renewal and other past, 

present, and reasonably foreseeable projects would be MODERATE.

Terrestrial 

Ecology

The NRC staff examined the cumulative effects of the construction of GGNS, 

agricultural runoff, nearby parks and conservation areas, and climate change. The 

NRC staff concludes that the minimal terrestrial impacts of continued GGNS operations 

would not contribute to the overall decline in the condition of terrestrial resources. The 

NRC staff believes that the cumulative impacts of other and future actions during the 

term of license renewal on terrestrial habitat and associated species, when added to 

past, present, and reasonably foreseeable future actions, would be MODERATE.
Environmental Impacts of Operation

4-44

Resource area Cumulative impact

Human Health

The radiological dose limits for protection of the public and workers have been 

developed by the NRC and EPA to address the cumulative impact of acute and 

long-term exposure to radiation and radioactive material. The NRC and the State of 

Mississippi would regulate any future actions in the vicinity of the GGNS site that could 

contribute to cumulative radiological impacts. In addition, the cumulative radiological 

impacts from operation of GGNS, the ISFSI, and a projected additional reactor unit

would be required to meet the radiation dose limits in 10 CFR Part 20 and 

40 CFR Part 190. For these reasons, cumulative radiological impacts would be 

SMALL.

Socioeconomics

As discussed in Section 4.10, continued operations during the license renewal term 

would have no impact on socioeconomic conditions in the region beyond those already 

being experienced. In addition, there would be no disproportionately high and adverse 

impacts to minority and low-income populations from the continued operations during 

the license renewal term. The cumulative effects on socioeconomic conditions and 

environmental justice populations in the region from past, present, and reasonably 

foreseeable future actions including continued operations combined with other planned 

activities in the region is not expected to increase appreciably beyond what is currently 

being experienced. Therefore, cumulative socioeconomic impacts would be SMALL.

Cultural 

Resources

As discussed in Section 4.10.6 of this SEIS, continued operation of GGNS during the 

license renewal term is likely to have a SMALL impact on historical or archaeological 

resources. Any future ground-disturbing activities may affect undiscovered historic and 

archaeological resources; however, any such activity would be reviewed in accordance 

with Entergy procedures designed to adequately protect historic and archaeological 

resources. Future urbanization would be governed by appropriate State and Federal 

laws to mitigate impacts on historic and archaeological resources. Therefore, the 

cumulative impacts on historic and archaeological resources during the license renewal 

term would be SMALL.

1 4.13 References

2 10 CFR Part 20. Code of Federal Regulations, Title 10, Energy, Part 20, “Standards for 

3 protection against radiation.”

4 10 CFR Part 50. Code of Federal Regulations, Title 10, Energy, Part 50, “Domestic licensing of 

5 production and utilization facilities.”

6 10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

7 protection regulations for domestic licensing and related regulatory functions.”

8 10 CFR Part 54. Code of Federal Regulations, Title 10, Energy, Part 54, “Requirements for 

9 renewal of operating licenses for nuclear power plants.”

10 40 CFR Part 81. Code of Federal Regulations, Title 40, Protection of the Environment, Part 81, 

11 “Designation of areas for air quality planning purposes.”

12 40 CFR Part 190. Code of Federal Regulations, Title 40, Protection of Environment, Part 190, 

13 “Environmental radiation protection standards for nuclear power operations.”

14 50 CFR Part 402. Code of Federal Regulations, Title 50, Wildlife and Fisheries, Part 402, 

15 “Interagency cooperation—Endangered Species Act of 1973, as amended.”
Environmental Impacts of Operation

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37 NRC, to S. Ricks, Mississippi Field Office, FWS. Subject: Request for list of protected species 

38 within the area under evaluation for the Grand Gulf Nuclear Station, Unit 1, license renewal 

39 application. January 20, 2012. ADAMS Accession No. ML12025A069.

40 [NRC] U.S. Nuclear Regulatory Commission. 2012c. Letter from D. Wrona, RPB2 Branch Chief, 

41 NRC, to D. Bernhart, Southeast Assistant Regional Administrator for Protected Resources, 

42 NMFS. Subject: Request for list of protected species within the area under evaluation for the 

43 Grand Gulf Nuclear Station, Unit 1, license renewal application. January 19, 2012. ADAMS 

44 Accession No. ML11350A173.
Environmental Impacts of Operation

4-49

1 [NRC] U.S. Nuclear Regulatory Commission. 2012d. Letter from D. Wrona, RPB2 Branch Chief, 

2 NRC, to S. Surrette, Mississippi Natural Heritage Program, Mississippi Department of Wildlife, 

3 Fisheries, and Parks. Subject: Request for list of protected species within the area under 

4 evaluation for the Grand Gulf Nuclear Station, Unit 1, license renewal application. 

5 January 20, 2012. ADAMS Accession No. ML11349A003.

6 [NRC] U.S. Nuclear Regulatory Commission. 2012e. Letter from D. Wrona, RPB2 Branch Chief, 

7 NRC, to C. Michon, Louisiana Natural Heritage Program, Louisiana Department of Wildlife and 

8 Fisheries. Subject: Request for list of protected species within the area under evaluation for the 

9 Grand Gulf Nuclear Station, Unit 1, license renewal application. February 6, 2012. ADAMS 

10 Accession No. ML12005A163.

11 [NRC] U.S. Nuclear Regulatory Commission. 2012f. Letter from D.J. Wrona, NRC, to R. 

12 Nelson, Advisory Council on Historic Preservation. Subject: Grand Gulf Nuclear Station License 

13 Renewal Environmental Review. January 19, 2012. ADAMS Accession No. ML11348A088. 

14 [NRC] U.S. Nuclear Regulatory Commission. 2012g. Letter from D.J. Wrona, NRC, to Phil 

15 Boggan, Office of Historic Preservation. Subject: Grand Gulf Nuclear Station License Renewal 

16 Environmental Review. January 20, 2012. ADAMS Accession No. ML11348A353.

17 [NRC] U.S. Nuclear Regulatory Commission. 2012h. Letter from D.J. Wrona, NRC, to H.T. 

18 Holmes, Mississippi Department of Archives and History. Subject: Grand Gulf Nuclear Station, 

19 Unit 1, License Renewal Environmental Review. January 19, 2012. ADAMS Accession No. 

20 ML11348A090.

21 [NRC] U.S. Nuclear Regulatory Commission. 2012i. Letters from D.J. Wrona, NRC, to Chief 

22 Gregory E. Pike, Choctaw Nation of Oklahoma; The Honorable Phyliss Anderson, Chief, 

23 Mississippi Band of Choctaw Indians; Chairman Earl J. Barbry Jr., Tunica-Biloxi Tribe of 

24 Louisiana; and Principal Chief B. Cheryl Smith, Jena Band of Choctaw Indians. Subject: 

25 Request for Scoping Comments Concerning the Grand Gulf Nuclear Station, Unit 1, License 

26 Renewal Application Review. January 19, 2012. ADAMS Accession No. ML11342A121.

27 [NRC] U.S. Nuclear Regulatory Commission. 2012j. Letter from A. B. Wang, NRC, to Vice

28 President, Operations, Entergy Operations, Inc., Subject: Grand Gulf Nuclear Station, Unit 1 -

29 Issuance of Amendment RE: Extended Power Uprage. July 18, 2012 (TAC No. ME4679) 

30 ADAMS Accession No. ML121210020.

31 [NRC] U.S. Nuclear Regulatory Commission. 2013a. Generic Environmental Impact Statement

32 for License Renewal of Nuclear Plants. Washington, DC: Office of Nuclear Reactor Regulation. 

33 NUREG-1437, Revision 1, Volumes 1, 2, and 3. June 2013. ADAMS Accession Nos. 

34 ML13106A241, ML13106A242, and ML13106A244. [NRC] U.S. Nuclear Regulatory 

35 Commission. 2013b. Standard Review Plans for Environmental Reviews for Nuclear Power 

36 Plants, Supplement 1: Operating License Renewal. Washington, D.C.: Office of Nuclear Reactor 

37 Regulation. NUREG-1555, Supplement 1, Revision 1. June 2013. ADAMS Accession No. 

38 ML13106A246.

39 Rabalais NN, Turner RE, Díaz RJ, Justić D. 2009. Global change and eutrophication of coastal 

40 waters. ICES Journal of Marine Science, 66:1528-1537.

41 [USCB] U.S. Census Bureau. 2012. American FactFinder, 2010 American Community Survey 

42 and Data Profile Highlights Information on Mississippi Counties: Adams, Amite, Claiborne, 

43 Copiah, Franklin, Hinds, Issaquena, Jefferson, Lincoln, Madison, Rankin, Sharkey, Simpson, 

44 Warren, Wilkinson, Yazoo; and Louisiana Counties: Caldwell, Catahoula, Concordia, East 

45 Carroll, Franklin, Madison, Richland, Tensas. Available at <http://factfinder.census.gov> and 

46 <http://quickfacts.census.gov> (accessed April 2012).
Environmental Impacts of Operation

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1 [USFS] U.S. Forest Service. 2003. Decision Notice and Finding of No Significant Impact: Utility 

2 Corridor Maintenance for Wildlife Habitat Enhancement. September 2003. 139 p. Meadville, 

3 MS: USFS Southern Region 8. ADAMS Accession No. ML12157A550.

4 [USGCRP] U.S. Global Change Research Program. 2009. Global Climate Change Impacts in 

5 the United States. Karl TR, Melillo JM, Peterson TC, eds. Cambridge University Press: 

6 New York, NY. Available at <http://library.globalchange.gov/products/assessments/2009-

7 national-climate-assessment/2009-global-climate-change-impacts-in-the-united-states>

8 (accessed 11 May 2012).

9 [USGS] U.S. Geological Survey. 2001. “Mississippi Valley Loess Plains.” Available at 

10 <http://landcovertrends.usgs.gov/east/eco74Report.html> (accessed 13 June 2012).
5-1 

1 5.0 ENVIRONMENTAL IMPACTS OF POSTULATED ACCIDENTS

2 This chapter describes environmental impacts from postulated accidents that might occur during 

3 the period of extended operation. The term “accident” refers to any unintentional event outside 

4 the normal plant operational envelope that results in a release or the potential for release of 

5 radioactive materials into the environment. Two classes of postulated accidents are evaluated 

6 in NUREG–1437, Generic Environmental Impact Statement (GEIS) for License Renewal of 

7 Nuclear Plants (NRC 1996). These are design-basis accidents (DBAs) and severe accidents. 

8 5.1 Design-Basis Accidents

9 To receive U.S. Nuclear Regulatory Commission (NRC) approval to operate a nuclear power 

10 facility, an applicant for an initial operating license must submit a safety analysis report (SAR) as 

11 part of its application. The SAR presents the design criteria and design information for the 

12 proposed reactor and comprehensive data on the proposed site. The SAR also discusses 

13 various hypothetical accident situations and the safety features that are provided to prevent and 

14 mitigate accidents. The NRC staff reviews the application to determine whether the plant 

15 design meets the Commission’s regulations and requirements and includes, in part, the nuclear 

16 plant design and its anticipated response to an accident.

17 DBAs are those accidents that both the licensee and NRC staff evaluate to ensure that the plant 

18 can withstand normal and abnormal transients and a broad spectrum of postulated accidents

19 without undue hazard to the health and safety of the public. A number of these postulated 

20 accidents are not expected to occur during the life of the plant, but are evaluated to establish 

21 the design basis for the preventive and mitigative safety systems of the facility. The acceptance 

22 criteria for DBAs are described in Title 10 of the Code of Federal Regulations (10 CFR) Part 50, 

23 “Domestic Licensing of Production and Utilization Facilities,” and 10 CFR Part 100, “Reactor 

24 Site Criteria.” 

25 The environmental impacts of DBAs are evaluated during the initial licensing process, and the 

26 ability of the plant to withstand these accidents is demonstrated to be acceptable before 

27 issuance of the operating license. The results of these evaluations are found in licensee 

28 documentation, such as the applicant’s final safety analysis report, the safety evaluation report, 

29 the final environmental statement, and Section 5.1 of this supplemental environmental impact 

30 statement. A licensee is required to maintain the acceptable design and performance criteria 

31 throughout the life of the plant, including any extended-life operation. The consequences for 

32 these events are evaluated for the hypothetical maximum exposed individual; as such, changes 

33 in the plant environment will not affect these evaluations. Because of the requirements that 

34 continuous acceptability of the consequences and aging management programs be in effect for 

35 the period of extended operation, the environmental impacts, as calculated for DBAs, should not 

36 differ significantly from initial licensing assessments over the life of the plant, including the 

37 period of extended operation. Accordingly, the design of the plant relative to DBAs during the 

38 period of extended operation is considered to remain acceptable, and the environmental 

39 impacts of those accidents were not examined further in the GEIS. 

40 The Commission has determined that the environmental impacts of DBAs are of SMALL 

41 significance for all plants because the plants were designed to successfully withstand these 

42 accidents. Therefore, for the purposes of license renewal, DBAs are designated as a 

43 Category 1 issue (Table 5–1). The early resolution of the DBAs makes them a part of the 

44 current licensing basis of the plant; the current licensing basis of the plant is to be maintained by 
Environmental Impacts of Postulated Accidents

5-2 

1 the licensee under its current license and, therefore, under the provisions of 10 CFR 54.30, 

2 “Matters Not Subject to Renewal Review,” is not subject to review under license renewal. 

3 Table 5–1. Issues Related to Postulated Accidents

Issue Category

Design-basis accidents 1 

Severe accidents 2 

Two issues related to postulated accidents are evaluated under the National Environmental Policy Act in 

the license renewal review, design-basis accidents, and severe accidents.

4 No new and significant information related to DBAs was identified during the review of the 

5 Entergy Operations, Inc., (Entergy) Environmental Report (ER) (Entergy 2011) or evaluation of 

6 other available information. Therefore, there are no impacts related to these issues beyond 

7 those discussed in the GEIS. 

8 5.2 Severe Accidents 

9 Severe nuclear accidents are those that are more severe than DBAs because they could 

10 result in substantial damage to the reactor core, whether or not there are serious offsite 

11 consequences. In the GEIS, the NRC staff assessed the impacts of severe accidents during the 

12 license renewal period, using the results of existing analyses and site-specific information to 

13 conservatively predict the environmental impacts of severe accidents for each plant during the 

14 renewal period.

15 Severe accidents initiated by external phenomena such as tornadoes, floods, earthquakes, 

16 fires, and sabotage have not traditionally been discussed in quantitative terms in final 

17 environmental statements and were not specifically considered for the Grand Gulf Nuclear 

18 Station (GGNS) site in the GEIS (NRC 1996). However, the GEIS did evaluate existing impact 

19 assessments performed by the NRC and by the industry at 44 nuclear plants in the 

20 United States and concluded that the risk from beyond-design-basis earthquakes at existing 

21 nuclear power plants is SMALL. The GEIS for license renewal performed a discretionary 

22 analysis of terrorist acts in connection with license renewal and concluded that the core damage 

23 and radiological release from such acts would be no worse than the damage and release 

24 expected from internally initiated events. In the GEIS, the Commission concludes that the 

25 probability-weighted consequences of severe accidents are SMALL and, additionally, that the 

26 risks from other external events are adequately addressed by a generic consideration of 

27 internally initiated severe accidents (NRC 1996).

28 Based on information in the GEIS, the Commission found that

29 The probability-weighted consequences of atmospheric releases, fallout onto 

30 open bodies of water, releases to ground water, and societal and economic 

31 impacts from severe accidents are small for all plants. However, alternatives to 

32 mitigate severe accidents must be considered for all plants that have not 

33 considered such alternatives.

34 The NRC staff identified no new and significant information related to postulated accidents

35 during the review of Entergy’s ER (Entergy 2011, 2012c) or evaluation of other available 

36 information. Therefore, there are no impacts related to these issues beyond those discussed in 

37 the GEIS. However, in accordance with 10 CFR 51.53(c)(3)(ii)(L), the NRC staff has reviewed 
Environmental Impacts of Postulated Accidents

5-3 

1 severe accident mitigation alternatives (SAMAs) for GGNS. The results of the review are 

2 discussed in Section 5.3.

3 5.3 Severe Accident Mitigation Alternatives 

4 If the NRC staff has not previously evaluated SAMAs for the applicant's plant in an 

5 environmental impact statement (EIS) or related supplement or in an environmental 

6 assessment, 10 CFR 51.53(c)(3)(ii)(L) requires that license renewal applicants consider 

7 alternatives to mitigate severe accidents. The purpose of this consideration is to ensure that 

8 plant changes (i.e., hardware, procedures, and training) with the potential for improving severe 

9 accident safety performance are identified and evaluated. SAMAs have not previously been 

10 considered for GGNS; therefore, the remainder of Chapter 5 addresses those alternatives.

11 5.3.1 Overview of SAMA Process

12 This section presents a summary of the results of the SAMA evaluation for GGNS conducted by 

13 Entergy, as described in Attachment E of Entergy’s ER (Entergy 2011, 2012c), the NRC staff’s 

14 review of Entergy’s SAMA evaluation provided in detail in Appendix F, and associated requests 

15 for additional information (RAIs) issued by the NRC staff and responses from Entergy 

16 (Entergy 2012a, 2012b, 2012c, 2012d). The NRC staff performed its review with contract 

17 assistance from the Center for Nuclear Waste Regulatory Analyses. 

18 The SAMA evaluation for GGNS was conducted with a four-step approach. In the first step, 

19 Entergy quantified the level of risk associated with potential reactor accidents using the 

20 plant-specific probabilistic risk assessment (PRA) and other risk models.

21 In the second step, Entergy examined the major risk contributors and identified possible ways 

22 (SAMAs) of reducing that risk. Common ways of reducing risk are changes to components, 

23 systems, procedures, and training.

24 In the third step, Entergy estimated the benefits and the costs associated with each of the 

25 candidate SAMAs. Estimates were made of how much each SAMA could reduce risk. Those 

26 estimates were developed in terms of dollars in accordance with NRC guidance for performing 

27 regulatory analyses. The costs of implementing the candidate SAMAs also were estimated.

28 In the fourth step, Entergy compared the cost and benefit of each of the remaining SAMAs to 

29 determine whether the SAMA was cost-beneficial, meaning the benefits of the SAMA were 

30 greater than the cost (a positive cost-benefit ratio). Finally, the four potentially cost-beneficial 

31 SAMAs are evaluated to determine if they are in the scope of license renewal, i.e., are they 

32 subject to aging management.

33 5.3.2 Estimate of Risk

34 Entergy submitted an assessment of SAMAs for the GGNS as part of the ER 

35 (Entergy 2011, 2012c). The assessments were based on the most recent GGNS PRA available 

36 at that time, a plant-specific offsite consequence analysis performed using the MELCOR 

37 Accident Consequence Code System 2 (MACCS2) computer code, and insights from the GGNS 

38 individual plant examination (IPE) (Entergy 1992) and individual plant examination of external 

39 events (IPEEE) (Entergy 1995).

40 Entergy combined two distinct analyses to form the basis for the risk estimates used in the 

41 SAMA analysis: (1) the GGNS Level 1 and 2 PRA model, and (2) a supplemental analysis of 

42 offsite consequences and economic impacts (essentially a Level 3 PRA model) developed 

43 specifically for the SAMA analysis. The SAMA analysis is based on the most recent GGNS 
Environmental Impacts of Postulated Accidents

5-4 

1 Level 1 and Level 2 PRA model available at the time of the ER, referred to as the 2010 

2 extended power uprate (EPU) model.

The GGNS core damage frequency (CDF) is approximately 2.9 × 10−6 3 per reactor year as 

4 determined from quantification of the Level 1 PRA model with the revised Level 2 model. This 

5 value was used as the baseline CDF in the SAMA evaluations (Entergy 2012c, 2012d). The 

6 CDF is based on the risk assessment for internally initiated events, which includes internal

7 flooding. Entergy did not explicitly include the contribution from external events within the 

8 GGNS risk estimates; however, it did account for external event impacts on the potential risk 

9 reduction associated with SAMA implementation by multiplying the estimated risk reduction for 

10 internal events by a factor of 11. This is discussed further in Sections F.2.2 and F.6.2. Using 

11 the calculated risk reduction as a quantitative measure of the potential benefit from SAMA 

12 implementation, Entergy performed a cost-benefit comparison, as described in Section 5.3.5.

13 The breakdown of CDF by initiating event is provided in Table 5–2. As shown in this table, loss 

14 of offsite power and power conversion system available transient are the dominant contributors 

15 to the CDF. Not listed explicitly in Table 5–2 because multiple initiators contribute to their 

occurrence, station blackouts contribute about 37 percent (1.1 × 10−6 16 per reactor year) of the 

17 total CDF, while anticipated transients without scram contribute about 0.2 percent 

(4.4 × 10−9 18 per reactor year) to the total CDF (Entergy 2012c). 

19 The Level 2 PRA model that forms the basis for the GGNS SAMA evaluation is essentially a 

20 new model and reflects power uprate conditions. The Level 2 model uses containment event 

21 trees (CETs) containing both phenomenological and systemic events. The Level 1 core 

22 damage sequences are binned into accident classes (or plant damage states) that provide the 

23 interface between the Level 1 and Level 2 CET analysis. The CETs are linked directly to the 

24 Level 1 event trees, and CET nodes are evaluated using subordinate trees and logic rules.

25 Table 5–2. GGNS Core Damage Frequency (CDF) for Internal Events

Initiating Event CDF (per year) % CDF Contribution

Loss of Offsite Power Initiator 1.2 × 10−6 40

Power Conversion System Available Transient 5.9 × 10−7 20

Loss of Power Conversion System Initiator 2.5 × 10−7 8 

Loss of Condensate Feed Water Pumps 2.3 × 10−7 8 

Loss of Instrument Air 1.4 × 10−7 5 

Closure of Main Steam Isolation Valves (Initiator) 1.2 × 10−7 4 

Loss of Service Transformer 21 1.2 × 10−7 4 

Large Loss of Coolant Accident (LOCA) 9.7 × 10−8 3 

Loss of Service Transformer 11 8.3 × 10−8 3 

Loss of Alternating Current Division 2 Initiator 6.2 × 10−8 2 

Other Initiating Events1 3.3 × 10−8 1 

Loss of Alternating Current Division 1 Initiator 2.7 × 10−8 1 

Intermediate LOCA 1.4 × 10−8 1 

Total CDF (Internal Events) 2.9 × 10−6 100

1 Multiple initiating events, with each contributing 0.3 percent

 or less
Environmental Impacts of Postulated Accidents

5-5 

1 The CET considers the influence of physical and chemical processes on the integrity of the 

2 containment and on the release of fission products once core damage has occurred. The 

3 quantified CET sequences are binned into a set of end states that are subsequently grouped 

4 into 13 release categories (or release modes) that provide the input to the Level 3 

5 consequence analysis. The frequency of each release category was obtained by summing the 

6 frequency of the individual accident progression CET endpoints binned into the release 

7 category. Source terms were developed for the release categories using the results of Modular 

8 Accident Analysis Program (MAAP 4.0.6) computer code calculations. From these results, 

9 source terms were chosen to be representative of the release categories. The results of this 

10 analysis for GGNS are provided in the revised Table E.1-9 of ER Attachment E (Entergy 2012c).

11 Entergy computed offsite consequences for potential releases of radiological material using the 

12 MACCS2 Version 1.13.1 code and analyzed exposure and economic impacts from its 

13 determination of offsite and onsite risks. Inputs for these analyses include plant-specific and 

14 site-specific input values for core radionuclide inventory, source term and release 

15 characteristics, site meteorological data, projected population distribution and growth within a 

16 50-mile (80-kilometer) radius, emergency response evacuation modeling, and local economic 

17 data. Radionuclide inventory in the reactor core is based on a plant-specific evaluation and 

18 corresponds to that for the extended power uprate to 4,408 megawatts thermal (Entergy 2011). 

19 The estimation of onsite impacts (in terms of cleanup and decontamination costs and 

20 occupational dose) is based on guidance in NUREG/BR–0184, Regulatory Analysis Technical 

21 Evaluation Handbook (NRC 1997). 

22 In the ER, the applicant estimated the dose risk to the population within 80 kilometers (50 miles) 

23 of the GGNS site to be 0.00609 person-sieverts (Sv) per year (0.609 person-roentgen 

24 equivalent in man (rem) per year) (Entergy 2012c). The breakdown of the population dose risk 

25 and offsite economic cost risk by containment release mode is summarized in Table 5–3. 

26 Medium releases provide the greatest contribution, totaling approximately 67 percent of the 

27 population dose risk and 75 percent of the offsite economic cost risk for all timings. High early 

28 (H/E) releases alone contribute only about 10 percent, and high releases for all timings 

29 contribute 17 percent of the population dose risk.

30 The NRC staff has reviewed Entergy’s data and evaluation methods and concludes that the 

31 quality of the risk analyses is adequate to support an assessment of the risk reduction potential

32 for candidate SAMAs. Accordingly, the NRC staff based its assessment of offsite risk on the 

33 CDFs and offsite doses reported by Entergy. 

34 5.3.3 Potential Plant Improvements

35 Entergy's process for identifying potential plant improvements (SAMAs) consisted of the 

36 following elements: 

37 • review of industry documents and consideration of other plant-specific 

38 enhancements not identified in published industry documents

39 • review of potential plant improvements identified in the GGNS IPE and IPEEE

40 • review of potential modifications for the risk-significant events in the current 

41 GGNS PRA Levels 1 and 2 models 
Environmental Impacts of Postulated Accidents

5-6 

1 Table 5–3. Base Case Mean Population Dose Risk and Offsite Economic Cost Risk 

2 for Internal Events

Release Mode Population Dose Risk1 Offsite Economic Cost Risk

ID2 Frequency

(per year) person-rem/yr % Contribution $/yr % Contribution

H/E 1.0 × 10−7 6.2 × 10−2 10 1.7 × 10+2 11

H/I 1.2 × 10−8 6.2 × 10−3 1 1.7 × 10+1 1 

H/L 9.2 × 10−8 3.8 × 10−2 6 9.6 × 10+1 6 

M/E 3.7 × 10−7 1.7 × 10−1 28 4.8 × 10+2 32

M/I 1.8 × 10−7 1.2 × 10−1 20 3.3 × 10+2 22

M/L 3.0 × 10−7 1.2 × 10−1 19 3.2 × 10+2 21

L/E 4.1 × 10−9 4.0 × 10−4 <0.1 3.0 × 10−1 <0.1

L/I 3.6 × 10−8 1.2 × 10−2 2 2.7 × 10+1 2 

L/L 4.4 × 10−7 7.8 × 10−2 13 7.4 × 10+1 5 

LL/E 2.2 × 10−9 7.9 × 10−7 <0.1 1.0 × 10−3 <0.1

LL/I 2.1 × 10−9 3.8 × 10−7 <0.1 9.7 × 10−4 <0.1

LL/L 7.1 × 10−9 2.0 × 10−3 <1 3.4 × 10 <1

NCF 1.4 × 10−6 5.0 × 10−4 <0.1 6.4 × 10−1 <0.1

6.1 × 10−1 100 1.5 × 10+3 100

1 Unit Conversion Factor: 1 Sv = 100 rem

2 Release Mode Nomenclature (Magnitude/Timing)

 Magnitude: 

 High (H) – Greater than 10 percent release fraction for Cesium Iodide

 Medium (M) – 1 to 10 percent release fraction for Cesium Iodide

 Low (L) – 0.1 to 1 percent release fraction for Cesium Iodide

 Low-low (LL) – Less than 0.1 percent release fraction for Cesium Iodide

 No containment failure (NCF) – Much less than 0.1 percent release fraction for Cesium Iodide

 Timing: 

 Early (E) – Less than 4 hours

 Intermediate (I) – 4 to 24 hours

 Late (L) – Greater than 24 hours

3 Based on this process, Entergy identified an initial set of 249 candidate SAMAs, referred to as 

4 Phase I SAMAs. In Phase I of the evaluation, Entergy performed a qualitative screening of 

5 the initial list of SAMAs and eliminated SAMAs from further consideration using the 

6 following criteria: 

7 • the SAMA modified features not applicable to GGNS. 

8 • the SAMA has already been implemented at GGNS. 

9 • the SAMA is similar in nature and could be combined with another SAMA 

10 candidate.
Environmental Impacts of Postulated Accidents

5-7 

1 Based on this screening, 60 of the Phase I SAMA candidates were screened out because they 

2 were not applicable to GGNS, 98 candidates were screened out because they had already been 

3 implemented at GGNS, and 28 candidates were screened out because they were similar in 

4 nature and could be combined with another SAMA candidate. Thus, a total of 186 SAMAs were 

5 eliminated, leaving 63 SAMAs for further evaluation. The results of the Phase I screening 

6 analysis for each SAMA candidate were provided in a response to an NRC staff RAI

7 (Entergy 2012a). The remaining SAMAs, referred to as Phase II SAMAs, are listed in 

8 Table E.2–2 of Attachment E to the ER in the original submittal (Entergy 2011) and in the 

9 revised analysis (Entergy 2012c). In Phase II, a detailed evaluation was performed for each of 

10 the 63 remaining SAMA candidates.

11 The NRC staff concludes that Entergy used a systematic and comprehensive process for 

12 identifying potential plant improvements for GGNS, and that the set of SAMAs evaluated in the 

13 ER, together with those evaluated in response to NRC staff inquiries, is reasonably 

14 comprehensive and, therefore, acceptable. This search included reviewing insights from the 

15 GGNS plant-specific risk studies that included internal initiating events, as well as fire, seismic, 

16 and other external initiated events, and reviewing plant improvements considered in previous 

17 SAMA analyses.

18 5.3.4 Evaluation of Risk Reduction and Costs of Improvements

19 In the ER, the applicant evaluated the risk-reduction potential of the 63 SAMAs that were not 

20 screened out in the Phase I analysis and retained for the Phase II evaluation. The SAMA

21 evaluations were performed using generally conservative assumptions.

22 Except for two SAMAs associated with internal fires, Entergy used model re-quantification to 

23 determine the potential benefits for each SAMA. The CDF, population dose, and offsite 

24 economic cost reductions were estimated using the GGNS 2010 EPU PRA model for the nonfire 

25 SAMAs. The changes made to the model to quantify the impact of SAMAs are detailed in 

26 Section E.2.3 of Attachment E to the ER (Entergy 2011). Bounding evaluations (or analysis 

27 cases) were performed to address specific SAMA candidates or groups of similar SAMA 

28 candidates. For the two fire-related SAMAs (SAMA Nos. 54 and 55), the benefit was 

29 determined by assuming the CDF contribution for the fire area impacted by the SAMA was 

30 reduced to zero and that the resulting benefit was determined by the product of the fraction of 

31 the internal events total CDF represented by the fire area CDF and the maximum total internal 

32 events benefit.

33 For the SAMAs determined to be potentially cost-beneficial, Table 5–4 lists the assumptions 

34 considered to estimate the risk reduction, the estimated risk reduction in terms of percent 

35 reduction in CDF, population dose risk and offsite economic cost risk, and the estimated total 

36 benefit (present value) of the averted risk. The estimated benefits reported in Table 5–4 reflect 

37 the combined benefit in both internal and external events. The determination of the benefits for 

38 the various SAMAs is further discussed in Section F.6.

39 Entergy estimated the costs of implementing the 63 Phase II SAMAs through the use of other 

40 licensees’ estimates for similar improvements and the development of site-specific cost 

41 estimates, where appropriate. Information on the assumptions, risk reduction, estimated total

42 benefit, and implementation costs for the 63 Phase II SAMAs is presented in Table F–5. 
Environmental Impacts of Postulated Accidents

5-8 

Table 5–4. Severe Accident Mitigation Alternatives Cost-Benefit Analysis for GGNS. Percentage Risk R1 

Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), and Offsite Economic C2 

Analysis Case, Analysis Assumption, Individual SAMA, and Cost Estimate

% Risk Reduction

CDF PDR OECR

Inte

a

Ext

Be

Case 28. Increase Availability of Containment Heat Removal

Assumption: Eliminates failure of cooled flow from residual heat removal 

pump A and B

SAMA No. 39—Procedural change to cross-tie open cycle cooling 

system to enhance containment spray system

$25,000

17.8% 45.6% 50.2% $29

Case 30. Increase Availability of the Condensate Storage Tank

Assumption: Eliminates failure of high pressure core spray and reactor 

core isolation cooling suction

SAMA No. 42—Enhance procedures to refill condensate storage 

tank from demineralized water or service water system

$200,000

4.4% 12.6% 13.5% $77

Case 43. Increase Recovery Time of Emergency Core Cooling System Upon Loss of 

Standby Service Water 

Assumption: Eliminates failure of standby service water to the low pressure 

core spray room cooler

SAMA No. 59—Increase operator training for alternating operation 

of the low-pressure emergency core cooling system pumps 

(low-pressure coolant injection and low-pressure core spray) for 

loss of standby service water scenarios

$50,000

4.5% 5.2% 5.5% $53
Environmental Impacts of 

5-9

Analysis Case, Analysis Assumption, Individual SAMA, and Cost Estimate

% Risk Reduction

CDF PDR OECR

Inte

a

Ext

Be

Case 22. Increase Availability of the Diesel Generator System through Heating, 

Ventilation, and Air Conditioning Improvements 

Assumption: Eliminates failure of heating, ventilation, and air conditioning

for diesel generator rooms

SAMA (Unnumbered) in Response to Request for Additional 

Information No. 8a—Revise procedures to direct the operator 

monitoring a running diesel generator to ensure that the 

ventilation system is running or take action to open doors or use 

portable fans

$50,000 to

$200,000

23.9% 16.6% 12.3% $23
Environmental Impacts of Postulated Accidents

5-10

1 Entergy stated the following cost ranges were used based on the review of previous 

2 SAMA applications.

3 Table 5–5. Estimated Cost Ranges for SAMA Applications

Type of Change Estimated Cost Range

Procedural only $25K to $50K

Procedural change with engineering or training required $50K to $200K

Procedural change with engineering and testing or 

training required

$200K to $300K

Hardware modification $100K to >$1,000K

Source: Entergy 2011

4 Entergy stated that the GGNS site-specific cost estimates were based on the engineering 

5 judgment of project engineers experienced in performing design changes at the facility. The 

6 detailed cost estimates considered engineering, labor, materials, and support functions, such as 

7 planning, scheduling, health physics, quality assurance, security, safety, and fire watch. The 

8 estimates included a 20 percent contingency on the design and installation costs but did not 

9 account for inflation, replacement power during extended outages necessary for SAMA

10 implementation, or increased maintenance or operation costs following SAMA implementation.

11 In response to an NRC staff RAI concerning the applicability of cost estimates taken directly 

12 from previous SAMA applications, Entergy stated that engineering judgment by project 

13 engineers familiar with the costs of modifications at Entergy plants was used to determine if the 

14 cited cost estimates from other SAMA analyses were valid for GGNS. If the GGNS project 

15 engineers’ rough conceptual cost estimate of the modification was larger than the other plant's 

16 cost estimate, the other plant's estimate was adopted without further detailed cost analysis 

17 (Entergy 2012a).

18 The NRC staff reviewed the applicant’s cost estimates, presented in Table E.2-2 of 

19 Attachment E to the ER in the original submittal (Entergy 2011) and as a response to NRC staff 

20 RAIs (Entergy 2012a, 2012c). For certain improvements, the NRC staff also compared the cost 

21 estimates to estimates developed elsewhere for similar improvements, including estimates 

22 developed as part of other licensees’ analyses of SAMAs for operating reactors. The NRC staff 

23 concludes that, with the above clarifications, the cost estimates provided by Entergy are 

24 sufficient and appropriate for use in the SAMA evaluation.

25 5.3.5 Cost-Benefit Comparison

26 If the implementation costs for a candidate SAMA exceeded the calculated benefit, the SAMA 

27 was determined to be not cost-beneficial. If the benefit exceeded the estimated cost, the SAMA

28 candidate was considered to be cost-beneficial. In Entergy’s original submittal and revised 

29 analysis, three SAMA candidates were found to be potentially cost-beneficial

30 (Entergy 2011, 2012c). In response to an RAI by NRC staff concerning potential low-cost 

31 alternatives, Entergy determined that a procedure revision to direct that the operator monitoring 

32 a running diesel ensure the ventilation system is running, or take action to open doors, or use 

33 portable fans would be potentially cost-beneficial (Entergy 2012a, 2012c). Results of the 

34 cost-benefit evaluation are presented in Table 5–4 for the four potentially cost-beneficial
Environmental Impacts of Postulated Accidents

5-11

1 SAMAs. Entergy initiated a condition report to evaluate these potentially cost-beneficial SAMAs 

2 within the corrective action process.

3 The potentially cost-beneficial SAMAs are:

4 • SAMA No. 39—Change procedure to cross tie open cycle cooling system to 

5 enhance containment spray system.

6 • SAMA No. 42—Enhance procedures to refill condensate storage tank from 

7 demineralized water or service water system.

8 • SAMA No. 59—Increase operator training for alternating operation of the low 

9 pressure emergency core cooling system pumps (low-pressure coolant 

10 injection and low pressure core spray) for loss of standby service water 

11 scenarios.

12 • SAMA (Unnumbered) in Response to RAI No. 8a—Revise procedures to 

13 direct the operator monitoring a running diesel generator to ensure that the 

14 ventilation system is running or take action to open doors or use portable 

15 fans.

16 A sensitivity analysis considered two cases: a discount rate of 7 percent with a 33-year period 

17 for remaining plant life and a lower (i.e., more conservative) discount rate of 3 percent with a 

18 20-year license renewal period (Entergy 2011). Based on its sensitivity analysis, Entergy did 

19 not identify any additional cost-beneficial SAMAs. Sensitivity analysis results were recast in the 

20 revised SAMA analysis (Entergy 2012c). In response to an NRC RAI on the unexpected large 

21 increase in the sensitivity to the discount rate shown in the revised results, Entergy described 

22 that the sensitivity calculation for the lower discount rate of 3 percent inadvertently included the 

23 cumulative effect of both the longer time period of remaining plant life of 33 years and the lower 

24 discount rate (Entergy 2012d). Without the additional effect from a longer time period, 

25 increases in the benefit solely because of a lower discount rate would be smaller than those 

26 results reported by Entergy (2012c).

27 Individual (as well as cumulative) increases in the estimated benefits from the sensitivity 

28 parameters were smaller than the factor of 3 applied by the applicant to account for uncertainty. 

29 In the revised analysis, neither individual nor cumulative sensitivity effects resulted in benefit 

30 estimates for individual SAMAs that exceeded GGNS implementation costs beyond the SAMAs 

31 previously identified by Entergy to be potentially cost-beneficial. Based primarily on 

32 NUREG/BR–0184 (NRC 1997) and discount rate guidelines in NEI 05-01 (NEI 2005), the 

33 cost-benefit analysis performed by Entergy was consistent with the guidance. The applicant 

34 considered possible increases in benefits from analysis uncertainties on the results of the SAMA

35 assessment. In the ER (Entergy 2011), Entergy stated that the 95th percentile value of the 

36 GGNS CDF was a factor of 2.38 greater than the mean CDF. A multiplication factor of 3 was 

37 selected by the applicant to account for uncertainty. This multiplication factor was applied in 

38 addition to a separate multiplication factor of 11 for CDF increases caused by external events. 

39 Entergy’s assessment accounted for the potential risk-reduction benefits associated with both 

40 internal and external events. NRC staff considers the multipliers of 3 for uncertainty and 11 for 

41 external events provide adequate margin and are acceptable for the SAMA analysis.

42 5.3.6 Conclusions

43 Entergy considered 249 candidate SAMAs based on risk-significant contributors at GGNS from 

44 updated probabilistic safety assessment models, its review of SAMA analyses from other 

45 boiling-water reactor (BWR) plants, NRC and industry documentation of potential plant 
Environmental Impacts of Postulated Accidents

5-12

1 improvements, and GGNS individual plant examination of internal and external events, including 

2 available updates. Phase I screening reduced the list to 63 unique SAMA candidates by 

3 eliminating SAMAs that were not applicable to GGNS, had already been implemented at GGNS, 

4 or were combined into a more comprehensive or plant-specific SAMA.

5 For the remaining SAMA candidates, Entergy performed a cost-benefit analysis. Entergy’s 

6 cost-benefit analysis identified three potentially cost-beneficial SAMAs (Phase II SAMA 

7 Nos. 39, 42, and 59). In response to an NRC staff RAI concerning potential low-cost 

8 alternatives, Entergy identified one additional cost-beneficial SAMA. Sensitivity cases were 

9 analyzed for the present value discount rate and time period for remaining plant life. No 

10 additional SAMAs were identified as potentially cost-beneficial from the sensitivity analysis.

11 NRC staff reviewed the Entergy SAMA analysis and concludes that, subject to the discussion in 

12 this chapter and Appendix F, the methods used and implementation of the methods were

13 sound. On the basis of the applicant’s treatment of SAMA benefits and costs, NRC staff finds 

14 that the SAMA evaluations performed by Entergy are reasonable and sufficient for the license 

15 renewal submittal.

16 The NRC staff agrees with Entergy’s conclusion that four candidate SAMAs are potentially 

17 cost-beneficial, a decision based on a reasonable treatment of costs, benefits, and 

18 uncertainties. This conclusion of a small number of potentially cost-beneficial SAMAs is 

19 consistent with the low residual level of risk stated in the GGNS PRA and the fact that Entergy 

20 has already implemented the plant improvements identified from the IPE and IPEEE. 

21 Finally, the four potentially cost-beneficial SAMAs are evaluated to determine if they are in the 

22 scope of license renewal, i.e., are they subject to aging management. This evaluation considers 

23 whether the systems, structures, and components (SSCs) associated with these SAMAs: 

24 (1) perform their intended function without moving parts or without a change in configuration or 

25 properties; and (2) that these SSCs are not subject to replacement based on qualified life or 

26 specified time period. Because the potentially cost-beneficial SAMAs do not relate to aging 

27 management during the period of extended operation, they do not need to be implemented as 

28 part of license renewal in accordance with 10 CFR Part 54. Nevertheless, Entergy issued a 

29 condition report under the corrective action process to evaluate these potentially cost-beneficial 

30 SAMAs. The NRC staff accepts this course of action.

31 5.4 References

32 [Entergy] Entergy Operations, Inc. 1992. “Individual Plant Examination (IPE) for Grand Gulf 

33 Nuclear Station Unit 1.” December 1992. 

34 [Entergy] Entergy Operations, Inc. 1995. Letter from M.J. Meisner, Entergy, to U.S. NRC 

35 Document Control Desk. Subject: “Grand Gulf Nuclear Station Docket No. 50–416 License 

36 No. NPF–29 Individual Plant Examination of External Events (IPEEE) Schedule Final 

37 Submittal.” November 15, 1995 (not publicly available). 

38 [Entergy] Entergy Operations, Inc. 2011. Grand Gulf Nuclear Station, Unit 1, License Renewal 

39 Application, Appendix E, Applicant’s Environmental Report, Operating License Renewal Stage.

40 Agencywide Documents Access and Management System (ADAMS) Accession 

41 No. ML11308A234.

42 [Entergy] Entergy Operations, Inc. 2012a. Letter from Michael Perito, Entergy, to U.S. Nuclear 

43 Regulatory Commission Document Control Desk. Subject: “Response to Request for Additional 

44 Information (RAI) on Severe Accident Mitigation Alternatives dated May 21, 2012, Grand Gulf 
Environmental Impacts of Postulated Accidents

5-13

1 Nuclear Station, Unit 1, Docket No. 50–416, License No. NPF–29.” Port Gibson, MS. 

2 July 19, 2012. Accessible at ADAMS Accession No. ML12202A056. 

3 [Entergy] Entergy Operations, Inc. 2012b. Letter from Michael Perito, Entergy, to U.S. Nuclear 

4 Regulatory Commission Document Control Desk. Subject: “Response to Request for Additional 

5 Information (RAI) on Severe Accident Mitigation Alternatives dated August 23, 2012, Grand Gulf 

6 Nuclear Station, Unit 1, Docket No. 50–416, License No. NPF–29.” Port Gibson, MS. 

7 October 2, 2012. Accessible at ADAMS Accession No. ML12277A082. 

8 [Entergy] Entergy Operations, Inc. 2012c. Letter from Michael Perito, Entergy, to U.S. Nuclear 

9 Regulatory Commission Document Control Desk. Subject: “Reanalysis of Severe Accident 

10 Mitigation Alternatives, Grand Gulf Nuclear Station, Unit 1, Docket No. 50–416, License 

11 No. NPF–29.” Port Gibson, MS. November 19, 2012. Accessible at ADAMS Accession 

12 No. ML12325A174. 

13 [Entergy] Entergy Operations, Inc. 2012d. Letter from Kevin J. Mulligan, Entergy, to 

14 U.S. Nuclear Regulatory Commission Document Control Desk. Subject: “Response to 

15 Clarification Questions on Reanalysis of Severe Accident Mitigation Alternatives (SAMA) Letter 

16 dated November 19, 2012, Grand Gulf Nuclear Station, Unit 1, Docket No. 50–416, License 

17 No. NPF-29.” Port Gibson, MS. December 19, 2012. ADAMS Accession No. ML12359A038.

18 [NEI]Nuclear Energy Institute. 2005. “Severe Accident Mitigation Alternative (SAMA) Analysis 

19 Guidance Document.” NEI 05–01, Revision A. Washington, DC. November 2005.

20 [NRC] U.S. Nuclear Regulatory Commission. 1996. Generic Environmental Impact Statement

21 for License Renewal of Nuclear Plants. NUREG–1437, Washington, DC. Accessible at 

22 <http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1437/> (accessed 

23 August 29, 2012).

24 [NRC] U.S. Nuclear Regulatory Commission. 1997. Regulatory Analysis Technical Evaluation 

25 Handbook. NUREG/BR–0184. Washington, DC. ADAMS No. ML050190193.

6-1 

1 6.0 ENVIRONMENTAL IMPACTS OF THE URANIUM FUEL CYCLE, 

2 SOLID WASTE MANAGEMENT, AND GREENHOUSE GAS EMISSIONS

3 6.1 The Uranium Fuel Cycle

4 This section addresses issues related to the uranium fuel cycle and solid waste management 

5 during the period of extended operation (listed in Table 6–1). The uranium cycle includes 

6 uranium mining and milling, the production of uranium hexafluoride, isotopic enrichment, fuel 

7 fabrication, reprocessing of irradiated fuel, transportation of radioactive materials and 

8 management of low-level wastes and high-level wastes related to uranium fuel cycle activities. 

9 The generic potential impacts of the radiological and non-radiological environmental impacts of 

10 the uranium fuel cycle and transportation of nuclear fuel and wastes are described in detail in 

11 the Generic Environmental Impact Statement (GEIS) (NRC 1996, 1999). They are based, in 

12 part, on the generic impacts provided in Title 10, Part 51.51(b) of the Code of Federal 

13 Regulations (10 CFR 51.51(b)), Table S–3, “Table of Uranium Fuel Cycle Environmental Data,” 

14 and in 10 CFR 51.52(c), Table S–4, “Environmental Impact of Transportation of Fuel and Waste 

15 to and from One Light-Water-Cooled Nuclear Power Reactor.”

16 Table 6–1. Issues Related to the Uranium Fuel Cycle and Solid Waste Management.

17 There are nine generic issues related to the fuel cycle and waste management. There are no 

18 site-specific issues.

Issues GEIS Sections Category

Offsite radiological impacts (individual effects from other 

than the disposal of spent fuel and high-level waste)

6.1; 6.2.1; 6.2.2.1; 6.2.2.3; 6.2.3; 6.2.4; 

6.6

1

Offsite radiological impacts (collective effects) 6.1; 6.2.2.1; 6.2.3; 6.2.4; 6.6 1 

Offsite radiological impacts (spent fuel and high-level 

waste disposal)

6.1; 6.2.2.1; 6.2.3; 6.2.4; 6.6 1

Non-radiological impacts of the uranium fuel cycle 6.1; 6.2.2.6; 6.2.2.7; 6.2.2.8; 6.2.2.9; 

6.2.3; 6.2.4; 6.6

1 

Low-level waste storage and disposal 6.1; 6.2.2.2; 6.4.2; 6.4.3; 6.4.3.1; 

6.4.3.2; 6.4.3.3; 6.4.4; 6.4.4.1; 6.4.4.2; 

6.4.4.3; 6.4.4.4; 6.4.4.5; 6.4.4.5.1; 

6.4.4.5.2; 6.4.4.5.3; 6.4.4.5.4; 6.4.4.6;

6.6

1

Mixed waste storage and disposal 6.4.5.1; 6.4.5.2; 6.4.5.3; 6.4.5.4; 

6.4.5.5; 6.4.5.6; 6.4.5.6.1; 6.4.5.6.2; 

6.4.5.6.3; 6.4.5.6.4; 6.6

1

Onsite spent fuel 6.1; 6.4.6; 6.4.6.1; 6.4.6.2; 6.4.6.3; 

6.4.6.4; 6.4.6.5; 6.4.6.6; 6.4.6.7; 6.6

1

Non-radiological waste 6.1; 6.5; 6.5.1; 6.5.2; 6.5.3; 6.6 1

Transportation 6.1; 6.3.1; 6.3.2.3; 6.3.3; 6.3.4; 6.6, 

Addendum 1

1

19 The NRC staff’s evaluation of the environmental impacts associated with spent nuclear fuel is 

20 addressed in two issues in Table 6–1, “Offsite radiological impacts (spent fuel and high-level 

21 waste disposal)” and “Onsite spent fuel.” However, as explained later in this section, the scope 

22 of the evaluation of these issues in this supplemental environmental impact statement (SEIS) 

23 has been revised. The issue, “Offsite radiological impacts (spent fuel and high-level waste 
Environmental Impacts of the Uranium Fuel Cycle, 

Solid Waste Management, and Greenhouse Gas Emissions

6-2 

1 disposal),” from Table 6–1 is not evaluated in this SEIS. In addition, the issue, “Onsite spent 

2 fuel” only evaluates the environmental impacts during the license renewal term.

3 For the term of license renewal, the NRC staff did not find any new and significant information 

4 related to the remaining uranium fuel cycle and solid waste management issues listed in 

5 Table 6–1 during its review of the GGNS environmental report (ER) (Entergy 2011), the site 

6 visit, and the scoping process. Therefore, there are no impacts related to these issues beyond 

7 those discussed in the GEIS. For these Category 1 issues, the GEIS concludes that the 

8 impacts are SMALL, except for the issue, “Offsite radiological impacts (collective effects),” which 

9 the NRC has not assigned an impact level. This issue assesses the 100-year radiation dose to 

10 the U.S. population (i.e., collective effects or collective dose) from radioactive effluents released 

11 as part of the uranium fuel cycle for a nuclear power plant during the license renewal term 

12 compared to the radiation dose from natural background exposure. It is a comparative 

13 assessment for which there is no regulatory standard to base an impact level.

14 For the radiological impacts resulting from spent fuel and high-level waste disposal and the 

15 onsite storage of spent fuel, which will occur after the reactors have been permanently 

16 shutdown, the NRC’s Waste Confidence Decision and Rule represented the Commission’s 

17 generic determination that spent fuel can continue to be stored safely and without significant 

18 environmental impacts for a period of time after the end of the licensed life for operation. This 

19 generic determination meant that the NRC did not need to consider the storage of spent fuel 

20 after the end of a reactor’s licensed life for operation in National Environmental Policy Act

21 (NEPA) documents that support its reactor and spent fuel storage application reviews.

22 The NRC first adopted the Waste Confidence Decision and Rule in 1984. The NRC amended 

23 the decision and rule in 1990, reviewed them in 1999, and amended them again in 2010 

24 (49 FR 34694; 55 FR 38474; 64 FR 68005; and 75 FR 81032 and 81037). The Waste 

25 Confidence Decision and Rule are codified in 10 CFR 51.23.

26 On December 23, 2010, the Commission published in the Federal Register a revision of the 

27 Waste Confidence Decision and Rule to reflect information gained from experience in the 

28 storage of spent fuel and the increased uncertainty in the siting and construction of a permanent 

29 geologic repository for the disposal of spent nuclear fuel and high-level waste (75 FR 81032 and 

30 81037). In response to the 2010 Waste Confidence Decision and Rule, the states of New York, 

31 New Jersey, Connecticut, and Vermont—along with several other parties—challenged the 

32 Commission’s NEPA analysis in the decision, which provided the regulatory basis for the rule. 

33 On June 8, 2012, the United States Court of Appeals, District of Columbia Circuit in New York v. 

34 NRC, 681 F.3d 471 (D.C. Cir. 2012) vacated the NRC’s Waste Confidence Decision and Rule, 

35 after finding that it did not comply with NEPA.

36 In response to the court’s ruling, the Commission, in CLI-12-16 (NRC 2012a), determined that it 

37 would not issue licenses that rely upon the Waste Confidence Decision and Rule until the issues 

38 identified in the court’s decision are appropriately addressed by the Commission. In CLI-12-16, 

39 the Commission also noted that the decision not to issue licenses only applies to final license 

40 issuance; all licensing reviews and proceedings should continue to move forward. 

41 In addition, the Commission directed, in SRM-COMSECY-12-0016 (NRC 2012b), that the NRC 

42 staff proceed with a rulemaking that includes the development of a generic environmental 

43 impact statement (EIS) to support a revised Waste Confidence Rule and to publish both the EIS 

44 and the revised decision and rule in the Federal Register within 24 months (by 

45 September 2014). The Commission indicated that both the EIS and the revised Waste 

46 Confidence Rule should build on the information already documented in various NRC studies 

47 and reports, including the existing environmental assessment that the NRC developed as part of 
Environmental Impacts of the Uranium Fuel Cycle,

Solid Waste Management, and Greenhouse Gas Emissions

6-3 

1 the 2010 Waste Confidence Decision and Rule. The Commission directed that any additional 

2 analyses should focus on the issues identified in the court’s decision. The Commission also 

3 directed that the NRC staff provide ample opportunity for public comment on both the draft EIS 

4 and the proposed rule.

5 The revised rule and supporting EIS are expected to provide the necessary NEPA analyses of 

6 waste confidence-related human health and environmental issues. As directed by the 

7 Commission, the NRC will not issue a renewed license before the resolution of waste 

8 confidence-related issues. This will ensure that there will be no irretrievable or irreversible 

9 resource commitments or potential harm to the environment before waste confidence impacts 

10 have been addressed. 

11 If the results of the Waste Confidence Rule and supporting EIS identify information that requires 

12 a supplement to this SEIS, the NRC staff will perform any appropriate additional NEPA review 

13 for those issues before the NRC makes a final licensing decision. 

14 6.2 Greenhouse Gas Emissions

15 This section discusses the potential impacts from greenhouse gases (GHGs) emitted from the 

16 nuclear fuel cycle. The GEIS does not directly address these emissions, and its discussion is 

17 limited to an inference that substantial carbon dioxide (CO2) emissions may occur if coal- or 

18 oil-fired alternatives to license renewal are carried out.

19 6.2.1 Existing Studies

20 Since the development of the GEIS, the relative volumes of GHGs emitted by nuclear and other 

21 electricity generating methods have been widely studied. However, estimates and projections 

22 of the carbon footprint of the nuclear power lifecycle vary depending on the type of study done. 

23 Additionally, considerable debate also exists among researchers on the relative effects of 

24 nuclear and other forms of electricity generation on GHG emissions. Existing studies on GHG 

25 emissions from nuclear power plants generally take two different forms:

26 (4) qualitative discussions of the potential to use nuclear power to reduce GHG emissions and 

27 mitigate global warming, and

28 (5) technical analyses and quantitative estimates of the actual amount of GHGs generated by 

29 the nuclear fuel cycle or entire nuclear power plant life cycle and comparisons to the 

30 operational or life cycle emissions from other energy generation alternatives. 

31 6.2.1.1 Qualitative Studies

32 The qualitative studies consist primarily of broad, large-scale public policy, or investment 

33 evaluations of whether an expansion of nuclear power is likely to be a technically, economically, 

34 or politically workable means of achieving global GHG reductions. Studies the staff found 

35 during the subsequent literature search include the following:

36  Evaluations to determine if investments in nuclear power in developing 

37 countries should be accepted as a flexibility mechanism to assist 

38 industrialized nations in achieving their GHG reduction goals under the Kyoto 

39 Protocols (IAEA 2000, NEA 2002, Schneider 2000). Ultimately, the parties to 

40 the Kyoto Protocol did not approve nuclear power as a component under the 

41 clean development mechanism (CDM) because of safety and waste disposal 

42 concerns (NEA 2002).
Environmental Impacts of the Uranium Fuel Cycle, 

Solid Waste Management, and Greenhouse Gas Emissions

6-4 

1  Analyses developed to assist governments, including the United States, in 

2 making long-term investment and public policy decisions in nuclear power 

3 (Hagen et al. 2001, Keepin 1988, MIT 2003).

4 Although the qualitative studies sometimes reference and critique the existing quantitative 

5 estimates of GHGs produced by the nuclear fuel cycle or life cycle, their conclusions generally 

6 rely heavily on discussions of other aspects of nuclear policy decisions and investment, such as 

7 safety, cost, waste generation, and political acceptability. Therefore, these studies typically are 

8 not directly applicable to an evaluation of GHG emissions associated with the proposed license 

9 renewal for a given nuclear power plant.

10 6.2.1.2 Quantitative Studies

11 A large number of technical studies, including calculations and estimates of the amount of 

12 GHGs emitted by nuclear and other power generation options, are available in the literature and 

13 were useful in the staff’s efforts to address relative GHG emission levels. Examples of these 

14 studies include—but are not limited to—Mortimer (1990), Andseta et al. (1998), Spadaro (2000), 

15 Storm van Leeuwen and Smith (2008), Fritsche (2006), Parliamentary Office of Science and 

16 Technology (POST) (2006), Atomic Energy Authority (AEA) (2006), Weisser (2006), Fthenakis 

17 and Kim (2007), and Dones (2007). In addition, Sovacool (2008) provides a review and 

18 synthesis of studies in existence through 2008; however, the Sovacool synthesis ultimately uses 

19 only 19 of the 103 studies initially considered (the remaining 84 were excluded because they 

20 were more than 10 years old, not publicly available, available only in a language other than 

21 English, or they presented methodological challenges by relying on inaccessible data, providing 

22 overall GHG estimates without allocating relative GHG impacts to different parts of the nuclear 

23 lifecycle, or they were otherwise not methodologically explicit).

24 Comparing these studies and others like them is difficult because the assumptions and 

25 components of the lifecycles that the authors evaluate vary widely. Examples of areas in which 

26 differing assumptions make comparing the studies difficult include the following:

27  energy sources that may be used to mine uranium deposits in the future,

28  reprocessing or disposal of spent nuclear fuel,

29  current and potential future processes to enrich uranium and the energy 

30 sources that will power them,

31  estimated grades and quantities of recoverable uranium resources,

32  estimated grades and quantities of recoverable fossil fuel resources,

33  estimated GHG emissions other than CO2, including the conversion to CO2

34 equivalents per unit of electric energy produced,

35  performance of future fossil fuel power systems,

36  projected capacity factors for alternatives means of generation, and

37  current and potential future reactor technologies.

38 In addition, studies may vary with respect to whether all or parts of a power plant’s lifecycle are 

39 analyzed (i.e., a full lifecycle analysis will typically address plant construction, operations, 

40 resource extraction—for fuel and construction materials, and decommissioning), whereas a 

41 partial lifecycle analysis primarily focuses on operational differences. In addition, as 

42 Sovacool (2008) noted, studies vary greatly in terms of age, data availability, and 

43 methodological transparency.
Environmental Impacts of the Uranium Fuel Cycle,

Solid Waste Management, and Greenhouse Gas Emissions

6-5 

1 In the case of license renewal, a GHG analysis for the portion of the plant’s lifecycle attributable 

2 to license renewal (operation for an additional 20 years) would not involve GHG emissions 

3 associated with construction because construction activities already have been completed at the 

4 time of relicensing. In addition, the proposed action of license renewal also would not involve 

5 additional GHG emissions associated with facility decommissioning because that 

6 decommissioning must occur whether the facility is relicensed or not. However, in many 

7 studies, the specific contribution of GHG emissions from construction, decommissioning, or 

8 other portions of a plant’s lifecycle cannot be clearly separated from one another. In such 

9 cases, an analysis of GHG emissions would overestimate the GHG emissions attributed to a 

10 specific portion of a plant’s lifecycle. As Sovacool (2008) noted, many of the available analyses 

11 provide markedly lower GHG emissions per unit of plant output when one assumes that a power 

12 plant operates for a longer period of time. Nonetheless, available studies supply some 

13 meaningful information on the relative magnitude of the emissions among nuclear power plants 

14 and other forms of electric generation, as discussed in the following sections.

15 In Tables 6–2, 6–3, and 6–4, the staff presents the results of the above-mentioned quantitative 

16 studies to supply a weight-of-evidence evaluation of the relative GHG emissions that may result 

17 from the proposed license renewal compared to the potential alternative use of coal-fired, 

18 natural gas-fired, and renewable generation. Most studies from Mortimer (1990) onward 

19 (through Sovacool 2008) indicate that uranium ore grades and uranium enrichment processes 

20 are leading determinants in the ultimate GHG emissions attributable to nuclear power 

21 generation. These studies show that the relatively lower order of magnitude of GHG emissions 

22 from nuclear power, when compared to fossil-fueled alternatives (especially natural gas), could

23 potentially disappear if available uranium ore grades drop sufficiently while enrichment 

24 processes continued to rely on the same technologies.

25 Sovacool’s synthesis of 19 existing studies found that nuclear power generation causes carbon 

26 emissions in a range of 1.4 grams of carbon equivalent per kilowatt-hour (g Ceq/kWh) to 

27 288 g Ceq/kWh, with a mean value of 66 g Ceq/kWh. The results of his synthesis and the results 

28 of others’ efforts are included in the tables in this section.

29 6.2.1.3 Summary of Nuclear Greenhouse Gas Emissions Compared to Coal

30 Considering that coal fuels the largest share of electricity generation in the United States and 

31 that its burning results in the largest emissions of GHGs for any of the likely alternatives to 

32 nuclear power generation, including GGNS, many of the available quantitative studies focused 

33 on comparing the relative GHG emissions of nuclear to coal-fired generation. The quantitative 

34 estimates of the GHG emissions associated with the nuclear fuel cycle (and, in some cases, the 

35 nuclear lifecycle), as compared to an equivalent coal-fired plant, are presented in Table 6–2. 

36 The following table does not include all existing studies, but it gives an illustrative range of 

37 estimates that various sources have developed.
Environmental Impacts of the Uranium Fuel Cycle, 

Solid Waste Management, and Greenhouse Gas Emissions

6-6 

1 Table 6–2. Nuclear Greenhouse Gas Emissions Compared to Coal

Source GHG Emission Results

Mortimer (1990) Nuclear—230,000 tons CO2 

Coal—5,912,000 tons CO2

Note: Future GHG emissions from nuclear to increase because of 

declining ore grade.

Andseta et al. (1998) Nuclear energy produces 1.4% of the GHG emissions compared to coal.

Note: Future reprocessing and use of nuclear-generated electrical 

power in the mining and enrichment steps are likely to change the 

projections of earlier authors, such as Mortimer (1990). 

Spadaro (2000) Nuclear—2.5–5.7 g Ceq/kWh

Coal—264–357 g Ceq/kWh

Fritsche (2006) (values 

estimated from graph in 

Figure 4)

Nuclear—33 g Ceq/kWh

Coal—950 g Ceq/kWh

POST (2006) (nuclear 

calculations from AEA 2006)

Nuclear—5 g Ceq/kWh

Coal—>1,000 g Ceq/kWh

Note: Decrease of uranium ore grade to 0.03% would raise nuclear to 

6.8 g Ceq/kWh. Future improved technology and carbon capture and 

storage could reduce coal-fired GHG emissions by 90%. 

Weisser (2006) (compilation 

of results from other studies)

Nuclear—2.8–24 g Ceq/kWh

Coal—950–1,250 g Ceq/kWh

Sovacool (2008) Nuclear—66 g Ceq/kWh

Coal —960–1,050 g Ceq/kWh

(coal adopted from Gagnon et al. 2002)

2 6.2.1.4 Summary of Nuclear Greenhouse Gas Emissions Compared to Natural Gas

3 The quantitative estimates of the GHG emissions associated with the nuclear fuel cycle (and, in 

4 some cases, the nuclear lifecycle), as compared to an equivalent natural gas-fired plant, are 

5 presented in Table 6–3. The following table does not include all existing studies, but it gives an 

6 illustrative range of estimates various sources have developed.
Environmental Impacts of the Uranium Fuel Cycle,

Solid Waste Management, and Greenhouse Gas Emissions

6-7 

1 Table 6–3. Nuclear Greenhouse Gas Emissions Compared to Natural Gas

Source GHG Emission Results

Spadaro (2000) Nuclear—2.5–5.7 g Ceq/kWh

Natural gas—120–188 g Ceq/kWh

Storm van Leeuwen and 

Smith (2008) 

Nuclear fuel cycle produces 20–33% of the GHG emissions compared to 

natural gas (at high ore grades).

Note: Future nuclear GHG emissions will increase because of declining 

ore grade.

Fritsche (2006) (values 

estimated from graph in 

Figure 4)

Nuclear—33 g Ceq/kWh

Cogeneration combined cycle natural gas—150 g Ceq/kWh

POST (2006) (nuclear 

calculations from AEA, 2006)

Nuclear—5 g Ceq/kWh

Natural gas—500 g Ceq/kWh

Note: Decrease of uranium ore grade to 0.03% would raise nuclear to 

6.8 g Ceq/kWh. Future improved technology and carbon capture and 

storage could reduce natural gas GHG emissions by 90%. 

Weisser (2006) (compilation 

of results from other studies)

Nuclear—2.8–24 g Ceq/kWh

Natural gas—440–780 g Ceq/kWh

Dones (2007) Author critiqued methods and assumptions of Storm van Leeuwen and 

Smith (2005), and concluded that the nuclear fuel cycle produces 

15-27% of the GHG emissions of natural gas.

Sovacool (2008) Nuclear—66 g Ceq/kWh 

Natural gas—443 g Ceq/kWh 

(natural gas adopted from Gagnon et al. 2002)

2 6.2.1.5 Summary of Nuclear Greenhouse Gas Emissions Compared to Renewable Energy 

3 Sources

4 The quantitative estimates of the GHG emissions associated with the nuclear fuel cycle (and, in 

5 some cases, the nuclear lifecycle), as compared to equivalent renewable energy sources, are 

6 presented in Table 6–4. Calculation of GHG emissions associated with these sources is more 

7 difficult than the calculations for nuclear energy and fossil fuels because of the large variation in 

8 efficiencies and capacity factors because of their different technologies, sources, and locations. 

9 For example, the efficiency of solar and wind energy is highly dependent on the wind or solar 

10 resource in a particular location. Similarly, the range of GHG emissions estimates for 

11 hydropower varies greatly depending on the type of dam or reservoir involved (if used at all). 

12 Therefore, the GHG emissions estimates for these energy sources have a greater range of 

13 variability than the estimates for nuclear and fossil fuel sources. The following table does not 

14 include all existing studies, but it gives an illustrative range of estimates various sources have 

15 developed.
Environmental Impacts of the Uranium Fuel Cycle, 

Solid Waste Management, and Greenhouse Gas Emissions

6-8 

1 Table 6–4. Nuclear Greenhouse Gas Emissions Compared to Renewable Energy Sources

Source GHG Emission Results

Mortimer (1990) Nuclear—230,000 tons CO2 

Hydropower—78,000 tons CO2 

Wind power—54,000 tons CO2 

Tidal power—52,500 tons CO2

Note: Future GHG emissions from nuclear are expected to increase 

because of declining ore grade.

Spadaro (2000) Nuclear—2.5–5.7 g Ceq/kWh

Solar PV—27.3–76.4 g Ceq/kWh

Hydroelectric—1.1–64.6 g Ceq/kWh

Biomass—8.4–16.6 g Ceq/kWh

Wind—2.5–13.1 g Ceq/kWh

Fritsche (2006) (values 

estimated from graph in 

Figure 4)

Nuclear—33 g Ceq/kWh

Solar PV—125 g Ceq/kWh

Hydroelectric—50 g Ceq/kWh

Wind—20 g Ceq/kWh

POST (2006) (nuclear 

calculations from AEA 2006)

Nuclear—5 g Ceq/kWh

Biomass—25–93 g Ceq/kWh

Solar PV—35–58 g Ceq/kWh

Wave/Tidal—25–50 g Ceq/kWh

Hydroelectric—5–30 g Ceq/kWh

Wind—4.64–5.25 g Ceq/kWh

Note: Decrease of uranium ore grade to 0.03% would raise nuclear to 

6.8 g Ceq/kWh. 

Weisser (2006) (compilation 

of results from other studies)

Nuclear—2.8–24 g Ceq/kWh

Solar PV—43–73 g Ceq/kWh

Hydroelectric—1–34 g Ceq/kWh

Biomass—35–99 g Ceq/kWh

Wind—8–30 g Ceq/kWh

Fthenakis and Kim (2007) Nuclear—16–55 g Ceq/kWh

Solar PV—17–49 g Ceq/kWh

Sovacool (2008) (adopted 

from other studies)

Nuclear—66 g Ceq/kWh 

Wind—9–10 g Ceq/kWh 

Hydroelectric (small, distributed)—10–13 g Ceq/kWh

Biogas digester—11 g Ceq/kWh

Solar thermal—13 g Ceq/kWh

Biomass—14–35 g Ceq/kWh

Solar PV—32 g Ceq/kWh

Geothermal (hot, dry rock)—38 g Ceq/kWh

(solar PV value adopted from Fthenakis et al. 2008; all other 

renewable generation values adopted from Pehnt 2006)

2 6.2.2 Conclusions: Relative Greenhouse Gas Emissions

3 The sampling of data presented in Tables 6–2, 6–3, and 6–4 demonstrates the challenges of 

4 any attempt to determine the specific amount of GHG emission attributable to nuclear energy 

5 production sources because different assumptions and calculation methods will yield differing 
Environmental Impacts of the Uranium Fuel Cycle,

Solid Waste Management, and Greenhouse Gas Emissions

6-9 

1 results. The differences and complexities in these assumptions and analyses will further 

2 increase when they are used to project future GHG emissions. Nevertheless, several 

3 conclusions can be drawn from the information presented.

4 First, the various studies show a general consensus that nuclear power currently produces 

5 fewer GHG emissions than fossil-fuel-based electrical generation (e.g., GHG emissions from a 

6 complete nuclear fuel cycle currently range from 2.5–66 grams of carbon equivalent per kilowatt 

7 hour (g Ceq/kWh), as compared to the use of coal plants (264–1,250 g Ceq/kWh) and natural gas 

8 plants (120-780 g Ceq/kWh)). The studies also provide estimates of GHG emissions from five 

9 renewable energy sources based on current technology. These estimates included 

10 solar-photovoltaic (17–125 g Ceq/kWh), hydroelectric (1–64.6 g Ceq/kWh), biomass 

11 (8.4–99 g Ceq/kWh), wind (2.5–30 g Ceq/kWh), and tidal (25–50 g Ceq/kWh). The range of these 

12 estimates is wide, but the general conclusion is that current GHG emissions from nuclear power 

13 generation are of the same order of magnitude as from these renewable energy sources.

14 Second, the studies show no consensus on future relative GHG emissions from nuclear power 

15 and other sources of electricity. There is substantial disagreement among the various authors 

16 about the GHG emissions associated with declining uranium ore concentrations, future uranium

17 enrichment methods, and other factors, including changes in technology. Similar disagreement 

18 exists about future GHG emissions associated with coal and natural gas for electricity 

19 generation. Even the most conservative studies conclude that the nuclear fuel cycle currently 

20 produces fewer GHG emissions than fossil-fuel-based sources and is expected to continue to 

21 do so in the near future. The primary difference between the authors is the projected cross-over 

22 date (the time at which GHG emissions from the nuclear fuel cycle exceed those of 

23 fossil-fuel-based sources) or whether cross-over will actually occur. 

24 Considering current estimates and future uncertainties, it appears that GHG emissions 

25 associated with the proposed GGNS relicensing action are likely to be lower than those 

26 associated with fossil fuel-based energy sources. The staff bases this conclusion on the 

27 following rationale:

28  As shown in Tables 6–2 and 6–3, current estimates of GHG emissions from 

29 the nuclear fuel cycle are far below those for fossil fuel-based energy 

30 sources.

31  License renewal of a nuclear power plant such as GGNS may involve 

32 continued GHG emissions caused by uranium mining, processing, and 

33 enrichment, but will not result in increased GHG emissions associated with 

34 plant construction or decommissioning (since the plant will have to be 

35 decommissioned at some point whether the license is renewed or not).

36  Few studies predict that nuclear fuel cycle emissions will exceed those of 

37 fossil fuels within a timeframe that includes the GGNS period of extended 

38 operation. Several studies suggest that future extraction and enrichment 

39 methods, the potential for higher-grade resource discovery, and technology 

40 improvements could extend this timeframe.

41 With respect to the comparison of GHG emissions among the proposed GGNS license renewal 

42 action and renewable energy sources: 

43  It appears likely that there will be future technology improvements and 

44 changes in the type of energy used for mining, processing, manufacturing, 

45 and constructing facilities of all types. 
Environmental Impacts of the Uranium Fuel Cycle, 

Solid Waste Management, and Greenhouse Gas Emissions

6-10

1  Currently, the GHG emissions associated with the nuclear fuel cycle and 

2 renewable energy sources are within the same order of magnitude. 

3  Because nuclear fuel production is the most significant contributor to possible 

4 future increases in GHG emissions from nuclear power—and since most 

5 renewable energy sources lack a fuel component—it is likely that GHG 

6 emissions from renewable energy sources will be lower than those 

7 associated with GGNS at some point during the period of extended operation.

8 The staff provides additional discussion on the contribution of GHG to cumulative air quality 

9 impacts in Section 4.11.2 of this supplemental EIS. 

10 6.3 References

11 75 FR 81032. U.S. Nuclear Regulatory Commission. Consideration of environmental impacts of 

12 temporary storage of spent fuel after cessation of reactor operation. Federal Register

13 75(246):81032-81037. December 23, 2010.

14 75 FR 81037. U.S. Nuclear Regulatory Commission. Waste confidence decision update. 

15 Federal Register 75(246):81037-81076. December 23, 2010.

16 [AEA] AEA Technology. 2006. “Carbon Footprint of the Nuclear Fuel Cycle, Briefing Note.” East 

17 Kilbride. UK: British Energy Group. March 2006. Available at <http://www.british-energy.com/

18 documents/carbon_footprint.pdf> (accessed 21 May 2012).

19 Andseta S, Thompson MJ, Jarrell JP, Pendergast DR. 1998. CANDU Reactors and Greenhouse 

20 Gas Emissions. Proceedings of the 19th Annual Conference, Canadian Nuclear Society; 

21 1998 October 18-21; Toronto, Ontario. Available at <http://www.computare.org/Support%

22 20documents/Publications/Life%20Cycle.htm> (accessed 21 May 2012). 

23 [Entergy] Entergy Operations, Inc. 2011. Grand Gulf Nuclear Station, Unit 1, License Renewal 

24 Application, Appendix E, Applicant’s Environmental Report, Operating License Renewal Stage. 

25 Agencywide Documents Access and Management System (ADAMS) Accession No. 

26 ML11308A234.

27 Dones R. 2007. Critical Note on the Estimation by Storm Van Leeuwen JW and Smith P of the 

28 Energy Uses and Corresponding CO2 Emissions for the Complete Nuclear Energy Chain. 

29 Villigen, Switzerland: Paul Sherer Institute. April 2007. Available at 

30 <http://gabe.web.psi.ch/pdfs/Critical%20note%20GHG%20PSI.pdf> (accessed 21 May 2012).

31 Fritsche UR. 2006. Comparison of Greenhouse-Gas Emissions and Abatement Cost of Nuclear 

32 and Alternative Energy Options from a Life-Cycle Perspective. Freiburg, Germany: Oko-Institut. 

33 January 2006. Available at <http://www.oeko.de/oekodoc/315/2006-017-en.pdf> (accessed 

34 21 May 2012).

35 Fthenakis VM, Kim HC. 2007. Greenhouse-gas emissions from solar-electric and nuclear 

36 power: A life cycle study. Energy Policy 35(4):2549–2557.

37 [IAEA] International Atomic Energy Agency. 2000. Nuclear Power for Greenhouse Gas 

38 Mitigation under the Kyoto Protocol: The Clean Development Mechanism (CDM). Vienna, 

39 Austria: IAEA. November 2000. Available at <http://www.iaea.org/Publications/Booklets/

40 GreenhouseGas/greenhousegas.pdf> (accessed 22 May 2012).
Environmental Impacts of the Uranium Fuel Cycle,

Solid Waste Management, and Greenhouse Gas Emissions

6-11

1 Mortimer N. 1990. World warms to nuclear power. SCRAM Safe Energy Journal Dec 89/Jan90. 

2 Available at <http://www.no2nuclearpower.org.uk/articles/mortimer_se74.php> (accessed 

3 22 May 2012).

4 [NEA and OECD] Nuclear Energy Agency and the Organization for Economic Co-operation and 

5 Development. 2002. Nuclear Energy and the Kyoto Protocol. Paris, France: OECD. Available at 

6 <http://www.nea.fr/ndd/reports/2002/nea3808-kyoto.pdf> (accessed 22 May 2012).

7 [NRC] U.S. Nuclear Regulatory Commission. Code Manual for MACCS2: Volume 1, User’s 

8 Guide. Washington, DC. NRC. NUREG/CR–6613. May 1998. ADAMS Accession 

9 No. ML063550020.

10 [NRC] U.S. Nuclear Regulatory Commission. 1999. Section 6.3–Transportation, Table 9.1, 

11 Summary of findings on NEPA issues for license renewal of nuclear power plants. In: Generic 

12 Environmental Impact Statement for License Renewal of Nuclear Plants. Washington, DC: 

13 NRC. NUREG–1437, Volume 1, Addendum 1. August 1999. ADAMS Accession 

14 No. ML04069720. 

15 [NRC] U.S. Nuclear Regulatory Commission. 2012a. “Commission, Memorandum and Order 

16 CLI-12-16.” August 7, 2012. ADAMS Accession No. ML12220A094.

17 [NRC] U.S. Nuclear Regulatory Commission. 2012b. “SRM-COMSECY-12-0016–Approach for 

18 Addressing Policy Issues Resulting from Court Decision To Vacate Waste Confidence Decision 

19 and Rule.” September 6, 2012. ADAMS Accession No. ML12250A032.

20 [POST] Parliamentary Office of Science and Technology. 2006. Carbon footprint of electricity 

21 generation. Postnote 268. October 2006. Available at <http://www.parliament.uk/

22 documents/post/postpn268.pdf> (accessed 22 May 2012).

23 Schneider M. 2000. Climate Change and Nuclear Power. Gland, Switzerland: WWF-World 

24 Wildlife Fund for Nature. April 2000. Available at <http://assets.panda.org/downloads/

25 fullnuclearreprotwwf.pdf> (accessed 22 May 2012).

26 Sovacool, BK. 2008. “Valuing the Greenhouse Gas Emissions from Nuclear Power: A Critical 

27 Survey.” Energy Policy 36:2940–2953. 

28 Spadaro JV, Langlois L, Hamilton B. 2000. “Greenhouse Gas Emissions of Electricity 

29 Generation Chains: Assessing the Difference.” Vienna, Austria: International Atomic Energy 

30 Agency. 

31 Storm van Leeuwen JW, Smith P. 2008. Nuclear Power—The Energy Balance. Chaam, 

32 Netherlands: Ceedata Consultancy. February 2008. Available at <http://www.stormsmith.nl/>

33 (accessed 22 May 2012).

34 Weisser D. 2006. A guide to life-cycle greenhouse gas (GHG) emissions from electric supply 

35 technologies. Energy 32(9): 1543–1559. Available at 

36 <http://www.iaea.org/OurWork/ST/NE/Pess/assets/GHG_manuscript_pre37 print_versionDanielWeisser.pdf> (accessed 22 May 2012).

7-1 

1 7.0 ENVIRONMENTAL IMPACTS OF DECOMMISSIONING

2 Environmental impacts from the activities associated with the decommissioning of any reactor

3 before or at the end of an initial or renewed license are evaluated in Supplement 1 of 

4 NUREG-0586, Final Generic Environmental Impact Statement on Decommissioning of Nuclear 

5 Facilities Regarding the Decommissioning of Nuclear Power Reactors (NRC 2002). The

6 U.S. Nuclear Regulatory Commission (NRC) staff’s (the staff’s) evaluation of the environmental 

7 impacts of decommissioning—presented in NUREG-0586, Supplement 1—notes a range of 

8 impacts for each environmental issue.

9 Additionally, the incremental environmental impacts associated with decommissioning activities 

10 resulting from continued plant operation during the renewal term are discussed in 

11 NUREG-1437, Generic Environmental Impact Statement (GEIS) for License Renewal of Nuclear 

12 Plants (NRC 1996, 1999). The GEIS includes a determination of whether the analysis of the 

13 environmental issue could be applied to all plants and whether additional mitigation measures 

14 would be warranted. Issues were then assigned a Category 1 or a Category 2 designation. 

15 Section 1.4 in Chapter 1 explains the criteria for Category 1 and Category 2 issues and defines 

16 the impact designations of SMALL, MODERATE, and LARGE. The staff analyzed site-specific 

17 issues (Category 2) for Grand Gulf Nuclear Station (GGNS) and assigned them a significance 

18 level of SMALL, MODERATE, or LARGE, or not applicable to GGNS because of site 

19 characteristics or plant features. There are no Category 2 issues related to decommissioning.

20 7.1 Decommissioning

21 Table 7–1 lists the Category 1 issues in Table B–1 of Title 10 of the Code of Federal 

22 Regulations (CFR) Part 51, Subpart A, Appendix B that are applicable to GGNS

23 decommissioning following the renewal term.

24 Table 7–1. Issues Related to Decommissioning

Issues GEIS section Category

Radiation doses 7.3.1; 7.4 1 

Waste management 7.3.2; 7.4 1 

Air quality 7.3.3; 7.4 1 

Water quality 7.3.4; 7.4 1 

Ecological resources 7.3.5; 7.4 1 

Socioeconomic impacts 7.3.7; 7.4 1 

25 Decommissioning would occur whether GGNS were shut down at the end of its current 

26 operating license or at the end of the period of extended operation. There are no site-specific 

27 issues related to decommissioning.

28 A brief description of the staff’s review and the GEIS conclusions, as codified in Table B–1, 

29 10 CFR Part 51, for each of the issues follows:

30 Radiation doses. Based on information in the GEIS, the NRC noted that “[d]oses to the public 

31 will be well below applicable regulatory standards regardless of which decommissioning method 
Environmental Impacts of Decommissioning

7-2 

1 is used. Occupational doses would increase no more than 1 person-rem (1 person-mSv) 

2 caused by buildup of long-lived radionuclides during the license renewal term.”

3 Waste management. Based on information in the GEIS, the NRC noted that 

4 “[d]ecommissioning at the end of a 20-year license renewal period would generate no more 

5 solid wastes than at the end of the current license term. No increase in the quantities of 

6 Class C or greater than Class C wastes would be expected.”

7 Air quality. Based on information in the GEIS, the NRC noted that “[a]ir quality impacts of 

8 decommissioning are expected to be negligible either at the end of the current operating term or 

9 at the end of the license renewal term.”

10 Water quality. Based on information in the GEIS, the NRC noted that “[t]he potential for 

11 significant water quality impacts from erosion or spills is no greater whether decommissioning 

12 occurs after a 20-year license renewal period or after the original 40-year operation period, and 

13 measures are readily available to avoid such impacts.”

14 Ecological resources. Based on information in the GEIS, the NRC noted that 

15 “[d]ecommissioning after either the initial operating period or after a 20-year license renewal 

16 period is not expected to have any direct ecological impacts.”

17 Socioeconomic impacts. Based on information in the GEIS, the NRC noted that 

18 “[d]ecommissioning would have some short-term socioeconomic impacts. The impacts would 

19 not be increased by delaying decommissioning until the end of a 20-year relicense period, but 

20 they might be decreased by population and economic growth.”

21 Entergy Operations, Inc. (Entergy) stated in its environmental report (ER) (Entergy 2011) that it 

22 is not aware of any new and significant information on the environmental impacts of GGNS 

23 license renewal. The staff has not found any new and significant information during its 

24 independent review of Entergy’s ER, the site visit, the scoping process, or its evaluation of other 

25 available information. Therefore, the NRC staff concludes that there are no impacts related to 

26 these issues, beyond those discussed in the GEIS. For all of these issues, the NRC staff 

27 concluded in the GEIS that the impacts are SMALL, and additional plant-specific mitigation

28 measures are not likely to be sufficiently beneficial to be warranted.

29 7.2 References

30 10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, “Environmental 

31 protection regulations for domestic licensing and related regulatory functions.”

32 [Entergy] Entergy Operations, Inc. 2011. Grand Gulf Nuclear Station, Unit 1, License Renewal 

33 Application. Appendix E, Applicant’s Environmental Report. Agencywide Documents Access 

34 and Management System (ADAMS) Accession No. ML11308A234.

35 [NRC] U.S. Nuclear Regulatory Commission. 1996. GEIS. NRC. NUREG–1437. May 1996. 

36 ADAMS Accession Nos. ML040690705 and ML040690738.

37 [NRC] U.S. Nuclear Regulatory Commission. 1999. Section 6.3–Transportation, Table 9.1, 

38 Summary of findings on NEPA issues for license renewal of nuclear power plants. In: GEIS. 

39 NRC. NUREG–1437, Volume 1, Addendum 1. August 1999. ADAMS Accession 

40 No. ML04069720.

41 [NRC] U.S. Nuclear Regulatory Commission. 2002. Final Generic Environmental Impact 

42 Statement on Decommissioning of Nuclear Facilities Regarding the Decommissioning of 

43 Nuclear Power Reactors. Washington, DC: NRC. NUREG–0586, Supplement 1. 

44 November 2002. ADAMS Accession Nos. ML023470304 and ML023500295.
8-1 

1 8.0 ENVIRONMENTAL IMPACTS OF ALTERNATIVES

2 The National Environmental Policy Act (NEPA) requires the consideration of a range of 

3 reasonable alternatives to the proposed action in an environmental impact statement (EIS). In 

4 this case, the proposed action is whether to issue a renewed license for Grand Gulf Nuclear 

5 Station (GGNS), which will allow the plant to operate for 20 years beyond its current license 

6 expiration date. A license is just one of many conditions that a licensee must meet in order to 

7 operate its nuclear plant. State regulatory agencies and the owners of the nuclear power plant 

8 ultimately decide whether the plant will operate, and economic and environmental 

9 considerations play a primary role in this decision. The U.S. Nuclear Regulatory Commission

10 (NRC)’s responsibility is to ensure the safe operation of nuclear power facilities and not to 

11 formulate energy policy or encourage or discourage the development of alternative power 

12 generation (or replacement power alternatives). 

13 The license renewal process is designed to assure safe operation of the nuclear power plant 

14 and protection of the environment during the license renewal term. Under the NRC’s 

15 environmental protection regulations in Title 10, Part 51, of the Code of Federal Regulations

16 (10 CFR Part 51), which implement Section 102(2) of NEPA, renewal of a nuclear power plant 

17 operating license requires the preparation of an EIS.

18 To support the preparation of these EISs, the NRC staff (the staff) prepared the Generic 

19 Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437, 

20 in 1996. The license renewal GEIS was prepared to assess the environmental impacts of 

21 continued nuclear power plant operations during the license renewal term. The intent was to 

22 determine which environmental impacts would result in essentially the same impact at all 

23 nuclear power plants and which ones could result in different levels of impacts at different plants 

24 and would require a plant-specific analysis to determine the impacts. For those issues that 

25 could not be generically addressed, the NRC develops a plant-specific supplemental 

26 environmental impact statement (SEIS) to the GEIS.

27 NRC regulations in 10 CFR 51.71(d) for license renewal require that a SEIS consider and weigh

28 the environmental effects of the proposed action [license renewal]; the 

29 environmental impacts of alternatives to the proposed action; and alternatives 

30 available for reducing or avoiding adverse environmental effects[.]

31 While the GEIS reached generic conclusions on many environmental issues associated with 

32 license renewal, it did not determine which alternatives are reasonable or reach conclusions 

33 about site-specific environmental impact levels. As such, the NRC must evaluate environmental 

34 impacts of alternatives on a site-specific basis.

35 As stated in Chapter 1 of this SEIS, alternatives to renewing GGNS’s operating license must 

36 meet the purpose and need for the proposed action. They must do the following: 

37 provide an option that allows for power generation capability beyond the term of 

38 a current nuclear power plant operating license to meet future system generating 

39 needs, as such needs may be determined by State, utility, and, where 

40 authorized, Federal (other than NRC) [decisionmakers]. (NRC 1996)

41 The NRC ultimately makes no decision about which alternative (or the proposed action) to carry 

42 out because that decision falls to the appropriate energy-planning decisionmakers.
Environmental Impacts of Alternatives

8-2 

1 Comparing the environmental effects of these 

2 alternatives will help the NRC decide if the 

3 adverse environmental impacts of license renewal 

4 are great enough to deny the option of license 

5 renewal for energy-planning decisionmakers 

6 (10 CFR 51.95(c)(4)). If the NRC acts to issue a 

7 renewed license, all of the alternatives, including 

8 the proposed action, will be available to 

9 energy-planning decisionmakers. If the NRC 

10 decides not to renew the license, then 

11 energy-planning decisionmakers may no longer 

12 elect to continue operating GGNS and will have to 

13 resort to another alternative—which may or may 

14 not be one of the alternatives considered in this 

15 section—to meet the energy needs that GGNS 

16 now satisfies.

17 In evaluating alternatives to license renewal, 

18 energy technologies or options currently in 

19 commercial operation are considered, as well as 

20 some technologies not currently in commercial 

21 operation but likely to be commercially available 

22 by the time the current GGNS operating license 

23 expires. The current GGNS operating license will expire on November 1, 2024, and reasonable 

24 alternatives must be available (constructed, permitted, and connected to the grid) by the time 

25 the current GGNS license expires to be considered likely to become available.

26 The staff eliminated alternatives that cannot meet future system needs and whose costs or 

27 benefits do not justify inclusion in the range of reasonable alternatives. The staff evaluated the 

28 remaining alternatives, which are discussed in-depth in this chapter. Each alternative 

29 eliminated from detailed study is briefly discussed in Section 8.5, and a basis for its removal is 

30 provided. In total, 16 energy technology options and alternatives to the proposed action were 

31 considered (see text box) and then narrowed to the four alternatives considered in 

32 Sections 8.1–8.4. The no-action alternative is considered in Section 8.6.

33 The GEIS presents an overview of some energy technologies but does not reach any 

34 conclusions about which alternatives are most appropriate. Since 1996, many energy 

35 technologies have evolved significantly in capability and cost, while regulatory structures have 

36 changed to either promote or impede development of particular alternatives.

37 As a result, the analyses include updated information from sources such as the Energy 

38 Information Administration (EIA), other organizations within the U.S. Department of Energy

39 (DOE), the U.S. Environmental Protection Agency (EPA), industry sources and publications, 

40 and information submitted by the applicant in its environmental report (ER).

41 The evaluation of each alternative considers the environmental impacts across seven impact 

42 categories: (1) air quality, (2) groundwater use and quality, (3) surface water use and quality, 

43 (4) ecology, (5) human health, (6) socioeconomics, and (7) waste management. A three-level 

44 standard of significance—SMALL, MODERATE, or LARGE—is used to show the intensity of 

45 environmental effects for each alternative that is evaluated in depth. The order of presentation 

46 is not meant to imply increasing or decreasing level of impact, nor does it imply that an 

47 energy-planning decisionmaker would select one or another alternative.

Alternatives Evaluated In-Depth:

• new nuclear

• natural gas-fired combined cycle (NGCC)

• supercritical coal-fired

• combination alternative (NGCC, demandside management, purchased power, 

and biomass)

Other Alternatives Considered:

• demand-side management

• wind power

• solar power

• hydroelectric power

• wave and ocean energy

• geothermal power

• municipal solid waste

• biomass

• oil-fired power

• fuel cells

• purchased power

• delayed retirement
Environmental Impacts of Alternatives

8-3 

1 For each alternative where it is feasible to do so, the NRC considers the environmental effects 

2 of locating the alternative at the existing GGNS site. Selecting the existing plant site allows for 

3 the maximum use of existing transmission and cooling system infrastructures and minimizes the 

4 overall environmental impact.

5 In addition, to ensure that the alternatives analysis is consistent with State and regional energy 

6 policies, the NRC reviewed energy relevant statutes, regulations, and policies. The NRC also 

7 considered the current generation capacity mix and electricity production data within Mississippi, 

8 where GGNS is located and production data for Entergy’s six operating companies that operate 

9 under a System Agreement. The System Agreement allows the operating companies to share 

10 generating capacity power reserves, provides the basis for the planning, construction and 

11 operation of electric generation and transmission, and regulates the price for wholesale 

12 electricity used or exchanged by the Entergy operating companies (Entergy 2012). In 2010, 

13 electric generators in Mississippi had an installed generating capacity of approximately 

14 15,691 megawatts electric (MWe). This capacity included units fueled by natural gas 

15 (74 percent), coal (16 percent), nuclear (8 percent), and biomass-fired generation (1.5 percent)

16 (EIA 2012a). In 2010, the electric industry in Mississippi provided approximately 54.5 million

17 megawatt-hours of electricity. Electricity produced in Mississippi was dominated by natural gas

18 (54 percent) followed by coal (25 percent), nuclear (18 percent), and biomass-fired generation

19 (2.8 percent) (EIA 2012a).

20 Sections 8.1–8.4 describe the environmental impacts of alternatives to license renewal. These 

21 alternatives include a new nuclear generation option in Section 8.1; a new natural gas-fired 

22 combined-cycle (NGCC) plant in Section 8.2; a new supercritical pulverized coal (SCPC) plant 

23 in Section 8.3; and a combination alternative of NGCC, demand-side management (DSM), 

24 purchased power, and biomass-fired generation in Section 8.4. A summary of these 

25 alternatives considered in depth is provided in Table 8–1. In Section 8.5, alternatives 

26 considered but eliminated from detailed study are briefly discussed. Finally, Section 8.6 

27 describes environmental effects that may occur if the NRC takes no action and does not issue a 

28 renewed license for GGNS. Section 8.7 summarizes the impacts of each of the alternatives 

29 considered in detail.
Environmental Impacts of Alternatives

8-4 

1 Table 8–1. Summary of Alternatives Considered In Depth

New Nuclear 

Alternative

Natural Gas 

(NGCC) 

Alternative

Supercritical 

Pulverized Coal 

(SCPC) 

Alternative

Combination 

Alternative

Summary of 

Alternative

One unit ESBWR 

nuclear plant

Three 530-MWe 

units for a total of 

1,590 MWe

Three 583-MWe 

SCPC units (total 

of 1,749 MWe) 

One 530-MWe 

NGCC unit; Nine 

50-MW biomass

units (360 MWe

total); 280 MWe 

from DSM; and 

305 MWe from 

purchased power

Location At GGNS; Would 

use existing 

infrastructure, 

including Ranney 

wells, draft cooling 

tower, and 

transmission lines

At GGNS; Would 

use existing 

infrastructure, 

including Ranney 

wells, draft cooling 

tower, and 

transmission lines

An existing power 

plant site (other 

than GGNS) in 

Mississippi; Some 

infrastructure 

upgrades may be 

required 

NGCC at GGNS; 

Biomass units at 9 

sites throughout 

Mississippi; DSM 

and purchased 

power throughout 

Mississippi 

Cooling 

System

Ranney wells; 

Consumptive water 

use would be 

similar to GGNS 

Unit 1

Ranney wells; 

Consumptive water 

use would be less 

than GGNS Unit 1

Closed-cycle with 

natural-draft 

cooling towers; 

Consumptive 

water use would 

be similar to 

GGNS Unit 1

NGCC unit same 

as the NGCC 

alternative but 

water use would be 

1/3 less; Closedcycle cooling for 

biomass units

Land 

Requirements

234 ac (95 ha) 

(Entergy 2011); 

1,000 ac (400 ha) 

for uranium mining 

and processing 

(NRC 1996)

195 acres (79 

hectares) (NRC 

1996); 5,700 ac 

(2,307 ha) for wells, 

collection site, 

pipeline (NRC 

1996)

2,744 ac (1,110 

ha) for the plant 

(NRC 1996); 

35,508 ac (14,370 

ha) for coal mining 

and waste 

disposal (NRC 

1996)

NGCC unit 

approximately 1/3 

the land as for the 

NGCC alternative; 

15 ac (6 ha) for 

each 50-MWe 

biomass unit, for a 

total of 135 ac 

(55 ha) (NREL 

2003, Palmer 

Renewable Energy 

2011)

Work Force 3,150 during 

construction; 690 

during operations 

(Entergy 2011)

1,900 during 

construction; 150 

during operations 

(NRC 1996)

4,035 during 

construction; 404 

during operations 

(NRC 1996)

NGCC portion 

would require 633 

during construction 

and 50 during 

operations 

(NRC 1996); 

Biomass units

would require 450 

during construction 

and 198 during 

operations

2 8.1 New Nuclear Generation

3 In this section, the NRC evaluates the environmental impacts of a new nuclear generation 

4 alternative at the GGNS site.
Environmental Impacts of Alternatives

8-5 

1 The NRC considers the construction of a new nuclear plant to be a reasonable alternative to 

2 GGNS license renewal because nuclear generation currently provides baseload power in 

3 Entergy’s service territory and Entergy has expressed interest in adding nuclear generation to 

4 its energy portfolio. For example, on October 16, 2003, an application was submitted for an 

5 early site permit (ESP) on the existing GGNS site and the NRC issued an ESP on April 7, 2007 

6 (NRC 2012a). An ESP is an NRC approval of a site for one or more nuclear power facilities. 

7 Before construction and operation of any new nuclear unit(s), Entergy would need to obtain a 

8 construction permit and operating license. On February 27, 2008, Entergy submitted an 

9 application for a combined operating license (COL) for an Economic Simplified Boiling-Water 

10 Reactor (ESBWR) at the GGNS site. On January 9, 2009, Entergy informed the NRC that it 

11 was considering alternate reactor design technologies and requested that the NRC suspend its 

12 review effort (NRC 2012b). Entergy continues to evaluate the potential for new nuclear 

13 generation and could pursue it as an option for meeting long-term baseload needs in the future 

14 (Entergy 2009, 2010). Although the ESP does not specify a scheduled timeline, the NRC 

15 determined that there is sufficient time for Entergy to prepare and submit an application, build, 

16 and operate a new nuclear unit before the GGNS license expires in November 2024. This 

17 section presents the environmental impacts of the new nuclear generation alternative, which 

18 includes constructing and operating one new nuclear plant at the GGNS site.

19 In evaluating the new nuclear alternative, the NRC assumed that a replacement reactor would 

20 be installed on the GGNS site, allowing for the maximum use of existing ancillary facilities such 

21 as the cooling system and transmission infrastructure. The GGNS site is situated on 

22 2,100 acres (ac) (850 hectares [ha]), of which, approximately 1,000 ac (405 ha), is in a 

23 floodplain and not suitable for plant construction. The remaining 1,100 ac (445 ha) would be 

24 sufficient for construction of a new nuclear plant (Entergy 2011). The NRC assumed that the 

25 replacement reactor would be an ESBWR. Although the NRC has suspended its review of the 

26 COL application, it uses information from the ESP EIS in the following sections, where 

27 applicable, because it provides a site-specific environmental analysis of a new nuclear plant at 

28 the GGNS site. 

29 For the purpose of this analysis, the NRC assumed that the new reactor would have a net 

30 electrical output of 1,475 MWe, which would be the same output as the existing reactor. 

31 Entergy (2008) estimated that 234 ac (95 ha) would be required for new reactor construction for 

32 the power block and ancillary facilities, and that sufficient acreage was available on the GGNS 

33 site. The heat-rejection demands of a new nuclear unit would be similar to those of the existing 

34 reactor. Therefore, the NRC assumed that the new reactor would use the existing cooling 

35 system (including natural draft cooling towers and intake and discharge structures), and that no 

36 structural modifications would be needed. The existing transmission lines leaving the site, as 

37 well as construction, drinking water and Ranney wells are expected to serve the new reactor 

38 with no modifications required. 

39 The NRC also considered the installation of multiple small and modular reactors at the GGNS 

40 site as an alternative to renewing the GGNS license. The NRC established the Advanced 

41 Reactor Program in the Office of New Reactors because of considerable interest in small and 

42 modular reactors along with anticipated license applications by vendors. As of December 2012, 

43 the NRC has not received any applications. Because there are no applications to construct and 

44 operate small modular reactors on a commercial scale, this analysis focused on nuclear 

45 generation by larger nuclear units.

46 8.1.1 Air Quality

47 As discussed in Section 2.2.2.1, the GGNS site is located in Claiborne County, Mississippi, 

48 which is on the western edge of the Mobile (Alabama)-Pensacola-Panama City 
Environmental Impacts of Alternatives

8-6 

1 (Florida)-Southern Mississippi Interstate Air Quality Control Region (AQCR) (40 CFR 81.68). 

2 The area across the Mississippi River from the site is in the Monroe (Louisiana)-El Dorado 

3 (Arkansas) Interstate AQCR (40 CFR 81.92). EPA has designated all of the counties in these 

4 AQCRs adjacent to the GGNS site as in compliance with the National Ambient Air Quality 

5 Standards (NAAQS) (40 CFR 81.310). The State of Mississippi is in attainment with primary 

6 and secondary NAAQS for all criteria pollutants, except De Soto County, which is located about 

7 200 miles (322 km) north-northeast of GGNS and part of which is a marginal nonattainment

8 area for the 2008 8-hour ozone standard.

9 Construction activities for a new nuclear alternative would cause some localized temporary air 

10 quality impacts because of fugitive dust emissions from operation of earth-moving and 

11 material-handling equipment. Emissions from construction worker vehicles and motorized 

12 construction equipment exhaust would be temporary. The NRC assumes that mitigation

13 measures, including wetting of unpaved roads and construction areas, and seeding or mulching 

14 bare areas would control and reduce fugitive dust. 

15 During operations, a new nuclear alternative would have air emissions similar to those of the 

16 existing GGNS plant. These emissions are primarily from testing of emergency generators and 

17 diesel pumps and the periodic use of auxiliary boilers or generators during outages (Entergy 

18 2011). The NRC expects a new nuclear alternative to have similar air permitting conditions and 

19 regulatory requirements as the existing plant. For example, a new nuclear alternative would be 

20 subject to conditions in an air permit established by the Mississippi Department of 

21 Environmental Quality (MDEQ) (Entergy 2011). 

22 Subpart P of 40 CFR Part 51 contains the visibility protection regulatory requirements, including 

23 the review of new sources to be constructed in attainment or unclassified areas that may affect 

24 visibility in any mandatory Class I Federal area (designated national parks and wilderness 

25 areas). If a new nuclear plant were located close to a mandatory Class I Federal area, 

26 additional air pollution control requirements may be required. As noted in Section 2.2.2.1, there 

27 are no mandatory Class I Federal areas within 186 mi (300 km) of the GGNS site.

28 8.1.1.1 Greenhouse Gases

29 Operation of a new nuclear alternative would have similar effects on climate change as the 

30 existing GGNS (which are discussed in Section 4.2). Operation of the reactor does not result in 

31 the release of GHGs. However, GHG emissions do result from some activities, such as the 

32 periodic use of auxiliary boilers or generators, worker vehicles, and motorized construction 

33 equipment exhaust. The impacts on climate from a new nuclear alternative on the GGNS site 

34 would be SMALL. 

35 8.1.1.2 Conclusion

36 The overall air quality impacts of a new nuclear plant located at the GGNS site would not 

37 noticeably alter air quality, therefore, air quality impacts would be SMALL.

38 8.1.2 Groundwater Resources

39 The amount of groundwater required for construction of a new nuclear alternative would be 

40 much less than required during plant operation. Water for construction would be obtained from 

41 the existing Ranney wells. Groundwater quality and use impacts from construction of a new 

42 nuclear alternative are expected to be SMALL.

43 The amount of water required to operate a new nuclear power plant would be similar to that 

44 required for the existing power plant. Cooling water would be obtained from the existing 

45 Ranney wells. The potable water system would operate from existing wells using similar 
Environmental Impacts of Alternatives

8-7 

1 chemicals, processes, and withdrawal rates as the existing GGNS facility. Groundwater quality 

2 and use impacts from operation of a new nuclear alternative are expected to be SMALL.

3 8.1.3 Surface Water Resources 

4 If dredging of streams or rivers occurs during construction, surface water quality immediately 

5 downstream of the dredging activities could be temporarily degraded by increases in suspended 

6 sediment concentration. During operation, a new nuclear alternative would discharge blowdown 

7 from the cooling system at approximately the same rate as the existing unit. Stormwater 

8 discharge, blowdown, sanitary, and other effluents, would be regulated under a National 

9 Pollutant Discharge Elimination System (NPDES) permit. Given that the discharge rate and 

10 composition would be similar to the existing plant and regulated by an NPDES permit and the 

11 effects of any dredging needed for construction would be temporary, the impacts to surface 

12 water use and quality are expected to be SMALL. 

13 8.1.4 Aquatic Ecology

14 Construction activities for the new nuclear alternative (such as construction of heavy-haul roads 

15 and the power block) could affect onsite aquatic features, including the Mississippi River near 

16 GGNS, Hamilton and Gin Lakes, a borrow pit, three small ponds, streams “A” and “B,” and 

17 ephemeral drainages. Minimal impacts on aquatic ecology resources are expected because the 

18 plant operator would likely implement best management practices (BMPs) to minimize erosion 

19 and sedimentation. Stormwater control measures, which would be required to comply with 

20 Mississippi NPDES permitting, would minimize the flow of disturbed soils into aquatic features. 

21 To bring new materials to the site, the plant operator would dredge near the barge slip to 

22 transport some materials using barges, which could result in increased sedimentation and 

23 turbidity within aquatic habitats in the Mississippi River. Permits and certifications from the 

24 U.S. Army Corps of Engineers and other agencies would require the implementation of BMPs to 

25 minimize impacts. Due to the short-term nature of the dredging activities, the hydrological 

26 alterations to aquatic habitats would be localized and temporary.

27 During operations, the new nuclear alternative would require a similar amount of cooling water 

28 to be withdrawn from Ranney wells and a similar amount of water to be discharged into the 

29 Mississippi River as required for GGNS. The number of fish and other aquatic resources 

30 affected by cooling water discharge operations, such as thermal stress, would be similar to 

31 those of GGNS. 

32 Consultation under several Federal acts, including the Endangered Species Act (ESA) and 

33 Magnuson-Stevens Act, would be required to assess the occurrence and potential impacts to 

34 Federally protected aquatic species and habitats within affected surface waters. Coordination 

35 with State natural resource agencies would further ensure that Entergy would take appropriate 

36 steps to avoid or mitigate impacts to State-listed species, habitats of conservation concern, and 

37 other protected species and habitats. The NRC assumes that these consultations would result 

38 in avoidance or mitigation measures that would minimize or eliminate potential impacts to 

39 protected aquatic species and habitats.

40 The impacts on aquatic ecology would be minor because erosion and sedimentation would be 

41 minimized by BMPs during construction and stormwater and surface water discharges would be 

42 managed by regulatory permits similar to the existing plant. Therefore, the staff concludes that 

43 impacts on aquatic ecology would be SMALL
Environmental Impacts of Alternatives

8-8 

1 8.1.5 Terrestrial Ecology

2 Entergy estimates that construction of a new nuclear alternative, including a reactor unit and 

3 auxiliary facilities would affect 234 ac (95 ha) of land on the GGNS site, which is a slightly 

4 smaller area of land than that disturbed for construction of GGNS. A new nuclear alternative 

5 would use existing site infrastructure, transmission lines, and cooling system to the extent 

6 practicable. Thus, only minimal disturbances to undisturbed land would occur for a new nuclear 

7 alternative. However, the level of direct impacts would vary based on the specific location of 

8 new buildings and infrastructure on the site. Erosion and sedimentation, fugitive dust, and 

9 construction debris impacts would be minor with implementation of appropriate BMPs. 

10 Construction noise could modify wildlife behavior; however, these effects would be temporary. 

11 Road improvements or construction of additional service roads to facilitate construction could 

12 result in the temporary or permanent loss of terrestrial habitat. Impacts to terrestrial habitats 

13 and species from the operation of a new nuclear alternative would be similar to those of GGNS 

14 and would, therefore, be SMALL. Impacts to terrestrial habitats and species from transmission 

15 line operation and corridor vegetation maintenance would be similar in magnitude and intensity 

16 to those resulting from operating nuclear reactors and would, therefore, be SMALL. The offsite 

17 land requirement (1,000 ac [400 ha]) and impacts associated with uranium mining and fuel 

18 fabrication to support a new nuclear alternative would be no different from those occurring in 

19 support of GGNS. Overall, the impacts from construction of a new nuclear alternative on 

20 terrestrial species and habitats would be MODERATE, and the impacts of operation would be 

21 SMALL.

22 As discussed under aquatic ecology impacts, consultation with U.S. Fish and Wildlife Service

23 (FWS) under the ESA would avoid potential adverse impacts to Federally listed species or 

24 adverse modification or destruction of designated critical habitat. Coordination with State 

25 natural resource agencies would further ensure that Entergy would take appropriate steps to 

26 avoid or mitigate impacts to State-listed species, habitats of conservation concern, and other 

27 protected species and habitats. The NRC assumes that these consultations would result in 

28 avoidance or mitigation measures that would minimize or eliminate potential impacts to 

29 protected terrestrial species and habitats. Consequently, the impacts of construction and 

30 operation of a new nuclear alternative on protected species and habitats would be SMALL.

31 8.1.6 Human Health

32 Impacts on human health from construction of a new nuclear alternative would be similar to 

33 impacts associated with the construction of any major industrial facility. Compliance with worker 

34 protection rules would control those impacts on workers at acceptable levels. Impacts from 

35 construction on the general public would be minimal because the plant operator would limit 

36 active construction area access to authorized individuals assuming BMPs are followed. Impacts 

37 on human health from the construction of a new nuclear alternative would be SMALL.

38 The human health effects from the operation of a new nuclear alternative would be similar to 

39 those of the existing GGNS plant. Therefore, impacts on human health from the operation of a 

40 new nuclear alternative would be SMALL.

41 8.1.7 Land Use

42 The GEIS generically evaluates the impacts of constructing and operating various replacement 

43 power plant alternatives on land use, both on and off each plant site. The analysis of land use 

44 impacts focuses on the amount of land area that would be affected by the construction and 

45 operation of a new single-unit nuclear power plant at the GGNS site.
Environmental Impacts of Alternatives

8-9 

1 Entergy estimated 234 ac (95 ha) of land would be needed to construct and operate a new 

2 single-unit nuclear power plant on the GGNS site (Entergy 2011). A sufficient amount of land is 

3 available on the GGNS site for a new nuclear power plant. Maximizing the use of the 

4 established infrastructure at the existing nuclear power plant site would further reduce the 

5 amount of additional land needed to support the new unit. Land use impacts from constructing 

6 and operating one new unit at the GGNS site would be SMALL.

7 The GEIS also estimated an additional 1,000 acres (400 ha) of land would be affected by 

8 uranium mining and processing during the life of the new nuclear alternative. Impacts 

9 associated with uranium mining and fuel fabrication to support the new nuclear alternative would 

10 generally be no different from those occurring in support of the existing GGNS facility. Since the 

11 new unit would be located at GGNS, overall land use impacts from a new nuclear alternative 

12 would be SMALL.

13 8.1.8 Socioeconomics 

14 Socioeconomic impacts are defined in terms of changes to the demographic and economic 

15 characteristics and social conditions of a region. For example, the number of jobs created by 

16 the construction and operation of a power plant could affect regional employment, income, and 

17 expenditures.

18 This alternative would create two types of jobs: (1) construction jobs, which are transient, short 

19 in duration, and less likely to have a long-term socioeconomic impact; and (2) power plant 

20 operation jobs, which have a greater potential for permanent, long-term socioeconomic impacts. 

21 Workforce requirements for the construction and operation of the new nuclear generation 

22 alternative were evaluated to measure its possible effects on current socioeconomic conditions.

23 Entergy estimated a construction workforce of up to 3,150 (maximum) workers would be 

24 required to build a single-unit nuclear plant (Entergy 2011). The relative economic impact of 

25 construction workers on the local economy and tax base would vary, with the greatest impacts 

26 occurring in the communities where the majority of construction workers reside and spend their 

27 income. As a result, local communities could experience a short-term economic “boom” from 

28 increased tax revenue and income generated by construction worker expenditures and the 

29 increased demand for temporary (rental) housing and business services. After completing 

30 construction of the new nuclear plant, local communities could experience a return to 

31 pre-construction economic conditions. Given the magnitude of the estimated number of 

32 workers, socioeconomic impacts during construction in communities near the GGNS site could 

33 range from SMALL to LARGE.

34 Entergy estimated that 690 operations workers would be required at a new nuclear power plant, 

35 which is equivalent to the number of operations workers at GGNS (Entergy 2011). GGNS 

36 operations workers would likely transfer from the existing facility to the new nuclear power plant. 

37 This would not have a noticeable effect on socioeconomic conditions in the region. 

38 Socioeconomic impacts associated with the operation of a new nuclear alternative at the GGNS 

39 site would therefore be SMALL.

40 8.1.9 Transportation

41 Transportation impacts associated with construction and operation of a new nuclear alternative 

42 would consist of commuting workers and truck deliveries of construction materials to the power 

43 plant site. During periods of peak construction activity, up to 3,150 workers could be commuting 

44 daily to the site (Entergy 2011). Workers commuting to the construction site would use site 

45 access roads and the volume of traffic on nearby roads could increase substantially during shift 
Environmental Impacts of Alternatives

8-10

1 changes. In addition to commuting workers, trucks would be transporting construction materials 

2 and equipment to the worksite, thus increasing the amount of traffic on local roads. The 

3 increase in vehicular traffic would peak during shift changes, resulting in temporary levels of 

4 service impacts and delays at intersections. Materials also could be delivered by barge to the 

5 GGNS site. Traffic-related transportation impacts during construction likely would range from 

6 MODERATE to LARGE. 

7 Traffic-related transportation impacts on local roads would be greatly reduced after construction 

8 is completed. The estimated number of operations workers would be 690 (Entergy 2011). 

9 Transportation impacts would include daily commuting by the operating workforce, equipment

10 and materials deliveries, and the removal of commercial waste material to offsite disposal or 

11 recycling facilities by truck. Traffic-related transportation impacts would be similar to those 

12 experienced during current operations at GGNS, because the new unit would employ the same 

13 number of workers as GGNS currently employs. Overall, for a new nuclear alternative, 

14 transportation impacts would be SMALL during operations.

15 8.1.10 Aesthetics

16 The analysis of aesthetic impacts focuses on the degree of contrast between the new nuclear 

17 alternative and the surrounding landscape and the visibility of the new power plant. 

18 During construction, clearing and excavation would occur on site. Some of these activities may 

19 be visible from offsite roads. Since the GGNS site already appears industrial, construction of 

20 the new plant would appear similar to onsite activities during refueling outages. 

21 During reactor operations, the visual appearance of the GGNS site would not change since the 

22 power block for the new nuclear reactor would look virtually identical to the existing GGNS 

23 power block. Adding a new reactor unit would increase the overall size of developed land at the 

24 GGNS site. Given the industrial appearance of the GGNS site and the similarity of the new unit 

25 to the existing unit, the new reactor unit would blend in with the surroundings. In addition, the 

26 amount of noise generated during reactor operations of a new nuclear alternative would be the 

27 same as those generated during existing GGNS operations, which consists predominantly of the 

28 noise from routine industrial processes and communications. In general, aesthetic changes 

29 would be limited to the immediate vicinity of the GGNS site, and any impacts would be SMALL.

30 8.1.11 Historic and Archaeological Resources

31 The potential for impacts on historic and archaeological resources from a new nuclear 

32 alternative would vary greatly depending on the location of the proposed plants on the GGNS 

33 site. Any construction on the GGNS site would need to avoid the previously identified Grand 

34 Gulf Mound area (Site 22Cb522) and Archaic Period village (22Cb528), as described in 

35 Section 2.2.10.2 of this document. As portions of the GGNS site have been previously 

36 identified as not containing significant historic and archaeological resources, use of these areas 

37 for the new nuclear alternative would result in a SMALL impact on historic and archaeological 

38 resources. Alternate plant locations on the GGNS site would need to be surveyed and 

39 inventoried for potential resources. Resources found in these surveys would need to be 

40 evaluated for eligibility on the National Register of Historic Properties (NRHP) and mitigation of 

41 adverse effects would need to be addressed if eligible resources were encountered. The level 

42 of impact at these locations would vary depending on the specific resources found to be present 

43 in the area of potential effect. However, given that the preference is to use previously surveyed 

44 and/or disturbed areas, avoidance of significant historic and archaeological resources should be 

45 possible and effectively managed under current laws and regulations. Therefore, the impacts 

46 on historic and archaeological resources from the new nuclear alternative would be SMALL. 
Environmental Impacts of Alternatives

8-11

1 8.1.12 Environmental Justice

2 The environmental justice impact analysis evaluates the potential for disproportionately high and 

3 adverse human health, environmental, and socioeconomic effects on minority and low-income 

4 populations that could result from the construction and operation of a new power plant. Adverse 

5 health effects are measured in terms of the risk and rate of fatal or nonfatal adverse impacts on 

6 human health. Disproportionately high and adverse human health effects occur when the risk or 

7 rate of exposure to an environmental hazard for a minority or low-income population is 

8 significant and exceeds the risk or exposure rate for the general population or for another 

9 appropriate comparison group. Disproportionately high environmental effects refer to impacts or 

10 risk of impact on the natural or physical environment in a minority or low-income community that 

11 are significant and appreciably exceed the environmental impact on the larger community. 

12 Such effects may include biological, cultural, economic, or social impacts. Some of these 

13 potential effects have been discussed in the other sections of this chapter. For example, 

14 increased demand for rental housing during replacement power plant construction could 

15 disproportionately affect low-income populations that rely on inexpensive rental housing.

16 Section 4.9.7, Environmental Justice, presents demographic information about minority and low17 income populations living near the GGNS site. 

18 Potential impacts to minority and low-income populations from the construction of a new nuclear 

19 power plant at the GGNS site would mostly consist of environmental and socioeconomic effects 

20 (e.g., noise, dust, traffic, employment, and housing impacts). Noise and dust impacts during 

21 construction would be short-term and primarily limited to onsite activities. Minority and low22 income populations residing along site access roads would be directly affected by increased 

23 commuter vehicle and truck traffic. However, because of the temporary nature of construction,

24 these effects are not likely to be high and adverse and would be contained to a limited time 

25 period during certain hours of the day. Increased demand for rental housing during construction 

26 could cause rental costs to rise disproportionately affecting low-income populations living near 

27 GGNS who rely on inexpensive housing. However, given the proximity of GGNS to the 

28 Jackson and Vicksburg metropolitan areas, some workers could commute to the construction

29 site, thereby reducing the need for rental housing. 

30 Potential impacts to minority and low-income populations from nuclear power plant operations 

31 would be similar to those of the existing GGNS plant. Radiation doses from the new nuclear 

32 power plant are expected to be well below regulatory limits. People living near the power plant 

33 would be exposed to the same potential effects from the existing GGNS power plant operations 

34 and any impacts would depend on the magnitude of the change in ambient air quality

35 conditions. Permitted air emissions are expected to remain within regulatory standards. 

36 Based on this information and the analysis of human health and environmental impacts 

37 presented in this section, the construction and operation of a new nuclear power plant would not 

38 have disproportionately high and adverse human health and environmental effects on minority 

39 and low-income populations living near GGNS.

40 8.1.13 Waste Management

41 During the construction of a new nuclear plant, land clearing and other construction activities 

42 would generate waste that could be recycled, disposed of on site, or shipped to an offsite waste 

43 disposal facility. Because the new nuclear plant would be constructed on the previously 

44 disturbed GGNS site, the amount of wastes produced would be less than comparable 

45 construction on an unimproved property.
Environmental Impacts of Alternatives

8-12

1 During the operational stage, normal plant operations, routine plant maintenance, and cleaning 

2 activities would generate nonradioactive waste as well as mixed waste, low-level waste, and 

3 high-level waste. Quantities of nonradioactive waste (discussed in Section 2.1.3 of this 

4 document) and radioactive waste (discussed in Section 6.1 of this document) generated by 

5 GGNS would be comparable to that generated by a new nuclear alternative.

6 According to the GEIS (NRC 1996), the generation and management of solid nonradioactive 

7 and radioactive waste during the license renewal term is not expected to result in significant 

8 environmental impacts. A new single-unit nuclear plant would generate waste streams similar 

9 to the existing nuclear plant. Based on this information, waste impacts would be SMALL for a 

10 new single-unit nuclear plant located at the GGNS site.

11 8.1.14 Summary of Impacts of New Nuclear Generation

12 Table 8–2 summarizes the environmental impacts of the new nuclear alternative compared to 

13 continued operation of GGNS.

14 Table 8–2. Summary of Environmental Impacts of the New Nuclear Alternative

15 Compared to Continued Operation of GGNS

Category New Nuclear Generation

(use existing infrastructure)

Continued GGNS Operation

Air Quality SMALL SMALL

Groundwater Resources SMALL SMALL

Surface Water Resources SMALL SMALL

Aquatic Ecology SMALL SMALL

Terrestrial Ecology SMALL to MODERATE SMALL

Human Health SMALL SMALL

Land Use SMALL SMALL

Socioeconomics SMALL to LARGE SMALL

Transportation SMALL to LARGE SMALL

Aesthetics SMALL SMALL

Historic and Archaeological

Resources

SMALL SMALL

Waste Management a SMALL SMALL a As described in Chapter 6, the issue, "offsite radiological impacts (spent fuel and high level waste disposal)," is not 

evaluated in this EIS.

16 8.2 Natural Gas-Fired Combined-Cycle Generation

17 In this section, the NRC evaluates the environmental impacts of natural gas-fired 

18 combined-cycle (NGCC) generation at the GGNS site.

19 In 2010, natural gas accounted for 54 percent of all electricity generated in Mississippi, a 

20 144 percent increase from 10 years earlier in 2000 (EIA 2012b). Natural gas provides the 

21 greatest share of electrical power in Mississippi (EIA 2012b). Development of new natural 

22 gas-fired plants may be affected by perceived or actual action to limit greenhouse gas (GHG) 

23 emissions. Like other fossil fuel sources, natural gas-fired plants are a source of GHG, 

24 principally carbon dioxide (CO2). A gas-fired power plant, however, produces significantly fewer 

25 GHGs per unit of electrical output than other fossil fuel-powered plants. In addition, NGCC 

26 systems can have high capacity factors and are capable of economically providing baseload 

27 power. Natural gas-fired power plants are a feasible and commercially available option for 

28 providing baseload electrical generating capacity beyond GGNS’s current license expiration. 
Environmental Impacts of Alternatives

8-13

1 Therefore, the NRC considered NGCC generation a reasonable alternative to GGNS license 

2 renewal.

3 NGCC plants differ considerably from coal-fired boilers and existing nuclear power plants. 

4 NGCC plants obtain the majority of their electrical output from a gas-turbine and subsequently 

5 generate additional power through a second steam turbine-cycle without any fuel combustion. 

6 This combined-cycle approach provides greater thermal efficiency than a single-cycle system, 

7 with efficiencies reaching 60 percent (as compared to typical thermal efficiencies of coal-fired 

8 plants of 39 percent) (Siemens 2007, NETL 2007). Because the natural gas-fired alternative 

9 generates much of its power from a gas-turbine combined-cycle plant and the overall thermal 

10 efficiency of this type of plant is high, an NGCC alternative would require less cooling water than 

11 GGNS. Thus, the NRC assumed that the NGCC alternative would use the existing cooling 

12 system (including natural draft cooling towers and intake and discharge structures), and that the 

13 cooling system at GGNS could meet the heat-rejection demands of the NGCC alternative with 

14 no structural modifications.

15 To replace the 1,475 MWe that GGNS generates, the NRC considered three hypothetical 

16 gas-fired units, each with a net capacity of 530 MWe, for the NGCC alternative. For purposes of 

17 this analysis, the hypothetical units would be similar to General Electric’s (GE’s) H-class 

18 gas-fired combined-cycle units. While any number of commercially available combined-cycle 

19 units could be installed in a variety of combinations to replace the power GGNS currently 

20 produces, GE’s H-class units are highly efficient models that would minimize environmental 

21 impacts. Other manufacturers, such as Siemens, offer similar high efficiency models.

This 1,590 MWe NGCC plant would consume 70.7 billion cubic feet (ft3 22 ) (2,000 million cubic 

meters [m3 23 ]) of natural gas annually, assuming an average heat content of 1,020 British thermal 

unit(s) per cubic feet (BTU/ft3 24 ). Natural gas would be extracted from the ground through wells, 

25 then treated to remove impurities (such as hydrogen sulfide), and blended to meet pipeline gas 

26 standards before arriving at the plant site. This gas-fired alternative would produce relatively 

27 little waste, primarily in the form of spent catalysts used for control of nitrogen oxide (NOx) 

28 emissions.

29 GGNS is situated on a 2,100 ac (850 ha) site. Approximately 1,000 ac (405 ha) are located in a 

30 floodplain and not suitable for a NGCC plant, and 169 ac (68 ha) are dedicated to existing 

31 GGNS facilities and structures. Entergy’s ER concluded that buildable land of sufficient acreage 

32 and appropriate location would be available to support an onsite NGCC plant (Entergy 2011). 

33 Site crews would clear vegetation, prepare the site surface and relocate existing facilities, if 

34 necessary, and begin excavations for foundations and buried utilities before other crews begin 

35 actual construction on the plant and associated infrastructure. The three NGCC units would be 

36 approximately 100 feet (ft) (30 meters [m]) tall, with two exhaust stacks up to 150 ft (46 m) tall. 

37 Also, offsite impacts would occur as a result of construction of a natural gas pipeline connecting 

38 the site to existing infrastructure. 

39 8.2.1 Air Quality

40 The GGNS site is located in Claiborne County, Mississippi, which is on the western edge of the 

41 Mobile (Alabama)-Pensacola-Panama City (Florida)-Southern Mississippi Interstate Air Quality 

42 Control Region (AQCR) (40 CFR 81.68). The area across the Mississippi River from the site is 

43 in the Monroe (Louisiana)-El Dorado (Arkansas) Interstate AQCR (40 CFR 81.92). EPA has 

44 designated all of the counties in these AQCRs adjacent to the GGNS site as in compliance with 

45 the National Ambient Air Quality Standards (NAAQS) (40 CFR 81.310). The State of 

46 Mississippi is in attainment with NAAQS for all criteria pollutants, except De Soto County, which 
Environmental Impacts of Alternatives

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1 is located about 200 miles (322 km) north-northeast of GGNS and part of which recently was 

2 designated as a marginal nonattainment area for the 2008 8-hour ozone standard.

3 Construction activities for this alternative would generate fugitive dust. However, mitigation

4 measures, including wetting of unpaved roads and construction areas, and seeding or mulching 

5 bare areas would minimize fugitive dust. Construction worker vehicles and motorized 

6 construction equipment would create exhaust emissions. However, these emissions would end 

7 upon completion of construction. 

8 Various Federal and state regulations aimed at controlling air pollution would affect a fossil 

9 fuel-fired power plant, including an NGCC alternative located in Mississippi. A new NGCC 

10 plant, which will be located in an attainment or unclassified area, would qualify as a new 

11 major-emitting industrial facility and would be subject to Prevention of Significant Deterioration 

12 (PSD) requirements under the Clean Air Act (CAA) (EPA 2012a). The NGCC alternative would 

13 need to comply with the standards of performance for electric utility steam generating units set 

14 forth in 40 CFR Part 60 Subpart KKKK. The plant also would require an operating permit from 

15 MDEQ. 

16 If the NGCC alternative were located close to a mandatory Class I area, additional air pollution 

17 control requirements would be required (Subpart P of 40 CFR Part 51) as mandated by the 

18 Regional Haze Rule. The rule would likely not apply to this NGCC alternative, however, 

19 because there are no Class I Federal areas within 186 mi (300 km) of the GGNS site 

20 (EPA 2012b). 

21 The emissions from the NGCC alternative, projected by the staff based on published EIA data, 

22 EPA emission factors, performance characteristics for this alternative, and likely emission 

23 controls, would be:

24  sulfur oxides (SOx)—123 tons (111 metric tons [MT]) per year

25  nitrogen oxides (NOx)—469 tons (425 MT) per year

26  particulate matter ≤ 10 μm (PM10) and ≤ 2.5 μm (PM2.5)—238 tons (216 MT) 

27 per year

28  carbon monoxide (CO)—1,082 tons (982 MT) per year

29  carbon dioxide (CO2)—4.0 million tons (3.6 million MT) per year

30 8.2.1.1 Sulfur Oxide and Nitrogen Oxide

31 As stated above, the NGCC alternative would produce 123 tons (111 MT) per year of SOx and 

32 469 tons (425 MT) per year of NOx based on the use of dry low-NOx combustion technology and 

33 use of selective catalytic reduction to significantly reduce NOx emissions. The new plant would 

34 be subjected to the continuous monitoring requirements of SO2 and NOx as specified in 

35 40 CFR Part 75. 

36 8.2.1.2 Greenhouse Gases

37 The NGCC alternative would release GHGs, such as CO2 and methane. The NGCC alternative 

38 would emit approximately 4.0 million tons (approximately 3.6 million MT) per year of CO2

39 emissions. The plant would be subjected to continuous monitoring requirements for CO2, as 

40 specified in 40 CFR Part 75. 

41 On July 12, 2012, EPA issued a final rule tailoring the criteria that determine which stationary 

42 sources and modification to existing projects become subject to permitting requirements for 

43 GHG emissions under the PSD and Title V Programs of the CAA (77 FR 41051). According to 

44 this rule, GHGs are a regulated new source review pollutant under the PSD major source 
Environmental Impacts of Alternatives

8-15

1 permitting program if the source is otherwise subject to PSD (for another regulated new source 

2 review pollutant) and has a GHG potential to emit equal to or greater than 75,000 tons 

3 (68,000 MT) per year of CO2 equivalent (“carbon dioxide equivalent” adjusts for different global 

4 warming potentials for different GHGs). Beginning January 2, 2011, operating permits issued to 

5 major sources of GHGs under the PSD or Title V Federal permit programs must contain 

6 provisions requiring the use of Best Available Control Technology (BACT) to limit the emissions 

7 of GHGs if those sources would be subject to PSD or Title V permitting requirements. If the 

8 NGCC alternative meets the GHG emission thresholds established in the rule, then GHG 

9 emissions from this alternative would be regulated under the PSD and Title V permit programs. 

10 8.2.1.3 Particulates

11 The NGCC alternative would produce uncontrolled emission of 238 tons (216 MT) per year of 

12 particulates, all of which would be emitted as PM10 and PM2.5. Small amounts of particulate 

13 would be released as drift from the cooling tower. However, because the NGCC facility would 

14 have a smaller heat rejection demand than GGNS, the drift would be less than what is currently 

15 released from the cooling tower at GGNS.

16 As described above, onsite activities during the construction of an NGCC plant would generate 

17 fugitive dust as well as exhaust emissions from vehicles and motorized equipment. These 

18 impacts would be short-term and construction crews would use applicable dust control 

19 measures to minimize dust generation. 

20 8.2.1.4 Hazardous Air Pollutants

21 In December 2000, EPA issued regulatory findings (65 FR 79825) on emissions of hazardous 

22 air pollutants (HAPs) from electric utility steam-generating units, which identified that natural 

23 gas-fired plants emit HAPs such as arsenic, formaldehyde and nickel and stated:

24 . . . the impacts due to HAP emissions from natural gas-fired electric utility steam 

25 generating units were negligible based on the results of the study. The 

26 Administrator finds that regulation of HAP emissions from natural gas-fired 

27 electric utility steam generating units is not appropriate or necessary. 

28 As a result of the EPA Administrator’s conclusion, the staff finds no significant air quality effects 

29 from HAPs.

30 8.2.1.5 Conclusion

31 The impact from SO2 and NOX emissions would be noticeable and subject to a Title V permit. 

32 GHG emissions also would be noticeable; CO2 emissions would be almost two orders of 

33 magnitude larger than the threshold in EPA’s tailoring rule for GHG (75,000 tons [68,000 MT]

34 per year of carbon dioxide equivalent) that would trigger a regulated new source review. The 

35 overall air quality impacts associated with construction and operation of an NGCC alternative 

36 located at the GGNS site would be SMALL to MODERATE.

37 8.2.2 Groundwater Resources

38 The amount of groundwater required for construction of the NGCC alternative would be much 

39 less than required during plant operation. Water for construction would be obtained from the 

40 existing Ranney wells. Groundwater quality and use impacts from construction of the NGCC 

41 alternative are expected to be SMALL.

42 The amount of water required to operate the three-unit NGCC alternative would be less than 

43 that required for the existing power plant. Cooling water would be obtained from the existing 

44 Ranney wells. Potable water and other plant groundwater requirements would be similar to 
Environmental Impacts of Alternatives

8-16

1 GGNS. Groundwater quality and use impacts from operation of the NGCC alternative are 

2 expected to be SMALL.

3 8.2.3 Surface Water Resources

4 If dredging of streams or rivers occurs during construction, surface water quality immediately 

5 downstream of the dredging activities could be temporarily degraded by increased suspended 

6 sediment. During plant operations, an NGCC alternative would discharge cooling system

7 blowdown at approximately half of the current facility rate. Stormwater discharge, blowdown, 

8 sanitary, and other effluents would be permitted under an NPDES permit. Given these 

9 assumptions, the impacts on surface water use and quality would be SMALL.

10 8.2.4 Aquatic Ecology

11 Construction activities for the NGCC alternative (such as construction of heavy-haul roads, a 

12 new pipeline, and the power block) could affect onsite aquatic features, including the Mississippi 

13 River near GGNS, Hamilton and Gin Lakes, a borrow pit, three small ponds, streams “A” and 

14 “B,” and ephemeral drainages. Minimal impacts on aquatic resources are expected because 

15 the plant operator would likely implement BMPs to minimize erosion and sedimentation. 

16 Stormwater control measures, which would be required to comply with Mississippi NPDES

17 permitting, would minimize the flow of disturbed soils into aquatic habitats. To bring new 

18 materials to the site, NRC assumed the plant operator would dredge near the barge slip to 

19 transport some materials using barges, which could result in increased sedimentation and 

20 turbidity within aquatic habitats in the Mississippi River. Permits and certifications from the 

21 U.S. Army Corps of Engineers and other agencies would require the implementation of BMPs to 

22 minimize impacts. Due to the short-term nature of the dredging activities, the hydrological 

23 alterations to aquatic habitats would be localized and temporary.

24 During operations, the NGCC alternative would require less cooling water to be withdrawn from 

25 Ranney wells, and less water to be discharged into the Mississippi River than required for 

26 GGNS. Therefore, thermal impacts would be less for the NGCC alternative than GGNS. The 

27 cooling system for a new NGCC plant would have similar chemical discharges as GGNS. Air 

28 emissions from the NGCC plant would emit particulates that would settle onto the river surface 

29 and introduce a new source of pollutants as described in Section 8.1.1. However, the flow of 

30 the Mississippi River would likely dissipate and dilute the concentration of pollutants resulting in 

31 minimal exposure to aquatic biota. 

32 Consultation under several Federal acts, including the ESA and Magnuson-Stevens Act, would 

33 be required to assess the occurrence and potential impacts to Federally protected aquatic 

34 species and habitats within affected surface waters. Coordination with State natural resource 

35 agencies would further ensure that the NGCC operator would take appropriate steps to avoid or 

36 mitigate impacts to State-listed species, habitats of conservation concern, and other protected 

37 species and habitats. The NRC assumes that these consultations would result in avoidance or 

38 mitigation measures that would minimize or eliminate potential impacts to protected aquatic 

39 species and habitats.

40 The impacts on aquatic ecology would be minor because construction activities would require 

41 BMPs and stormwater management permits. Also, surface water discharge for this alternative 

42 would be less than for GGNS. Deposition of pollutants into aquatic habitats from the plant’s air 

43 emissions would be minimal because the concentration of pollutants would be diluted with the 

44 river flow. Therefore, the staff concludes that impacts on aquatic ecology would be SMALL.
Environmental Impacts of Alternatives

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1 8.2.5 Terrestrial Ecology

2 Construction of an NGCC alternative would occur on the GGNS site and would use existing 

3 transmission lines. Because the onsite land requirement is relatively small (225 ac [91 ha]), the 

4 entire NGCC alternative construction footprint would likely be sited in already developed areas 

5 of the GGNS site, which would minimize impacts to terrestrial habitats and species. However, 

6 the level of direct impacts would vary based on the specific location of new buildings and 

7 infrastructure on the site. Offsite construction would occur mostly on land where gas extraction 

8 is already occurring. Erosion and sedimentation, fugitive dust, and construction debris impacts 

9 would be minor with implementation of BMPs. Construction noise could modify wildlife 

10 behavior; however, these effects would be temporary. Road improvements or construction of 

11 additional service roads to facilitate construction could result in the temporary or permanent loss 

12 of terrestrial habitat. Construction of gas pipelines along existing, previously disturbed utility 

13 corridors would result in temporary noise and displacement of wildlife, but would minimize the 

14 removal or destruction of undisturbed habitats. Impacts to terrestrial habitats and species from 

15 transmission line operation and corridor vegetation maintenance, and operation of the cooling 

16 towers would be similar in magnitude and intensity as those resulting from GGNS and would, 

17 therefore, be SMALL. Overall, the impacts of construction and operation of an NGCC 

18 alternative to terrestrial habitats and species would be SMALL to MODERATE.

19 As discussed under aquatic ecology impacts, consultation with the FWS under the ESA would 

20 ensure that the construction and operation of an NGCC alternative would not adversely affect 

21 any Federally listed species or adversely modify or destroy designated critical habitat. 

22 Coordination with State natural resource agencies would further ensure that the NGCC operator 

23 would take appropriate steps to avoid or mitigate impacts to State-listed species, habitats of 

24 conservation concern, and other protected species and habitats. The NRC assumes that these 

25 consultations would result in avoidance or mitigation measures that would minimize or eliminate 

26 potential impacts to protected terrestrial species and habitats. Consequently, the impacts of 

27 construction and operation of a new nuclear alternative on protected species and habitats would 

28 be SMALL.

29 8.2.6 Human Health

30 Impacts on human health from construction of the NGCC alternative would be similar to impacts 

31 associated with the construction of any major industrial facility. Compliance with worker 

32 protection rules would control those impacts on workers at acceptable levels. The plant 

33 operator would likely follow BMPs, such as limiting active construction area access to 

34 authorized individuals. Impacts on human health from the construction of the NGCC alternative 

35 would be SMALL.

36 During operations, human health effects of gas-fired generation are generally low. However, in 

37 Table 8.2 of the GEIS (NRC 1996), the staff identified cancer and emphysema as potential 

38 health risks from gas-fired plants. NOx emissions contribute to ozone formation, which in turn 

39 contributes to human health risks. Emission controls on the NGCC alternative can be expected 

40 to maintain NOx emissions well below air quality standards established to protect human health, 

41 and emissions trading or offset requirements mean that overall NOx releases in the region would 

42 not increase. Health risks for workers also may result from handling spent catalysts used for 

43 NOx control that may contain heavy metals. However, health risks can be minimized through 

44 the use of occupational health and safety procedures and protective equipment. Impacts on 

45 human health from the operation of the NGCC alternative would be SMALL.
Environmental Impacts of Alternatives

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1 8.2.7 Land Use

2 The GEIS generically evaluates the impact of constructing and operating various replacement 

3 power plant alternatives on land use, both on and off each plant site. The analysis of land use 

4 impacts focuses on the amount of land area that would be affected by the construction and 

5 operation of a three-unit NGCC power plant at the GGNS site. Locating the new NGCC power 

6 plant at the GGNS site would maximize the availability of support infrastructure and reduce the 

7 need for additional land.

8 Entergy estimated 195 acres (79 hectares) would be required for construction of power block, 

9 support facilities and a natural gas pipeline to the nearest natural gas distribution line for a 

10 1,584 MWe NGCC alternative (Entergy 2011). Depending on the location and availability of 

11 existing natural gas pipelines, a 100-ft-wide right-of-way would be needed for a new pipeline. 

12 Land use impacts from NGCC construction would be SMALL to MODERATE.

13 In addition to onsite land requirements, land would be required off site for natural gas wells and 

14 collection stations. Scaling from GEIS estimates, approximately 5,700 ac (2,307 ha) (based on 

15 3,600 ac per 1,000 MWe and 1,584 MWe for NGCC) (NRC 1996) would be required for wells, 

16 collection stations, and pipelines to bring the gas to the plant. Most of this land requirement 

17 would occur on land where gas extraction already occurs. 

18 The elimination of uranium fuel for GGNS would partially offset some of the land requirements 

19 for an NGCC alternative. Scaling from GEIS estimates, approximately 1,033 ac (418 ha) (based 

20 on 35 ac/yr disturbed per 1,000 MWe for 20 yr) would no longer be needed for mining and 

21 processing uranium during the operating life of the plant (NRC 1996). Land use impacts during 

22 power plant operations would be SMALL.

23 8.2.8 Socioeconomics

24 Socioeconomic impacts are defined in terms of changes to the demographic and economic 

25 characteristics and social conditions of a region. For example, the number of jobs created by 

26 the construction and operation of a power plant could affect regional employment, income, and 

27 expenditures.

28 The alternative would create two types of jobs: (1) construction jobs, which are transient, short 

29 in duration, and less likely to have a long-term socioeconomic impact; and (2) power plant 

30 operation jobs, which have a greater potential for permanent, long-term socioeconomic impacts. 

31 Workforce requirements for the construction and operation of the NGCC alternative were 

32 evaluated for their possible effects on current socioeconomic conditions.

33 Scaling from GEIS estimates, the construction workforce would peak at 1,900 workers. The 

34 relative economic impact of this many workers on the local economy and tax base would vary 

35 with the greatest impacts occurring in the communities where the majority of construction 

36 workers would reside and spend their income. As a result, local communities could experience 

37 a short-term economic “boom” from increased tax revenue and income generated by 

38 construction expenditures and the increased demand for temporary (rental) housing and 

39 business services. 

40 After completing the installation of the three-unit NGCC plant, local communities could 

41 experience a return to pre-construction economic conditions. Based on this information and 

42 given the number of workers, socioeconomic impacts during construction in communities near 

43 the GGNS site could range from SMALL to MODERATE.

44 Scaling from GEIS estimates, an NGCC alternative would employ approximately 150 workers

45 during operation. GGNS has an operation workforce of approximately 690. The potential 
Environmental Impacts of Alternatives

8-19

1 reduction in overall employment at the GGNS site would likely affect property tax revenue and 

2 income in local communities and businesses. In addition, the permanent housing market could 

3 also experience increased vacancies and decreased prices if operations workers and their 

4 families move out of the region. Socioeconomic impacts during operations of an NGCC 

5 alternative could range from SMALL to MODERATE.

6 8.2.9 Transportation

7 Transportation impacts associated with construction and operation of an NGCC alternative

8 would consist of commuting workers and truck deliveries of construction materials. During 

9 periods of peak construction activity, up to 1,900 worker would be commuting daily to GGNS, a 

10 substantial increase from the GGNS current operational force of 690 workers. The increase in 

11 vehicular traffic would peak during shift changes, resulting in temporary levels of service 

12 impacts and delays at intersections. Pipeline construction and modification to existing natural 

13 gas pipeline systems could also have a temporary impact. Materials also could be delivered by 

14 barge or rail. Traffic-related transportation impacts during construction likely would be 

15 MODERATE.

16 Traffic-related transportation impacts would be greatly reduced after completing the installation 

17 of the NGCC alternative. Transportation impacts would include daily commuting by the 

18 operating workforce, equipment and materials deliveries, and the removal of commercial waste 

19 material to offsite disposal or recycling facilities by truck. The estimated NGCC alternative 

20 operation workforce of approximately 150 is considerably less than the GGNS operation 

21 workforce of approximately 690. Traffic-related transportation impacts would be considerably 

22 less than current operations because an NGCC alternative would employ far fewer workers than 

23 the existing GGNS. Since fuel is transported by pipeline, the transportation infrastructure would 

24 experience little to no increased traffic from fuel operations. Overall, transportation impacts 

25 would be SMALL during plant operations.

26 8.2.10 Aesthetics

27 The analysis of aesthetic impacts focuses on the degree of contrast between an NGCC 

28 alternative and the surrounding landscape and the visibility of an NGCC alternative at the 

29 GGNS site. During construction, clearing and excavation would occur on site. Some of these 

30 activities may be visible from offsite roads. Since the GGNS site already appears industrial, 

31 construction of an NGCC alternative would appear similar to onsite activities during refueling 

32 outages.

33 The three NGCC units would be approximately 100 ft (30 m) tall, with exhaust stacks up to 

34 150 ft (46 m) tall. The facility would be visible off site during daylight hours, and some 

35 structures may require aircraft warning lights. The plant would use the existing natural draft 

36 cooling tower, which is over 500 ft (152 m) high (Entergy 2011). Noise generated during NGCC 

37 power plant operations would be limited to routine industrial processes and communications. 

38 Pipelines delivering natural gas fuel could be audible off site near gas compressor stations.

39 In general, given the industrial appearance of the GGNS site, an NGCC alternative would blend 

40 in with the surroundings if the existing GGNS facility remains. Aesthetic changes would be 

41 limited to the immediate vicinity of the existing GGNS site, and any impacts would be SMALL.

42 8.2.11 Historic and Archaeological Resources

43 The potential for impacts on historic and archaeological resources from an NGCC alternative 

44 would vary greatly depending on the location of the proposed plants on the GGNS site. Any 
Environmental Impacts of Alternatives

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1 construction would need to avoid the previously identified Grand Gulf Mound area 

2 (Site 22Cb522) and Archaic Period village (22Cb528) as described in Section 2.2.10.2 of this 

3 document. As portions of the GGNS site have been previously identified as not containing 

4 significant historic and archaeological resources, use of these areas for an NGCC alternative 

5 would result in a SMALL impact on historic and archaeological resources. Alternate plant and 

6 new pipeline locations would need to be surveyed and inventoried for potential resources. 

7 Resources found in these surveys would need to be evaluated for eligibility on the National 

8 Register of Historic Places (NRHP) and mitigation of adverse effects would need to be 

9 addressed if eligible resources were encountered. The level of impact at these locations would 

10 vary depending on the specific resources found to be present in the area of potential effect. 

11 However, given that the preference is to use previously surveyed and/or disturbed areas, 

12 avoidance of significant historic and archaeological resources should be possible and effectively 

13 managed under current laws and regulations. Therefore, the impacts on historic and 

14 archaeological resources from the NGCC alternative would be SMALL.

15 8.2.12 Environmental Justice

16 The environmental justice impact analysis evaluates the potential for disproportionately high and 

17 adverse human health, environmental, and socioeconomic effects on minority and low-income 

18 populations that could result from the construction and operation of a new power plant. As 

19 previously discussed in Section 8.1.12, such effects may include human health, biological, 

20 cultural, economic, or social impacts. Section 4.10.7, Environmental Justice, presents 

21 demographic information about minority and low-income populations residing in the vicinity of 

22 the GGNS site.

23 Potential impacts to minority and low-income populations from the construction and operation of 

24 an NGCC alternative at the GGNS site would mostly consist of environmental and 

25 socioeconomic effects (e.g., noise, dust, traffic, employment, and housing impacts). Noise and 

26 dust impacts during construction would be short-term and primarily limited to onsite activities. 

27 Minority and low-income populations residing along site access roads would be directly affected 

28 by increased commuter and truck traffic. However, because of the temporary nature of 

29 construction, these effects are not likely to be high and adverse and would be contained to a 

30 limited time period during certain hours of the day. Increased demand for rental housing during 

31 construction could cause rental costs to rise disproportionately affecting low-income populations 

32 living near GGNS who rely on inexpensive housing. However, given the proximity of GGNS to 

33 the Jackson and Vicksburg metropolitan areas, workers could commute to the construction site, 

34 thereby reducing the need for rental housing.

35 As discussed in Section 4.10.7.1, 144 of the 294 census block groups located within the 50-mi 

36 (80-km) radius of GGNS were determined to have meaningfully greater minority populations 

37 than the other census block groups within the 50-mi (80-km) radius of GGNS. However, 

38 emissions from the NGCC alternative are expected to be maintained within regulatory 

39 standards. Accordingly, disproportionately high and adverse impacts on minority and low 

40 income populations are not expected.

41 Based on this information and the analysis of human health and environmental impacts 

42 presented in this section, the construction and operation of an NGCC alternative would not have 

43 disproportionately high and adverse human health and environmental effects on minority and 

44 low-income populations in the vicinity of GGNS.
Environmental Impacts of Alternatives

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1 8.2.13 Waste Management

2 During the construction stage of this alternative, land clearing and other construction activities 

3 would generate waste that can be recycled, disposed of on site, or shipped to an offsite waste 

4 disposal facility. Because an NGCC alternative would most likely be constructed on previously 

5 disturbed portions of the GGNS site, the amount of wastes produced during land clearing would 

6 be minimal.

7 During the operational stage, spent selective catalytic reduction catalysts used to control NOx

8 emissions would make up the majority of the industrial waste generated by this alternative. 

9 Because the specific NOx emission control equipment cannot be specified at this time, the 

10 amount of spent catalysts that would be generated during each year of operation of the NGCC 

11 alternative also cannot be calculated with precision. However, the amount would be modest. 

12 During operations, domestic and sanitary wastes would be expected to decrease from amounts 

13 now generated because of a reduced operating workforce for the NGCC alternative in 

14 comparison to GGNS. 

15 According to the GEIS (NRC 1996) a natural gas-fired plant would generate minimal waste; 

16 therefore, waste impacts would be SMALL for an NGCC alternative located at the GGNS site.

17 8.2.14 Summary of Impacts of NGCC Alternative

18 Table 8–3 summarizes the environmental impacts of the NGCC alternative compared to 

19 continued operation of GGNS.

20 Table 8–3. Summary of Environmental Impacts of the NGCC Alternative

21 Compared to Continued Operation of GGNS

Category NGCC Alternative

(use existing infrastructure)

Continued GGNS Operation

Air Quality SMALL to MODERATE SMALL

Groundwater Resources SMALL SMALL

Surface Water Resources SMALL SMALL

Aquatic Ecology SMALL SMALL

Terrestrial Ecology SMALL to MODERATE SMALL

Human Health SMALL SMALL

Land Use SMALL to MODERATE SMALL

Socioeconomics SMALL to MODERATE SMALL

Transportation SMALL to MODERATE SMALL

Aesthetics SMALL SMALL

Historic and Archaeological

Resources

SMALL SMALL

Waste Management a SMALL SMALL a As described in Chapter 6, the issue, "offsite radiological impacts (spent fuel and high level waste disposal)," is 

not evaluated in this EIS.

22 8.3 Supercritical Pulverized Coal-Fired Generation

23 In this section, the NRC evaluates the environmental impacts of supercritical pulverized coal 

24 (SCPC) generation.

25 In 2010, coal-fired generation accounted for 25 percent of all electricity generated in Mississippi, 

26 a 32 percent decrease from 10 years earlier in 2000 (EIA 2012b). Coal provides the second 

27 greatest share of electrical power in Mississippi (EIA 2012b). Historically, coal has been the 
Environmental Impacts of Alternatives

8-22

1 largest source of electricity in the United States and is expected to remain so through 2035 

2 (EIA 2011a). Supercritical coal-fired plants are a feasible, commercially available option for 

3 providing electrical generating capacity beyond GGNS’s current license expiration. Therefore, 

4 the NRC considered supercritical coal-fired generation a reasonable alternative to GGNS 

5 license renewal.

6 Baseload coal units have proven their reliability and can routinely sustain capacity factors as 

7 high as 85 percent. Among the technologies available, pulverized coal boilers producing 

8 supercritical steam (SCPC boilers) are increasingly common for new coal-fired plants given their 

9 generally high thermal efficiencies and overall reliability. Although SCPC facilities are more 

10 expensive to construct than subcritical coal-fired plants, SCPC facilities consume less fuel per 

11 unit output, reducing environmental impacts. In a supercritical coal-fired power plant, burning 

12 coal heats pressurized water. As the supercritical steam and water mixture moves through 

13 plant pipes to a turbine generator, the pressure drops and the mixture flashes to steam. The 

14 heated steam expands across the turbine stages, which then spin and turn the generator to 

15 produce electricity. After passing through the turbine, any remaining steam is condensed back 

16 to water in the plant’s condenser.

17 To replace the 1,475 MWe that GGNS generates, the NRC considered three hypothetical SCPC 

18 units, each with a net capacity of 538 MWe. The hypothetical SCPC alternative would be 

19 located at a site other than GGNS because insufficient space exists at the GGNS site to support 

20 this alternative (Entergy 2011). The NRC assumes that the SCPC site would be located in 

21 Mississippi. Using an existing site (such as an existing power plant site) would maximize 

22 availability of infrastructure and reduce disruption to land and populations. However, impacts 

23 would be greater if the SCPC alternative were located at a site that has been previously 

24 disturbed but not located at an existing power plant site. For example, the site might need new 

25 intake and discharge facilities and a new cooling system. The SCPC alternative would use 

26 about the same amount of water as GGNS, and the NRC assumes the cooling system would 

27 use a closed-cycle system with natural draft cooling towers. 

28 Various coal sources are available to coal-fired power plants in Mississippi. For the purpose of 

29 this evaluation, the NRC assumes that the SCPC alternative would burn a combination of 

30 lignite, bituminous, and subbituminous coal, based on the type of coal used in electric plants in 

31 Mississippi. Coal-fired power plants in Mississippi are fueled by coal shipped primarily from 

32 Mississippi, Colorado, and Wyoming. EIA reported that in 2009, Mississippi produced electricity 

33 from coal with a heating value of 8,541 BTU/lb, sulfur content of 0.53 percent, and ash content 

34 of 11.27 percent (EIA 2010a). The NRC used a CO2 emission factor of 210 lb/million BTU for 

35 CO2 calculations in this evaluation, based on the type of coal burned in Mississippi and CO2

36 emissions factors for types of coal as reported by the EIA (EIA 2012c). Based on technology 

37 forecasts from EIA, the staff expects that the SCPC alternative would operate at a heat rate of 

38 8,740 BTU/kWh (EIA 2011b). Depending on the specific site, construction of onsite visible 

39 structures could include the boilers, exhaust stacks, intake/discharge structures, transmission 

40 lines, and an electrical switchyard. Based on GEIS estimates, the SCPC alternative would 

41 require approximately 2,744 ac (1,110 ha) of land, although it is assumed that most of this land 

42 would have been previously disturbed. To build the SCPC alternative, site crews would clear 

43 the plant site of vegetation, prepare the site surface, and begin excavation before other crews 

44 began actual construction on the plant and associated infrastructure. Construction materials 

45 would be delivered by rail spur, truck, or barge. 

46 The NRC also considered an integrated gasification combined-cycle (IGCC) coal-fired plant. 

47 IGCC is an emerging technology for generating electricity with coal that combines modern coal 

48 gasification technology with both gas-turbine and steam-turbine power generation. The 

49 technology is cleaner than conventional pulverized coal plants because major pollutants can be 
Environmental Impacts of Alternatives

8-23

1 removed from the gas stream before combustion. An IGCC alternative would also generate 

2 less waste than the pulverized coal-fired alternative. IGCC units do not produce ash or 

3 scrubber wastes. In spite of the advantages, the NRC concludes that a new IGCC plant is not a 

4 reasonable alternative for the following reasons: 

5  The few existing IGCC plants in the United States have considerably smaller 

6 capacity (approximately 250 MWe each) than GGNS (1,475 MWe);

7  System reliability of existing IGCC plants has been lower than pulverized coal 

8 plants;

9  IGCC plants are more expensive than comparable pulverized coal plants 

10 (NETL 2007);

11  Existing IGCC plants have had an extended (though ultimately successful) 

12 operational testing period (NPCC 2005); and,

13  A lack of overall plant performance warranties for IGCC plants has hindered 

14 commercial financing (NPCC 2005). 

15 Mississippi Power is constructing a 582 MWe IGCC plant in Kemper County, Mississippi. The 

16 plant is scheduled to begin operations in May 2014 and is experiencing legal, regulatory, and 

17 financial challenges (Reuters 2012).

18 8.3.1 Air Quality

19 Mississippi contains three designated air quality control regions: the Northeast Mississippi 

20 Intrastate Air Quality Control Region (AQCR); the Mobile (Alabama)-Pensacola-Panama City 

21 (Florida)-Southern Mississippi Interstate AQCR; and, the Mississippi Delta Intrastate AQCR

22 (40 CFR 81.62, 40 CFR 81.68, 40 CFR 81.122). The State of Mississippi is in attainment with 

23 national primary and secondary air quality standards for all criteria pollutants, except De Soto 

24 County which is located about 200 miles (322 km) north-northeast of GGNS and part of which is 

25 designated as a marginal nonattainment area for the 2008 8-hour ozone standard.

26 Construction activities for this alternative would generate fugitive dust. However, mitigation

27 measures, including wetting of unpaved roads and construction areas, and seeding or mulching 

28 bare areas would minimize fugitive dust. Construction worker vehicles and motorized 

29 construction equipment would create exhaust emissions. However, these emissions would end 

30 upon completion of construction. 

31 Various Federal and State regulations aimed at controlling air pollution would affect the SCPC 

32 alternative. A new SCPC plant would qualify as a new major-emitting industrial facility and 

33 would require a PSD permit if the location is in attainment or unclassifiable with the NAAQS and 

34 a Title V operating permit that would specify limits to emissions of all criteria pollutants. 

35 The SCPC alternative would also need to comply with new source performance standards (see 

36 40 CFR 60 Subpart Da and limits for particulate matter and opacity (40 CFR 60.42(a)), SO2

37 (40 CFR 60.43(a)), and NOx (40 CFR 60.44 Subpart Da(a)(1)). If the SCPC alternative were 

38 located close to a mandatory Class I area, additional air pollution control requirements would be 

39 required (Subpart P of 40 CFR Part 51) as mandated by the Regional Haze Rule. The rule 

40 would not apply to this coal-fired alternative, however, because there are no Class I Federal 

41 areas within 186 mi (300 km) of the GGNS site (EPA 2012b). 

42 Emissions from the SCPC alternative, projected by the staff based on published EIA data, EPA

43 emission factors, and performance characteristics for this alternative and likely emission 

44 controls, would be:
Environmental Impacts of Alternatives

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1  sulfur oxides (SOX)—2,869 tons (2,603 MT) per year

2  nitrogen oxides (NOX)—3,118 tons (2,829 MT) per year

3  particulate matter ≤ 10 μm (PM10)—80 tons (73 MT) per year

4  particulate matter ≤ 2.5 μm (PM2.5)—21 tons (19 MT) per year

5  carbon monoxide (CO)—1,547 tons (1,403 MT) per year

6  carbon dioxide (CO2)—11.1 million tons (10.1 million MT) per year

7 8.3.1.1 Sulfur Oxide and Nitrogen Oxide

8 As stated above, the SCPC alternative would produce 2,869 tons (2,603 MT) total SOX

9 emissions per year. SO2 emissions from an SCPC alternative would be subject to the 

10 requirements of Title IV of the CAA. Title IV regulations were enacted to reduce emissions of 

11 SO2 and NOx by restricting emissions of these pollutants from power plants. Title IV caps 

12 aggregate annual power plant SO2 emissions and imposes controls on SO2 emissions through a 

13 system of marketable allowances. EPA issues one allowance for each ton of SO2 that a unit is 

14 allowed to emit. New units do not receive allowances, but are required to have secured 

15 allowances (or offsets) from existing sources to cover their SO2 emissions. Owners of new units 

16 must therefore purchase allowances from owners of other power plants or reduce SO2

17 emissions at other power plants they own. Allowances can be banked for use in future years. 

18 Thus, provided a new SCPC power plant is able to purchase sufficient allowances to operate, it 

19 would not add to net regional SO2 emissions, although it might do so locally.

20 An SCPC alternative at an alternate site would most likely employ various available NOx control 

21 technologies, which can involve combustion modifications, post-combustion controls, or both. 

22 Combustion modifications include low-NOx burners, overfire air, and operational modifications. 

23 Post-combustion processes include selective catalytic reduction and selective non-catalytic 

24 reduction. An effective combination of the combustion modifications and post-combustion 

25 processes allow the reduction of NOx emissions by up to 95 percent.

26 8.3.1.2 Greenhouse Gases

27 An SCPC alternative would release GHGs, such as CO2 during operations as well as during 

28 mining, processing, and transportation, which the GEIS indicates could contribute to global 

29 warming and connected climate changes. The amount of CO2 released per unit of power 

30 produced would depend on the quality of the fuel and the firing conditions and overall firing 

31 efficiency of the boiler. As discussed above, the NRC assumes that a coal-fired alternative 

32 would burn the same coal as was burned in Mississippi in 2009 with a CO2 emission factor of 

33 210 lb/million BTU. 

34 On July 12, 2012, EPA issued a final rule tailoring the criteria that determine which stationary 

35 sources and modifications to existing projects become subject to permitting requirements for 

36 GHG emissions under the PSD and Title V Programs of the CAA (77 FR 41051). According to 

37 this rule, GHGs are a regulated new source review pollutant under the PSD major source 

38 permitting program if the source is otherwise subject to PSD (for another regulated new source 

39 review pollutant) and has a GHG potential to emit equal to or greater than 75,000 tons 

40 (68,000 MT) per year of CO2 equivalent (“carbon dioxide equivalent” adjusts for different global 

41 warming potentials for different GHGs). Beginning January 2, 2011, operating permits issued to 

42 major sources of GHGs under the PSD or Title V Federal permit programs must contain 

43 provisions requiring the use of Best Available Control Technology (BACT) to limit the emissions 

44 of GHGs if those sources would be subject to PSD or Title V permitting requirements. If the 

45 SCPC alternative meets the GHG emission thresholds established in the rule, then GHG 

46 emissions from this alternative would be regulated under the PSD and Title V permit programs. 
Environmental Impacts of Alternatives

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1 8.3.1.3 Particulates

2 As described above, onsite activities during the construction of an SCPC alternative would also 

3 generate fugitive dust as well as emissions from vehicles and motorized equipment. These 

4 impacts would be intermittent, temporary, and minimized by dust-control measures.

5 During operations, the SCPC alternative would produce 80 tons (73 MT) per year and 21 tons 

6 (19 MT) per year of particulate matter PM10 and PM2.5, respectively. The SCPC alternative 

7 would use fabric filters to remove particulates from flue gases with an expected 99.9 percent 

8 removal efficiency (NETL 2007). Coal-handling equipment would introduce fugitive dust 

9 emissions when fuel is being transferred to onsite storage and then moved from storage for use 

10 in the plant. 

11 8.3.1.4 Hazardous Air Pollutants 

12 In addition to being major sources of criteria pollutants, coal-fired plants can also be sources of 

13 HAPs as a result of hazardous constituents contained in the coal. EPA has determined that 

14 coal- and oil-fired electric utility steam-generating units are significant emitters of the following 

15 HAPs: arsenic, beryllium, cadmium, chromium, dioxins, hydrogen chloride, hydrogen fluoride, 

16 lead, manganese, and mercury (EPA 2000b). EPA concluded that mercury is the HAP of 

17 greatest concern and that (1) a link exists between coal combustion and mercury emissions, 

18 (2) electric utility steam-generating units are the largest domestic source of mercury emissions, 

19 and (3) certain segments of the U.S. population (e.g., the developing fetus and subsistence 

20 fish-eating populations) are believed to be at potential risk of adverse health effects resulting 

21 from mercury exposures caused by the consumption of contaminated fish (EPA 2000b). 

22 Consequently, the SCPC alternative would be subject to the Mercury and Air Toxics Standards 

23 rule that was finalized in March 2011. The rule set technology-based emission limitation 

24 standards for all HAPs. The rule applies to coal-fired power plants with a capacity of 25 MWe or 

25 greater.

26 8.3.1.5 Conclusion

27 While the GElS mentions global warming from unregulated CO2 emissions and acid rain from 

28 SO2 and NOx emissions as potential impacts, it does not quantify emissions from coal-fired 

29 power plants. However, the GElS does imply that air impacts from coal plant operation would 

30 be substantial (NRC 1996). The above analysis shows that emissions of air pollutants, 

31 including SOx, NOx, CO, and particulates, far exceed those produced by the existing nuclear 

32 power plant during operation, as well as those of the other fossil fuel alternatives considered in 

33 this section. The NRC analysis of air quality impacts for an SCPC alternative indicates that 

34 impacts would have clearly noticeable effects, but given existing regulatory regimes, permit 

35 requirements, and emissions controls, the coal-fired alternative would not destabilize air quality. 

36 Federal and state regulations would require the installation of pollution control equipment to 

37 meet applicable local requirements and permit conditions and may eventually require 

38 participation in emissions trading scenarios. Therefore, air impacts from an SCPC alternative 

39 located at an alternate site would be MODERATE. 

40 8.3.2 Groundwater Resources

41 The amount of groundwater required for construction of the SCPC alternative would be much 

42 less than required during plant operation. NRC assumes that ground water use for construction 

43 would comply with State and local permit and monitoring requirements. Groundwater quality 

44 and use impacts from construction of the SCPC alternative are expected to be SMALL.

45 The amount of water required to operate the SCPC alternative would be similar to that required 

46 for GGNS. Potable water and other plant groundwater requirements would be similar to GGNS. 
Environmental Impacts of Alternatives

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1 Coal, fly ash, and clinker storage could cause groundwater contamination, but with proper 

2 storage facility design and operation, the impacts could be mitigated. Given these assumptions, 

3 the impacts to groundwater use and quality would be SMALL.

4 8.3.3 Surface Water Resources

5 The SCPC cooling system would consist of natural draft cooling towers requiring approximately 

6 the same amount of water as the existing nuclear plant. Within the service territory, the 

7 Mississippi River, other rivers, alluvial aquifers, or reservoirs might be a source of cooling water. 

8 If the Mississippi River or its alluvial aquifer was used, other consumers of surface water are 

9 unlikely to be affected because of the large volume of water flowing within the river and in its 

10 alluvium. In other rivers, if the amount of water flowing is large, the impact on other surface 

11 water users is likely to be minor. If the water flow is moderate and there are few other surface 

12 water users, the impact on other surface water users should also be minor. However, impacts 

13 on other surface water users could result in the case of a small river with many surface water 

14 users. The NRC assumes that the SCPC would not be sited on a small river with many surface 

15 water users. These impacts could be mitigated by the use of more efficient cooling technology 

16 or other water sources (i.e., import water, perhaps by pipeline from other surface water bodies). 

17 If dredging of streams or rivers occurs during construction, surface water quality immediately 

18 downstream of the dredging activities could be temporarily degraded by increases in suspended 

19 sediment concentration. During plant operation, surface water discharges largely would consist 

20 of cooling tower blowdown similar to GGNS. Assuming public sewers are not available, process 

21 waste and treated sanitary wastewater effluent may also be discharged to the surface water 

22 body. An NPDES permit would regulate discharges. Runoff from coal storage, fly ash, and 

23 clinker material would be controlled and regulated by an NPDES permit. Overall, impacts to 

24 surface water use and quality would be SMALL.

25 8.3.4 Aquatic Ecology

26 Construction activities for the SCPC alternative (such as construction of heavy-haul roads and 

27 the power block) could affect onsite aquatic features. Minimal impacts on aquatic ecology 

28 resources are expected because the plant operator would likely implement BMPs to minimize 

29 erosion and sedimentation. Stormwater control measures, which would be required to comply 

30 with Mississippi NPDES permitting, would minimize the flow of disturbed soils into aquatic 

31 habitats. Depending on the available infrastructure at the selected site, the SCPC alternative 

32 may require modification or expansion of the existing intake or discharge structures, or 

33 construction of new intake and discharge structures. Construction of new or modified intake 

34 and discharge structures may require dredging. In addition, dredging may be required to 

35 transport new materials to the site, which could result in increased sedimentation and turbidity. 

36 Dredging activities would require BMPs for in-water work to minimize sedimentation and 

37 erosion. Due to the short-term nature of the dredging activities, the hydrological alterations to 

38 aquatic habitats would likely be localized and temporary.

39 During operations, the SCPC alternative would require a similar amount of cooling water as 

40 GGNS. However, the cooling water may be withdrawn from surface water bodies, rather than 

41 from groundwater. If the cooling water is withdrawn from surface water bodies, aquatic 

42 resources may be impacted from impingement and entrainment. Impingement and 

43 entertainment would be minimized because NRC assumes that the plant would use a 

44 closed-cycle cooling system. A similar amount of water would be discharged as at GGNS. 

45 Therefore, thermal impacts would be similar for the SCPC alternative as for GGNS. The cooling 

46 system for a new SCPC plant would have similar chemical discharges as GGNS, but the air 
Environmental Impacts of Alternatives

8-27

1 emissions from the SCPC plant would emit ash and particulates that could settle onto a river 

2 surface and introduce a new source of pollutants. However, the flow of the river would likely 

3 dissipate and dilute the concentration of pollutants resulting in minimal exposure to aquatic 

4 biota. 

5 Consultation under several Federal acts, including the ESA and Magnuson-Stevens Act, would 

6 be required to assess the occurrence and potential impacts to Federally protected aquatic 

7 species and habitats within affected surface waters. Coordination with Mississippi natural 

8 resource agencies would further ensure that the plant operator would take appropriate steps to 

9 avoid or mitigate impacts to state-listed species, habitats of conservation concern, and other 

10 protected species and habitats. The NRC assumes that these consultations would result in 

11 avoidance or mitigation measures that would minimize or eliminate potential impacts to 

12 protected aquatic species and habitats.

13 The impacts on aquatic ecology would be minor because construction activities would require 

14 BMPs and stormwater management permits. Deposition of pollutants into aquatic habitats from 

15 the plant’s air emissions would be minimal because the concentration of pollutants would be 

16 diluted with the river flow. Therefore, the staff concludes that impacts on aquatic ecology would 

17 be SMALL.

18 8.3.5 Terrestrial Ecology

19 Construction of an SCPC alternative would require 2,744 ac (1,110 ha) of land, which would 

20 include construction of the plant and associated infrastructure. The SCPC alternative may 

21 require up to 35,508 ac (14,370 ha) of additional land for coal mining and processing. Because 

22 of the relatively large land requirement for the site, a portion of the site would likely be land that 

23 had not been previously disturbed, which would directly affect terrestrial habitat by destroying 

24 existing vegetation communities and displacing wildlife. This alternative could also include 

25 construction of new transmission lines and a railroad spur, depending on the specific site, which 

26 would require additional habitat loss and fragmentation. Thus, the level of direct impacts would 

27 vary substantially based on site selection. Offsite construction would occur mostly on land 

28 where coal extraction is ongoing. Erosion and sedimentation, fugitive dust, and construction 

29 debris impacts would be minor with implementation of appropriate BMPs. Construction noise 

30 could modify wildlife behavior; however, these effects would be temporary. Road improvements 

31 or construction of additional service roads to facilitate construction could result in the temporary 

32 or permanent loss of terrestrial habitat. Operational impacts to terrestrial habitats and species 

33 from transmission line operation and corridor vegetation maintenance, and operation of the 

34 cooling system would be similar in magnitude and intensity as those resulting from GGNS. 

35 Because of the potentially large area of undisturbed habitat that could be affected from 

36 construction of an SCPC alternative, the impacts of construction to terrestrial habitats and 

37 species could range from MODERATE to LARGE depending on the specific site location. The 

38 impacts of operation would be SMALL to MODERATE. 

39 As discussed under aquatic ecology impacts, consultation with FWS under the ESA would avoid 

40 potentially adverse impacts to Federally listed species or adverse modification or destruction of 

41 designated critical habitat. Coordination with State natural resource agencies would further 

42 ensure that the plant operator would take appropriate steps to avoid or mitigate impacts to 

43 State-listed species, habitats of conservation concern, and other protected species and habitats. 

44 The NRC assumes that these consultations would result in avoidance or mitigation measures 

45 that would minimize or eliminate potential impacts to protected terrestrial species and habitats. 

46 Consequently, the impacts of construction and operation of a new nuclear alternative on 

47 protected species and habitats would be SMALL.
Environmental Impacts of Alternatives

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1 8.3.6 Human Health

2 Impacts on human health from construction of the SCPC alternative would be similar to impacts 

3 associated with the construction of any major industrial facility. Compliance with worker 

4 protection rules would control those impacts on workers at acceptable levels. Impacts from 

5 construction on the general public would be minimal because the plant operator would likely 

6 follow BMPs and limit access to the active construction area to authorized individuals. Impacts 

7 on human health from the construction of the SCPC alternative would be SMALL.

8 Coal-fired power plants introduce worker risks from coal and limestone mining, coal and 

9 limestone transportation, and disposal of coal combustion residues and scrubber wastes. In 

10 addition, there are public risks from inhalation of stack emissions and the secondary effects of 

11 eating foods grown in areas subject to deposition from plant stacks.

12 Human health risks of coal-fired power plants are described, in general, in Table 8.2 of the GEIS

13 (NRC 1996). Cancer and emphysema as a result of the inhalation of toxins and particulates are 

14 identified as potential health risks to occupational workers and members of the public 

15 (NRC 1996). The human health risks associated with coal-fired power plants, both for 

16 occupational workers and members of the public, are greater than those of the current GGNS 

17 reactor, because of exposures to chemicals such as mercury; SOx; NOx; radioactive elements, 

18 such as uranium and thorium contained in coal and coal ash; and polycyclic aromatic 

19 hydrocarbon (PAH) compounds, including benzo(a)pyrene. 

20 Regulations restricting emissions enforced by either EPA or delegated state agencies have 

21 reduced potential health effects, but have not entirely eliminated them. These agencies also 

22 impose site-specific emission limits as needed to protect human health. Even if the SCPC 

23 alternative were located in a nonattainment area, emission controls and trading or offset 

24 mechanisms could prevent further regional degradation; however, local effects could be visible. 

25 Many of the byproducts of coal combustion responsible for health effects are largely controlled, 

26 captured, or converted in modern power plants, although some level of health effects may 

27 remain.

28 Aside from emissions impacts, the SCPC alternative introduces the risk of coal pile fires and for 

29 those plants that manage coal combustion residue liquids and sludge in waste impoundments, 

30 the release of the waste may result because of a failure of the impoundment. Good 

31 housekeeping practices to control coal dust greatly reduce the potential for coal dust explosions 

32 or coal pile fires. Although there have been several instances in recent years, sludge 

33 impoundment failures are still rare. Free water could also be recovered from such waste 

34 streams and recycled and the solid or semi-solid portions removed to permitted offsite disposal 

35 facilities.

36 Overall, given extensive health-based regulation and controls likely to be imposed as permit 

37 conditions applicable to waste handling and disposal, the staff expects human health impacts 

38 from operation of the SCPC alternative at an alternate site to be SMALL.

39 8.3.7 Land Use

40 The GEIS generically evaluates the impact of constructing and operating various replacement 

41 power plant alternatives on land use, both on and off each power plant site. The analysis of 

42 land use impacts focuses on the amount of land area that would be affected by the construction 

43 and operation of an SCPC power plant at an existing power plant site other than GGNS.

44 Based on scaled GEIS estimates, approximately 2,744 ac (1,100 ha) would be needed to 

45 support an SCPC alternative to replace GGNS, excluding land needed for coal mining and 
Environmental Impacts of Alternatives

8-29

1 processing. It is expected that the SCPC alternative would be located at an existing power plant 

2 site or otherwise disturbed industrial site, and thus the land use impacts from construction would 

3 range from SMALL to MODERATE.

4 Offsite land use impacts would occur from coal mining, in addition to land use impacts from the 

5 construction and operation of the new power plant. Using the GEIS estimate, the SCPC 

6 alternative might require up to 35,508 ac (14,370 ha) of land for coal mining and waste disposal 

7 during power plant operations, based on an assumption of 22,000 ac (8,903 ha) of land required 

8 per 1,000 MWe and a 1,614 MWe SCPC plant (NRC 1996). However, much of the land in 

9 existing coal mining areas has already experienced some level of disturbance. 

10 The elimination of uranium fuel for GGNS would partially offset some of the land requirements 

11 for the SCPC alternative. Scaling from GEIS estimates, approximately 1,033 ac (418 ha) 

12 (based on an assumption of 35 ac/yr disturbed per 1,000 MWe) would no longer be needed for 

13 mining and processing uranium during the operating life of the SCPC plant (NRC 1996). 

14 Overall, land use impacts from SCPC power plant operations would be SMALL to MODERATE 

15 depending on the extent of coal mining.

16 8.3.8 Socioeconomics

17 As previously discussed, socioeconomic impacts are defined in terms of changes to the 

18 demographic and economic characteristics and social condition of a region. For example, the 

19 number of jobs created by the construction and operation of a power plant could affect regional 

20 employment, income, and expenditures. This alternative would create two types of jobs: 

21 (1) construction jobs, which are transient, short in duration, and less likely to have a long-term 

22 socioeconomic impacts; and (2) power plant operation jobs, which have a greater potential for 

23 permanent, long-term socioeconomic impacts. Workforce requirements for the construction and 

24 operation of the SCPC alternative were evaluated to measure their possible effects on current 

25 socioeconomic conditions.

26 Scaling from GEIS estimates, the construction workforce would peak at 4,035 workers. The 

27 relative economic impact of this many workers on the local economy and tax base would vary, 

28 with the greatest impacts occurring in the communities where the majority of construction 

29 workers would reside and spend their income. As a result, local communities could experience 

30 a short-term “boom” from increased tax revenue and income generated by construction 

31 expenditures and the increased demand for temporary (rental) housing and business services. 

32 After construction, local communities could be temporarily affected by the loss of construction 

33 jobs, the associated loss in demand for business services, and the rental housing market could 

34 experience increased vacancies and decreased prices. The impact of construction on 

35 socioeconomic conditions could range from SMALL to MODERATE because of the fluctuation 

36 of the workforce.

37 Scaling from GEIS estimates, the workforce during plant operations would be 404 workers. This 

38 alternative would result in a loss of approximately 690 relatively high-paying jobs at GGNS, with 

39 a corresponding reduction in purchasing activity and tax contributions to the regional economy. 

40 However, a larger amount of property taxes may be paid to local jurisdictions under the SCPC 

41 alternative as more land may be required for coal-fired power plant operations than GGNS. 

42 Therefore, socioeconomic impacts during operations could range from SMALL to MODERATE.

43 8.3.9 Transportation

44 Transportation impacts associated with construction of the SCPC alternative would consist of 

45 commuting workers and truck deliveries of construction materials. During periods of peak 
Environmental Impacts of Alternatives

8-30

1 construction activity, 4,035 workers could be commuting daily to the site significantly adding to 

2 the normal flow of traffic (NRC 1996). Vehicular traffic would peak during shift changes, 

3 resulting in temporary levels of service impacts and delays at intersections. Materials also could 

4 be delivered by rail or barge, depending on site location. Traffic-related transportation impacts 

5 during construction likely would range from MODERATE to LARGE. 

6 Once construction of the SCPC alternative is complete, traffic-related transportation impacts on 

7 local roads would be greatly reduced. The estimated number of operations workers would be 

8 404 (NRC 1996). Traffic on roadways would peak during shift changes, resulting in temporary 

9 levels of service impacts and delays at intersections. Frequent deliveries of coal and limestone 

10 by rail would cause levels of service impacts on certain roads because of delays at railroad 

11 crossings. Onsite coal storage would make it possible to receive several trains per day at a site 

12 with rail access. Limestone delivered by rail could also add additional traffic (though 

13 considerably less traffic than that generated by coal deliveries). If a site on navigable waters 

14 were used, barge delivery of coal and other materials would be feasible. Overall, the SCPC 

15 alternative transportation impacts would be SMALL to MODERATE during plant operations.

16 8.3.10 Aesthetics 

17 The analysis of aesthetics impacts focuses on the degree of contrast between the SCPC 

18 alternative and the surrounding landscape and the visibility of the new SCPC plant at an existing 

19 power plant site or a former plant (brownfield) site. Most construction, clearing, and excavation 

20 activities would take place within the existing power plant or brownfield site, and these activities 

21 could be visible from offsite roads. Since power plant and brownfield sites look industrial, 

22 construction-related activities would appear similar to other ongoing industrial activities.

23 The SCPC plant buildings would be approximately 100 ft (30 m) tall, with two to four exhaust 

24 stacks up to 150 ft (46 m) tall. The SCPS alternative would be visible offsite during daylight 

25 hours and some structures may require aircraft warning lights. Condensate plumes from the 

26 cooling towers would add to the visual impact. The cooling towers would be 400–500 ft 

27 (122–152 m) in height. The power block of the SCPC alternative could look very similar to 

28 GGNS. Noise generated during power plant operations would be limited to routine industrial 

29 processes and communications.

30 In general, given the industrial appearance of existing industrial and brownfield sites, the SCPC 

31 alternative would blend in with the surroundings. Aesthetic changes would therefore be limited 

32 to the immediate vicinity of the existing power plant and brownfield sites, and any impacts would 

33 be SMALL.

34 8.3.11 Historic and Archaeological Resources

35 Lands needed to support construction of an SCPC plant and associated corridors would need to 

36 be surveyed for historic and archaeological resources. Resources found in these surveys would 

37 need to be evaluated for eligibility on the National Register of Historic Properties (NRHP) and 

38 mitigation of adverse effects would need to be addressed if eligible resources were 

39 encountered. When constructing an SCPC plant on a previously disturbed former plant 

40 (brownfield) site, an inventory may still be necessary if the site has not been previously 

41 surveyed or to verify the level of disturbance and evaluate the potential for intact subsurface 

42 resources. The potential for impacts on historic and archaeological resources from the SCPC 

43 alternative would vary greatly depending on the resource richness and location of the proposed 

44 site. However, given that the preference is to use a previously disturbed former plant site, 

45 avoidance of significant historic and archaeological resources should be possible and effectively 
Environmental Impacts of Alternatives

8-31

1 managed under current laws and regulations. Therefore, the impacts on historic and 

2 archaeological resources from the SCPC alternative would be SMALL to MODERATE. 

3 8.3.12 Environmental Justice

4 The environmental justice impact analysis evaluates the potential for disproportionately high and 

5 adverse human health, environmental, and socioeconomic effects on minority and low-income 

6 populations that could result from the construction and operation of a new power plant. As 

7 previously discussed in Section 8.1.12, such effects may include human health, biological, 

8 cultural, economic, or social impacts. 

9 Potential impacts to minority and low-income populations from the construction of an SCPC 

10 alternative would mostly consist of environmental and socioeconomic effects (e.g., noise, dust, 

11 traffic, employment, and housing impacts). Noise and dust impacts from construction would be 

12 short-term and primarily limited to onsite activities. Minority and low-income populations 

13 residing along site access roads would be directly affected by increased commuter vehicle 

14 traffic during shift changes and truck traffic. However, because of the temporary nature of 

15 construction, these effects are not likely to be high and adverse and would be contained to a 

16 limited time period during certain hours of the day. Increased demand for rental housing during 

17 construction could cause rental costs to rise disproportionately affecting low-income populations 

18 who rely on inexpensive housing. However, given the likelihood of locating the SCPC 

19 alternative at the site of an existing or former power plant and the proximity of most power plant 

20 sites to metropolitan areas, workers could commute to the construction site, thereby reducing 

21 the need for rental housing.

22 Potential impacts to minority and low-income populations from operation of an SCPC plant 

23 would consist mainly of the effects of emissions. Because permitted emissions are expected to 

24 remain within regulatory standards, impacts are not expected to be high and adverse. 

25 Based on this information and the analysis of human health and environmental impacts 

26 presented in this section, the construction and operation of the SCPC alternative would not have 

27 disproportionately high and adverse human health and environmental effects on minority and

28 low-income populations.

29 8.3.13 Waste Management

30 During construction of an SCPC alternative, land clearing and other construction activities would 

31 generate waste that could be recycled, disposed of on site, or shipped to an offsite waste 

32 disposal facility. Because the alternative would be constructed at an existing power plant site, 

33 or a previously disturbed site, the amounts of wastes produced during land clearing would be 

34 reduced.

35 The burning of coal generates coal combustion products (CCP) such as bottom ash or fly ash (a 

36 dry solid) and sludge (a semi-solid byproduct of emission control system operation). According 

37 to the American Coal Ash Association, in 2010, approximately 130 million tons of CCPs were 

38 generated by coal-fueled electric utilities. Fly ash accounted for over 67 million tons of CCP, 

39 bottom ash accounted for over 17 million tons, and scrubber sludge about 22 million tons. 

40 Approximately 38 percent of the fly ash and 42 percent of the bottom ash was recycled. 

41 Approximately 48 percent of the scrubber sludge was recycled (ACAA 2010). The boilers 

42 comprising the SCPC alternative are assumed to have the following pollution control devices:

43  fabric filter for particulate control, operating at 99.9 percent removal 

44 efficiency; 
Environmental Impacts of Alternatives

8-32

1  wet calcium carbonate SO2 scrubber, operating at 95 percent removal 

2 efficiency; and

3  low-NOx burners with overfire air and selective catalytic reduction for nitrogen 

4 oxide controls capable of attaining a NOx removal of 86 percent. 

5 This coal-fired alternative would produce roughly 696,839 tons (632,173 MT) of ash, and 

6 50 percent (348,420 tons [316,086 MT]) of the ash would be recycled for beneficial use. 

7 Disposal of the remaining waste could have noticeable effects. However, proper disposal, 

8 monitoring, and management practices as required by local ordinances and State regulations 

9 would minimize these impacts. After closure of the waste site and revegetation, the land could 

10 be available for other uses.

11 The impacts from waste generated during operation of this SCPC alternative would be 

12 MODERATE because the impacts would be clearly visible but would not destabilize important 

13 resources.

14 8.3.14 Summary of Impacts of SCPC Alternative

15 Table 8–4 summarizes the environmental impacts of the SCPC alternative compared to 

16 continued operation of GGNS.

17 Table 8–4. Summary of Environmental Impacts of the SCPC Alternative

18 Compared to Continued Operation of GGNS

Category SCPC Alternative Continued GGNS Operation

Air Quality MODERATE SMALL

Groundwater Resources SMALL SMALL

Surface Water Resources SMALL SMALL

Aquatic Ecology SMALL SMALL

Terrestrial Ecology SMALL to LARGE SMALL

Human Health SMALL SMALL

Land Use SMALL to MODERATE SMALL

Socioeconomics SMALL to MODERATE SMALL

Transportation SMALL to LARGE SMALL

Aesthetics SMALL SMALL

Historic and Archaeological

Resources

SMALL to MODERATE SMALL

Waste Management a MODERATE SMALL a As described in Chapter 6, the issue, "offsite radiological impacts (spent fuel and high level waste disposal)," is 

not evaluated in this EIS.

19 8.4 Combination Alternative

20 In this section, the NRC evaluates the environmental impacts from a combination of 

21 alternatives. This combination includes 530 MWe from one NGCC unit similar to the units 

22 described in Section 8.2, 360 MWe from biomass-fired units, 280 MWe from demand-side 

23 management (DSM), and 305 MWe from purchased power.

24 The NRC assumed that one new NGCC unit of the type described in Section 8.2 would be 

25 constructed and installed at the GGNS site with a capacity of 530 MWe. The NRC estimates 

26 that it would require about one third of the area necessary for the alternative considered in 

27 Section 8.2 and that construction and operational effects would scale accordingly.
Environmental Impacts of Alternatives

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1 The NRC assumed that biomass-fired generation, located in Mississippi, would replace 

2 360 MWe of GGNS output. Electricity generation from biomass-fired generation is currently the 

3 only commercially available renewable resource in operation in Mississippi, with a total of 

4 235 MWe installed capacity (EIA 2012a). The development of biomass resources is also 

5 consistent with Entergy’s Strategic Resource Plan (SRP). The SRP estimates about 700 MWe 

6 of new renewable energy generation (spread across Entergy’s six current operating companies) 

7 will come from biomass-fired generation from 2009 to 2019 (Entergy 2009). The SRP 

8 concluded that by 2019, commercially available renewable energy is expected to be limited 

9 primarily to biomass-fired generation in Mississippi. Mississippi currently does not require 

10 electric utilities to generate a portion of their electricity from renewable sources.

11 The NRC assumed a DSM program would replace 280 MWe of GGNS output. Although 

12 Mississippi does not require DSM programs, Entergy commissioned a study by ICF International 

13 to calculate possible savings through a DSM program (ICF 2009). According to the study, the 

14 potential energy savings across Entergy’s six operating companies could reach 729 MWe by 

15 2019 and 1,050 MWe by 2029 (Entergy 2009). Because Entergy Mississippi, Inc. (EMI) 

16 represents 13 percent of Entergy’s total energy sales, the NRC estimates that the potential 

17 savings would reach 95 MWe by 2019 and 136 MWe by 2029 in Mississippi. In addition, the 

18 Federal Energy Regulatory Commission (FERC) evaluated potential energy savings using DSM 

19 in 5- and 10-year horizons for four development scenarios that varied in level of participation 

20 (FERC 2009). FERC’s analysis indicates that by the year 2019, the achievable participation 

21 scenario would yield a 1,602 MWe peak demand reduction in Mississippi (FERC 2009). Since 

22 EMI provides 34 percent of Mississippi’s electricity generation, if these demand reductions were 

23 achieved, it would translate to a reduction of 539 MWe for EMI. The 280 MWe reduction in 

24 energy use for this alternative falls between the ICF International and FERC study outcomes 

25 projecting potential DSM savings. Therefore, the NRC finds 280 MWe of DSM savings to be a 

26 reasonable portion of the combination alternative. No major construction would be necessary 

27 for the DSM component of the combination alternative.

28 For the combination alternative, the NRC assumes that nine 50 MWe biomass-fired units with a 

29 capacity factor of 80 percent would be required to replace 360 MWe of GGNS output. Biomass 

30 resources typically include forest residue, primary mill residues, secondary mill residues, and 

31 urban wood residues (NREL 2005). The biomass-fired units would be similar in appearance 

32 and operation to fossil fuel-fired power plants. The technology used for conversion of biomass 

33 to electricity would be direct combustion, which involves the burning of biomass, producing hot 

34 gases which, in turn, boil water to produce steam. The steam is used to spin a turbine that 

35 generates electricity. Biomass combustion systems also require feedstock storage and 

36 handling systems, as well as a cooling water system with cooling towers. The NRC assumes 

37 that approximately 15 ac (6 ha) of land would be required for each 50-MWe plant, for a total of 

38 135 ac (55 ha) (NREL 2003, Palmer Renewable Energy 2011). The combustion of biomass 

39 resources would affect air quality, but would generate fewer SO2 and NOx emissions per unit of 

40 energy delivered than coal. In addition, environmental impacts would occur from harvesting 

41 wood resources. Biomass-fired power plants generate greater emissions than either natural 

42 gas or nuclear plants of equal electrical generation capacity (NREL 1999).

43 For the combination alternative, 305 MWe would be purchased to replace that amount of GGNS 

44 generation. In its Strategic Resource Plan, Entergy’s Reference Planning Scenario assumes 

45 that by the time GGNS’s license expires in November 2024, EMI will purchase 500 MWe from 

46 non-Entergy generation (Entergy 2009). Therefore, it is reasonable to assume that 305 MWe 

47 will be available for purchase. The impacts of purchased power could be wide-ranging, 

48 depending on the energy type and location selected. The power would likely come from the 

49 most common types of energy generation in the region: gas, coal, or nuclear plants. 
Environmental Impacts of Alternatives

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1 Construction and operation impacts would be similar to those described in Sections 8.1 

2 through 8.3. The purchased power would either be purchased from existing plants, or from new 

3 plant construction, depending on the availability of power sources. Additional impacts could 

4 occur if new plants need to be built to produce the additional 305 MWe of power. 

5 8.4.1 Air Quality

6 Air quality impacts would result primarily from the energy generated from the NGCC and 

7 biomass-fired units. There also would be impacts to air quality from the purchased power 

8 portion of the alternative, with the magnitude of impact dependent on the source of the 

9 purchased power. As described in Section 8.4, the purchased power would likely come from 

10 the most common types of energy generation in the region: gas, coal, or nuclear plants. 

11 Therefore, air quality impacts would be similar to those described in Sections 8.1.1, 8.2.1, and 

12 8.3.1. Impacts to air quality from the NGCC portion would be similar to the impacts in 

13 Section 8.2.1, but scaled down by approximately one-third. 

14 Mississippi contains three designated air quality control regions: the Northeast Mississippi 

15 Intrastate Air Quality Control Region (AQCR); the Mobile (Alabama)-Pensacola-Panama City 

16 (Florida)-Southern Mississippi Interstate AQCR; and, the Mississippi Delta Intrastate AQCR

17 (40 CFR 81.62, 40 CFR 81.68, 40 CFR 81.122). The State of Mississippi is in attainment with 

18 national primary and secondary air quality standards for all criteria pollutants, except De Soto 

19 County which is located about 200 miles (322 km) north-northeast of GGNS and part of which is 

20 designated as a marginal nonattainment area for the 2008 8-hour ozone standard.

21 Construction activities for this alternative would generate fugitive dust. However, mitigation

22 measures, including wetting of unpaved roads and construction areas, and seeding or mulching 

23 bare areas would minimize fugitive dust. Construction worker vehicles and motorized 

24 construction equipment would create exhaust emissions. However, these emissions would end 

25 upon completion of construction. 

26 Various Federal and State regulations aimed at controlling air pollution would impact NGCC and 

27 biomass-fired facilities located in Mississippi. Both the NGCC plant and biomass-fired units 

28 would be subject to NAAQS, which would limit emissions for criteria pollutants and reflect 

29 existing ambient air quality at the selected location. Biomass-fired generation produces air 

30 quality impacts similar to that of coal. Emissions from the 50-MWe facilities may not be large 

31 individually, but cumulatively could have more significant air quality impacts. Both the NGCC 

32 and biomass-fired plants would qualify as new major emitting industrial facilities and would be 

33 subject to PSD requirements under the Clean Air Act (CAA) (EPA 2012a). The NGCC and 

34 biomass-fired plants would require Title V operating permits that would specify limits to 

35 emissions of all criteria pollutants. The NGCC portion of the alternative would need to comply 

36 with new source performance standards (40 CFR Part 60 Subpart KKKK) and the biomass37 portion of the alternative would need to comply with 40 CFR Part Subpart Db. If the NGCC or 

38 biomass-fired plants were located close to a mandatory Class I area, additional air pollution 

39 control requirements might be required (Subpart P of 40 CFR Part 51) as mandated by the 

40 Regional Haze Rule. The rule would not apply to this alternative, however, because there are 

41 no Class I Federal areas in Mississippi or within 186-mi (300-km) of the GGNS site 

42 (EPA 2012b). 

43 The emissions from the NGCC portion of the combination alternative, projected by the staff

44 based on published EIA data, EPA emission factors, and performance characteristics for this 

45 alternative, and likely emission controls, would be:
Environmental Impacts of Alternatives

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1  sulfur oxides (SOX)—41 tons (37 MT) per year

2  nitrogen oxides (NOX)—156 tons (142 MT) per year

3  particulate matter ≤10 μm (PM10) and ≤ 2.5 μm (PM2.5)—79 tons (72 MT) per 

4 year

5  carbon monoxide (CO)—361 tons (327 MT) per year

6  carbon dioxide (CO2)—1.3 million tons (1.2 million MT) per year

7 National Energy Technology Laboratory (NETL) estimated emissions factors for biomass-fired 

8 power plants by averaging 34 biomass facilities in California and based on a heat rate of 

9 13.8 MMBTU/MWh. Emissions from the nine biomass-fired plants considered in this alternative 

10 could vary based on technology or other factors. The emissions from all nine of the 

11 biomass-fired plants under the combination alternative, based on emissions factors and the heat 

12 rate estimated by National Renewable Energy Laboratory (NREL) would be: 

13  SOX—126 tons (114 MT) per year 

14  NOX—2,681 tons (2,432 MT) per year

15  Particulate matter ≤ 10 μm (PM10) and ≤ 2.5 μm (PM2.5)—650 tons (590 MT) 

16 per year

17  CO—13,560 tons (12,302 MT) per year

18 8.4.1.1 Sulfur Oxide and Nitrogen Oxide

19 The natural gas-fired plant would produce SOx and NOx based on the use of the dry low-NOx

20 combustion technology and selective catalytic reduction to significantly reduce NOx emissions. 

21 Both the NGCC and biomass-fired plants would be subject to the continuous monitoring 

22 requirements of SO2 and NOx specified in 40 CFR Part 75.

23 8.4.1.2 Greenhouse Gases

24 Both the NGCC and biomass-fired plants would release GHGs, such as CO2 and methane, and 

25 would be subject to continuous monitoring requirements for CO2, as specified in 

26 40 CFR Part 75. 

27 On July 12 2012, EPA issued a rule tailoring the criteria that determine which stationary sources 

28 and modifications to existing projects become subject to permitting requirements for GHG 

29 emissions under the PSD and Title V Programs of the CAA (77 FR 41051). According to this 

30 rule, GHGs are a regulated new source review pollutant under the PSD major source permitting 

31 program if the source is otherwise subject to PSD (for another regulated new source review 

32 pollutant) and has a GHG potential to emit equal to or greater than 75,000 tons (68,000 MT) per 

33 year of CO2 equivalent (“carbon dioxide equivalent” adjusts for different global warming 

34 potentials for different GHGs). Beginning January 2, 2011, operating permits issued to major 

35 sources of GHGs under the PSD or Title V Federal permit programs must contain provisions 

36 requiring the use of Best Available Control Technology (BACT) to limit the emissions of GHGs if 

37 those sources would be subject to PSD or Title V permitting requirements. If the alternative 

38 meets the GHG emission thresholds established in the rule, then GHG emissions from this 

39 alternative would be regulated under the PSD and Title V permit programs.

40 8.4.1.3 Particulates

41 Both the NGCC and biomass-fired plants would produce particulates. For the biomass-fired 

42 plants, fugitive particulate matter emissions would be produced from the wood fuel receiving, 
Environmental Impacts of Alternatives

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1 processing, and storage operations, but they could be minimized using enclosures and a water 

2 misting system (Palmer Renewable Energy 2011).

3 As described above, construction activities associated with both the NGCC and biomass-fired 

4 plants would generate fugitive dust as well as exhaust emissions from vehicles and motorized 

5 equipment. These impacts would be short-term and would be minimized by dust control 

6 measures. 

7 8.4.1.4 Hazardous Air Pollutants

8 In December 2000, EPA issued regulatory findings (EPA 2000) on emissions of HAPs from 

9 electric utility steam-generating units, which identified that natural gas-fired plants emit HAPs 

10 such as arsenic, formaldehyde and nickel and stated that 

11 . . . the impacts due to HAP emissions from natural gas-fired electric utility steam 

12 generating units were negligible based on the results of the study. The 

13 Administrator finds that regulation of HAP emissions from natural gas-fired 

14 electric utility steam generating units is not appropriate or necessary. 

15 As a result of the EPA’s conclusion, the staff finds no significant air quality effects from HAPs for 

16 the NGCC portion of the combination alternative. The biomass-fired plants would also release 

17 HAPs, but each 50-MWe unit is likely to emit less than 10 tons/yr (9.1 MT/yr) of any individual 

18 HAP or 25 tons/yr (22.7 MT/yr) for any combination of HAPs (Palmer Renewable Energy 2011).

19 8.4.1.5 Conclusion

20 Air quality impacts would result primarily from the NGCC and biomass-fired portions of the 

21 combination alternative. The purchased power portion would likely come from gas, coal, and/or

22 nuclear sources, the largest sources of power generation in Mississippi. The impacts to air 

23 quality from gas, coal, and nuclear power are described in Sections 8.1.1, 8.2.1, and 8.3.1, but 

24 they would be proportionally smaller. Air quality impacts from the DSM portion of the 

25 combination alternative would be negligible. Based on this information, the overall air quality 

26 impacts of the combination alternative would be SMALL to MODERATE. 

27 8.4.2 Groundwater Resources

28 Twenty-one percent of the power supplied by this alternative will be purchased power from 

29 some combination of natural gas, coal, or nuclear power plants. The impact of these types of 

30 power plants on groundwater use and quality are described in Sections 8.1 through 8.3. 

31 Impacts on groundwater for these types of facilities have been characterized as SMALL for both 

32 operation and construction. If power is purchased from existing facilities, impacts would be 

33 smaller than that described in Sections 8.1 through 8.3 because no construction would occur. 

34 Impacts on groundwater use and quality for purchased power would be SMALL.

35 Twenty-four percent of the power supplied by this alternative would come from biomass-fired 

36 generation. A biomass-fired plant would be similar in appearance and operation to a coal-fired 

37 power plant. Groundwater would be consumed to construct the new plants. The amount of 

38 construction water consumed would be much less than the amount consumed by long-term 

39 operation of the biomass-fired plants. Potable water and other plant groundwater requirements 

40 would be about one-third of GGNS requirements. Impacts from biomass-fired generation on 

41 groundwater use and quality would be SMALL. 

42 Thirty-six percent of the power supplied by this alternative would come from the combustion of 

43 natural gas. The hydrologic impact of this type of power plant on groundwater use and quality 

44 would be less than that described in Section 8.2 because one NGCC unit, rather than three 
Environmental Impacts of Alternatives

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1 NGCC units, would be built for the combination alternative. Therefore, impacts on groundwater 

2 use and quality would be SMALL. 

3 Nineteen percent of the power for this alternative would come from DSM and impacts on 

4 groundwater use and quality would be SMALL.

5 The impact of the combination alternative on groundwater use and quality would be SMALL.

6 8.4.3 Surface Water Resources

7 Twenty-one percent of the power supplied by this alternative will be purchased power from 

8 some combination of gas, coal, or nuclear power plants. The impact of these types of power 

9 plants on surface water use and quality are SMALL and are described in Sections 8.1 through 

10 8.3. The impact of the purchased power portion of this alternative on surface water would be 

11 SMALL. 

12 Twenty-four percent of the power supplied by this alternative would come from biomass-fired 

13 generation. If dredging of streams or rivers occurs during construction of the biomass facilities, 

14 surface water quality immediately downstream of the dredging activities could be temporarily 

15 degraded by increases in suspended sediment concentration. In addition, the biomass facilities 

16 would require cooling water. Within the service territory, the Mississippi River, other rivers, or 

17 reservoirs might be a source of cooling water. The small size of these facilities means the 

18 impact on surface water use and quality would be SMALL.

19 Thirty-six percent of the power supplied by this alternative would come from the combustion of 

20 natural gas. The hydrologic impact of this type of power plant on surface water use and quality 

21 is described in Section 8.2. During plant operations, the NGCC plant in the combination 

22 alternative would discharge cooling system blowdown at approximately one-sixth of the existing 

23 GGNS rate. Stormwater discharge, blowdown, sanitary, and other effluents would be permitted 

24 under an NPDES permit. The impacts on surface water use and quality from the NGCC portion 

25 of this alternative would be SMALL.

26 Nineteen percent of the power for this alternative would come from DSM and impacts on 

27 surface water use and quality would be SMALL. 

28 The impact of the combination alternative on surface water use and quality would be SMALL.

29 8.4.4 Aquatic Ecology

30 Construction activities for the combination alternative (such as construction of heavy-haul roads, 

31 and the power blocks for the NGCC and biomass-fired plants) could affect onsite aquatic 

32 features at GGNS for the NGCC plant and onsite aquatic features that may occur where the 

33 biomass-fired plants would be built. Minimal impacts on aquatic ecology resources are 

34 expected because BMPs would likely be used to minimize erosion and sedimentation. 

35 Stormwater control measures, which would be required to comply with Mississippi NPDES

36 permitting, would minimize the flow of disturbed soils into aquatic features. Depending on the 

37 available infrastructure at the selected biomass-fired plant sites, new or expanded intake and 

38 discharge structures may be required. Construction of new or modified intake and discharge 

39 structures may require dredging. In addition, dredging may be required to transport new 

40 materials to the NGCC and biomass-fired plant sites, which could result in increased 

41 sedimentation and turbidity. Dredging activities would require BMPs for in-water work to 

42 minimize sedimentation and erosion. Due to the short-term nature of the dredging activities, the 

43 hydrological alterations to aquatic habitats would likely be localized and temporary.
Environmental Impacts of Alternatives

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1 During operations, the NGCC plant would require approximately one-third of the cooling water 

2 to be discharged into the Mississippi River compared to the NGCC alternative analyzed in 

3 Section 8.2. Therefore, the thermal impacts would be less for the combination alternative than 

4 for license renewal and the NGCC alternative. The cooling system for a new NGCC plant would 

5 have similar chemical discharges as GGNS, but the air emissions from the NGCC plant would 

6 emit particulates that would settle onto the river surface and introduce a new source of 

7 pollutants that would not exist if GGNS continued operating. However, the flow of the 

8 Mississippi River would dissipate pollutants, which would minimize the exposure of fish and 

9 other aquatic organisms to pollutants.

10 During operations, the biomass-fired plants would require cooling water. If cooling water is 

11 withdrawn from and discharged into surface water bodies, aquatic resources may be impacted 

12 from impingement, entrainment, and thermal stress. Impingement, entertainment, and thermal 

13 stress would be minimized because the NRC assumes that the biomass-fired plants would use 

14 closed-cycle cooling systems. 

15 Consultation under several Federal acts, including the ESA and Magnuson–Stevens Act, would 

16 be required to assess the occurrence and potential impacts to Federally protected aquatic 

17 species and habitats within affected surface waters. Coordination with State natural resource 

18 agencies would further ensure that the plant operators would take appropriate steps to avoid or 

19 mitigate impacts to State-listed species, habitats of conservation concern, and other protected 

20 species and habitats. The NRC assumes that these consultations would result in avoidance or 

21 mitigation measures that would minimize or eliminate potential impacts to protected aquatic 

22 species and habitats.

23 The DSM portion of this alternative would have little to no impact on aquatic resources because 

24 there would be little to no water required. 

25 The impacts to aquatic resources from purchased power would be similar to those already 

26 described for the NGCC, SCPC, and nuclear alternatives. If power is purchased at existing 

27 plants, the impacts would likely be smaller than those analyzed for the NGCC, SCPC, and 

28 nuclear alternatives because no construction impacts would occur. 

29 The impacts on aquatic ecology would be minor for the combination alternative because 

30 construction activities would require BMPs and stormwater management permits and the 

31 discharge for this alternative would be similar to or less than for GGNS. Therefore, the impacts 

32 on aquatic ecology would be SMALL.

33 8.4.5 Terrestrial Ecology

34 The NGCC component of this alternative would be smaller and require less land than the NGCC 

35 plant described in Section 8.2. This alternative assumes that the NGCC plant would be located 

36 on the GGNS site, and predominantly previously developed or pre-disturbed land would be 

37 affected. The impacts of construction and operation of this alternative on terrestrial species and 

38 habitats would be SMALL because of this alternative’s extensive use of developed land. The 

39 DSM portion of this alternative would have no impact on terrestrial species and habitats. The 

40 purchased power portion of the alternative would have wide-ranging impacts that are hard to 

41 specifically assess because this portion of the alternative could include a mixture of coal, gas, 

42 and nuclear across many different sites. However, the purchased power portion of this 

43 alternative would be more likely to intensify already existing effects at power generating facilities 

44 than create wholly new effects on terrestrial species and habitats. The biomass portion of this 

45 alternative would disturb a total of 135 ac (55 ha) over nine sites (an average of 15 ac [6 ha] per 

46 site). Depending on the location of the biomass-fired plant sites, terrestrial habitat could be 

47 destroyed or fragmented during construction. Particulate air pollution resulting from operation of 
Environmental Impacts of Alternatives

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1 the biomass-fired plants could accumulate in waterways and wetlands and be taken up by 

2 plants and animals. However, air emissions could be reduced by the use of advanced 

3 technologies aimed at lowering emissions. Because of the difficulty of characterizing impacts 

4 resulting from this combination alternative, the staff concludes that impacts could range from 

5 SMALL to MODERATE.

6 As discussed under aquatic ecology impacts, consultation with FWS under the ESA would avoid 

7 potential adverse impacts to Federally listed species or adverse modification or destruction of 

8 designated critical habitat. Coordination with State natural resource agencies would further 

9 ensure that plant operators would take appropriate steps to avoid or mitigate impacts to 

10 State-listed species, habitats of conservation concern, and other protected species and habitats. 

11 The NRC assumes that these consultations would result in avoidance or mitigation measures 

12 that would minimize or eliminate potential impacts to protected terrestrial species and habitats. 

13 Consequently, the impacts of construction and operation of a new nuclear alternative on 

14 protected species and habitats would be SMALL.

15 8.4.6 Human Health

16 Impacts on human health from construction of the NGCC, biomass-fired and purchased power 

17 portions of this alternative would be similar to impacts associated with the construction of any 

18 major industrial facility. Compliance with worker protection rules would control those impacts on 

19 workers at acceptable levels. Impacts from construction on the general public would be minimal 

20 since limiting active construction area access to authorized individuals is expected assuming the 

21 plant operator follows BMPs. Impacts on human health from the construction of the NGCC, 

22 biomass-fired and purchased power portions of this alternative would be SMALL.

23 Construction and operation impacts for the DSM portion of this alternative would be minimal and 

24 localized to activities such as weatherization efficiency of an end-user’s home or facility. The 

25 GEIS notes that the environmental impacts are likely to be centered on indoor air quality 

26 (NRC 1996). This is because of increased weatherization of the home in the form of extra 

27 insulation and reduced air turnover rates from the reduction in air leaks. However, the actual 

28 impact is highly site specific and not yet well established. Impacts on human health from the 

29 construction activities involved in the DSM portion of this alternative would be SMALL.

30 Human health effects of gas-fired generation are generally low, although in Table 8.2 of the 

31 GEIS (NRC 1996), the staff identified cancer and emphysema as potential health risks from 

32 gas-fired plants. NOx emissions contribute to ozone formation, which in turn contributes to 

33 human health risks. Emission controls on the NGCC portion of this alternative can be expected 

34 to maintain NOx emissions well below air quality standards established to protect human health, 

35 and emissions trading or offset requirements mean that overall NOx releases in the region would 

36 not increase. Health risks for workers may also result from handling spent catalysts used for 

37 NOx control that may contain heavy metals. Impacts on human health from the operation of the 

38 NGCC portion of the combination alternative would be SMALL.

39 Using biomass for energy consists of the direct burning of forest residue/wood waste, which

40 would likely include forest residue, primary mill residues, secondary mill residues, or urban 

41 wood residues. Given this method of fuel for power generation, the health impacts would be 

42 similar to those found in a fossil-fuel power generation facility. As discussed in the NGCC and 

43 the SCPC alternatives, regulations restricting emissions enforced by either EPA or delegated 

44 state agencies have reduced the potential health effects from plant emissions, but have not 

45 entirely eliminated them. These agencies also impose site-specific emission limits as needed to 

46 protect human health. As discussed in the NGCC and SCPC alternatives, proper emissions 

47 controls would protect workers and the public from the harmful effects of burning the biomass 
Environmental Impacts of Alternatives

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1 fuel. Therefore, impacts to human health from the biomass portion of the combination 

2 alternative would be SMALL.

3 Purchased power most likely would come from natural gas, coal, or nuclear power generating

4 plants. The human health impacts from the operation of these types of plants are discussed in 

5 detail in the NGCC, SCPC, and nuclear alternatives sections of this chapter. The human health 

6 impacts from the operation of power-generation plants that would provide purchased power are 

7 SMALL.

8 Overall, human health risks to occupational workers and to members of the public from the 

9 combination alternative would be SMALL.

10 8.4.7 Land Use

11 The GEIS generically evaluates the impact of constructing and operating various replacement 

12 power plant alternatives on land use, both on and off each plant site. The analysis of land use 

13 impacts focuses on the amount of land area that would be affected by the construction and 

14 operation of a combination alternative consisting of a natural gas-fired power plant (one NGCC 

15 unit), biomass-fired power plants, DSM, and purchased power.

16 Land use impacts for the NGCC plant would be approximately one-third of that described for the 

17 NGCC alternative discussed in Section 8.2.7 as it would require three units and the combination 

18 alternative would require one unit.

19 The biomass power plants would require approximately 15 ac (6 ha) per 50-MWe unit for a total 

20 of 135 ac (55 ha) on an industrial zoned brownfield site. Forest residue and wood waste are 

21 byproducts of the timber industry, and thus activities associated with the production of this 

22 feedstock will occur regardless of whether a biomass-fired power plant is available to use the 

23 feedstock. Accordingly, the land use impacts associated with the production of this feedstock 

24 will be the same regardless whether the feedstock is used for electricity generation or not. 

25 However, additional land would be required for storing, loading, and transporting forest residue 

26 and wood waste power plant feedstock. Ultimately, land use impacts would depend on the 

27 characteristics of the affected forested lands and the effects of storing, loading and transporting 

28 the biomass feedstock. DSM would have little to no direct land use impacts. However, quickly 

29 replacing old inefficient appliances and other equipment could generate waste material and 

30 potentially increase the size of landfills. However, given time for program development and 

31 implementation, the cost of replacements, and the average life of an appliance; the replacement 

32 process likely would be gradual. For example, older appliances would be replaced by more 

33 efficient appliances as they fail (especially in the case of frequently replaced items, such as light 

34 bulbs). In addition, many appliances and industrial equipment have substantial recycling value 

35 and would not be disposed of in landfills. 

36 Purchased power would also have no direct land use impacts. However, impacts could occur if 

37 existing power plants in the region could not support the demand for purchased power. The 

38 construction of any new replacement power generating facilities could substantially impact

39 existing land-use. Purchased power from coal- and natural gas-fired plants could also have a 

40 noticeable impact on land use due to the amount of land required for coal mining and gas 

41 drilling. Wind energy projects would have a noticeable land-use impact because of the large 

42 amount of land required for wind farms. However, new replacement power generating facilities 

43 could be constructed at existing power plant sites to minimize land use impacts. Impacts could 

44 also be minimized by collocating any new transmission lines within existing right-of-ways.

45 The elimination of uranium fuel for GGNS would partially offset some of the land requirements 

46 for the NGCC and biomass-fired power plant. Scaling from GEIS estimates, approximately 
Environmental Impacts of Alternatives

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1 1,033 ac (418 ha) (based on 35 ac/yr disturbed per 1,000 MWe for 20 years (see GEIS 6.2.2.6) 

2 and 1,475 MWe for GGNS) would no longer be needed for mining and processing uranium 

3 during the operating life of these power plants (NRC 1996). Based on this information, overall 

4 land use impacts from the construction and operation of the combination alternative could range 

5 from SMALL to LARGE.

6 8.4.8 Socioeconomics

7 As previously discussed, socioeconomic impacts are defined in terms of changes to the 

8 demographic and economic characteristics and social conditions of a region. For example, the 

9 number of jobs created by the construction and operation of NGCC and biomass-fired plants

10 could affect regional employment, income, and expenditures. This alternative would create two 

11 types of jobs: (1) construction jobs, which are transient, short in duration, and less likely to have 

12 a long-term socioeconomic impact; and (2) power plant jobs, which have a greater potential for 

13 permanent, long-term socioeconomic impacts. Workforce requirements for the construction and 

14 operation of an NGCC power plant, biomass-fired power plants, DSM, and purchased power 

15 components of this combination alternative were evaluated to estimate their possible effects on 

16 current socioeconomic conditions.

17 The NGCC component would be one-third the size of the NGCC alternative discussed in 

18 Section 8.2.8, and would require about 633 construction workers during peak construction and 

19 50 operations workers. Fifty construction workers are required for each biomass-fired plant, 

20 totaling 450 construction workers if all nine units are constructed at the same time. Each 

21 biomass unit is assumed to require 22 operations workers, for a total of 198 operations workers 

22 for this component of the combination alternative. 

23 The DSM component could generate additional employment, depending on the nature of the 

24 conservation programs and the need for direct measure installations in homes and office 

25 buildings. Jobs would likely be few and scattered throughout the region, and would not have a 

26 noticeable effect on the local economy.

27 Purchased power from existing power plants would not generate any additional employment 

28 opportunities as there would be no change in power plant operations or workforce. However, 

29 new employment opportunities could be created if new electrical power generating facilities

30 were needed to support the demand for purchased power. Construction of a new replacement 

31 power facility could cause noticeable short-term socioeconomic impacts, similar to those 

32 described previously for the other replacement power alternatives. Operation of new 

33 replacement power generating facilities would cause long-term socioeconomic impacts through 

34 job creation, new housing demand, increased tax contribution, and additional purchasing 

35 activity. Construction and operational impacts would vary depending on the location and type of 

36 replacement power generating facility. Therefore, impacts from purchased power could range 

37 from SMALL to LARGE.

38 This combination alternative would also result in a loss of approximately 690 relatively 

39 high-paying jobs at GGNS, with a corresponding reduction in purchasing activity and tax 

40 contributions to the regional economy. However, a larger amount of property taxes may be paid 

41 to local jurisdictions from the NGCC, biomass, DSM, and purchased power components as 

42 more land may be required to support this combination alternative than GGNS. 

43 Because of the relatively small number of construction workers needed for the NGCC and 

44 biomass-fired plants and the various locations of the biomass-fired plants, the socioeconomic 

45 impact of construction on local communities and the tax base would be SMALL. Given the 

46 small number of operations workers required, socioeconomic impacts associated with operation 

47 of this combination alternative would also be SMALL. Construction and operational impacts 
Environmental Impacts of Alternatives

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1 from purchased power would range from SMALL to LARGE. Therefore, overall socioeconomic 

2 impacts from this combination alternative could range from SMALL to LARGE.

3 8.4.9 Transportation

4 Transportation impacts during the construction and operation of the NGCC and biomass 

5 components of this combination alternative would be less than the impacts for any of the 

6 previous alternatives discussed in Sections 8.1.9, 8.2.9, and 8.3.9. This is because the 

7 construction workforce for each component and the volume of materials and equipment to be 

8 transported to each respective construction site would be smaller than each of the other 

9 alternatives. Additionally, the transportation impacts would not be concentrated as they are in 

10 the other alternatives; they would be spread out over a wider area. 

11 During construction, commuting workers and trucks transporting construction materials and 

12 equipment to the work site would increase the amount of traffic on local roads. The increase in 

13 vehicular traffic would peak during shift changes, resulting in temporary levels of service 

14 impacts and delays at intersections. Transporting heavy and oversized components on local 

15 roads could have a noticeable impact over a large area. Some components and materials also 

16 could be delivered by rail or barge, depending on location. Traffic-related transportation impacts 

17 during construction could range from SMALL to MODERATE in the vicinity of the NGCC power 

18 plant at GGNS and biomass power plant units, depending on current road capacities and 

19 average daily traffic volumes. During operations, transportation impacts from the NGCC and 

20 biomass portions of the combination alternative would be less noticeable than during 

21 construction and would be SMALL.

22 No incremental operations impacts would be expected for the DSM or purchased power 

23 components of this alternative. As previously discussed, purchased power from existing power 

24 plants would not generate any additional employment opportunities as there would be no 

25 change in power plant operations or workforce. Traffic volumes on local roads would remain 

26 unchanged. 

27 However, traffic conditions could be substantially impacted if new electrical power generating 

28 facilities were needed to support the demand for purchased power. Construction of new power 

29 generating facilities would cause noticeable short-term transportation impacts on local roads 

30 due to the increased volume of worker and truck delivery traffic required to build the new power 

31 plant, especially during shift changes. However, traffic volumes would decrease after 

32 construction is completed. Construction and operations-related transportation impacts would 

33 vary depending on the location and type of facility. Therefore, impacts from purchased power 

34 could range from SMALL to LARGE. 

35 Based on this information, overall transportation impacts from the combination alternative could 

36 range from SMALL to LARGE.

37 8.4.10 Aesthetics

38 The analysis of aesthetics impact focuses on the degree of contrast between the NGCC and 

39 biomass power plants and surrounding landscapes and the visibility of a new NGCC plant at 

40 GGNS and the new biomass plants. In general, aesthetic changes would be limited to the 

41 immediate vicinity of these power plants, although minor visual impacts may be associated with 

42 the staging, processing, and transport of biomass feedstock.

43 Aesthetic impacts from the NGCC plant component of the combination alternative would be 

44 essentially the same as those described for the NGCC alternative in Section 8.2.10, except 

45 there would be one unit rather than three. Plant infrastructure generally would be smaller and 
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1 less noticeable than GGNS containment and turbine buildings. In addition to the plant 

2 structures, construction of the natural gas pipeline would have a short-term impact. In general, 

3 aesthetic changes would be limited to the immediate vicinity of GGNS and would be SMALL. 

4 Most noise generated during NGCC plant operations would be limited to industrial processes 

5 and communications. Pipelines delivering natural gas fuel could be audible off site near gas 

6 compressor stations. Noise during construction activities for the NGCC alternative may be 

7 detectable off site, but would be for a short duration. Pipeline companies and the plant operator

8 would need to adhere to local ordinances regarding maximum noise levels during construction

9 and operations. Therefore, impacts from noise would be SMALL.

10 The biomass plant would look similar to other fossil fuel power plants with a boiler stack and 

11 cooling towers. In addition, it would have feedstock storage, handling, and processing facilities, 

12 similar to a timber mill. Combustion exhaust and cooling steam plumes may be visible in close 

13 proximity to the plant depending on atmospheric conditions. Noise during construction activities 

14 and plant operations may be detectable off site. The plant operator would need to adhere to 

15 local ordinances regarding maximum noise levels during construction and operations. 

16 Therefore, impacts from noise would be SMALL.

17 No aesthetic or noise impacts would be expected for the DSM and purchased power 

18 components of this alternative. However, impacts could occur if new electrical power 

19 generating facilities were needed to support the demand for purchased power. Impacts would 

20 vary depending on the location and type of power generating facility. If constructed at an 

21 existing power plant site, aesthetic changes would be limited and any impacts could range from

22 SMALL to MODERATE due to the industrial appearance of the site. However, if constructed in 

23 a rural and previously undisturbed area, the effects could range from MODERATE to LARGE. 

24 Therefore, aesthetic impacts from purchased power could range from SMALL to LARGE.

25 Based on this information, overall aesthetic impacts from the combination alternative could 

26 range from SMALL to LARGE. 

27 8.4.11 Historic and Archaeological Resources

28 Impacts on historic and archaeological resources from the NGCC and biomass power plant 

29 components of this alternative would be similar to those discussed for the NGCC alternative in 

30 Section 8.2. A cultural resource survey and inventory would be needed before construction 

31 could begin for either alternative. Resources found in these surveys would need to be 

32 evaluated for eligibility on the National Register of Historic Properties (NRHP) and mitigation of 

33 adverse effects would need to be addressed if eligible resources were encountered. 

34 Construction of either alternative on a brownfield site could minimize impacts to historic and 

35 archaeological resources, however a survey should still be performed to inventory cultural 

36 resources and verify level of disturbance. Given that the sites for biomass-fired units are small 

37 in size (approximately 15 acres) and a preference is given to use previously disturbed 

38 brownfield sites, avoidance of significant historic and archaeological resources should be 

39 possible and effectively managed under current laws and regulations. Impacts to historic and 

40 archaeological resources from the NGCC and biomass portions of this alternative would be 

41 SMALL to MODERATE. 

42 No direct impacts on historic and archaeological resources are expected from DSM or 

43 purchased power . If new transmission lines were needed to convey power to consumers 

44 previously served by GGNS, surveys similar to those discussed for the NGCC unit would need 

45 to be performed. However, transmission lines would likely be collocated within existing right-of46 ways minimizing any impacts to historic and archaeological resources, making direct impacts 

47 SMALL. 
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1 Indirectly, construction of new electrical power generating facilities and any new transmission 

2 lines needed to support the increased demand for power from the closure of GGNS could 

3 impact archaeological and historic resources. Any areas potentially affected by construction 

4 and operation would need to be surveyed and evaluated for NRHP eligibility. The potential for 

5 impacts on historic and archaeological resources would vary greatly depending on the location 

6 of the proposed sites; however, using previously disturbed sites could greatly minimize impacts 

7 to historic and archaeological resources. Areas with the greatest sensitivity could be avoided or 

8 effectively managed under current laws and regulations. Impacts would also vary by type of 

9 energy power facility chosen and the level of ground disturbance it would require for 

10 construction and operation. Therefore, depending on the resource richness of the sites chosen

11 for construction and the type of electrical power generating facility chosen, the impacts could 

12 range from SMALL to LARGE. 

13 The potential for impacts on historic and archaeological resources from the combination 

14 alternative would vary greatly depending on the resource richness of the location of the 

15 proposed sites associated with each component of the alternative. Therefore, the overall impact 

16 on historic and archaeological resources could range from SMALL to LARGE.

17 8.4.12 Environmental Justice

18 The environmental justice impact analysis evaluates the potential for disproportionately high and 

19 adverse human health, environmental, and socioeconomic effects on minority and low-income 

20 populations that could result from the construction and operation of a combination of NGCC and 

21 biomass-fired plants, and DSM and purchased power activities. As previously discussed in 

22 Section 8.1.12, such effects may include human health, biological, cultural, economic, or social 

23 impacts. 

24 Potential impacts to minority and low-income populations from the construction and operation of 

25 a new NGCC and biomass power plants would mostly consist of environmental and 

26 socioeconomic effects (e.g., noise, dust, traffic, employment, and housing impacts). Noise and 

27 dust impacts during construction would be short-term and primarily limited to onsite activities. 

28 Minority and low-income populations residing along site access roads would be directly affected 

29 by increased commuter vehicle traffic during shift changes and truck traffic. However, because 

30 of the temporary nature of construction, these effects are not likely to be high and would be 

31 contained to a limited time period during certain hours of the day. Increased demand for rental 

32 housing during construction could cause rental costs to rise disproportionately affecting low33 income populations living near GGNS for the NGCC plant and the biomass-fired plant locations 

34 who rely on inexpensive housing. However, given the small number of construction workers 

35 and the possibility that workers could commute to the construction site, the potential increased 

36 demand for rental housing would not be significant. No incremental human health or 

37 environmental impacts related to construction would be expected from the purchased power or 

38 DSM component of this alternative.

39 Minority and low-income populations living in close proximity to the power generating facilities 

40 could be disproportionately affected by emissions associated with NGCC power plant and 

41 biomass operations. However, because emissions are expected to remain within regulatory 

42 standards, impacts from emissions are not expected to be high and adverse. 

43 Low-income populations could benefit from weatherization and insulation programs in a DSM 

44 energy conservation program. This could have a greater effect on low-income populations than 

45 the general population, as low-income households generally experience greater home energy 

46 burdens than the average household. Low-income populations could also be disproportionately 

47 affected by increased utility bills due to the cost of purchased power. However, programs, such 
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1 as the Mississippi Low Income Home Energy Assistance Program, are available to assist low2 income families in paying for increased electrical costs, thus mitigating the adverse 

3 socioeconomic impact of this alternative on low-income populations. 

4 Overall, the construction and operation of the NGCC and biomass-fired plants, and DSM and 

5 purchased power activities would not have disproportionately high and adverse human health 

6 and environmental effects on minority and low-income populations.

7 8.4.13 Waste Management

8 During the construction stage for the NGCC plant, land clearing and other construction activities 

9 would generate wastes that could be recycled, disposed of on site, or shipped to an offsite 

10 waste disposal facility. During the operational stage, spent selective catalytic reduction

11 catalysts, which control NOX emissions from the NGCC plant, would make up the majority of 

12 waste generated by this alternative.

13 For DSM, there may be an increase in wastes generated during installation or implementation of 

14 energy conservation measures, such as appropriate disposal of old appliances, installation of 

15 control devices, and building modifications. New and existing recycling programs would help 

16 minimize the amount of generated waste.

17 For the purchased power portion of this alternative, the types of waste generated would be 

18 similar to the alternatives described in Sections 8.1.13, 8.2.13, and 8.3.13.

19 During construction of a the biomass-fired plants, land clearing and other construction activities 

20 would generate waste that could be recycled, disposed of on site, or shipped to an offsite waste 

21 disposal facility. A wood biomass-fired plant may use as fuel the residues from forest clear cut 

22 and thinning operations, noncommercial species, or harvests of forests for energy purposes. In 

23 addition to the gaseous emissions, wood ash is the primary waste product of wood combustion. 

24 Waste would be handled in accordance with appropriate Mississippi Commission of 

25 Environmental Quality waste management regulations (MSCEQ 2012).

26 Overall, waste impacts from the combination alternative would be SMALL.

27 8.4.14 Summary of Impacts of Combination Alternative

28 Table 8–5 summarizes the environmental impacts of the combination alternative compared to 

29 continued operation of GGNS.
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1 Table 8–5. Summary of Environmental Impacts of the Combination Alternative 

2 Compared to Continued Operation of GGNS

Category Combination Alternative Continued GGNS Operation

Air Quality SMALL to MODERATE SMALL

Groundwater Resources SMALL SMALL

Surface Water Resources SMALL SMALL

Aquatic Ecology SMALL SMALL

Terrestrial Ecology SMALL to MODERATE SMALL

Human Health SMALL SMALL

Land Use SMALL to LARGE SMALL

Socioeconomics SMALL to LARGE SMALL

Transportation SMALL to LARGE SMALL

Aesthetics SMALL to LARGE SMALL

Historic and Archaeological Resources SMALL to LARGE SMALL

Waste Management a SMALL SMALL a As described in Chapter 6, the issue, "offsite radiological impacts (spent fuel and high level waste disposal)," is 

not evaluated in this EIS.

3 8.5 Alternatives Considered But Dismissed

4 8.5.1 Demand-Side Management

5 Demand-side management (DSM) includes energy efficiency programs designed to improve the 

6 energy efficiency of facilities and equipment, reduce energy demand through behavioral 

7 changes (energy conservation), and demand response initiatives aimed to lessen customer 

8 usage or change energy use patterns during peak periods (ICF 2009). Energy conservation 

9 and energy efficiency would not require the addition of new generating capacity. To be 

10 considered a viable alternative, a DSM alternative would need to reduce the baseload demand 

11 within Entergy’s Mississippi service territory by 1,475 MWe, which is equivalent to the amount 

12 GGNS provides. 

13 In a 2009 staff report, the Federal Energy Regulatory Commission (FERC) outlined the results 

14 of a national assessment of demand response potential, required of FERC by Section 529 of the 

15 Energy Independence and Security Act of 2007. The report evaluated potential energy savings 

16 in 5- and 10-year horizons for four development scenarios: Business As Usual, Expanded 

17 Business As Usual, Achievable Participation, and Full Participation, each representing greater 

18 demand response program opportunities and proportionally increasing levels of customer 

19 participation (FERC 2009). FERC’s Mississippi-specific analysis indicates that by 2019, the Full 

20 Participation scenario, in which the greatest level of reduction would occur, would yield a 

21 2,247 MWe peak demand reduction in Mississippi (18.6 percent of projected peak demand). 

22 The Business as Usual scenario suggests that demand response programs would yield a 

23 reduction of 75 MWe (0.6 percent of projected peak demand) (FERC 2009). Entergy 

24 Mississippi provides 33.7 percent of Mississippi’s electricity, indicating that if Entergy achieved 

25 the full participation demand reductions, it would yield a reduction of 765 MWe. This amount 

26 would not be sufficient to replace the 1,475 MWe GGNS provides. In addition, according to an 

27 ICF International study, the potential savings from energy conservation and energy efficiency 

28 across Entergy’s six operating companies could reach 729 MWe by 2019 and 1,050 MWe by 

29 2029, adjusted for a reasonable implementation and approval timeline. Mississippi offers 

30 voluntary financial incentive programs, an energy efficiency leasing program for public 

31 institutions and hospitals, and low interest loans for energy efficiency projects, but it does not 

32 require utilities to participate in DSM programs to reduce energy demand. While significant 
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1 energy savings are possible in Mississippi through DSM, the NRC nevertheless does not 

2 consider DSM to be a reasonable alternative to license renewal of GGNS. NRC evaluated an 

3 alternative with DSM programs in combination with an NGCC plant, biomass-fueled plants, and 

4 purchased power in Section 8.4.

5 8.5.2 Wind Power

6 As an intermittent energy source, the feasibility of wind generation to serve as baseload power 

7 depends on the availability, constancy, and accessibility of wind resources within a specific 

8 region. At the current stage of wind energy technology, DOE’s National Renewable Energy 

9 Laboratory (NREL) considers areas with annual average wind speeds around 6.5 meters per 

10 second (m/s) (21 ft/s) and greater (at a height of 80 m [262 ft]) to have a wind resource suitable 

11 for wind development (NREL 2012a). The majority of Mississippi has wind speeds between 4.0 

12 and 5.0 m/s, although a small area in the northwest part of the state has wind speeds of 5.5 m/s 

13 (NREL 2012a). NREL has estimated the windy land area and wind energy potential, including 

14 potential megawatts of rated capacity and estimated potential annual wind energy generation,

15 for each state (NREL 2012b). According to their analyses, Mississippi does not have sufficient 

16 wind resources for any utility-scale wind energy generation. 

17 In addition, the issue of intermittent wind, and subsequent intermittent generation of power, 

18 must be overcome for wind generation to provide baseload power by 2024 when the current 

19 GGNS operating license expires. Currently, limited viable energy storage opportunities exist, 

20 although research is ongoing to connect wind farms with storage technologies such as pumped 

21 water storage, batteries, and compressed air energy storage (CAES) (EAC 2008). EIA is not 

22 projecting any growth in pumped water storage capacity through 2035 (EIA 2011a). As 

23 described below, the potential for new hydroelectric development in Mississippi is limited. 

24 Therefore, the NRC concludes that the use of pumped water storage in combination with wind 

25 farms is unlikely in Mississippi. A CAES plant is another potential storage option that could 

26 possibly serve as a way for wind to provide baseload power. A CAES plant compresses air in 

27 an underground storage cavern. To extract the stored energy, compressed air is combusted, 

28 through a gas-turbine connected to an electrical generator (NREL 2010a). Currently, besides 

29 pumped hydropower storage, deployment of storage technologies in the United States has been 

30 limited to a 110-MWe CAES facility in Alabama and two planned CAES projects with a 

31 combined capacity of 450 MWe (NREL 2010a, Sandia 2012). Current and proposed CAES 

32 projects have a much smaller capacity than would be necessary to replace GGNS; therefore, 

33 the NRC concludes that the use of CAES in combination with wind turbines to generate 

34 1,475 MWe in Mississippi is unlikely.

35 Another solution to overcoming intermittency is the concept of interconnected wind farms. Wind 

36 farms located at a great distance from one another and connected through the transmission grid 

37 could increase the capacity factor compared to a single wind farm in one location. As more 

38 farms are interconnected, the probability that they will all experience the same wind 

39 environment decreases, and the array acts more like a single wind farm with a steady wind 

40 speed (Archer et al. 2007). In Mississippi, however, the wind generation potential is so low that 

41 even when combined with energy storage or interconnected wind farms, it is very unlikely that 

42 wind could serve as baseload power to replace GGNS. 

43 Offshore Wind. The potential for offshore wind generation off the coast of Mississippi is not 

44 likely sufficient to replace GGNS. Although the wind resources are generally stronger in 

45 offshore areas, the wind speeds off the coast of Mississippi and Louisiana are weak compared 

46 to offshore resources in other areas of the United States. Off shore from the Louisiana coast, 

47 wind speeds range between 7.0–8.0 m/s at 90 m compared to 9.0–10.0 m/s at 90 m off the 

48 coast of the Northeast United States where the only utility-scale offshore wind farm has been 
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1 approved (NREL 2010b). Texas has the most potential for offshore wind development in the 

2 gulf coast with wind speeds reaching between 7.5–9.0 m/s (NREL 2010b), and is the only State 

3 in the region to express interest in developing offshore wind energy resources. The Texas 

4 General Land Office has approved leases for offshore wind projects; however none have started 

5 construction (offshorewindfarm.net 2012). Currently, no wind energy projects are proposed off 

6 the coasts of Mississippi or Louisiana (offshorewindfarm.net 2012). 

7 The capital costs for offshore wind projects are much greater than the costs for land-based wind 

8 projects, which will likely prohibit offshore wind development in the near future. A paper 

9 published by the U.S. Offshore Wind Collaborative estimates that initial capital costs for offshore 

10 wind projects are 30 to 60 percent greater than for land-based wind projects. Construction 

11 costs are 33 percent higher for offshore wind farms (USOWC 2009). Foundations for wind 

12 turbines are much more expensive because they must be designed to withstand high winds and 

13 waves. Costs for facility foundations, towers, transmission, and installation are much more 

14 expensive than those for land-based farms (USOWC 2009). In addition, the current 

15 commercially available offshore wind turbines may not be able to withstand major hurricanes. 

16 Currently, the most stringent class of specifications for wind turbines assumes gusts no stronger 

17 than 70 m/s, while Category 4 and 5 hurricanes, which often come through coastal Mississippi 

18 and Louisiana, can have gusts greater than 80 m/s (NREL 2010c).

19 Conclusion. Given the low wind resource potential both on and off shore in Mississippi and the 

20 surrounding region, high costs, and intermittency experienced in wind generation, the NRC does 

21 not consider wind to be a reasonable alternative to license renewal.

22 8.5.3 Solar Power

23 Solar power, including solar photovoltaic and concentrated solar power technologies, produce 

24 power generated from sunlight. Photovoltaics convert sunlight directly into electricity using solar 

25 cells, made from silicon or cadmium telluride (NREL 2012c). By contrast, concentrating solar 

26 power uses heat from the sun to boil water and produce steam to drive a turbine connected to a 

27 generator to produce electricity (NREL 2012c). 

28 In 2010, according to EIA, neither Mississippi, nor any of the surrounding States of Alabama, 

29 Louisiana, or Arkansas produced any large-scale electricity from solar energy (NREL 2012d). 

30 DOE’s National Renewable Energy Laboratory (NREL) reports that Mississippi has average 

solar insolation useful for solar applications ranging between 4.0–5.9 kWh/m2 31 /day 

(NREL 2012d). For utility-scale development, insolation levels below 6.5 kWh/m2 32 /day are not 

33 considered economically viable given current technologies (BLM/DOE 2010). There is more 

34 potential for solar development with local photovoltaic applications, such as rooftop solar panels 

35 than through utility-scale solar facilities. In addition, a solar facility can only generate electricity 

36 when the sun is shining. Energy storage can be used to overcome intermittency for solar 

37 facilities, however, current and foreseeable storage technologies have a much smaller capacity 

38 than would be necessary to replace GGNS (as described above in the discussion of wind 

39 power). Taking all of the factors above into account, it is unlikely that solar photovoltaic or 

40 concentrated solar power technologies could serve as baseload power in Mississippi. Given the 

41 modest levels of solar energy available throughout the State, the lack of any installed solar 

42 capacity in Mississippi and the weather-dependent intermittency of solar power, the NRC does 

43 not currently consider solar energy to be a reasonable alternative to license renewal.

44 8.5.4 Hydroelectric Power

45 Hydroelectric power uses the force of water to turn turbines, which spins a generator to produce 

46 electricity. In a run-of-the-river system, the force of a river current provides the force to create 
Environmental Impacts of Alternatives

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1 the needed pressure for the turbine. In a storage system, water is accumulated in reservoirs 

2 created by dams and is released as needed to generate electricity. DOE’s Idaho National 

3 Environmental Engineering Laboratory completed a comprehensive survey of hydropower 

4 resources in Mississippi in 1997. Mississippi has little hydroelectric potential, with a total 

5 generating potential of 92–128 MWe (INEEL 1997). EIA reported that Mississippi did not 

6 generate any electricity from conventional hydroelectric power in 2010 (EIA 2012a). Given the 

7 small potential capacities and actual power generation of hydroelectric facilities in Mississippi, 

8 the NRC does not consider hydroelectric power to be a reasonable alternative to license 

9 renewal. 

10 8.5.5 Wave and Ocean Energy

11 Wave energy is generated by the movement of a device either floating on the surface of the 

12 ocean or anchored to the ocean floor. Kinetic energy from waves pumps fluid through turbines 

13 to create electric power (DOE 2009). Waves, currents, and tides are often predictable and 

14 reliable, making them attractive candidates for potential renewable energy generation. 

15 There are modest wave energy resources available off the Gulf Coast. However, wave energy 

16 technology is still in the early stages of development. The potential for wave and ocean energy 

17 in Mississippi is limited because the Gulf of Mexico is shallow and semi-enclosed (TCPA 2008). 

18 Because most technologies are relatively undeveloped (and none are developed on the scale of 

19 GGNS), and because the Gulf of Mexico has limited potential for wave and ocean energy, the 

20 NRC did not consider wave and ocean energy as a reasonable alternative to GGNS license 

21 renewal.

22 8.5.6 Geothermal Power

23 Geothermal technologies extract the heat contained in geologic formations to produce steam to 

24 drive a conventional steam turbine generator. Facilities producing electricity from geothermal 

25 energy have demonstrated capacity factors of 95 percent or greater, making geothermal energy 

26 eligible as a source of baseload electric power. However, the feasibility of geothermal power 

27 generation to provide baseload power depends on the regional quality and accessibility of 

28 geothermal resources. Utility-scale geothermal energy generation requires geothermal 

29 reservoirs with a temperature above 200 °F (93 °C). Utility-scale power plants range from small 

30 300 kWe to 50 MWe and greater (TEEIC 2012). In general, geothermal resources are 

31 concentrated in the western United States. Specifically, these resources are found in Alaska, 

32 Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, 

33 Washington, and Wyoming (USGS 2008). The largest geothermal generation project in 

34 Mississippi was a 0.5 MWe geothermal coproduction demonstration project completed in 2011, 

35 which was funded by a Department of Energy’s Research Partnership to Secure Energy for 

36 America (RPSEA) grant (GEA 2012). The project generated electricity from water produced as 

37 a byproduct of oil production. The 6-month demonstration project has since been concluded. 

38 The high cost to produce electricity using geothermal coproduction limited its commercial 

39 deployment, though the demonstration project established its technical viability 

40 (ElectraTherm 2012). No other electricity is currently being produced from geothermal 

41 resources in Mississippi (DOE 2012). Given the low resource potential in Mississippi, the NRC 

42 does not consider geothermal to be a reasonable alternative to GGNS license renewal.

43 8.5.7 Municipal Solid Waste

44 Municipal solid waste combustors use three types of technologies—mass burn, modular, and 

45 refuse-derived fuel. Mass burning is currently the method used most frequently in the 
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1 United States and involves no (or little) sorting, shredding, or separation. Consequently, toxic or 

2 hazardous components present in the waste stream are combusted, and toxic constituents are 

3 exhausted to the air or become part of the resulting solid wastes. As of 2010, approximately 

4 86 waste-to-energy plants are in operation in 24 states, processing 97,000 tons of municipal 

5 solid waste per day (ERC 2010). These waste-to-energy plants have an aggregate capacity of 

6 2,572 MWe and can operate at capacity factors greater than 90 percent. The average 

7 waste-to-energy plant produces about 50 MWe, with some reaching 77 MWe (ERC 2010). No 

8 waste-to-energy facilities operate in Mississippi (ERC 2010). More than 29 average-sized 

9 plants would be necessary to provide the same level of output as GGNS, increasing national 

10 waste-to-energy generation by 57 percent.

11 The decision to burn municipal waste to generate energy is usually driven by the need for an 

12 alternative to landfills rather than energy considerations. Given the improbability that additional 

13 stable supplies of municipal solid waste would be available to support approximately 29 new 

14 facilities and that no waste-to-energy plants operate in Mississippi, the NRC does not consider 

15 municipal solid waste combustion to be a reasonable alternative to GGNS license renewal.

16 8.5.8 Biomass

17 Biomass resources used for biomass-fired generation include crop residues, switch grass, forest 

18 residues, methane from landfills, methane from animal manure management, primary wood mill 

19 residues, secondary wood mill residues, urban wood wastes, and methane from domestic 

20 wastewater treatment. Using biomass-fired generation for baseload power depends on the 

21 geographic distribution, available quantities, constancy of supply, and energy content of 

22 biomass resources. As described in more detail in Section 8.4, the technology used for 

23 conversion of biomass to electricity would be direct combustion.

24 In the GEIS, the NRC indicated a wood waste facility could provide baseload power and operate 

25 with capacity factors between 70 and 80 percent (NRC 1996). Mississippi generated only 

26 236 MWe from biomass fuels in 2010 (EIA 2012b). It is unlikely that Mississippi could increase 

27 its capacity by adding 1,475 MWe of electricity from biomass-fired generation by the time 

28 GGNS’s license expires in 2024. 

29 Biomass-fired generation plants generally are small and can reach capacities of 50 MWe, 

30 meaning that 30 new facilities would be required before 2024. In addition, according to an 

31 NREL report, Mississippi has almost 16 million tons/year total available biomass resources 

32 (NREL 2005). For the hypothetical biomass plant using wood residue described in Section 8.4, 

33 approximately 2,000 tons/day of fuel would be consumed to support one 50 MWe unit 

34 (ARI 2007). Based on a similar consumption rate, all of the available biomass in Mississippi 

35 could support 1,000 MWe of power generation. Therefore, there would be insufficient biomass 

36 in Mississippi to support 1,475 MWe of biomass-fired generation. In addition, small plant sizes 

37 (20–50 MWe) lead to higher capital costs per kWh. Biomass-fired power plants typically are 

38 less efficient than other energy sources; the biomass industry average is 20 percent compared 

39 to 35 percent average efficiency for U.S. electricity generation. An inefficient power plant can 

40 be more sensitive to changes in the price of fuel inputs (i.e., wood waste). High capital costs 

41 combined with low efficiency have led to electricity prices ranging from $0.08 to $0.12/kWh 

42 (NREL 2003). Given the large amount of biomass resources required to replace GGNS 

43 compared to available resources, and potentially high cost, the NRC does not consider biomass 

44 a reasonable alternative to GGNS. The NRC evaluated an alternative with biomass-fired 

45 generation in combination with an NGCC plant, DSM, and purchased power in Section 8.4.
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1 8.5.9 Oil-Fired Power

2 EIA projects that oil-fired plants will account for a 2 percent increase in new electricity

3 generation from 2010 to 2030 in the United States (EIA 2008b). In Mississippi, the percent of 

4 electricity from oil-fired generation fell from 7.9 percent to 0.1 percent from 2000 to 2012 

5 (EIA 2012a). 

6 The variable costs of oil-fired generation tend to be greater than those of nuclear or coal-fired 

7 operations, and oil-fired generation tends to have greater environmental impacts than natural 

8 gas-fired generation. The high cost of oil has resulted in a steady decline in its use for electricity 

9 generation. Given the high cost of oil and the decline in use of oil-fired power plants in 

10 Mississippi over the past 10 years, the NRC does not consider oil-fired generation a reasonable 

11 alternative to GGNS license renewal.

12 8.5.10 Fuel Cells

13 Fuel cells oxidize fuels without combustion and its environmental side effects. Fuel cells 

14 function as an energy conversion technology that allows the energy stored in hydrogen to be 

15 converted back into electrical energy for end use (EIA 2008a). The only byproducts (depending 

16 on fuel characteristics) are heat, water, and CO2. Hydrogen fuel can come from a variety of 

17 hydrocarbon resources. Natural gas typically is used as the hydrogen source.

18 Presently, fuel cells are not economically or technologically competitive with other alternatives

19 for electricity generation. EIA projects that fuel cells may cost $6,835 per installed kW (total 

20 overnight capital costs, 2010 dollars), which is high compared to other alternative technologies 

21 analyzed in this section (EIA 2010b). More importantly, fuel cell units are likely to be small in 

22 size (approximately 10 MWe). It would be extremely costly to replace the power GGNS 

23 provides; it would require approximately 148 units and modifications to the existing transmission 

24 system. Given the immature status of fuel cell technology and high cost, the NRC does not 

25 consider fuel cells to be a reasonable alternative to GGNS license renewal.

26 8.5.11 Purchased Power

27 Under a purchased power alternative, no new generating capacity would necessarily be built 

28 and operated by Entergy. Instead, 1,475 MWe would be purchased from other generators. 

29 Those generators could be located anywhere within or outside Entergy’s service territory. 

30 Entergy’s six operating companies rely on purchased power for a third of their energy needs 

31 (Entergy 2009). Entergy’s Strategic Resource Plan states that the six operating companies plan 

32 on purchasing 1,400 MWe in limited-term purchases (1- to 5-year contracts) by 2025 

33 (Entergy 2010). Limited-term purchases expose the utility and its customers to risk associated 

34 with market price volatility and power availability. In its Strategic Resource Plan, Entergy 

35 outlines how it plans to manage this risk by seeking to limit the amounts of limited-term 

36 purchased power used to meet reliability requirements. Entergy also recognizes that the 

37 amount of uncommitted capacity in the region is declining, and that purchased power may not 

38 provide sufficient resources. In that case, Entergy acknowledges that it may need to build more 

39 capacity than currently anticipated (Entergy 2009). For Entergy to replace the 1,475 MWe 

40 provided by GGNS, it would have to double its amount of planned power purchases. If a 

41 sufficient amount of additional energy from existing plants is not available, new power plants 

42 would need to be constructed. Depending on location, the incorporation of new generation 

43 sources from locations that are remote or distant from load centers likely would involve 

44 significant expenditures in transmission infrastructure expansions. The NRC does not consider 

45 purchased power to be a reasonable alternative to GGNS license renewal.
Environmental Impacts of Alternatives

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1 8.5.12 Delayed Retirement

2 Currently, Entergy owns or controls 20,559 MWe of electricity generation and fails to meet their

3 system reliability requirement by approximately 1 GW (Entergy 2009). This conclusion is based 

4 on current capacity ratings of the existing operating facilities, the expected peak load 

5 requirement, and the planning reserve margin target (Entergy 2011). In addition, the projected 

6 growth in demand over the next 20 years is expected to be 600 MWe/yr (Entergy 2011). Any 

7 currently operating units scheduled for retirement that could be delayed would be needed to 

8 meet this projected growth in demand and would be unavailable to replace existing generation. 

9 Therefore, the NRC does not consider delayed retirement to be a reasonable alternative to 

10 GGNS license renewal. 

11 8.6 No-Action Alternative

12 This section examines environmental effects that would occur if the NRC took no action. No 

13 action in this case means that the NRC decides to not issue a renewed operating license for 

14 GGNS and the license expires at the end of the current license term, in November 2024. Under 

15 the no-action alternative, the plant would shut down at or before the end of the current license. 

16 After shutdown, plant operators would initiate decommissioning in accordance with

17 10 CFR 50.82.

18 This section addresses only those impacts that arise directly as a result of plant shutdown. The 

19 environmental impacts from decommissioning and related activities already have been 

20 addressed in several other documents, including Supplement 1 of NUREG–0586, Final Generic 

21 Environmental Impact Statement on Decommissioning of Nuclear Facilities Regarding the 

22 Decommissioning of Nuclear Power Reactors (NRC 2002); Chapter 7 of the license renewal 

23 GEIS (NRC 1996); and Chapter 7 of this SEIS. These analyses either directly address or bound 

24 the environmental impacts of decommissioning whenever Entergy ceases operating GGNS. 

25 Even with a renewed operating license, GGNS will eventually shut down, and the environmental 

26 effects addressed in this section will occur at that time. Since these effects have not otherwise 

27 been addressed in this SEIS, the impacts will be addressed in this section. As with 

28 decommissioning effects, shutdown effects are expected to be similar whether they occur at the 

29 end of the current license or at the end of a renewed license.

30 8.6.1 Air Quality

31 Shutdown of GGNS would result in a reduction in emissions from activities related to plant 

32 operation, such as use of diesel generators and employee vehicles. The staff determined that 

33 these emissions would have a SMALL impact on air quality during the renewal term (see 

34 Chapter 4); therefore, if emissions decrease, the impact to air quality would also decrease and 

35 would be SMALL.

36 8.6.2 Groundwater Resources

37 Shutdown of GGNS would result in a reduction in groundwater use over that of continued plant 

38 operation. Since it was determined that continued plant operations would have a SMALL impact 

39 on groundwater use and quality during the renewal term (see Chapter 4), the impacts of 

40 shutdown on groundwater use and quality would also be SMALL.
Environmental Impacts of Alternatives

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1 8.6.3 Surface Water Resources

2 Shutdown of GGNS would result in a reduction in surface water use over that of continued plant 

3 operation. Since it was determined that continued plant operations would have a SMALL impact 

4 on surface water use and quality during the renewal term (see Chapter 4), the impacts of 

5 shutdown on surface water use and quality would also be SMALL. 

6 8.6.4 Aquatic Ecology

7 If the plant were to cease operating, impacts on aquatic ecology would decrease because the 

8 plant would withdraw and discharge less water than it does during operations. Shutdown would 

9 reduce the already SMALL impacts on aquatic ecology.

10 8.6.5 Terrestrial Ecology

11 If the plant were to cease operating, the terrestrial ecology impacts would be SMALL, assuming

12 that no additional land disturbances on or off site would occur during decommissioning 

13 activities.

14 8.6.6 Human Health

15 In Chapter 4 of this SEIS, the staff concluded that the impacts of continued plant operation on 

16 human health would be SMALL. After cessation of plant operations, the amounts of radioactive 

17 material released to the environment in gaseous and liquid forms, all of which are currently 

18 within respective regulatory limits, would be reduced or eliminated. Therefore, the staff 

19 concludes that the impact of plant shutdown on human health would also be SMALL. In 

20 addition, the potential for a variety of accidents would also be reduced to only those associated 

21 specifically with shutdown activities and fuel handling. In Chapter 5 of this SEIS, the staff 

22 concluded that impacts of accidents during operation would be SMALL. It follows, therefore, 

23 that impacts on human health from a reduced suite of potential accidents after reactor operation 

24 ceases would also be SMALL. Therefore, the staff concludes that impacts on human health 

25 from the no-action alternative would be SMALL.

26 8.6.7 Land Use

27 Plant shutdown would not affect onsite land use. Plant structures and other facilities would 

28 remain in place until decommissioning. Most transmission lines connected to GGNS would 

29 remain in service after the plant stops operating. Maintenance of most existing transmission 

30 lines would continue as before. The transmission lines could be used to deliver the output of 

31 any new replacement power-generating facilities added to the GGNS site. Impacts on land use 

32 from plant shutdown would be SMALL.

33 8.6.8 Socioeconomics

34 Plant shutdown would have a noticeable impact on socioeconomic conditions in the 

35 communities located in the immediate vicinity of GGNS. Should GGNS shut down, there would 

36 be immediate socioeconomic impact from the loss of jobs (some, though not all, of the 

37 690 employees would begin to leave), and tax payments may be reduced. Since the majority of 

38 GGNS employees reside in Claiborne, Hinds, Jefferson, and Warren Counties, socioeconomic 

39 impacts from plant shutdown would be concentrated in these counties, with a corresponding 

40 reduction in purchasing activity and tax contributions to the regional economy. Revenue losses 

41 from GGNS operations would directly affect Claiborne County and other state taxing districts 
Environmental Impacts of Alternatives

8-54

1 that are most reliant on the nuclear plant’s tax revenue. The impact of the job loss, however, 

2 may not be as noticeable given the amount of time required for decommissioning of the existing 

3 facilities and the proximity of GGNS to metropolitan areas. The socioeconomic impacts of plant 

4 shutdown (which may not entirely cease until after decommissioning) would, depending on the 

5 jurisdiction, range from SMALL to LARGE.

6 8.6.9 Transportation

7 Traffic volumes on the roads in the vicinity of GGNS would be reduced after plant shutdown. 

8 Most of the reduction in traffic volume would be associated with the loss of jobs at the nuclear 

9 power plant. The number of deliveries to the power plant would be reduced until 

10 decommissioning. Transportation impacts would be SMALL as a result of plant shutdown.

11 8.6.10 Aesthetics

12 Plant structures and other facilities would remain in place until decommissioning. Once 

13 operations cease there would be no plume from the cooling tower. Therefore, aesthetic impacts 

14 of plant shutdown would be SMALL.

15 8.6.11 Historic and Archaeological Resources

16 In Chapter 4, the staff concluded that the impacts of continued plant operation on historic and 

17 archaeological resources would be SMALL. Onsite land use would not be affected immediately 

18 by the cessation of operations. Plant structures and other facilities are likely to remain in place

19 until decommissioning. A separate environmental review would be conducted for 

20 decommissioning that would address the protection of known historic and archaeological 

21 resources at GGNS. Therefore, the impacts on historic and archaeological resources from plant 

22 shutdown would be SMALL.

23 8.6.12 Environmental Justice

24 Impacts to minority and low-income populations would depend on the number of jobs and the 

25 amount of tax revenues lost by communities in the immediate vicinity of the power plant after 

26 GGNS ceases operations. Closure of GGNS would reduce the overall number of jobs (there 

27 are currently 690 employees working at GGNS) and tax revenue attributed to nuclear plant 

28 operations. The reduction in tax revenue could decrease the availability of public services in 

29 Claiborne County. This could disproportionately affect minority and low-income populations that

30 may have become dependent on these services. See also Appendix J of NUREG-0586, 

31 Supplement 1 (NRC 2002), for additional discussion of these impacts.

32 8.6.13 Waste Management

33 If the no-action alternative were implemented, the generation of high-level waste would stop, 

34 and generation of low-level and mixed waste would decrease. Waste management impacts 

35 from implementation of the no-action alternative are expected to be SMALL.

36 8.6.14 Summary of Impacts of Combination Alternative

37 Table 8–6 summarizes the environmental impacts of the no-action alternative compared to 

38 continued operation of GGNS.
Environmental Impacts of Alternatives

8-55

1 Table 8–6. Summary of Environmental Impacts of the No-action Alternative

2 Compared to Continued Operation of GGNS

Category No-action Alternative Continued GGNS Operation

Air Quality SMALL SMALL

Groundwater Resources SMALL SMALL

Surface Water Resources SMALL SMALL

Aquatic Ecology SMALL SMALL

Terrestrial Ecology SMALL SMALL

Human Health SMALL SMALL

Land Use SMALL SMALL

Socioeconomics SMALL to LARGE SMALL

Transportation SMALL SMALL

Aesthetics SMALL SMALL

Historic and Archaeological

Resources

SMALL SMALL

Waste Management a SMALL SMALL a As described in Chapter 6, the issue, "offsite radiological impacts (spent fuel and high level waste disposal)," is 

not evaluated in this EIS.

3 8.7 Alternatives Summary

4 In this chapter, the staff considered the following alternatives to GGNS license renewal: new 

5 nuclear generation; NGCC generation; supercritical coal-fired generation; and a combination 

6 alternative of natural gas, biomass-fired generation, DSM, and purchased power. No action by 

7 NRC and its effects also were considered. The impacts for all alternatives to GGNS license 

8 renewal are summarized in Table 8–7.

9 The environmental impacts of the proposed action (issuing a renewed GGNS operating license) 

10 would be SMALL for all impact categories, except for the Category 1 issue, “Offsite radiological 

11 impacts (collective effects)” which the Commission concluded that the impacts are acceptable. 

12 The issue, “Offsite radiological impacts (spent fuel and high level waste disposal” was not 

13 reviewed in this SEIS because it relies on the Commission’s Waste Confidence Decision 

14 (WCD). The WCD was vacated on June 8, 2012, by the U.S. Court of Appeals for the District of 

15 Columbia Circuit. The WCD is explained in more detail in Chapter 6 of this SEIS. 

16 In conclusion, the environmental impacts from all other alternatives would be larger than the 

17 impacts associated with license renewal. As Table 8–7 shows, all other alternatives capable of 

18 meeting the needs currently served by GGNS entail potentially greater impacts than the 

19 proposed action of license renewal of GGNS. To make up the lost generation if license renewal 

20 is denied, the no-action alternative would necessitate the implementation of one or a 

21 combination of alternatives, all of which have greater impacts than the proposed action. Hence, 

22 the staff concludes that the no-action alternative will have environmental impacts greater than or 

23 equal to the proposed license renewal action.

24 In this chapter, the NRC staff considered the following alternatives to GGNS license renewal: 

25 new nuclear generation; NGCC generation; supercritical coal-fired generation; a combination 

26 alternative of natural gas, biomass, DSM and purchased power. No action by NRC and its 

27 effects were also considered. The impacts for GGNS license renewal and for all alternatives to 

28 GGNS license renewal are summarized in Table 8–7.

29 In conclusion, the environmentally preferred alternative is the license renewal of GGNS. All 

30 other alternatives capable of meeting the needs currently served by GGNS entail potentially 
Environmental Impacts of Alternatives

8-56

1 greater impacts than the proposed action of license renewal of GGNS. In order to make up the 

2 lost generation if license renewal is denied, the no-action alternative necessitates the 

3 implementation of one or a combination of alternatives, all of which have greater impacts than 

4 the proposed action. Hence, the NRC staff concludes that the no-action alternative will have 

5 environmental impacts greater than or equal to the proposed license renewal action.
Environmental I

8-57

Table 8–7. Summary of Environmental Impacts of Proposed Action and Alternatives 1 

Alternative

Air QualityGroundwater and Surface Water ResourcesAquatic and Terrestrial EcologyHuman HealthLand UseSocioeconomics (including Transportation and Aesthetics)Archaeological and Historic Resources

License renewal SMALL SMALL SMALL SMALL SMALL SMALL SMALL 

New nuclear at 

GGNS site SMALL SMALL SMALL to MODERATE SMALL SMALL SMALL to LARGE SMALL 

NGCC at GGNS 

site 

SMALL to 

MODERATE SMALL SMALL to MODERATE SMALL SMALL to MODERATE

SMALL to 

MODERATE SMALL 

SCPC at alternate 

site MODERATE SMALL SMALL to LARGE SMALL SMALL to MODERATE

SMALL to 

LARGE 

SMALL to 

MODERATE 

Combination 

alternative

SMALL to

MODERATE SMALL SMALL to MODERATE SMALL SMALL to LARGE

SMALL to 

LARGE 

SMALL to 

LARGE 

No-action 

alternative SMALL SMALL SMALL SMALL SMALL SMALL TO LARGE SMALL 
Environmental Impacts of Alternatives

8-58

1 8.8 References

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5 Wind Resource Potential. June 2010. Available at 

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8 the United States: Assessment of Opportunities and Barriers. September. Available at 

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9-1

1 9.0 CONCLUSION

2 This draft supplemental environmental impact statement (SEIS) contains the environmental 

3 review of Entergy Operations, Inc.’s (Entergy’s) application for a renewed operating license for 

4 Grand Gulf Nuclear Station, Unit 1 (GGNS), as required by Title 10 of the Code of Federal 

5 Regulations Part 51 (10 CFR Part 51), the U.S. Nuclear Regulatory Commission’s (NRC’s) 

6 regulations that implement the National Environmental Policy Act (NEPA). This chapter 

7 presents conclusions and recommendations from the site-specific environmental review of 

8 GGNS and summarizes site-specific environmental issues of license renewal that the NRC staff 

9 (staff) noted during the review. Section 9.1 summarizes the environmental impacts of license 

10 renewal; Section 9.2 presents a comparison of the environmental impacts of license renewal 

11 and energy alternatives; Section 9.3 discusses unavoidable impacts of license renewal, energy 

12 alternatives, and resource commitments; and Section 9.4 presents conclusions and staff

13 recommendations.

14 9.1 Environmental Impacts of License Renewal

15 Based on the staff’s review of site-specific environmental impacts of license renewal presented 

16 in this SEIS, the staff concludes that issuing a renewed license would have SMALL impacts. 

17 The site-specific review included applicable Category 2 issues and uncategorized issues. The 

18 staff considered mitigation measures for each Category 2 issue, as applicable. The staff 

19 concluded that no additional mitigation measure is warranted. 

20 The staff also considered cumulative impacts of past, present, and reasonably foreseeable 

21 future actions, regardless of what agency (Federal or non-Federal) or person undertakes them. 

22 The staff concluded in Section 4.12 that cumulative impacts of GGNS’s license renewal would 

23 be SMALL for all areas, except aquatic and terrestrial resources. For aquatic resources, the 

24 staff concluded that the cumulative impact would be MODERATE. For terrestrial resources, the 

25 cumulative impacts would be MODERATE.

26 9.2 Comparison of Alternatives

27 In the conclusion to Chapter 8, the staff considered the following alternatives to GGNS license 

28 renewal:

29  new nuclear,

30  natural gas-fired combined-cycle (NGCC),

31  supercritical pulverized coal,

32  combination alternative of NGCC, biomass, demand-side management and 

33 purchased power, and

34  no-action.

35 The NRC staff concluded that the environmental impacts of renewal of the operating license for 

36 GGNS would be smaller than those of feasible and commercially viable alternatives. The 

37 no-action alternative would have SMALL environmental impacts in most areas, with the 

38 exception of socioeconomic impacts. Continued operation would have SMALL environmental 

39 impacts in all areas. The staff concluded that continued operation of the existing GGNS is the 

40 environmentally preferred alternative.
Conclusion

9-2

1 9.3 Resource Commitments

2 9.3.1 Unavoidable Adverse Environmental Impacts

3 Unavoidable adverse environmental impacts are impacts that would occur after implementation 

4 of all workable mitigation measures. Carrying out any of the energy alternatives considered in 

5 this SEIS, including the proposed action, would result in some unavoidable adverse 

6 environmental impacts.

7 Minor unavoidable adverse impacts on air quality would occur because of emission and release 

8 of various chemical and radiological constituents from power plant operations. Nonradiological 

9 emissions resulting from power plant operations are expected to comply with 

10 U.S. Environmental Protection Agency emissions standards. Chemical and radiological 

11 emissions are not expected to exceed the National Emission Standards for hazardous air 

12 pollutants.

13 During nuclear power plant operations, workers and members of the public would face 

14 unavoidable exposure to radiation and hazardous and toxic chemicals. Workers would be 

15 exposed to radiation and chemicals associated with routine plant operations and the handling of 

16 nuclear fuel and waste material. Workers would have higher levels of exposure than members 

17 of the public, but doses would be administratively controlled and would not exceed standards or 

18 administrative control limits. In comparison, the alternatives involving the construction and 

19 operation of a non-nuclear power generating facility also would result in unavoidable exposure 

20 to hazardous and toxic chemicals to workers and the public.

21 The generation of spent nuclear fuel and waste material, including low-level radioactive waste,

22 hazardous waste, and nonhazardous waste, also would be unavoidable. In comparison, 

23 hazardous and nonhazardous wastes also would be generated at non-nuclear power generating 

24 facilities. Wastes generated during plant operations would be collected, stored, and shipped for 

25 suitable treatment, recycling, or disposal in accordance with applicable Federal and State 

26 regulations. Because of the costs of handling these materials, power plant operators would be 

27 expected to carry out all activities and optimize all operations in a way that generates the 

28 smallest amount of waste possible.

29 9.3.2 Short-Term Versus Long-Term Productivity

30 The operation of power generating facilities would result in short-term uses of the environment, 

31 as described in Chapters 4, 5, 6, 7, and 8. “Short-term” is the period of time that continued 

32 power generating activities take place.

33 Power plant operations require short-term use of the environment and commitment of resources 

34 (e.g., land and energy), indefinitely or permanently. Certain short-term resource commitments 

35 are substantially greater under most energy alternatives, including license renewal, than under 

36 the no-action alternative because of the continued generation of electrical power and the 

37 continued use of generating sites and associated infrastructure. During operations, all energy 

38 alternatives require similar relationships between local short-term uses of the environment and 

39 the maintenance and enhancement of long-term productivity.

40 Air emissions from power plant operations introduce small amounts of radiological and 

41 nonradiological constituents to the region around the plant site. Over time, these emissions 

42 would result in increased concentrations and exposure, but they are not expected to impact air 

43 quality or radiation exposure to the extent that public health and long-term productivity of the 

44 environment would be impaired.
Conclusion

9-3

1 Continued employment, expenditures, and tax revenues generated during power plant 

2 operations directly benefit local, regional, and State economies over the short term. Local 

3 governments investing project-generated tax revenues into infrastructure and other required 

4 services could enhance economic productivity over the long term.

5 The management and disposal of spent nuclear fuel, low-level radioactive waste, hazardous 

6 waste, and nonhazardous waste requires an increase in energy and consumes space at 

7 treatment, storage, or disposal facilities. Regardless of the location, the use of land to meet 

8 waste disposal needs would reduce the long-term productivity of the land.

9 Power plant facilities are committed to electricity production over the short term. After 

10 decommissioning these facilities and restoring the area, the land could be available for other 

11 future productive uses.

12 9.3.3 Irreversible and Irretrievable Commitments of Resources

13 This section describes the irreversible and irretrievable commitment of resources that have 

14 been noted in this SEIS. Resources are irreversible when primary or secondary impacts limit 

15 the future options for a resource. An irretrievable commitment refers to the use or consumption 

16 of resources that are neither renewable nor recoverable for future use. Irreversible and 

17 irretrievable commitment of resources for electrical power generation include the commitment of 

18 land, water, energy, raw materials, and other natural and manmade resources required for 

19 power plant operations. In general, the commitment of capital, energy, labor, and material 

20 resources also are irreversible.

21 The implementation of any of the energy alternatives considered in this SEIS would entail the 

22 irreversible and irretrievable commitment of energy, water, chemicals, and—in some cases—

23 fossil fuels. These resources would be committed during the license renewal term and over the 

24 entire life cycle of the power plant, and they would be unrecoverable.

25 Energy expended would be in the form of fuel for equipment, vehicles, and power plant 

26 operations and electricity for equipment and facility operations. Electricity and fuel would be 

27 purchased from offsite commercial sources. Water would be obtained from existing water 

28 supply systems. These resources are readily available, and the amounts required are not 

29 expected to deplete available supplies or exceed available system capacities.

30 9.4 Recommendations

31 The NRC staff’s preliminary recommendation is that the adverse environmental impacts of 

32 license renewal for GGNS are not great enough to deny the option of license renewal for 

33 energy-planning decisionmakers. This recommendation is based on the following:

34  the analysis and findings in NUREG-1437, Volumes 1 and 2, Generic 

35 Environmental Impact Statement for License Renewal of Nuclear Plants,

36  the environmental report submitted by Entergy,

37  consultation with Federal, State, and local agencies,

38  the NRC’s environmental review, and

39  consideration of public comments received during the scoping process.

10-1 

1 10.0 LIST OF PREPARERS

2 Members of the U.S. Nuclear Regulatory Commission’s (NRC’s) Office of Nuclear Reactor 

3 Regulation (NRR) prepared this supplemental environmental impact statement (SEIS) with 

4 assistance from other NRC organizations and contract support from Argonne National 

5 Laboratory (ANL), Pacific Northwest National Laboratory (PNNL), the Center for Nuclear Waste 

6 Regulatory Analyses (CNWRA) and a private contractor. Table 10–1 identifies each 

7 contributor’s name, affiliation, and function or expertise.

8 Table 10–1. List of Preparers

Name Affiliation Function or Expertise

NRC

D. Wrona NRR Management oversight

M. Wong NRR Management oversight

D. Drucker NRR Project management

W. Rautzen NRR Radiological, human health and alternatives

S. Klementowicz NRR Radiological, human health and alternatives

B. Ford NRR Hydrology and alternatives

M. Moser NRR Aquatic ecology and alternatives

B. Grange NRR Terrestrial ecology and alternatives 

E. Larson NRR Cultural resources, cumulative impacts and alternatives

J. Rikhoff NRR Socioeconomic, environmental justice, and land use 

and alternatives

E. Keegan NRR Air quality and meteorology (climatology), alternatives

and nonradiological waste management

N. Martinez NRR Air quality and meteorology (climatology)

J. Dozier NRR Severe Accident Mitigation Alternatives

Contractor(a)(b)(c)

J. Quinn ANL Hydrology and alternatives

K. Wescott ANL Cultural resources and alternatives

E. Moret ANL Alternatives

Y. Chang ANL Air quality and meteorology (climatology) and 

alternatives

D. Anderson PNNL Socioeconomic, environmental justice, and land use

R. Benke CNWRA Severe Accident Mitigation Alternatives

E. R. Schmidt Contractor Severe Accident Mitigation Alternatives

(a) ANL is operated by UChicago Argonne, LLC, for the U.S. Department of Energy. (b) PNNL is operated by Battelle for the U.S. Department of Energy. (c) CNWRA is a federally funded research and development center sponsored by the NRC.

11-1 

1 11.0 LIST OF AGENCIES, ORGANIZATIONS, AND PERSONS 

2 TO WHOM COPIES OF THIS SEIS ARE SENT

Name and Title Affiliation and Address

Chief Phyliss Anderson

Tribal Nation—Mississippi Band of Choctaw Indians

P.O. Box 6010

Choctaw Branch Choctaw, MS 39350

Principal Chief B. Cheryl Smith

Tribal Nation—Jena Band of Choctaw Indians

P.O. Box 14

Jena, LA 71342

Chief Gregory Pyle

Tribal Nation—Choctaw Nation of Oklahoma

P. O. Box 1210

Durant, OK 74702-1210

Chairman Earl J. Barbry, Jr.

Tribal Nation—Tunica-Biloxi Tribe of Louisiana

P.O. Box 1589

Marksville, LA 71351

Reid Nelson, Director

Advisory Council on Historic Preservation

Office of Federal Agency Programs

1100 Pennsylvania Avenue, NW, Suite 803 

Washington, DC 20004

David Bernhart, 

Assistant Regional Administrator

National Marine Fisheries Service, 

Southeast Regional Office 

263 13th Avenue, 

South Saint Petersburg, FL 33701

Stephen Ricks, Field Supervisor

U.S. Fish and Wildlife Service, 

Mississippi Field Office

6578 Dogwood View Parkway, Suite A 

Jackson, MS 39213

Jeffrey Weller, Field Supervisor

U.S. Fish and Wildlife Service, Louisiana Field Office

646 Cajundome Blvd., Suite 400 

Lafayette, LA 70506

Andy Sanderson, Ecologist

Mississippi, Department of Wildlife, Fisheries and Parks

2148 Riverside Drive

Jackson, MS 39202

Amity Bass, Ecologist

Louisiana, Department of Wildlife and Fisheries

P.O. Box 98000

Baton Rouge, LA 70898-9000

Greg Williamson, 

Review and Compliance Officer

Mississippi State Historic Preservation Office

P.O. Box 571

Jackson, MS 39205

Phil Boggan, Deputy Director

Louisiana State Historic Preservation Office

P.O. Box 44247

Baton Rouge, LA 70804

James Johnston, Administrator

Claiborne County, Mississippi, Office of the Administrator

P.O. Box 689

510 Main St.

Port Gibson, MS 39150

Fred Reeves, Mayor

City of Port Gibson, Mississippi

1005 College Street

Port Gibson, MS 39150

Debra Chambliss, Deputy City Clerk

Office of the Mayor, Port Gibson, Mississippi

1005 College Street

Port Gibson, MS 39150
List of Agencies, Organizations, and Persons

To Whom Copies of This SEIS Are Sent

11-2 

Name and Title Affiliation and Address

Bryan Collins, Chief, Energy and 

Transportation Branch

Mississippi Department of Environmental Quality

P.O. Box 2261

Jackson, MS 39225

B. J. Smith, Director

Mississippi Division of Radiological Health 

3150 Lawson St.

P.O. Box 1700

Jackson, MS 39215-1700

Cheryl Chubb, Project Manager

Louisiana Department of Environmental Quality

602 North Fifth Street

Baton Rouge, LA 70802

Patricia Hemphill, Deputy Chief, 

Programs & Project Management

U.S. Army Corps of Engineers, Vicksburg District

4155 East Clay Street

Vicksburg, MS 39183-3435

Jan Hillegas, Acting Chair

Green Party of Mississippi

8 Gumtree Drive

Oxford, MS 38655

Heinz Mueller, Chief, 

Environmental Assessment Branch 

U.S. Environmental Protection Agency, Region 4

Room 9T-25

Office of Environmental Accountability, Atlanta Federal Center, 

61 Forsyth Street, SW

Atlanta, GA 30303-3104

EIS Filing Section

U.S. Environmental Protection Agency

1200 Pennsylvania Ave., NW

Washington, D.C. 20004

Also sent via EPA’s e-NEPA Web site
12-1 

1 12.0 INDEX

2 A 

3 accidents, 2-1, 2-6, 5-1, 5-3, 5-4, 5-5, A-3, F-3, 

4 F-6, F-10, F-11, F-12, F-16, F-17, F-33, F-35, 

5 F-40, F-41

6 Advisory Council on Historic Preservation 

7 (ACHP), 21, 1-7, 4-24, 4-53, 11-1, D-1, E-1 

8 aesthetic, 4-26, 8-10, 8-11, 8-20, 8-44, 8-45, 

9 8-56

10 alternatives, iii, xviii, 1-6, 4-33, 5-3, 5-12, 5-13, 

11 6-3, 6-5, 6-6, 8-1, 8-2, 8-3, 8-9, 8-18, 8-26, 

12 8-30, 8-34, 8-40, 8-41, 8-42, 8-43, 8-44, 8-47, 

13 8-53, 8-57, 8-58, 9-1, 9-2, 9-3, 10-1, B-10, F-1, 

14 F-2, F-23, F-24, F-44, F-45

15 archaeological resources, xvii, 1-7, 2-78, 

16 2-79, 2-81, 2-82, 3-2, 4-21, 4-25, 4-45, 4-46, 

17 4-48, 8-11, 8-20, 8-32, 8-45, 8-46, 8-56, B-9, 

18 D-1 

19 B 

20 biota, 2-39, 2-40, 2-41, 2-44, 2-46, 4-6, 4-39, 

21 8-17, 8-28, B-2 

22 boiling water reactor, xxi, 2-1, 3-1 

23 burnup, 2-1, 12-1, B-14

24 C 

25 Choctaw Nation of Oklahoma, 1-7, 4-24, 4-53, 

26 11-1, D-1,D-2, E-1, E-3 

27 chronic effects, 1-3, 4-1, 4-13, 4-18, B-8 

28 Clean Air Act (CAA), xx, 2-22, 2-23, 2-85, 

29 8-14, 8-15, 8-25, 8-36, 8-37, C-2 

30 closed-cycle cooling, 4-40, 4-41, 4-47, 8-23, 

31 8-28, 8-39, B-5 

32 Coastal Zone Management Act (CZMA), xx, 

33 C-2 

34 cold shock, 4-41

35 cooling system, xvi, xvii, 1-4, 1-6, 2-12, 2-15, 

36 2-34, 4-6, 4-8, 4-9, 4-40, 4-41, 4-47, 5-8, 5-9, 

37 5-12, 8-3, 8-5, 8-7, 8-8, 8-13, 8-16, 8-17, 8-23, 

38 8-27, 8-28, 8-39, B-1, B-2, B-3, B-4, F-7, F-30, 

39 F-32, F-37, F-42, F-43

40 core damage frequency (CDF), xiii, xiv, xx, 

41 5-4, 5-5, 5-8, 5-12, F-1, F-2, F-4, F-6, F-7, F-8, 

42 F-9, F-10, F-11, F-12, F-13, F-14, F-15, F-16, F43 20, F-21, F-23, F-24, F-25, F-26, F-27, F-28, F44 29, F-30, F-31, F-32, F-33, F-34, F-35, F-36, F45 37, F-38, F-41, F-42, F-43

46 Council on Environmental Quality (CEQ), xx, 

47 1-4, 4-26, 4-38, 4-49

48 critical habitat, 2-55, 2-58, 2-59, 2-60, 2-62, 

49 2-63, 2-64, 2-84, 4-10, 4-11, 4-13, 4-14, 8-8, 

50 8-18, 8-29, 8-40, C-3 

51 cultural resources, 2-81, 4-25, 4-45, 8-45, C-1 

52 D 

53 demography, 2-66

54 design-basis accident, xx, 4-31, 5-1, 5-2, B-10

55 discharges, 2-9, 2-11, 2-12, 2-22, 2-31, 2-33, 

56 2-35, 2-39, 2-40, 2-42, 2-43, 2-45, 2-55, 2-63, 

57 2-90, 4-5, 4-6, 4-7, 4-8, 4-12, 4-14, 4-37, 4-41, 

58 8-5, 8-7, 8-13, 8-16, 8-17, 8-23, 8-27, 8-39, 

59 8-40, 8-55, B-1, B-3, B-8 

60 dose, xxvi, xxvii, 2-6, 4-17, 4-18, 4-19, 4-43, 

61 4-44, 4-48, 5-6, 5-8, 6-2, B-7, B-11, B-12, F-1, 

62 F-3, F-4, F-9, F-18, F-24, F-25, F-40, F-41

63 dredging, 2-33, 2-39, 8-7, 8-16, 8-17, 8-27, 

64 8-38, 8-39

65 E 

66 education, 2-67, 3-2, 4-21, B-9 

67 electromagnetic fields, xxiii, 1-3, 4-1, 4-8, 

68 4-20, B-6, B-8 
Index

12-2 

1 endangered and threatened species, xvii, 

2 1-7, 2-56, 2-83, 3-2, 4-10, 4-40, 4-41, B-7, D-1 

3 Endangered Species Act (ESA), vi, xviii, xxiii, 

4 1-7, 1-8, 2-54, 2-55, 2-58, 2-63, 2-65, 2-85, 

5 2-89, 4-1, 4-9, 4-10, 4-11, 4-49, 8-7, 8-8, 8-17, 

6 8-18, 8-28, 8-29, 8-39, 8-40, C-3, D-1 

7 entrainment, 4-40, 8-28, 8-39, B-2, B-4 

8 environmental justice (EJ), xviii, 1-3, 1-6, 

9 2-85, 3-2, 4-1, 4-21, 4-26, 4-31, 4-45, 4-48, 

10 4-49, 8-11, 8-21, 8-32, 8-46, 10-1, B-1, B-15

11 EPA, 4-18

12 essential fish habitat (EFH), 2-54, 2-92, C-3, 

13 D-1 

14 eutrophication, 4-54

15 F 

16 Fish and Wildlife Coordination Act (FWCA),

17 C-3 

18 G 

19 GEIS, 4-17

20 Generic Environmental Impact Statement 

21 (GEIS), iii, v, xv, xvi, xvii, xviii, xix, xxiv, 1-3, 1-4, 

22 1-5, 1-6, 1-8, 1-9, 2-70, 2-92, 3-1, 3-2, 3-3, 4-1, 

23 4-2, 4-3, 4-4, 4-5, 4-6, 4-7, 4-8, 4-9, 4-10, 4-15, 

24 4-16, 4-19, 4-20, 4-21, 4-22, 4-23, 4-26, 4-33, 

25 4-52, 4-54, 5-1, 5-2, 5-3, 5-14, 6-1, 6-2, 6-3, 

26 6-12, 7-1, 7-2, 7-3, 8-1, 8-2, 8-9, 8-12, 8-18, 

27 8-19, 8-22, 8-23, 8-25, 8-29, 8-30, 8-31, 8-41, 

28 8-42, 8-52, 8-54, 8-62, 9-3, B-1, B-10

29 greenhouse gases, xxiv, 2-22, 2-69, 2-84, 

30 4-35, 4-49, 6-3, 6-12, 8-13

31 ground water, 4-17

32 groundwater, xvii, 1-6, 2-15, 2-33, 2-34, 2-35, 

33 2-36, 2-37, 2-67, 2-68, 2-86, 3-1, 4-4, 4-5, 4-6, 

34 4-17, 4-18, 4-32, 4-38, 4-47, 8-2, 8-7, 8-16, 

35 8-26, 8-27, 8-28, 8-38, 8-55, B-1, B-4, B-5, 

36 B-10, C-1 

37 H 

38 hazardous waste, 2-8, 9-2, 9-3, C-3 

39 heat shock, 4-12, 12-2, B-4 

40 high-level waste, xvi, 1-4, 6-1, 6-2, 8-12, 8-57, 

41 B-10, B-11, B-12, B-13, B-14

42 I 

43 impingement, 4-40, 8-28, 8-39, B-2, B-4 

44 independent spent fuel storage installation 

45 (ISFSI), xxiv, 2-6, 2-69, 4-34, 4-44, 4-48, A-2 

46 Indian tribes, 2-80, 4-26, 4-31

47 invasive species, 4-43

48 J 

49 Jena Band of Choctaw Indians, 1-7, 4-24, 

50 4-54, 11-1, D-1, D-2, E-1, E-2 

51 L 

52 long-term dose, F-41

53 Louisiana Division of Historic Preservation,

54 1-7 

55 Louisiana Natural Heritage Program, 1-7, 

56 4-51, 4-53, D-1, D-2, E-2 

57 low-level waste, 6-1, 8-12, A-2, A-3, B-13

58 M 

59 Magnuson-Stevens Fishery Conservation 

60 and Management Act (MSA), xxvi, 1-7, 8-7, 

61 8-17, 8-28, C-3 

62 Marine Mammal Protection Act (MMPA), xxv, 

63 C-3 

64 maximum occupational doses, 4-16, B-8 

65 Mississippi Band of Choctaw Indians, 1-7, 

66 4-24, 4-53, 11-1, D-1, E-1, E-2 

67 Mississippi Department of Archives and 

68 History, xxv, 1-7, 2-79, 2-85, 2-89, 2-94, 4-25, 

69 4-51, 4-53
Index

12-3 

1 Mississippi Natural Heritage Program, xxv, 

2 1-7, 2-55, 2-90, 2-91, 4-52, 4-53, D-1, E-2 

3 mitigation, xvi, 1-4, 1-6, 4-15, 4-17, 4-20, 4-37, 

4 4-46, 5-3, 7-1, 7-2, 8-6, 8-8, 8-11, 8-14, 8-17, 

5 8-18, 8-21, 8-24, 8-28, 8-29, 8-32, 8-35, 8-40, 

6 8-45, 9-1, 9-2, E-3 

7 mixed waste, 2-7, 8-12, 8-57, B-14

8 N 

9 National Environmental Policy Act (NEPA),

10 xv, xvi, xvii, xxvi, 1-1, 1-5, 1-6, 1-8, 2-82, 2-91, 

11 2-92, 3-3, 4-10, 4-24, 4-26, 4-38, 4-49, 4-50, 

12 4-52, 5-2, 6-2, 6-3, 6-12, 7-3, 8-1, 9-1, 11-2, 

13 B-1, B-11, B-13

14 National Marine Fisheries Service (NMFS),

15 xxvi, 1-7, 2-54, 2-55, 2-56, 2-83, 2-92, 4-10, 

16 4-52, 4-53, 11-1, C-3, D-1, D-2, E-2, E-3 

17 National Pollutant Discharge Elimination 

18 System (NPDES), xxvi, 2-9, 2-11, 2-31, 2-33, 

19 2-90, 4-12, 4-14, 4-37, 4-41, 8-7, 8-16, 8-17, 

20 8-27, 8-39, B-2, C-1, C-2, C-4 

21 Native American tribes, 2-80, 4-31

22 no-action alternative, iii, xviii, xix, 4-9, 4-38, 

23 4-42, 8-2, 8-54, 8-55, 8-57, 8-58, 9-1, 9-2 

24 nonattainment, 2-24, 3-2, 4-35, 4-47, 8-6, 

25 8-14, 8-24, 8-29, 8-35, B-7 

26 O 

27 once-through cooling, 2-15, B-2, B-3, B-4 

28 P 

29 peak dose, B-12

30 postulated accidents, 4-31, 5-1, 5-2, 5-3, A-4 

31 power uprate, xxiii, 4-44, 5-4, 5-5, A-3, F-2, F-3 

32 pressurized water reactor, 3-1 

33 R 

34 radon, 4-17, 12-3, B-10, B-11

35 Ranney wells, 2-11, 2-12, 2-33, 2-34, 2-35, 

36 4-4, 4-5, 4-41, 4-47, 8-4, 8-5, 8-7, 8-16, 8-17, 

37 B-5 

38 reactor, xv, xvi, xxviii, 1-5, 2-1, 2-6, 2-9, 2-11, 

39 2-12, 2-15, 2-25, 2-26, 2-27, 2-36, 2-82, 4-5, 

40 4-6, 4-22, 4-34, 4-37, 4-38, 4-40, 4-41, 4-44, 

41 4-48, 5-1, 5-2, 5-3, 5-4, 5-5, 5-8, 5-13, 6-2, 6-5, 

42 6-11, 7-1, 8-5, 8-6, 8-8, 8-10, 8-29, 8-55, A-2, 

43 A-3, A-4, B-5, B-11, F-1, F-2, F-3, F-6, F-7, F44 12, F-14, F-16, F-23, F-24, F-29, F-30, F-31, F45 33, F-37, F-39, F-42, F-44

46 refurbishment, xviii, 3-1, 3-2, 3-3, 4-2, 4-3, 4-9, 

47 4-11, 4-13, 4-19, 4-22, 4-26, 4-36, B-1, B-2, B48 4, B-7, B-8, B-9, F-41

49 replacement power, xxviii, 5-11, 8-1, 8-9, 8-11, 

50 8-18, 8-30, 8-42, 8-43, 8-55, F-39, F-41, F-42

51 S 

52 salinity gradients, 4-3, B-1 

53 scoping, iii, xv, xvii, xix, 1-2, 1-3, 1-6, 4-2, 4-3, 

54 4-4, 4-6, 4-7, 4-8, 4-15, 4-16, 4-17, 4-21, 4-25, 

55 4-34, 6-2, 7-2, 9-4, A-1, E-1, E-2 

56 seismic, xxviii, 2-26, 5-7, F-1, F-10, F-11, F-15, 

57 F-21, F-23, F-24

58 severe accident mitigation alternative 

59 (SAMA), vii, xiii, xiv, xviii, xxviii, 5-3, 5-4, 5-7, 

60 5-8, 5-9, 5-10, 5-11, 5-12, 5-13, 5-14, 9-1, E-3, 

61 F-1, F-2, F-3, F-6, F-8, F-9, F-10, F-11, F-15, 

62 F-17, F-18, F-19, F-20, F-21, F-22, F-23, F-24, 

63 F-25, F-26, F-27, F-28, F-29, F-30, F-31, F-32, 

64 F-33, F-34, F-35, F-36, F-37, F-38, F-39, F-40, 

65 F-42, F-43, F-44, F-45, F-46

66 severe accidents, xviii, 4-31, 5-1, 5-2, 5-3, 

67 B-10, E-3, F-1, F-6, F-11, F-15, F-17, F-23, 

68 F-41, F-42

69 solid waste, xviii, 2-7, 2-8, 6-1, 6-2, 7-2, 8-52, 

70 B-15, C-1, C-3 
Index

12-4 

1 spent fuel, xvi, 1-4, 2-6, 4-44, 6-1, 6-2, 6-11, 

2 8-13, 8-22, 8-34, 8-48, 8-57, A-1, A-2, A-3, 

3 B-10, B-11, B-12, B-13, B-14

4 State Historic Preservation Office (SHPO),

5 xxviii, 2-81, 2-93, 4-24, 4-25, 4-46, 11-1, B-9, 

6 C-3, D-1, D-2, E-2 

7 State Pollutant Discharge Elimination 

8 System (SPDES), C-1 

9 stormwater, 8-8, 8-17, 8-28, 8-40, C-4 

10 surface runoff, 2-39, 2-45, 4-39, 4-40, 4-41, 

11 4-42, 4-43, 4-48

12 surface water, 2-11, 2-15, 2-31, 3-1, 4-3, 4-17, 

13 4-31, 4-32, 4-37, 4-41, 4-47, 8-2, 8-7, 8-8, 8-16, 

14 8-17, 8-27, 8-28, 8-38, 8-39, 8-55, B-1, B-5, 

15 C-1, C-2 

16 T 

17 taxes, 2-75, 2-77, 4-24, 8-31, 8-43

18 transmission line corridors, 2-10, 2-54, 2-55, 

19 2-64, 2-65, 4-9, 4-10, 4-13, 4-14, 4-25, 4-42

20 transmission lines, 2-10, 2-18, 2-47, 2-54, 

21 2-55, 2-57, 2-64, 2-81, 4-1, 4-2, 4-8, 4-9, 4-13, 

22 4-14, 4-19, 4-20, 4-21, 4-25, 4-42, 8-4, 8-5, 8-8, 

23 8-17, 8-18, 8-23, 8-28, 8-42, 8-45, 8-55, B-6, 

24 B-7, B-10

25 tritium, 2-36, 4-5, 4-6 

26 Tunica-Biloxi Tribe of Louisiana, 1-7, 4-24, 

27 4-54, 11-1, E-1 

28 U 

29 U.S. Department of Energy (DOE), xx, 4-20, 

30 8-2, 8-49, 8-50, 8-51, 8-60, 8-61, 8-62, 10-2, 

31 B-12

32 U.S. Environmental Protection Agency 

33 (EPA), xv, xxiii, 1-1, 2-7, 2-8, 2-9, 2-10, 2-22, 

34 2-23, 2-24, 2-25, 2-33, 2-35, 2-36, 2-67, 2-68, 

35 2-70, 2-84, 2-86, 2-87, 4-5, 4-10, 4-12, 4-14, 

36 4-18, 4-35, 4-38, 4-39, 4-42, 4-43, 4-48, 4-49, 

37 4-50, 6-2, 8-1, 8-2, 8-6, 8-14, 8-15, 8-16, 8-24, 

38 8-25, 8-26, 8-29, 8-36, 8-37, 8-41, 8-60, 8-61, 

39 9-1, 9-2, 11-2, B-1, B-13, C-1, C-2, C-3 

40 U.S. Fish and Wildlife Service (FWS), xxiii, 

41 1-7, 2-25, 2-54, 2-55, 2-56, 2-57, 2-58, 2-59, 

42 2-60, 2-61, 2-62, 2-63, 2-65, 2-83, 2-84, 2-87, 

43 2-88, 2-93, 4-10, 4-11, 4-12, 4-13, 4-15, 4-50, 

44 4-51, 4-53, 8-8, 8-18, 8-29, 8-40, 11-1, C-3 

45 U.S. Fish and Wildlife Service (FWS), 

46 Louisiana Field Office, 1-7, 11-1 

47 U.S. Fish and Wildlife Service (FWS), 

48 Mississippi Field Office, 1-7 

49 uranium, xxvi, 2-1, 2-6, 4-43, 6-1, 6-2, 6-4, 6-5, 

50 6-7, 6-8, 6-9, 6-10, 8-4, 8-8, 8-9, 8-19, 8-29, 

51 8-30, 8-42, B-10, B-13, B-14

52 W 

53 wastewater, 2-8, 2-9, 2-31, 2-33, 2-90, 4-3, 

54 8-27, 8-52, B-2 

55 Y 

56 Yucca Mountain, B-12, B-13, B-14
1 APPENDIX A 

2 COMMENTS RECEIVED ON THE GGNS ENVIRONMENTAL REVIEW

A-1 

1 A. COMMENTS RECEIVED ON THE GGNS ENVIRONMENTAL REVIEW

2 A.1 Comments Received During the Scoping Period

3 The scoping process began on December 29, 2011, with the publication of the U.S. Nuclear 

4 Regulatory Commission’s (NRC’s) Notice of Intent to conduct scoping in the Federal Register

5 (76 FRN 81996). The scoping process included two public meetings held at the Port Gibson 

6 City Hall, Port Gibson, Mississippi, on January 31, 2012. Approximately 30 people attended the 

7 meetings. After the NRC’s prepared statements pertaining to the license renewal process, the 

8 meetings were open for public comments. Attendees provided oral statements that were 

9 recorded and transcribed by a certified court reporter. Transcripts of the two meetings are 

10 available using the NRC’s Agencywide Documents Access and Management System (ADAMS). 

11 ADAMS Public Electronic Reading Room is accessible at http://www.nrc.gov/reading12 rm/adams.html. Transcripts for the afternoon and evening meetings are listed under Accession 

13 Numbers ML12037A222 and ML12037A223, respectively.

14 Table A–1 identifies the individuals who provided comments and an accession number to

15 identify the source document of the comments in ADAMS.

16 Table A–1. Individuals Who Provided Comments During the Scoping Comment Period

Commenter Affiliation (If Stated) Comment Source ADAMS Accession 

Number

Jan Hillegas Green Party of Mississippi Regulations.gov ML12060A334

Fred Reeves Mayor of Port Gibson Evening transcript ML12037A223

Debra Chambliss City of Port Gibson Evening transcript ML12037A223

17 Note - No comments were received during the afternoon meeting. 

18 Comments received during the scoping comment period applicable to this environmental review 

19 are presented in this section along with the NRC response. The comments that are general or 

20 outside the scope of the environmental review for Grand Gulf Nuclear Station (GGNS) license 

21 renewal are not included here but can be found in the Scoping Summary Report (ADAMS 

22 Accession No. ML12201A623). Unless otherwise identified, comments presented in this section 

23 are from Ms. Jan Hillegas.

24 A.1.1 Waste Management

25 Comment: I did not receive an answer to my question (Transcript, p. 35) about “the 

26 approximate square footage or cubic yards” of radioactive waste now on site and “how much 

27 more accumulates every year.” Mr. Smith’s answer (Transcript, pp. 36-38) in terms of bundles, 

28 canisters, and so on, gave no dimensions. Please provide the dimensions and capacities of the 

29 containers and of the stored waste. And the NRC’s Environmental Review needs to calculate 

30 and evaluate the onsite storage of spent fuel under current and other possible conditions 

31 through at least 2044.
Appendix A

A-2 

1 Response: There are two broad classifications of radioactive waste generated at GGNS: 

2 high-level and low-level waste. High-level radioactive waste results primarily from the fuel that 

3 has been used in a nuclear power reactor and is “spent” or is no longer efficient in generating 

4 power to the reactor to produce electricity. Low-level radioactive waste results from reactor 

5 operations and typically consists contaminated protective shoe covers and clothing, wiping rags, 

6 mops, filters, reactor water treatment residues, equipment, and tools.

7 GGNS does not permanently store low-level radioactive waste on site. As stated on page 3-16 

8 of the applicant’s Environmental Report (ADAMS Accession No. ML11308A234): GGNS 

9 transports low level radioactive waste to a licensed processing facility in Tennessee where the 

10 wastes are further processed prior to being sent to a facility such as EnergySolutions in Clive, 

11 Utah.

12 GGNS stores its spent nuclear fuel in its spent fuel pool and in dry casks. The spent fuel pool is 

13 a strong structure, constructed of steel-reinforced concrete walls with a stainless steel liner, and 

14 filled with water. The spent fuel pool is located inside the plant’s protected area. The NRC 

15 regularly inspects GGNS’s spent fuel storage program to ensure the safety of the spent fuel 

16 stored in the spent fuel pool.

17 GGNS also stores spent nuclear fuel in NRC approved dry cask canisters made of leak-tight 

18 welded and bolted steel. These containers are approximately 16 feet high with an approximate 

19 exterior diameter of 6 feet. A canister with spent fuel is placed in a concrete cask forming a dry 

20 cask storage system. A typical dry cask storage system is detailed at the following website: 

21 http://www.nrc.gov/waste/spent-fuel-storage/diagram-typical-dry-cask-system.html. The

22 concrete casks used at GGNS are approximately 20 feet high with an exterior diameter of 

23 11 feet and are stored on a concrete pad within a secure area. The NRC regularly inspects 

24 GGNS’s dry cask storage system to ensure it complies with NRC requirements. The latest NRC 

25 inspection report of the GGNS ISFSI is available at ADAMS Accession No. ML12303A002. 

26 As reported on page 5 of the GGNS ISFSI Inspection Report 05000416/2012009 (ADAMS 

27 Accession No. ML12303A002) dated October 26, 2012: “The current ISFSI pad can hold 40 

28 casks with provisions for four additional spaces to allow for cask unloading, if required. Future 

29 plans are to add a second pad that will increase the capacity of the ISFSI to 88 storage 

30 locations with 4 spare locations.” Currently, 17 GGNS ISFSI storage locations are occupied. 

31 Every other year, GGNS adds five to seven casks to the ISFSI. 

32 The existing license expiration date for GGNS is November 1, 2024. The requested renewal 

33 would extend the license expiration date to November 1, 2044. The NRC’s safety requirements 

34 for the storage of spent nuclear fuel during licensed operations ensures that the expected 

35 increase in the volume of spent fuel during the license renewal term can be safely stored on site 

36 with small environmental effects.

37 Determining the square feet, cubic yards, and bundles of GGNS spent fuel is not necessary for

38 the license renewal environmental review decision-making process.

39 High-level radioactive waste is discussed in Section 6.1 of this SEIS.

40 A.1.2 Extended Power Uprate

41 Comment: Mayor Fred Reeves asked “what effect would the current upgrade at Grand Gulf

42 have to do with the process?” (Transcript, p. 39) The only answer he was given was that “The 

43 EPU process that [is] currently ongoing is its own independent process. There are aspect[s] of 

44 the plant modifications that are going on that could impact our review, but we have processes in 

45 place to account for that.” (Transcript, pp. 39-40) Please provide Mayor Reeves and me with 

46 an actual answer to his question: What effect will the upgrade have on the processing of the 
Appendix A

A-3 

1 application for license renewal? The NRC’s Environmental Review needs to evaluate all 

2 aspects of the upgraded plant, after it has been operating at the upgraded capacity, before 

3 being able to make a credible report on the environmental impacts of consuming more land and 

4 water, having more personnel on-site, storing more spent fuel, transporting low-level waste, etc.

5 Comment from Mayor Reeves: My other question is what effect would the current upgrade at 

6 Grand Gulf have to do with the process? Would that have an impact on the process?

7 Response: This comment expresses concern that the NRC’s license renewal review should 

8 consider the impacts of the GGNS extended power uprate (EPU) license amendment request. 

9 The NRC granted the EPU license amendment request for GGNS on July 18, 2012 (ADAMS 

10 Accession No. ML121210020). In accordance with 10 CFR 51.21, the NRC prepared an 

11 Environmental Assessment (EA) with a Finding of No Significant Impact (FONSI) for the EPU. 

12 The EA was published in the Federal Register (77 FR 41814) on July 16, 2012, and can be 

13 found at ADAMS Accession No. ML12167A257. 

14 The license renewal environmental review process for GGNS considers environmental impacts 

15 based on the reactor power level requested in the EPU license amendment request. The 

16 impacts on land use are discussed in Section 4.1 of this SEIS. The impacts on water are 

17 discussed in Sections 4.4 and 4.5. A discussion of the number of employees at the site during 

18 the license renewal term is provided in Section 4.10.2 of this SEIS. The impacts of spent fuel, 

19 low-level waste, and transportation of radioactive materials are discussed in Section 6.1 of this

20 SEIS.

21 A.1.3 Extended Power Uprate/Process

22 Comment: I asked about the date of the announcement of what turns out to have been a 

23 “license amendment request” (Transcript, p. 61) to increase the capacity of Grand Gulf, which 

24 was granted without general public knowledge, and the expansion is now under construction. 

25 Please provide the date of that request and the steps in the process between the filing of the 

26 request and the commencement of expansion, including any required public notices, meetings 

27 or comment periods, and whether those included any news releases in addition to Federal 

28 Register publication or legal ads. The NRC’s Environmental Review needs to evaluate all 

29 aspects of the impacts of the additional capacity on Grand Gulf, the Mississippi River, and all 

30 people and properties possibly affected by any catastrophic events at the expanded plant.

31 Response: This comment incorrectly asserts that an extended power uprate (EPU) license 

32 amendment request to increase the maximum reactor core power operating limit at GGNS was 

33 granted on or before February 27, 2012. This comment was received on February 27, 2012, 

34 and at that time a decision to grant or deny the EPU request had not been made. 

35 Entergy Operations, Inc., et al., submitted an EPU license amendment request (ADAMS 

36 Accession No. ML1002660403) on September 8, 2010, supplemented by 47 letters, dated from 

37 November 18, 2010 to June 12, 2012. 

38 The NRC published a Notice of Consideration of Issuance of Amendments to Facility Operating 

39 Licenses, Proposed No Significant Hazards Consideration Determination, and Opportunity for a 

40 Hearing in the Federal Register (76 FR 1464) on January 11, 2011, regarding the GGNS EPU 

41 license amendment request with a 60-day public comment period. The NRC made a proposed 

42 determination that the GGNS EPU amendment request involved no significant hazards 

43 consideration. Under the NRC regulations in 10 CFR 50.92, this means that operation of the 

44 facility in accordance with the proposed amendment would not (1) involve a significant increase 

45 in the probability or consequences of an accident previously evaluated; or (2) create the 

46 possibility of a new or different kind of accident from any accident previously evaluated; or 
Appendix A

A-4 

1 (3) involve a significant reduction in a margin of safety. No comments were received on this 

2 notice.

3 In addition, in accordance with 10 CFR 51.21, the NRC prepared a draft Environmental 

4 Assessment (EA) with a preliminary Finding of No Significant Impact (FONSI) for the proposed 

5 action. The draft EA was published in the Federal Register (77 FR 27804) with a 30-day public 

6 comment period that ended on June 11, 2012. No comments were received on this draft EA. 

7 The final EA was published in the Federal Register (77 FR 41814) on July 16, 2012, and can be 

8 found at ADAMS Accession No. ML12167A257. The EPU license amendment request was 

9 granted on July 18, 2012, and can be found at ADAMS Accession No. ML121210020.

10 The license renewal environmental review process for GGNS considers environmental impacts 

11 based on the reactor power level requested in the EPU license amendment request. The 

12 environmental impacts on GGNS and vicinity are discussed in Chapter 4 and the environmental 

13 impacts of postulated accidents are discussed in Chapter 5 of this SEIS.
1 APPENDIX B

2 NATIONAL ENVIRONMENTAL POLICY ACT ISSUES FOR LICENSE 

3 RENEWAL OF NUCLEAR POWER PLANTS

B-1 

1 B. NATIONAL ENVIRONMENTAL POLICY ACT ISSUES FOR LICENSE 

2 RENEWAL OF NUCLEAR POWER PLANTS

3 The table in this appendix summarizes the National Environmental Policy Act (NEPA) issues 

4 that the applicant was required to consider for potential environmental impacts in developing its 

5 license renewal application environmental report submitted to the U.S. Nuclear Regulatory 

6 Commission (NRC) on November 1, 2011. On June 20, 2013, the NRC published a final rule 

7 (78 FR 37282) revising the list of issues requiring consideration.

8 In addition to the issues listed in the table in this appendix, the NRC also considered the new 

9 issues contained in the June 20, 2013, final rule. The new Category 1 (generic) issues include 

10 geology and soils, exposure of terrestrial organisms to radionuclides, exposure of aquatic 

11 organisms to radionuclides, human health impact from chemicals, and physical occupational 

12 hazards. Radionuclides released to groundwater, effects on terrestrial resources (non-cooling 

13 system impacts), minority and low-income populations (i.e., environmental justice), and 

14 cumulative impacts were added as new Category 2 (site-specific) issues. The June 20, 2013, 

15 final rule revised list of NEPA issues is found in Table B–1 in Appendix B, Subpart A, to Title 10 

16 of the Code of Federal Regulations, Part 51, “Environmental Protection Regulations for 

17 Domestic Licensing and Related Regulatory Functions,” (10 CFR Part 51). Data supporting this 

18 revised list are contained in NUREG–1437, Generic Environmental Impact Statement for 

19 License Renewal of Nuclear Plants. 

20 Table B–1. Summary of Issues and Findings

Issue Type of Issue Findings

Surface Water Quality, Hydrology, and Use

Impacts of 

refurbishment on 

surface water quality

Generic SMALL. Impacts are expected to be negligible during 

refurbishment because best management practices are 

expected to be employed to control soil erosion and spills.

Impacts of 

refurbishment on 

surface water use

Generic SMALL. Water use during refurbishment will not increase 

appreciably or will be reduced during plant outage.

Altered current patterns 

at intake and discharge

structures

Generic SMALL. 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.

Altered salinity 

gradients

Generic SMALL. 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.

Altered thermal 

stratification of lakes

Generic SMALL. Generally, lake stratification has not been found 

to be a problem at operating nuclear power plants and is 

not expected to be a problem during the license renewal 

term.

Temperature effects on 

sediment transport 

capacity

Generic SMALL. 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.
Appendix B

B-2 

Issue Type of Issue Findings

Scouring caused by 

discharged cooling 

water

Generic SMALL. 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.

Eutrophication Generic SMALL. 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.

Discharge of chlorine or 

other biocides

Generic SMALL. Effects are not a concern among regulatory and 

resource agencies, and are not expected to be a problem 

during the license renewal term.

Discharge of sanitary 

wastes and minor 

chemical spills

Generic SMALL. Effects are readily controlled through a National 

Pollutant Discharge Elimination System (NPDES) permit 

and periodic modifications, if needed, and are not 

expected to be a problem during the license renewal term.

Discharge of other 

metals in wastewater

Generic SMALL. 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.

Water use conflicts 

(plants with oncethrough cooling 

systems) 

Generic SMALL. These conflicts have not been found to be a 

problem at operating nuclear power plants with 

once-through heat dissipation systems.

Water use conflicts 

(plants with cooling 

ponds or cooling towers 

using makeup water 

from a small river with 

low flow)

Site-Specific SMALL OR MODERATE. The issue has been a concern 

at nuclear power plants with cooling ponds and at plants 

with cooling towers. Impacts on in-stream and riparian 

communities near these plants could be of moderate 

significance in some situations. 

See 10 CFR 51.53(c)(3)(ii)(A).

Aquatic Ecology (all plants)

Refurbishment Generic SMALL. During plant shutdown and refurbishment there 

will be negligible effects on aquatic biota because of a 

reduction of entrainment and impingement of organisms or 

a reduced release of chemicals.

Accumulation of 

contaminants in 

sediments or biota

Generic SMALL. 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.

Entrainment of 

phytoplankton and 

zooplankton

Generic SMALL. 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.
Appendix B 

B-3 

Issue Type of Issue Findings

Cold shock Generic SMALL. 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.

Thermal plume barrier 

to migrating fish

Generic SMALL. 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.

Distribution of aquatic 

organisms

Generic SMALL. Thermal discharge may have localized effects 

but is not expected to affect the larger geographical 

distribution of aquatic organisms.

Premature emergence 

of aquatic insects

Generic SMALL. 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.

Gas supersaturation 

(gas bubble disease)

Generic SMALL. Gas supersaturation was a concern at a small 

number of operating nuclear power plants with 

once-through cooling systems but has been satisfactorily 

mitigated. It has not been found to be a problem at 

operating nuclear power plants with cooling towers or 

cooling ponds and is not expected to be a problem during 

the license renewal term.

Low dissolved oxygen in 

the discharge

Generic SMALL. 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.

Losses from predation, 

parasitism, and disease 

among organisms 

exposed to sublethal 

stresses

Generic SMALL. 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.

Stimulation of nuisance 

organisms 

(e.g., shipworms)

Generic SMALL. 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.
Appendix B

B-4 

Issue Type of Issue Findings

Aquatic Ecology (for plants with once-through and cooling pond heat dissipation systems)

Entrainment of fish and 

shellfish in early life 

stages

Site-Specific SMALL, MODERATE, OR LARGE. The impacts of 

entrainment are small at many plants but may be 

moderate or even large at a few plants with once-through

and cooling-pond cooling systems. Further, ongoing 

efforts in the vicinity of these plants to restore fish 

populations may increase the numbers of fish susceptible 

to intake effects during the license renewal period, such 

that entrainment studies conducted in support of the 

original license may no longer be valid. 

See 10 CFR 51.53(c)(3)(ii)(B).

Impingement of fish and 

shellfish

Site-Specific SMALL, MODERATE, OR LARGE. The impacts of 

impingement are small at many plants but may be 

moderate or even large at a few plants with once-through

and cooling-pond cooling systems. See 

10 CFR 51.53(c)(3)(ii)(B).

Heat shock Site-Specific SMALL, MODERATE, OR LARGE. Because of continuing 

concerns about heat shock and the possible need to 

modify thermal discharges in response to changing 

environmental conditions, the impacts may be of moderate 

or large significance at some plants. See 

10 CFR 51.53(c)(3)(ii)(B).

Aquatic Ecology (for plants with cooling-tower-based heat dissipation systems)

Entrainment of fish and 

shellfish in early life 

stages

Generic SMALL. Entrainment of fish has not been found to be a 

problem at operating nuclear power plants with this type of 

cooling system and is not expected to be a problem during 

the license renewal term.

Impingement of fish and 

shellfish

Generic SMALL. The impacts of impingement have not been 

found to be a problem at operating nuclear power plants 

with this type of cooling system and are not expected to be 

a problem during the license renewal term.

Heat shock Generic SMALL. Heat shock has not been found to be a problem 

at operating nuclear power plants with this type of cooling 

system and is not expected to be a problem during the 

license renewal term.

Impacts of 

refurbishment on 

groundwater use and 

quality

Generic SMALL. Extensive dewatering during the original 

construction on some sites will not be repeated during 

refurbishment on any sites. Any plant wastes produced 

during refurbishment will be handled in the same manner 

as in current operating practices and are not expected to 

be a problem during the license renewal term.
Appendix B 

B-5 

Issue Type of Issue Findings

Groundwater use 

conflicts (potable and 

service water; plants 

that use <100 gallons 

per minute [gpm])

Generic SMALL. Plants using less than 100 gpm are not expected 

to cause any groundwater use conflicts.

Groundwater use 

conflicts (potable and 

service water, and 

dewatering plants that 

use >100 gpm)

Site-Specific SMALL, MODERATE, OR LARGE. Plants that use more 

than 100 gpm may cause groundwater use conflicts with 

nearby groundwater users. See 10 CFR 51.53(c)(3)(ii)(C).

Groundwater use 

conflicts (plants using 

cooling towers 

withdrawing makeup 

water from a small river)

Site-Specific SMALL, MODERATE, OR LARGE. Water use conflicts 

may result from surface water withdrawals from small 

water bodies during low flow conditions which may affect 

aquifer recharge, especially if other groundwater or 

upstream surface water users come on line before the 

time of license renewal. See 10 CFR 51.53(c)(3)(ii)(A).

Groundwater use 

conflicts (Ranney wells) 

Site-Specific SMALL, MODERATE, OR LARGE. Ranney wells can 

result in potential groundwater depression beyond the site 

boundary. Impacts of large groundwater withdrawal for 

cooling tower makeup at nuclear power plants using 

Ranney wells must be evaluated at the time of application 

for license renewal. See 10 CFR 51.53(c)(3)(ii)(C).

Groundwater quality 

degradation (Ranney 

wells) 

Generic SMALL. Groundwater quality at river sites may be 

degraded by induced infiltration of poor-quality river water 

into an aquifer that supplies large quantities of reactor

cooling water. However, the lower quality infiltrating water 

would not preclude the current uses of groundwater and is 

not expected to be a problem during the license renewal 

term.

Groundwater quality 

degradation (saltwater 

intrusion)

Generic SMALL. Nuclear power plants do not contribute 

significantly to saltwater intrusion.

Groundwater quality 

degradation (cooling 

ponds in salt marshes)

Generic SMALL. Sites with closed-cycle cooling ponds may 

degrade groundwater quality. Because water in salt 

marshes is brackish, this is not a concern for plants 

located in salt marshes.

Groundwater quality 

degradation (cooling 

ponds at inland sites)

Site-Specific SMALL, MODERATE, OR LARGE. Sites with 

closed-cycle cooling ponds may degrade groundwater

quality. For plants located inland, the quality of the 

groundwater in the vicinity of the ponds must be shown to 

be adequate to allow continuation of current uses. 

See 10CFR 51.53(c)(3)(ii)(D).
Appendix B

B-6 

Issue Type of Issue Findings

Terrestrial Ecology

Refurbishment impacts Site-Specific SMALL, MODERATE, OR LARGE. Refurbishment 

impacts are insignificant if no loss of important plant and 

animal habitat occurs. However, it cannot be known 

whether important plant and animal communities may be 

affected until the specific proposal is presented with the 

license renewal application. See 

10 CFR 51.53(c)(3)(ii)(E).

Cooling tower impacts 

on crops and 

ornamental vegetation

Generic SMALL. Impacts from salt drift, icing, fogging, or 

increased humidity associated with cooling tower 

operation 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.

Cooling tower impacts 

on native plants

Generic SMALL. Impacts from salt drift, icing, fogging, or 

increased humidity associated with cooling tower 

operation 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.

Bird collisions with 

cooling towers

Generic SMALL. These collisions 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.

Cooling pond impacts 

on terrestrial resources

Generic SMALL. Impacts of cooling ponds on terrestrial ecological 

resources are considered to be of small significance at all 

sites.

Power line right-of-way

management (cutting 

and herbicide 

application)

Generic SMALL. The impacts of right-of-way maintenance on 

wildlife are expected to be of small significance at all sites.

Bird collisions with 

power lines

Generic SMALL. Impacts are expected to be of small significance 

at all sites.

Impacts of 

electromagnetic fields

on flora and fauna

Generic SMALL. 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.

Floodplains and wetland 

on power line 

right-of-way

Generic SMALL. 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.
Appendix B 

B-7 

Issue Type of Issue Findings

Threatened or Endangered Species

Threatened or 

endangered species

Site-Specific SMALL, MODERATE, OR LARGE. Generally, plant 

refurbishment and continued operation are not expected to 

adversely affect threatened or endangered species. 

However, consultation with appropriate agencies would be 

needed at the time of license renewal to determine 

whether threatened or endangered species are present 

and whether they would be adversely affected. See 

10 CFR 51.53(c)(3)(ii)(E).

Air Quality

Air quality during 

refurbishment

(nonattainment and 

maintenance areas)

Site-Specific SMALL, MODERATE, OR LARGE. Air quality impacts 

from plant refurbishment associated with license renewal 

are expected to be small. However, vehicle exhaust 

emissions could be cause for concern at locations in or 

near nonattainment or maintenance areas. The 

significance of the potential impact cannot be determined 

without considering the compliance status of each site and 

the numbers of workers expected to be employed during 

the outage. See 10CFR 51.53(c)(3)(ii)(F).

Air quality effects of 

transmission lines

Generic SMALL. Production of ozone and oxides of nitrogen is 

insignificant and does not contribute measurably to 

ambient levels of these gases.

Land Use

Onsite land use Generic SMALL. Projected onsite land use changes required 

during refurbishment and the renewal period would be a 

small fraction of any nuclear power plant site and would 

involve land that is controlled by the applicant.

Power line right-of-way Generic SMALL. Ongoing use of power line rights-of-way would 

continue with no change in restrictions. The effects of 

these restrictions are of small significance.

Human Health

Radiation exposures to 

the public during 

refurbishment

Generic SMALL. During refurbishment, the gaseous effluents 

would result in doses that are similar to those from current 

operation. Applicable regulatory dose limits to the public 

are not expected to be exceeded.

Occupational radiation 

exposures during 

refurbishment

Generic SMALL. Occupational doses from refurbishment are 

expected to be within the range of annual average 

collective doses experienced for pressurized-water 

reactors and boiling-water reactors. Occupational 

mortality risk from all causes, including radiation, is in the 

mid-range for industrial settings.
Appendix B

B-8 

Issue Type of Issue Findings

Microbiological 

organisms (occupational 

health)

Generic SMALL. Occupational health impacts are expected to be 

controlled by the continued application of accepted 

industrial hygiene practices to minimize worker exposures.

Microbiological 

organisms (public 

health)(plants using 

lakes or canals, or 

cooling towers or 

cooling ponds that 

discharge to a small 

river)

Site-Specific SMALL, MODERATE, OR LARGE. These organisms are 

not expected to be a problem at most operating plants, 

except possibly at plants using cooling ponds, lakes, or 

canals that discharge to small rivers. Without site-specific 

data, it is not possible to predict the effects generically. 

See 10 CFR 51.53(c)(3)(ii)(G).

Noise Generic SMALL. 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.

Electromagnetic fields—

acute effects (electric 

shock)

Site-Specific SMALL, MODERATE, OR LARGE. Electric shock 

resulting from direct access to energized conductors or 

from induced charges in metallic structures has not been 

found to be a problem at most operating plants and 

generally is not expected to be a problem during the 

license renewal term. However, site-specific review is 

required to determine the significance of the electric shock 

potential at the site. See 10 CFR 51.53(c)(3)(ii)(H).

Electromagnetic fields—

chronic effects 

Uncategorized UNCERTAIN. Biological and physical studies of 60-Hz 

electromagnetic fields have not found consistent evidence 

linking harmful effects with field exposures. However, 

research is continuing in this area and a consensus 

scientific view has not been reached.

Radiation exposures to 

public (license renewal 

term)

Generic SMALL. Radiation doses to the public will continue at 

current levels associated with normal operations.

Occupational radiation 

exposures (license 

renewal term)

Generic SMALL. 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.

Socioeconomic Impacts

Housing impacts Site-Specific SMALL, MODERATE, OR LARGE. Housing impacts are 

expected to be of small significance at plants located in a 

medium- or high-population area and not in an area where 

growth control measures, that limit housing development, 

are in effect. Moderate or large housing impacts of the 

workforce, associated with refurbishment, may be 

associated with plants located in sparsely populated areas 

or in areas with growth control measures that limit housing 

development. See 10 CFR 51.53(c)(3)(ii)(I).
Appendix B 

B-9 

Issue Type of Issue Findings

Public services: public 

safety, social services, 

and tourism and 

recreation

Generic SMALL. Impacts to public safety, social services, and 

tourism and recreation are expected to be of small 

significance at all sites.

Public services: public 

utilities

Site-Specific SMALL OR MODERATE. An increased problem with 

water shortages at some sites may lead to impacts of 

moderate significance on public water supply availability. 

See 10 CFR 51.53(c)(3)(ii)(I).

Public services: 

education

(refurbishment)

Site-Specific SMALL, MODERATE, OR LARGE. Most sites would 

experience impacts of small significance but larger 

impacts are possible depending on site- and projectspecific factors. See 10 CFR 51.53(c)(3)(ii)(I).

Public services: 

education (license 

renewal term)

Generic SMALL. Only impacts of small significance are expected

Offsite land use 

(refurbishment)

Site-Specific SMALL OR MODERATE. Impacts may be of moderate 

significance at plants in low population areas. See 

10 CFR 51.53(c)(3)(ii)(I).

Offsite land use 

(license renewal term)

Site-Specific SMALL, MODERATE, OR LARGE. Significant changes in 

land use may be associated with population and tax 

revenue changes resulting from license renewal. See 

10 CFR 51.53(c)(3)(ii)(I).

Public services: 

transportation

Site-Specific SMALL, MODERATE, OR LARGE. Transportation 

impacts (level of service) of highway traffic generated 

during plant refurbishment and during the term of the 

renewed license are generally expected to be of small 

significance. However, the increase in traffic associated 

with the additional workers and the local road and traffic 

control conditions may lead to impacts of moderate or 

large significance at some sites. 

See 10 CFR 51.53(c)(3)(ii)(J).

Historic and 

archaeological 

resources

Site-Specific SMALL, MODERATE, OR LARGE. Generally, plant 

refurbishment and continued operation are expected to 

have no more than small adverse impacts on historic and 

archaeological resources. However, the National Historic 

Preservation Act requires the Federal agency to consult 

with the State Historic Preservation Officer to determine 

whether there are properties present that require 

protection. See 10 CFR 51.53(c)(3)(ii)(K).

Aesthetic impacts 

(refurbishment)

Generic SMALL. No significant impacts are expected during 

refurbishment.

Aesthetic impacts 

(license renewal term)

Generic SMALL. No significant impacts are expected during the 

license renewal term.
Appendix B

B-10

Issue Type of Issue Findings

Aesthetic impacts of 

transmission lines

(license renewal term)

Generic SMALL. No significant impacts are expected during the 

license renewal term.

Postulated Accidents

Design-basis accidents Generic SMALL. The NRC staff has concluded that the 

environmental impacts of design-basis accidents are of 

small significance for all plants.

Severe accidents Site-Specific SMALL. The probability weighted consequences of 

atmospheric releases, fallout onto open bodies of water, 

releases to groundwater, and societal and economic 

impacts from severe accidents are small for all plants. 

However, alternatives to mitigate severe accidents must 

be considered for all plants that have not considered such 

alternatives. See 10 CFR 51.53(c)(3)(ii)(L).

Uranium Fuel Cycle and Waste Management 

(impacts discussed further in Chapter 6 of this SEIS)

Offsite radiological 

impacts (individual 

effects from other than 

the disposal of spent 

fuel and high-level 

waste)

Generic SMALL. Offsite impacts of the uranium fuel cycle have 

been considered by the Commission in Table S-3 of this 

part. Based on information in the GEIS, impacts on 

individuals from radioactive gaseous and liquid releases, 

including radon-222 and technetium-99, are small.
Appendix B 

B-11

Issue Type of Issue Findings

Offsite radiological 

impacts (collective 

effects)

Generic The 100-year environmental dose commitment to the 

U.S. population from the fuel cycle, high-level waste, and 

spent fuel disposal is calculated to be about 

14,800 person-rem, or 12 cancer fatalities, for each 

additional 20-year power reactor operating term. Much of 

this, especially the contribution of radon releases from 

mines and tailing piles, consists of tiny doses summed 

over large populations.

This same dose calculation can theoretically be extended 

to include many tiny doses over additional thousands of 

years, as well as doses outside the United States. The 

result of such a calculation would be thousands of cancer 

fatalities from the fuel cycle, but this result assumes that 

even tiny doses have some statistical adverse health 

effects which will not ever be mitigated (for example, no 

cancer cure in the next thousand years), and that these 

doses projected over thousands of years are meaningful. 

However, these assumptions are questionable. In 

particular, science cannot rule out the possibility that there 

will be no cancer fatalities from these tiny doses. For 

perspective, the doses are very small fractions of 

regulatory limits, and even smaller fractions of natural 

background exposure to the same populations.

Nevertheless, despite all the uncertainty, some judgment 

as to the regulatory NEPA implications of these matters 

should be made and it makes no sense to repeat the same 

judgment in every case. Even taking the uncertainties into 

account, the Commission concludes that these impacts 

are acceptable in that these impacts would not be 

sufficiently large to require the NEPA conclusion, for any 

plant, that the option of extended operation under 

10 CFR Part 54 should be eliminated. Accordingly, while 

the Commission has not assigned a single level of 

significance for the collective effects of the fuel cycle, this 

issue is considered Category 1 (Generic).
Appendix B

B-12

Issue Type of Issue Findings

Offsite radiological 

impacts (spent fuel and 

high-level waste

disposal)

Generic For the high-level waste and spent fuel disposal 

component of the fuel cycle, there are no current 

regulatory limits for offsite releases of radionuclides for the 

current candidate repository site. However, if it is 

assumed that limits are developed along the lines of the 

1995 National Academy of Sciences (NAS) report, 

“Technical Bases for Yucca Mountain Standards,” and that 

in accordance with the Commission’s Waste Confidence 

Decision, 10 CFR 51.23, a repository can and likely will be 

developed at some site which will comply with such limits, 

peak doses to virtually all individuals will be 

100 milliroentgen equivalent man (millirem) per year or 

less. However, while the Commission has reasonable 

confidence that these assumptions will prove correct, there 

is considerable uncertainty since the limits are yet to be 

developed, no repository application has been completed 

or reviewed, and uncertainty is inherent in the models 

used to evaluate possible pathways to the human 

environment. The NAS report indicated that 100 millirem 

per year should be considered as a starting point for limits 

for individual doses, but notes that some measure of 

consensus exists among national and international bodies 

that the limits should be a fraction of the 100 millirem per 

year. The lifetime individual risk from 100 millirem annual 

dose limit is about 3 x 10-3. 

Estimating cumulative doses to populations over 

thousands of years is more problematic. The likelihood 

and consequences of events that could seriously 

compromise the integrity of a deep geologic repository 

were evaluated by the U.S. Department of Energy in the 

“Final Environmental Impact Statement: Management of 

Commercially Generated Radioactive Waste,” 

October 1980. The evaluation estimated the 70-year 

whole-body dose commitment to the maximum individual 

and to the regional population resulting from several 

modes of breaching a reference repository in the year of 

closure, after 1,000 years, after 100,000 years, and after 

100,000,000 years. Subsequently, the NRC and other 

Federal agencies have expended considerable effort to 

develop models for the design and for the licensing of a 

high-level waste repository, especially for the candidate 

repository at Yucca Mountain. More meaningful estimates 

of doses to the population may be possible in the future as 

more is understood about the performance of the 

proposed Yucca Mountain repository. Such estimates 

would involve great uncertainty, especially with respect to 

cumulative population doses over thousands of years. 

The standard proposed by the NAS is a limit on maximum 

individual dose. The relationship of potential new 

regulatory requirements, based on the NAS report, and 
Appendix B 

B-13

Issue Type of Issue Findings

Offsite radiological 

impacts (spent fuel and 

high-level waste

disposal)

[continued from 

previous page]

Generic cumulative population impacts has not been determined, 

although the report articulates the view that protection of 

individuals will adequately protect the population for a 

repository at Yucca Mountain. However, the 

U.S. Environmental Protection Agency’s (EPA) generic 

repository standards in 40 CFR Part 191 generally provide 

an indication of the order of magnitude of cumulative risk 

to the population that could result from the licensing of a 

Yucca Mountain repository, assuming the ultimate 

standards will be within the range of standards now under 

consideration. The standards in 40 CFR Part 191 protect 

the population by imposing the amount of radioactive 

material released over 10,000 years. The cumulative 

release limits are based on the EPA’s population impact 

goal of 1,000 premature cancer deaths worldwide for a 

100,000-metric ton (MTHM)repository. 

Nevertheless, despite all the uncertainty, some judgment 

as to the regulatory NEPA implications of these matters 

should be made and it makes no sense to repeat the same 

judgment in every case. Even taking the uncertainties into 

account, the Commission concludes that these impacts 

are acceptable in that these impacts would not be 

sufficiently large to require the NEPA conclusion, for any 

plant, that the option of extended operation under 

10 CFR Part 54 should be eliminated. Accordingly, while 

the Commission has not assigned a single level of 

significance for the impacts of spent fuel and high-level 

waste disposal, this issue is considered in Category 1 

(Generic).

Nonradiological impacts 

of the uranium fuel cycle

Generic SMALL. The nonradiological impacts of the uranium fuel 

cycle resulting from the renewal of an operating license for 

any plant are found to be small.

Low-level waste storage 

and disposal

Generic SMALL. The comprehensive regulatory controls that are 

in place and the low public doses being achieved at 

reactors ensure that the radiological impacts to the 

environment will remain small during the term of a 

renewed license. The maximum additional onsite land that 

may be required for low-level waste storage during the 

term of a renewed license and associated impacts will be 

small. Nonradiological impacts on air and water will be 

negligible. The radiological and nonradiological 

environmental impacts of long-term disposal of low-level 

waste from any individual plant at licensed sites are small. 

In addition, the Commission concludes that there is 

reasonable assurance that sufficient low-level waste 

disposal capacity will be made available when needed for 

facilities to be decommissioned consistent with NRC 

decommissioning requirements.
Appendix B

B-14

Issue Type of Issue Findings

Mixed waste storage 

and disposal

Generic SMALL. The comprehensive regulatory controls and the 

facilities and procedures that are in place ensure proper 

handling and storage, as well as negligible doses and 

exposure to toxic materials for the public and the 

environment at all plants. License renewal will not 

increase the small, continuing risk to human health and 

the environment posed by mixed waste at all plants. The 

radiological and nonradiological environmental impacts of 

long-term disposal of mixed waste from any individual 

plant at licensed sites are small. In addition, the 

Commission concludes that there is reasonable assurance 

that sufficient mixed waste disposal capacity will be made 

available when needed for facilities to be decommissioned 

consistent with NRC decommissioning requirements.

Onsite spent fuel Generic SMALL. The expected increase in the volume of spent 

fuel from an additional 20 years of operation can be safely 

accommodated on site with small environmental effects 

through dry or pool storage at all plants if a permanent 

repository or monitored retrievable storage is not available.

Nonradiological waste Generic SMALL. No changes to generating systems are 

anticipated for license renewal. Facilities and procedures 

are in place to ensure continued proper handling and 

disposal at all plants.

Transportation Generic SMALL. The impacts of transporting spent fuel enriched 

up to 5 percent uranium-235 with average burnup for the 

peak rod to current levels approved by the NRC up to 

62,000 megawatt days per metric ton uranium 

(MWd/MTU) and the cumulative impacts of transporting 

high-level waste to a single repository, such as Yucca 

Mountain, Nevada are found to be consistent with the 

impact values contained in 10 CFR 51.52(c), Summary 

Table S-4, “Environmental Impact of Transportation of 

Fuel and Waste to and from One Light-Water-Cooled 

Nuclear Power Reactor.” If fuel enrichment or burnup 

conditions are not met, the applicant must submit an 

assessment of the implications for the environmental 

impact values reported in 10 CFR 51.52.
Appendix B 

B-15

Issue Type of Issue Findings

Decommissioning

Radiation doses Generic SMALL. Doses to the public will be well below applicable 

regulatory standards regardless of which decommissioning 

method is used. Occupational doses would increase no 

more than 1 man-rem caused by the buildup of long-lived 

radionuclides during the license renewal term.

Waste management Generic SMALL. Decommissioning at the end of a 20-year license 

renewal period would generate no more solid wastes than 

at the end of the current license term. No increase in the 

quantities of Class C or greater than Class C wastes 

would be expected.

Air quality Generic SMALL. Air quality impacts of decommissioning are 

expected to be negligible either at the end of the current 

operating term or at the end of the license renewal term.

Water quality Generic SMALL. The potential for significant water quality impacts 

from erosion or spills is no greater whether 

decommissioning occurs after a 20-year license renewal 

period or after the original 40-year operation period, and 

measures are readily available to avoid such impacts.

Ecological resources Generic SMALL. Decommissioning after either the initial operating 

period or after a 20-year license renewal period is not 

expected to have any direct ecological impacts.

Socioeconomic impacts Generic SMALL. Decommissioning would have some short-term 

socioeconomic impacts. The impacts would not be 

increased by delaying decommissioning until the end of a 

20-year license renewal period, but they might be 

decreased by population and economic growth.

Environmental Justice

Environmental justice Uncategorized NONE. The need for and the content of an analysis of 

environmental justice will be addressed in plant-specific 

reviews.

Table source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

1 APPENDIX C

2 APPLICABLE REGULATIONS, LAWS, AND AGREEMENTS

C-1 

1 C. APPLICABLE REGULATIONS, LAWS, AND AGREEMENTS

2 The Atomic Energy Act of 1954, as amended (42 USC § 2011 et seq.), authorizes the 

3 U.S. Nuclear Regulatory Commission (NRC) to enter into agreement with any State to assume 

4 regulatory authority for certain activities (see 42 USC § 2012 et seq.). For example, through the 

5 Agreement State Program, Mississippi assumed regulatory responsibility over certain 

6 byproduct, source, and quantities of special nuclear materials not sufficient to form a critical 

7 mass. The Division of Radiological Health, Mississippi Department of Health, administers the 

8 Mississippi State Agreement Program. 

9 In addition to carrying out some Federal programs, State legislatures develop their own laws. 

10 State statutes supplement, as well as implement, Federal laws for protection of air, water 

11 quality, and groundwater. State legislation may address solid waste management programs, 

12 locally rare and endangered species, and historic and cultural resources.

13 The Clean Water Act (33 USC § 1251 et seq., herein referred to as CWA) allows for primary 

14 enforcement and administration through State agencies, given that the State program is at least 

15 as stringent as the Federal program. The State program must conform to the CWA and to the 

16 delegation of authority for the Federal National Pollutant Discharge Elimination System

17 (NPDES) program from the U.S. Environmental Protection Agency (EPA) to the State. The 

18 primary mechanism to control water pollution is the requirement for direct dischargers to obtain 

19 an NPDES permit, or in the case of States where the authority has been delegated from the 

20 EPA, a State Pollutant Discharge Elimination System permit, under the CWA. In Mississippi, 

21 the Mississippi Department of Environmental Quality issues and enforces NPDES permits.

22 One important difference between Federal regulations and certain State regulations is the 

23 definition of waters that the State regulates. Certain State regulations may include underground 

24 waters, whereas the CWA only regulates surface waters. The Mississippi Department of 

25 Environmental Quality is charged with conserving, managing and protecting the surface water 

26 and groundwater resources of Mississippi (MDEQ 2013). 

27 C.1 Federal and State Environmental Requirements

28 Grand Gulf Nuclear Station (GGNS) is subject to Federal and State requirements for its 

29 environmental program. 

30 Table C–1 lists the principle Federal and State environmental regulations and laws associated 

31 with the environmental review of the GGNS license renewal application. 

32 Table C–1. Federal and State Environmental Requirements

Law/regulation Requirements

Current operating license and license renewal

Atomic Energy Act (42 

U.S.C. § 2011 et seq.)

This Act is the fundamental U.S. law on both the civilian and the military 

uses of nuclear materials. On the civilian side, it provides for both the 

development and the regulation of the uses of nuclear materials and 

facilities in the United States. The Act requires that civilian uses of nuclear 

materials and facilities be licensed, and it empowers the NRC to establish 

by rule or order, and to enforce, such standards to govern these uses as 

“the Commission may deem necessary or desirable in order to protect 

health and safety and minimize danger to life or property.”
Appendix C 

C-2 

Law/regulation Requirements

10 CFR Part 51. Title 10 

Code of Federal 

Regulations (10 CFR) Part 

51, Energy

“Environmental Protection Regulations for Domestic Licensing and 

Related Regulatory Functions.” This part contains environmental 

protection regulations applicable to the NRC’s domestic licensing and 

related regulatory functions.

10 CFR Part 54 “Requirements for Renewal of Operating Licenses for Nuclear Power 

Plants.” This part focuses on managing adverse effects of aging rather 

than noting all aging mechanisms. The rule is intended to ensure that 

important systems, structures, and components will maintain their 

intended function during the period of extended operation.

10 CFR Part 50 “Domestic Licensing of Production and Utilization Facilities.” Regulations 

that the NRC issues under the Atomic Energy Act of 1954, as amended 

(68 Stat. 919), and Title II of the Energy Reorganization Act of 1974 

(88 Stat. 1242), provide for the licensing of production and utilization 

facilities. This part also gives notice to all persons who knowingly 

supply—to any licensee, applicant, contractor, or subcontractor—

components, equipment, materials, or other goods or services that relate 

to a licensee’s or applicant’s activities subject to this part, that they may be 

individually subject to NRC enforcement action for violation of § 50.5.

Air quality protection

Clean Air Act (CAA) 

(42 USC § 7401 et seq.)

The Clean Air Act (CAA) is a comprehensive Federal law that regulates air 

emissions. Among other things, this law authorizes EPA to establish 

National Ambient Air Quality Standards (NAAQS) to protect public health 

and public welfare and to regulate emissions of hazardous air pollutants. 

EPA has promulgated NAAQS for six criteria pollutants: sulfur dioxide, 

nitrogen dioxide, carbon monoxide (CO), ozone, lead, and particulate 

matter. All areas of the United States must maintain ambient levels of 

these pollutants below the ceilings established by the NAAQS.

Mississippi Air and Water 

Pollution Control Act 

(Mississippi Code 

§§ 49-17-1 to 49-17-43)

The Mississippi Air and Water Pollution Control Act authorizes the setting 

of ambient air quality standards as necessary to protect the public health 

and welfare and emission standards for the purpose of controlling air 

contamination, air pollution, and the sources of air pollution.

Land use resources protection

Coastal Zone Management 

Act (16 USC § 1451 et seq.)

The Coastal Zone Management Act (CZMA) was established to preserve, 

protect, develop and where possible, restore or enhance, the resources of 

the Nation’s coastal zone. 

Water resources protection

Clean Water Act (CWA) 

(33 USC § 1251 et seq.) 

and the NPDES

(40 CFR 122)

The Clean Water Act (CWA) establishes the basic structure for regulating 

discharges of pollutants into the waters of the United States and regulating 

quality standards for surface waters. 

Wild and Scenic River Act 

(16 USC § 1271 et seq.)

The Wild and Scenic River Act created the National Wild and Scenic 

Rivers System, which was established to protect the environmental values 

of free flowing streams from degradation by affecting activities, including 

water resources projects.

Safe Drinking Water Act

(42 USC § 300f et seq.)

The Safe Drinking Water Act (SDWA) is the principal Federal law that 

ensures safe drinking water for the public. Under the SDWA, EPA is 

required to set standards for drinking water quality and oversees all states, 

localities, and water suppliers that implement these standards.

Mississippi

Department of 

Environmental Quality 

Regulation WPC-1

Wastewater Regulations for National Pollutant Discharge Elimination 

System (NPDES) Permits, Underground Injection Control (UIC) Permits, 

State Permits, Water Quality Based Effluent Limitations and Water Quality 

Certification
Appendix C

C-3 

Law/regulation Requirements

Waste management and pollution prevention

Resource Conservation and 

Recovery Act (RCRA) 

(42 USC § 6901 et seq.)

RCRA gives EPA authority to control hazardous waste. Before a material 

can be classified as a hazardous waste, it first must be a solid waste as 

defined under the Resource Conservation and Recovery Act (RCRA). 

Hazardous waste is classified under Subtitle C of the RCRA. Parts 261, 

“Identification and Listing of Hazardous Waste,” and 262, “Standards 

Applicable to Generators of Hazardous Waste,” of 40 CFR contain all 

applicable generators of hazardous waste regulations. 

Pollution Prevention Act 

(42 USC § 13101 et seq.)

The Pollution Prevention Act formally established a national policy to 

prevent or reduce pollution at its source whenever feasible. The Act 

supplies funds for state and local pollution prevention programs through a 

grant program to promote the use of pollution prevention techniques by 

business.

Protected species

Endangered Species Act

(ESA) (16 USC § 1531 et 

seq.)

The Endangered Species Act (ESA) forbids any government agency, 

corporation, or citizen from taking (e.g., harming or killing) endangered 

animals without an Endangered Species Permit. The ESA also requires 

Federal agencies to consult with the U.S. Fish and Wildlife Service or 

National Marine Fisheries Service if any Federal action may adversely 

affect any listed species or designated critical habitat.

Magnuson–Stevens Fishery 

Conservation and 

Management Act (MSA) 

(P.L. 94-265), as amended 

through January 12, 2007

The Magnuson–Stevens Fishery Conservation and Management Act 

(MSA) includes requirements for Federal agencies to consider the impact 

of Federal actions on essential fish habitat and to consult with the National 

Marine Fisheries Service if any activities may adversely affect essential 

fish habitat.

Marine Mammal Protection 

Act (MMPA)

(16 USC § 1361 et seq.)

The Marine Mammal Protection Act (MMPA) prohibits the take of marine 

mammals in U.S. waters or by U.S. citizens on the high seas without an 

MMPA Take Permit issued by the National Marine Fisheries Service. 

MMPA also prohibits importation of marine mammals and marine mammal 

products into the United States.

Fish and Wildlife 

Coordination Act

(16 USC § 661 et seq.)

To minimize adverse impacts of proposed actions on fish and wildlife 

resources and habitat, the Fish and Wildlife Coordination Act requires that 

Federal agencies consult Government agencies regarding activities that 

affect, control, or modify waters of any stream or bodies of water. It also 

requires that justifiable means and measures be used in modifying plans 

to protect fish and wildlife in these waters.

Historic preservation

National Historic 

Preservation Act (NHPA) 

(16 USC § 470 et seq.)

The National Historic Preservation Act (NHPA) directs Federal agencies to 

consider the impact of their actions on historic properties. To comply with 

NHPA, Federal agencies must consult with State Historic Preservation 

Officers and, when applicable, tribal historic preservations officers. NHPA 

also encourages state and local preservation societies.

1 C.2 Operating Permits and Other Requirements

2 Table C–2 lists the permits and licenses issued by Federal, State, and local authorities for 

3 activities at GGNS.
Appendix C 

C-4 

1 Table C–2. Licenses and Permits

Permit Number Dates Responsible Agency

Operating license NPF-29 Issued: 11/1/1984

Expires: 11/1/2024

NRC

401 Water Quality

Certification

None Issued: 2/5/1974

Expires: None

Mississippi Air and Water 

Pollution Control 

Commission

NPDES Permit MS0029521 Expires: 08/31/2016 Mississippi Department of 

Environmental Quality

(MDEQ)

Baseline Stormwater

General NPDES Permit

MSR000883 Expires: 09/28/15 MDEQ

Large Construction

General Permit - Discharge 

of stormwater to

waters of the State

MSR10-5946 Expires: 12/31/15 MDEQ

Air Permit - Operation of air 

emission sources 

(emergency diesel

generators, diesel engines

and pumps, diesel fueled

outage equipment, and

cooling towers)

0420-00023 Expires: 05/31/09

Timely renewal 

application was 

submitted; therefore, 

permit has been 

administratively 

continued.

MDEQ 

Hazardous waste generator 

identification

MSD000644617 Expires: N/A MDEQ

Groundwater withdrawal MS-GW-02972 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02971 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02970 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02969 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-00371 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-16714 Expires: 03/10/2020 MDEQ

Groundwater withdrawal MS-GW-02967 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-14989 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-15026 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02979 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02978 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02977 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02976 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02975 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02974 Expires: 09/25/2016 MDEQ

Groundwater withdrawal MS-GW-02973 Expires: 09/25/2016 MDEQ

Underground diesel fuel

storage

5913 Expires: 06/30/2014 MDEQ

Transportation of radioactive 

waste through Mississippi

4600 Expires: 06/30/2014 Mississippi Emergency 

Management Agency

Radioactive and hazardous 

materials shipments

061013550003V Expires: 06/30/2014 U.S. Department of

Transportation

Taking of migratory birds MB798276-0 Expires: 03/31/2014 U.S. Fish & Wildlife Service

Shipment of radioactive

material into Tennessee to a

disposal/processing facility

T-MS002-L13 Expires: 12/31/2013 Tennessee Department of 

Environmental Conservation

Source: Entergy 2011
Appendix C

C-5 

1 C.3 References

2 [Entergy] Entergy Operations, Inc. 2011. Grand Gulf Nuclear Station, Unit 1, License Renewal 

3 Application. Appendix E, Applicant’s Environmental Report. October 2011. ADAMS Accession 

4 No. ML11308A234

5 [MDEQ] Mississippi Department of Environmental Quality. 2013. Home – The Office of Land 

6 and Water Resources. Available at http://www.deq.state.ms.us/mdeq.nsf/page/l%26w_home

7 (accessed 8 January 2013).

1 APPENDIX D

2 CONSULTATION CORRESPONDENCE

D-1 

1 D. CONSULTATION CORRESPONDENCE

2 D.1 Background

3 The Endangered Species Act of 1973, as amended; the Magnuson Stevens Fisheries 

4 Management Act of 1996, as amended; and the National Historic Preservation Act of 1966 

5 (NHPA) require that Federal agencies consult with applicable State and Federal agencies and 

6 groups before taking action that may affect threatened or endangered species, essential fish 

7 habitat, or historic and archaeological resources, respectively. Table D–1 contains a list of 

8 correspondence between the U. S. Nuclear Regulatory Commission (NRC) and other agencies 

9 pursuant to compliance with these Federal acts. 

10 Table D-1. Consultation Correspondence

Author Recipient Date of Letter/Email

NRC (D. Wrona) Advisory Council on Historic Preservation (R. Nelson) January 19, 2012 

(ML11348A088)

NRC (D. Wrona) Tribal Nation— Mississippi Band of Choctaw Indians (P. 

Anderson)

January 19, 2012 

(ML11342A121)

NRC (D. Wrona) Tribal Nation— Jena Band of Choctaw Indians (B. Smith) January 19, 2012 

(ML11342A121)

NRC (D. Wrona) Tribal Nation— Choctaw Nation of Oklahoma (G. Pyle) January 19, 2012 

(ML11342A121)

NRC (D. Wrona) Tribal Nation— Tunica -Biloxi Tribe of Louisiana (E. Barbry) January 19, 2012 

(ML11342A121)

NRC (D. Wrona) National Marine Fisheries Service (D. Bernhart) January 19, 2012 

(ML11350A173)

NRC (D. Wrona) U.S. Fish & Wildlife Service (USFWS), Louisiana Field Office 

(R. Watson)

January 19, 2012 

(ML11349A001)

NRC (D. Wrona) Mississippi State Historic Preservation Office (SHPO) January 19, 2012 

(ML11348A090)

NRC (D. Wrona) Mississippi Natural Heritage Program (S. Surrette) January 20, 2012 

(ML11349A003)

NRC (D. Wrona) USFWS, Mississippi Field Office (S. Ricks) January 20, 2012 

(ML11348A354)

NRC (D. Wrona) Louisiana SHPO (P. Boggan) January 20, 2012 

(ML11348A353)

USFWS 

Mississippi Field 

Office (S. Ricks)

NRC (D. Drucker) February 3, 2012 

(ML12047A113) 

NRC (D. Wrona) Louisiana Natural Heritage Program (C. Michon) February 6, 2012

(ML12005A163)

Mississippi Natural 

Heritage Program

(A. Sanderson)

NRC (D. Wrona) February 13, 2012

(ML12055A312) 

Tribal Nation—

Mississippi Band 

of Choctaw 

Indians

(C. Wallace)

NRC (D. Wrona) February 13, 2012

(ML12047A127) 
Appendix D

D-2 

Author Recipient Date of Letter/Email

Louisiana Natural 

Heritage Program

(C. Michon)

NRC (D. Wrona) February 16, 2012

(ML12060A098) 

Mississippi SHPO

(G. Williamson) NRC (D. Wrona) February 28, 2012(ML12073A084)

USFWS Louisiana 

Field Office 

(J. Weller)

NRC (D. Wrona) February 29, 2012

(ML12082A141) 

Jena Band of 

Choctaw Indians

(D. Masters)

NRC (Chief, Rules, Announcements, & Directives Branch) March 1, 2012 

(ML12089A020) 

National Marine 

Fisheries Service

(D. Bernhart)

NRC (D. Wrona) March 1, 2012

(ML12065A167) 

Choctaw Nation of 

Oklahoma

(J. Jacobs)

NRC (D. Wrona) March 26, 2012 

(ML12101A124) 
CHRONOL OGY OF EN VIR ONMENT AL REVIEW CORRESPONDEN

CE

1 APPENDIX E 

2 CHRONOLOGY OF ENVIRONMENTAL REVIEW CORRESPONDENCE

E-1 

1 E. CHRONOLOGY OF ENVIRONMENTAL REVIEW 

2 CORRESPONDENCE

3 This appendix contains a chronological listing of correspondence between the U.S. Nuclear 

4 Regulatory Commission (NRC) and external parties as part of its environmental review for 

5 Grand Gulf Nuclear Station (GGNS). All documents are available electronically from the NRC’s 

6 Public Electronic Reading Room found on the Internet at the following Web address: 

7 http://www.nrc.gov/reading-rm.html. From this site, the public can gain access to the NRC’s 

8 Agencywide Documents Access and Management System (ADAMS), which provides text and 

9 image files of the NRC’s public documents in ADAMS. The ADAMS accession number for each 

10 document is included in the following list.

11 E.1 Environmental Review Correspondence

12 Table E–1 lists the environmental review correspondence, by date, beginning with the request 

13 by Entergy to renew the operating license for GGNS.

14 Table E–1. Environmental Review Correspondence

Date Correspondence Description ADAMS No.

October 28, 2011 Transmittal of license renewal application (LRA) for 

GGNS, Unit 1 ML11308A052

November 9, 2011 Receipt and availability of GGNS, Unit 1 LRA ML11293A013

December 16, 2011

Determination of acceptability and sufficiency for 

docketing, proposed review schedule, and opportunity 

for a hearing regarding the application from Entergy 

Operations, Inc. (Entergy), for renewal of the operating 

license for GGNS, Unit 1

ML11335A340

December 22, 2011

Notice of intent to prepare an environmental impact 

statement (EIS) and conduct scoping process for 

license renewal for GGNS, Unit 1

ML11342A073

January 6, 2012

Forthcoming meeting to discuss the license renewal 

process and environmental scoping for GGNS, Unit 1, 

LRA review

ML11362A433

January 19, 2012 GGNS LRA review Advisory Council on Historic 

Preservation ML11348A088

January 19, 2012 Mississippi Band of Choctaw Indians—request for 

comments concerning GGNS LRA review ML11342A121

January 19, 2012 Choctaw Nation of Oklahoma—request for comments 

concerning GGNS LRA review ML11342A121

January 19, 2012 Tunica-Biloxi Tribe of Louisiana—request for

comments concerning GGNS LRA review ML11342A121

January 19, 2012 Jena Band of Choctaw Indians—request for comments 

concerning GGNS LRA review ML11342A121
Appendix E

E-2 

Date Correspondence Description ADAMS No.

January 19, 2012

Request for list of protected species within the area 

under evaluation for the GGNS, Unit 1, license renewal 

review application, U.S. Fish & Wildlife Service 

(USFWS), Louisiana Field Office

ML11349A001

January 19, 2012 GGNS LRA review, Mississippi State Historic 

Preservation Office (SHPO) ML11348A090

January 19, 2012 GGNS LRA review, National Marine Fisheries Service 

(NMFS) ML11350A173

January 20, 2012 GGNS LRA review Louisiana SHPO ML11348A353

January 20, 2012

Request for list of protected species within the area 

under evaluation for GGNS license renewal review 

application, Mississippi Natural Heritage Program

ML11349A003

January 20, 2012

Request for list of protected species within the area 

under evaluation for GGNS license renewal review 

application, USFWS, Mississippi Field Office

ML11348A354

January 31, 2012 Transcript from afternoon public scoping meeting ML12037A222

January 31, 2012 Transcript from evening public scoping meeting ML12037A223

February 3, 2012

Response from USFWS, Mississippi Field Office, to 

NRC request for list of protected species within the 

area under evaluation for GGNS LRA review

ML12047A113

February 6, 2012

Request for list of protected species within the area 

under evaluation for GGNS, Unit 1, license renewal 

review application, Louisiana Natural Heritage Program

ML12005A163

February 13, 2012

Response from Mississippi Natural Heritage Program

to NRC request for list of protected species within the 

area under evaluation for GGNS LRA review

ML12055A312

February 13, 2012 Response from Mississippi Band of Choctaw Indians to 

NRC request for comments on GGNS LRA review ML12047A127

February 13, 2012 Scoping comment from the National Park Service 

referencing the GGNS LRA review ML12048A674

February 16, 2012

Response from Louisiana Natural Heritage Program to 

NRC request for list of protected species within the 

area under evaluation for GGNS LRA review

ML12060A098

February 27, 2012 Scoping comments from J. Hillegas, Green Party of 

Mississippi ML12060A334

February 28, 2012 Mississippi SHPO response to NRC letter referencing

GGNS LRA review ML12073A084

February 29, 2012

Response from USFWS, Louisiana Field Office, to 

NRC request for list of protected species within the 

area under evaluation for GGNS LRA review

ML12082A141

March 1, 2012 Response from Jena Band of Choctaw Indians to NRC 

request for comments concerning GGNS LRA review ML12089A020
Appendix E

E-3 

Date Correspondence Description ADAMS No.

March 1, 2012 Response from NMFS to NRC request for comments 

concerning GGNS LRA review ML12065A167

March 22, 2012 Transmittal of environmental audit plan to Entergy ML12060A112

March 26, 2012 Response from Choctaw Nation of Oklahoma to NRC 

request for comments concerning GGNS LRA review ML12101A124

April 23, 2012 Transmittal of environmental requests for additional 

information (RAIs) ML12083A188

May 8, 2012 Transmittal of air RAIs ML12123A081

May 21, 2012 Transmittal of severe accident mitigation alterative 

(SAMA) RAIs

ML12115A101

May 23, 2012 Entergy response to environmental RAIs ML12157A173

June 6, 2012 Entergy response to air RAIs ML12158A445

July 19, 2012 Entergy response to SAMA RAIs ML12202A056

August 23, 2012 Transmittal of 2nd round SAMA RAIs ML12227A735

September 7, 2012 Schedule change letter ML12242A545

October 10, 2012 Entergy partial response to 2nd round SAMA RAIs ML12277A082

November 19, 2012 Entergy complete response to 2nd round SAMA RAIs ML12325A174

December 19, 2012 Entergy response to SAMA clarification questions ML12359A038

February 26, 2013 Schedule change letter ML13002A430

April 16, 2013 Scoping Summary Report ML12201A623

August 15, 2013 Schedule change letter ML13207A156

1 APPENDIX F 

2 U.S. NUCLEAR REGULATORY COMMISSION STAFF EVALUATION OF 

3 SEVERE ACCIDENT MITIGATION ALTERNATIVES FOR 

4 GRAND GULF NUCLEAR STATION IN SUPPORT OF 

5 LICENSE RENEWAL APPLICATION REVIEW

Appendix F

F-1 

1 F. U.S. NUCLEAR REGULATORY COMMISSION STAFF EVALUATION 

2 OF SEVERE ACCIDENT MITIGATION ALTERNATIVES FOR GRAND 

3 GULF NUCLEAR STATION IN SUPPORT OF LICENSE RENEWAL 

4 APPLICATION REVIEW 

5 F.1 Introduction

6 Entergy Operations, Inc. (Entergy or the applicant) submitted an assessment of severe accident

7 mitigation alternatives (SAMAs) for Grand Gulf Nuclear Station, Unit 1 (GGNS), in Section 4.21 

8 and Attachment E of the Environmental Report (ER) (Entergy 2011). This assessment was 

9 based on the most recent revision to the GGNS probabilistic risk assessment (PRA), including 

10 an internal events model and a plant-specific offsite consequence analysis performed using the 

11 MELCOR Accident Consequence Code System 2 (MACCS2) computer code, as well as

12 insights from the GGNS individual plant examination (IPE) (Entergy 1992) and individual plant 

13 examination of external events (IPEEE) (Entergy 1995). In identifying and evaluating potential 

14 SAMAs, Entergy considered SAMAs that addressed the major contributors to core damage 

15 frequency (CDF) and population dose at GGNS, as well as insights and SAMA candidates

16 found to be potentially cost beneficial from the analysis of nine other boiling-water reactor

17 (BWR) nuclear power generating stations. Entergy initially identified a list of 249 potential 

18 SAMAs. This list was reduced to 63 unique SAMA candidates by eliminating SAMAs that

19 (a) were not applicable to GGNS, (b) had already been implemented at GGNS, or (c) were 

20 combined into a more comprehensive or plant-specific SAMA. Entergy concluded in the ER that 

21 three candidate SAMAs are potentially cost beneficial.

22 As a result of the review of the SAMA assessment, the U.S. Nuclear Regulatory Commission 

23 (NRC) staff issued requests for additional information (RAIs) to Entergy by letters dated 

24 May 21, 2012, (NRC 2012a) and August 23, 2012 (NRC 2012b). Key questions concerned: 

25 • changes and updates to Level 1 and Level 2 PRA models that most affect

26 CDF, 

27 • differences in CDF values and importance measures reported in the ER, 

28 • the impact of open items and issues from the peer review of the PRA, 

29 • the process used to assign release categories to containment event tree 

30 (CET) end states for incorporating Level 1 results into the Level 2 analysis, 

31 • selection of representative sequences for each release category in the 

32 Level 2 analysis, 

33 • the impact of new information on fire and seismic initiated sequences, and 

34 • further information on the cost-benefit analysis of several specific candidate 

35 SAMAs and low-cost alternatives. 

36 Entergy submitted additional information by letters dated July 19, 2012 (Entergy 2012a), 

37 October 2, 2012 (Entergy 2012b), November 19, 2012 (Entergy 2012c), and 

38 December 19, 2012 (Entergy 2012d). In response to the staff RAIs, Entergy provided further 

39 information on: 

40 • the history and key changes to PRA models, 

41 • the resolution of peer review comments, 
Appendix F

F-2 

1 • the development of the Level 2 containment release model, 

2 • the reasons for differences between CDF values given in the submittal, 

3 • the results of an updated cost-benefit analysis based on resolution of CDF

4 differences, 

5 • the impact of new information on external events, and

6 • the cost of various SAMAs and potential low-cost alternatives. 

7 Entergy’s responses addressed the staff’s concerns and resulted in the identification of one 

8 additional potentially cost-beneficial SAMA. 

9 An assessment of the SAMAs for GGNS is presented below.

10 F.2 Estimate of Risk for GGNS

11 Section F.2.1 summarizes Entergy’s estimates of offsite risk at GGNS. The summary is

12 followed by the staff’s review of Entergy’s risk estimates in Section F.2.2.

13 F.2.1 Entergy’s Risk Estimates

14 Two distinct analyses are combined to form the basis for the risk estimates used in the SAMA

15 analysis: (1) the GGNS Level 1 and 2 PRA model, which is an updated version of the IPE 

16 (Entergy 1992), and (2) a supplemental analysis of offsite consequences and economic impacts 

17 (essentially a Level 3 PRA model) developed specifically for the SAMA analysis. The original 

18 SAMA analysis was based on the most recent GGNS Level 1 and Level 2 PRA model available 

19 at the time of the ER, referred to as the 2010 extended power uprate (EPU) model 

20 (Entergy 2011). Subsequent to the original submittal, errors were found in the interpretation of 

21 the results of the Level 2 model that led Entergy to change the Level 2 model and cost-benefit 

22 analysis (Entergy 2012b, 2012c, 2012d). The results discussed in this appendix are for the 

23 updated analysis. The corrections to the model are discussed in Section F.2.2. The scope of 

24 the current GGNS PRA does not include external events.

The GGNS CDF is approximately 2.9 × 10−6 25 per reactor-year as determined from quantification 

26 of the Level 1 PRA model with the revised Level 2 model. This value was used as the baseline 

27 CDF in the SAMA evaluations (Entergy 2012c, 2012d). The CDF is based on the risk 

28 assessment for internally initiated events, which includes internal flooding. Entergy did not 

29 explicitly include the contribution from external events within the GGNS risk estimates; however, 

30 it did account for the potential risk reduction benefits associated with external events by 

31 multiplying the estimated benefits for internal events by a factor of 11. This is discussed further 

32 in Sections F.2.2 and F.6.2.

33 The breakdown of CDF by initiating event is provided in Table F–1. As shown in this table, loss 

34 of offsite power and power conversion system available transient are the dominant contributors 

35 to the CDF. While not listed explicitly in Table F–1 because they can occur as a result of 

36 multiple initiators, Entergy stated that station blackouts contribute about 37 percent 

(1.1 × 10−6 37 per reactor-year) of the total CDF; anticipated transients without scram contribute 

about 0.2 percent (4.4 × 10−9 38 per reactor-year) to the total CDF (Entergy 2012c).

39 The Level 2 GGNS PRA model that forms the basis for the SAMA evaluation is essentially a 

40 new model and reflects power uprate conditions. The Level 2 model uses CETs containing both 

41 phenomenological and systemic events. The Level 1 core damage sequences are binned into 

42 accident classes (or plant damage states) that provide the interface between the Level 1 and 
Appendix F

F-3 

1 Level 2 CET analysis. The CETs are linked directly to the Level 1 event trees and CET nodes 

2 are evaluated using subordinate trees and logic rules.

3 The CET considers the influence of physical and chemical processes on the integrity of the 

4 containment and on the release of fission products once core damage has occurred. The 

5 quantified CET sequences are binned into a set of end states that are subsequently grouped 

6 into 13 release categories (or release modes) that provide the input to the Level 3 consequence 

7 analysis. The frequency of each release category was obtained by summing the frequency of 

8 the individual accident progression CET endpoints binned into the release category. Source 

9 terms were developed for the release categories using the results of Modular Accident Analysis 

10 Program (MAAP 4.0.6) computer code calculations. From these results, source terms were 

11 chosen to be representative of the release categories. The results of this analysis for GGNS 

12 are provided in the revised Table E.1-9 of ER Attachment E (Entergy 2012c).

13 Entergy computed offsite consequences for potential releases of radiological material using the 

14 MACCS2 Version 1.13.1 code and analyzed exposure and economic impacts from its 

15 determination of offsite and onsite risks. Inputs for these analyses include plant-specific and 

16 site-specific input values for core radionuclide inventory, source term and release 

17 characteristics, site meteorological data, projected population distribution and growth within a 

18 50-mile (mi) (80-kilometer (km)) radius, emergency response evacuation modeling, and local 

19 economic data. Radionuclide inventory in the reactor core is based on a plant-specific 

20 evaluation and corresponds to that for the EPU power of 4,408 megawatts thermal (MWt) 

21 (Entergy 2011, Attachment E). The estimation of onsite impacts (in terms of clean-up and 

22 decontamination costs and occupational dose) is based on guidance in NUREG/BR–0184, 

23 Regulatory Analysis Technical Evaluation Handbook (NRC 1997a). Additional details on the 

24 input parameter assumptions are discussed below.
Appendix F

F-4 

1 Table F–1. Grand Gulf Nuclear Station Core Damage Frequency (CDF) for Internal Events

Initiating Event CDF (per year) % CDF Contribution

Loss of Offsite Power Initiator 1.2 × 10−6 40

Power Conversion System Available Transient 5.9 × 10−7 20

Loss of Power Conversion System Initiator 2.5 × 10−7 8 

Loss of Condensate Feed Water Pumps 2.3 × 10−7 8 

Loss of Instrument Air 1.4 × 10−7 5 

Closure of Main Steam Isolation Valves (Initiator) 1.2 × 10−7 4 

Loss of Service Transformer 21 1.2 × 10−7 4 

Large Loss of Coolant Accident (LOCA) 9.7 × 10−8 3 

Loss of Service Transformer 11 8.3 × 10−8 3 

Loss of Alternating Current Division 2 Initiator 6.2 × 10−8 2 

Other Initiating Events1 3.3 × 10−8 1 

Loss of Alternating Current Division 1 Initiator 2.7 × 10−8 1 

Intermediate LOCA 1.4 × 10−8 1 

Total Core Damage Frequency (Internal Events) 2.9 × 10−6 100

1 Multiple initiating events with each contributing 0.3 percent or less

2 In the ER, the applicant estimated the dose risk to the population within 80 km (50 mi) of the 

3 GGNS site to be 0.00609 person-sieverts (Sv) per year (0.609 person-roentgen equivalent in 

4 man (rem) per year) (Entergy 2012c). The breakdown of the population dose risk by 

5 containment release mode is summarized in Table F–2. Medium releases provide the greatest 

6 contribution, totaling approximately 67 percent of the population dose risk and 75 percent of the 

7 offsite economic cost risk for all timings. High early (H/E) releases alone contribute only about 

8 10 percent, and high releases for all timings contribute 17 percent of the population dose risk.

9 F.2.2 Review of Entergy’s Risk Estimates

10 Entergy’s determination of offsite risk at GGNS is based on three major elements of analysis:

11 • the Level 1 and 2 risk models that form the bases for the 1992 IPE submittal 

12 (Entergy 1992), and the external event analyses of the 1995 IPEEE submittal 

13 (Entergy 1995);

14 • the major modifications to the IPE model that have been incorporated in the 

15 GGNS 2010 EPU PRA; and

16 • the combination of offsite consequence measures from MACCS2 analyses 

17 with release frequencies and radionuclide source terms from the Level 2 PRA 

18 model.
Appendix F

F-5 

1 Table F–2. Base Case Mean Population Dose Risk and Offsite Economic Cost Risk 

2 for Internal Events

3 Each analysis element was reviewed to determine the acceptability of Entergy’s risk estimates 

4 for the SAMA analysis, as summarized further in this section. 

5 F.2.2.1 Internal Events CDF Model

6 The staff's review of the GGNS IPE is described in an NRC letter dated March 7, 1996 

7 (NRC 1996). From its review of the IPE submittal, the staff concluded that the IPE process is 

8 capable of identifying the most likely severe accidents and severe accident vulnerabilities, and 

Release Mode Population Dose Risk1 Offsite Economic Cost Risk

ID2

Frequency 

(per year) person-rem/yr

%

Contribution $/yr % Contribution

H/E 1.0 × 10−7 6.2 × 10−2 10 1.7 × 10+2 11

H/I 1.2 × 10−8 6.2 × 10−3 1 1.7 × 10+1 1 

H/L 9.2 × 10−8 3.8 × 10−2 6 9.6 × 10+1 6 

M/E 3.7 × 10−7 1.7 × 10−1 28 4.8 × 10+2 32

M/I 1.8 × 10−7 1.2 × 10−1 20 3.3 × 10+2 22

M/L 3.0 × 10−7 1.2 × 10−1 19 3.2 × 10+2 21

L/E 4.1 × 10−9 4.0 × 10−4 <0.1 3.0 × 10−1 <0.1

L/I 3.6 × 10−8 1.2 × 10−2 2 2.7 × 10+1 2 

L/L 4.4 × 10−7 7.8 × 10−2 13 7.4 × 10+1 5 

LL/E 2.2 × 10−9 7.9 × 10−7 <0.1 1.0 × 10−3 <0.1

LL/I 2.1 × 10−9 3.8 × 10−7 <0.1 9.7 × 10−4 <0.1

LL/L 7.1 × 10−9 2.0 × 10−3 <1 3.4 × 10+0 <1

NCF 1.4 × 10−6 5.0 × 10−4 <0.1 6.4 × 10−1 <0.1

Total 2.9 × 10−6 6.1 × 10−1 100 1.5 × 10+3 100

1 Unit Conversion Factor: 1 Sv = 100 rem

2 Release Mode Nomenclature (Magnitude/Timing)

 Magnitude: 

 High (H) – Greater than 10 percent release fraction for Cesium Iodide

 Medium (M) – 1 to 10 percent release fraction for Cesium Iodide

 Low (L) – 0.1 to 1 percent release fraction for Cesium Iodide

 Low-Low (LL) – Less than 0.1 percent release fraction for Cesium Iodide

 No containment failure (NCF) – Much less than 0.1 percent release fraction for Cesium Iodide

 Timing: 

 Early (E) – Less than 4 hours

 Intermediate (I) – 4 to 24 hours

 Late (L) – Greater than 24 hours
Appendix F

F-6 

1 therefore, that the GGNS IPE has met the intent of Generic Letter (GL) 88–20 (NRC 1988). 

2 Although no vulnerabilities were identified in the IPE, 11 improvements were identified by 

3 Entergy. The ER stated that five of these improvements have been implemented, one was 

4 considered to be no longer applicable, and five were retained as potential SAMAs.

The internal events CDF value from the 1992 IPE (1.7 × 10−5 5 per reactor-year) is near the 

6 average of the values reported for other General Electric (GE) BWR 5/6 units. Figure 11.2 of 

7 NUREG–1560, Volume 2, Individual Plant Examination Program: Perspectives on Reactor 

8 Safety and Plant Performance Parts 2–5, Final Report (NRC 1997b) shows that the IPE-based 

total internal events CDF for GE BWR 5/6 plants ranges from 1 × 10−6 per year to 4 × 10−4 9 per 

year, with an average CDF for the group of 2 × 10−5 10 per year. Other plants have updated the 

11 values for CDF subsequent to the IPE submittals to reflect modeling and hardware changes. 

The internal events CDF result for GGNS used for the SAMA analysis (2.9 × 10−6 12 per year) is 

13 somewhat lower than that for other plants of similar vintage.

14 GGNS was one of the units analyzed in considerable detail in the analysis of the risk of five 

15 nuclear power plants found in NUREG–1150, Severe Accident Risks: An Assessment for Five 

16 U.S. Nuclear Power Plants (NRC 1990). NUREG–1150 stated that the mean internal events 

CDF for GGNS was 4 × 10−6 17 per year, which is very similar to the current Entergy estimate.

18 There have been four revisions to the IPE Level 1 model since the 1992 IPE submittal. A listing 

19 of the changes made to the GGNS PRA since the original IPE submittal was provided in the ER 

20 (Entergy 2011) and is summarized in Table F–3, including information requested by the NRC 

21 (Entergy 2012a, 2012d). A comparison of internal events CDF between the 1992 IPE and the 

22 current PRA model indicates a decrease of about a factor of six in the total CDF (from 

1.7 × 10−5 per reactor-year to 2.9 × 10 23 −6 per reactor-year). This reduction can be attributed to 

24 incorporation of plant-specific data, improved modeling details, and removal of conservatism.
Appendix F

F-7 

1 Table F–3. Major GGNS Probabilistic Safety Assessment (PSA) Models

PSA 

Model Summary of Significant Changes from Prior Model CDF 

(per year)

LERF (per 

year)

1992 

(IPE) 1.7 × 10−5 5.2 × 10−7

1997 

(R1)

• Incorporation of updated plant-specific data for system 

maintenance and testing unavailability

• Incorporation of updated plant-specific data for initiating 

event frequencies

• Incorporation of updated plant-specific data for certain 

important components (i.e., diesel generators, high pressure 

core spray, and reactor core isolation cooling pumps)

• Various modeling changes to system models to correct minor 

modeling errors and incorporate modifications since the 

original IPE

5.5 × 10−6 Not 

Updated

2002 

(R2)

• Modeling changes to reflect installation of new type of plant 

service water radial well pumps and support systems

• Addition of heating, ventilation, and air conditioning (HVAC) 

systems to the model, including addition of the new standby 

service water pump-house high temperature alarm

• Modeling of changes to the backup scram valves and logic in 

the anticipated transient without scram portion of the fault 

tree

• Use of more comprehensive human reliability analysis 

methods

• Use of the convolution method for recovery of loss of offsite 

power (LOSP)

• Addition of an interfacing systems LOCA initiator

• Inclusion of operating data through December 31, 2000

4.3 × 10−6 2.0 × 10−7

2010 

(R3)

• Update of plant-specific data and initiator frequencies 

(through August 2006) and generic initiator frequencies

• New initiators: loss of service transformer, reactor vessel 

rupture, Loss of control rod drive, and Break (LOCA) outside 

of containment

• Major changes to LOSP modeling

• Inclusion of modeling for loss of emergency core cooling 

system pumps due to containment failure

• Revision of instrument air system modeling to incorporate 

new plant air compressors

• Revision of modeling of control rod drive—less credit for 

control rod drive

2.7 × 10−6 1.4 × 10−7

2010 

(EPU)

• Power level change (13 percent EPU) 

• Hardware changes

• Procedural changes

• Operational changes

2.9 × 10−6

1.5 × 10−7 

(Note 1)

Note 1. This LERF value is from the Revision 3 EPU LERF model and is different from the Table F–2 value for the 

High Early (H/E) release category, which was obtained from the full Level 2 model (Entergy 2012d). Refer to 

additional discussion in Section F.2.2.
Appendix F

F-8 

1 The GGNS 2010 EPU model reflects GGNS design, component failure, and unavailability data 

2 as of August 2006, modified to reflect the EPU configuration. Entergy states that there have 

3 been no major plant hardware changes or procedural modifications since August 2006 that 

4 would have a significant impact on the results of the SAMA analysis. In response to the staff 

5 RAIs, Entergy (2012a) clarified what was meant by “significant” and also stated that a review of 

6 plant equipment performance since August 2006 indicated no degradation issues that would 

7 impair the SAMA analysis (Entergy 2011). A change that would have a significant impact is 

8 described as a grade A (extremely important and necessary to assure the technical adequacy or 

9 quality of the PRA) or grade B (important and necessary to address, but may be deferred until 

10 the next model update) model change request (MCR). The MCR database is used to track 

11 plant changes, procedure revisions, nuclear licensing revisions, and model improvements that 

12 impact the PRA models. The RAI response stated that there were one grade A and 12 grade B 

13 MCRs. The single grade A MCR involved modeling for the temporary condition when a 

14 low-pressure feedwater heater is taken out of service and would not impact the SAMA analysis; 

15 the grade B MCRs either impacted the fire model and not the SAMA model, involved systems 

16 that are not risk-significant, or would result in a decrease in risk (Entergy 2012a). The staff 

17 concludes that there have been no major plant hardware changes or procedural modifications 

18 since August 2006 that would have a significant impact on the results of the SAMA analysis.

19 In response to a staff RAI, Entergy explained that the maintenance rule system health reports 

20 indicated no equipment reliability issues that would impair the SAMA analysis and that the plant 

21 data issues identified during the expert panel reviews of the model updates or during the expert 

22 panel review of the Level 2 cutsets were resolved in the model used for the SAMA analysis

23 (Entergy 2012b). 

24 Although Entergy suggested the unavailability of the high-pressure core spray (HPCS) system 

25 and the B diesel-driven fire pump had increased recently, Entergy also stated that the 

26 unavailability for these systems remains within the error band of the unavailability distribution 

27 (Entergy 2012b). Based on this response and the staff's review of the GGNS SAMA analysis, 

28 the staff concludes that, while the inclusion of more recent plant data might increase the CDF

29 contribution for these two systems, it would not be expected to change the conclusions related 

30 to cost-beneficial SAMAs.

31 The staff considered the peer reviews and other assessments performed for the GGNS PRA 

32 and the potential impact of the review findings on the SAMA evaluation. The most relevant of 

33 these are the peer review of the GGNS 1997, Revision 1 model and the staff review of the 

34 GGNS 2010 EPU model as part Entergy's EPU application.

35 The 1997 (Revision 1) Level 1 and large early release frequency (LERF) model was 

36 peer-reviewed before the 2002 PRA, Revision 2, using the BWR Owners Group (BWROG) 

37 process. The review team used the BWROG Probabilistic Safety Assessment (PSA) Peer 

38 Review Certification Implementation Guidelines, Revision 3, January 1997. Entergy stated that 

39 all of the “A” priority (extremely important and necessary to address to ensure the technical 

40 adequacy of the PSA) PRA peer review comments have been addressed and incorporated into 

41 the GGNS PRA model, as appropriate. It also stated that all of the “B” priority (important and 

42 necessary to address but may be deferred until the next PSA update) comments have been 

43 addressed, except for one documentation item related to the internal flood modeling.

44 In response to a staff RAI concerning A and B priority comments addressed by internal reviews 

45 in which Entergy concluded that changes to the model were not needed or the fact and 

46 observation was incorrect, Entergy stated that (a) those which were considered incorrect 

47 involved documentation issues that would not impact the SAMA PRA, (b) involved comments on 

48 the Level 2 model, which has since been completely updated, or (c) for the other observations 
Appendix F

F-9 

1 for which no change was considered necessary, provided a discussion of additional information 

2 concerning the issues and confirmed that the disposition remained valid at the EPU power and 

3 the SAMA assessment (Entergy 2012a, 2012b). Entergy (2012b) provided clarification for 

4 Observation 85 concerning the Level 1 general transient event tree. Despite a disposition 

5 statement that no changes were necessary, Entergy stated that the structure of the event tree 

6 was changed subsequent to the peer review, and that the changes addressed the concern 

7 raised in the observation.

8 The staff review of Entergy’s EPU application is documented in a safety evaluation report (SER) 

9 (NRC 2012c). In Section 2.13.1 of the EPU SER, the technical evaluation of the EPU focused 

10 on the impact on CDF and LERF while operating at EPU conditions. In its review of PRA 

11 quality, the staff noted the disposition of an additional nine findings on the Level 2 model. The 

12 internal flooding issue was determined to be solely a documentation issue, while eight of the 

13 nine Level 2 issues were resolved in the Level 2 model used for the SAMA analysis. In 

14 response to an RAI concerning the impact on the SAMA analysis, Entergy stated that vacuum 

15 breaker failures and low suppression pool level were incorporated in the SAMA Level 2 model 

16 and that personnel hatch seal failure was negligible when compared with hatch failure due to 

17 either overpressurization or buckling (Entergy 2012a). The staff found that the Level 2 issues 

18 were acceptably addressed and concluded that failure to model vacuum breakers, low 

19 suppression pool level, and personnel hatch seal would not significantly impact the delta risk 

20 results for the EPU application.

21 The EPU SER states:

22 Based on its evaluation, the NRC staff concludes that the GGNS PRA models 

23 used to support the risk evaluation for this application have sufficient scope, level 

24 of detail, and technical adequacy to support the evaluation of the EPU.

25 The SER further states:

26 The NRC staff concludes that the licensee’s evaluation of the impact of the 

27 proposed EPU on at-power risk from internal events is reasonable and concludes 

28 that the base risk due to the proposed EPU is acceptable and that there are no 

29 issues that rebut the presumption of adequate protection provided by the 

30 licensee meeting the currently specified regulatory requirements.

31 The staff concludes that, while the EPU application is focused on delta CDF and LERF as 

32 opposed to absolute values, these conclusions do lend support for the adequacy for the SAMA

33 application.

The staff noted that the LERF value of 1.48 × 10−7 per year (rounded to 1.5 × 10−7 34 per year in 

Table F–3) given in the ER for the EPU model is different from the value of 1.04 × 10−7 35 per year

(rounded to 1.0 × 10−7 36 per year in Table F–2) for the H/E release category. In response to an 

RAI, Entergy (2012d) stated that the value of 1.48 × 10−7 37 per year is from a separate Revision 3 

EPU LERF model and the value of 1.04 × 10−7 38 per year is from the full Level 2 model. In the 

39 analysis for GGNS, LERF is not a dominant contributor to the population dose risk or economic 

40 cost risk. The staff concludes that the H/E release category frequency obtained from the full 

41 Level 2 analysis (along with the other release category frequencies) is appropriate for use in the 

42 SAMA consequence analysis.

43 In the ER, Entergy describes two internal expert panel reviews of the Revision 2 and Revision 3 

44 models before their finalization. Various departments (Training, Operations, Engineering, and 

45 Nuclear Safety) within the GGNS organization were invited to participate. Each of the top 100 

46 cutsets was reviewed individually. In addition, cutsets from accident sequences representing 

47 approximately 99 percent of the total CDF also were reviewed if there were no cutsets from 

48 these sequences in the top 100. The focus of the review was to identify poor assumptions, 
Appendix F

F-10

1 over-simplifications, incorrect credit for human actions, sequence timing errors, system 

2 modeling errors, and incorrect event probabilities. The reviews resulted in modifications to the 

3 model and to the credit given for human actions. 

4 In response to an RAI, Entergy briefly described the process and procedures for assuring

5 technical quality of PRA updates since the peer review. The PRA maintenance and update 

6 procedure describes the process for maintaining the PRA models current with the as-built and 

7 as operated plants and gives specific instructions for identifying model change requests, 

8 documenting those requests, and incorporating those requests into the PRA model. The PRA 

9 analysts performing model updates are experienced, trained professionals, and each change is 

10 reviewed by a second, experienced, trained PRA analyst. In addition, as described above, 

11 expert panel reviews are used to enhance the technical quality of the PRA updates. Changes 

12 from the expert panel review for an update are immediately incorporated into that update of 

13 the model (Entergy 2012a). 

14 In the original SAMA submittal (Entergy 2011), Entergy took the internal events CDF to be the

15 sum of all the Level 2 release categories including the no containment failure (NCF) sequences. 

This summation resulted in a CDF value of 2.05 × 10−6 16 per year compared to the CDF from the 

Level 1 analysis value of 2.92 × 10−6 17 per year. In response to a staff RAI to explain this 

18 difference, Entergy stated that the Level 2 results were misinterpreted because it was assumed 

19 that the NCF sequences were adequately modeled and the resulting frequencies were valid. 

20 From investigating the reasons for the difference, Entergy found the assumption to be invalid, 

21 and it subsequently used the CDF value from the Level 1 model in a reanalysis of the SAMAs. 

22 Additionally, Entergy identified and addressed a number of discrepancies in the Level 2 

23 recovery rule file. Typically, Level 2 model changes would not be expected to impact the 

Level 1 result; however, incorporated changes led to the CDF value of 2.93 × 10−6 24 per year 

25 used in the revised SAMA analysis (Entergy 2012b, 2012c, 2012d). 

26 Given that the GGNS internal events PRA model has been peer-reviewed and the peer review 

27 findings were all addressed, that the model has been reviewed by the staff as part of the EPU

28 application approval, that Entergy has satisfactorily addressed staff questions regarding the 

29 PRA, and that the misinterpretation of Level 2 results discussed above has been corrected in 

30 the revised SAMA analysis, the staff concludes that the internal events Level 1 PRA model is of 

31 sufficient quality to support the SAMA evaluation.

32 F.2.2.2 External Events

33 As stated above, the GGNS PRA does not include external events. The SAMA submittals cite 

34 the GGNS IPEEE to assess the impact of seismic, internal events and other external events. 

35 The final GGNS IPEEE was submitted in 1995 (Entergy 1995), in response to Supplement 4 of 

36 GL 88–20 (NRC 1991a). Except for one potential seismic vulnerability, no fundamental 

37 weaknesses or vulnerabilities to severe accident risk in regard to the external events were 

38 identified in the GGNS IPEEE. In a letter dated March 16, 2001 (NRC 2001), the staff stated 

39 that, on the basis of its review of the PRA and IPEEE submittal, the staff concludes that the 

40 GGNS IPEEE process is capable of identifying the most likely severe accidents and severe 

41 accident vulnerabilities and, therefore, the GGNS IPEEE has met the intent of Supplement 4 to 

42 GL 88–20.

43 Seismic Events

44 The GGNS IPEEE seismic analysis was a reduced scope seismic margins assessment (SMA) 

45 following NRC guidance (NRC 1991a, 1991b). The SMA was performed using a Safe 

46 Shutdown Equipment List with plant walkdowns in accordance with the guidelines and 

47 procedures in Electrical Power Research Institute (EPRI) Report NP–6041–SL (EPRI 1991). 
Appendix F

F-11

1 Since GGNS is a reduced scope SMA plant, the original design-basis safe shutdown 

2 earthquake (SSE) ground response spectra and corresponding in-structure response spectra 

3 were used as the review level earthquake (RLE) input for the walkdown and evaluation. The 

4 SMA approach is deterministic in nature and does not result in probabilistic risk information. As 

5 a reduced scope plant, the determination of high confidence of low probability of failure values 

6 also is not required. 

7 The IPEEE submittal (Entergy 1995) concludes that GGNS is seismically rugged and that all 

8 components identified in the Safe Shutdown Path meet the seismic requirements. All 

9 anchorage to these components was found to be rugged. One potential vulnerability to a 

10 seismic event was identified, which has been corrected. The potential vulnerability involved the 

11 standby service water (SSW) piping in the Control Building where the grouted condition of 

12 several penetrations into the building were not accounted for in the stress analysis of the piping 

13 systems. To correct the situation and to meet design requirements, the grout was removed and 

14 a design change was issued to repair the penetration. The as-found grouted condition was 

15 evaluated for operability considerations and was determined not to be an operability concern. In 

16 addition, a number of “design enhancements” were implemented, including issuance of a new 

17 standard to address seismic housekeeping problems, securing of “S” hooks on lighting fixtures, 

18 installation of missing clips and screws on several items, and revision to several design-basis 

19 calculations (NRC 2001).

20 Based on the results of the IPEEE seismic assessment as described above, Entergy stated in 

21 the ER that since seismic events are not dominant contributors to external event risk and 

22 quantitative analysis of these events is not practical, they are assumed negligible in estimation 

23 of the external events multiplier. An August 2010 NRC report, “Generic Issue 199 (GI-199), 

24 Implications of Updated Probabilistic Seismic Hazard Estimates in Central and Eastern United 

25 States on Existing Plants” (NRC 2010) shows a decrease in GGNS seismic CDF, using 2008 

26 U.S. Geological Survey (USGS) seismic hazards curve when compared against 1994 Lawrence 

27 Livermore National Lab Hazard Curves, but an increase compared to the seismic CDF based on 

28 the EPRI hazard curves. Based on a simplified approach to estimate CDF from a seismic 

29 margins analysis and using the latest published USGS seismic hazards information, the staff 

estimates the GGNS seismic CDF is about 1 × 10−5 30 per year and is not negligible. In response 

31 to a staff RAI (Entergy 2012a), Entergy discussed the impact of this seismic CDF on the SAMA

32 analysis. This topic is discussed further in Section F.3.2 and in the subsection on high winds, 

33 floods, and other external events of this section. 

34 Fire Events

35 The GGNS IPEEE fire assessment is a fire PRA that uses key assumptions and the general 

36 approach specified in the EPRI Fire PRA Implementation Guide (EPRI 1994) and the 

37 Fire-Induced Vulnerability Evaluation (FIVE) methodology (EPRI 1992). Additionally, the fire 

38 PRA incorporates information from the GGNS Fire Hazards Analysis. 

39 The overall approach involved four tasks: develop fire-induced sequences, develop fire 

40 scenarios, evaluate fire damage sequences and their uncertainties, and document and verify 

41 the analysis. In implementing these tasks, four levels of fire area screening were employed:

42 (1) screen fire compartments inside containment

43 (2) screen compartments with no safe shutdown or PRA equipment

44 (3) screen assuming all equipment in compartment fails

45 (4) credit detailed recovery

46 Fires inside containment were screened out because there are few combustible loads to ignite a 

47 fire inside containment and a fire in containment would have a minor impact on the ability to 
Appendix F

F-12

1 safely shutdown the plant because of the limited safe shutdown equipment and cables located 

2 inside containment. For the other screening steps, conditional core damage probabilities 

3 (CCDPs) were determined using the IPE internal events PRA with increasing refinements 

4 concerning the extent of fire damage and recovery actions and a screening CDF criteria of 

1 × 10−6 5 per year. Thirteen fire areas not screened out after the last screening step were 

6 subjected to a more detailed analysis incorporating fire modeling to support fire propagation and 

7 suppression analyses, location of critical targets, definition of accident scenarios, evaluation of 

8 CCDPs for the scenarios, apportioning the compartment fire frequency among the scenarios, 

9 and evaluation of the probability of suppression before damage occurs. The estimated fire CDF

for the unscreened areas is 8.9 × 10−6 10 per reactor-year.

11 The GGNS IPEEE fire PRA was reviewed by Sandia National Laboratory (SNL). The SNL 

12 review concluded that: 

13 Based on the GGNS IPEEE submittal and the response to RAIs on the submittal, 

14 the reviewers recommend that a sufficient level of documentation and 

15 appropriate bases for analysis have been established to conclude that the 

16 subject licensee submittal has met the intent of GL 88–20 (NRC 2001). 

17 While no vulnerabilities with respect to fire were identified, the IPEEE submittal identifies one 

18 plant improvement related to reducing the impact of fires. The licensee stated that upgrades of 

19 existing thermo-lag barriers were scheduled to be completed by the end of 1996 (Entergy 1995). 

20 In a subsequent response to an IPEEE RAI, Entergy stated that the upgrades had been 

21 completed (Entergy 1998).

22 The ER includes a listing of all fire areas, screened and unscreened, in Table E.1-10. The CDF

23 for the unscreened fire areas is provided below in Table F–4. In response to an RAI 

24 (Entergy 2012a), Entergy confirmed that these fire zone CDFs are directly from the IPEEE and 

25 are based on the IPE internal events model. Given that the current EPU internal events CDF is 

26 considerably lower than that from the IPE, the staff concludes that if the EPU PRA had been 

27 used to determine the CCDPs, the fire CDF would most likely be reduced. In response to a staff 

28 RAI to assess recent fire research and guidance in NUREG/CR–6850, EPRI/NRC-RES Fire 

29 PRA Methodology for Nuclear Power Facilities (NRC 2005), Entergy (2012a) cited a 

30 December 2010 industry assessment (NEI 2010) that concluded: 

31 Based on the results and insights from industry fire PRAs, it has been identified 

32 that the methods described in NUREG/CR–6850/EPRI TR–1011989 contain 

33 excess conservatisms that bias the results and skew insights. While the prior 

34 frequently asked question process made some incremental progress in 

35 addressing areas of excessive conservatism, many more remain in need of 

36 enhancement. 

37 In the staff’s view, it is not clear if applying the new guidance to the GGNS fire assessment 

38 would result in excessive conservatism or not. The staff, however, notes the GGNS fire PRA 

39 makes use of CCDPs from the IPE internal events PRA to assess the impact of a fire. Based 

40 on the NRC review of existing information, the staff expects that the CCDPs using the EPU 

41 model would be lower than the CCDPs from the IPE model and, thus, would result in a lower fire 

42 CDF. Therefore, any increase in fire risk to using NUREG/CR–6850/EPRI TR–1011989, would 

43 be at least partially offset by the expected reduction in fire risk associated with using the EPU 

44 internal events models rather than the IPE models.

45 Considering that the GGNS fire PRA model has been reviewed by the staff for the IPEEE, and 

46 that Entergy has addressed staff RAIs regarding the fire PRA, the staff concludes that the fire 

47 PRA model, as discussed above, provides an acceptable basis for identifying and evaluating the 

48 benefits of SAMAs.
Appendix F

F-13

1 Table F–4. GGNS Fire IPEEE Core Damage Frequency (CDF) Results for 

2 Unscreened Compartments

3 High Winds, Floods, and Other External Events

4 The GGNS IPEEE analysis of high winds, floods, and other external events followed the 

5 recommendations in GL 88–20, Supplement 4. The methodology employed a screening 

6 approach following the criteria of the 1975 Standard Review Plan (SRP). 

7 The GGNS IPEEE submittal states that the plant’s current licensing basis conforms with the 

8 1975 SRP criteria for high winds, tornado loads, and tornado-generated missiles. The submittal 

9 notes that all safety-related structures and components, except the SSW system components, 

10 are protected against high winds, tornado wind loads, and tornado-generated missiles. For 

11 these components, a walkdown by Entergy confirmed that damage from high winds or tornado 

12 wind loads are not a concern and a frequency assessment of tornado-generated missiles was 

performed. This frequency was estimated to be 7.7 × 10−9 13 per reactor-year, an acceptably low 

14 value (NRC 2001).

15 With regard to external flooding, the IPEEE submittal states that the plant’s current licensing 

16 basis for flood protection meets the 1975 SRP criteria. Therefore, in accordance with the 

17 guidance in NUREG–1407, Procedural and Submittal Guidance for the Individual Plant 

18 Examination of External Events (IPEEE) for Severe Accident Vulnerabilities, external floods can 

Fire 

Compartment

Fire Compartment 

Description

Compartment 

CDF (per year)

% Contribution to 

Unscreened Fire CDF

CC502 Control Room 3.9 × 10−6 43

CC202 Division 1 Switchgear Room 9.4 × 10−7 11

CA301

Auxiliary Building Corridors. 

139'-0" Elevation A422, 

1A324

6.7 × 10−7 8 

CA201 Auxiliary Building Corridors. 

119'-0" Elevation 6.4 × 10−7 7 

CC210 Division 3 (HPCS) 

Switchgear Room 6.1 × 10−7 7 

CA101 Auxiliary Building Corridors. 

93'-0" Elevation 5.7 × 10−7 7 

CC215 Division 2 Switchgear Room 4.1 × 10−7 5 

CT100 Turbine Building Floor, 

93'-0" Elevation 3.2 × 10−7 4 

CC402 Cable Spreading Room 2.8 × 10−7 3 

CC104 Hot Machine Shop 2.4 × 10−7 3 

CC302 HVAC Equipment Room 2.1 × 10−7 2 

CD306 Division 3 (HPCS) Diesel 

Generator Room 1.7 × 10−7 2 

CT200 Turbine Building Floor, 

113'-0" Elevation 7.1 × 10−9 <1

Total 8.9 × 10−6 100a

a Column values may not total 100 percent because of rounding.
Appendix F

F-14

1 be screened out as a significant hazard (NRC 1991b). In addition, the licensee performed 

2 reevaluations of the potential flooding from the Mississippi River and the probable maximum 

3 precipitation (PMP) induced flood (for site watershed). As part of their response to GL 89–22, 

4 the licensee also addressed Generic Safety Issue (GSI) 103, Design for Probable Maximum 

5 Precipitation, and made use of the latest rainfall data (Hydro Meteorological Reports (HMR) 

6 No. 51 and 52). While the roof drains and overflows were found adequate, GGNS implemented 

7 several improvements including: increased maintenance on drainage structures, revised 

8 procedures to explicitly include at-grade former Unit 2 doors, and revised procedures to 

9 periodically inspect roof drains and overflows to ensure they are not blocked. In addition, 

10 consideration of the new PMP led to the identification of five further improvements in local 

11 drainage and flood prevention provisions. These improvements were not implemented at the 

12 time of the IPEEE and, while listed in Table E.2-1 of the ER, are stated to not be cost beneficial 

13 due to the minor risk from external flooding. The response to a staff RAI to provide further 

14 support for this disposition is discussed below in Section F.3.2.

15 A review of transportation and nearby facility accidents confirmed that there were no severe 

16 accident vulnerabilities from these accidents. The licensee found that the plant’s current 

17 licensing basis for these events meets the 1975 SRP criteria.

18 As stated in the ER (Entergy 2011), a multiplier of 11 was used to adjust the internal event risk 

19 benefit associated with a SAMA to account for external events. This multiplier was based on a 

20 fire CDF equal to the sum of the screened and unscreened fire zone CDF values or 

approximately 2.74 × 10−5 21 per year and the assumption that seismic and other external events 

are negligible. Using the original Level 1 internal event CDF of 2.92 × 10−6 22 per year the ratio of 

23 external to internal event CDFs is 9.4, which leads to a multiplier of 10.4 which was rounded up 

24 to 11. In response to an RAI concerning the impact of the GI–199 (NRC 2010) estimated 

seismic CDF, Entergy states that use of the GI–199 estimate of approximately 1 × 10−5 25 per year 

along with the IPEEE fire CDF for unscreened fire zones of 8.9 × 10−6 26 per year results in an 

external events multiplier of 7 using the 2.93 × 10−6 27 per year internal event CDF and the 

28 continued use of the multiplier of 11 more than compensates for the impact of the seismic CDF 

29 (Entergy 2012c). The staff agrees that the use of the unscreened fire CDF is valid and that the 

30 use of the multiplier of 11 appropriately incorporates the impact of seismic risk.

31 Given that the GGNS IPEEE external events assessments has been reviewed by the staff, and 

32 that Entergy has satisfactorily addressed staff questions regarding the assessment, the staff 

33 concludes that the external events assessments, combined with the results of the analysis of 

34 the impacts of new fire and seismic information, is of sufficient quality to support the SAMA

35 evaluation.

36 F.2.2.3 Level 2 Fission Product Release Analysis

37 The staff reviewed the general process used by Entergy to translate the results of the Level 1 

38 PRA into containment releases, as well as the results of the Level 2 analysis, as described in 

39 the ER and in responses to staff RAIs (Entergy 2012a, 2012b, 2012c). Plant damage states 

40 (PDSs) provide the link between the Level 1 and Level 2 CET analyses. In the PDS analyses, 

41 Level 1 results are grouped together according to characteristics that define the status of the 

42 reactor, containment, core cooling and heat removal systems at the time of core damage. The 

43 PDSs identify which CET the Level 1 results are to be transferred. The information specifically 

44 transferred through the PDSs and the direct linking of the Level 1 model with the Level 2 model 

45 is:

46 • Equipment failures in Level 1. The repair or recovery of failed equipment is 

47 not allowed unless an explicit evaluation has been performed as part of the 

48 Level 2 analysis.
Appendix F

F-15

1 • Reactor pressure vessel (RPV) status. The RPV pressure condition is 

2 explicitly transferred from the Level 1 analysis to the CET.

3 • Containment status. The containment status is explicitly transferred from the 

4 Level 1 analysis to the CET. 

5 • Differences in accident sequence timing are transferred with the Level 1 

6 sequences. Timing affects such sequences as: station blackout, internal 

7 flooding, and containment bypass (interfacing systems LOCA).

8 The Level 2 analysis is linked to the Level 1 model by extending the model to include the CET, 

9 which characterizes the accident phenomena. The CET considers the influence of physical and 

10 chemical processes on the integrity of the containment and on the release of fission products. 

11 The ER lists and describes 15 functional nodes incorporated in the GGNS Level 2 CETs. These 

12 nodes (or branches or questions) address events occurring before vessel breach (including post 

13 core damage depressurization and the potential for in-vessel recovery), the phenomena 

14 associated ex-vessel accident progression (including early drywell and containment failure 

15 caused by hydrogen ignition, high pressure melt ejection, steam explosions, and vapor 

16 suppression failure) and the impact of mitigating systems on containment integrity including 

17 containment sprays, containment heat removal, and containment venting.

18 The CET end points represent the outcomes of possible containment accident progression 

19 sequences with each end point representing a complete sequence from initiator to release to 

20 the environment. Associated with each CET end point or end state is an atmospheric 

21 radionuclide source term including the timing, magnitude, and other conditions associated with 

22 the release. Because of the large number of CET end points, they are grouped into release 

23 categories (RCs). Entergy has established 13 RCs based on magnitude of release (four levels) 

24 and timing of containment failure relative to the time of the declaration of a general emergency 

25 (three time groups) with one RC for NCF. In response to a staff RAI, Entergy states that the 

26 CET end points were assigned to the appropriate RC based on consideration of several 

27 fundamental variables, including Level 1 accident sequence, initial containment failure mode, 

28 RPV pressure at RPV breach, water availability for containment spray or flooding, and auxiliary 

29 building effectiveness (Entergy 2012a). As previously stated for the updated analysis, the 

30 frequency of the NCF release category was determined from the difference between the Level 1 

31 CDF and the sum of frequencies for the other release categories (Entergy 2012c).

32 In developing the response to the staff RAI concerning the difference between the Level 1 and 

33 Level 2 results, Entergy discovered and corrected a number of discrepancies in the Level 2 

34 analysis. Despite having a relatively minor impact on the release category frequencies, these 

35 corrections were described and incorporated in the updated analysis (Entergy 2012c, 2012d).

36 The release characteristic for each RC was determined from the results of MAAP 4.0.6 

37 calculations for representative sequences selected for the RC. In response to staff RAIs 

38 concerning the selection of representative sequences and the resulting release magnitude and 

39 timings, Entergy identified the representative sequence for each RC and described the basis for 

40 the selection. The predominant accident class (based on frequency) that contributes to each of 

41 the radionuclide release categories was first identified. Once the accident class was identified, 

42 the timings and magnitudes of the releases from the results of the various Level 2 MAAP runs 

43 for that accident class were reviewed to select an appropriate sequence to represent the 

44 release category (Entergy 2012a). 

45 In response to a staff RAI to justify the representative sequence as the sequence with the 

46 highest frequency versus selecting a sequence with a higher source term and a lower but still 

47 important frequency, Entergy, in its updated analysis, revised the Level 3 consequence analysis 
Appendix F

F-16

1 to use the sequence with the highest source term (in terms of cesium iodide release fraction) to 

2 represent each release category (Entergy 2012b, 2012c).

3 In the original ER Figure E.1-1, the NCF or negligible release category accounted for 44 percent 

4 of the total release frequency, yet the offsite consequences from this release category were not 

5 provided. In response to a staff RAI, Entergy revised the consequence analysis to incorporate 

6 releases appropriate for the no-containment-failure category (Entergy 2012c).

7 As stated above, the current GGNS Level 2 PRA model is a complete revision of that used in 

8 the IPE. No vulnerabilities were identified in the IPE back-end (i.e., Level 2) analysis performed 

9 by the applicant. Risk related insights and improvements discussed in the IPE submittal were 

10 discussed previously. The staff and contractor review of the IPE Level 2 analysis concluded 

11 that the applicant has made reasonable use of the PRA techniques in performing the back-end 

12 analysis and that the techniques employed are capable of identifying severe accident

13 vulnerabilities (NRC 1996).

14 In response to a staff RAI regarding the steps taken to assure the technical adequacy of the 

15 new Level 2 model, Entergy stated that:

16 • The developing contractor performed a self assessment of the Level 2 model

17 against the American Society of Mechanical Engineering (ASME)/American 

18 Nuclear Society (ANS) PRA Standard implemented in accordance with 

19 Regulatory Guide 1.200 (NRC 2009). 

20 • A technical acceptance review was performed by Entergy, with comments

21 resolved by the contractor.

22 • An expert panel review of the Level 2 cutsets was performed as further 

23 assurance of the quality of the Level 2 PRA. The expert panel consisted of 

24 members of the Grand Gulf engineering, PRA, and operations departments.

25 From its review of the Level 2 methodology, Entergy's responses to staff RAIs, and the 

26 subjection of the Level 2 model to an internal self-assessment and expert panel review, the staff 

27 concludes that the Level 2 PRA, as used in the revised SAMA analysis, provides an acceptable 

28 basis for evaluating the benefits associated with various SAMAs. 

29 F.2.2.4 Level 3 Consequence Analysis

30 Entergy used the MACCS2 Version 1.13.1 code and a core inventory from a plant-specific 

31 calculation to determine the offsite consequences from potential releases of radioactive material 

32 (Entergy 2011). Using the ORIGEN 2.1 code, Entergy calculated the core inventory for 

33 4,408 MWt, which is consistent with the EPU to 115 percent of the originally licensed 

34 thermal power that was approved in July 2012. 

35 The staff reviewed the process used by Entergy to extend the containment performance 

36 (Level 2) portion of the PRA to an assessment of offsite consequences (Level 3 PRA model). 

37 Source terms used to characterize fission product releases for the applicable containment 

38 release categories and the major input assumptions used in the offsite consequence analyses 

39 were considered. In response to a staff RAI on radionuclides from the core inventory used in 

40 the radiological dose calculation, the applicant confirmed that all radionuclides listed in 

41 Table E.1-12 of Attachment E to the ER (Entergy 2011) were included in the Level 3 analysis 

42 (Entergy 2012a). Entergy clarified that consideration was given to the 24-month refueling cycles 

43 in the core radionuclide inventory determination and confirmed that no additional changes are 

44 planned or being considered that would affect the core radionuclide inventory (Entergy 2012a). 

45 Plant-specific input to the assessment includes the core release fractions and source terms for 

46 each release category (Entergy 2011, Table E.1-9), site-specific meteorological data, projected 
Appendix F

F-17

1 population distribution and expected growth out to the year 2044 within an 80-km (50-mi) radius, 

2 emergency evacuation modeling, and economic data. This information is provided in 

3 Section E.1.5 of Attachment E to the ER (Entergy 2011). Because the staff review determined 

4 Entergy’s source term information is consistent with NRC guidance (NEI 2005) and includes 

5 satisfactory responses to NRC questions, the staff concludes that Entergy’s source term 

6 estimates are acceptable for use in the SAMA analysis.

7 Entergy considered site-specific meteorological data for the calendar years 2005 through 2009 

8 and selected meteorological data from 2009 for the analysis as input to the MACCS2 code 

9 because they resulted in the highest release quantities (Entergy 2011). Meteorological data 

10 was acquired from the meteorological monitoring system at GGNS and regional National 

11 Weather Service stations. Meteorological data included wind speed, wind direction, 

12 atmospheric stability class, precipitation, and atmospheric mixing heights. In response to an 

13 NRC RAI on the source of precipitation data, modeling of precipitation events, and precipitation 

14 influence on calculated doses, Entergy stated that the total population dose and offsite 

15 economic cost were calculated in determining the meteorological dataset for use in the SAMA

16 analysis (Entergy 2012a). 

17 Missing meteorological data were estimated by data substitution using valid data from the 

18 previous hour and other elevations on the meteorological tower. In response to questions on 

19 the amount of missing data, Entergy clarified that 1 hour of precipitation data and 95 hours of 

20 lower wind data were missing in the 8,760-hour data set for 2009. When missing temperature 

21 data were included, data substitution for missing data was applied to less than 3 percent of the 

22 meteorological records (Entergy 2012a). The sources of data and models for atmospheric 

23 dispersion used by the applicant are consistent with standard industry practice and acceptable 

24 for calculating consequences from potential airborne releases of radioactive material. Because 

25 multiple years of meteorological data were considered by the applicant and the annual data set 

26 that resulted in the largest total population dose and offsite economic cost was selected for the 

27 SAMA analysis, the staff finds that the data selection was performed in accordance with NRC 

28 guidance (NEI 2005) and, thus, the meteorological data are appropriate for use in the SAMA 

29 analysis.

30 Entergy projected population distribution and expected growth within a radius of 80 km (50 mi) 

31 out to the year 2044 to account for an anticipated 33-year period of remaining plant life for 

32 13 years remaining on the original operating license plus a 20-year license renewal period 

33 (Entergy 2011). For counties or parishes with declining population projections, census data 

34 from earlier years were used to avoid underestimating future population and estimated

35 population doses. The Entergy assessment incorporated U.S. Census 2010 data 

36 (Enercon 2011). Entergy also used data on Louisiana and Mississippi state tourism to calculate 

37 a transient to permanent population ratio to increase the projected population to account for 

38 visitors (Entergy 2011). The applicant provided additional information on the incorporation of 

39 transient population into the SAMA analysis (Entergy 2012a). Transient population was 

40 determined from annual visitor numbers for the state and an average stay duration. The ratio of 

41 transient additions to the permanent population was assumed to be the same for each county or 

42 parish in the state. The staff considers the methods and assumptions for estimating population 

43 reasonable and acceptable for purposes of the SAMA evaluation because its review of 

44 Entergy’s assessment determined that Entergy considered appropriate data sources, used a 

45 reasonable approach for applying data, followed NRC guidance (NEI 2005), and added 

46 conservatism by not accounting for projected population decline. 

47 Entergy analyzed evacuation travel times for the Mississippi and Louisiana sides of the 

48 Mississippi River within the 16-km (10-mi) emergency planning zone (Entergy 2011). The 

49 analysis stated that 100 percent of the population would be prepared to begin evacuation within 
Appendix F

F-18

1 195 minutes from emergency notification for evacuation and 100 percent of the population could 

2 be evacuated in 250 minutes or less following an evacuation order. The applicant concluded 

3 that use of this information is still relevant because population within the emergency planning 

4 zone has declined since the analysis in 2006. Entergy performed sensitivity analyses on 

5 MACCS2 input parameters for an increased evacuation time delay and for a slower evacuation 

6 speed. Consequence deviations were found to be less than 1 percent (Entergy 2011). 

7 The staff notes that the percentage of population evacuated within the emergency planning 

8 zone used by Entergy in the SAMA analysis exceeded the generic value of 99.5 percent

9 (NRC 1997a, Section 5.7.1). However, the staff finds the applicant’s value to be acceptable 

10 because, based on the staff’s review of the applicant’s analysis, the staff determined that the 

11 value was derived from a recent site-specific analysis that adequately considered the spatial 

12 distribution of individuals in the two counties and one parish included within the emergency 

13 planning zone, accounted for response differences due to the time of the week when the 

14 evacuation order could be given, and addressed the influence of potential inclement weather 

15 conditions. Given that the applicant performed a site-specific analysis to determine evacuation 

16 assumptions and parameters, showed radiological consequence results were insensitive to 

17 changes to certain evacuation parameters in a sensitivity study, and furnished a rationale for the 

18 current appropriateness of the previously collected site-specific data, the staff concludes that 

19 the evacuation assumptions and analysis are reasonable and acceptable for the purposes of the 

20 SAMA analysis at GGNS.

21 Entergy used regional economic data from the 2007 U.S. Census of Agriculture, the 

22 U.S. Department of Commerce, the U.S. Bureau of Labor Statistics, and the Consumer Price 

23 Index for estimating farm and nonfarm values. County representation within a spatial element 

24 was based on the county with the greatest area contribution. Data for certain counties and 

25 parishes were not incorporated into the analysis because of small area contributions within a 

26 spatial element. Regional crop values, obtained from 2007 U.S. Census of Agriculture data, 

27 were summed with the 80-km (50-mi) area and applied to the MACCS2 crop categories. 

28 The staff considers these data sources used by the applicant to be current and finds them 

29 acceptable for the SAMA analysis. Entergy estimated present dollar values based on the 

30 internal events PRA at GGNS. Onsite economic costs provided the greatest contribution, about 

31 70 percent of the total dollar value. Offsite economic costs contributed about 16 percent to the 

32 total dollar value (Entergy 2012c, Table 4.21-1) for a discount rate of 7 percent, 20-year license 

renewal period, and updated CDF of 2.9 × 10−6 33 per year. Offsite population doses and onsite 

34 doses contributed 13 and 1 percent of the total dollar value, respectively. Section F.6 provides 

35 more detailed information on the cost-benefit calculation and its evaluation.

36 In summary, the staff reviewed Entergy’s assessments of the source term, radionuclide 

37 releases, meteorological data, projected population distribution, emergency response, and 

38 regional economic data and evaluated Entergy’s responses to the staff’s requests for additional 

39 information, as previously described in this subsection. Based on the staff’s review, the staff 

40 concludes that Entergy’s consequence analysis is acceptable and Entergy’s methodology to 

41 estimate offsite consequences for GGNS and consideration of parameter sensitivities provide 

42 an acceptable basis to assess the risk reduction potential for candidate SAMAs. Accordingly, 

43 the staff based its assessment of offsite risk on the CDFs, population doses, and offsite 

44 economic costs reported by Entergy.

45 F.3 Potential Plant Improvements

46 The process for identifying potential plant improvements (SAMAs), an evaluation of that 

47 process, and the improvements evaluated in detail by Entergy are discussed in this section. 
Appendix F

F-19

1 F.3.1 Process for Identifying Potential Plant Improvements 

2 Entergy’s process for identifying potential plant improvements consisted of the following 

3 elements: 

4 • review of industry documents and consideration of other plant-specific 

5 enhancements not identified in published industry documents,

6 • review of potential plant improvements identified in the GGNS IPE and 

7 IPEEE, and

8 • review of the risk-significant events in the current GGNS PRA Levels 1 and 2 

9 models modifications for inclusion in the comprehensive list of SAMA

10 candidates. 

11 Based on this process, Entergy identified an initial set of 249 candidate SAMAs, referred to as 

12 Phase I SAMAs. In Phase I of the evaluation, Entergy performed a qualitative screening of the 

13 initial list of SAMAs and eliminated SAMAs from further consideration using the following 

14 criteria: 

15 • the SAMA modified features not applicable to GGNS, 

16 • the SAMA has already been implemented at GGNS, or 

17 • the SAMA is similar in nature and could be combined with another SAMA 

18 candidate.

19 Based on this screening, 60 of the Phase I SAMA candidates were screened out because they 

20 were not applicable to GGNS, 98 were screened out because they had already been 

21 implemented at GGNS, and 28 were screened out because they were similar in nature and 

22 could be combined with another SAMA candidate. Thus, a total of 186 SAMAs were eliminated, 

23 leaving 63 for further evaluation. The results of the Phase I screening analysis for each SAMA 

24 candidate were provided in a response to a staff RAI (Entergy 2012a). The remaining SAMAs, 

25 referred to as Phase II SAMAs, are listed in Table E.2-2 of Attachment E to the ER in the 

26 original submittal (Entergy 2011) and in the revised analysis (Entergy 2012c). In Phase II, a 

27 detailed evaluation was performed for each of the 63 remaining SAMA candidates, as discussed 

28 in Sections F.4 and F.6 below.

29 F.3.2 Review of Entergy’s Process 

30 Entergy’s efforts to identify potential SAMAs included explicit consideration of potential SAMAs 

31 primarily for internal events because the current GGNS PRA does not include external events. 

32 Potential SAMAs for external events were included based on the GGNS IPEEE probabilistic 

33 analysis of internal fires and deterministic analysis of seismic and other external events. 

34 The initial SAMA list was developed primarily from the review of generic industry SAMAs 

35 (NEI 2005), as well as SAMAs from nine previous BWR license renewal applications. To this 

36 list, a number of SAMAs were added based on improvements identified in the IPE and IPEEE. 

37 Finally, SAMAs were added based on the review of the GGNS PRA Level 1 and Level 2 

38 LERF results.

39 Entergy provided a tabular listing of the Level 1 PRA basic event CDF importances, down to a

40 risk reduction worth (RRW) of 1.005. SAMAs affecting these basic events would have the 

41 greatest potential for reducing risk. An RRW of 1.005 corresponds to a reduction in CDF of 

42 approximately 0.5 percent, given 100 percent reliability of the SAMA. Based on the maximum 

43 averted cost risk including external events and uncertainty (see Section F.6.1 below), this 
Appendix F

F-20

1 equates to a benefit of approximately $17,000. This is well below the minimum implementation

2 cost associated with a procedure change given by Entergy of $25,000 (refer to Section F.5) and 

3 is not cost beneficial. All basic events in the Level 1 listing were reviewed to identify potential 

4 SAMAs and the listing annotated to indicate the Phase II SAMAs mitigating the failure 

5 associated with the basic event. All basic events, except flag events, which do not represent 

6 failures, were addressed by one or more Phase II SAMAs either from the list based on the 

7 generic industry SAMAs or GGNS specific SAMAs (Entergy 2011).

8 Entergy also provided and reviewed the basic events with large early release frequency RRWs 

9 down to 1.005. All basic events in the Level 2 LERF (or release category H/E) listing were 

10 reviewed to identify potential SAMAs and all were addressed by one or more Phase II SAMAs, 

11 except those that are flag or split fractions for which no SAMA would be appropriate 

12 (Entergy 2011). The staff notes that because LERF makes up only about 10 percent of the CDF

13 and cost risk, LERF basic events with RRW less than about 1.1 would not be expected to be 

14 cost beneficial unless they are also important to CDF.

15 As a result of the review of the Level 1 and Level 2 LERF basic events, four additional SAMAs 

16 were identified as most of the basic events were addressed by SAMAs in the generic list.

17 Entergy also considered the potential plant improvements described in the GGNS IPE and 

18 IPEEE in the identification of plant-specific candidate SAMAs. As a result of the review of the 

19 IPE, 11 improvements were identified and are listed in Table E.2-1 of Attachment E of the ER. 

20 The ER stated that five of these improvements have been implemented, one considered no 

21 longer applicable and five retained as potential SAMAs.

22 As a result of the IPEEE, eight potential improvements concerning external flooding were 

23 identified and are listed in Table E.2-1 of Attachment E of the ER. The ER stated that three of 

24 these improvements have been implemented, but five are stated to not be cost beneficial 

25 because of the minor risk from external flooding. They are:

26 • Remove the wooden foot bridge crossing the northwest ditch near its 

27 upstream end. 

28 • Remove the 38-cm (15-inch) corrugated metal pipe located in the small 

29 auxiliary ditch parallel to the northwest ditch.

30 • Re-hang the security fence gates west of the control building.

31 • Grade down and remove the access road, the raised berm parallel to the 

32 access road, and curbs adjacent to the access road.

33 • Replace the C8 × 1.5 channel forming the flood barrier across the SSW A

34 equipment hatch opening.

35 In response to a staff RAI to provide further support for this disposition, Entergy stated that site 

36 topography has changed considerably since the time of the IPEEE, and it addressed the current 

37 status of the items listed above. All were either no longer applicable or otherwise adequately 

38 addressed. Although the channel identified in the last bullet has not been replaced, Entergy 

39 described features of the interior of the pump house, which minimize the impact of flooding, and 

40 it stated that contingency actions are available to place sand bags in front of the doors

41 (Entergy 2012b). 

42 In addition, Entergy stated it had re-evaluated the site during the 2011 Mississippi River flood 

43 and determined it to be adequately protected against external flooding. The NRC resident and 

44 region inspectors performed a review of the flooding procedures and site actions for seasonal 

45 extreme flooding of the Mississippi River. Additionally, the inspectors performed an inspection 
Appendix F

F-21

1 of the protected area to identify any modifications to the site that would inhibit site drainage or 

2 that would allow ingress past a barrier during a probable maximum precipitation event. No 

3 recommendations for improved flood protection were identified. Further, Entergy provided an 

4 estimate of $2,300 in the original response (Entergy 2012a) and $2,200 in the revised analysis 

5 (Entergy 2012c) for the benefit associated with the above probable maximum precipitation 

6 flooding modifications assuming they would eliminate the potential for core damage. This was 

7 based on the IPEEE-assessed frequency of the probable maximum participation with coincident 

8 wind wave activity. Based on the disposition of the cited improvements, the results of the recent 

9 inspection and the low benefit associated with the modifications, the staff agrees with the 

10 Entergy treatment of external flooding for the SAMA analysis. 

11 Entergy also considered SAMAs for the two largest fire risk contributors based on the IPEEE 

12 evaluation whose results are summarized in Table F–4.

13 The staff review of the Phase I SAMA screening identified a number of questions concerning the 

14 adequacy of the basis for not considering the SAMA in the Phase II analysis. In response to an 

15 RAI, Entergy (Entergy 2012b, 2012c, 2012d) stated that: 

16 • The Division 3 direct current (DC) system used for the HPCS is independent 

17 of the other DC buses; hence, a SAMA to reduce the DC dependence 

18 between high-pressure injection and the automatic depressurization system 

19 has essentially been implemented at GGNS.

20 • GGNS does not have another security or other emergency generator beyond 

21 the three now installed that could be used for providing DC power through 

22 direct connections to necessary loads following a station blackout. Therefore, 

23 providing a procedure for this connection is not feasible. Also, for 

24 nonstation-blackout situations, the benefit is less than the potential cost.

25 • GGNS SAMA No. 6, improve 4.16-kV bus cross-tie ability, already includes 

26 installing key-locked control switches to enable alternating current bus 

27 cross-ties; hence, a separate, new SAMA is not necessary. 

28 • The benefit of a SAMA to provide capability for alternate injection via the 

29 reactor water cleanup system was evaluated and found to be less than the 

30 associated cost. Extensive modifications would be required to use the 

31 reactor water cleanup system for alternate injection. Piping modifications and 

32 a source of water would be needed because the only existing reactor water 

33 cleanup suction source is the reactor pressure vessel itself. Key-locked 

34 switches would have to be installed to permit bypassing existing reactor water 

35 cleanup interlocks to permit use for injection. Also, the system has power 

36 dependencies with the other alternate injection systems which would have to

37 be modified to obtain a significant benefit.

38 • The severe accident guidelines implemented at GGNS included 

39 considerations of flooding the reactor pressure vessel and/or containment to 

40 various levels relative to the core and/or core debris and the impact on the 

41 need for containment venting. No further restrictions are deemed 

42 appropriate.

43 • Simulator training at GGNS includes training on severe accident scenarios.

44 The staff review of the identification of SAMAs from the Level 1 and Level 2 importance analysis 

45 identified several basic events for which the associated SAMA required further explanation or 

46 justification. For several human error basic events with high failure probabilities, Entergy was 
Appendix F

F-22

1 asked to consider improvements in procedures or training. In response, Entergy described 

2 each of the events as being combined with other human error basic events in the recovery rule 

3 application process so that the combined failure rate was lower and supported by procedures 

4 and training already in place. For several significant valve failures for high-pressure injection 

5 systems, Entergy was asked to consider the potential for lower cost alternatives than the 

6 SAMAs originally considered. In response, Entergy described the valves and stated that review 

7 of generic SAMAs did not identify any feasible lower cost alternative. The potential for manually 

8 opening the HPCS minimum flow isolation valve was considered and determined not to be 

9 feasible in the time available (Entergy 2012a, 2012b).

10 As stated above, the GGNS IPEEE used a seismic margins assessment, which neither provided 

11 quantitative risk information nor deterministic seismic capacities for specific GGNS systems, 

12 structures, or components. It is thus not possible to identify and evaluate GGNS-specific 

13 SAMAs to mitigate seismic risk. Based on the conclusions of the IPEEE seismic assessment 

14 “...that Grand Gulf Nuclear Station is seismically rugged and that all components identified in 

15 the Safe Shutdown Path have adequately considered the seismic input. All anchorage to these 

16 components was found to be rugged,” the low GGNS internal events CDF, and the staff 

17 observation that SAMAs to mitigate the impact of seismic events are expected to be relatively 

18 costly and therefore are not likely to be cost beneficial, the staff concludes that the exclusion of 

19 seismic-specific SAMAs from the evaluation is acceptable.

20 On the basis of its review of the foregoing information, the staff concludes that the set of SAMAs 

21 evaluated in the ER, together with those identified in response to staff RAIs, addresses the 

22 major contributors to both internal and external event CDF. 

23 The staff questioned the applicant about additional potentially lower cost alternatives to some of 

24 the SAMAs evaluated (NRC 2012a), including:

25 • Revise procedures for operators to manually initiate emergency diesel 

26 generator (EDG) heating, ventilation, and HVAC if the existing automatic logic 

27 fails and/or procedures for the plant auxiliary operators to check on any 

28 automatic start of the EDG could allow HVAC failures to be discovered and 

29 might eliminate the need for alarms.

30 • Provide directions to use jumpers to bypass the low reactor pressure interlock

31 instead of installing a bypass switch to allow operators to bypass interlock 

32 circuitry. 

33 • Consider using other air compressors (service air) that might be connected to 

34 the instrument air system instead of providing new compressors. 

35 • Consider improving control room fire-detection system response for a limited 

36 number of key cabinets.

37 In response to the RAIs, the applicant addressed the suggested lower cost alternatives

38 (Entergy 2012a), which are discussed further in Section F.6.2. 

39 The staff notes that the set of SAMAs submitted is not all-inclusive because additional, possibly 

40 even less expensive, design alternatives can always be proposed. However, the staff 

41 concludes that the benefits of any additional modifications are unlikely to exceed the benefits of 

42 the modifications evaluated and that the alternative improvements likely would not cost less 

43 than the least expensive alternatives evaluated, when the subsidiary costs associated with 

44 maintenance, procedures, and training are considered. 

45 The staff concludes that Entergy used a systematic and comprehensive process for identifying 

46 potential plant improvements for GGNS, and that the set of SAMAs evaluated in the ER, 
Appendix F

F-23

1 together with those evaluated in response to staff inquiries, is reasonably comprehensive and, 

2 therefore, acceptable. This search included reviewing insights from the GGNS plant-specific 

3 risk studies that included internal initiating events as well as fire, seismic and other external 

4 initiated events, and reviewing plant improvements considered in previous SAMA analyses.

5 F.4 Risk Reduction Potential of Plant Improvements

6 In the ER, the applicant evaluated the risk-reduction potential of the 63 SAMAs that were not 

7 screened out in the Phase I analysis and retained for the Phase II evaluation. The SAMA

8 evaluations were performed using generally conservative assumptions.

9 Except for two SAMAs associated with internal fires, Entergy used model re-quantification to 

10 determine the potential benefits for each SAMA. The CDF, population dose, and offsite 

11 economic cost reductions were estimated using the GGNS 2010 EPU PRA model for the 

12 non-fire SAMAs. The changes made to the model to quantify the impact of SAMAs are detailed 

13 in Section E.2.3 of Attachment E to the ER (Entergy 2011). Bounding evaluations (or analysis 

14 cases) were performed to address specific SAMA candidates or groups of similar SAMA 

15 candidates. For the two fire-related SAMAs (SAMA Nos. 54 and 55), the benefit was 

16 determined by assuming the CDF contribution for the fire area impacted by the SAMA was 

17 reduced to zero and that the resulting benefit was determined by the product of the fraction of 

18 the internal events total CDF represented by the fire area CDF and the maximum total internal 

19 events benefit.

20 Table F–5 lists the assumptions considered to estimate the risk reduction for each of the 

21 evaluated SAMAs, the estimated risk reduction in terms of percent reduction in CDF, population 

22 dose risk and offsite economic cost risk, and the estimated total benefit (present value) of the 

23 averted risk. The estimated benefits reported in Table F–5 reflect the combined benefit in both 

24 internal and external events. The determination of the benefits for the various SAMAs is further 

25 discussed in Section F.6.

26 Phase II evaluation, Cases 6 and 10, were used to evaluate SAMA No. 7 (install an additional, 

27 buried offsite power source) and SAMA No. 18 (protect transformers from fire), respectively. 

28 Entergy stated that for these cases, loss of offsite power (LOSP) initiating event frequencies 

29 were multiplied by the ratios of 19/24 and 9/24 to account for severe weather and plant-centered

30 causes of LOSP, respectively. In response to a staff RAI concerning the source of these 

31 values, Entergy stated that of the 24 LOSP events applicable to GGNS, 5 were weather-related, 

32 15 were plant- or switchyard-related, and 4 were grid-related (Entergy 2012a). The ratio 19/24 

33 then represents the fraction of LOSP frequency if severe weather causes are eliminated. 

34 The ratio 9/24 then represents the fraction of LOSP frequency if the plant-centered causes 

35 are eliminated. The staff concludes that this approach is valid for the assessment of 

36 these SAMAs.
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Statio

1 

Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), and Offsite 2 

(OECR) 3 

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction Interna

and

Externa

BenefitCDF PDR OECR

Case 1. Direct Current Power 

Assumption: Eliminates all cutsets for station blackout 

(Analysis Case for SAMA Nos. 1, 2, 11, 12, & 15)

1—Provide additional direct current battery capacity $2,131,000

2—Replace lead-acid batteries with fuel cells $4,080,000

11—Portable generator for direct current power: This SAMA

involves the use of a portable generator to supply direct current 

power to the battery chargers during a station blackout.

$1,278,000

12—Portable generator for direct current power: This SAMA

involves the use of a portable generator to supply direct current 

power to the individual panels during a station blackout. $1,278,000

15—Use direct current generators to provide power to operate the 

switchyard power control breakers while a 480-V alternating 

current generator could supply the air compressors for 

breaker support

$1,428,000

37.1% 27.3% 21.3% $374,00

Case 2. Improve Charger Reliability 

Assumption: Failure of chargers contribution at zero

(Analysis Case for SAMA Nos. 3 & 13)

3—Add battery charger to existing direct current system $90,000

13—Proceduralize battery charger high-voltage shutdown 

circuit inhibit

$50,000

0.7% 2.0% 2.1% $12,10

Case 3. Add Direct Current System Cross-Ties 

Assumption: Eliminates failure of direct current power gates

(Analysis Case for SAMA No. 4)

4—Provide direct current bus cross-ties $300,000

3.6% 8.4% 9.0% $57,00

F

–24
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 4. Increase Availability of Onsite Alternating Current Power

Assumption: Eliminates failure of diesel generators 11, 12, and 13 to 

their alternating current buses

(Analysis Case for SAMA Nos. 5 & 8)

5—Provide an additional diesel generator $20,000,000

8—Install a gas turbine generator with tornado protection $2,000,000

42.1% 31.4% 25.6% $427,00

Case 5. Improve Alternating Current Power 

Assumption: Eliminates the loss of the most important 4.16-kV bus

(Analysis Case for SAMA Nos. 6 & 17)

6—Improve 4.16-kV bus cross-tie ability $656,000

17—Provide alternate feeds to essential loads directly from an 

alternate emergency bus

$656,000

7.5% 29.5% 23.5% $145,00

Case 6. Reduce Loss of Offsite Power During Severe Weather

Assumption: Eliminates the weather centered loss of offsite power 

initiating event

(Analysis Case for SAMA No. 7)

7—Install an additional, buried offsite power source $2,485,000

8.4% 6.0% 4.8% $84,20

Case 7. Provide Backup Emergency Diesel Generator Cooling 

Assumption: Eliminates failure of service water cooling to the emergency 

diesel generators

(Analysis Case for SAMA Nos. 9 & 10)

9—Use fire water system as backup source for diesel cooling $1,344,000

10—Add new backup source of diesel cooling $2,000,000

7.6% 6.4% 4.6% $77,80

Case 8. Increase Emergency Diesel Generator Reliability

Assumption: Eliminates failure of emergency diesel generators to run

(Analysis Case for SAMA No. 14)

14—Provide a portable emergency diesel generator fuel oil 

transfer pump

$1,477,000

4.0% 4.3% 4.0% $45,50

F-25
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 9. Improve Diesel Generator Reliability

Assumption: Eliminates the common cause failure contribution of failure 

to start emergency diesel generators

(Analysis Case for SAMA No. 16)

16—Provide a diverse swing diesel generator air start compressor $100,000

0.8% 0.6% 0.4% $7,85

Case 10. Reduce Plant-Centered Loss of Offsite Power

Assumption: Removes contribution of plant- and switchyard-centered 

events

(Analysis Case for SAMA No. 18)

18—Protect transformers from failure $780,000

25.0% 17.6% 13.9% $250,00

Case 11. Redundant Power to Torus Hard Pipe Vent Valves 

Assumption: Eliminates failure of power to containment vents

(Analysis Case for SAMA No. 19)

19—Provide redundant power to direct torus hard pipe vent valves 

to improve the reliability of the direct torus vent valves and 

enhance the containment heat removal capability.

$714,000

<0.1% 5.4% 6.0% $18,60

Case 12. High Pressure Injection System

Assumption: Eliminates failure of the high pressure core spray

(Analysis Case for SAMA Nos. 20 & 61)

20—Install an independent active or passive high-pressure 

injection system $8,800,000

61—Install a backup water supply and pumping capability that is 

independent of normal and emergency alternating current power

$6,410,000

53.7% 62.2% 58.0% $622,00

F-26
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 13. Extend Reactor Core Isolation Cooling Operation

Assumption: Eliminates failure of trip due to pressure

(Analysis Case for SAMA No. 21)

21—Raise backpressure trip set points for high-pressure coolant 

injection/reactor core isolation cooling [High-pressure coolant 

injection backpressure trip set point has already been raised. This 

SAMA evaluates raising the reactor core isolation cooling 

backpressure trip set point.]

$200,000

<0.1% <0.1% <0.1% <$

Case 14. Improve Automatic Depressurization System 

Assumption: Eliminates failure of automatic depressurization system valves

(Analysis Case for SAMA No. 22)

22—Modify automatic depressurization system components to 

improve reliability [This SAMA will add larger accumulators thus 

increasing reliability during station blackouts].

$1,177,000

33.6% 12.7% 13.1% $310,00

Case 15. Improve Automatic Depressurization System Signals

Assumption: Eliminates failure of the safety relief valve failing to open

(Analysis Case for SAMA No. 23)

23—Add signals to open safety relief valves automatically in a 

main steam isolation valve closure transient.

$1,500,000

6.0% 4.5% 4.2% $61,90

Case 16. Low Pressure Injection System 

Assumption: Eliminates failure of the low pressure coolant injection and low 

pressure core spray

(Analysis Case for SAMA No. 24)

24—Add a diverse low-pressure injection system. $8,800,000

11.4% 45.4% 40.5% $229,00

F-27
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 17. Emergency Core Cooling System Low-Pressure Interlock

Assumption: Eliminates emergency core cooling system permissives and

interlock failure

(Analysis Case for SAMA No. 25)

25—Install a bypass switch to allow operators to bypass the low 

reactor pressure interlock circuitry that inhibits opening the 

low-pressure coolant injection or core spray injection valves 

following sensor or logic failures that prevent all low pressure 

injection valves from opening.

$1,000,000 

<0.1% <0.1% <0.1% $

Case 18. Residual Heat Removal Heat Exchangers

Assumption: Eliminates failure of standby service water to provide 

cooling to the residual heat removal heat exchangers

(Analysis Case for SAMA No. 26)

26—Implement modifications to allow manual alignment of the fire 

water system to residual heat removal heat exchangers.

$1,950,000

12.5% 30.9% 34.1% $205,00

Case 19. Emergency Service Water System Reliability

Assumption: Eliminates failure of service water pumps

(Analysis Case for SAMA No. 27)

27—Add service water pump to increase availability of cooling water $5,900,000

3.5% 6.0% 6.3% $47,20

Case 20. Main Feedwater System Reliability 

Assumption: Eliminates failure to inject from feedwater

(Analysis Case for SAMA No. 28)

28—Add a motor-driven feed water pump $1,650,000

7.5% 22.2% 23.7% $134,00

Case 21. Increase Availability of Room Cooling 

Assumption: Eliminates failure of room cooling to low-pressure core 

spray, high-pressure core spray, standby service water and safeguard 

switchgear battery rooms

(Analysis Case for SAMA No. 29)

29—Provide a redundant train or means of ventilation $2,203,000

17.9% 15.1% 16.0% $193,00

F-28
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 22. Increase Availability of the Diesel Generator System through 

HVAC Improvements 

Assumption: Eliminates failure of HVAC for diesel generator rooms

(Analysis Case for SAMA Nos. 30, 32, & 33)

30—Add a diesel building high temperature alarm or redundant 

louver and thermostat

$1,305,000

32—Diverse emergency diesel generator HVAC logic $1,148,000

33—Install additional fan and louver pair for emergency diesel 

generator HVAC

$6,000,000

23.9% 16.6% 12.3% $237,00

Case 23. Increased Reliability of Room Cooling for High-Pressure Coolant injection 

and Reactor Core Isolation Cooling 

Assumption: Eliminates failure of power to the high-pressure core spray pump 

room cooler (Reactor core isolation cooling pump continued operation is not 

dependent on room cooling.)

(Analysis Case for SAMA No. 31)

31—Create ability to switch high-pressure coolant injection and 

reactor core isolation cooling room fan power supply to direct 

current in an station blackout event

$300,000

<0.1% <0.1% <0.1% $

Case 24. Increase Reliability of Instrument Air 

Assumption: Eliminates failure of the instrument air

(Analysis Case for SAMA Nos. 34 & 35)

34—Modify procedure/hardware to provide ability to align diesel 

power to more air compressors $1,200,000

35—Replace service and instrument air compressors with more 

reliable compressors which have self-contained air cooling by 

shaft-driven fans

$1,395,000

10.6% 17.1% 18.7% $143,00

F-29
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 25. Backup Nitrogen to Safety Relief Valve 

Assumption: Eliminates operator failure to install air bottles

(Analysis Case for SAMA No. 36)

36—Install nitrogen bottles as backup gas supply for safety 

relief valves $1,723,000

5.9% 0.1% 0.0% $46,90

Case 26. Improve Availability of Safety Relief Valves and Main Steam Isolation 

Valves 

Assumption: Eliminates failure of non-automatic-depressurization-system safety 

relief valves

(Analysis Case for SAMA No. 37)

37—Improve safety relief valve and main steam isolation valve 

pneumatic components

$1,500,000

33.7% 12.9% 13.3% $312,00

Case 27. Improve Suppression Pool Cooling 

Assumption: Eliminates the failure of flow to the residual heat removal heat 

exchangers

(Analysis Case for SAMA No. 38)

38—Install an independent method of suppression pool cooling $5,800,000

12.5% 30.9% 34.1% $206,00

Case 28. Increase Availability of Containment Heat Removal

Assumption: Eliminates failure of cooled flow from residual heat removal pump A 

and B 

(Analysis Case for SAMA Nos. 39 & 41)

39—Procedural change to cross-tie open cycle cooling system to 

enhance containment spray system

$25,000

41—Use the fire water system as a backup source for the drywell 

spray system

$1,950,000

17.8% 45.6% 50.2% $297,00

F-30
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 29. Decay Heat Removal Capability – Drywell Spray

Assumption: Eliminates failure of residual heat removal spray

(Analysis Case for SAMA No. 40)

17.8% 45.6% 50.2% $297,00

40—Install a passive drywell spray system to provide redundant 

drywell spray method $5,800,000

Case 30. Increase Availability of the Condensate Storage Tank

Assumption: Eliminates failure of high-pressure core spray and reactor 

core isolation cooling suction

(Analysis Case for SAMA No. 42)

42 – Enhance procedures to refill condensate storage tank from 

demineralized water or service water system

$200,000

4.4% 12.6% 13.5% $77,00

Case 31. Filtered Vent to Increase Heat Removal Capacity for 

Non-Anticipated Transient without Scram Events 

Assumption: Reduces the baseline accident progression source terms 

by a factor of 2

(Analysis Case for SAMA No. 43)

43—Install a filtered containment vent to provide fission 

product scrubbing $1,500,000

0.0% 31.6% 40.6% $118,00

Case 32. Reduce Hydrogen Ignition 

Assumption: Eliminates failure of hydrogen igniters

(Analysis Case for SAMA Nos. 44 & 45)

44—Provide post-accident containment inerting capability $2,665,000

45—Install a passive hydrogen control system $760,000

0.0% 18.8% 19.9% $62,50

F-31
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 33. Controlled Containment Venting 

Assumption: Eliminates failure of air-operated valves to open

(Analysis Case for SAMA Nos. 46 & 47)

46—Provide passive overpressure relief by changing the 

containment vent valves to fail open and improving the strength of 

the rupture disk

$1,000,000

47—Enable manual operation of all containment vent valves via 

local controls

$150,000

1.3% 3.1% 3.5% $21,20

Case 34. Interfacing Systems Loss of Coolant Accident

Assumption: Removes all interfacing systems LOCA initiators

(Analysis Case for SAMA Nos. 48, 50, & 51)

48—Increase frequency of valve leak testing to reduce interfacing 

systems LOCA frequency

$100,000

50—Revise emergency operating procedures to improve 

interfacing systems LOCA identification

$50,000

51—Improve operator training on interfacing systems LOCA

coping

$112,000

0.0% 0.1% 0.1% $12

Case 35. Main Steam Isolation Valve Design 

Assumption: Eliminates failure of the main steam isolation valves to close or 

remain closed

(Analysis Case for SAMA No. 49)

49—Improve main steam isolation valve design to decrease the 

likelihood of containment bypass scenarios

$1,000,000

0.0% 0.1% 0.0% $

F-32
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 36. Standby Liquid Control System 

Assumption: Eliminates failure to initiate standby liquid control and failures of 

alternate boron injection

(Analysis Case for SAMA No. 52)

52—Increase boron concentration in the standby liquid control 

system [Reduced time required to achieve shutdown provides 

increased margin in the accident timeline for successful initiation 

of standby liquid control]

$50,000

0.1% 0.1% 0.1% $59

Case 37. Safety Relief Valve Reseat 

Assumption: Eliminates the initiator for safety relief valves inadvertently being open 

and basic events for stuck open safety relief valves

(Analysis Case for SAMA No. 53)

53—Increase safety relief valve reseat reliability to address the 

risk associated with dilution of boron caused by the failure of the 

safety relief valves to reseat after standby liquid control injection

$2,200,000

4.2% 3.9% 4.1% $46,50

Case 38. Add Fire Suppressiona

Assumption: Eliminates fire CDF from the critical switchgear rooms

(Analysis Case for SAMA No. 54)

54—Add automatic fire suppression systems to the dominant fire 

zones $375,000

n/a n/a n/a $32,60

Case 39. Reduce Risk from Fires that Require Control Room Evacuationa

Assumption: Eliminates fire CDF from the main control room

(Analysis Case for SAMA No. 55)

55—Upgrade the alternate shutdown system panel to include 

additional system controls for opposite division

$787,000

n/a n/a n/a $134,00

F-33
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 40. Large Break Loss of Coolant Accident 

Assumption: Eliminates large break LOCA

(Analysis Case for SAMA No. 56)

56—Provide digital large break LOCA protection to identify 

symptoms and/or precursors of a large break LOCA (a leak before 

break)

$2,000,000

3.3% 13.3% 14.5% $71,30

Case 41. Trip/Shutdown Risk 

Assumption: Reduces all initiating events except pipe breaks, floods, 

and loss of offsite power by 10 percent

(Analysis Case for SAMA No. 57)

57—Generation risk assessment implementation into plant 

activities (trip/shutdown risk modeling)

$500,000

5.7% 6.1% 6.5% $65,80

Case 42. Increase Availability of Pump House Ventilation System for Standby 

Service Water 

Assumption: Eliminates failure of standby service water pump house ventilation

(Analysis Case for SAMA No. 58)

58—Increase the training emphasis and provide additional control 

room indication on the operational status of standby service water 

pump house ventilation system

$100,000

1.5% 1.6% 1.6% $16,80

F-34
Table F–5. Severe Accident Mitigation Alternatives Cost/Benefit Analysis for Grand Gulf Nuclear Station

Risk Reductions are Presented for Core Damage Frequency (CDF), Population Dose Risk (PDR), an

Economic Cost Risk (OECR) (continued)

Analysis Case, Analysis Assumption, Individual SAMAs, and Cost Estimates

% Risk Reduction

CDF PDR OECR

Interna

and

Externa

Benefit

Case 43. Increase Recovery Time of Emergency Core Cooling System Upon Loss 

of Standby Service Water 

Assumption: Eliminates failure of standby service water to the low pressure 

core spray room cooler

(Analysis Case for SAMA No. 59)

59—Increase operator training for alternating operation of the 

low-pressure emergency core cooling system pumps 

(low-pressure coolant injection and low-pressure core spray) for 

loss of standby service water scenarios

$50,000

4.5% 5.2% 5.5% $53,30

Case 44. Additional Containment Heat Removal 

Assumption: Eliminates failure of suppression pool cooling and containment 

spray systems

(Analysis Case for SAMA No. 60)

60—Install an additional method of heat removal from 

containment $4,352,000

17.8% 47.1% 51.9% $302,00

Case 45. Improve Heat Exchanger Availability for Residual Heat Removal 

Assumption: Eliminates failure of residual heat removal heat exchanger 

cooler inlet and outlet valves

(Analysis Case for SAMA No. 62)

62—Add a bypass around the residual heat removal heat 

exchanger inlet and outlet valves

$2,832,000

2.0% 6.4% 7.0% $37,80

Case 46. Improve Lube Oil Cooling for Reactor Core Isolation Cooling 

Assumption: Eliminates failure to cool lube oil for reactor core isolation cooling

(Analysis Case for SAMA No. 63)

63—Add a redundant reactor core isolation cooling lube oil cooling 

path $1,803,000

7.4% 3.1% 2.5% $68,20

a These analysis cases only affected external events and were evaluated differently.

b Clarified by the applicant to be reduced by 10 percent in response to a request for additional information.

F-35
Appendix F

F-36

1 Case 8, used to evaluate the benefit of SAMA No. 14 (provide a portable EDG fuel oil transfer 

2 pump), assumed that the EDGs’ failure to run was eliminated. In its review, the staff noted that 

3 the failure to run of the Division 3, HPCS diesel was not eliminated. In response to an RAI, 

4 Entergy stated that the Division 3 diesel did not have a common fuel oil transfer pump with the 

5 other two EDGs and if the Division 3 diesel were included in the assessment, either two portable 

6 fuel transfer pumps would be needed, or the pump would have to be moved to fill the additional 

7 day tank. Entergy stated this would increase implementation costs and would not change the 

8 results of the cost-benefit assessment (Entergy 2012a). While the staff disagrees that the 

9 added cost of moving the portable transfer pump would be appreciable, in considering the 

10 conservatism in the assumption that all failures to run would be eliminated by having a portable 

11 pump, the staff concludes that the assessment of the benefit of SAMA No. 14 is acceptable. 

12 Case 32, used to evaluate the benefit of SAMAs Nos. 44 and 45 (both changes to eliminate 

13 hydrogen ignition containment failures), was evaluated by eliminating failures of the hydrogen 

14 igniter system. A staff RAI on the original ER submittal (NRC 2012a) noted that Entergy results 

15 indicated the assumption would lead to a 16 percent reduction in CDF, whereas it should have 

16 no impact on CDF. In response, Entergy stated that the elimination of igniter failures in the 

17 Level 2 analysis was done by setting a gate to TRUE, which eliminated all hydrogen igniter 

18 failure cut sets from the Level 2 results, and therefore, led to the reduction in CDF in the original 

19 analysis (Entergy 2012a). This inconsistency was resolved in the revised SAMA analysis. In 

20 the revised analysis, there is no reduction in CDF for Case 32 (Entergy 2012c). The staff 

21 concludes that the revised evaluation, as described, is appropriate for the SAMA analysis.

22 In the description of the updated analysis, Entergy stated that the assumptions for evaluating 

23 the benefit for Case 5 used for SAMA No. 6 (Improve 4.16-kV bus cross-tie ability) and SAMA 

24 No. 17 (Provide alternate feeds to essential loads directly from an alternate emergency bus)

25 were revised to remove some of the excess conservatism in the prior evaluation 

26 (Entergy 2012c). Because the applicant’s additional information addressed the questions raised 

27 by the staff and provided a sufficient basis for justifying the cost-benefit conclusions, the staff 

28 concludes that the revised evaluation, as described, is appropriate for the SAMA analysis.

29 F.5 Cost Impacts of Candidate Plant Improvements

30 Entergy estimated the costs of implementing the 63 Phase II SAMAs through the use of other 

31 licensees’ estimates for similar improvements and the development of site-specific cost 

32 estimates where appropriate.

33 Entergy stated that the following cost ranges were used based on the review of previous 

34 SAMA applications.

35 Table F–6. Estimated Cost Ranges for SAMA Applications

Type of Change Estimated Cost Range

Procedural only $25K–$50K

Procedural change with engineering or training required $50K–$200K

Procedural change with engineering and testing or 

training required

$200K–$300K

Hardware modification $100K to > $1000K
Appendix F

F-37

1 Entergy stated that the GGNS site-specific cost estimates were based on the engineering 

2 judgment of project engineers experienced in performing design changes at the facility. 

3 The detailed cost estimates considered engineering, labor, materials, and support functions, 

4 such as planning, scheduling, health physics, quality assurance, security, safety, and fire watch. 

5 The estimates included a 20 percent contingency on the design and installation costs but did not 

6 account for inflation, replacement power during extended outages necessary for SAMA

7 implementation, or increased maintenance or operation costs following SAMA implementation.

8 In response to a staff RAI for more information concerning the applicability of cost estimates

9 taken directly from previous SAMA applications, Entergy stated that engineering judgment by 

10 project engineers familiar with the costs of modifications at Entergy plants was used to 

11 determine if the cited cost estimates from other SAMA analyses were valid for GGNS. If the 

12 GGNS project engineers’ rough conceptual cost estimate of the modification was larger than the 

13 other plant's cost estimate, the other plant’s estimate was adopted without further detailed cost 

14 analysis (Entergy 2012a). 

15 The staff reviewed the applicant’s cost estimates, presented in Table E.2-2 of Attachment E to 

16 the ER in the original submittal (Entergy 2011) and in responses to staff RAIs 

17 (Entergy 2012a, 2012c). For certain improvements, the staff also compared the cost estimates 

18 to estimates developed elsewhere for similar improvements, including estimates developed as 

19 part of other licensees’ analyses of SAMAs for operating reactors.

20 The staff noted that the new plant-specific cost estimates incorporated into the revised 

21 cost-benefit analysis for a number of SAMAs are considerably greater than those previously 

22 given and appear large compared to that implied by the SAMA description. In response to an 

23 RAI, Entergy provided more details on what is specifically included in the new cost estimates for 

24 SAMA Nos. 1, 9, 11, 14, and 63 to justify those estimates (Entergy 2012d). Based on the 

25 additional information provided, comparison of the costs with those provided in other SAMA 

26 submittals, conservatisms in the determination of the benefit, and consideration of the margins 

27 between the cost and the benefit, the staff concludes that the applicant’s cost estimates are 

28 acceptable for determining the cost-benefit ratio of these SAMAs. 

29 In the revised cost-benefit analysis, Entergy stated that the cost estimate for SAMA No. 6 

30 (Improve 4.16-kV bus cross-tie ability) and SAMA No. 17 (Provide alternate feeds to essential 

31 loads directly from an alternate emergency bus) of $656,000 was taken from the Susquehanna 

32 SAMA analysis. In response to a staff RAI that pointed out the value used from Susquehanna 

33 was for two reactor units, Entergy described the basis for concluding that the cost for these 

34 SAMAs at GGNS would exceed the $656,000 value and justified use of this value for the GGNS 

35 SAMA analysis (Entergy 2012d) on the basis of extensive changes to the electrical bus control 

36 scheme, supporting calculations, documentation changes, required hardware, installation, and 

37 testing. Based on the information provided for implementing these SAMAs at GGNS, the staff 

38 concludes that Entergy’s cost estimates are acceptable for determining the cost-benefit ratio of 

39 these SAMAs.

40 The staff concludes that, with the above clarifications, the cost estimates provided by Entergy 

41 are sufficient and appropriate for use in the SAMA evaluation.
Appendix F

F-38

1 F.6 Cost-Benefit Comparison

2 Entergy’s cost-benefit analysis and the staff’s review are described in the following sections.

3 F.6.1 Entergy’s Evaluation 

4 The methodology used by Entergy was based primarily on NRC’s guidance for performing 

5 cost-benefit analysis; i.e., NUREG/BR–0184 (NRC 1997a). As described in Section 4.21.5.4 of 

6 the ER (Entergy 2011), the net value was determined for each SAMA according to the 

7 following formula:

8 Net Value = (APE + AOC + AOE + AOSC) – COE 

9 where

10 APE (averted public exposure) = present value of APE costs ($)

11 AOC (averted offsite property damage costs) = present value of AOC costs ($)

12 AOE (averted occupational exposure) = present value of AOE costs ($)

13 AOSC (averted onsite costs) = present value of AOSC ($)

14 COE = cost of enhancement ($)

15 If the net value of a SAMA is negative, the cost of implementing the SAMA is larger than the 

16 benefit associated with the SAMA, and it is not considered to be cost beneficial. Entergy’s 

17 derivation of each of the associated costs is summarized next.

18 NEI guidance states that two sets of estimates should be developed for discount rates of 

19 7 percent and 3 percent (NEI 2005). Entergy provided a base set of results using a discount 

20 rate of 7 percent and a 20-year license renewal period. Two sensitivity cases were developed

21 by Entergy: one used a discount rate of 7 percent with a 33-year period for remaining plant life 

22 and another used a more conservative discount rate of 3 percent with a 20-year license 

23 renewal period. 

24 F.6.1.1 Averted Public Exposure (APE) Costs

25 Entergy defined APE cost as the monetary value of accident risk avoided from population doses 

26 after discounting (Entergy 2011). The APE costs were calculated using the following formula:

27 APE = Annual reduction in public exposure (Δ person-rem per year)

28 × monetary equivalent of unit dose ($2,000 per person-rem)

29 × present value conversion corresponding to NRC (1997a, Equation on p. 5.27 

30 for C when a facility is already operating)

31 The annual reduction in public exposure was calculated according to the following formula: 

32 Annual reduction in public exposure = (Accident frequency without modification ×

33 accident population dose without modification) – (Accident frequency with 

34 modification × accident population dose with modification)

35 As stated in NUREG/BR–0184 (NRC 1997a), it is important to note that the monetary value of 

36 the public health risk after discounting does not represent the expected reduction in public 

37 health risk due to a single accident. Rather, it is the present value of a stream of potential 

38 losses extending over the remaining lifetime (in this case, the 20-year renewal period) of the 

39 facility. Thus, it reflects the expected annual loss due to a single accident, the possibility that 

40 such an accident could occur at any time over the renewal period, and the effect of discounting 
Appendix F

F-39

1 these potential future losses to present value. As previously stated, Entergy also considered an 

2 extended period of 33 years for the remaining facility lifetime as a sensitivity case. For a 

3 discount rate of 7 percent and a 20-year license renewal period in the revised analysis with a 

CDF of 2.93 × 10−6 4 per year, the applicant calculated an APE cost of $13,116 for internal events 

5 (Entergy 2012c).

6 F.6.1.2 Averted Offsite Property Damage Costs (AOC)

7 Entergy defined AOC as the monetary value of risk avoided from offsite property damage after 

8 discounting (Entergy 2011). The AOC values were calculated using the following formula:

9 AOC = Annual reduction in offsite property damage × present value conversion 

10 corresponding to NRC (1997a, Equation for C on p. 5.27 for an operational 

11 facility). 

12 The annual reduction in offsite property damage was calculated according to the 

13 following formula:

14 Annual reduction in offsite property damage = (Accident frequency without 

15 modification × accident property damage without modification) – (Accident frequency 

16 with modification × accident property damage with modification)

17 For a discount rate of 7 percent and a 20-year license renewal period in the revised analysis 

with a CDF of 2.93 × 10−6 18 per year, the applicant calculated an AOC of $16,264 for internal 

19 events (Entergy 2012c).

20 F.6.1.3 Averted Occupational Exposure (AOE) Costs

21 Entergy defined AOE as the avoided onsite exposure (Entergy 2011). Similar to the APE 

22 calculations, the applicant calculated costs for immediate onsite exposure. Long-term onsite 

23 exposure costs were calculated consistent with guidance in NUREG/BR–0184 (NRC 1997a), 

24 which included an additional term for accrual of long-term doses.

25 Entergy derived the values for averted occupational exposure from information provided in 

26 Section 5.7.3 of NUREG/BR–0184 (NRC 1997a). Best estimate values provided for immediate

27 occupational dose (3,300 person-rem) and long-term occupational dose (20,000 person-rem 

28 over a 10-year clean-up period) were used. The present value of these doses was calculated 

29 using the equations provided in the handbook in conjunction with a monetary equivalent of unit 

30 dose of $2,000 per person-rem, a real discount rate of 7 percent, and a time period of 20 years 

31 to represent the license renewal period. Entergy assumed an accident frequency with 

32 modification of zero to overestimate and bound the long-term onsite exposure costs. Immediate 

33 and long-term onsite exposure costs were summed to determine AOE cost. For a CDF of 

2.93 × 10−6 34 per year in its revised analysis, the applicant calculated an AOE cost of $1,115 for 

35 internal events (Entergy 2012c).

36 F.6.1.4 Averted Onsite Costs (AOSC)

37 AOSC include averted cleanup and decontamination costs and averted power replacement 

38 costs. Repair and refurbishment costs are considered for recoverable accidents only and not 

39 for severe accidents. The applicant derived the values for AOSC based on information provided 

40 in Section 5.7.6 of NUREG/BR–0184 (NRC 1997a). This cost element was divided into two 

41 parts: the onsite cleanup and decontamination cost, also commonly referred to as averted 

42 cleanup and decontamination costs; and the replacement power cost (RPC).
Appendix F

F-40

1 Averted cleanup and decontamination costs (ACC) were calculated using the following formula:

2 ACC = Annual CDF reduction

3 × present value of clean-up costs per core damage event

4 × present value conversion factor

5 The total cost of clean-up and decontamination subsequent to a severe accident is estimated in 

NUREG/BR–0184 to be $1.5 × 109 6 (undiscounted). This value was converted to present costs 

7 over a 10-year clean-up period and integrated over the term of the proposed license extension.

8 Long-term RPCs were calculated using the following formula: 

9 RPC = Annual CDF reduction

10 × present value of replacement power for a single event

11 × factor to account for remaining service years for which replacement power

12 is required

13 × reactor power scaling factor

14 Accounting for the GGNS EPU, the applicant based its calculations on a net electric output of 

15 1,475 megawatts-electric (MWe) and scaled up from the 910 MWe reference plant in 

16 NUREG/BR-0184 (NRC 1997a). Therefore, the applicant applied a power-scaling factor of 

1.62 (1475 / 910 = 1.62) to determine the RPCs. For a CDF of 2.93 × 10−6 17 per year in its 

18 revised analysis, Entergy calculated an AOSC of $71,500 from internal events for the 20-year 

19 license renewal period (Entergy 2012c).

20 Using the above equations, Entergy estimated the total present dollar value equivalent 

21 associated with completely eliminating severe accidents due to internal events at GGNS to be 

22 about $101,995 (Entergy 2012c, Table 4.21-1). The applicant multiplied the internal events 

23 estimated benefit by 11 to account for the risk contributions from external events and yield the 

24 internal and external benefit. Additionally, internal and external benefits were multiplied by a 

25 factor of 3 to account for uncertainties in the CDF calculation (Entergy 2011). In total, a 

26 multiplication factor of 33 was applied to the estimated benefit from internal events to obtain the 

27 total estimated benefit for internal and external events with uncertainty, which was used in 

28 Entergy’s cost-benefit comparisons.

29 F.6.1.5 Entergy’s Results

30 If the implementation costs for a candidate SAMA exceeded the calculated benefit, the SAMA 

31 was determined to be not cost beneficial. If the benefit exceeded the estimated cost, the SAMA 

32 candidate was considered to be cost beneficial. In Entergy’s original submittal and revised 

33 analysis, three SAMA candidates were found to be potentially cost beneficial (Entergy 2011, 

34 Section 4.21.6; Entergy 2012c, Table 4.21-2). Results of the cost-benefit evaluation are 

35 presented in Table F–5.

36 The potentially cost-beneficial SAMAs are:

37 • SAMA No. 39—Change procedure to cross tie open cycle cooling system to 

38 enhance containment spray system, 

39 • SAMA No. 42—Enhance procedures to refill condensate storage tank from 

40 demineralized water or service water system), and

41 • SAMA No. 59—Increase operator training for alternating operation of the 

42 low-pressure emergency core cooling system pumps (low-pressure coolant 
Appendix F

F-41

1 injection and low-pressure core spray) for loss of standby service water 

2 scenarios.

3 Entergy stated that a condition report to implement these potentially cost-beneficial SAMAs has 

4 been initiated within the corrective action process.

5 A sensitivity analysis considered two cases: a discount rate of 7 percent with a 33-year period 

6 for remaining plant life and a more conservative discount rate of 3 percent with a 20-year 

7 license renewal period (Entergy 2011, Section 4.21.5 and Table E.2-3; Entergy 2012c, 2012d). 

8 Based on its sensitivity analysis in the original submittal and revised analysis, Entergy did not 

9 identify any additional cost-beneficial SAMAs.

10 F.6.2 Review of Entergy’s Cost-Benefit Evaluation 

11 Based primarily on NUREG/BR–0184 (NRC 1997a) and NEI guidelines on discount rates 

12 (NEI 2005), the staff determined the cost-benefit analysis performed by Entergy was consistent 

13 with the guidance. Three SAMA candidates were found to be potentially cost beneficial.

14 The applicant considered possible increases in benefits from analysis uncertainties on the 

15 results of the SAMA assessment. In the ER (Entergy 2011), Entergy stated that the 

95th 16 percentile value of the GGNS CDF was a factor of 2.38 greater than the mean CDF. 

17 A multiplication factor of 3 was conservatively selected by the applicant to account for 

18 uncertainty. This multiplication factor was applied in addition to a separate multiplication factor 

19 of 11 for CDF increases due to external events. Entergy’s assessment accounted for the 

20 potential risk-reduction benefits associated with both internal and external events. The staff 

21 considers the multipliers of 3 for uncertainty and 11 for external events provide adequate margin 

22 and are acceptable for the SAMA analysis.

23 At the staff’s request, Entergy provided further information on the uncertainty analysis that 

indicated the 95th percentile CDF was 7.14 × 10−6

/yr for a cutset truncation of 1 × 10−11 24 /yr. The 

point estimate and mean values for CDF were 2.82 × 10−6

/yr and 3.00 × 10−6 25 /yr 

(Entergy 2012a). The ratio of the 95th 26 percentile to the point estimate, which should be used in 

27 determining the uncertainty multiplier, is therefore 2.53 versus the 2.38 discussed above. 

28 Because a multiplier of 3 was conservatively used in the assessment, the results of the SAMA

29 assessment are not affected by this correction.

30 Sensitivity to the discount rate and time period for remaining plant life was analyzed by the 

31 applicant. Compared to Entergy’s baseline benefits in the original submittal (Entergy 2011, 

32 Table E.2-3), benefit increases for individual SAMAs ranged from 20 to 59 percent and from 

33 20 to 40 percent for the first and second sensitivity cases, respectively. Additional sensitivity 

34 analyses were performed on MACCS2 input parameters for an increased evacuation time delay 

35 and for a slower evacuation speed. The applicant indicated consequence deviations of less 

36 than 1 percent to the sensitivity case results for the MACCS2 parameters (Entergy 2011). 

37 The staff requested additional information related to costs for a few SAMAs within $10,000 of 

38 estimated benefits in the sensitivity analysis. Entergy provided additional information that the 

39 margin between the cost benefit and actual implementation cost would be greater than $10,000

40 (Entergy 2012a, 2012c). For SAMA No. 13 on a procedure change to inhibit high-voltage circuit 

41 shutdown for battery charging, Entergy explained that the cost-benefit ratio in the SAMA 

42 analysis is an overestimate because other failure mechanisms, not precluded by the procedure 

43 change, were included into the benefit calculation. The implementation cost selected by 

44 Entergy was the minimum value from the typical range for procedure changes with engineering 

45 or training required. For SAMA Nos. 14 and 63 (provide portable EDG fuel oil transfer pump 

46 and adding a redundant path for reactor core isolation cooling lube oil cooling), Entergy 
Appendix F

F-42

1 provided refined, plant-specific cost estimates of $1,477,000 and $1,803,000, respectively, for 

2 these modifications that involve piping changes to safety-related systems. Based on this 

3 additional information, additional cost-beneficial SAMAs were not identified. 

4 Sensitivity analysis results were recast in the SAMA reanalysis (Entergy 2012c). In response to 

5 an NRC clarification question on the unexpected large increase in the sensitivity to the discount 

6 rate shown in the revised results, Entergy described that the sensitivity calculation for the lower 

7 discount rate of 3 percent inadvertently included the cumulative effect of both the longer time 

8 period of remaining plant life of 33 years and the lower discount rate (Entergy 2012d). Without 

9 the additional effect from a longer time period, increases in the benefit solely due to a lower 

10 discount rate would be smaller than those results reported in Entergy (2012c). Individual (as 

11 well as cumulative) increases in the estimated benefits from the sensitivity parameters were 

12 smaller than the factor of 3 applied by the applicant to account for uncertainty. In the revised 

13 analysis, neither individual nor cumulative sensitivity effects resulted in benefit estimates for 

14 individual SAMAs that exceeded GGNS implementation costs beyond the three SAMAs 

15 previously identified by Entergy to be potentially cost beneficial. 

16 The staff asked the applicant to evaluate potentially lower cost alternatives to several 

17 candidates SAMAs, as summarized below:

18 • Revising procedures for operators to manually initiate EDG HVAC if the 

19 existing automatic logic fails or procedures for the plant auxiliary operators to 

20 check on any automatic start of the EDG that could allow HVAC failures to be 

21 discovered and might eliminate the need for alarms.

22 • Providing directions to use jumpers to bypass the low reactor pressure 

23 interlock instead of installing a bypass switch to allow operators to bypass 

24 interlock circuitry. 

25 • Using other air compressors (service air) that might be connected to the 

26 instrument air system instead of providing new compressors. 

27 • Improving control room fire-detection system response for a limited number of 

28 key cabinets.

29 Concerning the first alternative, Entergy agreed that a procedure revision to direct that the 

30 operator monitoring a running diesel ensure the ventilation system is running, or take action to 

31 open doors or use portable fans, would be potentially cost beneficial. Entergy stated that a 

32 condition report to implement this potentially cost-beneficial SAMA has been initiated within the 

33 corrective action process (Entergy 2012a).

34 Concerning the second alternative, Entergy concluded that because of system design and the 

35 number of failures that would initiate the need for this action, the likelihood of performing this 

36 action successfully would be low and the benefit small. Thus, this alternative was not 

37 considered cost beneficial (Entergy 2012a).

38 Concerning the third alternative, Entergy stated that a modification to connect service air with 

39 instrument air has already been implemented (Entergy 2012a).

40 Concerning the fourth alternative, Entergy stated that the control room is already protected by 

41 smoke detectors in the underfloor area and in every cabinet except P680 (i.e., the console at 

42 which the operator sits). Since the control room is continuously occupied and, thus, provides 

43 the capability of prompt detection and suppression, the use of “very early warning” or “incipient” 

44 detection is not expected to provide a significant improvement and would not be cost beneficial 

45 (Entergy 2012a).
Appendix F

F-43

1 The staff agrees with the Entergy disposition of the above lower-cost alternatives. 

2 F.7 Conclusions

3 Entergy considered 249 candidate SAMAs based on risk-significant contributors at GGNS from 

4 updated probabilistic safety assessment models, its review of SAMA analyses from other BWR 

5 plants, NRC and industry documentation of potential plant improvements, and GGNS individual 

6 plant examination of internal and external events including available updates. Phase I 

7 screening reduced the list to 63 unique SAMA candidates by eliminating SAMAs that were not 

8 applicable to GGNS, had already been implemented at GGNS, or were combined into a more 

9 comprehensive or plant-specific SAMA.

10 For the remaining SAMA candidates, Entergy performed a cost-benefit analysis with results 

11 shown in Table F–5. The cost-benefit analysis identified three potentially cost-beneficial SAMAs 

12 (Phase II SAMA Nos. 39, 42, and 59). Sensitivity cases were analyzed for the present value 

13 discount rate and time period for remaining plant life. No additional SAMAs were identified as 

14 potentially cost beneficial from the sensitivity analysis. In response to a staff RAI concerning 

15 potential low-cost alternatives, Entergy determined that a procedure revision to direct that the 

16 operator monitoring a running diesel ensure the ventilation system is running, or take action to 

17 open doors, or use portable fans would be potentially cost beneficial. 

18 The staff reviewed the Entergy SAMA analysis and concludes that, subject to the discussion 

19 in this appendix, the methods used and implementation of the methods were sound. On the 

20 basis of the applicant’s treatment of SAMA benefits and costs, the staff finds that the 

21 SAMA evaluations performed by Entergy are reasonable and sufficient for the license 

22 renewal submittal.

23 The staff agrees with Entergy’s conclusion that the four candidate SAMAs discussed in this 

24 section are potentially cost beneficial, which was based on generally conservative treatment of 

25 costs, benefits, and uncertainties. This conclusion of a small number of potentially 

26 cost-beneficial SAMAs is consistent with the low residual level of risk indicated in the GGNS 

27 PRA and the fact that Entergy has already implemented the plant improvements identified from 

28 the IPE and IPEEE. Because the potentially cost-beneficial SAMAs do not relate to aging 

29 management during the period of extended operation, they do not need to be implemented as 

30 part of license renewal in accordance with Title 10 of the Code of Federal Regulations, Part 54. 

31 Nevertheless, Entergy issued a condition report under the corrective action process to consider 

32 implementation of these potentially cost-beneficial SAMAs. The staff accepts this course of 

33 action.

34 F.8 References

35 Electric Power Research Institute (EPRI). 1991. “A Methodology for Assessment of Nuclear 

36 Power Plant Seismic Margin.” NP–6041–SL, Rev. 1. Jack R. Benjamin and Associates, 

37 Inc., et al. Palo Alto, CA. August 1991.

38 Electric Power Research Institute (EPRI). 1992. “Fire-Induced Vulnerability Evaluation (FIVE),” 

39 TR-100370. Professional Loss Control, Inc. Palo Alto, CA. April 1992.

40 Electric Power Research Institute (EPRI). 1994. “EPRI Fire PRA Implementation Guide.” 

41 EPRI Report Project 3385–01. Draft, Parkinson, W.J., et al. Palo Alto, CA. January 1994.

42 Enercon Services, Inc. (Enercon). 2011. Permanent, Transient, and Total Population Projection 

43 in Sectors. Calc. No. ENTGGG084–CALC–001, Revision 1. Oklahoma City, OK. May 27, 2011.
Appendix F

F-44

1 Entergy Operations, Inc. (Entergy). 1992. “Individual Plant Examination (IPE) for Grand Gulf 

2 Nuclear Station Unit 1.” December 1992. Accessible at Agencywide Documents Access 

3 Management System (ADAMS) No. ML080090496 (nonpublic document).

4 Entergy Operations, Inc. (Entergy). 1995. Letter from M.J. Meisner, Entergy, to U.S. NRC 

5 Document Control Desk. Subject: “Grand Gulf Nuclear Station Docket No. 50–416 License 

6 No. NPF–29 Individual Plant Examination of External Events (IPEEE) Schedule Final 

7 Submittal.” November 15, 1995 (nonpublic document).

8 Entergy Operations, Inc. (Entergy). 1998. Letter from W. K. Hughey, Entergy, to U.S. NRC 

9 Document Control Desk. Subject: “Grand Gulf Nuclear Station Unit 1 Docket No. 50–416 

10 License No. NPF–29 Response to Request for Additional Information Related to Individual Plant 

11 Examination of External Events.” February 10, 1998 (nonpublic document).

12 Entergy Operations, Inc. (Entergy). 2011. “Applicant’s Environmental Report Operating License 

13 Renewal Stage Grand Gulf Nuclear Generating Station.” Appendix E to Grand Gulf Nuclear 

14 Station (GGNS) License Renewal Application (LRA). Port Gibson, MS. October 2011. 

15 Accessible at ADAMS No. ML11308A234.

16 Entergy Operations, Inc. (Entergy). 2012a. Letter from Michael Perito, Entergy, to U.S. Nuclear 

17 Regulatory Commission Document Control Desk. Subject: “Response to Request for Additional 

18 Information (RAI) on Severe Accident Mitigation Alternatives dated May 21, 2012, Grand Gulf 

19 Nuclear Station, Unit 1, Docket No. 50-416, License No. NPF–29.” Port Gibson, MS. 

20 July 19, 2012. Accessible at ADAMS No. ML12202A056.

21 Entergy Operations, Inc. (Entergy). 2012b. Letter from Michael Perito, Entergy, to U.S. Nuclear 

22 Regulatory Commission Document Control Desk. Subject: “Response to Request for Additional 

23 Information (RAI) on Severe Accident Mitigation Alternatives dated August 23, 2012, Grand Gulf 

24 Nuclear Station, Unit 1, Docket No. 50-416, License No. NPF–29.” Port Gibson, MS. 

25 October 2, 2012. Accessible at ADAMS No. ML12277A082. 

26 Entergy Operations, Inc. (Entergy). 2012c. Letter from Michael Perito, Entergy, to U.S. Nuclear 

27 Regulatory Commission Document Control Desk. Subject: “Reanalysis of Severe Accident 

28 Mitigation Alternatives, Grand Gulf Nuclear Station, Unit 1, Docket No. 50–416, License 

29 No. NPF-29.” Port Gibson, MS. November 19, 2012. Accessible at ADAMS No. ML12325A174. 

30 Entergy Operations, Inc. (Entergy). 2012d. Letter from Kevin J. Mulligan, Entergy, to 

31 U.S. Nuclear Regulatory Commission Document Control Desk. Subject: “Response to 

32 Clarification Questions on Reanalysis of Severe Accident Mitigation Alternatives (SAMA) Letter 

33 dated November 19, 2012, Grand Gulf Nuclear Station, Unit 1, Docket No. 50–416, License 

34 No. NPF–29.” Port Gibson, MS. December 19, 2012. Accessible at ADAMS No. ML12359A038.

35 Nuclear Energy Institute (NEI). 2005. “Severe Accident Mitigation Alternative (SAMA) Analysis 

36 Guidance Document.” NEI 05–01, Rev. A. Washington, DC. November 2005.

37 Nuclear Energy Institute (NEI). 2010. “Roadmap for Attaining Realism in Fire PRA.” 

38 Washington, DC. December 2010. Accessible at ADAMS No. ML110210990. 

39 U.S. Nuclear Regulatory Commission (NRC). 1988. “Individual Plant Examination for Severe 

40 Accident Vulnerabilities.” Generic Letter 88–20. November 23, 1988. Accessible at ADAMS 

41 No. ML031470299.

42 U.S. Nuclear Regulatory Commission (NRC). 1990. Severe Accident Risks: An Assessment for 

43 Five U.S. Nuclear Power Plants. NUREG–1150. Washington, DC. Accessible at ADAMS 

44 Nos. ML040140729 and ML120960691.
Appendix F

F-45

1 U.S. Nuclear Regulatory Commission (NRC). 1991a. “Individual Plant Examination of External 

2 Events (IPEEE) for Severe Accident Vulnerabilities.” Generic Letter 88–20, Supplement 4. 

3 Washington, DC. June 28, 1991. Accessible at ADAMS No. ML031150485.

4 U.S. Nuclear Regulatory Commission (NRC). 1991b. Procedural and Submittal Guidance for the 

5 Individual Plant Examination of External Events (IPEEE) for Severe Accident Vulnerabilities. 

6 NUREG–1407. Washington, DC. May 1991. Accessible at ADAMS No. ML063550238.

7 U.S. Nuclear Regulatory Commission (NRC). 1996. U.S. NRC to R. Hutchinson (GGNS). 

8 “Individual Plant Examination (IPE)—Internal Events—Grand Gulf Nuclear Station (TAC 

9 No. M74415).” Generic Letter 88–20. Correspondence No. GNRI–96/00067. March 7, 1996. 

10 Available via the NRC Public Document Room by e-mail to pdr.resource@nrc.gov.

11 U.S. Nuclear Regulatory Commission (NRC). 1997a. Regulatory Analysis Technical Evaluation 

12 Handbook. NUREG/BR–0184. Washington, DC. Accessible at ADAMS No. ML050190193.

13 U.S. Nuclear Regulatory Commission (NRC). 1997b. Individual Plant Examination Program: 

14 Perspectives on Reactor Safety and Plant Performance Parts 2–5, Final Report.” 

15 NUREG–1560, Vol. 2. Washington, DC. December 31, 1997. Accessible at ADAMS 

16 No. ML0635550228 (nonpublic document).

17 U.S. Nuclear Regulatory Commission (NRC). 2001. Letter from S.P. Sekerak, NRC, to William 

18 A. Eaton, Entergy. Subject: “Grand Gulf Nuclear Station, Unit 1 – Re: Staff Evaluation of 

19 Licensee Response to Generic Letter 88–20, Supplement 4, ‘Individual Plant Examination for

20 Severe Accident Vulnerabilities,’ (TAC No. M83625).” March 16, 2001 (nonpublic document).

21 U.S. Nuclear Regulatory Commission (NRC). 2005. EPRI/NRC-RES Fire PRA Methodology 

22 for Nuclear Power Facilities. NUREG/CR–6850. Vols. 1 and 2. Washington, DC. 

23 September 2005. Accessible at ADAMS Nos. ML052580075 and ML052580118.

24 U.S. Nuclear Regulatory Commission (NRC). 2009. “An Approach for Determining the Technical 

25 Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities.” Regulatory 

26 Guide 1.200, Revision 2. March 2009. Accessible at ADAMS No. ML090410014.

27 U.S. Nuclear Regulatory Commission (NRC). 2010. “NRC Information Notice 2010–18: Generic 

28 Issue 199, Implications of Updated Probabilistic Seismic Hazard Estimates in Central and 

29 Eastern United States on Existing Plants.” Washington, DC. September 2, 2010. Accessible at 

30 ADAMS No. ML101970221.

31 U.S. Nuclear Regulatory Commission (NRC). 2012a. Letter from David Drucker, NRC, to 

32 Michael Perito, Entergy. Subject: “Request for Additional Information on Severe Accident 

33 Mitigation Alternatives for the Review of the Grand Gulf Nuclear Station, Unit 1, License 

34 Renewal Application.” May 21, 2012. Accessible at ADAMS No. ML12115A101.

35 U.S. Nuclear Regulatory Commission (NRC). 2012b. Letter from David Drucker, NRC, to 

36 Michael Perito, Entergy. Subject: “Request for Additional Information on Severe Accident 

37 Mitigation Alternatives for the Review of the Grand Gulf Nuclear Station, Unit 1, License 

38 Renewal Application.” August 23, 2012. Accessible at ADAMS No. ML12227A735.

39 U.S. Nuclear Regulatory Commission (NRC). 2012c. Letter from Alan Wang, NRC, to Vice 

40 President, Operations, Entergy. Subject: “Grand Gulf Nuclear Station, Unit 1 – Issuance of 

41 Amendment Re: Extended Power Uprate (TAC No. ME4679).” Enclosure 2, Safety Evaluation 

42 by the Office of Nuclear Reactor Regulation Related to Amendment No. 191 to Facility 

43 Operating License No. NPF-29, Entergy Operations, Inc., Grand Gulf Nuclear Station, Unit 1, 

44 Docket No. 50–416. July 18, 2012. Accessible at ADAMS No. ML121210020. 




UNITED STATES 

NUCLEAR REGULATORY COMMISSION

WASHINGTON, DC 20555-0001

--------------------

OFFICIAL BUSINESS
NUREG-1437

Draft

Supplement 50

Generic Environmental Impact Statement for License Renewal of Nuclear Plants 

Regarding Grand Gulf Nuclear Station, Unit 1