Generic Environmental 

Impact Statement for License 

Renewal of Nuclear Plants

Supplement 55 

Regarding Braidwood Station, 

Units 1 and 2 

Final Report

Office of Nuclear Reactor Regulation

NUREG-1437

Supplement 55 
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Generic Environmental

Impact Statement for License 

Renewal of Nuclear Plants

Supplement 55 

Regarding Braidwood Station, 

Units 1 and 2

Final Report

Manuscript Completed: November 2015

Date Published: November 2015

Office of Nuclear Reactor Regulation

NUREG-1437

Supplement 55

iii

COVER SHEET

Responsible Agency: U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor

Regulation. There are no cooperating agencies involved in the preparation of this document.

Title: Generic Environmental Impact Statement for License Renewal of Nuclear Plants, 

Supplement 55, Regarding Braidwood Station, Units 1 and 2, Final Report (NUREG-1437). 

Braidwood Station (Braidwood), Units 1 and 2, are located in Will County, Illinois.

For additional information or copies of this document contact:

Division of License Renewal

U.S. Nuclear Regulatory Commission

Office of Nuclear Reactor Regulation

Mail Stop O-11F1

11555 Rockville Pike

Rockville, Maryland 20852

Phone: 1-800-368-5642, extension 6223

E-mail: richard.baum@nrc.gov

ABSTRACT

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

an application submitted by Exelon Generation Company, LLC (Exelon), to renew the operating 

license for Braidwood Station (Braidwood), Units 1 and 2, for an additional 20 years.

This SEIS includes the analysis that evaluates the environmental impacts of the proposed 

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

coal-integrated gasification combined cycle, natural gas combined cycle, combination 

alternative (wind power, natural gas combined cycle, and solar power), and purchased power.

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

environmental impacts of license renewal for Braidwood are not so great that preserving the

option of license renewal for energy-planning decisionmakers would be unreasonable. This 

recommendation is based on the following:

 the analysis and findings in NUREG–1437, Generic Environmental Impact

Statement for License Renewal of Nuclear Plants; 

 the Environmental Report submitted by Exelon; 

 consultation with Federal, State, local, and Tribal government agencies;

 the NRC staff’s environmental review; and

 consideration of public comments received during the scoping process and 

received on the draft SEIS.

Side bars indicate updates and changes since the development of the Draft 

Supplemental Environmental Impact Statement (DSEIS). 

v 

TABLE OF CONTENTS

ABSTRACT.............................................................................................................................. iii

FIGURES................................................................................................................................. xv

TABLES ................................................................................................................................ xvii

EXECUTIVE SUMMARY ........................................................................................................ xxi

ABBREVIATIONS AND ACRONYMS ................................................................................. xxvii

1.0 INTRODUCTION............................................................................................................. 1-1

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

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

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

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

1.5 Supplemental Environmental Impact Statement .................................................... 1-5

1.6 Decision to Be Supported by the SEIS................................................................... 1-5

1.7 Cooperating Agencies ........................................................................................... 1-6

1.8 Consultations......................................................................................................... 1-6

1.9 Correspondence .................................................................................................... 1-6

1.10 Status of Compliance............................................................................................. 1-6

1.11 Related Federal and State Activities ...................................................................... 1-7

1.12 References ............................................................................................................ 1-7

2.0 ALTERNATIVES INCLUDING THE PROPOSED ACTION............................................. 2-1

2.1 Proposed Action .................................................................................................... 2-1

2.1.1 Plant Operation During the License Renewal Term................................. 2-1

2.1.2 Refurbishment and Other Activities Associated With License 

Renewal.................................................................................................. 2-2

2.1.3 Termination of Nuclear Power Plant Operation and 

Decommissioning After the License Renewal Term ................................ 2-2

2.2 Alternatives............................................................................................................ 2-3

2.2.1 No-Action Alternative .............................................................................. 2-3

2.2.2 Replacement Power Alternatives ............................................................ 2-4

2.2.2.1 New Nuclear Alternative ....................................................... 2-10

2.2.2.2 Coal (Integrated Gasification Combined Cycle) 

Alternative............................................................................. 2-11

2.2.2.3 Natural Gas Combined Cycle Alternative.............................. 2-13

2.2.2.4 Combination of Interconnected Wind Farms, Solar 

Photovoltaic, and Natural Gas .............................................. 2-14

2.2.2.5 Purchased Power ................................................................. 2-17

2.3 Alternatives Considered but Dismissed................................................................ 2-17

2.3.1 Energy Conservation and Energy Efficiency ......................................... 2-17

2.3.2 Solar ..................................................................................................... 2-18
Table of Contents

vi

2.3.3 Wind ..................................................................................................... 2-18

2.3.3.1 Offshore Wind....................................................................... 2-19

2.3.3.2 Wind Power With Storage..................................................... 2-19

2.3.3.3 Conclusion Summary............................................................ 2-20

2.3.4 Biomass................................................................................................ 2-20

2.3.5 Hydroelectric......................................................................................... 2-20

2.3.6 Wave and Ocean Energy ...................................................................... 2-21

2.3.7 Fuel Cells.............................................................................................. 2-21

2.3.8 Delayed Retirement .............................................................................. 2-22

2.3.9 Geothermal........................................................................................... 2-22

2.3.10 Municipal Solid Waste........................................................................... 2-23

2.3.11 Oil-Fired Power..................................................................................... 2-23

2.3.12 Supercritical Pulverized Coal ................................................................ 2-23

2.4 Comparison of Alternatives.................................................................................. 2-24

2.5 References .......................................................................................................... 2-26

3.0 AFFECTED ENVIRONMENT.......................................................................................... 3-1

3.1 Description of Nuclear Power Plant Facilities and Operation ................................. 3-1

3.1.1 External Appearance and Setting............................................................ 3-1

3.1.2 Nuclear Reactor Systems ....................................................................... 3-4

3.1.3 Cooling and Auxiliary Water Systems ..................................................... 3-4

3.1.4 Radioactive Effluent, Waste, and Environmental Monitoring 

Programs .............................................................................................. 3-10

3.1.4.1 Liquid Waste Processing Systems........................................ 3-10

3.1.4.2 Gaseous Waste Processing System..................................... 3-12

3.1.4.3 Solid Waste Management..................................................... 3-13

3.1.4.4 Radioactive Waste Storage .................................................. 3-14

3.1.4.5 Radiological Environmental Monitoring Program................... 3-14

3.1.4.6 Reasonably Foreseeably Radiological Projects at 

Braidwood............................................................................. 3-15

3.1.5 Nonradiological Waste Management Systems ...................................... 3-15

3.1.6 Utility and Transportation Infrastructure ................................................ 3-16

3.1.6.1 Electricity .............................................................................. 3-16

3.1.6.2 Fuel ...................................................................................... 3-16

3.1.6.3 Water.................................................................................... 3-16

3.1.6.4 Transportation Systems........................................................ 3-16

3.1.6.5 Power Transmission Systems............................................... 3-16

3.1.7 Nuclear Power Plant Operation and Maintenance................................. 3-17

3.2 Land Use and Visual Resources.......................................................................... 3-17

3.2.1 Land Use .............................................................................................. 3-17

3.2.2 Visual Resources.................................................................................. 3-18
Table of Contents

vii

3.3 Meteorology, Climatology, Air Quality, and Noise ................................................ 3-18

3.3.1 Meteorology and Climatology................................................................ 3-18

3.3.2 Air Quality ............................................................................................. 3-20

3.3.3 Noise .................................................................................................... 3-22

3.4 Geologic Environment ......................................................................................... 3-23

3.4.1 Physiography and Geology ................................................................... 3-23

3.4.2 Soils...................................................................................................... 3-25

3.4.3 Seismic Setting ..................................................................................... 3-25

3.5 Water Resources................................................................................................. 3-25

3.5.1 Surface Water Resources ..................................................................... 3-25

3.5.1.1 Surface Water Hydrology...................................................... 3-25

3.5.1.2 Surface Water Use ............................................................... 3-27

3.5.1.3 Surface Water Quality and Effluents ..................................... 3-27

3.5.2 Groundwater Resources ....................................................................... 3-32

3.5.2.1 Site Description and Hydrogeology....................................... 3-32

3.5.2.2 Groundwater Use.................................................................. 3-35

3.5.2.3 Groundwater Quality............................................................. 3-38

3.6 Terrestrial Resources .......................................................................................... 3-41

3.6.1 Braidwood Ecoregion............................................................................ 3-41

3.6.2 Summary of Past Braidwood Site Surveys and Reports........................ 3-42

3.6.3 Braidwood Site...................................................................................... 3-43

3.6.3.1 Vegetation ............................................................................ 3-44

3.6.3.2 Animals................................................................................. 3-47

3.6.3.3 Important Species and Habitats ............................................ 3-48

3.7 Aquatic Resources............................................................................................... 3-49

3.7.1 Aquatic Ecosystem Descriptions ........................................................... 3-49

3.7.1.1 Kankakee River .................................................................... 3-49

3.7.1.2 Braidwood Cooling Pond ...................................................... 3-50

3.7.2 Aquatic Surveys and Monitoring............................................................ 3-51

3.7.2.1 Kankakee River .................................................................... 3-51

3.7.2.2 Braidwood Cooling Pond ...................................................... 3-54

3.7.3 Aquatic Communities near Braidwood .................................................. 3-54

3.7.3.1 Kankakee River .................................................................... 3-54

3.7.3.2 Braidwood Cooling Pond ...................................................... 3-70

3.7.4 Cooling Pond Fish Kill Events ............................................................... 3-75

3.7.5 Important Species and Habitats ............................................................ 3-76

3.7.5.1 State-Listed Species............................................................. 3-76

3.7.5.2 Important Habitats ................................................................ 3-79

3.7.6 Non-Native Species .............................................................................. 3-79
Table of Contents

viii

3.8 Federally Protected Species and Habitats ........................................................... 3-79

3.8.1 Action Areas ......................................................................................... 3-80

3.8.2 Federally Protected Species and Habitats Considered.......................... 3-81

3.9 Historic and Cultural Resources........................................................................... 3-88

3.9.1 Cultural Background ............................................................................. 3-90

3.9.2 Braidwood Historic and Cultural Resources .......................................... 3-92

3.10 Socioeconomics .................................................................................................. 3-92

3.10.1 Power Plant Employment and Expenditures ......................................... 3-93

3.10.2 Regional Economic Characteristics....................................................... 3-93

3.10.2.1 Employment and Income ...................................................... 3-94

3.10.2.2 Unemployment ..................................................................... 3-95

3.10.3 Demographic Characteristics ................................................................ 3-95

3.10.3.1 Transient Population............................................................. 3-97

3.10.3.2 Migrant Farm Workers .......................................................... 3-98

3.10.4 Housing and Community Services ...................................................... 3-100

3.10.4.1 Housing .............................................................................. 3-100

3.10.4.2 Education............................................................................ 3-100

3.10.4.3 Public Water Supply ........................................................... 3-100

3.10.5 Tax Revenues..................................................................................... 3-102

3.10.6 Local Transportation ........................................................................... 3-106

3.11 Human Health.................................................................................................... 3-107

3.11.1 Radiation Protection Program ............................................................. 3-107

3.11.2 Chemical Hazards............................................................................... 3-109

3.11.3 Microbiological Hazards...................................................................... 3-109

3.11.3.1 Thermophilic Microorganisms of Concern........................... 3-109

3.11.3.2 Prevalence of Waterborne Diseases Associated With 

Recreational Waters ........................................................... 3-110

3.11.4 Electromagnetic Fields........................................................................ 3-111

3.11.5 Other Hazards .................................................................................... 3-112

3.12 Environmental Justice........................................................................................ 3-112

3.12.1 Minority Population ............................................................................. 3-113

3.12.2 Low-Income Population....................................................................... 3-116

3.13 Waste Management and Pollution Prevention ................................................... 3-118

3.13.1 Radioactive Waste.............................................................................. 3-118

3.13.2 Nonradioactive Waste......................................................................... 3-118

3.14 References ........................................................................................................ 3-118
Table of Contents

ix

4.0 ENVIRONMENTAL CONSEQUENCES AND MITIGATING ACTIONS........................... 4-1

4.1 Evaluation of Braidwood License Renewal and Alternatives to License 

Renewal ................................................................................................................ 4-1

4.2 Land Use and Visual Resources............................................................................ 4-1

4.2.1 Proposed Action ..................................................................................... 4-1

4.2.2 No-Action Alternative .............................................................................. 4-2

4.2.2.1 Land Use ................................................................................ 4-2

4.2.2.2 Visual Resources.................................................................... 4-2

4.2.3 New Nuclear Alternative.......................................................................... 4-3

4.2.3.1 Land Use ................................................................................ 4-3

4.2.3.2 Visual Resources.................................................................... 4-3

4.2.4 Coal (Integrated Gasification Combined Cycle) Alternative ..................... 4-3

4.2.4.1 Land Use ................................................................................ 4-3

4.2.4.2 Visual Resources.................................................................... 4-3

4.2.5 Natural Gas Combined Cycle Alternative ................................................ 4-4

4.2.5.1 Land Use ................................................................................ 4-4

4.2.5.2 Visual Resources.................................................................... 4-4

4.2.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas............................................................................................. 4-4

4.2.6.1 Land Use ................................................................................ 4-4

4.2.6.2 Visual Resources.................................................................... 4-5

4.2.7 Purchased Power.................................................................................... 4-5

4.2.7.1 Land Use ................................................................................ 4-5

4.2.7.2 Visual Resources.................................................................... 4-5

4.3 Air Quality and Noise............................................................................................. 4-5

4.3.1 Proposed Action ..................................................................................... 4-5

4.3.1.1 Air Quality............................................................................... 4-6

4.3.1.2 Noise ...................................................................................... 4-6

4.3.2 No-Action Alternative .............................................................................. 4-6

4.3.2.1 Air Quality............................................................................... 4-6

4.3.2.2 Noise ...................................................................................... 4-7

4.3.3 New Nuclear Alternative.......................................................................... 4-7

4.3.3.1 Air Quality............................................................................... 4-7

4.3.3.2 Noise ...................................................................................... 4-9

4.3.4 Coal (Integrated Gasification Combined Cycle) Alternative ................... 4-10

4.3.4.1 Air Quality............................................................................. 4-10

4.3.4.2 Noise .................................................................................... 4-13

4.3.5 Natural Gas Combined Cycle Alternative .............................................. 4-13

4.3.5.1 Air Quality............................................................................. 4-13

4.3.5.2 Noise .................................................................................... 4-16
Table of Contents

x 

4.3.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas........................................................................................... 4-16

4.3.6.1 Air Quality............................................................................. 4-17

4.3.6.2 Noise .................................................................................... 4-18

4.3.7 Purchased Power.................................................................................. 4-20

4.3.7.1 Air Quality............................................................................. 4-20

4.3.7.2 Noise .................................................................................... 4-21

4.4 Geologic Environment ......................................................................................... 4-21

4.4.1 Proposed Action ................................................................................... 4-22

4.4.2 No-Action Alternative ............................................................................ 4-22

4.4.3 New Nuclear Alternative........................................................................ 4-23

4.4.4 Coal (Integrated Gasification Combined Cycle) Alternative ................... 4-23

4.4.5 Natural Gas Combined Cycle Alternative .............................................. 4-23

4.4.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas........................................................................................... 4-23

4.4.7 Purchased Power.................................................................................. 4-23

4.5 Water Resources................................................................................................. 4-23

4.5.1 Proposed Action ................................................................................... 4-24

4.5.1.1 Surface Water Resources..................................................... 4-24

4.5.1.2 Groundwater Resources....................................................... 4-26

4.5.2 No-Action Alternative ............................................................................ 4-28

4.5.2.1 Surface Water Resources..................................................... 4-28

4.5.2.2 Groundwater Resources....................................................... 4-28

4.5.3 New Nuclear Alternative........................................................................ 4-28

4.5.3.1 Surface Water Resources..................................................... 4-28

4.5.3.2 Groundwater Resources....................................................... 4-29

4.5.4 Coal (Integrated Gasification Combined Cycle) Alternative ................... 4-29

4.5.4.1 Surface Water Resources..................................................... 4-29

4.5.4.2 Groundwater Resources....................................................... 4-29

4.5.5 Natural Gas Combined Cycle Alternative .............................................. 4-29

4.5.5.1 Surface Water Resources..................................................... 4-29

4.5.5.2 Groundwater Resources....................................................... 4-29

4.5.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas........................................................................................... 4-30

4.5.6.1 Surface Water Resources..................................................... 4-30

4.5.6.2 Groundwater Resources....................................................... 4-30

4.5.7 Purchased Power.................................................................................. 4-30

4.5.7.1 Surface Water Resources..................................................... 4-30

4.5.7.2 Groundwater Resources....................................................... 4-30
Table of Contents

xi

4.6 Terrestrial Resources .......................................................................................... 4-30

4.6.1 Proposed Action ................................................................................... 4-30

4.6.1.1 GEIS Category 1 Issues ....................................................... 4-31

4.6.1.2 Impacts on Terrestrial Resources (Non-Cooling System 

Impacts)................................................................................ 4-31

4.6.1.3 Water Use Conflicts With Terrestrial Resources ................... 4-33

4.6.2 No-Action Alternative ............................................................................ 4-33

4.6.3 New Nuclear Alternative........................................................................ 4-34

4.6.4 Coal (Integrated Gasification Combined Cycle) Alternative ................... 4-34

4.6.5 Natural Gas Combined Cycle Alternative .............................................. 4-35

4.6.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas........................................................................................... 4-36

4.6.7 Purchased Power.................................................................................. 4-36

4.7 Aquatic Resources............................................................................................... 4-37

4.7.1 Proposed Action ................................................................................... 4-38

4.7.1.1 GEIS Category 1 Issues ....................................................... 4-38

4.7.1.2 Impingement and Entrainment of Aquatic Organisms ........... 4-38

4.7.1.3 Thermal Impacts on Aquatic Organisms ............................... 4-63

4.7.1.4 Water Use Conflicts With Aquatic Resources ....................... 4-68

4.7.2 No-Action Alternative ............................................................................ 4-68

4.7.3 New Nuclear Alternative........................................................................ 4-69

4.7.4 Coal (Integrated Gasification Combined Cycle) Alternative ................... 4-70

4.7.5 Natural Gas Combined Cycle Alternative .............................................. 4-70

4.7.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas........................................................................................... 4-71

4.7.7 Purchased Power.................................................................................. 4-71

4.8 Special Status Species and Habitats ................................................................... 4-71

4.8.1 Special Status Species and Habitats Impacts of License Renewal 

(Proposed Action) ................................................................................. 4-72

4.8.2 No-Action Alternative ............................................................................ 4-78

4.8.3 New Nuclear Alternative........................................................................ 4-79

4.8.4 Coal (Integrated Gasification Combined Cycle) Alternative ................... 4-79

4.8.5 Natural Gas Combined Cycle Alternative .............................................. 4-80

4.8.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas........................................................................................... 4-80

4.8.7 Purchased Power.................................................................................. 4-81

4.9 Historic and Cultural Resources........................................................................... 4-81

4.9.1 Proposed Action ................................................................................... 4-81

4.9.2 No-Action Alternative ............................................................................ 4-83

4.9.3 New Nuclear Alternative........................................................................ 4-83

4.9.4 Coal (Integrated Gasification Combined Cycle) Alternative ................... 4-84

4.9.5 Natural Gas Combined Cycle Alternative .............................................. 4-84
Table of Contents

xii

4.9.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas........................................................................................... 4-85

4.9.7 Purchased Power.................................................................................. 4-86

4.10 Socioeconomic .................................................................................................... 4-86

4.10.1 Proposed Action ................................................................................... 4-86

4.10.2 No-Action Alternative ............................................................................ 4-87

4.10.3 New Nuclear Alternative........................................................................ 4-87

4.10.4 Coal (Integrated Gasification Combined Cycle) Alternative ................... 4-89

4.10.5 Natural Gas Combined Cycle Alternative .............................................. 4-90

4.10.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas........................................................................................... 4-91

4.10.7 Purchased Power.................................................................................. 4-92

4.11 Human Health...................................................................................................... 4-93

4.11.1 Proposed Action ................................................................................... 4-93

4.11.1.1 Normal Operating Conditions................................................ 4-93

4.11.1.2 Environmental Impacts of Postulated Accidents.................... 4-97

4.11.1.3 Severe Accident Mitigation Alternatives (SAMAs)................. 4-99

4.11.2 No-Action Alternative .......................................................................... 4-104

4.11.3 New Nuclear Alternative...................................................................... 4-104

4.11.4 Coal (Integrated Gasification Combined Cycle) Alternative ................. 4-105

4.11.5 Natural Gas Combined Cycle Alternative ............................................ 4-105

4.11.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas......................................................................................... 4-106

4.11.7 Purchased Power................................................................................ 4-106

4.12 Environmental Justice........................................................................................ 4-106

4.12.1 Proposed Action ................................................................................. 4-107

4.12.2 Environmental Impacts of Alternatives to the Proposed Action............ 4-108

4.12.2.1 No-Action Alternative .......................................................... 4-109

4.12.2.2 New Nuclear Alternative ..................................................... 4-109

4.12.2.3 Coal (Integrated Gasification Combined Cycle) 

Alternative........................................................................... 4-109

4.12.2.4 Natural Gas Combined Cycle Alternative............................ 4-110

4.12.2.5 Combination of Interconnected Wind Farms, Solar 

Photovoltaic, and Natural Gas ............................................ 4-110

4.12.2.6 Purchased Power ............................................................... 4-111

4.13 Waste Management and Pollution Prevention ................................................... 4-112

4.13.1 Proposed Action ................................................................................. 4-112

4.13.1.1 10 CFR 51.23 (Continued Storage Rule) and 10 CFR 51, 

Subpart A, Table B-1 (License Renewal) ............................ 4-113

4.13.1.2 CLI-14-08: Holding That Revised 10 CFR 51.23 and 

NUREG-2157 Satisfy NRC’s NEPA Obligations for 

Continued Storage and Directing Staff to Account for 

Environmental Impacts In NUREG-2157............................. 4-115
Table of Contents

xiii

4.13.1.3 At-Reactor Storage............................................................. 4-115

4.13.1.4 Away-From-Reactor Storage .............................................. 4-116

4.13.1.5 Cumulative Impacts of Continued Storage.......................... 4-118

4.13.1.6 Conclusion.......................................................................... 4-118

4.13.2 No-Action Alternative .......................................................................... 4-119

4.13.3 New Nuclear Alternative...................................................................... 4-119

4.13.4 Coal (Integrated Gasification Combined Cycle) Alternative ................. 4-119

4.13.5 Natural Gas Combined Cycle Alternative ............................................ 4-120

4.13.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and 

Natural Gas......................................................................................... 4-120

4.13.7 Purchased Power................................................................................ 4-120

4.14 Evaluation of New and Potentially Significant Information.................................. 4-120

4.15 Impacts Common to All Alternatives .................................................................. 4-121

4.15.1 Fuel Cycles ......................................................................................... 4-121

4.15.1.1 Uranium Fuel Cycle ............................................................ 4-122

4.15.1.2 Replacement Power Fuel Cycles ........................................ 4-122

4.15.2 Terminating Power Plant Operations and Decommissioning............... 4-123

4.15.2.1 Existing Nuclear Power Plant (Proposed Action)................. 4-123

4.15.2.2 Replacement Power Plants................................................. 4-124

4.15.3 Greenhouse Gas Emissions and Climate Change .............................. 4-125

4.15.3.1 Greenhouse Gas Emissions From the Proposed Project 

and Alternatives.................................................................. 4-125

4.15.3.2 Existing Nuclear Power Plant (Proposed Action)................. 4-125

4.15.3.3 No-Action Alternative .......................................................... 4-126

4.15.3.4 New Nuclear Alternative ..................................................... 4-126

4.15.3.5 Coal (Integrated Gasification Combined Cycle) 

Alternative........................................................................... 4-127

4.15.3.6 Natural Gas Combined Cycle Alternative............................ 4-127

4.15.3.7 Combination of Interconnected Wind Farms, Solar 

Photovoltaic, and Natural Gas ............................................ 4-127

4.15.3.8 Purchased Power ............................................................... 4-127

4.15.3.9 Summary of GHG Emissions From the Proposed Action 

and Alternatives.................................................................. 4-128

4.15.3.10 Climate Change Impacts to Resource Areas ...................... 4-128

4.16 Cumulative Impacts of the Proposed Action....................................................... 4-133

4.16.1 Air Quality and Noise .......................................................................... 4-134

4.16.1.1 Air Quality........................................................................... 4-134

4.16.1.2 Noise .................................................................................. 4-136

4.16.2 Geology and Soils............................................................................... 4-137
Table of Contents

xiv

4.16.3 Water Resources ................................................................................ 4-138

4.16.3.1 Surface Water Resources................................................... 4-138

4.16.3.2 Ground Water Resources ................................................... 4-140

4.16.3.3 Water Resource Conclusion Summary ............................... 4-142

4.16.4 Terrestrial Ecology.............................................................................. 4-142

4.16.5 Aquatic Ecology .................................................................................. 4-144

4.16.6 Historic and Cultural Resources.......................................................... 4-147

4.16.7 Socioeconomics.................................................................................. 4-147

4.16.8 Human Health..................................................................................... 4-149

4.16.9 Environmental Justice......................................................................... 4-150

4.16.10 Waste Management............................................................................ 4-151

4.16.11 Global Climate Change....................................................................... 4-152

4.16.12 Summary of Cumulative Impacts ........................................................ 4-154

4.17 Resource Commitments Associated With the Proposed Action ......................... 4-156

4.17.1 Unavoidable Adverse Environmental Impacts ..................................... 4-156

4.17.2 Relationship Between Short-Term Use of the Environment and 

Long-Term Productivity....................................................................... 4-157

4.17.3 Irreversible and Irretrievable Commitments of Resources ................... 4-158

4.18 References ........................................................................................................ 4-158

5.0 CONCLUSION ................................................................................................................ 5-1

5.1 Environmental Impacts of License Renewal........................................................... 5-1

5.2 Comparison of Alternatives.................................................................................... 5-1

5.3 Recommendation................................................................................................... 5-2

6.0 LIST OF PREPARERS ................................................................................................... 6-1

7.0 LIST OF AGENCIES, ORGANIZATIONS, AND PERSONS TO WHOM COPIES 

OF THIS SEIS ARE SENT .............................................................................................. 7-1

8.0 INDEX............................................................................................................................. 8-1

APPENDIX A COMMENTS RECEIVED ON THE BRAIDWOOD STATION 

ENVIRONMENTAL REVIEW ......................................................................... A-1

APPENDIX B APPLICABLE REGULATIONS, LAWS, AND AGREEMENTS...................... B-1

APPENDIX C CONSULTATION CORRESPONDENCE....................................................... C-1

APPENDIX D CHRONOLOGY OF ENVIRONMENTAL REVIEW 

CORRESPONDENCE.................................................................................... D-1

APPENDIX E ACTIONS AND PROJECTS CONSIDERED IN CUMULATIVE 

ANALYSIS ..................................................................................................... E-1

APPENDIX F U.S. NUCLEAR REGULATORY COMMISSION STAFF EVALUATION 

OF SEVERE ACCIDENT MITIGATION ALTERNATIVES FOR 

BRAIDWOOD STATION, UNITS 1 AND 2, IN SUPPORT OF LICENSE 

RENEWAL APPLICATION REVIEW ............................................................. F-1
Table of Contents

xv 

FIGURES

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

Figure 1–2. Environmental Issues Evaluated for License Renewal .................................... 1-4

Figure 2–1. Territories of the MISO and PJM Interconnection............................................ 2-5

Figure 3–1. Braidwood 50-mi (80-km) Radius Map ............................................................ 3-2

Figure 3–2. Braidwood 6-mi (10-km) Radius Map .............................................................. 3-3

Figure 3–3. Closed-Cycle Cooling System With Cooling Pond........................................... 3-5

Figure 3–4. Braidwood Cooling Pond and Kankakee River Blowdown Line ....................... 3-6

Figure 3–5. Braidwood Plant Layout .................................................................................. 3-7

Figure 3–6. Braidwood Site Topography.......................................................................... 3-24

Figure 3–7. Kankakee River Basin................................................................................... 3-26

Figure 3–8. Braidwood NPDES Outfall Locations ............................................................ 3-29

Figure 3–9. Illustrative Geologic Cross-Section................................................................ 3-33

Figure 3–10. Generalized Geologic Column of Deep Aquifer............................................. 3-34

Figure 3–11. Public and Private Water Wells Near Braidwood Station............................... 3-37

Figure 3–12. Tritium Concentrations in the Upper Aquifer in 2006 ..................................... 3-39

Figure 3–13. Tritium Concentrations in the Upper Aquifer in 2012 ..................................... 3-40

Figure 3–14. Mazonia–Braidwood Fish and Wildlife Area .................................................. 3-46

Figure 3–15. Kankakee River Fish Sampling Locations ..................................................... 3-53

Figure 3–16. Comparison of Relative Abundance of Most Prevalent Fish Families in 

Historic and Recent Kankakee River Monitoring Samples............................. 3-64

Figure 3–17. Braidwood Mussel Sampling Locations, 2009 Survey ................................... 3-68

Figure 3–18. Cooling Pond Fish Sampling Locations......................................................... 3-73

Figure 3–19. Braidwood Site Property ............................................................................... 3-89

Figure 3–20. Minority Block Groups Within a 50-mi Radius of Braidwood........................ 3-115

Figure 3–21. Low-Income Block Groups Within a 50-mi Radius of Braidwood ................. 3-117

Figure 4–1. Braidwood Ichthyoplankton Sampling Locations ........................................... 4-50

Figure 4–2. Species Richness During Preoperational and Recent Operational 

Periods ......................................................................................................... 4-58

Figure 4–3. Relative Abundance of Most Prevalent Fish Families in the Kankakee 

River Over Time............................................................................................ 4-59

Figure 4–4. Changes in Deep Sandstone Wells in Northeast Illinois Between 2000 

and 2007..................................................................................................... 4-141

Table of Contents

xvii

TABLES

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

License Renewal............................................................................................ xxiii

Table 2–1. Summary of Replacement Power Alternatives and Key Characteristics 

Considered in Depth ....................................................................................... 2-8

Table 2–2. Summary of Environmental Impacts of Proposed Action and 

Alternatives ................................................................................................... 2-25

Table 3–1. Braidwood Site Acreage by Land Use........................................................... 3-17

Table 3–2. Wind Direction, Wind Speed, and Precipitation Data for 2008 Through 

2012 from the Braidwood Tower ................................................................... 3-19

Table 3–3. Estimated Air Emissions for Permitted Combustion Sources at 

Braidwood..................................................................................................... 3-21

Table 3–4. Common Noise Sources and Noise Levels ................................................... 3-22

Table 3–5. Annual Surface Water Withdrawals and Return Discharges to the 

Kankakee River, Braidwood Station.............................................................. 3-27

Table 3–6. National Pollutant Discharge Elimination System-Permitted Outfalls, 

Braidwood Station......................................................................................... 3-30

Table 3–7. Wildlife in the Illinois and Indiana Prairies Level IV Ecoregion....................... 3-42

Table 3–8. Braidwood Aquatic Survey Sampling Locations ............................................ 3-52

Table 3–9. Fish Collected in the Kankakee River and Horse Creek by Family and 

Species, 1981–1982 ..................................................................................... 3-58

Table 3–10. Fish Collected in the Kankakee River Monitoring Samples by Family 

and Species, 2009–2013 .............................................................................. 3-60

Table 3–11. Mussels Collected in the Kankakee River Near the Braidwood 

Discharge by Species, 2008 and 2015.......................................................... 3-66

Table 3–12. Mussels Collected in the Kankakee River Near the Braidwood 

Discharge by Location, August 2008............................................................. 3-67

Table 3–13. Historic and Recent Mussel Species Collected in the Kankakee River.......... 3-69

Table 3–14. Fish Collected During Braidwood Cooling Pond Surveys by Relative 

Abundance, 1980–2007................................................................................ 3-71

Table 3–15. Fish Collected During Braidwood Cooling Pond Surveys by Relative 

Abundance, 2009–2012................................................................................ 3-74

Table 3–16. State-Listed Aquatic Species in the Kankakee River Basin ........................... 3-77

Table 3–17. Federally Listed Species in Will County, Illinois............................................. 3-82

Table 3–18. Exelon Generation Employees Residence by County ................................... 3-93

Table 3–19. Employment by Industry in the Braidwood ROI (5-year estimates 

2008–2012)................................................................................................... 3-94

Table 3–20. Top 10 Employers in Will County in 2012...................................................... 3-95

Table 3–21. Estimated Income Information for the Braidwood ROI (5-year estimates 

2008–2012)................................................................................................... 3-95

Table 3–22. Population and Percent Growth in Braidwood ROI Counties 

1970–2010, 2012 (estimated), and Projected for 2020–2060........................ 3-96
Table of Contents

xviii

Table 3–23. Illinois Department of Commerce and Economic Opportunity (DCEO) 

Population Projections for 2000–2030........................................................... 3-97

Table 3–24. Demographic Profile of the Population in the Braidwood ROI in 2010........... 3-97

Table 3–25. 2007-2011 Estimated Seasonal Housing in Counties Located Within 

50 Miles of Braidwood................................................................................... 3-98

Table 3–26. Migrant Farm Workers and Temporary Farm Labor in Counties Located 

Within 50 Miles of Braidwood ........................................................................ 3-99

Table 3–27. Housing in the Braidwood ROI (2008−2012, 5-year estimate)..................... 3-100

Table 3–28. Local Public Water Supply Systems (in million gallons per day (mgd))........ 3-101

Table 3–29. PIAT Payments and Recipients, 2008......................................................... 3-102

Table 3–30. Property Tax Payment Comparison, All Taxing Districts Combined ............ 3-103

Table 3–31. Property Tax Payment Comparison, Reed-Custer School District 255U ..... 3-104

Table 3–32. 2011 Property Tax Payment Comparison, Each Taxing District 

Individually .................................................................................................. 3-105

Table 3–33. 2012 Property Tax Payment Comparison, Each Taxing District 

Individually .................................................................................................. 3-106

Table 3–34. Major Commuting Routes in the Vicinity of Braidwood: 2012 Average 

Annual Daily Traffic Count........................................................................... 3-107

Table 4–1. Land Use and Visual Resource Issues............................................................ 4-2

Table 4–2. Air Quality and Noise ...................................................................................... 4-6

Table 4–3. Estimated Direct Air Emissions From Operation of the Proposed Action 

and Alternatives (Ton/Year) .......................................................................... 4-20

Table 4–4. Geology and Soils Issues.............................................................................. 4-22

Table 4–5. Surface Water Resources Issues.................................................................. 4-25

Table 4–6. Groundwater Issues...................................................................................... 4-26

Table 4–7. Terrestrial Resource Issues .......................................................................... 4-31

Table 4–8. Aquatic Resource Issues .............................................................................. 4-37

Table 4–9. Estimated Fish Impingement by Abundance, Dec. 1980–Feb. 1981 ............. 4-41

Table 4–10. Relative Abundance of Fish Families Collected in Kankakee River 

Sampling, 1981–1982, and Impingement Sampling, 1980–1981................... 4-42

Table 4–11. Fish Collected in Impingement Samples by Abundance, 

Oct. 1988–Oct. 1989..................................................................................... 4-44

Table 4–12. Fish Collected in Impingement Samples by Abundance, 

April–June 1991............................................................................................ 4-48

Table 4–13. Summary of Eggs Collected in Entrainment Samples, 1988.......................... 4-52

Table 4–14. Numbers and Relative Abundance of Larvae Collected in Entrainment 

Samples by Family and Location, 1988......................................................... 4-53

Table 4–15. Estimated Ichthyoplankton Drift and Entrainment, 1988................................ 4-54

Table 4–16. Host Fish of Common Kankakee River Mussels............................................ 4-60

Table 4–17. Special Status Species and Habitat Issues ................................................... 4-72

Table 4–18. Federally Listed Species in Will County, Illinois............................................. 4-78

Table 4–19. Category 1 Socioeconomic NEPA Issues Affected by License Renewal ....... 4-86

Table 4–20. Human Health Issues.................................................................................... 4-93
Table of Contents

xix

Table 4–21. Issues Related to Postulated Accidents ........................................................ 4-98

Table 4–22. Braidwood Core Damage Frequency (CDF) for Internal Events .................. 4-100

Table 4–23. Breakdown of Population Dose and Offsite Economic Cost by 

Containment Release Mode........................................................................ 4-101

Table 4–24. Waste Management Issues......................................................................... 4-112

Table 4–25. Issues Related to the Uranium Fuel Cycle .................................................. 4-122

Table 4–26. Issues Related to Decommissioning ........................................................... 4-124

Table 4–27. Estimated GHG Emissions From Operations at Braidwood Station............. 4-126

Table 4–28. Direct Uncontrolled GHG Emissions From Operation of the Proposed 

Action and Alternatives ............................................................................... 4-128

Table 4–29. Comparison of GHG Emission Inventories.................................................. 4-153

Table 4–30. Summary of Cumulative Impacts on Resource Areas ................................. 4-155

Table 6–1. List of Preparers.............................................................................................. 6-2

Table A–1. Individuals Providing Comments During the Scoping Comment Period........... A-2

Table A–2. Individuals Providing Comments During the Draft SEIS Comment 

Period ........................................................................................................... A-17

Table B–1. Federal, State, and Local Laws and Other Requirements ............................... B-2

Table B–2. Licenses and Permits...................................................................................... B-7

Table C–1. NHPA Correspondence................................................................................... C-2

Table C–2. Section 7 Consultation Correspondence ......................................................... C-6

Table D–1. Environmental Review Correspondence ......................................................... D-2

Table E–1. Projects Considered in Cumulative Impact Analysis........................................ E-2

Table F–1. Braidwood Core Damage Frequency (CDF) for Internal Events ...................... F-2

Table F–2. Breakdown of Population Dose and Offsite Economic Cost by 

Containment Release Mode............................................................................ F-4

Table F–3. Summary of Major PRA Models and Corresponding CDF and 

LERF Results.................................................................................................. F-5

Table F–4(a). Major Braidwood Unit 1 Contributors to Fire CDF ......................................... F-11

Table F–4(b). Major Braidwood Unit 2 Contributors to Fire CDF ......................................... F-12

Table F–5. SAMA Cost and Benefit Screening Analysis for Braidwood Station............... F-27

xxi

EXECUTIVE SUMMARY

BACKGROUND

By letter dated May 29, 2013, Exelon Generation Company, LLC (Exelon), submitted an 

application to the U.S. Nuclear Regulatory Commission (NRC) to issue renewed operating 

licenses for Braidwood Station, Units 1 and 2 (Braidwood), for an additional 20-year period.

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

renewal of a power reactor operating license requires preparation of an environmental impact 

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

connection with the renewal of an operating license, the NRC shall prepare an EIS, which is a 

supplement to the Commission’s NUREG-1437, Generic Environmental Impact Statement

(GEIS) for License Renewal of Nuclear Plants, Revision 1. 

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

process described in 10 CFR Part 51, “Environmental protection regulations for domestic 

licensing and related regulatory functions,” by publishing a notice of intent to prepare a 

supplemental EIS (SEIS) and conduct scoping. In preparation of this SEIS for Braidwood, 

the NRC staff performed the following:

 conducted public scoping meetings on August 21, 2013, in Fossil Ridge 

library in Will County, Illinois;

 conducted a site audit at Braidwood on November 19, 2013;

 reviewed Exelon’s Environmental Report (ER) and compared it to the GEIS; 

 consulted with Federal, state, and local agencies;

 conducted a review of the issues following the guidance set forth in 

NUREG-1555, Standard Review Plans for Environmental Reviews for

Nuclear Power Plants, Supplement 1, Revision 1: Operating License 

Renewal; 

 considered public comments received during the scoping process; and

 considered public comments received on the draft SEIS. 

PROPOSED FEDERAL ACTION

Exelon initiated the proposed Federal action—issuance of renewed power reactor operating 

licenses—by submitting an application for license renewal of Braidwood, for which the existing 

licenses (NPF-72 and NPF-77) expire on October 17, 2026, and December 18, 2027, 

respectively. The NRC’s Federal action is the decision whether or not to renew the licenses for 

an additional 20 years. In accordance with 10 CFR 2.109, if a licensee of a nuclear power plant 

files an application to renew an operating license at least 5 years before the expiration date of 

that license, the existing license will not be deemed to have expired until the safety and 

environmental reviews are completed and the NRC has made a final decision to either deny 

the application or issue a renewed license for the additional 20 years.

PURPOSE AND NEED FOR THE PROPOSED FEDERAL ACTION

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

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

xxii

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

determined by other energy-planning decisionmakers, such as state, utility (plant owner), and, 

where authorized, Federal agencies (other than NRC). This definition of purpose and need 

reflects the NRC’s recognition that, unless there are findings in the safety review required by the 

Atomic Energy Act or findings in the National Environmental Policy Act (NEPA) environmental 

analysis that would lead the NRC to reject a license renewal application, the NRC does not 

have a role in the energy-planning decisions as to whether a particular nuclear power plant 

should continue to operate.

ENVIRONMENTAL IMPACTS OF LICENSE RENEWAL

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

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

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

criteria:

 The environmental impacts associated with the issue 

are determined to apply either to all plants or, for 

some issues, to plants having a specific type of 

cooling system or other specified plant or site 

characteristics. 

 A single significance level (i.e., SMALL, MODERATE, 

or LARGE) has been assigned to the impacts, except 

for collective offsite radiological impacts from the fuel 

cycle and from high-level waste and spent fuel

disposal.

 Mitigation of adverse impacts associated with the 

issue is considered in the analysis, and it has been 

determined that additional plant-specific mitigation 

measures are likely not to be sufficiently beneficial 

to warrant implementation.

For Category 1 issues, no additional site-specific analysis is 

required in this SEIS unless new and significant information is identified. Section 4.14 of this 

SEIS presents the process for identifying new and significant information. Site-specific issues 

(Category 2) are those that do not meet one or more of the criteria for Category 1 issues; 

therefore, an additional site-specific review for these non-generic issues is required, and the 

results are documented in the SEIS.

Neither Exelon nor the NRC identified information that is both new and significant related to 

Category 1 issues that would call into question the conclusions in the GEIS. This conclusion is 

supported by the NRC’s review of the applicant’s ER and other documentation relevant to the 

applicant’s activities, the public scoping process and substantive comments raised, and the 

findings from the environmental site audit conducted by the NRC staff. The NRC staff, 

therefore, relies upon the conclusions of the GEIS for all Category 1 issues applicable 

to Braidwood.

Table ES-1 summarizes the Category 2 issues relevant to Braidwood, as well as the NRC staff’s 

findings related to those issues. If the NRC staff determined that there were no Category 2 

issues applicable for a particular resource area, the findings of the GEIS, as documented in 

Appendix B to Subpart A of 10 CFR Part 51, are incorporated for that resource area.

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

xxiii

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

of License Renewal

Resource Area Relevant Category 2 Issues Impacts

Surface Water Resources Surface water use conflicts SMALL

Groundwater Resources Radionuclides released to 

groundwater

SMALL

Terrestrial Resources Effects on terrestrial resources 

(noncooling system impacts)

Water use conflicts with terrestrial 

resources (plants with cooling ponds 

or cooling towers using makeup 

water from a river)

SMALL

SMALL

Aquatic Resources Impingement and entrainment

of aquatic organisms

Thermal impacts on 

aquatic organisms

Water use conflicts with 

aquatic resources

SMALL to MODERATE (a)

SMALL to MODERATE (b)

SMALL

Special Status Species Threatened or endangered species No effect to May affect, but 

not likely to adversely affect (c)

Historic and Cultural Historic and cultural resources No adverse effect (d)

Human Health Microbiological hazards to the 

public health

Electric shock hazards

SMALL

SMALL

Environmental Justice Minority and low-income populations See note below (e)
Executive Summary

xxiv

Resource Area Relevant Category 2 Issues Impacts

Cumulative Impacts Surface Water

Ground Water

Terrestrial resources

Aquatic resources

Environmental Justice

Global Climate Change

All other resource areas

SMALL to MODERATE

MODERATE to LARGE

MODERATE to LARGE

MODERATE

See note below (e)

MODERATE

SMALL

(a) Impingement and entrainment effects would be SMALL for aquatic resources in the Kankakee River as a whole. 

Impacts to cyprinids, especially uncommon cyprinids (pallid shiner (Notropis amnis), mimic shiner (N. volucellus), 

and ghost shiner (N. buchanani)); darters; and Percina spp. would be MODERATE. The NRC cannot make a 

determination on the impact of impingement and entrainment on the aquatic resources in the cooling pond because 

no studies exist on impingement and entrainment at the lake screen house.

(b) Thermal effects would be SMALL for aquatic resources in the Kankakee River and SMALL to MODERATE for 

aquatic resources in the cooling pond. MODERATE impacts would primarily be experienced by gizzard shad 

(Dorosoma cepedianum) and other nonstocked and species with low tolerance to heat.

(c) For Federally protected species, the NRC reports the effects from continued operation of Braidwood during the 

license renewal period in terms of its Endangered Species Act (ESA) findings of “no effect,” “may affect, but not 

likely to adversely affect,” or “may affect, and is likely to adversely affect.” 

(d) The National Historic Preservation Act of 1966, as amended (NHPA) requires Federal agencies to consider the 

effects of their undertakings on historic properties.

(e) There would be no disproportionately high and adverse impacts to minority and low-income populations and 

subsistence consumption from continued operation of Braidwood during the license renewal period and from 

cumulative impacts.

SEVERE ACCIDENT MITIGATION ALTERNATIVES

Since the staff had not previously considered severe accident mitigation alternatives (SAMAs) 

for Braidwood in an environment impact statement or related supplement or in an environmental 

assessment (to reduce the likelihood or potential consequences of a variety of highly 

uncommon but potentially serious accidents at Braidwood), 10 CFR 51.53(c)(3)(ii)(L) requires 

that a consideration of alternatives to mitigate severe accidents must be provided in the course 

of the license renewal review. SAMAs are potential ways to reduce the risk or potential impacts 

of uncommon, but potentially severe accidents, and they may include changes to plant 

components, systems, procedures, and training.

The NRC staff reviewed Exelon’s ER evaluation of potential SAMAs. Based on the staff’s 

review, the NRC staff concluded that none of the potentially cost-beneficial SAMAs relate to 

adequately managing the effects of aging during the period of extended operation. Therefore, 

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

“Requirements for renewal of operating licenses for nuclear power plants.”

ALTERNATIVES

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

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

xxv 

Braidwood operating license (the no-action alternative). The feasible and commercially viable 

replacement power alternatives considered were:

 new nuclear,

 coal-integrated gasification combined cycle (IGCC),

 natural gas combined-cycle (NGCC),

 combination alternative (wind power, natural gas combined cycle, and solar 

power), and

 purchased power.

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

to the license renewal of Braidwood; these were later dismissed because of technical, resource 

availability, or commercial limitations that currently exist and that the NRC staff believes are 

likely to continue to exist when the existing Braidwood licenses expire. The no action alternative 

and the effects it would have were also considered by the NRC staff.

Where possible, the NRC staff evaluated potential environmental impacts for these alternatives

located both at the Braidwood site and at some other unspecified alternate location. 

Alternatives considered, but dismissed, were:

 energy efficiency and conservation,

 solar power,

 wind power,

 biomass,

 hydroelectric power,

 wave and ocean energy,

 fuel cells,

 delayed retirement,

 geothermal power,

 municipal solid waste, 

 petroleum, and

 supercritical pulverized coal (SCPC).

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

evaluating impacts from license renewal.

RECOMMENDATION

The NRC staff’s recommendation is that the adverse environmental impacts of license renewal 

for Braidwood are not so great that preserving the option of license renewal for energy-planning 

decisionmakers would be unreasonable. This recommendation is based on the following:

 the analyses and findings in the GEIS; 

 the ER submitted by Exelon;

 the NRC staff’s consultation with Federal, state, and local agencies;
Executive Summary

xxvi 

 the NRC staff’s independent environmental review; and

 the NRC staff’s consideration of public comments received during the scoping

process and received on the draft SEIS. 
xxvii 

ABBREVIATIONS AND ACRONYMS

°C degree(s) Celsius

°F degree(s) Fahrenheit

AADT average annual daily traffic

ac acre(s)

ACC averted cleanup and decontamination costs

ACHP Advisory Council on Historic Preservation

ACS American Community Survey

ADAMS Agencywide Documents Access and Management System

AEA Atomic Energy Act of 1954

AEC U.S. Atomic Energy Commission

AEL Alternative Energy Law

AFW auxiliary feedwater

ALARA as low as is reasonably achievable

AMSAC ATWS mitigating system actuation circuitry

ANS American Nuclear Society

ANSI American National Standards Institute

AOC averted offsite property damage costs

AOE averted occupational exposure

AOSC averted onsite costs

AP auxiliary power

APE area of potential effect, averted public exposure

AQCR Air Quality Control Region

ASA Acoustical Society of America

ASME American Society of Mechanical Engineers

ATWS anticipated transient(s) without scram

AWEA American Wind Energy Association

AWT Association of Water Technologies

BACT best available control technology

BEA Bureau of Economic Analysis

BGEPA Bald and Golden Eagle Protection Act

BLH BLH Technologies, Inc.

BLM Bureau of Land Management

BLS Bureau of Labor Statistics
Abbreviations and Acronyms

xxviii 

BMP best management practice

BOEM Bureau of Ocean Energy Management

BP before present

Braidwood Braidwood Station, Units 1 and 2

BSER best system of emission reduction

CAA Clean Air Act, as amended through 1990

CAES compressed air energy storage

CAIR Clean Air Interstate Rule

Callaway Unit 2 Callaway Nuclear Power Plant Unit 2

CAP Community Advisory Panel

CCS carbon capture and sequestration/storage

CCW component cooling water

CDC Centers for Disease Control and Prevention

CDF core damage frequency

CDII Channahon Dresden Island Illinois

CDL Cropland Data Layer

CEC Commission for Environmental Cooperation

CED Center for Economic Development

CEQ Council on Environmental Quality

CET containment event tree

CFE early containment failure

CFR Code of Federal Regulations

cfs cubic foot (feet) per second

CH4 methane

cm centimeter(s)

CMA Chicago Metropolitan Area

CMAP Chicago Metropolitan Agency for Planning

CO carbon monoxide

CO2 carbon dioxide

CO2/MWh carbon dioxide per megawatt hour

CO2e carbon dioxide equivalent(s)

COE cost of enhancement

COL Combined License

ComEd Commonwealth Edison Company

CPI Consumer Price Index
Abbreviations and Acronyms

xxix

CPUE catch-per-unit-effort

CRA Conestoga-Rovers & Associates

CRMP Cultural Resources Management Plan

CSAPR Cross-State Air Pollution Rule

Cs cesium

CsI cesium iodide

CsOH cesium hydroxide

CSP concentrating solar power

CUSD Community Unit School District

CVCS chemical and volume control system

CWA Clean Water Act of 1972

CWS cooling water system

DAW dry active waste

dB decibel(s)

dBA decibels adjusted

DBA design-basis accident

DCEO Illinois Department of Commerce and Economic Opportunity

DLOOP dual unit loss(es) of offsite power

DMR Discharge Monitoring Report

DMS Diverse Mitigation System

DNPS Dresden Nuclear Power Station

DNR [Illinois] Department of Natural Resources

DO dissolved oxygen

DOE U.S. Department of Energy

DOI digital object identifier

DSEIS draft supplemental environmental impact statement

DSIRE Database of State Incentives for Renewables & Efficiency

DSM demand-side management

DTS dry transfer system

E&E Ecology and Environment, Inc.

E.O. Executive Order

EA environmental assessment

EAV equalized assessed value

ECCS emergency core cooling system

EcoCAT Ecological Compliance Assessment Tool
Abbreviations and Acronyms

xxx 

EDPR EDP Renewables

EFH Essential Fish Habitat

EIA Energy Information Administration (of DOE)

EIS environmental impact statement

ELF extremely low frequency

Elv. Elevation

EMF electromagnetic field

EPA U.S. Environmental Protection Agency

EPAct Energy Policy Act

EPCRA Emergency Planning and Community Right-to-Know Act of 1986

EPRI Electric Power Research Institute

EPT Ephemeroptera, Plecoptera, and Trichoptera

EPZ emergency planning zone

ER Environmental Report

ERC Energy Recovery Council

ESA Endangered Species Act of 1973, as amended

ESF engineered safety feature

ESFAS engineered safety features actuation system

ESI Ecological Specialists, Inc.

ESP early site permit

ESW emergency service water

ET Earth Tech, Inc.

Exelon Exelon Generation Company, LLC

F&O fact and observation

FAQ frequently asked question

FCT Fuel Cell Technologies

FE Federally endangered

FEMA Federal Emergency Management Agency

FERC Federal Energy Regulatory Commission

Fermi Unit 3 Enrico Fermi Atomic Power Plant, Unit 3

FES Final Environmental Statement

FES-C Final Environmental Statement for Braidwood Construction

FES-O Final Environmental Statement for Braidwood Operation

FESOP Federally Enforceable State Operating Permit

FHA Fuel Handling Accident
Abbreviations and Acronyms

xxxi 

FIVE fire-induced vulnerability evaluation

FPIE Full Power Internal Events

fps foot (feet) per second

FR Federal Register

FRA Federal Railroad Administration

FRN Federal Register notice

FSEIS Final Supplemental Environmental Impact Statement

ft foot (feet)

ft3 cubic foot (feet)

FW feedwater

FWS U.S. Fish and Wildlife Service

g Ceq/kWh gram(s) of carbon equivalent per kilowatt-hour

gal gallon(s)

GE General Electric

GEIS Generic Environmental Impact Statement for License Renewal of 

Nuclear Plants, NUREG–1437

GHG greenhouse gas

GI gastrointestinal, generic issue

GL generic letter

gpd gallon(s) per day

gpm gallon(s) per minute

GWP global warming potential

GWPS gaseous waste processing system

H2O water

ha hectare(s)

ha/MW hectare(s) per megawatt

HAI healthcare-associated infections

HCLPF high confidence in low probability of failure

HDPE high density polyethylene

HDR HDR Engineering, Inc.

HEP human error probability

HFC hydrofluorocarbon

HFE human failure event

HFO high winds, floods, and other

HIC high-integrity container
Abbreviations and Acronyms

xxxii 

HMTA Hazardous Materials Transportation Act of 1975

HRA human reliability analysis (analyses)

HRSG heat recovery steam generator

HSR high-speed rail

HTGR high-temperature gas-cooled reactor

HUD U.S. Department of Housing and Urban Development

HX heat exchanger

IAC Illinois Administrative Code

IBI Index of Biological Integrity

IBRC Indiana Business Research Center

ICEC Illinois Clean Energy Coalition

IDNR Illinois Department of Natural Resources

IDOT Illinois Department of Transportation

IDPH Illinois Department of Public Health

IEA International Energy Agency

IEEE Institute of Electrical and Electronics Engineers, Inc.

IEMA Illinois Emergency Management Agency

IEPA Illinois Environmental Protection Agency

IGCC integrated gasification combined cycle

IGNN Illinois Government News Network

IHPA Illinois Historic Preservation Agency

ILCS Illinois Compiled Statutes

ILGA Illinois General Assembly 

INAI Illinois Natural Areas Inventory

INDNR Indiana Department of Natural Resources

INEEL Idaho National Engineering and Environmental Laboratory

INHS Illinois Natural History Survey

IPA integrated plant assessment

IPaC Information, Planning, and Conservation System

IPCC Intergovernmental Panel on Climate Change

IPE individual plant examination

IPEEE individual plant examination(s) of external events

IRSF Interim Radwaste Storage Facility

ISBE Illinois State Board of Education

ISFSI independent spent fuel storage installation
Abbreviations and Acronyms

xxxiii 

ISGS Illinois State Geological Survey

ISLOCA interfacing-systems loss-of-coolant accident

ISM Illinois State Museum

ISO independent [transmission] system operator, 

International Organization for Standardization

ITA Illinois Transportation Archaeological Research Program

JHEP joint human error probability

JOAAP Joliet Army Ammunition Plant

kg kilogram(s)

kHz kilohertz

km kilometer(s)

km2 square kilometer(s)

kV kilovolt(s)

kW kilowatt(s)

kWe kilowatt(s) electrical

kWh kilowatt hour(s)

kWh/m2

/day kilowatt hour(s) per square meter per day

L liter(s) 

L/min liter(s) per minute

L/sec liter(s) per second

lb pound(s)

Ldn day-night average sound level—the 24-hour A-weighted 

equivalent sound level, with a 10-decibel penalty applied 

to nighttime levels

LER large, early release

LERF large early release frequency

LLC limited liability company

LLRW low-level radioactive waste

LLW low-level [radioactive] waste

LMFW loss of main feedwater

LOCA loss-of-coolant accident

LOE line(s) of evidence

LOOP loss(es) of offsite power

LOS level(s) of service

Lpd liter(s) per day

LRA license renewal application
Abbreviations and Acronyms

xxxiv 

LRMP land resource management plan

LRWS liquid radwaste system

m meter(s)

m/s meter(s) per second

m3 cubic meter(s)

m3

/d cubic meter(s) per day

m3

/s cubic meter(s) per second

m3

/y cubic meter(s) per year

MAAP Modular Accident Analysis Program

MACCS2 MELCOR Accident Consequence Code System version 2

MACR maximum averted cost-risk

MAE Center Mid-America Earthquake Center

MATS Mercury and Air Toxics Standards

MBTA Migratory Bird Treaty Act

MCC motor control center

MCR main control room

MDNR Minnesota Department of Natural Resources

mg/L milligram(s) per liter

mgd million gallons per day

mGy milligray

mgy million gallons per year

mi mile(s)

mi2 square mile(s)

MiSA Micropolitan Statistical Area

MISO Midcontinent Independent System Operator, Inc.

mm millimeter(s)

MMT million metric tons

MODNR Missouri Department of Natural Resources

MOV motor-operated valve

MPCA Minnesota Pollution Control Agency

mph mile(s) per hour

mrad millirad

mrem millirem

MSA Magnuson–Stevens Fishery Conservation and Management Act, 

as amended through 2006
Abbreviations and Acronyms

xxxv 

mSv millisievert

MT metric ton(s)

MUDS makeup water demineralizer system

MUR measurement uncertainty recapture

MW megawatt(s)

MWe megawatt(s) electrical

MWh megawatt hour(s)

MWt megawatt(s) thermal

N2O nitrous oxide

NA not applicable

NAA nonattainment area

NAAQS National Ambient Air Quality Standards

NAGPRA Native American Graves Protection and Repatriation Act

NARUC National Association of Regulatory Utility Commissioners

NASA National Aeronautics and Space Administration

NASS National Agricultural Statistics Service

NCADAC National Climate Assessment and Development 

Advisory Committee

NCDC National Climatic Data Center

NCES National Center for Education Statistics

NCZVED National Center for Zoonotic, Vector-Borne, and Enteric Diseases

NEA Nuclear Energy Agency

NEAC [DOE] Nuclear Energy Advisory Committee

NEI Nuclear Energy Institute

NEIS Nuclear Energy Information Service

NEPA National Environmental Policy Act

NERI Nuclear Energy Research Initiative

NESC® National Electrical Safety Code®

NETL National Energy Technology Laboratory

NGCC natural-gas-fired combined-cycle 

NGNP Next Generation Nuclear Plant

NH3 ammonia

NHPA National Historic Preservation Act of 1966, as amended

NIEHS National Institute of Environmental Health Sciences

NIOSH National Institute for Occupation Safety and Health
Abbreviations and Acronyms

xxxvi 

NLEB northern long-eared bat

NMFS National Marine Fisheries Service (of NOAA)

NO2 nitrogen dioxide

NOAA National Oceanic and Atmospheric Administration

NOED Notice of Enforcement Discretion

NOI Notice of Intent

NOx nitrogen oxide(s)

NP National Park

NPDES National Pollutant Discharge Elimination System

NPS National Park Service

NRC U.S. Nuclear Regulatory Commission

NREL National Renewable Energy Laboratory

NRHP National Register of Historic Places

NRIS National Register Information System

NRR Nuclear Reactor Regulation

NSC National Safety Council

NSPS New Source Performance Standards

NSR New Source Review

O3 ozone

ODCM Offsite Dose Calculation Manual

OECD Organisation for Economic Co-operation and Development

OECR offsite economic cost risk

OSHA Occupational Safety and Health Administration

OTEC Ocean Thermal Energy Conversion

OWR [Illinois Department of Natural Resources or DNR] Office of 

Water Resources

oz ounce(s)

PAM primary amebic meningoencephalitis

Pb lead

PC pulverized coal

PCB polychlorinated biphenyl

pCi/L picocurie(s)/liter

PDS plant damage state

PECO PECO Energy Company [an Exelon company, 

formerly Philadelphia Electric Company]
Abbreviations and Acronyms

xxxvii 

PEIS programmatic environmental impact statement

PFC perfluorocarbon

PHS pumped hydroelectric storage

PIAT payment(s) in addition to taxes

PIMW potentially infectious medical waste

PJM central Atlantic and Midwestern regional electric 

distribution network

PM particulate matter

PM10 particulate matter with aerodynamic diameters of 10 microns 

or less

PM2.5 particulate matter with aerodynamic diameters of 2.5 microns 

or less

PNNL Pacific Northwest National Laboratory

PORV power-operated relief valve

PRA probabilistic risk assessment

PSA probabilistic safety assessment

PSD Prevention of Significant Deterioration

psi pound(s) per square inch

PTE potential to emit

PV photovoltaic

PWR pressurized-water reactor

RAI request for additional information

RCP reactor coolant pump

RCRA Resource Conservation and Recovery Act of 1976, as amended

RCS reactor coolant system

RDS Research and Development Solutions, LLC

rem roentgen equivalent(s) man

REMP radiological environmental monitoring program

RGPP Radiological Groundwater Protection Plan

RHR Regional Haze Rule, residual heat removal

RKm river kilometer(s)

RM river mile(s)

ROI region(s) of influence

ROW right-of-way

RPC replacement power cost

RPV reactor pressure vessel
Abbreviations and Acronyms

xxxviii 

RRW risk reduction worth

RTO regional transmission organization

RWSPG [Northeastern Illinois] Regional Water Supply Planning Group

RWST refueling water storage tank

SAFSTOR a period of safe storage of the stabilized and defueled facility 

followed by final decontamination, dismantlement, and 

license termination

SAMA severe accident mitigation alternative

SAT system auxiliary transformer

SBO station blackout

SCPC supercritical pulverized coal

SCR selective catalytic reduction

SDWIS Safe Drinking Water Information System

SECPOP2000 Sector Population, Land Fraction, and Economic 

Estimation Program

SEIS supplemental environmental impact statement

SER safety evaluation report

SERC Southeastern Electric Reliability Council

SF6 sulfur hexafluoride

SG steam generator

SGTR steam generator tube rupture

SHPO State Historic Preservation Officer

SI safety injection

SIP State Implementation Plan

SMA seismic margin assessment

SMITTR surveillance, monitoring, inspection, testing, trending, 

and recordkeeping

SNL Sandia National Laboratories

SO2 sulfur dioxide

SOARCA State-of-the-Art Reactor Consequence Analyses

SOx sulfur oxide(s)

SPDES State Pollutant Discharge Elimination System

SR supporting requirement

SSA South Suburban Airport

SSC structure, system, and component

SSEL Safe Shutdown Equipment List
Abbreviations and Acronyms

xxxix 

Sv sievert

SW service water

SWPPP Stormwater Pollution Prevention Plan

SX essential service water

t ton(s)

T&RM Training and Reference Material

TAC Technical Assignment Control

TCEQ Texas Commission on Environmental Quality

TEEIC Tribal Energy and Environmental Information Clearinghouse

TEP Threatened, Endangered, and Proposed

TES thermal energy storage

Tg teragram(s)

TMDL total maximum daily load

tpy ton(s) per year

TS technical specification

TSP total suspended particulates

TSS transmission substation

U.S. United States

U.S.C. United States Code

UFSAR Updated Final Safety Analysis Report

UNL University of Nebraska—Lincoln

UP Union Pacific

USACE United States Army Corps of Engineers

USCB U.S. Census Bureau

USDA U.S. Department of Agriculture

USFS U.S. Forest Service

USGCRP U.S. Global Change Research Program

USGS U.S. Geological Survey

V volt(s)

VEGP Vogtle Electric Generating Plant

VOC volatile organic compound

WA Wilderness Area

WAW wet active waste

WCAP Westinghouse Commercial Atomic Power

WCD Waste Confidence Decision
Abbreviations and Acronyms

xl

WGFD Wyoming Game and Fish Department

WHC Wildlife Habitat Council

WJE Wiss, Janney, Elstner Associates, Inc.

WNS white-nose syndrome

WOE weight of evidence

yd yard(s)

yd3 cubic yard(s)

YOY young of the year

yr year(s)

Δ change of quantity
1-1 

1.0 INTRODUCTION

U.S. Nuclear Regulatory Commission (NRC) environmental protection regulations in Part 51 of 

Title 10 of the Code of Federal Regulations (10 CFR 51) implement the National Environmental 

Policy Act (NEPA). Section 51.20 of 10 CFR requires the preparation of an environmental 

impact statement (EIS) for the issuance or renewal of a nuclear power plant operating license.

The Atomic Energy Act of 1954 (AEA) specifies that licenses for commercial power reactors can 

be granted for up to 40 years. NRC regulations (10 CFR 54.31) allow for an option to renew a 

license for up to an additional 20 years. The initial 40-year licensing period was based on 

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

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

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

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

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

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

operation.

1.1 Proposed Federal Action

Exelon Generation Company, LLC (Exelon) requested the proposed Federal action by 

submitting an application for license renewal of Braidwood Station (Braidwood), Units 1 and 

2, for which the existing licenses (NPF-72 and NPF-77) expire on October 17, 2026, and 

December 18, 2027, respectively. The NRC’s proposed Federal action is the decision whether 

to issue the renewed licenses for an additional 20 years.

1.2 Purpose and Need for the Proposed Federal Action

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

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

plant operating license to meet future system generating needs, as such needs may be 

determined by other energy-planning decisionmakers. This definition of purpose and need 

reflects the NRC’s recognition that, unless there are findings in the safety review required by the 

AEA or findings in the NEPA environmental analysis that would lead the NRC to reject a license 

renewal application (LRA), the NRC does not have a role in the energy-planning decisions of 

State regulators and utility officials as to whether a particular nuclear power plant should 

continue to operate.

1.3 Major Environmental Review Milestones

Exelon submitted an Environmental Report (ER) as part of its LRA (Exelon 2013) in May 2013. 

After reviewing the LRA and ER for sufficiency, the NRC staff published a Federal Register

Notice of Acceptability and Opportunity for Hearing (78 FR 44603) on July 24, 2013. Then, on 

July 31, 2013, the NRC published another notice in the Federal Register (78 FR 46379) on the 

intent to conduct scoping, thereby beginning the 60-day scoping period.

The NRC staff held two public scoping meetings on August 21, 2013, in Will County, Illinois. 

The comments received during the scoping process are presented in their entirety in 

“Environmental Impact Statement Scoping Process, Summary Report, Braidwood Station, 

Units 1 and 2, Will County,” published in 2014 (NRC 2014). The staff presents comments 
Introduction

1-2 

considered to be within the scope of the environmental license renewal review and the 

NRC responses in Appendix A of this supplemental environmental impact statement (SEIS).

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

audit at Braidwood, Units 1 and 2, in November 2013. During the site audit, the staff met with 

plant personnel, reviewed specific documentation, toured the facility, and met with interested 

Federal, State, and local agencies. A summary of that site audit and the attendees is contained 

in the Audit Summary Report, published in December 2013 (NRC 2013b).

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

draft SEIS. This document was made available for public comment for 45 days. During this 

time, the staff hosted public meetings and collect public comments. Based on the information 

gathered, it amended the draft SEIS findings, as necessary, and published this final SEIS for 

license renewal. Figure 1–1 shows the major milestones of the NRC’s license renewal 

application environmental review.

Figure 1–1. Environmental Review Process

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

reasonable period with clear requirements to assure safe plant operation for up to an additional 

20 years of plant life. The NRC staff conducts the safety review simultaneously with the 

environmental review. The staff documents the findings of the safety review in a safety 

evaluation report (SER). The findings in the SEIS and the SER are both factors in the NRC’s 

decision to either grant or deny the issuance of a renewed license.
Introduction

1-3 

1.4 Generic Environmental Impact Statement

The NRC staff performed a generic assessment of the environmental impacts associated 

with license renewal to improve the efficiency of its license renewal review. The Generic 

Environmental Impact Statement for License Renewal of Nuclear Plants (GEIS), NUREG-1437, 

Revision 1 (NRC 2013a), documented the results of the staff’s systematic approach to evaluate 

the environmental consequences of renewing the licenses of individual nuclear power plants 

and operating them for an additional 20 years. The staff analyzed in detail and resolved those 

environmental issues that could be resolved generically in the GEIS.

The GEIS establishes separate environmental impact issues for the NRC staff to independently 

verify. Of these issues, the NRC staff determined that some issues are generic to all plants 

(Category 1). Other issues do not lend themselves to generic consideration (Category 2 or 

uncategorized). The staff evaluated these issues on a site-specific basis in a SEIS. Appendix B 

to Subpart A of 10 CFR 51 provides a summary of the staff findings in the GEIS.

For each potential environmental issue, in the GEIS, the NRC staff performs the following:

 describes the activity that affects the environment,

 identifies the population or resource that is affected,

 assesses the nature and magnitude of the impact on the affected population 

or resource,

 characterizes the significance of the effect for both beneficial and 

adverse effects,

 determines whether the results of the analysis apply to all plants, and

 considers whether additional mitigation measures would be warranted 

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

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

Environmental Quality terminology for “significant.” The NRC established three levels 

of significance for potential impacts—SMALL, MODERATE, and LARGE, as defined below.

SMALL: Environmental effects are not 

detectable or are so minor that they will neither 

destabilize nor noticeably alter any important 

attribute of the resource.

MODERATE: Environmental effects are 

sufficient to alter noticeably, but not to destabilize, 

important attributes of the resource.

LARGE: Environmental effects are clearly noticeable and are sufficient to destabilize important 

attributes of the resource.

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

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

are assigned a Category 1 or a Category 2 designation. As set forth in the GEIS, Category 1 

issues are those that meet the following criteria:

 The environmental impacts associated with the issue have been determined 

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

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

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.
Introduction

1-4 

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

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

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

 Mitigation of adverse impacts associated with the issue has been considered 

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

mitigation measures are likely not to be sufficiently beneficial to warrant 

implementation.

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

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

significant information is presented in Section 4.14. Site-specific issues (Category 2) are 

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

site-specific review for these issues is required. A site-specific analysis is required for 17 of 

those 78 issues evaluated in the GEIS. The results of that site-specific analysis are 

documented in the SEIS. Figure 1–2 illustrates the evaluation of environmental issues 

for license renewal.

Figure 1–2. Environmental Issues Evaluated for License Renewal
Introduction

1-5 

1.5 Supplemental Environmental Impact Statement

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

operation of Braidwood, Units 1 and 2, alternatives to license renewal, and mitigation measures 

for minimizing adverse environmental impacts. Chapter 4 contains analysis and comparison of 

the potential environmental impacts from alternatives while Chapter 5 presents the 

recommendation of the NRC on whether or not the environmental impacts of license renewal 

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

recommendation was made after consideration of comments received on the draft SEIS during 

the public comment period.

In the preparation of the SEIS for Braidwood, Units 1 and 2, the NRC staff carried out the 

following activities:

 reviewed the information provided in Exelon’s ER;

 consulted with other Federal, State, local agencies, and tribal nations; 

 conducted an independent review of the issues during site audit; and

 considered the public comments received for the review (during the scoping

process and, subsequently, on the draft SEIS).

New information can be identified from many 

sources, including the applicant, the NRC, other 

agencies, or public comments. If a new issue is 

revealed, it is first analyzed to determine whether 

it is within the scope of the license renewal 

environmental evaluation. If the new issue is 

not addressed in the GEIS, the NRC staff would 

determine the significance of the issue and document the analysis in the SEIS.

1.6 Decision to Be Supported by the SEIS

The decision to be supported by the SEIS is whether or not to renew the operating licenses 

for Braidwood for an additional 20 years. The NRC decision standard is specified in 

10 CFR 51.103(a)(5):

In making a final decision on a license renewal action pursuant to Part 54 of this 

chapter, the Commission shall determine whether or not the adverse 

environmental impacts of license renewal are so great that preserving the option 

of license renewal for energy planning decisionmakers would be unreasonable.

There are many factors that the NRC takes into consideration when deciding whether to 

renew the operating license of a nuclear power plant. The analyses of environmental impacts 

evaluated in the GEIS would provide the NRC’s decisionmaker (in this case, the Commission) 

with important environmental information for use in the overall decisionmaking process. There 

are also decisions outside the regulatory scope of license renewal that cannot be made on the 

basis of the final GEIS analysis. These decisions concern the following issues: changes to 

plant cooling systems, disposition of spent nuclear fuel, emergency preparedness, safeguards 

and security, need for power, and seismicity and flooding (NRC 2013a).

New and significant information must be 

both new and bear on the proposed action or its 

impacts, presenting a seriously different picture of 

the impacts from those envisioned in the GEIS

(i.e., impacts of greater severity than impacts 

considered in the GEIS, considering their intensity 

and context).
Introduction

1-6 

1.7 Cooperating Agencies

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

agencies in the preparation of this SEIS.

1.8 Consultations

The Endangered Species Act of 1973, as amended (ESA); the Magnuson–Stevens Fisheries 

Management Act of 1996, as amended (MSA); and the National Historic Preservation Act

(NHPA) of 1966 require that Federal agencies consult with applicable State and Federal 

agencies and groups prior to taking action that may affect endangered species, fisheries, or 

historic and archaeological resources, respectively. The NRC consulted with the following 

agencies and groups:

 State Historic Preservation Office (SHPO),

 U.S. Fish and Wildlife Service (FWS),

 Ho-Chunk Nation, 

 Miami Tribe of Oklahoma, 

 Peoria Tribe of Indians of Oklahoma, 

 Citizen Potawatomi Nation, 

 Sac and Fox Tribe of the Mississippi in Iowa (Meskwaki), 

 Sac and Fox Nation of Missouri in Kansas and Nebraska, 

 Sac and Fox Nation, 

 Pokagon Band of Potawatomi, 

 Forest County Potawatomi, 

 Hannahville Indian Community, Band of Potawatomi, 

 Prairie Band of Potawatomi Nation, 

 Winnebago Tribe of Nebraska, 

 Kickapoo Tribe in Kansas, and

 Kickapoo Tribe of Oklahoma.

The Tribes were selected based on their historical and cultural ties with the local areas. 

Appendix C provides a listing of the consultation documents.

1.9 Correspondence

Appendix D contains a chronological list of all documents sent and received during 

the environmental review, including consultation documents listed in Section 1.8.

1.10 Status of Compliance

Exelon is responsible for complying with all applicable NRC regulations and other applicable 

Federal, State, and local requirements. Appendix B describes some of the major applicable 

Federal statutes.
Introduction

1-7 

There are numerous permits and licenses issued by Federal, State, and local authorities for 

activities at Braidwood, Units 1 and 2. Appendix B contains further discussion about Braidwood 

status of compliance.

1.11 Related Federal and State Activities

The NRC reviewed the possibility that activities of other Federal agencies might impact the 

renewal of the operating license for Braidwood. There are no Federal projects that would make 

it necessary for another Federal agency to become a cooperating agency in the preparation of 

this supplemental EIS. There are no known American Indian lands within 50 mi (80 km) of 

Braidwood. There are three Federally owned facilities within 50 mi of Braidwood: (1) Joliet 

Army Ammunition Plant, (2) Argonne National Laboratory, and (3) Fermi National 

Accelerator Laboratory.

The NRC is required under Section 102(2)(C) of NEPA to consult with and obtain the comments 

from any Federal and state agency that has jurisdiction by law or special expertise with respect 

to any environmental impact involved in the subject matter of the EIS. For example, during the 

course of preparing the SEIS, the NRC consulted with the FWS. A complete list of key 

consultation correspondences is listed in Appendix C.

1.12 References

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

protection regulations for domestic licensing and related regulatory functions.”

10 CFR Part 54. Code of Federal Regulations, Title 10, Energy, Part 54, “Requirements 

for renewal of operating licenses for nuclear power plants.”

78 FR 37282. U.S. Nuclear Regulatory Commission. “Revisions to environmental review for 

renewal of nuclear power plant operating licenses.” Federal Register 78(119):37282–37324. 

June 20, 2013.

78 FR 44603. U.S. Nuclear Regulatory Commission. “Byron Nuclear Station, Units 1 and 2, 

and Braidwood Nuclear Station, Units 1 and 2; Exelon Generation Company, LLC.” Federal 

Register 78(142):44603–44605. July 24, 2013.

78 FR 46379. U.S. Nuclear Regulatory Commission. “Exelon Generation Company, LLC, 

license renewal application for Braidwood Station, Units 1 and 2.” Federal 

Register 78(147):46379–46381. July 31, 2013.

[AEA] Atomic Energy Act of 1954, as amended. 42 U.S.C. §2011 et seq.

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

[Exelon] Exelon Generation Company, LLC. 2013. “Braidwood Station, Units 1 and 2, 

Docket Nos. 50–456, 50–457, License Renewal Application.” May 29, 2013. Agencywide 

Documents Access and Management System (ADAMS) No. ML131550528.

[MSA] Magnuson–Stevens Fishery Conservation and Management Act, as amended. 

16 U.S.C. §1801 et seq.

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

[NHPA] National Historic Preservation Act of 1966. 16 U.S.C. §470 et seq.
Introduction

1-8 

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

for License Renewal of Nuclear Plants. Washington, DC: NRC. NUREG-1437, Revision 1, 

Volumes 1, 2, and 3. June 2013. 1,535 p. ADAMS Nos. ML13106A241, ML13106A242, 

and ML13106A244.

[NRC] U.S. Nuclear Regulatory Commission. 2013b. Letter from T. Tran, Project Manager, to 

M. Gallagher, Vice President, Nuclear Licensing Projects, Exelon Generating Company, LLC. 

Subject: Summary of site audit related to the review of the license renewal application for 

Braidwood Station, Units 1 and 2. December 3, 2013. ADAMS No. ML13318A238.

[NRC] U.S. Nuclear Regulatory Commission. 2014. Environmental Impact Statement Scoping

Process, Summary Report, Braidwood Station, Units 1 and 2, Will County, IL. Washington, DC: 

NRC. 2014. ADAMS No. ML13337A503.
2-1 

2.0 ALTERNATIVES INCLUDING THE PROPOSED ACTION 

Although the U.S. Nuclear Regulatory Commission’s (NRC’s) decisionmaking authority in 

license renewal is limited to deciding whether or not to renew a nuclear power plant’s operating 

license, the NRC’s implementation of the National Environmental Policy Act (NEPA) requires 

consideration of the environmental impacts of potential alternatives to renewing a plant’s 

operating license. While the ultimate decision about which alternative (or the proposed action) 

to carry out falls to utility (or plant owners), state, or Federal officials (not the NRC or non-NRC), 

comparing the impacts of renewing the operating license to the environmental impacts of 

alternatives allows the NRC to determine whether the environmental impacts of license renewal 

are so great that preserving the option of license renewal for energy-planning decisionmakers 

would be unreasonable (Title 10 of the Code of Federal Regulations (10 CFR) 51.95(c)(4)).

Energy-planning decisionmakers and owners of the nuclear power plant ultimately decide 

whether the plant will continue to operate, and economic and environmental considerations play 

important roles in this decision. In general, the NRC’s responsibility is to ensure the safe 

operation of nuclear power facilities and not to formulate energy policy or encourage or 

discourage the development of alternative power generation. The NRC does not engage in 

energy-planning decisions and makes no judgment as to which energy alternatives evaluated 

would be the most likely alternative in any given case.

The remainder of this chapter provides: (1) a description of the proposed action, (2) a 

description of alternatives to the proposed action (including the no-action alternative), and 

(3) alternatives to Braidwood Station, Units 1 and 2 (Braidwood), license renewal that the staff 

considered and eliminated from detailed study. Chapter 4 of this plant-specific supplemental 

environmental impact statement (SEIS) compares the impacts of renewing the operating 

licenses of Braidwood and continued plant operations to the environmental impacts of 

alternatives.

2.1 Proposed Action

As stated in Chapter 1, the NRC’s proposed Federal action is the decision of whether to renew 

the Braidwood operating licenses for an additional 20 years. For the NRC to determine the 

impacts from continued operation of Braidwood, an understanding of that operation is needed. 

A description of normal power plant operations during the license renewal term is provided in 

Section 2.1.1. Braidwood is a two-unit, nuclear-powered steam-electric generating facility. The 

nuclear reactor for each unit is a pressurized water reactor (PWR), producing a reactor core 

rated thermal power of 3,645 megawatts thermal (Braidwood licenses, NPF-72 and NPF-77).

2.1.1 Plant Operation During the License Renewal Term

Most Braidwood operation activities during license renewal term would be the same as 

or similar to those occurring during the current license term. Section 2.1.1 of the Generic 

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

Volume 1, Revision 1, (GEIS) (NRC 2013a) summarizes the general types of activities that 

are carried out during the operation of a nuclear power plant such as Braidwood, as follow:

 reactor operation;

 waste management;

 security;
Alternatives Including the Proposed Action

2-2 

 office and clerical work;

 laboratory analysis;

 surveillance, monitoring, and maintenance; and

 refueling and other outages (unanticipated).

As stated in the Environmental Report (ER), Braidwood will continue to operate in the 

same manner as during the current license term except for, as appropriate, additional 

aging management programs to address structures and components aging, in 

accordance with 10 CFR Part 54. The ER further states Braidwood operation during the 

license renewal term is documented in the Braidwood Updated Final Safety Analysis 

Report (UFSAR) as required by NRC requirements.

2.1.2 Refurbishment and Other Activities Associated With License Renewal

The GEIS (NRC 2013a) states: “NRC assumed that licensees would need to conduct major 

refurbishment activities to ensure the safe and economic operation of nuclear plants beyond the 

current license term.” The major refurbishment class of activities characterized in the GEIS is 

intended to encompass actions that typically take place only once in the life of a nuclear plant, 

if at all (e.g., replacement of steam generators for PWR).

As a result of its refurbishment evaluation, Exelon Generation Company, LLC (Exelon), did not 

identify the need to undertake any major refurbishment or replacement activities associated with 

license renewal to support the continued operation of Braidwood beyond the end of the existing 

operating license. Therefore, the staff does not discuss refurbishment activities as part of the 

proposed action in Chapter 4.

However, Exelon identified two hypothetical refurbishment activities that may occur during the 

period of continued operation:

 steam generator replacement for Unit 2 and

 reactor pressure vessel head replacement for both or either unit.

The staff discusses the impacts of these hypothetical refurbishments as part of the cumulative 

impact in Chapter 4 (Section 4.16).

2.1.3 Termination of Nuclear Power Plant Operation and Decommissioning After the 

License Renewal Term

The impacts of decommissioning are described in the Generic Environmental Impact Statement

on Decommissioning of Nuclear Facilities: Regarding the Decommissioning of Nuclear Power 

Reactors, NUREG-0586 (NRC 2002a). The majority of the activities associated with plant 

operations would cease with reactor shutdown. Some activities (e.g., security and oversight 

of spent nuclear fuel) would remain unchanged, while others (waste management, office and 

clerical work, laboratory analysis, and surveillance, monitoring, and maintenance) would 

continue at reduced or altered levels. Systems dedicated to reactor operations would cease 

operations; however, impacts from their physical presence may continue if not removed after 

reactor shutdown. For sites such as Braidwood, with more than one unit, shared systems may 

operate at reduced capacities. Impacts associated with dedicated systems that remain in place 

or shared systems that continue to operate at normal capacities would remain unchanged.

Decommissioning would occur whether Braidwood was shut down at the end of its current 

operating licenses or at the end of the period of extended operation, and the decommission plan 

requires NRC approval. There are no site-specific issues related to decommissioning. In the 
Alternatives Including the Proposed Action

2-3 

GEIS, the NRC staff concluded that impacts of terminating operation and decommissioning are 

SMALL (Category 1) on all resources for nuclear power plants.

2.2 Alternatives

The NRC has the obligation to consider reasonable alternatives to the proposed action of 

renewing the license for a nuclear reactor. In addition to the no-action alternative, a reasonable 

alternative (power replacement) must be commercially viable on a scale capable of producing 

baseload power and must be operational prior to the expiration of the reactor’s operating 

license(s), or expected to become commercially viable or expected to produce baseload power 

and be operational prior to the expiration of the reactor’s operating license(s).

The GEIS incorporated the latest information on replacement power alternatives; however, 

rapidly evolving technologies will inevitably outpace the information presented in the GEIS. 

Additionally, the range of reasonable alternatives will also vary by location because of 

availability of renewable energy resources, current status of infrastructure and technology within 

the region, and local laws and regulations that may promote or inhibit certain energy producing 

technologies. As such, a site-specific analysis of alternatives must be performed for each SEIS, 

taking into account changes in technology and science.

2.2.1 No-Action Alternative

This section examines the environmental effects that would occur if NRC takes no action. 

“No-action” in this SEIS means that the NRC does not issue renewed operating licenses for 

Braidwood, and the licenses expire at the end of the current terms. If the NRC takes no action, 

the two units would shut down at or before the end of the current licenses. After shutdown, 

plant owners would initiate decommissioning in accordance with 10 CFR 50.82.

The no-action alternative examines those impacts that arise directly as a result of plant 

shutdown. The environmental impacts from decommissioning and related activities are 

addressed in several other documents, including the Final Generic Environmental Impact 

Statement on Decommissioning of Nuclear Facilities, NUREG-0586, Supplement 1 (NRC 2002); 

the license renewal GEIS, Chapter 4 (NRC 2013a); and Chapter 4 of this SEIS. These 

analyses either directly address or bound the environmental impacts of decommissioning 

whenever Exelon ceases operating Braidwood.

Even if NRC grants renewed operating licenses, Braidwood will eventually shut down, and the 

environmental effects addressed in Chapter 4 under the no-action alternative will occur at that 

time. As with decommissioning effects, shutdown effects are expected to be similar whether 

they occur at the end of the current licenses or at the end of renewed licenses.

Termination of operations at Braidwood would result in the total cessation of electrical power 

production. Unlike the alternatives described in Section 2.2.2, the no-action alternative does not 

provide a means of delivering baseload power to meet future electric system needs. Assuming 

that a need currently exists for the power generated by Braidwood, the no-action alternative 

would likely create a need for replacement power. That need could be met by installation of 

additional generating capacity, adoption or expansion of energy conservation and energy 

efficiency programs, purchased power, or some combination of measures to offset and replace 

the power currently generated by Braidwood.

Although the NRC’s authority extends only to the decision of whether to renew the Braidwood 

operating licenses, the staff describes the replacement power alternatives in the following 

sections to represent reasonable options for energy-planning decisionmakers, should NRC 

choose not to renew the Braidwood licenses.
Alternatives Including the Proposed Action

2-4 

2.2.2 Replacement Power Alternatives

For replacement power alternatives, the NRC staff selected 

alternatives based on the reviews of energy technologies that 

are either currently a commercially viable source of producing 

baseload power, or can be expected to become a 

commercially viable source of baseload power before the 

expiration of the reactors’ operating licenses. The NRC staff’s 

analysis assumed that an alternative must be available (able 

to be constructed, permitted, and connected to the grid) by the 

time the current Braidwood licenses expire.

The NRC staff eliminated alternatives that cannot meet future 

system needs or whose costs do not justify inclusion in the 

range of reasonable alternatives. For example, energy 

technologies that are not practical because of geographical 

location or for other reasons are identified but not evaluated 

in detail. Alternatives that the NRC staff has dismissed from 

further analysis are discussed in Section 2.3.

To determine the reasonableness of various alternatives, 

the NRC staff reviewed the information in the GEIS, which 

presents an overview of some energy technologies. Because 

many energy technologies are continually evolving in 

capability and cost and vary by geographic area, and because 

regulatory structures have changed to either promote or 

impede development of particular alternatives, the analyses 

in this chapter may include updated information from the 

following sources:

 Energy Information Administration (EIA),

 other offices within the U.S. Department of 

Energy (DOE),

 U.S. Environmental Protection Agency (EPA),

 industry sources and publications, and

 information submitted by Exelon in its ER.

In addition, the NRC reviewed energy relevant statutes, 

regulations, and policies to ensure that the alternatives

analysis is consistent with State and regional energy policies. 

The NRC staff also reviewed the current generation capacity 

mix and electricity production data within the region where 

Braidwood is located.

Based on the results of the information review, the NRC staff considered 17 energy technology 

options and alternatives to the proposed action (listed in the text box) and then narrowed the 

range of reasonable alternatives to the 5 alternatives to be evaluated in depth. These are 

discussed in Sections 2.2.2.1 through 2.2.2.5.

The NRC staff evaluated the environmental impacts for each reasonable alternative in 

Chapter 4 of this SEIS. This evaluation considers the impacts across several categories: 

land use and visual resources, air quality and noise, geologic environment, water resources, 

Alternatives Evaluated 

in Depth:

• new nuclear,

• coal-integrated 

gasification combined 

cycle,

• natural gas 

combined cycle,

• combination alternative 

(wind power, natural gas 

combined cycle, and 

solar power), and 

• purchased power.

Other Alternatives 

Considered but Dismissed: 

• energy efficiency and 

conservation,

• supercritical pulverized 

coal,

• wind power,

• solar power,

• hydroelectric power,

• wave and ocean energy,

• geothermal power,

• municipal solid waste,

• biomass,

• oil-fired power,

• fuel cells, and

• delayed retirement.

 

 

 

 

 

 

 
Alternatives Including the Proposed Action

2-5 

ecological resources, historic and cultural resources, socioeconomics, human health, 

environmental justice, and waste management. The order of presentation for the 

five reasonable alternatives is not meant to imply increasing or decreasing level of impact. Nor 

does it imply that an energy-planning decisionmaker would be more likely to select any given 

alternative.

Region of Influence

The region of influence (ROI) defines the geographical scope of the staff’s alternative analysis. 

Braidwood is owned and operated by Exelon and provides electricity to the ROI through 

transmission lines owned by Commonwealth Edison Company (ComEd) (Exelon 2013). 

ComEd operates under the PJM Interconnection, a regional transmission organization (RTO) 

that coordinates the movement of wholesale electricity in 13 states across the Midwest and 

Northeast (Exelon 2013). ComEd provides service to 3.8 million customers across northern 

Illinois. Its service territory borders Iroquois County to the south, the Wisconsin border to the 

north, the Iowa border to the west, and the Indiana border to the east (ComEd 2013). However, 

electricity consumption in Illinois is not limited to electricity that is generated within the state. 

Although northern Illinois relies on electricity from ComEd, the rest of Illinois and surrounding 

states, which are not part of the PJM Interconnection, are part of the Midcontinent Independent 

System Operator, Inc. (MISO) (see Figure 2–1) (Exelon 2013).

Figure 2–1. Territories of the MISO and PJM Interconnection

Source: FERC 2014

If renewed licenses were not issued, replacement power for Braidwood would be required in 

northern Illinois. Electricity could be replaced by generation sources from a variety of locations. 

Electricity could be transported from within the PJM Interconnection; however, the PJM 

Interconnection in Illinois is geographically distant from the rest of the PJM region (see 

Figure 2.2-1). It is also possible that electricity within MISO could be purchased by PJM, and 

efforts are currently being made to increase coordination and deliverability between the RTOs 

(PJM 2013b). In addition, the State of Illinois has a renewable portfolio standard that includes a 

geographic eligibility requirement stipulating that eligible renewable resources must be procured 

from facilities located in Illinois or states that adjoin Illinois (Wisconsin, Indiana, Iowa, Kentucky, 

Michigan, and Missouri) (ILGA 2011). Renewable resources can only be obtained from other 

regions of the country if they are not available in Illinois or in adjoining states (ILGA 2011).
Alternatives Including the Proposed Action

2-6 

Therefore, because replacement power would be required in northern Illinois and any renewable 

energy resources would need to be procured from facilities in Illinois or adjoining states, the 

NRC staff evaluated the impacts of locating replacement power facilities within the states of 

Illinois, Indiana, Iowa, Kentucky, Michigan, Missouri, and Wisconsin. These seven states 

constitute the ROI for the NRC staff’s alternative analyses. The NRC assumes that 

replacement power would either be produced in northern Illinois within the PJM region, or would 

be purchased by PJM from MISO.

In 2012, electric generators in the ROI had a net summer generating capacity of approximately 

179,000 megawatts (MW). This capacity included units fueled by coal (49 percent), natural gas 

(27 percent), nuclear (11 percent), and wind (6.6 percent) (EIA 2014b).

In 2011, the electric industry in the ROI provided approximately 744 million megawatt hours 

(MWh) of electricity. Electricity produced in the ROI was dominated by coal (67 percent) and 

nuclear (21 percent). While natural gas makes up nearly 30 percent of the installed generating 

capacity in the ROI, it provides only 6 percent of electricity in the region. Non-hydroelectric 

renewable energy produced 1.3 percent of the electricity in the ROI (EIA 2014a).

Renewable Energy Legislation in the Region of Influence

Renewable energy legislation in Illinois allows the purchase of electricity generation in adjoining 

states; therefore, any legislation targeting renewable energy in these states could impact a 

state’s incentive to develop renewable resources. Five states in the ROI (Illinois, Iowa, 

Missouri, Wisconsin, and Michigan) have legally mandated renewable energy legislation. The 

State of Indiana has a voluntary program, and Kentucky does not have any renewable energy 

requirements. The paragraphs below briefly outline each state’s program, including renewable 

energy goals and benchmarks.

In August 2007, Illinois adopted a renewable portfolio standard that requires the State’s utilities 

to produce at least 25 percent of their power from renewable sources by 2025, 75 percent of 

which must come from wind. Solar Photovoltaic must comprise 6 percent of the annual 

requirement for calendar year 2015 and thereafter. Other eligible sources include biomass 

and existing hydroelectric power (DSIRE 2012a). The law also includes an energy efficiency 

standard that requires utilities to implement cost-effective energy efficiency measures to meet 

energy savings of 2 percent by calendar year 2015 and thereafter (ILGA 2011). For electric 

utilities (including ComEd), eligible resources must be located in Illinois; resources can be 

purchased from adjoining states only if there are insufficient in-State resources (ILGA 2011).

Iowa’s Alternative Energy Production Law requires the state’s two investor-owned utilities to 

generate a combined total of 105 megawatts (MW) of their generating capacity from 

renewable-energy sources. A 2007 order allows the utilities to participate in renewable energy 

credit trading programs by distinguishing between renewable electricity production capacity 

used to comply with Iowa law and that which can be used to satisfy other states’ renewable 

portfolio standards (DSIRE 2012c).

Missouri adopted a renewable portfolio standard that requires investor-owned utilities to 

increase their use of renewable sources by 15 percent by 2021 and includes a provision 

specifying that 2 percent of the renewable portfolio standard requirement must be met by 

solar energy. Resources can be purchased from outside of Missouri, but renewable energy 

generated in State receives a multiplier of 1.25 compared to out-of-State generation 

(DSIRE 2013b).

Wisconsin’s renewable portfolio standard requires utilities to produce 10 percent of their 

electricity from renewable sources by 2015. Included in the renewable portfolio standard is 

a provision that allows electricity providers to create and sell or transfer renewable resource 
Alternatives Including the Proposed Action

2-7 

credits and renewable energy certificates. Renewable energy generated outside of Wisconsin 

is eligible, provided that the electricity is distributed to Wisconsin customers (DSIRE 2012d).

Michigan enacted a Renewable Energy Standard in 2008 that requires utilities to generate 

10 percent of their retail electricity sales from renewable energy resources by 2015. The 

standard also allows energy efficiency and advanced cleaner energy systems to meet part of 

the requirement. Renewable energy credits can be purchased from in-state or out-of-state 

facilities, provided that the facilities are located within the retail electric service territory of a 

utility as recognized by the Michigan Public Service Commission (DSIRE 2013a).

Indiana does not have a mandatory renewable or alternative energy portfolio standard. On 

July 9, 2012, Indiana adopted a Clean Energy Portfolio Standard, which sets a voluntary goal 

of 10 percent clean energy by 2025, based on the amount of electricity supplied by the utility in 

2010. Unlike many of the other ROI states, up to 30 percent of the goal may be met with clean 

coal technology, nuclear energy, combined heat and power systems, natural gas that displaces 

electricity from coal, and net-metered distributed generation facilities. Fifty percent of qualifying 

energy must come from within the State (DSIRE 2012b).

Kentucky is the only state in the ROI that does not have mandatory or voluntary renewable 

energy requirements.

Given known technology and technological and demographic trends, the EIA predicts that 

32 percent of electricity in the United States will be generated by coal in 2040 (EIA 2013b). 

In all the Midwest case projections, coal accounts for 42 percent in 2040 (EIA 2013b). Natural 

gas generation rose from 16 percent in 2000 to 24 percent in 2011 and is projected to increase 

to 35 percent in 2040, surpassing coal as the largest share of U.S. electric power generation 

(EIA 2013b, 2013d). Electricity generation from renewable energy is expected to grow from 

13 percent of total generation in 2011 to 16 percent in 2040. However, there are uncertainties 

that could affect this forecast, particularly the implementation of policies aimed at reducing 

greenhouse gas (GHG) emissions that would have a direct effect on fossil-fuel-based 

generation technologies (EIA 2013b).

Alternatives Evaluated in Depth

The remainder of this section describes the replacement power alternatives to license renewal 

that are evaluated in depth. These include a new nuclear alternative in Section 2.2.2.1; a 

coal-integrated gasification combined cycle (IGCC) alternative in Section 2.2.2.2; a 

natural-gas-fired combined-cycle (NGCC) in Section 2.2.2.3; a combination natural gas, 

wind, and solar power alternative in Section 2.2.2.4; and a purchased power alternative in 

Section 2.2.2.5. Table 2–1 summarizes key design characteristics of the alternative 

technologies evaluated in depth. The environmental impacts of these alternatives are 

evaluated in Chapter 4.
Alternatives Including the Proposed Action

2-8 

Table 2–1. Summary of Replacement Power Alternatives and Key Characteristics 

Considered in Depth (a)

New Nuclear 

Alternative

IGCC NGCC Alternative Combination 

Alternative

Summary of 

Alternative

Two-unit nuclear plant, 

each with 1,120 MWe 

for a total of 

2,240 MWe

Four 618-MWe 

units for a total 

of 2,472 MWe

Five 560-MWe units, 

for a total of 

2,800 MWe

One 360-MWe 

NGCC unit; a 

1,813-MWe wind 

farm; and a 

227-MWe solar 

photovoltaic facility, 

for a total of 

2,400 MWe

Location An existing nuclear 

plant site or retired 

coal plant site. New 

transmission line(s) 

and other 

infrastructure 

upgrades may be 

required. Some 

facilities (i.e., support 

buildings, potable 

water supply, sanitary 

discharge structures) 

could be shared with 

existing plant.

An existing plant site 

or retired coal plant 

site. New 

transmission line(s) 

and other 

infrastructure 

upgrades may be 

required. Some 

facilities (i.e., support 

buildings, potable 

water supply, sanitary 

discharge structures) 

could be shared with 

existing plant.

An existing plant site 

or retired coal plant 

site. New 

transmission line(s) 

and other 

infrastructure 

upgrades may be 

required; would 

require construction 

of a new or 

upgraded pipeline. 

Some facilities 

(i.e., support 

buildings, potable 

water supply, 

sanitary discharge

structures) could be 

shared with 

existing plant.

Spread across 

multiple sites 

throughout the ROI

Cooling 

System

Closed-cycle with 

natural draft cooling 

towers. Cooling water 

withdrawal—54 mgd 

consumptive water 

use—40 mgd 

(NRC 2008).

Closed-cycle with 

mechanical draft 

cooling towers. 

Cooling water 

withdrawal—25 mgd; 

consumptive water 

use—20 mgd 

(NETL 2013a).

Closed-cycle with 

mechanical draft 

cooling towers. 

Cooling water 

withdrawal—17 mgd; 

consumptive water 

use—13 mgd 

(NETL 2013a).

For NGCC portion, 

closed-cycle with 

mechanical draft 

cooling towers. 

Cooling water would 

be 15% of that 

required for NGCC 

alternative. Minimal 

water use for wind 

and solar.
Alternatives Including the Proposed Action

2-9 

New Nuclear 

Alternative

IGCC NGCC Alternative Combination 

Alternative

Land 

Requirements

556 ac (225 ha) 

(NRC 2008); 520 ac 

(210 ha) for uranium

mining and 

processing (b)

(NRC 2013c)

2,000 ac (800 ha) for 

the major permanent 

facilities; 1,100 ac 

(450 ha) per year for 

mining (DOE 2010c)

94 ac (38 ha) for the 

plant, including 

pipelines 

(Exelon 2013); 

10,080 ac (4,079 ha) 

for gas extraction 

and collection 

(NRC 1996)

Wind farms would 

require 3,376 ac 

(1,366 ha) to 

10,127 ac 

(4,098.3 ha) 

(Western and 

FWS 2013); solar 

photovoltaic facilities 

would require 

6,749 ac (2,731 ha) 

(Ong et al. 2013). 

For NGCC portion, 

land use would 

remain the same 

at 94 ac (38 ha) 

(Exelon 2013).

Work Force 3,500 workers during 

peak construction; 

812 workers 

during operations 

(NRC 2008)

4,600 workers during 

peak construction; 

420 workers 

during operations 

(DOE 2010c)

1,783 workers during 

peak construction; 

94 workers during 

operations 

(Exelon 2013)

Solar photovoltaic—

600 workers during 

peak construction, 

60 workers during 

operations; wind—

931 workers 

during construction, 

566 workers during 

operations 

(DOE 2010b). 

The number of 

construction and 

operations workers 

would be less than 

the standalone 

alternative but would 

not be a linear 

reduction because 

of the need for a 

minimum number of 

workers regardless 

of the size of the 

NGCC plant.

(a) Due to the speculative nature of using purchased power to replace Braidwood capacity and the inherent variability 

of characteristics associated with such an approach, the purchased power alternative is not included in this table.

(b) Normalized to model light water reactor annual fuel requirement. Forty-two percent of this land requirement is 

temporarily committed land. 

Sources: DOE 2010b, 2010c; Exelon 2013; NETL 2013a; NRC 1996, 2008, 2013c; Ong et al. 2013; Western and 

FWS 2013
Alternatives Including the Proposed Action

2-10

2.2.2.1 New Nuclear Alternative

In this section, NRC staff describes the new nuclear alternative. NRC staff evaluates the 

environmental impacts from this alternative in Chapter 4.

The NRC staff considered the construction of a new nuclear plant to be a reasonable alternative 

to license renewal. For example, nuclear generation currently provides 21 percent of electricity 

generation in the ROI (EIA 2014a). Twelve nuclear power plants operate in the ROI; six plants 

have received renewed licenses and three additional plants have applied for renewed licenses 

from the NRC (including Braidwood) (NRC 2013a). In addition, there is an interest in new 

nuclear power plant development in the region; combined license (COL) applications have been 

filed for two new nuclear power plants in the ROI. On July 24, 2008, Union Electric Company 

submitted a COL application for Callaway Nuclear Power Plant Unit 2 (Callaway Unit 2) in 

Callaway County, Missouri, on the existing Callaway site (AmerenUE 2009). However, that 

application has since been suspended (NRC 2009b). An application was also filed in 

September 2008 for Enrico Fermi Atomic Power Plant, Unit 3 (Fermi Unit 3), in Monroe County, 

Michigan, on the existing Fermi site. The NRC staff published the Final Environmental Impact 

Statement for Fermi 3 in January 2013 (NRC 2013a). Although the State of Indiana does not 

currently have any nuclear power plants, its voluntary clean energy initiative includes nuclear as 

an eligible technology (DSIRE 2012b).

For alternative analysis, the NRC staff assumed that there is sufficient time for Exelon to 

prepare and submit an application, build, and operate two new nuclear units before the 

Braidwood licenses expire in October 2026 and December 2027. For example, the NRC 

staff review of a COL application that references a certified design takes about 30 months. 

Noncertified designs would take 48 to 60 months to review (NRC 2009a). The recently licensed 

Vogtle Electric Generating Plant, Units 3 and 4 (Vogtle Units 3 and 4), nuclear power plant 

anticipates a construction schedule of 6 to 7 years (Southern 2013).

In evaluating the new nuclear alternative, the NRC staff assumed that two new nuclear reactors

would be installed on an existing nuclear or coal power plant site, allowing for the maximum use 

of existing ancillary facilities at those locations, such as support buildings and transmission 

infrastructure. In 1987, Illinois enacted a moratorium preventing the construction of new nuclear 

power plants within the State. Until the moratorium is lifted, a new nuclear alternative would 

require siting elsewhere in the ROI. For the purposes of this analysis, the NRC relied on the 

Vogtle Units 3 and 4 COL environmental impact statement for technological parameters for the 

new nuclear alternative because the Vogtle Units 3 and 4 COL considers two new nuclear 

reactor units with similar output as Braidwood and is representative of the reactors that could be 

constructed in the ROI before Braidwood’s licenses expire (NRC 2011). As such, the NRC staff 

assumed two Westinghouse AP1000 reactors with a net electrical output of 2,240 megawatts 

electrical (MWe) would replace Braidwood’s current reactors for this alternative. The NRC staff 

estimated that 324 acres (ac) (131 hectares (ha)) of land would be required on a long-term 

basis for permanent facilities, and an additional 232 ac (94 ha) would be disturbed for temporary 

facilities, a laydown area, and storage of dredge material (NRC 2008).

The heat rejection demands of a new nuclear alternative would be similar to those of 

Braidwood. The new reactors may require a new cooling system (including natural draft cooling 

towers and intake and discharge structures). The NRC staff assumes that water requirements 

for the new nuclear alternative would be similar to current water use at Braidwood. A new 

onsite transmission line and drinking water wells may be required if insufficient infrastructure 

occurs on the site. Construction materials would be delivered via rail spur, truck, or barge, or all 

three depending on the specific site location. It is possible that modifications would be required 
Alternatives Including the Proposed Action

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to deliver such materials depending on the existing infrastructure at the site; modifications could 

include new rail lines or access roads.

The NRC staff also considered the installation of multiple small modular reactors as an 

alternative to renewing the Braidwood licenses. The NRC established the Advanced Reactor 

Program in the Office of New Reactors because of considerable interest in small modular 

reactors along with anticipated license applications by vendors. Small modular reactors are 

approximately 300 MW or less, would have lower initial capacity than large-scale units, and 

would have siting flexibility for locations that are not large enough to accommodate traditional 

nuclear reactors (DOE undated). As of January 2014, no applications for small modular 

reactors have been submitted to the NRC. The DOE has estimated that the technology may 

achieve commercial operation by 2021 to 2025 (DOE undated). Because small modular 

reactors are not expected to be operational at a commercial scale until near the time 

Braidwood’s licenses expire, it is unlikely that eight new small modular reactors (the number of 

units required to replace Braidwood’s current output) could be constructed in the ROI; therefore, 

this analysis focused on nuclear generation by larger nuclear units.

2.2.2.2 Coal (Integrated Gasification Combined Cycle) Alternative

In this section, the NRC staff describes the IGCC alternative. The NRC staff evaluates the 

environmental impacts from this alternative in Chapter 4.

Coal provides the greatest share of electrical power in the ROI, and in 2010, coal represented 

46 percent of installed generation capacity and accounted for 69 percent of all electricity 

generated in the ROI (EIA 2012a). Integrated gasification combined cycle is an emerging 

technology that generates electricity from coal and combines modern coal gasification 

technology with both gas-turbine and steam-turbine power generation. The technology is 

cleaner than conventional pulverized coal plants because some of the major pollutants can 

be removed from the gas stream before combustion. An IGCC power plant consists of coal 

gasification and combined-cycle power generation. Coal gasifiers convert coal into a gas 

(synthesis gas, also referred to as syngas) which fuels the combined-cycle power generating 

units. The combined-cycle system for a 618-MWe IGCC power plant includes two combustion 

turbines, two heat recovery steam generators (HRSGs), and a steam turbine. The 

combined-cycle units combust gas in one or more combustion turbines, and the resulting hot 

exhaust gas is then used to heat water into steam to drive a steam turbine. The steam turbine 

then uses the heat from the gas turbine’s exhaust through an HRSG to produce additional 

electricity (DOE 2010c). This two-cycle process has high rates of efficiency since the exhaust 

heat that would otherwise be lost is captured and reused. In addition, the power plant would 

reduce sulfur dioxide, nitrogen oxides, mercury, and particulate emissions by removing 

constituents from the syngas before combustion. Nearly 100 percent of the nitrogen from the 

syngas would be removed prior to combustion in the gas turbines and would result in lower 

nitrogen oxide emissions compared to conventional coal-fired power plants (DOE 2010c).

Integrated gasification combined cycle power plants have been in operation since the 

mid-1990s. The Wabash Rice IGCC repowering project in Indiana and the Polk Power Station 

in Florida are two examples of operating IGCC plants. Recently, there has been an increased 

interest in new IGCC projects, and multiple new projects have been proposed or have recently 

begun operations in the United States. The Duke Energy Edwardsport Generation Station in 

Indiana is a 618-MWe IGCC power plant in the ROI that began commercial operation in 

June 2013. Duke Energy estimates that the IGCC plant will produce 10 times as much power 

as the retired coal plant it replaced, with 70 percent fewer emissions of sulfur dioxide, nitrogen 

oxides, and particulates. The IGCC plant will reduce carbon emissions per MWh by nearly half 

compared to conventional coal-fired power plants (Duke Energy 2013). In addition, the 
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Edwardsport Generation Station has potential for carbon capture and geologic sequestration; 

space has been reserved at the site for carbon dioxide capture equipment (NETL 2013b).

Many IGCC power plants have been designed with a carbon capture system to further reduce 

carbon dioxide emissions. The Kemper County IGCC project in east-central Mississippi 

proposes to use a carbon capture system to reduce carbon dioxide emissions by almost 

70 percent by removing carbon from the syngas postgasification (DOE 2010c). According to 

a 2013 NETL report, nine IGCC projects totaling over 4,000 MW are currently active; these 

projects are either in the planning stages or have begun construction. Thirteen projects have 

been proposed and subsequently cancelled for a variety of reasons, including air quality issues, 

state laws and regulations, redirected focus on gas-fired generation and renewables, and 

unanticipated rising costs (NETL 2013c).

Integrated gasification combined cycle technology and proposed projects have experienced a 

number of setbacks and opposition, hindering the technology’s ability to fully integrate into the 

energy market. The most significant roadblock is IGCC’s high capital cost compared to 

conventional coal-fired power plants. Cost overruns have been experienced at both the 

Edwardsport IGCC project and the Kemper County IGCC project. FutureGen, an IGCC plant 

featuring carbon capture and storage (CCS), lost DOE financial support because of escalating 

cost estimates (Reuters 2012). Other issues include but are not limited to:

 construction timeline overruns,

 limited track record for reliable performance, and

 opposition from an environmental perspective (Rosenberg 2004).

Despite these issues, the NRC staff considers IGCC technology to be a reasonable source of 

baseload power to replace Braidwood by the time its licenses expire in 2026 and 2027, for the 

following reasons:

 existence of active IGCC plants within the ROI and

 how well the technology aligns with recent regulatory actions targeting fossil 

fuel-fired electric utility steam generating units.

Specifically, on January 8, 2014, EPA issued a proposed rule for carbon pollution that would 

apply performance standards to utility boilers and IGCC units based on partial implementation of 

a CCS system as the best method of emission reduction. The proposed emission limit for these 

sources is 1,100 lb carbon dioxide per megawatt hour (CO2/MWh). The proposed rule cites a 

number of IGCC projects and concludes that the projects are “consistent with the EIA modeling 

which projects that few, if any, new coal-fired units would be built in this decade and that those 

that are built would include CCS” (79 FR 1430). Therefore, for alternative analysis, the NRC 

staff considers IGCC power plants as a reasonable alternative to Braidwood because the 

Edwardsport IGCC project in Indiana is currently in operation and the Kemper IGCC project in 

Mississippi is under construction. The technology parameters for these plants are considered to 

be the current state of technology and are used here to describe a hypothetical IGCC power 

plant located on an existing power plant site within the ROI.

To replace the electricity that Braidwood generates, the NRC staff considered four IGCC units, 

each with a net capacity of 618 MWe. Various coal sources are available to coal-fired power 

plants in the ROI. For the purpose of this evaluation, the NRC staff assumes that the IGCC 

alternative would burn a subbituminous coal, based on the type of coal used in electric plants in 

Illinois. NRC staff presumes that coal burned in Illinois will be representative of coal that would 

be burned in an IGCC alternative regardless of where it may be located (EIA 2012b). The IGCC 

units would reduce sulfur dioxide, nitrogen oxides, mercury, and particulate emissions by 
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removing constituents from the syngas. The removal of nearly 100 percent of the nitrogen from 

the syngas prior to combustion in the gas turbines would result in significantly lower nitrogen 

oxide emissions compared to conventional coal-fired power plants (DOE 2010c). In addition, 

the units would be designed with the potential to add carbon capture systems at a later date. In 

a carbon capture system, carbon dioxide emissions would be compressed and piped off site 

where it could be sold for beneficial use or geologic storage. Additional discussion of air quality 

impacts associated with the IGCC alternative is presented in Chapter 4.

The IGCC alternative would be located at an existing site (such as an existing power plant site) 

to maximize availability of infrastructure and reduce other environmental impacts. Depending 

on the specific site location, there might be a need to construct new intake and discharge

facilities and a new cooling system. The IGCC alternative would use about the same amount 

of water as Braidwood and a similar amount as the Edwardsport IGCC plant. The NRC staff 

assumes the cooling system would use a closed-cycle system with mechanical draft cooling 

towers. This system would withdraw 25 million gallons per day (mgd) (95 million liters per day 

(Lpd)) of water and consume 20 mgd (76 million Lpd). Onsite visible structures could include 

the boilers, exhaust stacks, intake/discharge structures, mechanical draft cooling towers, 

transmission lines, and an electrical switchyard. Construction materials would be delivered via 

rail spur, truck, or barge, or all three depending on the specific site location. Modifications may 

be required to deliver such materials; modifications could include new rail lines or access roads.

The NRC staff also initially considered, but subsequently dismissed the use of supercritical 

pulverized coal (SCPC) as an alternative to renewing the Braidwood licenses (see Section 2.3).

2.2.2.3 Natural Gas Combined Cycle Alternative

In this section, the NRC staff describes the natural-gas-fired combined-cycle (NGCC) 

alternative. The NRC staff evaluates the environmental impacts from this alternative in 

Chapter 4.

Natural gas represents nearly 30 percent of installed generation capacity in the ROI, but 

provides only 6 percent of all electrical power in the ROI (EIA 2014a, 2014b). Nationwide, the 

percentage of power generated by natural gas is expected to rise by 2040, although the actual 

rise in natural gas generation will depend on future natural gas prices (EIA 2013b). For its 

analysis, the NRC staff considers the construction of an NGCC power plant to be a reasonable 

alternative to license renewal because it is a feasible, commercially available option for 

providing electrical generating capacity beyond the expiration of Braidwood’s current licenses.

Baseload NGCC power plants have proven their reliability and can have capacity factors as high 

as 85 percent. In an NGCC system, electricity is generated using a gas turbine that burns 

natural gas. A steam turbine uses the heat from the gas turbine’s exhaust through an HRSG

to produce additional electricity. This two-cycle process has high rates of efficiency since the 

exhaust heat that would otherwise be lost is captured and reused. Like other fossil fuel sources, 

NGCC power plants are a source of GHGs, including carbon dioxide. An NGCC power plant, 

however, produces significantly fewer GHGs per unit of electrical output than conventional 

coal-powered plants.

To replace the electricity that Braidwood generates, the NRC staff considered five NGCC units, 

each with a net capacity of 560 MWe (NETL 2007). The NRC staff assumes that each plant 

configuration consists of two combustion turbine generators, two HRSGs, and one steam 

turbine generator with mechanical draft cooling towers for heat rejection. To minimize the 

plant’s nitrogen oxide emissions, the power plant incorporates a selective catalytic reduction 

system (NETL 2007).
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This 2,800 MWe NGCC plant would consume 124 billion cubic feet (3,500 million cubic meters 

(m3)) of natural gas annually, assuming an average heat content of 1,021 British thermal units 

per cubic foot (EIA 2013c). Natural gas would be extracted from the ground through wells, then 

treated to remove impurities and blended to meet pipeline gas standards before being piped 

through the state pipeline system to the plant site. This NGCC alternative would produce 

relatively little waste, primarily in the form of spent catalysts used for control of nitrogen 

oxide emissions.

The NGCC alternative would be located at an existing power plant site to maximize availability 

of infrastructure and reduce other environmental impacts. Depending on the specific site 

location, there might be a need to construct new intake and discharge facilities and a new 

cooling system. Because NGCC power plants generate much of their power from a gas-turbine 

combined-cycle plant and the overall thermal efficiency of this type of plant is high, an NGCC 

alternative would require less cooling water than Braidwood. This system would withdraw 

17 mgd of water (64 million Lpd) and consume 13 mgd (49 million Lpd). The NRC staff 

assumes the cooling system would use a closed-cycle system with mechanical-draft cooling 

towers. Onsite visible structures could include the cooling towers, exhaust stacks, 

intake/discharge structures, transmission lines, natural gas pipelines, and an electrical 

switchyard. Construction materials would be delivered via rail spur, truck, or barge, or all three 

depending on the specific site location. Modifications may be required to deliver such materials; 

modifications could include new rail lines or access roads.

2.2.2.4 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

In this section, NRC staff describes the combination alternative to the continued operation of 

Braidwood consisting of an NGCC facility constructed at an existing power plant site, operating 

in conjunction with land-based wind farms as well as solar energy facilities, all of which would 

be located within the ROI. The NRC staff evaluates the environmental impacts from this 

alternative in Chapter 4.

To serve as an effective baseload power alternative to the Braidwood reactors, this combination 

alternative must be capable of providing an equivalent amount of baseload power. For the 

purpose of this evaluation and based on location-feasibility reasonableness, the NRC staff 

presumes that 15 percent of the annual power producing potential of the Braidwood reactors 

would be replaced by an NGCC plant, 75 percent would be replaced by wind farms, and the 

remaining 10 percent would come from solar photovoltaic facilities.

NGCC Portion of the Combination Alternative

To produce its required share of power, the NGCC portion, operating at an expected capacity 

factor of 85 percent (NETL 2007), would need to have a nameplate rating of approximately 

425 MWe.

In 2013, the EIA reported that natural gas-fired power plants are generally used infrequently for 

shorter periods of time to meet peak demand. Capacity factors for natural gas plants averaged 

less than 5 percent during offpeak demand hours for most regions of the country. Natural gas is 

used for these “peaker plants” because natural gas combustion turbines can respond quickly, so 

they tend to be used to meet short-term increases in electricity demand (EIA 2013d). A report 

prepared by CITI Research stated that gas-fired power plants can help overcome the 

intermittent nature of renewable energy (Channell et al. 2012). The peaking aspect of natural 

gas-fired power plants makes these plants an ideal addition to an otherwise renewable energy 

combination alternative.

NRC staff assumed that one new NGCC unit of the type described in Section 2.2.2.3 would 

be constructed and installed at an existing power plant site with a total net capacity of 
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approximately 360 MWe. The appearance of an NGCC unit would be similar to that of the full 

NGCC alternative considered in Section 2.2.2.3, although only one unit would be constructed. 

The NRC staff assumed that the NGCC portion of this alternative, which is assumed to be 

located at an existing power plant site, would use existing electrical switchyards, substations, 

and transmission lines. Depending on the existing site conditions, it is possible that intake and 

discharge structures of the existing cooling system could continue in service, but would be 

connected to a new closed-cycle cooling system. For the purposes of this analysis, the NRC 

staff assumes that the NGCC portion of the combination would use mechanical draft cooling 

towers.

Wind Portion of the Combination Alternative

The NRC staff assumed that the wind-generated power from this combination alternative would 

come from land-based wind farms which would be located in the ROI within the states of Illinois, 

Indiana, Iowa, Kentucky, Michigan, Missouri or Wisconsin. The wind portion, assuming a 

capacity factor of 30 percent, would require a nameplate capacity of 6,042 MWe (Western and 

FWS 2013).

The American Wind Energy Association (AWEA) reports a total of more than 60,000 MW 

of installed wind energy capacity nationwide as of March 31, 2013 (AWEA 2013). As of 

March 2013, Texas is by far the leader in installed land-based capacity with 12,214 MW. 

Two states in the ROI have the third- and fourth-largest installed capacity: Iowa with 5,133 MW, 

followed by Illinois with 3,568 MW (AWEA 2013). The installed wind capacity in the ROI has 

been increasing annually by 1,000 MWe to 2,500 MWe in each of the past 6 years, for a total of 

over 11,000 MWe of additional wind capacity from 2007 to 2012 (DOE 2013a). Therefore, NRC 

staff considers 6,042 MW of wind energy to be a reasonable amount by the time the Braidwood 

licenses expire in 2026 and 2027. As is the case with other renewable energy sources, the 

feasibility of wind resources serving as alternative baseload power is dependent on the location 

(relative to expected load centers), value, accessibility, and constancy of the resource. Wind 

energy must be converted to electricity at or near the point where it is extracted, and there are 

limited energy storage opportunities available to overcome the intermittency and variability of 

wind resource availability. At the current stage of wind energy technology development, wind 

resources in wind power class 3 and higher are suitable for most utility-scale applications 

(NREL 2014). Wind power class 3 is defined as having a wind speed of 15.7 miles per hour 

(mph) (7.0 meters per second (m/s)) and a wind density of 500 watts per square meter at 164 ft 

(50 m) (NREL 2014). Individual wind turbine capacity increased from 0.71 MW in 1999 to 

1.79 MW in 2010. The size of turbine most frequently installed in the United States in recent 

years is the 1.5-MW turbine (Western and FWS 2013). For the purposes of this analysis, the 

NRC staff assumes wind turbines with a capacity of 1.79 MW. The capacity factors of 

land-based wind farms are lower than offshore wind farms (Western and FWS 2013). For 

the wind portion of the combination alternative, the NRC staff assumed a capacity factor of 

30 percent, resulting in an estimated total net capacity of 1,813 MWe. Wind turbines must be 

well-separated from each other to avoid interferences to wind flowing through the wind farm, 

resulting in wind farms requiring substantial amounts of land. Wind turbines may require as 

much as 1 to 3 ac (0.4 to 1.2 ha) of land for each turbine (Western and FWS 2013). Based on 

the size of the turbines and amount of land required between each turbine, approximately 

3,376 turbines and 3,376 to 10,127 ac (1,366 to 4,098 ha) would be required for the wind 

portion of the combination alternative.

Wind energy’s intermittency affects its viability and value as a baseload power source. 

However, the variability of wind-generated electricity can be lessened if the proposed wind 

farms were located at a large distance from one another and operated as interconnected wind 

farms, an aggregate controlled from a central point. Distance separation ensures that the 
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two wind farms will not simultaneously experience the same climate, and power will likely 

be produced at some of the wind farms at any given time (Archer and Jacobson 2007).

Solar Photovoltaic Portion of the Combination Alternative

The solar portion of the combination alternative would be generated through one or more solar 

photovoltaic energy facilities located in the ROI. Assuming a capacity factor of 19 percent, the 

solar energy facilities would need a collective nameplate rating of 1,193 MWe. Solar 

photovoltaic technologies could be installed on building roofs at existing residential, commercial, 

or industrial sites or at larger standalone solar facilities.

Nationwide, growth in large solar photovoltaic facilities (greater than 5 MW) has resulted in an 

increase from 70 MW in 2009 to over 700 MW installed capacity in 2011. As of January 2012, it 

is estimated that more than 11,000 MW of large solar photovoltaic projects have signed power 

purchase agreements (Mendelsohn et al. 2012). Over 9,000 MW of those solar projects are 

50 MW or greater, although most are located in the southwestern United States 

(Mendelsohn et al. 2012). As described in Section 2.2.2, two states in the ROI (Missouri and 

Illinois) have renewable energy legislation that includes requirements for solar photovoltaic 

technology. Missouri’s renewable portfolio standard includes a provision specifying that 

2 percent of the renewable portfolio standard requirement must be met by solar energy by 2021. 

Illinois’ renewable portfolio standard specifies that solar photovoltaic must comprise 6 percent of 

the annual requirement for the year 2015-2016 and thereafter. As of 2010, only 9 MW of solar 

energy capacity had been installed in the ROI.

Photovoltaic solar resources in the ROI range from 4.0 to 5.0 kilowatt hours per square meter 

per day (kWh/m2

/day). The most viable solar resources are located in Missouri, Iowa, and 

southern Illinois and Indiana (NREL 2013a). Economically viable solar resources are 

considered to be 6.75 kWh/m2/day and greater (BLM and DOE 2010). As is the case with wind 

energy sources, the feasibility of solar energy resources serving as alternative baseload power 

is dependent on the location, value, accessibility, and constancy of the resource. Solar 

photovoltaic uses solar panels to convert solar radiation into usable electricity. Solar cells are 

formed into solar panels by solar manufacturers which can then be linked into photovoltaic 

arrays to generate electricity. The electricity generated can be stored, used directly, fed into 

a large electricity grid, or combined with other electricity generators as a hybrid plant. Solar 

photovoltaic can generate electricity whenever there is sunlight, regardless of whether or not the 

sun is directly shining on solar panels. Therefore, solar photovoltaic technologies do not need 

to directly face and track the sun which has allowed solar photovoltaic systems to have broader 

geographical use than concentrated solar power (CSP) (Ardani and Margolis 2011a). Because 

the ROI contains average solar photovoltaic resources and solar photovoltaic is a commercially 

available option for providing electrical generating capacity, the NRC staff considers the 

construction of solar photovoltaic facilities to be a reasonable alternative to license renewal 

when combined with wind and NGCC.

For the purposes of this analysis, the NRC staff assumes solar photovoltaic facilities with a 

capacity factor of 19 percent (Ardani and Margolis 2011). Solar photovoltaic facilities may 

require 6.2 ac (2.5 ha)/MW of land (NRC 2013a). Although not all of this land would be cleared 

of vegetation and permanently impacted, the area (6.2 ac) represents the land enclosed in the 

total site boundary of the solar facility (Ong et al. 2013). For the solar portion of this 

combination alternative, approximately 7,397 ac (2,993 ha) would be required to support an 

installed net capacity of 227 MWe. In this analysis, the NRC staff does not speculate on the 

number and size of individual solar facilities, nor their location within the ROI. However, as 

stated above, some of the output could be realized by solar photovoltaic installations on building 

roofs at existing residential, commercial, or industrial sites or at larger standalone solar facilities. 
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As long as rooftop or building-integrated solar photovoltaic installations remain popular, effects 

to land use would be relatively minor. Solar photovoltaic systems do not require water for 

cooling purposes, but a small amount of water is needed to clean the panels and for potable 

water for the workforce. Impacts identified in the Solar Energy Programmatic Environmental 

Impact Statement (PEIS) (BLM and DOE 2010, 2012) among other technical reports, provide 

information used in the analyses presented in the impact sections in Chapter 4.

2.2.2.5 Purchased Power

In this section, the NRC staff describes purchased power as an alternative to the continued 

operation of Braidwood.

The specific characteristics associated with any purchased power alternative would depend 

substantially on the generation technologies used to supply the purchased power. As discussed 

in Section 2.2.2, replacement power for Braidwood would be required in northern Illinois and 

could come from anywhere within Illinois or adjoining states in either the PJM or MISO RTOs. 

Given the large geographic area, multiple RTOs within the ROI, and wide-ranging generating 

facilities, the NRC staff considers purchased power to be a feasible source of baseload power 

to replace Braidwood by the time the licenses expire in 2026 and 2027.

Purchased power would likely come from the most common types of electricity generation within 

the ROI: coal, natural gas, nuclear, and wind. Each of these power sources is discussed as an 

alternative to license renewal of Braidwood and is identified in Sections 2.2.2.1 to 2.2.2.4. 

Construction and operational impacts from these sources of electricity generation are 

considered in Chapter 4. Purchased power may require new transmission lines (which may 

require new construction). Purchased power also may rely on older and less-efficient power 

plants operating at higher capacities than they currently operate or new facilities that would be 

constructed. During operations, impacts from nuclear, coal-fired, and natural gas-fired plants, 

wind, and solar energy projects would be similar to those described under the new nuclear, 

coal, natural gas, and combination alternatives detailed in Chapter 4 for all resource areas.

2.3 Alternatives Considered but Dismissed

Alternatives to Braidwood license renewal that were considered and eliminated from detailed 

analysis are presented in this section. These alternatives were eliminated because of technical, 

resource availability, or current commercial limitations. Many of these limitations will continue to 

exist when the current Braidwood licenses expire.

2.3.1 Energy Conservation and Energy Efficiency

Energy conservation can include reducing energy demand through behavioral changes or 

altering the shape of the electricity load and usually does not require the addition of new 

generating capacity. Conservation and energy efficiency programs are more broadly referred 

to as demand-side management (DSM).

Conservation and energy efficiency programs can be initiated by a utility, by transmission 

operators, by the state, or by other load-serving entities. The State of Illinois’ renewable 

portfolio standard includes an energy efficiency portfolio standard that requires utilities to reduce 

electric usage by 2 percent of demand by 2015 (DSIRE 2012a), which is equivalent to 

4 million MWh, only 20 percent of the amount that would be required to offset Braidwood’s 

current electrical generation.

In general, residential electricity consumers have been responsible for the majority of peak 

load reductions, and participation in most programs is voluntary. Therefore, the existence of 
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a program does not guarantee that reductions in electricity demand would occur. The GEIS

concludes that, while the energy conservation or energy efficiency potential in the United States 

is substantial, there are likely no cases where an energy efficiency or conservation program has 

been implemented expressly to replace or offset a large baseload generation station 

(NRC 2013b). While significant energy savings are possible in the ROI through DSM and 

energy efficiency programs, conservation and energy efficiency programs are not likely to 

replace Braidwood as a standalone alternative, and therefore the NRC staff does not consider 

conservation and energy efficiency to be a reasonable alternative to license renewal.

2.3.2 Solar

Solar power, including solar photovoltaic and CSP technologies, produces power generated 

from sunlight. Photovoltaics convert sunlight directly into electricity using solar cells made from 

silicon or cadmium telluride. Concentrating solar power uses heat from the sun to boil water 

and produce steam to drive a turbine connected to a generator to produce electricity (NREL 

2013b). To be considered a viable alternative, a solar alternative must replace the amount of 

electricity Braidwood provides. Assuming a capacity factor of 19 percent (Ardani and Margolis 

2011), approximately 12,400 MWe of electricity would need to be generated by solar energy 

facilities in the seven-state ROI.

In 2011, 14 MWh of electricity was generated from solar energy in the ROI (EIA 2014b). The 

National Renewable Energy Laboratory (NREL) within DOE reports that the states in the ROI 

receive solar insolation of 4.0–5.0 kWh/m2

/day, which is considered low to average 

(NREL 2013a). For utility-scale development, insolation levels below 6.5 kWh/m2

/day are not 

considered economically viable given current technologies (BLM and DOE 2010). There is 

more potential for solar development using local photovoltaic applications, such as rooftop solar 

panels, than through utility-scale solar facilities. In addition, a solar facility can only generate 

electricity when the sun is shining. Energy storage can be used to overcome intermittency for 

CSP facilities; however, current and foreseeable storage technologies that have been paired 

with solar power facilities have a much smaller capacity than would be necessary to replace 

Braidwood. Taking all of the factors above into account, it is unlikely that solar photovoltaic or 

CSP technologies could serve as baseload power in the ROI to replace Braidwood’s current 

electricity output. Given the modest levels of solar energy available throughout the ROI, the 

lack of substantial installed solar capacity in the ROI, and the weather-dependent intermittency 

of solar power, the NRC staff concludes that a solar power energy facility in the ROI would not 

be a reasonable alternative to license renewal. The NRC staff evaluated an alternative of solar 

power in combination with wind and an NGCC plant in Section 2.2.2.4.

2.3.3 Wind

Two states in the ROI have the third- and fourth-largest installed capacity in the Nation: Iowa 

with 5,133 MW, followed by Illinois with 3,568 MW (AWEA 2013). The installed wind capacity in 

the ROI has been increasing annually by 1,000 MWe to 2,500 MWe in each of the past 6 years, 

for a total of over 11,000 MWe of additional wind capacity from 2007 to 2012 (DOE 2013a). 

All of the wind energy facilities and the electricity generation from wind currently being produced 

in the ROI are land-based. To be considered a viable alternative, a wind alternative must 

replace the amount of electricity Braidwood provides. Assuming a capacity factor of 30 percent 

for land-based wind and 40 percent for offshore wind, a range of 5,665 to 7,553 MWe of 

electricity would need to be generated by some combination of land-based and offshore 

wind energy facilities in the seven-state ROI.
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As is the case with other renewable energy sources, the feasibility of wind resources serving 

as alternative baseload power is dependent on the location (relative to expected load centers), 

value, accessibility, and constancy of the resource. Wind energy must be converted to 

electricity at or near the point where it is extracted, and there are limited energy storage 

opportunities available to overcome the intermittency and variability of wind resource availability. 

Although wind power is intermittent and individual facilities are unable to provide baseload 

power, it has been proposed that multiple interconnected wind installations separated by long 

distances could theoretically function as a virtual power plant and provide baseload power, 

since individual facilities would be exposed to different weather and wind conditions. To date, 

however, no states or utilities operate arrays of wind installations as virtual power plants.

Given the amount of wind capacity necessary to replace Braidwood and the intermittency 

of wind power, the NRC staff finds a completely wind-based alternative to be unreasonable. 

However, the NRC staff also concludes that, when used in combination with other technologies 

with inherently higher capacity factors, wind energy can provide a viable alternative. The NRC 

staff described such a possible combination alternative in Section 2.2.2.4.

2.3.3.1 Offshore Wind

The United States currently does not have any offshore wind farms in operation; however, 

approximately 20 projects representing more than 2,000 MW of capacity are in the planning 

and permitting process as of 2010 (Musial and Ram 2010). Offshore wind projects have been 

developed in Europe, most of which are located close to shore and in shallow water below 

98.4 ft (30.0 m) in depth. Total worldwide installed capacity has been estimated at 2,377 MW 

(Musial and Ram 2010).

While wind data suggest there is potential for offshore wind farms in the Great Lakes, project 

costs likely limit the future potential of large-scale projects (Tidball et al. 2010). Tidball et al. 

(2010) estimated that offshore project costs would run approximately 200 to 300 percent higher 

than land-based systems. Also, based on current prices for wind turbines, the 20-year levelized 

cost of electricity produced by an offshore wind farm would be above the current production 

costs from existing power generation facilities. In addition to cost, other barriers include the 

immature state of the technology, limited resource area, and high risks and uncertainty (Tidball 

et al. 2010). As no offshore wind capacity yet exists in either the Great Lakes or on the Atlantic 

Coast and as none appears likely to exist on a large commercial scale in the Great Lakes by 

2026 (given the current state of development), the NRC staff finds that offshore wind will not be 

a reasonable alternative to Braidwood during the license renewal term.

2.3.3.2 Wind Power With Storage

Energy storage is one possible way to overcome intermittency. Besides pumped hydroelectric 

facilities, compressed air energy storage (CAES) is the technology most suited for storage of 

large amounts of energy. In CAES systems, electricity generated during low-demand periods 

can be stored by using a compressor to pressurize and store air, and during high-demand 

periods, the compressed air can be used to drive a turbine to generate electricity. A 2011 DOE

report analyzed various power generation sources, including wind, coupled with CAES systems 

(DOE 2011b). The report considered siting criteria, using (1) proximity to natural gas lines, 

high-voltage transmission, and a market for wholesale electric power and (2) availability of 

geology and wind resources. The results show that within the ROI there is potential for 

one CAES site in northwest Iowa. Without detailed wind-speed data, specific site information, 

and detailed information on the energy-storage capacity of the potential CAES site, it is difficult 

to estimate how much wind capacity would be necessary and whether or not it could provide for 

an all-wind alternative. Furthermore, the NRC staff is not aware of a CAES project coupled with 
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wind generation that is providing baseload power. Therefore, the NRC staff concludes that the 

use of CAES in combination with wind turbines to replace the Braidwood power plant is unlikely.

2.3.3.3 Conclusion Summary

Despite the relatively high reliability demonstrated by modern turbines, the recent technological 

advancements in turbine design and wind farm operation, and wind energy’s dramatic market 

penetrations of recent years, empirical data on wind farm capacity factors and wind energy’s 

limited ability to store power for delayed production of electricity give reasons for the NRC staff 

to conclude that wind energy—on shore, off shore, or a combination thereof—could not serve as 

a discrete alternative to the baseload power supplied by the Braidwood reactors. However, the 

NRC staff also concludes that, when used in combination with other technologies with inherently 

higher capacity factors, wind energy can provide a viable alternative. The NRC staff described 

such a possible combination alternative in Section 2.2.2.4.

2.3.4 Biomass

Biomass resources used for biomass-fired generation include agricultural residues, animal 

manure, wood wastes from forestry and industry, residues from food and paper industries, 

municipal green wastes, dedicated energy crop, and methane from landfills (IEA 2007). Using 

biomass-fired generation for baseload power depends on the geographic distribution, available 

quantities, constancy of supply, and energy content of biomass resources. For this analysis, the 

NRC staff assumed that biomass would be combusted for power generation in the electricity 

sector. Biomass is also used for space heating in residential and commercial buildings and can 

be converted to a liquid form for use in transportation fuels (Haq undated).

In the GEIS, the NRC staff indicated a wood waste facility could provide baseload power and 

operate with capacity factors between 70 and 80 percent (NRC 2013b). Although the ROI 

currently produces electricity from biomass fuels, the plants operating within the ROI generated 

569 MWe in 2010 (EIA 2012a). Based on the relatively low electricity generation currently 

produced at biomass plants, it is unlikely that these plants, or the construction of several new 

biomass plants, could increase capacity by adding 2,400 MWe of electricity from biomass-fired 

generation by the time Braidwood’s licenses expire in 2026 and 2027.

For utility-scale biomass electricity generation, the NRC staff assumes that the technologies 

used for biomass conversion would be similar to fossil fuel plants including the direct 

combustion of biomass in a boiler to produce steam (NRC 2013b). Biomass generation 

is generally more cost-effective when cofired with coal plants (IEA 2007). Biomass-fired 

generation plants generally are small and can reach capacities of 50 MWe, meaning that over 

40 new facilities would be required before the Braidwood licenses expire. After reevaluating 

current technologies, the NRC staff finds biofuel-fired alternatives as still unable to reliably 

replace the Braidwood capacity. For this reason, the NRC staff does not consider biofuels to be 

a reasonable alternative to Braidwood license renewal.

2.3.5 Hydroelectric

Hydroelectric power uses the force of water to turn turbines, which spin a generator to produce 

electricity. In a run-of-the-river system, the force of a river current provides the force to create 

the needed pressure for the turbine. In a storage system, water is accumulated in reservoirs 

created by dams and is released as needed to generate electricity.

DOE’s Idaho National Engineering and Environmental Laboratory (INEEL) (now Idaho National 

Laboratory) completed a comprehensive survey of hydropower resources in 1997. The ROI has 

hydroelectric generating potential of 1,954 MW, adjusting for environmental, legal, and 
Alternatives Including the Proposed Action

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institutional constraints (INEEL 1998). These constraints could include (1) scenic, cultural, 

historical, and geological values; (2) Federal and state land use; and (3) legal protection issues 

such as Wild and Scenic legislation, and Threatened or Endangered Fish and Wildlife legislative 

protection. A separate assessment by DOE of nonpowered dams (dams that do not produce 

electricity) concluded that there is potential for a total of 4,185 MW of electricity in the ROI 

(Hadjerioua et al. 2012). These nonpowered dams serve various purposes such as providing 

water supply to inland navigation.

The EIA reported that the states comprising the ROI generated 2,262 MW electricity from 

hydroelectric power in 2012 (EIA 2014a). To replace Braidwood’s current output, hydroelectric 

generation across the ROI would need to double by 2026. Although there is potential for 

anywhere between 1,954 MW and 4,185 MW of hydroelectric power, it is unlikely that the 

maximum levels of development would occur across the entire ROI by the time Braidwood’s 

licenses expire in 2026 and 2027 given that the generating capacity of hydroelectric power is 

projected to continue to decrease in generating capacity through 2040 (EIA 2013a). Given the 

decrease in projected power generation from hydroelectric facilities, the NRC staff does not 

consider hydroelectric power to be a reasonable alternative to Braidwood license renewal.

2.3.6 Wave and Ocean Energy

Waves, currents, and tides are often predictable and reliable, making them attractive candidates 

for potential renewable energy generation. There are four major technologies that may be 

suitable to harness wave energy: (1) terminator devices, which range from 500 kilowatts (kW) 

to 2 MW; (2) attenuators; (3) point absorbers; and (4) overtopping devices (BOEM undated). 

Point absorbers and attenuators use floating buoys to convert wave motion into mechanical 

energy, driving a generator to produce electricity. Overtopping devices trap a portion of a wave 

at a higher elevation than the sea surface; waves then enter a tube, compressing air that is 

used to drive a generator which produces electricity (NRC 2013b). Some designs are 

undergoing demonstration testing at commercial scales, but none are currently used to 

provide baseload power (BOEM undated).

The Great Lakes do not experience large tides, and there is limited energy output for wave 

technologies in the Great Lakes. The Electric Power Research Institute (EPRI) published a 

document that assessed ocean wave energy resources in the United States. The Great Lakes 

were not included in the analysis, suggesting that the resource potential is not great enough to 

use on a commercial scale (EPRI 2011). Consequently, the limited resource availability and 

infancy of the technologies in the Great Lakes support the NRC staff’s conclusion that wave and 

ocean energy technologies are not feasible substitutes for Braidwood license renewal.

2.3.7 Fuel Cells

Fuel cells oxidize fuels without combustion and its environmental side effects. Fuel cells use a 

fuel (e.g., hydrogen) and oxygen to create electricity through an electrochemical process. The 

only byproducts (depending on fuel characteristics) are heat, water, and carbon dioxide

(depending on hydrogen fuel type) (DOE 2010a). Hydrogen fuel can come from a variety 

of hydrocarbon resources. Natural gas typically is used as the hydrogen source.

Presently, fuel cells are not economically or technologically competitive with other alternatives

for electricity generation. The EIA projects that fuel cells may cost $6,835 per installed kW (total 

overnight capital costs, 2010 dollars), which is high compared to other alternative technologies 

analyzed in this section (EIA 2010). More importantly, fuel cell units are likely to be small in size 

(approximately 10 MWe). It would be prohibitively costly to replace the power Braidwood 

provides; it would require approximately 230 units and modifications to the existing transmission 
Alternatives Including the Proposed Action

2-22

system. Given the immature status of fuel cell technology and high cost, the NRC staff does not 

consider fuel cells to be a reasonable alternative to Braidwood license renewal.

2.3.8 Delayed Retirement

A delayed retirement alternative would consider deferring the retirement of generating 

facilities in Illinois and its six adjoining states which include MISO and PJM RTOs.

To maintain reliable operations, electric systems must be able to meet peak load requirements. 

To ensure sufficient capacity, this must also include a planning reserve margin (FERC 2013). 

The projected MISO reserve margin for 2021 is 18.6 percent, which exceeds the reserve margin 

requirement of 17.4 percent. However, pending EPA regulations may lead to increased coal 

plant retirements at a faster pace than projected. In that case, 3,000 MW to 12,600 MW of plant 

retirements could decrease the projected reserves anywhere from 16.22 to 6.9 percent, well 

below the reserve margin requirement (MISO 2011).

PJM is facing similar constraints due, in large part, to retirements of coal plants given air quality 

regulations (PJM 2013a). This indicates an emerging reliability problem potentially affecting 

major population centers within the PJM region in the near future (PJM 2013a). Because the 

current generation mix has not resulted in the long-term commitment of generation needed for 

reliability, generation retirements that have occurred with short notice have created 

unanticipated reliability problems for PJM (PJM 2013a). 

The 2014 Annual Energy Outlook is predicting that there will be more coal plant retirements 

before 2016 than previously predicted. These accelerated retirements are driven by low natural 

gas prices, slow growth in electricity demand, and the requirements of the Mercury and Air 

Toxics Standards which will require significant reductions in plant emissions (EIA 2014). Exelon 

also expects increased generation retirements for a variety of reasons, including increased 

operating costs for older facilities, increased environmental regulations and competition, and 

decreased load (Exelon 2010). As generators are required to adhere to future regulations, 

some power plant owners may opt for early retirement of older units rather than incurring the 

cost of compliance. Exelon has stated that some of its nuclear fleet may be retired early 

because of low wholesale energy prices and current energy policy (Bloomberg 2014). Because 

of the uncertain regulatory environment and concerns expressed by MISO and PJM regarding 

the retirement pace of coal power plants, the NRC staff does not consider delayed retirement to 

be a reasonable alternative to Braidwood license renewal.

2.3.9 Geothermal

Geothermal technologies extract the heat contained in geologic formations to produce steam to 

drive a conventional steam turbine generator. Facilities producing electricity from geothermal 

energy have demonstrated capacity factors of 95 percent or greater, making geothermal energy 

a potential source of baseload electric power. However, the feasibility of geothermal power 

generation to provide baseload power depends on the regional quality and accessibility of 

geothermal resources. Utility-scale geothermal energy generation requires geothermal 

reservoirs with a temperature above 200 °F (93 °C). Utility-scale power plants range from small 

300 kilowatts electrical to 50 MWe and greater (TEEIC undated). Geothermal resources are 

concentrated in the Western United States. Specifically, these resources are found in Alaska, 

Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, 

Washington, and Wyoming (USGS 2008). In general, most assessments of geothermal 

resources have been concentrated on these Western states. Geothermal resources are used 

in the ROI for heating and cooling purposes, but no electricity is currently being produced from 
Alternatives Including the Proposed Action

2-23

geothermal resources in the ROI (EIA 2012a). Given the low resource potential in the ROI, the 

NRC staff does not consider geothermal to be a reasonable alternative to Braidwood license 

renewal.

2.3.10 Municipal Solid Waste

Energy recovery from municipal solid waste converts nonrecyclable waste materials into usable 

heat, electricity, or fuel through combustion (EPA 2013a). The three types of combustion 

technologies include mass burning, modular systems, and refuse-derived fuel systems 

(EPA 2013b). Mass burning is currently the method used most frequently in the United States. 

The heat released from combustion is used to convert water to steam, which is used to drive a 

turbine generator to produce electricity. Ash is collected and taken to a landfill, and particulates 

are captured through a filtering system (EPA 2013b). As of 2010, approximately 

86 waste-to-energy plants are in operation in 25 states, processing more than 28 million tons 

of waste per year (EPA 2013a). These waste-to-energy plants have an aggregate capacity of 

2,720 MWe, and although some plants have expanded to handle additional waste and produce 

more energy, no new plants have been built in the United States since 1995 (EPA 2013a). The 

average waste-to-energy plant produces about 50 MWe, with some reaching 77 MWe, and can 

operate at capacity factors greater than 90 percent (Michaels 2010). Indiana has one waste 

recovery facility that produces steam; Iowa has one waste-to-energy facility that produces 

10 MW of electricity; Michigan has three facilities that produce a total of 89.7 MW of electricity; 

and Wisconsin has two facilities that generate a total of 32.3 MW of electricity (Michaels 2010). 

In total, as of 2010, the ROI had a municipal solid waste generating capacity of 132 MW. More 

than 46 average-sized plants would be necessary to provide the same level of output as 

Braidwood, almost doubling the national waste-to-energy generation.

The decision to burn municipal waste to generate energy is usually driven by the need for an 

alternative to landfills rather than energy considerations. Given the improbability that additional 

stable supplies of municipal solid waste would be available to support approximately 46 new 

facilities and that so few existing plants operate in the ROI, the NRC staff does not consider 

municipal solid waste combustion to be a reasonable alternative to Braidwood license renewal.

2.3.11 Oil-Fired Power

In the ROI, the percent of electricity from oil-fired generation was 0.5 percent in 2010 and had a 

generating capacity of 5,942 MW (EIA 2012a).

The variable costs of oil-fired generation tend to be greater than those of the nuclear or coal 

fired operations, and oil-fired generation tends to have greater environmental impacts than 

natural gas-fired generation. The high cost of oil has resulted in a steady decline in its use for 

electricity generation (EIA 2013b). Given the high cost of oil and the small generating capacity 

from oil-fired power plants in the ROI, the NRC staff does not consider oil-fired generation a 

reasonable alternative to Braidwood license renewal.

2.3.12 Supercritical Pulverized Coal

In general, supercritical pulverized coal (SCPC) power plants are feasible, commercially 

available options for providing electrical generating capacity. Baseload coal units have proven 

their reliability and can sustain capacity factors as high as 79 percent. Pulverized coal power 

generation uses crushed coal that is fed into a boiler where it is burned to create heat. The heat 

produces steam that is used to spin one or more turbines to generate electricity. Among the 

technologies available, pulverized coal boilers producing supercritical steam (SCPC boilers) are 

increasingly common for new coal-fired plants given their high operating temperatures and 
Alternatives Including the Proposed Action

2-24

pressures which increase thermal efficiencies and overall reliability. Supercritical pulverized 

coal facilities consume less fuel per unit output, reducing environmental impacts 

(NETL undated).

As described in Section 2.2.2.2, the EPA has issued a proposed rule for carbon pollution that 

would apply to new fossil fuel-fired power plants, including SCPC facilities. The action proposes 

performance standards and has identified a CCS system as the best method of emission 

reduction. The proposed emission limit for these sources is 1,100 lb CO2/MWh. The EIA 

modeling projects that if the proposed rule is implemented, few, if any, new coal-fired units 

would be built and that those that are built would include CCS (79 FR 1430). If this rule 

becomes final, any new coal-fired power plants would likely require CCS in order to achieve 

the 1,100 lb CO2/MWh emission limit.

In addition, given known technology and technological and demographic trends, EIA predicts 

that by 2040 natural gas will surpass coal as the largest share of U.S. electric power generation 

(EIA 2013b). This does not consider the proposed EPA rule described above, but indicates a 

general trend away from coal-fired facilities in favor of natural gas-fired power plants due to 

falling natural gas prices. MISO projects that the pending EPA regulations could lead to 

increased coal plant retirements and estimates retirements between 3,000 MW and 12,600 MW, 

which could have a large impact on MISO’s reserve margin in the future (MISO 2011).

Although SCPC plants are currently the most widely used source of electricity generation within 

the ROI, given the potential for stringent air quality regulations and trends towards natural 

gas-fired power plants, the NRC staff does not consider SCPC to be a reasonable alternative 

to Braidwood license renewal. Instead, the NRC staff describes an IGCC plant under the coal 

alternative in Section 2.2.2.2 for analysis.

2.4 Comparison of Alternatives

In this chapter, the NRC staff considered the following alternatives to Braidwood license 

renewal: new nuclear generation; coal-IGCC generation; NGCC generation; a combination 

alternative of natural gas, wind, and solar; and purchased power. No-action alternative and 

its impacts also were considered. Table 2–2 provides a summary of the impacts analyzed in 

Chapter 4.

The environmental impacts of the proposed action (issuing renewed Braidwood operating 

licenses) would be SMALL for all impact categories, except for the issues of “Chronic effects

of electromagnetic fields (EMFs)” and “Offsite radiological impacts of spent nuclear fuel and 

high-level waste disposal” which both have an impact level of “Uncertain Impact” and the issue 

of “Offsite radiological impacts – collective impacts from other than the disposal of spent fuel

and high-level waste” to which the NRC has not assigned an impact level. The environmental 

impacts from all other alternatives would be larger than those of the proposed license renewal, 

as indicated in Table 2–2.

In conclusion, the environmentally preferred alternative is the license renewal of Braidwood. All 

other alternatives capable of meeting the needs currently served by Braidwood entail potentially 

greater impacts than the proposed action of license renewal of Braidwood. To make up the lost 

generation if a renewed license is not issued (the no-action alternative), one or a combination of 

alternatives would be implemented, all of which have greater impacts than the proposed action. 

Hence, the NRC staff concludes that the no-action alternative will have environmental impacts 

greater than or equal to the proposed license renewal action.
2-25

Table 2–2. Summary of Environmental Impacts of Proposed Action and Alternatives

Alternative

Air QualityNoise

and Groundwater

Surface Water ResourcesAquatic ResourcesTerrestrial ResourcesHuman HealthEnvironmental JusticeLand Use 

Resources Visual 

Socioeconomics Transportation

License 

renewal SMALL SMALL SMALL SMALL to MODERATE SMALL SMALL NA (b) SMALL SMALL SMALL SMALL 

New nuclear at 

an existing site SMALL SMALL SMALL to MODERATE SMALL SMALL to MODERATE SMALL NA (b) SMALL SMALL to MODERATE

SMALL 

to 

LARGE

SMALL to 

LARGE 

NGCC at an 

existing site MODERATE SMALL SMALL SMALL to MODERATE 

SMALL to 

MODERATE SMALL NA (b) SMALL SMALL to 

MODERATE

SMALL 

to 

LARGE

SMALL to 

LARGE 

IGCC at an 

existing site MODERATE SMALL to MODERATE SMALL SMALL to MODERATE MODERATE SMALL NA (b) SMALL to MODERATE

SMALL to 

MODERATE

SMALL 

to 

LARGE

SMALL to 

LARGE 

Combination 

alternative

(NGCC, Wind, 

and Solar)

SMALL to 

MODERATE 

SMALL to 

MODERATE SMALL SMALL SMALL to MODERATE SMALL NA (b) SMALL to 

MODERATE

SMALL to 

LARGE SMALL SMALL to 

MODERAT

Purchased 

power 

alternative

SMALL to 

MODERATE

SMALL to 

MODERATE SMALL SMALL SMALL SMALL NA (b) SMALL SMALL

SMALL 

to 

LARGE

SMALL to 

LARGE

No-action

alternative SMALL SMALL SMALL SMALL SMALL SMALL NA (b) SMALL to MODERATE SMALL

SMALL 

to 

LARGE

SMALL 

(a) The NRC staff concludes that there would be no adverse effect on historic and cultural resources for license renewal alternatives. (b) Except for No-Action alternative, there are no disproportionately high and adverse human health and environmental effects on minority 

populations. The No-Action alternative could disproportionately affect minority and low-income populations.
Alternatives Including the Proposed Action

2-26

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[DSIRE] Database of State Incentives for Renewables & Efficiency. 2012d. 

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3-1 

3.0 AFFECTED ENVIRONMENT

Braidwood Station (Braidwood) is located in Will County, Illinois. The plant consists of 

two reactor units. Each nuclear reactor is a pressurized water reactor (PWR) with steam 

generators producing steam that turns turbines to generate electricity. For purposes of the 

evaluation in this report, the “affected environment” is the environment that currently exists at 

and around Braidwood. Because existing conditions are at least partially the result of past 

construction and operation at the plant, the impacts of these past and ongoing actions and 

how they have shaped the environment are presented here. The facility and its operation are 

described in Section 3.1. The affected environment is presented in Section 3.2 to 3.13.

3.1 Description of Nuclear Power Plant Facilities and Operation

Braidwood is a two-unit, nuclear-powered steam electric generating facility that began 

commercial operation in July 1988 (Unit 1) and October 1988 (Unit 2). The nuclear reactor

for each unit is a Westinghouse PWR, producing a reactor core rated thermal power of 

3,586 megawatts thermal. Generally, U.S. Nuclear Regulatory Commission (NRC) staff drew 

information about Braidwood facilities and operation from Exelon’s Environmental Report (ER), 

Updated Final Safety Analysis Report, and Braidwood licenses. In this supplemental 

environmental impact statement (SEIS), the use of “Braidwood” is referring to the site (including 

the station) where the “Braidwood Station, Units 1 and 2” are located. The use of “Exelon” is 

referring to the applicant (Exelon Generation Company, LLC) who submitted the license renewal 

application (LRA).

3.1.1 External Appearance and Setting

Braidwood Station is located approximately 80 to 97 km (50 to 60 mi) southwest of the Chicago 

Metropolitan Area (CMA), and 32 to 40 km (20 to 25 mi) south-southwest of Joliet. The site is 

located on the Kankakee plain in an area where former farmlands were displaced by strip coal 

mining (Exelon 2013a, 2013b, 2013c). The Kankakee River is approximately 8 km (5 mi) east 

of the eastern site boundary.

The Braidwood site occupies an area of approximately 1,804 hectares (ha) (4,457 acres (ac)). 

It has a cooling pond of approximately 1,030 ha (2,540 ac). Figures 3–1 and 3–2 are extracted 

from the ER, which show the Braidwood 50-mi and 6-mi Radius Maps, respectively. The pond 

is used to dissipate waste heat from the reactor. The public has access to the cooling pond as 

a result of a 1991 long-term lease agreement between Exelon Generation and the Illinois 

Department of Natural Resources (IDNR). The cooling pond is part of the Mazonia-Braidwood 

State Fish and Wildlife Area. It is managed jointly by Exelon Generation and the IDNR 

(Exelon 2013a, 2013b, 2013c). The cooling pond takes makeup water from and discharges

(blowdown) to the Kankakee River. A right-of-way (ROW) for the water intake and discharge 

pipes runs from the northeast site boundary approximately 8 km (5 mi), east to the Kankakee 

River (Exelon 2013a, 2013b, 2013c).

The nuclear generating facilities are located in the northwest quadrant of the site and include 

the two reactor containment buildings and related structures (e.g., auxiliary and turbine 

buildings), a switchyard, administration buildings, warehouses, and other features 

(Exelon 2013a, 2013b, 2013c).

One Braidwood 345-kilovolt (kV) transmission line ROW provides connection from Braidwood 

to a substation near Crete, Illinois, and the electric grid (Exelon 2013a, 2013b, 2013c).
Affected Environment

3-2 

Figure 3–1. Braidwood 50-mi (80-km) Radius Map

Source: Exelon 2013e
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Figure 3–2. Braidwood 6-mi (10-km) Radius Map

Source: Exelon 2013e
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3-4 

3.1.2 Nuclear Reactor Systems

The nuclear steam supply system at Braidwood is a four-loop Westinghouse PWR. The reactor

core heats water, which is pumped to four steam generators where the heat boils the water on 

the shell-side into steam that is routed to the turbines. The steam turns the turbines, which are 

connected to the electrical generator. The Unit 1 steam generators were replaced in 1998. The 

ER indicates that the Unit 2 steam generators have not been replaced.

The nuclear fuel is low-enriched uranium dioxide with enrichments to a nominal 5 percent by 

weight uranium-235 and an allowable fuel burnup levels not to exceed 60,000 megawatt-days 

per metric ton uranium. Braidwood operates on an 18-month refueling cycle.

The reactor, steam generators, and related systems are enclosed in a containment building. 

The containment building is a steel-lined post-tensioned, reinforced concrete cylinder with a slab 

base and a shallow dome. A welded steel liner is attached to the inside face of the concrete 

shell to ensure a high degree of leak tightness. In addition, the thick concrete walls serve as a 

radiation shield to limit personnel exposure to less than NRC regulated limits. In addition, the 

containment systems would ensure the off-site doses resulting from postulated accidents are 

below NRC guidelines.

3.1.3 Cooling and Auxiliary Water Systems

Braidwood uses a closed-cycle cooling system that includes an artificial cooling pond for heat 

dissipation. In this type of closed-cycle system, the cooling pond serves as the primary source 

of water to cool plant condensers and other system components as well as the primary 

receiving body for excess heat, which is dissipated through mixing and evaporation. Water 

that is not lost to evaporation is either recirculated through the system as cooling water or 

discharged as blowdown (i.e., water that is periodically removed from the cooling pond to avoid 

the buildup of dissolved solids and other impurities that may degrade plant performance) to a 

secondary receiving water body. Water lost to evaporation or discharged as blowdown must be 

replaced; this water is referred to as makeup water. Figure 3–3 provides a basic schematic 

diagram of a closed-cycle cooling system with a cooling pond. All of Braidwood’s systems 

withdraw makeup water from and discharge blowdown to the Kankakee River. Unless 

otherwise cited, the description of Braidwood’s cooling and auxiliary water systems is derived 

from the ER (Exelon 2013e).
Affected Environment

3-5 

Figure 3–3. Closed-Cycle Cooling System With Cooling Pond

Source: Modified from NRC 2013a, Figure 3.1-4 

Cooling Pond. Braidwood’s cooling pond was created in 1980 and 1981 by pumping water 

from the Kankakee River into a diked area, which surrounds portions of a former strip mine, 

inundating deep pits, borrow areas, and depressions. It is approximately 2,540 ac (1,030 ha) 

in size and accounts for approximately 57 percent of the site acreage. The pond typically holds 

22,300 acre-feet (27.5 million cubic meters (m3

)) of water. Cooling water is withdrawn from the 

cooling pond through the lake screen house, which is located at the north end of the pond. 

Heated water returns to the cooling pond through a discharge canal west of the lake screen 

house intake that is separated from the intake by a dike. This and other dikes throughout the 

cooling pond aid in heat dissipation by slowing water circulation and increasing the time water 

resides in the pond between discharge and intake. The average residence time for cooling 

pond water is approximately 4 days (AEC 1974).

The essential cooling pond is the portion of the cooling pond that serves as the ultimate heat 

sink; it encompasses a 99-ac (40-ha) excavated area of the pond directly in front of the lake 

screen house. The essential cooling pond is capable of supplying Braidwood’s cooling system

with 30 days of station operation without additional makeup water.

The Kankakee River serves as the source of makeup water for the cooling pond. The river also 

receives continuous blowdown from the cooling pond. Figure 3–4 depicts the cooling pond, 

essential cooling pond, and the blowdown line to the Kankakee River. Figure 3-5 shows 

Braidwood plant layout.

The State of Illinois classifies the cooling pond as a treatment facility for the dissipation of waste 

heat. Therefore, the station’s National Pollutant Discharge Elimination System (NPDES) permit 

(IEPA 1997) does not contain water quality standards applicable to the cooling pond. The IDNR

regulates Exelon’s operation and maintenance of the cooling pond dam through Permit 

No. NE2000125 (IDNR 2000).
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Figure 3–4. Braidwood Cooling Pond and Kankakee River Blowdown Line

Source: Exelon 2013e, Figure 3.1-1 
Affected Environment

3-7 

Figure 3–5. Braidwood Plant Layout

Source: Exelon 2013e, Figure 3.1-2 
Affected Environment

3-8 

Kankakee River Makeup and Blowdown. Cooling pond makeup water from the Kankakee River 

is drawn into a river screen house on the south bank of the river. Water enters the river screen 

house through an intake bay equipped with bar grills, 3/8-in.-mesh travelling screens, and trash 

rakes to prevent debris and aquatic biota from entering the system (Exelon 2014e). Water 

velocity at the river screen house ranges from 0.32 to 0.48 foot per second (fps) (0.10 to 

0.15 meter per second (m/s)). These velocities are within the 0.5-fps (0.15-m/s) intake velocity 

set by the U.S. Environmental Protection Agency (EPA) for protection of aquatic organisms 

(79 FR 48300). Debris and biota collected in the intake bay are deposited into trash baskets, 

the contents of which are transferred to an independent contractor for offsite disposal. The river 

screen house does not contain a fish return system (Exelon 2014e). From the river screen 

house, circulating water pumps route water to the site via underground pipes that connect to a 

small freshwater holding pond on the northeast shoreline of the cooling pond (see Figure 3–4). 

During normal operations, two of three circulating water pumps typically operate and withdraw 

3,028 liters per second (L/sec) (48,000 gallons per minute (gpm)) of water. Withdrawal volume 

is limited to a maximum of 4,531 L/sec (160 cubic feet per second (cfs)) by an agreement with 

the State of Illinois (IDOT 1977a, 1977b). Once river water reaches the site, the water is 

collected in the cooling pond for use in Braidwood’s cooling and auxiliary water systems.

Cooling pond blowdown returns to the Kankakee River via a blowdown pipeline that discharges

water approximately 500 ft (150 m) downstream of the river screen house. Water enters the 

river through a submerged multi-port diffuser at mid-river, which is regulated under Braidwood’s 

NPDES permit (IEPA 2014c) as Outfall 001. The permit indicates that the daily average 

blowdown flow from Outfall 001 is estimated to be 43.2 million gallons per day (mgd) 

(164,000 cubic meters (m3)). The permit also limits the thermal characteristics of blowdown. 

Special Condition 3A stipulates that at the edge of Braidwood’s thermal mixing zone, discharges 

from Outfall 001 shall not cause the Kankakee River water to rise above natural temperatures 

by more than 2.8 °C (5 °F) (IEPA 1997). Special Condition 3B stipulates that temperatures at 

the edge of the mixing zone shall not exceed the monthly maximum limits of 90 °F (32 °C) from 

April through November and 60 °F (16 °C) from December through March for more than 

1 percent of the hours in a 12-month period and at no time shall water temperatures exceed the 

monthly maximum limits by more than 3 °F (1.7 °C) (IEPA 1997). Section 3.5.1 discusses the 

NPDES permit and characteristics of the Kankakee River in more detail.

Circulating Water System. The circulating water system provides cooling water to the main 

condensers to cool the Braidwood reactor cores. Prior to entering the system, water passes 

into the lake screen house through two separate intake bays, each of which are equipped with 

bar grills, 3/8-in.-mesh travelling screens, and trash rakes to prevent debris and aquatic biota

from entering the system (Exelon 2014e). Water velocity at the lake house traveling screen is 

about 2.37 fps (0.72 m/s) assuming clean screens and a low water depth of 20.7 ft (6.3 m) 

(Exelon 2014e). As with the river screen house, the lake screen house does not include a fish 

return system. From the lake screen house, six circulating water pumps (three for each unit) 

draw water into the circulating water system. During normal operations, two pumps per unit 

pump 41,640 L/sec (660,000 gpm) of water for use in the system. In addition, any debris or 

aquatic biota collected (i.e., neither the lake screen house traveling screen nor the river screen 

house traveling screen has a fish return system) at the river screen house is disposed of offsite 

(Exelon 2014e).

Following use for cooling, heated water is returned to the cooling pond through the discharge

canal. Upon exiting the plant, circulating water temperatures are maintained below 

approximately 123 °F (50.5 °C). Exelon measures the cooling pond’s average and maximum 

temperatures by grab sample taken several times a week in front of the trash racks at the lake 

screen house. During the period from 2004 through 2013, the annual average temperatures at 
Affected Environment

3-9 

the sampling point ranged from 66.4 °F (19.1 °C) (in 2007) to 71.2 °F (21.8 °C) (in 2012) 

(Exelon 2014g). The maximum temperature for this period was 99.3 °F (37.4 °C), which 

was recorded on July 19, 2013 (Exelon 2014g).

Nonessential Service Water System. The nonessential service water system provides cooling 

water for non-safety related equipment. It has three dedicated pumps that draw cooling pond 

water from the lake screen house. Each pump is rated at 2,208 L/sec (35,000 gpm). During 

normal operations, two pumps are in service (one per unit) with the third available as a backup 

for either unit. Water from this system returns to the cooling pond through the discharge canal.

Essential Service Water System. The essential service water system removes heat from 

safety-related equipment necessary for safe shutdown of the reactor. This system includes 

four pumps (two per unit) in the auxiliary building that draw water from the cooling pond. Each 

pump is rated at 1,514 L/sec (24,000 gpm). Water returns to the cooling pond through the 

discharge canal.

Cooling and Auxiliary Water Monitoring and Treatment. Exelon monitors, cleans, and treats 

the Kankakee river intake and discharge equipment, the cooling pond intake and discharge 

equipment, and each water system to prevent corrosion, scaling (i.e., the build-up of inorganic 

nutrients, such as calcium, magnesium, and silica), and biofouling.

Exelon personnel routinely monitor the river screen house for excessive sedimentation or 

macro-biological fouling in the intake bays and silt accumulation on the Kankakee River bottom 

in front of the bar grills (Exelon 2014e). If personnel identify the potential need for maintenance, 

divers further inspect conditions and perform follow-up maintenance on an “as needed” basis 

(Exelon 2014e). In the case of excessive sedimentation, Exelon will periodically dredge the 

river in front of the makeup water intake bay to maintain adequate makeup water flow. Most 

recently, Exelon (2009d) submitted a dredging permit application to the United States Army 

Corps of Engineers (USACE) in 2009 to mechanically dredge 1,000 cubic yards (760 m3

) of 

accumulated river sediments for a 0.14-ac (570-m3

) area in front of the river screen house. The 

USACE (2009) authorized the dredging in June 2009, and the permit was effective through 

June 1, 2011.

Divers inspect the river discharge structure on an annual basis to evaluate the need for 

maintenance (Exelon 2014e). Generally, maintenance on the discharge structure can be 

completed without impeding the flow of blowdown to the Kankakee River. Dredging is not 

performed near the discharge structure because the multi-port diffuser flushes sediments away 

from the area (Exelon 2014e).

Within the cooling pond, Exelon follows a company procedure (No. CY-BR-120-4130) to 

address macrobiological challenges, including bryozoan deposition and growth, aquatic plant 

growth, and biofouling by mussels and clams (Exelon 2014k). Divers inspect for and, as 

needed, physically remove bryozoan colonies from the lake screen house bays once per year 

(Exelon 2014k). An Exelon vendor inspects for aquatic plant growth twice per year and plants 

may be controlled or eliminated, as appropriate (Exelon 2014k). To control biofouling, Exelon 

continuously treats the circulating water and service water systems, when in service, with 

sodium hypochlorite for up to 2 hours (120 minutes) per day per unit (ComEd 2000; 

Exelon 2014i). In accordance with Special Condition 4 of the NPDES permit (IEPA 1997), water 

discharged to the Kankakee River may not contain more than an instantaneous maximum 

concentration of 0.2 milligram per liter (mg/L) of residual chlorine or 0.05 mg/L of residual 

oxides, as measured at Outfall 001. As needed, sodium biosulfite is added to water prior to 

discharge to remove residual chlorine and maintain compliance with NPDES permit limitations 

(Exelon 2014i). The NPDES permit stipulates that chlorinated or brominated water may not be 

discharged from each unit’s main cooling condensers for more than 2 hours per day. Exelon 
Affected Environment

3-10

also conducts regular inspections for zebra mussels and nuisance bryzoan and, as needed, 

performs mechanical cleaning of the affected equipment (Exelon 2014k).

3.1.4 Radioactive Effluent, Waste, and Environmental Monitoring Programs

As part of normal operations and as a result of equipment repairs and replacements due to 

normal maintenance activities, nuclear power plants routinely generate both radioactive and 

nonradioactive wastes. Nonradioactive wastes include hazardous and nonhazardous wastes. 

There is also a class of waste, called mixed waste that is both radioactive and hazardous. The 

systems used to manage (i.e., treat, store, and dispose of) these wastes are described in this 

section. Waste minimization and pollution prevention measures commonly employed at nuclear 

power plants are also discussed in this section.

All nuclear plants were licensed with the expectation that they would release radioactive 

material to both the air and water during normal operation. However, NRC regulations require 

that gaseous and liquid radioactive releases from nuclear power plants must meet the radiation 

dose-based limits specified in Title 10 of the Code of Federal Regulations (CFR) Part 20, and 

the as low as is reasonably achievable (ALARA) criteria in Appendix I to 10 CFR Part 50. 

Regulatory limits are placed on the radiation dose that members of the public can receive 

from radioactive effluents released by a nuclear power plant. All nuclear power plants use 

radioactive waste management systems to control and monitor radioactive wastes.

Braidwood uses liquid, gaseous, and solid waste processing systems to collect and process, 

as needed, radioactive materials produced as a by-product of plant operations. The liquid and 

gaseous radioactive effluents are processed to reduce the levels of radioactive material prior to 

discharge into the environment. This is to ensure that the dose to members of the public from 

radioactive effluents is reduced to levels that are ALARA in accordance with NRC’s regulations. 

The radioactive material removed from the effluents is converted into a solid form for eventual 

disposal at a licensed radioactive disposal facility (Exelon 2013e).

Braidwood has a radiological environmental monitoring program (REMP) to assess the 

radiological impact, if any, to the public and the environment from radioactive effluents released 

during operations at Braidwood. The REMP measures the aquatic, terrestrial, and atmospheric 

environment for radioactivity, as well as the ambient radiation. In addition, the REMP measures 

background radiation (i.e., cosmic sources, global fallout, and naturally occurring radioactive 

material, including radon) (Teledyne 2013). 

Braidwood has an Offsite Dose Calculation Manual (ODCM) that contains the methods and 

parameters used to calculate offsite doses resulting from radioactive liquid and gaseous 

effluents and the scope and requirements for the REMP. The ODCM addresses the type of 

samples (i.e., gaseous and liquid effluents, environmental samples of drinking water, vegetation, 

food products, ambient radiation levels, etc.), sampling frequency, type of analysis, and lower 

limit of detection (i.e., sensitivity) for the analysis. These controls ensure that radioactive 

effluents released from the plant meet NRC and EPA regulatory dose standards and that 

the environment is monitored for radioactivity (Exelon 2013i).

3.1.4.1 Liquid Waste Processing Systems

Radioactive liquids are controlled and processed by the liquid radwaste system (LRWS) for 

either recycle for use in the plant or for release to the environment. The LRWS is designed to 

control and process radioactive liquid waste designated for release into the environment so that 

radioactivity levels are within NRC and EPA standards.

The LRWS consists of two subsystems: the steam generator blowdown system and the 

non-blowdown subsystem. The non-blowdown subsystem treats waste streams from the 
Affected Environment

3-11

auxiliary building equipment drains and floor drains, the chemical waste drains, the regeneration 

waste drains, the laundry drains, the turbine building equipment and floor drains (if 

contaminated) and the condensate polisher sump when its stream is contaminated.

The radioactive liquid waste processing system is shared by both units. However, each liquid 

radioactive waste stream is collected in its own storage tank. The liquid waste is periodically 

sampled and analyzed to determine the level of radioactivity and thus, the appropriate amount 

of processing to reduce the radioactivity below NRC and EPA standards. The radioactivity in 

the liquid waste is reduced using filtration, demineralization, evaporation, chemical or ultraviolet 

treatment, and reverse osmosis. After processing, the purified effluent can either be reused or 

released to the Kankakee River via the blowdown line. A radiation detector monitors the liquid 

in the discharge line to ensure radioactivity levels meet NRC and EPA standards 

(Exelon 2013e).

Dose estimates for members of the public from the radioactive liquid effluent are calculated 

based on the amounts of radioactivity in the liquid, aquatic transport models, and exposure 

pathways (i.e., consumption of contaminated water and fish). Exelon submits an annual 

radiological effluent release report to the NRC that contains a detailed presentation of the 

radioactive liquid effluents released from Braidwood Units 1 and 2 and the resultant calculated 

doses. The NRC staff reviewed 5 years of radioactive effluent release data; 2008 through 2012 

(Exelon 2009c, 2010c, 2011b, 2012b, 2013d). A 5-year period provides a data set that covers a 

range of activities that occur at a nuclear power plant such as refueling outages, routine 

operation, and maintenance activities that can affect the generation of radioactive effluents. 

The NRC staff compared the data against NRC dose limits and looked for indication of adverse 

trends (i.e., increasing dose levels) over the period of 2008 through 2012. The following 

summarizes the calculated annual doses from radioactive liquid effluents released during 2012:

Unit 1. The total-body dose to an offsite member of the public from Braidwood Unit 1 

radioactive liquid effluents was 2.41×10−2 millirem (mrem) (2.41×10−4 millisievert (mSv)), 

which is well below the 3 mrem (0.03 mSv) dose criterion in Appendix I to 10 CFR Part 50.

 The organ dose (adult gastrointestinal (GI)-tract) to an offsite member of the 

public from Braidwood Unit 1 radioactive liquid effluents was 3.43×10−2 mrem 

(3.43×10−4 mSv), which is well below the 10 mrem (0.1 mSv) dose criterion in 

Appendix I to 10 CFR Part 50.

Unit 2. The total-body dose to an offsite member of the public from Braidwood Unit 2 

radioactive liquid effluents was 2.41×10−2 mrem (2.41×10−4 mSv), which is well below the 

3 mrem (0.03 mSv) dose criterion in Appendix I to 10 CFR Part 50.

 The organ dose (adult GI-tract) to an offsite member of the public from 

Braidwood Unit 2 radioactive liquid effluents was 3.43×10−2 mrem 

(3.43×10−4 mSv), which is well below the 10 mrem (0.1 mSv) dose criterion in 

Appendix I to 10 CFR Part 50.

Based on its review of Braidwood’s radioactive liquid effluent data (release data from Braidwood 

effluent control program), the staff concluded that radiation doses to members of the public were 

controlled within NRC’s and EPA’s radiation protection standards contained in Appendix I to 

10 CFR Part 50, 10 CFR Part 20, and 40 CFR Part 190. No adverse trends were observed in 

the dose levels.
Affected Environment

3-12

3.1.4.2 Gaseous Waste Processing System

The gaseous waste processing system (GWPS) is designed to remove radioactive fission 

product gases from the reactor coolant and minimize the amount of radioactive material 

released into the environment.

The GWPS consists of two waste-gas compression packages, six holding tanks, and associated 

piping, valves, and instrumentation. Radioactive gaseous wastes are generated during plant 

operation and include the following activities: removing gas from the liquid reactor coolant, 

purging the volume control tank, displacing the cover gases in tanks as they fill up with liquid 

waste, purging various equipment and pipes, operating the boron recycle system, and 

performing surveillance activities that involve sampling and analysis of plant systems containing 

radioactive material. Radioactive gases are collected in one of six holding tanks and stored 

temporarily to allow for radioactive decay. When the plant is ready to release the radioactive 

gaseous effluent, the gas is sampled and analyzed in accordance with the requirements in the 

ODCM prior to being released into the atmosphere to ensure the radioactivity levels are within 

NRC and EPA radiation protection standards. Radioactive gaseous effluents are released into 

the atmosphere in a controlled and monitored manner through the plant vent. The radioactive 

gaseous waste sampling and analysis program specifications provided in the ODCM address 

the gaseous release type, sampling frequency, minimum analysis frequency, type of activity 

analysis, and lower limit of detection (i.e., sensitivity) for the radiation monitor (Exelon 2013e).

Dose estimates for members of the public are calculated based on radioactive gaseous effluent 

release data, atmospheric transport models, and exposure pathways (i.e., inhalation and 

ingestion of radioactive material from the air or on food products). Exelon’s annual radioactive 

material release report contains a detailed presentation of the radioactive gaseous effluents 

released from Braidwood and the resultant calculated doses. The NRC staff reviewed 5 years 

of radioactive effluent release data; 2008 through 2012 (Exelon 2009c, 2010c, 2011b, 2012b, 

2013d). A 5-year period provides a data set that covers a range of activities that occur at 

Braidwood such as refueling outages, non-refueling outage years, routine operation, and 

maintenance activities that can affect the generation of radioactive effluents. The NRC staff 

compared the data against NRC dose limits and looked for indication of adverse trends 

(i.e., increasing dose levels) over the period of 2008 through 2012. The following summarizes 

the calculated doses from radioactive gaseous effluents released during 2012 (Exelon 2013d):

Unit 1: 

 The air dose at the site boundary from gamma radiation in gaseous effluents 

from Braidwood Unit 1 was 4.41×10−6 millirad (mrad) (4.41×10−8 milligray 

(mGy)), which is well below the 10 mrad (0.1 mGy) dose criterion in 

Appendix I to 10 CFR Part 50.

 The air dose at the site boundary from beta radiation in gaseous effluents 

from Braidwood Unit 1 was 1.72×10−5 mrad (1.72×10−7 mGy), which is well 

below the 20 mrad (0.2 mGy) dose criterion in Appendix I to 10 CFR Part 50.

 The dose to an organ (child bone) from radioactive iodine, radioactive 

particulates, and carbon-14 from Braidwood Unit 1 was 1.11 mrem 

(0.01 mSv), which is well below the 15 mrem (0.15 mSv) dose criterion 

in Appendix I to 10 CFR Part 50.
Affected Environment

3-13

Unit 2: 

 The air dose at the site boundary from gamma radiation in gaseous effluents 

from Braidwood Unit 2 was 4.41×10−6 mrad (4.41×10−8 mGy), which is well 

below the 10 mrad (0.1 mGy) dose criterion in Appendix I to 10 CFR Part 50.

 The air dose at the site boundary from beta radiation in gaseous effluents 

from Braidwood Unit 2 was 1.72×10−5 mrad (1.72×10−7 mGy), which is well 

below the 20 mrad (0.2 mGy) dose criterion in Appendix I to 10 CFR Part 50.

 The dose to an organ (child bone) from radioactive iodine, radioactive 

particulates, and carbon-14 from Braidwood Unit 2 was 1.11 mrem 

(0.01 mSv), which is well below the 15 mrem (0.15 mSv) dose criterion 

in Appendix I to 10 CFR Part 50.

Based on its review of Braidwood’s radioactive gaseous effluent data (release data from 

Braidwood effluent control program), the staff concluded that radiation doses to members of 

the public were controlled within NRC’s and EPA’s radiation protection standards contained in 

Appendix I to 10 CFR Part 50, 10 CFR Part 20, and 40 CFR Part 190. No adverse trends were 

observed in the dose levels.

3.1.4.3 Solid Waste Management

Radioactive solid low-level radioactive waste (LLW) is generated by the removal of radioactive 

material from liquid waste streams, filtration of gaseous effluents, and removal of contaminated 

equipment and waste material from various areas within the radiation controlled areas of the 

plant.

Radioactive solid waste is collected from throughout the two Braidwood units, packaged, and 

stored temporarily onsite until it can be shipped offsite for treatment, if needed, and disposed of 

in a licensed LLW disposal facility. Low-level radioactive waste is classified as Class A, 

Class B, Class C, or greater than Class C depending on the types and amounts of radioactivity 

it contains. The waste is further divided into two categories: dry active waste (DAW) and wet 

active waste (WAW). Class A waste contains the smallest amounts of radioactivity and includes 

both DAW and WAW. Classes B and C contain higher levels of radioactivity than Class A and 

are normally WAW, such as spent resins from demineralizers and filter cartridges. The majority 

of LLW generated at Braidwood is Class A waste. Classes B and C wastes make up a low 

percentage by volume of the total LLW generated at Braidwood.

The DAW is composed of material that is either equipment, or tools, or both that are broken 

or cannot be decontaminated and reused within the plant or waste such as used air filters, 

miscellaneous paper trash, rags, contaminated clothing, and laboratory glassware and sample 

containers. The WAW is typically composed of used deep bed demineralizer resins and 

disposable cartridge filter elements. The LLW is typically packaged in drums or large metal 

boxes that are sealed and staged for transport to a licensed LLW disposal facility in accordance 

with NRC regulations in 10 CFR Parts 20, 61, and 71 (Exelon 2013e).

Braidwood, on an infrequent basis, generates small quantities of mixed waste (i.e., waste 

having both a hazardous component and a radioactive component). The Illinois Environmental 

Protection Agency (IEPA) regulates the hazardous component of the waste and the Illinois 

Emergency Management Agency Division of Nuclear Safety and NRC regulate the radioactive 

component. The mixed waste is stored temporarily on site in the DAW storage area in 

accordance with Illinois Administrative Code (IAC) 35 Part 726, Standards for the Management 

of Specific Hazardous Waste and Specific Types of Hazardous Waste Management Facilities 
Affected Environment

3-14

(IEPA 2013f) and NRC’s 10 CFR Part 20. The mixed waste is transported to a licensed offsite 

facility for treatment and disposal (Exelon 2013e).

Braidwood uses Waste Control Specialists, LLC (WCS), to treat and dispose of its LLW in an 

LLW disposal facility. The facility is licensed by the State of Texas and is located in Andrews 

County, Texas.

3.1.4.4 Radioactive Waste Storage

With the availability of the WCS disposal facility, existing onsite LLW handling and staging areas 

are expected to handle the temporary storage of LLW generated during the license renewal 

term. Exelon stated in its ER that radioactive solid waste processing capability is adequate to 

handle the maximum expected volume of LLW generated during refueling and maintenance 

outages during the license renewal term. No long-term storage of LLW is expected. However, 

in the event of temporary delays in transportation or interruption in LLW disposal capability, 

Braidwood has the capability to store its LLW for approximately 2 years (Exelon 2013e).

Braidwood stores its spent nuclear fuel in a spent fuel pool and also maintains an independent 

spent fuel storage installation (ISFSI) onsite within a restricted area. Spent fuel transfers to the 

ISFSI began in 2011. The ISFSI is used to safely store spent fuel in licensed and approved dry 

cask storage containers. The installation and monitoring of this facility is governed by NRC 

requirements in 10 CFR Part 72, “Licensing Requirements for the Independent Storage of Spent 

Nuclear Fuel, High-Level Radioactive Waste, and Reactor-Related Greater Than Class C 

Waste.” The Braidwood ISFSI would remain in place until the U.S. Department of Energy takes 

possession of the spent fuel and removes it from the site for permanent disposal. Expansion of 

the onsite spent fuel storage capacity may be required during the license renewal term 

(Exelon 2013e).

3.1.4.5 Radiological Environmental Monitoring Program

Exelon conducts a REMP to assess the radiological impact to the public and the environment 

from the operations at Braidwood. 

The REMP measures the aquatic, terrestrial, and atmospheric environment for radioactivity, 

as well as the ambient radiation by sampling air, water, milk, foods, soil, fish, and shoreline 

sediment. The REMP also measures background radiation (i.e., cosmic sources, global fallout, 

and naturally occurring radioactive material, including radon) and cumulative radiological 

impacts from other nuclear power plants that may be nearby. The radiation detection devices 

and analysis methods used to determine ambient radiation levels and radioactivity in 

environmental samples are very sensitive and accurate.

In addition to the REMP, Braidwood has an onsite groundwater protection program designed 

to monitor the onsite plant environment for detection of leaks from plant systems and pipes 

containing radioactive liquid (Exelon 2013e). Information on the ground water protection 

program is contained in section 3.5.2 of this document.

The NRC staff reviewed 5 years of annual radiological environmental monitoring data; 2008 

through 2012 (Teledyne 2009, 2010, 2011, 2012, 2013). A 5-year period provides a data set 

that covers a range of activities that occur at Braidwood such as refueling outages, routine 

operation, and maintenance activities that can affect the generation and release of radioactive 

effluents into the environment. The NRC staff looked for indication of adverse trends 

(i.e., build-up of radioactivity levels) over the period of 2008 through 2012.

The NRC staff’s review of Exelon’s data showed no indication of an adverse trend in 

radioactivity levels in the environment. The data showed that there was no measurable 

impact to the environment from operations at Braidwood.
Affected Environment

3-15

3.1.4.6 Reasonably Foreseeably Radiological Projects at Braidwood

In its ER, Exelon stated that no refurbishment activities are necessary or planned to support 

the continued operation of Braidwood during the license renewal term. Nevertheless, Exelon 

discussed the potential impacts associated with the hypothetical replacement of the Unit 2 

steam generators and reactor pressure vessel heads for both units (Exelon 2013e). If Exelon 

conducts these potential refurbishment activities during the license renewal term, Exelon is 

required to maintain its radiation protection program to limit radiation dose to its workers and 

members of the public in accordance with NRC and EPA radiation protection standards.

Based on the NRC staff’s review of the radioactive waste management program discussed 

in Section 3.1.4 and the radiation protection program discussed in Section 3.11.1 of this 

document, the NRC staff expects that Braidwood would conduct the hypothetical refurbishment

activities in accordance with NRC and EPA radiation protection standards.

3.1.5 Nonradiological Waste Management Systems

Like any other industrial facility, nuclear power plants generate wastes that are not 

contaminated with either radionuclides or hazardous chemicals. These wastes include 

trash, paper, wood, and sewage.

Braidwood has a nonradioactive waste management program to handle its nonradioactive 

hazardous and nonhazardous wastes. The waste is collected in central collection areas within 

the plant site and managed in accordance with Exelon’s procedures. The materials are 

received in various forms and packaged to meet regulatory requirements prior to final 

disposition at an offsite facility licensed to receive and manage the waste. Listed below is a 

summary of the types of waste materials generated and managed at Braidwood.

 Braidwood is registered as a small quantity hazardous waste generator; 

however, hazardous wastes are managed according to large quantity 

generator standards. The amount of hazardous wastes generated are only 

a small percentage of the total wastes generated; consisting of paints and 

paint-related materials, spent and off-specification and shelf-life expired 

chemicals, laboratory chemical wastes, and occasional project-specific 

wastes. Braidwood has contracts in place to transfer hazardous waste 

to licensed off-site treatment and disposal facilities.

 Braidwood’s nonhazardous wastes include potentially infectious medical 

waste (PIMW), regulated asbestos-containing material, used oil, grease, 

antifreeze, adhesives, and other petroleum-based liquids. PIMW is 

generated at a health facility onsite and can include used and unused 

hypodermic needles and syringes, as well as items contaminated with human 

blood. PIMW is considered a unique special waste category in Illinois and 

transportation and disposal of this waste is regulated under 35 IAC 1420.

 Universal wastes (e.g., batteries, pesticides, mercury-containing equipment, 

bulbs (lamps)) are recycled when possible, according to Exelon procedures 

and Illinois regulations.

 General plant trash is collected in dumpsters and transported to a statelicensed regional landfill permitted to accept solid wastes. General trash 

typically consists of garbage, paper, plastic, packing materials, leather, 

rubber, glass, soft drink and food cans, dead animals and fish, floor 

sweepings, ashes, wood, textiles, and scrap metal.
Affected Environment

3-16

Exelon operated a sewage treatment package plant onsite prior to 2012. Effluent discharge to 

the Kankakee River was regulated under NPDES permit IL0048321. Operation of the sewage 

treatment plant ceased in October 2012. Since then, sewage has been routed to the City of 

Braidwood Sewage Treatment Plant, which discharges to an unnamed tributary of Claypool 

Ditch. This effluent discharge is regulated under the town’s NPDES permit IL0054992 

(Exelon 2013e).

3.1.6 Utility and Transportation Infrastructure

The following sections briefly describe the existing utility and transport infrastructure 

at Braidwood.

3.1.6.1 Electricity

Electrical service to Braidwood is supplied by other offsite power plants, as needed. The onsite 

345-kV switchyard provides independent offsite power to Braidwood from the grid, as needed 

(Exelon 2013g). Exelon also maintains four diesel generators (two per reactor unit), each of 

which is capable of generating 5,500 kilowatts (kW) in the event of total loss of auxiliary power 

from offsite sources (Exelon 2013h). For operation, much of the time, Braidwood consumes its 

own generation fed back from the grid.

3.1.6.2 Fuel

Braidwood Fuel Oil System includes four 25,000-gallon (gal) (85-m3

) diesel oil storage tanks 

for Unit 1’s diesel generators and two 50,000-gal (190-m3

) storage tanks for Unit 2’s diesel 

generators (Exelon 2010a).

3.1.6.3 Water

Section 3.1.1 describes Braidwood’s cooling and auxiliary water systems. In addition to water 

needed for cooling, Braidwood requires potable water for sanitary purposes and everyday use 

by personnel (e.g., drinking, showering, cleaning, laundry, toilets, and eye washes). Braidwood 

uses a deep water-supply well that draws water from the Ironton-Galesville deep sand aquifer 

for its potable water system (Exelon 2013g). This well also supplies water to the make-up 

demineralizer system (Exelon 2013g). Section 3.5.2 describes site groundwater use in 

more detail.

3.1.6.4 Transportation Systems

The Braidwood site includes extensive paved surfaces, parking lots, and roads connecting 

power plant infrastructure. Illinois State Routes 53, 113, and 129 provide direct access to the 

site, and Interstate 55 lies less than 3 km (2 mi) west-northwest of the site (Exelon 2013g). 

SEIS Section 3.10.6 describes local transportation systems, including roadway access, in more 

detail. The Canadian National Railway (formerly Illinois Central Gulf Railroad) maintains a 

railroad spur to Braidwood that connects the site with the Illinois Central Railroad.

3.1.6.5 Power Transmission Systems

For license renewal, the NRC (2013a) evaluates those transmission lines that connect the 

nuclear power plant to the substation where electricity is fed into the regional power distribution 

system and transmission lines that supply power to the nuclear plant from the grid. Regarding 

power transmission systems at Braidwood, the plant’s main power transformers connect to an 

intermediate, onsite transmission line that runs from the plant to an onsite 345-kV switchyard 

that lies east of the reactor containment buildings. This switchyard connects the plant to the 

Mid-America Interpool Network (i.e., the regional grid) (Exelon 2010a, 2014d). No separate 

transmission lines supply offsite power to Braidwood from the grid (Exelon 2013g). 
Affected Environment

3-17

Commonwealth Edison Company (ComEd) owns and operates all transmission lines 

associated with Braidwood (Exelon 2013g).

3.1.7 Nuclear Power Plant Operation and Maintenance

Maintenance activities conducted at Braidwood include inspection, testing, and surveillance to 

maintain the current licensing basis of the facility and to ensure compliance with environmental 

and safety requirements. Various programs and activities currently exist at Braidwood to 

maintain, inspect, test, and monitor the performance of facility equipment. These maintenance 

activities include inspection requirements for reactor vessel materials, boiler and pressure 

vessel inservice inspection and testing, and maintenance of water chemistry.

Additional programs include those carried out to meet technical specification (TS) surveillance 

requirements, those implemented in response to the NRC generic communications, and various 

periodic maintenance, testing, and inspection procedures. Certain program activities are carried 

out during the operation of the unit, while others are carried out during scheduled refueling 

outages. Braidwood must periodically discontinue the production of electricity for refueling, 

periodic inservice inspection, and scheduled maintenance. The Braidwood reactor units are 

on staggered 18-month refueling cycles.

3.2 Land Use and Visual Resources

3.2.1 Land Use

The Braidwood site encompasses 4,457 ac (1,804 ha) in Will County, Illinois, approximately 

80 km (50 mi) southwest of the CMA (Exelon 2013e). The site is located on the Kankakee 

plain, and the Kankakee River lies approximately 5 mi (8 km) east of the site (Exelon 2013e). 

The natural vegetative communities for this area are tallgrass prairie and deciduous forest. 

However, the Braidwood site was already highly disturbed at the time of Braidwood construction 

and consisted of a mixture of coal strip-mine spoil, cultivated fields, fallow fields, and open 

woodlands (AEC 1974). Much of the strip-mine spoils on the site were flooded to create a 

2,540-ac (1,028-ha) artificial cooling pond, which provides Braidwood with a source of cooling 

water. Several large islands occur within the pond. The reactor containment buildings and 

related structures, a switchyard, administration buildings, warehouses, the makeup/blowdown 

pipeline corridor, and a river screen house occupy the developed portions of the site. The 

remainder of the site consists of small forested tracts, old fields, early successional grasslands, 

and areas leased for agriculture and recreation. Table 3–1 provides a breakdown of 

site acreage by land use. Figures 3–4 and 3–5 depict the site layout.

Table 3–1. Braidwood Site Acreage by Land Use

Land Use Acres (Hectares) Percentage (%)

Developed for industrial use 264 (107) 5.9

Cooling pond 2,540 (1,028) 57.0

Natural areas

Leased for recreation 1,280 (518) 28.7

Leased for agriculture 67 (27) 1.5

Unleased forest, old fields, and 

early successional grasslands 306 (124) 6.9

Total 4,457 (1,804) 100

Sources: Exelon 2013e, 2014
Affected Environment

3-18

The cooling pond is part of the Mazonia-Braidwood State Fish and Wildlife Area, which Exelon 

and the IDNR jointly manage. Much of the cooling pond is accessible to the public for fishing, 

waterfowl hunting, and fossil collecting through a 1991 lease agreement between Exelon and 

IDNR (IDNR 2014d). The Mazonia-Braidwood State Fish and Wildlife Area also includes 

IDNR-owned lands adjacent to the Braidwood site to the south and southwest of the 

cooling pond.

The Braidwood site is accessible from Illinois State Routes 53, 113, and 129. The site also 

includes a railroad spur, which connects to the Illinois Gulf Railroad Canadian National Railway 

(formerly Illinois Central Gulf Railroad) (Exelon 2013e).

Will County, in which Braidwood is located, encompasses 537,000 ac (217,000 ha) 

(USCB 2014h). The county’s Land Resource Management Plan (Will County 2011) classifies 

the current land uses within the county as: agricultural (60 percent), developed (20 percent), 

and vacant (20 percent). Will County is one of the fastest-growing counties in the CMA. From 

1990 to 2000, the population grew by more than 40 percent (from 350,000 individuals to just 

over 500,000), and the population is expected to grow by another 60 percent (to over 

800,000 individuals) in the next 20 years (Will County 2011). Despite such growth, the 

County’s Land Resource Management Plan (Will County 2011) concludes that the county has 

more capacity for growth than there is demand.

3.2.2 Visual Resources

Braidwood is situated on flat to rolling topography. Predominant features at the Braidwood 

site include the two reactor containment buildings, the auxiliary building, the turbine building, 

administration buildings, warehouses, the makeup/blowdown pipeline corridor, the river screen 

house, the switchyard, an ISFSI, and the cooling pond (Exelon 2013e).

The most noticeable feature of the site is the cooling pond, which occupies the majority 

(57 percent) of the site. However, the cooling pond is not readily visible from offsite locations. 

The reactor containment buildings and switchyard are the most visible structures from offsite. 

The rolling topography and small forested tracts on and near the site provides some visual 

screening.

3.3 Meteorology, Climatology, Air Quality, and Noise

3.3.1 Meteorology and Climatology

The Braidwood site is located in Will County in northeastern Illinois, approximately 55 mi 

(90 km) southwest of the CMA and 23 mi (36 km) south-southwest of Joliet, Illinois. Local towns 

near the Braidwood site include the town of Godley (1 mi (1.6 km)), Braidwood (2 mi (3.2 km)), 

and Wilmington (6 mi (9.6 km)). The Kankakee River is about 5 mi (8 km) east of the 

Braidwood site’s eastern boundary. The land area of Braidwood and surrounding area is former 

farmland that was subsequently used for strip coal mining (Exelon 2013b).

The climate of the region is continental and marked by strong seasonality in temperature, which 

is characteristic of an inland location. During fall, winter, and spring, the polar jet stream is 

located near or over northeastern Illinois which causes large scale synoptic storms to move 

through the area bringing precipitation, winds, and often dramatic temperature changes 

(NOAA 2005). Lake Michigan has an influence on the climate of northeastern Illinois. During 

the summer months, the lake causes a stabilizing effect on the atmosphere which tends to lower 

temperature and reduce precipitation when winds blow from the north or northeast. During 
Affected Environment

3-19

winter, the lake keeps temperatures higher than surrounding areas and enhances precipitation 

by producing lake-effect snow when winds blow from the north or northeast (NOAA 2005).

The staff obtained climatological data collected at the Channahon Dresden Island Illinois (CDII) 

climate observation station, 11 mi (17.7 km) northwest of Braidwood. Additionally, Exelon 

maintains a 320-ft (97.5-m) high meteorological tower at Braidwood. The tower base is 

approximately 600 ft (183 m) above sea level and is located 0.4 mi (0.7 km) northeast of 

Braidwood (as measured from a point midway between Unit 1 and Unit 2). The tower measures 

wind speed and direction, temperature, and dew point (Exelon 2014c). Data from these stations 

was used to characterize the region’s climate and is presented below.

For the period 1981 to 2010 from the CDII climate observation station, the coldest weather 

occurred in January (monthly mean temperature of 23.2 °F (−4.9 °C)), and the warmest 

occurred in July (monthly mean temperature 73.7 °F (23.2 °C)) (NOAA 2014a). At the 

Braidwood meteorological tower, the average monthly temperature over the period 1974 to 

2012 was 50.2 °F (10.1 °C); the coldest month was January (monthly mean temperature of 

23.7 °F (−4.6 °C), and the warmest month was July (monthly mean temperature 73.0 °F 

(22.8 °C)) (Exelon 2014c).

Annual meteorological reports from the Braidwood meteorological tower provided wind direction 

and speed data and precipitation (Exelon 2014c). Wind direction and speed data for the last 

5 years (2008 through 2012) are shown in Table 3–2. Precipitation data for the same period 

measured at the Braidwood tower site are also shown in Table 3–2. For comparison, average 

annual precipitation for the 1981 to 2010 period as measured at the CDII climate observation 

station, was 92.7 cm (36.5 in.); the lowest monthly mean rainfall occurred in February (4.04 cm 

(1.59 in.)) with the highest monthly mean occurring in June and July (10.6 cm (4.17 in.) each 

month) (NOAA 2014a).

Table 3–2. Wind Direction, Wind Speed, and Precipitation Data for 2008 Through 2012 

from the Braidwood Tower

Year

Prevailing 

Wind 

Direction

Annual Wind 

Speed 

Category (mph)

Annual 

Precipitation 

(inches)

Maximum 

24-Hour 

Precipitation 

(inches)

Maximum 

1-Hour 

Precipitation 

(inches)

2008 W 3.6 to 7.5 33.4 3.04 1.08

2009 WNW 3.6 to 7.5 47.05 2.37 1.06

2010 W 3.6 to 7.5 34.2 2.33 1.07

2011 W 3.6 to 7.5 36.7 2.87 0.85

2012 S 3.6 to 7.5 30.6 3.78 1.70

W = west; WNW = west-northwest; S = south

Source: Exelon 2014c

Severe weather associated with thunderstorm activity occurs in Will County during the summer. 

Severe thunderstorms may produce tornadoes, hail, and high wind gusts. Severe winter 

weather conditions can also occur in the area in the form of heavy snowfall, high winds causing 
Affected Environment

3-20

blowing and drifting snow and blizzard conditions, and ice storms. For the period 

January 1, 1996, through October 31, 2013, the following number of days with severe 

events was recorded in Will County (NOAA 2014b):

 Hail – 91 days;

 Tornadoes – 10 days (16 separate tornado events);

 Thunderstorm Wind above 50 knots – 110 days (4 days with winds above 

70 knots);

 Blizzard – 4 days;

 Heavy Snow – 10 days;

 Ice Storm – 2 days; and

 General Winter Storm classification event – 22 days.

3.3.2 Air Quality

Under the Clean Air Act (CAA), EPA has set primary and secondary National Ambient Air 

Quality Standards (NAAQS, 40 CFR 50) for six common criteria pollutants to protect public 

health and the environment. The NAAQS criteria pollutants include carbon monoxide (CO), 

lead (Pb), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO2), and particulate matter (PM). 

PM is further categorized by size—PM10 (diameter of 10 micrometers or less) and PM2.5

(diameter of 2.5 micrometers or less).

The EPA designates areas of “attainment” and “nonattainment” with respect to the NAAQS. 

Areas that have insufficient data to determine designation status are denoted as 

“unclassifiable.” Areas that were once in non-attainment, but are now in attainment, are 

called “maintenance” areas; these areas are under a 10-year monitoring plan to maintain 

the attainment designation status.

Air quality designations are generally made at the county level. For the purpose of planning and 

maintaining ambient air quality with respect to the NAAQS, the EPA has developed Air Quality 

Control Regions (AQCRs). AQCRs are intrastate or interstate areas that share a common 

airshed (40 CFR 81). The Braidwood site is located in Will County, IL; this county, along with 

Cook, DuPage, Grundy, Kane, Kankakee, Kendall, Lake, and McHenry counties in Illinois and 

Lake County and Porter counties in Indiana are in the Metropolitan Chicago Interstate AQCR 

(40 CFR 81.14). With regards to the NAAQS criteria pollutants, Will County is designated as 

nonattainment for the 2008 8-hour ozone NAAQS and 2010 sulfur dioxide NAAQS (partial 

county designation) and designated maintenance area for the annual 1997 PM2.5 NAAQS. 

States have primary responsibility for ensuring attainment and maintenance of the NAAQS 

(40 CFR 81.314; EPA 2015b). Under section 110 of the CAA (42 U.S.C. 7410) and related 

provisions, States are to submit, for EPA approval, State Implementation Plans (SIPs) that 

provide for the timely attainment and maintenance of the NAAQS.

Existing air emission sources at Braidwood are regulated under a Federally Enforceable State 

Operating Permit (FESOP) (I.D. No. 197816AAB) issued by the IEPA. A source is eligible for a 

FESOP (also known as “synthetic minor” air permit) if the potential to emit from the source 

triggers CAA Permit Program requirements, but maximum actual emissions are below, or can 

be restricted to remain below, major source thresholds. Braidwood’s FESOP was issued 

May 29, 2001, and expired April 29, 2007. Exelon filed a timely renewal application on 

October 30, 2006, and received correspondence from IEPA indicating continued operation 

was allowed during the renewal application. No further correspondence regarding the renewal 
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application has been received by Exelon (Exelon 2014c). Regulated air pollutants including 

sulfur dioxide, carbon monoxide, nitrogen oxide, carbon dioxide, and particulates are emitted 

at the Braidwood site from four large diesel generators, various small diesel engines (less than 

600 horsepower) used for electric generation and water pumping, two diesel engine auxiliary 

feedwater pumps, a rad-waste volume reduction system, fuel storage tanks, and two auxiliary 

boilers. Emissions during the last 5 years (2008 to 2012) are shown in Table 3–3 

(Exelon 2014a). For each pollutant, Braidwood is classified as a minor emission source.

Table 3–3. Estimated Air Emissions for Permitted Combustion Sources at Braidwood

Year NOx (T)(a) CO (T)(a) SOx (T)(a) PM2.5 (T)(a) PM10 (T)(a) VOC (T)(a) CO2e (T)(a)

2008 25.9 6.9 0.05 0.48 0.47 0.75 1,311

2009 27.1 7.2 0.06 0.48 0.50 0.79 1,361

2010 21.9 5.8 0.09 0.39 0.41 0.65 1,111

2011 21.4 5.7 0.11 0.38 0.39 0.62 1,132

2012 21.6 5.7 0.11 0.38 0.40 0.63 1,110

(a) To convert T to MT, multiply by 0.91.

NOx = nitrogen oxides; CO = carbon monoxide; SOx = sulfur oxides; PM2.5 = particulate matter with a diameter 

of 2.5 micrometers or less; PM10 = particulate matter with an aerodynamic diameter between 2.5 and 

10 micrometers; VOC = volatile organic compound; CO2e = carbon dioxide equivalent(s)

Source: Exelon 2014a

On October 30, 2009, the EPA published a rule for the mandatory reporting of greenhouse

gases (GHGs) from sources that in general emit 25,000 metric tons or more of carbon dioxide 

equivalents (CO2e)1 per year in the United States (74 FR 56260). Most small industrial facilities 

fall below the 25,000 metric ton threshold and are not required to report GHG emissions to EPA. 

On June 3, 2010, the EPA promulgated the Prevention of Significant Deterioration (PSD) and 

Title V GHG Tailoring Rule (75 FR 31514). Beginning January 2, 2011,2 operating permits 

issued to major sources of GHG under the prevention of significant deterioration (PSD) or 

Title V Federal permit programs must contain provisions requiring the use of best available 

control technology to limit the emissions of GHGs if those sources would be subject to PSD or 

Title V permitting requirements because of their non-GHG pollutant emission potentials and 

their estimated GHG emissions are at least 75,000 tons per year of CO2e. As discussed above, 

Braidwood is a synthetic minor source. GHG emissions from combustion sources at Braidwood 

are below the GHG Mandatory Reporting and Tailoring Rules thresholds; therefore, the NRC 

staff anticipates that Braidwood would be exempted from GHG emission limits.

The EPA promulgated the Regional Haze Rule (RHR) to improve and protect visibility in 

national parks and wilderness areas from haze, which is caused by numerous, diverse sources 

 

1 Carbon dioxide equivalents (CO2e) is a metric used to compare the emissions of GHG based on their Global warming potential 

(GWP). GWP is a measure used to compare how much heat a GHG traps in the atmosphere. GWP is the total energy that a gas 

absorbs over a period of time, compared to carbon dioxide. Carbon dioxide equivalent is obtained by multiplying the amount of the 

GHG by the associated GWP. For example, the GWP of CH4 is estimated to be 21; therefore, one ton of CH4 emission is 

equivalent to 21 tons of CO2 emissions.

2 On June 23, 2014, the U.S. Supreme Court issued a decision that the EPA may not treat GHGs as an air pollutant for purposes of 

determining whether a source is a major source required to obtain a PSD or Title V permit, but could continue to require PSD and 

Title V permits, otherwise required based on emissions of conventional pollutants. In July 2014, the EPA issued a memorandum 

in response to the Supreme Court’s decision and acknowledged that, while the decision is pending judicial action, the EPA will no 

longer require PSD or Title V permits for GHG-emitting sources that are not sources subject to PSD or Title V permits based on 

emissions of conventional pollutants (nitrogen oxides, carbon monoxide, etc.) (EPA 2014b).
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located across a broad region (40 CFR 51.308-309). Specifically, 40 CFR 81 Subpart D lists 

mandatory Class I Federal Areas where visibility is an important value. The RHR requires 

States to develop SIPs to reduce visibility impairment at Class I Federal Areas. The closest 

Federal Class I area to Braidwood is the U.S. Fish and Wildlife Service (FWS) Mingo 

Wilderness Area, approximately 500 km (300 mi) southwest of the Braidwood site. Generally, 

minor emissions sources, such as Braidwood, that are located more than 100 km (62 mi) from a 

Class I area are considered to have no effect on a Class I area. The air pollutant emissions 

from Braidwood would not have any adverse impact at the Mingo Wilderness Class I area due 

to the minor source emission levels and the large distance separating the Braidwood site from 

the Mingo Wilderness Area.

3.3.3 Noise

Any pressure variation that the human ear can detect is considered as sound, and noise is 

defined as unwanted sound. Sound is described in terms of amplitude (perceived as loudness) 

and frequency (perceived as pitch). Sound pressure levels are typically measured by using the 

logarithmic decibel (dB) scale. A-weighting (denoted by dBA) is widely used to account for 

human sensitivity to frequencies of sound (i.e., less sensitive to lower and higher frequencies 

and most sensitive to sounds between 1 and 5 kHz), which correlates well with a human’s 

subjective reaction to sound (ASA 1983, 1985). Table 3–4 presents common noise sources 

found in many locations and their respective noise levels.

Table 3–4. Common Noise Sources and Noise Levels

Source Noise Level (dBA)

Jet Plane (at 100 ft distance) 130

Diesel truck (at 30 ft distance) 100

Food blender (at 3 ft distance) 90

Car (50 mph at 50 ft distance) 65

Conversation 55

Threshold of hearing 0

Sources: MMSHT 2008, SFU undated 

Nuclear power generation is an industrial process that can generate noise. Noise sources 

at the Braidwood site include circulating water make-up pumps, main steam valves, water 

discharge system, transmission lines, PA system, security drills, and transformers 

(Exelon 2014c; NRC 2013a). Exelon identified the nearest residence in each of 16 sectors 

(each sector covering 22.5 degrees) around Braidwood during their annual land use survey. 

The nearest noise receptors from the station are located in sectors to the southwest, and west 

through north-northwest. Residences in these sectors are 0.4 mi (0.64 km) from Braidwood’s 

reactor buildings. Noise levels from the plant may be occasionally heard at these receptors but 

are barely noticeable above other noise sources common to residential area activity, and noise 

from traffic on Illinois state highway 53 and the Union Pacific (UP) rail line.

Braidwood has received a few noise complaints related to the cooling water discharge system 

into the Kankakee River. Prior to 2011, this system produced noticeable noise at the discharge 

location. In 2011, a new diffuser was installed for water discharge into the Kankakee River 

which, among other environmental benefits, has nearly eliminated noise from the discharge 

location. In 2010 Braidwood also received noise complaints related to steam releases that can 

have a 26 to 36 hour duration. As a result of the noise complaints related to steam releases, 
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Braidwood notifies the public about the impending activity and the potential for noise via their 

notification system (Exelon 2014c). The notification system alerts residences and other 

locations within 1 mi of Braidwood prior to planned activities that may affect the surrounding 

area. This practice has reduced noise complaints during subsequent years (Exelon 2014c).

In addition to noise sources from the Braidwood site, noise sources around the Braidwood site 

include local traffic, nearby community activities and events, and rail line. Illinois state 

highway 53 and the UP rail line, which hosts freight and passenger trains on a daily basis, 

are on the western edge of Godley. This section of the rail line is part of the Illinois high-speed 

rail (HSR) plan. According to the HSR environmental impact statement, existing train traffic 

passing along the section of track near Godley produces day-night (Ldn) noise levels of 

approximately 60 dB at 300 ft from the tracks (IDOT and FRA 2013).

The EPA uses a threshold level of 55 dBA to protect against excess noise during outdoor 

activities. However, according to EPA, this threshold does “not constitute a standard, 

specification, or regulation,” but was intended to provide a basis for State and local 

governments establishing noise standards (EPA 1974). The Federal Housing Administration 

has established noise assessment guidelines and finds that noise 65 dBA or less are 

acceptable (HUD 2014). The Will County Code of Ordinances contains noise regulations in 

Title IX (General Regulations), Chapter 93 (Public Nuisances), sections 93.080 through 93.087 

(Will County 2014). The Will County noise ordinance adopts by reference the noise regulations 

found in Title 35 IAC, Subtitle H (Noise), Chapter 1 (Pollution Control Board), Part 900 (General 

Provisions) and Part 901 (Sound Emission Standards and Limitations for Property Line Noise 

Sources) (35 IAC H). These noise regulations have allowable octave-band sound levels 

according to emitting and receiving land class and time of day.

3.4 Geologic Environment

This section describes the current geologic environment of the Braidwood site and vicinity, 

including landforms, geology, soils, and seismic conditions.

3.4.1 Physiography and Geology

The Braidwood site is located in an area which contains non-lithified (not solid rock) glacial 

deposits overlying a bedrock surface. These deposits formed during successive periods of 

glaciation. The topography, in general, slopes gently to the north toward the Illinois River 

(Figure 3–6). The Cooling Lake immediately adjacent to and south of the station was formed 

from prior coal strip mining operations. Large areas of former coal strip mined land occurs north 

and south of the station and a number of small excavations (now water filled ponds) occur north 

and northeast of the plant site (CRA 2006b) (Figure 3–6). The underlying bedrock was largely 

formed in ancient seas prior to glacial activity and consists of 4,500 ft (1,372 m) of dolomite, 

sandstone, and shale rock (See Section 3.5.2.1). In turn, these rocks are underlain by granites 

and possibly metamorphic rocks to a great depth (Frankie and Nelson 2003).

Coal mining in the area ceased in 1974, when it was no longer economical to continue mining. 

North and northeast of the station, the surficial formation has been mined for its sand content 

(See Section 3.5.2.1). This same formation underlies the generating station. Access to this 

formation as a source of sand is readily available outside the station over a wide area.
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Figure 3–6. Braidwood Site Topography

Source: Modified from CRA 2011
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3.4.2 Soils

The soils at Braidwood have developed from sandy glacial outwash (water from a glacial ice) 

deposits and lake deposits. The soils are established on relatively flat topography and can be 

characterized as fine sand and sandy loams. These soils are moderately to well drained and 

have moderate to rapid permeability (CRA 2006b; USDA 2013). Because of their large sand 

component they are not considered as suitable for prime farmland and because of the high 

water table they may require dewatering to be used for farming.

3.4.3 Seismic Setting

The only reported injury from an earthquake that occurred in Illinois happened on April 12, 1883, 

when an old frame house was shaken down, resulting in slight injury to the inhabitants. A 

number of earthquakes (USGS 2012a, 2013a, 2013b) have originated within Illinois and include:

 May 26, 1909, a large earthquake knocked over many chimneys in Aurora 

and swayed buildings in Chicago.

 July 18, 1909, an earthquake knocked down chimneys in Petersburg.

 August 14, 1965, a sharp local earthquake knocked down chimneys at 

Elco, Unity, Olive Branch, and Olmstead.

 November 9, 1968, a magnitude 5.3 earthquake was felt over a large area.

Dozens of earthquakes originating outside Illinois have been felt inside the State without 

causing damage. These earthquakes originated in Missouri, Arkansas, Kansas, Nebraska, 

Tennessee, Indiana, Ohio, Michigan, Kentucky, and Canada. However, southern Illinois could 

experience major damage should a large magnitude earthquake occur in the New Madrid 

Seismic Zone (located in southern Illinois and neighboring states) (MODNR 2014; USGS 2009). 

The site is located in northeast Illinois that has a very small probability of experiencing 

damaging earthquakes (FEMA 2013; MAE Center 2009). The NRC requires every nuclear 

plant to be designed for site-specific ground motions that are appropriate for its location.

3.5 Water Resources

3.5.1 Surface Water Resources

This section describes the current surface water resources within and near the Braidwood 

Station. Surface water encompasses all water bodies that occur above the ground surface, 

including rivers, streams, lakes, ponds, and man-made reservoirs or impoundments.

3.5.1.1 Surface Water Hydrology

The Braidwood site is situated in the Upper Illinois/Mazon River watershed. The Mazon River 

is approximately 33 mi long and the basin drains an area of 455 square miles (mi2

). The Mazon 

River empties into the Illinois River near Morris, Illinois (IDNR 2014e). While the site is located 

in the Mazon River watershed, it consumes surface water from the Kankakee River Basin. The 

Kankakee River is located about 5 mi (8 km) to the east of Braidwood. The river originates near 

South Bend, Indiana and flows west into Illinois near Momence, Illinois, until it joins the 

Des Plaines River to ultimately form the Illinois River. In total, the Kankakee River is 

approximately 150 mi long and the basin drains an area of 5,165 mi2 (see Figure 3–7). The 

Illinois portion of the Kankakee River runs for about 59 mi and drains an area of 2,168 mi2

(Bhowmik and Demissie 2000). There are three dams along the river’s main stem in Momence, 
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Wilmington, and Kankakee, IL. The largest tributary to the Kankakee River is the Iroquois River; 

the Iroquois River is 94 mi long and has a drainage area of 2,137 mi2

. 

Figure 3–7. Kankakee River Basin

Source: Modified from Phipps et al. 1995

Makeup water for Braidwood’s cooling pond is withdrawn from the Kankakee River through an 

intake structure (river screen house). The U.S. Geological Survey (USGS) maintains a gaging 

station on the Kankakee River in Wilmington, IL (station 05527500) located approximately 

14 km (8.8 mi) downstream from Braidwood’s intake structure. River discharge data have been 

collected at this site since 1932. Because of its location and long period of record data, this 

gauge was chosen to be representative of long-term river flow characteristics in the vicinity of 

Braidwood. The mean annual discharge measured at the USGS gage at Wilmington, for water 

years 1934 through 2012, is 4,805 cfs (136 cubic meters per second (m3

/s)) (USGS 2012b). 

Over this period of time the highest annual mean discharge was 10,380 cfs (294 m3

/s) in 1993 

and the lowest annual mean discharge was 1,407 cfs (40 m3

/s) in 1964 (USGS 2012b).

Braidwood’s stormwater discharges are released into the Mazon River. The stormwater 

drainage system directs runoff from the plant’s protected area and surrounding Exelon-owned 

land to three outfalls designated in the site’s NPDES permit. Exelon implements and maintains 

a Stormwater Pollution Prevention Plan (SWPPP) to comply with Special Condition 9 of the 
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site’s Illinois-issued NPDES permit (IEPA 2014c). The site’s NPDES permit is further discussed 

in Section 3.5.1.3.

Braidwood’s cooling pond is approximately 1,030 ha (2,540 ac) (Exelon 2013a, 2013b, 2013c). 

The cooling pond is available for public access for fishing, waterfowl hunting, and fossil 

collecting as a result of an agreement between Exelon and the IDNR. The cooling pond is 

further discussed in Section 3.1.3.

3.5.1.2 Surface Water Use 

Braidwood withdraws surface water from the Kankakee River to provide makeup water to the 

cooling pond that is lost to evaporation and seepage. Cooling pond blowdown is discharged 

back to the Kankakee River via a multi-port diffuser at a point located about 152 m (500 ft.) 

downstream of the plant’s intake at the river screen house.

Table 3–5 summarizes Braidwood’s surface water withdrawals for the period 2008 to 2012. 

Based on the staff’s review of Braidwood’s Illinois State Water Survey submittals, Braidwood’s 

surface water withdrawals have averaged 16,806.3 million gallons per year (mgy) (64 million 

cubic meters per year (m3

/y)). This is equivalent to an average withdrawal rate of 71 cfs. 

Return discharges to the Kankakee River have averaged 8,445.9 mgy (32 million m3

/y). This is 

equivalent to an average discharge rate of 36 cfs. The average consumptive rate for this period 

of time was 8,360.4 mgy (31.6 million m3

/y) or 35 cfs.

Table 3–5. Annual Surface Water Withdrawals and Return Discharges to the Kankakee 

River, Braidwood Station

Year Withdrawals (mgy) mgd Discharges (mgy) mgd

2008 14,819.8 41 7,550.3 21

2009 15,935.0 44 9,407.5 26

2010 18,159.6 50 8,893.2 24

2011 16,754.2 46 8,550.8 23

2012 18,364.3 50 7,827.9 21

Average 16,806.6 46 8,445.9 23

Note: Reported values are rounded. To convert million gallons per year (mgy) to million cubic meters (m3), divide 

by 264.2.

mgd = million gallons per day

Source: Exelon 2014c

Braidwood’s surface water withdrawals are subject to an April 1977 construction permit 

(No. 15039) from the Illinois Department of Transportation (IDOT), Division of Water Resources 

(now the IDNR). The provisions of this permit limit Braidwood’s maximum makeup withdrawal 

rate from the river to 160 cfs (71,808 gpm or 4.5 m3

/s). The provisions specify to stop 

withdrawing water from the river when the flow rate falls below 442 cfs (198,383 gpm or 

12.5 m3/s) (Exelon 2014c). Braidwood has operating procedures to comply with these 

provisions and stipulate actions that plant personnel must take during conditions of low 

river flow (Exelon 2013b).

3.5.1.3 Surface Water Quality and Effluents

The Illinois Pollution Control Board, a sister Agency to the Illinois EPA, promulgates water 

quality standards in Illinois. Two Sections of Title 35 of the IAC (35 IAC 302; 35 IAC 303) 
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contain the standards applicable to lakes and streams. Procedures to be followed in using 

water quality standards to set NPDES permit limits are found in Section 309 (35 IAC 309). 

Designated uses prescribed by 35 IAC 303 are those uses specified in water quality standards 

for each lake, river, stream, and groundwater resource. In designating uses for a water body, 

the Illinois Pollution Control Board takes into consideration the use and value of the water body 

for public water supply; for propagation of fish, shellfish, and wildlife; and for recreational, 

agricultural, industrial, and navigational purposes.

The Kankakee River and Mazon River are designated as “general use water” by the Illinois 

Pollution Control Board. Waters in the general use category must meet water quality standards 

protective of aquatic life, wildlife, agricultural use, secondary contact use, as well as most 

industrial uses and aesthetic quality (35 IAC 303.201). These standards pertain to pH, 

phosphorus, dissolved oxygen (DO), radioactivity (gross beta, strontium-90, and radium-226 

and -228), and various chemical constituents (metals and organic compounds), fecal coliform, 

and other toxic substances (as appropriate).

Section 303(d) of the Federal Clean Water Act of 1972 (CWA) requires the State of Illinois and 

other states to identify all “impaired” waters for which effluent limitations and pollution control 

activities are not sufficient to attain water quality standards in such waters. The 303(d) list 

includes those water quality limited stream segments that require the development of total 

maximum daily loads (TMDLs) to assure future compliance with water quality standards. The 

IEPA has identified an 8.22-mi-long segment of the Kankakee River adjacent to the Braidwood 

plant site as impaired and not meeting designated uses, or water quality standards, or both 

(IEPA 2014b). This segment is listed due to contamination from polychlorinated biphenyls 

(PCBs) and mercury (impairing fish consumption use), as well as for phenols (impairing public 

water supplies).

An 18.7-mi segment (IL_DV-04) of the Mazon River, which includes the segment that receives 

stormwater discharge from Braidwood, is also identified as impaired. This segment is listed due 

to contamination from polychlorinated biphenyls (PCBs) and mercury (impairing fish 

consumption use) and fecal coliform (impaired primary-contact recreation or nuisance for 

recreation use). Special Condition 6 of the station’s NPDES permit prohibits the discharge 

of PCBs in plant effluents (IEPA 2014c).

To operate a nuclear power plant, licensees must comply with the CWA, including associated 

requirements imposed by the EPA or the state, as part of the NPDES permitting system under 

Section 402 of the CWA as well as state water quality certification requirements under 

Section 401 of the CWA. The EPA or the state, not the NRC, sets the limits for effluents and 

operational parameters in plant-specific NPDES permits. Nuclear power plants cannot operate 

without a valid NPDES permit and a current Section 401 Water Quality Certification. The State 

of Illinois has been delegated responsibility by the U.S. EPA for administration of the NPDES 

program in Illinois. NPDES permits are issued by the IEPA on a 5-year cycle.

Braidwood is currently operating under NPDES Permit No. IL0048321, issued on July 31, 2014 

(IEPA 2014c). The NPDES permit specifies the discharge standards and monitoring 

requirements for effluent chemical and thermal quality and for stormwater discharges through 

the plant’s outfalls to the Kankakee River and Mazon River. The plant’s outfalls are identified in 

Figure 3–8, and Table 3–6 summarizes the outfalls discharges.
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Figure 3–8. Braidwood NPDES Outfall Locations

Note: A01= outfall 001(a); C01= outfall 001(c); D01=outfall 001(d); E01= outfall 001(e)

Source: Modified from Exelon 2014c
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Table 3–6. National Pollutant Discharge Elimination System-Permitted Outfalls, 

Braidwood Station

Outfall (f) Average Flow

Rate (mgd) (a) (b)

Description

001 43.2 Cooling Pond Blowdown line; continuous discharge to the 

Kankakee River

001(a) (c) 0.081 Wastewater Treatment Plant Effluent; discharge to the Kankakee River

001(c) (c) 0.003 Radwaste Treatment System Effluent; continuous discharge to the 

Kankakee River

001(d) (d) 0.028 Demineralizer Regenerant Wastes; continuous discharge to the 

Kankakee River

001(e) No discharge River Intake Screen Backwash

002 (d) (e) Intermittent North Site Stormwater Runoff Basin; discharges to the Mazon River

003 (e) Intermittent South Site Stormwater Runoff Basin; discharges to the Mazon River

004 (e) Intermittent Switchyard Area Runoff; discharges to the Mazon River

(a) To convert million gallons per day (mgd) to million cubic meters (m3

), divide by 264.2.

(b) Braidwood’s NPDES permit (IL0048321) limits the pH range to 6.0–9.0, total residual chlorine daily maximum 

concentration to 0.2 mg/L, and total residual oxidant daily maximum concentration to 0.05 mg/L at Outfall 001. 

Special Conditions 4C and 4D of the NPDES permit limit water temperatures at Outfall 001. Special 

Condition 4C stipulates that at the edge of Braidwood’s thermal mixing zone, discharges from Outfall 001 shall 

not cause the Kankakee River water to rise above natural temperatures by more than 2.8 °C (5 °F). Special 

Condition 4D stipulates that temperatures at the edge of the mixing zone shall not exceed the monthly maximum 

limits of 90 °F (32 °C) from April through November and 60 °F (16 °C) from December through March for more 

than 1 percent of the hours in a 12-month period and at no time shall water temperatures exceed the monthly 

maximum limits by more than 1.7 °C (3 °F). 

(c) Braidwood’s NPDES permit (IL0048321) limits the total suspended solid concentration 30-day average 

concentration to 15 mg/L and daily maximum concentration to 30 mg/L and oil & grease 30-day average 

concentration to 15 mg/L and daily maximum concentration to 20 mg/L at Outfalls 001(a) and 001(c).

(d) Braidwood’s NPDES permit (IL0048321) limits the total suspended solid 30-day average concentration 

to 15 mg/L and daily maximum concentration to 30 mg/L at Outfalls 001(d) and 002.

(e) NPDES permit requires that a Stormwater Pollution Prevention Plan (SWPPP) be maintained for stormwater 

associated with industrial activity of the facility.

(f) In accordance with Braidwood’s NPDES permit (IL0048321), no discharge of polychlorinated biphenyl 

compounds is allowed.

Sources: Exelon 2014c; IEPA 1995, 2013b, 2014c

Exelon has prepared an SWPPP for Braidwood to manage its stormwater discharges in 

compliance with Special Condition 9 of the NPDES permit. Braidwood’s SWPPP identifies 

potential pollutant sources that could affect stormwater discharge into the three designated 

stormwater outfalls. These include diesel and gasoline storage tanks, lime silo, oil storage 

tanks, sodium hypochlorite tank, sodium bromide tank, and transformer areas. Engineering 

controls are employed to prevent pollutant spills, such as double wall tanks with leak detection 

instrumentation, underdrain systems to direct flow to oil separator prior to entering outfalls, and 

berms to retain potential leakage. Additionally, plant personnel perform routine inspections of 

equipment to identify leaks or hazards. Discharges from the Braidwood are monitored. 

Monitoring results are reported in monthly Discharge Monitoring Reports (DMRs) submitted to 

the State. Braidwood has received no notices of violation associated with NPDES permitted 

discharges during the 2008 through 2012 time period. However, a review of DMRs from 2008 
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through 2012 indicates that five occurrences of noncompliance with NPDES permit limits or 

conditions occurred for short periods of time (Exelon 2014c):

 July 2009: sewage treatment plant effluent (outfall 001(b))3 exceeded the 

30-day average concentration for biochemical oxygen demand

 April 2011: sewage treatment plant effluent (outfall 001(b)) exceeded the 

30-day average concentration for biochemical oxygen demand

 May 2011: demineralizer regenerant wastes effluent (outfall 001(d)) 

exceeded the daily maximum limit for total suspended solids

 March 2012: cooling pond blowdown line effluent (outfall 001) exceeded the 

limit for temperature

 November 2012: cooling pond blowdown line effluent (outfall 001) exceeded 

the limit for maximum pH

Exelon notified the IEPA regarding the noncompliances listed above. With respect to the 

March 2012 exceedance, the IEPA granted Braidwood a provisional variance from the NPDES

water discharge permitted temperature limits due to warm weather conditions (IEPA 2012). 

During the variance, as required by IEPA, Exelon continuously monitored the discharge and 

receiving water temperatures and visually inspected all discharge areas at least three times a 

day. Furthermore, Exelon identified and implemented corrective actions to prevent future 

occurrences subsequent to these noncompliances (Exelon 2014c).

Section 401 of the CWA requires an applicant for a Federal license to conduct activities that 

may cause a discharge of regulated pollutants into navigable waters to provide the licensing 

agency with water quality certification from the state. This certification implies that discharges 

from the project or facility to be licensed will comply with CWA requirements and will not cause 

or contribute to a violation of state water quality standards. If the applicant has not received 

Section 401 certification, the NRC cannot issue a license unless that state has waived the 

requirement. The NRC recognizes that some NPDES-delegated States explicitly integrate their 

401 certification process with NPDES permit issuance. Braidwood’s NPDES permit does not 

explicitly convey water quality certification under CWA Section 401.

The Chicago District of the USACE sent a letter to Exelon in July 2012 stating that no permit 

was required from the USACE and that it had no objection to renewing the Section 401 

certification for Braidwood (Exelon 2013b). Previously, by letter dated May 18, 2012, Exelon 

submitted an application to the IEPA Bureau of Water Pollution Control requesting certification 

that renewal of the plant’s NRC operating licenses would not violate state water quality 

standards (Exelon 2013b). In May 2013, the IEPA Division of Water Pollution Control 

responded to the Exelon request and sent a letter to the NRC regarding Braidwood’s 

401 certification, providing the 401 certification subject to inclusion of two conditions into the 

NRC license for Braidwood (IEPA 2013e). In November 2014, NRC staff responded to IEPA, 

noting that since the two conditions are license requirements either because they are imposed 

as a matter of law or they state existing statutory provisions, no further NRC action is needed 

with respect to these two conditions: (1) Exelon must obtain CWA Section 402 (NPDES) 

permits from the State in accordance with 33 U.S.C. § 1342, and (2) a 401 certification does not 

authorize activities that require authorizations under Section 404 of the CWA, 33 U.S.C. § 1344 

 

3 In October 2012, Braidwood’s sewage treatment plant ceased operation, and sewage was rerouted directly into the City of 

Braidwood Sewage Treatment Plant (Exelon 2014c). Outfall 001(b) has been removed from the July 31, 2014, Reissued NPDES

Permit (IEPA 2014c).
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(i.e., the permits for discharges of dredged or fill material, which are issued by the USACE) 

(NRC 2014). 

In order to maintain Braidwood’s surface water intake system at the river screen house, Exelon 

conducts dredging to remove accumulated river sediment. There is no prescribed frequency for 

dredging, and divers are used to periodically examine the area to assess the need. Dredging 

was performed in 2009 (Exelon 2014c). Similarly, Braidwood’s diffuser discharge structure is 

inspected annually by divers to evaluate the need for maintenance. Dredging is conducted in 

accordance with USACE Nationwide Permits in accordance with Section 10 of the Rivers and 

Harbors Act and Section 404 of the CWA. In the USACE letter to Exelon in July 2012, there is 

no mention of dredging maintenance.

3.5.2 Groundwater Resources

This section describes the current groundwater resources at the Braidwood site and vicinity.

3.5.2.1 Site Description and Hydrogeology

The site is located in an area which contains glacially deposited material overlying a bedrock 

surface. These deposits are the Equality Formation and the underlying Wedron Clay Till. The 

Equality Formation, hereafter called the “Upper Aquifer” (Figure 3–9), is approximately 20 ft 

(6.1 m) thick and is a uniform fine-grained sand. Figure 3-9 shows an illustration of the 

Geologic Cross-Section. The Upper Aquifer is a water-table (unconfined) aquifer and locally is 

used as a source of potable water. The water table occurs near the land surface. The depth to 

water ranges from 5 to 15 ft (1.5 to 4.6 m). In some areas, this aquifer has been mined as a 

source of sand to build roads. As these pits were excavated below the water table, they are 

now water filled ponds (Section 3.4.1) (CRA 2006b).

The Wedron Clay Till underlies the Upper Aquifer. The Wedron Clay Till is a silty clay and 

ranges from 15 to 20 ft (4.6 to 6.1 m) thick. The Wedron Clay has a very low permeability 

(transmits water very poorly) and is considered an aquitard. The Wedron Clay is underlain by 

the bedrock. The bedrock that underlies the Wedron Clay is the Francis Creek Shale. This 

shale is approximately 40 to 50 ft (12.2 to 15.2 m) thick and because of its low permeability is 

considered an aquitard. Beneath the Wedron Clay is a siltstone/conglomerate. It is about 10 ft 

(3 m) thick. Beneath this siltstone conglomerate is the Colchester Coal (No. 2) Seam, which 

averages 3 ft (1 m) thick.

The Colchester Coal Seam is underlain by the Spoon Formation. This formation is made up of 

limestone rock, with a thickness of 80 ft (24.4 m) to 90 ft (27.4 m). This formation is underlain 

by the Maquoketa Shale with a thickness of at least 120 ft (37 m). The Maquoketa Shale is 

considered an aquitard and is laterally continuous throughout the area. It overlies the 

Galena-Platteville Dolomite, St. Peter Sandstone aquifer, the Knox Megagroup, and the 

Ironton–Galesville aquifer. Regionally, these units are hydraulically connected and hereafter 

they are called the “Deep Aquifer” (Figure 3–10). Within the Deep Aquifer, the St. Peter 

Sandstone aquifer and the Ironton-Galesville aquifer are the most productive aquifers and 

are used as a source of water (see Section 3.5.2.2) (Exelon 2013e).
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Figure 3–9. Illustrative Geologic Cross-Section

Source: NRC Staff–Generated Graphic
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Figure 3–10. Generalized Geologic Column of Deep Aquifer

Source: Modified from CRA 2010

The Upper Aquifer is recharged by local precipitation, and discharges to nearby ponds, streams, 

and strip mines. At the site, the lateral direction of groundwater flow in this aquifer is generally 

from south to north (Exelon 2013e). The Deep Aquifer is hydraulically isolated from the 

Upper Aquifer by the Wedron Clay Till and the Maquoketa Shale. This aquifer is not recharged 

locally. It is recharged in areas where the Maquoketa Shale is not found. These areas are 

located west and northwest of the site in north-central Illinois (Burch 2008) (Figure 4-1, in 
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Cumulative Impact Section). Lateral groundwater flow in the Deep Aquifer beneath the 

Braidwood site is toward the northeast (Burch 2002; Exelon 2013e).

Mining the Colchester Coal (No. 2) Seam was previously a significant activity in the local area, 

but today mining of this coal seam is no longer profitable. Coal was discovered in the Coal City 

area in 1854. Underground mining began in the 1870s. Strip-mining began in the 1920s and 

continued until 1974. Both abandoned underground and strip mines can be found within 1 to 

1.5 mi (1.6 to 2.4 km) in all directions from the site (Illinois State Geological Survey 2012; 

Obrad 2006; Obrad and Chenoweth 2007).

Coal mining activities stopped above the Spoon Formation. As a result the Maquoketa Shale 

was undisturbed by mining activities and remains a significant barrier (aquitard) to the vertical 

movement of groundwater. Mining never occurred beneath the station. However the coal seam 

(or vein) was strip mined over a large area south and east of the station. This strip mine 

operated until 1974. The strip mine was excavated to a depth of about 100 ft (30.5 m) below 

ground surface. As each new cut was excavated into the earth the geologic materials that 

overlay the coal were placed into the previously mined cut. This had the effect of filling most 

of the former coal mine excavation with the rock layers which previously overlay the coal.

The cooling lake for the Braidwood Station was constructed from this former coal mine 

operation and from adjacent farmland. As previously explained, while mining went to a depth of 

100 ft (30.5 m) most of the old excavations were filled with geologic units that overlay the coal 

(mine spoils). As a result, the average depth of the cooling lake is only 8 ft (2.4 m) (CRA 2006b; 

Larimore and Skelly 1984). Dikes were constructed around and in this area. These dikes in 

association with existing spoil banks were designed to contain and guide water flow through the 

cooling pond. To reduce lateral water losses out the sides of the cooling lake and into the 

Equality Formation, a slurry wall of low permeability material was built around the entire cooling 

lake when the facility was constructed. This slurry wall was constructed from the land surface 

and into the top of the Wedron Clay Till (CRA 2006a, 2006b). The cooling pond was completely 

filled with water pumped from the Kankakee River from December 1, 1980, to 

February 18, 1981.

A small abandoned underground coal mine is located 0.25 mi (0.4 km) east of the facility. From 

1904 to 1909, vertical shafts and a long-wall mining technique were used to extract coal from 

the Colchester Coal (No. 2) Seam. The underground mine went to a depth of 81 ft (24.7 m) and 

covered 33 ac (13.4 ha) (Obrad 2006).

3.5.2.2 Groundwater Use

Groundwater in the site area is mainly extracted from two primary aquifers; the Upper Aquifer 

and the Deep Aquifer (CRA 2006b). However, a small number of local water wells supplying 

private residences may extract water from the Siltstone Conglomerate or from the Spoon 

Formation (Exelon 2013e).

Within 1 mi (1.6 km) from the center of the plant buildings there are approximately 40 private 

wells (Figure 3–11) (CRA 2010). Many of these wells are screened within the Upper Aquifer. 

The Deep Aquifer, made up of the St. Peter Sandstone and the Ironton–Galesville aquifer, is 

used by both public and private water users (Exelon 2013e). Within 1 mi (1.6 km) of the site, 

six private wells are completed in the Deep Aquifer.

The nearest public water supply wells to the site are owned by the Godley Public Water District. 

These wells are located approximately 0.86 to 1 mi (1.4 to 1.6 km) southwest of Braidwood and 

are completed into the St. Peter Sandstone of the Deep Aquifer (Figure 3–11) (CRA 2010; 

Exelon 2013e). Together these wells average a combined production rate of 34,840 gallons 

per day (gpd) (131,900 liters per day (Lpd)) (Exelon 2013e).
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The next nearest public water supply well is located approximately 1.4 mi (2.2 km) 

north-northeast of the site and belongs to the City of Braidwood (Figure 3–11). This well pumps 

water at an average rate of 1.8 mgd (6.8 million Lpd) (Exelon 2013e). The City of Braidwood 

also owns the next closest public water well. This well is located approximately 2.5 mi (4.0 km) 

north of the site. Pumping rates for this well are not available (Exelon 2013e). Both wells are 

completed into the Ironton–Galesville Aquifer of the Deep Aquifer (Exelon 2013e).

The plant obtains water from an onsite well completed into the Deep Aquifer. This well is cased 

to a depth of 1,200 ft (365.7 m) and obtains water from the Ironton-Galesville Aquifer. Water 

from this well is used to supply the plant potable water system and make-up demineralizer 

system at a rate of approximately 83,000 gpd or (314,000 Lpd) (Exelon 2013e).
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Figure 3–11. Public and Private Water Wells Near Braidwood Station

(The circle has a 1-mi radius.)

Source: Modified from CRA 2010
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3.5.2.3 Groundwater Quality

The water quality of both the Upper Aquifer and the Deep Aquifer is acceptable for public use 

and consumption.

Controlled effluent from plant operations, which may include radionuclides produced in the 

reactor coolant system, may be released to the Kankakee River via the discharge or “blowdown” 

pipeline. Before the effluent is released into the pipeline it is sampled, analyzed, and processed 

to ensure the liquid released complies with NRC and EPA regulations. In 2005, Exelon 

determined that water from the blowdown pipeline had been released by three malfunctioning 

vacuum breaker valves located along a section of the pipeline approximately 0.5 mi (0.8 km) 

east of the plants eastern boundary. Exelon determined that water containing tritium had been 

released from the pipeline in 1996, 1998, 2000, 2003, and 2005. The water released from the 

blowdown pipeline infiltrated into the groundwater in the Upper Aquifer (Figure 3-12) 

(CRA 2006a; Exelon 2013e).

The highest on-site tritium concentration, detected in Upper Aquifer groundwater was 

282,000 picocuries per liter (pCi/L), and the highest offsite concentration (230,000 pCi/L) was 

found in a monitoring well located immediately adjacent to the 2005 Braidwood property line. 

Only one private well was found to contain tritium above the lower limit of detection (200 pCi/L) 

(CRA 2006a). The maximum concentration of tritium in this well was 1,524 pCi/L. This 

concentration is well below EPA’s safe level for public drinking water of 20,000 pCi/L 

(CRA 2006a, Table 6.4).

The blowdown pipeline was evaluated for structural integrity. Vacuum breakers along the 

blowdown pipeline were repaired or permanently closed, and groundwater monitoring wells 

were installed along the pipeline. Continuous monitoring systems were installed in the 

operating vacuum breaker boxes to warn of any wastewater releases from the vacuum 

breakers. Remediation of the contaminated groundwater began in 2006, principally by pumping 

water from a small Braidwood-owned pond (a former sand borrow pit). This lowered the water 

table in the Upper Aquifer around the pond, which in turn caused contaminated groundwater to 

flow into the pond. Water from the pond was pumped into the repaired blowdown pipe, where it 

was combined with water obtained from the Braidwood cooling pond and then discharged to the 

Kankakee River in compliance with NRC regulations (Exelon 2013e).

Both off-site and on-site groundwater contamination in the Upper Aquifer has been successfully 

remediated. In 2013, the Illinois EPA determined that the contamination in the Upper Aquifer 

had been successfully remediated and that active groundwater remediation could be terminated 

(CRA 2011; Exelon 2009b, 2010b, 2011a, 2012c, 2012d, 2013c, 2013e; IEPA 2013b, 2013c, 

2013d). At the end of active remediation, the size of the area contaminated had been reduced 

by 97 percent and the highest concentrations of tritium had been reduced by 99 percent 

(Exelon 2013e). Figure 3–12 shows tritium 2006 concentrations from areas of the Upper 

Aquifer impacted by the releases from the blowdown pipeline and Figure 3–13 shows 2012 

tritium concentrations near the end of active remediation.
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Figure 3–12. Tritium Concentrations in the Upper Aquifer in 2006

Source: Modified from Exelon 2013e
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Figure 3–13. Tritium Concentrations in the Upper Aquifer in 2012

Source: Modified from Exelon 2013e

In accordance with a Nuclear Energy Institute Industry Groundwater Protection Initiative, 

hydrogeologic investigations were conducted by an independent consultant in 2006 and 2011 

(CRA 2006a, 2011). As part of these investigations, groundwater samples were collected and 

analyzed for tritium, strontium-89 and -90, and gamma-emitting radionuclides. In addition to the 

areas where leaks had occurred from the blowdown pipeline, in 2006, tritium was also detected 

in both the Upper Aquifer and construction-fill adjacent to the west side of the plant buildings. 
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The source of the tritium is believed to be from historical releases that infiltrated into the 

groundwater (CRA 2011; Exelon 2013e). The concentration in the groundwater from these 

releases ranged from just above the detection limit of 200 pCi/L to a high of 1,040 pCi/L 

(CRA 2006a). All of these values are well below EPA’s safe level for public drinking water 

(20,000 pCi/L).

Much more data was available for the 2011 study. Tritium in groundwater within the site was 

not detected above the EPA safe level for public drinking water. Tritium concentrations in all 

offsite private and public wells were determined to be below the lower limit of detection 

(CRA 2011). The report concluded that tritium is not migrating off the Braidwood property at 

detectable concentrations. Tritium and other radionuclides above the lower limit of detection 

have not been found in wells that monitor the bedrock or bedrock aquifers (CRA 2011). Tritium 

concentrations within the site have continued to remain well below the EPA safe level for public 

drinking and no other radionuclides have been detected above their baseline values 

(Teledyne 2012, 2013).

3.6 Terrestrial Resources

3.6.1 Braidwood Ecoregion

Braidwood lies within the Illinois/Indiana Prairies Level IV Ecoregion. This ecoregion 

encompasses 19,557 mi2 (50,652 square kilometers (km2

) in eastern and central Illinois and 

western Indiana (Woods et al. 2006). It is composed of vast glaciated, flat to rolling plains with 

terminal and recessional moraines, prairie potholes, and old lake beds. Historically, tallgrass 

prairie covered the majority of the land surface. Oak-hickory forests were common on moraines 

and floodplains, and marshes and wet prairies occurred in poorly drained areas. Beginning in 

the 19th century, agricultural land began to replace the natural vegetation, and it is now the 

dominant land type (Woods et al. 2006). Prairie remnants lack many natural ecosystem 

functions due to their small size, and areas of prairie restoration often lack forbs or are overly 

dominated by big bluestem (Andropogon gerardii) or Indiangrass (Sorghastrum nutans) 

(IDNR 2005). Historically, forests were dominated by oak (Quercus spp.), hickory (Carya spp.), 

elm (Ulmus spp.), ash (Fraxinus spp.), beech (Fagus spp.), and maple (Acer spp.) species 

(CEC 2008). Remaining forests are highly fragmented and are experiencing species 

composition shifts to sugar maple (A. saccharum) and other mesophytic species due to fire 

suppression (IDNR 2005). Many of the wetlands areas have been drained for row crops, and 

agriculture now accounts for over 75 percent of land use within this ecoregion (IDNR 2005).

Table 3–7 lists representative wildlife for this ecoregion, as well as species that the IDNR

considers to be “critical” to the conservation and restoration of the region’s native habitats; 

species that are indicative of ecosystem health (known as “indicator species”); and species 

that are native to the region, but are now extirpated or imperiled.

The IDNR maintains the Illinois Wildlife Action Plan (IDNR 2005), which addresses 

native habitat and species decline and contains a statewide conservation plan.
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Table 3–7. Wildlife in the Illinois and Indiana Prairies Level IV Ecoregion

Wildlife representative of the ecoregion

American black bear

(Ursus americanus)

eastern bluebird

(Sialia sialis)

North American porcupine

(Erethizon dorsatum)

American redstart

(Setophaga ruticilla)

eastern chipmunk

(Tamias striatus)

raccoon

(Procyon lotor)

bobcat

(Lynx rufus)

eastern gray squirrel

(Sciurus carolinensis)

tree sparrow

(Passer montanus)

Canada warbler

(Cardellina canadensis)

gray fox

(Urocyon cinereoargenteus)

white-footed mouse

(Peromyscus leucopus)

coyote

(Canis latrans)

indigo bunting

(Passerina cyanea)

white-tailed deer

(Odocoileus virginianus)

Wildlife critical to the conservation and restoration of the ecoregion’s native habitats

American badger

(Taxidea taxus)

Henslow’s sparrow

(Ammodramus henslowii)

northern harrier

(Circus cyaneus)

eastern massasauga(a)

(Sistrurus catenatus)

Illinois chorus frog

(Pseudacris streckeri illinoensis)

ornate box turtle

(Terrapene ornata ornata)

four-toed salamander

(Hemidactylium scutatum)

Indiana bat(b)

(Myotis sodalis)

red squirrel

(Sciurus vulgaris)

gray bat

(Myotis grisescens)

Kirtland’s snake

(Clonophis kirtlandii)

short-eared owl

(Asio flammeus)

Wildlife indicative of ecosystem health (indicator species)

black rat snake

(Elaphe obsoleta obsoleta)

eastern meadowlark

(Sturnella magna)

prairie vole

(Microtus ochrogaster)

black-capped chickadee

(Poecile atricapillus)

great blue heron

(Ardea herodias)

red-headed woodpecker

(Melanerpes erythrocephalus)

eastern box turtle

(Terrapene carolina carolina)

horned lark

(Eremophila alpestris)

red-tailed hawk

(Buteo jamaicensis)

eastern kingbird

(Tyrannus tyrannus) 

prairie king snake

(Lampropeltis calligaster 

calligaster)

tufted titmouse

(Baeolophus bicolor) 

Extirpated or imperiled wildlife

American bison

(Bison bison)

Blanding’s turtle

(Emys blandingii)

Franklin’s ground-squirrel

(Poliocitellus franklinii)

(a) The eastern massasauga is proposed for listing as threatened under the Endangered Species Act of 1973, 

as amended (ESA). It and other Federally listed species are discussed in Section 3.8.

(b) The Indiana bat is Federally listed as endangered under the ESA. While the Indiana bat occurs within the 

Illinois and Indiana Prairies Level IV Ecoregion, the FWS (2014b) indicates that it does not occur in Will County.

Sources: CEC 1997; IDNR 2005; Wiken et al. 2011

3.6.2 Summary of Past Braidwood Site Surveys and Reports

Commonwealth Edison Company, the company that constructed and first operated Braidwood, 

conducted baseline preconstruction surveys of the terrestrial vegetation and wildlife in autumn 

of 1972 and continued these surveys seasonally through the winter, spring, and summer of 

1973. The results of these surveys were recorded in the ER for Braidwood construction 

(ComEd 1973b). ComEd conducted follow-up surveys from 1974 through 1975, the results of 

which appeared in the ER for Braidwood operation (ComEd 1985). In September 2005, a 

Wildlife Habitat Council (WHC) biologist conducted a 1-day site assessment that included a 

species inventory of plants, mammals, birds, insects, and fish as part of Exelon’s application for 
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a Wildlife at Work Certification (Exelon 2013j). The site assessment is included in Exelon’s 

2013 Wildlife Management Plan for Braidwood (Exelon 2013f). These surveys, as well as the 

Final Environmental Statement for Braidwood Construction (FES-C) (AEC 1974) and the ER for 

license renewal (Exelon 2013g) inform the description of the terrestrial resources on the 

Braidwood site in the following sections.

3.6.3 Braidwood Site

The Braidwood site encompasses 4,457 ac (1,804 ha) in Will County, Illinois (Exelon 2013g). 

The majority of the site consists of the cooling lake and plant buildings and infrastructure. Small 

forested tracts of land occur east and west of the developed portion of the site, and several 

large islands occur within the cooling pond (Exelon 2013g). The Braidwood site was highly 

disturbed prior to construction and operation of the site, and the majority of natural areas were 

previously coal strip-mine spoils or cultivated fields. Strip mining within the boundaries of the 

Braidwood site began in the early 1940s, and the U.S. Forest Service (USFS) undertook 

reclamation of the site beginning in the late 1940s and continuing through the early 1960s as 

part of a statewide program to address strip-mine spoils (ComEd 1973b). Following the 

passage of reclamation laws in the State of Illinois, Peabody Coal Company began systematic 

plantings on the site in the 1960s through early 1970s. The company topped and seeded spoil 

ridges with grasses and forbs. American sycamore (Platanus occidentalis), eastern red cedar 

(Juniperus virginiana), and eastern cottonwood (Populus deltoides) trees were hand-planted, 

but mortality of these species was high. Black locust (Robinia pseudoacacia), autumn olive 

(Elaeagnus umbellata), Russian olive (E. angustifolia), and various pines (Pinus spp.) were later 

planted with higher success rates (ComEd 1973b). The natural vegetative communities for the 

Braidwood site are tallgrass prairie and deciduous forest characterized by sassafras (Sassafras 

albidum), white oak (Quercus alba), red oak (Q. rubra), black oak (Q. velutina), and Hortulan 

plum (Prunus hortulana) (ComEd 1973b, 1985). The Braidwood site was highly disturbed prior 

to Braidwood construction and operation. For this reason, the preoperational surveys 

determined that no such communities existed on the site (ComEd 1973b, 1985).

The Braidwood site currently includes 264 ac (107 ha) of land developed for industrial use and 

1,653 ac (669 ha) of natural areas (Exelon 2014f). Exelon (2014f) leases 67 ac (27 ha) of 

natural areas to private individuals for agricultural use and 1,280 ac (518 ha) to the IDNR for 

recreational use. The cooling pond occupies the remaining 2,540 ac (1,028 ha) of the site. 

Section 3.2 describes the current land uses on the Braidwood site in more detail.

Exelon maintains a WHC-certified Wildlife Management Plan (Exelon 2013f) for the Braidwood 

site. The plan outlines the goals and projects of Exelon’s Wildlife at Work program, which 

includes ecological management of the cooling pond (referred to as “Braidwood Lake” in the 

plan) through fish population management, underwater habitat restoration, and shoreline habitat 

restoration. Exelon’s shoreline habitat restoration efforts have included water willow (Justicia 

americana) plantings in 2008, and the plan indicates that Exelon will consider planting other 

native shoreline plants, in consultation with IDNR, in the future (Exelon 2013f). Exelon will also 

evaluate the potential for controlling and removing some of the non-native invasive common 

reed (Phragmites australis) with mechanical methods and aquatic-safe herbicides. Non-native 

species are not currently being controlled (Exelon 2013f). Exelon first received WHC 

certification for its plan in 2005 (Exelon 2014h), and the WHC most recently renewed Exelon’s 

certification in October 2013 (WHC 2013). WHC certification lasts for 2-year periods. Exelon 

intends to seek WHC recertification and continue to implement wildlife protection programs 

during the proposed license renewal term (Exelon 2014h). In its comments on the draft SEIS, 

the EPA (2015a) commended Exelon on its Wildlife Management Plan and encouraged 
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incorporation of additional native shoreline plantings and removal of terrestrial and aquatic 

non-native, invasive species. 

3.6.3.1 Vegetation

Cultivated Fields. At the time of Braidwood construction, approximately 1,021 ac (413 ha) of 

the site was cultivated for soybeans (Glycine max), wheat (Triticum spp.), and alfalfa (Medicago 

sativa) on a rotating basis (ComEd 1973b). ComEd (1973b, 1985) reported that weeds such as 

black nightshade (Solanum americanum), common thistle (Cirsium spp.), asters (Aster spp.), 

and ivy-leafed morning glory (Ipomoea hederacea) were also present in these areas. Today, 

Exelon continues to lease 67 ac (27 ha) of the Braidwood site for agricultural use 

(Exelon 2014f).

Fallow Fields and Grasslands. ComEd (1973b) reports that approximately 471 ac (191 ha) of 

fallow fields occurred in the western portion of the site. Prior to ComEd’s purchase of the site, 

these fields had likely been cultivated for wheat. During baseline terrestrial surveys, these fields 

were composed of various annual and herbaceous perennials with localized stands of alfalfa, 

frostweed (Aster pilosus), late boneset (Eupatorium serotinum), and common ragweed 

(Ambrosia artemisiifolia). Exelon (2014f) indicates that 306 ac (124 ha) of forest, old fields, or 

early successional grasslands remain on the site today, but the specific acreage of remaining 

fields and grasslands is unavailable.

Woodlands. During baseline surveys, approximately 395 ac (160 ha) of the Braidwood site 

consisted of open woodlands. ComEd (1973b) indicates that these woodlands occupied thin 

strips between cultivated fields in the northwest corner of the site. Red and white oak 

dominated the overstory vegetation, and the understory included sassafras, prairie willow (Salix 

humilis), and hazelnut (Corylus americana). Cinnamon ferns (Osmundastrum cinnamomeum) 

were present in localized stands. The average canopy height was 35 to 40 ft (11 to 12 m) and 

ground cover was between 60 to 75 percent. Other areas of the site supported small 

communities of red oak, eastern cottonwood, osage orange (Maclura pomifera), silver maple 

(Acer saccharinum), and sugar maple. Lombardy poplar (Populus italica) had also been planted 

as windbreaks in certain areas. Exelon (2014f) indicates that 306 ac (124 ha) of forest, old 

fields, or early successional grasslands remain on the site today, but the specific acreage of 

remaining forest is unavailable.

The woodland species recorded by the WHC during the 2005 site assessment varied somewhat 

from those species reported during baseline surveys. Silver maple, eastern cottonwood, willow, 

oak species, and raspberry were reported in both preoperational surveys and in the 2005 

inventory. The 2005 inventory also reported the following additional species in wooded areas: 

chicory (Cichorium intybus), eastern red cedar, and burr oak (Quercus macrocarpa). Because 

the methodology for the 2005 species inventory is unknown, it is unclear whether additional 

forest species reported in the baseline surveys no longer occur on the site or whether they were 

simply not observed or reported in 2005.

Strip-Mine Spoils. Approximately 2,433 ac (985 ha) of the site consisted of strip-mine spoils 

during preoperational terrestrial surveys (ComEd 1973b). These areas were characterized by 

long ridges separated by deep gullies that contained intermittent ponds. The majority 

(80 percent) of the strip-mine spoils were bare prior to Braidwood construction, and vegetation 

on ridge tops was dominated by those species planted during reclamation. Naturally occurring 

forbs included Russian thistle (Salsola pestifer), sweet clover (Melilotis officinalis), and 

goosefoot (Chenopodium berlandieri), and the most commonly occurring grasses were 

bromegrass (Bromus inermis) and foxtail (Setaria faberii). Marshy, sloped areas were 

dominated by broad-leaved cattail (Typha latifolia) and black willow (Salix nigra), and drainages 

supported threeawn grass (Aristida spp.), spike-rush (Eleocharis ovata), great bulrush (Scirpus 
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acutus), and pondweed (Potamogeton natans). Those areas that had been mined earliest (in 

the 1940s) supported a more diverse community of black willow, black locust, quaking aspen 

(Populus tremuloides), and understory species including poison ivy (Toxicodendron radicans), 

Virginia creeper (Parthenocissus quinquefolia), frost grape (Vitis vulpina), sweet clover, and 

black raspberry (Rubus occidentalis).

• During Braidwood construction, creation of the cooling pond inundated abandoned mine 

pits and borrow areas associated with strip-mining on the property in the 1940s. The 

cooling pond includes large islands with trees and shrubs, which represent the remaining 

former strip-mine terrestrial habitat. Figure 3–14 is a map of the Mazonia–Braidwood 

State Fish and Wildlife Area, which depicts the network of islands within the cooling 

pond (labeled “Braidwood Lake” in the figure).
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Figure 3–14. Mazonia–Braidwood Fish and Wildlife Area

Source: IDNR 2014d
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3.6.3.2 Animals

Mammals. The baseline surveys documented mammals on the site based on observations of 

tracks, droppings, or individuals during the autumn of 1972 and 1973. ComEd (1973b, 1985) 

reported 24 species of mammals as occurring on the Braidwood site. White-tailed deer 

(Odocoileus virginianus), cottontail rabbit (Sylvilagus floridanus), red (Vulpes vulpes) and gray 

(Urocyon cinereoargenteus) foxes, deer mice (Peromyscus maniculatus), and North American 

voles (Scalopus aquaticus) were observed in most site habitats. ComEd (1985) noted that 

strip-mine spoils, though sparsely vegetated, supported a diversity of mammals typical of 

marshes, ponds, or other semi-aquatic habitats, such as muskrat (Ondatra zibethica), beaver 

(Castor canadensis), and otter (Lutra canadensis).

The 2005 WHC site assessment reported seven mammal species as occurring on the 

Braidwood site (Exelon 2013f): groundhog (Marmota monax), striped skunk (Mephitis mephitis), 

white-tailed deer, raccoon (Procyon lotor), eastern gray squirrel (Sciurus carolinensis), eastern 

chipmunk (Tamias striatus), and red fox. Six of these species were also reported in the 

baseline surveys, and one species (the eastern chipmunk) did not appear in baseline surveys. 

It is possible that the creation of the cooling pond, which flooded most of the abandoned mine 

pits and borrow areas associated with strip-mining on the property in the 1940s, affected the 

diversity of mammals on the site. However, Exelon’s Wildlife Management Plan (Exelon 2013f) 

does not specify the methodology of the 2005 site assessment, so a meaningful comparison 

between the baseline surveys and the 2005 data is not possible.

Birds. The baseline surveys documented birds on the site by visual observations and bird calls 

during four seasons in 2 survey years (1972-1973 and 1973-1974). A total of 91 migratory and 

resident species were identified. The greatest species diversity was found in woodlands 

(48 species), and fallow fields held the least diversity of birds (6 species). Several waterfowl—

including mallard (Anas platyrhynchos), black duck (A. rubripes), blue-winged teal (A. discors), 

and wood duck (Aix sponsa)—and shorebird species—including green heron (Butorides 

virescens), sora rail (Porzana carolina), upland sandpiper (Bartramia longicauda), and least 

bittern (Ixobrychus exilis)—were observed in the ponds formed between strip-mine spoil ridges. 

Strip-mine spoils were inhabited by birds typical of open or edge habitats. Many species of 

migratory songbirds occurred on the site on spring and fall survey days including eastern 

bluebird (Sialia sialis), cedar waxwing (Bombycilla cedrorum), eastern meadowlark (Sturnella 

magna), American goldfinch (Carduelis tristis), indigo bunting (Passerina cyanea), black-capped 

chickadee (Poecile atricapillus), eight species of warblers, and nine species of sparrows. 

Year-long residents included bobwhite (Colinus virginianus), ring-necked pheasant (Phasianus 

colchicus), mourning dove (Zenaida macroura), horned lark (Eremophila alpestris), blue jay 

(Cyanocitta cristata), American crow (Corvus brachyrhynchos), field sparrow (Spizella pusilla), 

and song sparrow (Melospiza melodia). Birds of prey included the eastern screech owl 

(Megascops asio), osprey (Pandion haliaetus), and six species of hawks.

The 2005 WHC site assessment reported 27 bird species as occurring on the Braidwood site 

(Exelon 2013f). Eighteen of these species were also reported in the baseline surveys. Notable 

additions not reported in the baseline surveys include the bald eagle (Haliaeetus 

leucocephalus), American kestrel (Falco sparverius), and wild turkey (Meleagris gallopavo). As 

indicated previously, Exelon’s Wildlife Management Plan (Exelon 2013j) does not specify the 

methodology of the 2005 site assessment, so a meaningful comparison between the baseline 

surveys and the 2005 data is not possible.

Amphibians and Reptiles. The baseline surveys documented amphibians and reptiles on the 

site during spring, summer, and fall of the 2 survey years (1972-1973 and 1973-1974). A total 

of 27 species were recorded on the site with the greatest diversity of species occurring in 
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strip-mine spoil habitat (ComEd 1972, 1985). Cricket frogs (Acris crepitans) were the most 

abundant species, and cricket frogs, chorus frogs (Pseudacris spp.), and American toads (Bufo 

americanus) were present at all sampling locations. Aquatic turtles—including the painted turtle 

(Chrysemys picta marginata × belli), common snapping turtle (Chelydra serpentina), Blanding’s 

turtle, and spiny softshell turtle (Trionyx spiniferus)—inhabited ponds between strip-mine spoil

ridges. The ornate box turtle (Terrapene ornata), a terrestrial turtle, was also present. 

Observed snakes included the eastern garter (Thamnophis sirtalis), eastern hognose 

(Heterodon platirhinos), eastern yellow-bellied racer (Coluber constrictor flaviventris), northern 

water snake (Nerodia sipedon). Other species of note included the eastern tiger salamander 

(Ambystoma tigrinum), five-lined skink (Eumeces fasciatus), and six-lined race runner 

(Cnemidophorus sexlineatus).

The 2005 habitat assessment did not include amphibians or reptiles.

3.6.3.3 Important Species and Habitats

Important Species. The IDNR (2013b) identifies 58 State-listed terrestrial species (39 plants, 

9 birds, 5 reptiles, 3 insects, 1 mammal, and 1 amphibian) as occurring in Will County. In 

March 2012, Exelon further refined this list of species when it generated an IDNR Ecological 

Compliance Assessment Tool (EcoCAT) report that included Illinois Natural Heritage Database 

information on species that could potentially be affected by the proposed license renewal. The 

EcoCAT reported is included in Appendix C of the ER (Exelon 2013g). The report indicates that 

four terrestrial State-listed species may occur on or near the Braidwood site: the ornate box 

turtle, Blanding’s turtle (Emys blandingii), Oklahoma grass pink orchid (Calopogon 

oklahomensis), and pale-green orchid (Platanthera flava var. herbiola). Of these, ComEd 

(1973b, 1985) indicates that the ornate box turtle and Blanding’s turtle were observed during 

baseline surveys of the Braidwood site. No State-listed species were identified in the 

2005 habitat assessment. Federally protected species are discussed in Section 3.8.

The ornate box turtle is listed as threatened in Illinois (IDNR 2013b). It inhabits prairies and 

sandy, treeless grasslands, and open woodlands with loose soils suitable for burrowing 

(WGFD 2010). The Blanding’s turtle is listed as endangered in Illinois (IDNR 2013b). It inhabits 

wetland complexes with rich aquatic vegetation and adjacent sandy uplands as well as 

ephemeral wetlands and backwater pools (MDNR 2014a). The Braidwood site may provide 

some marginal habitat for these two species, but it is unlikely to support large populations of 

either turtle because of the lack of optimal habitat.

The Oklahoma grass pink orchid is a State-endangered terrestrial orchid that inhabits a variety 

of habitats, including seasonally dry-mesic prairie, upland prairie, open woodlands, and bogs 

edges (IDNR 2013b). The FWS indicates that in Illinois, 7 to 42 historic populations occurred 

in the state, of which, 1 to 2 still exist (76 FR 61307). One of these populations occurs in 

Braidwood Dunes and Savanna Nature Preserve, which lies approximately 2 mi (2.4 km) 

northeast of the Braidwood site. Illinois Nature Preserves are high-quality natural areas that 

provide permanent protection to habitats and native biota within the preserves. The FWS 

recognize Illinois Nature Preserves as providing appropriate protection for the continued 

existence of Oklahoma grass pink orchid (76 FR 61307).

The pale-green orchid is a State-threatened terrestrial orchid that inhabits wet woods and 

meadows with sandy soil and high leaf litter (IDNR 2013b; NatureServe 2014b). The IDNR 

(2014a) indicates that this species also occurs northeast of the Braidwood site in the Braidwood 

Dunes and Savanna Nature Preserve.

In addition to State-listed species, in a letter to NRC, the FWS (2013d) indicated that the bald 

eagle, which is Federally protected under the Bald and Golden Eagle Protection Act (BGEPA) 
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and Migratory Bird Treaty Act (MBTA), has nested on one of the cooling pond islands in the 

past. The BGEPA and MBTA provide certain protections to bald and golden (Aquila chrysaetos) 

eagles and migratory birds, respectively. The FWS Chicago Ecological Services Field Office 

provided technical assistance to Exelon to ensure that the eagles were protected and that 

Exelon appropriately complied with the BGEPA. In its ER, Exelon (2013g) indicated that bald 

eagles have not nested on the cooling pond islands in recent years. Exelon (2015a) has not 

observed bald eagles nesting on the site in 2014 or 2015. Most of the islands in the cooling 

pond are within areas leased and managed by the IDNR as part of the Mazonia–Braidwood 

State Fish and Wildlife Area. The lease requires that IDNR assure compliance with all 

environmental laws, including those that protect bald eagles. Accordingly, if Exelon (2015a) 

personnel observe nesting bald eagles in the leased area of the cooling pond, Exelon will inform 

IDNR of the observation and request that IDNR undertake its responsibilities in accordance with 

the lease. If Exelon (2015a) personnel observe nesting bald eagles in the restricted access 

portion of the cooling pond, Exelon will notify the FWS and coordinate with the agency to ensure 

adherence to BGEPA and MBTA.

Important Habitats. In its Illinois Natural Areas Inventory (INAI), the IDNR (2013a) identifies 

38 Will County sites as Category I (“high quality natural community and natural community 

restorations”), Category II (‘specific suitable habitat for state-listed species or state-listed 

species relocations”), Category III (“State-dedicated Nature Preserves, Land and Water 

Reserves, & Natural Heritage Landmarks”), or a combination of the three categories. The 

2012 EcoCAT report (Appendix C in Exelon 2013g) indicates that two of these sites lie near the 

Braidwood site: Braidwood Dunes and Savanna Nature Preserve and Godley Railroad Prairie.

The Braidwood Dunes and Savanna Nature Preserve (INAI Site No. 0935) lies 2 mi (2.4 km) 

northeast of the Braidwood site. It is 314 ac (127 ha) in size and includes dry-mesic sand 

savanna remnant habitat with prairie, sedge meadow, and marsh habitats representative of the 

Kankakee Sand Area Section of the Grand Prairie Natural Division (IDNR 2014a). The IDNR 

(2013a) designates this INAI site as Category I, II, and III.

The Godley Railroad Prairie (INAI Site No. 0898) in Will County encompasses 235 ac (95 ha). 

The IDNR (2013a) designated this INAI as Category I.

The Mazonia-Braidwood State Fish and Wildlife Area, which Exelon and the IDNR jointly 

manage, includes the Braidwood cooling pond as well as IDNR-owned lands adjacent to the 

Braidwood site to the south and southwest of the cooling pond. In total, the wildlife area 

consists of 2,640 ac (1,068 ha) of land. The IDNR (2014d) manages the area to enhance 

habitat for sport fish, waterfowl, and State-listed threatened and endangered species. 

3.7 Aquatic Resources

The aquatic communities of interest for the Braidwood site occur in the Kankakee River and 

in the site’s artificial cooling pond. The Kankakee River lies 5 mi (8 km) east of the site. It 

supplies makeup water to Braidwood’s cooling system and receives cooling system blowdown. 

The cooling pond is the site’s main source of cooling water and ultimate heat sink. 

Section 3.1.3 describes the cooling system in detail, and Section 3.5.1 describes the 

surface water characteristics of Kankakee River and the cooling pond.

3.7.1 Aquatic Ecosystem Descriptions

3.7.1.1 Kankakee River

The Kankakee River is a tributary of the Illinois River. It flows southwest from its headwaters 

near South Bend, St. Joseph County, Indiana, and continues into Illinois through Kankakee and 
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Will Counties to its confluence with the Des Plaines River near Channahon, Illinois. At this 

point, the Kankakee and Des Plains River together form the Illinois River. The total length of the 

Kankakee River is approximately 140 mi (225 km), of which 59 mi (95 km) is in Illinois (Pescitelli 

and Rung 2008). The river’s width varies from 200 to 800 ft (60 to 240 m) with depths of up to 

15 ft (6 m) (IDNR 1998).

The river’s watershed drains a total of 2,989 mi2 (4,810 km2

) in northwestern Indiana, 2,169 mi2

(3,490 km2

) in northeast Illinois, and 7 mi2 (11 km2) in southwest Michigan (INDNR 1990). Major 

tributaries include the Iroquois River, Singleton Ditch, Trim Creek, Baker Creek/Exline Slough, 

Rock Creek, Horse Creek, Forked Creek, and Prairie Creek. Agriculture accounts for 

75 percent of land use in the watershed (Pescitelli and Rung 2008).

In Indiana, the Kankakee River was extensively channelized in the late 1800s and early 1900s. 

Within Illinois, the river remains largely unmodified with the exception of three dams: a small 

side channel dam at Momence in Kankakee County and a larger dam at the city of Kankakee—

both of which are upstream of Braidwood—as well as an overflow dam at Wilmington 

downstream of Braidwood in Will County (Bhowmik and Demissie 2000). The river in the 

vicinity of Braidwood includes numerous riffles, small pools, and islands and the river bottom 

is composed of gravel, cobble, and sand (Pescitelli and Rung 2008).

The Kankakee River basin supports a large diversity of aquatic biota, including 84 species of 

fish, 37 mussels, 14 crustaceans, and a variety of aquatic macroinvertebrates. Common fish 

include the spotfin shiner (Cyprinella spiloptera), red shiner (C. lutrensis), rosyface shiner 

(Notropis rubellus), striped shiner (Luxilus chrysocephalus), sand shiner (N. stramineus), grass 

pickerel (Esox americanus vermiculatus), shorthead redhorse (Moxostoma macrolepidotum), 

smallmouth bass (Micropterus dolomieu), longear sunfish (Lepomis megalotis), and banded 

darter (Etheostoma zonale). Within Kankakee River tributaries, creek chub (Semotilus spp.), 

bluntnose minnow (Pimephales notatus), red shiner, rock bass (Ambloplites rupestris), and 

johnny darter (Etheostoma nigrum) are prevalent. The most common species of mussels are 

the mucket (Actinonaias ligamentina), pimpleback (Quadrula pustulosa), threeridge (Amblema 

plicata), fatmucket (Lampsilis siliquoidea), white heelsplitter (Lasmigona complanata), and plain 

pocketbook (Lampsilis cardium) (IDNR 1998).

The IEPA (2014b) has rated the Kankakee River in the vicinity of Braidwood as fully supporting 

aquatic life. The IDNR has designated the Kankakee River from Momence in Kankakee County 

to the Des Plains Wildlife Conservation Area in Will County as a Biologically Significant Stream 

because it supports one of the state’s most diverse aquatic communities (Page et al. 1991). 

This designation includes the portion of the river affected by Braidwood operation. Silted pools 

separated by solid bedrock in the portion of the Kankakee River designated as a Biologically 

Significant stream support several State-listed fish, including pallid shiner (N. amnis; 

State-endangered), weed shiner (N. texanus; State-endangered), western sand darter 

(Ammocrypta clarum; State-endangered), river redhorse (Moxostoma carinatum; 

State-threatened), and a diversity of mussels, including the Federally endangered sheepnose 

(Plethobasus cyphyus) (Page et al. 1991). The blacknose shiner (N. heterolepis) and the 

northern brook lamprey (Ichthyomyzon fossor), both of which are State-endangered, are thought 

to have been extirpated from the river (Page et al. 1991). Sections 3.7.5 and 3.8 address

State-listed and Federally listed species, respectively, that may be in the vicinity of Braidwood,

in detail.

3.7.1.2 Braidwood Cooling Pond

Braidwood’s 2,540-ac (1,030-ha) cooling pond was created in 1980 and 1981 by pumping water 

from the Kankakee River into a diked area, which surrounds portions of a former strip mine, 

inundating deep pits, borrow areas, and depressions. In the fall of 1991, the Illinois Department 
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of Conservation (now the IDNR) entered into a long-term lease agreement with ComEd (the 

constructor and original operator of Braidwood) to allow general public access to a portion of 

the cooling pond for fishing, waterfowl hunting, and fossil collecting (IDNR 2014d). The leased 

portion of the cooling pond is part of the Mazonia–Braidwood State Fish and Wildlife Area, 

which also includes IDNR-owned lands adjacent to the Braidwood site to the south and 

southwest of the cooling pond. Exelon and the IDNR continue to jointly manage this area 

to enhance habitat for sport fish, waterfowl, and State-listed species (IDNR 2014d).

Since the beginning of the lease agreement, the IDNR has stocked the cooling pond with a 

variety of game species, including largemouth bass (Micropterus salmoides), smallmouth bass, 

blue catfish (Ictalurus furcatus), striped bass (Morone saxatilis), crappie (Pomoxis spp.), 

walleye, and tiger muskellunge (Esox masquinongy × lucius). Because of the high water 

temperatures experienced in the summer months, introductions of warm-water species, such as 

largemouth bass and blue catfish, have been more successful than introductions of cool-water 

species, such as walleye and tiger muskellunge (Exelon 2013e). High summer temperatures 

have also contributed to a number of fish kills in the cooling pond. Section 3.7.4 discusses 

these events.

3.7.2 Aquatic Surveys and Monitoring

3.7.2.1 Kankakee River

Preoperational monitoring of the Kankakee River aquatic resources began in 1972 when 

Westinghouse Electric Corporation initiated a monitoring program within a 2.5-km (1.5-mi) reach 

of the Kankakee River and its tributary, Horse Creek, approximately 23.5 km (14.6 mi) upstream 

from the confluence of the Kankakee and Des Plaines Rivers (HDR 2013b). Eleven sampling 

locations (listed in Table 3–8 lists and illustrated in Figure 3–15) were established as part of the 

program, and the same locations continue to be sampled today. Results of the first study, 

conducted from October 1972 through November 1973, as well as the projected impacts of 

construction on aquatic resources were described in ComEd’s 1973 ER (ComEd 1973a) and the 

U.S. Atomic Energy Commission’s 1974 FES-C (AEC 1974). Three additional sampling periods 

(1974-1975, 1977-1979, and 1981-1982), as well as the projected impacts of operation, were 

addressed in ComEd’s 1983 ER and the NRC’s 1984 Final Environmental Statement for 

Braidwood Operation (FES-O) (NRC 1984).
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Table 3–8. Braidwood Aquatic Survey Sampling Locations

Sampling 

Location(s) Description Representative Conditions

1L, 1R South/left (L) and north/right (R) banks 

of the Kankakee River 1 km (0.6 mi) 

upstream of the makeup water 

intake point

Representative of upstream areas 

uninfluenced by Braidwood operations

2 In Horse Creek 150 m (500 ft) upstream 

from its confluence with the Kankakee 

River

Representative of a potential fish spawning 

area for the Kankakee River

3L, 3R Left and right banks of the Kankakee 

River in the area of Braidwood’s makeup 

water intake point at the river screen 

house

Representative of areas that may be 

affected by withdrawal of makeup water

4L, 4R Left and right banks of the Kankakee 

River in the area of Braidwood’s 

discharge point

Representative of areas that may be affected 

by thermal and chemical attributes of 

blowdown

5L, 5R Left and right banks of the Kankakee 

River 300 m (1000 ft) downstream of 

the discharge point

Representative of nearfield recovery from 

any impacts associated with blowdown

6L, 6R Left and right banks of the Kankakee 

River 1.6 km (1.0 mi) downstream of 

the discharge point

Representative of farfield recovery from 

any impacts associated with blowdown

Source: HDR 2009
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Figure 3–15. Kankakee River Fish Sampling Locations

Source: HDR 2014

Beginning in 1977, the Illinois Natural History Survey (INHS) conducted annual fish sampling of 

the Braidwood Station Aquatic Monitoring Area. INHS continued surveys through 1990. Since 

1991, various private companies have performed the sampling; most recently HDR Engineering, 

Inc. (HDR), has conducted annual sampling since 2005. The description of Kankakee River 

aquatic communities in Section 3.7.3 relies on available sampling program data (HDR 2009, 

2011b, 2013b; Larimore and Peterson 1989).
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In 2008, Exelon commissioned two studies (ESI 2009; HDR 2008) to determine the presence of 

State-listed fish and mussel species near the Braidwood discharge channel on the Kankakee 

River. These studies supported Exelon’s assessment of potential impacts to aquatic biota that 

could result from replacing the discharge channel with a multi-port discharge diffuser, a project 

that was later completed in 2010. In 2015, Ecological Specialists, Inc. (Exelon 2015b), 

completed a follow-up study to determine whether the discharge diffuser replacement had 

affected the mussel colonization or recolonization rate in the vicinity of the discharge. The 

studies are considered in the description of Kankakee River aquatic communities in 

Sections 3.7.3 and the discussion of important species and habitats in Section 3.7.5.

In support of the LRA, Exelon commissioned EA Engineering, Science, and Technology, Inc. 

(EA Engineering 2012), to perform benthic macroinvertebrate sampling in the Kankakee River at 

locations upstream and downstream of Braidwood. EA Engineering conducted the sampling in 

2011, and it included artificial substrate samplers, grab samples, and kick net samples along 

several river transects. Also in support of the LRA, HDR (2014) compiled aquatic monitoring 

data for the period 1991 through 2013. Section 3.7.3 discusses the results of these studies.

A number of impingement and entrainment studies have been conducted to determine the 

impacts of Braidwood’s cooling system on Kankakee River aquatic organisms. Several 

preoperational studies are described in the FES-O (NRC 1984). Operational studies include a 

1988-1989 impingement and entrainment study (EA Engineering 1990) and a 1991 

impingement study (summarized in EA Engineering 2012). Exelon also commissioned 

EA Engineering (2012) to perform historical fish and benthos comparisons that consider 

impingement and entrainment to support preparation of the LRA. These studies are discussed 

in the NRC’s assessment of impacts to aquatic resources in Section 4.7.

3.7.2.2 Braidwood Cooling Pond

The IDNR has conducted fish surveys of the cooling pond since 1980 when the cooling lake 

was first impounded with Kankakee River water. The IDNR continued to conduct surveys 

annually from 1980 through 1992, in 1994, and every other year from 1997 through 2007. HDR 

(2010) summarizes the results of these surveys.

Beginning in 2009, Exelon commissioned HDR (2010, 2011a, 2012, 2013a) to begin sampling 

the cooling pond and to create a set of procedures that could predict conditions that would 

create a high likelihood for fish kill events following several events between 2001 and 2007 

(discussed in detail in Section 3.7.4). HDR continues these surveys today.

These studies inform the description of the cooling pond’s aquatic communities in Section 3.7.3.

3.7.3 Aquatic Communities near Braidwood

3.7.3.1 Kankakee River

Phytoplankton. Phytoplankton are microscopic floating photosynthetic organisms that form 

one base of aquatic food webs by producing biomass from inorganic compounds. As primary 

producers, phytoplankton play key ecosystem roles in the distribution, transfer, and recycling of 

nutrients and minerals.

Kankakee River phytoplankton community characteristics were assessed during 1972-1973 

preoperational surveys and summarized in the FES-C (AEC 1974). Phytoplankton was again 

assessed during three additional preoperational sampling periods (1974-1975, 1977-1979, and 

1981-1982) and summarized in the FES-O (NRC 1984). During 1972-1973, 1-liter dip samples 

were taken biweekly in October and November 1972 and monthly from December 1972 through 

September 1973. Samples were collected at mid-stream along the transects listed in Table 3–8 
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(ComEd 1973a). Diatoms were the most abundant phytoplankton, particularly from December 

through April (AEC 1974). Other phytoplankton present included blue-green algae, which was 

most abundant in early October; green algae, which was most prevalent in late October and 

November; and flagellates (Euglenophyta), which were most prevalent in February. The FES-C 

concluded that the Kankakee River phytoplankton community in the vicinity of Braidwood is 

characteristic of temperate zone rivers. The FES-O (NRC 1984) notes that during the 

1974-1975 monitoring period, samples yielded 5 phyla and 200 species of phytoplankton. Most 

species belonged to the phyla Bacillariophyta (diatoms) or Chlorophyta (green algae). Diatoms 

again dominated the phytoplankton community in both Kankakee River and Horse Creek 

samples. The NRC staff is not aware of any additional phytoplankton surveys that may have 

been conducted in the vicinity of Braidwood since the plant began operating in 1988.

Periphyton. Periphyton includes a mixture of algae, cyanobacteria, heterotrophic microbes, 

and detritus that attach to submerged surfaces. Like phytoplankton, periphyton are primary 

producers and provide a source of nutrients to many bottom-feeding organisms.

The river’s periphyton community was assessed during 1972-1973 preoperational surveys and 

summarized in the FES-C (AEC 1974). Artificial substrate diatometer and drain tile samples 

were collected in 8 months in 1972 and 1973 along the transects listed in Table 3–8 

approximately 20 ft (6 m) from either shore (ComEd 1973a). The FES-C provides little 

information on periphyton beyond stating that diatoms were more numerous than either green 

or blue-green algae. The FES-C also notes that several species that are tolerant of organic 

enrichment, including the diatoms Gomphonema olivaceum, Navicula crytocella, Nitzschia 

filiformis, and Nitzschia palea, were present. Additional periphyton monitoring was conducted in 

1974-1975, 1977-1979, and 1981-1982. The FES-O (NRC 1984) notes that diatoms dominated 

each of these sample periods and that over 400 diatom species were identified across the 

11 sample sites. The NRC staff is not aware of any additional periphyton surveys that may 

have been conducted in the vicinity of Braidwood since the plant began operating in 1988.

Zooplankton. Zooplankton are small animals that float, drift, or weakly swim in the water column 

and include ichthyoplankton (fish eggs and larvae) with no or limited swimming ability and larvae 

of benthic invertebrates. Zooplankton are important trophic links between primary producers 

(e.g., phytoplankton and periphyton) and carnivores (e.g., fish).

Kankakee River zooplankton community characteristics were assessed during 1972-1973 

preoperational surveys and summarized in the FES-C (AEC 1974). Samples were collected 

biweekly in October and November 1972 and monthly from December 1972 through 

September 1973 via metered surface tows with 202-micron (μ) mesh plankton nets at 

mid-stream along the transects listed in Table 3–8 (ComEd 1973a). Species diversity and 

abundance was greatest in the spring when over 125 species were identified (AEC 1974). 

Glochidia (freshwater mussel larvae), crustaceans in the family Cyclopidae and the order 

Ostracoda were most abundant in spring samples, while the mayfly Stenonema was most 

abundance in fall samples (AEC 1974). The FES-O (NRC 1984) does not provide any 

additional information on the results of subsequent periods of zooplankton monitoring.

The NRC staff is not aware of any additional zooplankton surveys that may have been 

conducted in the vicinity of Braidwood since the plant began operating in 1988.

Benthic Macroinvertebrates. Benthic macroinvertebrates include aquatic annelids (aquatic 

worms, flatworms, and leeches), mollusks, crustaceans, and insect larvae that inhabit aquatic 

sediments. They accelerate detrital decomposition and nutrient cycling, and serve as a food 

source for fish and other aquatic biota. 
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During the preoperational monitoring period, the INHS collected seasonal Hester-Dendy (HD) 

and Ponar grab or kick net samples of benthic macroinvertebrates from the Kankakee River in 

1979. The samples were collected at eight river locations (1L, 1R, 4L, 4R, 5L, 5R, 6L, and 6R; 

see Table 3–8) in June, August, September (HD samples) and May, August, and November 

(grab and kick net samples). The August collections, which incorporated all gear types, yielded 

82 taxa, of which 29 were larvae of mayflies (order Ephemeroptera), stoneflies (order 

Plecoptera), or caddisflies (order Trichoptera). Dominant taxa included caddisflies 

(Cheumatopsyche spp., Hydropsyche phalerata, Maccaffertium integrum); mayflies in the 

genera Hexagenia, Isonychia, Stenacron, and Tricorythodes; midges in the genera Polypedilum

and Tanytarsus; and oligochaete worms (family Naididae). Species richness and density was 

greatest near the Braidwood discharge point (location 4R) in HD samples and downstream of 

the discharge point (location 5L) in grab samples. (EA Engineering 2012)

In 2011, EA Engineering (2012) conducted benthic macroinvertebrate sampling at five river 

locations (1L, 4L, 4R 5L, and 5R; See Table 3–8). HD samples were collected at four locations 

(all but 5L) and Ponar grab or kick net samples were taken at all five locations. The sampling 

yielded a total of 72 taxa, of which 24 were midges (family Chironomidae), 15 were mayflies 

(order Ephemeroptera), and 6 were mollusks (class Bivalvia). Eleven taxa of Ephemeroptera, 

Plecoptera, and Trichoptera (EPT) were identified. In HD samples, taxa richness was highest at 

locations 1L and 4R (30 taxa), followed by location 5R (27 taxa), and location 4L (20 taxa). 

Density was highest at location 4R and lowest at location 5R. Dominant taxa included mayflies 

(Baetis intercalaris, Caenis spp., Stenacron spp., and Tricorythodes spp.), midges 

(Dicrotendipes neomodestus, Chironomus spp., and Glyptotendipes spp.), flatworms (class 

Turbellaria), oligochaete worms (family Naididae), the amphipod crustacean Hyalella azteca, 

and freshwater snails in the genus Pleurocera. 

EA Engineering (2012) concluded that the benthic community had remained similar in the 

32 years between the 1979 and 2011 samples. Species richness and density was similar for 

individual locations across the 2 sample years, and in both years, taxa that tend to be less 

tolerant of environmental stressors were generally more abundant at upstream locations, while 

tolerant species were more abundant downstream. Both surveys attributed these longitudinal 

differences to differences in substrate composition at upstream and downstream locations.

The largest difference between the two studies appears to be the EPT richness. EPT taxa are 

generally considered to be intolerant of environmental stress. Thus, a relatively high EPT 

richness typically represents a high quality benthic community. In 1979, 29 EPT taxa were 

collected, while in 2011, only 11 EPT taxa were collected. The change in EPT richness appears 

to contradict EA Engineering’s (2012) conclusions because it signals a possible degradation in 

water quality. Section 3.5.1 addresses surface water quality.

Fish. Preoperational fish monitoring began in 1972. However, the only available information is 

on the 1974-1975 and 1981-1982 sample years. The FES-O (NRC 1984) indicates that during 

this period, 38 species of fish were collected from the Kankakee River, and 46 species were 

collected from both the Kankakee River and Horse Creek at the 11 sampling survey locations 

listed in Table 3–8. Gear types included electrofishing, seining, baited hoop netting, and gill 

netting (ComEd 1973a). The majority of the fish belonged to the families Cyprinidae (minnows, 

shiners, and carp), Centrarchidae (sunfish), and Catostomidae (suckers), which accounted 

for 33, 24, and 14 percent of the total number of species collected, respectively (NRC 1984). 

Other families present included Aphredoderidae (pirate perch), Atherinidae (silversides), 

Clupeidae (herring), Esocidae (pike), Ictaluridae (catfish), Lepisosteidae (gar), Percidae (perch), 

and Salmonidae (trout). Within Kankakee River sample sites, the most abundant species 

(accounting for 5 percent or more of the total collection) were bluegill (Lepomis macrochirus), 

rock bass, mimic shiner (Notropis volucellus), spotfin shiner, shorthead redhorse, white crappie 
Affected Environment

3-57

(Pomoxis annularis), and spottail shiner (Notropis hudsonius). Several years later in 1981 to 

1982, 51 taxa were collected. Cyprinids (33.8 percent), centrarchids (33.7 percent), and 

catostomids (22.1 percent) continued to dominate samples. Table 3–9 lists the number 

of individuals collected and relative abundance in 1981-1982 by family and species.

Kankakee River fish surveys have continued since Braidwood began operating, as described in 

Section 3.7.2.1. Exelon’s current Kankakee River sampling program includes electrofishing and 

seine samples from the 11 locations identified in Table 3–8 during the first and third weeks of 

August of each year. Electrofishing is conducted with a boat-mounted, boom-type electrofisher. 

River locations 1, 5, and 6 are sampled for 30 minutes over a distance of 500 ft (150 m), which 

represents one unit effort, and locations 3 and 4 are sampled for 15 minutes over 250 ft (75 m). 

Location 2 (Horse Creek) is electrofished from the stream mouth to a point 1,000 ft (300 m) 

upstream for 30 minutes. Shoreline seining is performed with 25 ft x 4 ft (7.6 m x 1.2 m) nets 

with 3/16-in. (4.8-mm) mesh and a 4-ft x 4-ft (1.2-m x 1.2-m) bag of 3/16-in. (4.8-mm) mesh. 

Two seine hauls are made at each location during each sampling effort. Collections are taken 

across 15 m (50 ft) of shoreline in a downstream direction, and the second haul is taken 

upstream of the first (HDR 2009).

Since 1977, 84 species in 19 families have been collected from the Kankakee River and Horse 

Creek (HDR 2013b). In the past 5 data years (2009 through 2013), HDR (2014) has collected 

69 species of fish in 15 families. The most commonly collected species during this period (both 

sampling gear types, all sampling locations) were spotfin shiner (37.1 percent), longear sunfish 

(28.5 percent), bullhead minnow (Pimephales vigilax; 21.7 percent), bluntnose minnow 

(16.5 percent), sand shiner (13.6 percent), and largemouth bass (6.9 percent). Two State-listed 

species were collected during electrofishing samples: two pallid shiner (State-endangered) in 

2011 and one river redhorse (State-threatened) in 2009. Table 3–10 lists the number and 

relative abundance of individuals collected by gear type, family, and species from 2009 

through 2013.

Common carp (Cyprinus carpio) have consistently dominated sample biomass since 1993 in all 

but 3 years. Other significant biomass contributors include gizzard shad (Dorosoma

cepedianum), channel catfish (Ictalurus punctatus), smallmouth bass, redhorse spp., 

carpsucker spp. (Carpiodes spp.), buffalo spp. (Ictiobus spp.), and longear sunfish.

Several species have become more abundant in recent years. HDR (2013b) indicates that 

largemouth bass, blackstripe topminnow (Fundulus notatus), brook silverside (Labidesthes 

sicculus), bluegill, and walleye have consistently increased in sample abundance. The 

appearance of an increasing number of walleye is likely due to IDNR’s recent stocking efforts in 

the Kankakee River (HDR 2013b). Walleye steadily increased in numbers over the 2009-2013 

period from 8 individuals (0.5 percent of individuals collected) in 2009 to 50 individuals 

(2.2 percent) in 2013.

Historically, the Kankakee River aquatic community in the vicinity of Braidwood was 

dominated by insectivores and piscivores of intermediate pollution tolerance (as defined in 

Barbour et al. (1999)). In recent years, insectivores and omnivores of intermediate to high 

pollution tolerance have dominated the community. Rock bass and white crappie, which were 

prevalent piscivores in preoperational monitoring sampling, only accounted for 1.8 and 

0.3 percent of individuals collected from 2009-2013, while bluntnose minnow and bullhead 

minnow, both omnivores, have accounted for a combined 23.2 percent of collected individuals 

in recent years (2009-2013). The increased prevalence of bluntnose minnow and spotfin shiner 

accounts for the majority of the shift to more pollution-tolerant species. The mimic shiner and 

rosyface shiner, which are pollution intolerant, were prevalent in preoperational studies, but 

have only accounted for 0.1 and 0.7 percent of the total catch from 2009-2013.
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Table 3–9. Fish Collected in the Kankakee River and Horse Creek

by Family and Species, 1981–1982

Family and Species (a) Common Name

Number of 

Individuals 

Collected

Relative 

Abundance 

(%)

Cyprinidae 362 33.8

Campostoma anomalum stoneroller 1 0.1

Cyprinella spiloptera spotfin shiner 41 3.8

Cyprinus carpio common carp 49 4.6

Luxilus chrysocephalus striped shiner 83 7.7

Lythrurus umbratilis redfin shiner 8 0.7

Notemigonus crysoleucas golden shiner 6 0.6

Notropis amnis pallid shiner 2 0.2

Notropis buccatus silverjaw minnow 1 0.1

Notropis rubellus rosyface shiner 70 6.5

Notropis stramineus sand shiner 21 2.0

Notropis volucellus mimic shiner 4 0.4

Notropis spp. minnow spp. 2 0.2

Phenacobius mirabilis suckermouth minnow 12 1.1

Pimephales notatus bluntnose minnow 47 4.4

Pimephales vigilax bullhead minnow 14 1.3

Semotilus atromaculatus creek chub 1 0.1

Centrarchidae 361 33.7

Ambloplites rupestris rock bass 43 4.0

Lepomis cyanellus green sunfish 75 7.0

Lepomis cyanellus × macrochirus green sunfish × bluegill hybrid 3 0.3

Lepomis humilis orangespotted sunfish 19 1.8

Lepomis macrochirus bluegill 10 0.9

Lepomis megalotis longear sunfish 50 4.7

Lepomis hybrid sunfish hybrid 1 0.1

Lepomis spp. sunfish spp. 13 1.2

Micropterus dolomieu smallmouth bass 100 9.3

Micropterus salmoides largemouth bass 26 2.4

Pomoxis annularis white crappie 11 1.0

Pomoxis nigromaculatus black crappie 10 0.9

Catostomidae 229 22.1

Carpiodes cyprinus quillback 43 4.0

Hypentelium nigricans northern hogsucker 18 1.7

Ictiobus cyprinellus bigmouth buffalo 2 0.2

Moxostoma anisurum silver redhorse 46 4.3

Moxostoma carinatum river redhorse 10 0.9

Moxostoma duquesnei black redhorse 3 0.3

Moxostoma erythrurum golden redhorse 83 7.7

Moxostoma macrolepidotum shorthead redhorse 22 2.1

Moxostoma spp. redhorse spp. 2 0.2
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Family and Species (a) Common Name

Number of 

Individuals 

Collected

Relative 

Abundance 

(%)

Clupeidae 66 6.2

Dorosoma cepedianum gizzard shad 66 6.2

Percidae 26 2.4

Etheostoma nigrum johnny darter 20 1.9

Percina maculata blackside darter 5 0.5

Sander vitreum walleye 1 0.1

Esocidae 11 1.0

Esox americanus grass pickerel 1 0.1

Esox lucius northern pike 10 0.9

Ictaluridae 2 0.3

Ictalurus punctatus channel catfish 1 0.1

Noturus flavus stonecat 1 0.1

Amiidae 2 0.2

Amia calva bowfin 2 0.2

Lepisosteidae 2 0.2

Lepisosteus osseus longnose gar 2 0.2

Fundulidae 1 0.1

Fundulus notatus blackstripe topminnow 1 0.1

Umbridae 1 0.1

Umbra limi central mudminnow 1 0.1

(a) Families ordered by decreasing relative abundance, and species within each family ordered alphabetically.

Source: NRC 1984

Another major change in the aquatic community is the significant shift in species distribution 

towards cyprinids. Cyprinids accounted for 33.8 percent of total collected individuals in 1982, 

while they accounted for an average of 57.2 percent of fish collected over the 2009-2013 period. 

Centrarchid abundance has decreased from 33.7 percent to 28.8 percent between 1982 and 

2009-2013. Catostomids, which accounted for 22.1 percent of the total catch in 1982, have only 

comprised an average of 5.0 percent in recent years. Percids have also decreased in relative 

abundance (see Figure 3–16).

Species composition has also changed. Three families have appeared in recent years that 

were not present in preoperational sampling: Scianidae (freshwater drum) began appearing in 

monitoring samples in the early 1990s and Poeciliidae (mosquitofish) and Petromyzontidae 

(lamprey) began appearing in samples in 2008 and 2010, respectively (HDR 2014). One family 

(Amiidae or bowfin) has not appeared in samples since Braidwood began operating, and 

another family (Umbridae or mudminnows) has not appeared in samples since 2001.
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Table 3–10. Fish Collected in the Kankakee River Monitoring Samples

by Family and Species, 2009–2013

Electrofishing Seining

All Gear 

Types

Species

Common 

Name No. % No. % No. % 

Cyprinidae 4,430 43.4 6,267 73.7 10,697 57.1

Cyprinella lutrensis red shiner 2 <0.1 1 <0.1 3 <0.1

Cyprinella spiloptera spotfin shiner 1,206 11.8 3,000 35.3 4,206 22.5

Cyprinus carpio common carp 52 0.5 2 <0.1 54 0.3

Luxilus 

chrysocephalus striped shiner 100 1.0 123 1.4 223 1.2

Lythrurus umbratilis redfin shiner 15 0.1 45 0.5 60 0.3

Nocomis biguttatus

hornyhead 

chub 2 <0.1 7 0.1 9 <0.1

Notemigonus 

crysoleucas golden shiner 1 <0.1 – – 1 <0.1

Notropis amnis pallid shiner 4 <0.1 – – 4 <0.1

Notropis 

atherinoides emerald shiner 1 <0.1 2 <0.1 3 <0.1

Notropis buchanani ghost shiner 50 0.5 22 0.3 72 0.4

Notropis rubellus rosyface shiner 33 0.3 96 1.1 129 0.7

Notropis stramineus sand shiner 1,068 10.5 472 5.6 1,540 8.2

Notropis volucellus mimic shiner 10 0.1 3 <0.1 13 0.1

Pimephales notatus

bluntnose 

minnow 1,041 10.2 836 9.8 1,877 10.0

Pimephales 

promelas fathead minnow 23 0.2 6 0.1 29 0.2

Pimephales vigilax

bullhead 

minnow 821 8.0 1,646 19.4 2,467 13.2

Semotilus 

atromaculatus creek chub 1 <0.1 6 0.1 7 <0.1
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3-61

Electrofishing Seining

All Gear 

Types

Species

Common 

Name No. % No. % No. % 

Centrarchidae 4,434 43.4 1,535 18.1 5,969 31.9

Ambloplites rupestris rock bass 315 3.1 28 0.3 343 1.8

Lepomis cyanellus green sunfish 94 0.9 6 0.1 100 0.5

Lepomis gibbosus pumpkinseed 4 <0.1 – – 4 <0.1

Lepomis humilis

orangespotted 

sunfish 173 1.7 41 0.5 214 1.1

Lepomis 

macrochirus bluegill 343 3.4 59 0.7 402 2.1

Lepomis 

macrochirus ×

megalotis

bluegill × 

longear sunfish 

hybrid 1 <0.1 – – 1 <0.1

Lepomis megalotis longear sunfish 2,553 25.0 682 8.0 3,235 17.3

Lepomis 

microlophus redear sunfish 1 <0.1 – – 1 <0.1

Lepomis hybrid sunfish hybrid 1 <0.1 – – 1 <0.1

Lepomis spp. sunfish spp. 84 0.8 385 4.5 469 2.5

Micropterus 

salmoides

largemouth 

bass 576 5.6 203 2.4 779 4.2

Pomoxis annularis white crappie 4 <0.1 44 0.5 48 0.3

Pomoxis 

nigromaculatus black crappie 12 0.1 44 0.5 56 0.3
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Electrofishing Seining

All Gear 

Types

Species

Common 

Name No. % No. % No. % 

Catostomidae 621 6.1 78 0.4 972 3.5

Carpiodes carpio river carpsucker 35 0.3 1 <0.1 36 0.2

Carpiodes cyprinus quillback 7 0.1 1 <0.1 8 <0.1

Carpiodes spp. carpsucker spp. 2 <0.1 5 0.1 7 <0.1

Catostomus 

commersoni white sucker – – 1 <0.1 1 <0.1

Hypentelium 

nigricans

northern 

hogsucker 6 0.1 – – 6 <0.1

Ictiobus bubalus

smallmouth 

buffalo 8 0.1 – – 8 <0.1

Ictiobus cyprinellus

bigmouth 

buffalo 5 <0.1 – – 5 <0.1

Micropterus 

dolomieu

smallmouth 

bass 273 2.7 43 0.5 316 1.7

Minytrema melanops spotted sucker 7 0.1 – – 7 <0.1

Moxostoma 

anisurum silver redhorse 119 1.2 2 <0.1 121 0.6

Moxostoma 

carinatum river redhorse 1 <0.1 – – 1 <0.1

Moxostoma 

duquesnei black redhorse 7 0.1 – – 7 <0.1

Moxostoma 

erythrurum

golden 

redhorse 371 3.6 – – 371 2.0

Moxostoma 

macrolepidotum

shorthead 

redhorse 7 0.1 – – 7 <0.1

Moxostoma spp. redhorse spp. 46 0.5 25 0.3 71 0.4

Percidae 233 2.3 258 3.0 491 2.6

Etheostoma nigrum johnny darter 46 0.5 226 2.7 272 1.5

Etheostoma zonale banded darter 8 0.1 2 <0.1 10 0.1

Percina caprodes logperch 9 0.1 14 0.2 23 0.1

Percina maculata blackside darter 24 0.2 15 0.2 39 0.2

Percina 

phoxocephala

slenderhead 

darter 9 0.1 1 <0.1 10 0.1

Sander vitreum walleye 137 1.3 – – 137 0.7

Fundulidae 114 1.1 215 2.5 329 1.8

Fundulus notatus

blackstripe 

topminnow 114 1.1 215 2.5 329 1.8
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Electrofishing Seining

All Gear 

Types

Species

Common 

Name No. % No. % No. % 

Atherinopsidae 73 0.7 112 1.3 185 1.0

Labidesthes sicculus brook silverside 73 0.7 112 1.3 185 1.0

Clupeidae 159 1.6 23 0.3 182 1.0

Dorosoma 

cepedianum gizzard shad 159 1.6 23 0.3 182 1.0

Ictaluridae 71 0.7 33 0.4 104 0.6

Ameiurus melas black bullhead 1 <0.1 1 <0.1 2 <0.1

Ameiurus natalis yellow bullhead 4 <0.1 1 <0.1 5 <0.1

Ictalurus punctatus channel catfish 58 0.6 28 0.3 86 0.5

Noturus flavus stonecat 1 <0.1 – – 1 <0.1

Noturus gyrinus

tadpole 

madtom 1 <0.1 3 <0.1 4 <0.1

Pylodictis olivaris flathead catfish 6 0.1 – – 6 <0.1

Esocidae 39 0.4 16 0.2 55 0.3

Esox americanus grass pickerel 27 0.3 16 0.2 43 0.2

Esox lucius northern pike 12 0.1 – – 12 0.1

Sciaenidae 27 0.3 – <0.1 27 0.1

Aplodinotus 

grunniens

freshwater 

drum 27 0.3 – – 27 0.1

Lepisosteidae 10 0.1 3 <0.1 13 0.1

Lepisosteus osseus longnose gar 10 0.1 3 <0.1 13 0.1

Poeciliidae – <0.1 5 0.1 5 <0.1

Gambusia affinis mosquitofish – – 5 0.1 5 <0.1

Moronidae 4 <0.1 – <0.1 4 <0.1

Morone americana white perch 2 <0.1 – – 2 <0.1

Morone 

mississippiensis yellow bass 2 <0.1 – – 2 <0.1

Aphredoderidae – <0.1 1 <0.1 1 <0.1

Aphredoderus 

sayanus pirate perch – – 1 <0.1 1 <0.1

Petromyzontidae 1 <0.1 – – 1 <0.1

Petromyzontidae 

spp. lamprey spp. 1 <0.1 – – 1 <0.1

Source: HDR 2014
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Figure 3–16. Comparison of Relative Abundance of Most Prevalent (a) Fish Families in

Historic and Recent Kankakee River Monitoring Samples

(a) Families that constituted 1.0 percent or less of both historic and recent monitoring samples are not represented in 

this figure.

Sources: HDR 2014; NRC 1984

During a 2008 special study associated with the discharge canal replacement, HDR (2008) 

sampled fish in conjunction with the annual Kankakee River sampling program to determine 

the presence of State-listed species in the vicinity of the discharge channel. HDR collected 

samples by electrofishing and seining on August 4 and 5, 2008. HDR also preformed mussel 

sampling, the methods and results of which are described later in this section. During the study, 

two pallid shiner were collected by electrofishing at locations 5L and 5R approximately 975 ft 

(300 m) downstream from the discharge channel (600 ft (180 m) downstream of the currently 

functioning discharge diffuser) in areas of deeper water neighboring a sand bar. One river 

redhorse was collected by electrofishing at location 1L approximately 3,250 ft (1,000 m)

upstream of the discharge channel (3,000 ft (900 m) upstream of the currently functioning 

discharge diffuser). No State-listed species were collected during seining. The pallid shiner 

and river redhorse are described in more detail in Section 3.7.5.

Mussels. The FES-O (NRC 1984) indicates that 15 species of mussels were collected from 

the Kankakee River in the vicinity of Braidwood during preoperational surveys. The majority of 

mussels were collected in shallow riffles with fast currents, and the predominant species was 

the mucket. The remaining 14 species are unspecified, but a 1978 study (Suloway 1981) 

conducted at 13 sites throughout the Kankakee River in Illinois provides insight as to what 

species were likely present prior to Braidwood operation. Suloway (1981) recorded 20 species 

among 1,006 live individuals collected in samples. The mucket was the most abundantly 

collected species, and the fatmucket, which occurred at all sample sites, was the most widely 

distributed species.

HDR (2008) conducted the first operational mussel survey near Braidwood in 2008 as part of a 

special study on the presence of State-listed species that could be affected by installation of the 
Affected Environment

3-65

multi-port discharge diffuser (described previously). HDR conducted the survey in two phases, 

both of which occurred on August 8, 2008. In the first phase, six people hand-picked mussels 

along the shoreline for 2.5 hours each, and in the second phase, nine 220-m (720-ft) brail (a 

collection device for mussels) runs were conducted in the center of the river. Live individuals 

were recorded by area and returned to the river upstream of the discharge channel.

HDR (2008) collected 212 live individuals of 15 species and shells of an additional 8 species 

(see Table 3–11). Mucket, the most commonly collected species, comprised the majority 

(54.2 percent) of live individuals. Threeridge (Amblema plicata) was the second most 

commonly collected species (13.2 percent) followed by flutedshell (Lasmigona costata; 

6.1 percent) and pimpleback (Quadrula pustulosa; 5.6 percent). The remaining 11 species each 

accounted for less than 5 percent of live collections. Three live purple wartyback (Cyclonaias 

tuberculata), a State-threatened species, were collected. Of the eight species collected as 

shells, one dead sheepnose (Plethobasus cyphyus), a Federally endangered species, was 

collected (see Section 3.8 for a discussion of Federally listed species) and relict shells of 

two State-threatened species, spike (Elliptio dilatata) and black sandshell (Ligumia recta), 

were collected (Section 3.7.5 discusses these State-listed species in more detail).

The majority of individuals were collected from hand-picking along the south shore upstream 

of the effluent pipe (156 live individuals). Hand-picking on the south shore downstream of the 

discharge and brail runs in the center of the river yielded the remaining live individuals. No 

mussels were found on the north shore, which HDR (2008) attributed to unsuitable habitat 

conditions. Table 3–12 lists the habitat attributes, collection method, and number of individuals 

and species collected at each surveyed location.

In October 2008, Ecological Specialists, Inc. (ESI 2009), conducted a more comprehensive dive 

study to better characterize and map the distribution of freshwater mussels near the Braidwood 

discharge channel. The study included semi-quantitative, quantitative, and qualitative sampling 

methods. Ecological Specialists (ESI 2009) used semi-qualitative sampling to assess mussel 

distribution by surveying five 200-m (670-ft) transects perpendicular to river flow starting 

approximately 20 to 40 m (65 to 130 ft) upstream of the multi-port discharge diffuser (which had 

yet to be constructed at the time) (see Figure 3–17). A diver collected all mussels within 1 m 

(3.2 ft) of the line in 10-m (33-ft) sections for a total of 20 samples per transect. Based on the 

quantitative samples, qualitative samples were taken in areas with higher mussel density or 

where State-listed species had been identified.
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Table 3–11. Mussels Collected in the Kankakee River Near

the Braidwood Discharge by Species, 2008 and 2015

Species (a) Common Name

No. Collected 

in August 

2008 (b)

No. Collected 

in October 

2008 (b)

No. Collected 

in September 

2015 (b) Status (c)

Actinonaias 

ligamentina mucket 115 L 97 L 393 L – 

Amblema plicata threeridge 28 L 13 L 13 L –

Lasmigona costata flutedshell 13 L 1 L 2 L –

Quadrula pustulosa pimpleback 12 L 1 L WD –

Lasmigona complanata white heelsplitter 10 L – 1 L –

Utterbackia imbecillis paper pondshell 7 L 1 L – –

Lampsilis siliquoidea fatmucket 5 L – 3 L –

Pleurobema sintoxia round pigtoe 5 L – – –

Cyclonaias tuberculata purple wartyback 3 L 1 L 6 L ST

Lampsilis cardium plain pocketbook 3 L 2 L 8 L –

Leptodea fragilis fragile papershell 3 L 2 L 2 L –

Pyganodon grandis giant floater 3 L – – –

Quadrula metanevra monkeyface 2 L 1 L 4 L –

Quadrula quadrula mapleleaf 2 L – 1 L –

Venustaconcha 

ellipsiformis ellipse 1 L 2 L 1 L – 

Alasmidonta marginata elktoe D – 1 L –

Fusconaia flava Wabash pigtoe D 1 L – –

Megalonaias nervosa washboard D 2 L 2 L –

Plethobasus cyphyus sheepnose D – – FE, SE

Potamilus alatus pink heelsplitter D – 2 L –

Elliptio dilatata spike R 2 L 1 L ST

Ligumia recta black sandshell R – 16 L ST

Strophitus undulatus creeper R – – –

(a) Species ordered by decreasing number of individuals collected in the August 2008 survey.

(b) L = live; D = dead (valves with tissue present or shiny nacre and intact periostracum); R = relict (valves with chalky 

nacre and worn periostracum); WD = weathered dead shell; – = none collected

(c) FE = Federally endangered; SE = State-endangered in Illinois; ST = State-threatened in Illinois;

– = species is not Federally or State-listed as endangered or threatened

Sources: ESI 2009; Exelon 2015b; HDR 2008; IDNR 2011
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Table 3–12. Mussels Collected in the Kankakee River Near

the Braidwood Discharge by Location, August 2008

Location Habitat Attributes

Collection 

Method

No. Live 

Individuals 

Collected

No. Species 

Collected

River channel habitat not assessed due 

to water depth (>2 m) Brail Run 20 3 

South shore upstream

of Braidwood discharge

silted-sand with small patches 

of mud and gravel Hand-picking 156 15

North shore mud and rip-rap Hand-picking 0 0 

South shore downstream 

of Braidwood discharge

silted-sand with large 

fluctuations in water temperature Hand-picking 36 5 

Source: HDR 2008

ESI (2009) collected 126 live individuals of 13 species (see Table 3–11). Mucket was again 

the most collected species. No unique species were present that had not been collected in the 

August 2008 survey. Three live State-listed individuals (one purple wartyback and two spike) 

were collected from upstream portions of the survey transects. In the previous survey, spike 

had only been collected as relict shells. No black sandshell or sheepnose were collected in the 

October 2008 survey. Ecological Specialists (ESI 2009) concluded that the mussel community 

in the vicinity of the Braidwood discharge exhibits moderate to high species richness and 

relatively low abundance due to lack of suitable substrate. No juveniles or other indications of 

recruitment were observed during the survey, which suggests that the mussels in the vicinity of 

Braidwood likely come from larger, stable, and reproducing upstream populations.

In September 2015, ESI (Exelon 2015b) conducted a follow-up to the 2008 survey to determine 

whether the discharge diffuser replacement project had affected the mussel colonization or 

recolonization rate in the vicinity of the discharge. The study repeated the 2008 study’s 

methods, and ESI supplemented with additional sampling to increase the probability of finding 

Federally listed species (discussed in more detail in Section 3.8). ESI (Exelon 2015b) collected 

456 live individuals of 16 species (see Table 3–11). Mucket was the most collected species 

(393 individuals or 86 percent of the total collected). Three State-listed species were collected: 

purple wartyback, spike, and black sandshell. Similar to previous studies, individuals were 

sparsely scattered throughout the survey area, and the majority of individuals occurred in the 

middle of the river and adjacent or downstream of the diffuser.

Species diversity within the mussel community appears to be relatively high and to have 

remained similar since Braidwood began operation. Available literature indicates that 

20 species were identified as occurring in the Illinois portions of the Kankakee River in the 

late 1970s (Suloway 1981). The 2008 and 2015 Braidwood surveys (ESI 2009; Exelon 2015b; 

HDR 2008) identified 23 species (live individuals of 18 species and shells of 5 additional 

species) and 17 species (live individuals of 16 species and weathered dead shell of an 

additional species), respectively. Only three species of mussels from 1978 were not collected 

in 2008, and it is unknown whether these species historically occurred in the reach of the river 

near Braidwood. The Braidwood surveys also yielded a higher species diversity than a 

2010 INHS mussel survey of the Kankakee River basin (Price et al. 2012). Table 3–13 

compares species identified during the historical and recent mussel surveys.
3-68

Figure 3–17. Braidwood Mussel Sampling Locations, 2009 Survey

Source: ESI 2009
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Table 3–13. Historic and Recent Mussel Species Collected in the Kankakee River

Location of Study on the Kankakee River(b)

Species(a)

Common 

Name

Throughout 

Illinois, 

1978(c)

In the 

Vicinity of 

Braidwood, 

2008(d) 

Upstream and 

Downstream of 

Braidwood, 

2010(e)

In the Vicinity 

of Braidwood, 

2015 (d)

Actinonaias ligamentina mucket x x x x

Alasmidonta marginata elktoe x D x x

Amblema plicata threeridge x x x

Cyclonaias tuberculata purple 

wartyback x x x x 

Elliptio dilatata spike x x R x

Fusconaia flava Wabash pigtoe x x x

Lampsilis cardium plain 

pocketbook x x x 

Lampsilis ovata pocketbook x

Lampsilis siliquoidea fatmucket x x x

Lasmigona complanata white 

heelsplitter x x x x 

Lasmigona compressa creek 

heelsplitter x 

Lasmigona costata flutedshell x x x x

Leptodea fragilis fragile 

papershell x x x 

Ligumia recta black sandshell x R x x

Megalonaias nervosa washboard x x x x

Plethobasus cyphyus sheepnose D

Pleurobema cordatum Ohio pigtoe x

Pleurobema sintoxia round pigtoe x x

Potamilus alatus pink heelsplitter D x

Pyganodon grandis giant floater x x R

Quadrula metanevra monkeyface x x x x

Quadrula pustulosa pimpleback x x x D

Quadrula quadrula mapleleaf x x R x

Strophitus undulatus creeper R

Truncilla trancata deertoe x

Utterbackia imbecillis paper 

pondshell x x 
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Location of Study on the Kankakee River(b)

Species(a)

Common 

Name

Throughout 

Illinois, 

1978(c)

In the 

Vicinity of 

Braidwood, 

2008(d) 

Upstream and 

Downstream of 

Braidwood, 

2010(e)

In the Vicinity 

of Braidwood, 

2015 (d)

Venustaconcha 

ellipsiformis ellipse x x D x 

Total number of species collected 20 23 18 17

(a) Some species’ names differ from those in Suloway (1981) to reflect the most current taxonomy.

(b) x = live individuals collected during study; D = dead shells collected; R = relict shells collected

(c) Suloway (1981) surveyed 13 locations in the Kankakee River in Kankakee and Will Counties, Illinois, in the fall of 1978.

(d) HDR (2008) and Ecological Specialists (ESI 2009; Exelon 2015b) surveyed mussels within the Kankakee River in the 

vicinity of the Braidwood makeup water discharge channel in August 2008, October 2008, and September 2015, 

respectively.

(e) Price et al. (2012) surveyed 21 sites in the Kankakee River and its tributaries from June through September 2010. Only 

those species collected at Sites 5 and 6, which are the closest upstream and downstream sampling locations to Braidwood, 

are included in this table.

Sources: ESI 2009; Exelon 2015b; HDR 2008; Price et al. 2012; Suloway 1981

Species abundance in the vicinity of Braidwood appears to be similar to that in other regions of 

the Kankakee River. During the hand-picking portion of the August 2008 survey, HDR (2008)

reported a catch-per-unit-effort (CPUE) of 0.48 individuals per minute. Suloway (1981) 

collected 1,006 individuals in 37 man-hours, which yields a CPUE of 0.45 individuals per 

minute, and Price et al. (2012) reported a CPUE of 0.67 individuals per minute at mainstem 

locations. In 2015, the CPUE in the vicinity of Braidwood was 2.49 individuals per minute. ESI 

(Exelon 2015b) reports that assessing the apparent increase in CPUE over time in the vicinity of 

Braidwood is difficult because extensive pre-operational baseline surveys were not conducted. 

ESI (Exelon 2015b) notes that the percentage of mussels near the substrate-water interface 

varies seasonally and by species, which may be due to water temperature, disturbance (abrupt 

changes in temperature, velocity, water level, turbidity), or reproductive activity.

3.7.3.2 Braidwood Cooling Pond

In 1980, the IDNR began annual fish sampling of the Braidwood cooling pond, as described in 

Section 3.7.2.2. Sampling continued through 1992, in 1994, and every other year from 1997 

through 2007. Table 3–14 lists the fish species IDNR collected during these surveys by relative 

abundance. Information on the IDNR surveys described in this section is obtained from 

summaries in HDR (2010). Survey materials and methods for the IDNR surveys are 

unavailable.

IDNR has collected 47 species in the Braidwood cooling pond. Common carp, gizzard shad, 

largemouth bass, and bluegill have consistently been among the most abundant species in the 

cooling pond. Channel catfish have also become relatively abundant during the operational 

period. Bluegill, which can tolerate high temperatures with relatively high survival according to 

Banner and Van Arman (1973), have noticeably increased in relative abundance from 

9.6 percent of preoperational samples to 23.5 percent of operational survey samples. By family, 

clupeids (primarily gizzard shad), centrarchids, and cyprinids have consistently been the most 

abundant throughout both sampling periods. One State-endangered river redhorse individual 

was collected in 1999 during the operational period.
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Table 3–14. Fish Collected During Braidwood Cooling Pond Surveys

by Relative Abundance, 1980–2007

Preoperational 

(1980–1987)(b) 

Operational 

(1988–2007)(c) Total

Species (a) Common Name No. % No. % No. %

Dorosoma cepedianum gizzard shad 4,160 27.4 16,110 37.3 20,270 34.7

Lepomis macrochirus bluegill 1,462 9.6 10,139 23.5 11,601 19.9

Cyprinus carpio common carp 4,328 28.6 7,068 16.3 11,396 19.5

Micropterus salmoides largemouth bass 2,225 14.7 3,028 7.0 5,253 9.0

Ictalurus punctatus channel catfish 85 0.6 3,561 8.2 3,646 6.2

Dorosoma petenense threadfin shad 564 3.7 363 0.8 927 1.6

Lepomis cyanellus green sunfish 462 3.0 353 0.8 815 1.4

Cyprinella spiloptera spotfin shiner 10 <0.1 603 1.4 613 1.0

Carpiodes cyprinus quillback 271 1.8 258 0.6 529 0.9

Perca flavescens yellow perch 401 2.6 74 0.2 475 0.8

Labidesthes sicculus brook silverside 150 1.0 299 0.7 449 0.8

Ameiurus melas black bullhead 319 2.1 - - 319 0.5

Sander vitreum walleye 151 1.0 156 0.4 307 0.5

Aplodinotus grunniens freshwater drum 45 0.3 209 0.5 254 0.4

Percina caprodes logperch - - 226 0.5 226 0.4

Micropterus dolomieu smallmouth bass - - 163 0.4 163 0.3

Pomoxis annularis white crappie 118 0.8 28 <0.1 146 0.3

Notropis stramineus sand shiner 6 <0.1 121 0.3 127 0.2

Lepomis hybrid sunfish hybrid 72 0.5 50 0.1 122 0.2

Pimephales notatus bluntnose minnow 11 <0.1 105 0.2 116 0.2

Pomoxis nigromaculatus black crappie 61 0.4 51 0.1 112 0.2

Notemigonus crysoleucas golden shiner 88 0.6 5 <0.1 93 0.2

Ameiurus natalis yellow bullhead 56 0.4 15 <0.1 71 0.1

Notropis atherinoides emerald shiner 3 <0.1 50 0.1 53 <0.1

Esox americanus grass pickerel 39 0.3 - - 39 <0.1

Lepomis megalotis longear sunfish - - 37 <0.1 37 <0.1

Luxilus cornutus common shiner 31 0.2 4 <0.1 35 <0.1

Moxostoma macrolepidotum shorthead redhorse 1 <0.1 32 <0.1 33 <0.1

Morone saxatilis striped bass 2 <0.1 28 <0.1 30 <0.1

Esox masquinongy × lucius tiger muskellunge 11 <0.1 17 <0.1 28 <0.1

Lepisosteus osseus longnose gar 3 <0.1 13 <0.1 16 <0.1

Pylodictis olivaris flathead catfish - - 15 <0.1 15 <0.1
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Preoperational 

(1980–1987)(b) 

Operational 

(1988–2007)(c) Total

Species (a) Common Name No. % No. % No. %

Luxilus chrysocephalus striped shiner 14 <0.1 - - 14 <0.1

Pimephales vigilax bullhead minnow - - 11 <0.1 11 <0.1

Moxostoma erythrurum golden redhorse 2 <0.1 8 <0.1 10 <0.1

Carassius auratus goldfish - - 7 <0.1 7 <0.1

Fundulus notatus blackstripe topminnow - - 6 <0.1 6 <0.1

Ambloplites rupestris rock bass - - 5 <0.1 5 <0.1

Percina phoxocephala slenderhead darter - - 5 <0.1 5 <0.1

Lepomis microlophus redear sunfish - - 4 <0.1 4 <0.1

Moxostoma anisurum silver redhorse 1 <0.1 2 <0.1 3 <0.1

Lepomis humilis orangespotted sunfish - - 3 <0.1 3 <0.1

Carpiodes velifer highfin carpsucker 2 <0.1 - - 2 <0.1

Morone mississippiensis yellow bass 1 <0.1 1 <0.1 2 <0.1

Etheostoma nigrum johnny darter 2 <0.1 - - 2 <0.1

Lythrurus umbratilis redfin shiner - - 1 <0.1 1 <0.1

Moxostoma carinatum river redhorse - - 1 <0.1 1 <0.1

Total Number 15,157 43,235 58,392

Total Species 34 42 47

(a) Species ordered by decreasing total relative abundance.

(b) The preoperational period includes 8 surveys that were conducted annually from 1980 through 1987.

(c) The operational period includes 12 surveys that were conducted annually from 1988 through 1992, in 1994, and 

every other year from 1997 through 2007.

Source: HDR 2010

Since 2009, HDR (2010, 2011a, 2012, 2013a) has sampled fish populations in the cooling pond 

by electrofishing, trap netting, and gill netting in July and August of each year at the locations 

identified in Figure 3–18. Electrofishing is conducted at eight locations (E-1 through E-8) with a 

boat-mounted, boom-type electrofisher. Each location is sampled for 30 minutes during daytime 

hours (30 minutes after sunrise to 30 minutes before sunrise). Trap nets are set at 

eight locations (TN-1 through TN-8) during late afternoon or early evening and left to collect fish 

overnight for approximately 12 hours. Two 125-ft (38.1-m)-long and 6-ft (1.8-m)-deep gill nets 

are used to collect fish at two locations (GN-1 and GN-2) at depths of 6 to 10 ft (1.8 to 3.1 m) for 

60 to 90 minutes. Table 3–15 lists the number and relative abundance of each species 

collected by HDR for the available years (2009 through 2012).
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Figure 3–18. Cooling Pond Fish Sampling Locations

Source: HDR 2010
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Table 3–15. Fish Collected During Braidwood Cooling Pond Surveys

by Relative Abundance, 2009–2012

Species(a) Common Name

No. 

Collected

Relative 

Abundance (%)

Lepomis macrochirus bluegill 2,499 28.4

Ictalurus punctatus channel catfish 1,387 15.8

Dorosoma petenense threadfin shad 1,130 12.9

Cyprinus carpio common carp 801 9.1

Cyprinella spiloptera spotfin shiner 644 7.3

Pimephales vigilax bullhead minnow 555 6.3

Dorosoma cepedianum gizzard shad 435 5.0

Pimephales notatus bluntnose minnow 357 4.1

Micropterus salmoides largemouth bass 336 3.8

Lepomis megalotis longear sunfish 165 1.9

Lepomis cyanellus green sunfish 145 1.7

Ictalurus furcatus blue catfish 74 0.8

Lepomis microlophus redear sunfish 51 0.6

Notropis stramineus sand shiner 46 0.5

Luxilus chrysocephalus striped shiner 34 0.4

Labidesthes sicculus Brook silverside 26 0.3

Notropis rubellus rosyface shiner 21 0.2

Lepomis hybrid sunfish hybrid 17 0.2

Lepisosteus osseus longnose gar 9 0.1

Micropterus dolomieu smallmouth bass 9 0.1

Aplodinotus grunniens freshwater drum 9 0.1

Pylodictis olivaris flathead catfish 8 <0.1

Pimephales promelas fathead minnow 7 <0.1

Lepomis spp. sunfish spp. 5 <0.1

Ictiobus bubalus smallmouth buffalo 3 <0.1

Ameiurus natalis yellow bullhead 3 <0.1

Lepomis humilis orangespotted sunfish 3 <0.1

Gambusia affinis mosquitofish 2 <0.1

Lepisosteus platostomus shortnose gar 1 <0.1

Luxilus cornutus common shiner 1 <0.1

Ictiobus cyprinellus bigmouth buffalo 1 <0.1

Pseudoplatystoma spp. tiger shovelnose catfish 1 <0.1

Morone saxatilis hybrid striped bass hybrid 1 <0.1

Pomoxis nigromaculatus black crappie 1 <0.1

Total Collected 8,787

(a) Species are ordered by relative abundance (highest to lowest).

Sources: HDR 2010, 2011a, 2012, 2013a
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HDR has collected 34 species representing 10 families between 2009 and 2012. HDR collected 

several species that had not been previously collected in the cooling pond (shortnose gar, 

bigmouth buffalo, smallmouth buffalo, fathead minnow, rosyface shiner, and shovelnose tiger 

catfish), while other species that had been previously collected by the IDNR did not appear in 

HDR’s collections. Common carp, gizzard shad, and largemouth bass remained abundant in 

samples, though these species have declined in relative abundance compared to the IDNR 

survey periods. Bluegill has continued to increase in abundance and was the most abundant 

species collected over the 4-year period. Gizzard shad, one of the most frequently affected 

species during periods of elevated pond temperatures, have decreased in abundance 

dramatically in recent years and comprised only 5.0 percent of total catch over the 4-year 

period. IDNR-stocked warm water game species, such as largemouth bass and blue catfish, 

have persisted in small numbers, while cooler water stocked species, such as walleye and tiger 

muskellunge, no longer appear in collections. HDR did not collect the State-endangered river 

redhorse.

3.7.4 Cooling Pond Fish Kill Events

Since 2001, six fish kill events have occurred in the Braidwood cooling pond. A brief description 

of each event follows.

July 22, 2001

Exelon staff identified a fish kill of approximately 700 fish due to high temperatures in the 

cooling pond. Pond temperatures peaked at 98.4 °F (36.9 °C) (Exelon 2001a), which is above 

the upper thermal tolerance for most of the fish species in the lake with the exception of juvenile 

bluegill, which can tolerate temperatures of up to 102.6 °F (39.2 °C) for 24-hour periods with 

relatively high survival (Banner and Van Arman 1973). An IDNR representative performed an 

onsite inspection on July 23, 2001, and determined that the fish kill was attributable to high 

temperatures resulting from Braidwood operation (Exelon 2001a).

August 27, 2001

A second fish kill occurred in August of the same year. Exelon staff identified an unspecified 

number of dead fish, most of which were gizzard shad, in the cooling pond on August 27, 2001. 

The following day, an independent lake specialist assessed cooling pond temperature, oxygen, 

and pH levels. The fish kill was attributed to a sudden increase in cooling water temperatures 

resulting from operation of Braidwood’s cooling system coupled with depleted oxygen levels in 

the lake (Exelon 2001b).

June 28, 2005

Exelon (2005) reported a fish kill of approximately 10,000 fish. Specific species were not 

identified, but Exelon (2005) indicated that temperatures in the pond exceeded the upper 

thermal tolerances of threadfin shad (Dorosoma petenense) and gizzard shad. An IDNR

representative performed an assessment of the cooling pond the following day and determined 

that the fish kill was attributable to high temperatures associated with Braidwood operation.

August 21, 2007

A Braidwood plant employee noted a large number of dead fish near the circulating water intake 

during inspection of the intake area and cooling pond banks. The following day, an Exelon 

Fishery Specialist observed several thousand dead gizzard shad and threadfin shad and 

several dozens of channel catfish throughout the cooling pond while performing DO

measurements at various locations in the pond. The Exelon Fishery Specialist, in consultation 

with an IDNR biologist, concluded that die-off and decay of phytoplankton during the several 
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days preceding the fish kill event triggered a rapid decline in DO concentrations, which then 

suffocated a large number of fish. Braidwood personnel concluded that the fish kill was not 

directly attributable to plant operations (Exelon 2014j).

June 24, 2009

Exelon (2009a) reported a fish kill of a few thousand gizzard shad and an unspecified number 

of various game fish species on June 24, 2009. An IDNR representative performed an 

assessment of the cooling pond the following day and determined that the fish kill was 

attributable to high temperatures associated with Braidwood operation.

July 7 and 8, 2012

Prolonged hot weather in northern Illinois from July 4 through July 8, 2012, caused ultimate heat 

sink (i.e., essential portion of the cooling pond) temperatures to exceed the TS limit of 100 °F 

(38 °C) on July 7 and 8. The NRC approved a Notice of Enforcement Discretion that allowed 

Exelon to operate for a period of 18 hours with ultimate heat sink temperatures of up to 102 °F 

(38.9 °C) (NRC 2012). During this time, Braidwood personnel found approximately 3,000 dead 

gizzard shad and 100 dead bass, catfish, and carp in the cooling pond (Exelon 2014j).

3.7.5 Important Species and Habitats

3.7.5.1 State-Listed Species

IDNR lists 31 fish and 25 mussel species as State-endangered or threatened (IDNR 2011). Of 

these, information from the IDNR (2013) indicates that 14 species (9 fish, 5 mussels) occur in 

Will County, and available aquatic surveys (ESI 2009; HDR 2008, 2014; IDNR 1998; Price 

et al. 2012) indicate that 10 of these species (5 fish, 5 mussels) occur within the Kankakee 

River and its tributaries (see Table 3–16).

In May 2009, Exelon applied for an incidental take authorization with the IDNR for State-listed 

species that had the potential to be affected by the replacement of the discharge channel with a 

multi-port discharge diffuser (Mostardi Platt 2009). In December 2009, the IDNR (2009) issued 

Exelon an incidental take permit for western sand darter, pallid shiner, river redhorse, purple 

wartyback, spike, black sandshell, and sheepnose. The incidental take permit prohibited 

construction activities from occurring during the spring spawning season and required relocation 

of state-listed freshwater mussels prior to the commencement of construction. In July 2010, 

Ecological Specialists (ESI 2010) collected and relocated 911 live mussels within the area that 

had the potential to be impacted by construction. Relocated mussels included 16 State-listed 

mussels (8 purple wartyback and 8 black sandshell) (ESI 2010). Exelon completed installation 

of the new discharge diffuser in December 2010 (Exelon 2013e). The 2009 incidental take 

permit also requires Exelon to complete a follow-up survey of fish and mussels near the 

construction area 5 years after completion of construction. The ER (Exelon 2013e) indicates 

that this survey will be undertaken in 2016. The mussel portion of this survey was conducted in 

September 2015 (Exelon 2015b). The State-listed species included in the incidental take permit 

are discussed individually below. The sheepnose, which was Federally listed as endangered in 

2012, is discussed in Section 3.8.
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Table 3–16. State-Listed Aquatic Species in the Kankakee River Basin

Recorded Occurrences(b)

Species Common Name

State 

Status(a)

Kankakee River Area Assessment, 1998(c)Kankakee River Basin Fish Survey, 2005(d) Kankakee River Freshwater Mussel Survey, 2010(e)Braidwood Aquatic Monitoring Surveys, 1991

–2013 for fish 

and 2008 and 2015for mussels(f) 

Fish

Ammocrypta clara western sand darter SE x

Hybopsis amnis pallid shiner SE x x

Moxostoma carinatum river redhorse ST x x x

Notropis chalybaeus ironcolor shiner ST x x

Notropis texanus weed shiner SE x

Mussels

Alasmidonta viridis slippershell ST x R

Cyclonaias tuberculata purple wartyback ST x x

Elliptio dilatata spike ST x x x

Ligumia recta black sandshell ST x x

Plethobasus cyphyus(g) sheepnose SE x x

(a) SE = State-endangered in Illinois; ST = State-threatened in Illinois

(b) x = live individuals collected during study; R = relict shells collected

(c) IDNR 1998

(d) Pescitelli and Rung 2008

(e) Price et al. 2012

(f) ESI 2009; HDR 2008, 2014

(g) The sheepnose is Federally endangered. Section 3.8 discusses this species.

Sources: ESI 2009; Exelon 2015b; HDR 2008, 2014; IDNR 1998; Pescitelli and Rung 2008; Price et al. 2012

Western Sand Darter. The western sand darter is a small perch that inhabits sandy runs of 

clear to moderately turbid rivers in areas of coarse sand or fine gravel (NatureServe 2014a). 

Barbour et al. (1999) classify the species as an insectivore that is intolerant of pollution and 

other environmental stressors. Although the species was included in the incidental take permit 

for the 2010 construction of the Braidwood discharge diffuser (IDNR 2009), it has not been 

collected during preoperational or operational surveys (HDR 2014; Larimore and 

Peterson 1989; NRC 1984) or during impingement and entrainment studies 

(EA Engineering 2010).

Pallid Shiner. The pallid shiner is a small, short-lived minnow that inhabits medium to 

large rivers in areas of slow-moving waters with mud, sand, gravel, and rocky substrate 

(MDNR 2014b). Barbour et al. (1999) classify the species as an insectivore that is intolerant of 

pollution and other environmental stressors. Pallid shiner have consistently appeared in both 

preoperational and operational aquatic monitoring surveys (HDR 2014; NRC 1984). HDR 
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(2014) indicates that the species generally accounts for less than 0.1 percent of total individuals 

collected each year during Braidwood surveys. The species was most prevalent in 1991 

(152 individuals collected) and was absent from samples in 1993, 2009, 2010, and 2012 

(HDR 2014). EA Engineering (1990) also collected pallid shiner in impingement samples taken 

in 1988 and 1989. EA Engineering (1990) estimated that about 73 individuals are impinged 

annually and that most impingement occurs from mid-April through early June. Impingement 

is discussed in detail in Section 4.7.

River Redhorse. The river redhorse inhabits large river systems, including impoundments and 

pools, in areas of moderate to swift current and clean gravel substrate (NatureServe 2014f). 

Barbour et al. (1999) classify the species as an insectivore that is intolerant of pollution and 

other environmental stressors. River redhorse were collected in preoperational surveys 

(NRC 1984) and have occasionally appeared in operational surveys (HDR 2014). Between 

1991 and 2013, a total of 13 individuals were collected across 8 of the 23 years (HDR 2014). 

The species was most abundant in 1993 samples, during which five individuals were collected. 

In the past 10 years, HDR (2014) has collected only one individual in 2009. EA Engineering 

(1990) also collected river redhorse in impingement samples taken in 1988 and 1989, which are 

discussed in detail in Section 4.7.

Purple Wartyback. The purple wartyback is a freshwater mussel that inhabits medium to 

large rivers in gravel or mixed sand and gravel substrates (Cummings and Mayer 1992). It 

is distributed throughout southern Ontario, the upper Mississippi River drainage, and south to 

Arkansas and Missouri (NatureServe 2013c). The species has been recorded as occurring in 

the Kankakee River basin since the early 1900s (Baker 1906) and most recently, Price et al. 

(2012) found live individuals or shells at six sites within the river’s mainstem during a 2010 

mussel survey. As previously discussed, within the vicinity of Braidwood, HDR (2008) and 

Ecological Specialists (ESI 2009) collected a total of four live individuals upstream of 

Braidwood’s discharge during 2008 studies associated with construction of the Braidwood 

discharge diffuser (see Table 3–11), and Ecological Specialists (ESI 2010) relocated 

eight individuals in July 2010 prior to the commencement of construction. In 2015, ESI 

(Exelon 2015b) collected six live individuals.

Spike. The spike is a freshwater mussel that inhabits shoals of medium streams to large 

rivers, reservoirs, and lakes with sand and gravel substrates (MDNR 2014c). It is distributed 

throughout the eastern United States, the Mississippi River system, and portions of the 

Great Lakes (NatureServe 2013d). The species has been recorded as occurring in the 

Kankakee River basin since the early 1900s (Baker 1906) and most recently, Price et al. (2012) 

found live individuals or shells at six sites within the river’s mainstem during a 2010 mussel 

survey. As previously discussed, within the vicinity of Braidwood, HDR Engineering 

(HDR 2008) and Ecological Specialists (ESI 2009) collected relict shells of the species in 

August 2008 and two live individuals in October 2008 (see Table 3–11). The relict shells were 

collected along the southern shore of the river both upstream and downstream of Braidwood’s 

discharge point; the location of the live individuals was unspecified. Ecological Specialists 

(ESI 2010) did not identify any spike individuals during July 2010 mussel relocations. In 2015, 

ESI (Exelon 2015b) collected one individual.

Black Sandshell. The black sandshell is a freshwater mussel that inhabits riffles of medium 

to large rivers in gravel or firm sand substrates (Cummings and Mayer 1992). It is distributed 

throughout the eastern and central United States in the Great Lakes basin and in the Mississippi 

River drainage to Louisiana (NatureServe 2013e). The species has been recorded as occurring 

in the Kankakee River basin since the early 1900s (Baker 1906). Most recently, Price et al. 

(2012) collected live individuals or shells at all surveyed mainstem sites during a 2010 mussel 

survey. As previously discussed, within the vicinity of Braidwood, HDR (2008) collected relict 
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shells of the species in August 2008 (see Table 3–11). Ecological Specialists (ESI 2009) did 

not identify the species in its follow-up study in October 2010, nor was it collected and relocated 

in July 2010 (ESI 2010) prior to the commencement of the discharge diffuser construction.

However, in 2015, ESI (Exelon 2015b) collected 16 individuals.

3.7.5.2 Important Habitats

The northern boundary of the Kankakee River State Park lies approximately 3 mi (5 km) 

southeast and upstream of the Braidwood river screen house. The park is open to the public for 

smallmouth bass, channel catfish, walleye and northern pike fishing (IDNR 2014c). Within the 

park, the IDNR established the Kankakee River Nature Preserve in 1966. The preserve 

comprises a 135-ac (55-ha) area that includes an island in the middle of the river, and the IDNR 

has designated the portion of the river bordered by the preserve as a Biologically Significant 

Stream because it supports one of the State’s most diverse aquatic communities (IDNR 2014b; 

Page et al. 1991).

3.7.6 Non-Native Species

Several non-native species, including the common carp, Asian clam (Corbicula fluminea), 

and rusty crayfish (Orconectes rusticus), have been introduced into the Kankakee River 

(IDNR 1998).

Common carp feed by rooting through substrates for insects, crustaceans, and benthic worms. 

This behavior can dislodge shallowly rooted plants, which causes decreased food or shelter for 

species that rely upon aquatic vegetation, increased water turbidity, and decreased water 

clarity. The IDNR (1998) indicates that the effect of the species in Illinois is difficult to determine 

because the species has been present in Illinois waters since the earliest recorded surveys. 

Common carp were present in the vicinity of the site prior to Braidwood operation (AEC 1974; 

NRC 1984) and have consistently dominated annual operational monitoring sample biomass 

since 1993 (HDR 2013b).

The Asian clam was first documented in the Kankakee River in 1978 (IDNR 1998). The species 

competes with native mussels for limited food and habitat resources. Asian clams have 

occurred in the vicinity of Braidwood since the plant began operating (NRC 1984), and Exelon 

treats its cooling water system to prevent biofouling (see Section 3.1.3).

The rusty crayfish, which was likely introduced by fishers as bait, outcompetes native crayfish, 

including the ecologically similar White River crayfish (Procambarus acutus). No surveys have 

assessed crustacean populations in the vicinity of Braidwood, so it is unknown whether this 

species occurs in the vicinity of the site.

3.8 Federally Protected Species and Habitats

Because NRC’s issuance of a renewed license for power plants is a Federal action, the NRC’s 

National Environmental Policy Act (NEPA) process considers species and habitats that are 

protected under Federal acts and possibly affected by license renewal. Federal acts that 

protect species and habitats possibly affected by the renewal of a nuclear plant license include 

the Endangered Species Act of 1973, as amended (ESA); the BGEPA of 1940, as amended; 

the MBTA of 1918, as amended; the Magnuson-Stevens Fishery Conservation and 

Management Act, as amended (MSA); and the Marine Mammal Protection Act of 1972, as 

amended. Of these, the NRC has direct responsibilities only under the ESA and MSA. No 

species protected under the MSA, which protects habitat for certain marine and anadromous 

fish species, occur near Braidwood. Species protected under the ESA are discussed in this 

section, and species protected under other Federal acts where the NRC has no direct 
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responsibilities and under state acts are discussed in sections for terrestrial and 

aquatic resources.

Section 7(a)(2) of the ESA states that each Federal agency shall, in consultation with the 

Secretary (Secretary of Commerce or Secretary of the Interior), insure that any action they 

authorize, fund, or carry out is not likely to jeopardize the continued existence of a listed species 

or result in the destruction or adverse modification of designated critical habitat. In fulfilling 

these requirements, each agency is to use the best scientific and commercial data available. 

This section of the Act sets out the consultation process, which is further implemented by 

regulation (50 CFR 402). The ESA makes it unlawful for a person to take a listed animal without 

a permit, where “take” under the ESA is defined as “to harass, harm, pursue, hunt, shoot, 

wound, kill, trap, capture, or collect or attempt to engage in any such conduct.” Through 

regulations, the term “harm” is defined as “an act which actually kills or injures wildlife. Such 

act may include significant habitat modification or degradation where it actually kills or injures 

wildlife by significantly impairing essential behavioral patterns, including breeding, feeding or 

sheltering (50 CFR 17.3). Listed plants are not protected from take, although collecting or 

maliciously harming them on Federal land is illegal.

The FWS and the National Marine Fisheries Service (NMFS) jointly administer the ESA. The 

FWS manages the protection of and recovery efforts for listed terrestrial and freshwater species, 

and the NMFS manages the protection of and recovery efforts for listed marine and 

anadromous species, of which none occur in the Kankakee River.

3.8.1 Action Areas

The ESA regulations at 50 CFR 402.02 define “action area” to mean all areas to be affected 

directly or indirectly by the Federal action and not merely the immediate area involved in the 

action. The action area helps frame the ESA effects analysis because species that occur within 

the action area may be affected by the Federal action, while species that do not occur within the 

action area would likely not be affected by the Federal action. Depending on biology, different 

species may require different action areas.

Braidwood occupies about 1804 ha (4,457 ac) in Will County, Illinois, including a 1030-ha 

(2,540-ac) cooling pond created by flooding portions of a former strip mine (Exelon 2013e). 

A ROW for the water intake and discharge pipes runs from the northeast site boundary 

approximately 8 km (5 mi) east to the Kankakee River, which is the source of the cooling pond’s 

makeup water and the receiving body for the cooling pond’s discharge. Braidwood is connected 

to the regional grid at the onsite 345-kV Braidwood switchyard (Exelon 2013e). Under the 

2013 generic environmental impact statement (GEIS) (NRC 2013a), only the transmission lines 

going to the onsite switchyard that connects Braidwood to the regional grid are in scope for this 

license renewal environmental review.

For Federally protected terrestrial species, the action area is the site, including the water intake 

and discharge pipe ROW, and areas immediately around the site that could include natural 

populations affected by plant operations. Within the action area, Federally listed terrestrial 

species could experience impacts such as habitat disturbance associated with refurbishment

or other ground-disturbing activities, cooling tower drift, collisions with cooling towers and 

transmission lines, exposure to radionuclides, and other direct and indirect impacts associated 

with station, cooling system, and in-scope transmission line operation and maintenance 

(NRC 2013a).

For Federally protected aquatic species, the action area is the site and the Kankakee River 

in the area affected by water withdrawal and discharge as well as the range of any species 

affected by water withdrawal and discharge. The license renewal of nuclear plants action can 
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affect Federally listed aquatic species in several ways, such as impingement or entrainment of 

individuals into the cooling system, alteration of the riverine environment through water level 

reductions, changes in DO, gas supersaturation, eutrophication, thermal discharges from 

cooling system operation, habitat loss or alteration from dredging, and exposure to 

radionuclides (NRC 2013a).

3.8.2 Federally Protected Species and Habitats Considered

On September 11, 2013, NRC sent a letter to FWS requesting concurrence with a list of 

Federally-listed species for Braidwood (NRC 2013c). On September 24, 2013, FWS (2013d) 

replied with a letter that included scoping comments and comments on the NRC’s list of 

Federally-listed species for Braidwood. Following release of the 2013 GEIS, which redefines 

the in-scope area of transmission lines for the purposes of NEPA, the NRC decided to change 

geographic scope of the Braidwood SEIS to follow the 2013 GEIS in regard to transmission 

lines. This change of in-scope area changed the list of listed species compared to NRC’s 

September 11 letter to FWS. Because the FWS’s Rock Island Field Office no longer responds 

to species list requests (FWS 2013a), NRC staff did not submit a revised list to FWS. The NRC 

compiled the list of species in Table 3–17 from the FWS’s Endangered Species Program online 

database (FWS 2014a, 2014c) and recent listing of northern long-eared bat (80 FR 17974).
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Table 3–17. Federally Listed Species in Will County, Illinois

Group Federally Listed 

Species Common Name Federal Status(a) Habitat

Clams and 

Mussels

Plethobasus 

cyphyus sheepnose mussel E Shallow areas in larger 

rivers and streams

Epioblasma 

triquetra snuffbox E 

Small to medium-sized 

creeks and some larger 

rivers, in areas with a 

swift current

Insects Somatochlora 

hineana

Hine’s emerald 

dragonfly E Spring-fed wetlands, wet marshes, and marshes

Plants Platanthera 

leucophaea

eastern prairie 

fringed orchid T 

Mesic prairie, wetlands, 

sedge meadows, marsh 

edges, and bogs with full 

sun and little to no 

woody encroachment

Hymenopsis 

herbacea lakeside daisy T Dry, rocky prairies

Dalea foliosa leafy prairie clover E Prairie remnants on 

thin soil over limestone

Asclepias meadii Mead’s milkweed T 

Late successional 

tallgrass prairie, tallgrass 

prairie converted to hay 

meadow, and glades or 

barriers with thin soil

Mammals Myotis 

septentrionalis

northern long-eared 

bat T Winter: caves and minesSummer: mature forests

Proposed Species

Reptiles 

(snakes) Sistrurus catenatus eastern massasauga PT

Graminoid-dominated 

plant communities (fens, 

sedge meadows, 

peatlands, wet prairies, 

open woodlands, and 

shrublands)

Candidate Species

Insects Papaipema eryngii rattlesnake-master 

borer moth

Undisturbed prairie and 

woodland openings that 

contain their only food 

plant, rattlesnake-master

Critical Habitat

None

(a) E=endangered; T=threatened; PT=proposed threatened

Sources: 80 FR 58688; FWS 2014a, 2014c

Sheepnose Mussel (Plethobasus cyphyus). The FWS listed the sheepnose mussel (also called 

just sheepnose) as endangered on March 13, 2012, with an effective date of April 12, 2012 

(77 FR 14914). The sheepnose mussel is a freshwater mussel in the family Unionidae. 
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According to Parmalee and Bogan (1998), adult mussels may reach 11 to 12 cm (4.3 to 4.8 in) 

in length. Adult mussels are found partially or completely buried in the substrate. They are 

suspension feeders and eat bacteria, algae, microscopic animals, and detritus (77 FR 14914). 

It is found in large rivers in gravel or mixed sand and gravel (INHS 2013). Further, in 

unimpounded rivers, sheepnose mussels can be found in less than 0.6 m (2 ft) of water and in 

relatively fast currents. In reservoirs, sheepnose mussels occupy depths of 3.6 to 4.6 m (12 to 

15 ft) (Parmalee and Bogan 1998), though they have also been reported at depths exceeding 

6 m (20 ft) (77 FR 14914). Sheepnose mussels are long-lived and can live nearly 100 to 

200 years (FWS 2013h).

Like other unionids, sheepnose has an unusual life cycle. After fertilization, the eggs live in 

special gill chambers of the females and develop into microscopic larvae called glochidia. 

Females brood the glochidia. When the glochidia are ready, the female expels the glochidia, 

which then must attach to the host fish’s gills or fins to complete development by enclosing 

themselves in a cyst (encysting). They drop off the host fish as newly transformed juveniles. 

The sauger (Sander canadensis) is the only known natural host for sheepnose mussel 

glochidia. The FWS (77 FR 14914) reports that in laboratory studies, sheepnose glochidia 

have successfully transformed on several other species, including fathead minnow (Pimephales 

promelas), creek chub (Semotilus atromaculatus), central stoneroller (Campostoma anomalum), 

and brook stickleback (Culaea inconstans). Golden shiner (Notemigonus crysoleucas) is a host 

species that FWS (2014d) has used in laboratory to culture sheepnose. Interactions between 

these potential host species and sheepnose may be rare and infrequent in nature due to habitat 

preferences.

The sheepnose mussel is found across the Southeast and the Midwest, although it has 

been eliminated from about two-thirds of its range. Today, the sheepnose mussel is found 

in Alabama, Illinois, Indiana, Iowa, Kentucky, Minnesota, Mississippi, Missouri, Ohio, 

Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin. Section 4.8 reviews 

occurrence of sheepnose in the Kankakee River near Braidwood.

Snuffbox (Epioblasma triquetra). Snuffbox is a freshwater mussel belonging to the family 

Unionidae that the FWS designated as endangered through its range in 2012 (77 FR 8632). 

Unless otherwise cited, information for the present summary is from the FWS’s listing document 

(77 FR 8632). Adults are small to medium sized mussels: males attain lengths up to 7.0 cm 

(2.8 in.) and females 4.5 cm (1.8 in.). The shells are somewhat triangular in females and oblong 

or ovate in males, with the anterior of the shell being rounded and the posterior truncated. The 

shells are solid and thick and typically smooth and yellowish or yellowish-green in young 

individuals and become darker with age. Snuffbox reproductive and maximum ages are 

unknown, but unionids are generally long-lived and maximum ages can exceed that of humans.

Juveniles and adults live in the substrate of small to medium-sized creeks with swift currents 

with riffles and in sand, gravel, and pebbles of wave-washed lake shores. Except when 

spawning, they live in burrows that are deep into the substrate. The adults are suspension 

feeders that consume algae, bacteria, detritus, and microscopic animals. They may also 

deposit-feed on particles in the sediment.

Snuffbox has separate male and female individuals. Like other unionids, snuffbox has an 

unusual life cycle, although all the details are not known for snuffbox. After fertilization, the 

eggs live in special gill chambers of the females and develop into microscopic larvae called 

glochidia. Females may brood the glochidia from September to May. When the glochidia are 

ready, female snuffbox move to the surface and may attract host fish, whereupon the female 

expels the glochidia, which then must attach to the host fish’s gills or fins to complete 
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development by enclosing themselves in a cyst (encysting). They drop off the host fish 

as newly transformed juveniles.

Different unionid species require different host fishes. In the laboratory, juvenile snuffbox 

have successfully transformed on logperch (Percina caprodes), blackside darter (P. maculata), 

rainbow darter (Etheostoma caeruleum), Iowa darter (E. exile), blackspotted topminnow 

(Fundulus olivaceous), mottled sculpin (Cottus bairdii), banded sculpin (Cottus carolinae), Ozark 

sculpin (Cottus hypselurus), largemouth bass (Micropterus salmoides), and brook stickleback. 

Tiemann (2010) reports that logperch may be the predominant host fish in Illinois, and logperch 

populations have been declining there.

The snuffbox was once widespread and occurred in 210 lakes and streams in 18 states and 

1 Canadian province, and today, extant (currently existing) populations are known from 

79 streams in 14 states and 1 Canadian province. Many of these extant populations are small, 

highly fragmented, and restricted to short stream reaches, and 25 of the 79 extant populations 

are represented by only one or two recent live or fresh-dead individuals. The primary cause of 

the reduction in range has been the modification and destruction of river and stream habitats. 

This is due primarily to construction of impoundments because dams interrupt a river’s 

ecological processes by modifying flood pulses; controlling impounded water elevations; altering 

water flow, sediments, nutrients, and energy inputs and outputs; increasing depth; decreasing 

habitat heterogeneity; decreasing stability due to subsequent sedimentation; blocking host fish 

passage; and isolating mussel populations from fish hosts. Other causes include modification 

or destruction of habitat due to dredging and channelization, chemical contamination from 

industrial and agricultural sources, legacy pollutants in sediments, mining runoff in some areas 

(e.g., gravel mining along the Kankakee River), siltation, draining of wetlands, removal of 

riparian areas, development in flood plains, invasive species, and reduction of fish host 

populations from all of the above (77 FR 8632; Tiemann 2010). Regarding cumulative effects, 

the warming due to climate change can increase the toxicity of many contaminants to 

freshwater mussels.

In Illinois, the snuffbox is presently known only in the Kankakee and Embarras Rivers. 

Fresh-dead individuals were found in Will County (where Braidwood is located) in 1988 and 

Kankakee County in 1991, and only relic shells have been found in the Kankakee River since 

then. If an extant Kankakee River population exits, it most likely is small, localized, and of 

doubtful viability, and Tiemann (2010) considers the snuffbox to be functionally extinct in Illinois.

Hine’s Emerald Dragonfly (Somatochlora hineana). Hine’s emerald dragonfly has 

emerald-green eyes and a dark brown and metallic green body, with yellow stripes on its sides. 

Its body is about 2.5 in. (6.4 cm) long, and its wingspan is about 3.3 in. (84 cm). It has probably 

been extirpated in Alabama, Indiana, and Ohio, and today can only be found in Illinois, 

Michigan, Missouri, and Wisconsin. This dragonfly lives in calcareous (high in calcium 

carbonate) spring-fed marshes and sedge meadows overlaying dolomite bedrock.

Adults, which live only about 3 to 4 weeks, catch and eat smaller flying insects, including 

mosquitoes, biting flies, and gnats. The adult males defend small breeding territories, and 

pursue and mate with females who enter their territories. The females lay eggs in shallow 

water. Later in the season or the following spring, immature dragonflies, called nymphs, hatch 

from the eggs. The nymphs live in the water for 2 to 4 years, eat smaller aquatic insects, and 

shed their skins many times as they grow. In turn, the nymphs are important food for fish. FWS

reviews (FWS 2006, 2013b) provide more information on this species.

The FWS listed Hine’s emerald butterfly as an endangered species in 1995 (60 FR 5267), 

designated critical habitat for it in 2007 (72 FR 51102) and revised the critical habitat 

designation in 2010 (75 FR 21394). FWS did not designate critical habitat on or immediately 
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adjacent to the Braidwood site, and Exelon (2013e) reports that the nearest designated critical 

habitat to the Braidwood site is about 37 km (23 mi) away. Exelon (2013e) reports no 

observations of this species on the Braidwood site.

Eastern Prairie Fringed Orchid (Platanthera leucophaea). The eastern prairie fringed orchid is 

1 of at least 200 North American orchid species and is a perennial herb. Plants are about 8 to 

40 in. (0.2 to 1 m) tall. An upright leafy stem carries a flower cluster called an inflorescence. 

The 3- to 8-in. (76- to 200-cm) lance-shaped leaves sheath the stem. Each plant has one single 

flower spike composed of 5 to 40 creamy white flowers, and the blossoms often rise just above 

the height of the surrounding grasses and sedges. Blooming occurs in late June and early July. 

Night-flying hawkmoths (family Sphingidae) pollinate the nocturnally fragrant flowers.

This species typically inhabits tallgrass prairies east of the Mississippi River that have 

calcareous silt loam soils and calcareous wetlands with open portions of fends, sedge 

meadows, marshes, and bogs. While once numerous and wide spread, populations have 

declined with the disappearance of eastern prairies by conversion of habitat for crop fields, 

grazing, intensive and continuous hay mowing, drainage, and related human uses. Other 

reasons for the decline include succession to woody vegetation, competition from non-native 

species, and over-collection. Remaining populations tend to be small, unprotected, and 

unmanaged. The FWS designated the eastern prairie fringed orchid as an endangered species

in 1989 (54 FR 39857) and in 2012 initiated a 5-year status review of the listing (77 FR 38762). 

In addition to the FWS listing document, another source of information is an FWS fact sheet 

(FWS 2013g). FWS did not designate critical habitat for this species. Exelon (2013e) reports 

no observations of this species on the Braidwood site. 

Lakeside Daisy (Hymenopsis (also Tetraneurus) herbacea). Lakeside daisy is a member of the 

Asteraceae (also called Compositae) family, a large group of plants with over 23,000 species 

that includes asters, daisies, and sunflowers. It is an herbaceous, spring-blooming perennial 

with yellow blossoms. This plant is found in dry, rocky prairie grassland underlain by limestone, 

and it requires open sites with full sun. Fire suppression practices have eliminated the wildfires 

that once regularly cleared prairie grasslands of the encroaching woods, and the expansion of 

shrubs and trees threatens the daisy. Other threats to the species include habitat destruction by 

quarrying, over collection, off-road vehicles, and herbivory by rabbits, deer, and weevils 

(FWS 2013c).

While it may once have been widespread in the Great Lakes region, it is now found in only a 

few sites in the U.S. Although lakeside daisy has been reported from Will County, Illinois, where 

Braidwood is located, the FWS (53 FR 23742) considers the Illinois populations to be extirpated. 

The FWS listed the lakeside daisy as a threatened species in 1988 (53 FR 23742). FWS did 

not designate critical habitat. Exelon (2013e) reports no observations of lakeside daisy on the 

Braidwood site.

Leafy Prairie-Clover (Dalea foliosa). The FWS listed the leafy prairie-clover as endangered 

throughout its range in 1991 (56 FR 19953), when it was known to be present only in two sites 

in Alabama, nine sites in Tennessee, and three sites in Illinois. The FWS did not designate 

critical habitat for leafy prairie-clover. The species is perennial and a member of the pea family 

(Fabaceae). The plants grow erect stems about 0.5-m (1.5-ft) tall, on the end of which grow 

small purple flowers in dense spikes. Flowering begins in August, and seeds ripen in early 

October, after which the above-ground portion of the plant dies while the below ground portion 

survives the winter (56 FR 19953).

This plant is typically found in dry prairies, often in dolomitic soils. In Illinois, leafy prairie-clover 

was originally known from six counties in the northeastern part of the state, but by 1991 only 

three populations were known in the state, all in Will County (where Braidwood is located) in 
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prairie remnants along the Des Plaines River (56 FR 19953). The USFS (undated a) lists the 

reasons for its decline as plant and habitat loss from inundation by dams, road work, and ROW

management, including herbicide effects; botanical and horticultural collection; off-road vehicle 

impacts to plants and habitat; predation by deer and rabbits; encroachment of woody plants; 

and severe drought. Its habitat is being lost as dolomite prairies are being converted to 

industrial, commercial, and residential uses (USFS undated b). Recovery efforts by a 

partnership of the FWS (Chicago Field Office), the USFS, the Forest Preserve District of Will 

County, the Department of the Army (Joliet Training Area), the IDNR, the Forest Preserve 

District of Kane County, and Midewin National Tallgrass Prairie are underway in northeastern 

Illinois (USFS undated b). Exelon (2013e) reports no observations of this species on the 

Braidwood site.

Mead’s Milkweed (Asclepias meadii). Mead’s milkweed is a long-lived prairie perennial herb 

belonging to the family Asclepiadaceae (milkweeds), which is part of the subclass Asteridae 

(asters). It has a slender, unbranched stalk that at maturity carries an umbrella-like cluster of 

greenish, cream-colored flowers. It may take 15 years or more to mature from a germinating 

seed to a flowering plant. This milkweed requires moderately wet to moderately dry upland 

tallgrass prairie or glade-and-barren habitat characterized by vegetation adapted for drought 

and fire.

The historic range of Mead’s milkweed included much of the eastern tallgrass prairie of the 

central U.S. It is now restricted to sites in 34 counties in southern Illinois, south-central Iowa, 

eastern Kansa, and Missouri. Recovery actions include land management for existing 

populations and reintroductions.

It is threatened by the destruction of tall grass prairie due to agricultural expansion, urban 

growth, and agricultural practices such as mowing and grazing that are detrimental to the plant’s 

reproductive cycle. The tallgrass prairie habitat required by Mead’s milkweed is being 

eliminated by plowing, conversion to grazing, and development. Habitat fragmentation may 

help explain the loss of genetic diversity and failure of the plants to mature, as smaller habitat 

fragments support lower numbers of plants that may not attract sufficient numbers and types of 

pollinators (FWS 2013e).

The FWS designated Mead’s milkweed as a threatened species in 1988. The FWS 

(53 FR 33992) did not designate critical habitat because “no benefit to the species can be 

identified that would outweigh the potential threat of vandalism or collection, which might be 

exacerbated by the publication of a detailed critical habitat map.” Exelon (2013e) reports no 

observations of Mead’s milkweed on the Braidwood site.

Northern Long-Eared Bat (Myotis septentrionalis). In December 2013, the FWS (78 FR 72058) 

found that listing of the northern long-eared bat as an endangered species under the ESA was 

warranted. Earlier in October 2013, the FWS (78 FR 61046) had found that it could not 

determine critical habitat for this species. The FWS listed the northern long-eared bat as 

threatened throughout its range on April 2, 2015 (80 FR 17974). The following information is 

from those listing documents. The northern long-eared bat is a medium-sized bat species with 

average adult body weights of 5 to 8 g (0.2 to 0.3 oz), adult body lengths between 77 to 95 mm 

(3.0 to 3.7 in.) and wingspans between 228 and 258 mm (8.9 to 10.2 in.). Adult fur is typically 

brown, darker on top than below. The range includes much of the eastern and north central 

United States (it occurs in 39 states) and all Canadian provinces west to the southern 

Yukon Territory and eastern British Columbia. Throughout the majority of this range, however, it 

is patchily distributed, and historically it was less common in the southern and western part of its 

range than in the northern portion. The bats gather and hibernate in winter in areas called 

hibernacula, typically mines and caves, where they are now usually found only in low numbers. 
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They migrate out of the hibernacula in summer, when they forage at night and roost during 

daylight in small numbers in live and dead trees and change roosts often. Their diet includes 

moths, flies, leafhoppers, caddisflies, and beetles, although the diet differs geographically and 

seasonally, and an individual can consume 3,000 insects each night. Mating occurs in the 

autumn and birthing in May or June. Mature forests are an important habitat type for northern 

long-eared bats, although they occasionally act as forager over forest clearings and 

along roads. The northern long-eared bat has experienced a sharp decline, estimated at 

approximately 99 percent from hibernacula data, in the northeastern portion of its range due 

to the recent emergence of a fungal disease known as white-nose syndrome (WNS; currently 

called Geomyces destructans), and FWS expects similar declines in the western part of its 

range as this disease spreads. Human activities that threaten this species include constructing 

physical barriers at cave accesses and destruction of habitat through mining, flooding, 

vandalism, development, timber harvest, and other activities. Surveys in Shawnee National 

Forest in Illinois, about 300 mi south of Braidwood, consistently catch northern long-eared bats. 

FWS has confirmed the presence of WNS in Illinois. Exelon (2013e) plans no 

landscape-changing activities that might require an ESA consultation on northern 

long-eared bats.

Eastern Massasauga (Sistrurus catenatus). The FWS (76 FR 66370) listed the eastern 

massasauga, a rattlesnake, as a candidate species. A candidate species is one for which FWS 

has on file sufficient information on biological vulnerability and threats to support a proposal to 

list as endangered or threatened, but for which preparation and publication of a proposal is 

precluded by higher priority listing actions. Candidate species do not receive the Federal 

protection afforded to threatened and endangered species. In 2011, FWS reviewed and 

changed the priority of eastern massasauga as a candidate species (76 FR 66370) when 

recent information indicated that it was a distinct species rather than one of three subspecies 

of massasauga. In September 2015, FWS (80 FR 58688) proposed to list the eastern 

massasauga rattlesnake as a threatened species.

The eastern massasauga is a small, thick-bodied rattlesnake that occupies shallow wetlands 

and adjacent upland habitat in portions of Illinois, Indiana, Iowa, Michigan, Minnesota, 

New York, Ohio, Pennsylvania, Wisconsin, and Ontario. The current range resembles the 

historical range, but populations have decreased. About 40 percent of the counties that it 

previously occupied no longer support populations, and FWS considers less than 35 percent 

of the remaining populations secure. The FWS lists threats to this species as “habitat 

modification, habitat succession, incompatible land management practices, illegal collection 

for the pet trade, and human persecution” (76 FR 66370).

In Illinois, eastern massasauga has been historically recorded for Cook, DuPage, Lake, and 

Will Counties. The FWS Chicago Field office is working with the IDNR to establish an Illinois 

Eastern Massasauga Recovery Team to work on conserving remaining Illinois populations of 

this species (FWS 2013f). Exelon (2013e) reports no observations of this species on the 

Braidwood site.

Rattlesnake-Master Borer Moth (Papaipema eryngii). Rattlesnake-master borer moths (also 

called Eryngium stem borers) feed exclusively on a prairie plant, rattlesnake-master (Eryngium 

yuccifolium), from which the moth derives its name. On August 14, 2013, the FWS identified the 

rattlesnake-master borer moth as a candidate species for listing as an endangered or 

threatened species (78 FR 49422, 78 FR 70104). The following information is from those listing 

documents. Females drop their eggs near rattlesnake-master plants in mid-October, where the 

eggs overwinter in leaf litter. The young larvae hatch between mid-May and June and feed on 

the leaves of the host plant. Later larval stages burrow into the stem or root, where they actively 

bore and create a chamber where they may remain until they pupate. The boring activities may 
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kill the host plant or prevent it from flowering. Adults emerge from mid-September to 

mid-October and fly through mid- to late October. Adults make a single short mating flight per 

year and do not disperse widely. Their nocturnal habits make them hard to observe, so that 

adult feeding habits are unknown. Their biology suggests that they likely feed on dew or oozing 

sap for moisture.

Rattlesnake-master borer moths require a habitat of undisturbed prairie and woodland openings 

that contain their only food plant, rattlesnake-master. The moth is currently known to occur in 

five States: Illinois, Arkansas, Kentucky, North Carolina, and Oklahoma. Because its food plant 

ranges across 26 States, the historical range was no doubt much larger. Between 82 and 

99 percent of original tallgrass prairie habitat has been lost, with most prairie destruction 

occurring between 1840 and 1900, and most of the remaining high-quality prairies are small and 

scattered across the landscape. Although the rattlesnake-master borer moth is common in such 

remnant prairies, it occurs at low densities. The continuing effects of habitat fragmentation and 

isolation of small populations are a threat to the rattlesnake-master borer moth across its range. 

Documented and predicted climate-related changes indicate increased future threats from 

increased severity and frequency of droughts, floods, fires, and other climate-related changes.

The State of Illinois has the most rattlesnake-master borer moth sites of any state: 10 known 

sites in 8 counties (Will, Cook, Grundy, Livingston, Kankakee, Marion, Effingham, and Fayette). 

Two sites occur in Will County, in which Braidwood is located. FWS considers one of the sites 

to harbor an extant population but is unsure of the status on the other site because the most 

recent survey (2008) found no sign of the species and it may now be extirpated. Exelon 

(2013e) reports no observations of this species on the Braidwood site.

Summary of the Occurrence of Listed Species Within the Action Area. The 10 species listed in 

Table 3-17 are under the FWS’s jurisdiction within Will County, although the information is not 

specific to the Braidwood site. For the several species identified for Will County (Table 3-17), 

the NRC staff did not identify any within the action area after review of the ER (Exelon 2013e), a 

site visit that included discussions with site staff and review of on-site documents, and published 

and online sources. Sections 3.6 Terrestrial Resources and 3.7 Aquatic Resources summarize 

the ecological surveys performed on and near the Braidwood site that would detect protected 

species. Exelon (2013e) reports that the only species on Table 3-17 observed on or near the 

Braidwood site was a “fresh-dead” sheepnose mussel collected in the Kankakee River in the 

vicinity of the Braidwood discharge diffuser in 2008. Discussions between NRC staff and FWS 

staff indicate that northern long-eared bats have also been observed near the site.

3.9 Historic and Cultural Resources

This section discusses the cultural background and the known historic and cultural resources

found on and in the vicinity of Braidwood. The discussion is based on a review of historic and 

cultural resource surveys and other background information on the region surrounding 

Braidwood. In addition, a records search was performed via the Illinois Historic Preservation 

Agency (IHPA) (Pauketat 1993) to obtain the most updated information about historic and 

cultural resources in the region.

The Area of Potential Effect (APE) is the area at the Braidwood power plant site, the 

transmission lines up to the first substation, and immediate environs that may be affected by 

the license renewal decision and land-disturbing activities associated with continued reactor

operations. For this analysis, the first substation (345 kV Braidwood switchyard) is located on 

the Braidwood site (Exelon 2014b). The APE may extend beyond the immediate environs in 

instances where land-disturbing maintenance and operations activities during the license 

renewal term or refurbishment activities could potentially have an effect. See Figure 3–19.
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Figure 3–19. Braidwood Site Property

Source: Exelon 2013e, Figure 3.1-1 
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3.9.1 Cultural Background

Human occupation in the vicinity of Braidwood site is generally characterized according to the 

following chronological sequence (Pauketat 1993):

 Paleo-Indian Period (12,000 – 10,000 before present (BP)),

 Archaic Period (10,000 – 3,000 BP),

 Woodland Period (3,000 – 1,100 BP),

 Mississippian Period (1,100 – 400 BP (ca. A.D. 900 – 1600)), and

 Protohistoric/Historic Period (400 – present (ca. A.D. 1600 – present)).

Paleo-Indian Period (12,000 – 10,000 B.P.). The earliest evidence of people living in Illinois 

dates to the Paleo-Indian Period. Paleo-Indian sites are generally found upland or on river 

terraces and are characterized by specific types of projectile points (i.e., fluted Clovis and 

Folsom points) and stone tools such as gravers, scrapers or large blades. These artifacts often 

occur in association with mastodon remains, suggesting a reliance on megafauna 

(e.g., mammoth, ground sloth, and saber-tooth tiger) for subsistence along with plants, small 

game, birds, and amphibians. Social organization consisted of small, highly nomadic bands of 

hunter-gathers, leaving Paleo-Indian sites with little detailed archaeological information (Neusius 

and Gross 2007; Pauketat 1993).

Archaic Period (10,000 – 3,000 B.P.). The Archaic Period was a time of major climatic shifts as 

colder environments transitioned to warmer environments similar to modern conditions. In 

response to this shift, new technologies and subsistence strategies were developed during this 

time. The Archaic Period is often divided into early, middle, and late subperiods. The Early 

Archaic Period is characterized by a shift from nomadic to sedentary settlement patterns, with 

central base camps located on river terraces and smaller hunting camps located in upland 

areas. This subperiod also shows an increased reliance on wild plant foods, small game, and 

aquatic resources. The Middle Archaic Period is characterized by an increased number of 

settlement sites on high stream terraces, which may reflect population increases. While 

subsistence and settlement patterns remained fairly similar to the Early Archaic Period, artifact 

assemblages suggest increased exploitation of aquatic resources as well as new artifacts 

(e.g., pecked and ground stone tools used for intensive processing of nuts; banner stones that 

signaled the innovation of a new projectile technology called the atlatl or spear-thrower; and 

grooved axes). The Late Archaic Period is characterized by an increase in the number and size 

of settlement sites, which indicates an increase in population and a more sedentary lifestyle. 

New features of Late Archaic artifact assemblages, such as crude ceramic vessels, represent a 

shift towards increased reliance on horticulture as a subsistence strategy, although hunting and 

gathering would have continued (Fagan 2005; Neusius and Gross 2007; Pauketat 1993).

Woodland Period (3,000 – 1,100 B.P.). The Woodland Period is also often divided into early, 

middle, and late periods. However, the distinction between the early and middle period is not 

fixed. The Woodland Period is marked by an increase in more permanent settlements, changes 

in burial practices, increased cultivation of plants such as sunflowers and cucurbits 

(i.e., squashes, gourds, melons, etc.), and a rise in the manufacture and use of pottery 

(Fagan 2005). During the Middle Woodland Period, the large and complex Hopewell Culture 

emerged in the northeastern and midwestern United States, including Illinois. This culture is 

characterized by settlement in villages, increased reliance on intensive horticulture, burial 

mounds, and long distance trade networks. These long distance networks allowed the trade of 

exotic materials, such as marine shells from the Gulf Coast, obsidian from the Rocky Mountains, 

copper from Lake Superior, and mica from the Appalachian Mountains far outside their 
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immediate locations. Evidence of the Illinois Hopewell culture is found primarily in the bluffs and 

floodplains of the Illinois River Valley. The burial mounds of this period often included central 

features, lined with logs, and filled with grave goods. Different burial treatments within the 

mounds point to social stratification within society, but through sex and age rather than 

hereditary lineage (Neusius and Gross 2007). The Late Woodland Period is characterized by 

an increase in settlement sites, which suggests (a) a rise in population, or (b) a change in 

settlement patterns from large, centralized village sites to smaller, dispersed habitation sites, 

or both. Late Woodland Period artifact assemblages are characterized by an increase in 

thin-walled plain ceramic types and stemmed and side-notched projectile points. The sudden 

appearance of very small, thin triangular projectile points between 1,300 and 1,400 BP indicates 

the invention of bow-and-arrow technology and suggests a corresponding change in hunting 

techniques (Fagan 2005).

Mississippian Period (1,100 – 400 B.P. (ca. A.D. 900 – 1600)). The Mississippian Period is 

characterized by major changes in settlement, subsistence patterns, and social structure. Large 

highly centralized chiefdoms with permanent settlements sites supported by numerous satellite 

villages emerged during this period. The platform mound, a new ceremonial earthen mound 

appeared in association with these permanent settlements. Platform mounds, burial mounds, 

and defensive structures, such as moats and palisades, were often constructed in clusters in 

settlements of this period and were common in the larger river valleys of the Midwest. 

Mississippian Period subsistence relied heavily on maize agriculture, as well as hunting and 

gathering. Long distance trading increased and craft specialists produced highly specialized 

lithic and ceramic artifacts, beadwork and shell pendants (Fagan 2005). Examples of 

Mississippian Period occupation within Will County is the Fisher site, 16.5-ac village site 

containing habitation and burial features, and the Briscoe Mounds, a site containing two burial 

mounds estimated to have been constructed between A.D. 1000 and A.D. 1200 (WJE 2009). In 

southern Wisconsin and northern Illinois, the emerging Mississippian culture was blended with 

the receding Woodland culture to produce the Oneota tradition. The Oneota cultural complex is 

marked by permanent villages, produced unique ceramic artifacts, and relied on a mixed 

subsistence strategy of hunting and gathering, though cultivation of maize was practiced. Burial 

traditions varied from the mounds of the Woodland Period to non-mounded cemeteries near 

villages (Exelon 2013; Neusius and Gross 2007).

Protohistoric/Historic Period (A.D. 1600 – Present). The end of the Mississippian Period is 

characterized by severe social, political, and demographic changes that resulted from indirect 

and direct contact with Europeans. In particular, it is believed that the introduction of European 

infectious diseases such as smallpox, yellow fever, typhoid, and influenza severely decimated 

Native American populations, which had no immunity to these diseases. The spread of these 

diseases, which were fatal to large numbers of Native Americans, resulted in the widespread 

abandonment of villages and a concurrent collapse of Native American socioeconomic 

networks, such that by the time of widespread European contact and settlement, the 

Mississippian chiefdoms were gone (Fagan 2005). In 1832 in Will County, approximately 

one-third of the Native American population in the region died during a smallpox epidemic 

(WJE 2009). During the historic period, Illinois was primarily populated with a confederation of 

tribes known as the Illinois, or Illiniwek, and the Miami tribe. During the 1700s and early 1800s, 

new tribes migrated to Illinois, including the Iroquois, Fox (Mesquakie), Ioway, Kickapoo, 

Mascouten, Piankashaw, Potawatomi, Sauk, Shawnee, Wea, and Winnebago. Competition for 

resources led to sporadic war among the Illinois, surrounding tribes, and European immigrants 

to the area for approximately the next 120 years (ISM 2002). In 1673, the expedition of Father 

Jacques Marquette and Louis Jolliet traveled along the Mississippi River and up the Illinois 

River to Will County claiming the region for France. French influence in the Illinois territory 

began to wane by the mid-1700s during the French and Indian War and in 1763 the French 
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ceded land east of the Mississippi to the British who controlled the region until the Revolutionary 

War. Illinois became part of the Northwestern Territory at the close of the American Revolution. 

On January 12, 1836, Will County was created (WJE 2009). The area surrounding the 

Braidwood site has principally been used for agriculture and coal mining from this period onward 

(Exelon 2013e).

3.9.2 Braidwood Historic and Cultural Resources

Braidwood historic and cultural resources include prehistoric era and historic era archaeological

sites, historic districts, and buildings, as well as any site, structure, or object that may be 

considered eligible for listing on the National Register of Historic Places (NRHP). Historic 

and cultural resources also include traditional cultural properties that are important to a living 

community of people for maintaining their culture. “Historic property” is the legal term for a 

historic or cultural resource that is eligible for listing on the NRHP.

A review of databases maintained by the National Park Service indicates that there are 

35 properties listed in the NRHP within Will County, including one that has been designated a 

National Historic Landmark (IHPA 2013). These historic properties reflect the historic cultural 

contexts for the Braidwood property and include a prehistoric mound and historic buildings, 

structures and districts dating from the mid-18th through mid-20th centuries. However, none of 

the historic properties are located within the boundaries of the Braidwood property (IHPA 2013). 

The closest NRHP eligible site is in Wilmington, Illinois, approximately 6 mi (9 km) to the 

northeast.

In 1973, Phase I archaeological surveys were undertaken by the Illinois State Museum (ISM) 

for all lands purchased by ComEd for the proposed construction of Braidwood Units 1 and 2. 

These surveys identified 16 prehistoric era archaeological sites within the area. Sites were 

primarily debris scatters, composed of lithics, fire-cracked rock, and ceramics. Survey methods 

were mostly at the surface reconnaissance level, though subsurface surveys were conducted 

for two sites, which yielded a projectile point and Late-Woodland era pottery sherds. Surveyors 

concluded that construction at Braidwood would destroy the 16 sites found during the survey, 

via plant construction or reservoir inundation. However, the destruction would not be of a 

significant impact on the overall archaeological resources of Will County. Collections of the 

existing sites were made and site locations were recorded at the ISM. None of the sites were 

deemed eligible for the NRHP (McMillan 1973).

A search of the Illinois State Archaeological Site Files, a database maintained by the Illinois 

State Historic Preservation Officer, by NRC staff identified the 16 archaeological sites noted in 

the 1973 Phase I survey performed by the ISM (ISM 2014). No other cultural resources within 

the current confines of the Braidwood site were identified.

3.10 Socioeconomics

This section describes current socioeconomic factors that have the potential to be directly or 

indirectly affected by changes in operations at Braidwood. Braidwood, and the communities 

that support it, can be described as a dynamic socioeconomic system. The communities supply 

the people, goods, and services required to operate the nuclear power plant. Power plant 

operations, in turn, supply wages and benefits for people and dollar expenditures for goods and 

services. The measure of a community’s ability to support Braidwood operations depends on its 

ability to respond to changing environmental, social, economic, and demographic conditions.
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3.10.1 Power Plant Employment and Expenditures

The socioeconomics region of influence (ROI) is defined by the areas where Braidwood 

employees and their families reside, spend their income, and use their benefits, thus affecting 

the economic conditions of the region. Exelon Generation employs a permanent workforce of 

approximately 885 employees and 20 long-term contract employees (Exelon 2013a, 2014a). 

Approximately 80 percent of Braidwood employees reside in a three-county area in northeastern 

Illinois in Will, Grundy, and Kankakee Counties. Most of the remaining 20 percent of the 

workforce are spread among 12 other counties in Illinois and 6 counties outside of Illinois, with 

numbers ranging from 1 to 37 employees per county (Exelon 2014a). Given the residential 

locations of Braidwood employees, the most significant effects of plant operations are likely 

to occur in Will, Grundy, and Kankakee counties. Table 3–18 summarizes the Braidwood 

workforce geographic distribution. The focus of the socioeconomic impact analysis in this SEIS 

is, therefore, on the impacts of continued Braidwood operations on these three counties, also 

termed the ROI.

Table 3–18. Exelon Generation Employees Residence by County

County Number of Employees Percentage of Total

Cook 36 4

DuPage 37 4

Grundy 216 24

Kankakee 95 11

Will 356 40

Other counties 145 17

Total 885 100

Source: Exelon 2014a

Exelon purchases goods and services to facilitate Braidwood operations. While specialized 

equipment and services are procured from a wider region, some proportion of the goods and 

services used in plant operations are acquired from within the ROI. These transactions fuel a 

portion of the local economy, as jobs are provided and additional local purchases are made by 

plant suppliers.

The Braidwood units are on staggered 18-month refueling intervals. During refueling 

outages, site employment typically increases by an average of 1,400 temporary workers for 

approximately 20 days (Exelon 2013a). Outage workers are drawn from all regions of the 

country; however, the majority would be expected to come from Illinois, Wisconsin, and other 

Midwestern states.

3.10.2 Regional Economic Characteristics

This section presents information on employment and income in the Braidwood socioeconomic 

ROI. The three-county ROI is predominantly rural and agricultural. Agricultural and forested 

land comprises the majority of the land use in Will, Grundy, and Kankakee Counties. Urban 

developed land only makes up about 10, 32, and 10 percent of total land area of each county, 

respectively (NASS 2014).
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3.10.2.1 Employment and Income

From 2000 to 2012, the labor force in the Braidwood ROI increased approximately 28 percent

to just over 454,000. The number of employed persons increased by about 21 percent over the 

same period, to approximately 410,000. Consequently, the number of unemployed people in 

the ROI has increased nearly 187 percent in the same period, to over 42,800, or about 

9.4 percent of the current workforce – up from 4.2 percent in 2000 (BLS 2014).

According to the U.S. Census Bureau’s (USCB’s) 2008–2012 American Community Survey 

(ACS) 5-Year Estimates, the educational, health, and social services industry represented the 

largest employment sector in the socioeconomic ROI (22.2 percent) followed by manufacturing 

(12.3 percent) and retail (11.8 percent). A list of employment by industry in each county of 

the ROI is provided in Table 3–19.

Table 3–19. Employment by Industry in the Braidwood ROI (5-year estimates 

2008–2012)

Industry Will Grundy Kankakee Total Percent

Total employed civilian workers 324,409 23,258 50,106 397,773 –

Agriculture, forestry, fishing, hunting, 

and mining 1,385 342 998 2,725 0.7

Construction 20,801 1,947 3,074 25,822 6.5

Manufacturing 39,165 2,852 6,935 48,952 12.3

Wholesale Trade 11,599 724 1,937 14,260 3.5

Retail Trade 38,425 2,872 5,982 47,279 11.8

Transportation, warehousing, and utilities 24,523 2,300 2,946 29,769 7.4

Information 6,682 294 644 7,620 1.9

Finance, insurance, 

real estate, rental, and leasing 23,392 1,103 2,876 27,371 6.8

Professional, scientific, management, 

administrative, and waste 

management services

35,101 1,552 2,837 13,226 9.9

Educational, health, and social services 70,314 4,720 13,572 88,606 22.2

Arts, entertainment, recreation, 

accommodation, and food services 26,517 2,665 4,192 33,374 8.3

Other services (except public administration) 14,370 971 2,324 17,665 4.4

Public administration 12,135 926 1,789 14,850 3.7

Source: USCB 2014c

Major employers in Will County, the county in which Braidwood is located, are listed in 

Table 3–20. Provena St. Joseph Medical Center is shown as the largest employer in 

the county.

Estimated income information for the Braidwood ROI is presented in Table 3–21. According 

to the USCB’s 2008–2012 ACS 5-Year Estimates, Will County had a median household income 

and per capita income higher than the State of Illinois. Grundy County had a higher median 

household income than the State of Illinois, but a lower per capita income. Kankakee County 

had a lower median household income and per capita income than the State of Illinois. 

Kankakee has the highest percentages of persons (16.1 percent) living below the official poverty 

level when compared to the other two counties and the State of Illinois as a whole. Will and 

Grundy Counties had 7.7 and 8.6 percent, respectively, and the State of Illinois as a whole had 

13.7 percent. The percentage of families living below the poverty level in Will and Grundy 
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Counties (5.9 and 6.5 percent, respectively) was lower than the percentage of families in 

Kankakee County and the State of Illinois as a whole (12.5 percent and 10 percent, 

respectively) (USCB 2014c).

Table 3–20. Top 10 Employers in Will County in 2012

Employer (City or Village) Industry/Product/Service

Number of 

Employees

Provena St. Joseph Medical 

Center (Joliet) Health care 2,673

Silver Cross Hospital (New Lenox) Health care 1,800

Caterpillar, Inc. (Joliet) Manufacturing of construction and 

mining equipment 1,500

Harrah’s Joliet Casino (Joliet) Casino and entertainment facility 1,100

Midwest Generation (Joliet) Energy production 987

Southern Wine & Spirits of 

Illinois (Bolingbrook) Wine and spirits distributor 900

Quantum Foods, Inc. (Bolingbrook) Meat production and distribution 700

Comcast Cable Call Center Customer service 700

Applied Systems (University Park) Information services 700

RR Donnelly (Bolingbrook) Information services 700

Source: Will County 2012 

Table 3–21. Estimated Income Information for the Braidwood ROI (5-year estimates 

2008–2012)

Will Grundy Kankakee Illinois

Median household income (dollars)(a) 76,352 63,840 49,994 56,853

Per capita income (dollars)(a) 30,407 28,075 23,535 29,519

Individuals living below the poverty level (percent) 7.7 8.6 16.1 13.7

Families living below the poverty level (percent) 5.9 6.5 12.5 10.0

(a) In 2012 inflation adjusted dollars

Source: USCB 2014c

3.10.2.2 Unemployment

According to the USCB’s 2008-2012 ACS 5-Year Estimates, the unemployment rates (averaged 

estimates) were: Will County, 6.5 percent; Grundy County, 7 percent; and Kankakee County, 

7.2 percent. Comparatively, the State of Illinois’s unemployment rate during this same time 

period was 9.9 percent (USCB 2014c).

3.10.3 Demographic Characteristics

According to the 2010 Census, an estimated 191,099 people lived within 20 mi (32 km) 

of Braidwood, which equates to a population density of 152 per mi2 (Exelon 2013a). This 

translates to a Category 4, “least sparse” population density using the GEIS measure of 
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sparseness (greater than or equal to 120 persons per mi2 within 20 mi). An estimated 

4,968,734 people live within 50 mi (80 km) of Braidwood with a population density of 

634 persons per mi2 (Exelon 2013a). This translates to a Category 4 density, using the 

GEIS measure of proximity (more than 190 people per mi2 within 50 mi (80 km) of the plant). 

Therefore, Braidwood is located in a high-population area based on the GEIS sparseness and 

proximity matrix.

Table 3–22 shows population projections and percent growth from 1970 to 2060 in the 

three-county Braidwood ROI. The population in the ROI has increased over the previous 

2 decades (2000 and 2010). Based on State forecasts, the population is expected to continue 

to increase at a moderate to high rate due in part to the close proximity of the ROI to Chicago. 

Population projections for years 2020 and 2030 shown in the table were developed by the 

Illinois Department of Commerce and Economic Opportunity (DCEO 2012) and are based on 

projected 2000 population census estimates (see Table 3–23). As a result, the projected 2020 

and 2030 population estimates may be overstated, as actual population data from the 2000 and 

2010 decennial census were lower than the 2000 and 2010 population estimates projected by 

the DCEO.

Table 3–22. Population and Percent Growth in Braidwood ROI Counties 1970–2010, 2012 

(estimated), and Projected for 2020–2060

Year

Will County Grundy County Kankakee County

Population

Percent 

Growth Population

Percent 

Growth Population

Percent 

Growth

1970 249,498 - 26,535 – 97,250 –

1980 324,460 30.0 30,582 15.3 102,926 5.8

1990 357,313 10.1 32,337 5.7 96,255 −6.5

2000 502,266 40.6 37,353 15.5 103,833 7.9

2010 677,560 34.9 50,063 34.0 113,449 9.3

2012 681,591 0.6 50,208 0.2 112,847 −0.5

2020 907,625 33.1 46,454 −7.4 119,655 6.0

2030 1,093,207 20.4 50,414 8.5 126,509 5.7

2040 1,308,444 19.7 49,328 −2.2 132,931 5.1

2050 1,516,268 15.9 49,504 0.4 139,461 4.9

2060 1,724,091 13.7 49,679 0.4 145,991 4.7

Sources: Decennial population data for 1970-2010, and estimated 2012 (USCB 2014g); projections for 2020-2030 

by Illinois Department of Commerce and Economic Opportunity (DCEO 2012); 2040-2060 calculated
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Table 3–23. Illinois Department of Commerce and Economic Opportunity (DCEO) 

Population Projections for 2000–2030

Year

Will County Grundy County Kankakee County

Population

Percent 

Growth Population

Percent 

Growth Population

Percent 

Growth

2000 503,162 – 18,694 – 104,010 –

2010 706,639 40.4 20,689 10.6 110,659 6.3

2020 907,625 28.4 22,960 10.9 119,655 8.1

2030 1,093,207 20.4 24,686 7.5 126,509 5.7

Source: DCEO 2012

The 2010 Census demographic profile of the three-county ROI population is presented in 

Table 3–24. According to the 2010 Census, minorities (race and ethnicity combined) comprised 

30.6 percent of the total three-county population. The largest minority populations in the 

three-county ROI are Hispanic or Latino (14.3 percent) and Black or African American 

(10.9 percent).

Table 3–24. Demographic Profile of the Population in the Braidwood ROI in 2010

Will Grundy Kankakee ROI

Total Population 677,560 50,063 113,449 841,072

Race (percent of total population, Not-Hispanic or Latino)

White 67.2 88.9 73.4 69.4

Black or African American 11.0 1.2 15.0 10.9

American Indian & Alaska Native 0.1 0.1 0.2 0.1

Asian 4.5 0.6 0.9 3.8

Native Hawaiian & Other Pacific Islander 0.0 0.0 0.0 0.0

Some other race 0.1 0.0 0.1 0.1

Two or more races 1.3 0.8 1.4 1.3

Ethnicity

Hispanic or Latino 105,817 4,096 10,167 120,080

Percent of total population 15.6 8.2 9.0 14.3

Minority population (including Hispanic or Latino ethnicity)

Total minority population 221,418 5,505 30,123 257,046

Percent minority 32.7 11.0 26.6 30.6

Source: USCB 2014f

3.10.3.1 Transient Population

Within 50 mi (80 km) of Braidwood, colleges and recreational opportunities attract daily 

and seasonal visitors who create a demand for temporary housing and services. In 2013, 

approximately 49,000 students attended colleges and universities within 50 mi (80 km) of 

Braidwood (NCES 2013).

Based on the 2008−2012 ACS estimates, approximately 22,965 seasonal housing units are 

located within 50 mi (80 km) of Braidwood. Of those, 1,615 were located in the Braidwood ROI. 
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Table 3–25 presents information about seasonal housing for the counties located all or partly 

within 50 mi (80 km) of Braidwood.

Table 3–25. 2007-2011 Estimated Seasonal Housing in Counties Located Within 50 Miles 

of Braidwood

County(a) Total Housing Units

Vacant Housing Units: for 

Seasonal, Recreational, or 

Occasional Use Percent

Illinois

Bureau 15,712 219 1.4

Cook 2,178,739 15,363 0.7

DeKalb 40,932 305 0.7

Du
age 356,37 991 0.3

Ford 6,265 26 0.4

Grundy 19,919 295 1.5

Iroquois 13,460 206 1.5

Kane 181,587 399 0.2

Kankakee 45,175 445 1.0

Kendall 40,002 82 0.2

LaSalle 49,924 731 1.5

Lee 15,049 373 2.5

Livingston 15,863 52 0.3

Mclean 69,691 431 0.6

Marshall 5,922 373 6.3

Putnam 3,083 326 10.6

Will 237,175 875 0.4

Woodford 15,155 137 0.9

County Subtotal 3,310,023 21,629 1.7

Indiana

Jasper 13,165 130 1.0

Lake 208,913 1,123 0.5

Newton 6,023 83 1.4

County Subtotal 228,101 1,336 1.0

Total 3,538,124 22,965 0.9%

(a) Counties within 50 mi (80 km) of Braidwood with at least one block group located within the 50-mi (80-km) radius

Source: USCB 2014a

3.10.3.2 Migrant Farm Workers

Migrant farm workers are individuals whose employment requires travel to harvest agricultural 

crops. These workers may or may not have a permanent residence. Some migrant workers 

follow the harvesting of crops, particularly fruit, throughout rural areas of the United States. 

Others may be permanent residents near Braidwood and travel from farm to farm 

harvesting crops.

Migrant workers may be members of minority or low-income populations. Because they travel 

and can spend a significant amount of time in an area without being actual residents, migrant 
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workers may be unavailable for counting by census takers. If uncounted, these workers would 

be “underrepresented” in USCB minority and low-income population counts.

Information about migrant farm and temporary labor was collected in the 2007 Census of 

Agriculture. Table 3–26 supplies information about migrant farm workers and temporary farm 

labor (less than 150 days) within 50 mi (80 km) of Braidwood. According to the 2007 Census of 

Agriculture, approximately 11,700 farm workers were hired to work for less than 150 days and 

were employed on 3,707 farms within 50 mi (80 km) of Braidwood. The county with the highest 

number of temporary farm workers (1,014) on 223 farms was DeKalb County, Illinois 

(NASS 2012).

Table 3–26. Migrant Farm Workers and Temporary Farm Labor in Counties Located 

Within 50 Miles of Braidwood 

County(a)

Number of Farms 

with Hired 

Farm Labor(b)

Number of Farms 

Hiring Workers for 

Less Than 150 Days(b)

Number of Farm 

Workers Working 

for Less Than 

150 Days(b)

Number of 

Farms Reporting 

Migrant Farm 

Labor(b)

Illinois

Bureau 321 278 786 4

Cook 77 50 363 3

DeKalb 269 223 1,014 16

DuPage 34 28 318 4

Ford 145 128 308 0

Grundy 120 101 312 3

Iroquois 407 343 953 8

Kane 231 172 798 13

Kankakee 233 211 899 23

Kendall 111 94 371 11

LaSalle 402 338 760 9

Lee 242 203 462 10

Livingston 371 323 816 9

Mclean 410 361 823 4

Marshall 97 86 207 3

Putnam 27 26 141 0

Will 222 185 602 12

Woodford 205 191 607 4

County Subtotal 3,924 3,341 10,540 136

Indiana

Jasper 206 163 646 5

Lake 122 97 349 15

Newton 118 106 262 6

County Subtotal 446 366 1,257 26

Total 4,370 3,707 11,797 162

(a) Counties within 50 mi of Braidwood with at least one block group located within the 50-mi radius

(b) Table 7. Hired farm Labor—Workers and Payroll: 2007

Source: 2007 Census of Agriculture — County Data (NASS 2012)

In the 2002 Census of Agriculture, farm operators were asked for the first time whether or not 

they hired migrant workers—defined as a farm worker whose employment required travel—to 

do work that prevented the migrant workers from returning to their permanent place of residence 

the same day. A total of 162 farms, in the 50-mi radius of the Braidwood, reported hiring 
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migrant workers in the 2007 Census of Agriculture. Kankakee County, Illinois, reported the 

most farms with migrant farm labor (23 farms) (NASS 2012).

3.10.4 Housing and Community Services

This section presents information regarding housing and local public services, including 

education and water supply.

3.10.4.1 Housing

Table 3–27 lists the total number of occupied and vacant housing units, vacancy rates, and 

median value in the ROI. Based on USCB’s 2008–2012 ACS 5-Year Estimates, there were 

approximately 302,000 housing units in the socioeconomic region, of which approximately 

281,000 were occupied. The median values of owner-occupied housing units in the ROI range 

from $149,000 in Kankakee County to about $228,000 in Will County. The vacancy rate in 

Grundy and Kankakee Counties were similar (9.7 and 9.0, respectively), while Will County, 

where Braidwood is located, was 6.3 percent (USCB 2014d).

Table 3–27. Housing in the Braidwood ROI (2008−2012, 5-year estimate)

Will Grundy Kankakee ROI

Total housing units 237,175 19,919 45,175 302,269

Occupied housing units 222,092 17,987 41,068 281,147

Total vacant housing units 15,083 1,932 4,107 21,122

Percent total vacant 6.3 9.7 9.0 6.9

Owner occupied units 185,671 13,691 28,406 227,768

Median value (dollars) 228,900 186,500 149,200 564,600

Owner vacancy rate (percent) 1.9 2.0 2.3 1.3 (avg)

Renter occupied units 36,421 4,296 12,662 45,421

Median rent (dollars/month) 960 889 781 707

Rental vacancy rate (percent) 6.7 9.4 6.7 5.4 (avg)

Source: USCB 2014d

3.10.4.2 Education

There are 12 public school districts in Grundy County and an average daily total enrollment 

of approximately 12,650 students during the 2010–2011 school year. Kankakee County has 

12 public school districts and an average daily total enrollment of approximately 

19,000 students. In Will County, the county in which Braidwood is located, there are 29 public 

school districts with 116,000 students enrolled (ISBE 2012).

3.10.4.3 Public Water Supply

Table 3–28 lists the largest public water systems, their maximum design yields (i.e., pump 

capacity), reported annual average usage, and population served in Will, Grundy, and 

Kankakee Counties. The discussion of public water supply systems is limited to major 

municipal water systems in the local area.
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Table 3–28. Local Public Water Supply Systems (in million gallons per day (mgd))

Public Water 

System County Source

Usage 

(mgd)

Pump 

Capacity 

(mgd)

Population 

Served(a)

Crest Hill Will Groundwater 1.97 3.82 14,889

Frankfort Will Groundwater 3.44 9.74 24,648

Illinois American—

Homer Township Will Purchased Surface Water 1.90 10.08 22,038

Illinois American—

West Suburban Will Purchased Surface Water 8.97 26.64 66,429

Joliet Will Groundwater 15.00 31.61 147,433

Lockport Will Groundwater 3.34 9.89 24,839

Mokena Will Purchased 

Surface Water 1.76 9.30 18,669

New Lenox Will Purchased 

Surface Water 2.18 17.86 24,394

Plainfield Will Purchased 

Surface Water 3.10 32.40 8,259

Romeoville Will Groundwater 4.35 12.57 52,000

Shorewood Will Groundwater 1.29 6.04 16,000

Minooka Grundy Groundwater 1.05 5.70 10,925

Morris Grundy Groundwater 1.46 2.88 12,000

Aqua-Illinois 

Kankakee Kankakee Surface Water 11.60 22.00 78,738

NA = Not available

(a) Safe Drinking Water Search for the State of Illinois (EPA 2014a)

Sources: EPA 2014a; Exelon 2013a

Public water suppliers in Will County obtain water from groundwater or purchase surface water

from another water supplier. In Grundy County, most public water suppliers obtain water from 

groundwater. In Kankakee County, with the exception of the largest public water supplier, Aqua 

Illinois-Kankakee, most public water suppliers use groundwater (Exelon 2013a). Aqua 

Illinois-Kankakee obtains its water supply from the Kankakee River, Lake Vermilion, Vermilion 

River and groundwater (Aqua 2014). Braidwood gets its potable water from one deep 

groundwater well and is not connected to a public water system (Exelon 2013a).

Northeastern Illinois has not experienced water supply shortages. However, as the CMA 

continues to expand, State legislators have called for development of regional water supply 

plans throughout northeastern Illinois. To address future water supply planning issues, the 

Chicago Metropolitan Agency for Planning (CMAP), in conjunction with the IDNR, formed the 

Northeastern Illinois Regional Water Supply Planning Group (RWSPG). The RWSPG was 

tasked with a 3-year mission culminating in a final report addressing water supply and drought 

planning and management for an 11-county region. In this report, Will, Grundy, and Kankakee 

County were identified as priority planning areas (CMAP 2010). CMAP is currently 

implementing recommendations from RWSPG’s final report (CMAP 2014).
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3.10.5 Tax Revenues

Property taxes paid by Exelon Generation for Braidwood are generally determined using the 

equalized assessed value (EAV) set by the county assessor, and the tax levy and rates set by 

each taxing district. Periodically, Exelon Generation enters into negotiations (which may result 

in a “settlement agreement”) with Will County and the other taxing districts to set the EAV for 

Braidwood. Negotiations can consider, but are not limited to, property valuation approaches, 

tax “triggers” (or limits), and payments in addition to taxes (PIAT). Exelon’s last settlement 

agreement for Braidwood was signed on March 12, 2008, and covered tax years 2007 through 

2011, which included negotiated triggers or tax limits. If tax levies exceeded these negotiated 

triggers, Exelon Generation could reduce Braidwood’s property tax obligation by the amounts in 

excess of the triggers. Exelon Generation also agreed to make PIAT (additional payments) to 

specific tax recipients. These payments are not considered tax payments in the traditional 

sense. They have fewer limitations for use and provide additional benefits for recipients. In 

accordance with the 2008 settlement agreement, Exelon Generation made PIAT payments of 

$3,711,150 in 2008 and the $3,643,566 in 2009 (Exelon 2013a). Table 3–29 lists the larger of 

the PIAT payments (2008) and their recipients. Reed-Custer School District 255U received the 

majority of the PIAT payment, with 68.2 percent of the total payment.

Table 3–29. PIAT Payments and Recipients, 2008

Tax Recipients Dollars

Percent of 

Total

Fossil Ridge Public Library District 91,004 2.5

Godley Park District 188,585 5.2

Reed Township Mosquito Abatement District 19,483 0.5

Reed-Custer School District 255U 2,486,545 68.2

Will County/Will County Building Commission 339,460 9.3

Reed Township 24,334 0.7

Reed Township Road District 30,088 0.8

Will County Forest Preserve 101,759 2.8

Braidwood Fire Protection District 214,563 5.9

Joliet Junior College 147,745 4.1

Total 3,643,566 100.0

Source: Exelon 2013a

Exelon Generation and the taxing bodies have not entered into another settlement agreement, 

although negotiations have begun. Negotiations are in the early stages, and PIAT payments 

may be included as part of any future settlement agreement. Exelon Generation expects the 

recipients would remain the same as those listed in Table 3–29, because those are the taxing 

institutions that levy tax on the two power block Property Index Numbers (PINs). The settlement 

agreements have historically only settled the EAV for the two power block PINs (Exelon 2014a).

The Will County Assessor set the EAV for the 2012 tax year to be $470 million. Exelon 

Generation believes the higher EAV overvalues Braidwood because an independent appraiser 

set the 2012 value of the station at $2 billion, which equates to an EAV of approximately 

$333.3 million. On this basis, Exelon Generation appealed the 2012 assessment to Will County 

Board of Review. Upon an unfavorable ruling by the Board of Review, Exelon Generation then 

appealed the assessment to the Illinois Property Tax Appeal Board. The company will continue 
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to negotiate with the taxing bodies to reach a settlement agreement, and in its absence, will 

appeal any assessment that does not reflect a valuation of the plant that they believe is fair 

(Exelon 2013a, 2014a).

Pending the outcome of such actions, Exelon Generation has paid the tax assessed for 2012 

(an increase of more than $3 million over the prior year, see Table 3–30). This increase was 

based on the EAV set by the assessor for the three combined power block PINs. Exelon 

Generation actually pays property taxes on 78 land parcels or PINs at Braidwood. The total 

taxes paid by Exelon Generation include taxes for all of the PINs (Exelon 2013a, 2014a).

As previously discussed, the Will County Treasurer collects the property tax payment and 

disperses it to various institutions within the county to partially fund their operating budgets. 

These include, but are not limited to, the Will County Forest Preserve, Braidwood Fire District, 

Will County, Reed Custer School District 255-U (255U), and the Godley Park District (Exelon 

RAI). From 2008 through 2012, Will County’s total adjusted property tax levies ranged from 

approximately $1.5 to $1.6 billion annually (see Table 3–30). From 2008 through 2012, 

Braidwood’s total property tax payments (after tax triggers and not including PIAT payments) 

represented 1.2 to 1.4 percent of Will County’s total adjusted property tax levy (see Table 3–30).

Table 3–30. Property Tax Payment Comparison, All Taxing Districts Combined

Year

Total Combined Taxing 

District Levy - Will 

County (after 

adjustments) (billions 

of dollars)

Braidwood Property Tax

Payment (after tax 

triggers have been 

applied and not 

including PIAT 

payments) (millions 

of dollars)

Braidwood 

Payment as 

Percent of Total 

District Levy 

(percent)

2008 1.5 18.5 1.2

2009 1.5 19.3 1.2

2010 1.6 20.4 1.3

2011 1.6 20.5 1.3

2012 1.6 24.5 1.4

Sources: Exelon 2013a, 2014a

The recipient of the largest percentage of Braidwood’s property tax payment is the Reed-Custer 

School District 255U (Exelon 2013a). Table 3–31 compares Braidwood’s property tax payments 

(after tax triggers and not including PIAT payments) to the Braidwood Reed-Custer School 

District 255U’s adjusted total property tax levies. From 2008 through 2012, Braidwood’s 

property tax payments to the school district represented 67 to 79.5 percent of the school 

district’s total adjusted property tax levies (see Table 3–31).

Exelon Generation pays property taxes directly to Will County in accordance with tax bills 

received from Will County each year. Each bill shows all of the taxing bodies that are imposing 

a tax on each tax parcel. As the Braidwood property is large, some of its tax parcels fall within 

multiple taxing districts. Exelon Generation, however, has no control over how the tax money is 

allocated to the respective taxing districts. Each district has the ability to levy against all 

taxpayers within its respective district according to its own charter and according to state law. 

The Will County Treasurer then allocates the tax money according to predetermined levies once 

all taxes have been collected (Exelon 2014a).
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Table 3–31. Property Tax Payment Comparison, Reed-Custer School District 255U

Year

Total Reed Custer School 

District 255U Levy (after 

adjustments)

(millions of dollars)

Reed Custer School District 255U 

Portion of Braidwood Property Tax

Payment (after tax triggers have 

been applied and not including 

PIAT payments)

(millions of dollars)

Braidwood Payment as 

Percent of Total 

District Levy

(percent)

2008 15.8 12.4 78.1

2009 16.4 12.7 77.7

2010 17.3 13.8 79.5

2011 20.1 13.5 67

2012 21.4 16 75

Sources: Exelon 2013a, 2014a

The following tables show the total levy for each taxing body and the amount paid by Exelon 

Generation to each taxing body. The tables also show the percentage of total revenue 

represented by Exelon Generation’s tax payment for the tax years 2011 and 2012 (see 

Tables 3–32 and 3–33, respectively). The 2012 data are preliminary and the total levies for any 

one of the taxing bodies within Will County may change when the tax year closes 

(Exelon 2013a, 2014a).

Although variations in tax levies are not completely under its control, Exelon Generation expects 

that Braidwood’s annual property tax payments will remain relatively constant through the 

license renewal period. In 1998, Braidwood replaced the Unit 1 steam generators. Because the 

replacement was considered one-for-one, the Station’s assessed value was unaffected. Exelon 

Generation expects that any future one-for-one replacement projects will also not affect the 

station’s assessed value (Exelon 2013a).
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Table 3–32. 2011 Property Tax Payment Comparison, Each Taxing District Individually

Taxing Body

Total Taxing 

District Levy 

(dollars)

Taxing District 

Portion of 

Braidwood 

Property Tax

Payment

(dollars)

Braidwood 

Payment as 

Percent of 

Taxing District 

Levy

(percent)

Will County Forest Preserve 33,991,038 726,125 2 

Will County Building Commission 4,015,499 85,779 2 

Reed Township Town Funds 170,009 122,365 72 

Reed Township Road Funds 178,530 144,527 81 

Braidwood Fire District 1,546,592 1,113,239 72 

Essex Fire District 15,106 3,646 24 

Custer Township Town Funds 84,196 2,034 2 

Custer Township Road Funds 200,060 4,857 2 

Custer Fire District 70,096 1,944 3 

School District 255-U 20,141,090 13,594,795 67 

Joliet Junior Community College 525 40,559,603 1,056,376 3 

Godley Park District 936,736 865,880 92 

Village of Braceville Road and Bridge 160 91 57 

Braidwood Park District 154,986 7,122 5 

Fossil Ridge Public Library 636,060 429,327 67 

Reed Township Mosquito Abatement 131,964 94,997 72 

Will County 107,435,329 2,295,036 2 

Claypool Drainage District 96,479 276 0.2

Braidwood Park District 154,986 7,122 5 

Source: Exelon 2014a
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Table 3–33. 2012 Property Tax Payment Comparison, Each Taxing 

District Individually

Taxing Body

Total Taxing 

District Levy 

(dollars)

Taxing District 

Portion of 

Braidwood 

Property Tax

Payment

(dollars)

Braidwood 

Payment as 

Percent of 

Taxing District 

Levy

(percent)

Will County Forest Preserve 35,103,179 886,752 3 

Will County Building Commission 4,003,154 101,125 3 

Reed Township Town Funds 177,882 140,903 79 

Reed Township Road Funds 189,927 167,040 88 

Braidwood Fire District 1,649,412 1,306,774 79 

Essex Fire District 15,907 4,041 25 

Custer Township Town Funds 86,815 2,255 3 

Custer Township Road Funds 201,819 5,304 3 

Custer Fire District 72,233 1,987 3 

School District 255-U 21,476,914 16,039,297 75 

Joliet Junior Community College 525 42,887,756 1,320,350 3 

Godley Park District 1,249,133 1,234,838 99 

Village of Braceville Road and Bridge 115 43 38 

Braidwood Park District 158,705 7,548 5 

Fossil Ridge Public Library 673,848 503,240 75 

Reed Township Mosquito Abatement 138,820 109,961 79 

Will County 107,557,817 2,717,021 3 

Claypool Drainage District 96,278 276 0.2 

Source: Exelon 2014a

3.10.6 Local Transportation

Major freeways serving Will County include interstates I-55, I-57, and I-80. Other major 

roadways serving the county state routes are: 1, 7, 50, 53, 59, 102, 113, 126, 171, and 394; 

and U.S. Highways 6, 30, 45, and 52. Road access to Braidwood is via State Highway 53, a 

rural northeast-southwest two-lane highway. Braidwood has one access road which intersects 

State Highway 53 approximately 2 mi (3 km) southwest of the City of Braidwood. In the City of 

Braidwood, State Highway 53 intersects State Highway 113, which in turn intersects State 

Highway 129. State Highway 129 runs north, eventually intersecting I-55. Employees traveling 

from the west, northwest, north, northeast, and east to the Braidwood site would use some 

combination of these routes. Employees traveling from the west, southwest, south, and 

southeast to the Braidwood site would use a combination of I-55 and State Highway 53.
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Exelon Generation employees report that there has been no traffic congestion in the area during 

normal operations (Exelon 2013a).

During major refueling or maintenance outages, there is congestion at the intersection of State 

Highways 53 and 113, and the intersection of State Highways 113 and 129 in the City of 

Braidwood. To lessen outage congestion, local law enforcement is used to direct traffic during 

shift changes and periods of high activity (Exelon 2013a).

Table 3–34 lists commuting routes to the Braidwood site and average annual daily traffic 

(AADT) volume values. The AADT values represent traffic volumes for a 24-hour period 

factored by both the day of the week and the month of the year.

Table 3–34. Major Commuting Routes in the Vicinity of Braidwood: 2012 Average Annual 

Daily Traffic Count

Roadway and Location Average Annual Daily Traffic (AADT)(a)

The section of Highway 53 between the City of 

Braidwood and the Village of Godley 3,450

On Highway 53, at the intersection of Highway 113 in 

the City of Braidwood 5,050(b)

On Highway 113, at the intersection of Highway 53, in 

the City of Braidwood 6,100-7,500(b)

On I-55, at the intersection of W. Kennedy Rd, west of 

the City of Braidwood 20,800-24,800

On I-55, at the intersection of West Division Street, 

northeast of the Village of Godley 24,800

(a) Unless otherwise indicated, all AADTs represent traffic volume during the average 24-hour day during 2012.

(b) AADTs in 2011.

Source: IDOT 2014

3.11 Human Health

3.11.1 Radiation Protection Program

As required by NRC regulation, 10 CFR 20.1101, Exelon has a radiation protection program 

designed to protect onsite personnel, including employees, contractor employees, visitors, and 

offsite members of the public from radiation and radioactive material generated at Braidwood.

The radiation protection program is extensive and includes, but is not limited to the following:

 Organization and Administration (i.e., a Radiation Protection Manager who is 

responsible for the program and having trained and qualified workers),

 Implementing procedures,

 ALARA Program to minimize dose to workers and members of the public,

 Dosimetry Program (i.e., measure radiation dose of plant workers),
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 Radiological Controls (i.e., protective clothing, shielding, filters, respiratory 

equipment, and individual work permits with specific radiological 

requirements),

 Radiation Area Entry and Exit Controls (i.e., locked or barricaded 

doors, interlocks, local and remote alarms, personnel contamination 

monitoring stations),

 Posting of Radiation Hazards (i.e., signs and notices alerting plant personnel 

of potential hazards),

 Record Keeping and Reporting (i.e., documentation of worker dose and 

radiation survey data),

 Radiation Safety Training (i.e., classroom training and use of mock-ups to 

simulate complex work assignments),

 Radioactive Effluent Monitoring Management (i.e., control and monitor 

radioactive liquid and gaseous effluents released into the environment),

 Radioactive Environmental Monitoring (i.e., sampling and analysis of 

environmental media, such as air, water, vegetation, food crops, direct 

radiation, and milk to measure the levels of radioactive material in the 

environmental that may impact human health), and

 Radiological Waste Management (i.e., control, monitor, process, and dispose 

of radioactive solid waste).

Regarding the radiation exposure to Braidwood personnel, the NRC staff reviewed the data 

contained in NUREG-0713, Occupational Radiation Exposure at Commercial Nuclear Power 

Reactors and Other Facilities 2011: Forty-Fourth Annual Report (NUREG-0713, Volume 33). 

This report, which was the most recent available at the time of this review, summarizes the 

worker’s radiation dose data through 2011 that are maintained in the NRC’s Radiation Exposure 

Information and Reporting System database. Nuclear power plants are required by 

10 CFR 20.2206 to report their occupational exposure data to the NRC annually (NRC 2013b).

NUREG-0713 contains data on the trends in radiation dose received by workers at nuclear 

power plants as well as other industries licensed by the NRC to produce, use, or possess 

radioactive material. These other industries include: industrial radiography, manufacturing and 

distribution of radioactive material, independent spent fuel storage facilities, fuel cycle licensees 

for the fabrication, processing and uranium enrichment, and uranium fluoride production plants. 

The NRC staff used the data in NUREG-0713 to compare Braidwood’s occupational dose to the 

data on the 3-year average collective dose for other nuclear power plants. The 3-year average 

collective dose is one of the metrics that the NRC uses in the Reactor Oversight Program 

(i.e., NRC reactor inspection program) to evaluate the effectiveness of a nuclear power plant’s 

radiation protection program to maintain worker doses that are ALARA. Collective dose is the 

sum of the individual doses received by workers at a nuclear plant over a 1-year time period. 

The annual collective dose at each plant varies based on the amount of work performed inside 

the radiation areas of the plant (i.e., maintenance work and refueling outages). There are no 

NRC or EPA standards for collective dose; as previously stated, it is a comparative value used 

in the NRC’s reactor inspection program to assess performance. Based on the data for 

operating PWRs like those at Braidwood, the 3-year average annual collective dose per all 

PWRs for the period 2009 – 2011 was 59.712 person-rem (0.597 person-sievert). In 

comparison, Braidwood reported an annual collective dose per reactor of 46.015 person-rem 

(0.460 person-sievert).
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In addition, as reported in NUREG-0713 for 2011, Braidwood measured the dose of 

3,165 workers. There were 2,094 workers with no measurable dose; 859 workers that had less 

than 0.100 rem (0.001 sievert (Sv)); 192 workers had between 0.100 rem (0.001 Sv) but less 

than 0.250 rem (0.002 Sv) and 20 workers had between 0.250 rem (0.002 Sv) but less than 

0.500 rem (0.005 Sv). No worker at Braidwood received a dose of 0.500 rem (0.005 Sv) or 

greater. The NRC’s annual worker dose limit in 10 CFR 20.1201 is 5.0 rem (0.05 Sv). 

Braidwood maintained its worker’s doses within NRC dose limits.

3.11.2 Chemical Hazards

The use, storage, and discharge of chemicals, biocides, and sanitary wastes, as well as minor 

chemical spills are regulated by state and Federal environmental agencies. Chemical hazards 

to Braidwood’s workers during the license renewal term are expected to be minimized by 

implementing good industrial hygiene practices as required by Federal and State regulations. 

Discharges of chemical and sanitary wastes are monitored and controlled as part of the 

Braidwood’s NPDES permit IL0048321 to minimize impacts to the public and the environment 

(Exelon 2013e).

3.11.3 Microbiological Hazards

Nuclear plants that have cooling towers and that discharge thermal effluents to cooling ponds, 

lakes, canals, or rivers, such as Braidwood, have the potential to promote the increased growth

of thermophilic microorganisms, which could result in adverse health effects for plant workers 

and the public. Microorganisms of particular concern include several types of bacteria 

(Legionella spp., Salmonella spp., Shigella spp., and Pseudomonas aeruginosa) and the 

free-living amoeba Naegleria fowleri. 

Nuclear plant workers can be exposed to Legionella spp. when performing maintenance 

activities on plant cooling systems if workers inhale cooling tower vapors because vapors are 

often within the optimum temperature range for Legionella growth. Plant personnel most likely 

to come in contact with Legionella aerosols would be workers who clean biofilms off of 

condenser tubes, cooling towers, and related system components or equipment. Exposure 

of the public to Legionella from nuclear plant operations is generally not a concern because 

Legionella exposure would be confined to a small area of the site within the protected area. In 

the case of Braidwood, which does not have cooling towers, exposure of workers to Legionella

is unlikely.

The public can be exposed to the thermophilic microorganisms Salmonella, Shigella, 

P. aeruginosa, and N. fowleri during swimming, boating, or other recreational uses of 

freshwater. If a nuclear plant’s thermal effluent enhances the growth of thermophilic 

microorganisms, recreational users could experience an elevated risk of exposure when 

using waters near the plant’s discharge. 

3.11.3.1 Thermophilic Microorganisms of Concern

Legionella is a genus of common warm water bacteria that occurs in lakes, ponds, and other 

surface waters, as well as some groundwater sources and soils. The bacteria are pathogenic 

to humans when aerosolized and inhaled into the lungs. Approximately 2 to 5 percent of those 

exposed in this way to Legionella develop an acute bacterial infection of the lower respiratory 

tract known as Legionnaires’ disease (Pearson 2003). Optimal growth occurs in stagnant 

surface waters with biofilms or slimes that range in temperature from 35 to 45 °C (95 to 113 °F), 

though the bacteria can persist in waters from 20 to 50 °C (68 to 122 °F) (Pearson 2003). 

Elderly and immunocompromised individuals are most susceptible to Legionnaires’ disease 
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(Pearson 2003). According to data from the Centers for Disease Control and Prevention 

(CDC 2011a) from 2000 through 2009, New England and Mid-Atlantic states generally had 

the highest number of reported legionellosis cases each year.

Approximately 2,000 serotypes of Salmonella spp. cause the bacterial infection salmonellosis 

in humans. Of these, the serotypes Typhimurium and Enteritidis are the most common in the 

United States (CDC 2010a). Salmonellosis is most common in summer months, and it is 

transmitted through contact with food, water, or animals contaminated with human or animal 

feces (CDC 2010a). The bacteria have an optimal growth temperature of 37 °C (98.6 °F) but 

can grow at temperatures ranging from 6 to 46 °C (43 to 115 °F) (Albrecht 2013a). Studies 

examining the persistence of Salmonella spp. outside of a host have found that Salmonella

can survive for several months in water and in aquatic sediments (Moore et al. 2003).

Shigella is a genus of bacteria species that causes shigellosis (i.e., bacterial dysentery), which 

is spread through consuming fecal-contaminated food or water or by swimming in contaminated 

water. Its optimum growth temperature is 37 °C (98.6 °F), though it can grow in water 

temperatures ranging from 10 to 40 °C (50 to 104 °F) (Albrecht 2013b). Shigellosis is most 

common in summer months and among toddlers age 2 to 4 in childcare settings (CDC 2013e).

Pseudomonas aeruginosa is a free-living bacterium found in soil, water, and plant surfaces. It 

is most commonly linked to infections transmitted in healthcare settings. However, as a 

waterborne pathogen, it can cause ear infections (i.e., “swimmer’s ear”), eye infections, and skin 

rashes after exposure to contaminated hot tubs, swimming pools, or other recreational waters 

(CDC 2013a). Its optimum growth temperature is 37 °C (98.6 °F), though it can grow at 

temperatures as high as 42 °C (107.6 °F) (Todar 2004). P. aeruginosa almost exclusively 

infects immunocompromised individuals or already injured or inflamed sites on the skin 

(Todar 2004).

Naegleria fowleri is a free-living amoeba that occurs in warm lakes, rivers, or hot springs. It is 

the causative agent of human primary amoebic meningoencephalitis (PAM). Infection occurs 

when contaminated freshwater enters the nose, and the amoeba migrates to brain tissue; the 

ensuing illness is usually fatal (CDC 2013b). N. fowleri grows best at higher temperatures up to 

46 °C (115 °F) (CDC 2013b), though it has also been isolated from thermally altered waters 

surrounding power plant discharges at temperatures ranging from 35 to 41 °C (95 to 105.8 °F) 

(Stevens et al. 1977).

3.11.3.2 Prevalence of Waterborne Diseases Associated With Recreational Waters

From 2002 through 2011, the CDC (2003, 2004a, 2005, 2006a, 2007, 2008a, 2009, 2010b, 

2011b, 2012) reported an average of 2,774 cases of Legionnaires’ disease per year, of which 

between 28 and 151 per year were reported from Illinois. Although Legionella is often present 

in the cooling tower vapors of power plants, cases of Legionnaires’ disease from this type of 

exposure are rare due to workers’ use of appropriate respiratory protection, and as indicated 

above, this type of exposure does not apply to Braidwood because the cooling system does not 

include cooling towers.

The Illinois Department of Public Health (IDPH) indicates that approximately 1,500 to 

2,000 cases of salmonellosis are reported in the state each year (IDPH 2009). However, the 

overwhelming majority of salmonellosis cases are foodborne (CDC 2010a). The CDC reports 

biannually on waterborne disease outbreaks associated with recreational waters. A review of 

the past 10 available data years (1999 through 2008) of these reports indicates that no 

outbreaks or cases of waterborne Salmonella infection from recreational waters occurred in the 

United States during this timeframe (CDC 2002, 2004b, 2006b, 2008b, 2011c). From 2006 to
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2013, all CDC-reported salmonellosis outbreaks have been caused by contaminated produce, 

meats, or prepared foods or through contact with contaminated animals (CDC 2013d).

Approximately 1,300 confirmed cases of shigellosis are reported in Illinois each year 

(IDPH 2013). CDC reports (2002, 2004b, 2006b, 2008b, 2011c) indicate that less than a 

dozen shigellosis outbreaks have been attributed to lakes, reservoirs, and other recreational 

waters in the past 10 available data years (1999 through 2008). None of these cases were 

in Illinois.

Infections attributed to Pseudomonas aeruginosa are most commonly contracted in pools, 

spas, and hot tubs. No cases of infection linked to contaminated recreational waters in the 

United States have been reported within the past 10 available data years (1999 through 2008) 

(CDC 2002, 2004b, 2006b, 2008b, 2011c).

The N. fowleri-caused disease, PAM, is rare in the United States. Since 1962, between zero 

and eight cases of PAM have been reported to the CDC annually, and no cases have been 

reported in Illinois (CDC 2013c).

3.11.4 Electromagnetic Fields

Based on the GEIS, the Commission found that 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, a site-specific review is required to determine the significance 

of the electric shock potential along the portions of the transmission lines that are within the 

scope of this SEIS.

In the GEIS, the NRC found that without a review of the conformance of each nuclear plant 

transmission line with National Electrical Safety Code (NESC) criteria, it was not possible to 

determine the significance of the electric shock potential (IEEE 2002). Evaluation of individual 

plant transmission lines is necessary because the issue of electric shock safety was not 

addressed in the licensing process for some plants. For other plants, land use in the vicinity 

of transmission lines may have changed, or power distribution companies may have chosen to 

upgrade line voltage. To comply with 10 CFR 51.53(c)(3)(ii)(H), the applicant must provide an 

assessment of the impact of the proposed action on the potential shock hazard from the 

transmission lines if the transmission lines that were constructed for the specific purpose of 

connecting the plant to the transmission system do not meet the recommendations of the NESC 

for preventing electric shock from induced currents. The NRC uses the NESC criteria and the 

applicant’s adherence to these during the current operating license as its baseline to assess the 

potential human health impact of the induced current from an applicant’s transmission lines. As 

discussed in the GEIS, the issue of electric shock is of small significance for transmission lines 

that are operated in adherence with the NESC criteria.

As discussed in the GEIS, each nuclear power plant is connected to an independent regional 

power distribution grid. Power transmission systems consist of switching stations (also called 

switchyards or substations), and the transmission lines need to transfer electrical power from 

the nuclear plant to the regional electrical power distribution grid. Only those transmission lines 

that connect the power plant to the switchyard where electricity is fed into the regional power 

distribution system (encompassing those lines that connect the nuclear plant to the first 

substation of the regional power distribution grid) and power lines that feed the plant from the 

grid during outages are considered within the regulatory scope of license renewal environmental 

review (NRC 2013a).
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Based on the above, Braidwood’s transmission lines that are within the scope of the NRC’s 

license renewal environmental review are limited to those transmission lines that connect the 

nuclear plant’s switchyard to the substation where electricity is fed into the regional power 

distribution system and transmission lines that supply power to the nuclear plant from the grid. 

At Braidwood, the main power transformers connect to an intermediate, onsite transmission line 

that runs from the plant to an onsite 345-kV switchyard that lies east of the reactor containment 

buildings. This switchyard connects the plant to the Mid-America Interpool Network (i.e., the 

regional grid) (Exelon 2010a, 2014d). No separate transmission lines supply offsite power to 

Braidwood from the grid (Exelon 2013g).

Therefore, there are no offsite transmission lines that are in scope for the environmental review 

for license renewal that would be a potential shock hazard to offsite members of the public. As 

discussed in Section 3.11.5, Braidwood maintains an occupational safety program in 

accordance with the Occupational Safety and Health Administration (OSHA) regulations for its 

workers, which includes protection from acute electric shock.

3.11.5 Other Hazards

Two additional human health issues are addressed in this section: physical occupational 

hazards and electric shock hazards.

Nuclear power plants are industrial facilities that have many of the typical occupational hazards 

found at any other electric power generation utility. Workers at or around nuclear power plants 

would be involved in some electrical work, electric power line maintenance, repair work, and 

maintenance activities and exposed to some potentially hazardous physical conditions 

(e.g., falls, excessive heat, cold, noise, electric shock, and pressure). The issue of physical 

occupational hazards is generic to all nuclear power plants.

The OSHA is responsible for developing and enforcing workplace safety regulations. OSHA 

was created by the Occupational Safety and Health Act of 1970 (29 USC 651 et seq.), which 

was enacted to safeguard the health of workers. With specific regard to nuclear power plants, 

plant conditions which result in an occupational risk, but do not affect the safety of licensed 

radioactive materials, are under the statutory authority of OSHA rather than the NRC as set 

forth in a Memorandum of Understanding (53 FR 43950, October 31, 1988) between the NRC 

and OSHA. Occupational hazards can be minimized when workers adhere to safety standards 

and use appropriate protective equipment; however, fatalities and injuries from accidents can 

still occur.

Exelon’s maintains a worker safety program at Braidwood. In 2010, Exelon was awarded the 

Green Cross for Safety Medal by the National Safety Council (NSC). The award recognized 

Exelon’s outstanding safety achievements in the workplace and off-the-job safety (NSC 2010).

3.12 Environmental Justice

Under Executive Order (E.O.) 12898 (59 FR 7629), Federal agencies are responsible for 

identifying and addressing, as appropriate, disproportionately high and adverse human health 

and environmental impacts on minority and low-income populations. In 2004, the Commission 

issued a Policy Statement on the Treatment of Environmental Justice Matters in NRC 

Regulatory and Licensing Actions (69 FR 52040), which states, “The Commission is committed 

to the general goals set forth in E.O. 12898, and strives to meet those goals as part of its NEPA

review process.”
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The Council on Environmental Quality (CEQ) provides the following information in 

Environmental Justice: Guidance Under the National Environmental Policy Act (CEQ 1997):

Disproportionately High and Adverse Human Health Effects.

Adverse health effects are measured in risks and rates that could result in latent 

cancer fatalities, as well as other fatal or nonfatal adverse impacts on human 

health. Adverse health effects may include bodily impairment, infirmity, illness, or 

death. Disproportionately high and adverse human health effects occur when the 

risk or rate of exposure to an environmental hazard for a minority or low-income 

population is significant (as employed by NEPA) and appreciably exceeds the 

risk or exposure rate for the general population or for another appropriate 

comparison group. [CEQ 1997]

Disproportionately High and Adverse Environmental Effects.

A disproportionately high environmental impact that is significant (as employed 

by NEPA) refers to an impact or risk of an impact on the natural or physical 

environment in a low-income or minority community that appreciably exceeds 

the environmental impact on the larger community. Such effects may include 

ecological, cultural, human health, economic, or social impacts. An adverse 

environmental impact is an impact that is determined to be both harmful and 

significant (as employed by NEPA). In assessing cultural and aesthetic

environmental impacts, impacts that uniquely affect geographically dislocated 

or dispersed minority or low-income populations or American Indian tribes are 

considered. [CEQ 1997]

The environmental justice analysis assesses the potential for disproportionately high and 

adverse human health or environmental effects on minority and low-income populations that 

could result from the operation of Braidwood during the renewal term. In assessing the impacts, 

the following definitions of minority individuals and populations and low-income population were 

used (CEQ 1997):

Minority individuals

Individuals who identify themselves as members of the following population 

groups: Hispanic or Latino, American Indian or Alaska Native, Asian, Black or 

African American, Native Hawaiian or Other Pacific Islander, or two or more 

races, meaning individuals who identified themselves on a Census form as being 

a member of two or more races, for example, [White] and Asian.

Minority populations

Minority populations are identified when (1) the minority population of an affected 

area exceeds 50 percent or (2) the minority population percentage of the affected 

area is meaningfully greater than the minority population percentage in the 

general population or other appropriate unit of geographic analysis.

Low-income population

Low-income populations in an affected area are identified with the annual 

statistical poverty thresholds from the Census Bureau’s Current Population 

Reports, Series P60, on Income and Poverty.

3.12.1 Minority Population

According to 2010 Census data, approximately 48 percent of the population residing within a 

50-mi (80-km) radius of Braidwood (in contrast to the ROI data) identified themselves as 

minority individuals. The largest minority group was Black or African American (22 percent), 

followed by Hispanic or Latino (of any race) (21 percent) (USCB 2014f).
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According to 2010 Census data, minority populations in the socioeconomic ROI (Will, Grundy, 

and Kankakee counties) composed 30.6 percent of the total three-county population (see 

Table 3–24). Figure 3–20 shows predominantly minority population block groups, using 

2010 Census data for race and ethnicity, within a 50-mi (80-km) radius of Braidwood.

Census block groups were considered minority population block groups if the percentage of 

the minority population within any block group exceeded 48 percent (the percent of the minority 

population within the 50-mi radius of Braidwood). A minority population exists if the percentage 

of the minority population within the block group is meaningfully (statistical significant 

consideration) greater than the minority population percentage in the 50-mi (80-km) radius. 

Approximately 1,716 of the 3,648 census block groups located within the 50-mi (80-km) radius 

of Braidwood have meaningfully greater minority populations (USCB 2014f).

As shown in Figure 3–20, the nearest minority population block groups (race and ethnicity) are 

mostly clustered near Joliet, Kankakee, and the Chicago metropolitan statistical area. None of 

the block groups near Braidwood have meaningfully greater minority populations.
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Figure 3–20. Minority Block Groups Within a 50-mi Radius of Braidwood

Source: USCB 2014f
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3.12.2 Low-Income Population

According to USCB’s 2008–2012 ACS 5 Year Estimates an average of 7.9 percent of families 

and 13.5 percent of individuals residing in the 16 counties within a 50-mi (80-km) radius of 

Braidwood were identified as living below the Federal poverty threshold (USCB 2014b). The 

2012 Federal poverty threshold was $23,942 for a family of four.

According to the USCB’s 2008–2012 ACS 5-Year Estimates, Will County had a median 

household income and per capita income higher than the State of Illinois. Grundy County had 

a higher median household income than the State of Illinois, but a lower per capita income. 

Kankakee County had a lower median household income and per capita income than the State 

of Illinois. Kankakee has the highest percentages of persons (16.1 percent) living below the 

official poverty level when compared to the other two counties and the State of Illinois as a 

whole. Will and Grundy Counties had 7.7 and 8.6 percent, respectively, and the State of Illinois 

as a whole had 13.7 percent. The percentage of families living below the poverty level in Will 

and Grundy Counties (5.9 and 6.5 percent, respectively) was lower than the percentage of 

families in Kankakee County and the State of Illinois as a whole (12.5 percent and 10 percent, 

respectively) (USCB 2014c).

Figure 3–21 shows the location of predominantly low-income population block groups within a 

50-mi (80-km) radius of Braidwood. Census block groups were considered low-income 

population block groups if the percentage of individuals living below the Federal poverty 

threshold within any block group exceeded 13.5 percent (the percent of the individuals living 

below the Federal poverty threshold within the 50-mi radius of Braidwood). Approximately 

1,472 of the 3,648 census block groups located within the 50-mi (80-km) radius of Braidwood 

have meaningfully (statistical significant consideration) greater low-income populations 

(USCB 2014e).

Several census block groups including the block group where Braidwood is located are 

considered low-income block groups. In addition to these groups, as shown in Figure 3–21, 

the nearest low-income population block groups are mostly clustered near Chicago, Joliet, and 

Morris, Illinois.
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Figure 3–21. Low-Income Block Groups Within a 50-mi Radius of Braidwood

 

Source: USCB 2014e
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3.13 Waste Management and Pollution Prevention 

3.13.1 Radioactive Waste

As discussed in Section 3.1.4 of this SEIS, Braidwood uses liquid, gaseous, and solid waste

processing systems to collect and treat, as needed, radioactive materials produced as a 

by-product of plant operations. Radioactive materials in liquid and gaseous effluents are 

reduced prior to being released into the environment so that the resultant dose to members of 

the public from these effluents is well within NRC and EPA dose standards. Radionuclides that 

can be efficiently removed from the liquid and gaseous effluents prior to release are converted 

to a solid waste form for disposal in a licensed disposal facility.

3.13.2 Nonradioactive Waste

Waste minimization and pollution prevention are important elements of operations at all nuclear 

power plants. The licensees are required to consider pollution prevention measures as dictated 

by the Pollution Prevention Act (Public Law 101-508) and Resource Conservation and Recovery 

Act of 1976, as amended (PL 94-580) (NRC 2013).

As described in Section 3.1.5, Braidwood has a nonradioactive waste management program to 

handle this nonradioactive waste. In addition to managing its nonradioactive waste, Exelon has 

programs in place to minimize the generation of this waste. Braidwood implements a waste 

minimization plan to reduce, to the extent feasible, waste generated, treated, accumulated, or 

disposed. In addition to a focus on recycling operations, Exelon’s waste minimization plan 

focuses on identifying waste reduction opportunities and preventing waste before it happens. 

Exelon implements best management practices for solid, special, hazardous, mixed waste, and 

chemicals to control and minimize waste generation to the maximum extent practicable 

(Exelon 2012a).

Braidwood has an SWPPP that identifies potential sources of pollution that may affect the 

quality of stormwater discharges from each permitted outfall. The SWPPP also describes 

practices that are used to reduce pollutants in stormwater discharges to assure compliance with 

the site’s NPDES permit. As part of Braidwood’s Spill Prevention Control and Countermeasure 

Plan, measures are in place to monitor areas within the site that have the potential for spills of 

regulated substances, such as oil (Exelon 2013e).

3.14 References

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10 CFR Part 61. Code of Federal Regulations, Title 10, Energy, Part 61, “Licensing 

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SWAP_ORNATEBOXTURTLE0000581.pdf> (accessed 5 February 2014).

[WHC] Wildlife Habitat Council. 2013. Letter from M. O’Gorman, President, to B. O’Connor, 

Exelon Generation, LLC. Subject: “Wildlife at Work” Recertification. October 18, 2013. ADAMS 

No. ML14030A264.

Wiken E, Jiménez Nava F, Griffith G. 2011. North American Terrestrial Ecoregions—Level III. 

Montréal, Canada: Commission for Environmental Cooperation. May 2011. 149 p. Available at 

<ftp://ftp.epa.gov/wed/ecoregions/pubs/

NA_TerrestrialEcoregionsLevel3_Final-2june11_CEC.pdf> (accessed 13 November 2013).

Will County. 2011. Will County, Illinois, Land Resource Management Plan. Revised 

January 20, 2011. 280 p. Available at 

<http://willcountylanduse.com/resource/document/land-resource-management-plan-lrmp> 

(accessed 3 February 2014).

Will County. 2012. Will County, Illinois, Comprehensive Annual Financial Report, As of and 

for the Fiscal Year Ended November 30, 2012. Joliet, IL: Will County. 299 p. Available at 

<http://www.willcountyillinois.com/DepartmentDirectory/Finance/tabid/561/Default.aspx> 

(accessed April 2014).

Will County. 2014. “Will County Clerk: Code of Ordinances.” Available at 

<http://www.thewillcountyclerk.com/connect/site/index.jsp?menuItemId=140> (accessed 

17 February 2014).
Affected Environment

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[WJE] Wiss, Janney, Elstner Associates, Inc. 2009. Rural Historic Structural Survey of 

Channahon Township, Will County, Illinois. Northbrook, IL: WJE. April 2009. 152 p. Available 

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Woods AJ (Oregon State University), Omernik JM (U.S. Geological Survey), Pederson CL 

(Eastern Illinois University), Moran BC (Indus Corporation). 2006. Level III and IV Ecoregions 

of Illinois. Washington, DC: U.S. Environmental Protection Agency. EPA/600/R-06/104. 

September 2006. 45 p. Available at <ftp://ftp.epa.gov/wed/ecoregions/il/il_report.pdf> (accessed 

13 November 2013).
4-1 

4.0 ENVIRONMENTAL CONSEQUENCES AND MITIGATING ACTIONS

4.1 Evaluation of Braidwood License Renewal and Alternatives to License 

Renewal

In this chapter, the U.S. Nuclear Regulatory Commission (NRC) staff (or the staff) evaluates the 

environmental consequences of the proposed action (i.e., license renewal of Braidwood Station, 

Units 1 and 2 (Braidwood)), including the (1) impacts associated with continued operations 

similar to those that have occurred during the current license terms; (2) impacts of various 

alternatives to the proposed action (e.g., Coal-integrated Gasification Combined Cycle (IGCC) 

and Natural-gas-fired Combined-cycle (NGCC)); (3) impacts from the termination of nuclear 

power plant operations and decommissioning after the license renewal term (with emphasis on 

the incremental effect caused by an additional 20 years of operation); (4) impacts associated 

with the uranium fuel cycle; (5) impacts of postulated accidents (design-basis accidents (DBAs)

and severe accidents); (6) cumulative impacts of the proposed action; and (7) resource 

commitments associated with the proposed action, including unavoidable adverse impacts, the 

relationship between short term use and long-term productivity, and irreversible and irretrievable 

commitment of resources. The NRC also considers new and potentially significant information 

on environmental issues related to operation during the renewal term.

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

(NRC 2013f) identifies 78 issues to be evaluated in the license renewal environmental review 

process. Generic issues (Category 1) rely on the analysis presented in the GEIS, unless 

otherwise noted. Applicable site-specific issues (Category 2) have been analyzed for 

Braidwood and assigned a significance level of SMALL, MODERATE, or LARGE. Section 1.4 

of this supplemental environmental impact statement (SEIS) provides an explanation of the 

criteria for Category 1 and Category 2 issues, as well as the definitions of SMALL, MODERATE, 

and LARGE. Resource-specific impact significance level definitions are provided where 

applicable.

4.2 Land Use and Visual Resources

This section describes the potential impacts of the proposed action (license renewal) and 

alternatives to the proposed action on land use and visual resources.

4.2.1 Proposed Action

Section 3.2 of this SEIS describes land use and visual resources in the vicinity of the Braidwood 

site. The four generic (Category 1) issues that apply to land use and visual resources during 

the proposed license renewal period appear in Table 4–1. The GEIS (NRC 2013f) discusses 

these issues in Section 4.2.1. The GEIS does not identify any site-specific (Category 2) land 

use or visual resource issues.

The NRC staff did not identify any new and significant information related to the generic 

(Category 1) issues listed above during the review of the applicant’s Environmental Report (ER) 

(Exelon 2013c), the site audit, or the scoping process. Therefore, the NRC expects no impacts 

associated with these issues beyond those discussed in the GEIS. The GEIS concludes that 

the impact level for each of these issues is SMALL.
Environmental Consequences and Mitigating Actions

4-2 

Table 4–1. Land Use and Visual Resource Issues

Issue GEIS Section Category

Land Use

Onsite land use 4.2.1.1 1

Offsite land use 4.2.1.1 1

Offsite land use in transmission line right-of-ways (ROWs)(a) 4.2.1.1 1

Visual Resources

Aesthetic impacts 4.2.1.2 1

(a) This issue applies only to the in-scope portion of electric power transmission lines, which are defined as 

transmission lines that connect the nuclear power plant to the substation where electricity is fed into the regional 

power distribution system and transmission lines that supply power to the nuclear plant from the grid.

Source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

4.2.2 No-Action Alternative

4.2.2.1 Land Use

If Braidwood were to shut down, the impacts to land use would remain similar to those during 

operations until the plant is fully decommissioned. Temporary buildings and staging or laydown 

areas may be required during large component and structure dismantling. Braidwood is likely to 

have sufficient space within previously disturbed areas for these needs, and therefore, no 

additional land would need to be disturbed that would result in changes to current land uses. In 

NUREG–0586, Generic Environmental Impact Statement on Decommissioning of Nuclear 

Facilities, Supplement 1 (NRC 2002d), NRC concludes generically that land use during 

decommissioning activities would be SMALL. For Braidwood, the continuation of the lease 

agreement between Exelon Generation Company, LLC (Exelon), and the Illinois Department 

of Natural Resources (IDNR) for the Mazonia-Braidwood State Fish and Wildlife Area could be 

affected by decommissioning. Loss of these lands as a State-managed area could result in land 

use changes depending upon any future use of the site. In addition, the GEIS (NRC 2013f) 

notes that land use impacts could occur in other areas beyond the immediate nuclear plant site 

as a result of the no-action alternative if new power plants are needed to replace lost capacity. 

The NRC staff concludes that the no-action alternative could, but may not necessarily, alter land 

use noticeably. Thus, the NRC staff concludes that the impacts of the no-action alternative on 

land use during the proposed license renewal term would be SMALL to MODERATE.

4.2.2.2 Visual Resources

If Braidwood were to shut down, visual resource impacts would be similar to those experienced 

during operations until the site is fully decommissioned. As indicated in Section 3.2.2, the 

majority of site buildings are not tall, and the rolling topography and small forested tracts on 

and near the Braidwood site provide visual screening. Construction equipment associated with 

decommissioning could create some visual impacts, but these impacts would be temporary and 

localized. Therefore, the NRC staff concludes that the impacts of the no-action alternative on 

visual resources would be SMALL.
Environmental Consequences and Mitigating Actions

4-3 

4.2.3 New Nuclear Alternative

4.2.3.1 Land Use

The new nuclear alternative assumes that the new facility would be built at an existing nuclear 

or retired coal plant site within the region of influence (ROI) but outside of Illinois. Construction 

of the new nuclear plant would require an estimated 324 acres (ac) (131 hectares (ha)) for 

permanent buildings and facilities and an additional 232 ac (94 ha) for temporary facilities and 

laydown areas. The NRC staff assumes that this alternative would use existing onsite 

structures and previously disturbed areas to the extent practicable to minimize development of 

undisturbed land. Thus, this alternative would not significantly affect existing land uses. Given 

the land requirements, it is expected that some undisturbed lands would be affected, which 

would result in the conversion of natural areas to industrial land. No additional land use 

changes would result from operation of the nuclear facility. The NRC staff concludes that the 

impacts to land use from construction and operation of a new nuclear alternative would be 

SMALL.

4.2.3.2 Visual Resources

Because the facility would be located on an existing site, visual resources impacts of most new 

buildings and infrastructure would be minimal. If proposed, the construction of natural draft 

cooling towers would be the largest visual impact because both the towers themselves and the 

plume could be visible from a distance. The magnitude of this impact would vary based on the 

topography of the chosen site and surrounding area. The NRC staff concludes that the impacts 

to visual resources from construction and operation of a new nuclear alternative would be 

SMALL to MODERATE.

4.2.4 Coal (Integrated Gasification Combined Cycle) Alternative

4.2.4.1 Land Use

The IGCC alternative assumes that the new facility would be built at an existing 

energy-producing site or a retired coal plant site in Illinois or another state within the ROI. 

Construction of the facility would require 2,000 ac (809 ha) of land. The NRC staff assumes that 

this alternative would use existing onsite structures and previously disturbed areas to the extent 

practicable to minimize new development in undisturbed areas. However, because the footprint 

of the facility would be large, it is likely that construction would require clearing of lands that are 

currently in a different land use, such as agricultural, forested, or other natural areas. The 

impacts of this would vary widely based on the specific site selection and land uses that would 

be lost due to construction. No additional land use changes would result from operation of the 

IGCC facility. The NRC staff concludes that the impacts to land use from construction and 

operation of an IGCC alternative would be SMALL to MODERATE, primarily due to the potential 

for conversion of land to industrial use during construction.

4.2.4.2 Visual Resources

Because the facility would be located on an existing site, visual resources impacts would be 

minimal. The mechanical draft cooling towers would likely not be significantly taller than other 

buildings on the site. However, the plume created from operation of the towers could create 

noticeable visual impacts depending on the topography of the chosen site and surrounding 

area. The NRC staff concludes that the impacts to visual resources from construction and 

operation of an IGCC alternative would be SMALL to MODERATE.
Environmental Consequences and Mitigating Actions

4-4 

4.2.5 Natural Gas Combined Cycle Alternative

4.2.5.1 Land Use

The NGCC alternative assumes that the facility would be built at an existing energy-producing 

site or a retired coal plant site in Illinois or another state within the ROI. The facility would 

require 94 ac (38 ha) of land for the plant and associated pipelines. Because the footprint of the 

facility would be relatively small, the entire construction footprint could likely be sited in already 

developed areas of the site, which would minimize land use changes. No additional land use 

changes would result from operation of the new NGCC facility. The NRC staff concludes that 

the impacts to land use from construction and operation of an NGCC alternative would be 

SMALL.

4.2.5.2 Visual Resources

Because the facility would be located on an existing site, visual resources impacts would be 

minimal. The mechanical draft cooling towers would likely not be significantly taller than other 

buildings on the site. However, the plume created from operation of the towers could create 

noticeable visual impacts depending on the topography of the chosen site and surrounding 

area. The NRC staff concludes that the impacts to land use and visual resources from 

construction and operation of a new nuclear alternative would be SMALL to MODERATE.

4.2.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

4.2.6.1 Land Use

The NGCC component of this alternative would require the same amount of land as the NGCC 

alternative (94 ac (38 ha)), but the NGCC component would likely make better use of existing 

infrastructure because it would be sited at an existing power plant in Illinois or another state 

within the ROI and could use buildings and structures that are already in place and operational 

for the existing facility. Land use impacts would be similar to or less than those described in 

Section 4.2.5 for the NGCC alternative and would, therefore, be SMALL.

The wind component of the combination alternative would require 3,376 ac (1,366 ha) to 

10,127 ac (4,098 ha) at sites across the ROI. However, the majority of this land would only 

be temporarily disturbed during construction. Permanently disturbed land would hold the wind 

turbines, access roads, and transmission lines. Land used for equipment laydown and turbine 

component assembly and erection could be returned to its original state. Given the large 

footprint of the wind component, land use could be affected. However, some land uses, such 

as agriculture, could continue once the wind turbines are operational. Land use impacts for the 

wind component would range from SMALL to MODERATE depending on the amount and types 

of land that would be affected by wind turbine construction.

The solar component would require 6,749 ac (2,731 ha) of land across the ROI. The majority 

of solar installations could be installed on building roofs at existing residential, commercial, or 

industrial sites or at larger standalone solar facilities, and thus, it is possible that little land would 

be required for construction. However, the exact magnitude of impacts on land use would 

depend on the amount of land that is required to be converted for construction of solar 

installations. Unlike wind power, solar-powered installations often cannot be co-located with 

existing land uses (such as in a crop-producing agricultural field). The impacts of the solar 

component of this alternative on land use would range from SMALL to MODERATE depending 

on the amount and types of land that would be affected by construction of the solar installations.
Environmental Consequences and Mitigating Actions

4-5 

The NRC staff concludes that the impacts of the combination alternative on land use would be 

SMALL to MODERATE. This range is primarily the result of the variability in land required for 

the wind and solar components of the alternative.

4.2.6.2 Visual Resources

Visual resource impacts for the NGCC component of this alternative would be similar to or 

less than those described in Section 4.2.5 for the NGCC alternative and would, therefore, be 

SMALL. Visual resources would be significantly affected by construction of the wind 

component. Although specific effects would vary based on the topography and remoteness of 

the wind turbine locations, the visual impact of wind energy is often one of the most significant 

impacts and could range from MODERATE to LARGE. The visual impacts of the solar 

component would also vary based on the topography of the area but are expected to be minimal 

because individual solar installations are not tall or expansive. Thus, the impacts of the solar 

component would likely be SMALL. Overall, the NRC concludes that the impacts of the 

combination alternative on visual resources would be SMALL to LARGE.

4.2.7 Purchased Power

4.2.7.1 Land Use

The purchased power alternative would have wide-ranging impacts that are hard to specifically 

assess because this alternative could include a mixture of coal, natural gas, nuclear, and wind 

across many different sites in the ROI. This alternative would likely have little to no construction 

impacts because it would include power from already-existing power generating facilities 

(e.g., from excess capacity or peak capacity). The construction of additional transmission 

lines, as needed, could affect land uses if the lines require the clearing of new transmission 

line corridors. The types of operational impacts would be similar to the effects discussed in the 

preceding alternative sections. This alternative would be more likely to intensify already existing 

effects (impacts) at power generating facilities than create wholly new effects on land use. 

Existing facilities would likely have best management practices (BMPs) and other procedures in 

place to ensure that effects to the environment during operations are minimized. The NRC staff 

concludes that the impacts on land use from the purchased power alternative would be SMALL.

4.2.7.2 Visual Resources

The purchased power alternative would not result in the construction of any buildings or facilities 

or any other changes to existing visual resources. Thus, the NRC staff concludes that the 

purchased power alternative would have no impact on visual resources, and as such, it would 

be SMALL.

4.3 Air Quality and Noise

This section describes the potential impacts of the proposed action (license renewal) and 

alternatives to the proposed action on air quality and noise.

4.3.1 Proposed Action

Section 3.3 describes the meteorological, air quality, and noise conditions in the vicinity of 

Braidwood. Title 10 of Code of Federal Regulations (CFR) Part 51, Subpart A, Appendix B, 

Table B-1 lists a summary of findings on National Environmental Policy Act (NEPA) issues for 

license renewal of nuclear power plants. Two Category 1 air quality issues are applicable to 

Braidwood, “air quality impacts (all plants)” and “air quality effects of transmission lines” (see 
Environmental Consequences and Mitigating Actions

4-6 

Table 4–2). There are no Category 2 issues for air quality. One Category 1 noise issue 

is applicable to Braidwood, “noise impacts”; there are no Category 2 issues for noise.

Table 4–2. Air Quality and Noise

Issue GEIS Section Category

Air quality impacts (all plants) 4.3.1.1 1

Air quality effects of transmission lines 4.3.1.1 1

Noise impacts 4.3.1.2 1

Source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

4.3.1.1 Air Quality

Section 3.3.2 discusses the air quality conditions in the vicinity of Braidwood as well as air 

emissions resulting from operation of Braidwood. The Category 1 issue “air quality effects of 

transmission lines” considers the production of ozone and oxides of nitrogen; the GEIS found 

that minute and insignificant amounts of ozone and nitrogen oxides are generated during 

transmission. The Category 1 issue “air quality impacts (all plants),” considers the air quality 

impacts from continued operation and refurbishment associated with license renewal. The 

GEIS concludes that the impact of refurbishment activities on air quality during the license 

renewal term would be SMALL for most plants, but could be cause for concern at plants located 

in or near air quality nonattainment or maintenance areas (NRC 2013d).

The NRC staff did not identify any new and significant information during the review of Exelon’s 

ER in the license renewal application (LRA) (Exelon 2013a), the site audit, or during the scoping 

process. As a result, no information or impacts related to these issues were identified that 

would change the conclusions presented in the GEIS. Therefore, there are no impacts related 

to these issues beyond those discussed in the GEIS.

4.3.1.2 Noise

Section 3.3.3 discusses the noise conditions in the vicinity of Braidwood as well as noise 

sources resulting from operation of Braidwood. One Category 1 noise issue is applicable to 

Braidwood, “noise impacts” (see Table 4–2). The 1996 GEIS (NRC 1996) concluded that noise 

was not a problem at operating plants and was not expected to be a problem at any nuclear 

plant during the license renewal term, and the 2013 GEIS did not identify new information that 

would alter this conclusion; therefore, offsite (beyond the Braidwood site boundary) noise 

impacts are expected to be SMALL. The NRC staff did not identify any new and significant 

information during the review of Exelon’s ER in the LRA (Exelon 2013a), the site audit, or during 

the scoping process. As a result, no information or impacts related to these issues were 

identified that would change the conclusions presented in the GEIS. Therefore, there are no 

impacts related to these issues beyond those discussed in the GEIS. The GEIS concludes that 

the impact level related to these issues is SMALL.

4.3.2 No-Action Alternative

4.3.2.1 Air Quality

When the plant stops operating, there would be a reduction in emissions from activities related 

to plant operation such as use of stationary combustion sources (e.g., diesel generators, 

auxiliary boilers, diesel engine auxiliary feedwater (AFW) pumps) and vehicle traffic 
Environmental Consequences and Mitigating Actions

4-7 

(e.g., workers and delivery). Therefore, if emissions decrease, the impact on air quality from 

shutdown (decommissioning) of the Braidwood Station would be SMALL.

4.3.2.2 Noise

When the plant stops operating, there will be no noise from activities related to plant operation 

such as circulating water make-up pumps, main steam valves, water discharge system, and 

vehicle traffic (e.g., workers and delivery). In other words, noise levels around the site would 

be back to the background levels before the Braidwood Station was built. Therefore, if noise 

sources are reduced, the impact on ambient noise levels would also be reduced and would 

be SMALL.

4.3.3 New Nuclear Alternative

4.3.3.1 Air Quality

Because of the moratorium preventing the construction of new nuclear power plants within 

Illinois, the new nuclear alternative would be located elsewhere in the ROI. The ROI is defined 

as the states of Illinois, Indiana, Iowa, Kentucky, Michigan, Missouri, and Wisconsin. The 

reactor would be installed on an existing nuclear or coal power plant site in the ROI, allowing 

for the maximum use of existing ancillary facilities such as support buildings and transmission 

infrastructure.

Within the ROI states, the majority of the area is designated as attainment for all pollutants. 

However, existing air quality conditions range from attainment to nonattainment areas within the 

ROI. Nonattainment areas within the ROI are primarily associated with the heavily urbanized 

areas near Chicago, IL, and St. Louis, MO (EPA 2014c). Therefore, it is possible that the new 

nuclear alternative could be located in an air quality area meeting all current National Ambient 

Air Quality Standards (NAAQS) or in a location not meeting one or more current NAAQS 

(nonattainment). It is also possible that air quality attainment/nonattainment designations 

may change prior to the development of the new nuclear alternative within the ROI.

Construction

Construction of the new nuclear plant would result in temporary impacts on local air quality. 

During construction, air quality would be affected by the release of criteria pollutants (nitrogen 

oxides, sulfur dioxide, carbon monoxide, particulate matter (PM)) and greenhouse gases 

(GHGs) from combustion of fuel in construction vehicles and equipment, workforce commuting 

vehicles, and material delivery vehicles (i.e., engine exhaust and fugitive dust). Greenhouse 

gas emissions during construction would result primarily from the consumption of fossil fuels in 

the operation of construction vehicles and equipment and from the operation of delivery vehicles 

and vehicles used by the commuting workforce. Greenhouse gas emissions are controlled by 

using fuels that meet U.S. Environmental Protection Agency (EPA) requirements in all vehicles 

and equipment and keeping all vehicles and equipment maintained in accordance with 

manufacturers’ specifications. Some releases of volatile organic compounds (VOCs) would 

be expected from onsite vehicle and equipment fueling activities and from the use of cleaning 

agents and corrosion control coatings. Ground disturbance—such as from ground-clearing and 

cut-and-fill activities, movement of construction vehicles on unpaved and disturbed land 

surfaces, and delivery and stockpiling of materials used in construction (e.g., sand and gravel)—

would produce fugitive dust releases.

Construction lead times for nuclear plants are anticipated to be 7 years (NRC 2013j). Air 

emissions would be intermittent and vary based on the level and duration of a specific activity 

throughout the construction phase. Construction of a new nuclear plant would be expected to 

employ BMPs, if necessary, to reduce construction-related air quality impacts to acceptable 
Environmental Consequences and Mitigating Actions

4-8 

levels. State and Federal permits and regulated practices for managing air emissions from 

construction equipment and temporary stationary sources and vehicle inspection and traffic 

management plans will limit potential impacts on air quality from building a nuclear power plant. 

Since air emission from construction activities would be limited, local, and temporary, the NRC 

staff concludes that the overall air quality impacts associated with construction of a new nuclear 

alternative would be SMALL.

Operation

Operation of a new nuclear generating plant would result in similar air emissions to those of the 

existing Braidwood site. Sources of air emissions can include stationary combustion sources 

(e.g., emergency diesel generators, pumps, auxiliary boilers) and mobile sources (worker 

vehicles, onsite heavy equipment and support vehicles, and delivery of materials and disposal 

of wastes). The new nuclear power plant would likely use natural draft cooling towers as 

opposed to a once-through cooling system as currently used at Braidwood and will result in 

additional PM as drift.

In general, most stationary combustion sources at a nuclear power plant would operate only 

for limited periods, often for periodic maintenance testing. Thus, emissions from stationary 

combustion sources would fall far below the threshold for major sources (100 tons per year 

(tons/yr)) and threshold for mandatory GHG reporting (25,000 metric tons (MT) per year). In 

contrast, cooling towers would operate continuously for the entire year. However, a nuclear 

power plant located in the ROI would use cooling water taken from a nearby river or lake, which 

would have relatively low concentrations of total dissolved solids. In addition, the modern 

cooling towers would be equipped with drift eliminators to minimize the loss of cooling water 

from the tower via drift. Thus, PM emissions from cooling towers are anticipated to be minimal.

Air pollutants emitted from stationary combustion sources (e.g., criteria pollutants, VOCs, 

hazardous air pollutants (HAPs), and GHGs) and from cooling towers (PM as drift) associated 

with operations of a nuclear power plant would be permitted in accordance with State and 

Federal regulatory requirements. The new nuclear plant would be required to apply for and 

obtain an air quality permit to operate from the state air regulatory authority for the state in 

which the plant would be located. The permit would be similar to the synthetic minor source 

air permit issued by the Illinois Environmental Protection Agency (IEPA) currently governing 

operation of Braidwood’s air emission sources. Section 51.307 in Subpart P of 40 CFR Part 51 

contains the visibility protection regulatory requirements, including the review of the new 

sources that may affect visibility in any Federal Class I area. If a new nuclear plant were 

located near a mandatory Class I area, additional air pollution control requirements may 

be required.

Air emissions for combustion sources from a new nuclear plant are expected to be similar to 

what is emitted at Braidwood:

 sulfur dioxide (SO2): 0.06 tons (0.05 MT) per year,

 nitrogen oxides (NOx): 27.1 tons (25 MT) per year,

 carbon monoxide (CO): 7.2 tons (6.5 MT) per year,

 particulate matter (PM10): 0.50 tons (0.45 MT) per year, and

 carbon dioxide equivalents (CO2e): 1,361 tons (1,230 MT) per year.

A new nuclear plant would have slightly higher total PM10 emissions due to the use of natural 

draft cooling towers. During operation, air quality impacts would also include releases of criteria 

pollutants from vehicles used by the commuting workforce and vehicles (primarily trucks) used 

to deliver supplies and equipment to the site.
Environmental Consequences and Mitigating Actions

4-9 

The NRC staff evaluated potential impacts on air quality associated with criteria pollutants and 

GHG emissions from operating a new nuclear alternative. Based on its review (discussed 

above), the NRC staff determined that the impacts would be minimal. Therefore, the NRC 

staff concludes that the impacts of operation of a new nuclear alternative on air quality from 

emissions of criteria pollutants and GHGs would be SMALL.

Conclusion

The NRC staff concludes that the air quality impacts associated with construction and operation 

of a new nuclear alternative would be SMALL.

4.3.3.2 Noise

Construction

Construction of a new nuclear power plant is similar to that of other large industrial projects and 

involves many noise-generating activities. In general, noise emissions vary with each phase of 

construction, depending on the level of activity, the mix of construction equipment for each 

phase, and site-specific conditions. Noise propagation to receptors is affected by several 

factors, including source-receptor configuration, land cover, meteorological conditions 

(temperature, relative humidity, and vertical profiles of wind and temperature), and screening 

(such as topography and natural or man-made barriers). Typical construction equipment, such 

as dump trucks, loaders, bulldozers, graders, scrapers, air compressors, generators, and mobile 

cranes, would be used, and pile driving and blasting activities would take place during the 

construction of a new nuclear power plant. Another noise source includes commuter, delivery, 

and support vehicular traffic traveling within, to, and from the facility.

Noise is produced by the equipment and vehicles used to construct the facility. Construction 

equipment and vehicles produce engine noise during operation within the construction site; 

delivery vehicles also produce noise outside the construction site on roads in the vicinity of the 

site. Noise is also produced during demolition of any existing structures, excavation and 

transport of soil, transport of construction materials, preparation of building materials for 

installation (cutting, hammering, grinding, etc.), and construction of the buildings and equipment.

Noise emissions from construction equipment are predicted to be in the 85 to 100 decibels 

adjusted (dBA) range (Knauer and Pedersen 2011); however, noise levels attenuate rapidly 

with distance such that at half-a-mile distance from construction equipment, 85 to 90 dBA noise 

levels can drop to 51 to 61 dBA (NRC 2002a). Additionally, noise abatement and controls can 

be incorporated to reduce noise impacts. Accounting for attenuation from the construction site 

and noise controls, predicted noise levels can be less than Housing and Urban Development’s 

acceptable noise level guideline of 65 dBA. Based on the temporary nature of construction 

activities, consideration of noise attenuation from the construction site to residences, the 

location and characteristics (i.e., ground cover), and good noise control practices, the NRC 

staff concludes that the potential noise impacts of construction activities from a new nuclear 

alternative would be SMALL.

Operation

During the operation phase, noise sources from the new nuclear power plant would come from 

cooling towers, main steam valves, transformers, turbines, and auxiliary equipment such as 

standby generators or auxiliary boilers, and vehicular traffic (commuting, delivery, support), 

similar to those for Braidwood discussed in Section 3.3.3 of this SEIS. Although the plant layout 

and the distance from primary noise sources to the nearby receptors at Braidwood might be 

different from those at a new nuclear alternative and the new nuclear alternative will likely have 

cooling towers, the NRC staff does not expect noise impacts for a new nuclear plant to be any 
Environmental Consequences and Mitigating Actions

4-10

greater than that analyzed for the existing Braidwood site. Therefore, the noise impacts of a 

new nuclear plant located within the ROI region would be SMALL.

Conclusion

The NRC staff concludes that the noise impacts associated with operation and construction of a 

new nuclear alternative would be SMALL.

4.3.4 Coal (Integrated Gasification Combined Cycle) Alternative

4.3.4.1 Air Quality

The IGCC alternative consists of 2,472 MWe of new generation produced by four 618 MWe 

IGCC units. The IGCC plant would be installed (or located) on one or more existing nuclear or 

coal power plant sites in the ROI, allowing for the maximum use of existing ancillary facilities, 

such as support buildings and transmission infrastructure. The ROI and existing air quality 

discussion in Section 4.3.3.1 also applies to the IGCC alternative. It is possible that the IGCC 

alternative could be located in an air quality area meeting all current NAAQS (attainment), or in 

a location not meeting one or more current NAAQS (nonattainment), depending on the 

availability of suitable sites for development. It is also possible that air quality 

attainment/nonattainment designations may change prior to the development of the IGCC 

alternative within the ROI. For instance, if the IGCC alternative were to be located at the 

Braidwood site, Will County would be designated as nonattainment for the 2008 8-hour ozone 

(marginal) NAAQS and 2010 sulfur dioxide NAAQS (partial county designation) and designated 

maintenance area for the 1997 PM2.5 NAAQS (40 CFR 81.314; EPA 2015).

Construction

Construction of an IGCC plant would be similar to that of other large industrial projects and 

involves many activities similar to those for a new nuclear alternative presented in 

Section 4.3.3.1. Construction of an IGCC plant would result in the release of various criteria 

pollutants (PM, nitrogen oxides, carbon monoxide, and sulfur dioxide), VOCs, HAPs, and GHGs

from operation of internal combustion engines in construction vehicles, equipment, delivery 

vehicles, and vehicles used by the commuting construction workforce. In addition, soil 

disturbance activities such as earthmoving and material handling would generate fugitive dust. 

Release of VOCs will result from the onsite storage and dispensing of vehicle and equipment 

fuels. Air emissions would be intermittent and vary based on the level and duration of a specific 

activity throughout the construction phase. Construction lead times for IGCC plants are 

estimated to be 3 years (NETL 2007). Impacts would be localized, intermittent, and short-lived, 

and adherence to well-developed and well-understood construction BMPs would mitigate such 

impacts. The NRC staff concludes that construction-related impacts on air quality from an IGCC 

alternative would be of relatively short duration and would be SMALL.

Operation

The sources of air emissions during operation of the IGCC include heat recovery steam 

generator (HRSG) stacks, the wet gas sulfuric acid system exhaust, acid gas removal process 

startup/shutdown vents, startup stacks, flares, material handling equipment, and mechanical 

draft cooling towers (DOE 2010b; EPA 2006; NETL 2007). The HRSG stacks would release the 

most emissions. Auxiliary boilers and firewater pumps would also generate emissions on an 

infrequent basis.

Compared to conventional coal-fired power plants, the proposed IGCC power plant would 

reduce sulfur dioxide, nitrogen oxide, mercury, and PM emissions by removing constituents 

from the syngas (DOE 2010b). The IGCC alternative would also result in lower nitrogen oxide 
Environmental Consequences and Mitigating Actions

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emissions since nearly 100 percent of the fuel-bound nitrogen from the syngas would be 

removed from the syngas before combustion in the gas turbine. Sulfur removal technology 

would remove more than 99 percent of the sulfur in the syngas. The use of sulfide-activated 

carbon could remove more than 92 percent of mercury from the syngas. More than 

99.9 percent of particulate emissions would be removed from the syngas using 

high-temperature, high-pressure filtration.

Various Federal and state regulations aimed at controlling air pollution would affect an IGCC 

alternative located in the seven-state ROI. A new 2,472-MWe IGCC plant (or multiple plants in 

different locations totaling 2,472 MWe) would qualify as a new major source of criteria pollutants 

and GHGs and would require a Prevention of Significant Deterioration (PSD) of air quality 

review under New Source Review (NSR) regulations (42 U.S.C. § 7401 et seq. (Clean Air Act

(CAA))), as implemented by the applicable state regulatory authority. If the IGCC alternative is 

located in an air quality area designated nonattainment, emissions of the nonattainment 

pollutant would be reviewed under nonattainment NSR.

The NSR air permit application review process would include evaluation of all potentially 

applicable air quality regulations, identify those that apply to the IGCC plant, and develop 

control, compliance, reporting, and recordkeeping requirements to demonstrate compliance with 

applicable regulations. The new IGCC plant would be required to secure a Title V operating 

permit from the state agency. Analysis regarding NAAQS compliance would be conducted at 

the specific site location. The IGCC plant would need to comply with applicable New Source 

Performance Standards, such as the standards of performance for electric utility steam 

generating units set forth in 40 CFR Part 60, Subpart Da (electric utility steam generating units).

If the IGCC alternative were located close to a mandatory Class I area, additional air pollution 

control requirements would be necessary (Subpart P of 40 CFR Part 51) as mandated by the 

Regional Haze Rule. Within the ROI, there are five Class I Federal areas, including: Mammoth 

Cave National Park (NP) in Kentucky (40 CFR 81.411), Isle Royale NP and Seney Wilderness 

Area (WA) in Michigan (40 CFR 81.414), and Hercules-Glades WA and Mingo WA in Missouri 

(40 CFR 81.416). The rule could apply to the IGCC alternative, but would depend on specific 

site locations(s). If an IGCC plant was located close to a mandatory Class I area, additional air 

pollution analyses, and permitting and control requirements would potentially apply.

Air emissions for the IGCC alternative were estimated based on data presented in Table 4.3-1 

in the GEIS (NRC 2013f). The resulting IGCC emissions are estimated to be as follows:

 sulfur dioxide (SO2)— 820 tons (740 MT) per year,

 nitrogen oxides (NOx)— 3,000 tons (2,720 MT) per year,

 particulate matter (PM10)— 480 tons (435 MT) per year,

 carbon monoxide (CO)— 2,045 tons (1,850 MT) per year, and

 carbon dioxide equivalents (CO2e)— 14.3 million tons (13.0 million MT) 

per year.

The IGCC alternative would produce 820 tons (740 MT) of sulfur dioxide and 3,000 tons 

(3,000 MT) per year of nitrogen oxide. The IGCC plant would have to comply with Title IV of the 

CAA (42 U.S.C. § 7651) reduction requirements for sulfur oxide and nitrogen oxide, which are 

the main precursors of acid rain and the major causes of reduced visibility. Title IV establishes 

maximum sulfur oxide and nitrogen oxide emission rates from the existing plants and a system 

of sulfur oxide emission allowances that can be used, sold, or saved for future use by the new 

plants. The new plant would be subjected to the continuous monitoring requirements of sulfur 
Environmental Consequences and Mitigating Actions

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dioxide and nitrogen oxide as specified in 40 CFR Part 75. The Clean Air Interstate Rule 1

(CAIR) requires 27 states (including Indiana, Iowa, Michigan, Missouri, Kentucky, and 

Wisconsin) to improve air quality requiring power plants to reduce sulfur dioxide and nitrogen 

oxide emissions (EPA 2014c). A new IGCC plant would be subject to these additional rules 

and regulations.

The IGCC alternative would emit approximately 14.3 million tons (approximately 

13.0 million MT) per year of carbon dioxide equivalent emissions. The plant would be subjected 

to the continuous monitoring requirements for carbon dioxide, as specified in 40 CFR Part 75. 

On July 12, 2012, EPA issued a final rule tailoring the criteria that determine which stationary 

sources and modifications to existing projects become subject to permitting requirements for 

GHG emissions under the PSD and Title V Programs of the CAA (77 FR 41051). Beginning 

January 2, 2011,2 operating permits issued to major sources of GHG under the PSD or Title V 

Federal permit programs must contain provisions requiring the use of best available control 

technology (BACT) to limit the emissions of GHGs if those sources would be subject to PSD 

or Title V permitting requirements because of their non-GHG pollutant emission potentials and 

their estimated GHG emissions are at least 75,000 tons/yr of carbon dioxide equivalents. If the 

IGCC alternative meets PSD or Title V permitting requirements for non-GHG pollutant 

emissions and the GHG emission thresholds established in the rule, then GHG emissions 

from this alternative would be regulated under the PSD and Title V permit programs.

In response to the Consolidated Appropriations Act of 2008 (Public Law 110-161), EPA issued 

final mandatory GHG reporting regulations for major sources effective in December 2009 

(EPA 2012b). Major sources are defined as those emitting more than 25,000 tons/yr of all 

GHGs. An IGCC alternative would be subject to these reporting regulations with or without 

carbon capture. On January 8, 2014, the EPA issued a new proposal for GHG emissions from 

new fossil fuel-fired electric utility steam generating units (79 FR 1430). It also proposes 

standards of performance for IGCC units that burn coal. The performance standards are based 

on partial implementation of carbon capture and sequestration (CCS) as the best system of 

emission reduction (BSER). Although the proposed rule has not been finalized, the IGCC 

alternative analysis includes an option for future implementation of CCS.

An IGCC alternative also would be subject to the Mercury and Air Toxics Standards (MATS) 

final rule, finalized by EPA on December 16, 2011 (EPA 2012c). MATS sets standards for 

emissions of heavy metals (mercury, arsenic, chromium, and nickel) and acid gases 

(hydrochloric acid and hydrofluoric acid). Mercury is the most prominent HAP emitted and 

is subject to regulation by the MATS rule. New IGCC units are required to meet a mercury 

emission limit of 0.003 pounds per gigawatt hour (40 CFR Part 63 Subpart UUUUU). NRC staff 

estimates that an IGCC alternative replacing the electrical output of Braidwood would generate 

from 0.03 tons (0.02 MT) of mercury per year.

 

1 The Clean Air Interstate Rule (CAIR) was first issued by EPA in 2005; however, the Federal rule was vacated by the D.C. Circuit 

Court on February 8, 2008. In December 2008, the U.S. Court of Appeals for the D.C. Circuit reinstated the rule, allowing it to 

remain in effect but also requiring EPA to revise the rule and its implementation plan. On July 6, 2010, EPA proposed replacing 

CAIR with the Cross-State Air Pollution Rule (CSAPR) for control of sulfur dioxide and nitrogen oxide emissions that cross state 

lines, the regulations of which would be implemented in 2011 and finalized in 2012. However, CSAPR was vacated by the 

D.C. Circuit Court on August 21, 2012. On April 29, 2014, the U.S. Supreme Court reversed the D.C. Circuit opinion vacating 

CSAPR. EPA is reviewing the opinion and CAIR remains in effect. 

2 On June 23, 2014, the U.S. Supreme Court issued a decision that EPA may not treat GHGs as an air pollutant for purposes of 

determining whether a source is a major source required to obtain a PSD or Title V permit, but could continue to require PSD and 

Title V permits, otherwise required based on emissions of conventional pollutants. In July 2014, EPA issued a memorandum in 

response to the Supreme Court’s decision and acknowledged that while the decision is pending judicial action, EPA will no longer 

require PSD or Title V permits for GHG-emitting sources that are not sources subject to PSD or Title V permits based on 

emissions of conventional pollutants (nitrogen oxides, carbon monoxide, etc.) (EPA 2014d).
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4-13

The impact from sulfur dioxide and nitrogen oxide emissions would be significant and subject to 

a Title V permit. GHG emissions also would be noticeable and significant; GHG emissions 

would be much larger than the threshold in EPA’s GHG Tailoring Rule and GHG emissions may 

be regulated under the PSD and Title V permit programs. The NRC staff concludes that the air 

quality impacts associated with operation of an IGCC alternative would be MODERATE.

Conclusion

The NRC staff concludes that the overall air quality impacts associated with construction and 

operation of an IGCC alternative would be MODERATE.

4.3.4.2 Noise

Construction

Construction of an IGCC plant is similar to that of other large industrial projects, and 

construction-related noise sources would be virtually the same as those for construction of the 

nuclear alternative. However, the construction period for the IGCC alternative would be shorter 

and the level of activities scattered over a wide area would be less extensive compared with 

construction of a nuclear alternative. Consequently, with construction-related noise for the 

nuclear alternative as a bounding condition, the NRC staff concludes that construction-related 

noise associated with the IGCC alternative would be SMALL.

Operation

Operation of an IGCC plant would introduce mechanical sources of noise that would be audible 

offsite. Continuous sources include the mechanical equipment associated with normal plant 

operations and mechanical draft cooling towers. Intermittent sources include the equipment 

related to coal handling, solid waste disposal, transportation related to coal and lime/limestone 

delivery, use of outside loudspeakers, and the commuting of plant employees. Noise 

associated with rail delivery of coal and lime/limestone would extend beyond the plant site 

boundary and would be most significant for residents living in the vicinity of the facility and along 

the rail route. Noise impacts associated with rail delivery are predicted to be in the 80 to 96 dBA 

range (NRC 2002a). At this sound level range, transportation-related noise has the potential to 

be noticeable and cause an adverse community response as this noise source can reach 

beyond the plant site boundary. The NRC staff concludes that the potential impacts of noise 

on residents in the vicinity of the facility of IGCC alternative and the rail line are considered to 

range from SMALL to MODERATE, depending on the distance from primary noise sources to 

nearby sensitive receptors.

Conclusion

The NRC staff concludes that the overall potential impacts of noise associated with construction 

and operation of the IGCC alternative and the rail line are considered to range from SMALL to 

MODERATE.

4.3.5 Natural Gas Combined Cycle Alternative

4.3.5.1 Air Quality

This alternative includes the construction and operation of five NGCC 560-MW units (total 

2,800 MW) and a capacity factor of 85 percent. These sites could be located at an existing 

power plant site in the ROI. Some infrastructure upgrades may be required and would require 

construction of a new or upgraded pipeline. Using existing power plant sites maximizes 

availability of infrastructure and reduces disruption to land and populations.
Environmental Consequences and Mitigating Actions

4-14

Construction

Construction of an NGCC power plant would be similar to that of other large industrial projects. 

Construction of an NGCC power plant would result in the release of various criteria pollutants 

(PM, nitrogen oxides, carbon monoxide, and sulfur dioxide), VOCs, HAPs, and GHGs from the 

operation of internal combustion engines in construction vehicles, equipment, delivery vehicles, 

and vehicles used by the commuting construction workforce. In addition, onsite soil disturbance 

activities such as earthmoving and material handling would generate fugitive dust. Releases of 

VOCs will also result from the onsite storage and dispensing of vehicle and equipment fuels. Air 

emissions would be intermittent and vary based on the level and duration of a specific activity 

throughout the construction phase. Gas-fired power plants are constructed relatively quickly; 

construction lead times for NGCC plants are around 2 to 3 years (Dujardin 2005; EIA 2011). 

Impacts would be localized, intermittent, and short-lived, and adherence to well-developed and 

well-understood construction BMPs would mitigate such impacts. Therefore, the NRC staff 

concludes that construction-related impacts on air quality from an NGCC alternative would be 

of relatively short duration and would be SMALL.

Operation

Operation of the NGCC plant would result in significant emissions of certain criteria pollutants, 

including carbon monoxide, nitrogen oxide, and PM. The sources of air emissions during 

operation include gas turbines through HRSG stacks and mechanical draft cooling towers. 

Auxiliary boilers and emergency generators would also generate emissions on an 

infrequent basis.

Various Federal and state regulations aimed at controlling air pollution would affect an NGCC 

alternative located in the seven-state ROI. It is possible that the NGCC alternative could be 

located in an air quality area meeting all current NAAQS (attainment), or in a location not 

meeting one or more current NAAQS (nonattainment), depending on the availability of suitable 

sites for development. For instance, if the NGCC alternative were to be located at the 

Braidwood site, Will County is designated as nonattainment for the 2008 8-hour ozone 

(marginal) NAAQS and 2010 sulfur dioxide NAAQS (partial county designation) and designated 

maintenance area for the 1997 PM2.5 NAAQS (40 CFR 81.314; EPA 2015). An NGCC plant 

would be subject to the NSR permitting program to ensure air emissions are minimized and the 

local air quality is not substantially degraded (EPA 2013b). The new NGCC plant would be 

required to secure a Title V operating permit from the state agency. The NGCC plant would 

need to comply with the standards of performance for stationary combustion turbines set forth in 

40 CFR Part 60 Subpart KKKK. If the NGCC alternative were located close to a mandatory 

Class I area, additional air pollution control requirements would be required (Subpart P of 

40 CFR Part 51) as mandated by the Regional Haze Rule. A detailed discussion of these 

Federal and state regulations is provided in Section 4.3.4.1.

Air emissions for the NGCC alternative were estimated based on data presented in Table 4.3-2 

in the GEIS and EPA emission factors (NRC 2013, EPA 2000). The estimate is based on using 

advanced F class gas turbines at one or multiple sites within the ROI. The resulting NGCC 

emissions are estimated to be as follows:

 sulfur dioxide (SO2)— 380 tons (350 MT) per year,

 nitrogen oxides (NOx)— 600 tons (540 MT) per year,

 particulate matter (PM10)— 210 tons (190 MT) per year,
Environmental Consequences and Mitigating Actions

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 carbon monoxide (CO)— 1,690 tons (1,530 MT) per year, and

 carbon dioxide equivalents (CO2e)— 7.9 million tons (7.2 million MT) per 

year.

The NGCC alternative would produce 380 tons (350 MT) per year of sulfur dioxide and 600 tons 

(540 MT) per year of nitrogen oxide. The new plant would be subjected to the continuous 

monitoring requirements of sulfur dioxide and nitrogen oxide as specified in 40 CFR Part 75. 

Under the Federal Acid Rain Program, a new natural gas-fired plant would have to comply with 

Title IV of the CAA reduction requirements for sulfur dioxide and nitrogen oxides, which are the 

main precursors of acid rain and the major cause of reduced visibility. The CAIR requires 

27 states (including Indiana, Iowa, Michigan, Missouri, Kentucky, and Wisconsin) to improve 

air quality requiring power plants to reduce sulfur dioxide and nitrogen oxide emissions 

(EPA 2014c). A new NGCC plant would be subject to these additional rules and regulations.

The NGCC alternative would emit approximately 7.9 million tons (approximately 7.2 million MT) 

per year of carbon dioxide equivalents. The plant would be subjected to the continuous 

monitoring requirements for carbon dioxide, as specified in 40 CFR Part 75. On July 12, 2012, 

EPA issued a final rule tailoring the criteria that determine which stationary sources and 

modification to existing projects become subject to permitting requirements for GHG emissions 

under the PSD and Title V Programs of the CAA (77 FR 41051). Beginning January 2, 2011, 

operating permits issued to major sources of GHG under the PSD or Title V Federal permit 

programs must contain provisions requiring the use of BACT to limit the emissions of GHGs 

(if those sources would be subject to PSD or Title V permitting requirements because of their 

non-GHG pollutant emission potentials and their estimated GHG emissions are at least 

75,000 tons/yr of carbon dioxide equivalents). If the NGCC alternative meets PSD or Title V 

permitting requirements for non-GHG pollutant emissions and the GHG emission thresholds 

established in the rule, then GHG emissions from this alternative would be regulated under the 

PSD and Title V permit programs. In response to the Consolidated Appropriations Act of 2008 

(Public Law 110-161), EPA issued final mandatory GHG reporting regulations for major sources 

effective in December 2009 (EPA 2012b). Major sources are defined as those emitting more 

than 25,000 tons/yr of all GHGs. An NGCC alternative would be subject to these reporting 

regulations with or without carbon capture. On January 8, 2014, the EPA issued a new 

proposal for GHG emissions from new fossil fuel-fired electric utility steam generating units 

(79 FR 1430). It also proposes standards of performance for natural gas-fired stationary 

combustion turbines based on modern, efficient NGCC technology as the BSER. Although the 

proposed rule has not been finalized, the IGCC alternative analysis includes an option for future 

implementation of CCS.

In December 2000, EPA issued regulatory findings on emissions of HAPs from electric utility 

steam-generating units (65 FR 79825). These findings indicated that natural gas-fired plants 

emit HAPs such as arsenic, formaldehyde, and nickel and stated that:

[t]he impacts due to hazardous air pollutants (HAP) emissions from natural 

gas-fired electric utility steam generating units were negligible based on the 

results of the study. The Administrator finds that regulation of HAP emissions 

from natural gas-fired electric utility steam generating units is not appropriate 

or necessary.

Mercury is not emitted from NGCC power plants due to the lack of mercury in natural gas used 

as fuel.

Considerable air emissions are emitted from operations of the NGCC alternative. The impacts 

from nitrogen oxide and sulfur dioxide emissions would be significant and subject to a Title V 

permit. GHG emissions also would be noticeable and significant; carbon dioxide emissions 
Environmental Consequences and Mitigating Actions

4-16

would be much larger than the threshold in EPA’s GHG Tailoring Rule. The NRC staff 

concludes that the overall air quality impacts associated with operation of an NGCC alternative 

would be MODERATE.

Conclusion

The NRC staff concludes that the overall air quality impacts associated with construction and 

operation of an NGCC alternative would be MODERATE.

4.3.5.2 Noise

Construction

The construction-related noise sources for an NGCC alternative would be virtually the same as 

those for construction of the IGCC alternative. Construction vehicles and equipment associated 

with the construction of the NGCC plant would generate noise; these impacts would be 

intermittent and last only through the duration of plant construction. Noise emissions from 

common construction equipment would be in the 85 to 100 dBA range (Knauer and 

Pedersen 2011). However, noise abatement and controls can be incorporated to reduce noise 

impacts. The NRC staff concludes that construction-related noise impacts associated with the 

NGCC alternative would be SMALL.

Operation

Noise impacts from operations would include cooling towers (water pumps, cascading water, 

or fans), transformers, turbines, pumps, compressors, exhaust stack, the combustion inlet filter 

house, condenser fans, high-pressure steam piping, and vehicles (Saussus 2012). Pipelines 

delivering natural gas fuel could be audible off site near gas compressor stations, but such 

noise impacts would be similar to impacts already occurring in the vicinity of the existing pipeline 

to which the new NGCC site would connect. Most noise-producing equipment is located inside 

the power block buildings and no outside fuel-handling activities will occur. Minor offsite noise 

source could be pipeline compressor stations. The NRC staff concludes that operation-related 

noise impacts from the NGCC alternative would be SMALL.

Conclusion

The NRC staff concludes that construction and operation-related noise impacts from the NGCC 

alternative would be SMALL.

4.3.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

The combination alternative relies on NGCC, wind, and solar generating capacity. The total 

installed solar photovoltaic (PV) capacity is 1,193 MW, the total installed wind capacity is 

6,042 MW of onshore wind, and the total installed capacity for NGCC is 267 MW in this 

alternative. All portions of the combination alternative would be located in Illinois or other 

adjoining states in the ROI (Indiana, Iowa, Michigan, Missouri, Kentucky, and Wisconsin).

The NGCC alternative would require one 267-MW unit. For the NGCC portion of the 

combination alternative, it is assumed that sites would be located at an existing power plant site 

which maximizes availability of infrastructure and reduces disruption to land and populations. 

Most of the wind farms would likely be located on open agricultural cropland, which would 

remain largely unaffected by the wind turbines. The solar portion requires 1,193 MW and it is 

assumed that some of the capacity would be from small units and may be installed on building 

roofs or on existing residential, commercial, or industrial sites.
Environmental Consequences and Mitigating Actions

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4.3.6.1 Air Quality

Construction

Air emissions associated with the construction of the NGCC portion of the combination 

alternative are similar to the NGCC alternative but reduced considerably because its electricity 

output is approximately 10 percent that of the NGCC alternative. As discussed in 

Section 4.3.5.1, construction activities for an NGCC alternative would cause some temporary 

impacts to air quality from dust generation during operation of the earthmoving and material 

handling equipment and exhaust emissions from worker vehicles and construction equipment. 

These emissions include criteria pollutants, VOCs, GHGs, and small amounts of HAPs. 

However, these impacts would be localized, intermittent, and short-lived, and adherence to 

well-developed and well-understood construction BMPs would mitigate such impacts. The NRC 

staff concludes that construction-related impacts on air quality from an NGCC portion of the 

combination alternative would be of relatively short duration and would be SMALL.

Only a small percentage of site land (5 percent or less) would be disturbed by construction 

activities because wind turbines need to be separated from one another in order to maximize 

energy production and avoid wake turbulences created by upwind turbines. Construction of the 

wind portion of the combination alternative would involve a number of activities, including road 

and staging/laydown area construction, land clearing, topsoil stripping, earthmoving operations, 

grading, ground excavation, drilling, foundation treatment, wind turbine erection, ancillary 

building/structure construction, and electrical and mechanical installation. For most wind energy 

facilities, the site preparation phase would last for only a few months, followed by a year-long 

construction phase (depending on size of the wind energy facility) (Tegen 2006). Air emissions 

associated with construction activities result from fugitive dust from soil disturbances and engine 

exhaust from heavy equipment and vehicular traffic. These emissions include criteria pollutants, 

VOCs, GHGs, and HAPs. Dust suppression methods and other mitigation measures could 

reduce impacts from fugitive dust. The wind portion of the combination alternative would have 

no power block, for which intensive construction activities would occur. Accordingly, the number 

of heavy equipment and workforce, level of activities, and construction duration would be 

substantially lower than other alternatives. Therefore, the NRC staff concludes that the overall 

air quality impacts associated with construction of the wind portion of the combination 

alternative would be SMALL.

Construction of the solar portion of the combination alternative would cause temporary impacts 

to air quality from fugitive dust from soil disturbances and engine exhaust from heavy equipment 

and from vehicular traffic. Air emissions associated with construction activities include criteria 

pollutants, VOCs, GHGs, and HAPs to a lesser amount. Dust suppression methods and other 

mitigation measures could reduce impacts from fugitive dust. The solar PV portion of 

combination alternative would have no power block, for which intensive construction activities 

would occur. Accordingly, the number of heavy equipment and workforce, level of activities, 

and construction duration would be substantially lower than those for other alternatives. 

Therefore, the NRC staff concludes that the overall air quality impacts associated with 

construction of the solar PV portion of the combination alternative would be SMALL.

Operation

Air emissions associated with the operation of the NGCC portion of the combination alternative 

are similar to the NGCC alternative in Section 4.3.5.1 but reduced proportionally because its 

electricity output is approximately 13 percent that of the NGCC alternative. Section 4.3.5 

discusses the various State and Federal regulations that would control the construction and 

operation of an NGCC plant. The same regulatory controls discussed in Section 4.3.5 would 

apply to air emissions from the NGCC under this alternative.
Environmental Consequences and Mitigating Actions

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Air emissions for the NGCC alternative were estimated based on data presented in Table 4.3-2 

in the GEIS and Energy Information Administration (EIA) emission factors (EIA 1999; 

NRC 2013f). The estimate is based on using advanced F class gas turbines at one or 

multiple sites within the ROI. The resulting NGCC emissions are estimated to be as follows:

 sulfur dioxide (SO2)— 50 tons (45 MT) per year,

 nitrogen oxides (NOx)— 80 tons (70 MT) per year,

 particulate matter (PM10)— 30 tons (25 MT) per year,

 carbon monoxide (CO)— 220 tons (200 MT) per year, and

 carbon dioxide equivalents (CO2e)— 1.0 million tons (0.9 million MT) 

per year.

Annual emissions of sulfur dioxide and nitrogen oxide would be lower than the major source 

threshold, while those of carbon monoxide would exceed major source threshold. The overall 

air quality impacts associated with operation of the NGCC portion of the combination alternative 

would be SMALL to MODERATE.

In general (taking into account full operation and maintenance activities), air emissions 

associated with the operation of solar energy facilities are negligible because no fossil fuels 

are burned to generate electricity. Emissions from the operation of wind energy facilities would 

include minor dust and engine exhaust emissions from vehicles and heavy equipment 

associated with site inspections, maintenance activities, and wind erosion from cleared land and 

access roads. Small amounts of emissions would be produced during the operation of diesel 

emergency generators but would be used on an infrequent basis. The types of emission 

sources and pollutants during operation would be similar to those during construction, but much 

fewer emissions would be released during operation. The NRC staff concludes that the overall 

air quality impacts associated with the operation of the wind portion of the combination 

alternative would be SMALL.

In general, air emissions associated with the operation of solar energy facilities are negligible 

because no fossil fuels are burned to generate electricity. Emissions from solar fields would 

include fugitive dust and engine exhaust emissions from vehicles and heavy equipment 

associated with site inspections, maintenance activities (mirror washing, replacement of broken 

mirrors), and wind erosion from cleared lands and access roads. The types of emission sources 

and pollutants during operation would be similar to those during construction, but much fewer 

emissions would be released during operation. These emissions should not cause 

exceedances of air quality standards or have any impacts on climate change. The NRC staff 

concludes that the overall air quality impacts associated with the operation of the solar PV 

portion of the combination alternative would be SMALL.

Conclusion

The overall air quality impacts associated with construction and operation of the combination 

alternative would be SMALL to MODERATE.

4.3.6.2 Noise

Construction

The construction-related noise sources for the NGCC portion of the combination alternative 

would be virtually the same as those for construction of the NGCC alternative. The construction 

period for the NGCC portion would be shorter, and the level of construction activities would be 
Environmental Consequences and Mitigating Actions

4-19

less extensive than the NGCC alternative. Consequently, the NRC staff concludes that 

construction-related noise associated with the NGCC portion of combination alternative would 

be SMALL.

Construction of the wind portion of the combination alternative would involve a number of 

activities, as described above. The wind portion of the combination alternative would have no 

power block, for which intensive construction activities would occur. Accordingly, the number of 

heavy equipment and workforce, level of activities, and construction duration would be 

substantially lower than other alternatives. Considering these factors, the NRC staff concludes 

that construction-related noise associated with the wind portion of combination alternative would 

be SMALL.

Construction of the solar PV portion of the combination alternative would involve a number of 

activities. The solar PV portion of the combination alternative would have no power block for 

which intensive construction activities would occur. Accordingly, the number of heavy 

equipment and workforce, level of activities, and construction duration would be substantially 

lower than other alternatives. Considering these factors, the NRC staff concludes that 

construction-related noise associated with the solar PV portion of combination alternative 

would be SMALL.

Operation

Besides noise from the power block area, cooling towers, and vehicular traffic, operation-related 

noise for the NGCC would include limited outdoor waste-handling activities. Pipelines delivering 

natural gas fuel could be audible off site near gas compressor stations, but such sound impacts 

would be similar to impacts already occurring in the vicinity of the existing pipeline to which the 

new NGCC site would connect. Most noise-producing equipment is located inside the power 

block buildings and no outside fuel-handling activities will occur. Minor offsite noise source 

could be pipeline compressor stations. The NRC staff concludes that operation-related noise 

from the NGCC portion of combination alternative would be SMALL.

Noise impacts from wind generation operations would include aerodynamic noise from the 

turbine rotors and mechanical noise from the turbine drivetrain components. Noise levels are 

dependent on the wind and atmospheric conditions, which vary with time, and on site-specific 

conditions: the number and size of wind turbines, their layout, distance to the nearby sensitive 

receptors, land cover, and topography. Wind turbine noise levels can reach 105 dBA; however, 

studies show that at approximately 1,000 ft (300 m) from a wind turbine, noise levels can reach 

43 dBA (GE 2010; Hessler 2011). Therefore, masking effects of background noise should be 

taken into consideration. Unless noise from wind turbines is masked by high background levels 

(e.g., near major highways or industrial complexes), it can be noticeable and annoying at farther 

distances. One study indicated that, for the same A-weighted sound level, proportions of 

respondents annoyed by wind turbine noise are higher than for other community noise, such as 

aircraft, road, or railway traffic, and that the proportion annoyed increases more rapidly (higher 

rate over time) (Pedersen and Persson Waye 2004). Therefore, the NRC staff concludes that 

operation-related noise from the wind portion of the combination alternative would be SMALL to 

MODERATE, depending on the layout and location of the wind facility and the distance to 

nearby sensitive receptors.

The solar PV potion of the combination alternative would have no power block and cooling 

towers, and thus there would be a minimal number of noise sources with low-level noises. 

Noise sources include small-scale cooling systems to dissipate heat from solar module 

assemblies, solar tracking devices, inverters, transformers, and vehicle traffic for maintenance 

and inspection. Because of minimal noise-generating activities, noise from a solar PV facility 

would be typically anticipated to be inaudible or barely perceptible at the facility boundaries. 
Environmental Consequences and Mitigating Actions

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Considering the minimum number of sources with low-noise levels and the area size of solar 

PV facility, the NRC staff concludes that operation-related noise from the solar PV portion of 

combination alternative would be SMALL.

Conclusion

The noise impacts associated with construction and operation of the combination alternative 

would be SMALL to MODERATE.

4.3.7 Purchased Power

4.3.7.1 Air Quality

Estimated air emissions from operations of the proposed action and five alternatives are 

presented in Table 4–3. In general, air emissions from the proposed action and the new nuclear 

alternative would be lowest, while the IGCC alternative would release the highest emissions, 

followed by the NGCC alternative. Air emissions from the combination alternative would fall 

between the nuclear alternative and the NGCC alternative. It is apparent that the IGCC and 

NGCC alternatives will produce significantly greater air pollutant emissions than those 

associated with the proposed action (license renewal of Braidwood), new nuclear alternative, or 

the combination alternative. Air emissions from purchased power will vary and depend on the 

type of technology and if the purchased power is from existing or newly constructed technology. 

If purchased power is solely from coal-fired plants, air emissions would be higher than 

purchased power from nuclear power (source of less emission). It is assumed that purchased 

power will come from a combination of technologies. In 2012, coal, natural gas, and nuclear 

power accounted for 37-, 30-, and 19-percent shares, respectively, of total U.S. electricity 

generation (EIA 2014). Using these percent shares for the purchased power alternative, the 

NRC staff estimates that air emissions will be greater than the NGCC alternative, but less than 

the IGCC alternative. However, actual emissions may be greater or less than what is estimated 

in Table 4–3 and will depend on the technology from which the purchased power comes.

Table 4–3. Estimated Direct Air Emissions From Operation of the Proposed Action and 

Alternatives (Ton/Year)

Proposed 

Action (a)

New 

Nuclear (b)

IGCC NGCC Combination (c) Purchased 

Power (d)

NOx 28 28 3,000 600 80 1,290

SO2 0.06 0.06 820 380 50 420

PM10 0.50 0.50 480 210 30 240

CO 7.2 7.2 2,045 1,690 220 1,270

CO2e 1,361 1,361 14.3×106 7.9×106 1.0×106 7.7×106

(a) Highest annual emissions from the Braidwood Station during the 2008–2012 period

(b) Assumed air emissions from the Braidwood Station

(c) Assumed air emissions only from the NGCC portion of the combination alternative

(d) Assumed air emissions were estimated by assuming that purchased power coal accounted for a 37% share, 

natural gas a 30% share, nuclear a 19% share, and renewable a 14% share of electricity generation.

Key: CO = carbon monoxide, CO2e = carbon dioxide equivalents, NOx = nitrogen oxides, SO2 = sulfur dioxide
Environmental Consequences and Mitigating Actions

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Conclusion

Purchased power would come from common types of existing technology (coal, natural gas, and 

nuclear) within the ROI, and it is not likely that new facilities would be constructed to replace 

Braidwood. Construction of new transmission lines would result in additional amounts of air 

emissions. Air emissions associated with the construction of transmission lines would be from 

operation of the earthmoving and material handling equipment and exhaust emissions from 

worker vehicles and construction equipment. These emissions include criteria pollutants, 

VOCs, GHGs, and HAPs. However, these impacts would be temporary and not likely to be 

high. For purchased power from existing plants, the impact on air quality is expected to be 

SMALL as there would be no change in existing plant operations.

If new facilities were to be constructed for purchased power, the impact on air quality would 

depend on the plant technology constructed, since air emissions can vary substantially, as can 

be observed from the alternative air quality discussions provided above. For instance, natural 

gas- and coal-fired plants emit higher amounts of nitrogen oxides, sulfur oxides, PM, and carbon 

dioxide than nuclear plants. Purchased power from new nuclear plants would not have 

noticeable impacts on air quality. New natural gas- and coal-fired plants would have noticeable 

impacts on air quality as a result of the higher amounts of air emissions. Therefore, impacts on 

air quality from purchased power of new plants would be SMALL to MODERATE.

4.3.7.2 Noise

Purchased power from existing electricity generating facilities would not have noticeable 

impacts on noise as there would be no change in existing plant operations. Purchased power 

from new generating facilities could have impacts on noise. Construction and operation of new 

facilities could result in additional noise sources including mechanical equipment associated 

with normal plant operations and vehicular traffic. Additionally, construction of new transmission 

lines could increase noise levels. Increase in noise levels from construction of new 

transmission lines and new facilities would be dependent on the distance of residents to the 

noise sources. Noise levels from operation will also be dependent on the type of technology 

(e.g., operation of nuclear or wind power). Therefore, impacts from purchased power on noise 

would be SMALL to MODERATE (transmission lines).

Conclusion

As discussed in the sections above, noise levels and impacts from operation of the NGCC 

and New Nuclear combination alternatives would not be greater than those associated with 

operation of the Braidwood site and are expected to be SMALL. Noise levels and impacts from 

operation of the IGCC, Combination, and purchased power are expected to be SMALL to 

MODERATE. Noise levels for these three alternatives are dependent on the distance of 

residents to the noise sources unique to the technology. For instance, the IGCC alternative 

will introduce noise associated with rail delivery predicted to be in the 80 to 96 dBA range. The 

wind power portion of the Combination alternative will introduce wind turbine noise levels that 

can reach 105 dBA.

4.4 Geologic Environment

This section describes the potential impacts of the proposed action (license renewal) and 

alternatives to the proposed action on geologic and soil resources.

For all alternatives to the proposed action (with the exception of the no-action alternative), 

impacts to geology and soil resources would occur during construction and no additional land 

would be disturbed during operations. During construction, sources of aggregate material, such 
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as crushed stone and sand and gravel, would be required to construct buildings, foundations, 

roads, and parking lots. The NRC staff assumes that these resources would likely be obtained 

from commercial suppliers using local or regional sources. Land clearing during construction 

and the installation of power plant structures and impervious surfaces would expose soils to 

erosion and alter surface drainage. Best management practices would be implemented in 

accordance with applicable permitting requirements so as to reduce soil erosion. These 

practices would include the use of sediment fencing, staked hay bales, check dams, sediment 

ponds, riprap aprons at construction and laydown yard entrances, mulching and geotextile 

matting of disturbed areas, and rapid reseeding of temporarily disturbed areas. Removed soils 

and any excavated materials would be stored on site for redistribution such as for backfill at the 

end of construction. Construction activities would be temporary and localized. Therefore, for all 

the alternatives to the proposed action, construction impacts would be SMALL.

4.4.1 Proposed Action

Section 3.4 describes the local and regional geologic environment of the Braidwood site. 

Section 3.4.1 discusses the current geologic environment of the Braidwood site and vicinity.

Table B-1 of 10 CFR Part 51, Subpart A, Appendix B, lists a summary of findings on NEPA

issues for license renewal of nuclear power plants. Table 4–4 identifies issues related to 

geology and soils that are applicable to the Braidwood Station during the renewal term. 

One Category 1 geology and soil issue is applicable to Braidwood. There are no Category 2 

issues for geology and soils.

Table 4–4. Geology and Soils Issues

Issue GEIS Section Category

Geology and Soils 4.4.1 1

Source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

The NRC staff did not identify any new and significant information associated with the 

Category 1 geology and soils issue identified in Table 4–4 during the review of the applicant’s 

ER, the site audit, the scoping process, or the evaluation of other available information. As a 

result, no information or impacts related to these issues were identified that would change the 

conclusions presented in the GEIS (NRC 2013f). For these geology and soil issues, the GEIS 

concludes that the impacts are SMALL. It is expected that there would be no incremental 

impacts (in comparison to environmental base line in Chapter 3) related to these Category 1 

issues during the renewal term beyond those discussed in the GEIS; therefore, the impacts 

associated with these issues by the proposed action would be SMALL.

4.4.2 No-Action Alternative

There would not be any impacts to the geology and soils at the Braidwood site with shutdown of 

the facility. With the shutdown of the facility no additional land would be disturbed. Therefore, 

impacts would be SMALL.
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4.4.3 New Nuclear Alternative

This alternative would be located at an existing or retired plant site. As such, it would be located

in an area where the soils have already been disturbed by previous activities at the site. As 

discussed earlier in this Section 4.4, the impacts on the geology and soil resources would occur 

during construction, and the impacts of this alternative on geology and soil resources would be 

SMALL.

4.4.4 Coal (Integrated Gasification Combined Cycle) Alternative

This alternative would be located at an existing or retired plant site. As such, it would be located 

in an area where the soils have already been disturbed by previous activities at the site. As 

discussed earlier in this Section 4.4, the impacts on the geology and soil resources would occur 

during construction, and the impacts of this alternative on geology and soil resources would be 

SMALL.

4.4.5 Natural Gas Combined Cycle Alternative

This alternative would be located at an existing or retired plant site. As such, it would be located 

in an area where the soils have already been disturbed by previous activities at the site. As 

discussed earlier in this Section 4.4, the impacts on the geology and soil resources would occur 

during construction, and the impacts of this alternative on geology and soil resources would be 

SMALL.

4.4.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

The natural gas part of this alternative would be located at an existing or retired plant site. As 

such, it would be located in an area where the soils have already been disturbed by previous 

activities at the site. The solar PV and the windfarm part of this alternative requires a large 

amount of land. However, much of the land would be undisturbed as only a small area would 

be disturbed by road and facility construction. In addition, some of the PV and windfarm 

facilities may be located at an existing or retired plant site, where the soils have already been 

disturbed by previous activities at the site. As discussed earlier in this Section 4.4, the impacts 

on the geology and soil resources would occur during construction and the impacts of this 

alternative on geology and soil resources would be SMALL.

4.4.7 Purchased Power

The impacts of this alternative are likely to be bounded by the impact descriptions of the other 

alternatives. Purchased power is likely to come from existing facilities, or if new facilities are 

constructed, it would likely be from one of the previously discussed alternatives. These 

alternatives have SMALL impacts. Therefore the impact of this alternative on geology and 

soil resources would be SMALL.

4.5 Water Resources

This section describes the potential impacts of the proposed action (license renewal) 

and alternatives to the proposed action on surface water and groundwater resources.

For all the alternatives (with the exception of the No-Action Alternative) discussed in this 

section, while they would be located at an existing or retired site (or both), construction activities 

will alter the surface water drainage features at the site, and stormwater runoff from construction 
Environmental Consequences and Mitigating Actions

4-24

areas and spills and leaks from construction equipment could potentially affect downstream 

surface water quality. Nevertheless, it is anticipated that appropriate soil erosion and sediment 

control measures, as described in Section 4.4 of this SEIS, would be observed. Application of 

BMPs in accordance with a State-issued National Pollutant Discharge Elimination System

(NPDES) general permit, including appropriate waste management, water discharge, 

stormwater pollution prevention plan, and spill prevention practices, would prevent or minimize 

and surface water or groundwater quality impacts during construction.

For the new nuclear power plants, IGCC, and NGCC alternatives, NRC assumes that any 

existing intake and discharge infrastructure at an alternative site location would be refurbished 

and used to maximize use of existing facilities. This would reduce construction related impacts 

on surface water quality. Any dredge-and-fill operations would be conducted under a permit 

from the U.S. Army Corps of Engineers and State-equivalent permits requiring the 

implementation of BMPs to minimize impacts. During construction, the dewatering of 

excavations is unlikely to consume enough water to affect offsite surface water or groundwater

bodies. Surface water and groundwater withdrawals would be subject to applicable State water 

appropriation and/or registration requirements. The NRC staff assumes construction water 

would be obtained from groundwater or purchased from a commercial water utility. Therefore, 

for all the alternatives to the proposed action, construction impacts on groundwater and surface 

water resources would be SMALL.

For the new nuclear power plants, IGCC, and NGCC alternatives, after the facility is constructed 

and operational, groundwater from onsite wells would be used as a source of potable water and 

for fire protection. Water for cooling would be obtained from surface water. Cooling water 

treatment additives used by these three alternatives would essentially be the same.

For all the alternatives, surface water and groundwater withdrawals would be subject to 

State-issued permits. Effluent discharges and storm water discharges would be subject to a 

State-issued NPDES permit. To prevent and respond to accidental non-nuclear releases to 

surface water, facility operations would be conducted in accordance with a spill prevention, 

control, and countermeasures plan; storm water pollution prevention plan; or equivalent plans 

and associated BMPs and procedures. Therefore, for all the alternatives to the proposed 

action, operational impacts on groundwater and surface water “quality” would be SMALL.

4.5.1 Proposed Action

As further discussed below, the impact by the proposed action on water resources are SMALL.

4.5.1.1 Surface Water Resources

The Category 1 (generic) and Category 2 surface water use and quality issues applicable 

to Braidwood Units 1 and 2, are discussed in the following sections and listed in Table 4–5. 

Surface water resources-related aspects and conditions relevant to the Braidwood site are 

described in Section 3.5.1.
Environmental Consequences and Mitigating Actions

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Table 4–5. Surface Water Resources Issues

Issue GEIS Section Category

Surface water use and quality (non-cooling system impacts) 4.5.1.1 1

Altered current patterns at intake and discharge structures 4.5.1.1 1

Scouring caused by discharged cooling water 4.5.1.1 1

Discharge of metals in cooling system effluent 4.5.1.1 1

Discharge of biocides, sanitary wastes, and minor chemical spills 4.5.1.1 1

Surface water use conflicts (plants with cooling ponds or cooling 

towers using makeup water from a river) 4.5.1.1 2 

Effects of dredging on surface water quality 4.5.1.1 1

Temperature effects on sediment transport capacity 4.5.1.1 1

Sources: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51 (78 FR 37282); NRC 2013f

Generic Surface Water Resources

The NRC staff did not identify any new and significant information with regard to the Category 1 

(generic) surface water issues based on review of the Braidwood ER (Exelon 2013), the public 

scoping process, or as a result of the environmental site audit. As a result, no information or 

impacts related to these issues were identified that would change the conclusions presented in 

the GEIS. Therefore, it is expected that there would be no incremental impacts related to these 

Category 1 issues during the renewal term beyond those discussed in the GEIS. For these 

surface water issues, the GEIS concludes that the impacts are SMALL.

Surface Water Use Conflicts

This section presents the NRC staff’s review of plant-specific (Category 2) surface water use 

conflict issue as listed in Table 4–3.

Plants With Cooling Ponds or Cooling Towers Using Makeup Water From a River

For nuclear power plants utilizing cooling towers or cooling ponds supplied with makeup water 

from a river, the potential impact on the flow of the river and its availability to meet the demands 

of other users is a Category 2 issue. This designation requires a plant-specific assessment, 

including the related potential impacts on terrestrial (riparian) ecological communities and with 

aquatic (in stream) communities. Sections 4.6.1 and 4.7.1 further discuss the impacts of the 

proposed action on terrestrial and aquatic resources, respectively.

In evaluating the potential impacts resulting from surface water use conflicts associated with 

license renewal, the NRC staff uses as its baseline the surface water resource conditions as 

described in Section 3.1.3 and 3.5.1 of this SEIS. These baseline conditions encompass the 

defined hydrologic (flow) regime of the surface water(s) potentially affected by continued 

operations as well as the magnitude of surface water withdrawals for cooling and other 

purposes (as compared to relevant appropriation and permitting standards).

The mean annual discharge for Kankakee River (see Section 3.5.1.1) measured at the 

U.S. Geological Survey (USGS) gage at Wilmington, for water years 1934 through 2012, is 

4,805 cubic feet per second (cfs) (136 cubic meters per second (m3

/s)) (USGS 2012). As 

described in Section 3.5.1.2, the average annual consumption for the Braidwood site from the 

Kankakee River is 41 cfs (1.14 m3

/s). This results in a rate of consumption of 0.9 percent of 

Kankakee River’s average flow. Compared to the lowest annual mean flow recorded for the 
Environmental Consequences and Mitigating Actions

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Kankakee River at the USGS gage at Wilmington, this consumption rate is 2.9 percent of the 

volume of water flowing in the river. However, the provisions of Braidwood’s intake construction 

permit (issued by the Illinois Department of Transportation (IDOT), Division of Water 

Resources—now the IDNR) limits the maximum makeup withdrawal rate from the river to 

160 cfs (71,808 gallons per minute (gpm) or 4.5 m3

/s) and requires Exelon to stop withdrawing 

water from the Kankakee River when the flow rate falls below 442 cfs (12.5 m3

/s) 

(Exelon 2014i). In accordance with these provisions, if Braidwood needs to cease withdrawing 

makeup water from the Kankakee River, cooling pond water levels will be drawn down 

temporarily.

Water use for irrigation, public water supply systems, and the power plant industry is withdrawn 

from the Kankakee River (Knapp 1992). In 2005, the public water systems withdrew 

approximately 13 million gallons per day (mgd) (24.2 cfs, 10,861 gpm, 0.69 m3

/s) from the 

Kankakee River (ISWS 2012). There are a total of 17 major effluent return flows to streams 

in the Illinois portion of the Kankakee watershed, most of which are from public wastewater

treatment facilities (Knapp 1992). While Illinois does not withdraw water from the Kankakee 

River for irrigation use, Indiana does withdraw from the Kankakee River for irrigation water use. 

Dresden Nuclear Power Station, Units 2 and 3, withdraw water from the Kankakee River, and 

net withdrawals vary between 46 cfs (1.3 m3

/s, 30 mgd) to 88 cfs (2.5 m3/s, 57 mgd) 

(NRC 2004).

As discussed above, major sources of water use from the Kankakee River include the public 

water supply systems and power plant industry. In adding the consumptive rates of these 

sources and comparing this rate (153 cfs) to the mean annual river flow of 4,805 cfs of the 

Kankakee River, surface flows in the Kankakee River appears well able to meet the current 

consumptive demand. For these reasons, the NRC staff concludes that the impact on surface 

water resources from continued withdrawals during the license renewal term would be SMALL.

4.5.1.2 Groundwater Resources

Table 4–6 identifies issues related to groundwater that are applicable to Braidwood Station 

during the renewal term. Section 3.5.2 describes groundwater resources at the Braidwood 

Station.

Table 4–6. Groundwater Issues

Issue GEIS Section Category

Groundwater Contamination and Use (Non-Cooling 

System Impacts) 4.5.1.2 1 

Groundwater Use Conflicts (Plants with Closed-Cycle 

Cooling Systems that Withdraw Makeup Water from a River) 4.5.1.2 2 

Groundwater Quality Degradation (Plants with Cooling Ponds 

at Inland Sites) 4.5.1.2 2 

Radionuclides Released to Groundwater 4.5.1.2 2

Source: Table B-1 in Appendix B, Subpart A to 10 CFR Part 51

The NRC staff did not identify any new and significant information associated with the 

Category 1 groundwater issues identified in Table 4–6 during the review of the applicant’s ER, 

the site audit, the scoping process, or the evaluation of other available information. As a result, 

no information or impacts related to these issues were identified that would change the 

conclusions presented in the GEIS (NRC 2013f). For these issues, the GEIS concludes that the 
Environmental Consequences and Mitigating Actions

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impacts are SMALL. Therefore, it is expected that there would be no incremental impacts 

related to these Category 1 issues during the renewal term beyond those discussed in the GEIS 

and therefore the impacts associated with these issues by the proposed action would be 

SMALL.

The three Category 2 issues (see also Table 4–6) related to groundwater during the renewal 

term are discussed in the following text.

Groundwater Use Conflicts (Plants With Closed-Cycle Cooling System That Withdraw Makeup 

Water From a River)

This issue looks at the potential impact of the consumption of river water on the availability of 

groundwater supplies. The Braidwood site uses a cooling pond and withdraws water from a 

small river. In turn, the cooling pond loses water to the atmosphere by evaporation. As a result, 

less water is returned to the Kankakee River than is withdrawn. This issue evaluates the impact 

of river water consumption and lowered river water levels on groundwater supplies.

The Kankakee River alluvium is hydrologically connected to the Upper Aquifer. As described in 

Section 4.5.1.1, there is a low impact by plant water consumption on river flows over the period 

of licensing. This means that river water levels are unlikely to be significantly impacted, which in 

turn means that local aquifers adjacent to the river are very unlikely to suffer dewatering. 

Therefore, the NRC staff concludes that impacts to groundwater use would be SMALL.

Groundwater Quality Degradation (Plants With Cooling Ponds at Inland Sites) 

This issues looks at the potential for closed cycle inland unlined cooling ponds to degrade the 

surrounding groundwater quality and reach off-site wells. The water in the cooling pond has 

high concentrations of total dissolved solids, alkalinity, hardness, sulfates, magnesium, calcium, 

and total phosphorus (Exelon 2014i; Teledyne 2013). The water quality in the cooling pond 

reflects the net result of Kankakee River water additions, water chemistry adjustments by the 

plant, high temperatures, losses to evaporation, and water discharges back to the Kankakee 

River. Radionuclides are not discharged to the cooling pond. Tritium concentrations in the 

cooling pond have not been detected above baseline values (Teledyne 2013).

As discussed in Section 3.5.2.1, the cooling pond was built with a slurry wall to isolate the pond 

from the Upper Aquifer. The slurry wall surrounding the cooling pond would prevent or greatly 

reduce any water movement between the Upper Aquifer and the cooling pond. Accordingly, the 

Upper Aquifer will not be either recharged or dewatered (i.e., no change) by water in the cooling 

pond.

The bottom of the cooling pond is filled with low-permeability shale, clay and siltstone mine 

spoils from former coal strip mining activities mine spoils (Teledyne 2013). As discussed in 

Section 3.5.2.1, coal mining activities stopped above the Spoon Formation. As a result the 

Maquoketa Shale was undisturbed by mining activities and remains a significant barrier 

(aquitard) to the vertical movement of groundwater from the cooling pond into the Deep Aquifer. 

Therefore, the impact of the cooling pond on groundwater quality would be SMALL.

Radionuclides Released to Groundwater

This issue looks at potential contamination of groundwater from the release of radioactive 

liquids from plant systems into the environment. Section 3.5.2.3 of this document contains 

a description of tritium contamination in groundwater. In evaluating the potential impacts on 

groundwater quality associated with license renewal, the NRC staff uses as its baseline the 

existing groundwater conditions as described in Section 3.5.2.3 of this SEIS. These baseline 

conditions encompass the existing quality of groundwater potentially affected by continued 

operations (as compared to relevant State or EPA primary drinking water standards) as well 
Environmental Consequences and Mitigating Actions

4-28

as the current and potential onsite and offsite uses and users of groundwater for drinking and 

other purposes. The baseline also considers other downgradient or in-aquifer uses and users 

of groundwater.

Historical releases of liquids containing tritium have not impacted groundwater quality beyond 

the site boundary. Both off-site and on-site groundwater contamination that resulted from the 

failure of three vacuum breaker valves on the discharge pipeline has been successfully 

remediated. Tritium concentrations in groundwater near the plant buildings remain below 

EPA’s safe level for public drinking water.

Present and future Braidwood operations are not expected to impact the quality of groundwater

in any aquifers that are a current or potential future source of water for offsite users. Therefore, 

the NRC staff concludes that the impacts on groundwater use and quality during the Braidwood 

license renewal term would be SMALL.

4.5.2 No-Action Alternative

4.5.2.1 Surface Water Resources

With the cessation of operations, the temperature of the cooling pond would drop. Lower 

temperatures would likely result in reduced evaporation rates, some changes in general pond 

chemistry, and during winter, partial or entire pond surface freezing.

The cooling pond was built with a slurry wall to hydraulically isolate the pond from the Upper 

Aquifer (see Section 3.5.2.1). After it was built, the cooling pond was filled with water from the 

Kankakee River. The slurry wall prevents or limits the inflow of groundwater as a source of 

recharge. As a result, water levels in the cooling pond would largely be driven by whichever 

is larger: water losses by evaporation or water gains from direct precipitation into the pond. 

Exelon owns the cooling pond and it is not known at this time what would become of the cooling 

pond after the site is decommissioned.

During operations, water losses from the pond have been made up with the addition of water 

obtained from the Kankakee River. The rate of consumptive use of Kankakee River water 

would greatly decrease and eventually cease. Wastewater discharges to the Kankakee River 

would be reduced considerably. Shutdown would reduce the impacts on Kankakee water use 

and quality. Therefore, the impact of this alternative on surface water resources would be 

SMALL.

4.5.2.2 Groundwater Resources

With the cessation of operations, the consumption of groundwater would be much less and 

there should be little or no impacts on groundwater quality. The slurry wall (see Section 3.5.2.1) 

surrounding the cooling pond would prevent or greatly reduce any water movement between the 

Upper Aquifer and the cooling pond. Accordingly, the Upper Aquifer will not be either recharged 

or dewatered (i.e., no change) by water in the cooling pond. Therefore, the impact of this 

alternative on groundwater resources would be SMALL.

4.5.3 New Nuclear Alternative

4.5.3.1 Surface Water Resources

As discussed earlier in this Section 4.5, construction impacts for all alternatives to the proposed 

action on surface water resources would be SMALL. The operational impacts for all alternatives 

to the proposed action on surface water quality would be SMALL.
Environmental Consequences and Mitigating Actions

4-29

The operation of the two new nuclear units would consume 40 mgd (151,416 cubic meters per 

day (m3

/d)) of surface water. As discussed in Sections 3.1.3 and 3.5.1.2, this alternative 

consumes 16 percent more surface water than the proposed action, which consumes 

approximately 34.2 mgd (129,461 m3

/d). Therefore, while the impacts of this alternative on 

surface water quality would be SMALL the operational impact on surface water availability 

would be SMALL to MODERATE.

4.5.3.2 Groundwater Resources

As discussed earlier in this Section 4.5, construction impacts for all alternatives to the proposed 

action on groundwater resources would be SMALL. Operational impacts for all alternatives to 

the proposed action on groundwater quality would be SMALL. During operations, the 

consumptive use of groundwater would be similar to the proposed action. Therefore, the 

impacts of this alternative on groundwater resources would be SMALL.

4.5.4 Coal (Integrated Gasification Combined Cycle) Alternative

4.5.4.1 Surface Water Resources

As discussed earlier in this Section 4.5, construction impacts for all alternatives to the proposed 

action on surface water resources would be SMALL. The operational impacts for all alternatives 

to the proposed action on surface water quality would be SMALL.

When operable, this alternative would consume 20 mgd (75,708 m3

/d) of surface water. This 

alternative would consume 41 percent less surface water than the proposed action, which 

consumes 34.2 mgd (129.461 m3

/d) (Sections 3.1.3 and 3.5.1.2) and the impacts on surface 

water availability would be SMALL. Therefore, the impact of this alternative on surface water 

resources would be SMALL.

4.5.4.2 Groundwater Resources

As discussed in Section 4.5, construction impacts for all alternatives to the proposed action on 

groundwater resources would be SMALL. Also as discussed in Section 4.5 operational impacts 

for all alternatives to the proposed action on groundwater quality would be SMALL. During 

operations, the consumptive use of groundwater would be similar to the proposed action and 

the impacts on groundwater availability would be SMALL. Therefore, the impacts of this 

alternative on groundwater resources would be SMALL.

4.5.5 Natural Gas Combined Cycle Alternative

4.5.5.1 Surface Water Resources

As discussed in Section 4.5, construction impacts for all alternatives to the proposed action on 

surface water resources would be SMALL. Also as discussed in Section 4.5, the operational 

impacts for all alternatives to the proposed action on surface water quality would be SMALL.

During operations, this alternative would consume 13 mgd (49,210 m3

/d) of surface water. This 

alternative would consume 61 percent less surface water than the proposed action, which 

consumes 34.2 mgd (129.461 m3

/d) (Sections 3.1.3 and 3.5.1.2) and the impacts on surface 

water availability would be SMALL. Therefore, the impact of this alternative on surface water 

resources would be SMALL.

4.5.5.2 Groundwater Resources

As discussed in Section 4.5, construction impacts for all alternatives to the proposed action on 

groundwater resources would be SMALL. Also as discussed in Section 4.5, operational impacts 

for all alternatives to the proposed action on groundwater quality would be SMALL. During 
Environmental Consequences and Mitigating Actions

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operations, the consumptive use of groundwater would be similar to the proposed action 

and the impacts on groundwater availability would be SMALL. Therefore, the impacts of 

this alternative on groundwater resources would be SMALL.

4.5.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

4.5.6.1 Surface Water Resources

As discussed in Section 4.5, construction impacts for all alternatives to the proposed action on 

surface water resources would be SMALL. Also as discussed in Section 4.5, the operational 

impacts for all alternatives to the proposed action on surface water quality would be SMALL.

It is estimated that when operable the natural gas alternative would consume 2 mgd 

(7,571 m3

/d) of surface water. This alternative would consume 94 percent less surface water 

than the proposed action, which consumes 34.2 mgd (129.461 m3

/d) and the impacts on surface 

water availability would be SMALL. Therefore, the impact of this alternative on surface water 

resources would be SMALL.

4.5.6.2 Groundwater Resources

As discussed in Section 4.5, construction impacts for all alternatives to the proposed action on 

groundwater resources would be SMALL. Also as discussed in Section 4.5, operational impacts 

for all alternatives to the proposed action on groundwater quality would be SMALL. During 

operations the consumptive use of groundwater would be much smaller than the proposed 

action and the impacts on groundwater availability would be SMALL. Therefore, the impacts 

of this alternative on groundwater resources would be SMALL.

4.5.7 Purchased Power

4.5.7.1 Surface Water Resources

The impacts of this alternative on surface water resources are likely to be bounded by the 

impact descriptions for the other alternatives. Purchased power is likely to come from existing 

facilities or if new facilities are constructed it would likely be from one of the previously 

discussed alternatives. These alternatives have SMALL impacts. Therefore, the impact of this 

alternative on surface water resources would be SMALL.

4.5.7.2 Groundwater Resources

The impacts of this alternative on groundwater resources are likely to be bounded by the impact 

descriptions for the other alternatives. Purchased power is likely to come from existing facilities 

or if new facilities are constructed it would likely be from one of the previously discussed 

alternatives. These alternatives have SMALL impacts. Therefore, the impact of this alternative 

on surface water resources would be SMALL.

4.6 Terrestrial Resources

This section describes the potential impacts of the proposed action (license renewal) and 

alternatives to the proposed action on terrestrial resources.

4.6.1 Proposed Action

Section 3.6 of this SEIS describes terrestrial resources on and in the vicinity of the Braidwood 

site. The generic (Category 1) and site-specific (Category 2) issues that apply to terrestrial 
Environmental Consequences and Mitigating Actions

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resources during the proposed license renewal period appear in Table 4–7. The GEIS

(NRC 2013f) discusses these issues in Section 4.6.1.1.

Table 4–7. Terrestrial Resource Issues

Issue GEIS Section Category

Effects on terrestrial resources (non-cooling system impacts) 4.6.1.1 2

Exposure of terrestrial organisms to radionuclides 4.6.1.1 1

Cooling system impacts on terrestrial resources (plants with 

once-through cooling systems or cooling ponds) 4.6.1.1 1

Cooling tower impacts on vegetation (plants with cooling towers) 4.6.1.1 (a)N/A

Bird collisions with plant structures and transmission lines (b) 4.6.1.1 1

Water use conflicts with terrestrial resources (plants with cooling 

ponds or cooling towers using makeup water from a river) 4.6.1.1 2 

Transmission line right-of-way (ROW) management impacts 

on terrestrial resources (b) 4.6.1.1 1 

Electromagnetic fields on flora and fauna (plants, agricultural crops, 

honeybees, wildlife, livestock) (b) 4.6.1.1 1 

(a) This issue does not apply because the Braidwood cooling system does not include cooling towers.

(b) This issue applies only to the in-scope portion of electric power transmission lines, which are defined as 

transmission lines that connect the nuclear power plant to the substation where electricity is fed into the regional 

power distribution system and transmission lines that supply power to the nuclear plant from the grid.

Source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

4.6.1.1 GEIS Category 1 Issues

The NRC staff did not identify any new and significant information related to the generic 

(Category 1) issues listed above during the review of the applicant’s ER (Exelon 2013c), the site 

audit, or the scoping process. Therefore, the NRC staff expects no impacts associated with 

these issues beyond those discussed in the GEIS. The GEIS concludes that the impact level 

for each of these issues is SMALL.

4.6.1.2 Impacts on Terrestrial Resources (Non-Cooling System Impacts)

In the GEIS (NRC 2013f), the NRC staff determined that noncooling system effects on terrestrial 

resources is a Category 2 issue (see Table 4–7) that requires site-specific evaluation during 

each license renewal review. According to the GEIS, non-cooling system impacts can include 

those impacts that result from landscape maintenance activities, stormwater management, 

elevated noise levels, and other ongoing operations and maintenance activities that would occur 

during the renewal period and that could affect terrestrial resources on and near the Braidwood 

site.

Section 3.6 indicates that approximately 1,653 ac (669 ha) of the Braidwood site (37 percent) 

remains as natural areas that are either leased for agricultural use, leased to the IDNR for 

recreational use, or are unmanaged (Exelon 2014d). The majority of site landscape 

maintenance is performed within the protected area and not within natural areas on the site 

(Exelon 2014f). Typically, only removal of trees and shrubs that pose a safety or security threat 

are removed from natural areas. Leased lands are maintained by the leasee and in accordance 
Environmental Consequences and Mitigating Actions

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with the standing lease. As described in Section 3.6, Exelon and the IDNR manage some of 

the natural areas on the site for recreational purposes and restoration of native shoreline plants.

Stormwater drainages direct Braidwood site runoff to three NPDES-permitted stormwater 

outfalls, all of which flow through an unnamed drainage ditch along the western boundary of the 

Braidwood property, past the Village of Godley, into the Mazon River (Exelon 2013c). Special 

Condition 9 of the NPDES permit requires Exelon to develop and implement a Stormwater 

Pollution Prevention Plan (Exelon 2013c). This plan identifies sources of pollution that could 

affect the quality of stormwater and describes practices that Exelon uses to reduce such 

pollutants. Areas with spill potential, such as areas around tanks that contain oil, are further 

monitored under the Braidwood Station Spill Prevention Control and Countermeasure Plan 

(Exelon 2013c). Collectively, these measures ensure that the effects to terrestrial resources 

from pollutants carried by stormwater would be small during the proposed license renewal term.

The GEIS (NRC 2013f) indicates that elevated noise levels could be a non-cooling system

impact to terrestrial resources. However, the GEIS also concludes that generic noise impacts 

would be small because noise levels would remain well below regulatory guidelines for offsite 

receptors during continued operations and refurbishment associated with license renewal. The 

NRC staff did not identify any information during its review that would indicate that noise 

impacts to terrestrial resources at Braidwood would be unique or require separate analysis.

Other operations and maintenance activities that could occur in the future include the 

replacement of the Unit 2 steam generators. While Exelon has previously replaced the Unit 1 

steam generators, Exelon has not replaced the Unit 2 steam generators. Exelon has no plans 

to replace the Unit 2 steam generators at this time, but Exelon may choose to replace them prior 

to the end of the 40-year initial license term. Because steam generator replacement is not 

necessary for safe operation during license renewal, the NRC does not consider it part of the 

proposed action. As such, the impacts of Unit 2 steam generator replacement on terrestrial 

resources are discussed in Section 4.15.4 (cumulative impacts) rather than in this section. 

Exelon (2014g) is planning no other land-disturbing activities or construction unrelated to 

possible Unit 2 steam generator replacement. No disturbances to natural habitats would occur 

during license renewal, and Exelon does not expect any changes in operations or changes to 

existing land uses during the proposed license renewal period. As such, no measurable 

impacts to the terrestrial environment are expected during the license renewal period.

When new activities that could impact the environment occur at Braidwood, Exelon follows 

several procedures to ensure that potential environmental effects are considered and 

appropriately addressed. Exelon maintains a procedure (No. EN-AA-103) that requires Exelon 

staff to screen proposed activities, such as maintenance activities, operational changes, 

procedure changes, and other facility activities, to determine if the activity warrants further 

evaluation for environmental impact or risk (Exelon 2014e). If the activity warrants further 

evaluation, Exelon Procedure No. EN-AA-103-0001 provides guidance to Exelon staff on 

performing such an evaluation and determining the environmental and regulatory impacts of 

the activity (Exelon 2014e). This procedure also requires that implementation of the activity be 

halted until any environmental impacts are addressed.

Based on the NRC staff’s independent review, the staff concludes that the landscape 

maintenance activities, stormwater management, elevated noise levels, and other ongoing 

operations and maintenance activities that Entergy might undertake during the renewal term 

would primarily be confined to disturbed areas of the Braidwood site. These activities would not 

have noticeable effects on terrestrial resources, nor would they destabilize any important 

attribute of the terrestrial resources on or in the vicinity of the Braidwood site. Therefore, the 
Environmental Consequences and Mitigating Actions

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staff expects non-cooling system impacts on terrestrial resources during the license renewal

term to be SMALL.

4.6.1.3 Water Use Conflicts With Terrestrial Resources

In the GEIS (NRC 2013f), the NRC staff determined that effects of water use conflicts on 

terrestrial resources is a Category 2 issue (see Table 4–7) that requires site-specific evaluation 

during each license renewal review. Water use conflicts occur when the amount of water 

needed to support terrestrial riparian communities is diminished as a result of demand for 

agricultural, municipal, or industrial use; decreased water availability due to droughts; or a 

combination of these factors.

As indicated in Section 4.5.1.1, the mean annual discharge for the Kankakee River measured 

at the USGS gaging station no. 05527500 at Wilmington for water years 1934 through 2012 is 

4,805 cfs (136 m3/s) (USGS 2012). As described in Section 3.5.1.2, the average annual 

consumption for the Braidwood site from the Kankakee River is 41 cfs (1.14 m3/s). Thus, 

Braidwood typically consumes 0.9 percent of Kankakee River’s average flow, and the plant 

could consume up to 2.9 percent of the river water volume when the lowest annual mean flow 

recorded for the Kankakee River at the Wilmington gaging station is taken into account. In 

times where the river flow is low, Exelon has an agreement with the IDNR to limit Kankakee 

River water consumption such that withdrawal of makeup water does not cause the Kankakee 

River flow to drop below 12,517 L/sec (442 cfs) (Exelon 2013c). Exelon maintains procedures 

to comply with these withdrawal restrictions, which would continue during the proposed license 

renewal term (Exelon 2013c).

The amount of Kankakee River water Braidwood consumes is minor in comparison to the flow 

of water past the plant, and regulatory mechanisms are in place to ensure that Braidwood does 

not consume an amount that would be harmful to riparian communities during low river flow 

conditions. The terrestrial resources near the plant (described in Section 3.6) do not appear to 

be affected by the consumption of water from the river. The NRC staff concludes that water use 

conflicts would not occur from the proposed license renewal or would be so minor that the 

effects on terrestrial resources would be undetectable. Thus, the NRC staff concludes that the 

impacts of water use conflicts on terrestrial resources during the proposed license renewal term 

would be SMALL.

4.6.2 No-Action Alternative

If Braidwood were to shut down, the impacts to terrestrial ecology would remain similar to those 

during operations until the plant is fully decommissioned. Temporary buildings and staging or 

laydown areas may be required during large component and structure dismantling. Braidwood 

is likely to have sufficient space within previously disturbed areas for these needs, and 

therefore, no additional land disturbances would occur on previously undisturbed land. Adjacent 

lands may experience temporary increases in erosional runoff, dust, or noise, but these impacts 

could be minimized with the implementation of standard BMPs (NRC 2002). In NUREG–0586, 

Generic Environmental Impact Statement on Decommissioning of Nuclear Facilities, 

Supplement 1 (NRC 2002), the NRC concludes generically that impacts to terrestrial ecology 

during decommissioning activities would be SMALL. In the case of Braidwood, the continuation 

of the lease agreement between Exelon and the IDNR for the Mazonia-Braidwood State Fish 

and Wildlife Area could be affected by decommissioning. Loss of these lands as a 

State-managed area could result in impacts to terrestrial resources depending upon any future 

land use of the site. Reclamation of the site following decommissioning could create terrestrial 

habitat in areas currently used as industrial areas. The GEIS (NRC 2013f) notes that terrestrial 

resource impacts could occur in other areas beyond the immediate nuclear plant site as a result 
Environmental Consequences and Mitigating Actions

4-34

of the no-action alternative if new power plants are needed to replace lost capacity. The NRC 

staff concludes that the no-action alternative is unlikely to noticeably alter or have more than 

minor effects on terrestrial resources. Thus, the NRC staff concludes that the impacts of the 

no-action alternative on terrestrial resources during the proposed license renewal term would 

be SMALL.

4.6.3 New Nuclear Alternative

The new nuclear alternative assumes that the new facility would be built at an existing nuclear 

or retired coal plant site within the ROI but outside of Illinois. Construction of the new nuclear 

plant would require an estimated 324 ac (131 ha) for permanent buildings and facilities and an 

additional 232 ac (94 ha) for temporary facilities and laydown areas. The NRC staff assumes 

that this alternative would use existing onsite structures and previously disturbed areas to the 

extent practicable to minimize new development in undisturbed areas. However, given the land 

requirements, it is expected that some undisturbed areas would be affected, which would 

directly impact terrestrial resources. During construction, terrestrial species could experience 

habitat loss or fragmentation, loss of food resources, and altered behavior due to noise and 

other construction-related disturbances. Erosion and sedimentation from clearing, leveling, and 

excavating land could affect adjacent riparian and wetland habitats, if present. Implementation 

of appropriate BMPs would minimize these effects. This alternative could also require 

construction of new transmission lines or upgrades to existing lines. Because the new nuclear 

facility would be located on an existing energy-producing site, transmission lines could likely be 

co-located within existing transmission line corridors to minimize land disturbance. Although 

construction activities could noticeably alter terrestrial resources through habitat loss or 

fragmentation, construction is unlikely to destabilize any important attributes of the terrestrial 

environment. The exact magnitude of impacts would vary based on the chosen location of the 

facility and the amount and types of undisturbed habitat that would be affected by construction 

of the alternative, and thus, impacts of construction could range from SMALL to MODERATE.

During operation, impacts would be similar in type and magnitude to those assessed in 

Section 4.6.1 for continued operation of Braidwood under the proposed renewal term and 

would, therefore, be SMALL.

The NRC concludes that the impacts of construction and operation of the new 

nuclear alternative on terrestrial resources would be SMALL to MODERATE.

4.6.4 Coal (Integrated Gasification Combined Cycle) Alternative

The IGCC alternative assumes that the new facility would be built at an existing 

energy-producing site or a retired coal plant site in Illinois or another state within the ROI. The 

facility would require 2,000 ac (809 ha) of land to construct the facility. The NRC staff assumes 

that this alternative would use existing onsite structures and previously disturbed areas to the 

extent practicable to minimize new development in undisturbed areas. However, because the 

footprint of the facility would be large, it is likely that construction would require clearing of 

previously undisturbed terrestrial habitats. This would result in habitat loss and fragmentation 

and loss of food resources. Terrestrial species may also alter their behaviors due to noise and 

other construction-related disturbances. Erosion and sedimentation from clearing, leveling, and 

excavating land could affect adjacent riparian and wetland habitats, if present. Implementation 

of appropriate BMPs would minimize these effects. This alternative could also require 

construction of new transmission lines or upgrades to existing lines. Because the IGCC facility 

would be located on an existing energy-producing site, any new transmission lines could likely 

be co-located within existing transmission line corridors to minimize land disturbance. 
Environmental Consequences and Mitigating Actions

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Depending on the site and terrestrial habitats present, construction activities could noticeably 

alter or destabilize attributes of the terrestrial environment due to the large land requirements of 

the facility. The exact magnitude of impacts would vary based on the chosen location of the 

facility and the amount and types of undisturbed habitat that would be affected by construction 

of the alternative. The NRC staff expects that impacts of construction would be MODERATE.

The GEIS (NRC 2013f) concludes that impacts to terrestrial resources from operation of fossil 

energy alternatives would essentially be similar to those from continued operations of a nuclear 

facility. Unique impacts would include periodic maintenance dredging if coal is delivered by 

barge, which could create noise, dust, and sedimentation. Dredging and delivery of coal to the 

site could introduce minerals and trace elements to water resources on which terrestrial biota

rely. Such minerals could also bioaccumulate in nearby riparian or wetland habitats. Air 

emissions during operation would include sulfur oxides and nitrogen oxides, which can combine 

with water vapor and create sulfuric and nitric acids. These acids would then be released back 

into the environment through precipitation, which could affect the acidity levels of water 

resources and have detrimental effects to plant foliage. Acid precipitation has the potential to 

destabilize the terrestrial environment by creating conditions that are too acidic for certain plants 

or animals. The IGCC facility would also emit various GHGs during operation, which is an effect 

that can have far-reaching consequences because GHGs contribute to climate change. The 

effects of climate change on terrestrial resources are discussed in Section 4.13.3.2. The 

various air emissions during operation of the IGCC facility could create noticeable impacts that 

could destabilize certain attributes of the terrestrial environment, and therefore, the operational 

impacts would be MODERATE.

The NRC concludes that the impacts of construction and operation of the IGCC alternative on 

terrestrial resources would be MODERATE.

4.6.5 Natural Gas Combined Cycle Alternative

The NGCC alternative assumes that the facility would be built at an existing energy-producing 

site or a retired coal plant site in Illinois or another state within the ROI. The facility would 

require 94 ac (38 ha) of land for the plant and associated pipelines. Because the footprint of the 

facility would be relatively small, the entire construction footprint could likely be sited in already 

developed areas of the site, which would minimize impacts to terrestrial habitats and species. 

However, the level of direct impact would vary based on the specific location of new buildings 

and infrastructure on the site. During construction, terrestrial species could experience habitat 

loss or fragmentation, loss of food resources, and altered behavior due to noise and other 

construction-related disturbances. Erosion and sedimentation from clearing, leveling, and 

excavating land could affect adjacent riparian and wetland habitats, if present. Implementation 

of appropriate BMPs would minimize these effects. This alternative could also require 

construction of new transmission lines or upgrades to existing lines. Because the NGCC facility 

would be located on an existing site, any new transmission lines could likely be co-located 

within existing transmission line corridors to minimize land disturbance. Similarly, any new 

pipelines could be co-located within existing pipeline corridors. Although construction activities 

could noticeably alter terrestrial resources, primarily through habitat loss or fragmentation, 

construction is unlikely to destabilize any important attributes of the terrestrial environment. 

The exact magnitude of impacts would vary based on the chosen location of the facility and 

the amount and types of undisturbed habitat that would be disturbed for construction of the 

alternative, and thus, impacts of construction could range from SMALL to MODERATE.

The GEIS (NRC 2013f) concludes that impacts to terrestrial resources from operation of fossil 

energy alternatives would essentially be similar to those from continued operations of a nuclear 

facility. Unique impacts would include air emissions of GHGs such as nitrogen oxides, carbon
Environmental Consequences and Mitigating Actions

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dioxide, and methane, all of which can have far-reaching consequences because they 

contribute to climate change. The effects of climate change on terrestrial resources are 

discussed in Section 4.13.3.2. Although the impacts of operating the NGCC alternative may be 

noticeable, they are unlikely to destabilize any important attribute of the terrestrial environment, 

and would, therefore, be SMALL.

The NRC concludes that the impacts of construction and operation of the NGCC alternative on 

terrestrial resources would be SMALL to MODERATE.

4.6.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

The NGCC component of this alternative would require the same amount of land as the NGCC 

alternative (94 ac [38 ha]), but the NGCC component would likely make better use of existing 

infrastructure because it would be sited at an existing power plant in Illinois or another state 

within the ROI and could use buildings and structures that are already in place and operational 

for the existing facility. The types of impacts on the terrestrial environment would be similar to 

those discussed in Section 4.6.5, but the NRC staff expects the magnitude of impacts to be less 

because of the use of existing infrastructure. Thus, the construction and operation of the NGCC 

component of the combination alternative would be SMALL.

The wind component of the combination alternative would require 3,376 ac (1,366 ha) to 

10,127 ac (4,098 ha) at sites across the ROI. However, the majority of this land would only 

be temporarily disturbed during construction. Permanently disturbed land would hold the wind 

turbines, access roads, and transmission lines. Land used for equipment laydown and turbine 

component assembly and erection could be returned to its original state. Use of BMPs would 

ensure that disturbed lands were appropriately restored to reduce the long-term impacts to the 

terrestrial environment. Operation of wind turbines could uniquely affect terrestrial species 

through mechanical noise, collision with turbines and meteorological towers, and interference 

with migratory behavior. Bat and bird mortality from turbine collisions is an ongoing concern for 

operating wind farms; however, recent developments in turbine design have reduced the 

potential for bird and bat strikes. The NRC staff expects that this component has the potential 

to noticeably alter terrestrial resources, primarily through the loss of habitat and bird and bat 

mortalities associated with wind turbine operation. However, it is unlikely that the wind 

component would destabilize any important attribute of the terrestrial environment, and 

thus, impacts would be MODERATE.

The solar component would require 6,749 ac (2,731 ha) of land across the ROI. The majority 

of solar installations could be installed on building roofs at existing residential, commercial, or 

industrial sites or at larger stand-alone solar facilities, and thus, it is possible that little terrestrial 

habitat would be disturbed during construction. However, the exact magnitude of impacts on 

terrestrial resources would depend on the amount of terrestrial habitat that is lost or fragmented 

during construction of solar installations. Operation would have no measurable effects on the 

terrestrial environment. Overall impacts from construction and operation of this component of 

the alternative would range from SMALL to MODERATE depending on the locations of solar 

installations and the amount of terrestrial habitat affected.

The NRC staff concludes that the impacts of the combination alternative on terrestrial resources 

would be SMALL to MODERATE.

4.6.7 Purchased Power

The purchased power alternative would have wide-ranging impacts that are hard to specifically 

assess because this alternative could include a mixture of coal, natural gas, nuclear, and wind 
Environmental Consequences and Mitigating Actions

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across many different sites in the ROI. This alternative would likely have little to no construction 

impacts because it would include power from already-existing power generating facilities. The 

construction of additional transmission lines would require implementation of BMPs to minimize 

erosion and sedimentation that could affect riparian areas and wetlands. The types of 

operational impacts would be similar to the effects discussed in the preceding alternative 

sections. This alternative would be more likely to intensify already existing effects at power 

generating facilities than create wholly new effects on terrestrial species and habitats. Existing 

facilities would likely have BMPs and other procedures in place to ensure that effects to the 

environment during operations are minimized. The NRC staff concludes that the impacts on 

terrestrial resources from the purchased power alternative would be SMALL.

4.7 Aquatic Resources

This section describes the potential impacts of the proposed action (license renewal) and 

alternatives to the proposed action on aquatic resources.

Section 3.1.3 of this SEIS describes the Braidwood cooling and auxiliary water systems, and 

Section 3.7 describes the aquatic resources of interest. The generic (Category 1) and 

site-specific (Category 2) issues that apply to aquatic resources at Braidwood during the 

proposed license renewal period appear in Table 4-8. The GEIS (NRC 2013f) discusses 

these issues in Section 4.6.1.2.

Table 4–8. Aquatic Resource Issues

Issue GEIS Section Category

All plants

Entrainment of phytoplankton and zooplankton 4.6.1.2 1

Infrequently reported thermal impacts 4.6.1.2 1

Effects of cooling water discharge on dissolved oxygen, gas 

supersaturation, and eutrophication 4.6.1.2 1 

Effects of non-radiological contaminants on aquatic organisms 4.6.1.2 1

Exposure of aquatic organisms to radionuclides 4.6.1.2 1

Effects of dredging on aquatic organisms 4.6.1.2 1

Effects on aquatic resources (non-cooling system impacts) 4.6.1.2 1

Impacts of transmission line right-of-way (ROW) management 

on aquatic resources (a) 4.6.1.2 1 

Losses from predation, parasitism, and disease among organisms 

exposed to sublethal stresses 4.6.1.2 1 

Plants with once-through cooling systems or cooling ponds

Impingement and entrainment of aquatic organisms 4.6.1.2 2

Thermal impacts on aquatic organisms 4.6.1.2 2

Plants with cooling ponds or cooling towers using makeup water 

from a river

Water use conflicts with aquatic resources 4.6.1.2 2

(a) This issue applies only to the in-scope portion of electric power transmission lines, which are defined as 

transmission lines that connect the nuclear power plant to the substation where electricity is fed into the regional 

power distribution system and transmission lines that supply power to the nuclear plant from the grid.

Source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51
Environmental Consequences and Mitigating Actions

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4.7.1 Proposed Action

4.7.1.1 GEIS Category 1 Issues

The GEIS concludes that the nine Category 1 issues listed in Table 4–8 would have a SMALL 

impact on aquatic resources during the license renewal term for all plants. For these issues, no 

additional plant-specific analysis is required unless new and significant information is identified.

During its review, the NRC staff considered Exelon’s ER, aquatic surveys and studies 

performed at Braidwood and in the Kankakee River, and available scientific literature; 

participated in a site audit; and considered Federal and State agency and public comments 

received during the scoping process. The NRC staff did not identify any new and significant 

information related to any of the Category 1 issues. Therefore, no site-specific analysis is 

required for these issues, and there would be no impacts associated with these issues beyond 

those discussed in the GEIS. 

4.7.1.2 Impingement and Entrainment of Aquatic Organisms

In the GEIS (NRC 2013f), the NRC determined that impingement and entrainment of aquatic 

organisms is a Category 2 issue (see Table 4–8) that requires site-specific evaluation during 

each license renewal review for plants with once-through cooling systems or cooling ponds, 

such as Braidwood.

Impingement is the entrapment of all life stages of fish and shellfish on the outer part of an 

intake structure or against a screening device during periods of water withdrawal 

(40 CFR 125.83). Impingement can kill organisms immediately or contribute to a slower death 

resulting from exhaustion, suffocation, injury, and other physical stresses. The potential for 

injury or death is generally related to the amount of time an organism is impinged, its 

susceptibility to injury, and the physical characteristics of the screen washing system and fish 

return (if present) of the plant.

Entrainment is the incorporation of all life stages of fish and shellfish with intake water flow 

entering and passing through a cooling-water intake structure and into a cooling water system 

(CWS) (40 CFR 125.83). Organisms susceptible to entrainment are generally of smaller size 

than those susceptible to impingement and include ichthyoplankton (fish eggs and larvae), larval 

stages of shellfish and other macroinvertebrates, zooplankton, and phytoplankton. Entrained 

organisms may experience physical trauma and stress, pressure changes, excess heat, and 

exposure to chemicals, all of which may result in injury or death (Mayhew et al. 2000).

A particular species can be subject to both impingement and entrainment if some individuals are 

impinged on screens while others pass through the screens and are entrained. For instance, 

adult individuals could be impinged, while juveniles could be entrained if they are small enough 

to pass through the intake screen openings.

At Braidwood, aquatic organisms may be impinged or entrained at two locations. Organisms 

that inhabit the Kankakee River may be impinged or entrained when makeup water is drawn 

from the river, through the river screen house, and into the cooling pond. Organisms that 

inhabit the cooling pond may be impinged or entrained when water is drawn from the pond, 

through the lake screen house, and into the CWS. A 1988 Braidwood entrainment survival 

study (EA Engineering 1990) indicates that some entrained organisms from the Kankakee River 

can survive the stresses of the makeup water intake and colonize the cooling pond. However, 

organisms that are entrained by passing through the cooling pond’s lake screen house and into 

the Braidwood CWS are subject to mechanical, thermal, and toxic stresses that make survival 

unlikely.
Environmental Consequences and Mitigating Actions

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This section’s analysis uses a retrospective assessment of the present and past impacts to 

the aquatic ecosystem resulting from Braidwood operation in order to provide a prospective 

assessment for the future impacts over the proposed license renewal term (i.e., through 2046 

for Unit 1 and through 2047 for Unit 2). The timeframe and geographic extent are two 

components of the assessment that bound the analysis. The timeframe defines how far back 

and how far forward the analysis will extend. In assessing the level of impact, the staff looked at 

the projected effects in comparison to a baseline condition. In agreement with NEPA guidance 

(CEQ 1997), the baseline of the assessment is the condition of the resource without the action 

(i.e., under the no-action alternative). Under the no-action alternative, the plant would shut 

down, and the resource would conceptually return to its condition without the plant, which is 

not necessarily the same as the condition before the plant was constructed. The timeframe for 

analyzing ecological resources extends far enough into the past to understand trends and to 

determine whether the resource is stable, which the NRC definitions of impact levels require. 

For assessing direct and indirect impacts, the geographic boundaries depend on the biology of 

the species under consideration.

The NRC staff used a modified weight-of-evidence (WOE) approach to evaluate the effects of 

impingement and entrainment on the aquatic resources in the Kankakee River and Braidwood 

cooling pond. NRC chose this approach because EPA recommends a WOE approach for 

ecological risk assessment (EPA 1998). The WOE approach is a useful tool due to the complex 

nature of assessing risk (or impact), and NRC has used this approach in other evaluations of 

the effects of nuclear power plant cooling systems on aquatic communities (e.g., NRC 2010, 

2011, 2013e). Menzie et al. (1996) defines WOE as “...the process by which multiple 

measurement endpoints are related to an assessment endpoint to evaluate whether significant 

risk of harm is posed to the environment.” In the present WOE approach, the NRC staff 

examined five lines of evidence (LOE) to determine if operation of Braidwood is contributing to 

adverse impacts on aquatic resources in the Kankakee River or Braidwood cooling pond. The 

lines of evidence are as follows:

LOE Description

1 Results of impingement studies performed at Braidwood

2 Results of entrainment studies performed at Braidwood 

3 A review of available Kankakee River fish sampling data

4 A review of available Kankakee River freshwater mussel surveys

5 Consideration of engineered designs and operational controls that 

affect impingement and entrainment rates

LOE 1: Impingement Studies

Three studies have been conducted to evaluate impingement resulting from Braidwood’s 

makeup water withdrawals from the Kankakee River. Commonwealth Edison Company 

(ComEd) commissioned an impingement study during filling of the cooling pond from 

December 1980 through February 1981 (summarized in NRC 1984). EA Engineering (1990) 

conducted an impingement and entrainment study from October 1988 through October 1989. 

EA Engineering also conducted an impingement study from April through June 1991 

(summarized in EA Engineering 2012). No studies have been conducted that assess 

impingement and entrainment resulting from withdrawal of cooling water from the cooling pond 

(Exelon 2014l).
Environmental Consequences and Mitigating Actions

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1980-1981 Kankakee River Impingement Study

The NRC’s Final Environmental Statement for Braidwood Operation (FES-O, NRC 1984) 

summarizes the results of the first impingement study, which was conducted from 

December 1, 1980, through February 21, 1981, during filling of the cooling pond and before 

Braidwood operation. The FES-O does not include a discussion of study methods. During the 

study, eight fish constituted 75 percent of the total number of fish impinged:

Percent (%) of Total Impinged

rock bass 17.9

rosyface shiner 11.6

channel catfish 11.1

bluegill 8.4

smallmouth bass 8.2

bullhead minnow 6.3

white crappie 6.1

orangespotted sunfish 5.9

The total estimated impingement for the period (December through February) was 

1,201 individuals representing 32 species (see Table 4–9). Most impinged fish were 

young-of-the-year (YOY). The NRC (1984) noted that the study correlated with the period of 

the year where impingement was expected to be highest due to low water temperatures that 

reduced fish swimming speeds.

Although the relative abundance of fish impinged during the 1980-1981 study period was 

generally proportional to the relative abundance of fish collected during 1981-1982 river 

sampling period (discussed in Section 3.7), some differences are apparent (see Table 4–10). 

Centrarchids (sunfishes) were the most commonly impinged family. Sunfishes may be more 

susceptible to impingement because individuals tend to aggregate in shallower, warmer waters 

with aquatic plants, such as in the vicinity of the river screen house. Clupeids, which accounted 

for 6.2 percent of river samples, were rarely impinged. Gizzard shad (Dorosoma cepedianum, a 

clupeid) grow rapidly, and YOY may have been large enough to swim against the intake current 

and avoid impingement given that the study was conducted in the winter. Ictalurids, which were 

rare in river samples, accounted for 13.4 percent of impinged fish. Two families appeared in 

impingement samples that did not appear in river samples: Aphredoderidae (pirate perch 

(Aphredoderus sayanus)) and Atherinopsidae (brook silverside (Labidesthes sicculus)).

Based on the study, the NRC (1984) concluded that operation of Braidwood would have minimal 

effects on Kankakee River fish because of the low numbers of the various species impinged 

during the study and the generally high natural mortality rates of YOY fish, which constituted 

the majority of impingement. 
Environmental Consequences and Mitigating Actions

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Table 4–9. Estimated Fish Impingement by Abundance, Dec. 1980–Feb. 1981

Species (a) Common Name

Number of 

Individuals

Relative 

Abundance 

(%)

Ambloplites rupestris rock bass 214.7 17.9

Notropis rubellus rosyface shiner 139.2 11.6

Ictalurus punctatus channel catfish 133.8 11.1

Lepomis macrochirus bluegill 101.0 8.4

Micropterus dolomieu smallmouth bass 98.8 8.2

Pimephales vigilax bullhead minnow 76.2 6.3

Pomoxis annularis white crappie 73.8 6.1

Lepomis humilis orangespotted sunfish 70.9 5.9

Lepomis cyanellus green sunfish 51.0 4.2

Pomoxis nigromaculatus black crappie 50.2 4.2

Cyprinella spiloptera spotfin shiner 39.6 3.3

Notropis stramineus sand shiner 35.6 3.0

Noturus flavus stonecat 20.8 1.7

Lepomis gibbosus pumpkinseed 16.4 1.4

Notropis spp. Notropis spp. 15.3 1.3

Lepomis microlophus redear sunfish 7.6 0.6

Notemigonus crysoleucas golden shiner 7.0 0.6

Pimephales notatus bluntnose minnow 7.0 0.6

Lepomis punctatus spotted sunfish 4.6 0.4

Phenacobius mirabilis suckermouth minnow 4.6 0.4

Dorosoma cepedianum gizzard shad 4.6 0.4

Ameiurus natalis yellow bullhead 4.6 0.4

Micropterus salmoides largemouth bass 2.3 0.2

Pimephales promelas fathead minnow 2.3 0.2

Carpiodes cyprinus quillback 2.3 0.2

Ameiurus melas black bullhead 2.3 0.2

Etheostoma zonale banded darter 3.0 0.2

Perca flavescens yellow perch 2.3 0.2

Aphredoderus sayanus pirate perch 2.3 0.2

Labidesthes sicculus brook silverside 2.3 0.2

Esox americanus grass pickerel 2.3 0.2

Lepisosteus osseus longnose gar 2.3 0.2

TOTAL 1,201.0 100.0

(a) Species are ordered by decreasing abundance.

Source: NRC 1984
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Table 4–10. Relative Abundance of Fish Families Collected in Kankakee River Sampling, 

1981–1982, and Impingement Sampling, 1980–1981

Relative Abundance (%)

Family (a)

River 

Sampling

Impingement

Sampling

Centrarchidae 33.7 57.6

Cyprinidae 33.8 25.9

Catostomidae 22.1 0.2

Clupeidae 6.2 0.4

Percidae 2.4 0.4

Ictaluridae 0.3 13.4

Lepisosteidae 0.2 0.2

Amiidae 0.2 -

Esocidae 1.0 0.2

Fundulidae 0.1 -

Umbridae 0.1 -

Aphredoderidae - 0.2

Atherinopsidae - 0.2

(a) Families ordered by decreasing relative abundance 

in river samples

Source: NRC 1984

1988-1989 Kankakee River Impingement Study

EA Engineering (1990) initiated a second study in 1988, the first year of Braidwood operation, 

and it included both entrainment and impingement components. For the impingement portion of 

the study, EA Engineering collected samples on 132 sample days between October 11, 1988, 

and October 4, 1989. For each sample, impinged fish were collected in the river screen house 

baskets over a 24-hour period. Before each sample period, the traveling screens were 

manually rotated, and station personnel removed all debris from the trash baskets. At the end 

of each sample period, station personnel manually operated each traveling screen to remove all 

impinged fish. All fish collected in the trash baskets were identified, counted, weighed, and 

measured. During the study period, EA Engineering collected three samples per week with 

the exception of holidays, periods in which makeup water was not pumped from the Kankakee 

River, and periods where there were mechanical problems at the intake.

EA Engineering collected 17,680 individuals of 59 species (see Table 4–11). The most 

prevalently impinged fish were as follows:

Individuals Collected Percent (%) of Total Impinged

gizzard shad 12,220 69.1

rock bass 1,816 10.3

smallmouth bass 553 3.1

longear sunfish 544 3.1
Environmental Consequences and Mitigating Actions

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The remaining 55 species each comprised less than 2 percent of the total collected individuals. 

Two State-listed species were collected: pallid shiner (Notropis amnis; 16 individuals) and river 

redhorse (Moxostoma carinatum; 2 individuals). Species richness was highest in March 

(47 species) and January (45 species). Total catch and catch-per-unit effort was highest in 

December 1988 at 6,310 individuals and 26.1 fish/hour. Catch was lowest in August, which was 

due to the lack of river water withdrawal from August 1 through 22. EA Engineering determined 

that that the majority of impinged fish were YOY based on length frequency distributions for the 

seven most common non-minnow species—gizzard shad, rock bass (Ambloplites rupestris), 

smallmouth bass (Micropterus dolomieu), longear sunfish (Lepomis megalotis), bluegill 

(Lepomis macrochirus), shorthead redhorse (Moxostoma macrolepidotum), and silver redhorse 

(Moxostoma anisurum).

EA Engineering estimated the total annual impingement for the study period with the 

assumption that for each week, impingement on unsampled days would be the average of the 

sampled days. Weekly estimates were then added together to yield annual estimates. The total 

estimated impingement during the 12-month study period was 53,111 fish, the majority of which 

(51 percent; 26,870 individuals) occurred from mid-December to mid-January. EA Engineering 

included species-specific estimates for the three most commonly impinged species:

Estimated Annual Impingement Percent (%) of Total Impinged

gizzard shad 36,608 68.9

rock bass 5,129 9.7

smallmouth bass 1,594 3.0

EA Engineering also estimated that Braidwood impinged 73 pallid shiner during the sample 

period. All impingement of this species occurred from mid-April through early June. Although 

collected in impingement samples, EA Engineering made no annual estimate for river redhorse.

While the 1980-1981 study had estimated that 1,201 fish would be impinged between 

December and February, the 1988–1989 study estimated a much larger number (32,821 fish). 

Gizzard shad accounted for much of this difference: the first study estimated that 5 individuals 

were impinged from December 1980 through February 1981, while the second study estimated 

that 28,969 gizzard shad were impinged during the same 3-month period in 1988 and 1989. For 

all other species, the two studies’ estimates also vary greatly: an estimated 1,196 non-gizzard 

shad individuals were impinged during the first study period versus an estimated 

3,852 non-gizzard shad individuals during the second study period. EA Engineering (1990) 

notes that in 1988, record low flows were observed in many Midwestern streams, including the 

Kankakee River, which likely yielded greater impingement losses than would occur in a typical 

year because a larger portion of the river was withdrawn for makeup water.
Environmental Consequences and Mitigating Actions

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Table 4–11. Fish Collected in Impingement Samples by Abundance, 

Oct. 1988–Oct. 1989

Species (a) Common Name Individuals 

Collected

Relative 

Abundance (%)

Dorosoma cepedianum gizzard shad 12,220 69.1

Ambloplites rupestris rock bass 1,816 10.3

Micropterus dolomieu smallmouth bass 553 3.1

Lepomis megalotis longear sunfish 544 3.1

Notropis rubellus rosyface shiner 300 1.7

Cyprinella spiloptera spotfin shiner 238 1.3

Labidesthes sicculus brook silverside 190 1.1

Lepomis macrochirus bluegill 175 1.0

Pimephales notatus bluntnose minnow 170 1.0

Notropis volucellus mimic shiner 149 0.8

Moxostoma macrolepidotum shorthead redhorse 119 0.7

Lepomis cyanellus green sunfish 104 0.6

Luxilus chrysocephalus striped shiner 97 0.5

Noturus flavus stonecat 90 0.5

Pimephales vigilax bullhead minnow 82 0.5

Moxostoma anisurum silver redhorse 80 0.5

Lepomis humilis orangespotted sunfish 72 0.4

Notemigonus crysoleucas golden shiner 70 0.4

Pimephales promelas fathead minnow 51 0.3

Ictalurus punctatus channel catfish 47 0.3

Percina maculata blackside darter 44 0.2

Micropterus salmoides largemouth bass 43 0.2

Nocomis biguttatus hornyhead chub 40 0.2

Pomoxis nigromaculatus black crappie 40 0.2

Percina caprodes logperch 36 0.2

Pomoxis annularis white crappie 31 0.2

Lepomis spp. Lepomis spp. 29 0.2

Moxostoma erythrurum golden redhorse 28 0.2

Carpiodes cyprinus quillback 27 0.2

Cyprinus carpio common carp 22 0.1

Notropis stramineus sand shiner 20 0.1

Ameiurus melas black bullhead 17 <0.1

Notropis amnis pallid shiner 16 <0.1

Ameiurus natalis yellow bullhead 14 <0.1

Notropis atherinoides emerald shiner 13 <0.1

Aplodinotus grunniens freshwater drum 9 <0.1

Ictiobus bubalus smallmouth buffalo 7 <0.1

Perca flavescens yellow perch 7 <0.1

Esox americanus grass pickerel 6 <0.1
Environmental Consequences and Mitigating Actions

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Species (a) Common Name Individuals 

Collected

Relative 

Abundance (%)

Hypentelium nigricans northern hogsucker 6 <0.1

Moxostoma spp. Moxostoma spp. 6 <0.1

Notropis buchanani ghost shiner 5 <0.1

Phenacobius mirabilis suckermouth minnow 5 <0.1

Minytrema melanops spotted sucker 3 <0.1

Ameiurus nebulosus brown bullhead 3 <0.1

Etheostoma nigrum johnny darter 3 <0.1

Etheostoma zonale banded darter 3 <0.1

Percina phoxocephala slenderhead darter 3 <0.1

Lepisosteus osseus longnose gar 2 <0.1

Esox lucius northern pike 2 <0.1

Cyprinella lutrensis red shiner 2 <0.1

Lythrurus umbratilis redfin shiner 2 <0.1

Cyprinella spiloptera × lutrensis spotfin × red shiner 2 <0.1

Carpiodes spp. Carpiodes spp. 2 <0.1

Moxostoma carinatum river redhorse 2 <0.1

Moxostoma duquesnei black redhorse 2 <0.1

Noturus gyrinus tadpole madtom 2 <0.1

Morone mississippiensis yellow bass 2 <0.1

Lepomis hybrid sunfish hybrid 2 <0.1

Carassius auratus goldfish 1 <0.1

Catostomus commersoni white sucker 1 <0.1

Aphredoderus sayanus pirate perch 1 <0.1

Fundulus notatus blackstripe topminnow 1 <0.1

Etheostoma caeruleum rainbow darter 1 <0.1

Total 17,680 100.0

(a) Species ordered by decreasing relative abundance

Source: EA Engineering 1990

Gizzard shad, the most commonly impinged species, was also the second most common 

species to be collected in an August 1988 Illinois Natural History Survey of the Kankakee River 

(Larimore and Peterson 1989). In northern portions of the species range, such as Illinois, 

individuals typically live to 5 to 7 years (Williamson and Nelson 1985). Fecundity typically peaks 

at 2 to 3 years of age, and fecundity has been reported as ranging from 12,500 eggs per female 

of age 2 in Acton Lake, Ohio (Williamson and Nelson 1985), to 378,900 eggs per female in 

western Lake Erie (Bodola 1966). Egg mortality rates are generally high in freshwater 

broadcast-spawning species, such as gizzard shad (Dahlberg 1979), and gizzard shad YOY 

are particularly susceptible to mortality caused by sudden or extreme changes of temperature, 

making winter die-offs common in northern waters when temperatures fall below 3.3 °C (38 °F) 

(Williamson and Nelson 1985). Because 78 percent of gizzard shad impingement occurred 

between early December and early February, many of the individuals were likely already 

stressed or weakened by cold temperatures. EA Engineering (1990) noted that a large 

percentage of the fish impinged at the Braidwood Station were likely already dead or would 
Environmental Consequences and Mitigating Actions

4-46

have died regardless of being impinged at the intake based on findings from impingement 

studies at other facilities. This hypothesis is supported by the low intake velocities (measured 

at an average of 0.30 to 0.37 foot per second (fps) (0.09 to 0.11 meter per second (m/s)) during 

the study year). These velocities are within the 0.5-fps (0.15-m/s) intake velocity recommended 

by the EPA for protection of aquatic organisms (79 FR 48300), and thus, healthy fish should 

have been able to avoid impingement.

EA Engineering (1990) concluded that the annual impingement of 5,129 rock bass YOY and 

1,594 smallmouth bass YOY also represents a small loss as female rock bass lay between 

2,000 to 11,000 eggs per year (Wallus and Simon 2008) and smallmouth bass lay between 

2,000 to 21,000 eggs per year (Brown et al. 2009). As with gizzard shad, because healthy fish 

would be able to avoid the low intake velocities, most impinged individuals would likely be 

already stressed or weakened.

Little is known about the spawning habits of the State-endangered pallid shiner (Kwak 1991), so 

a comparison of the impingement of 73 YOY to the average fecundity of an adult female is not 

possible. Impacts to the species are partially mitigated through Special Condition 8 in the 

Braidwood NPDES permit (IEPA 2014d). As a result of the 1988-1989 impingement study, the 

IEPA determined that pumping restrictions were appropriate to address entrainment (discussed 

later in this section). In 1991, IEPA incorporated a condition (Special Condition 8) into 

Braidwood’s NPDES permit that limits Kankakee River makeup water withdrawals during the 

peak entrainment period (the last 3 weeks in May and the first week in June). During this 

period, the NPDES permit restricts withdrawals to only those needed to fill the freshwater 

holding pond and to maintain efficient operation of the cooling pond. Withdrawals are prohibited 

during night hours (1 hour before sunset through 1 hour after sunrise).

Because pallid shiner are susceptible to impingement during this period, Special Condition 8 

also reduces the likelihood that this species would be impinged. For instance, from April 19 

through June 6, 1989, EA Engineering collected 16 pallid shiner individuals in impingement 

samples, and an estimated 73 individuals were impinged in total during this time period. Had 

the special condition been in place during the 1988-1989 impingement study, withdrawals would 

have been restricted from May 11 through June 7, 1989. During this period, EA Engineering 

collected 10 of the 16 impinged pallid shiner. Thus, had Special Condition 8 been in place 

during the study, the total estimated number of pallid shiner impinged would have been reduced 

by 62.5 percent from 73 individuals to about 27 individuals. Although not collected during the 

impingement study, Kankakee River monitoring data indicates that pallid shiner are also known 

to be present in the vicinity of Braidwood through mid-August and as late as November 

(Kwak 1991), and it is unknown how many impingements of pallid shiner have occurred during 

these months since the 1988-1989 study. Nevertheless, Special Condition 8 likely acts to 

greatly reduce, though not eliminate, the potential for impingement of pallid shiner. Specific 

population estimates are unavailable for the Kankakee River. However, in its Kankakee River 

Area Assessment, the IDNR (1998) indicates that, during that time period, the pallid shiner was 

“on the verge of extinction” in Illinois and that the Kankakee River population was the only large 

population remaining in the State. Based on this information, any losses of pallid shiner to 

impingement at Braidwood during this study’s time period could have contributed to a 

decreased ability for the Illinois population to survive and reproduce. Since the time of the 

Kankakee River Area Assessment, other studies in the Kankakee and Des Plaines Rivers 

indicate that the species’ numbers have increased and that its range has expanded. During fish 

monitoring performed in the vicinity of DNPS, Units 2 and 3, on the Des Plaines, Kankakee, and 

Illinois Rivers, EA Engineering (2015) has observed an increase in pallid shiner captures since 

2001. Pallid shiner captures have increased from 12 individuals in 2001 to as many as 

165 individuals in 2007 with an average of 82 individuals per year between 2001 and 2014 (EA 
Environmental Consequences and Mitigating Actions

4-47

Engineering 2015). The majority of captures occurred in the Kankakee River approximately 

12 mi (19 km) downstream of Braidwood. Additionally, during another fish monitoring study 

associated with the Upper Illinois Waterway, EA Engineering (2014) has observed the pallid 

shiner in several new locations within the Kankakee River and Illinois River watersheds since 

2000 when the species first appeared in monitoring samples. However, because the species 

remains State-endangered, any impingement at Braidwood during the proposed license renewal 

term could affect the population more significantly than it would affect the populations of 

non-State-listed species. The exact magnitude of effects would depend on the Kankakee River 

population’s decline or continued recovery during the proposed license renewal term.

Impacts to the State-threatened river redhorse are difficult to quantify from the 1988–1989 

impingement study because only two individuals were collected, and EA Engineering does not 

provide a species-specific entrainment estimate or discuss the species in detail in its results. 

The two individuals were collected on January 3 and June 6, 1989, which indicates that the 

species is likely present in the vicinity of Braidwood and susceptible to impingement the majority 

of the year. Had Special Condition 8 been in place during the study, only one individual would 

have been impinged. Thus, this condition may act to reduce the number of river redhorse 

impinged, but given the small sample size, it is unclear to what extent. The Illinois Endangered 

Species Protection Act (520 ILCS 10/1 et seq.) defines threatened species as those that are 

“...likely to become endangered in the wild in Illinois within the foreseeable future.” The Illinois 

Endangered Species Protection Board most recently reviewed the species’ status in 2011 and 

determined that it remained threatened (Mankowski 2012). Because the river redhorse was not 

in danger of extinction at the time of the study, the small losses from impingement at Braidwood 

are unlikely to have destabilized or noticeably altered the population in Illinois. If the species’ 

status changes during the proposed license renewal term, impingement at Braidwood could 

contribute more significantly to endangering the Illinois population’s continued existence

depending on the Kankakee River population’s overall recovery or decline during the 

time period. 

The 1988–89 impingement study provides evidence that impingement from Braidwood 

operations would only have a minor effect on most Kankakee River aquatic biota because 

impingement would not destabilize or noticeably alter the aquatic community in the vicinity 

of Braidwood. This conclusion is based on the fact that only a small number of fish would be 

impinged annually compared to the populations in the river; the majority of losses would be 

gizzard shad during winter months when temperature-related die-offs of this species are 

common; and most impinged individuals would already be stressed or weakened before 

impingement. Impacts to the State-listed pallid shiner and river redhorse, specifically, are 

partially mitigated by Special Condition 8 in the Braidwood NPDES permit. However, continued 

impingement of small numbers of pallid shiner—estimated to be as high as 73 individuals per 

year by EA Engineering (1990)—could result in a decreased ability for the Illinois population of 

this species to survive and reproduce depending on the future status (i.e., overall recovery or 

decline) of this species during the proposed license renewal term. Impingement of river 

redhorse, which the 1988–1989 study indicates is relatively rare, is unlikely to have more than a 

minor effect on the Illinois population of this species.

1991 Kankakee River Impingement Study

Braidwood’s 1991 renewed NPDES permit required impingement collections to be made 

whenever the river screen house makeup pumps operated between April and June 1991. 

During that period, the makeup water pumps operated on 49 days (14 days in April, 12 days in 

May, and 23 days in June), and EA Engineering collected and recorded all impinged fish during 
Environmental Consequences and Mitigating Actions

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this time with similar methodology as in the 1988–1989 study. EA Engineering (2012) 

summarizes the results of the 1991 study.

EA Engineering collected 813 fish of 42 species (see Table 4–12). The most prevalently 

impinged fish were:

Individuals Collected Percent (%) of Total Impinged

common carp 535 65.8

stonecat 37 4.6

longear sunfish 33 4.1

rock bass 28 3.4

The remaining species each comprised less than 2 percent of the total collected individuals. 

One pallid shiner was collected, and no river redhorse were present during the 3-month period.

Table 4–12. Fish Collected in Impingement Samples by Abundance, 

April–June 1991

Species (a) Common Name Number 

Collected

Relative 

Abundance (%)

Cyprinus carpio common carp 535 65.8

Noturus flavus stonecat 37 4.6

Lepomis megalotis longear sunfish 33 4.1

Ambloplites rupestris rock bass 28 3.4

Pimephales promelas fathead minnow 19 2.3

Carpiodes carpio river carpsucker 15 1.8

Notemigonus crysoleucas golden shiner 13 1.6

Pimephales vigilax bullhead minnow 10 1.2

Lepomis cyanellus green sunfish 10 1.2

Lepomis humilis orangespotted sunfish 8 1.0

Lepomis macrochirus bluegill 7 0.9

Ictalurus punctatus channel catfish 5 0.6

Pomoxis annularis white crappie 5 0.6

Pomoxis nigromaculatus black crappie 4 0.5

Micropterus dolomieu smallmouth bass 2 0.2

Esox lucius northern pike 2 0.2

Notropis amnis pallid shiner 1 0.1

Unspecified species unspecified species 79 9.8

Total 813 100.0

(a) Species ordered by decreasing relative abundance

Source: EA Engineering 2012

Overall, a significantly smaller number of fish were impinged in 1991 than was estimated during 

the previous impingement study. In the 1988-1989 study, EA Engineering (1990) calculated 

that 3,907 fish would be impinged from April through June, while the 1991 study only collected 

813 fish (20.8 percent of the previous estimate). Because the NPDES permit required that 
Environmental Consequences and Mitigating Actions

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sampling be conducted whenever pumping occurred, the 813 fish collected in 1991 represents 

the actual number of fish impinged during the 3-month period. EA Engineering (2012) attributed 

the lower numbers to differences in river flow that might affect the distribution of fishes in the 

river, differences in local population abundances near the plant intake, or other unknown 

factors. Based on the 1991 study, EA Engineering (2012) concluded that impingement in the 

spring months does not appear to have adverse effects on any species because impingement 

rates are so low.

LOE 1 Conclusion

Based on the available impingement studies, intake of makeup water from the Kankakee River 

appears to have a minor effect on the aquatic community in the vicinity of Braidwood, and the 

NRC staff finds that impingement is not likely to noticeably alter or destabilize any important 

attributes of the community. Impacts to the Kankakee River aquatic community as a whole, 

therefore, would be SMALL during the proposed license renewal term. Continued impingement 

of the State-threatened river redhorse are unlikely to create noticeable effects on this species’ 

population in the Kankakee River unless the species’ population further declines in the river 

system as a whole during the proposed license renewal term. Thus, impacts of the proposed 

license renewal on this species would be SMALL. Continued impingement of the 

State-endangered pallid shiner, however, may create a noticeable effect on this species’ 

population in the Kankakee River depending on the species’ future recovery or decline in the 

river system as a whole, and thus, impacts of the proposed license renewal to this species 

would be MODERATE. 

Although fish and aquatic biota are also impinged at the lake screen house when cooling pond 

water is drawn into Braidwood’s cooling system, the impacts of impingement on the aquatic 

community within the cooling pond are unknown because they have not been addressed in 

studies.

LOE 2: Entrainment Studies

One study has been conducted to evaluate entrainment resulting from Braidwood’s withdrawal 

of makeup water from the Kankakee River. EA Engineering (1990) conducted the study from 

April through September 1988 in conjunction with the previously discussed 1988–1989 

impingement and entrainment study. No studies have been conducted that assess entrainment 

resulting from withdrawal of cooling water from the cooling pond (Exelon 2014l).

1988 Entrainment Study

EA Engineering (1990) collected ichthyoplankton samples on 22 sample days between April 19 

and September 13, 1988, at four locations: the Kankakee River, Horse Creek, the Braidwood 

intake, and the Braidwood discharge (see Figure 4–1). All samples were taken with conical 

plankton nets (2.5 m (8.2 ft) in length with a 0.5-m (1.5-ft) opening and Number 0 (505-micron 

(μ)) mesh), and each location was sampled as follows.
Environmental Consequences and Mitigating Actions

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Figure 4–1. Braidwood Ichthyoplankton Sampling Locations

Source: EA Engineering 1990

Kankakee River. Collections were taken at four points (K1, K2, K3, and K4) from a boat 

anchored in position. Each location was sampled two times per 24-hour period (day and 

night) at two depths (surface and bottom), and two replicates were taken of each sample. 

This resulted in 32 samples each sample day. Collection times varied from 6 to 47 minutes, 

depending on water velocity, to yield sample volumes of 40 cubic meters (m3

) (130 cubic 

feet (ft3

)).

Horse Creek. Collections were taken 1.2 km (0.7 mi) upstream of the creek mouth at 

one location (H1). Four replicate samples were taken both day and night resulting in 

eight samples each sample day. Collections were made by hand, and collection times 

varied from 7 to 35 minutes to yield sample volumes of 40 m3 (130 ft3

).

Braidwood Intake. Collections were taken by suspending plankton nets each of the two intake 

forebays between the trash racks and traveling screens. Each intake bay was sampled at 

two locations (I1, I2, I3, and I4) and at two depths (surface and bottom) twice per 24-hours 

period (day and night). This resulted in 16 samples per sample day; however, low current 

velocities during the sample period prohibited collection of all 16 samples on many of the 

sampling days.

Braidwood Discharge. Collections were taken by suspending plankton nets in the discharge 

channel to the river approximately 10 m (33 ft) downstream of the outfall structure at 

one location (D1). Two replicates were collected per sample period, and collection time 

ranged from 8 to 35 minutes to yield a 40-m3 (130-ft3

) sample volume. The discharge was 

only sampled through June 28 (rather than through September 13 as with the other locations). 

It should be noted that this sample location no longer exists because Exelon replaced the 

discharge canal with a multiport diffuser in 2010.

The four locations yielded 853 samples. EA Engineering sorted and identified each sample 

to the lowest practical taxonomic group. Both eggs and larvae were measured to the nearest 
Environmental Consequences and Mitigating Actions

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0.1 mm, and larvae were categorized as yolk-sac, post yolk-sac, or juveniles. The samples 

yielded 7,197 larvae and 271 eggs. Table 4–13 summarizes the characteristics of the eggs 

collected, and Table 4–14 lists the number and relative abundance of larvae collected by family, 

taxa, and location.

Within Kankakee River and Horse Creek samples, eggs and larvae were most abundant at 

night and in late May. For the period of May 10 through June 7, 1988, an estimated 4 to almost 

10 million larvae were present in the river each week. EA Engineering determined that the 

majority of eggs collected at both river and creek sites were those of cyprinids. Within intake 

samples, the majority of eggs were common carp (Cyprinus carpio). Cyprinid eggs and 

one percid egg were also present. River, Horse Creek, and intake larvae samples were 

dominated by cyprinids, catostomids, and percids in the following distributions:

Percent (%) Composition Kankakee River Horse Creek Braidwood Intake

Cyprinids 44.4 17.6 54.1

Catostomids 34.9 74.8 16.3

Percids 12.4 5.2 19.3
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Table 4–13. Summary of Eggs Collected in Entrainment Samples, 1988

Sample Location

Kankakee 

River Horse Creek

Braidwood 

Intake

Braidwood 

Discharge

Sample Summary

Total samples taken 406 136 264 52

Total sample days 19 17 18 11

Sample days in which 

eggs were present

5 5 10 5

Egg Characteristics

Total collected 41 89 271 182

Average density 0.12/10m3 <0.2/10m3 0.44/10m3 1.8/10m3

Maximum density 0.64/10m3 1.9/10m3 2.35/10m3 5.6/10m3

Date of earliest 

collection

May 24 May 10 Apr 26 May 17

Date of 

latest collection

Jul 19 Jun 21 Jul 19 Jun 28

Date of highest 

density

Jul 19 May 31 May 17 May 31

Diameter range 1.3-2.0 mm 1.0-2.5 mm 1.0-2.0 mm 0.8-2.3 mm

Taxa present Cyprinid Cyprinid Carp (majority); 

other cyprinids; 

and darter spp. 

(one egg)

Centrarchid 

(90 percent), 

gizzard shad, 

freshwater drum, 

and cyprinid

Source: EA Engineering 1990

Over 90 percent of eggs collected in discharge samples were centrarchids. Eggs of gizzard 

shad, freshwater drum (Aplodinotus grunniens), and cyprinids were also present. Larvae 

samples were dominated by gizzard shad (39.1 percent) and crappie (Pomoxis spp.; 

33.1 percent). Cyprinid, percid, and catostomid larvae, which were the most prevalent groups 

at other sample sites, only accounted for 2.1, 1.7, and 0.8 percent, respectively. Because 

discharge samples represented water drawn from the cooling pond, through the discharge 

canal, and into the Kankakee River, the differences in species composition exhibited in 

discharge samples are attributable to the different species composition present in the cooling 

pond. As discussed in Section 3.7.1.2, the IDNR stocks the pond with a number of species that 

do not occur in the Kankakee River.
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Table 4–14. Numbers and Relative Abundance of Larvae Collected in Entrainment 

Samples by Family and Location, 1988

Sampling Location and Catch

Kankakee Total

River

Horse 

Creek

Braidwood 

Intake

Species (a) Common Name No. % No. % No. % No. %

Catostomidae 904 34.9 5,304 74.8 1,200 16.8 7,408 44.0

Hypentelium or 

Moxostoma spp.

Catostomid D (b) 538 20.8 5,188 73.2 908 12.7 6,634 39.4

unidentified subfamily 

Ictiobinae

unidentified subfamily 

Ictiobinae

301 11.6 11 0.2 126 1.8 438 2.6

other and unidentified 

Catostomid spp.

other and unidentified 

Catostomid spp.

65 2.5 105 1.5 166 2.3 336 2.0

Cyprinidae 1,151 44.4 1,244 17.6 3,863 54.1 6,258 37.2

Cyprinus carpio Common carp 467 18.0 10 0.1 1,187 16.6 1,664 9.9

Notropis spp. Notropis spp. 299 11.5 49 0.7 765 10.7 1,113 6.6

other and 

unidentified Cyprinids

other and 

unidentified Cyprinids

385 14.9 1,185 16.7 1,911 26.7 3,481 20.7

Percidae 320 12.4 368 5.2 1,377 19.3 2,065 12.3

Percina spp. Percina spp. 173 6.7 42 0.6 1,001 14.0 1,216 7.2

other and 

unidentified Percids

other and 

unidentified Percids

147 5.7 326 4.6 376 5.3 849 5.0

Centrarchidae 154 5.9 149 2.1 551 7.7 854 5.1

Lepomis spp. Lepomis spp. 149 5.8 149 2.1 547 7.7 845 5.0

other and unidentified 

Centrarchids

other and unidentified 

Centrarchids

5 0.2 - - 4 <0.1 9 <0.1

Other and Unidentified Families 61 2.4 22 0.3 156 2.2 239 1.4

other and unidentified 

species

other and 

unidentified species

61 2.4 22 0.3 156 2.2 239 1.4

Total 2,590 100.0 7,087 100.0 7,147 100.0 16,824 100.0

(a) Only those taxa that constituted 5.0% or more of the sample at one or more sample sites are listed individually. 

All other taxa are grouped as “other or unidentified” within the appropriate family.

(b) Catostomid D refers to individuals in the genera Hypentelium and Moxostoma, for which a positive separation 

could not be made due to overlapping characteristics in the larval stage.

Source: EA Engineering 1990
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Table 4–15. Estimated Ichthyoplankton Drift and Entrainment, 1988

Number of Individuals (in millions)

Drift in 

Kankakee River

Entrainment at 

Braidwood Intake

Percent (%) 

Entrained at Intake

Actual Actual (a) Worst Case (b) Actual Worst 

Case

Eggs 0.8 0.7 1.0 83.9 121.8

Larvae 37.7 5.8 11.2 15.5 29.8

Total 38.5 6.5 12.2 16.9 31.8

(a) The actual case is the estimated number of eggs and larvae that were entrained during 

the sample period (April 19–September 13) based on the actual total weekly volume of 

water withdrawn from the Kankakee River each week during the period.

(b) The worst case represents the estimated number of eggs and larvae that would be 

entrained if the plant were to withdraw Kankakee River water 24 hours a day, 7 days 

a week at the maximum capacity pump rate (50,000 gpm) over the sample period.

Source: EA Engineering 1990

EA Engineering preliminarily predicted that 20 percent or less of eggs and larvae would be 

entrained at the Braidwood intake assuming withdrawal of 20 percent of river flow at the plant’s 

maximum pumping rate of 50,000 gpm (100 cfs) during low flow conditions of 500 to 600 cfs 

(220,000 to 270,000 gpm). Using ichthyoplankton densities from the collected samples and 

USGS river flow data, EA Engineering determined actual and worst case scenario entrainment

as follows. The worst case scenario assumed that Braidwood would withdraw river water 

24 hours a day, 7 days a week at the maximum capacity pump rate (50,000 gpm [100 cfs]) 

over the sample period. Table 4–15 lists the estimated ichthyoplankton drift and entrainment 

in 1988.

Individuals (in millions) Eggs Larvae Total

Present in river 0.8 37.7 38.5

Entrained (actual) 0.7 5.8 6.5

Entrained (worst case) 1.0 11.2 12.2

Percent (%) Entrained

Actual 83.9 15.5 16.9

Worse Case 121.8 29.8 31.8

Egg entrainment was particularly high in both the actual (83.9 percent) and worst case 

(121.8 percent) scenarios. EA Engineering determined that two factors could have made the 

estimated entrainment rate appear higher than the actual entrainment rate. First, Horse Creek 

could be significantly contributing to Kankakee River egg drift. Because river samples were 

taken upstream of the confluence of Horse Creek (see Figure 4–1), this is a reasonable 

contributing factor. Second, EA Engineering determined that spawning may be taking place 

near or immediately upstream of the intake. Several taxa were present in intake egg samples 

that were not present in Kankakee River or Horse Creek samples (see Table 4–13), which 

supports this explanation. The river also includes a large, deep, slack-water area between the 

mouth of Horse Creek and the intake, which could serve as a spawning area for species that 

prefer to spawn in slower-moving waters. EA Engineering concluded that egg entrainment may 

create noticeable effects on a number of taxa, including cyprinids and darters, but that such 

effects would likely be restricted to the portion of the population near Braidwood.
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To determine whether the loss of 15.5 to 29.8 percent of larvae would be significant, 

EA Engineering considered several factors. First, EA Engineering considered whether 

the larvae captured in the samples were indicative of the larval populations susceptible to 

entrainment. For taxa that were common in samples, such as catostomids, cyprinids, and 

percids, the samples were found to be reasonably representative. For rare and occasional 

species, including ictalurids, esocids, and most centrarchids, EA Engineering determined that 

samples would greatly underestimate the abundance of these taxa’s presence in the river. 

Horse Creek contributed an additional 10 percent to the number of larvae present in upstream 

samples. Spawning near the intake, which is assumed to be a contributing factor to egg

entrainment, would also significantly contribute to the amount of larvae present near the intake. 

Thus, river samples taken during the study likely underestimated total larvae present in the 

vicinity of the Braidwood intake that were susceptible to entrainment.

Second, EA Engineering considered how the estimated entrainment losses at Braidwood would 

affect fish populations throughout the 58 mi (93 km) portion of the Kankakee River in Illinois 

based on methods discussed in Goodyear (1977). This area was chosen because the entire 

length of the river within Illinois is meandering, well-vegetated, and rocky, and it is reasonable to 

assume that this area could serve as a source of recruitment for losses of fish in the vicinity of 

Braidwood. Of the 58 mi (93 km), 14.5 mi (23.3 km) are located downstream of Braidwood. 

Larvae produced in this portion of the river would not be at risk of entrainment. EA Engineering 

determined that upstream of Braidwood, larvae within the 24.5 mi (39.4 km) portion of the river 

above the dam in Kankakee, Illinois are also not at risk of entrainment. Thus, only larvae that 

occur within a 19-mi (30.6-km) stretch (33 percent) of the river in Illinois are at risk of 

entrainment. Based on this information, EA Engineering calculated that Braidwood would 

entrain 5.1 percent of all larvae in the Illinois portion of the Kankakee River under the actual 

case scenario (15.5 percent larvae in the vicinity of Braidwood entrained during the 1988 study 

× 33 percent of the river in Illinois in which larvae are susceptible to entrainment) and 

9.8 percent under the worst case scenario (29.8 percent entrained during the study × 33 percent 

of the river in which larvae are susceptible to entrainment).

Third, EA Engineering considered how larval entrainment would affect different taxa groups 

based on biological or ecological criteria. EA Engineering determined that the groups least 

likely to be affected would be:

Taxa Least Likely to be Impacted Reason

catostomids, gizzard shad, 

common cyprinids (i.e., spotfin 

shiner, bluntnose minnow)

Larvae are abundant, taxa have high fecundity, 

and larvae are entrained less frequently than 

expected

centrarchids, esocids, ictalurids Larvae are not susceptible to the drift and/or 

have abundant populations in the river
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EA Engineering determined that the groups most likely to be affected would be:

Taxa Most Likely to be Impacted Reason

Percina spp. Larvae abundance is disproportionately high 

in entrainment samples in comparison to 

river population

most darters Larvae enter the drift regularly and taxa has 

low fecundity

uncommon cyprinids 

(i.e., pallid shiner, ghost 

shiner, mimic shiner) 

Taxa are rare or uncommon and largely 

restricted to the lower Kankakee River

Darters were determined to be the group most likely to experience impacts from larval 

entrainment at Braidwood because they have low populations in the river, produce relatively few 

eggs, and are disproportionately represented in the drift. Uncommon cyprinids restricted to the 

lower Kankakee River, such as the State-endangered pallid shiner, are likely to be 

disproportionately affected by larval entrainment, as well. Although impingement samples 

included pallid shiner, ghost shiner, and mimic shiner, larvae of these species were not 

identified in entrainment samples. It is possible, however, that these species were present as 

unidentified cyprinids, which accounted for 26.7 percent of larvae collected at the intake (see 

Table 4–14).

EA Engineering also conducted larval survival studies, which EA Engineering factors into 

its conclusions as a source of ichthyoplankton to the river that could mitigate losses from 

entrainment. Discharged larvae originate in the cooling pond, travel through the river screen 

house, and enter the Kankakee River with cooling pond blowdown. EA Engineering determined 

that 75 percent of larvae survive the discharge pathway from the cooling pond to the river.

Although it is possible that cooling pond larvae discharged into the river supplement some 

entrainment losses, the NRC will not consider the survival study in its conclusions for a number 

of reasons. First, the discharge survival study included only a small sample size (103 total 

larvae) because it was conducted on only 3 sample days in June and July 1988 during daylight 

hours. The larvae survivorship samples also yielded a significantly different species 

composition than the 52 ichthyoplankton drift samples collected between April 19 and 

June 28, 1988, and discussed previously in this section. Samples taken during the peak 

entrainment period (in May at night) would have yielded larger samples that were more 

representative of the actual species composition. Second, larval samples were sorted and 

identified within 20 minutes of collection. Thus, it is unknown how many of the larvae counted 

as “live” in the samples may have died in the hours following entrainment due to physical or 

thermal stresses experienced prior to discharge into the river. Third, while EA Engineering 

concluded that 75 percent of larvae would survive discharge into the river, this number is 

skewed by the large number of Lepomis postlarvae (79 postlarvae; 76.7 percent) collected in 

survivorship samples and the high survivorship of these individuals (80 percent). The only other 

live larvae collected were of Pomoxis spp. (3 postlarvae and 1 juvenile; 3.9 percent) with a 

survivorship rate of 33 percent. By dividing the total number of live larvae by the total number 

of larvae collected in all entrainment samples taken at the discharge (not just the survivorship 

samples), however, the result is a much different overall survival rate:

92 Lepomis larvae (0.8 survivorship)

+

213 Pomoxis larvae (0.33 survivorship)

734 total larvae collected = 19.6% overall survivorship
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For these reasons, NRC has not factored EA Engineering’s survivorship study into its 

conclusions below.

LOE 2 Conclusion

Based on the one entrainment study that has been conducted at Braidwood, it is difficult to 

determine whether entrainment of eggs and larvae has a detectable impact on fish populations 

in the Kankakee River. The study’s egg entrainment estimates are not useful in determining 

impacts to the fish community as a whole because they did not account for the contribution of 

spawning in Horse Creek or near the intake. Nevertheless, EA Engineering determined that 

entrainment of eggs may create noticeable effects on a number of species, including cyprinids

and darters, and that such effects would likely be restricted to the portion of the population near 

Braidwood. Because the impacts to these populations are likely noticeable but unlikely to 

create destabilizing effects, impacts from egg entrainment appear to be MODERATE for 

these taxa. 

Larval entrainment would only affect a small portion of the Kankakee River fish populations 

in Illinois—5.1 to 9.8 percent when adjusted for the portion of the populations in the river 

susceptible to entrainment—and many populations, including catostomids, gizzard shad, 

common cyprinids, centrarchids, esocids, and ictalurids, would likely not be noticeably affected. 

Thus, impacts from larval entrainment would be SMALL for these groups. Species that have 

low populations in the river or are restricted to the lower Kankakee River, produce relatively few 

eggs, and/or are disproportionately represented in the drift are more likely to experience 

noticeable effects as a result of larval entrainment. This includes Percina spp., darters, and less 

common cyprinids, such as the State-endangered pallid shiner. Impacts from larval entrainment 

would be MODERATE for these groups.

Although eggs and larval fish are also entrained at the lake screen house when cooling pond 

water is drawn into Braidwood’s cooling system, the impacts of entrainment on the aquatic 

community within the cooling pond are unknown because they have not been addressed 

in studies.

LOE 3: Kankakee River Fish Sampling Data

Impingement and entrainment from the withdrawal of makeup water from the Kankakee River 

has removed individuals from the river ecosystem since Braidwood began operating in 1988. 

Over this period of time, the aquatic community may have changed in a number of ways, 

including species richness (the number of species present), species composition (the kinds 

of species present), and species evenness (the relative abundance of species). This line of 

evidence (LOE) compares the community characteristics prior to and during operations to 

determine whether changes have occurred and if such changes can be attributed to 

Braidwood operations.

One way to determine whether species richness and composition has changed is to calculate 

the Jaccard index (or Jaccard similarity coefficient). This index provides a simple snapshot of 

species presence or absence. The index is calculated as J = a /(a+b+c), where J is the index 

value, a is the number at both sites, b is the number at the second site only, and c is the number 

at the first site only (Pielou 1977). A coefficient of 1.0 indicates that the exact same species are 

present in both samples, while a coefficient of zero would indicate that none of the species in 

either sample appear in the other sample (i.e., each sample has completely unique species). 

The NRC staff calculated the Jaccard similarity coefficient to compare the fish collected in 

studies conducted during the preoperational period with the fish collected during the last 5 years 

of monitoring data (2009-2013). Section 3.7.2.1 and Tables 4–9 and 4–11 identify the species 

considered. Only unique species or taxa groups were included (e.g., Notropis volucellus, but 
Environmental Consequences and Mitigating Actions

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not unidentified Notropis spp.). In total, 76 species or hybrids appeared in either the 

preoperational period, the recent operational period, or both. Of these, 61 species appeared in 

both periods, 11 species were unique to the preoperational period, and 4 species were unique 

to the recent operational period (see Figure 4–2, NRC staff generated graphic). The NRC staff 

calculated the Jaccard similarity coefficient to be 0.80. This coefficient indicates that the aquatic 

community has remained relatively similar, and thus, impingement and entrainment over the 

26 years of Braidwood operations has not noticeably altered species richness or composition.

Figure 4–2. Species Richness During Preoperational and Recent Operational Periods

Section 3.7.3.1 discusses several changes in species evenness since Braidwood began 

operating, and Figure 3–13 in Section 3.7.3.1 illustrates the shift in relative abundance of the 

most prevalent fish families in historic and recent Kankakee River monitoring samples. The 

major changes include a significant increase in the relative abundance of cyprinids and a 

decrease in the abundance of catostomids. Cyprinids accounted for 33.8 percent of total 

collected individuals in 1982, while they accounted for an average of 57.1 percent of fish 

collected over the 2009–2013 period. Catostomids, which accounted for 22.1 percent of 

the total catch in 1982, have only comprised an average of 3.5 percent in recent years. 

Centrarchids and clupeids have also decreased in abundance (33.7 to 31.9 percent and 6.2 to 

1.0 percent, respectively).

To determine whether these changes could be attributable to Braidwood operations or whether 

they are merely a reflection of changes in species abundance throughout the Kankakee River in 

Illinois, NRC staff considered the relative abundances of fish families captured during a 2005 

Kankakee River survey performed by IEPA and IDNR staff (Pescitelli and Rung 2008). The 

2005 survey included boat electrofishing, backpack electrofishing, electric seining, and standard 

seining at 13 locations on the mainstem of the Kankakee River form July 19 to July 22, 2005. 

11

unique 

species

61 species 

common to 

both 

periods

4

unique 

species

Preoperational 

period (1981-1988)

Recent operational 

period (2009-2013)
Environmental Consequences and Mitigating Actions

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Surveyors collected 5,630 fish representing 14 families and 68 species from all gear times 

combined. Figure 4–3 compares the relative abundance of the most prevalent fish families 

collected during the 2005 survey with the abundance of the same families during 1981–1982 

preoperational fish surveys (NRC 1984) and the 5 most recent years of operational fish 

sampling data (HDR 2014).

While a strict comparison cannot be made because no mainstem surveys are available from the 

preoperational period, several changes in the relative abundance of fish families in the vicinity of 

Braidwood do not appear to be correlated with the more recent river-wide abundance of those 

same families. For instance, the 2005 mainstem survey yielded a much more even distribution 

of catostomids (24.0 percent), centrarchids (27.8 percent), and cyprinids (20.9 percent) than 

recent Braidwood collections. Cyprinids have by far been the most abundant family in recent 

Braidwood collections, while catostomids have decreased in abundance and are proportionately 

much rarer in the vicinity of Braidwood than in Kankakee mainstem collections. Centrarchids 

have decreased slightly in abundance between preoperational surveys and recent years, 

although they appear to still be more abundant in the vicinity of Braidwood than in the 

Kankakee mainstem.

Figure 4–3. Relative Abundance of Most Prevalent Fish Families

in the Kankakee River Over Time

Figure data sources: HDR 2014; NRC 1984; Pescitelli and Rung 2008

The apparent local decline of catostomids cannot be readily correlated with impingement and 

entrainment because catostomids do not make up a significant portion of individuals collected 

in impingement studies or eggs or larvae collected in the entrainment study described in LOE 2. 

Other unknown natural and non-operation-related factors may be contributing to the change in 
Environmental Consequences and Mitigating Actions

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catostomid abundance, and it is unclear to what extent impingement and entrainment at 

Braidwood may be contributing.

LOE 3 Conclusion

While the species richness and composition has remained similar over the period of Braidwood 

operations, recent Braidwood survey information indicates that species evenness is significantly 

different than during the preoperational monitoring period. The relative abundance of cyprinids 

has noticeably increased, while the relative abundances of catostomids (to a larger extent) and 

centrarchids (to a lesser extent) have noticeably decreased. However, these changes cannot 

be readily correlated with impingement and entrainment at Braidwood based on the findings 

described in LOE 2. Accordingly, this LOE is inconclusive.

LOE 4: Mussel Surveys

Freshwater mussel eggs, juveniles, and adults are generally not susceptible to impingement

or entrainment because they live on bottom substrates rather than in the water column. Some 

species’ glochidia (the larval stage) require attachment to a fish host to mature. For these 

species, impingement or entrainment of glochidia is possible if the host fish is impinged.

Based on a review of possible host species, it does not appear that impingement of host fish is 

noticeably altering the mussel population in the vicinity of Braidwood. Table 4–16 lists the most 

commonly occurring mussel species near Braidwood and their host fish. Host fish species for 

each of these mussels were present in 1980–1981 and 1988–1989 impingement samples (see 

Tables 4–9 and 4–11). Section 3.7.3.1 discusses several mussel surveys conducted in the 

vicinity of Braidwood (Belt 2009; Belt and Dunn 2015; HDR 2008) as well as throughout the 

Kankakee River basin (Price et al. 2012; Suloway 1981). As indicated in that section, species 

diversity within the mussel community appears to be relatively high in the vicinity of Braidwood 

and has remained similar since Braidwood began operating. Although species abundance has 

varied in the vicinity of Braidwood over time, it appears to be similar in the vicinity of Braidwood 

as in other regions of the Kankakee River. Because no preoperational mussel surveys were 

done in the vicinity of Braidwood, it is not possible to determine whether this variance is the 

result of Braidwood operations or other factors. The most recent mussel survey (Belt and 

Dunn 2015) indicates a higher mussel abundance in the vicinity of Braidwood than in other 

regions of the Kankakee River.

Table 4–16. Host Fish of Common Kankakee River Mussels

Species Common Name Host Fish

Actinonaias ligamentina mucket sawfish, bluegill, bass, crappie, perch

Lasmigona complanata white heelsplitter common carp, bass, crappie

Lasmigona costata flutedshell common carp

Quadrula pustulosa pimpleback channel catfish, bullhead, sturgeon

Utterbackia imbecillis paper pondshell sunfish spp.

Source: Hess 2014

LOE 4 Conclusion

No noticeable changes in the mussel community have occurred since Braidwood began 

operating. Thus, impingement and entrainment of mussel glochidia through impingement 
Environmental Consequences and Mitigating Actions

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of host fish appears to have a SMALL impact on the mussel community in the vicinity of 

Braidwood.

LOE 5: Engineered Design and Operational Controls

In August 2014, the EPA published a final rule establishing requirements under section 316(b) 

of the Clean Water Act of 1972 (CWA) for cooling water intake structures at existing facilities 

(79 FR 48300). The final rule indicates that two basic approaches can reduce impingement and 

entrainment mortality: (1) flow reduction and (2) including technologies into the cooling water 

intake design that gently exclude organisms or collect and return organisms without harm to the 

water body. The EPA also notes that two additional approaches can reduce impingement and 

entrainment but that these technologies may not be available to all facilities. The two additional 

approaches are: relocating the facility’s intake to a less biologically rich area in a water body 

and reducing the intake velocity. The Braidwood CWS on the Kankakee River incorporates 

several of these approaches.

Flow Reduction

Reducing the amount of water that is withdrawn for cooling purposes from a water body reduces 

the number of aquatic organisms that are drawn through the intake structure and subject to 

impingement or entrainment. Because Braidwood uses a cooling pond-based heat-dissipation 

system, the majority of cooling water needed for plant operation is drawn from the cooling pond 

rather than the Kankakee River. The cooling pond system is similar to a closed-cycle cooling 

system in that water in the pond continues to be recirculated through the plant for cooling, and 

only makeup water (water lost to evaporation or discharged as blowdown) is drawn directly from 

the Kankakee River. Depending on the quality of the makeup water, closed-cycle cooling 

systems can consume significantly less water than if the same facility were to use a 

once-through cooling system.

Braidwood’s intake flow is also controlled by an agreement with the IDNR that was made in 

1977 upon issuance of a permit to construct the river screen house and blowdown discharge

canal (IDOT 1977). The agreement limits Kankakee River makeup withdrawal volume to a 

maximum of 160 cfs (4,531 L/sec), and in times where the river flow is low, Exelon must limit 

Kankakee River water consumption such that withdrawal of makeup water does not cause river 

flow to drop below 442 cfs (12,517 L/sec) (IDC 1977).

The most recently issued Braidwood NPDES permit (IEPA 2014d) requires further withdrawal 

reductions during the peak entrainment period each year. Special Condition 8 requires that 

during the last 3 weeks in May and first week in June, Kankakee River withdrawals be made 

only during the day (between 1 hour after sunrise and 1 hour before sunset). Pumping during 

the day must also be limited to only those occasions where additional water is needed to fill the 

freshwater holding pond and to maintain efficient operation of the cooling pond.

Technologies That Exclude or Collect and Return Organisms

The Braidwood cooling system has several technologies that help exclude organisms from 

becoming impinged or entrained. Water enters the river screen house through an intake bay 

equipped with bar grills, 3/8-in. (9.5-mm) mesh travelling screens, and trash rakes to prevent 

debris and aquatic biota from entering the system (Exelon 2014c). The space between the 

trash racks and the traveling screens allow fish to swim downstream and exit the intake 

structure. The EPA indicates that, ideally, traveling screens would be used with a fish handling 

and return system (79 FR 48300). Braidwood’s river screen house does not contain a fish 

return system (Exelon 2014c). However, the space between the trash racks and traveling 
Environmental Consequences and Mitigating Actions

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screens, paired with the low intake velocity (discussed below), should allow some fish to swim 

away and escape impingement. 

Location of the Facility’s Intake

Location of the intake system is another design factor that can affect impingement and 

entrainment because locating intake systems in areas with high biological productivity or 

sensitive biota can negatively affect aquatic life (EPA 2004). As discussed in Section 3.7, the 

IEPA (2014b) has rated the Kankakee River in the vicinity of Braidwood as fully supporting 

aquatic life, and the IDNR has designated the Kankakee River from Momence in Kankakee 

County to the Des Plains Wildlife Conservation Area in Will County as a Biologically Significant 

Stream because it supports one of the state’s most diverse aquatic communities 

(Page et al. 1991). Thus, the location of the Braidwood intake is not a factor that is likely to 

result in reductions in entrainment and impingement mortality.

Intake Flow

Water velocity associated with the intake structure greatly influences the rate of impingement

and entrainment. The higher the approach velocity, through-screen velocity, or both, the greater 

the number of organisms that will be impinged or entrained. At an approach velocity of 0.5 ft/s 

(0.15 m/s) or less, most fish can swim away and escape from the intake current (79 FR 48300). 

As indicated in Section 3.1.3, water velocity at the river screen house ranges from 0.32 to 

0.48 fps (0.10 to 0.15 m/s), depending on river level, when both units are operating 

(Exelon 2013c). Thus, the river screen house intake velocities are within the 0.5-fps (0.15-m/s) 

intake velocity recommended by the EPA for protection of aquatic organisms.

LOE 5 Conclusion

While flow control measures, including the IDNR agreement and NPDES Permit Special 

Condition 8, and low intake velocities reduce the effects of impingement and entrainment

mortality at Braidwood, the lack of a fish return system and high biological significance of the 

Kankakee River in the vicinity of Braidwood could contribute to impingement and entrainment 

effects. This LOE does not conclusively indicate whether impingement or entrainment at 

Braidwood is creating detectable effects on the Kankakee River aquatic community. Thus, 

this LOE, considered alone, is inconclusive.

Summary of Impingement and Entrainment Conclusion

Based on past and present impacts to aquatic resources resulting from Braidwood operation, 

the NRC concludes that impingement and entrainment associated with the proposed license 

renewal would result in SMALL impacts on aquatic resources in the Kankakee River as a whole. 

However, certain species and taxa would likely experience MODERATE impacts as follows.

 Cyprinids would likely experience MODERATE impacts due to entrainment of 

eggs. These impacts would be restricted to the portion of the population near 

Braidwood (LOE 2). Uncommon cyprinids (pallid shiner, mimic shiner, and 

ghost shiner) would likely also be affected by entrainment of larvae because 

taxa are rare or uncommon and largely restricted to the lower Kankakee 

River (LOE 2). Additionally, pallid shiner would be affected by impingement, 

which may create noticeable impacts depending on the species’ future 

recovery or decline in the river system as a whole (LOE 1).
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 Darters would likely experience MODERATE impacts due to entrainment of 

eggs and larvae, because this taxon enters the drift regularly and has low 

fecundity (LOE 2).

 Percina spp. would likely experience MODERATE impacts due to 

entrainment of larvae because larvae abundance of this taxon is 

disproportionately high in entrainment samples in comparison to the 

river population.

The NRC cannot make a determination on the impact of impingement and entrainment on 

the aquatic resources in the cooling pond because no studies exist on impingement and 

entrainment at the lake screen house.

Impingement and entrainment impacts are presently mitigated through special conditions of the 

NPDES permit (discussed under LOE 1) and the existing engineered design and operational 

controls (discussed under LOE 5). During the proposed license renewal term, impacts would be 

further reduced through the IDNR’s implementation of new requirements contained in the final 

CWA 316(b) regulations, which were published in August 2014 (79 FR 48300) and discussed in 

LOE 5. The new regulations require the EPA or the State, as applicable, to ensure that the 

location, design, construction, and capacity of existing power generation facilities with cooling 

water intake structures reflect the best technology available to minimize harmful adverse 

environmental impacts. For Braidwood, the IEPA would ensure Exelon’s adherence to the 

CWA 316(b) regulations through the NPDES permit renewal process. Braidwood’s current 

NPDES permit expires in July 2019. Although the NRC has no authority over the NPDES 

permitting process, the NRC staff assumes that this mitigation is reasonably certain to reduce 

existing impacts because it is required by Federal regulation.

4.7.1.3 Thermal Impacts on Aquatic Organisms

In the GEIS (NRC 2013f), the NRC determined that thermal impacts on aquatic organisms is 

a Category 2 issue (see Table 4-8) that requires site-specific evaluation during each license 

renewal review for plants with once-through cooling systems or cooling ponds, such as 

Braidwood.

The NRC staff used a modified WOE approach to evaluate thermal impacts on the aquatic 

resources in the Kankakee River and Braidwood cooling pond. The NRC staff examined the 

five lines of evidence as follows.

LOE Description

1 Results of past NRC reviews on thermal impacts of Braidwood operations

2 A review of regulatory controls on thermal effluents

3 Results of a 2010 thermal study conducted at Braidwood

4 Consideration of fish kills at Braidwood

5 A review of available cooling pond monitoring data

LOE 1: Past NRC Reviews

The NRC (1984) previously assessed the potential thermal impacts of Braidwood operations in 

the FES-O. The NRC determined that the thermal plume would be relatively small. The 2 °F 

(1.1 °C) isotherm would range from 0.52 ac (0.21 ha) in April to 5.4 ac (2.2 ha) in October, and 

in all months, the 5 °F (2.8 °C) isotherm would occupy an area of less than 0.5 ac (0.2 ha), and 

the 10 °F (5.6 °C) isotherm would occupy an area of less than 0.1 ac (0.4 ha). Limitations set 

forth by the Illinois Administrative Code (IAC) and NPDES permit (discussed in LOE 2) would 

also limit thermal additions to the river. Thus, the NRC (1984) concluded that juvenile and adult 
Environmental Consequences and Mitigating Actions

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fish would be able to avoid the thermal plume. Impacts to the phytoplankton community were 

determined to be minor and of minimal duration because the residence time within the plume is 

short and the regeneration time of phytoplankton is rapid. The NRC determined that benthic 

organisms would not be significantly affected by blowdown discharge. The NRC also concluded 

that cold water shock would not create significant effects because blowdown discharged to the 

river originates from the cooling pond, which would cool slowly upon station shutdown.

The NRC (1984) characterized the cooling pond as a “stressed system” and determined that 

Braidwood operation would have an adverse effect on aquatic organisms in the pond during 

periods when pond temperatures exceed 30 °C (86 °F). The NRC noted that while it was 

possible that fish could avoid high temperatures by taking refuge in deeper, cooler areas of the 

cooling pond, high temperatures would also create algal blooms and subsequent periods of 

algal die-off, which would reduce dissolved oxygen (DO) in the water column and likely kill fish 

that would have otherwise been able to withstand the higher temperatures. The NRC 

determined that the effects of thermal additions to the cooling pond were discountable because 

the State had not identified the pond as a fishery resource and because the applicant had 

indicated that the pond would only be used for cooling purposes. Since that time, the IDNR has 

regularly stocked the lake with game fish, and a portion of the pond is managed as part of the 

Mazonia-Braidwood State Fish and Wildlife Area. The pond can be characterized as a 

managed ecosystem where IDNR fish stocking and other human activities primarily influence 

the species composition and population dynamics. The pond also provides quality habitat, food, 

and water to waterfowl and migrating birds.

The NRC’s regulations at 10 CFR 51 concerning license renewal reviews and the GEIS direct 

the NRC to consider all aquatic resources that may be affected by plant operations regardless 

of the type of water body in which such resources reside. For instance, Section 4.2.2 of the 

1996 GEIS specifically notes that aquatic biota of cooling ponds may be affected by thermal 

discharges and that these effects should be considered the same as those considered for 

once-through cooling systems except that such effects mainly influence aquatic communities 

that did not exist before the creation of the cooling pond. The 2013 GEIS did not identify new 

information that would alter this methodology or alter any conclusions regarding impacts to 

aquatic populations in cooling ponds. The NRC, therefore, no longer considers effects to the 

cooling pond to be discountable as stated in the FES-O (NRC 1984). Consideration of impact 

on aquatic resources in cooling ponds is consistent with previous NRC license renewal reviews 

(e.g., NRC 2008b, 2013e).

LOE 1 Conclusion

The NRC’s past review of the thermal impacts resulting from Braidwood operation indicate that 

the impacts to the Kankakee River aquatic community would be minor and unnoticeable, and 

therefore, SMALL. The impacts to the cooling pond aquatic community, however, were 

determined be noticeable and adverse. The FES-O does not provide enough information to 

assess whether these impacts would destabilize the community. Thus, the NRC concludes that 

thermal impacts on the cooling pond aquatic community would be MODERATE.

LOE 2: Regulatory Controls

The IAC and the Braidwood NPDES permit (IEPA 2014d) impose regulatory controls on 

Braidwood’s thermal effluent that ensure that impacts on the aquatic environment are reduced 

or mitigated.

Title 35, Environmental Protection, Section 302, “Water Quality Standards,” of the IAC contains 

stipulations pertaining to effluent temperature as well as mixing zones and zones of initial 
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dilution. The following limitations and requirements included in Section 302 pertain to effluent 

temperature and serve to protect aquatic biota from the effects of such effluents.

The maximum temperature rise shall not exceed 2.8 °C (5 °F) above natural 

receiving water body temperatures. [35 IAC 302.211(d)]

Water temperature at representative locations in the main river shall at no time 

exceed 33.7 °C (93 °F) from April through November and 17.7 °C (63 °F) in other 

months. [35 IAC 302.211(e)]

Several IAC stipulations pertaining to mixing zones also protect aquatic biota from 

thermal effluents.

Mixing is not allowed in waters which include a tributary stream entrance. 

[35 IAC 302.102(b)(2)]

Mixing is not allowed in waters containing mussel beds, endangered species

habitat, fish spawning areas, areas of important aquatic life habitat, or any other 

natural features vital to the well-being of aquatic life. [35 IAC 302.102(b)(4)]

Mixing must allow for a zone of passage for aquatic life. [35 IAC 302.102(b)(6)]

The area and volume of mixing must not contain more than 25 percent of the 

cross-sectional area or volume of a stream and must not intersect any body of 

water in such a manner that the maintenance of aquatic life in the body of water 

as a whole would be adversely affected. [35 IAC 302.102(b)(7) and (8)]

The area and volume in which mixing occurs must be as small as is practicable, 

and in no circumstances larger than 26 ac (11 ha). [35 IAC 302.102(b)(12)]

The Braidwood NPDES permit (IEPA 2014d) also contains requirements related to thermal 

effluents. Special Condition 4 of the permit mirrors the temperature requirements at 

35 IAC 302.211 listed above. Additionally, the special condition requires that water temperature 

at the edge of the mixing zone not exceed 60 °F from December through March during more 

than 1 percent of the hours in a 12-month period and that at no time shall the water temperature 

at such locations exceed the maximum limits by more than 3 °F (i.e., 63 °F).

In the past 5 years, Braidwood has reported one noncompliance with Special Condition 4 to 

the IEPA. In March 2012, blowdown water discharged as effluent to the Kankakee River at 

Outfall 001 exceeded the permitted temperature limits at points beyond the mixing zone edge 

due to a period of extremely warm weather and little to no precipitation in Illinois (Exelon 2014l). 

On March 19, 2012, ambient water temperature upstream of Braidwood was recorded at 67.5 °F 

(IEPA 2012b). Accordingly, any thermal addition to the river would have exceeded the 

permitted limit of 63 °F. On March 22, 2012, the IEPA (2012b) granted a provisional variance 

from the requirements of the special condition that allowed temperatures to increase to a 

maximum of 70 °F at the edge of the mixing zone from March 21 through March 31, 2012. The 

provisional variance required Exelon to monitor the river for adverse environmental effects, such 

as fish mortalities. Exelon has not reported any such effects to the IEPA or NRC as a result of 

the variance.

LOE 2 Conclusion

Braidwood thermal effluent is limited by the IAC and the Braidwood NPDES permit to ensure 

that it does not create adverse effects on the aquatic communities in the Kankakee River. In 

the past 5 years, Exelon applied for and the IEPA granted one provisional variance to allow 

higher-than-permitted temperatures at the edge of the discharge mixing zone caused by a 

period of extremely warm weather and little to no precipitation. Exelon reported no fish kills or 

other events to the IEPA or the NRC that would indicate adverse environmental effects resulting 
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from the provisional variance. The NRC depends on the State to enforce the regulatory controls 

in place at Braidwood and effectively ensure that any environmental effects to Kankakee River 

aquatic communities are not detectable or so minor as to neither destabilize nor noticeably alter 

the community. Thus, this LOE indicates that thermal impacts to Kankakee River aquatic 

organisms would be SMALL during the proposed license renewal term.

LOE 3: Thermal Modeling

In 2009, Exelon commissioned HydroQual Environmental Engineers and Scientists, Inc., to 

develop a model that would assess the mixing zone and thermal impact of replacing the 

Braidwood discharge canal with a multi-port diffuser, a project that was later completed in 2010. 

As part of the modeling, Thuman (2009a) developed a CORMIX model for several different 

diffuser configurations; only the 7-port diffuser is discussed here as this was the configuration 

that was installed. The CORMIX simulation indicated that under normal blowdown rates 

(1,199 L/sec [19,000 gpm]) and extreme low river flow, the largest area that would experience 

the IAC’s maximum allowable temperature rise of 2.8 °C (5.0 °F) would occur in March and 

would extend approximately 64 ft (19.6 m) downstream. With lower or higher blowdown rates, 

the area of water exhibiting a 2.8 °C (5.0 °F) rise ranged from 48 to 72 ft (14.5 to 22 m).

The CORMIX model also indicated that under no scenario did the thermal plume exceed 

25 percent of the cross-sectional area of the river, in accordance with 35 IAC 302.102(b)(8). 

Thuman (2009a) estimated the cross sectional area to vary from 9.3 percent of the river’s 

cross-sectional area (in April) to 24.8 percent (in November). The surface area of the plume 

was determined to be 0.22 ac (0.1 ha).

LOE 3 Conclusion

The available thermal model indicates that Braidwood’s thermal effluent complies with the 

requirements of the IAC. As indicated in the previous LOE, the NRC relies on the State through 

its NPDES permitting process to ensure that thermal effluents do not create adverse effects on 

aquatic communities. Thus, this LOE is consistent with LOE 2’s conclusion of SMALL for 

Kankakee River aquatic organisms. 

LOE 4: Fish Kills

Since 2001, Exelon has identified six fish kill events in the Braidwood cooling pond; 

Section 3.7.4 describes these events. Exelon (2013c) attributes most of the fish kills to high 

temperatures in the cooling lake associated with operation of the Braidwood cooling system. 

Each event resulted in the mortality of several hundred to several thousand fish. The largest 

of these events occurred in June 2005 and included approximately 10,000 dead fish 

(Exelon 2005). Affected species have included gizzard shad, threadfin shad (Dorosoma 

petenense), channel catfish (Ictalurus punctatus), carp, bass, and other unspecified game fish 

species. The NRC expects that fish kills would continue during the proposed license renewal 

period based on HDR Engineering’s (2013) assessment, which states that “there are no 

practical or simple solutions that could prevent the occurrence of fish die-offs at 

Braidwood Lake.”

Because the cooling pond is a highly managed system that is stocked annually by the IDNR, 

the impact of fish kills on game species is difficult to quantify because population declines are 

temporary and may be localized within the cooling pond. While stocked species populations will 

rebound following fish kills upon restocking, non-stocked species could experience noticeable 

declines as a result of fish kills. As indicated in Section 3.7.3.2, gizzard shad, one of the most 

frequently affected species during periods of elevated pond temperatures, have decreased in 

abundance dramatically in recent years. Threadfin shad are also often affected by elevated 
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pond temperatures and have been present in a number of the fish kills described in 

Section 3.7.4.

Exelon (2015b) notes that the current lease between Exelon and IDNR for IDNR to manage 

and stock a portion of the cooling pond expires in 2026. Accordingly, there is no definitive 

mechanism for the State to stock the lake beyond this time period unless Exelon and IDNR 

renew the lease agreement at that time. Nevertheless, the NRC staff assumes that some 

stocked fish populations would continue to occur in the cooling pond throughout the proposed 

license renewal period without stocking, although the distribution of species and population 

sizes may change without artificial replenishment and with the elimination of recreational 

fishing pressure.

Exelon has not reported any fish kills on the Kankakee River since Braidwood began operating.

LOE 4 Conclusion

No fish kills have occurred on the Kankakee River. Thus, this LOE indicates that the effects 

of the thermal discharge on Kankakee River aquatic biota are not detectable and, therefore, 

SMALL.

Information on fish kills in the cooling pond indicates noticeable effects that are likely to persist 

while Braidwood is operational. Because the cooling pond is a highly managed system, the 

impacts to stocked species are difficult to determine because they are replenished annually. 

Accordingly, the NRC staff concludes that the effects of the thermal discharge on cooling pond 

aquatic biota as a whole are not detectable, and, therefore, SMALL. However, gizzard shad 

would likely experience MODERATE impacts due to noticeable declines in the species’ 

population over the course of Braidwood operation, which is likely the result of fish kill events.

LOE 5: Cooling Pond Fish Sampling Data

Section 3.7.3.2 discusses Braidwood cooling pond fish sampling that IDNR has conducted since 

1980 and HDR Engineering has conducted since 2009. The sampling data indicate that the 

cooling pond’s species composition has noticeably shifted towards heat-tolerant species. In 

particular, bluegill, which accounted for 9.6 percent of preoperational samples, increased to 

23.5 percent during the IDNR operational samples (1988–2007) and to 28.4 percent in 

HDR Engineering operational samples (2009–2012). Gizzard shad, one of the most frequently 

affected species during periods of elevated pond temperatures, has decreased in abundance 

dramatically; it was the most abundant species in preoperational surveys, while it only 

accounted for 5.0 percent of HDR Engineering’s 2009–2012 samples. IDNR-stocked warm 

water game species, such as largemouth bass and blue catfish, have persisted in small 

numbers, while cooler water stocked species, such as walleye and tiger muskellunge, a usually 

sterile hybrid of true muskellunge (Esox masquinongy) and the northern pike (Esox lucius), 

appear to no longer be present in the pond. HDR Engineering (2013) notes that with the 

exception of common carp and channel catfish, survival of many of the species in the cooling 

pond is limited by elevated water temperatures in the summer months.

LOE 5 Conclusion

This LOE indicates that the cooling pond’s aquatic community has noticeably changed over the 

course of Braidwood’s operation. The effects of IDNR stocking and other management efforts 

on fish may be contributing to this effect. However, fish sampling data paired with the fish kill 

information in LOE 4 indicate that operation of the Braidwood cooling system is also a 

contributing factor. As with LOE 4, this LOE indicates that the effects of the thermal discharge

on cooling pond aquatic biota are likely SMALL overall, but MODERATE for gizzard shad. 
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Summary of Thermal Impacts Conclusion

Based on past and present impacts to aquatic resources resulting from Braidwood operation, 

the NRC concludes that thermal impacts associated with the proposed license renewal would 

result in SMALL impacts to aquatic resources in the Kankakee River and SMALL to 

MODERATE impacts to aquatic resources in the cooling pond. MODERATE impacts would 

primarily be experienced by gizzard shad and other non-stocked and low–heat tolerant species.

The applicant has proposed no mitigation to reduce the MODERATE environmental impacts 

associated with thermal discharges to gizzard shad in the cooling pond. However, because the 

cooling pond is a highly managed system, any cascading effects resulting from the loss of 

gizzard shad (such as a reduction in prey for stocked species, which in turn could affect a 

stocked species’ population) could be mitigated through IDNR’s annual stocking and continual 

management of the pond.

4.7.1.4 Water Use Conflicts With Aquatic Resources

In the GEIS (NRC 2013f), the NRC determined that effects of water use conflicts on aquatic 

resources is a Category 2 issue (see Table 4-8) that requires site-specific evaluation during 

each license renewal review. Water use conflicts occur when the amount of water needed to 

support aquatic resources is diminished as a result of demand for agricultural, municipal, or 

industrial use or decreased water availability due to droughts, or a combination of these factors.

As indicated in Section 4.5.1.1, the mean annual discharge for the Kankakee River measured at 

the USGS gaging station no. 05527500 at Wilmington, Illinois for water years 1934 through 

2012 is 4,805 cfs (136 m3/s) (USGS 2012). As described in Section 3.5.1.2, the average annual 

consumption for the Braidwood site from the Kankakee River is 41 cfs (1.14 m3/s). Thus, 

Braidwood typically consumes 0.9 percent of Kankakee River’s average flow, and the plant 

could consume up to 2.9 percent of the river water volume when the lowest annual mean flow 

recorded for the Kankakee River at the Wilmington gaging station is taken into account. In 

times where the river flow is low, Exelon has an agreement with the IDNR to limit Kankakee 

River water consumption such that withdrawal of makeup water does not cause the Kankakee 

River flow to drop below 12,517 L/sec (442 cfs) (Exelon 2013c). Exelon maintains procedures 

to comply with these withdrawal restrictions, which would continue during the proposed license 

renewal term (Exelon 2013c).

The amount of Kankakee River water Braidwood consumes is minor in comparison to the flow 

of water past the plant, and regulatory mechanisms are in place to ensure that Braidwood does 

not consume an amount that would be harmful to aquatic biota during low flow conditions. The 

NRC staff did not identify any information that indicates that the Kankakee River biota are 

affected by the loss of river water consumed by Braidwood’s makeup water withdrawals. The 

NRC staff concludes that water use conflicts would not occur from the proposed license renewal 

or would be so minor that the effects on aquatic resources would be undetectable. Thus, the 

NRC staff concludes that the impacts of water use conflicts on aquatic resources during the 

proposed license renewal term would be SMALL.

4.7.2 No-Action Alternative

If Braidwood were to cease operating, impacts to aquatic ecology would decrease or stop 

following reactor shutdown. Some withdrawal of water from the Kankakee River would continue 

during the shutdown period as the fuel is cooled, although the amount of water withdrawn would 

decrease over time. The reduced demand for cooling water would substantially decrease the 

effects of impingement, entrainment, and thermal effluents. These effects would likely stop 

following the removal of fuel assemblies from the reactor cores. Given the small area of the 
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thermal plume in the Kankakee River under normal operating conditions, effects from cold

shock are unlikely. The cooling pond, however, would likely experience shifts in the relative 

abundances of fish populations because less heat-tolerant species would no longer be stressed 

by thermal additions to the pond. Some fish populations, such as stocked recreational species 

that thrive in warmer waters, may experience population declines or cease to occur in the 

cooling pond.

The continuation of the lease agreement between Exelon and the IDNR for the 

Mazonia-Braidwood State Fish and Wildlife Area could be affected by decommissioning. 

Loss of these lands as a State-managed area could result in impacts to aquatic resources in the 

cooling pond depending upon any future land use of the site. The GEIS (NRC 2013f) notes that 

aquatic resource impacts could occur in other areas beyond the immediate nuclear plant site as 

a result of the no-action alternative if new power plants are needed to replace lost capacity.

NUREG–0586, Generic Environmental Impact Statement on Decommissioning of Nuclear 

Facilities, Supplement 1, (NRC 2002d) concludes generically that impacts to aquatic ecology 

during decommissioning activities would be SMALL for facilities at which the decommissioning 

activities would be limited to existing operational areas. In the case of Braidwood, the NRC staff 

did not identify any effects that would have more than minor effects on aquatic resources. Thus, 

the NRC staff concludes that the impacts of the no-action alternative on aquatic resources 

during the proposed license renewal term would be SMALL.

4.7.3 New Nuclear Alternative

Construction of a new nuclear alternative would occur at an existing nuclear power plant site 

(other than the Braidwood site) or a retired coal plant site. Construction activities could degrade 

water quality of nearby streams, ponds, or rivers through erosion and sedimentation; result in 

loss of habitat through pond or wetland filling; or result in direct mortality of aquatic organisms 

from dredging or other in-water work. Due to the short-term nature of construction activities, 

these effects would likely be relatively localized and temporary. Siting the plant on an existing 

site could make use of existing transmission lines, roads, parking areas, and other 

infrastructure, which would limit the amount of habitat disturbance that would be required. Less 

habitat disturbance would create less erosion and sedimentation. The construction of intake 

and discharge structures could result in direct mortality of individuals as well as water quality 

degradation. Appropriate permits would ensure that water quality impacts would be addressed 

through mitigation or BMPs, as stipulated in the permits. The U.S. Environmental Protection 

Agency, U.S. Army Corps of Engineers, or the State would oversee applicable permitting, 

including a CWA Section 404 permit, Section 401 certification, and Section 402(p) NPDES

general stormwater permit. The NRC (2013b) has completed the review of one combined 

license application to build and operate a new nuclear plant in the ROI (Enrico Fermi 3 in 

Michigan) and concluded that construction would have SMALL impacts on aquatic resources. 

Without more specific details on the location of the new nuclear alternative, the NRC staff finds 

it reasonable to adopt its previous construction conclusions regarding Enrico Fermi 3 for the 

construction portion of this alternative.

Operational impacts would include those listed in Table 4-8, and the GEIS (NRC 2013f) 

conclusions of SMALL for Category 1 issues in the table would apply during the operational 

phase of the new nuclear alternative. Because this alternative would use a closed-cycle 

system, impingement, entrainment, and thermal effects would also be SMALL. Water use 

conflicts with aquatic resources would depend on the site location, water body, and specific 

aquatic community present and cannot be determined without more specific details on the 

location of this alternative.
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The NRC staff concludes that the impacts to aquatic resources from construction and operation 

of a new nuclear alternative would be SMALL.

4.7.4 Coal (Integrated Gasification Combined Cycle) Alternative

Construction of an IGCC alternative would occur at the Braidwood site or another existing power 

plant site in the ROI. The GEIS (NRC 2013f) indicates that the impacts of new power plant 

construction on ecological resources would be qualitatively similar. Thus, those impacts 

discussed under the new nuclear alternative would apply during the construction phase. 

Because the IGCC alternative would require significantly more land than the new nuclear 

alternative (2,000 ac [202 ha] versus 355 ac [144 ha]), the magnitude of impacts would likely be 

greater and could create noticeable effects on aquatic resources. Thus, construction impacts 

would be MODERATE.

Operation of the IGCC alternative would require less cooling water than Braidwood because the 

plant would operate with a closed-cycle system. Accordingly, impingement, entrainment, and 

thermal effects on aquatic resources would likely be smaller than for continued operation of 

Braidwood, though the exact magnitude would depend upon the water body and specific aquatic 

communities present. Chemical discharges from the cooling system would be similar to those 

at Braidwood. Operation would require coal deliveries, cleaning, and storage, which would 

require periodic dredging (if coal is delivered by barge); create dust, sedimentation, and 

turbidity; and introduce trace elements and minerals into the water. Air emissions from the 

IGCC units would include small amounts of sulfur dioxide, particulates, and mercury that would 

settle on water bodies or be introduced into the water from soil erosion. If the IGCC plant was 

located on the same water body (the Kankakee River) in the vicinity of the Braidwood site, 

overall operational impacts would be less than for the continued operation of Braidwood 

because of the reduced impingement, entrainment, and thermal effects. However, without 

knowing the location of the IGCC plant, the associated water body, aquatic species, and their 

interactions within the ecosystem, the NRC staff cannot assume that overall impacts of 

operation of an IGCC plant would be less than those for the continued operation of Braidwood,

which were determined to be SMALL for some issues and MODERATE for others.

The NRC staff concludes that the impacts to aquatic resources from construction of an IGCC 

plant would be MODERATE and the impacts of operation would be within the range of SMALL 

to MODERATE.

4.7.5 Natural Gas Combined Cycle Alternative

Construction of an NGCC alternative would occur at the Braidwood site or another existing 

power plant site in the ROI. The GEIS (NRC 2013f) indicates that the impacts of new power 

plant construction on ecological resources would be qualitatively similar. Thus, those impacts 

discussed under the new nuclear alternative would apply during the construction phase. 

Construction of new pipelines, if necessary, could impact previously undisturbed habitats. This 

impact would vary depending on the location of the plant and would be more likely to impact 

terrestrial resources than aquatic resources. Because the NGCC alternative would be built on 

an existing power plant site, new pipelines could be collocated in existing corridors to reduce 

impacts. Overall, construction impacts would be SMALL.

Operation of the NGCC alternative cooling system would be qualitatively similar to the IGCC 

alternative but would result in smaller impacts because the NGCC alternative would consume 

about half as much cooling water. Air emissions from the NGCC units would include nitrogen 

oxide, carbon dioxide, and particulates that would settle on water bodies or be introduced into 

the water from soil erosion. If the NGCC plant was located on the same water body (the 
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Kankakee River) in the vicinity of the Braidwood site, overall operational impacts would be less 

than for the continued operation of Braidwood due to the reduced impingement, entrainment, 

and thermal effects. However, without knowing the location of the NGCC plant, the associated 

water body, aquatic species, and their interactions within the ecosystem, the NRC staff cannot 

assume that overall impacts of operation of an NGCC plant would be less than those for the 

continued operation of Braidwood, which were determined to be SMALL for some issues and 

MODERATE for others.

The NRC staff concludes that the impacts to aquatic resources from construction of an IGCC 

plant would be SMALL and the impacts of operation would be within the range of SMALL to 

MODERATE.

4.7.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

The NGCC portion of this alternative could be located at the Braidwood site or another existing 

power plant site in the ROI. Construction and operation impacts would be qualitatively similar to 

those discussed for the NGCC alternative, but would be much less in magnitude because of the 

smaller footprint of the plant, reduced cooling water consumption, and lowered air emissions. 

The wind and solar portions of the alternative, which account for 90 percent of the alternative’s 

power generation, would not require cooling or consumptive water use during operation, and 

thus, would not affect aquatic resources. The NRC staff concludes that the impacts on aquatic 

resources from the combination alternative would be SMALL.

4.7.7 Purchased Power

The purchased power alternative would have wide-ranging impacts that are hard to specifically 

assess because this alternative could include a mixture of coal, natural gas, nuclear, and wind 

across many different sites in the ROI. This alternative would likely have little to no construction 

impacts because it would include power from already-existing power generating facilities, and 

the types of operational impacts would be similar to the effects discussed in the preceding 

alternative sections. This alternative would be more likely to intensify already existing effects 

at power generating facilities than create wholly new effects on aquatic species and habitats. 

Existing facilities would likely have permits with appropriate mitigation, BMPs, or other 

procedures in place to ensure that effects to the environment during operations are minimized. 

The NRC staff concludes that the impacts on aquatic resources from the purchased power 

alternative would be SMALL.

4.8 Special Status Species and Habitats

This section describes the potential impacts of the proposed action (license renewal) 

and alternatives to the proposed action on special status species and habitats.

Section 3.8 of this SEIS describes the special status species and habitats that have the 

potential to be affected by the proposed action. The discussion of species and habitats 

protected under the Endangered Species Act of 1973, as amended (ESA), includes a 

description of the action area as defined by the ESA section 7 regulations at 50 CFR 402.02. 

The action area encompasses all areas that would be directly or indirectly affected by the 

proposed Braidwood license renewal.

Table 4–17 lists the one site-specific (Category 2) issue related to special status species and 

habitats applicable to Braidwood. Appendix C contains information on the NRC staff’s section 7 

consultation with the U.S. Fish and Wildlife Service (FWS) for the proposed action.
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Table 4–17. Special Status Species and Habitat Issues 

Issue GEIS Section Category

Threatened, endangered, and protected species, critical habitat and 

essential fish habitat 4.6.1.3 2 

Source: Table B–1 in Appendix B, Subpart A, to 10 CFR Part 51

Correspondence

NRC staff identified no Federally listed species or Essential Fish Habitat (EFH) under 

National Marine Fisheries Service (NMFS) jurisdiction that would occur near Braidwood. On 

September 11, 2013, NRC (2013h) sent a letter to FWS requesting concurrence with a list of 

Federally listed species that might occur in the action area for Braidwood. On 

September 24, 2013, FWS (2013) replied with a letter that included scoping comments and 

comments on the NRC’s list of Federally-listed species for Braidwood. Following release of the 

2013 GEIS, which redefines the in-scope area of transmission lines for the purposes of NEPA

(staff’s review), the NRC decided to change geographic scope of the Braidwood SEIS (related 

to transmission lines) to follow the 2013 GEIS in regard to transmission lines. This change of 

in-scope area altered the list of listed species compared to NRC’s September 11 letter to FWS.

FWS’s (2013) comments note the possible presence of the Federally listed mussels, sheepnose 

(Plethobasus cyphyus) and snuffbox (Epioblasma triquetra), and requests that NRC give 

particular attention “to potential impacts from water quality (including temperature) and water 

quantity that may result from proposed operations” on those species. FWS (2013) also notes 

that northern long-eared bat (Myotis septentrionalis) is found in the project vicinity. FWS 

(2015b) commented on NRC’s assessment and determinations for Federally listed species in 

the draft supplemental environmental impact statement (DSEIS). The “Analysis and 

Determination of Effects” below incorporates new information resulting from those comments 

and NRC’s continued consultation with FWS.

4.8.1 Special Status Species and Habitats Impacts of License Renewal (Proposed Action)

Analysis and Determination of Effects

The NRC staff concludes that, of the Federally listed species identified in Section 3.8, none 

outside of the three species identified by FWS (2013) and the eastern massasauga (Sistrurus 

catenatus) rattlesnake, which FWS proposed for listing as threatened in September 2015, would 

occur in the action area based on habitat requirements, life history, wildlife and fish surveys and 

studies, and other available information. In addition, no designated or proposed critical habitat

under the ESA occurs in the action area. The NRC staff concludes that the proposed action 

would have no effect on those Federally listed and candidate species that do not occur within 

the action area. Concurrence from the FWS is not required in the case of no-effect findings. 

Assessments for the four other species follow.

ESA regulations at 50 CFR 402.12(f)(4) direct Federal agencies to consider cumulative effects 

as part of the proposed action effects analysis. Under the ESA, cumulative effects are defined 

as “those effects of future State or private activities, not involving Federal activities, that are 

reasonably certain to occur within the action area of the Federal action subject to consultation” 

(50 CFR 402.02). Unlike the NEPA definition of cumulative impacts (see Section 4.16), 

cumulative effects under the ESA do not include past actions or other Federal actions requiring 
Environmental Consequences and Mitigating Actions

4-73

separate ESA section 7 consultation. When formulating biological opinions under formal 

section 7 consultation, the FWS and NMFS (1998) consider cumulative effects when 

determining the likelihood of jeopardy or adverse modification. Therefore, consideration of

cumulative effects under the ESA is necessary only if listed species will be adversely affected 

by the proposed action (FWS 2014b).

Endangered Sheepnose and Snuffbox Mussels

These freshwater mussels species are Federally listed as endangered. They are both members 

of the family Unionidae, members of which have similar life histories in which eggs are brooded 

by the females, larvae are typically expelled into fish and must attach to the host fish’s gills or 

fins to complete development, after which they drop off the fish host as they transform to 

juveniles, and thereafter the juveniles and adults live in the river or stream substrate. Because 

the larvae are attached to host fish and juveniles and adults live in the river bottom, they are not 

directly susceptible to entrainment or impingement by power plants. Larvae are indirectly 

susceptible if the host fish species is susceptible. All life stages are directly or indirectly 

susceptible to dredging and to power plant effluents due to temperature and current alterations 

and chemical contaminants.

In conjunction with Exelon’s proposal to replace Braidwood’s cooling pond discharge, then a 

shoreline discharge channel, with a diffuser pipe placed on the bottom of and extending across 

the Kankakee River, HDR Engineering (2008) sampled the potentially affected Kankakee River 

reach for fish and freshwater mussels during August 4 – 8, 2008. The Kankakee River supports 

some of Illinois’ most diverse and abundant mussel populations (HDR 2008; Page et al. 1992), 

and HDR Engineering’s (2008) literature review identified 27 extant and 40 historical species 

from the river. HDR Engineering’s mussel sampling included 15 person-hours of hand picking 

along the shoreline and nine 220-m (240-yd) brail (a type of sampling gear used for freshwater 

mussels) transects. HDR Engineering concluded that the Kankakee River in the immediate 

vicinity of the Braidwood Station discharge channel, like the Kankakee River in general, 

supports a diverse and abundant mussel fauna.

The habitat at the south shore upstream of the discharge channel was silted-sand with small 

patches of mud and gravel, which is conducive for large mussel populations, while the habitat 

at the north shore was mud and rip-rap, not conducive for freshwater mussel populations. The 

habitat along the south shore downstream of the discharge channel was silted-sand with large 

fluctuations in water temperature mostly unsuitable for freshwater mussels. HDR Engineering 

(2008) could not sample or assess habitat in the center channel, which was over 2-m (about 

2 yd) deep, but did find mussels in river channel areas upstream of the Braidwood Station 

discharge channel. HDR Engineering reported collecting a total of 212 live individuals from 

15 species alive during the survey. The collections included one fresh-dead sheepnose and 

no snuffbox individuals or shells.

Ecological Specialists, Inc. (Belt 2009), conducted a mussel survey in October 2008 to 

supplement the HDR Engineering survey. The supplemental survey employed divers sampling 

along transects about 100 yards (about 100 m) above and below Exelon’s then proposed 

diffuser pipe location and was designed to include depths greater than 2 yards (about 2 m) and 

to provide information on distribution of species and the composition of the mussel community 

that could not be obtained by HDR Engineering’s brail sampling methods. Ecological 

Specialists, Inc., reported collecting no sheepnose and no snuffbox individuals or shells. They 

also recorded water depth and substrate type (Wentworth scale) at sampling sites. They found 

that mussel species were scattered throughout the survey area without observable correlation of 

habitat with distribution, so that any species might occur throughout their sampling area.
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Price et al. (2012) sampled 20 sites in the Kankakee River for freshwater mussels from June

through September 2010. The methods were hand grabbing and visual detection (e.g., trails, 

siphons, exposed shell) when water conditions permitted for 4 hours at each site in all available 

habitat types present at a site including riffles, pools, slack water, and areas of differing 

substrates. They found no snuffbox and concluded, based on their own survey and historical 

records, that the species had been extirpated from the Kankakee River. They found sheepnose 

at two sites.

Page et al. (1992) found that at that time no live snuffbox had been reported for 30 years and 

that the species was probably extirpated in the Kankakee River drainage. Subsequent mussel 

sampling studies (Belt 2009; HDR 2008; Price et al. 2012) reached a similar conclusion. The 

NRC staff concludes that the species has probably been extirpated from the Kankakee River so 

that continued operation of Braidwood would have no effect on snuffbox.

Price et al. (2012) reported live sheepnose in the Kankakee River, and HDR Engineering (2008) 

found a recently dead individual near the Braidwood’s then proposed diffuser pipe location in 

the river. Ecological Specialists, Inc. (Belt 2009), found that mussel species in the Kankakee 

River near the diffuser pipe were scattered throughout the survey area with observable 

correlation of habitat with distribution so that mussel species might occur throughout the 

sampling area. The FWS (77 FR 14914) found that decline of the species is primarily the 

result of habitat loss and degradation, and the main causes specifically include impoundments, 

channelization, chemical contaminants, mining, and sedimentation. Imminent threats also 

include climate change, temperature alterations, exotic species, and population fragmentation 

and isolation (77 FR 14914). Compared to the historical distribution, the presently fragmented 

populations are more susceptible to extirpation from single catastrophic events, such as toxic 

chemical spills, and also have a more limited ability to recolonize historically occupied streams 

and river reaches (77 FR 14914).

Sheepnose larvae are indirectly susceptible to impingement and entrainment of host fish, and 

the only known natural host species for sheepnose is sauger (Sander canadensis). Juvenile 

and adult sauger were not reported in surveys of the Kankakee River near the Braidwood intake 

or impingement collections in 1988 and 1989, and eggs and larvae were not reported from 

samples in the river or from entrainment collections in the same years (EA Engineering 1990). 

Monitoring studies of fish in the Kankakee River near Braidwood in the last 5 years also has not 

reported sauger in the collections (e.g., HDR 2009, 2013, 2014). Assuming that the results 

reflect future conditions, the indirect effect of impingement and entrainment of sauger on 

sheepnose from now until 20 years beyond the expiration of Braidwood’s present operating 

licenses is likely to be insignificant. Golden shiner (Notemigonus crysoleucas) is a host species 

that FWS (2014a) has used in laboratory to culture sheepnose. The FWS (77 FR 14914) also 

reports that, in laboratory studies, sheepnose glochidea have successfully transformed on 

several other species, including fathead minnow (Pimephales promelas), creek chub (Semotilus 

atromaculatus), central stoneroller (Campostoma anomalum), and brook stickleback (Culaea 

inconstans), although interactions between these species and sheepnose may be rare and 

infrequent in nature due to habitat preferences. Of these species, fathead minnow and golden 

shiner appear in impingement collections in low numbers, but the expected infrequent 

interaction of these species with sheepnose and the uncertainty that these species are natural 

hosts indicate that the indirect effects of impingement on these possible host species are likely 

to be insignificant. Future studies may identify additional natural host species for sheepnose 

that might modify this conclusion.

Sheepnose are also susceptible from direct and indirect effects (through host fish species) of 

Braidwood’s effluent due to temperature and current alterations and to chemical contaminants. 

The IEPA, not the NRC, regulates the discharge through its Illinois NPDES permitting program 
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to insure protection of aquatic species, and Braidwood must have an Illinois NPDES permit to 

operate.

In comments on the DSEIS, FWS (2015b) did not concur with NRC’s initial finding of “may 

affect, not likely to adversely affect” for the endangered sheepnose, because insufficient recent 

information was available to adequately determine the nature of effects and to determine the 

possible occurrence of sheepnose in the action area. Exelon proposed to conduct a mussel 

survey in the Kankakee River (Belt and Dunn 2015; Exelon 2015c) and submit the result for 

FWS and NRC staff review. The FWS (2015a) reviewed the proposal and indicated no 

concerns with the proposed survey.

Ecological Specialists, Inc. (Belt and Dunn 2015), recently conducted a study to update the 

distribution and species composition of mussels within previously surveyed areas of the 

Kankakee River near Braidwood. The study employed more intensive sampling than previous 

studies to increase the likelihood of finding State and Federally protected species. ESI 

concluded that habitat within the study area has not changed since construction of the 

Braidwood diffuser or within 5 years of diffuser operation and remains marginal habitat for 

unionids. ESI reported that, although Federally protected mussels have recently been found in 

the lower Kankakee River, no live Federally protected species have been observed within the 

Braidwood study area in the past 20 years. Individuals may move into and out of the study area 

with bedload transported by river current, and so the presence of Federally protected mussels 

cannot be ruled out as individuals could move into the study area in the future. ESI concluded 

that unionids do not seem to be affected by current Braidwood operations, because live mussels 

occur within and downstream of the mixing zone. Furthermore, ESI concluded that the 

construction and operation of the Braidwood diffuser should not impact the population of 

sheepnose within the Kankakee River, and, furthermore, if future Braidwood operating 

conditions remain similar to the past 10 years, sheepnose should not be affected.

The ESA section 7 consultation regarding sheepnose is presently in the “technical assistance” 

phase. In the DSEIS, the NRC staff made a biological assessment that the operation of 

Braidwood’s cooling water intake system may, but is not likely to, adversely affect

sheepnose. The NRC finds no new information in the September 2015 mussel survey to 

warrant changing that finding. Following FWS’s review of the mussel survey, the NRC and 

FWS may either enter into formal section 7 consultation or conclude the present consultation

regarding sheepnose. The NRC plans to present the final result of that consultation in the 

Record of Decision for the proposed renewal of Braidwood’s operating licenses.

Due to lack of evidence that snuffbox occurs in the action area, the NRC finds that operation of 

Braidwood’s cooling water intake system would have no effect on snuffbox.

Threatened Northern Long-Eared Bat

In October 2013, FWS (78 FR 61046) found that listing of this species is warranted, and it 

proposed to list the northern long-eared bat as an endangered species throughout its range. 

The FWS also found that it could not determine critical habitat for this species at this time. The 

FWS more recently listed the northern long-eared bat as threatened throughout its range on 

April 2, 2015 (80 FR 17974).

The FWS reports that surveys in Shawnee National Forrest in Illinois, about 300 mi south of 

Braidwood, consistently catch northern long-eared bats, and FWS (2013) states that they may 

be found on the Braidwood site. Winter hibernacula do not occur on the Braidwood site, but 

they migrate out of the hibernacula in summer, when they forage at night and roost during 

daylight in small numbers in live and dead trees and change roosts often.
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Regarding a section 7 consultation for northern long-eared bat, the FWS (78 FR 61046) says: 

Federal agency actions within the species’ habitat that may require conference or 

consultation or both...include management and any other landscape-altering 

activities on Federal lands administered by the U.S. Fish and Wildlife Service, 

U.S. Forest Service, NPS, and other Federal agencies; issuance of section 404 

Clean Water Act (33 U.S.C. 1251 et seq.) permits by the U.S. Army Corps of 

Engineers; and construction and maintenance of roads or highways by the 

Federal Highway Administration.

Over the duration of the proposed license renewal term, Exelon (2013c) reports no plans for 

landscape-altering activities, such as those that might adversely affect northern long-ear bats.

The FWS (78 FR 61046) identified the primary threat to northern long-ear bat as white nose 

syndrome, a disease caused by the fungus Geomyces destructans, and other sources of 

mortality to the species include wind-energy development, habitat modification, destruction and 

disturbance (e.g., vandalism to hibernacula, roost tree removal), effects of climate change, and 

contaminants.

Exelon (2013c) states in its assessment for Indiana bats (Myotis sodalis) that the Braidwood 

property offers no undisturbed natural habitat, no large blocks of mature forest, and no high 

quality roost habitat for bats, and in fact is “a noisy (PA [public address] system, pumps, diesels, 

heavy equipment), lighted industrial facility” where Indiana bats are not likely to be found. 

Compared to Indiana bats, however, northern long-ear bats are more opportunistic in roost 

selection and may roost in live trees, man-made structures, and other places where Indiana 

bats might not roost (78 FR 61046). Exelon (2014d) describes the Braidwood site as occupying 

about 4,457 ac (1,804 ha) with the following land uses: 2,540 ac (1,030 ha) of water, 264 ac 

(107 ha) in industrial use (including makeup-blowdown pipeline and river screen house), 67 ac 

(27 ha) in agriculture, 1,280 ac (518 ha) of former strip mine areas leased for recreation, and 

306 ac (124 ha) of former strip mine and re-vegetated areas not used for recreation. This site 

would probably not provide prime habitat for long-ear bats even though they are more 

opportunistic than Indiana bats in roost selection.

Exelon (2015a) reports that it does not expect tree clearing to be a recurring activity at the 

Braidwood site. Some tree clearing occurs near the meteorological tower to minimize the 

effects of obstructions to airflow in accordance with NRC Regulatory Guide 1.23, but past 

tree clearing there has prevented growth of mature trees that might have served as northern 

long-eared bat habitat and future tree clearing will not affect such habitat further. FWS (2015a)

has informed Exelon that if Exelon does propose tree clearing, the FWS should be informed and 

Exelon should follow the FWS recommendations provided to both the NRC and Exelon. Exelon 

(2015a) says that when it issues work orders for tree clearing near the meteorological tower, the 

orders will “include guidance to minimize effects on northern long-eared bats, such as restricting 

tree removal activities to months when bats would not be present.”

Due to the lack of suitable habitat on the Braidwood site, and due to the mitigation measures 

recommended by FWS and proposed by Exelon if tree clearing were to occur, the NRC staff 

concludes that the proposed action would have no effect on northern long-eared bat.

Proposed Eastern Massasauga (Sistrurus catenatus)

The FWS (76 FR 66370) listed the eastern massasauga, a rattlesnake, as a candidate species. 

In 2011, FWS reviewed and changed the priority of eastern massasauga as a candidate species 

(76 FR 66370) when recent information indicated that it was a distinct species rather than one of 

three subspecies of massasauga. In September 2015, FWS (80 FR 58688) proposed the 

eastern massasauga rattlesnake as a threatened species. The ESA (section 7(a)) requires 
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that each Federal agency confer with the FWS or NMFS on any agency action that is likely to 

jeopardize the continued existence of any species proposed to be listed under section 4 or 

result in the destruction or adverse modification of critical habitat proposed to be designated 

for such species. Information that follows is from the listing proposal (80 FR 58688), which 

contains detailed biological information on the species.

The historical range documented for eastern massasauga rattlesnakes included western 

New York, western Pennsylvania, the lower peninsula and on Bois Blanc Island in Michigan, the 

northern two-thirds of Ohio and Indiana, the northern three quarters of Illinois, the southern half 

of Wisconsin, extreme southeast Minnesota, east-central Missouri, the eastern third of Iowa, 

and far southwestern Ontario, Canada. Overall, the historical extent of occurrence range-wide 

has been reduced more than 46 percent. Eastern massasauga rattlesnakes hibernate in the 

winter and are active in spring, summer, and fall. Active season habitat use varies regionally 

and has been documented to include a wide variety of habitats, including old fields, bogs, fens, 

shrub swamps, wet meadows, marshes, sedge meadows, peatlands, forest edge, scrub shrub 

forest, floodplain forests, and coniferous forests. The most prominent risk factors to the species 

include habitat loss and fragmentation, especially through development and vegetative 

succession, road mortality, hydrologic alternation resulting in drought or flooding, persecution, 

collection, and prescribed fire and mowing. Habitat loss includes direct habitat destruction of 

native land types due to conversion to agricultural land, development, and infrastructure 

associated with development (e.g., roads and bridges). FWS did not propose designation of 

critical habitat because it finds that the increased threat to the eastern massasauga rattlesnake 

from the designation of critical habitat significantly outweighs any benefit of designation.

Exelon (2013e) reports no observations of this species on the Braidwood site, and so the NRC 

staff concludes that the proposed action would have no effect on the eastern massasauga 

rattlesnake.

All Species

If in the future, a Federally listed species is observed on the Braidwood site, the NRC has 

the obligation under the ESA to initiate section 7 consultation. Braidwood’s Unit 1 and Unit 2 

operating licenses, Appendix B, “Environmental Protection Plan” (NRC 2014a, 2014b) require 

Exelon to report to the NRC within 24 hours any “unusual or important event that indicates or 

could result in significant environmental impact causally related to plant operation.” The 

licenses give the specific example of “mortality or unusual occurrence of any species protected 

by the Endangered Species Act of 1973.” Additionally, the NRC’s regulations containing 

notification requirements require that operating nuclear power reactors report to the NRC within 

4 hours “any event or situation, related to...protection of the environment, for which a news 

release is planned or notification to other government agencies has been or will be made” 

(10 CFR 50.72(b)(2)(xi)). Such notifications include reports regarding Federally listed species, 

as described in Section 3.2.12 of NUREG 1022, “Event Reporting Guidelines for 10 CFR 50.72 

and 50.73” (NRC 2013c).
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Special Status Species and Habitats Impacts Summary

Table 4–18 summarizes the NRC staff’s findings.

Table 4–18. Federally Listed Species in Will County, Illinois

Group Federally Listed 

Species Common Name Federal Status (a) NRC Finding

Clams and 

Mussels

Plethobasus 

cyphyus sheepnose mussel E 

May, but not likely 

to adversely affect;

FWS and NRC are in 

the technical 

assistance phase 

of consultation (b)

Epioblasma triquetra snuffbox E No effect

Insects Somatochlora 

hineana

Hine’s emerald 

dragonfly E No effect

Plants Platanthera 

leucophaea

eastern prairie 

fringed orchid T No effect

Hymenopsis 

herbacea lakeside daisy T No effect

Dalea foliosa leafy prairie clover E No effect

Asclepias meadii Mead’s milkweed T No effect

Mammals Myotis 

septentrionalis

northern long-eared 

bat T No effect

Proposed Species

Reptiles 

(snakes) Sistrurus catenatus eastern massasauga PT No effect

Candidate Species

Insects Papaipema eryngii rattlesnake-master 

borer moth No effect

Critical Habitat

None Not applicable

(a) E = endangered; T = threatened, PT = proposed threatened

(b) Exelon has recently conducted a mussel survey in the action area. After FWS reviews the results of that survey, a 

final decision will be made to either conclude technical assistance phase or move to formal section 7 consultation.

4.8.2 No-Action Alternative

Under the no-action alternative, the plant would shut down. Federally listed species and 

designated critical habitat can be affected not only by operation of nuclear power plants but also 

by activities during shutdown. The ESA action area for the no-action alternative would most 

likely be the same as discussed in Section 3.8. The plant would require substantially less 

cooling water, so potential impacts to aquatic species and habitats discussed in Section 4.8.1 

would be reduced, although the plant would still require some cooling water for some time. 

Changes in land use and other shutdown activities might affect terrestrial species differently 

than under continued operation.
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Under the no-action alternative, NRC would assess the need for ESA consultation for plant 

shutdown. The ESA forbids “take” of a listed species, where “take” means “harass, harm, 

pursue, hunt, shoot, wound, kill, trap, capture, or collect, or attempt to engage in any such 

conduct.” In the case of a take, ESA section 7 requires that NRC initiate consultation with the 

FWS or NMFS. The implementing regulations at 50 CFR 402.16 also direct Federal agencies to 

reinitiate consultation in circumstances where (a) the incidental take limit in a biological opinion 

is exceeded, (b) new information reveals effects to Federally listed species or designated critical 

habitats that were not previously considered, (c) the action is modified in a manner that causes 

effects not previously considered, or (d) new species are listed or new critical habitat is 

designated that may be affected by the action. An ESA section 7 consultation could identify 

impacts on Federally listed species or critical habitat, require monitoring and mitigation to 

minimize such impacts, and provide a level of exempted takes. Regulations and guidance 

regarding the ESA section 7 consultation process are provided in 50 CFR Part 402 and in the 

Endangered Species Consultation Handbook (FWS and NMFS 1998).

The effects on ESA-listed aquatic species would likely be smaller than the effects under 

continued operation but would depend on the listed species and habitats present when the 

alternative is implemented. The types and magnitudes of adverse impacts to terrestrial 

ESA-listed species would depend on the shutdown activities and the listed species and habitats 

present when the alternative is implemented. Therefore, the NRC cannot forecast a particular 

level of impact for this alternative.

4.8.3 New Nuclear Alternative

This alternative entails shutdown and decommissioning of Braidwood and construction of a new 

nuclear unit at an alternative industrial location. Section 4.8.2 discusses ESA considerations for 

the shutdown of Braidwood.

Because the new nuclear alternative would be built on an existing power plant site outside 

of Illinois, which has restrictions on new nuclear power plant construction, the special status 

species and habitats affected by the action would be different than those considered under the 

proposed action. Because the NRC would be the licensing agency under this alternative, the 

ESA would require NRC to initiate consultation with the FWS and NMFS, as applicable, prior to 

construction to ensure that the construction and operation of the new nuclear plant would not 

adversely affect any Federally listed species or adversely modify or destroy designated critical 

habitat. Section 4.8.2 discusses general ESA considerations.

No EFH designated under the Magnuson–Stevens Act (MSA), which applies to only certain 

commercially harvested marine species, occurs within the ROI of this alternative, and no EFH 

consultation, which applies only to actions of Federal agencies, would be required. Because the 

types and magnitudes of adverse impacts to ESA-listed species would depend on the proposed 

site, plant design, operation, and species and habitats listed when the alternative is 

implemented, the NRC cannot forecast a particular level of impact for this alternative.

4.8.4 Coal (Integrated Gasification Combined Cycle) Alternative

This alternative entails shutdown and decommissioning of Braidwood and construction of a 

new IGCC facility at either the Braidwood site or an alternative industrial location. Section 4.8.2 

discusses ESA considerations for the shutdown of Braidwood.

Unlike the new nuclear alternative, the NRC does not license IGCC facilities, and the NRC 

would not be responsible for initiating section 7 consultation if listed species or habitats might 

be adversely affected under this alternative. The facilities themselves would be responsible for 
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protecting listed species because the ESA forbids “take” of a listed species, where “take” means 

“harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or attempt to engage in 

any such conduct.”

If the IGCC alternative were to be built on the Braidwood site, the ESA action area might be 

different, and the activities and structures associated with the site would be different than those 

described under continued operation. If the IGCC alternative were to be built a site other than 

the Braidwood site, the listed species and habitats affected by the action would be different than 

those identified for Braidwood. Because the types and magnitudes of adverse impacts to 

ESA-listed species would depend on the proposed site, plant design, operation, and species 

and habitats listed when the alternative is implemented, the NRC cannot forecast a particular 

level of impact for this alternative.

4.8.5 Natural Gas Combined Cycle Alternative

This alternative entails shutdown and decommissioning of Braidwood and construction of a new 

NGCC facility at either the Braidwood site or an alternative industrial location. Section 4.8.2 

discusses ESA considerations for the shutdown of Braidwood.

Unlike the new nuclear alternative, the NRC does not license NGCC facilities, and the NRC 

would not be responsible for initiating section 7 consultation if listed species or habitats might 

be adversely affected under this alternative. The facilities themselves would be responsible for 

protecting listed species because the ESA forbids “take” of a listed species, where “take” means 

“harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or attempt to engage in 

any such conduct.”

If the NGCC alternative were to be built on the Braidwood site, the ESA action area might be 

different, and the activities and structures associated with the site would be different than those 

described under continued operation. If the NGCC alternative were to be built a site other than 

the Braidwood site, the listed species and habitats affected by the action would be different than 

those identified for Braidwood. Because the types and magnitudes of adverse impacts to 

ESA-listed species would depend on the proposed site, plant design, operation, and species 

and habitats listed when the alternative is implemented, the NRC cannot forecast a particular 

level of impact for this alternative.

4.8.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

This alternative entails shutdown and decommissioning of Braidwood and construction of a new 

non-nuclear facilities at the Braidwood site and alternative industrial locations. Section 4.8.2 

discusses ESA considerations for the shutdown of Braidwood.

The combination alternative would involve construction and operation of wind turbines and solar 

PV systems throughout the ROI as well as an NGCC plant at an existing power plant site other 

than the Braidwood site. Unlike the new nuclear alternative, the NRC does not license NGCC, 

wind, or solar facilities, and the NRC would not be responsible for initiating section 7 

consultation if listed species or habitats might be adversely affected under this alternative. The 

facilities themselves would be responsible for protecting listed species because the ESA forbids 

“take” of a listed species, where “take” means “harass, harm, pursue, hunt, shoot, wound, kill, 

trap, capture, or collect, or attempt to engage in any such conduct.”

If part of the combination alternative were to be built on the Braidwood site, the ESA action area 

might be different, and the activities and structures associated with the site would be different 

than those described under continued operation. If parts of the combination alternative were to 

be built on a site or sites other than the Braidwood site, the listed species and habitats affected 
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by the action would be different than those identified for Braidwood. Because the types and 

magnitudes of adverse impacts to ESA-listed species would depend on the proposed site, plant 

design, operation, and species and habitats listed when the alternative is implemented, the NRC 

cannot forecast a particular level of impact for this alternative.

4.8.7 Purchased Power

Because the purchased power alternative might include a mixture of coal, natural gas, nuclear, 

and wind across many different sites in the ROI, the special status species and habitats affected 

by the action would be different than those considered under continued operation. Because the 

types and magnitudes of adverse impacts to ESA-listed species would depend on the proposed 

sites, plant designs, operation, and species and habitats listed at the various sites when the 

alternative is implemented, the NRC cannot forecast a particular level of impact for this 

alternative. As with the other alternatives discussed previously, the facilities themselves, 

and not the NRC, would be responsible for initiating section 7 consultation if listed species 

or habitats might be adversely affected under this alternative.

4.9 Historic and Cultural Resources

This section describes the potential impacts of the proposed action (license renewal) and 

alternatives to the proposed action on historic and cultural resources. 

The National Historic Preservation Act of 1966, as amended (NHPA) requires Federal agencies 

to consider the effects of their undertakings on historic properties, and renewing the operating 

license of a nuclear power plant is an undertaking that could potentially affect historic properties. 

Historic properties are defined as resources eligible for listing in the National Register of Historic 

Places (NRHP). The criteria for eligibility are listed in 36 CFR Part 60.4 and include: 

(1) association with significant events in history; (2) association with the lives of persons 

significant in the past; (3) embodiment of distinctive characteristics of type, period, or 

construction; and (4) sites or places that have yielded, or are likely to yield, 

important information.

The historic preservation review process (Section 106 of the NHPA) is outlined in regulations 

issued by the Advisory Council on Historic Preservation (ACHP) in 36 CFR Part 800.

4.9.1 Proposed Action

In accordance with the provisions of the NHPA, the NRC is required to make a reasonable effort 

to identify historic properties included in or eligible for inclusion in the NRHP in the Area of 

Potential Effect (APE). The APE for a license renewal action is the area at the power plant site, 

the transmission lines up to the first substation and immediate environs that may be affected by 

the license renewal decision, and land-disturbing activities associated with continued reactor

operations. For Braidwood, the first substation is located on-site at the 345-kilovolt (kV) 

Braidwood Station switchyard (Exelon 2013a, 2014b).

If historic properties are present within the APE, the NRC is required to contact the State 

Historic Preservation Office (SHPO), assess the potential impact, and resolve any possible 

adverse effects of the undertaking (license renewal) on historic properties. In addition, the NRC 

is required to notify the SHPO if historic properties would not be affected by license renewal or if 

no historic properties are present. The SHPO is part the Illinois Historic Preservation Agency

(IHPA).
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This section provides the NRC’s assessment of the potential effects from the proposed license 

renewal of Braidwood Units 1 and 2. Section 3.9 describes potentially affected historic and 

cultural resources and historic properties near the Braidwood site.

Consultation

In accordance with 36 CFR 800.8(c), on August 8, 2013, the NRC initiated consultations on the 

proposed action by writing to the ACHP and IHPA (NRC 2013a, b). Also on August 8, 2013, the 

NRC initiated consultation with the following 14 Federally recognized Tribes (NRC 2013i) (see 

Appendix C for a copy of these letters):

 Ho-Chunk Nation;

 Miami Tribe of Oklahoma;

 Peoria Tribe of Indians of Oklahoma;

 Citizen Potawatomi Nation;

 Sac and Fox Tribe of the Mississippi in Iowa/Meskwaki;

 Sac and Fox Nation of Missouri in Kansas and Nebraska;

 Sac and Fox Nation;

 Pokagon Band of Potawatomi;

 Forest County Potawatomi;

 Hannahville Indian Community, Band of Potawatomi;

 Prairie Band of Potawatomi Nation;

 Winnebago Tribe of Nebraska;

 Kickapoo Tribe in Kansas; and

 Kickapoo Tribe of Oklahoma.

By letter, the NRC provided information about the proposed action, defined the APE, and 

indicated that the NHPA review would be integrated with the NEPA process, according to 

36 CFR 800.8. NRC invited participation in the identification and possible decisions concerning 

historic properties and also invited participation in the scoping process. In September 2013, the 

NRC received a determination from the IHPA stating no objection to the undertaking and that no 

historic properties would be affected (Haaker 2013) (see Appendix C).

Exelon currently has no planned physical changes or license renewal-related ground-disturbing 

activities at the Braidwood site (Exelon 2013a). As described in Section 3.9, there are no 

historic properties or known NRHP-eligible historic or cultural resources located within the 

Braidwood APE. Of the 4,457 ac of land composing the Braidwood site, only 67 ac have the 

observable potential to contain undiscovered historic or cultural resources. The remaining acres 

are heavily disturbed due to power plant construction (e.g., power block, blowdown pipeline) 

and operation; are former strip mine land which has been repurposed or are revegetated; or are 

part of the man-made cooling pond created in 1980 and 1981 by pumping water from the 

Kankakee River into a diked area, which surrounds portions of a former strip mine, inundating 

deep pits, borrow areas, and depressions (Exelon 2014b). The Illinois Inventory of 

Archaeological Sites has not identified any areas in the immediate vicinity of the Braidwood site 

as having archaeological resource potential (IHPA 2014). However, Exelon has established a 

draft Cultural Resources Management Plan (CRMP) to ensure historic and cultural resources 

are considered prior to any ground disturbing activities at Braidwood. The CRMP instructs 
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Exelon’s staff on how to evaluate land disturbing activity for possible impacts to historic and 

cultural resources and identifies previously disturbed areas of the Braidwood property and any 

areas with the potential to contain undiscovered resources (Exelon 2014b). If historic or cultural 

resources are inadvertently discovered during operational activities, the CRMP directs Exelon 

staff to stop work, protect exposed resources, and contact Exelon environmental personnel 

to take appropriate action (Exelon 2013a). Supplemental cultural resource surveys may be 

performed on the affected areas based on consultation with the SHPO. Day-to-day 

maintenance of the Braidwood site follows guidelines based on the type of land use, and less 

developed areas are not regularly landscaped unless specially requested (Exelon 2014b). 

Cultural resource training is not currently required for Braidwood staff members (Exelon 2014b).

Based on (1) no current NRHP-eligible historic properties in the APE, (2) tribal input (SEIS 

Appendices A and C), (3) Exelon’s draft CRMP, (4) the fact that no license renewal-related 

physical changes or ground-disturbing activities would occur, (5) IHPA input, and (6) cultural 

resource assessment, license renewal would not affect any known historic properties (36 CFR 

Section 800.4(d)(1)). Exelon could reduce the risk of potential impacts to historic and cultural 

resources located on or near the Braidwood site by finalizing their draft CRMP, with input from 

the SHPO, and by providing training on cultural resources for Exelon staff engaged in planning 

and executing ground-disturbing activities.

4.9.2 No-Action Alternative

Not renewing the operating licenses and terminating reactor operations would have no effect 

on historic properties and cultural resources within the site boundaries of Braidwood. In the 

decommissioning GEIS, the NRC staff determined that, for all nuclear plant sites at which 

decommissioning does not anticipate disturbing lands beyond existing site boundaries, impacts 

to cultural resources would be SMALL. If disturbance beyond the operational areas is 

anticipated, the impacts may or may not be detectable or destabilizing, depending on 

site-specific conditions, and cannot be predicted generically. In those cases, the staff concludes 

that if disturbance beyond the operation areas is anticipated, the potential impacts may be 

SMALL, MODERATE, or LARGE and must be determined through site-specific analysis 

(NRC 2002a).

Title 10 of the CFR Section 50.82 requires power reactor licensees to submit to the NRC a 

post-shutdown decommissioning activities report (PSDAR). The PSDAR is required to be 

submitted within 2 years following permanent cessation of operations and contains a description 

of planned decommissioning activities to be completed at that time. Until the PSDAR is 

submitted, the NRC staff does not know whether land disturbance will remain within the existing 

site boundary after the plant is shut down. 

4.9.3 New Nuclear Alternative

Any land areas potentially affected by the construction of the new nuclear alternative power 

plant would need to be surveyed to identify and record historic and archaeological cultural 

resources. An inventory of a previously disturbed former plant industrial site may still be 

necessary if the site has not been previously surveyed or to verify the level of previous 

disturbance and to evaluate the potential for intact subsurface cultural resources to be present. 

Power plant developers would need to survey all potentially affected land areas associated with 

operation of the alternative (e.g., including land required for new roads, transmission corridors, 

other right-of-ways (ROWs)). Any cultural resources found during these surveys would need to 

be recorded and evaluated for eligibility for listing on the NRHP. Mitigation of adverse effects 

would need to be considered if eligible resources properties were encountered. Areas with the 
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greatest sensitivity (relative to cultural resource impacts) and most significant cultural resources 

should be avoided. Visual impacts on significant cultural resources, such as the historic 

property viewsheds near the proposed power plant site, should also be assessed and 

evaluated.

The potential for impacts to historic and cultural resources from the new nuclear alternative 

would vary greatly depending on the location of site selected for the proposed new nuclear 

power plant site. Construction of cooling towers for this alternative has the potential to impact 

the viewshed of historic properties within the area. However, given the preference to use a 

previously disturbed former power plant site, avoidance of further potential impacts to historic 

and cultural resources should be possible and effectively managed under current laws and 

regulations. Therefore, the impacts on historic and cultural resources from the construction 

and operation of a new nuclear alternative power plant would be SMALL.

4.9.4 Coal (Integrated Gasification Combined Cycle) Alternative

Any areas potentially affected by the construction of the IGCC alternative would need to be 

surveyed to identify and record historic and cultural resources. If the IGCC alternative is located 

on the existing Braidwood site, previously disturbed areas known to not contain historic and 

cultural resources could be used. If the alternative is sited on the approximately 67 ac (27 ha) 

of undisturbed land on the Braidwood site, a survey and inventory for potential historic and 

cultural resources should be performed. An inventory of a previously disturbed former plant 

site, other than Braidwood, may still be necessary if the site has not been previously surveyed 

or to verify the level of disturbance and evaluate the potential for intact subsurface resources. 

Any resources found in these surveys would need to be evaluated for eligibility on the NRHP, 

and mitigation of adverse effects would need to be addressed if eligible resources were 

encountered. Areas with the greatest sensitivity should be avoided. Visual impacts on 

significant cultural resources, such as the historic property viewshed of historic properties 

near the proposed power plant site, should also be assessed and evaluated.

The potential for impacts on historic and cultural resources from the IGCC alternative would 

vary greatly depending on the location of the proposed site. Given that the preference is to use 

a previously disturbed former plant site and no major infrastructure upgrades are necessary, 

avoidance of significant historic and cultural resources should be possible and effectively 

managed under current laws and regulations. Therefore, the impacts on historic and 

archaeological resources from the IGCC alternative would be SMALL.

4.9.5 Natural Gas Combined Cycle Alternative

Any areas potentially affected by the construction of the NGCC alternative would need to be 

surveyed to identify and record historic and cultural resources. If the NGCC alternative is 

located on the existing Braidwood site, previously disturbed areas known to not contain historic 

and cultural resources could be used. If the alternative is sited on the approximately 67 ac 

(27 ha) of undisturbed land on the Braidwood site, a survey and inventory for potential historic 

and cultural resources should be performed. An inventory of a previously disturbed former plant 

site, other than Braidwood, may still be necessary if the site has not been previously surveyed 

or to verify the level of disturbance and evaluate the potential for intact subsurface resources. 

Plant operators would need to survey all areas associated with operation of the alternative 

(e.g., a new pipeline, roads, transmission corridors, other ROWs). Any resources found in 

these surveys would need to be evaluated for eligibility on the NRHP, and mitigation of adverse 

effects would need to be addressed if eligible resources were encountered. Areas with the 

greatest sensitivity should be avoided. Visual impacts on significant cultural resources, such as 
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the historic property viewsheds of historic properties near the proposed power plant site, should 

also be assessed and evaluated.

The potential for impacts on historic and cultural resources from the NGCC alternative would 

vary greatly depending on the location of the proposed site. Given that the preference is to use 

a previously disturbed former plant site, avoidance of significant historic and cultural resources 

should be possible and effectively managed under current laws and regulations. However, 

historic and archaeological resources could potentially be affected, depending on the resource 

richness of the land required for a new pipeline; but, as with the plant site itself, avoidance of 

significant historic and cultural resources should be possible and potential impacts effectively 

managed under current laws and regulations. Therefore, the impacts on historic and 

archaeological resources from the NGCC alternative would be SMALL. 

4.9.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

Areas potentially affected by the construction of the NGCC, wind, and solar PV alternative 

would need to be surveyed to identify and record historic and archaeological resources. Any 

resources found in these surveys would need to be evaluated for eligibility on the NRHP and 

mitigation of adverse effects would need to be addressed if eligible resources were 

encountered. If the NGCC portion of this alternative is located on the existing Braidwood site, 

previously disturbed areas known to not contain historic and cultural resources could be used. 

If the alternative is sited on the approximately 67 ac (27 ha) of undisturbed land on the 

Braidwood site, a survey and inventory for potential historic and cultural resources should be 

performed. If any portion of the alternative is sited on a previously disturbed former plant site, 

other than Braidwood, a survey may still be necessary if the site has not been previously 

surveyed or to verify the level of disturbance and evaluate the potential for intact subsurface 

resources. Plant operators would need to survey all areas associated with operation of the 

alternative (e.g., new pipeline, roads, transmission corridors, other ROWs). Areas with the 

greatest sensitivity should be avoided. Visual impacts on significant cultural resources, such as 

the historic property viewsheds of historic properties near the proposed power plant site, should 

also be assessed and evaluated.

Impacts to historic and cultural resources from the NGCC portion of this alternative are similar 

to the NGCC alternative in Section 4.9.5. The potential for impacts on historic and cultural 

resources from the wind portion of this alternative would vary greatly, depending on the location 

of the proposed sites. Areas with the greatest sensitivity could be avoided or effectively 

managed under current laws and regulations. However, construction of wind farms and their 

support infrastructure have the potential to notably impact historic and archaeological resources 

because of earthmoving activities (e.g., grading and digging) and the aesthetic changes they 

may bring to the viewshed of historic properties located nearby. The impacts of the construction 

of a new solar PV alternative on historic and cultural resources will vary depending on the form 

of the solar capacity installed. Rooftop installations minimize land disturbance and the 

modifications necessary to the transmission system, thereby minimizing impacts to historic and 

cultural resources. Land-based installations are larger than rooftop installations and will require 

some degree of land disturbance for installation purposes, potentially causing greater impacts to 

historic and archaeological resources. Aesthetic changes caused by the installation of both 

forms could have a noticeable effect on the viewshed of nearby historic properties. Using 

previously disturbed sites for land-based installations and co-locating any new transmission 

lines with existing ROWs could minimize impacts to historic and archaeological resources. 

Areas with the greatest sensitivity could be avoided or effectively managed under current laws 

and regulations. Therefore, depending on the resource richness of the sites chosen for the 

NGCC, wind, and solar PV alternative, the impacts could range from SMALL to LARGE.
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4.9.7 Purchased Power

No direct impacts on historic and cultural resources are expected from purchased power. If new 

transmission lines were needed to convey power to the PJM Interconnection area, historic and 

cultural resource surveys would need to be performed. However, transmission lines would likely 

be collocated with existing ROWs minimizing any impacts to historic and cultural resources.

Indirectly, construction of new nuclear, coal-fired, and natural gas–fired plants, wind energy 

projects and any new transmission lines to support increased demand in the purchased power 

alternative could affect historic and cultural resources. Any areas potentially affected by the 

construction would need to be surveyed to identify and record historic and cultural resources. 

Resources found in these surveys would need to be evaluated for eligibility on the NRHP and 

mitigation of adverse effects would need to be addressed if eligible resources were 

encountered. Plant operators would need to survey all areas associated with operation of the 

alternative (e.g., roads, transmission corridors, other ROWs). The potential for impacts on 

historic and cultural resources would vary greatly depending on the location of the proposed 

sites; however, using previously disturbed sites could greatly minimize impacts to historic and 

cultural resources. Areas with the greatest sensitivity could be avoided or effectively managed 

under current laws and regulations. Therefore, depending on the resource richness of the sites 

chosen, the impacts could range from SMALL to LARGE.

4.10 Socioeconomic

This section describes the potential impacts of the proposed action (license renewal) and 

alternatives to the proposed action on socioeconomic (impact).

4.10.1 Proposed Action

The Category 1 (generic) socioeconomic NEPA issues in 10 CFR Part 51, Appendix B to 

Subpart A, Table B-1, applicable to the license renewal of Braidwood Units 1 and 2 are shown 

in Table 4–19. No Category 2 socioeconomic NEPA issues were identified during the review 

conducted for the 2013 GEIS revision (NRC 2013g). Socioeconomic effects of ongoing reactor

operations at Braidwood have become well established as regional socioeconomic conditions 

have adjusted to the presence of the nuclear power plant. These conditions are described in 

Section 3.10. Any changes in employment and tax payments caused by license renewal and 

any associated refurbishment activities could have a direct and indirect impact on community 

services and housing demand, as well as traffic volumes in the communities around a nuclear 

power plant.

Table 4–19. Category 1 Socioeconomic NEPA Issues Affected by License Renewal

Issue GEIS Section

Employment and income, recreation and tourism 4.8.1.1

Tax revenues 4.8.1.2

Community services and education 4.8.1.3

Population and housing 4.8.1.4

Transportation 4.8.1.5

The supplemental site-specific socioeconomic impact analysis for the license renewal of 

Braidwood Units 1 and 2 included a review of the Exelon ER, scoping comments, other 

information records, and a data gathering site visit to Braidwood. NRC staff did not identify any 

new and significant information during the review that would result in impacts that would exceed 
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the predicted socioeconomic impacts evaluated in the GEIS, and no additional socioeconomic 

NEPA issues were identified beyond those listed in Table B-1.

In addition, Exelon indicated in its ER that they have no plans to add non-outage workers during 

the license renewal term and that increased maintenance and inspection activities could be 

managed using the current workforce. Consequently, people living in the vicinity of Braidwood

are not likely to experience any changes in socioeconomic conditions during the license renewal 

term beyond what is currently being experienced. Therefore, the impact of continued reactor

operations during the license renewal term would not exceed the socioeconomic impacts 

predicted in the GEIS. For these issues, the GEIS predicted that the impacts would be SMALL 

for all nuclear plants.

4.10.2 No-Action Alternative

Not renewing the operating licenses and terminating reactor operations would have a noticeable 

impact on socioeconomic conditions in the communities located near Braidwood. The loss of 

jobs and income would have an immediate socioeconomic impact. Some, but not all, of the 

approximately 905 employees (885 Exelon and 20 long-term contract employees) would begin 

to leave after reactor operations are terminated; and overall tax revenue generated by plant 

operations would be reduced (Exelon 2013a). Exelon pays annual property taxes to a number 

of taxing entities within, and including, Will County. The Will County Treasurer collects 

Braidwood’s property tax payment and disperses it to the various taxing entities to partially fund 

their respective operating budgets. The taxing entities to which Exelon pays taxes include, but 

are not limited to, Will County Forest Preserve, Braidwood Fire District, Will Count, Reed Custer 

School District 255-U, and the Godley Park District (Exelon 2013a). The loss of tax revenue 

could reduce or eliminate some public and educational services. Indirect employment and 

income generated by plant operations would also be reduced.

Former Braidwood workers and their families could leave in search of employment elsewhere. 

The increase in available housing along with decreased demand could cause housing prices to 

fall. Since the majority of employees reside in Will, Grundy, and Kankakee counties, 

socioeconomic impacts from the termination of reactor operations would be concentrated in 

these counties, with a corresponding reduction in purchasing activity and tax revenue in the 

regional economy. Income and revenue losses from the termination of reactor operations at 

Braidwood would directly affect Will County and nearby communities most reliant on income 

from power plant operations. The impact of the job loss, however, may not be as noticeable in 

local communities given the amount of time required for decommissioning. The socioeconomic 

impacts from the termination of nuclear plant operations (which may not entirely cease until after 

decommissioning) would, depending on the jurisdiction, range from SMALL to LARGE.

Traffic congestion caused by commuting workers and truck deliveries on roads in the vicinity 

of Braidwood would be reduced after power plant shutdown. Most of the reduction in traffic 

volume would be associated with the loss of jobs. The number of truck deliveries to Braidwood 

would be reduced until decommissioning. Traffic-related transportation impacts would be 

SMALL as a result of the shutdown of the nuclear power plant.

4.10.3 New Nuclear Alternative

Socioeconomic impacts are defined in terms of changes to the demographic and economic 

characteristics and social conditions of a region. For example, the number of jobs created by 

the construction and operation of a power plant could affect regional employment, income, 

and expenditures.
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Two types of jobs would be created by this alternative: (1) construction jobs, which are 

transient, short in duration, and less likely to have a long-term socioeconomic impact; and 

(2) power plant operations jobs, which have the greater potential for permanent, long-term 

socioeconomic impacts. Workforce requirements for the construction and operation of a new 

nuclear power plant were evaluated to measure their possible effects on current 

socioeconomic conditions.

Exelon estimated the construction workforce would peak at 3,500 workers (NRC 2008a). The 

relative economic effect of this many workers on the local economy and tax base would vary 

with the greatest impacts occurring in the communities where the majority of construction 

workers would reside and spend their income. As a result, local communities could experience 

a short term economic “boom” from increased tax revenue and income generated by 

construction expenditures and the increased demand for temporary (rental) housing and 

public as well as commercial services.

After construction, local communities could experience a return to preconstruction economic 

conditions. Based on this information and given the number of workers, socioeconomic impacts 

during construction in communities near an existing nuclear power plant or retired coal site 

could range from MODERATE to LARGE.

An estimated 812 workers would be required during nuclear power plant operations 

(NRC 2008a). Some Braidwood operations workers could transfer to the new nuclear power 

plant. Local communities near the new nuclear power plant would experience the economic 

benefits from increased tax revenue and income generated by operational expenditures and 

demand for housing and public as well as commercial services. The amount of property tax 

payments under the new nuclear alternative may also increase if additional land is required to 

support this alternative.

This alternative would also result in a loss of approximately 905 relatively high-paying jobs at 

Braidwood and a corresponding reduction in purchasing activity and revenue contributions to 

the regional economy. Should Braidwood cease operations, there would be an immediate 

socioeconomic impact to local communities and businesses from the loss of jobs (some, but not 

all, of the 905 employees would begin to leave), and tax payments may be reduced. In addition, 

the housing market could also experience increased vacancies and decreased prices if 

operations workers and their families move out of the region. The impact of the job loss, 

however, may not be noticeable in local communities given the amount of time required for 

decommissioning of the existing Braidwood station facilities. Based on this information and 

given the number of operations workers, socioeconomic impacts during nuclear power plant 

operations on local communities could range from SMALL to MODERATE.

Transportation impacts associated with construction and operation of a new nuclear power plant 

would consist of commuting workers and truck deliveries of construction materials to the power 

plant site. During periods of peak construction activity, up to 3,500 workers could be commuting 

daily to the construction site (NRC 2008a). Workers commuting to the construction site would 

arrive via site access roads and the volume of traffic on nearby roads could increase 

substantially during shift changes. In addition to commuting workers, trucks would be 

transporting construction materials and equipment to the work site, thereby increasing the 

amount of traffic on local roads. The increase in vehicular traffic would peak during shift 

changes, resulting in temporary levels of service (LOS) impacts and delays at intersections. 

Materials could also be delivered by rail or barge, depending on the location. Traffic-related 

transportation impacts during construction would likely range from MODERATE to LARGE.

Traffic-related transportation impacts on local roads would be greatly reduced after the 

completion of the power plant. Transportation impacts would include daily commuting by the 
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operating workforce, equipment and materials deliveries, and the removal of commercial waste 

material to offsite disposal or recycling facilities by truck. Traffic on roadways would peak during 

shift changes, resulting in temporary LOS impacts and delays at intersections. Overall, at the 

new nuclear power plant site, transportation impacts would be SMALL to MODERATE 

during operations.

4.10.4 Coal (Integrated Gasification Combined Cycle) Alternative

As explained in Section 4.10.2.2, two types of jobs would be created by this alternative: 

(1) construction jobs, which are transient, short in duration, and less likely to have a long-term 

socioeconomic impact; and (2) power plant operations jobs, which have the greater potential for 

permanent, long-term socioeconomic impacts. Workforce requirements for the construction and 

operation of the IGCC alternative were evaluated to measure their possible effects on current 

socioeconomic conditions.

The construction workforce could peak at 4,600 workers (DOE 2010b), if the four new units are 

constructed at four different locations. Fewer construction workers would be required if multiple 

units are constructed at the same existing power plant site. The relative economic effect of this 

many workers on the local economy and tax base would vary with the greatest impacts 

occurring in the communities where the majority of construction workers would reside and 

spend their income. As a result, local communities could experience a short term economic 

“boom” from increased tax revenue and income generated by construction expenditures and the 

increased demand for temporary (rental) housing and public as well as commercial services.

After construction, local communities could experience a return to preconstruction economic 

conditions. Based on this information and given the number of workers, socioeconomic impacts 

during construction in communities near an existing power plant site could range from 

MODERATE to LARGE.

An estimated 420 workers would be required during power plant operations (DOE 2010b), if the 

four new units are operated at four different locations. Fewer workers would be required if 

multiple units are operated at the same site. Local communities would experience the economic 

benefits from increased tax revenue and income generated by operational expenditures and 

demand for housing and public as well as commercial services. The amount of property tax 

payments under the IGCC alternative may also increase if additional land is required to support 

this alternative.

This alternative would also result in a loss of approximately 905 relatively high-paying jobs at 

Braidwood and a corresponding reduction in purchasing activity and revenue contributions to 

the regional economy. Should Braidwood cease operations, there would be an immediate 

socioeconomic impact to local communities and businesses from the loss of jobs (some, but not 

all, of the 905 employees would begin to leave), and tax payments may be reduced. In addition, 

the housing market could also experience increased vacancies and decreased prices if 

operations workers and their families move out of the region. The impact of the job loss, 

however, may not be noticeable in local communities given the amount of time required for 

decommissioning of the existing Braidwood station facilities. Based on this information and 

given the number of operations workers, socioeconomic impacts during IGCC power plant 

operations on local communities could range from SMALL to MODERATE.

Transportation impacts associated with construction and operation of the four-unit, IGCC power 

plants would consist of commuting workers and truck deliveries of construction materials to the 

power plant site. During periods of peak construction activity, up to 4,600 workers could be 

commuting daily to one or more construction sites. Workers commuting to the construction site 

would arrive via site access roads and the volume of traffic on nearby roads could increase 
Environmental Consequences and Mitigating Actions

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substantially during shift changes. In addition to commuting workers, trucks would be 

transporting construction materials and equipment to the work site, thereby increasing the 

amount of traffic on local roads. The increase in vehicular traffic would peak during shift 

changes, resulting in temporary LOS impacts and delays at intersections. Materials could also 

be delivered by rail or barge, depending on location. Traffic-related transportation impacts 

during construction would likely range from MODERATE to LARGE.

Traffic-related transportation impacts on local roads would be greatly reduced after the 

completion of the power plant. The estimated maximum number of operations workers 

commuting daily to one or more power plant sites could be 420 (DOE 2010b). Fewer workers 

would be required if multiple units are operated at the same site. Frequent coal and limestone 

deliveries and ash removal by rail would add to the overall transportation impact. The increase 

in traffic on roadways would peak during shift changes, resulting in temporary LOS impacts and 

delays at intersections. Onsite coal storage would make it possible to receive several trains per 

day at a site with rail access. If the IGCC power plant is located on navigable waters, coal and 

other materials could be delivered by barge. Coal and limestone delivery and ash removal via 

rail would cause LOS impacts due to delays at railroad crossings. Overall, transportation 

impacts would be SMALL to MODERATE during IGCC power plant operations.

4.10.5 Natural Gas Combined Cycle Alternative

As explained in Section 4.10.2.2, two types of jobs would be created by this alternative: 

(1) construction jobs, which are transient, short in duration, and less likely to have a long-term 

socioeconomic impact; and (2) power plant operations jobs, which have the greater potential for 

permanent, long-term socioeconomic impacts. Workforce requirements for the construction and 

operation of the NGCC alternative were evaluated to measure their possible effects on current 

socioeconomic conditions.

The construction workforce would peak at 1,783 workers (Exelon 2013a). The relative 

economic effect of this many workers on the local economy and tax base would vary with the 

greatest impacts occurring in the communities where the majority of construction workers would 

reside and spend their income. As a result, local communities could experience a short term 

economic “boom” from increased tax revenue and income generated by construction 

expenditures and the increased demand for temporary (rental) housing and public as well as 

commercial services.

After construction, local communities could experience a return to preconstruction economic 

conditions. Based on this information and given the number of workers, socioeconomic impacts 

during construction in communities near an existing power plant site could range from 

MODERATE to LARGE.

An estimated 94 workers would be required during power plant operations (Exelon 2013a). 

Local communities would experience the economic benefits from increased tax revenue and 

income generated by operational expenditures and demand for housing and public as well as 

commercial services. The amount of property tax payments under the NGCC alternative may 

also increase if additional land is required to support this alternative.

This alternative would also result in a loss of approximately 905 relatively high-paying jobs at 

Braidwood and a corresponding reduction in purchasing activity and revenue contributions to 

the regional economy. Should Braidwood cease operations, there would be an immediate 

socioeconomic impact to local communities and businesses from the loss of jobs (some, but not 

all, of the 905 employees would begin to leave), and tax payments may be reduced. In addition, 

the housing market could also experience increased vacancies and decreased prices if 

operations workers and their families move out of the region. The impact of the job loss, 
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however, may not be noticeable in local communities given the amount of time required for 

decommissioning of the existing Braidwood station facilities. Based on this information and 

given the number of operations workers, socioeconomic impacts during NGCC power 

plant operations on local communities could range from SMALL to MODERATE.

Transportation impacts associated with construction and operation of a five-unit, NGCC power 

plant would consist of commuting workers and truck deliveries of construction materials to the 

power plant site. During periods of peak construction activity, up to 1,783 workers could be 

commuting daily to the construction site. Workers commuting to the construction site would 

arrive via site access roads and the volume of traffic on nearby roads could increase 

substantially during shift changes. In addition to commuting workers, trucks would be 

transporting construction materials and equipment to the work site, thus increasing the amount 

of traffic on local roads. The increase in vehicular traffic would peak during shift changes, 

resulting in temporary LOS impacts and delays at intersections. Pipeline construction and 

modification of existing natural gas pipeline systems could also have a temporary impact. 

Materials also could be delivered by barge or rail, depending on location. Traffic-related 

transportation impacts during construction would likely range from MODERATE to LARGE.

Traffic-related transportation impacts would be greatly reduced after completing the installation 

of the NGCC alternative. Transportation impacts would include daily commuting by the 

operating workforce, equipment and materials deliveries, and the removal of commercial 

waste material to offsite disposal or recycling facilities by truck. The operations workforce of 

94 workers would likely not be noticeable relative to total traffic volumes on local roadways. 

Since fuel is transported by pipeline, the transportation infrastructure would experience little 

to no increased traffic from plant operations. Overall, given the relatively small operations 

workforce estimate of 94 workers, transportation impacts would be SMALL during power 

plant operations.

4.10.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

As explained in Section 4.10.2.2, two types of jobs would be created by this alternative: 

(1) construction jobs, which are transient, short in duration, and less likely to have a long-term 

socioeconomic impact; and (2) operations jobs, which have the greater potential for permanent, 

long-term socioeconomic impacts. Workforce requirements for the construction and operation 

of the NGCC, wind, and solar generation components of this combination alternative were 

evaluated to estimate their possible effects on current socioeconomic conditions.

Fewer workers would be required to construct the single NGCC unit at an existing power plant 

site than the full-power NGCC alternative. Installation of an estimated 3,376 wind turbines 

would likely be done in stages and could employ up to 931 construction workers (DOE 2010a). 

Additional workers would be required to install solar PV systems on existing buildings or 

structures at already-developed residential, commercial, or industrial sites. Similar to the wind 

farms, installation would likely be done in stages and could employ up to 600 construction 

workers (DOE 2010a).

Conversely, a small number of operations workers would be needed to operate the single 

NGCC unit and additional small numbers of workers would be required to maintain the wind 

farms and PV systems. Local communities could experience the economic benefits from 

increased tax revenue and income generated by operational expenditures and demand for 

housing and public as well as commercial services. The amount of property tax payments 

under the wind and solar PV components may also increase if additional land is required to 

support this combination alternative.
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This combination alternative would also result in a loss of approximately 905 relatively 

high-paying jobs at Braidwood and a corresponding reduction in purchasing activity, tax

payments, and revenue contributions would occur in the surrounding regional economy. 

Should Braidwood cease operations, there would be an immediate socioeconomic impact to 

local communities and businesses from the loss of jobs (some, but not all, of the 905 employees 

would begin to leave), and tax payments may be reduced. In addition, the housing market could 

also experience increased vacancies and decreased prices if operations workers and their 

families move out of the region. The impact of the job loss, however, may not be noticeable 

in local communities given the amount of time required for decommissioning of the existing 

Braidwood station facilities. Based on this information and given the relatively small numbers 

of construction and operations workers, socioeconomic impacts during construction and 

operations on local communities would be SMALL.

Transportation impacts during the construction and operation of the NGCC unit as well as the 

wind and solar components of this combination alternative would be less than the impacts for 

any of the previous alternatives discussed. This is because the construction workforce for each 

component and the volume of materials and equipment needing to be transported to the 

respective construction site would be smaller than for any one of the individual replacement 

power alternatives. In other words, the transportation impacts would not be concentrated as 

in the other alternatives, but spread out over a wider area.

Workers commuting to the construction site would arrive via site access roads and the volume 

of traffic on nearby roads could increase during shift changes. In addition to commuting 

workers, trucks would be transporting construction materials and equipment to the work site, 

thereby increasing the amount of traffic on local roads. The increase in vehicular traffic would 

peak during shift changes, resulting in temporary LOS impacts and delays at intersections. 

Transporting heavy and oversized components on local roads could have a noticeable impact 

over a large area. Some components and materials could also be delivered by rail or barge, 

depending on location. Traffic-related transportation impacts during construction could range 

from SMALL to MODERATE at the NGCC power plant, wind farms and solar installations; 

depending on current road capacities and average daily traffic volumes.

During operations, transportation impacts would be less noticeable during shift changes and 

maintenance activities. Given the small numbers of operations workers, the LOS traffic impacts 

on local roads from NGCC, wind farm, and solar PV operations would be SMALL.

4.10.7 Purchased Power

Purchased power from existing power generating facilities would not have any socioeconomic 

impact, because there would be no change in power plant operations or workforce. If the 

amount of purchased power exceeds the available supply, new electrical power generating 

facilities would be needed. Construction and operation of a new electrical power generating 

facility to supply purchased power could cause noticeable socioeconomic impacts in the 

communities located near the new facility. The intensity of the impact would depend on the 

number of workers required to build and operate the new electrical power generating facility 

and the amount of increased demand for housing and public services.

Whether or not there would be a socioeconomic impact would depend on whether a new 

electrical power generating facility was needed to supply purchased power. If a new power 

generating facility is needed, socioeconomic impacts would range anywhere from SMALL 

to LARGE.

Similarly, purchased power from existing power generating facilities would also not have 

any transportation impact, because there would be no change in power plant operations or 
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workforce. Construction and operation of a new electrical power generating facility could cause 

noticeable transportation impacts depending on the number of workers and truck deliveries 

required to build and operate the new electrical power generating facility. Traffic volumes could 

increase noticeably on local roads during shift changes.

Whether or not there would be a transportation impact would depend on whether a new 

electrical power generating facility was needed to supply purchased power. If a new power 

generating facility is needed, transportation impacts would range anywhere from SMALL to 

LARGE.

4.11 Human Health

This section describes the potential impacts of the proposed action (license renewal) and 

alternatives to the proposed action on human health.

4.11.1 Proposed Action

4.11.1.1 Normal Operating Conditions

The human health issues applicable to Braidwood are discussed below and are listed in 

Table 4–20 for Category 1, Category 2, and uncategorized issues. Table B-1 of Appendix B to 

Subpart A of 10 CFR Part 51 contains more information on these issues.

Table 4–20. Human Health Issues

Issues GEIS Section Category

Radiation exposures to the public 4.9.1.1.1 1

Radiation exposures to plant workers 4.9.1.1.1 1

Human health impact from chemicals 4.9.1.1.2 1

Microbiological hazards to the plant workers 4.9.1.1.3 1

Microbiological hazards to the public 4.9.1.1.3 2

Chronic effects of electromagnetic fields (EMFs) 4.9.1.1.4 (a)N/A

Physical occupational hazards 4.9.1.1.5 1

Electric shock hazards 4.9.1.1.5 2

(a) N/A (not applicable) The categorization and impact finding definition does not apply to this issue.

Source: Table B-1 in Appendix B, Subpart A, to 10 CFR Part 51

Category 1 Issues

The NRC staff did not identify any new and significant information during its review of Exelon’s 

ER, the site audit, or the scoping process for the Category 1 issues listed in Table 4-20. 

Therefore, there are no impacts related to these issues beyond those discussed in the GEIS. 

For these Category 1 issues, the GEIS concluded that the impacts are SMALL (NRC 2013f).

Microbiological Hazards to Plant Workers

In the GEIS (NRC 2013f), NRC staff determined that effects of thermophilic microbiological 

organisms on plant workers is a generic (Category 1) issue (see Table 4–20). The GEIS 

concludes that the impact of this issue would be SMALL for all sites because occupational
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health impacts are expected to be controlled by continued application of accepted industrial 

hygiene practices to minimize worker exposures as required by permits and Federal and 

State regulations.

The NRC staff did not identify any new and significant information during the review of Exelon’s 

ER, the NRC staff’s site audit, the scoping process, and the evaluation of other available 

information. Therefore, the staff does not expect any impacts related to this issue during the 

proposed renewal term beyond those discussed in the GEIS. As indicated above, the GEIS 

concludes that the impact level for this issue is SMALL.

Chronic Effects of Electromagnetic Fields (EMFs)

In the GEIS, the chronic effects of 60-Hz EMFs from power lines were not designated as 

Category 1 or 2, and will not be until a scientific consensus is reached on the health implications 

of these fields.

The potential for chronic effects from these fields continues to be studied and is not known 

at this time. The National Institute of Environmental Health Sciences (NIEHS) directs related 

research through the U.S. Department of Energy (DOE).

The report by NIEHS (NIEHS 1999) contains the following conclusion:

The NIEHS concludes that ELF-EMF (extremely low frequency-electromagnetic 

field) exposure cannot be recognized as entirely safe because of weak scientific 

evidence that exposure may pose a leukemia hazard. In our opinion, this finding 

is insufficient to warrant aggressive regulatory concern. However, because 

virtually everyone in the United States uses electricity and therefore is routinely 

exposed to ELF-EMF, passive regulatory action is warranted such as continued 

emphasis on educating both the public and the regulated community on means 

aimed at reducing exposures. The NIEHS does not believe that other cancers or 

non-cancer health outcomes provide sufficient evidence of a risk to currently 

warrant concern.

This statement is not sufficient to cause the NRC staff to change its position with respect to 

the chronic effects of EMFs. The NRC staff considers the GEIS finding of “UNCERTAIN” still 

appropriate and will continue to follow developments on this issue (NRC 2013f).

Category 2 Issues

Electric Shock Hazards

Based on the GEIS, the Commission found that 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, a site-specific review is required to determine the significance 

of the electric shock potential to members of the public and plant workers along the portions of 

the transmission lines that are within the scope of the license renewal environmental review 

(NRC 2013f).

As discussed in Section 3.11.4, there are no offsite transmission lines that are within the 

regulatory scope of this environmental review. Therefore, there are no potential impacts 

to offsite members of the public from the transmission lines on the Braidwood site.

For the onsite transmission lines, as discussed in Section 3.11.5, Braidwood maintains 

an occupational safety program in accordance with the Occupational Safety & Health 

Administration regulations for its workers, which includes protection from acute electric shock. 
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Therefore, the NRC staff concludes that the potential impacts from acute electric shock during 

the license renewal term would be SMALL.

Microbiological Hazards to the Public

In the GEIS (NRC 2013f), the NRC staff determined that effects of thermophilic microorganisms 

on the public for plants using cooling ponds, lakes, or canals or cooling towers that discharge to 

a river is a Category 2 issue (see Table 4–20) that requires site-specific evaluation during each 

license renewal review.

In order to determine whether the continued operations of Braidwood could promote increased 

growth of thermophilic microorganisms, and thus have an adverse effect on the public, the NRC 

staff considered several factors: the thermophilic microorganisms of concern; Braidwood’s 

thermal effluent characteristics; Exelon’s chlorination procedures; recreational use of Braidwood 

Lake and the Kankakee River; and input from the Illinois Department of Public Health (IDPH).

Section 3.11.3 describes the thermophilic microorganisms that the GEIS identified to be of 

potential concern at nuclear power plants and summarizes data from the Centers for Disease 

Control and Prevention (CDC) on the prevalence of waterborne diseases associated with these 

microorganisms that have been linked to recreational water use in the past 10 available data 

years (1999 through 2008). CDC data indicate that no outbreaks or cases of waterborne 

Salmonella or Pseudomonas aeruginosa infection from recreational waters have occurred in the 

United States during this timeframe. Shigella and Naegleria fowleri infections linked to 

exposure in recreational waters were rarely reported, and none of the reported cases occurred 

in Illinois. Public exposure to aerosolized Legionella from nuclear plant operations is generally 

not a concern because such exposure would be confined to a small area of the site to which the 

public would not have access. Based on the information presented in Section 3.11.3, the 

thermophilic organisms most likely to be of potential concern at Braidwood are Shigella and 

N. fowleri. 

Braidwood’s circulating water system and two service water systems discharge heated water 

to the site’s artificial cooling pond through a discharge canal at the north end of the pond. 

Braidwood also continuously discharges blowdown to the Kankakee River, and this discharge 

(designated as Outfall 001) is subject to the limitations set forth in the site’s NPDES permit 

(IEPA 2014d). The permit limits blowdown discharges to the river to a 30-day average of 

54 million liters per day (Lpd) or 14.3 mgd. Sections 3.1.3 and 3.5.1 describe the cooling 

system and surface water characteristics, respectively.

Prior to mixing with the cooling pond, circulating water discharge temperatures exiting the plant 

are maintained below approximately 123 °F (50.6 °C) (Exelon 2013c). Because discharged 

water is higher in temperature than the maximum tolerance of both Shigella (104 °F (40.0 °C)) or 

N. fowleri (105.8 °F (41.00 °C)), these organisms are unlikely to be present in discharged 

waters. The circulating water system’s discharge to the cooling pond is also unlikely to create a 

thermal environment that would enhance the survival of thermophilic microorganisms, if already 

present in the cooling pond. Exelon measures the cooling pond’s average and maximum 

temperatures by grab sample taken several times a week in front of the trash racks at the lake 

screen house. During the period from 2004 through 2013, the annual average temperatures at 

the sampling point ranged from 19.1 °C (66.4 °F) (in 2007) to 21.8 °C (71.2 °F) (in 2010) 

(Exelon 2014h). These temperatures are below the optimal growth temperature of both Shigella

(37 °C (98.6 °F)) and N. fowleri (46.1 °C (115 °F)). In 2 years during the time period, maximum 

daily temperatures reached those within 1 °F (0.6 °C) of Shigella’s optimal growth temperature: 

Exelon (2014h) recorded temperatures of 37.3 °C (99.1 °F) on June 29, 2005, and 37.4 °C 

(99.3 °F) on July 19, 2013. Although these temperatures could reasonably enhance survival 
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or growth of Shigella, the short duration (1 day) and periodicity (twice in 10 years) of these 

temperatures are unlikely to have produced a measurable effect on the Shigella population, 

if present in the pond. Thus, thermal additions to the cooling pond as a result of Braidwood 

operations are unlikely to enhance the growth or survival of thermophilic organisms.

For blowdown to the Kankakee River, Special Conditions 4C and 4D of the NPDES permit 

limit water temperatures at Outfall 001. Special Condition 4C stipulates that at the edge of 

Braidwood’s thermal mixing zone, discharges from Outfall 001 shall not cause the Kankakee 

River water to rise above natural temperatures by more than 2.8 °C (5 °F). Special 

Condition 4D stipulates that temperatures at the edge of the mixing zone shall not exceed the 

monthly maximum limits of 90 °F (32 °C) from April through November and 60 °F (16 °C) from 

December through March for more than 1 percent of the hours in a 12-month period and at no 

time shall water temperatures exceed the monthly maximum limits by more than 1.7 °C (3 °F). 

These limits are consistent with Title 35, Environmental Protection, Section 302, “Water Quality 

Standards,” of the IAC, which stipulates that for thermal effluents, the maximum temperature 

rise shall not exceed 2.8 °C (5 °F) above natural receiving water body temperatures and that the 

water temperature at representative locations in the main river shall at no time exceed 33.7 °C 

(93 °F) from April through November and 17.7 °C (63 °F) in other months (35 IAC 302.211). In 

recent years, the average maximum monthly discharge temperature in summer months 

(calculated from Exelon’s monthly discharge monitoring reports (DMRs) for 2008 through 2013) 

has been 92.6 °F (33.7 °C), which is slightly lower than the NPDES permit limit of 93 °F (33.7 °C) 

(Exelon 2014j). This temperature is below the optimal growth temperature both Shigella and 

N. fowleri, and thus, would not enhance the growth or survival of these thermophilic organisms, 

if present in Kankakee River water.

In addition to temperature limitations, the IAC prohibits the area and volume of thermal mixing 

from being more than 25 percent of the cross-sectional area or volume of stream flow 

(35 IAC 302.102). In 2009, Exelon commissioned a thermal mixing zone analysis 

(Thuman 2009b). The analysis determined that Braidwood’s thermal mixing zone meets the 

IAC’s criteria: the surface area of the thermal mixing zone was estimated to be 0.1 ha (0.22 ac), 

which is a small fraction of the allowable area (10.5 ha or 26 ac) under the IAC water quality 

standard. Thus, the IAC’s thermal mixing limitations effectively minimize the area and volume 

over which microorganisms could experience enhanced growth or survival in the Kankakee 

River near the Braidwood discharge. 

Chlorine is an effective disinfectant for water containing the microorganisms of concern. The 

EPA (EPA 1999a) reports that chlorination at concentrations of 1 to 2 milligrams per liter (mg/L) 

in water at a pH of 6.0 to 8.0 can effectively eliminate health hazards caused by bacteria, 

including Shigella. The CDC (CDC 2013) reports that chlorine at a concentration of 1 ppm 

(1 mg/L) added to 77 °F (25 °C) clear water at a pH of 7.5 will reduce the number of viable 

N. fowleri trophozoites by 99.99 percent in 12 minutes.

Exelon treats water entering the circulating water system and service water systems with 

sodium hypochlorite for up to 120 minutes per day per unit to control biofouling (ComEd 2000; 

Exelon 2014c). Water discharged to the Kankakee River may not contain more than an 

instantaneous maximum concentration of 0.2 mg/L of residual chlorine or 0.05 mg/L of residual 

oxides, as measured at Outfall 001, per Special Condition 5 of the NPDES permit (IEPA 2014d). 

As needed, sodium biosulfite is added to water prior to discharge to remove residual chlorine 

and maintain compliance with NPDES permit limitations (Exelon 2014a). Although Exelon 

chlorinates station water at lower concentrations than those indicated by EPA and the CDC as 

most effectively eliminating the microorganisms of concern, chlorination of the system is likely to 

prevent some increased growth and survival of microorganisms that might otherwise result from 

operation of Braidwood.
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Both the cooling pond and the Kankakee River are used for recreational purposes. The cooling 

pond is part of the Mazonia–Braidwood State Fish and Wildlife Area, which Exelon and the 

IDNR jointly manage. It is open to the public for fishing from March 1 until 10 days prior to the 

opening of waterfowl season, which typically begins in late October (Exelon 2013c). Portions of 

the cooling pond within the exclusion zone, which includes the essential cooling pond, are off 

limits to the public, and these areas are clearly marked with buoys or signs (Exelon 2013c). 

Within public access areas, swimming, wading, water-skiing, and sailing are prohibited, which 

further reduces the potential for human exposure to the microorganisms of concern, if present in 

the cooling pond.

As discussed above, Braidwood’s thermal mixing zone in the Kankakee River is relatively small 

(0.1 ha (0.22 ac)), and the temperature limitations set forth in the NPDES permit are lower than 

those that would promoted increased growth or survival of thermophilic microorganisms. In 

accordance with the IAC, the discharge is not located near any public access areas because 

thermal mixing is prohibited “in water adjacent to bathing beaches, bank fishing areas, boat 

ramps or dockages or any other public access area” (35 IAC 302.102(b)(3)). Given the small 

area of thermally altered waters and the unlikelihood of the water to create conditions favorable 

to thermophilic microorganisms, exposure of recreational Kankakee River users to elevated 

concentrations of the microorganisms of concern is unlikely.

The environmental standard review plan for license renewal (NRC 2013k) directs NRC staff to 

consult with the state public health department—in this case, the IDPH—regarding concerns 

about the potential for waterborne disease outbreaks associated with license renewal. 

Appendix E of the ER (Exelon 2013c) includes copies of correspondence between Exelon 

and IDPH regarding this issue. In a January 2013 letter to IDPH, Exelon provided a brief 

assessment that concluded that the license renewal “would not contribute to any increase in 

adverse effects on public health from exposure to N. fowIeri or any other thermophilic pathogen 

in the Rock River.” The IDPH responded in a March 2013 letter and indicated that its staff does 

not have the expertise necessary to adequately evaluate Exelon’s assessment. Accordingly, 

the NRC staff did not separately contact the IDPH during its license renewal review.

Conclusion

The thermophilic microorganisms Shigella and N. fowleri have been linked to waterborne 

outbreaks in recreational waters within the United States. However, based on these 

microorganisms’ temperature tolerances, Shigella and N. fowleri are unlikely to be present in 

the vicinity of Braidwood. Additionally, Exelon’s chlorination procedures and the small thermal 

mixing zones in the cooling pond and Kankakee River make exposure of recreational water 

users to elevated levels of these microorganisms unlikely. The NRC staff concludes that the 

impacts of thermophilic microorganisms on the public are SMALL for Braidwood license 

renewal.

4.11.1.2 Environmental Impacts of Postulated Accidents

This section describes the environmental impacts from postulated accidents that Braidwood 

might experience during the period of extended operation. The term “accident” refers to any 

unintentional event outside the normal plant operational envelope that results in a release or the 

potential for release of radioactive materials into the environment. The two classes of 

postulated accidents listed in Table 4–21 are contained in Table B-1 of Appendix B to Subpart A 

of 10 CFR Part 51 and are evaluated in detail in the GEIS. These two classes of accidents are 

DBAs and severe accidents. 
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Table 4–21. Issues Related to Postulated Accidents

Issue GEIS Section Category

DBAs 4.9.1.2 1

Severe accidents 4.9.1.2 2

Source: Table B-1 in Appendix B, Subpart A, to 10 CFR Part 51

Design-Basis Accidents

DBAs are those accidents that both the nuclear power plant licensee and the NRC staff 

evaluate for all nuclear power plants to ensure that they can withstand normal and abnormal 

transients and a broad spectrum of postulated accidents, without undue hazard to the health 

and safety of the public. These postulated accidents are not expected to occur during the life of 

the plant but are evaluated to establish the design basis for the preventive and mitigative safety 

systems of the nuclear power plant. A licensee is required to maintain the acceptable design 

and performance criteria throughout the licensed life for operation of a reactor, including the 

license renewal term. Part 50 and Part 100 of Title 10 of the CFR describe the acceptance 

criteria for DBAs (NRC 2013f).

Exelon stated in its ER (Exelon 2013c) that it is not aware of any new and significant information 

related to DBAs associated with the renewal of Braidwood. The NRC staff has not found any 

new and significant information during its independent review of the Exelon ER, the site audit, 

or the scoping process. Therefore, the NRC staff concludes that there are no impacts related to 

DBAs, beyond those discussed in the GEIS. For this Category 1 issue, the GEIS concludes that 

the impacts are SMALL.

Severe Accidents

Severe nuclear accidents are those that are more severe than DBAs because they could 

result in substantial damage to the reactor core, whether or not there are serious offsite 

consequences. The GEIS assessed the effects of severe accidents during the period of 

extended operation, using the results of existing analyses and site-specific information to 

conservatively predict the environmental impacts of severe accidents for each plant during 

the period of extended operation.

The impacts from severe accidents initiated by external phenomena such as tornadoes, floods, 

earthquakes, fires, and sabotage were specifically considered in the GEIS. The GEIS evaluated 

existing impact assessments at selected nuclear power plants in the United States and 

concluded that the risk is SMALL. The GEIS also performed an analysis of sabotage, in 

connection with license renewal, and concluded that the core damage and radiological release 

from such acts would be no worse than the damage and release expected from internally 

initiated events. The GEIS concludes that the risk from sabotage at existing nuclear power 

plants is SMALL and, additionally, that the risks from other external events are adequately 

addressed by a generic consideration of internally initiated severe accidents (NRC 2013f).

The NRC found that:

The probability-weighted consequences of atmospheric releases, fallout onto 

open bodies of water, releases to ground water, and societal and economic 

impacts from severe accidents are small for all plants. However, alternatives

to mitigate severe accidents must be considered for all plants that have not 

considered such alternatives. [78 FR 37282, 78 FR 46255]
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The NRC staff found no new and significant information related to postulated accidents during 

the review of Exelon’s ER (Exelon 2013c), the site visit, or the scoping process. Therefore, as 

discussed in the GEIS, the probability-weighted consequences of severe accidents are SMALL.

4.11.1.3 Severe Accident Mitigation Alternatives (SAMAs)

Section 51.53(c)(3)(ii)(L) requires that license renewal applicants consider alternatives

to mitigate severe accidents if the NRC staff has not previously evaluated SAMAs for the 

applicant’s plant in an environmental impact statement (EIS) or related supplement or in an 

environmental assessment (EA). The purpose of this consideration is to ensure that plant 

changes (i.e., hardware, procedures, and training) with the potential for improving severe 

accident safety performance are identified and evaluated. SAMAs have not been previously 

considered for Braidwood; therefore, the remainder of this section addresses those alternatives.

Overview of SAMA Process

This section presents a summary of the SAMA evaluation for Braidwood conducted by Exelon 

and the NRC staff’s review of that evaluation. The NRC staff performed its review with contract 

assistance from Pacific Northwest National Laboratory. The NRC staff’s review is available in 

full in Appendix F; the Exelon’s SAMA evaluation is available in full in the ER.

The SAMA evaluation for Braidwood was conducted using a four-step approach. In the 

first step, Exelon quantified the level of risk associated with potential reactor accidents using the 

plant-specific probabilistic risk assessment (PRA) and other risk models.

In the second step Exelon examined the major risk contributors and identified possible ways 

(SAMAs) of reducing that risk. Common ways of reducing risk are changes to components, 

systems, procedures, and training. Exelon identified 35 potential SAMAs for Braidwood. 

Exelon performed an initial screening to determine if any SAMAs could be eliminated because 

(a) they are not applicable to Braidwood due to design differences, (b) they have already been 

implemented at Braidwood or their intent is achieved by other means, or (c) they have estimated 

implementation costs that would exceed the dollar value associated with completely eliminating 

all severe accident risk at Braidwood related to power generation operations. One SAMA was 

eliminated based on this screening, leaving 34 for further evaluation. This SAMA (eliminated 

during screening) was also further evaluated after considering analysis uncertainties.

In the third step Exelon estimated the benefits and the costs associated with each of the 

SAMAs. Estimates were made of how much each SAMA could reduce risk. Those estimates 

were developed in terms of dollars in accordance with NRC guidance for performing regulatory 

analyses (NRC 1997). The cost of implementing the proposed SAMAs was also estimated.

In the fourth step, the costs and benefits of each of the remaining SAMAs were compared to 

determine whether the SAMA was cost-beneficial, meaning the benefits of the SAMA were 

greater than the cost (a positive cost benefit). Exelon concluded in its ER that several of the 

SAMAs evaluated are potentially cost-beneficial (Exelon 2013c). No additional potentially 

cost-beneficial SAMAs were identified in response to NRC staff inquiries regarding estimated 

benefits for certain SAMAs and lower-cost alternatives (Exelon 2014k).

Finally, the potentially cost-beneficial SAMAs are evaluated to determine if they are in the scope 

of license renewal, (i.e., they are subject to aging management). This evaluation considers 

whether the systems, structures, and components (SSCs) associated with these SAMAs: 

(1) perform their intended function without moving parts or without a change in configuration 

or properties and (2) that these SSCs are not subject to replacement based on qualified life or 

specified time period. The potentially cost-beneficial SAMAs identified for Braidwood do not 

relate to adequately managing the effects of aging during the period of extended operation; 
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therefore, they need not be implemented as part of license renewal in accordance with 10 CFR 

Part 54, “Requirements for renewal of operating licenses for nuclear power plants.” Exelon’s 

SAMA analyses for Braidwood and the NRC’s review are discussed in more detail below.

Estimate of Risk

Exelon submitted an assessment of SAMAs for Braidwood as part of the ER (Exelon 2013c). 

This assessment was based on the most recent Braidwood PRA available at that time, a 

plant-specific offsite consequence analysis performed using the MELCOR Accident

Consequence Code System 2 (MACCS2) computer program, and insights from the Braidwood 

individual plant examination (ComEd 1994, 1997a) and individual plant examination of external 

events (ComEd 1997b).

The scope of the Level 1 PRA model includes both internal events and a limited fire PRA. 

However, the fire PRA is not fully integrated with the most recent internal events model and is 

an interim implementation of NUREG–6850 (EPRI and NRC 2005). Hence, Exelon performed 

a separate assessment of the risk (and risk reduction) for internal and fire events.

The baseline core damage frequency (CDF) for the purpose of the SAMA evaluation is 

approximately 3.6×10−5 per year for Unit 1 and 3.5×10−5 per year for Unit 2 for internal events 

(including internal flooding events). The total fire CDF for Unit 2 is approximately 5.9×10−5 per 

year. The Unit 1 fire CDF was reported as lower than the Unit 2 fire CDF, and so the Unit 2 fire 

CDF was used in the SAMA evaluation. Exelon accounted for the potential risk reduction 

benefits associated with internal events by quantifying the benefits using the internal events 

model. For internal event-related SAMAs, Exelon accounted for the potential risk reduction 

benefits associated with external events (e.g., seismic and fire events) by multiplying the 

estimated benefits for internal events by a factor of 3.0. For fire-related SAMAs, Exelon 

separately estimated the risk reduction benefits using the fire risk model. The breakdown 

of CDF by initiating event for Braidwood is provided in Table 4–22 for internal events.

Table 4–22. Braidwood Core Damage Frequency (CDF) for Internal Events 

Initiating Event

Unit 1 CDF

(per year)

Unit 1

Percent CDF

Contribution

Unit 2 CDF

(per year)

Unit 2 

Percent CDF

Contribution 

Loss of Essential Service Water (SX) 1.3×10−5 36 1.3×10−5 37

Small Loss-of-Coolant Accident

(LOCA) 6.4×10−6 18 6.3×10−6 18

Internal Flooding 5.7×10−6 16 5.6×10−6 16

Loss of Component Cooling 

Water (CCW) 3.2×10−6 9 3.2×10−6 9 

Loss of Auxiliary Power (AP) 2.1×10−6 6 1.4×10−6 4

Other Initiating Events 1.8×10−6 5 1.8×10−6 5

Medium Loss-of-Coolant 

Accident (LOCA) 1.4×10−6 4 1.4×10−6 4 

Steam Generator Tube 

Rupture (SGTR) 1.4×10−6 4 1.8×10−6 5 

General Transient and Loss of Main 

Feedwater (LMFW) 7.1×10−7 2 7.0×10−7 2 

Total (Internal Events)(a) 3.6×10−5 100 3.5×10−5 100

(a) Column totals may be different due to round off.
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As shown in these tables, internal event CDF is dominated by loss of essential service water 

(SX), small loss-of-coolant accident, internal flooding, and loss of component cooling water 

(CCW) for both units.

Exelon estimated the dose to the population within 50 mi (80 km) of the Braidwood site to be 

approximately 1.14 person-sievert (Sv) (114 person-rem) per year (Exelon 2013c) for internal 

events. The breakdown of the total population dose and offsite economic cost by containment 

release mode is summarized in Table 4–23. Containment overpressure accidents, interfacing 

system loss-of-coolant accident, and steam generator tube rupture (SGTR) are the dominant 

contributors to population dose risk from internal events.

Table 4–23. Breakdown of Population Dose and Offsite Economic Cost by Containment 

Release Mode (a)

Containment Release Mode Population Dose

(Person-rem (b)

Per Year)

Percent 

Contribution

Offsite 

Economic 

Cost ($/yr)

Percent 

Contribution

Containment over-pressure (late) 87.3 77 687,000 83

Interfacing system LOCA 15.5 14 54,400 7

Steam generator tube rupture 9.05 8 61,800 8

Containment isolation failure 1.18 1 3,800 <1

Containment intact 0.33 <1 300 <1

Early containment failure 0.29 <1 2,000 <1

Basemat melt-through (late) 0.06 <1 62 <1

Total (c) 114 100 810,000 100

(a) Values in table derived from Table F.3-9 of the ER

(b) One person-rem = 0.01 person-Sv 

(c) Column totals may be different due to round off.

The NRC staff has reviewed Exelon’s data and evaluation methods and concludes that the 

quality of the risk analyses is adequate to support an assessment of the risk reduction potential 

for candidate SAMAs. Accordingly, the staff based its assessment of offsite risk on the CDFs

and offsite doses reported by Exelon.

Potential Plant Improvements

Once the dominant contributors to plant risk were identified, Exelon searched for ways to reduce 

that risk. In identifying and evaluating potential SAMAs, Exelon considered insights from the 

plant-specific PRA and SAMA analyses performed for other operating plants that have 

submitted LRAs. This search included reviewing insights from the plant-specific risk studies, 

considering insights from the Braidwood PRA Group, and reviewing plant improvements 

considered in the IPE, IPEEE, and previous SAMA analyses. Exelon identified 35 potential 

risk-reducing improvements (SAMAs) to plant components, systems, procedures, and training. 

A detailed cost-benefit analysis was performed for each of the SAMAs.

The staff concludes that Exelon used a systematic and comprehensive process for identifying 

potential plant improvements for Braidwood and that the set of potential plant improvements 

identified by Exelon is reasonably comprehensive and, therefore, acceptable.
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Evaluation of Risk Reduction and Costs of Improvements

Exelon evaluated the risk reduction potential of the candidate SAMAs. The SAMA evaluations 

were performed using realistic assumptions with some conservatism. Exelon estimated the 

costs of implementing the candidate SAMAs through the development of Braidwood-specific 

cost estimates, the use of other licensees’ estimates for similar improvements, and, in some 

cases, combinations of these two sources. The cost estimates conservatively did not include 

the cost of replacement power during extended outages required to implement the 

modifications.

The staff reviewed Exelon’s bases for calculating the risk reduction for the various plant 

improvements and concludes that the rationale and assumptions for estimating risk reduction 

are reasonable and generally conservative (i.e., the estimated risk reduction is higher than what 

would actually be realized). Accordingly, the staff based its estimates of averted risk for the 

various SAMAs on Exelon’s risk reduction estimates.

The staff reviewed the bases for the applicant’s cost estimates. For certain improvements, 

the staff also compared the cost estimates to estimates developed elsewhere for similar 

improvements, including estimates developed as part of other licensees’ analyses of SAMAs

for operating reactors. The staff found the cost estimates to be reasonable, and generally 

consistent with estimates provided in support of other plants’ analyses.

The staff concludes that the risk reduction and the cost estimates provided by Exelon are 

sufficient and appropriate for use in the SAMA evaluation.

Cost-Benefit Comparison

The cost benefit analysis performed by Exelon was based primarily on NUREG/BR–0184 

(NRC 1997) and was executed consistent with this guidance. NUREG/BR–0058 has recently 

been revised to reflect the agency’s revised policy on discount rates. Revision 4 of 

NUREG/BR–0058 states that two sets of estimates should be developed—one at 3 percent and 

one at 7 percent (NRC 2004). Exelon provided both sets of estimates (Exelon 2013c, 2014k) 

and based its decisions on potentially cost-beneficial SAMAs on these values.

Exelon identified 18 potentially cost-beneficial SAMAs in the baseline analysis contained in 

the ER. The potentially cost-beneficial SAMAs are:

 SAMA 3 – Auto Start of Standby SX Pump

 SAMA 5 – Modify the Startup Feedwater pump to Start Using the AMSAC SG 

Low-Low-Low Level Signal to Mitigate AFW Failure

 SAMA 6 – Enhance Plant Procedures to Explicitly Confirm Adequate 

_SX007 Throttling

 SAMA 7 – Establish Flow to the RH HX on RH Pump Start

 SAMA 8 – Install Kill Switches for the Fire Protection Pumps in the MCR

 SAMA 9 – Install Flow Restrictors in Fire Protection Pipes

 SAMA 10 – Alter Ductwork Between the Aux BLDG Room and the SX Pump 

Room

 SAMA 11 – Implement DMS

 SAMA 13 – Alternate AFW Cooling with Seal Protection

 SAMA 15 – Resolve Regulatory Issues and Complete Implementation of the 

Inter Unit AFW Cross-tie
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 SAMA 16 – Install High Flow Sensors on the Non-Essential Service 

Water System

 SAMA 19 – Replace MOVs in the RHR Discharge Line with Valves That Can 

Isolate an ISLOCA Event

 SAMA 25 – Install a Filtered Containment Vent

 SAMA 26 – DMS Using a Dedicated Generator, Self-Cooled Charging Pump, 

and a Portable AFW Pump

 SAMA 27 – Protect RH.SI and CVCS Cubicle Cooling Fan Cables in Fire 

Zone 11.3-0 

 SAMA 28 – Install Fire Barriers around MCC 134X

 SAMA 29 – Seal the Inverter 111 Panel and Install Fire Barriers to Protect 

Nearby Equipment

 SAMA 33 – Unit 2 SAMA - Install Cable Wrap on the 141 to 241 4KV 

Cross-tie Cable in the Division 11 ESF Switchgear Room

Exelon performed additional analyses to evaluate the impact of parameter choices and 

uncertainties on the results of the SAMA assessment (Exelon 2013c, 2014k). If the benefits are 

increased by a factor of 2.29 (which was reduced to 1.97 in response to an NRC staff RAI) to 

account for uncertainties, eight additional SAMA candidates were determined to be potentially 

cost-beneficial:

 SAMA 1 – Install Diesel Driven SX Pump in a New Dedicated Building

 SAMA 2 – Replace the Positive Displacement Pump with a Self-Cooled, 

Auto Start Pump

 SAMA 4 – Install “No Leak” Seals

 SAMA 22 – Install the Same High Flow Isolation Logic Used on Valve_CC685 

on Valve_CC9438

 SAMA 31 – Install Fire Barriers around MCCs 132X5 and 132X

 SAMA 32 – Install Fire Barriers around MCC 131X2

 SAMA 34 – Unit 2 SAMA - Install Cable Wrap on the 141 to 241 4KV 

Cross-tie Cable in the Aux Building Elevation 426′ of the General Area

 SAMA 35 – Unit 2 SAMA - Install Cable Wrap to Protect 2AF005A, B, C, 

and D in the Division 21 Containment Electrical Penetrations Area

Exelon stated in the ER that the 26 SAMAs determined to be cost-beneficial in the ER baseline 

and uncertainty evaluations have been submitted to the Braidwood Plant Health Committee for 

further implementation consideration (Exelon 2013c).

The staff concludes that, with the exception of the potentially cost-beneficial SAMAs discussed 

above, the costs of the SAMAs evaluated would be higher than the associated benefits when 

they are considered independently.

Conclusions

The staff reviewed Exelon’s analysis and concluded that the methods used and the 

implementation of those methods was sound. The treatment of SAMA benefits and 
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costs support the general conclusion that the SAMA evaluations performed by Exelon are 

reasonable and sufficient for the license renewal submittal.

Based on its review of the SAMA analysis, the staff finds acceptable Exelon’s identification 

of areas in which risk can be further reduced in a cost-beneficial manner through the 

implementation of all or a subset of potentially cost-beneficial SAMAs. Given the potential for 

cost-beneficial risk reduction, the staff considers that further evaluation of these SAMAs by 

Exelon is warranted. Additionally, the NRC staff evaluated the 26 potentially cost-beneficial 

SAMAs to determine if they are in the scope of license renewal, (i.e., they are subject to aging 

management). This evaluation considers whether the systems, structures, and components 

(SSCs) associated with these SAMAs: (1) perform their intended function without moving parts 

or without a change in configuration or properties and (2) that these SSCs are not subject to 

replacement based on qualified life or specified time period. The NRC staff determined that 

these SAMAs do not relate to adequately managing the effects of aging during the period of 

extended operation. Therefore, they need not be implemented as part of the license renewal 

pursuant to 10 CFR Part 54.

4.11.2 No-Action Alternative

Human health risks would be smaller following plant shutdown. The two reactor units, which are 

currently operating within regulatory limits, would emit less gaseous, liquid, and solid radioactive 

material to the environment. In addition, following shutdown, the variety of potential accidents at 

the plant (radiological or industrial) would be reduced to a limited set associated with shutdown 

events and fuel handling and storage. In Section 4.11.1, the NRC staff concluded that the 

impacts of continued plant operation on human health would be SMALL, except for “Chronic 

effects of electromagnetic fields (EMFs),” for which the impacts are UNCERTAIN. In 

Section 4.11.1.2, the NRC staff concluded that the impacts of accidents during operation were 

SMALL. Therefore, as radioactive emissions to the environment decrease, and as the likelihood 

and types of accidents decrease following shutdown, the NRC staff concludes that the risk to 

human health following plant shutdown would be SMALL.

4.11.3 New Nuclear Alternative

Construction

Impacts on human health from construction of two new nuclear units would be similar to impacts 

associated with the construction of any major industrial facility. Compliance with worker 

protection rules would control those impacts on workers at acceptable levels. Construction 

of new nuclear units would increase traffic on local roads, which could affect the health of the 

general public. Human health impacts would be the same whether the new facility is located on 

greenfield sites, other existing power plant sites, or at the existing Braidwood nuclear plant site. 

Impacts from construction on the general public would be minimal since limiting active 

construction area access to authorized individuals is expected. Personal protective equipment, 

training, and engineered barriers would protect the workforce. Therefore, the impacts on human 

health from the construction of two new nuclear units would be SMALL (NRC 2013f).

Operation

The human health effects from the operation of two new nuclear power plants would be similar 

to those of the existing Braidwood units. As presented in Section 4.11.1.1, impacts on human 

health from the operation of Braidwood would be SMALL, except for “Chronic effects of 

electromagnetic fields (EMFs),” for which the impacts are UNCERTAIN. Therefore, the impacts 

on human health from the operation of two new nuclear plants would be SMALL.
Environmental Consequences and Mitigating Actions

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4.11.4 Coal (Integrated Gasification Combined Cycle) Alternative

Construction

Impacts on workers are expected to be similar to those experienced during construction of any 

major industrial facility. Impacts from construction of combustion-based renewable energy 

facilities are expected to be the same as those for construction of fossil fuel facilities. 

Construction would increase traffic on local roads, which could affect the health of the general 

public. Human health impacts would be the same for all facilities whether located on greenfield 

sites, other existing power plant sites, or at an existing nuclear plant. Personal protective 

equipment, training, and engineered barriers would protect the workforce (NRC 2013f). 

Therefore, the impacts on human health from the construction of an IGCC facility would 

be SMALL.

Operation

The IGCC alternative introduces worker risks from coal and limestone mining, worker and 

public risk from coal and lime/limestone transportation, worker and public risk from disposal of 

coal-combustion waste, and public risk from inhalation of stack emissions. In addition, human 

health risks are associated with the management and disposal of coal combustion waste. Coal 

combustion generates waste in the form of ash, and equipment for controlling air pollution 

generates additional ash and scrubber sludge. Human health risks may extend beyond the 

facility workforce to the public depending on their proximity to the coal combustion waste 

storage and/or disposal facility. The character and the constituents of coal combustion waste 

depend on both the chemical composition of the source coal and the technology used to 

combust it. Generally, the primary sources of adverse consequences from coal combustion 

waste are from exposure to sulfur oxide and nitrogen oxide in air emissions and radioactive 

elements such as uranium and thorium as well as the heavy metals and hydrocarbon 

compounds contained in fly ash and bottom ash, and scrubber sludge (NRC 2013f).

Regulatory agencies, including the EPA and state agencies, base air emission standards and 

requirements on human health impacts. These agencies also impose site-specific emission 

limits as needed to protect human health. Given the regulatory oversight exercised by the EPA 

and state agencies, the NRC staff concludes that the human health impacts from radiological 

doses and inhaled toxins and particulates generated from the IGCC alternative would be 

SMALL (NRC 2013f).

4.11.5 Natural Gas Combined Cycle Alternative

Construction

Impacts on workers are expected to be similar to those experienced during construction of any 

major industrial facility. Impacts from construction of combustion-based renewable energy 

facilities are expected to be the same as those for construction of fossil fuel facilities. 

Construction would increase traffic on local roads, which could affect the health of the general 

public. Human health impacts would be the same for all facilities whether located on greenfield 

sites, other existing power plant sites, or at an existing nuclear plant. Compliance with worker 

protection rules and personal protective equipment, training, and engineered barriers would 

protect the workforce (NRC 2013f). Impacts from construction on the general public would be 

minimal since crews would limit active construction area access to authorized individuals. 

Therefore, the NRC staff concludes that the impacts on human health from the construction 

of an NGCC facility would be SMALL.
Environmental Consequences and Mitigating Actions

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Operation

Impacts from the operation of an NGCC facility introduces public risk from inhalation of gaseous 

emissions. The risk may be attributable to nitrogen oxide emissions that contribute to ozone 

formation, which in turn contribute to health risk. Regulatory agencies, including the EPA and 

state agencies, base air emission standards and requirements on human health impacts. 

These agencies also impose site-specific emission limits as needed to protect human health. 

Given the regulatory oversight exercised by the EPA and state agencies, the NRC staff 

concludes that the human health impacts from the NGCC alternative would be SMALL.

4.11.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

Construction

Impacts on human health from construction of a combination of NGCC, wind, and solar PV 

alternatives would be similar to effects associated with the construction of any major industrial 

facility. Compliance with worker protection rules and personal protective equipment, training, 

and engineered barriers would protect the workforce (NRC 2013f). Impacts from construction

on the general public would be minimal since crews would limit active construction area access 

to authorized individuals. Based on the above, the NRC staff concludes that the Impacts on 

human health from the construction of the NGCC, wind, and solar alternative would be SMALL.

Operation

Operational hazards at an NGCC facility are discussed in Section 4.11.5.

Operational hazards at a wind facility for the workforce include working at heights, near rotating 

mechanical or electrically energized equipment, and working in extreme weather. Potential 

impacts to workers and the public include ice thrown from rotor blades and broken blades 

thrown caused by mechanical failure. Potential impacts also include EMF exposure, aviation 

safety (hazard related), and exposure to noise and vibration from the rotating blades.

Operational hazards at a solar PV facility may involve exposure to airborne toxic metals 

(e.g., cadmium) and silicon if the PV cell loses its integrity from a fire. Workers could also inhale 

silicon dust if the PV cell was smashed by an object or from a fall to the ground. However, 

based on worker and environmental protection rules, it is expected that remediation of toxic 

material would occur. Such remediation would minimize the impact to workers and the 

environment.

Therefore, given the expected compliance with worker and environmental protection rules and 

the use of personal protective equipment, training, and engineered barriers, the NRC staff 

concludes that the potential human health impacts would be SMALL.

4.11.7 Purchased Power

Purchased power is expected to come from the types of electricity generation available within 

the ROI: coal, natural gas, nuclear, and wind. The human health impacts from the operation of 

these types of power plants are discussed in sections 4.11.3, 4.11.4, 4.11.5, and 4.11.6. Based 

on the information in those sections, the NRC staff concludes that the human health impacts of 

the purchased power alternative using coal, natural gas, nuclear, and wind would be SMALL.

4.12 Environmental Justice

This section describes the potential impacts of the proposed action (license renewal) and 

alternatives to the proposed action on environmental justice. 
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The NRC addresses environmental justice matters for license renewal by (1) identifying the 

location of minority and low-income populations that may be affected by the continued operation 

of the nuclear power plant during the license renewal term, (2) determining if there would be any 

potential human health or environmental effects to these populations and special pathway 

receptors, and (3) determining if any of the effects may be disproportionately high and adverse. 

Adverse health effects are measured in terms of the risk and rate of fatal or nonfatal adverse 

impacts on human health. Disproportionately high and adverse human health effects occur 

when the risk or rate of exposure to an environmental hazard for a minority or low-income 

population is significant and exceeds the risk or exposure rate for the general population or for 

another appropriate comparison group. Disproportionately high environmental effects refer to 

impacts or risks of impacts on the natural or physical environment in a minority or low-income 

community that are significant and appreciably exceed the environmental impact on the larger 

community. Such effects may include biological, cultural, economic, or social impacts.

4.12.1 Proposed Action

Figures 3.12-1 and 3.12-2 show the location of predominantly minority and low-income 

population block groups residing within a 50-mi (80-km) radius of Braidwood. This area of 

impact is consistent with the impact analysis for public and occupational health and safety, 

which also focuses on populations within a 50-mi (80-km) radius of the plant. Chapter 4 

presents the assessment of environmental and human health impacts for each resource area.

Potential impacts on minority and low-income populations (including migrant workers or 

Native Americans) would mostly consist of socioeconomic and radiological effects; however, 

radiation doses from continued operations during the license renewal term are expected to 

continue at current levels, and they would remain within regulatory limits. Section 4.9.1.2 of this 

SEIS discusses the environmental impacts from postulated accidents that might occur during 

the license renewal term, which include both design-basis and severe accidents. In both cases, 

the Commission has generically determined that impacts associated with DBAs are small 

because nuclear plants are designed and operated to successfully withstand such accidents, 

and the probability weighted consequences of severe accidents are small.

Therefore, based on this information and the analysis of human health and environmental 

impacts presented in Chapter 4 of this SEIS, there would be no disproportionately high and 

adverse human health and environmental effects on minority and low-income populations from 

the continued operation of Braidwood during the license renewal term.

As part of addressing environmental justice concerns associated with license renewal, the NRC 

also assessed the potential radiological risk to special population groups (e.g., migrant workers 

or Native Americans) from exposure to radioactive material received through their unique 

consumption practices and interaction with the environment, including subsistence consumption 

of fish, native vegetation, surface waters, sediments, and local produce; absorption of 

contaminants in sediments through the skin; and inhalation of airborne radioactive material 

released from the plant during routine operation. This analysis is presented below.

Subsistence Consumption of Fish and Wildlife

The special pathway receptors analysis is an important part of the environmental justice

analysis because consumption patterns may reflect the traditional or cultural practices of 

minority and low-income populations in the area, such as migrant workers or Native Americans. 

Section 4-4 of Executive Order 12898 (published in the Federal Register (FR) at 59 FR 7629 in 

1994) directs Federal agencies, whenever practical and appropriate, to collect and analyze 

information about the consumption patterns of populations that rely principally on fish and/or 
Environmental Consequences and Mitigating Actions

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wildlife for subsistence and to communicate the risks of these consumption patterns to the 

public. In this SEIS, the NRC considered whether there were any means for minority or 

low-income populations to be disproportionately affected by examining impacts on 

American Indian, Hispanics, migrant workers, and other traditional lifestyle special pathway 

receptors. The assessment of special pathways considered the levels of radiological and 

nonradiological contaminants in native vegetation, crops, soils and sediments, groundwater, 

surface water, fish, and game animals on or near Braidwood.

The following is a summary discussion of Exelon’s radiological environmental monitoring 

programs that assess the potential impacts from the subsistence consumption of fish and 

wildlife near the Braidwood site.

Exelon has an ongoing comprehensive Radiological Environmental Monitoring Program (REMP) 

to assess the impact of Braidwood operations on the environment. To assess the impact of 

nuclear power plant operations, samples are collected annually from the environment and 

analyzed for radioactivity. A plant effect would be indicated if the radioactive material detected 

in a sample was significantly larger than background levels. Two types of samples are 

collected. The first type, a control sample, is collected from areas that are beyond the 

measurable influence of the nuclear power plant or any other nuclear facility. These samples 

are used as reference data to determine normal background levels of radiation in the 

environment. These samples are then compared with the second type of samples, indicator 

samples, collected near the nuclear power plant. Indicator samples are collected from areas 

where any contribution from the nuclear power plant will be at its highest concentration. These 

samples are then used to evaluate the contribution of nuclear power plant operations to 

radiation or radioactivity levels in the environment. An effect would be indicated if the 

radioactivity levels detected in an indicator sample was significantly larger than the control 

sample or background levels.

Samples of environmental media are collected from the aquatic, atmospheric, and terrestrial

pathways in the vicinity of Braidwood. The aquatic pathways include surface water, public 

water, well water, fish, and shoreline sediment. Atmospheric pathways include samples of air 

particulate and airborne iodine from eight different locations around Braidwood. The terrestrial 

pathways include airborne particulates, milk, and food products (i.e., cabbage, beets and beet 

greens, kohlrabi, potatoes, rhubarb leaves, onions, and turnips). During 2012, 1,602 analyses 

were performed on 1,368 samples of environmental media at Braidwood showed no significant 

or measurable radiological impact above background levels from site operations 

(Teledyne 2013).

Conclusion

Based on the radiological environmental monitoring data from Braidwood, the NRC finds that 

no disproportionately high and adverse human health impacts would be expected in special 

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

local food, fish, and wildlife. Continued operation of Braidwood would not have 

disproportionately high and adverse human health and environmental effects on 

these populations.

4.12.2 Environmental Impacts of Alternatives to the Proposed Action

As discussed in Section 4.12, the environmental justice impact analysis evaluates the potential 

for disproportionately high and adverse human health and environmental effects on minority and 

low-income populations. Some of these potential effects have been identified in resource areas 

discussed in this SEIS. For example, increased demand for rental housing during replacement 

power plant construction could disproportionately affect low-income populations. Minority 
Environmental Consequences and Mitigating Actions

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and low-income populations are subsets of the general public residing in the vicinity of all the 

alternatives listed below, and all are exposed to the same hazards generated by each 

alternative.

4.12.2.1 No-Action Alternative

Impacts on minority and low-income populations would depend on the number of jobs and the 

amount of tax revenues lost by communities in the immediate vicinity of the power plant after 

Braidwood ceases operations. Not renewing the operating licenses and terminating reactor

operations would have a noticeable impact on socioeconomic conditions in the communities 

located near Braidwood. The loss of jobs and income would have an immediate socioeconomic 

impact. Some, but not all, of the approximately 905 employees would begin to leave after 

reactor operations are terminated; and overall tax revenue generated by plant operations would 

be reduced. The reduction in tax revenue would decrease the availability of public services in 

Will County. This could disproportionately affect minority and low-income populations that may 

have become dependent on these services. Effects could be high or adverse depending on the 

needs of the individual impacted. See also Appendix J of NUREG–0586, Supplement 1 

(NRC 2002c), for additional discussion of these impacts.

4.12.2.2 New Nuclear Alternative

Potential impacts to minority and low-income populations from the construction and operation 

of a new nuclear power plant would mostly consist of environmental and socioeconomic effects 

(e.g., noise, dust, traffic, employment, and housing impacts). Noise and dust impacts from 

construction would be short-term and primarily limited to onsite activities. Minority and 

low-income populations residing along site access roads would be affected by increased 

commuter vehicle traffic during shift changes and truck traffic. However, these effects would be 

temporary during certain hours of the day and would not likely be high and adverse. Increased 

demand for rental housing during construction could affect low-income populations. However, 

given the proximity of some existing nuclear power plant sites to metropolitan areas, many 

construction workers could commute to the site, thereby reducing the potential demand for 

rental housing.

Potential impacts to minority and low income populations from new nuclear power plant 

operations would mostly consist of radiological effects; however, radiation doses are expected 

to be well below regulatory limits. All people (including minority and low income populations) 

living near the nuclear power plant would be exposed to the same potential effects from power 

plant operations, and any impacts would depend on the magnitude of the change in ambient air 

quality conditions. Permitted air emissions are expected to remain within regulatory standards.

Based on this information and the analysis of human health and environmental impacts 

presented in this SEIS, the construction and operation of a new nuclear power plant would not 

have disproportionately high and adverse human health and environmental effects on minority 

and low-income populations.

4.12.2.3 Coal (Integrated Gasification Combined Cycle) Alternative

Potential impacts to minority and low-income populations from the construction and operation 

of a new IGCC plant at an existing power plant site would consist of environmental and 

socioeconomic effects (e.g., noise, dust, traffic, employment, and housing impacts). Noise and 

dust impacts from construction would be short-term and primarily limited to onsite activities. 

Minority and low-income populations residing along site access roads would be affected by 

increased commuter vehicle traffic during shift changes and truck traffic. However, these effects 

would be temporary during certain hours of the day and would not likely be high and adverse. 

Increased demand for rental housing during construction could affect low-income populations. 
Environmental Consequences and Mitigating Actions

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However, given the proximity of some existing power plant sites to metropolitan areas, many 

construction workers could commute to the site, thereby reducing the potential demand for 

rental housing.

Emissions from the operation of an IGCC plant could affect minority and low income populations

as well as the general population living in the vicinity of the new power plant. However, all 

would be exposed to the same potential effects from IGCC power plant operations and any 

impacts would depend on the magnitude of the change in ambient air quality conditions. 

Permitted air emissions are expected to remain within regulatory standards.

Based on this information and the analysis of human health and environmental impacts 

presented in this SEIS, the construction and operation of a new IGCC plant would not have 

disproportionately high and adverse human health and environmental effects on minority and 

low-income populations.

4.12.2.4 Natural Gas Combined Cycle Alternative

Potential impacts to minority and low-income populations from the construction and operation 

of a new NGCC plant at an existing power plant site would mostly consist of environmental and 

socioeconomic effects (e.g., noise, dust, traffic, employment, and housing impacts). Noise and 

dust impacts from construction would be short-term and primarily limited to onsite activities. 

Minority and low-income populations residing along site access roads would be affected by 

increased commuter vehicle traffic during shift changes and truck traffic. However, these effects 

(impacts) would be temporary (only during certain hours of the day) and would not likely be high 

and adverse. Increased demand for rental housing during construction could affect low-income 

populations in the vicinity of the Braidwood site. However, given the proximity of some existing 

power plant sites to metropolitan areas, many construction workers could commute to the site, 

thereby reducing the potential demand for rental housing.

Emissions from the operation of an NGCC plant could affect minority and low income 

populations as well as the general population living in the vicinity of the new power plant. 

However, all would be exposed to the same potential effects from NGCC power plant 

operations, and any impacts would depend on the magnitude of the change in ambient air 

quality conditions. Permitted air emissions are expected to remain within regulatory standards.

Based on this information and the analysis of human health and environmental impacts 

presented in this SEIS, the construction and operation of a new NGCC plant would not have 

disproportionately high and adverse human health and environmental effects on minority and 

low-income populations.

4.12.2.5 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

Potential impacts to minority and low-income populations from the construction and operation 

of a new NGCC plant, wind turbines, and solar PV installations would mostly consist of 

environmental and socioeconomic effects (e.g., noise, dust, traffic, employment, and housing 

impacts). Noise and dust impacts from construction would be short-term and primarily limited 

to onsite activities. Minority and low-income populations residing along site access roads would 

be affected by increased commuter vehicle traffic during shift changes and truck traffic. 

However, these effects would be temporary during certain hours of the day and would not likely 

be high and adverse. Increased demand for rental housing during construction could affect 

low-income populations. However, given the small number of construction workers and the 

possibility that many workers could commute to these construction sites, the potential need for 

rental housing would not be significant.
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Minority and low income populations living in close proximity to wind farm and solar PV power 

generating installations could be disproportionately affected by maintenance and operations 

activities. However, everyone would be exposed to the same operational effects, and any 

effects would depend on the magnitude of change from current conditions. Operational impacts 

from the wind turbines and solar PV installations would mostly be limited to noise and aesthetic

effects. The general public living near the wind farms and solar PV installations would also be 

exposed to the same effects.

Based on this information and the analysis of human health and environmental impacts 

presented in this SEIS, the construction and operation of a new NGCC plant, wind farms, and 

solar PV installations would not have disproportionately high and adverse human health and 

environmental effects on minority and low-income populations.

4.12.2.6 Purchased Power

Purchased power from existing power generating facilities would not likely have any 

disproportionately high and adverse effects on minority populations, because there would be 

no change in power plant operations or workforce. However, low-income populations could be 

disproportionately affected by increased utility bills because of the cost of purchased power, 

although programs are available to assist low-income families in paying for increased 

electrical costs. 

If the amount of purchased power exceeds the available supply, new electric power generating 

facilities would be needed. Construction and operation of a new power generating facility to 

supply purchased power could create new human health and environmental effects in 

communities located near the new facility. Minority and low-income populations residing in the 

vicinity of the new electric power generating facility are subsets of the general population, and 

all would be exposed to the same hazards generated by construction activities and facility 

operations.

Some potential human health and environmental effects have already been described for other 

replacement power alternatives in this SEIS. Potential impacts from the construction of a new 

power generating facility would mostly consist of environmental effects (e.g., increased noise, 

dust, traffic, employment, and housing demand). Noise and dust impacts from construction 

would be short-term and primarily limited to onsite activities. Minority and low-income 

populations residing along site access roads would be affected by increased commuter vehicle 

traffic during shift changes and truck traffic. However, these effects would be temporary during 

certain hours of the day and would not likely be high and adverse. Increased demand for rental 

housing during construction could affect low-income populations. However, depending on the 

location of the new power generating facility and the possibility of construction workers 

commuting to the construction site, the potential need for rental housing may not be significant.

Minority and low income populations living in close proximity to power generating facilities could 

also be disproportionately affected by maintenance and operations activities. However, 

everyone living near the power plant site would be exposed to the same operational effects, 

and any effects would depend on the magnitude of change from current conditions. Operational 

impacts for all new power generating facilities would mostly be limited to noise and aesthetic

effects. Emissions from fossil-fueled power generating facilities could create disproportionate 

human health effects in minority and low income populations living in the vicinity of the new 

power plant. However, all populations would be exposed to the same potential human health 

and environmental effects from power plant operations and any impacts would depend on the 

magnitude of the change in ambient air quality conditions. In addition, permitted air emissions 

would be expected to remain within regulatory standards.
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Based on this information and the analysis of human health and environmental effects 

presented in this SEIS, the construction and operation of a new power generating facility may 

not have disproportionately high and adverse human health and environmental effects on 

minority and low-income populations.

4.13 Waste Management and Pollution Prevention

This section describes the potential impacts of the proposed action (license renewal) 

and alternatives to the proposed action on waste management and pollution prevention.

4.13.1 Proposed Action

The waste management issues applicable to Braidwood are discussed below and listed in 

Table 4–24. Table B-1 of Appendix B to Subpart A of 10 CFR Part 51 contains more 

information on these issues.

Table 4–24. Waste Management Issues

Issue GEIS Section Category

Low-level waste storage and disposal 4.11.1.1 1

Onsite storage of spent nuclear fuel 4.11.1.2(a) 1

Offsite radiological impacts of spent nuclear fuel and 

high-level waste disposal 4.11.1.3 1 

Mixed-waste storage and disposal 4.11.1.4 1

Nonradioactive waste storage 4.11.1.4 1

(a) The environmental impacts of this issue for the period beyond the licensed life for reactor operations are 

discussed in NUREG-2157 (NRC 2014d).

Source: Table B-1 in Appendix B, Subpart A, to 10 CFR Part 51

The NRC staff’s evaluation of the environmental impacts associated with spent nuclear fuel 

is addressed in two issues in Table 4-24, “Onsite storage of spent nuclear fuel” and “Offsite 

radiological impacts of spent nuclear fuel and high-level waste disposal.” However, as 

explained later in this section, these two issues now incorporate the generic environmental 

impact determinations codified in the revised 10 CFR 51.23 pursuant to the Continued Storage 

Rule (79 FR 56238) 3

. 

The NRC staff did not identify any new and significant information related to waste management 

issues listed in Table 4-24 during its review of the applicant’s ER (Exelon 2013), the site visit, or 

the scoping process. Therefore, there are no impacts related to these issues beyond those 

discussed in the GEIS (NRC 2013d) and the Generic Environmental Impact Statement for 

Continued Storage of Spent Nuclear Fuel, Volumes 1 and 2 (NUREG–2157) (NRC 2014d). 

During the license renewal term for these Category 1 issues, the GEIS concludes that the 

impacts are SMALL.

 

3 79 FR 56238. U.S. Nuclear Regulatory Commission. “Continued Storage of Spent Nuclear Fuel.” Federal 

Register 79 (182):56238–56263. September 19, 2014.
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4.13.1.1 10 CFR 51.23 (Continued Storage Rule) and 10 CFR 51, Subpart A, Table B-1 

(License Renewal)

The NRC’s findings regarding the environmental impacts associated with the renewal of a 

power reactor operating license are contained in Table B-1, “Summary of Findings on NEPA

Issues for License Renewal of Nuclear Power Plants.” The table is located in Appendix B to 

Subpart A of 10 CFR Part 51, “Environmental Effect of Renewing the Operating License of a 

Nuclear Power Plant” 4 (Table B-1). In 1996, as part of the 10 CFR Part 51 license renewal 

rulemaking, the NRC determined that offsite radiological impacts of spent nuclear fuel and 

high-level waste disposal would be a Category 1 (generic) issue with no impact level assigned 

(61 FR 28467, 28495; June 5, 1996). The NRC analyzed the EPA generic repository standards 

and dose limits in existence at the time and concluded that offsite radiological impacts 

warranted a Category 1 determination (61 FR 28467, 28478; June 5, 1996). In its 2009 

proposed rule, the NRC stated its intention to reaffirm that determination (74 FR 38117, 38127; 

July 31, 2009).

For the offsite radiological impacts resulting from spent fuel and high-level waste disposal and 

the onsite storage of spent fuel, which will occur after the reactors have been permanently shut 

down, the NRC’s Waste Confidence Decision and Temporary Storage Rule (WCD and rule) 

(10 CFR 51.23) historically represented the Commission’s generic determination that spent fuel 

can continue to be stored safely and without significant environmental impacts for a period of 

time after the end of the licensed life for operation. This generic determination meant that the 

NRC did not need to consider the storage of spent fuel after the end of a reactor’s licensed life 

for operation in NEPA documents that support its reactor and spent fuel storage application 

reviews.

The NRC first adopted the WCD and rule in 1984. The NRC amended the decision and rule 

in 1990, reviewed them in 1999, and amended them again in 2010, as published in the FR 

(49 FR 34685, 34694; 55 FR 38472, 38474; 64 FR 68005; and 75 FR 81032 and 81037). The 

WCD and rule are codified in 10 CFR 51.23.

On December 23, 2010, the Commission published in the FR a revision of the WCD and rule 

to reflect information gained from experience in the storage of spent fuel and the increased 

uncertainty in the siting and construction of a permanent geologic repository for the disposal of 

spent fuel and high-level waste (75 FR 81032 and 81037). In response to the 2010 WCD and 

rule, the States of New York, New Jersey, Connecticut, and Vermont—along with several other 

parties—challenged the Commission’s NEPA analysis in the decision, which provided the 

regulatory basis for the rule. On June 8, 2012, the United States Court of Appeals, District of 

Columbia Circuit in New York v. NRC, 681 F.3d 471 (D.C. Cir. 2012), vacated the NRC’s WCD 

and rule, after finding that it did not comply with NEPA.

In response to the court’s ruling, the Commission, in CLI-12-16 (NRC 2012a), determined that it 

would not issue licenses that rely upon the WCD and rule until the issues identified in the court’s 

decision are appropriately addressed by the Commission. In CLI-12-16, the Commission also 

noted that the decision not to issue licenses only applied to final license issuance; all licensing 

reviews and proceedings should continue to move forward.

In addition, the Commission directed in SRM-COMSECY-12-0016 (NRC 2012b) that the NRC 

staff proceed with a rulemaking that includes the development of a generic EIS to support a 

revised WCD and rule and to publish both the EIS and the revised decision and rule in the FR 

 

4 The Commission issued Table B-1 in June 1996 (61 FR 28467; June 5, 1996). The Commission issued an additional rule in 

December 1996 that made minor clarifying changes to, and added language inadvertently omitted from, Table B-1 (61 FR 66537; 

December 18, 1996). The NRC revised Table B-1 and other regulations in 10 CFR Part 51, relating to the NRC’s environmental 

review of a nuclear power plant’s license renewal application in a 2013 rulemaking (78 FR 37282; June 20, 2013).
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within 24 months (by September 2014). The Commission indicated that both the EIS and the 

revised WCD and rule should build on the information already documented in various NRC 

studies and reports, including existing EAs that the NRC developed as part of the 2010 WCD 

and rule. The Commission directed that any additional analyses should focus on the issues 

identified in the court’s decision. The Commission also directed that the NRC staff provide 

ample opportunity for public comment on both the draft EIS and the proposed WCD and rule.

As discussed above, in New York v. NRC, 681 F.3d 471 (D.C. Cir. 2012), the court vacated the 

Commission’s WCD and rule (10 CFR 51.23). In response to the court’s vacatur, the 

Commission developed a revised rule and associated Generic Environmental Impact Statement

for Continued Storage of Spent-Nuclear Fuel (NUREG-2157). Before the issuance of the 

revised 10 CFR 51.23 and NUREG–2157, the NRC issued the 2013 final license renewal rule, 

which amended Table B-1—along with other 10 CFR Part 51 regulations—and stated that upon 

finalization of the revised Waste Confidence rule and accompanying technical analyses,5 the 

NRC would make any necessary conforming amendments to Table B-1 (78 FR 37282, 37293; 

June 20, 2013).

On August 26, 2014, the Commission approved the Continued Storage Rule and associated 

Generic Environmental Impact Statement for Continued Storage of Spent Nuclear Fuel

(NUREG-2157, NRC 2014d). Subsequently, on September 19, 2014, the NRC published 

the final rule (79 FR 56238) in the FR along with NUREG-2157 (79 FR 53238, 56263). The 

Continued Storage Rule adopts the generic impact determinations made in NUREG-2157 and 

codifies the NRC’s generic determinations regarding the environmental impacts of continued 

storage of spent nuclear fuel beyond a reactor’s operating license (i.e., those impacts that could 

occur as a result of the storage of spent nuclear fuel at at-reactor or away-from-reactor sites 

after a reactor’s licensed life for operation and until a permanent repository becomes available). 

As directed by 10 CFR 51.23(b), the impacts assessed in NUREG-2157 regarding continued 

storage are deemed incorporated by rule into this license renewal SEIS.

In the Continued Storage Rule, the NRC made conforming changes to the two environmental 

issues in Table B-1 that were impacted by the vacated Waste Confidence rule: “Onsite spent 

fuel” and “Offsite radiological impacts (spent fuel and high-level waste disposal).” 6

 Although 

NUREG-2157 (the technical basis for the Continued Storage Rule) does not include high-level 

waste disposal in the analysis of impacts, it does address the technical feasibility of a repository 

in Appendix B of NUREG-2157 and concludes that a geologic repository for spent fuel is 

technically feasible and the same analysis applies to the feasibility of geologic disposal for 

high-level waste.

The Commission revised the Table B-1 finding for “Onsite storage of spent nuclear fuel” to add 

the phrase “during the license renewal term” to make clear that the SMALL impact is for the 

license renewal term only. Some minor clarifying changes were also made to the paragraph. 

The first paragraph of the column entry now reads, “During the license renewal term, SMALL. 

The expected increase in the volume of spent nuclear fuel from an additional 20 years of 

operation can be safely accommodated onsite during the license renewal term with small 

environmental impacts through dry or pool storage at all plants.”

In addition, a new paragraph is added to address the impacts of onsite storage of spent fuel

during the continued storage period. The second paragraph of the column entry reads, “For 

the period after the licensed life for reactor operations, the impacts of onsite storage of spent 

 

5 At the time of the 2013 final license renewal rule, the Continued Storage Rule was referred to as Waste Confidence.

6 These two issues were renamed ‘‘Onsite storage of spent nuclear fuel’ and ‘‘Offsite radiological impacts of spent nuclear fuel and 

high-level waste disposal,’’ respectively, by the 2013 license renewal rule. See “Revisions to Environmental Review for Renewal 

of Nuclear Power Plant Operating Licenses,” 78 FR 37282–37324 (June 20, 2013).
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nuclear fuel during the continued storage period are discussed in NUREG-2157 and as stated in 

§ 51.23(b), shall be deemed incorporated into this issue.” The changes reflect that this issue 

covers the environmental impacts associated with the storage of spent nuclear fuel during the 

license renewal term as well as the period after the licensed life for reactor operations.

The Table B-1 entry for “Offsite radiological impacts of spent nuclear fuel and high-level waste

disposal” also was revised to reclassify the impact determination as a Category 1 issue with no 

impact level assigned. The finding column entry for this issue includes reference to EPA’s 

radiation protection standards for the high-level waste and spent nuclear fuel disposal 

component of the fuel cycle. Although the status of a repository, including a repository at Yucca 

Mountain, is uncertain and outside the scope of the generic environmental analysis conducted 

to support the Continued Storage Rule, the NRC believes that the current radiation standards 

for Yucca Mountain are protective of public health and safety and the environment.

The changes to these two issues finalize the Table B-1 entries that the NRC had intended to 

issue in its 2013 license renewal rulemaking, but was unable to because the 2010 Waste 

Confidence rule had been vacated.

NUREG-2157 concludes that deep geologic disposal remains technically feasible, while the 

bases for the specific conclusions in Table B-1 are found elsewhere (e.g., the 1996 rule that 

issued Table B-1 and the 1996 license renewal GEIS, which provided the technical basis for 

that rulemaking, as reaffirmed by the 2013 rulemaking and final license renewal GEIS). Based 

on the Continued Storage Rule, these two issues were revised accordingly in Table B-1.

4.13.1.2 CLI-14-08: Holding That Revised 10 CFR 51.23 and NUREG-2157 Satisfy NRC’s 

NEPA Obligations for Continued Storage and Directing Staff to Account for 

Environmental Impacts In NUREG-2157

In CLI-14-08 (NRC 2014c), the Commission held that the revised 10 CFR 51.23 and associated 

NUREG-2157 cure the deficiencies identified by the court in New York v. NRC and stated that 

the rule satisfies the NRC’s NEPA obligations with respect to continued storage for initial, 

renewed, and amended licenses for reactors. 

As the Commission noted in CLI-14-08, the NRC staff must account for these environmental 

impacts before finalizing its licensing decision in this proceeding. To account for these impact 

determinations, the generic environmental impact determinations made pursuant to the 

Continued Storage Rule and the associated NUREG-2157 are deemed incorporated into 

this SEIS.

The NRC staff relies on the Continued Storage Rule and its supporting generic environmental 

impact statement (i.e., NUREG-2157) to provide the NEPA analyses of the environmental 

impacts of spent fuel storage at the reactor site or at an away-from-reactor storage facility 

beyond the licensed life for reactor operations. By virtue of revised 10 CFR 51.23, the impact 

determinations in NUREG–2157 regarding continued storage complete the analysis of the 

environmental impacts associated with spent fuel storage beyond the licensed life for reactor 

operations, and are deemed incorporated into this SEIS, as further described below.

4.13.1.3 At-Reactor Storage

The analysis in NUREG-2157 concludes that the potential impacts of at-reactor storage during 

the short-term timeframe (the first 60 years after the end of licensed life for operations of the 

reactor) would be SMALL (Section 4.20 of NUREG-2157). Further, the analysis in 

NUREG-2157 states that disposal of the spent fuel by the end of the short-term timeframe is the 

most likely outcome (see Section 1.2 of NUREG-2157).
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However, the analysis in NUREG-2157 also evaluated the potential impacts of continued 

storage if the fuel is not disposed of by the end of the short-term timeframe. The analysis in 

NUREG–2157 determined that the impacts to historic and cultural resources from at-reactor

storage during the long-term timeframe (the 100-year period after the short-term timeframe) and 

the indefinite timeframe (the period after the long-term timeframe) are dependent on factors that 

are unpredictable this far in advance and therefore concluded those impacts would be SMALL 

to LARGE (see Section 4.12 of NUREG-2157). Among other things, as discussed in 

NUREG-2157, the NRC cannot accurately determine at this time what resources may be 

present or discovered at a continued storage site a century or more in the future and whether 

those resources will be historically or culturally significant to future generations. Additionally, 

impacts greater than SMALL could occur if the activities to replace an independent spent fuel 

storage installation (ISFSI) and the dry transfer system (DTS) adversely affect cultural or historic 

resources and the effects cannot be mitigated. As discussed in NUREG-2157, given the 

minimal size of an ISFSI and DTS, and the large land areas at nuclear power plant sites, 

licensees should be able to locate these facilities away from historic and cultural resources. 

Potential adverse effects on historic properties or impacts on historic and cultural resources 

could also be minimized through development of agreements, license conditions, and 

implementation of the licensee’s historic and cultural resource management plans and 

procedures to protect known historic and cultural resources and address inadvertent discoveries 

during construction and replacement of these facilities. However, it may not be possible to 

avoid adverse effects on historic properties under the NHPA or impacts on historic and cultural 

resources under NEPA, and therefore, the analysis in NUREG-2157 concluded that impacts 

would be SMALL to LARGE (see Section 4.12.2 of NUREG-2157).

The analysis in NUREG-2157 also concludes that the impacts of nonradioactive waste in 

the indefinite timeframe would be SMALL to MODERATE, with the higher impacts potentially 

occurring if the waste from repeated replacement of the ISFSI and DTS exceeds local landfill 

capacity (see Section 4.15 of NUREG-2157). Although the NRC concluded that nonradioactive 

waste disposal would not be destabilizing (or LARGE), the range reflects uncertainty regarding 

whether the volume of nonradioactive waste from continued storage would contribute to 

noticeable waste management impacts over the indefinite timeframe when considered in 

the context of the overall local volume of nonradioactive waste.

As previously discussed, the NRC found in NUREG-2157 that disposal of the spent fuel is most 

likely to occur by the end of the short-term timeframe. Therefore, disposal during the long-term 

timeframe is less likely, and the scenario depicted in the indefinite timeframe—continuing to 

store spent nuclear fuel indefinitely—is unlikely. As a result, the most likely impacts of the 

continued storage of spent fuel are those considered in the short-term timeframe. In the unlikely 

event that fuel remains on site into the long-term and indefinite timeframes, the associated 

impact ranges in NUREG-2157 reflect the accordingly greater uncertainties regarding the 

potential impacts over these very long periods of time. Taking into account the impacts that the 

NRC considers most likely, which are SMALL; the greater uncertainty reflected in the ranges in 

the long-term and indefinite timeframes compared to the greater certainty in the SMALL 

findings; and the relative likelihood of the timeframes, the staff finds that the impact 

determinations for at-reactor storage presented in NUREG-2157 are deemed incorporated 

into this SEIS pursuant to 10 CFR 51.23.

4.13.1.4 Away-From-Reactor Storage

In NUREG-2157, the NRC concluded that a range of potential impacts could occur for some 

resource areas if the spent fuel from multiple reactors is shipped to a large (roughly 40,000 MT 

uranium) away-from-reactor ISFSI (see Section 5.20 of NUREG-2157). The ranges for some 
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resources are driven by the uncertainty regarding the location of such a facility and the local 

resources that would be affected.

For away-from-reactor storage, the unavoidable adverse environmental impacts for most 

resource areas is SMALL across all timeframes, except for air quality, terrestrial resources, 

aesthetics, waste management, and transportation where the impacts are SMALL to 

MODERATE. Socioeconomic impacts range from SMALL (adverse) to LARGE (beneficial) and 

historic and cultural resource impacts could be SMALL to LARGE across all timeframes. The 

potential MODERATE impacts on air quality, terrestrial wildlife, and transportation are based 

on potential construction-related fugitive dust emissions, terrestrial wildlife direct and indirect 

mortalities, terrestrial habitat loss, and temporary construction traffic impacts. The potential 

MODERATE impacts on aesthetics and waste management are based on noticeable changes 

to the viewshed from constructing a new away-from-reactor ISFSI, and the volume of 

nonhazardous solid waste generated by assumed facility ISFSI and DTS replacement 

activities for the indefinite timeframe, respectively. The potential LARGE beneficial impacts on 

socioeconomics are due to local economic tax revenue increases from an away-from-reactor 

ISFSI.

The potential impacts to historic and cultural resources during the short-term storage timeframe 

would range from SMALL to LARGE. The magnitude of adverse effects on historic properties 

and impacts on historic and cultural resources largely depends on where facilities are sited, 

what resources are present, the extent of proposed land disturbance, whether the area has 

been previously surveyed to identify historic and cultural resources, and if the licensee has 

management plans and procedures that are protective of historic and cultural resources. Even 

a small amount of ground disturbance (e.g., clearing and grading) could affect a small but 

significant resource. In most instances, placement of storage facilities on the site can be 

adjusted to minimize or avoid impacts on any historic and cultural resources in the area. 

However, the NRC recognizes that this may not always be possible. The NRC’s site-specific 

environmental review and compliance with the NHPA process could identify historic properties, 

identify adverse effects, and potentially resolve adverse effects on historic properties and 

impacts on other historic and cultural resources. Under the NHPA, mitigation does not eliminate 

a finding of adverse effect on historic properties. The potential impacts to historic and cultural 

resources during the long-term and indefinite storage timeframes would also range from SMALL 

to LARGE. This range takes into consideration routine maintenance and monitoring (i.e., no 

ground-disturbing activities), the absence or avoidance of historic and cultural resources, and 

potential ground-disturbing activities that could affect historic and cultural resources. The 

analysis also considers uncertainties inherent in analyzing this resource area over long 

timeframes. These uncertainties include any future discovery of previously unknown historic 

and cultural resources, resources that gain significance within the vicinity and the viewshed 

(e.g., nomination of a historic district) due to improvements in knowledge, technology, and 

excavation techniques and changes associated with predicting resources that future 

generations will consider significant. If construction of a DTS and replacement of the ISFSI and 

DTS occurs in an area with no historic or cultural resource present or construction occurs in a 

previously disturbed area that allows avoidance of historic and cultural resources, then impacts 

would be SMALL. By contrast, a MODERATE or LARGE impact could result if historic and 

cultural resources are present at a site and, because they cannot be avoided, are impacted by 

ground-disturbing activities during the long-term and indefinite timeframes.

Impacts on Federally listed species, designated critical habitat, and EFH would be based on 

site-specific conditions and determined as part of consultations required by the ESA and the 

Magnuson-Stevens Fishery Conservation and Management Act.
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Continued storage of spent nuclear fuel at an away-from-reactor ISFSI is not expected to cause 

disproportionately high and adverse human health and environmental effects on minority and 

low-income populations. As indicated in the Commission’s policy statement on environmental 

justice, should the NRC receive an application for a proposed away-from-reactor ISFSI, a 

site-specific NEPA analysis would be conducted, and this analysis would include consideration 

of environmental justice impacts. Pursuant to 10 CFR 51.23, the impact determinations for 

away-from-reactor storage presented in NUREG-2157 are deemed incorporated into this SEIS.

4.13.1.5 Cumulative Impacts of Continued Storage

NUREG-2157 examines the incremental impact of continued storage on each resource area 

analyzed in NUREG-2157 in combination with other past, present, and reasonably foreseeable 

future actions. NUREG-2157 indicates ranges of potential cumulative impacts for multiple 

resource areas (see Section 6.5 of NUREG-2157). However, these ranges are primarily driven 

by impacts from activities other than the continued storage of spent fuel at the reactor site; the 

impacts from these other activities would occur regardless of whether spent nuclear fuel is 

stored during the continued storage period. In the short-term timeframe, which is the most likely 

timeframe for the disposal of the fuel, the potential impacts of continued storage for at-reactor 

storage are SMALL and would, therefore, not be a significant contributor to the cumulative 

impacts. In the longer timeframes for at-reactor storage, or in the less likely case of 

away-from-reactor storage, some of the impacts from the storage of spent nuclear fuel could 

be greater than SMALL. As noted in NUREG-2157, other Federal and non-Federal activities 

occurring during the longer timeframes include uncertainties as well. It is primarily these 

uncertainties (i.e., those associated with activities other than continued storage) that contribute 

to the ranges of potential cumulative impacts discussed throughout Chapter 6 of NUREG-2157 

and summarized in Table 6-4 of NUREG-2157. Because, as stated above, the impacts from 

these other activities would occur regardless of whether continued storage occurs, the overall 

cumulative impact conclusions in NUREG-2157 would still be the stated ranges regardless of 

whether there are impacts of continued storage from any individual licensing action.

Taking into account the impacts that the NRC considers most likely, which are SMALL; 

the uncertainty reflected by the ranges in some impacts; and the relative likelihood of the 

timeframes, the impact determinations for cumulative impacts presented in NUREG-2157 

are deemed incorporated into this SEIS pursuant to 10 CFR 51.23.

4.13.1.6 Conclusion

Based on the information discussed above, the impacts of continued storage of spent nuclear 

fuel are those presented in NUREG-2157 and are deemed incorporated into this SEIS pursuant 

to 10 CFR 51.23. In addition, the revised 10 CFR 51.23 and NUREG-2157 have gone through 

the rulemaking process that involved significant input from the public. Therefore, the NRC staff 

concludes that the information in NUREG-2157 provides the appropriate NEPA analyses of the 

potential environmental impacts associated with the continued storage of spent fuel beyond the 

licensed life for reactor operations at the Braidwood Station, Units 1 and 2.

The NRC staff concludes that the revised 10 CFR 51.23, which adopts the generic impact 

determination regarding continued storage from NUREG-2157, satisfies the NRC’s NEPA

obligations with respect to continued storage of spent nuclear fuel, as it pertains to the issues, 

“Onsite storage of spent nuclear fuel” and “Offsite radiological impacts of spent nuclear fuel and 

high-level waste disposal” for the environmental review associated with the license renewal for 

Braidwood. 
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4.13.2 No-Action Alternative

If the no-action alternative were implemented, Braidwood would cease operation at the end 

of the initial operating licenses, or sooner, and enter decommissioning. The plants, which are 

currently operating within regulatory limits, would generate less spent nuclear fuel and emit less 

gaseous and liquid radioactive effluents into the environment. In addition, following shutdown, 

the variety if potential accidents at the plants (radiological and industrial) would be reduced to 

a limited set associated with shutdown events and fuel handling and storage. In Section 4.11 of 

this SEIS, the NRC staff concluded that the impacts of continued operations on human health 

would be SMALL. In Section 4.11 of this SEIS, the NRC staff concluded that the impacts of 

accidents would be SMALL. In Section 4.14.2 of this SEIS the NRC staff concludes that the 

impacts from decommissioning would be SMALL. Therefore, as radioactive emissions to the 

environment decrease, and the likelihood and variety of accidents decrease following shutdown 

and decommissioning, the NRC staff concludes that the risk to human health following plant 

shutdown would be SMALL.

4.13.3 New Nuclear Alternative

Construction

Construction-related nonradioactive waste would be generated during construction activities, 

and would be recycled or disposed of in approved landfills.

Operation

During normal plant operations, routine plant maintenance, and cleaning activities would 

generate radioactive low-level waste (LLW), spent nuclear fuel, and high-level waste as well as 

nonradioactive waste. Sections 3.1.4 and 3.1.5 discuss radioactive and nonradioactive waste 

management at Braidwood. Quantities of radioactive and nonradioactive waste generated by 

two new nuclear units would be comparable to that generated at Braidwood.

The GEIS concluded that the generation and management of solid radioactive and 

nonradioactive waste during the license renewal term are not expected to result in significant 

environmental impacts. Based on this information, the waste impacts from the new nuclear 

alternative would be SMALL (NRC 2013f).

4.13.4 Coal (Integrated Gasification Combined Cycle) Alternative

Construction

Construction-related debris would be generated during plant construction activities, and would 

be recycled or disposed of in approved landfills.

Operation

Coal combustion generates waste in the form of fly ash and bottom ash. In addition, equipment 

for controlling air pollution generates additional ash, spent selective catalytic reduction (SCR) 

catalyst, and scrubber sludge. The management and disposal of the large amounts of coal 

combustion waste is a significant part of the operation of a coal-fired power generating facility.

Although an IGCC facility is likely to use offsite disposal of coal combustion waste, some 

short-term storage of coal combustion waste (either in open piles or in surface impoundments) 

is likely to take place onsite, thus establishing the potential for leaching of toxic chemicals into 

the local environment.
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The impacts of managing the substantial amounts of solid waste, especially fly ash and 

scrubber sludge generated during operation of this alternative would be MODERATE 

(NRC 1996). The amount of the construction waste would be small compared to the amount of 

waste generated during the operational stage and much of it could be recycled (i.e., marketed 

for beneficial use). Therefore, the staff concludes that the overall waste management impacts 

from construction and operation of this alternative would be SMALL to MODERATE.

4.13.5 Natural Gas Combined Cycle Alternative

Construction

Construction-related debris would be generated during plant construction activities, and would 

be recycled or disposed of in approved landfills.

Operation

Waste generation from NGCC technology would be minimal. The only significant waste 

generated at an NGCC power plant would be spent SCR catalyst, which is used to control 

nitrogen oxide emissions.

The spent catalyst would be regenerated or disposed of offsite. Other than spent SCR catalyst, 

waste generation at an operating natural gas-fired plant would be limited largely to typical 

operations and maintenance nonhazardous waste. Overall, the NRC staff concludes that waste 

impacts from the NGCC alternative would be SMALL.

4.13.6 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

Construction

Construction-related debris would be generated during construction activities, and would be 

recycled or disposed of in approved landfills.

Operation

Waste generation from NGCC technology is discussed in Section 4.13.5.

Waste generation from a combination of wind and solar PV alternatives would be minimal, 

consisting of debris from routine maintenance and the disposal of worn or broken parts. Based 

on this information, the NRC staff concludes that waste impacts from the construction and 

operation of a combination wind and solar PV alternative would be SMALL.

4.13.7 Purchased Power

The types of waste generated by the alternative electricity generation sources (i.e., coal, 

natural gas, nuclear, and wind) used in the purchased power alternative are discussed in 

Sections 4.13.3, 4.13.4, 4.13.5, and 4.13.6. Depending on types of power-generation plants 

used to provide the electricity for the purchased power alternative, the NRC staff concludes that 

the waste management impacts would range from SMALL to MODERATE.

4.14 Evaluation of New and Potentially Significant Information

New and significant information is information that must be new, based on a review of the GEIS

(NRC 2013a), presenting a seriously different picture of the impacts from those envisioned in 

the GEIS (i.e., impacts of greater severity than impacts considered in the GEIS, considering 

their intensity and context).
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In accordance with 10 CFR 51.53(c), the ER that the applicant submits must provide an analysis 

of the Category 2 issues in Table B–1 of 10 CFR Part 51, Subpart A, Appendix B. Additionally, 

it must discuss actions to mitigate any adverse impacts associated with the proposed action and 

environmental impacts of alternatives to the proposed action. In accordance with 

10 CFR 51.53(c)(3), the ER does not need to contain an analysis of any Category 1 issue 

unless there is new and significant information on a specific issue.

The NRC process for identifying new and significant information is described in NUREG–1555, 

Supplement 1, Standard Review Plans for Environmental Reviews for Nuclear Power Plants, 

Supplement 1: Operating License Renewal (NRC 2013k). The search for new information 

includes:

• review of an applicant’s ER and the process for discovering and evaluating 

the significance of new information;

• review of public comments;

• review of environmental quality standards and regulations;

• coordination with Federal, state, Tribal, and local environmental 

protection and resource agencies; and

• review of technical literature.

New information that the staff discovers is evaluated for significance using the criteria set forth 

in the GEIS. For Category 1 issues, in which new and significant information is identified, 

reconsideration of the conclusions for those issues is limited in scope to assessment of the 

relevant new and significant information. The scope of this assessment does not include those 

facets of an issue that are not affected (or relevant to) by the new information.

The NRC staff reviewed the discussion of environmental impacts associated with operation 

during the renewal term in the GElS and has conducted its own independent review, including a 

public involvement process (e.g., public meetings) to identify new and significant issues for the 

Braidwood LRA environmental review. The NRC staff has not identified new and significant 

information on environmental issues related to operation of Braidwood during the renewal term. 

The NRC staff also determined that information provided during the public comment period did 

not identify any new issue that requires site-specific assessment.

4.15 Impacts Common to All Alternatives

This section describes the impacts that are considered common to all alternatives discussed in 

this SEIS, including the proposed action and replacement power alternatives. The continued 

operation of a nuclear power plant and replacement fossil fuel power plants both involve mining, 

processing, and the consumption of fuel, which results in comparative impacts (NRC 2013f). 

The termination of operations and the decommissioning of both a nuclear power plant and 

replacement fossil fueled power plants are also discussed in the following sections, as well 

as GHG emissions. 

4.15.1 Fuel Cycles

This section describes the environmental impacts associate with the fuel cycles of the proposed 

action and replacement power alternatives. Most replacement power alternatives employ a set 

of steps in the utilization of its fuel source, which can include extraction, transformation, 

transportation, and combustion. Emissions generally occur at each stage of the fuel cycle 

(NRC 2013f).
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4.15.1.1 Uranium Fuel Cycle

The uranium fuel cycle issues applicable to Braidwood are discussed below and listed in 

Table 4–25 for Category 1 issues. Table B-1 of Appendix B to Subpart A of 10 CFR Part 51 

contains more information on these issues.

Table 4–25. Issues Related to the Uranium Fuel Cycle

Issue GEIS Section Category

Offsite radiological impacts – individual impacts from other than the disposal 

of spent fuel and high-level waste 4.12.1.1 1 

Offsite radiological impacts – collective impacts from other than the disposal 

of spent fuel and high-level waste 4.12.1.1 1 

Nonradiological impacts of the uranium fuel cycle 4.12.1.1 1

Transportation 4.12.1.1 1

Source: Table B-1 in Appendix B, Subpart A, to 10 CFR Part 51

The uranium fuel cycle includes uranium mining and milling, the production of uranium 

hexafluoride, isotopic enrichment, fuel fabrication, reprocessing of irradiated fuel, transportation 

of radioactive materials, and management of LLWs and high-level wastes related to uranium 

fuel cycle activities. The generic potential impacts of the radiological and nonradiological 

environmental impacts of the uranium fuel cycle and transportation of nuclear fuel and wastes 

are described in detail in NUREG–1437, Generic Environmental Impact Statement (GEIS) for 

License Renewal of Nuclear Plants (NRC 2013f).

The NRC staff did not identify any new and significant information related to the uranium fuel 

cycle issues listed in Table 4-25 during its review of the applicant’s ER (Exelon 2013), the site 

visit, or the scoping process. Therefore, there are no impacts related to these issues beyond 

those discussed in the GEIS. For these Category 1 issues, the GEIS concludes that the 

impacts are SMALL, except for the issue, “Offsite radiological impacts - collective impacts,” 

which the NRC has not assigned an impact level. This issue assesses the 100-year radiation 

dose to the U.S. population (i.e., collective effects or collective dose) from radioactive effluent 

released as part of the uranium fuel cycle for a nuclear power plant during the license renewal 

term compared to the radiation dose from natural background exposure. It is a comparative 

assessment for which there is no regulatory standard to base an impact level.

4.15.1.2 Replacement Power Fuel Cycles

Fossil Fuel Energy Alternatives

Fuel cycle impacts for a fossil-fuel-fired plant result from the initial extraction of fuel, cleaning 

and processing of fuel, transport of fuel to the facility, and management and ultimate disposal 

of solid wastes from fuel combustion. These impacts are discussed in more detail in 

Section 4.12.1.2 of the GEIS (NRC 2013f) and can generally include:

 significant changes to land use and visual resources;

 impacts to air quality, including release of criteria pollutants, fugitive dust, 

VOCs, and coalbed methane in the atmosphere;

 noise impacts;

 geology and soil impacts due to land disturbances and mining;
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 water resource impacts, including degradation of surface water and 

groundwater quality;

 ecological impacts, including loss of habitat and wildlife disturbances;

 historic and cultural resources impacts within the mine footprint;

 socioeconomic impacts from employment of both the mining workforce 

and service and support industries;

 environmental justice impacts;

 health impacts to workers from exposure to airborne dust and methane 

gases; and

 the generation of coal and industrial wastes.

New Nuclear Energy Alternatives

Fuel cycle impacts for a nuclear plant result from the initial extraction of fuel, transport of fuel to 

the nuclear facilities, and management and ultimate disposal of spent fuel. The environmental 

impacts of the uranium fuel cycle are discussed above, in Section 4.14.1.1.

Renewable Energy Alternatives

The term “fuel cycle” has varying degrees of relevance for renewable energy facilities. The 

term has meaning for renewable energy technologies that rely on combustion of fuels such as 

biomass grown or harvested for the express purpose of power production. The term is 

somewhat more difficult to define for renewable technologies such as wind, solar, geothermal, 

and ocean wave and current. Those natural energy resources exist regardless of any effort to 

harvest them for electricity production. The common technological strategy for harvesting 

energy from such natural resources is to convert the kinetic or thermal energy inherent in that 

resource to mechanical energy or torque. The torque is then applied directly (e.g., as in the 

case of a wind turbine) or indirectly (e.g., for those facilities that utilize conventional steam 

cycles to drive turbines that drive generators) to produce electricity. However, because those 

renewable technologies capture very small fractions of the total kinetic or thermal energy 

contained in those resources, impacts from the presence or absence of the renewable energy 

technology are often indistinguishable (NRC 2013f). 

4.15.2 Terminating Power Plant Operations and Decommissioning

This section describes the environmental impacts associated with the termination of operations 

and the decommissioning of a nuclear power plant and replacement power alternatives. All 

operating power plants will terminate operations and be decommissioned at some point after 

the end of their operating life or after a decision is made to cease operations. For the proposed 

action, license renewal would delay this eventuality for an additional 20 years beyond the 

current license period.

4.15.2.1 Existing Nuclear Power Plant (Proposed Action)

Environmental impacts from the activities associated with the decommissioning of any 

reactor before or at the end of an initial or renewed license are evaluated in Supplement 1 of 

NUREG-0586, Final Generic Environmental Impact Statement on Decommissioning of Nuclear 

Facilities Regarding the Decommissioning of Nuclear Power Reactors (NRC 2002b). 

Additionally, the incremental environmental impacts associated with decommissioning activities 

resulting from continued plant operation during the renewal term are discussed in the GEIS 

(NRC 2013f).
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Table 4–26 lists the Category 1 issues in Table B-1 of 10 CFR Part 51, Subpart A, Appendix B 

that are applicable to Braidwood’s decommissioning following the license renewal term.

Table 4–26. Issues Related to Decommissioning

Issue GEIS Section Category

Radiation doses 4.12.2.1 1

Waste management 4.12.2.1 1

Air quality 4.12.2.1 1

Water quality 4.12.2.1 1

Ecological resources 4.12.2.1 1

Socioeconomic impacts 4.12.2.1 1

Source: Table B-1 in Appendix B, Subpart A, to 10 CFR Part 51

Decommissioning would occur whether Braidwood were shut down at the end of its current 

operating license or at the end of the period of the license renewal term. Exelon stated in its ER 

(Exelon 2013) that it is not aware of any new and significant information on the environmental 

impacts of Braidwood during the license renewal term. The staff has not found any new and 

significant information during its independent review of Exelon’s ER, the site visit, or the scoping

process. Therefore, the NRC staff concludes that there are no impacts related to these issues, 

beyond those discussed in the GEIS (license renewal). For all of these issues, the NRC staff 

concluded in the GEIS that the impacts are SMALL (NRC 2013f).

4.15.2.2 Replacement Power Plants

Fossil Fuel Energy Alternatives

The environmental impacts from the termination of power plant operations and 

decommissioning of a fossil-fuel-fired plant are dependent on the facility’s decommissioning 

plan. General elements and requirements for a fossil fuel plant decommissioning plan are 

discussed in Section 4.12 of the GEIS (license renewal) and can include the removal of 

structures to at least 3 ft (1 m) below grade, removal of all coal, combustion waste, and 

accumulated sludge, removal of intake and discharge structures, and the clean-up and 

remediation of incidental spills and leaks at the facility. The decommissioning plan outlines 

the actions necessary to restore the site to a condition equivalent in character and value to the 

greenfield or existing industrial site on which the facility was first constructed (NRC 2013f). A 

Greenfield site is a vacant land that has never been developed or was formerly occupied by 

farms or low-density development that left the land free of environmental contamination. A 

Greenfield site is typically located in suburban or ex-urban areas and can be less costly to 

develop than an existing industrial site that is often located in urban areas.

The environmental consequences of decommissioning are discussed in the GEIS (license 

renewal) and can generally include:

 short-term impacts on air quality and noise from the deconstruction of 

facility structures;

 short-term impacts on land use and visual resources;

 long-term reestablishment of vegetation and wildlife communities;
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 socioeconomic impacts due to decommissioning workforce and the long-term 

loss of jobs; and

 elimination of health and safety impacts on operating personnel and 

general public.

New Nuclear Alternatives

Termination of operations and decommissioning impacts for a nuclear plant include all activities 

related to the safe removal of the facility from service and the reduction of residual radioactivity 

to a level that permits release of the property under restricted conditions or unrestricted use and 

termination of a license (NRC 2013f). The environmental impacts of the uranium fuel cycle are 

discussed above, in Section 4.15.1.1.

Renewable Alternatives

Termination of power plant operation and decommissioning for renewable energy facilities 

would be similar to the impacts discussed for fossil-fuel-fired plants above. Decommissioning 

would involve the removal of facility components and operational wastes and residues to restore 

the site to a condition equivalent in character and value to the site on which the facility was first 

constructed (NRC 2013f).

4.15.3 Greenhouse Gas Emissions and Climate Change

The following sections discuss: (a) GHG emissions released from operation of Braidwood 

and alternatives and (b) the environmental impacts that could occur from changes in climate 

conditions. The cumulative impacts of GHG emissions on climate are discussed in 

Section 4.16.11, Global Climate Change.

4.15.3.1 Greenhouse Gas Emissions From the Proposed Project and Alternatives

Gases found in the Earth’s atmosphere that trap heat and play a role in Earth’s climate are 

collectively termed GHGs. Greenhouse gases include carbon dioxide, methane, nitrous oxide, 

water vapor, and fluorinated gases such as hydrofluorocarbons (HFCs), perfluorocarbons 

(PFCs), and sulfur hexafluoride. Earth’s climate responds to changes in concentration of GHG 

in the atmosphere as GHGs affect the amount of energy absorbed and heat trapped by the 

atmosphere. Increasing GHG concentration in the atmosphere generally increases Earth’s 

surface temperature. Atmospheric concentrations of carbon dioxide, methane, and nitrous

oxide have significantly increased since 1750 (Solomon et al. 2007). Carbon dioxide, methane, 

nitrous oxide, HFCs, PFCs, and sulfur hexafluoride (termed long-lived GHGs) are well-mixed 

throughout Earth’s atmosphere and their impact on climate is long lasting as a result of their 

long atmospheric lifetime (74 FR 66496). Carbon dioxide is of primary concern for global 

climate change due to its long atmospheric lifetime and it is the primary gas emitted as a result 

of human activities. Climate change research indicates that the cause of the Earth’s warming 

over the last 50 years is the buildup of GHGs in the atmosphere resulting from human activities 

(USGCRP 2014).

4.15.3.2 Existing Nuclear Power Plant (Proposed Action)

Plant operations at Braidwood release GHG emissions (primarily carbon dioxide) from 

stationary combustion sources, such as diesel generators, auxiliary boilers, AFW pumps, and 

diesel engines. Mobile combustion sources include vehicle traffic, such as worker and delivery 

vehicles. Other sources include fluorinated gases used in refrigeration systems and in electrical 

transmission and distribution systems. These fluorinated gases are typically emitted in small 

quantities but their impacts could be substantial because of their high global warming potential.
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The GHG emissions generated directly and indirectly by an entity can be classified into 

three “Scopes,” based on the source of the emissions (EPA 2013a). Scope 1 GHG emissions 

are direct emissions that are owned or controlled by the entity, which include emissions from 

fossil fuels burned onsite, emissions from entity-owned or agency-leased vehicles, and other 

direct sources. Scope 2 GHG emissions are indirect emissions resulting from the generation 

of electricity, heating and cooling, or steam generated off site but purchased by the reporting 

entity. Scope 3 GHG emissions are indirect emissions from sources not owned or directly 

controlled by the reporting entity but related to the entity’s activities such as vendor supply 

chains, delivery services, outsourced activities, and employee travel and commuting. 

Greenhouse gas emissions from nuclear power plants, including Braidwood, belong to all 

three Scopes. Annual total GHG emissions at Braidwood are presented in Table 4–27 for the 

2008-2012 period (based on the specific fuel-mix (energy related) that is purchased by 

Braidwood, related to indirect emission). Total (direct plus indirect) GHG emissions include 

permitted combustion sources (diesel generators and auxiliary boilers), fugitive gas emissions, 

direct fluorinated gases, indirect purchased electricity, and ozone depleting substances from 

refrigerants. However, total emissions do not include GHG emissions from mobile sources 

because Exelon does not compile site-specific data for such sources (Exelon 2014i). There are 

approximately 890 employees at Braidwood and about 80 percent of the employees live in Will, 

Grundy, or Kankakee Counties in Illinois (within 50 mi of Braidwood Station). The NRC staff 

estimates annual GHG emissions resulting from employee vehicles to be approximately 

8,400 MT carbon dioxide equivalents.

Table 4–27. Estimated GHG Emissions From Operations at Braidwood Station

Year CO2e (MT/year)

2008 20,413

2009 20,888

2010 25,040

2011 25,815

2012 35,029

Source: Exelon 2014i

4.15.3.3 No-Action Alternative

The no-action alternative represents a decision by the NRC not to renew the operating license 

of a nuclear power plant beyond the current operating license term. At some point, all nuclear 

plants will terminate operations and undergo decommissioning. Under the no-action alternative, 

plant operations for Braidwood would terminate at or before the end of the current license term 

(NRC 2013f). When the plant stops operating, there will be a reduction in GHG emissions from 

activities related to plant operation, such as use of diesel generators and employee vehicles. 

Greenhouse gas emissions are anticipated to be less than the emissions presented in 

Table 4–27.

4.15.3.4 New Nuclear Alternative

As discussed in Section 2.2.2.1, the NRC staff evaluated the new nuclear power plant 

alternative that would consist of two units with an approximate generating capacity of 

1,120 MWe each. The GEIS presents lifecycle GHG emissions associated with nuclear 
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power generation. As presented in Tables 4.12-4 through 4.12-6 of the GEIS, lifecycle 7

GHG emissions from nuclear power generation can range from 1 to 288 g carbon equivalent per 

kilowatt-hour (Ceq/kWh). Operations of nuclear power plants do not burn fossil fuels to generate 

electricity and so do not directly emit GHG emissions. Sources of GHG emissions include 

stationary combustion sources (e.g., emergency diesel generators, auxiliary boilers) and mobile 

sources (worker vehicles, onsite heavy equipment and support vehicles, and delivery of 

materials and disposal of wastes). As discussed in Section 4.3.3.1, it is anticipated that air 

emissions from a new nuclear power plant would be similar to those from Braidwood.

4.15.3.5 Coal (Integrated Gasification Combined Cycle) Alternative

As discussed in Section 2.2.2.2, the NRC staff evaluated the IGCC plant alternative that would 

consist of four units with a total output of 2,472 MWe. The IGCC alternative would release 

GHGs. The NRC staff estimates that operation of four IGCC units will directly emit about 

14.3 million tons (approximately 12.9 million MT) per year of carbon dioxide equivalents. 

Emissions were estimated for the IGCC alternative without CCS. Among the alternatives, GHG 

emissions are the highest from IGCC plants. As described in Chapter 2, the IGCC alternative 

assumes that the plants may install CCS technology at some point in the future, which would 

reduce carbon dioxide emissions considerably. The DOE’s National Energy Technology 

Laboratory (NETL) performed a study to establish the cost and performance for a range of 

carbon dioxide capture levels (up to 97 percent) for new IGCC power plant (NETL 2013a). The 

study identified technical configurations that were tailored to achieve a specific level of carbon 

capture.

4.15.3.6 Natural Gas Combined Cycle Alternative

As discussed in Section 2.2.2.3, the NRC staff evaluated an NGCC alternative that consists of 

five NGCC 560-MWe units (total 2800 MW). The GEIS presents lifecycle GHG emissions 

associated with natural gas power generation. As presented in Table 4.12-5 of the GEIS, 

lifecycle GHG emissions from natural gas can range from 120 to 930 g Ceq/kWh. The NRC 

staff estimates that operation of the NGCC alternative directly will emit about 7.9 million tons 

(approximately 7.2 million MT) per year of carbon dioxide equivalent emissions.

4.15.3.7 Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas

For the combination alternative, it is assumed that the majority of the GHG emissions result 

from the NGCC portion only because renewable portions (wind and solar PV) do not burn fossil 

fuels to generate electricity. The NGCC portion of the combination alternative would consist of 

360 MWe of generating capacity. The NRC staff estimates that operation of the combination 

alternative will directly emit 1.0 million tons (0.9 million MT) per year of carbon dioxide 

equivalents.

4.15.3.8 Purchased Power

Purchased power would come from common types of existing technology (coal, natural gas, 

and nuclear) within the ROI and it is not likely that new facilities would be constructed to replace 

Braidwood. GHG emissions from purchased power will vary and depended on the type and 

combination of technology purchased power comes from. In 2012, coal, natural gas, and 

nuclear power accounted for 37, 30, and 19 percent share, respectively, of total U.S. electricity 

generation (EIA 2014). Using these percent shares for the purchased power alternative, the 

NRC staff estimates 7.7 million tons (6.9 million MT) per year of carbon dioxide equivalents will 

 

7 Lifecycle carbon emissions analyses consider construction, operation, decommissioning, and associated processing of fuel 

(gas, coal, etc.).
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be emitted. However, GHG emissions may be greater or less than this estimate and will 

depend on the technology from which the purchased power comes from.

4.15.3.9 Summary of GHG Emissions From the Proposed Action and Alternatives

Table 4–28 presents the direct uncontrolled GHG emissions from operation of the proposed 

action and alternatives. GHG emissions from the proposed action (continued operation at 

Braidwood) and the new nuclear alternative would be lowest. The IGCC alternative would 

release the highest emissions, followed by the NGCC alternative. GHG emissions from the 

combination alternative would be about one-tenth of the NGCC alternative. GHG emissions for 

the IGCC, NGCC, combination, and purchased power alternatives are higher than those for the 

proposed action and a new nuclear alternative by several orders of magnitude.

Table 4–28. Direct Uncontrolled GHG Emissions From Operation of the Proposed Action 

and Alternatives

Technology CO2e (MT/year)

Braidwood Station continued operation 1,230

New Nuclear 1,230

NGCC 13.0×106

IGCC 7.2×106

Combination Alternative (a) 1.0×106

Purchased Power (b) 6.9×106

(a) Only NGCC portion of GHG emissions are presented.

(b) Assumed 10% NGCC, 80% Wind, and 10% Solar in generating capacity

4.15.3.10 Climate Change Impacts to Resource Areas

Climate change is the decades or longer change in climate measurements (temperature, 

precipitation, etc.) that has been observed on a global, national, and regional level (EPA 2012; 

Solomon et al. 2007; USGCRP 2014). Climate change can vary regionally, spatially, and 

seasonally depending on local, regional, and global factors. Just as the regional climate differs 

throughout the world, the impacts of climate change can vary between locations.

On a global level, from 1880 to 2012, average surface temperatures increased by 0.85 °C, and 

an increase in annual average precipitation (ranging from 1.01 to 2.77 mm/year per decade) has 

been observed for the 1901 to 2008 time period (Stocker et al. 2013). The observed global 

change in average surface temperature and precipitation has been accompanied by an increase 

in sea surface temperatures, a decrease in global glacier ice, increase in sea level, and 

changes in extreme weather events. Such extreme events include an increase in frequency of 

heat waves, heavy precipitation, and minimum and maximum temperatures (EPA 2012a; Karl 

et al. 2009; Solomon et al. 2007; USGCRP 2014).

In the United States, the U.S. Global Change Research Program (USGCRP) reports that from 

1895 to 2012, average surface temperature has increased by 1.3 °F to 1.9 °F (0.72 to 1.06 °C), 

and since 1900, average annual precipitation has increased by 5 percent (USGCRP 2014). On 

a seasonal basis, warming has been the greatest in winter and spring. From 1895 to 2001, an 

increase in the length of the freeze-free season, the period between the last occurrence of 0 °C 

(32 °F) in the spring and first occurrence of 0 °C (32 °F) in the fall has been observed for the 

contiguous United States; between 1991 and 2011 the average freeze-free season was 10 days 
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longer than between 1901 and 1960 (USGCRP 2014). Since the 1970s, the United States has 

warmed at a faster rate as the average surface temperature rose at an average rate of 0.17 to 

0.25 °C (0.31 to 0.45 °F) per decade. In addition, the year 2012 was the warmest on record 

(USGCRP 2014). Observed climate related changes in the United States include increases in 

the frequency and intensity of heavy precipitation, earlier onset of spring snowmelt and runoff, 

rise of sea level in coastal areas of the U.S., increase in occurrence of heat waves, and a 

decrease in occurrence of cold waves (EPA 2012a; Karl et al. 2009; NOAA 2013a; 

USGCRP 2014).

Temperature data indicates that the Midwest region, where Braidwood is located, experienced a 

0.06  ̊C (0.11  ̊F) per decade increase in annual mean temperature during the 1900-2010 period 

(NOAA 2013b). Temperature data for the recent past indicates an increased rate of warming for 

the Midwest: 0.12 C (0.22 F) per decade for the 1950–2010 time period and a 0.26  ̊C (0.47  F) 

temperature increase for the 1979-2010 time period. Average annual precipitation data for the 

Midwest exhibits an increasing trend of 0.31 inches per decade for the long term period 

(1895–2011) (NOAA 2013b). Precipitation data over the 1958–2007 period exhibit clear trends 

toward more very heavy precipitation events (defined as the heaviest 1 percent of all daily 

events) for the nation as a whole, and particularly in the Northeast and Midwest. At Braidwood, 

for the 1973–2013 period, an upward trend in ambient annual average temperature has also 

been observed (Exelon 2014i).

Future GHG emission concentration and climate models are commonly used to project 

possible climate change. Climate models indicate that over the next few decades, temperature 

increases will continue due to current GHG emissions concentrations in the atmosphere 

(USGCRP 2014). Over the longer term, the magnitude of temperature increases and climate 

change effects will depend on both past and future GHG emission scenarios (Karl et al. 2009; 

Solomon et al. 2007; USGCRP 2014). Climate models project a continued increase in global 

surface temperatures, more frequent and long-lasting heat waves, continued increase in sea 

level, continued decline in arctic sea ice, an increase in heavy precipitation events, and an 

increased frequency of severe droughts.

For the license renewal period of Braidwood, climate model simulations (between 2021–2050 

relative to the reference period (1971-1999)) indicate an increase in annual mean temperature 

in the Midwest region of 2.5–3.5  ̊F (NOAA 2013b). The predicted increase in temperature 

during this time period occurs for all seasons with the largest increase occurring in the 

summertime (June, July, and August). Climate model simulations (for the time period 

2021–2050) suggest spatial differences in annual mean precipitation changes for the Midwest 

with northern areas experiencing an increase in precipitation and the southern areas 

experiencing a decrease in precipitation. For Illinois, the models indicate a 0-3 percent increase 

in annual mean precipitation with fall, winter, and spring seasons experiencing precipitation 

change increases and the summer season experiencing a decrease in precipitation. However, 

these changes in precipitation were not significant and the models indicate changes that are 

less than normal year to year variations (NOAA 2013b). While future regional changes in 

precipitation are difficult to predict, the USGCRP reports that storm tracks are expected to 

shift northward, increases in heavy precipitation events will continue, the number of dry days 

between rainfalls will increase, and an increase in drought is expected (USGCRP 2014).

Changes in climate have broader implications for public health, water resources, land use and 

development, and ecosystems. For instance, changes in precipitation patterns and increase in 

air temperature can affect water availability and quality, distribution of plant and animal species, 

and land-use patterns and land-cover, which can in turn affect terrestrial and aquatic habitats. 

The sections below discuss how future climate change may impact air quality, water resources, 

land-use, terrestrial resources, aquatic resources, and human health in the region of interest for 
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Braidwood Station. Although there is uncertainty in the exact future climate change scenario, 

the discussions provided below demonstrate the potential implications of climate change on 

resources.

Air Quality

Air pollutant formation partially depends on the temperature and humidity of the atmosphere and 

is a result of the interactions between hourly changes in the physical and dynamic properties of 

the atmosphere, atmospheric circulation features, wind, topography, and energy use (Parry 

et al. 2007). In addition, air pollutant concentrations (i.e., after formation) are sensitive to winds, 

temperature, humidity, and precipitation (74 FR 66496). Hence, climate change can impact air 

quality as a result of the changes in meteorological conditions.

Ozone has been found to be particularly sensitive to climate change (EPA 2009; 

USGCRP 2014). Ozone is formed as a result of the chemical reaction of nitrogen oxides and 

VOCs in the presence of heat and sunlight. Sunshine, high temperatures, and air stagnation 

are favorable meteorological conditions to higher levels of ozone (EPA 2009). The emission of 

ozone precursors also depends on temperature, wind, and solar radiation (Parry et al. 2007); 

both nitrogen oxide and biogenic VOC emissions are expected to be higher in a warmer climate 

(EPA 2009). Warmer climate and weaker air circulation are conducive to higher ozone levels. 

Regional air quality modeling indicates that the northern regions of the United States can 

experience an increase in ozone concentration by the year 2050, but an increase in PM2.5

concentration around the Great Lakes region (Tagaris et al. 2009; USGCRP 2014). However, 

air quality projections (particularly ozone and PM2.5) are uncertain and indicate that 

concentrations are driven primarily by emissions rather than by physical climate change 

(Stocker et al. 2013). The combination of higher temperatures, stagnant air masses, sunlight, 

and emissions of precursors may make it difficult to meet ozone National Ambient Air Quality 

Standards (Karl et al. 2009).

Land Use

Anthropogenic land use is both a contributor to climate change as well as a receptor of climate 

change impacts (Dale 1997). As described previously in this section, the Midwest will likely 

experience rising temperatures and heavier precipitation events during the proposed license 

renewal period. Agriculture (the major land use in the vicinity of Braidwood) and growing urban 

areas will further exacerbate these changes by continuing to inhibit natural ecosystem functions 

that could moderate climate change effects. For instance, air temperatures and near-surface 

moisture levels change in areas where natural vegetation is converted to agricultural use, and 

in the Midwest, higher temperatures have been observed as a result of converting land to 

agricultural use (USGCRP 2014). The USGCRP (2014) indicates that land use changes, such 

as the continued expansion of urban areas, paired with climate change effects, such as heavier 

precipitation events, can exacerbate climate change effects, including reduced water filtration 

into the soil and increased surface runoff. While anthropogenic land uses will contribute to 

climate change in these and other ways, land uses will also be affected by climate change in 

several ways. For instance, plant winter hardiness zones are likely to shift one-half to one full 

zone by the end of the proposed license renewal period (USGCRP 2014). This will affect the 

ability to grow certain crops as the Midwest will likely contain plants now associated with the 

Southeast by the end of the century (USGCRP 2014). Water availability will likely affect urban 

areas, which are growing rapidly in the Midwest. Will County, in which Braidwood is located, is 

expected to grow by 60 percent in the next 20 years (Will County 2011). This growth will likely 

lead to water use conflicts as climate change reduces water availability and the growing 

population requires more water.
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Water Resources

Predicted changes in the timing, intensity, and distribution of precipitation would be likely 

to result in changes in surface water runoff affecting water availability across the Midwest. 

As discussed above, the Midwest may experience increased precipitation during the fall, winter 

and spring. As cited by the USGCRP, the loss of moisture from soils because of higher 

temperatures, as is projected for the Midwest, along with evapotranspiration from vegetation is 

likely to increase the frequency, duration, and intensity of droughts across the region into the 

future (Karl et al. 2009; USGCRP 2014); such conditions can reduce the amount of water 

available for surface runoff and streamflow. Runoff and streamflow at a regional scale for the 

Midwest region indicate no clear trend during the last half century; however, annual runoff and 

river flow are projected to increase in the upper Midwest (USGCRP 2014). Climate change 

impacts on groundwater availability depend on basin geology, frequency and intensity of 

high-rainfall periods, recharge, soil moisture, and groundwater–surface water interactions 

(USGCRP 2014). Precipitation and evapotranspiration are key drivers in aquifer recharge. 

Although exact responses in groundwater storage and flow to climate change are not 

well-understood, recent studies have started to consider the effects that climate change have on 

groundwater resources (USGCRP 2014).

Terrestrial Resources

As described above, the Midwest will likely experience rising temperatures and heavier 

precipitation events during the proposed license renewal period. As the climate changes, 

terrestrial resources will either need to be able to tolerate the new physical conditions or shift 

their population range to new areas with a more suitable climate. Scientists currently estimate 

that species are shifting their ranges at a rate of between 6.1 to 11 m (20 to 36 ft) in elevation 

per decade and 6.1 to 16.9 km (3.8 to 10.5 mi) in latitude per decade (Chen et al. 2011; 

Thuiller 2007). While some species may readily adapt to a changing climate, others may be 

more prone to experience adverse effects. For example, species whose ranges are already 

limited by habitat loss or fragmentation or who require very specific environmental conditions 

may not be able to successfully shift their ranges over time. Migratory birds that travel long 

distances may also be disproportionately affected because they may not be able to pick up on 

environmental clues that a warmer, earlier spring is occurring in the United States while 

overwintering in tropical areas. Fraser et al. (2013) found that songbirds overwintering in 

the Amazon did not leave their winter sites earlier, even when spring sites in the Eastern 

United States experienced a warmer spring. As a result, the song birds missed periods of peak 

food availability. Habitat ranges for forest systems in the Midwest, such as paper birch, balsam 

fir, and black spruce, are projected to decline across the Midwest as they shift northward, and 

species that are common farther south, such as oaks and pines, will expand their range north 

into the Midwest region (USGCRP 2014). Special status species and habitats, such as those 

that are Federally protected by the ESA, would likely be more sensitive to climate changes 

because these species’ populations are already experiencing threats that are endangering their 

continued existence throughout all or a significant portion of their ranges. Climate changes 

could also favor nonnative, invasive species and promote population increases of insect pests 

and plant pathogens, which may be more tolerant to a wider range of climate conditions.

Aquatic Resources

The potential effects of climate change, whether from natural cycles or man-made activities 

could result in changes that would affect aquatic resources in the Kankakee River. Raised air 

temperatures could result in higher water temperatures in the river and its tributaries. Higher 

water temperatures would increase the potential for thermal effects on aquatic biota and could 

exacerbate existing environmental stressors, such as excess nutrients, sedimentation, and 
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lowered DO associated with eutrophication (NCADAC 2013). The Midwest will likely experience 

an increased frequency of extreme rainfall events, which will cause erosion and could lead to a 

decline in water quality (USGCRP 2014). Species that require cleaner waters, such as 

freshwater mussels, could experience further population declines. The USGCRP (2014) 

predicts habitat loss and local extinctions of fish and other aquatic species throughout the 

United States from the combined effects of water withdrawal and climate change. Shifts in 

species assemblages and distributions are also likely as climate change continues 

(USGCRP 2014), which could alter the balance of the aquatic community in the Kankakee 

River. As discussed above under “terrestrial resources,” special status species, such as those 

that are Federally protected under the ESA, would be more sensitive to climate changes. 

Invasions of non-native species that thrive under a wide range of environmental conditions 

could further disrupt the current composition of aquatic communities (NRC 2013f).

Historic and Cultural Resources

Increases in river and lake water levels because of changes in meteorological conditions due to 

climate change could result in the loss of historic and cultural resources from flooding, erosion, 

or inundation. Because of water-level changes, some resources could be lost before they could 

be documented or otherwise studied. However, the limited extent of climate change that may 

occur during the 20-year license renewal term would not likely result in any significant loss of 

historic and cultural resources at Braidwood.

Socioeconomics

Rapid changes in climate conditions could have an impact on the availability of jobs in certain 

industries. For example, tourism and recreation are major job creators in some regions, 

bringing billions of dollars to regional economies. Across the nation, fishing, hunting, and other 

outdoor activities make important economic contributions to rural economies and are also a part 

of the cultural tradition. A changing climate would mean reduced opportunities for some 

activities in some locations and expanded opportunities for others. Hunting and fishing 

opportunities could also change as animals’ habitats shift and as relationships among species 

are disrupted by their different responses to climate change (USGCRP 2014).

Water-dependent recreation could also be affected (Karl et al. 2009). The USGCRP reports 

that increasing heat and humidity associated with climate change in parts of the Midwest region 

by the year 2050 could create unfavorable conditions for summertime outdoor recreation and 

tourism activity (USGCRP 2014). However, the limited extent of climate change that may occur 

during the 20-year license renewal term would not likely to cause any significant changes in 

socioeconomic conditions in the vicinity of Braidwood.

Human Health

Increasing temperatures due to changes in climate conditions could have an impact on human 

health. However, changes in climate conditions that may occur during the license renewal term 

will not result in any change to the impacts discussed in Section 4.11 from Braidwood’s 

radioactive and nonradioactive effluents.

Environmental Justice

Rapid changes in climate conditions could disproportionately affect minority and low-income 

populations. The USGCRP (Karl et al. 2009) indicates that “infants and children, pregnant 

women, the elderly, people with chronic medical conditions, outdoor workers, and people living 

in poverty are especially at risk from a variety of climate-related health effects.” Examples of 

these effects include increased heat stress, air pollution, extreme weather events, and diseases 

carried by food, water, and insects. The greatest health burdens related to climate change are
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likely to fall on the poor, especially those lacking adequate shelter and access to other 

resources such as air conditioning. Elderly people on fixed incomes, who are more likely to be 

poor, are more likely to have debilitating chronic diseases or limited mobility. In addition, the 

elderly have a reduced ability to regulate their own body temperature or sense when they are 

too hot. According to the USGCRP (Karl et al. 2009), they “are at greater risk of heart failure, 

which is further exacerbated when cardiac demand increases in order to cool the body during a 

heat wave.” The USGCRP study also found that people taking medications, such as diuretics 

for high blood pressure, have a higher risk of dehydration (Karl et al. 2009). The USGCRP 

(2014) study reconfirmed the previous report findings regarding the risks of climate change on 

low-income populations, and also warns that climate change could affect the availability and 

access to local plant and animal species, thus impacting the people that have historically 

depended on them for food or medicine. However, minority and low-income populations at 

Braidwood are not likely to experience disproportionately high and adverse impacts from climate 

change, based on the expected small or slow change, effectively, in the environment during the 

20-year license renewal term.

4.16 Cumulative Impacts of the Proposed Action

The NRC staff considered potential cumulative impacts in the environmental analysis of 

continued operation Braidwood during the 20-year license renewal period. Cumulative impacts 

may result when the environmental effects associated with the proposed action are overlaid or 

added to temporary or permanent effects associated with other past, present, and reasonably 

foreseeable actions. Cumulative impacts can result from individually minor, but collectively 

significant, actions taking place over a period of time. It is possible that an impact that may be 

SMALL by itself could result in a MODERATE or LARGE cumulative impact when considered in 

combination with the impacts of other actions on the affected resource. Likewise, if a resource 

is regionally declining or imperiled, even a SMALL individual impact could be important if it 

contributes to or accelerates the overall resource decline.

For the purposes of this cumulative analysis, past actions are those before the receipt of the 

LRA. Present actions are those related to the resources at the time of current operation of the 

power plant, and future actions are those that are reasonably foreseeable through the end of 

plant operation, including the period of extended operation. Therefore, the analysis considers 

potential impacts through the end of the current license terms as well as the 20-year renewal 

license term. The geographic area over which past, present, and reasonably foreseeable 

actions would occur depends on the type of action considered and is described below for each 

resource area.

To evaluate cumulative impacts, the incremental impacts of the proposed action, as described 

in Sections 4.1 to 4.13, are combined with other past, present, and reasonably foreseeable 

future actions regardless of what agency (Federal or non-Federal) or person undertakes such 

actions. The NRC staff used the information provided in the ER; responses to requests for 

additional information; information from other Federal, State, and local agencies; scoping

comments; and information gathered during the visits to the Braidwood site to identify other 

past, present, and reasonably foreseeable actions. To be considered in the cumulative 

analysis, the NRC staff determined if the project would occur within the noted geographic areas 

of interest and within the period of extended operation, was reasonably foreseeable, and if there 

would be a potential overlapping effect with the proposed project. For past actions, 

consideration within the cumulative impacts assessment is resource and project-specific. In 

general, the effects of past actions are included in the description of the affected environment 

in Chapter 3, which serves as the baseline for the cumulative impacts analysis. However, past 
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actions that continue to have an overlapping effect on a resource potentially affected by the 

proposed action are considered in the cumulative analysis.

Other actions and projects identified during this review and considered in the NRC staff’s 

analysis of the potential cumulative effects are described in Appendix E. Not all actions or 

projects listed in Appendix E are considered in each resource area due to the uniqueness of 

the resource and its geographic area of consideration.

4.16.1 Air Quality and Noise

This section addresses the direct and indirect effects of license renewal on air quality and noise 

when added to the aggregate effects of other past, present, and reasonably foreseeable future 

actions. As described in Section 4.3.1, the incremental impacts on air quality and noise levels 

from the proposed license renewal would be SMALL.

4.16.1.1 Air Quality

The geographic area considered in the cumulative air quality analysis is the county of the 

proposed action as air quality designations for criteria air pollutants are generally made at the 

county level. Counties are further grouped together based on a common air shed—known as 

an air quality control region (AQCR)—to provide for the attainment and maintenance of the 

National Ambient Air Quality Standards (NAAQS). Braidwood is located in Will County, Illinois. 

Air quality in Will County is under the jurisdiction of the Illinois EPA (IEPA). Will County is 

designated as a non-attainment area for the 2008 8-hour ozone (marginal) NAAQS and 2010 

sulfur dioxide NAAQS (partial county designation) and designated maintenance area for the 

1997 PM2.5 NAAQS (40 CFR 81.314; EPA 2015). Within the nonattainment area, air pollutant 

emission sources, both stationary and mobile, are prevalent, especially in and close to the 

Chicago Metropolitan Area (CMA).

As noted in Section 3.3, the IEPA’s Air Pollution Control Program has primary responsibility 

for regulating air emission sources within Illinois and Will County and in developing plans to 

achieve and maintain attainment with the NAAQS. The IEPA conducts ambient air monitoring 

in the State to assess compliance with the NAAQS. In 2012, the IEPA operated 75 sites 

throughout Illinois with approximately 170 monitors (IEPA 2012a).

Existing emission sources at Braidwood are regulated under a Federally Enforceable State 

Operating Permit (I.D. No. 197816AAB). As discussed in Section 3.3, regulated air pollutants—

including sulfur dioxide, carbon monoxide, nitrogen oxide, carbon dioxide, and particulates—are 

emitted at the Braidwood site from four large diesel generators, various small diesel engines 

(less than 600 horsepower) used for electric generation and water pumping, two diesel engine 

AFW pumps, a rad-waste volume reduction system, fuel storage tanks and two auxiliary boilers. 

Emissions during the last 5 years (2008 to 2012) are shown in Table 3.3.2-1 in Section 3.3.2. 

For each pollutant, Braidwood is classified as a minor emission source. A minor source 

classification typically indicates that the facility has little to no potential for significantly impacting 

air quality or interfering with plans to achieve compliance with the NAAQS in nonattainment

areas (IEPA 2014c). Since there will be no refurbishment related activities, the NRC staff 

expects similar emissions during the license renewal period. Accordingly, the incremental 

impacts on air quality (during the period of extended operation) from the proposed license 

renewal would be SMALL. Therefore, cumulative changes to air quality in Will County and 

AQCR would be the result of changes to present-day emissions as well as future projects and 

actions within the county.
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Cumulative Impacts

Appendix E provides a list of present and reasonably foreseeable projects that could contribute 

to cumulative impacts to air quality. The following existing operating nuclear power stations are 

in the region:

 Clinton, Unit 1, in DeWitt County;

 Byron Station, Units 1 and 2, in Ogle County;

 LaSalle County Station, Units 1 and 2, in LaSalle County; and

 Dresden Station, Units 2 and 3, in Grundy County.

Similar to Braidwood, these stations are also classified as minor emission sources, are distant 

(located in a different county or air shed from Braidwood) and unlikely to contribute to a 

cumulative impact due to their minor emission status and distance from Braidwood.

There are no plans for refurbishment of structures or components at the Braidwood site for 

license renewal. However, Unit 1 and 2 reactor pressure vessel head replacement (assumed 

to occur during a 7-day period with 340 additional workers) and Unit 2 steam generator 

replacement (estimated to require an additional 500 workers for 90 days) may occur at 

Braidwood. The main contributors to air quality impacts associated with these activities would 

be fugitive dust generation from construction activities, work to open containment to replace the 

steam generators and related equipment, and exhaust emissions from motorized equipment 

and vehicles of temporary workers. The additional vehicle air emissions resulting from the 

additional workforce for steam generator replacement activities (used as bounding conditions 

since steam generator replacement will require a larger number of workers and has longer 

activity duration) would be temporary and are estimated to result in an additional 3.3 tons of 

volatile organic compounds, 9.8 tons of nitrogen oxides, 0.04 tons of sulfur dioxide, and 

0.40 tons of PM2.5 (direct emissions) being emitted, which do not exceed the de minimis levels 

of 100 tons/yr for nitrogen oxides, volatile organic compounds, sulfur dioxide, or particulate 

matter set forth in 40 CFR 93.153(b). Steam generator replacement and pressure head 

replacement are not expected to occur simultaneously, and pressure vessel head replacement 

would require a lower additional workforce than what would be needed for steam generator 

replacement (Exelon 2013c). Therefore, vehicle emissions from the additional workforce 

needed for vessel head and steam generator replacement are not expected to exceed the 

de minimis levels set forth in 40 CFR 93.153(b).

Development and activities associated with regional growth of housing, business, and industry, 

as well as associated vehicular traffic can increase air emissions. As discussed in Section 2.3, 

Will County is one of the fastest-growing counties in the CMA and population is expected to 

grow by another 60 percent in the next 20 years. Regional air quality conditions could 

deteriorate from the effects of the growth of the county as growth gives rise to dust, exhaust, 

and emissions that can degrade air quality. The air quality effects of development are 

monitored through the statewide ambient air quality monitoring network. If degradation in air 

quality is observed, the IEPA can develop air quality control programs to mitigate the effects of 

development. Any new stationary sources of emissions that would be established in the region 

would be required to apply for an air permit from the IEPA. Prior to issuing an air permit to a 

new source (or to an existing source that proposes to undergo significant modification), IEPA 

will examine the potential air quality impacts using various modeling tools to assess any 

potential changes to compliance with the NAAQS.

EPA’s Enforcement and Compliance History Online database identifies 33 facilities that are 

major sources of air emissions in Will County (EPA 2014b). Two existing large coal-fired 
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electric generating facilities are the Joliet Station Power Plant, located approximately 18 mi 

(29 km) north-northeast of Braidwood and the Will County Power Station, located approximately 

28 mi (45 km) to the north-northeast. Both facilities are regulated by the IEPA through the 

Operating Permit program. In 2008, Joliet Station emitted 7,514 tons of nitrogen oxide and 

18,281 tons of sulfur dioxide; Will County Power Station emitted 7,192 tons of nitrogen oxide 

and 16,497 tons of sulfur dioxide (EPA 2014a). These two sources are the dominant emission 

sources within a 30-mi (50-km) radius of Braidwood.

Climate change can impact air quality as a result of changes in meteorological conditions. Air 

pollutant formation partially depends on the temperature and humidity of the atmosphere and is 

a result of the interactions between hourly changes in the physical and dynamic properties of 

the atmosphere, atmospheric circulation features, wind, topography, and energy use 

(IPCC 2009). As discussed in Section 4.14.3.2, ozone levels have been found to be particularly 

sensitive to climate change influences (EPA 2007). Sunshine, high temperatures and air 

stagnation are favorable meteorological conditions leading to higher levels of ozone 

(EPA 2009). Air quality projections (particularly ozone and PM2.5) are uncertain and indicate 

that concentrations are driven primarily by emissions rather than by physical climate change 

(Stocker et al. 2013). The combination of higher temperatures, stagnant air masses, sunlight, 

and emissions of precursors may make it difficult to for Will County to continue to meet ozone 

National Ambient Air Quality Standards (USGCRP 2009). States, however, must continue to 

comply with the CAA and ensure air quality standards are met.

Conclusion

Because of the small quantity of emissions from Braidwood, the distance between existing 

emission sources in the region and no expected emissions increase associated with license 

renewal, the potential for Braidwood to contribute to a cumulative impact with other air pollutant 

sources is SMALL. The NRC staff concludes that, combined with the emissions from other 

past, present, and reasonably foreseeable future actions, cumulative impacts on air quality from 

hazardous and criteria air pollutant emissions from Braidwood-related actions would be SMALL.

4.16.1.2 Noise

Section 3.3.3 presents a summary of noise sources at Braidwood and site vicinity. Noise 

emission sources from Braidwood include such things as circulating water make-up pumps, 

main steam valves, water discharge system, transmission lines, security drills, and 

transformers. In 2011, Braidwood redesigned its blowdown water discharge into the Kankakee 

River to reduce noise associated with the water discharge location, which was the subject of 

noise complaints. This action reduced the number of noise complaints Braidwood received. 

The surrounding land use in the immediate vicinity of the Braidwood site is residential and open 

land. Occasional train activity on the nearby rail line and truck traffic on nearby roads may 

cause a temporary noise increase while trains and trucks pass by the Braidwood site, with noise 

levels returning to background once the train or vehicle exits the area.

Cumulative Impacts

Ongoing or foreseeable future projects in and around the Braidwood Station as identified in 

Appendix E would increase noise levels in the vicinity of their noise sources. For instance, 

activities at the Braidwood site related to steam generator replacement or reactor pressure 

vessel head replacement, if they occur, would increase noise levels as a result of construction 

activities related to the storage facility, motorized equipment, and increased vehicles. 

Construction equipment, for instance, can result in noise levels in the range of 85–90 dBA; 

however, noise levels attenuate rapidly with distance such that at half-a-mile distance from 

construction equipment noise levels can drop to 51-61 dBA (NRC 2002). Additional noise from 
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construction activities would be temporary and intermittent and the majority of work activities 

would occur inside of buildings. Therefore, the NRC concludes that offsite noise levels will not 

be noticeable to nearby receptors and there are no long-term changes expected to existing 

noise levels associated with license renewal. Furthermore, as indicated in Appendix E, most of 

the projects considered for cumulative impacts are not located in Will County and only a few are 

located within 1 mi from Braidwood. Generally, as distance is doubled from a point source, 

noise levels decrease by 6 dBA (MPCA 2014). Therefore, noise levels from present and future 

actions of these projects (not in Will County) are not anticipated to contribute to noise impacts in 

the vicinity of Braidwood.

Conclusion

Cumulative impacts on noise environment are expected to be SMALL and remain minor during 

the license renewal term.

Air and Noise Cumulative Impact Summary

Cumulative impacts to air quality and noise are estimated based on the information available 

in the Braidwood Station ER and the NRC staff’s independent evaluation. Other past, present, 

and reasonably foreseeable future activities exist in the geographic areas of interest (local for 

noise; local and regional for criteria pollutants) that could affect air quality and noise resources. 

The cumulative impacts on the emissions of criteria pollutants from Braidwood Station and other 

projects would be minimal. The NRC staff concludes that cumulative impacts from other past, 

present, and reasonably foreseeable future actions on air quality and noise resources in the 

geographic areas of interest would be SMALL. The incremental contribution of impacts on air 

quality and noise resources from plant operations at Braidwood Station would be SMALL.

4.16.2 Geology and Soils

This section addresses the direct and indirect effects of license renewal on geology and soils 

when added to the aggregate effects of other past, present, and reasonably foreseeable 

future actions.

As noted in Section 4.4.1, the NRC staff concludes that the impact from license renewal on 

geology and soils would be SMALL.

Cumulative Impacts

The cumulative impacts on the geologic environment primarily relate to land disturbance and the 

potential for soil erosion and loss, as well as the projected consumption of geologic resources. 

Exelon has no plans to conduct refurbishment or replacement actions and ongoing operation 

and maintenance activities at the Braidwood site are expected to be confined to previously 

disturbed areas. Any use of geologic materials, such as aggregates, to support operation and 

maintenance activities would be procured from local and regional sources. Thus, activities 

associated with continued operations are not expected to affect the geologic environment. The 

NRC staff presumes that construction activities, as identified in Appendix E, would use material 

from local and regional sources as these materials are abundant in the region. These identified 

projects are of such a scale as to not be likely to impact regional sources and supplies of the 

identified resources. Furthermore, construction activities would need to be conducted in 

accordance with State and local requirements and development activities would be subject to 

BMPs for soil erosion and sediment control, which would serve to minimize soil erosion and 

loss. 
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Conclusion

Considering ongoing activities, past activities, and reasonably foreseeable actions, the NRC 

staff concludes that the cumulative impacts on geology and soils during the Braidwood license 

renewal term would be SMALL.

4.16.3 Water Resources

This section addresses the direct and indirect effects of license renewal on surface water

and groundwater when added to the aggregate effects of other past, present, and reasonably 

foreseeable future actions.

As described in Sections 4.5.1.1 and 4.5.1.2, the incremental impacts on water resources 

from continued operations of Braidwood, during the license renewal term would be SMALL.

NRC staff also conducted an assessment of other projects and actions for consideration in 

determining their cumulative impacts on water resources (see Appendix E). The geographic 

area considered for the surface water resources component of the cumulative impact spans the 

Illinois portion of the Kankakee River basin (see Figure 3.5-1). For groundwater, the geographic 

area of interest is comprised of the local groundwater basin relative to the Braidwood site, the 

Cambrian-Ordovician aquifer. As such, this review focused on those projects and activities that 

would (1) withdraw water or discharge water to the Kankakee River or (2) would use 

groundwater from Cambrian-Ordovician aquifer.

4.16.3.1 Surface Water Resources

The Kankakee River serves both public water supply systems and the nuclear plant industry. 

Consumers Illinois Water Company and the City of Wilmington began withdrawing water from 

the Kankakee River in 1886 and 1990, respectively (Knapp 1992). These public water systems 

withdraw approximately 13 mgd (24.2 cfs, 10,861 gpm, 0.69 m3

/s) from the Kankakee River and 

it is projected that withdrawals in 2050 will increase to approximately 17 mgd (31.6 cfs, 

14,182 gpm, 0.89 m3

/s) (ISWS 2012; City of Kankakee 2014). This is a 30 percent increase in 

projected public water supply withdrawals. Dresden Nuclear Power Station, Units 2 and 3 

(listed in Appendix E) are currently operating and withdrawal water from the Kankakee River. 

Total current consumptive rates from public water supply systems and nuclear plants 

(Braidwood and Dresden) are approximately 3 percent of the Kankakee River average flow (see 

Section 4.5.1.1.2). Furthermore, various wastewater discharges to the Kankakee River Basin 

are identified in Appendix E. There are a total of 17 major effluent return flows to streams in the 

Illinois portion of the Kankakee watershed and the average return flow from these sources is 

35 cfs (22.6 mgd, 15,708 gpm or 1.0 m3

/s) (Knapp 1992).

Cumulative Impacts

There are no proposed refurbishment activities associated with the license renewal of 

Braidwood; however, Exelon has indicated that during the period of license renewal there is a 

possibility for Unit 2 steam generator replacement and pressure vessel head replacement for 

both units. Steam generator and pressure vessel head replacement activities will require water 

for concrete production, dust control, and facility and equipment cleaning. However, water 

consumption for these non-cooling water related activities is anticipated to be negligible and 

temporary. Construction related activities would occur on previously disturbed land and are 

expected to be managed by a Stormwater Pollution Prevention Plan and implementation of 

BMPs.

In 2006, northeastern Illinois was selected as a priority water supply planning area. The 

northeastern Illinois region includes an 11-county area (including Will County, where Braidwood 
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is located) and encompasses the Kankakee River Basin. In 2010, a regional water plan was 

developed to guide future use, manage water demand, and protect water supplies by the 

Chicago Metropolitan Agency for Planning (CMAP). The surface waters of the Kankakee River 

watershed were identified as a future source of water for the suburban areas of northeastern 

Illinois due to increased demand resulting from future population growth in these areas, in 

particular the city of Joliet (CMAP 2010; ISWS 2012). Significant increases in water demand 

are also expected in the western and southern parts of the Chicago metropolitan region, which 

currently use Lake Michigan water, inland surface waters, and deep groundwater aquifers. The 

deep aquifer system and Lake Michigan water supply are now at or near their sustainable or 

legally mandated limits (Wehrmann and Knapp 2006). As the CMA grows and moves closer 

to the Kankakee River, the river will be viewed increasingly as a regional source of water 

(Wehrmann and Knapp 2006). As further discussed in Section 4.15.3.1, over pumping of the 

regional Cambrian-Ordovician Aquifer System has long been recognized as a regional problem. 

Proposed corrective actions have included increased reliance on the Kankakee River as a 

source of water. The City of Joliet has identified the Kankakee River as a likely source of water 

to replace over pumping of the regional aquifer by its wells (Wehrmann and Knapp 2006). The 

water plan recommends surface and groundwater modeling of the Kankakee River watershed to 

support water supply efforts in the future (CMAP 2010).

As discussed in Section 3.5.1.3, a segment of the Kankakee River near Braidwood does 

not meet designated uses or water quality standards (or both) and is listed as impaired 

(IEPA 2014a). Various segments (totaling 58 mi (93 km)) of the Kankakee River have been 

designated by the IEPA as impaired because of contamination from mercury, PCB’s, or phenols 

(impairing water supply use). However, water treatment technology can be utilized to ensure 

water quality standards are met and protect water quality. For instance, the Kankakee River 

Metropolitan Agency, as part of Illinois’ Clean Water Initiative, will upgrade the wastewater

treatment plant to prevent pollutants from entering the Kankakee River from effluent discharges

and protect water quality (IGNN 2014). Furthermore, compliance with the CWA and IEPA 

regulations impose limitations on discharges to ensure water quality does not decline.

Climate change can impact surface water as a result of changes in temperature and 

precipitation. As discussed in Section 4.14.3.2, the climate model simulations for the Midwest 

region indicate an increase in annual mean temperature. Increased precipitation results in 

increases in runoff and streamflow. However, higher temperatures increase evaporation that 

contributes to dry conditions and can reduce the amount of water available for surface runoff 

and streamflow (USGCRP 2009). Precipitation and evapotranspiration rates will be key drivers 

in determining future Kankakee River flow. The USGCRP (2014) reports that runoff and 

streamflow for the Midwest will increase. Additionally, higher air surface temperatures can lead 

to high cooling pond temperatures and an increase in evaporation of Braidwood’s cooling pond; 

this can subsequently result in additional makeup water withdrawals from the Kankakee River 

and higher temperature discharges to the Kankakee River. However, as discussed in 

Section 3.5.1.2, Braidwood is limited to a withdrawal rate of 160 cfs (71,808 gpm or 4.5 m3

/s) 

in accordance with the permit issued by IDOT, and Braidwood’s NPDES permit places thermal

limits on Outfall 001. Average annual Kankakee River water temperatures for the 2002 through 

2008 time period ranged between 55.9 °F and 57.4 °F (13.3 °C and 14.1 °C) and 53.1 °F and 

57.1 °F (11.7 °C and 13.9 °C) for the 2011 and 2013 time period (Exelon 2014j). Exelon submits 

monthly NPDES DMRs for the Braidwood Station to the IEPA as required per Braidwood’s 

NPDES Permit. The DMRs include the maximum temperature recorded from the cooling pond 

blowdown line effluent outfall. Annual maximum discharge temperatures for the 2008 through 

2012 time period (obtained from Exelon’s monthly DMRs) were: 95 °F (35 °C), 97.9 °F 

(36.6 °C), 97.9 °F (36.6 °C), 96.4 °F (35.7 °C), and 98.7 °F (37.1 °C) (Exelon 2014j). As 

discussed in Section 4.11, annual average water temperatures in the cooling pond for the 
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2004 to 2013 time period ranged between 19.1 °C and 21.8 °C (66.4 and 71.2 °F). Annual 

maximum cooling water temperatures in the cooling pond for the 2004 through 2013 time period 

were: 32.5 °C (90.5 °F), 37.3 °C (99.1 °F), 34.3 °C (93.7 °F), 35.0 °C (95.0 °F), 32.8 °C (91.0 °F), 

35.5 °C (95.9 °F), 34.3 °C (93.7 °F), 36.8 °C (98.2 °F), 36.8 °C (98.2 °F), 37.4 °C (99.3 °F). 

However, Kankakee River water temperatures for the time period discussed above and cooling 

pond temperature data between 2004 and 2013 do not display an increasing temperature trend 

(Exelon 2014i).

Conclusion

Given current water demand and use of the Kankakee River, increased regional demand and 

the potential increased reliance on the Kankakee River as a source of water, and impacts of 

climate change, the NRC staff concludes that the cumulative impacts on surface water

resources during the license renewal term would be SMALL to MODERATE. The regional 

impact will be influenced by climate change and future water demand and actions taken in the 

Kankakee River to address water supplies.

4.16.3.2 Ground Water Resources

This section addresses the direct and indirect effects of license renewal on groundwater

use and quality when added to the aggregate effects of other past, present, and reasonably 

foreseeable future actions.

All groundwater consumed at the Braidwood site is obtained from a single well completed in the 

Deep Aquifer (see Section 3.5.2.2). The Deep Aquifer makes up most of the regional 

Cambrian-Ordovician Aquifer System. The Cambrian-Ordovician Aquifer System is a major 

source of water in the Chicago Metropolitan Region. In Will County most of the public water is 

obtained from this aquifer (50 percent in 1983) (Woller and Sandersone 1983). It was estimated 

that in 2003, Joliet obtained 14,340,000 gallons per day (54,282,804 Lpd) from this aquifer 

system (Burch and Wehrmann 2007).

In the Chicago Metropolitan Region, extensive use of the Cambrian-Ordovician Aquifer System

has caused water levels in this system to drop (Burch 2002, 2008). Since 1865, groundwater

(potentiometric) levels declined by 500 ft (152.4 m) or more over a broad area of the Chicago 

region. During this same time period, some groundwater levels in the Joliet area declined 

850 to 900 ft (244 to 274 m) (Burch 2007). Up to 400 ft (122 m) of this decline in the Joliet area 

occurred between 2000 and 2007 in wells located in southeastern Kendall county that supply 

Joliet, Illinois with public water (Figure 4–4) (Burch 2008).

Over pumping of the Cambrian-Ordovician Aquifer System has long been recognized as a 

regional problem (CMAP 2010; Konikow 2013; Schicht and Moench 1971; Walton et al. 1960). 

Groundwater consumption projections suggest that by 2050, the continued drawdown of 

groundwater levels has a high potential to cause adverse impacts in southeastern Kane County 

and northern Will County. These impacts include decreasing well yields, increasing pumping 

expenses, increases in salinity in deep well water, and increased concentrations of radium, 

barium, and arsenic (ISWS 2012). Aurora and Joliet appear to be most at risk from projected 

future water demand scenarios (CMAP 2010, ISWS 2012). Suggested corrective actions 

include increased use of water from Lake Michigan, from Rivers, from near surface aquifers, 

and more efficient use of currently available water (CMAP 2010; USGS 2005).

Managing water extraction from the Cambrian-Ordovician Aquifer is anticipated to continue to 

be a long term regional concern. The contribution by the plant to the consumptive use of water 

obtained from the Cambrian-Ordovician Aquifer is SMALL.
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Figure 4–4. Changes in Deep Sandstone Wells in Northeast Illinois Between 2000 and 2007

Modified from Burch 2008

Cumulative Impacts

Consumptive use would continue to be SMALL, even if groundwater consumption temporarily 

increases during steam generator or reactor pressure vessel head replacement. The impact to 
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consumptive groundwater use by the Chicago Metropolitan Region is MODERATE to LARGE to 

which the plant contributes only a very SMALL incremental impact.

Contamination of groundwater obtained from shallow aquifers will be more of a concern if 

shallow aquifers, such as the Upper Aquifer, are increasingly accessed as a source of water 

in the Chicago Metropolitan Region during the license renewal term. This is because the 

groundwater in shallow aquifers is more vulnerable to contamination from surface-derived 

contaminants (such as road salt, agrichemicals, petrochemicals, and other man made 

pollutants) than the groundwater in deep aquifers. Future increases in land development may 

accelerate the degradation of shallow aquifers from surface-derived contaminants. Preventing 

the contamination of near surface aquifers is likely to be a long-term regional concern. As 

further described in Sections 3.5.2.3 and 4.5.1.2.1, at Braidwood, a program is in place to 

safeguard groundwater quality, and it would be employed during steam generator or reactor

pressure vessel head replacement. Therefore, while the impact by the plant to near surface 

aquifer water quality degradations is SMALL, the cumulative impact of future regional land 

development on near surface aquifer water quality is MODERATE.

Conclusion

Considering ongoing activities and reasonably foreseeable actions, the NRC staff concludes 

that the cumulative impacts to groundwater use and quality during the Braidwood license 

renewal term would be MODERATE to LARGE.

4.16.3.3 Water Resource Conclusion Summary

Considering ongoing activities and reasonably foreseeable actions, the NRC staff concludes 

that cumulative impact of the proposed license renewal when combined with other past, 

present, and reasonably foreseeable future activities on surface water resources would be 

SMALL to MODERATE, while impacts to groundwater resources would be MODERATE to 

LARGE. While the Braidwood facility is not expected to impact surface or groundwater 

resources, increased regional demand on both surface and groundwater resources is expected 

to grow throughout the license renewal term.

4.16.4 Terrestrial Ecology

This section addresses past, present, and future actions that could result in cumulative impacts 

on the terrestrial species and habitats described in Section 3.6. For purposes of this analysis, 

the geographic extent considered in this cumulative terrestrial resource analysis depends on the 

particular cumulative impacts being discussed. Direct and indirect impacts from Braidwood 

operation are largely limited to the Braidwood site and immediate vicinity. However, projects 

or actions located beyond this geographic area could directly or indirectly affect terrestrial 

resources in this area. Section 4.6 of this SEIS concludes that the impact from the proposed 

license renewal would not noticeably alter the terrestrial environment and would be SMALL.

As discussed in Section 3.6, the Braidwood site was highly disturbed prior to construction and 

operation of Braidwood, and the majority of natural areas were previously coal strip-mine spoils 

or cultivated fields. Strip mining within the boundaries of the Braidwood site began in the early 

1940s, and various reclamation projects took place on the site from the 1950s through the early 

1970s (ComEd 1973). Due to the highly disturbed condition of the site, preoperational surveys 

determined that no terrestrial climax communities existed on the site (ComEd 1973, 1985). 

During Braidwood construction, terrestrial habitat was further reduced: 2,540 ac (1,028 ha) of 

land was flooded to create the facility’s cooling pond, and an additional 264 ac (107 ha) was 

cleared for industrial use (Exelon 2013c, 2014i).
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In the broader area—the Illinois/Indiana Prairies Level IV Ecoregion—native prairies and 

wetlands have been converted to agricultural land, which now accounts for over 75 percent of 

land use within the ecoregion (IDNR 2005). Habitat loss, in general, can negatively affect 

breeding success, dispersal success, predation rate, and other animal behaviors (Fahrig 2003). 

Habitat fragmentation (the breaking up of a larger area of habitat into smaller patches of smaller 

total area) can also negatively affect terrestrial biota. In a study of breeding bird communities in 

24 Illinois grassland fragments, Herkert (1994) found that fragmentation was likely a factor in 

Midwestern grassland bird population declines. A study conducted in 2012 on the partridge pea 

(Chamaecrista fasciculata) (Mannouris and Byers 2013) concludes that native prairie plant 

species that occur in smaller, isolated prairie fragments are likely to suffer a reduction in genetic 

fitness. The IDNR (2005) indicates that habitat loss, fragmentation, and fire suppression in 

Illinois native forests is causing species composition shifts to sugar maple (Acer saccharum) 

and other mesophytic species.

Cumulative Impacts

Energy Production and Development

Four nuclear power plant sites with seven operating reactors lie within 50 mi (80 km) of the 

Braidwood site (see Appendix E). Because the effects of these facilities would primarily be 

limited to the terrestrial resources on each facility’s site and immediate vicinity, the operation 

of these facilities would not result in cumulative effects to the terrestrial resources affected by 

Braidwood operation.

Two wind farms operate near Braidwood: Top Crop I Wind Farm lies southwest of Braidwood 

and includes 68 units in La Salle and Livingston Counties, and Grand Ridge Wind Farm lies 

south of Braidwood and includes 66 units in La Salle County. An additional 132 wind-powered 

units are currently under construction in Grundy County as part of Top Crop II Wind Farm. All of 

these wind farms lie within approximately 25 mi (40 km) of the Braidwood site. Operation of 

wind farms can result in direct mortality of birds and bats through collision with turbine blades 

as well as indirect effects, such as avoidance of an area, habitat disruption, reduced nesting or 

breeding density, habitat abandonment, and behavioral effects (Stewart et al. 2005, 2007). 

Given that the majority of bird and bat species are migratory, effects of wind farms on bird and 

bat populations can be far-reaching.

Two other energy-producing facilities occur in the region: the coal- and natural gas-fired Joliet 

Station, which lies 18 mi (29 km) northeast of Braidwood in Joliet, Illinois, and the coal-fired Will 

County Station, which lies 27 mi (43 km) northeast of Braidwood in Romeoville, Illinois. Air 

emissions from these facilities include GHGs such as nitrogen oxides, carbon dioxide, and 

methane, all of which can have far-reaching consequences because they cumulatively 

contribute to climate change. The effects of climate change on terrestrial resources are 

discussed in Section 4.13.3.2.

Development, Urbanization, and Habitat Fragmentation

As the region surrounding the Braidwood site becomes more developed, habitat fragmentation 

will increase and the amount of forested, prairie, and wetland habitat is likely to decline further. 

Transmission lines and associated corridors established to connect Braidwood and other 

energy-producing facilities to the regional electric grid represent past habitat fragmentation 

because some of the corridors split otherwise continuous tracts of habitat. Construction of 

transmission lines associated with new energy projects may also result in habitat fragmentation 

if the lines are not co-located within existing corridors or sited within previously developed 
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areas. Edge species that prefer open or partially open habitats will likely benefit from the 

fragmentation, while species that require interior forest or wetland habitat will likely decline.

Continued urbanization in the future will likely include construction of additional housing units 

and associated commercial buildings; roads, bridges, and rail; and water or wastewater

treatment and distribution facilities and associated pipelines. Increased development will likely 

decrease the overall availability and quality of terrestrial habitats. Species that require larger 

ranges, especially predators, will likely suffer reductions in their populations. Similarly, species 

with threatened or endangered Federal or State status or otherwise declining populations would 

be more sensitive to declines in habitat availability and quality. Native prairie plants will likely 

continue to experience reductions in genetic fitness, as previously discussed.

Nature Preserves and State Parks

State parks and wildlife refuges located near Braidwood (Appendix E) provide valuable 

habitat to native wildlife, migratory birds, and protected terrestrial species and habitats. As 

fragmentation and conversion continues in the future, these protected areas will become 

ecologically more important because they provide large, continuous areas of minimally 

disturbed habitat. The Braidwood Dunes and Savanna Nature Preserve, which lies 

approximately 2 mi (2.4 km) northeast of the Braidwood site, provides particularly high-quality 

habitat and protection to native biota, including the State-endangered Oklahoma grass pink 

orchid (Calopogon oklahomensis) and State-threatened pale-green orchid (Platanthera flava 

var. herbiola) (see Section 3.6).

Conclusion

NRC staff concludes that the cumulative impacts on terrestrial resources in the vicinity of the 

Braidwood site are MODERATE to LARGE based on past, present, and reasonably foreseeable 

future actions. This level of impact is primarily the result of past habitat alteration and loss on 

the Braidwood site and within the larger Illinois/Indiana Prairies Level IV Ecoregion. The 

environmental effects of these actions are clearly noticeable and have destabilized important 

attributes of certain terrestrial communities. The loss of genetic fitness of native prairie species 

and the species composition shifts observed in native Illinois forests are demonstrative of such 

effects. The incremental, site-specific impact from the continued operation of Braidwood during 

the license renewal period would be an unnoticeable (SMALL) or minor contributor to 

cumulative impacts on terrestrial resources.

4.16.5 Aquatic Ecology

This section addresses the direct and indirect effects of license renewal on aquatic resources 

when added to the aggregate effects of other past, present, and reasonably foreseeable future 

actions. Section 4.7 of this document finds that the direct and indirect impacts on aquatic 

resources from the proposed license renewal when considered in the absence of the aggregate 

effects would be SMALL for some issues and MODERATE for others. The cumulative impact is 

the total effect on the aquatic resources of all actions taken, no matter who has taken the 

actions (the second principle of cumulative effects analysis in CEQ 1997).

Cumulative Impacts

The geographic extent considered in this cumulative aquatic resource analysis depends on 

the particular cumulative impacts being discussed. During Braidwood impingement and 

entrainment studies (discussed in Section 4.7), EA Engineering determined that the entire 

length of the Kankakee River in Illinois could serve as a source of recruitment for fish losses 

resulting from Braidwood operation. The Illinois portion of the river is meandering, 
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well-vegetated, and rocky, and it is reasonable to assume that similar species exist throughout. 

Accordingly, the NRC staff assumes that direct and indirect impacts from the Braidwood site are 

limited to the Illinois portion of the Kankakee River, which consists of 58 river miles (RM) 

(93 river kilometers (RKm)) in Kankakee and Will Counties, and that effects to aquatic resources 

that could result from continued operation of Braidwood and other actions could not be 

meaningfully discerned or described beyond the geographic area (i.e., the Illinois portion of the 

Kankakee River). However, for this cumulative impacts analysis, projects or actions located 

outside of this area could directly or indirectly affect the aquatic resources in this area. This 

section focuses on the cumulative effects of such actions. The baseline, or benchmark, for 

assessing cumulative impacts on aquatic resources takes into account the preoperational 

environment as recommended by the EPA (1999b) for its review of NEPA documents.

Past River Channelization and Damming

The Kankakee River in Illinois has remained largely unmodified with the exception of 

three dams: a small side channel dam at Momence in Kankakee County, a larger dam at the 

city of Kankakee, and an overflow dam at Wilmington downstream of Braidwood in Will County 

(Bhowmik and Demissie 2000). In the vicinity of Braidwood, the numerous riffles, small pools, 

and islands and varied substrates support a large diversity of aquatic biota, including several 

State-listed fish and mussels. The IDNR has designated the Kankakee River from Momence in 

Kankakee County to the Des Plains Wildlife Conservation Area in Will County as a Biologically 

Significant Stream because it supports one of the state’s most diverse aquatic communities 

(Page et al. 1991). In Indiana, the Kankakee River was extensively channelized in the late 

1800s and early 1900s. Today the channel is essentially man-made, and it extends straight for 

many miles between small bends (Bhowmik and Demissie 2000). The loss of microhabitats 

such as riffles, pools, and meandering bends through channelization in Indiana has likely 

affected the species composition, richness, and diversity in Indiana. This, in turn, has likely 

affected fish populations in Illinois because the Indiana portion of the river may no longer 

provide spawning grounds or serve as a source of recruitment.

Energy Development

Four nuclear power plant sites with seven operating reactors lie within 50 mi (80 km) of the 

Braidwood site (see Appendix E). Because the effects of these facilities would primarily be 

limited to the water body from which they draw cooling water and none of these facilities draw 

from the Kankakee River, the operation of these facilities (other than Braidwood) would not 

result in cumulative effects to the aquatic resources affected by Braidwood operation.

Two other energy-producing facilities occur in the region: the coal- and natural gas-fired Joliet 

Station, which lies 18 mi (29 km) northeast of Braidwood in Joliet, Illinois, and the coal-fired Will 

County Station, which lies 27 mi (43 km) northeast of Braidwood in Romeoville, Illinois. Both 

facilities are located on the Des Plains River. The Kankakee and Des Plains Rivers meet near 

Channahon, Illinois, and together form the Illinois River. Because direct effects to the aquatic 

environments caused by these facilities would likely be confined to the Des Plains River, the 

continued operation of these facilities during the proposed license renewal term would not result 

in direct impacts on Kankakee River aquatic communities. Air emissions from these facilities 

include GHGs such as nitrogen oxides, carbon dioxide, and methane, all of which can have 

far-reaching consequences because they cumulatively contribute to climate change. The 

effects of climate change on aquatic resources are discussed in Section 4.13.3.2.

Two wind farms also operate near Braidwood and a third is under construction (see 

Appendix E). These facilities would not have detectable impacts on Kankakee River 
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aquatic resources because, in general, they will not require water during operation and have no 

air emissions.

Future Urbanization and Transportation Development

Future urbanization in the vicinity of Braidwood will likely include construction of new housing 

units and associated commercial buildings; roads, bridges, and rail; and water or wastewater

treatment (or both) and distribution facilities and associated pipelines. Known future 

development projects include improvements to the Jane Addams Memorial Tollway (I-90) and 

construction of South Suburban Airport (see Appendix E). Continued development of the area 

has the potential to increase the rate and volume of stormwater runoff and reduce groundwater

recharge. If not managed appropriately, such development could result in increased flooding, 

higher and more frequent storm-related flows, and low flows of longer duration in streams. The 

increased runoff rates and high channel velocities from inappropriately managed sites could 

result in excessive bank erosion and associated sedimentation and stream degradation in the 

Kankakee River and its tributaries. As a result, aquatic biota populations may experience 

habitat degradation or loss, reduced food or prey availability, and increased susceptibility to 

exotic species invasions. Such potential impacts can be mitigated through implementation of 

BMPs that address stormwater quality, quantity, and discharge. Stormwater BMPs are often 

required by state and local regulations, which would ensure that impacts to aquatic resources 

resulting from future development would be appropriately mitigated.

Wildlife Preserves, Parks, and Recreational Areas

Several wildlife preserves, parks, and recreation sites lie within the vicinity of Braidwood (see 

Appendix E) including the Mazonia State Fish and Wildlife Area, part of which lies within the 

Braidwood site. The continued preservation of these areas will protect aquatic habitats and as 

land development continues, these areas will become ecologically more important because they 

will provide large areas of unfragmented natural habitat.

Illinois Wildlife Conservation Plan

The State of Illinois maintains a Comprehensive Wildlife Conservation Plan and Strategy 

(IDNR 2005), which is implemented by the IDNR and numerous Federal, State, local, and 

private partners. The plan addresses long-range landscape-level planning initiatives, which 

include projects to address declining wildlife populations and conservation and restoration of 

ecologically important, sensitive, and rare habitats. As part of the plan, the IDNR intends to 

restore in-stream habitat and natural processes in the Kankakee River in both Illinois and 

Indiana by restoring channelized stream portions, stabilizing stream banks, managing drainage 

practices to moderate water flows, and protecting and restoring remnant savanna, sand prairie, 

wetland, and other riparian habitats (IDNR 2005). Commitment to this plan will ensure that 

high-quality aquatic habitats are protected or restored such that the river will continue to support 

a diversity of aquatic life in the future.

Conclusion

Although the Illinois portion of the Kankakee River has remained a diverse ecosystem with 

many microhabitats and supportive of a diversity of aquatic life, the NRC cannot conclude with 

certainty that the future impacts of energy-generating facilities, urbanization, and transportation 

development will not result in detectable impacts on the aquatic environment. Continued 

protection of aquatic habitats through wildlife preserves, parks, and recreational areas, as well 

as the implementation of the Illinois Wildlife Conservation Plan will likely mitigate such effects, 

and, therefore, the NRC finds it reasonable to assume that these activities will ensure that future 
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actions do not destabilize important attributes of the aquatic resources in the Illinois portion 

of the Kankakee River. Accordingly, the NRC staff concludes that the cumulative impacts on 

aquatic resources in the Kankakee River are MODERATE based on past, present, and 

reasonably foreseeable future actions.

4.16.6 Historic and Cultural Resources

This section addresses the direct and indirect effects of license renewal on historic and 

cultural resources when added to the aggregate effects of other past, present, and reasonably 

foreseeable future actions. The geographic area considered in this analysis is the APE 

associated with the proposed undertaking, as described in Section 3.9.

The archaeological record for the region indicates prehistoric and historic occupation of the 

Braidwood site and its immediate vicinity. The construction of Braidwood Units 1 and 2 resulted 

in destruction of cultural resources within the Braidwood site and surrounding area.

Cumulative Impacts

Other historic land development in the vicinity of Braidwood also resulted in impacts on, and 

the loss of, cultural resources on the Braidwood site and its immediate vicinity. However, there 

remains the possibility for additional historic or cultural resources to be located within the 

Braidwood site. The present and reasonably foreseeable projects which could affect these 

resources reviewed in conjunction with license renewal are noted in Appendix E of this 

document. Direct impacts would occur if historic and cultural resources in the APE were 

physically removed or disturbed. Indirect visual or noise impact could occur from new 

construction or maintenance. The following projects are located within the geographic 

area considered for cumulative impacts:

 Unit 2 steam generator replacement,

 Units 1 and 2 reactor pressure vessel head replacement, and

 future urbanization in the immediate vicinity of Braidwood.

As described in Section 4.9, no known cultural resources would be adversely affected by 

Braidwood license renewal activities as no associated changes or ground-disturbing activities 

will occur (Exelon 2013a). Unit 2 steam generator replacement, Unit 1 and 2 reactor pressure 

vessel head replacement, and future urbanization all have the potential to result in impacts on 

cultural resources through inadvertent discovery during ground-disturbing activities. However, 

as discussed in Section 4.9, Exelon has established draft procedures to ensure cultural 

resources are considered in project planning during normal operation of Braidwood.

Conclusion

The NRC staff concludes that the cumulative impact of the proposed license renewal on historic 

and cultural resources, when combined with other past, present, and reasonably foreseeable 

future activities would be SMALL.

4.16.7 Socioeconomics

This section addresses socioeconomic factors that have the potential to be directly or indirectly 

affected by changes in operations at Braidwood in addition to the aggregate effects of other 

past, present, and reasonably foreseeable future actions.

The primary geographic area of interest considered in this cumulative analysis is Will, Grundy, 

and Kankakee counties, where approximately 80 percent of Braidwood employees reside (see 

Table 3.8.10-1). This is where the economy, tax base, and infrastructure would most likely be 
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affected because Braidwood workers and their families reside, spend their incomes, and use 

their benefits within these counties.

Cumulative Impacts

As discussed in Section 4.8.10 of this SEIS, continued operation of Braidwood during the 

license renewal term would have no impact on socioeconomic conditions in the region beyond 

those already being experienced. Since Exelon has no plans to hire additional workers during 

the license renewal term, overall expenditures and employment levels at Braidwood would 

remain relatively constant and unchanged with no additional demand for permanent housing 

and public services. In addition, as employment levels and tax payments would not change, 

there would be no population or tax revenue-related land-use impacts. Therefore, the only 

contributory effects would come from reasonably foreseeable future planned activities at 

Braidwood, unrelated to the proposed action (license renewal), and other reasonably 

foreseeable planned offsite activities. For example, residential development is forecast for the 

Braidwood area, but not to the point that population densities will be significant.

Unit 2 Steam Generator Replacement

Exelon indicated that the Unit 2 steam generator replacement would occur during the license 

renewal term. Exelon estimates that steam generator replacement would occur during a 90-day 

period paralleling (coinciding with) a refueling outage or other scheduled maintenance outage. 

Steam generator replacement would require approximately 500 personnel, in addition to the 

1,400 personnel required for refueling (Exelon 2013c). These additional workers would create a 

short-term increase in the demand for temporary (rental) housing, an increased use of public 

water and sewer services, and transportation impacts on access roads in the immediate vicinity 

of Braidwood. Given the short amount of time needed to replace the steam generator, the 

additional number of refueling outage and steam generator replacement workers and truck 

deliveries needed to support this one-time replacement, steam generator replacement could 

have a temporary cumulative effect on socioeconomic conditions in the vicinity of the nuclear 

plant. However, since the number of non-outage workers at Braidwood would not change after 

steam generator replacement, there would be no long-term cumulative socioeconomic impacts 

in the region.

Units 1 and 2 Reactor Pressure Vessel Head Replacement

Exelon indicated that the reactor vessel heads would be replaced before the license renewal 

term. Exelon estimates that each vessel head replacement would require a one-time increase 

of 340 outage workers for 1 week. If the vessel heads were replaced simultaneously, the 

number of outage workers would remain at 340, but an additional week of work would be 

necessary (Exelon 2013c). These additional workers would create a short-term increase in the 

demand for temporary (rental) housing, an increased use of public water and sewer services, 

and transportation impacts on access roads in the immediate vicinity of Braidwood. Given the 

short amount of time needed to replace the vessel head and the additional number of workers 

and truck deliveries needed to support this one-time replacement of the vessel head, vessel 

head replacement could have a temporary cumulative effect on socioeconomic conditions in the 

vicinity of the nuclear plant. However, since the number of non-outage workers at Braidwood 

would not change after reactor vessel head replacement, there would be no long-term 

cumulative socioeconomic impacts in the region.
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Conclusion

When combined with other past, present, and reasonably foreseeable future activities, there will 

be no additional contributory effect on socioeconomic conditions from the continued operation of 

Braidwood during the license renewal period beyond what is currently being experienced. 

Increases in the Braidwood workforce during steam generator and vessel head replacement 

would be temporary and have no long-term socioeconomic impact to the region. Therefore, the 

NRC staff concludes that the cumulative socioeconomic impact would be SMALL in the 

immediate vicinity of Braidwood.

4.16.8 Human Health

The NRC and EPA established radiological dose limits for protection of the public and workers 

from both acute and long-term exposure to radiation and radioactive materials. These dose 

limits are codified in 10 CFR Part 20 and 40 CFR Part 190. As discussed in Section 4.11.1, the 

NRC staff concluded impacts to human health from the continued operations of Braidwood are 

SMALL.

Cumulative Impacts

For the purposes of this analysis, the geographical area considered is the area included within 

an 80-km (50-mi) radius of the Braidwood plant site. There are four other nuclear power plants 

within the applicable geographical area: LaSalle County Station, Units 1 and 2, and DNPS, 

Units 2 and 3. In addition to storing its spent nuclear fuel in a storage pool, Braidwood also 

stores some of its spent nuclear fuel in an onsite ISFSI (Exelon 2013c).

EPA regulations in 40 CFR Part 190 limit the dose to members of the public from all sources in 

the nuclear fuel cycle, including nuclear power plants, fuel fabrication facilities, waste disposal 

facilities, and transportation of fuel and waste. As discussed in Section 3.1.4.5, Braidwood has 

a radiological environmental monitoring program (REMP). This program measures radiation 

and radioactive materials in the environment from Braidwood, its ISFSI, and other nuclear 

power plants, and other sources (i.e., medical and industrial facilities using radioactive material). 

As discussed in Section 4.11.1, the NRC staff reviewed the radiological environmental 

monitoring data for the 5-year period from 2008 to 2012 as part of the cumulative impacts 

assessment. The NRC staff reviewed Braidwood REMP data. The data showed no indication 

of an adverse trend in radiation or radioactivity levels in the environment from Braidwood, its 

ISFSI, other nuclear power plants, or other sources. The data showed that there was no 

measurable impact to the environment from the operations at Braidwood or any other facility 

using radioactive material.

In addition, as discussed in Section 3.1.4.6 of this SEIS, Exelon stated in its ER that it may 

replace the Braidwood Unit 2 steam generators and reactor pressure vessel heads for both 

units (Exelon 2013c). If Exelon conducts these potential refurbishment activities during the 

license renewal term, Exelon is required to maintain its radiation protection program to limit 

radiation dose to its workers and members of the public in accordance with NRC and EPA

radiation protection standards.

Based on Braidwood’s radiation protection program, the staff expects the dose to plant workers 

and members of the public from these potential projects would continue to be a small fraction of 

NRC and EPA’s radiation protection standards. The NRC and the State of Illinois will regulate 

any future development or actions in the vicinity of the Braidwood site that could contribute to 

cumulative radiological impacts.
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Conclusion

Based on the NRC staff’s review of Braidwood’s REMP data, radioactive effluent release data, 

and Braidwood’s expected continued compliance with Federal radiation protection standards 

during continued operation and the potential refurbishment activities, and regulation of any 

future development or actions in the vicinity of the Braidwood site by the NRC and the State 

of Illinois, the NRC staff concludes that the cumulative impacts would be SMALL.

4.16.9 Environmental Justice

The environmental justice cumulative impact analysis assesses the potential for 

disproportionately high and adverse human health and environmental effects on minority and 

low-income populations that could result from past, present, and reasonably foreseeable future 

actions, including Braidwood operations during the renewal term. Adverse health effects are 

measured in terms of the risk and rate of fatal or nonfatal adverse impacts on human health. 

Disproportionately high and adverse human health effects occur when the risk or rate of 

exposure to an environmental hazard for a minority or low-income population is significant 

and exceeds the risk or exposure rate for the general population or for another appropriate 

comparison group. Disproportionately high environmental effects refer to impacts or risks of 

impacts on the natural or physical environment in a minority or low-income community that are 

significant and appreciably exceed the environmental impact on the larger community. Such 

effects may include biological, cultural, economic, or social impacts. Some of these potential 

effects have been identified in resource areas presented in preceding sections of this SEIS.

Minority and low-income populations are part of the general public residing in the area and all 

would be exposed to the same hazards generated from Braidwood operations. As previously 

discussed in this chapter, the impact from license renewal for all resource areas (e.g., land, air, 

water, ecology, and human health) would be SMALL. Therefore, as discussed in Section 4.12 

of this SEIS, there would be no disproportionately high and adverse impacts on minority and 

low-income populations from the continued operation of Braidwood during the license 

renewal term.

Cumulative Impacts

Because Exelon has no plans to hire additional workers during the license renewal term (other 

than outages), employment levels at Braidwood would remain relatively constant, and there 

would be no additional demand for housing or increased traffic. Based on this information and 

the analysis of human health and environmental impacts presented in the preceding sections, it 

is not likely there would be any disproportionately high and adverse contributory effect on 

minority and low-income populations from the continued operation of Braidwood during the 

license renewal term. Therefore, the only contributory effects would come from the other 

reasonably foreseeable future planned activities at Braidwood, unrelated to the proposed 

action (license renewal), and other reasonably foreseeable planned offsite activities.

Unit 2 Steam Generator Replacement

Potential impacts to minority and low-income populations would mostly consist of environmental 

and socioeconomic effects (e.g., traffic, employment, and housing impacts). Noise and dust 

impacts from power plant modifications would be temporary and limited to onsite activities. 

Minority and low-income populations residing along site access roads could experience 

increased commuter vehicle traffic during shift changes. Increased demand for inexpensive 

rental housing during steam generator-related power plant modifications could 

disproportionately affect low-income populations; however, because of the short duration of the 
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work and the availability of housing, impacts to minority and low-income populations would be of 

short duration and limited. Radiation doses from plant operations after power plant 

modifications are not expected to change and will remain within regulatory limits.

Based on this information and the analysis of human health and environmental impacts 

presented in this section of the SEIS, Unit 2 steam generator replacement would not have 

disproportionately high and adverse human health and environmental effects on minority and 

low-income populations residing in the vicinity of Braidwood.

Units 1 and 2 Reactor Pressure Vessel Head Replacement

Similar to steam generator replacement, potential impacts to minority and low-income 

populations from reactor pressure vessel head replacement would mostly consist of 

environmental and socioeconomic effects (e.g., traffic, employment, and housing impacts). 

Noise and dust impacts from power plant modifications would be temporary and limited to onsite 

activities. Minority and low-income populations residing along site access roads could 

experience increased commuter vehicle traffic during shift changes. Increased demand for 

inexpensive rental housing during steam generator-related power plant modifications could 

disproportionately affect low-income populations; however, because of the short duration of the 

work and the availability of housing, impacts to minority and low-income populations would be of 

short duration and limited. Radiation doses from plant operations after power plant 

modifications are not expected to change and will remain within regulatory limits.

Based on this information and the analysis of human health and environmental impacts 

presented in this section of the SEIS, Unit 1 and 2 reactor pressure vessel head replacement 

would not have disproportionately high and adverse human health and environmental effects on 

minority and low-income populations residing in the vicinity of Braidwood.

Conclusion

The NRC staff concludes that the contributory effects of this action, when combined with other 

past, present, and reasonably foreseeable future activities considered, would not cause any 

disproportionately high and adverse human health and environmental effects on minority and 

low-income populations residing in the vicinity of Braidwood.

4.16.10 Waste Management

This section describes waste management impacts from Braidwood during the license renewal 

term when added to the cumulative impacts of other past, present, and reasonably foreseeable 

future actions. For the purpose of this cumulative impacts analysis, the area within a 50-mi 

(80-km) radius of Braidwood was considered.

The NRC staff concluded, in Section 4.11.1, that the potential human health impacts from 

Braidwood’s waste during the license renewal term would be SMALL.

Cumulative Impacts

As discussed in Sections 3.1.4 and 3.1.5, Exelon maintains waste management programs for 

radioactive and nonradioactive waste generated at Braidwood and is required to comply with 

Federal and state permits and other regulatory requirements for the management of waste 

material. The nuclear power plants and other facilities within a 50-mi (80-km) radius of 

Braidwood are also required to comply with appropriate NRC, EPA, and state requirements for 

the management of radioactive and nonradioactive waste. For cumulative impacts analysis, 

waste management activities at Braidwood are expected to be stable during the license renewal 

term and comply with Federal and State requirements for radioactive and nonradioactive waste. 
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Adequate disposal options at licensed disposal facilities are expected to handle the cumulative 

volume of radioactive and nonradioactive waste generated by Braidwood and other facilities. If 

access to a disposal facility is temporarily unavailable, the waste will be safely stored in 

accordance with NRC, EPA, and state requirements.

Conclusion

Based on the above information, the NRC staff concludes that the potential cumulative impact 

from radioactive and nonradioactive waste would be SMALL.

4.16.11 Global Climate Change

This section addresses the impact of GHG emissions resulting from continued operation of 

Braidwood Station on global climate change when added to the aggregate effects of other past, 

present, and reasonably foreseeable future actions.

The impacts of climate change on air, water, and ecological resources are discussed in 

Section 4.14.3. Climate is influenced by both natural and human-induced factors; the observed 

global warming (increase in Earth’s surface temperature) in the 21st century has been attributed 

to the increase in GHG emissions resulting from human activities (USGCRP 2009). Climate 

model projections indicate that future climate change is dependent on current and future GHG 

emissions (Parry et al. 2007; USGCRP 2009). As described in Section 4.14.3.1, operations at 

Braidwood emit GHG emissions directly and indirectly. Therefore, it is recognized that GHG 

emissions from continued Braidwood Station operation may contribute to climate change.

Cumulative Impacts

The cumulative impact of a GHG emission source on climate is global. GHG emissions are 

transported by wind and become well mixed in the atmosphere as a result of their long 

atmospheric time. Therefore, the extent and nature of climate change is not specific to where 

GHGs are emitted. In April 2013, EPA published the official U.S. inventory of GHG emissions, 

which identifies and quantifies the primary anthropogenic sources and sinks of GHGs. The EPA 

GHG inventory is an essential tool for addressing climate change and participating with the 

United Nations Framework Convention on Climate Change to compare the relative global 

contribution of different emission sources and GHGs to climate change. In 2011, the 

United States emitted 6,702 teragrams (Tg) (6,702 million metric tons (MMT) of carbon dioxide 

equivalents, and since 1990, emissions increased at an average annual rate of 0.4 percent 

(EPA 2013c). In 2010 and 2011, the total amount of carbon dioxide equivalent emissions 

related to electricity generation was 2,303 Tg (2,303 MMT) and 2,201 Tg (2,201 MMT), 

respectively (EPA 2013c). The EIA reported that, in 2010, electricity production alone in Illinois 

was responsible for 94 MMT carbon dioxide equivalents (EIA 2013). Facilities that emit 

25,000 MT carbon dioxide equivalents or more per year are required to annually report their 

GHG emissions to the EPA. These facilities are known as direct emitters and the data is 

publicly available in EPA’s facility-level information on GHGs tool (FLIGHT). In 2012, FLIGHT 

identified four facilities in Ogle County, Illinois where the Braidwood Station is located, that 

emitted a total of 0.33 MT carbon dioxide equivalents (EPA 2014e). In 2012, FLIGHT identified 

291 facilities in Illinois that emitted a total of 130.3 MMT carbon dioxide equivalents 

(EPA 2014e).

Appendix E provides a list of present and reasonable foreseeable projects that could contribute 

to GHG emissions. Permitting and licensing requirements and other mitigative measures can 

minimize the impacts of GHG emissions. For instance, in 2012 the EPA issued a final GHG 

Tailoring Rule to address GHG emissions from stationary sources under the CAA permitting 

requirements; the GHG Tailoring Rule establishes when an emission source will be subject to 
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permitting requirements and control technology to reduce GHG emissions. On June 25, 2013, 

President Obama set forward a plan to reduce carbon pollution. The Climate Action Plan will 

reduce carbon pollution, prepare the United States for the impacts of climate change, and lead 

international efforts to combat global climate change. Future actions and steps taken to reduce 

GHG emissions will lessen the impacts on climate change.

EPA’s U.S. inventory of GHG emissions, illustrates the diversity of GHG sources emitters, such 

as electricity generation, industrial processes, and agriculture. Direct GHG emissions resulting 

from operations at Braidwood range from 941 to 1,503 MT carbon dioxide equivalents 

(Table 4–29) and total emissions range from 10,872 to 13,962 MT carbon dioxide equivalents. 

In comparing Braidwood Station’s GHG emission contribution to different emissions sources, 

whether it be total U.S. GHG emissions, emissions from electricity production in Illinois, or 

emissions on a county level, GHG emissions from Braidwood are minor relative to these 

inventories; this is evident as presented in Table 4–29. The emissions impact of a single source 

on climate change requires that a climate model account for that specific source emissions to 

project the magnitude and extent of climate change. Climate models indicate that short-term 

climate change (through the year 2030) is dependent on past GHG emissions. Therefore, 

climate change is projected to occur with or without present and future GHG emissions from 

Braidwood. The NRC staff concludes that the incremental impact from the contribution of GHG 

emissions from continued operation of Braidwood on climate change would be SMALL. As 

discussed in Section 4.14.3.2, climate change and climate-related changes have been observed 

on a global level and climate models indicate that future climate change will depend on present 

and future GHG emissions. With continued increases in GHG emission rates, climate models 

project that Earth’s average surface temperature will continue to increase and climate-related 

changes will persist. Therefore, the cumulative impact of GHG emissions on climate change is 

noticeable but not destabilizing.

Table 4–29. Comparison of GHG Emission Inventories

Source CO2e MMT/year

Global Fossil Fuel Combustion Emissions (2011)(a) 31,800

U.S. Emissions (2011)(b) 6,702

Illinois (2012)(c) 130.3

Ogle County, Illinois (2012)(c) 0.33

Braidwood Station Emissions (2008–2012)(d) 0.010–0.013

(a) Source: IEA (2012)

(b) Source: EPA (2013a)

(c) GHG emissions account only for direct emitters, those facilities that emit 25,000 MT or more a year 

(EPA 2014e).

(d) Emissions include direct and indirect emissions from operation of Braidwood (Exelon 2013b).

Sources: EPA 2014e, 2013c; Exelon 2013b; IEA 2012

Conclusion

Although the incremental climate change impacts are SMALL due to greenhouse gas emissions 

from the continued operation of Braidwood, the cumulative impacts of past, present, and 

reasonably foreseeable future actions, including the incremental impact of Braidwood license 

renewal, are MODERATE.
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4.16.12 Summary of Cumulative Impacts

The NRC staff considered the potential impacts resulting from the operation of Braidwood 

during the period of extended operation and other past, present, and reasonably foreseeable 

future actions near Braidwood. The determination is that the potential cumulative impacts would 

range from SMALL to LARGE, depending on the resource. Table 4–30 summarizes the 

cumulative impacts on resource areas.
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Table 4–30. Summary of Cumulative Impacts on Resource Areas

Resource Area Cumulative Impact

Air Quality 

and Noise

Past, present, and reasonably foreseeable future activities exist in the geographic 

areas of interest (local for noise; local and regional for criteria pollutants) that could 

affect air quality and noise resources. However, the incremental contribution of 

impacts on air quality and noise resources from plant operations at Braidwood Station 

would be minimal. The NRC staff concludes that cumulative impacts from other past, 

present, and reasonably foreseeable future actions on air quality and noise resources 

in the geographic areas of interest would be SMALL.

Geology and 

Soils

Any use of geologic materials such as aggregates to support operation and 

maintenance activities would be procured from local and regional sources. These 

materials are abundant in the region and geologic conditions are not expected to 

change during the license renewal term. Thus, activities associated with continued 

operations are not expected to affect the geologic environment. Considering ongoing 

activities and reasonably foreseeable actions, the NRC staff concludes that the 

cumulative impacts on geology and soils during the Braidwood license renewal term 

would be SMALL.

Water Resources

Considering ongoing activities and reasonably foreseeable actions, the NRC staff 

concludes that cumulative impacts of the proposed license renewal when combined 

with other past, present, and reasonably foreseeable future activities on surface water

resources would be SMALL to MODERATE, while impacts to groundwater resources 

would be MODERATE TO LARGE. While the Braidwood facility is not expected to 

impact surface or groundwater resources, increased regional demand on both surface 

and groundwater resources is expected to grow throughout the license renewal term.

Terrestrial 

Ecology

NRC staff concludes that the cumulative impacts on terrestrial resources in the vicinity 

of the Braidwood site are MODERATE to LARGE based on past, present, and 

reasonably foreseeable future actions. This level of impact is primarily the result 

of past habitat alteration and loss on the Braidwood site and within the larger 

Illinois/Indiana Prairies Level IV Ecoregion. The environmental effects of these actions 

are clearly noticeable and have destabilized important attributes of certain terrestrial 

communities. The loss of genetic fitness of native prairie species and the species 

composition shifts observed in native Illinois forests are demonstrative of such effects. 

The incremental, site-specific impact from the continued operation of Braidwood during 

the license renewal period would be an unnoticeable or minor contributor to cumulative 

impacts on terrestrial resources.

Aquatic Ecology

The NRC staff concludes that the cumulative impacts on aquatic resources in the 

Kankakee River are MODERATE based on past, present, and reasonably foreseeable 

future actions. The NRC staff cannot conclude with certainty that future impacts of 

energy-generating facilities, urbanization, and transportation development will not result 

in detectable impacts on the aquatic environment of the Illinois portion of the Kankakee 

River. Continued protection of aquatic habitats through wildlife preserves, parks, and 

recreational areas, as well as the implementation of the Illinois Wildlife Conservation 

Plan will likely mitigate such effects, and, therefore, the NRC finds it reasonable to 

assume that these activities will ensure that future actions do not destabilize important 

attributes of the aquatic resources in the Illinois portion of the Kankakee River.

Cultural 

Resources

As described in Section 4.9, no cultural resources would be adversely affected by 

Braidwood license renewal activities as no associated changes or ground-disturbing 

activities will occur. Exelon has established draft procedures to ensure cultural 

resources are considered in project planning during normal operation of Braidwood. 

Therefore, the NRC staff concludes that the cumulative impact of the proposed license 

renewal when combined other past, present, and reasonable foreseeable future 

activities on historic and cultural resources would be SMALL.
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Resource Area Cumulative Impact

Socioeconomics

When combined with other past, present, and reasonably foreseeable future activities, 

there will be no additional contributory effect on socioeconomic conditions from the 

continued operation of Braidwood during the license renewal period beyond what is 

currently being experienced. Increases in the Braidwood workforce during steam 

generator and vessel head replacement would be temporary and have no long-term 

socioeconomic impact to the region. Therefore, the NRC staff concludes that the 

cumulative socioeconomic impact would be SMALL in the immediate vicinity of 

Braidwood.

Human Health

Based on the NRC staff’s review of Braidwood’s REMP data, radioactive effluent 

release data, and Braidwood’s expected continued compliance with Federal radiation 

protection standards during continued operation and the potential refurbishment

activities, and regulation of any future development or actions in the vicinity of the 

Braidwood site by the NRC and the State of Illinois, the NRC staff concludes that the 

cumulative impacts would be SMALL.

Environmental 

Justice

The NRC staff concludes that the contributory effects of this action, when combined 

with other past, present, and reasonably foreseeable future activities considered, would 

not cause any disproportionately high and adverse human health and environmental 

effects on minority and low-income populations residing in the vicinity of Braidwood.

Waste 

Management 

NRC staff concludes that the potential cumulative impacts from radioactive and 

nonradioactive waste during the license renewal term would be SMALL. Waste 

management activities at Braidwood are expected to be stable during the license 

renewal term and comply with Federal and State requirements for radioactive and 

nonradioactive waste. Adequate disposal options at licensed disposal facilities are 

expected to handle the cumulative volume of radioactive and nonradioactive waste 

generated by Braidwood and other facilities.

Global Climate 

Change

Continued increases in GHG emission rates, climate models project that Earth’s 

average surface temperature will continue to increase and climate-related changes 

will persist. Therefore, the cumulative impact of GHG emissions on climate change is 

noticeable but not destabilizing. The NRC staff concludes that the cumulative impacts 

from the proposed license renewal and other past, present, and reasonably 

foreseeable projects would be MODERATE.

4.17 Resource Commitments Associated With the Proposed Action

4.17.1 Unavoidable Adverse Environmental Impacts

Unavoidable adverse environmental impacts are impacts that would occur after implementation 

of all workable mitigation measures. Carrying out any of the energy alternatives considered in 

the SEIS, including the proposed action, would result in some unavoidable adverse 

environmental impacts.

Minor unavoidable adverse impacts on air quality would occur due to emission and release of 

various chemical and radiological constituents from power plant operations. Nonradiological 

emissions resulting from power plant operations are expected to comply with EPA emissions 

standards, though the alternative of operating a fossil-fueled power plant in some areas may 

worsen existing attainment issues. Chemical and radiological emissions would not exceed the 

national emission standards for HAPs.
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During nuclear power plant operations, workers and members of the public would face 

unavoidable exposure to radiation and hazardous and toxic chemicals. Workers would be 

exposed to radiation and chemicals associated with routine plant operations and the handling of 

nuclear fuel and waste material. Workers would have higher levels of exposure than members 

of the public, but doses would be administratively controlled and would not exceed standards or 

administrative control limits. In comparison, the alternatives involving the construction and 

operation of a non-nuclear power generating facility would also result in unavoidable exposure 

to hazardous and toxic chemicals to workers and the public.

The generation of spent nuclear fuel and waste material, including low-level radioactive waste 

(LLRW), hazardous waste, and nonhazardous waste would be unavoidable. Hazardous and 

nonhazardous wastes would be generated at non-nuclear power generating facilities. Wastes 

generated during plant operations would be collected, stored, and shipped for suitable 

treatment, recycling, or disposal in accordance with applicable Federal and state regulations. 

Because of the costs of handling these materials, power plant operators would be expected to 

carry out all activities and optimize all operations in a way that generates the smallest amount of 

waste possible.

4.17.2 Relationship Between Short-Term Use of the Environment and Long-Term 

Productivity

The operation of power generating facilities would result in short-term uses of the environment, 

as described in Chapters 3 and 4. “Short-term” is the period of time that continued power 

generating activities take place.

Power plant operations require short-term use of the environment and commitment of resources 

and commit certain resources (e.g., land and energy), indefinitely or permanently. Certain 

short-term resource commitments are substantially greater under most energy alternatives, 

including license renewal, than under the no-action alternative because of the continued 

generation of electrical power and the continued use of generating sites and associated 

infrastructure. During operations, all energy alternatives entail similar relationships between 

local short-term uses of the environment and the maintenance and enhancement of 

long-term productivity.

Air emissions from power plant operations introduce small amounts of radiological and 

nonradiological constituents to the region around the plant site. Over time, these emissions 

would result in increased concentrations and exposure, but they are not expected to impact air 

quality or radiation exposure to the extent that public health and long-term productivity of the 

environment would be impaired.

Continued employment, expenditures, and tax revenues generated during power plant 

operations directly benefit local, regional, and state economies over the short term. Local 

governments investing project-generated tax revenues into infrastructure and other required 

services could enhance economic productivity over the long term.

The management and disposal of spent nuclear fuel, LLRW, hazardous waste, and 

nonhazardous waste requires an increase in energy and consumes space at treatment, storage, 

or disposal facilities. Regardless of the location, the use of land to meet waste disposal needs 

would reduce the long-term productivity of the land.

Power plant facilities are committed to electricity production over the short term. After 

decommissioning these facilities and restoring the area, the land could be available for 

other future productive uses.
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4.17.3 Irreversible and Irretrievable Commitments of Resources

This section describes the irreversible and irretrievable commitment of resources that have 

been noted in the SEIS. Resources are irreversible when primary or secondary impacts limit 

the future options for a resource. An irretrievable commitment refers to the use or consumption 

of resources that are neither renewable nor recoverable for future use. Irreversible and 

irretrievable commitment of resources for electrical power generation include the commitment 

of land, water, energy, raw materials, and other natural and man-made resources required for 

power plant operations. In general, the commitment of capital, energy, labor, and material 

resources is also irreversible.

The implementation of any of the energy alternatives considered in the SEIS would entail the 

irreversible and irretrievable commitment of energy, water, chemicals, and—in some cases—

fossil fuels. These resources would be committed during the license renewal term and over the 

entire life cycle of the power plant, and they would be unrecoverable.

Energy expended would be in the form of fuel for equipment, vehicles, and power plant 

operations and electricity for equipment and facility operations. Electricity and fuel would be 

purchased from offsite commercial sources. Water would be obtained from existing water 

supply systems. These resources are readily available, and the amounts required are not 

expected to deplete available supplies or exceed available system capacities.

4.18 References

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protection against radiation.”

10 CFR Part 50. Code of Federal Regulations, Title 10, Energy, Part 50, “Domestic licensing of 

production and utilization facilities.”

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

protection regulations for domestic licensing and related regulatory functions.” 

10 CFR Part 54. Code of Federal Regulations, Title 10, Energy, Part 54, “Requirements 

for renewal of operating licenses for nuclear power plants.”

10 CFR Part 100. Code of Federal Regulations, Title 10, Energy, Part 100, “Reactor

site criteria.”

36 CFR Part 60. Code of Federal Regulations, Title 36, Parks, Forests, and Public Property, 

Part 60, “National Register of Historic Places.”

36 CFR Part 800. Code of Federal Regulations, Title 36, Parks, Forests, and Public Property, 

Part 800, “Protection of historic properties.”

40 CFR Part 51. Code of Federal Regulations, Title 40, Protection of Environment, Part 60, 

“Requirements for preparation, adoption, and submittal of implementation plans.”

40 CFR Part 60. Code of Federal Regulations, Title 10, Protection of Environment, Part 60, 

“Standards of performance for new stationary sources.”

40 CFR Part 63. Code of Federal Regulations, Title 10, Protection of Environment, Part 63, 

“National emission standards for hazardous air pollutants for source categories.”

40 CFR Part 75. Code of Federal Regulations, Title 40, Protection of Environment, Part 75, 

“Continuous emission monitoring.”
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40 CFR Part 81. Code of Federal Regulations, Title 40, Protection of Environment, Part 81, 

“Designation of areas for air quality planning purposes.”

40 CFR Part 93. Code of Federal Regulations, Title 40, Protection of Environment, Part 93, 

“Determining conformity of Federal action plans to State or Federal implementation plans.”

40 CFR Part 125. Code of Federal Regulations, Title 40, Protection of Environment, Part 125, 

“Criteria and standards for the National Pollutant Discharge Elimination System.”

40 CFR Part 190. Code of Federal Regulations, Title 40, Protection of Environment, Part 190, 

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50 CFR Part 402. Code of Federal Regulations, Title 50, Wildlife and Fisheries, Part 402, 

“Interagency Cooperation—Endangered Species Act of 1973, as Amended.”

49 FR 34658. U.S. Nuclear Regulatory Commission. “Waste Confidence Decision.” Federal 

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February 16, 1994.

61 FR 28467. U.S. Nuclear Regulatory Commission. “Environmental Review for Renewal 

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June 5, 1996.

61 FR 66537. U.S. Nuclear Regulatory Commission. “Environmental Review for Renewal 

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65 FR 79825. U.S. Environmental Protection Agency. “Regulatory Finding on the Emissions 

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Findings for Greenhouse Gases Under Section 202(a) of the Clean Air Act.” Federal 

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and Title V Greenhouse Gas Tailoring Rule.” Federal Register 75(106):31514–31608. 

June 3, 2010.
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75 FR 81032. U.S. Nuclear Regulatory Commission. “Consideration of Environmental Impacts 

of Temporary Storage of Spent Fuel after Cessation of Reactor Operation.” Federal 

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Federal Register 75(246):81037–81076. December 23, 2010.

76 FR 66370. U.S. Fish and Wildlife Service. “Endangered and threatened wildlife and plants; 

review of native species that are candidates for listing as endangered or threatened; annual 

notice of findings on resubmitted petitions; annual description of progress on listing actions.” 

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77 FR 14914. U.S. Fish and Wildlife Service. “Endangered and Threatened Wildlife and 

Plants: Determination of Endangered Status for the Sheepnose and Spectaclecase Mussels 

Throughout Their Range.” Federal Register 77(49):14914–14949. March 13, 2012.

77 FR 41051. U.S. Environmental Protection Agency. “Prevention of Significant Deterioration 

and Title V Greenhouse Gas Tailoring Rule Step 3 and GHG Plantwide Applicability Limits.” 

Federal Register 77(134):41051–41075. July 12, 2012.

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

Renewal of Nuclear Power Plant Operating Licenses.” Federal Register 78(119):37282–37324. 

June 20, 2013.

78 FR 46255. U.S. Nuclear Regulatory Commission. “Revisions to Environmental Review for 

Renewal of Nuclear Power Plant Operating Licenses; Correction.” Federal 

Register 78(147):46255–46256. July 31, 2013.

78 FR 56621. U.S. Nuclear Regulatory Commission. “Draft Waste Confidence 

Generic Environmental Impact Statement.” Federal Register 78(178):56621–56622. 

September 13, 2013.

78 FR 56776. U.S. Nuclear Regulatory Commission. “Waste Confidence—Continued Storage 

of Spent Nuclear Fuel.” Federal Register 78(178):56776–56805. September 13, 2013.

78 FR 61046. U.S. Fish and Wildlife Service. “Endangered and Threatened Wildlife and Plants; 

12-Month Finding on a Petition to List the Eastern Small-Footed Bat and the Northern 

Long-Eared Bat as Endangered or Threatened Species; Listing the Northern Long-Eared Bat as 

an Endangered Species.” Federal Register 78(191):61046–61080. October 2, 2013.

78 FR 72058. U.S. Fish and Wildlife Service. “Endangered and Threatened Wildlife and 

Plants; Listing the Northern Long-Eared Bat as an Endangered Species.” Federal 

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5-1 

5.0 CONCLUSION

This Final Supplemental Environmental Impact Statement (FSEIS) contains the environmental 

review of the application for renewed operating licenses for Braidwood Station, Units 1 and 2 

(Braidwood), submitted by Exelon Generation Company, LLC (Exelon), as required by the Code 

of Federal Regulations (CFR), Part 51 of Title 10 (10 CFR Part 51), the U.S. Nuclear Regulatory 

Commission’s (NRC’s) regulations that implement the National Environmental Policy Act. This 

chapter presents conclusions and recommendations from the site-specific environmental review 

of Braidwood. Section 5.1 summarizes the environmental impacts of license renewal, 

Section 5.2 presents a comparison of the environmental impacts of license renewal and 

energy alternatives, and Section 5.3 presents the NRC staff conclusions and recommendation.

5.1 Environmental Impacts of License Renewal

The NRC staff’s review of site-specific environmental issues in this supplemental environmental 

impact statement (SEIS) leads to the conclusion that issuing renewed licenses at Braidwood 

would have SMALL to MODERATE impacts for the Category 2 issues applicable to license 

renewal at Braidwood. The NRC staff considered mitigation measures for each Category 2 

issue, as applicable. The NRC staff concluded that no additional mitigation measure is 

warranted.

5.2 Comparison of Alternatives

In Chapter 4, the staff considered the following alternatives to Braidwood license renewal:

 no-action alternative,

 natural gas combined-cycle alternative,

 coal-integrated gasification combined cycle, 

 new nuclear alternative,

 combination alternative (wind, solar, and natural gas), and

 purchased power.

Based on the summary of environmental impacts provided in Table 2–2, the NRC staff 

concluded that the environmental impacts of renewal of the operating licenses for Braidwood 

would be smaller than those of feasible and commercially viable alternatives. The no-action

alternative—the act of shutting down Braidwood on or before its licenses expire—would have 

SMALL environmental impacts in most areas, with the exception of land use and socioeconomic 

impacts, which would have SMALL to MODERATE and SMALL to LARGE environmental 

impacts, respectively. Continued operations would have SMALL to MODERATE environmental 

impacts for Aquatic Resources, and SMALL impacts in all other areas. The staff concluded that 

continued operation of the existing Braidwood units is the environmentally preferred alternative.
Conclusion

5-2 

5.3 Recommendation

The NRC staff’s recommendation is that the adverse environmental impacts of license renewal 

for Braidwood are not so great that preserving the option of license renewal for energy-planning 

decisionmakers would be unreasonable. This recommendation is based on the following:

 the analysis and findings in NUREG-1437, Generic Environmental 

Impact Statement for License Renewal of Nuclear Plants; 

 the Environmental Report submitted by Exelon; 

 consultation with Federal, State, and local agencies; 

 the NRC staff’s environmental review; and

 consideration of public comments received during the scoping process.
6-1 

6.0 LIST OF PREPARERS

This supplemental environmental impact statement (SEIS) was prepared by members of the 

Office of Nuclear Reactor Regulation (NRR) with assistance from other U.S. Nuclear Regulatory 

Commission (NRC) organizations and contract support from Pacific Northwest National 

Laboratory (PNNL), Ecology and Environment, Inc. (E&E), and BLH Technologies, Inc. (BLH). 

Table 6–1 lists the NRC staff who contributed to the development of the SEIS. E&E provides 

contract support for air quality, meteorology (climatology), and alternative reviews. PNNL 

provides contract support for severe accident mitigation alternative (SAMA) reviews. BLH 

provides contract support for technical editing reviews.
List of Preparers

6-2 

Table 6–1. List of Preparers

Name Education/Experience Function or Expertise

NRC-NRR

Brian Wittick B.S., Systems Engineering; M.E., 

Acoustical Engineering; MBA with 

minor in Environmental Management; 

31 years of experience in operation 

and oversight of reactor programs, 

including 11 years at NRC, including 

as an NRC resident inspector; reactor 

engineer; senior licensing officer; 

executive technical assistant; and 

projects branch manager

Management oversight

David Wrona B.S., Electrical Engineering; 30 years 

of experience as an engineering 

inspector, including as an NRC 

resident inspector, reactor engineer,

project manager, and projects and 

technical branch manager

Management oversight

Richard Baum B.S., Community Planning and 

Development; M.S., Environmental 

Biology; 23 years in project and 

program management experience

Project management

Jeffrey Rikhoff M.R.P., Regional Planning; M.S., 

Economic Development and 

Appropriate Technology; 23 years 

of experience in NEPA compliance, 

socioeconomics and environmental 

justice impact analysis, cultural 

resource impacts, and comprehensive 

land-use and development planning

Socioeconomics and environmental justice

Stephen Klementowicz M.S., Health Physics; 33 years of 

commercial and regulatory experience 

in reactor health physics, radiological 

effluent and environmental monitoring 

programs, and radioactive waste

Human health, radiological, and waste 

management

Kevin Folk B.A., Geoenvironmental Studies;

M.S., Environmental Biology; 

25 years of experience in NEPA

compliance; geologic, hydrologic, and 

water quality impacts analysis; utility 

infrastructure analysis; and 

environmental regulatory compliance 

and water supply and wastewater

discharge permitting

Technical Monitor/Contracting 

Officer’s Representative

Briana Grange B.S., Conservation Biology; 10 years 

of experience in environmental impact 

analysis, section 7 consultations, and 

essential fish habitat consultations

Aquatic and terrestrial ecology, land use, 

visual resources, and microbiological 

hazards
List of Preparers

6-3 

Name Education/Experience Function or Expertise

Nancy Martinez A.M., Earth and Planetary Science;

B.S., Earth and 

Environmental Science; 4 years 

of experience in environmental 

impact analysis

Air quality, noise, climate change, 

and surface water resources

John Parillo M.S., Environmental Engineering;

B.S., Mechanical Engineering; over 

40 years of experience in engineering

SAMA

Emily Larson B.A., Anthropology; M.A., 

Archaeology; 3 years of experience 

in NEPA and historic preservation 

compliance

Historic and cultural resources, 

and cumulative impacts

Russell Chazell B.S., Liberal Studies; J.D, Law; M.S., 

Nuclear Engineering; Certificate in 

Project Management; Certificate in 

NEPA; approximately 9 years 

analytical/environmental laboratory 

experience, 5 years analytical project 

management experience, 4 years 

technical business development 

experience, 4 years engineering 

project management experience, 

and 2 years NEPA experience

Historic and cultural resources

William Ford M.S., Geology; 41 years of combined 

industry and government experience 

working on groundwater, surface 

water, and geology projects and 

associated technical and 

environmental analyses

Geology and groundwater resources

Robert Hoffman B.S., Environmental Resource 

Management; 29 years of experience 

in NEPA compliance, environmental 

impact assessment, alternatives

identification and development, and 

energy facility siting

Alternatives

Dennis Logan Ph.D., Marine Studies and Biological 

Oceanography; M.S., Biological 

Sciences, Marine Biology; B.S., 

Zoology; 40 years of experience in 

ecological studies, ecological risk 

assessment, environmental impact 

assessment, protected resource 

management, and project 

management

Threatened and endangered species

National Laboratory Personnel

Edward Schmitt—

PNNL (a)

B.S., Mechanical Engineering;

M.S., Nuclear Engineering

SAMA
List of Preparers

6-4 

Name Education/Experience Function or Expertise

Commercial Contractors (b)

J. Gillings—E&E M.S., Health Physics; 39 years of 

experience managing and performing 

environmental planning, review, and 

impact analysis projects

Task order manager

D. Kassel—E&E M.A., Biology; 28 years of 

experience in radiation protection and 

environmental impacts analysis and 

alternatives development and 

analysis

Alternatives

B. Wattle—E&E B.S., Atmospheric Science; 35 years 

of experience in the areas of 

meteorology, air quality, and noise 

for NEPA reviews and environmental 

permit acquisition for facility 

construction

Air quality and meteorology (climatology)

J. Moore—BLH Technical editing support to NRC

(a) Pacific Northwest National Laboratory (PNNL) is operated by Battelle for the U.S. Department of Energy. (b) Ecology and Environment, Inc. (E&E) is an environmental consulting, testing, engineering, and design firm with its 

headquarters offices in Lancaster, New York.
7-1 

7.0 LIST OF AGENCIES, ORGANIZATIONS, AND PERSONS TO WHOM 

COPIES OF THIS SEIS ARE SENT

Name Affiliation

R. Nelson Advisory Council on Historic Preservation

J. Greendeer Tribal Nation—Ho-Chunk Nation

D. Lankford Tribal Nation—Miami Tribe of Oklahoma

J. Froman Tribal Nation—Peoria Tribe of Indians in Oklahoma

T. Melius (FWS) U.S. Fish & Wildlife Service

L. Clemency (FWS) U.S. Fish & Wildlife Service

A. Haaker Illinois Historic Preservation Agency (State 

Historic Preservation Officer (SHPO) Office)

J. Barrett Tribal Nation—Citizen Potawatomi Nation

J. Bender Tribal Nation—Sac and Fox Tribe of the Mississippi 

in Iowa/Meskwaki

B. Robidoux Tribal Nation—Sac and Fox Nation of Missouri in Kansas 

and Nebraska

G. Thurman Tribal Nation—Sac and Fox Nation

J. Warren Tribal Nation—Pokagon Band of Potawatomi

H. Frank Tribal Nation—Forest County Potawatomi

K. Meshigaud Tribal Nation—Hannahville Indian Community, Band 

of Potawatomi

S. Ortiz Tribal Nation—Prairie Band of Potawatomi Nation

J. Blackhawk Tribal Nation—Winnebago Tribe of Nebraska

S. Cadue Tribal Nation—Kickapoo Tribe in Kansas

G. Salazar Tribal Nation—Kickapoo Tribe of Oklahoma

April 21, 2015, Public Meeting Participants

Michael Gallagher Exelon Generation Company

Mike Gorga Exelon Generation Company

John Grueling President & CEO of Will County Center for

Economic Development

Nathan Grider Illinois Department of Natural Resources

Angie Hutton President of the Braidwood Chamber

Rachel Leibowitz Illinois Historic Preservation

Lindsey Nelson U.S. Department of the Interior

Doug O’Brian Executive Director of the Illinois Clean Energy Coalition

Jay O’Connel Member of public

Greg Ridenour Representing Congressman Adam Kinzinger’s Office

David Schultz Member of public

David Tkac Representing Lawrence M. Walsh, County Executive for 

Will County

Robert Tovey Member of public

Peggy Warnick Exelon Generation Company
List of Agencies, Organizations, and Persons to Whom Copies of This SEIS Are Sent

7-2 

EIS Scoping Participant Affiliation

Bill Rulien Braidwood Mayor Office

Lawrence Walsh Will County Executive

Herbert Brooks, Jr. Will County Board

Seth Jansen U.S. Congressman Kinzinger Office

Rich Girof Braidwood Police Department

Mark Kanavos Exelon Generation Company

Mike Gallagher Exelon Generation Company

John Grueling Will County Center for Economic Development

Tom Wolf IL Chamber of Commerce

Don Moran Will County Board member, Union Sheet Metal Workers, and 

IL State Rifle Association

James King REED-Custer (CUSD255), Community Unit School 

District #255

Doug O’Brien IL Clean Energy Coalition

Irfan Khan Exelon

Dee deGroh Community Advisory Panel (CAP)

Angie Hutton Braidwood Chamber of Commerce

Chris Rosso Exelon Generation Company

Dave Kraft Nuclear Energy Information Service—Chicago

Sue Rezin Illinois State Senator, 38th District Office

Greg Ridenour U.S. Congressman Kinzinger Office

Denis Forrest Community—Exelon

Philip O’Connor Proactive Strategies, Inc.

Steve Quigley Will County Governmental League

Frank Antos CAP

Nancy Ammer Grundy Economic Development

Alan Keller Illinois Environmental Protection Agency

Tom Zimmer Braidwood resident

Shawn Cirton U.S. Fish & Wildlife Service

Anne Haaker SHPO Office

Kent Collier Kickapoo Tribe of Oklahoma

David A. Kraft Nuclear Energy Information Service
8-1 

8.0 INDEX

A 

accidents....xxiv, 3-112, 4-98, 4-99, 4-100, 

4-101, 4-104, 4-107, 4-119, 4-162, A-8, D-3, 

F-1, F-2, F-3, F-5, F-8, F-9, F-11, F-12, F-13, 

F-14, F-16, F-20, F-22, F-23, F-34, F-35, F-36, 

F-38, F-39, F-42, F-43, F-44, F-45

Advisory Council on Historic Preservation 

(ACHP)... 4-81, 4-82, 7-1, C-1, C-2, C-4 

aesthetic... 3-28, 3-113, 4-2, 4-86, 4-111, 4-112, 

4-117

alternatives . iii, xxiv, xxv, 1-5, 2-1, 2-3, 2-4, 2-5, 

2-7, 2-17, 2-20, 2-21, 2-24, 2-25, 4-1, 4-5, 4-17, 

4-19, 4-20, 4-21, 4-23, 4-24, 4-28, 4-29, 4-30, 

4-35, 4-37, 4-71, 4-81, 4-86, 4-92, 4-93, 4-99, 

4-100, 4-106, 4-107, 4-109, 4-111, 4-112, 4-120, 

4-121, 4-122, 4-124, 4-125, 4-127, 4-128, 4-156, 

4-157, 4-158, 5-1, 6-3, 6-4, A-1, A-3, A-4, A-5, 

A-6, A-8, A-9, A-32, A-78, A-92, A-93, A-111, 

A-112, A-123, A-133, A-134, D-3, F-24, F-25, 

F-45

archaeological resources... 1-6, 3-90, 3-92, 

3-133, 3-134, 3-137, 4-83, 4-84, 4-85, 4-86, 

4-147, B-6 

B 

biocide... 3-109, 4-25

biological assessment... 4-75, A-67, A-68

biota.... 3-8, 3-48, 3-50, 3-54, 3-55, 4-35, 4-47, 

4-49, 4-61, 4-62, 4-64, 4-65, 4-67, 4-68, 4-132, 

4-143, 4-144, 4-145, 4-146, A-14, A-89, A-91

burnup... 3-4 

C 

chronic effects... 2-24, 4-93, 4-94, 4-104, 4-105

Clean Air Act (CAA) .... 3-20, 3-125, 4-11, 4-12, 

4-15, 4-136, 4-153, 4-159, 4-161, 4-164, B-2 

closed-cycle cooling... 2-8, 2-13, 2-14, 2-15, 

3-4, 4-61, 4-69, 4-70

cold shock... 4-69

consumptive use.. 4-28, 4-29, 4-30, 4-141, 

4-142

cooling system....xxii, 1-3, 1-5, 2-10, 2-13, 

2-14, 2-15, 3-4, 3-5, 3-49, 3-54, 3-75, 3-80, 

3-81, 3-109, 3-110, 4-8, 4-19, 4-25, 4-31, 4-32, 

4-33, 4-37, 4-38, 4-39, 4-49, 4-57, 4-61, 4-63, 

4-64, 4-66, 4-67, 4-70, 4-96, A-76, A-89, A-92, 

F-8, F-21

core damage frequency (CDF)... 4-100, 4-101, 

4-102, F-1, F-2, F-4, F-5, F-6, F-7, F-8, F-9, 

F-10, F-11, F-12, F-19, F-20, F-23, F-25, F-26, 

F-27, F-31, F-32, F-35, F-36, F-38, F-39

Council on Environmental Quality (CEQ)

.... 1-3, 3-113, 3-124, 3-125, 4-39, 4-144, 4-162, 

A-78, A-92, A-93

critical habitat.... 3-80, 3-84, 3-85, 3-86, 4-72, 

4-76, 4-77, 4-79, 4-118, B-6, C-4 

cultural resources....xxiii, 2-5, 2-25, 3-88, 3-92, 

4-81, 4-82, 4-83, 4-84, 4-85, 4-86, 4-116, 4-117, 

4-123, 4-132, 4-147, 4-155, 6-2, 6-3, A-122, 

A-123, B-1 

D 

decommissioning .. 2-2, 2-3, 2-30, 4-1, 4-2, 

4-7, 4-33, 4-69, 4-79, 4-80, 4-83, 4-87, 4-88, 

4-90, 4-91, 4-92, 4-119, 4-122, 4-124, 4-125, 

4-127, 4-157, 4-171, A-9, A-32, A-122, E-7 

design-basis accident .. 4-1, 4-98, 4-107

discharges ... 2-8, 2-10, 2-13, 2-14, 2-15, 3-1, 

3-4, 3-5, 3-8, 3-9, 3-10, 3-11, 3-16, 3-22, 3-26, 

3-27, 3-28, 3-30, 3-31, 3-32, 3-34, 3-38, 3-52, 

3-54, 3-56, 3-64, 3-65, 3-67, 3-70, 3-76, 3-77, 

3-78, 3-79, 3-80, 3-88, 3-109, 3-110, 3-118, 

3-125, 3-129, 3-130, 3-132, 3-133, 4-7, 4-24, 

4-25, 4-27, 4-28, 4-33, 4-37, 4-49, 4-52, 4-56, 

4-61, 4-64, 4-65, 4-66, 4-67, 4-68, 4-69, 4-70, 

4-73, 4-75, 4-95, 4-96, 4-97, 4-103, 4-124, 

4-136, 4-138, 4-139, 4-146, 4-161, 4-166, 4-167, 

4-168, 6-2, A-11, A-12, A-13, A-68, A-73, A-75, 

A-76, A-77, A-89, A-91, A-104, A-106, A-111, 

A-120, B-2, B-3, B-7, C-6, C-7, D-5, E-3, E-5, 

F-29, F-33, F-37
Index

8-2 

dose.... 3-4, 3-10, 3-11, 3-12, 3-13, 3-15, 3-107, 

3-108, 3-109, 3-118, 3-127, 4-101, 4-102, 4-105, 

4-107, 4-109, 4-113, 4-122, 4-124, 4-149, 4-151, 

4-157, 4-173, A-10, A-14, F-3, F-4, F-17, F-18, 

F-19, F-20, F-25, F-27, F-30, F-34, F-35, F-39

dredging... 2-10, 3-9, 3-32, 3-81, 3-84, 3-126, 

3-132, 3-138, 4-24, 4-25, 4-35, 4-37, 4-69, 4-70,

4-73, B-6, D-4 

E 

education ... 3-100, 3-133, 3-135, 4-87, 4-174, 

6-2, A-25

electromagnetic fields ... 2-24, 4-31, 4-93, 

4-94, 4-104, 4-105, 4-106

endangered and threatened species...xxiii, 

1-6, 3-49, 3-65, 3-84, 3-85, 3-86, 3-87, 4-47, 

4-65, 4-76, 4-77, 4-170, 6-3, A-67, A-72, A-73, 

A-106, A-135, B-1, B-6, C-5 

Endangered Species Act (ESA) .... xxiv, 1-6, 

1-7, 3-42, 3-79, 3-80, 3-86, 3-119, 3-125, 4-71, 

4-72, 4-75, 4-77, 4-79, 4-80, 4-81, 4-118, 4-132, 

4-159, 4-165, 4-168, A-66, A-67, A-72, B-6, C-4, 

C-5, C-6, C-7 

entrainment... xxiii, xxiv, 3-54, 3-77, 3-81, 

3-125, 4-37, 4-38, 4-39, 4-42, 4-46, 4-47, 4-49, 

4-54, 4-55, 4-56, 4-57, 4-58, 4-60, 4-61, 4-62, 

4-63, 4-68, 4-69, 4-70, 4-71, 4-73, 4-74, 4-145, 

4-163, 4-168, 4-170, A-66, A-67, A-75, A-104, 

A-105, A-106, A-111, A-119, A-120, A-121

environmental justice (EJ) ...2-5, 3-113, 4-107, 

4-108, 4-109, 4-118, 4-123, 4-150, 6-2 

essential fish habitat (EFH)... 4-72, 4-79, 

4-118, 6-2 

eutrophication ... 3-81, 4-37, 4-132

G 

Generic Environmental Impact Statement 

(GEIS).... iii, xxi, xxii, xxv, 1-3, 1-4, 1-5, 1-8, 2-1, 

2-2, 2-3, 2-4, 2-18, 2-20, 2-30, 2-31, 3-80, 3-81, 

3-95, 3-111, 3-125, 3-136, 4-1, 4-2, 4-6, 4-11, 

4-14, 4-18, 4-22, 4-25, 4-26, 4-31, 4-32, 4-33, 

4-35, 4-37, 4-38, 4-63, 4-64, 4-68, 4-69, 4-70, 

4-72, 4-83, 4-86, 4-87, 4-93, 4-94, 4-95, 4-98, 

4-99, 4-112, 4-113, 4-114, 4-115, 4-119, 4-121, 

4-122, 4-123, 4-124, 4-125, 4-127, 4-160, 4-161, 

4-167, 4-171, 4-172, 4-173, 5-2, A-9, A-15, 

A-19, A-76, A-89, A-90, A-111, A-122, A-134, 

D-4, F-44

greenhouse gases ... 2-7, 2-13, 2-26, 2-28, 

3-21, 3-120, 3-125, 4-7, 4-8, 4-9, 4-10, 4-11, 

4-12, 4-13, 4-14, 4-15, 4-17, 4-21, 4-35, 4-122, 

4-125, 4-126, 4-127, 4-128, 4-129, 4-143, 4-146, 

4-152, 4-153, 4-154, 4-156, 4-159, 4-160, 4-164, 

4-173, A-3, A-5, A-19, A-78, A-92, A-93, A-115, 

A-134

groundwater... xxiii, 2-25, 3-14, 3-16, 3-28, 

3-32, 3-34, 3-35, 3-38, 3-40, 3-41, 3-101, 3-109, 

3-124, 4-23, 4-24, 4-26, 4-27, 4-28, 4-29, 4-30, 

4-99, 4-108, 4-123, 4-131, 4-138, 4-139, 4-140, 

4-142, 4-146, 4-155, 4-170, 4-174, 4-175, 6-3, 

A-10, A-13, A-19, B-1, E-3 

H 

hazardous waste.... 3-15, 4-157, B-4 

high-level waste ..xxii, 1-4, 2-24, 4-112, 4-113, 

4-114, 4-115, 4-119, 4-122

I 

Illinois Department of Commerce and 

Economic Opportunity (DCEO) ... 3-96, 3-125, 

F-17, F-42

Illinois Department of Natural Resources 

(IDNR).... 3-1, 3-5, 3-18, 3-25, 3-27, 3-41, 3-42, 

3-43, 3-46, 3-48, 3-49, 3-50, 3-51, 3-54, 3-57, 

3-66, 3-70, 3-75, 3-76, 3-77, 3-79, 3-86, 3-87, 

3-101, 3-121, 3-129, 3-130, 3-131, 3-137, 4-2, 

4-26, 4-31, 4-33, 4-46, 4-52, 4-58, 4-61, 4-62, 

4-63, 4-64, 4-66, 4-67, 4-68, 4-69, 4-97, 4-143, 

4-145, 4-146, 4-161, 4-168, 4-169, 4-173, 4-174, 

7-1, A-17, A-42, A-73, A-74, A-77, A-88, A-89, 

A-90, A-91, A-105, A-115, E-4, E-5, E-6 

Illinois Department of Public Health (IDPH)

.... 3-110, 3-111, 3-132, 4-95, 4-97

Illinois Department of Transportation (IDOT)

.... 3-8, 3-23, 3-27, 3-107, 3-131, 3-132, 4-26, 

4-61, 4-139, 4-169, A-77
Index

8-3 

Illinois Endangered Species Protection 

Board (IESPB).... 3-131, 4-47, 4-170, A-106

Illinois Environmental Protection Agency 

(IEPA)... 3-5, 3-8, 3-9, 3-13, 3-20, 3-27, 3-28,

3-30, 3-31, 3-38, 3-50, 3-124, 3-127, 3-132, 

3-133, 3-136, 4-8, 4-46, 4-58, 4-61, 4-62, 4-63, 

4-64, 4-65, 4-75, 4-95, 4-97, 4-134, 4-135, 

4-136, 4-139, 4-140, 4-162, 4-169, 7-2, A-2, 

A-11, A-12, A-68, A-77, A-80, A-105, A-106, 

B-2, B-3, B-4, B-5, B-7, E-3, E-5, E-6 

Illinois Historic Preservation Agency (IHPA)

....3-88, 3-92, 3-133, 3-137, 4-82, 4-83, 4-172, 

7-1, A-17, C-2, C-4 

Illinois State Geological Survey 

(ISGS) .... 3-35, 3-133

impingement...xxiii, xxiv, 3-54, 3-77, 3-78, 

3-81, 3-125, 4-37, 4-38, 4-39, 4-40, 4-42, 4-43, 

4-45, 4-46, 4-47, 4-48, 4-49, 4-56, 4-57, 4-58, 

4-60, 4-61, 4-62, 4-63, 4-68, 4-69, 4-70, 4-71, 

4-73, 4-74, 4-145, 4-163, A-66, A-67, A-75, 

A-104, A-105, A-106, A-111, A-119, A-120, 

A-121

independent spent fuel storage installation 

(ISFSI).... 3-14, 3-18, 4-116, 4-117, 4-118, 4-149

Indian tribes.... 3-91, 3-113, 3-133, 4-107, 

4-108, A-133, B-6 

invasive species... 3-44, 3-84, 4-132, A-74, 

A-75, A-121

L 

long-term dose .... F-15

low-level waste .... 4-112, 4-119

M 

Magnuson-Stevens Fishery Conservation 

and Management Act (MSA).... 1-6, 1-7, 3-79, 

3-134, 4-79, 4-118, 4-170

Marine Mammal Protection Act (MMPA)

....3-79, 3-134

mitigation ...xxii, 1-3, 1-4, 1-5, 4-17, 4-63, 4-68, 

4-69, 4-71, 4-77, 4-79, 4-84, 4-85, 4-86, 4-117, 

4-156, 4-174, 5-1, A-9, A-78, A-80, A-105, 

A-106, D-3, F-15, F-20, F-21, F-28, F-38, F-39, 

F-43, F-45

mixed waste.... 3-10, 3-13, 3-118, 4-112

N 

National Environmental Policy Act (NEPA)

....xxii, 1-1, 1-7, 2-1, 2-30, 3-79, 3-81, 3-112, 

3-113, 3-124, 3-125, 3-135, 4-5, 4-22, 4-39, 

4-72, 4-82, 4-86, 4-87, 4-113, 4-115, 4-116, 

4-118, 4-119, 4-145, 4-162, 4-163, 4-170, 5-1, 

6-2, 6-3, 6-4, A-9, A-13, A-76, A-78, A-79, A-88, 

A-92, A-112, C-1, C-4, C-7, F-10

National Historic Preservation Act (NHPA)

....xxiv, 1-6, 1-7, 4-81, 4-82, 4-116, 4-117, 

4-171, A-102, B-6, C-1, C-4, C-7 

National Marine Fisheries Service (NMFS)

.... 3-80, 3-119, 4-72, 4-73, 4-77, 4-79, 4-168, 

C-4, C-5, C-7 

National Pollutant Discharge Elimination 

System (NPDES) ...3-5, 3-8, 3-9, 3-16, 3-26, 

3-28, 3-30, 3-31, 3-109, 3-118, 3-120, 3-124, 

3-132, 3-133, 4-24, 4-32, 4-46, 4-47, 4-48, 4-61, 

4-62, 4-63, 4-64, 4-65, 4-66, 4-69, 4-75, 4-95, 

4-96, 4-97, 4-139, 4-159, 4-160, 4-162, 4-169, 

A-12, A-13, A-68, A-75, A-76, A-77, A-105, 

A-106, B-1, B-2, D-4, E-3, E-6 

Native American tribes.... 1-6, 3-91, 3-133, 

4-82, 4-107, 4-108, 4-173, 7-1, 7-2, A-3, A-133, 

B-6, C-2, C-3, C-4, D-2 

no-action alternative... xxv, 2-1, 2-3, 2-24, 

2-25, 4-2, 4-21, 4-34, 4-39, 4-69, 4-79, 4-119, 

4-127, 4-157, 5-1, A-8, A-9, A-123, A-134

nonattainment .. 3-20, 3-125, 4-6, 4-7, 4-10, 

4-11, 4-14, 4-134, 4-135, 4-164, 4-165, A-5, A-6 

O 

once-through cooling... 4-8, 4-31, 4-37, 4-38, 

4-61, 4-63, 4-64, A-89

P 

postulated accidents .. 3-4, 4-1, 4-98, 4-99, 

4-107

power uprate .. F-16, F-42

pressurized water reactor.... 2-1, 2-2, 3-1, 3-4, 

3-108, A-9, F-13, F-21
Index

8-4 

R 

radon ... 3-10, 3-14

reactor...iii, xxi, 1-1, 2-1, 2-2, 2-3, 2-4, 2-10, 

2-11, 2-14, 2-20, 2-27, 2-30, 2-31, 3-1, 3-4, 3-8, 

3-9, 3-12, 3-14, 3-15, 3-16, 3-17, 3-18, 3-22, 

3-38, 3-88, 3-108, 3-112, 3-119, 3-133, 3-136, 

4-7, 4-68, 4-78, 4-82, 4-83, 4-86, 4-87, 4-98, 

4-99, 4-102, 4-104, 4-109, 4-112, 4-113, 4-114, 

4-115, 4-116, 4-117, 4-118, 4-119, 4-124, 4-135, 

4-137, 4-142, 4-143, 4-145, 4-147, 4-148, 4-149, 

4-151, 4-158, 4-159, 4-160, 4-171, 4-173, 6-1, 

6-2, A-7, A-9, A-11, A-79, A-80, A-111, E-2, E-5, 

E-6, E-7, F-5, F-7, F-8, F-13, F-16, F-21, F-24, 

F-30, F-32, F-33, F-36, F-41, F-44

refurbishment.... 2-2, 3-15, 3-80, 3-88, 4-6, 

4-32, 4-86, 4-135, 4-137, 4-138, 4-149, 4-150, 

4-156, A-9, A-79, A-80, B-2, B-3, F-35

replacement power ... xxv, 2-3, 2-4, 2-5, 2-6, 

2-7, 2-17, 4-92, 4-102, 4-109, 4-111, 4-121, 

4-122, 4-124, A-112, A-134, F-32, F-36

S 

scoping....iii, xxi, xxii, xxvi, 1-1, 1-2, 1-5, 1-6, 

1-8, 3-81, 4-1, 4-6, 4-22, 4-25, 4-26, 4-31, 4-38, 

4-72, 4-82, 4-87, 4-94, 4-98, 4-99, 4-113, 4-122, 

4-124, 4-134, 4-173, 5-2, 7-2, A-1, A-2, A-3, A-8, 

A-10, A-13, A-14, A-32, C-2, C-5, D-2, D-3 

seismic .. 3-23, 3-25, 3-134, 3-139, 4-100, F-1, 

F-4, F-8, F-9, F-12, F-24, F-38, F-42, F-44

severe accident mitigation alternative 

(SAMA) ....xxiv, 4-99, 4-100, 4-102, 4-103, 

4-104, 4-167, 6-1, 6-3, D-3, F-1, F-2, F-3, F-4, 

F-6, F-7, F-8, F-9, F-10, F-11, F-12, F-13, F-15, 

F-16, F-17, F-18, F-19, F-20, F-21, F-22, F-23, 

F-24, F-25, F-26, F-27, F-31, F-32, F-33, F-34, 

F-36, F-37, F-38, F-39, F-40, F-41, F-43, F-45

severe accidents .. xxiv, 4-1, 4-98, 4-99, 4-107, 

4-167, 6-1, F-1, F-8, F-19, F-34, F-35, F-36, 

F-43, F-45

solid waste.. xxv, 2-23, 3-10, 3-13, 3-14, 3-15, 

3-108, 3-118, 4-13, 4-117, 4-120, 4-123, B-1 

spent fuel ...xxii, 1-4, 2-24, 3-14, 3-108, 4-113, 

4-114, 4-115, 4-116, 4-117, 4-118, 4-119, 4-122, 

4-123, E-2, F-33

State Historic Preservation Officer (SHPO)

....1-6, 3-92, 4-82, 4-83, 7-1, 7-2, A-3, B-6 

State Pollutant Discharge Elimination 

System (SPDES)... B-1 

stormwater... 3-26, 3-28, 3-30, 3-118, 4-23, 

4-24, 4-31, 4-32, 4-69, 4-139, 4-146, A-12, A-75, 

A-76, B-2 

surface runoff... 3-26, 3-30, 3-84, 4-23, 4-32, 

4-33, 4-129, 4-131, 4-139, 4-146

surface water....xxiii, 3-25, 3-27, 3-32, 3-49, 

3-56, 3-101, 3-109, 4-23, 4-24, 4-25, 4-26, 4-28, 

4-29, 4-30, 4-96, 4-108, 4-123, 4-131, 4-138, 

4-139, 4-140, 4-142, 4-155, 6-3, A-76, A-77, 

A-119, B-1 

T 

taxes... 3-102, 3-103, 3-104, 3-105, 3-106, 4-86, 

4-87, 4-88, 4-89, 4-90, 4-91, 4-92, 4-109, 4-117, 

4-148, 4-157, A-4, A-8, A-9, A-19, A-25, A-39, 

A-54, A-59, A-115

transmission line corridors .. 4-5, 4-34, 4-35

transmission lines ... 2-5, 2-8, 2-13, 2-14, 2-15, 

2-17, 3-1, 3-16, 3-22, 3-80, 3-81, 3-86, 3-88, 

3-111, 3-112, 4-2, 4-4, 4-5, 4-6, 4-21, 4-31, 

4-34, 4-35, 4-36, 4-37, 4-69, 4-72, 4-82, 4-84, 

4-85, 4-86, 4-95, 4-136, 4-144, A-122, A-123

tritium.... 3-38, 3-40, 3-41, 3-124, 4-27, 4-28, 

A-10, A-11, A-13, A-14

U 

U.S. Department of Energy (DOE).... 2-4, 2-9, 

2-11, 2-12, 2-13, 2-15, 2-16, 2-17, 2-18, 2-19, 

2-20, 2-21, 2-26, 2-27, 2-28, 2-29, 2-30, 2-32, 

3-14, 3-136, 4-10, 4-89, 4-90, 4-92, 4-94, 4-127, 

4-162, 4-163, 4-170, 4-171, 4-173, 4-175, 6-4 

U.S. Environmental Protection Agency (EPA)

....xxii, 1-1, 2-1, 2-4, 2-12, 2-22, 2-23, 2-24, 

2-26, 2-28, 2-29, 3-8, 3-10, 3-11, 3-12, 3-13, 

3-15, 3-20, 3-21, 3-23, 3-27, 3-28, 3-38, 3-41, 

3-43, 3-79, 3-101, 3-108, 3-118, 3-120, 3-121, 

3-125, 3-132, 3-133, 3-136, 3-140, 4-5, 4-7, 4-8, 

4-10, 4-12, 4-13, 4-14, 4-15, 4-16, 4-27, 4-28, 

4-39, 4-46, 4-61, 4-62, 4-63, 4-65, 4-69, 4-97, 

4-105, 4-106, 4-113, 4-115, 4-126, 4-128, 4-129, 

4-130, 4-134, 4-136, 4-145, 4-149, 4-150, 4-151, 

4-152, 4-153, 4-156, 4-159, 4-160, 4-163, 4-164, 

4-165, 4-169, A-5, A-6, A-9, A-11, A-12, A-15, 

A-18, A-32, A-46, A-72, A-73, A-74, A-75, A-76, 

A-78, A-79, A-80, A-112, B-1, B-2, B-3, B-4, B-5, 

C-1, D-4, E-3, E-4, E-5, E-6, F-17, F-43
Index

8-5 

U.S. Fish and Wildlife Service (FWS) ... 1-6, 

1-7, 2-9, 2-15, 2-32, 3-22, 3-42, 3-48, 3-80, 

3-81, 3-82, 3-83, 3-84, 3-85, 3-86, 3-87, 3-88, 

3-119, 3-120, 3-129, 3-130, 3-136, 4-71, 4-72, 

4-73, 4-74, 4-75, 4-76, 4-77, 4-78, 4-79, 4-160, 

4-161, 4-167, 4-168, 4-173, 4-175, 7-1, A-3, 

A-66, A-67, A-68, A-72, A-73, A-74, B-6, C-4, 

C-5, C-6, C-7, D-2 

universal waste ... 3-15

uranium ... 2-9, 3-4, 3-108, 4-1, 4-105, 4-117, 

4-122, 4-123, 4-125, A-112

W 

wastewater.... 3-30, 3-38, 4-26, 4-28, 4-138, 

4-139, 4-144, 4-146, 6-2, A-12, A-88, A-89, B-2, 

E-3, E-5 

Y 

Yucca Mountain .. 4-115

APPENDIX A 

COMMENTS RECEIVED ON THE BRAIDWOOD STATION 

ENVIRONMENTAL REVIEW

A-1 

A.COMMENTS RECEIVED ON THE BRAIDWOOD STATION 

ENVIRONMENTAL REVIEW

A.1 Comments Received During the Scoping Period

The scoping process began on July 31, 2013, with the publication of the U.S. Nuclear 

Regulatory Commission (NRC) notice of intent to conduct scoping in the Federal Register

(78 FR 46379). The scoping process included two public meetings held at the Fossil Ridge 

library in Will County, Illinois, on August 21, 2013. Approximately 60 members of the public 

attended the meetings. After the NRC staff prepared statements related to the license renewal 

process, the meetings were open for public comments. Attendees provided oral statements that 

were recorded and transcribed by a certified court reporter. Any written statements submitted at 

the public meeting are documented in the transcript of the meetings. Transcripts of the 

two meetings are attachments to the scoping meeting summary, dated September 28, 2013 

(Agencywide Documents Access and Management System (ADAMS) No. ML13248A191). In 

addition to the comments received during the public meetings, comments were also received 

electronically and through the mail.

Each commenter was given a unique identifier so that every comment could be traced back to 

its author. Table A–1 identifies the individuals who provided comments and the Commenter ID 

associated with each person’s set of comments. 

Specific comments were categorized and consolidated by topic. Comments with similar specific 

objectives were combined to capture the common essential issues raised by participants. 

Comments fall into one of the following general groups:

• Specific comments that address environmental issues within the purview of 

the NRC environmental regulations related to license renewal (Category 1 

and Category 2 issues, or not addressed in NUREG-1437). The comments 

also address alternatives to license renewal and related Federal actions.

• General comments (expression) in support of or opposed to nuclear power or 

license renewal, or comments regarding the renewal process, the NRC’s 

regulations, and the regulatory process.

• Comments that address issues that do not fall within or are specifically 

excluded from the purview of NRC environmental regulations related to 

license renewal. These comments typically address issues such as the need 

for power, emergency preparedness, security, current operational safety 

issues, and safety issues related to operation during the renewal period.

The comments that are general or outside the scope of the environmental review for Braidwood 

Station (Braidwood) license renewal are not included here but can be found in the scoping

summary report (ADAMS No. ML13281A537). To maintain consistency with the scoping 

summary report, the unique identifier used in that report for each set of comments is retained in 

this Appendix A.
Appendix A

A-2 

Table A–1. Individuals Providing Comments During the Scoping Comment Period

Commenter Commenter 

ID Affiliation (if stated) ADAMS No.

Bill Rulien Braidwood 1 Braidwood Mayor Office ML13248A191

Lawrence Walsh Braidwood 2 Will County Executive ML13248A191, 

ML13247A009

Herbert Brooks, 

Jr. Braidwood 3 Will County Board ML13248A191

Seth Jansen Braidwood 4 U.S. Congressman Kinzinger Office ML13248A191

Rich Girof Braidwood 5 Braidwood Police Department ML13248A191

Mark Kanavos Braidwood 6 Exelon ML13248A191

Mike Gallagher Braidwood 7 Exelon ML13248A191

John Grueling* Braidwood 8 Will County Center for Economic Development ML13248A191

Tom Wolf Braidwood 9 IL Chamber of Commerce ML13248A191

Don Moran* Braidwood 10 Will County Board member, Union Sheet Metal 

Workers, and IL State Rifle Association ML13248A191

James King Braidwood 11 REED-Custer (CUSD) ML13248A191

Doug Obrien Braidwood 12 IL Clean Energy Coalition (ICEC) ML13248A191

Irfan Khan Braidwood 13 Exelon ML13248A191

Dee deGroh Braidwood 14 Community Advisory Panel (CAP) ML13248A191

Angie Hutton Braidwood 15 Braidwood Chamber of Commerce ML13248A191

Chris Rosso Braidwood 16 Exelon ML13248A191

Dave Kraft* Braidwood 17 Nuclear Energy Information Service—Chicago ML13248A191

Sue Rezin Braidwood 18 State Senator, 38th District Office ML13248A191, 

ML13248A271

Greg Ridenour Braidwood 19 U.S. Congressman Kinzinger Office ML13248A191

Denis Forrest Braidwood 20 Community - Exelon ML13248A191

Philip O’Connor Braidwood 21 Proactive Strategies, Inc. ML13248A191

Steve Quigley Braidwood 22 Will County Governmental League ML13248A191

Frank Antos Braidwood 23 CAP ML13248A191

Nancy Ammer* Braidwood 24 Grundy Economic Development ML13248A191

Alan Keller Braidwood 25 Illinois Environmental Protection Agency

(May 22, 2013, prior to the scoping period) ML13207A105

Tom Zimmer Braidwood 26 Braidwood resident ML13263A219
Appendix A

A-3 

Commenter Commenter 

ID Affiliation (if stated) ADAMS No.

Shawn Cirton Braidwood 27 U.S. Fish and Wildlife Service ML13269A373

Anne Haaker Braidwood 28 Office of the State Historic Preservation Officer ML13269A369

Kent Collier Braidwood 29 Kickapoo Tribe of Oklahoma ML13274A239

David A. Kraft Braidwood 30 Nuclear Energy Information Service ML13277A305

* Scoping participant who provided mailing address or e-mail address and requested to be on the NRC 

distribution list.

Applicable scoping comments are grouped in the following categories and presented in the 

following order:

• Alternatives to License Renewal of Braidwood,

• Socioeconomic Impact of Braidwood,

• Water Usage or Hydrology,

• Human Health,

• Terrestrial or Aquatic Ecology, and

• Climate Change.

A.1.1 Alternatives to License Renewal of Braidwood, Units 1 and 2

The comments in this category are in Section 5 of the scoping summary report and labeled with 

the following identifiers: 1-1, 4-2, 7-1, 9-1, 10-2, 11-2, 12-1, 19-2, 1-3, 7-2, 10-4, 12-3, 21-1, and 

30-3. The comments listed below are extracted from the original sources in Section 5 of the 

scoping summary report.

Comment 1-1: I was about ten years old, I used to get my dad’s newspaper and read it. And I 

started to learn about the first commercial nuclear power plant in the whole country that started 

producing power. And it was just an amazing thing to me with no fuel and no pollution. And 

that plant was started by Commonwealth Edison. That’s our little Dresden plant over there. 

They were on the cutting edge of this technology.

Now, when I was about 20, I built my first solar collector. And I also decided to build and 

experimented with some wind generators. Didn’t take me too long to figure out when the wind 

don’t blow, it would make great supplemental power, but could never be reliable as a source 

of power.

In the 43 years since then, almost nothing has changed. If you want reliable, safe, massed 

produced pollution free power, you’re going to get it from a nuclear power plant. So, as far as 

we can see in the future, that’s what our future holds for us.

Comment 4-2: While many areas of Illinois struggle to meet clean air standards, the generating 

station at Braidwood offers affordable, abundant energy with a fraction of the greenhouse gas 

emissions as other conventional energy sources.

Comment 7-1: We also took a look at the environmental aspects and impacts of continuing to 

operate Braidwood. We looked at all aspects of continuing impacts of the plant on the 
Appendix A

A-4 

environment. And our conclusion is that the impacts on the environment are small. And I use 

the term small in the sense of the regulation. The regulations define small as the environmental 

effects are not detectible or are minor.

We also reviewed the alternatives if Braidwood would not have its license renewed and another 

source of electric generation would have to be installed either here on site or someplace else to 

generate that replacement electricity. We concluded that any other means of generating the 

replacement electricity would have more have an impact on the environment than the continued 

operation of Braidwood.

Comment 9-1: To maintain an abundant and diverse electricity supply and to be able to provide 

that supply at competitive rates, Illinois relies heavily on its fleet of nuclear generation stations.

Illinois has more nuclear power generation than any state in the country. Nearly 45 percent of 

Illinois’ electricity is produced from nuclear power and 90 percent of Illinois’ carbon-free 

electricity is produced from nuclear power. If you want to impress your friends at a cocktail 

party, test that trivia on the number one state for nuclear. They very rarely guess Illinois.

Whether or not you agree with President Obama’s recent push on making America a leader in 

reducing carbon emissions, every kind of energy generation is looking to improve its cost, 

efficiency, reliability, and yes, its carbon footprint. While coal and gas remain viable, an 

important source of electricity and our renewable sector continues to grow, Illinois’ nuclear 

industry combines capacity, reliability, and efficiency without carbon emissions.

At the same time, nuclear generation employs thousands of Illinoisians and [in]jects billions of 

dollars into our state’s economy every year. In today’s political world, it’s hard to get any kind of 

serious energy policy going and it’s hard to predict how new technologies will affect future 

electricity generation opportunities, but it doesn’t take a nuclear physicist, and I’m not a nuclear 

physicist, but it doesn’t take one to figure out that a diverse reliable supply of electricity will 

create cost competitive power that our economy and our businesses need to thrive.

So, in that light, because Braidwood has been a key part of Illinois’ nuclear fleet, which has in 

turn been a critical part of Illinois’ electricity infrastructure, because Exelon has shown itself to 

be an excellent, responsible owner and operator of the Braidwood generation facility and its 

other nuclear plants in Illinois and across the country, and because Braidwood is such a benefit 

for the community in terms of employment, tax revenue, direct and indirect spending and 

community involvement, for all those reasons and more, the Illinois Chamber of Commerce 

strongly supports this application and hopes you see fit to grant Exelon the license renewal.

Comment 10-2: As Illinois struggles in today’s competitive business market, we cannot afford to 

ignore any of the things that help us put us on better footing. One of the building blocks to 

economic development is affordable and reliable electricity. The Illinois’s diverse network of

electricity generation coming from coal, wind, and nuclear gives us an advantage in enticing 

new and retaining existing businesses to the area.

Unlike the rolling blackouts experienced in California during 2000 and 2001, our local electrical 

generation and transmission systems have provided consistent reliable electricity and have 

done so with diminishing cost to consumers as compared to the CPI.

I remember cooling my first home, a tiny 900 square foot house with summer monthly electric 

bills of over $200 in the mid-80s. Today, I live in a modest town home about three times that 

large and pay about $150 in summer months to cool it. Quite the bargain compared to nearly 

30 years ago, especially when considered next to the cost associated with fueling your car or 

paying for health care.
Appendix A

A-5 

Comment 11-2: And I also would like to say on a personal note that the reason I mentioned that 

I grew up and was born eight miles from here is because I used to play on the spoils for the coal 

mining that was done there. It’s probably illegally but back then nobody said anything about it. 

We played in those lakes, we played on those spoils. And when I go back there to this day and 

visit my relatives, and I see all of the red lights flashing from all of the windmills, it kind of makes 

me sick to my stomach to see what has happened to some of the environmental, you talk about 

environmental impact, that to me, when you drive south of DeWitt and you see all of those 

windmills, and then you realize that the generation from those windmills is slight in comparison 

to the small footprint of this plant.

Comment 12-1: And the benefits derived from Braidwood and the other nuclear plants in Illinois 

are not limited to the economy. It’s an enormous benefit that the generation of 

18 million megawatts of electricity at Braidwood last year produced no carbon air admissions.

Earlier this year, NASA’s Goddard Institute sought to quantify the real impact of nuclear power’s 

carbon emissions free operations. The Goddard study found that replacing nuclear power with 

fossil fuel generation would lead to an estimated 76,000 deaths per year globally, primarily as a 

result of increased cardio and pulmonary disease.

And this is even more important here in Illinois. The Chicago metropolitan area is designated a 

non-attainment area by the EPA due to air pollution. And this situation would be greatly 

acerbated without the existence of the Braidwood generating station which produces enough 

electricity to power two million homes without adding to this environmental problem.

And I think it’s also important to note we’re talking a great deal about two parts of our 

environment. We’re talking about ecosystem and the impacts that we traditionally think of as 

environmental. We talk about emissions and we talk about impacts on the air and the water.

Comment 19-2: While many areas of Illinois struggle to meet clean air standards, the 

generating station at Braidwood offers affordable, abundant energy with a fraction of the 

greenhouse gas emissions as other conventional energy sources. As Americans’ and 

Illinoisans’ demand for energy rises, nuclear generating stations like Braidwood will be vital to 

meeting the energy needs of our citizens.

Comment 1-3: When I was about 10 years old I used to read my dad’s newspaper, and the first 

commercial nuclear power plant in about 1960 came online, and it was an amazing thing to me. 

It produced power with almost no fuel, no pollution. Commonwealth Edison, the parent 

company of Exelon, was the cutting edge of technology, the company that brought that to us.

When I was about 20, I built a solar collector, and I also experimented with a wind generator. It 

didn’t take too long to realize when the breeze quit that it was great supplemental power but it 

wasn’t something you could really rely on as a source of power. In the 43 years since then, 

there hasn’t been anything much that’s changed. If you want reliable, mass produced pollution 

free electric power, nuclear power is the proven technology and the way to go for now, and as 

far as we can see into the future.

Comment 7-2: We’ve also reviewed the alternatives if Braidwood would not have its license 

renewed and another source of electric generation would have to be installed, either here on 

site or someplace else to generate the replacement electricity organization studying the impacts 

of climate change, sought to quantify the impact of nuclear power’s carbon free emissions. 

Goddard’s study found that replacing nuclear power with [fossil] fuel generation, would lead to 

approximately 76,000 deaths globally every year, primarily as a result of increased cardio and 

pulmonary disease.
Appendix A

A-6 

This is even more important here in Illinois, as we all know the Chicago metropolitan area is 

designated as a non-attainment area by the EPA due to air pollution, and this situation would be 

greatly exacerbated without the existence of the Braidwood Generating Station, which produces 

energy to power up to two million homes, without adding to our existing environmental 

problems.

We concluded that any other means of generating the replacement electricity would have more 

an impact to the environment than the continued operation of Braidwood.

Comment 10-4: As Illinois struggles in today’s competitive business market, we cannot afford to 

ignore any of the things that helped put us on a better footing. One of the building blocks to 

economic development is affordable and reliable electricity. Illinois’ diverse network of 

electricity generation coming from coal, wind and nuclear gives us an advantage in enticing new 

and retaining existing businesses to the area.

Unlike the rolling blackouts experienced in California during 2000 and 2001, our local electric 

generation and transmission systems have provided consistent, reliable electricity and have 

done so with a diminishing cost to consumers, as compared to the CPI.

I remember cooling my first home, a tiny, 900 square foot house, with summer monthly electric 

bills of over $200 in the mid 80's. Today I live in a modest town home about three times that 

large and I pay about $150 in the summer months to cool it, quite the bargain compared to 

nearly 30 years ago, especially if considered next to the costs associated with fuel in your car or 

paying for healthcare.

Comment 12-3: And the benefits derived at Braidwood and other nuclear plants are not limited 

to the economy. It’s an enormous benefit that the generation of 18 million megawatts of 

electricity at Braidwood last year produced no carbon air emissions. And that’s an objective, 

that’s a goal we all want to strive to in our country.

Earlier this year NASA’s Goddard Institute, which is a leading research organization studying 

the impacts of climate change, sought to quantify the impact of nuclear power’s carbon free 

emissions. Goddard’s study found that replacing nuclear power with foss[i]l fuel generation, 

would lead to approximately 76,000 deaths globally every year, primarily as a result of 

increased cardio and pulmonary disease.

This is even more important here in Illinois, as we all know the Chicago metropolitan area is 

designated as a non-attainment area by the EPA due to air pollution, and this situation would be 

greatly exacerbated without the existence of the Braidwood Generating Station, which produces 

energy to power up to two million homes, without adding to our existing environmental 

problems.

Comment 21-1: Second, in an era in which there’s been both great uncertainty about the 

economics as well as the environmental aspects of fossil fuels, these two stations have had the 

advantage of a low cost, non-fossil fuel supply and all of the intended consequences of that.

Comment 30-3: 

Incomplete and faulty analysis in Section 7.0 - Alternatives to the Proposed Action

In reviewing the scenarios Exelon examined to come up with its evaluations concerning the 

viability of options replacing the power output of Braidwood, we find that Exelon uses 

information that is perhaps not current, and leaves out significant other real world options for 

consideration and analysis:

• Role of renewables too narrow, inaccurate, inappropriate: Exelon tends to 

treat the renewable energy resources as if they are just some variant of 
Appendix A

A-7 

traditional fossil and nuclear plants. They are not. As a result they analyze 

these renewables solely in ways amenable to their own narrow view of 

functioning, which is not necessarily the best or optimal use of the particular 

renewable energy resource. For example only centralized energy station use 

of both wind and solar are considered, with no consideration of “distributed 

generation” in any meaningful way. Pairing up one renewable with natural 

gas is the only permutation analyzed, when pairing up of solar with wind to 

compliment the strengths of both is ignored. Further, it is not clear the 

degree to which the operational efficiencies of these renewables either in the 

present or the future is accurately analyzed.

Improvements in technology, higher wind towers, increased solar panel 

efficiencies, etc. are all very real prospects even before the 2024/26 license 

expirations of the two Braidwood nuclear reactors. We believe that this 

section needs a serious revision, perhaps from an outside independent 

consultant to more accurately reflect both the real, and the realistically 

anticipated world of renewable energy contributions.

• Anachronistic business model used exclusively: The Exelon ER examines 

the contributions of all competitors to the Braidwood nuclear plant - not just 

the renewables - on the assumption that Braidwood can only be replaced by 

“baseload” power. While indeed that is the way things are structured at 

present, current trends and real world energy discussions are starting to 

envision the end of this business model and approach. The notion of 

“distributed power” has been around for over a decade. Recently FERC 

officials have seriously talked about “baseload” being a concept of the past, 

which technological developments in both generation and grid dispatching will 

render increasingly meaningless. Some major US utilities are even setting up 

exploration of a non-baseload oriented system in trial increments within their 

existing systems.

The purpose of the license extension proceeding for Braidwood is NOT to 

analyze its past performance and compare it to the present; it is to look at its 

present performance and extrapolate that out an additional 20 years (31 and 

33 years from now), attempting to envision the energy world at that time to 

see if the “present” can compete or even function in that world. Insufficient 

attention has been paid to this analysis in the Exelon ER. Section 7 reads 

like a convenient cherry-picked self-fulfilling prophecy.

Even Exelon itself cannot think that the business model is uses today will be 

the one that Braidwood will operate in from 2024 to 2044. A way to prove 

that is to ask: does Exelon TODAY operate with the business model it had in 

2002 (11 years AGO)? This was just a handful of years out from utility 

deregulation and unbundling of utilities here in Illinois. Exelon did not even 

exist. Its predecessor’s predecessor was just in the process of selling off its 

coal plants.

Before these critiques are summarily dismissed by NRC as out of the scope 

of this docket, we would remind you that a “nuclear safety culture” demands 

that kind of “out of the box” thinking and analysis to “...ensure protection of 

people and the environment.” You said so yourselves. Analyzing the 

functioning of Braidwood in the energy world of the future will have serious 
Appendix A

A-8 

implications for Exelon’s analysis of socio-economic impacts. Until that 

analysis is done, their “small” conclusions must be held in serious doubt.

Recommendation: Order Exelon to re-examine its Section 7 comparisons, incorporating: 

1) distributed generation and decline of the “baseload power” business model; 2) better data on 

the capabilities of wind and solar, based on expected improvements in technology, or better and 

more optimal use decisions; 3) expected upgrades, improvements and additions of grid and 

dispatching systems in the MISO and PJM Interconnection areas.

Response: These comments provide information for consideration in the staff’s environmental 

analysis of the alternatives to license renewal, including the alternative of not renewing the 

operating license—also known as the “no-action” alternative. In Chapters 2 and 4 of this 

supplemental environmental impact statement (SEIS), the staff discusses the alternatives to 

license renewal. In addition, in Chapter 4 of this SEIS, the staff considered other alternatives 

that were subsequently dismissed for reasons of technical, resource availability, or commercial 

limitations.

A.1.2 Socioeconomic Impact of Braidwood, Units 1 and 2

The comment in this category is in Section 5 of the scoping summary report and labeled with 

the following identifier: 30-2.

Comment 30-2 (a): 

Analysis of socio-economic impacts are incomplete. No analysis of impacts of early or 

unexpected closure are considered or provided. 

The Exelon ER documents a significant local tax impact for the presence of the Braidwood 

Nuclear Station, yet only addresses the positive impacts. No mention or analysis of negative 

impacts resulting from abrupt, planned, or unexpected early closure of Braidwood is presented. 

This is a significant omission.

According to the Exelon ER Braidwood represents less than 2% of the Will County total tax

base, roughly $20 million annually for the years 2008 through 2010. However, it accounts for 

upwards of 78% of the Reed-Custer School District 255U’s adjusted property tax levy. These 

are not insignificant amounts for the local communities around Braidwood, as opposed to the 

county as a whole. Their abrupt disappearance would wreak local economic havoc on the 

affected governmental and essential service entities’ ability to operate; while leaving Will County 

as a whole largely unaffected.

The ER either fails to recognize or mention at all some of the possible events that could result in 

such a situation:

• Unexpected major accident, resulting in immediate and presumably 

premature closure

• NRC ordered shut down

• Exelon’s unilateral decision to close the plant on economic or other grounds, 

as it did at Zion, resulting in an immediate loss of about 55% of Zion’s tax

base

• Devaluation through sale, as occurred at the Clinton station, resulting in 

enormous loss of tax base

• Eventual old-age, license expiration closure (the outcome most hoped for)
Appendix A

A-9 

Exelon even provides a possible indication of the kinds of circumstances that would lead it to 

close Braidwood on economic grounds. Section 3.2 on Refurbishment indicates that Exelon is 

well aware that Braidwood Unit 2 may need a steam generator replacement during the extended 

operational lifetime. It is also tracking the potential for reactor vessel head replacements at its 

operating PWRs at both Byron and Braidwood. Should either or both of these conditions 

emerge at a time of deflated energy prices, or at a time Exelon acknowledges might occur as 

early as 2024 when renewables are much more cost competitive and approaching base load 

capabilities (Sec. 7.2, page 7-9), or as the result of multi-season drought curtailing water 

availability - Exelon being a business will certainly make the calculations it made when it closed 

Zion, and decide if Braidwood should continue to operate.

In this omission the ER makes the same mistake the U.S. Government made when it invaded 

Iraq - it had no exit strategy. To simply assume that the only socio-economic effects of 

Braidwood’s presence will be positive ones is simply irrational.

Finally, the Exelon ER is somewhat dismissive of the effects that Braidwood seems to have on 

local property values. Exelon seems to focus primarily on “property value,” as opposed to 

salability, which anecdotally seems to be of much greater concern in the communities directly 

surrounding the reactor site. It matters little what your property is “worth” if you are trying to sell 

it to move out of the area and can’t. Such figures should be easy to obtain from local realtors, 

and should be included in t[h]e ER.

Response: Information about Exelon Generation Company, LLC’s (Exelon’s), tax payments is 

described in Chapter 3 in the SEIS, and the socioeconomic impacts of station closure and the 

termination of reactor operations due to the expiration of the Braidwood operating licenses is 

described as part of the no action alternative in Chapter 4 in the SEIS. The impacts of closing 

(or decommissioning a nuclear power plant) are also described in the Generic Environmental 

Impact Statement on Decommissioning of Nuclear Facilities: Regarding the Decommissioning 

of Nuclear Power Reactors, (NUREG-0586). The environmental consequences of closing or 

decommissioning of Braidwood would be addressed in a separate environmental National 

Environmental Policy Act (NEPA) review.

Regarding cost competitiveness, as stated in Title 10 of the Code of Federal Regulations 

(10 CFR) 51.45(c), “Environmental reports prepared at the license renewal stage under 

§ 51.53(c) need not discuss the economic or technical benefits and costs of either the proposed 

action or alternatives except if these benefits and costs are either essential for a determination 

regarding the inclusion of an alternative in the range of alternatives considered or relevant to 

mitigation. In addition, environmental reports prepared under § 51.53(c) need not discuss 

issues not related to the environmental effects of the proposed action [license renewal] and its 

alternatives.” Comment petitioning to issue, amend, or rescind the license renewal rule is 

governed by 10 CFR 2.802, “Petition for Rulemaking,” and is beyond the scope of this 

environmental review for Braidwood license renewal.

Comment 30-2 (b): 

Recommendation: Planning for some kind of eventual closure must be made long before it 

happens to minimize economic and service disruptions to the entities whose tax base will be 

affected. Debate about the license extension serves as a good reminder of this fact, and an 

opportunity to take action. We recommend that dependent governmental and taxing entities 

begin formal negotiations with Exelon to establish an escrowed “closure mitigation fund,” based 

on some mutually agreeable assessment and payment structure, so that dependent entities will 

have some kind of temporary funds available to soften the economic blow of closure, and not 
Appendix A

A-10

radically disrupt essential services. Salability of property should be investigated and reported 

more directly, especially in the communities adjacent to the plant.

Response: This portion of the comment is directed at dependent governmental and taxing 

entities. The staff will not respond to this comment.

A.1.3 Water Usage or Hydrology

The original sources for the comments in this category (water usage) can be found in Section 5 

of the scoping summary report and are labeled with the following identifiers: 6-2, 6-6, 25-1, 

26-1, and 30-1. These comments are extracted from the original sources.

Comment 6-2: Radiation monitors are staged in over 40 locations within a [10-mile] radius of 

our station to monitor any radiation of those levels and ensure the safety of the community.

We’ve also had great success in our tritium re-mediation efforts. In the last [7] years, Braidwood 

has made significant progress. [Hydrogeologists] have confirmed that re-mediation is having 

the intended effect. As of today, the square footage of land [affected] by tritium has been 

reduced by 97 percent. And the highest concentrations of tritium in the ground have been 

reduced by 99 percent. We will continue to monitor and we still retain the ability to re-mediate 

via pumping should it become necessary.

Braidwood’s environmental management systems are certified under the strictest criteria of the 

International Organization of Standardization or ISO. Specifically, we receive the ISO 14001 

re-certification which is an industry recognition of our environmental efforts.

This is an internationally recognized benchmark for environmental management. The 

ISO 14001 certification requires a commitment to excellence in meeting our regulatory 

requirements in the prevention of pollution and continuous improvement of our 

environmental systems. 

Comment 6-6: We have a comprehensive on-site environmental groundwater protection 

program for monitoring and detecting the presence of radioactivity in the ground water before it 

has a chance to migrate off of our property. This program includes 19 on-site monitoring wells 

designed to protect, detect and alert us of any unusual events, levels of radiation in the 

groundwater, so that we can assess and address any changes quickly.

We have detailed procedures that outline how we test all the water leaving our station. 

Radiation monitors are staged at 40 locations within a [10-mile] radius around the [plant] to 

monitor any radiation levels and dose to ensure the safety of the community.

We also have had great success in our tritium remediation efforts. In the last [7] years 

Braidwood has made significant progress. Hydrogeologists have confirmed that remediation is 

having the intended effect. As of today the square footage of land affected by tritium has been 

reduced by 96 percent, and the highest concentrations of tritium in the groundwater have been 

reduced by 99 percent. We’ll continue to monitor and retain the ability to remediate via 

pumping, should that become necessary.

Braidwood’s environmental management systems are certified under the strictest criteria, the 

International Organization of Standardization, or ISO, specifically we have received the 

ISO 14001 [standard] certification, an industry standard recognition. This is an internationally 

recognized benchmark for environmental management. The ISO 14000[‘s] certification requires 

a commitment to excellence in meeting our regulatory requirements, and the prevention of 

pollution and continuous improvement in our environmental programs and systems. 
Appendix A

A-11

Comment 26-1: We live approximately 1800 ft from Braidwood nuclear remediation pond. 

When they pump down their pond, our pond levels also drop. We have talked to other 

neighbors who have the same problem. One was paid and told not to say anything by Exelon. 

Also when they 1st began pumping, they were sued by Forest Preserve District for draining their 

wet lands killing wildlife. Forest Preserve won lawsuit. Also, the property Exelon purchased 

next to my home is not maintained. I have talked to them about it and they said they would only 

cut vegetation once a year. I feel all the above is an environmental and health issue. Also, I 

feel that all the previous tritium spills of thousands of gallons and steam releases of tritium 

should be taken into consideration before the 20 year license extension is given.

Comment 30-1:

The ER submitted by Exelon is incomplete in not providing evidence that it has examined the 

projected effects of predicted Illinois climate disruption on future operations. NRC regulations 

are inadequate for not requiring this examination. 

Consideration of climate disruption projections is not an extraordinary request. Many other 

sections of Exelon’s applications require them to project into the future their analysis of how 

Braidwood will be operating at some future date. An issue that could well determine whether 

Braidwood has sufficient water to either operate or sufficiently cool safety-related functions at 

the plant should not be cavalierly dismissed; it should be at the top of the list for evaluation.

Current climate models suggest that Illinois will gradually assume a climate resembling that of 

East Texas or Mississippi by mid-Century (within the period of operational life extension of 

Braidwood), depending on whether one is running a low- or high- emissions model. Summer 

temperatures are expected to increase on average from 3.30 F to 8.60 F. While total 

precipitation is expected to remain about the same, seasonal variation will increase, and 

frequency of heavy precipitation events-measured in terms of number of days per year with 

more than 2 inches of rain, and annual maximum 24-hr, 5-day and 7-day rainfall totals--is likely 

to continue to increase, particularly closer to the Great Lakes, a factor which will have 

implications in the Comments below.

The implications of these projections do not seem to be incorporated into the ER analysis 

provided by Exelon, which invariably result in the conclusion of “small” impact. The ER clearly 

states that the Kankakee River is a “small river” by definition. It is essential for the adequate 

functioning of the ultimate heat sink for the reactors - the cooling pond. Increased evaporation 

and less recharge in a climate disrupted Illinois will add stress to the pond, which according to 

the Exelon ER experienced 5 fish kills from 2001 to 2007. [Sec. 2.2.4.4., p. 2-15], as a result of 

high water temperatures and low dissolved oxygen levels in summer. These conditions are 

expected to worsen over time in stressed waterways.

Make-up water for the mechanical draft cooling tower system relies on the Kankakee River. 

Decreased volume and flow rates expected under projected climate disruption models for Illinois 

could have an adverse effect on cooling functions at Braidwood.

Exelon’s historic penchant to request license variances on water use and thermal discharge

from IEPA [Illinois Environmental Protection Agency] suggests the possibility for greater effect 

than is characterized in the Exelon ER document. The alternative would be curtailment of 

operation, which also does not appear factored into the Exelon ER in any manner.

Recommendation: NRC should require a more thorough projection of water use at Braidwood, 

based on the best possible climate modeling for Illinois between now and mid-century. Because 

this variation in climate disruption and its effects are local/regional, it falls outside the scope of a 

generic analysis or regulation.
Appendix A

A-12

Response: These comments provided input (or data) for the staff’s environmental analysis of 

water resource impacts of Braidwood on local and regional communities. These comments are 

related to Braidwood’s water usage of the Kankakee River. The staff discusses water usage 

impacts in Chapters 3 and 4 of the SEIS.

Clean Water Act Section 401 certification

Comment 25-1: This Agency [IEPA] received a request on May 22, 2012[,] from Exelon 

Generating Company requesting necessary comments concerning the renewal of the Nuclear 

Regulatory Commission operating licenses for the Braidwood Generating Stations Units 1 and 2 

in Will County. We offer the following comments.

This Agency [IEPA] hereby issues certification under Section 401 of the Clean Water Act 

(PL 95-217), subject to the applicant’s compliance with the following conditions:

(1) The applicant shall be responsible for obtaining NPDES permits required for 

wastewater or stormwater discharges to waters of the State from the 

proposed activity.

(2) This certification does not cover future activities that require a federal authorization 

under Section 404 of the Clean Water Act.

This certification becomes effective when the Nuclear Regulatory Commission includes the 

above conditions # 1 through # 2 as conditions of the requested license issued under the 

Atomic Energy Act of 1954.

This certification does not grant immunity from any enforcement action found necessary by 

this Agency [IEPA] to meet its responsibilities in prevention, abatement, and control of 

water pollution.

Response: This comment provided input (or data) for the staff’s environmental analysis of 

water resource impacts of Braidwood on local and regional communities. This comment 

addresses Clean Water Act of 1972 (CWA) Section 401 matters. The staff discusses impacts 

on water resource in Chapters 3 and 4 of the SEIS. In addition, the NRC staff responded to the 

Illinois EPA in an NRC letter (ADAMS No. ML14220A382).

The NRC understands the importance of the CWA and a delegated State’s role in implementing 

the statute. As early as 1984, the Commission recognized that in revising its regulations, NRC 

licenses are subject to conditions deemed imposed by the CWA as a matter of law and that the 

NRC need not duplicate the U.S. Environmental Protection Agency’s (EPA’s) or a delegated 

State agency’s water quality reviews.1

 To explicitly recognize that conditions are deemed 

imposed by the CWA and to obviate the need to undertake amendments to incorporate 

conditions imposed by statute that could be subject to frequent changes by certifying States, the 

Commission added 10 CFR 50.54(aa)2 to specifically provide that each 10 CFR Part 50 “license 

shall be subject to all conditions deemed imposed as a matter of law by section 401(a)(2) and 

401(d) of the CWA (33 U.S.C.A. 1341(a)(2) and (d)), as amended).” To keep informed of the 

environmental effects of NRC licensing actions, the Commission relies on reporting 

requirements of National Pollutant Discharge Elimination System (NPDES) permits to alert the 

NRC of environmental effects of NRC licensing action. As the Commission stated, “The NRC’s 

role in the water quality area is limited to regulating radiological discharges into aquatic bodies 

 

1 49 FR 9352, 9359-60. “Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions and 

Related Conforming Amendments.” March 12, 1984.

2 49 FR 9352, 9360.
Appendix A

A-13

and NEPA matters such as weighing aquatic impacts in NEPA analyses which NRC is required 

to make before reaching a major Federal licensing decision.”3

Because the two 401 certification conditions are license requirements either because they are 

imposed as a matter of law or they state existing statutory provisions, no further NRC action is 

needed with respect to these two conditions. Specifically, (1) Exelon must obtain a CWA 

Section 402 (NPDES) permit from the State in accordance with 33 U.S.C. § 1342, and (2) a 

401 certification does not authorize activities that require an authorization under Section 404 of 

the CWA, 33 U.S.C. § 1344 (i.e., the permits for discharges of dredged or fill material, which are 

issued by the U.S. Army Corps of Engineers). Appendix B, paragraph 3.2 of the current 

Braidwood licenses further requires that Exelon provides the NRC with copies of any NPDES 

permit or State certification (or changes to those documents) within 30 days of approval. If the 

licenses are renewed, this requirement will be carried over to the renewed licenses for 

Braidwood Units 1 and 2.

A.1.4 Human Health

The original sources for the comments in this category (Human Health or Radiation Impact) 

can be found in Section 5 of the scoping summary report and are labeled with the following 

identifiers: 6-1, 8-3, 15-1, 6-5, 8-6, and 15-3. These comments are extracted from the 

original sources. 

Comment 6-1: I’m proud to say that we’ve been a key part of this community for over 25 years. 

Braidwood generating station operates in a manner that preserves the environment. We 

maintain a comprehensive radiological monitoring program that extensively monitors the air and 

the water and the food products around the facility that ensures that we are not adversely 

impacting the environment.

We also have a comprehensive on-site environmental ground water protection program that can 

monitor and detect the presence of radioactivity in ground water before it has a chance to 

migrate off-site. This program includes 19 on-site wells designed to detect and alert us of any 

unusual level of radiation in the ground water so that we can address any changes that we see 

quickly. We have detailed procedures which outline how we test all water leaving our station.

Comment 8-3: The CED recognizes that a good environmental steward Exelon is at their 

Braidwood facility. The radiological monitoring and the ground water protection programs in 

place today give the community a sense of safety and environmental protection that we expect 

from a world-class facility like Braidwood.

Comment 15-1: Exelon has been here a long time and they’ve been a good neighbor. And with 

the exception of the tritium leak, they did take care of it, maybe not like some people want it, but 

it has been taken care of. It did open the communication up a lot.

Comment 6-5: Braidwood Generating Station operates under the manner that preserves the 

environment. We maintain a comprehensive, radiological monitoring program that extensively 

monitors the air, water and food products around the facility to ensure that we did not adversely 

impact the environment.

Comment 8-6: The CED [Center for Economic Development] recognizes what a good 

environmental steward Exelon has been and will continue to be at their Braidwood facility. The 

radiological monitoring and the groundwater protection programs in place today give the 

 

3 49 FR 9352, 9380.
Appendix A

A-14

community a sense of safety and environmental protection we expect from a world class facility 

like Braidwood.

Comment 15-3: And there was an issue with the tritium, and as being a good neighbor, which 

they promised when they started, they did remediate the area, they bought the property that 

was impacted, and with that they took aggressive action so that it doesn’t happen again. And 

with that they also opened up great communications.

Response: These comments provided information for the staff’s consideration in its description 

of and evaluation of (a) impacts to human health, and (b) environmental impacts related to 

possible radioactive leaks from Braidwood.

Radiation doses to members of the public from the current operations of Braidwood are 

discussed in the SEIS in Chapters 3 and 4. In these chapters, the staff reviewed the radioactive 

releases from Braidwood (i.e., radioactive gaseous and liquid effluents, radiation from 

radioactive waste storage buildings, radiological impacts from refueling and maintenance 

activities, and tritium leaks) and the results of Braidwood’s radiological environmental monitoring 

program (REMP) (i.e., analysis of air, water (surface, ground, and drinking), sediment, 

vegetation, and aquatic and terrestrial biota for radioactivity).

A.1.5 Terrestrial or Aquatic Ecology

The original sources for the comments in this category can be found in Section 5 of the scoping

summary report and are labeled with the following identifiers: 6-3 and 6-7. These comments 

are extracted from the original sources.

Comment 6-3: Last year, the Wildlife Habitat Council recognized Braidwood generating 

station’s commitment to the environmental stewardship by awarding us the Wildlife at Work 

certification. This distinction was awarded for our commitment to ensuring the continuance of 

healthy wildlife in and around our plant, and our fish habitat restoration project. The project 

places artificial habitats in the Braidwood lake the greatly benefit the fish throughout their life. It 

has greatly enhanced the fishery.

Comment 6-7: Last year the Wildlife Habitat Counsel recognized Braidwood Generating 

Station’s commitment to the environmental stewardship by awarding us the Wildlife award 

certification. This distinction was awarded to our commitment for ensuring that the continuance 

of the healthy wildlife around our planet, through our fish habitat restoration project. This project 

places artificial habitats in the Braidwood Lake, and that greatly benefits the fish throughout their 

life, and greatly enhances the fishery.

Response: These comments provided information for the staff’s consideration in its description 

of and evaluation of impacts to aquatic and terrestrial resources at Braidwood. The staff 

discusses terrestrial and aquatic resources in Chapters 3 and 4 of the SEIS.

A.1.6 Climate Change

The original source for the comment in this category can be found in Section 5 of the scoping

summary report and is labeled with the following identifier: 30-4. The comment is extracted 

from the original source.

Comment 30-4: 

Sec. 5.0 - Assessment of New and Significant Information

Since, “...The environmental report must contain any new and significant information regarding 

the environmental impacts of license renewal of which the applicant is aware.” 
Appendix A

A-15

(10 CFR 51.53(c)(3)(iv)), and Exelon and NRC have now been made [aware] of new information 

not previously analyzed, the law requires that this information be researched, and reported in a 

revised ER.

Since the climate disruption issues raised above are uniquely local in their manifestation and 

effects, a generic ruling on them is both inappropriate and would be inaccurate.

Since no apparent investigation has been done concerning either the effects of climate 

disruption, or the effects of abrupt closure on socio-economic factors, results would certainly 

“...lead to an impact finding that presents a seriously different picture of the environmental 

impact of the proposed project in comparison with what was previously envisioned.” (Sec. 5.1, 

page 5-3)

Response: This comment provided information for the staff’s consideration in its description of 

and evaluation of climate change impacts at Braidwood. The staff discusses climate change 

(climatology) impacts to individual resource areas in Chapters 3 and 4. The staff provides 

responses to socioeconomic concerns about abrupt closure of Braidwood in Section A.1.2.

A.2 Comments Received on the Draft SEIS

On March 18, 2015, the NRC issued and made publically available the Generic Environmental 

Impact Statement for License Renewal of Nuclear Plants Regarding Braidwood Nuclear Plant, 

Draft Report for Comment (NUREG–1437, Supplement 55, referred to as the draft SEIS or 

DSEIS) to Federal, tribal, state, and local government agencies and interested members of the 

public. The U.S. Environmental Protection Agency issued its Notice of Availability regarding the 

draft SEIS on March 27, 2015 (80 FR 16384). The public comment period ended on 

May 12, 2015. As part of the process to solicit public comments on the draft SEIS, the NRC did 

the following:

 placed a copy of the draft SEIS at the Fossil Ridge Library in Will 

County, Illinois;

 made the draft SEIS available in the NRC’s Public Document Room in 

Rockville, Maryland;

 placed a copy of the draft SEIS on the NRC Web site, at 

http://www.nrc.gov/reading-rm/

doc-collections/nuregs/staff/sr1437/supplement55/; 

 provided a copy of the draft SEIS to members of the public who

requested one;

 sent copies of the draft SEIS to certain Federal, tribal, state, and local 

government agencies;

 published a notice of availability of the draft SEIS in the Federal Register on 

March 25, 2015 (80 FR 15827);

 filed the draft SEIS with the EPA; and

 announced and held two public meetings (afternoon and evening) at the 

Godley Park District, Godley, Illinois, on April 21, 2015, to describe the 

preliminary results of the environmental review, answer any related 

questions, and take public comments.

Approximately 30 people attended the afternoon meetings and 21 attended the evening 

meetings. A certified court reporter prepared written transcripts of the meetings. A meeting 
Appendix A

A-16

summary is available in ADAMS (ADAMS Nos. ML15121A796—afternoon and ML15121A803—

evening). The NRC received only oral comments during both the afternoon and evening 

meetings. No written comments were submitted. In addition to oral comments made at the 

public meeting, additional letter comments were also submitted after the public meeting.

To identify individual comments, the NRC reviewed the comment submittals for the afternoon 

and evening meeting transcript and provided each commenter a unique identifier, so every 

comment could be traced back to its author. Table A–2 identifies both individuals who provided 

oral comments during the public meetings and written letters and the Commenter ID associated 

with each person’s set of comments.
A-17

Table A–2. Individuals Providing Comments During the Draft SEIS Comment Period

(*comments identified in this appendix)

Commenter Affiliation (if stated) Commenter ID Comment Source ADAMS No

Anonymous Member of public *017 Submission to Reg.Gov ML15138A08

Michael Gallagher

Michael Gallagher

Michael Gallagher

Exelon

Generation

Company

*014

*019

020

Letter dated May 12, 2015

Letter dated May 15, 2015

Additional Minor Edits

ML15138A08

ML15146A05

ML15154A50

Mike Gorga Exelon Generation 

Company

*018 Afternoon public meeting ML15121A79

John Greuling President and CEO of 

Will County Center for 

Economic Development

*002 Afternoon public meeting ML15121A79

Nathan Grider Illinois Department of 

Natural Resources

*016 Letter dated May 12, 2015 ML15138A08

Angie Hutton President of the 

Braidwood Chamber

*009 Afternoon public meeting

Evening public meeting

ML15121A79

ML15121A80

Rachel Leibowitz Illinois Historic 

Preservation Agency

*015 Letter dated April 15, 2015 ML15124A02

Lindy Nelson U.S. Department of 

the Interior

*012 Letter dated May 8, 2015 ML15131A00

Doug O’Brian Executive Director of 

the Illinois Clean 

EnergyCoalition

*004 Afternoon public meeting

Evening public meeting

ML15121A79

ML15121A80

Jay O’Connel Member of public *006 Afternoon public meeting ML15121A79

Dean Rankovich Representing Operating 

Engineers Local 150

*010 Afternoon public meeting ML15121A79

Greg Ridenour Representing 

Congressman 

Adam Kinzinger’s Office

*001 Afternoon public meeting

Evening public meeting

ML15121A79

ML15121A80
A-18

Commenter Affiliation (if stated) Commenter ID Comment Source ADAMS No

Chris Rosso Member of public *007 Afternoon public meeting ML15121A79

Dave Schultz Member of public *011 Evening public meeting ML15121A80

Robert Schwartz Representing Members 

of the Will and Grundy 

Building Trade

*003 Afternoon public meeting ML15121A79

David Tkac Representing Lawrence 

M. Walsh, County 

Executive for Will County

*005 Afternoon public meeting ML15121A79

Robert Tovey Member of public *008 Afternoon public meeting ML15121A79

Kenneth Westlake Environmental Protection 

Agency

*013 Letter dated May 12, 2015 ML15154A50
Appendix A

A-19

In sections below, each comment has a comment ID consisting of two numbers separated by a 

hyphen. The part of the comment ID before the hyphen is the Commenter ID from Table A–2. 

The part of the comment ID after the hyphen is the comment number, which refers to the 

sequential comment given by the commenter. For example, comment xx-yy is the yy comment 

from the Commenter xx.

In response to the comments, the staff did not identify any new and significant information 

provided on Category 1 issues or information that required further evaluation of Category 2 

issues. Therefore, the conclusions in the GEIS and draft SEIS remained valid and bounding, 

and no further evaluation was performed.

The following section presents the comments and the NRC responses to them. Consistent with 

10 CFR 51.91, when comments have resulted in modification or supplementation of information 

presented in the draft SEIS, those changes are noted within the NRC response. When 

comments do not warrant further response, the NRC staff explains why, citing sources, 

authorities, or reasons that support the explanation, as appropriate. Changes made to the 

draft document are marked with a change bar (vertical lines) on the side margin of the page.

A.2.1 Oral Comments From Greg Ridenour, Representing Congressman 

Adam Kinzinger’s Office (from both afternoon and evening public 

meeting transcripts)

Comment 001-1-General: The issue of maintaining our current fleet of clean, affordable 

energy generation in Illinois is of the utmost importance to residents, consumers and elected 

officials throughout the region. Illinois continues to be a leader in the production of carbon-free 

electricity, with six nuclear plants providing nearly half of the overall electricity generating 

portfolio and over 90 percent of the carbon-free electricity in the state. Four of those facilities 

reside within the 16th Congressional District alone, where they have been a driving force in 

stabilizing not only the price of power, but also the reliability of the grid overall. If this source of 

clean base load power generation, approximately 12,000 megawatts overall, were not available, 

there is little doubt that prices would rise exponentially, and grid stability would be negatively 

impacted.

Comment 001-2-General: Additionally, the nuclear energy industry has a substantial impact 

on the economy at the state and local level. These plants are directly responsible for providing 

thousands of quality, high paying jobs for high skilled workers and, in turn, provide a huge boost 

to our economy worth nearly $9 billion annually. The 825 employees of the Braidwood facility 

earn over $60 million annually in payroll. And given that the majority of these employees reside 

in Grundy and Will counties, they are able to provide a foundation in which to support the local 

tax base.

Comment 001-3-General: We are here today to discuss the license renewal application of the 

Braidwood Generating Station, which has been providing reliable power to the grid for nearly 

three decades without emitting greenhouse gases or carbon dioxide that we find with other 

forms of energy. Moreover, the amount of carbon-free electricity annually produced by 

Braidwood is comparable to removing 2.9 million passenger vehicles from the road. In addition 

to providing clean energy, Braidwood must maintain a radiological environmental monitoring 

program, along with an onsite ground water protection program to detect any presence of 

radioactivity in the water. Braidwood’s detailed monitoring and consistent compliance with NRC 

regulations show Braidwood’s sincerity and determined work towards ensuring environmental 

protection. The process being followed by the NRC is amiable in the transparent manner in 

which it conducts these hearings, allowing members of the public the opportunity to provide 
Appendix A

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comments on the environmental aspects of the process, shows a level of commitment 

to transparency that should take place in all aspects of government licensing.

It is also important to note that the NRC also requires that the plant’s application to include an 

additional environmental report based solely on the plant’s potential impact to the environment, 

should the application be extended beyond its initial license. This extra step helps to ensure the 

safety and environmental benefits of the facility’s surrounding area. It’s my hope that as this 

multi-year effort takes place, it will continue to do so in as expeditious manner as possible. 

Extending the life of this facility for 20 years will ensure that a clean source of energy for millions 

of consumers is able to move forward with certainty in their future operations.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.2 Oral Comments From John Greuling (from afternoon public meeting transcripts)

Comment 002-1-General: Over the last 15 years, Will County has been one of the fastest 

growing counties in Illinois and the Midwest. Our 700,000 residents and our 18,000 businesses 

need reliable, clean and affordable energy to sustain and grow our economy and support our 

high quality of life. We believe nuclear energy helps us do that. To that end, the CED supports 

the renewal of the Braidwood operating license by the NRC. Illinois’ six nuclear plants generate 

48 percent of the states electricity power supply. Braidwood Station is an important of that vital 

energy supply. Braidwood is, and always has been, transparent about its plant operations, and 

is interested in hearing public feedback in how it can better communicate with surrounding 

communities. As a member of the plant’s community advisory panel, the CAP, I recently 

attended an Exelon community information night, I think it was in Minooka, right, that was 

hosted by Exelon. And we learned, excuse me, an event that provided information on the 

impact of Braidwood, Dresdan and LaSalle Stations on each of those communities. These 

plants provide critical funding for education through property taxes, support for community 

organizations that meet identified needs in the communities, and they provide a strong 

economic foundation to stimulate commerce and new development.

Comment 002-2-General: Braidwood Station, like its sister Illinois nuclear plants, is an 

unrivaled environmental asset for Illinois. Illinois’ abundant supply of reliable, carbon-free power 

makes the state an environmental leader and an attractive location for businesses. In addition, 

it employees 864 jobs. It contributes over $27 million to the local tax base. Overall, the plant 

directly and indirectly provides nearly $1 billion annually to the Illinois economy. That’s a lot of 

money. The CED strongly supports the renewal of the operating license for the Braidwood 

facility. Thank you.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.3 Oral Comments From Robert Schwartz (from afternoon public meeting transcripts)

Comment 003-1-General: I represent members of the Will and Grundy building trades who 

have built and currently maintain the mechanical equipment at the powerhouse. And they 

maintain it to meet all the requirements of the NRC and all the different codes that are required 

of it.

Comment 003-2-General: And it’s obvious from the presentation today that Exelon has 

exceeded the environmental requirements of the NRC to continue its operating license. And I 

respectfully request that the NRC, based on their findings, grant Exelon their renewal license.

It’s also important to note, too, that because of the nuclear power generated at the station, that 

when the wind doesn’t blow and the sun doesn’t shine, the turbines keep spinning to provide 

electricity for the safety and convenience of all the residents.

If there’s no electricity, no reliable electricity, you wouldn’t have lights on at night. Your 

sump pumps wouldn’t run. Traffic signals wouldn’t work. Power wouldn’t be at hospitals, 

fire departments or police stations to provide safety for our residents. So it’s important that 

Braidwood Station gets their license renewed.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.4 Oral Comments From Doug O’Brian (from both afternoon and evening public 

meeting transcripts)

Comment 004-1-General: And we’re here today for what is called the NRC’s environmental 

scoping hearing on the Braidwood Station renewal. So I want to talk a little more specifically 

about the environmental impacts of the plant.

It has to be stated clearly that the future of our carbon footprint in Illinois depends on the 

continued operation of this and other nuclear plants in Illinois. Without them, we face potential 

for huge increases in carbon dioxide and other pollutants, including mercury that negatively 

impact our environment and lead to huge societal costs. The operation of this plant alone 

displaces the generation of millions of tons of harmful CO2 emissions every year. Every 

megawatt of electricity produced by nuclear power is a megawatt that does not rely on carbon 

polluting, carbon pollution-emitting fossil fuels. According to the Illinois Clean Energy 

Coalition’s 2014 study, Illinois’ nuclear fleet prevented the emissions of over 92 million tons of 

CO2. And that’s the equivalent of the pollution emitted by every passenger car registered in 

Illinois and Indiana and Wisconsin and Iowa. Other sources of clean energy are vital to our 

future, as well. But the simple truth is that we cannot quickly or easily replace nuclear 

generation with other clean sources. And a nuclear plant like Braidwood would require 

thousands of new wind turbines to replace its generation. But we still cannot rely on wind 24/7. 

And the process of siting wind farms, the capital needed to build them, and the siting aspects 

are daunting.

Comment 004-2-General: Losing any of our nuclear plants would leave us with no short-term 

alternatives but to increase our use of fossil fuels, which is a move in the wrong direction. The 

US EPA has announced new rules for states to reduce carbon emissions. Simply put, there is 

no way Illinois can hope to meet these goals, nor can we as a nation hope to meaningfully 

reduce carbon emissions if we do not ensure the continued operation of our nuclear fleet. 

We’ve seen the consequences of this scenario very clearly across the Atlantic in Germany, 

where the decommissioning of much of their nuclear fleet, supposedly for environmental 

reasons, has led to huge increases in the reliance on carbon-polluting energy sources, not 

to mention a doubling of consumer energy costs. So from an environmental standpoint, 

Braidwood is a critical component in our drive to reduce pollution and change the course on 

climate change. It cannot be replaced in the short-term without incurring the significant increase 

in carbon emissions, and it has responsibly stepped up to the need for safe and secure used 

fuel storage. So from an environmental standpoint, the Braidwood Station is a huge positive for 

Illinois and the US, and the Illinois Clean Energy Coalition urges renewal of their operating 

license.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.

Comment 004-3-General: I’m Doug O’Brien with the Illinois Clean Energy Coalition, a coalition 

of business, labor, and civic leaders who are committed to developing clean energy sources and 

maintaining a competitive market in Illinois. And I want to echo what was said previously, I 

spoke earlier today and those comments are on the record. But I think it’s critically important 

from an environmental perspective that we maintain our nuclear fleet in Illinois. The potential of 

replacing any of these plants generation with additional fossil fuel production would devastate 

our ability to meet clean air targets and to move towards a cleaner environment.
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Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.5 Oral Comments From David Tkac (from afternoon public meeting transcripts)

Comment 005-1-General: But there are some important things to note here in Exelon’s pursuit 

of a licensing renewal. First of all, Will County needs and must have a reliable energy source. 

If we’re going to grow, and if we’re going to prosper the way our county executive believes we 

will, then this is an essential element of that growth and that prosperity.

Comment 005-2-General: The second things I’d like to talk about is the, and this is from 

a personal perspective, I was able to tour the facility, the Braidwood facility in October or 

November of last year. I was very impressed with how secure that facility is. And I’m sure I 

only got to see a small part of them, or the public portion of the security apparatus there. But I 

felt so much better knowing, seeing that and knowing that today, especially given the world that 

we live in, unfortunately. But on the brighter side of things, Braidwood is, it represents 

employment opportunities for, and good, solid employment opportunities for over 800 local 

residents. And that is something that cannot be understated. Exelon, at Braidwood, has an 

excellent safety record, and an outstanding emergency preparedness program that they 

coordinate with other first responding and emergency management agencies, including the 

counties. And there’s something to be said for that, because it goes beyond an emergency 

at the plant. But to also help marshal all the resources county-wide for a different kind of 

emergency altogether. And it’s good practice for such a thing. And so, I wanted to point that 

out, as well.

Comment 005-3-General: And lastly, the Exelon Corporation is a, is a good corporate resident 

of Will County, providing $26 million a year to our annual tax base here, property tax base here 

in Will County, and that’s important to everybody. So, having said that, I’d like to thank you, 

again, for having us here today and for allowing me to speak on Mr. Walsh’s behalf.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.6 Oral Comments From Jay O’Connel (from afternoon public meeting transcripts)

Comment 006-1-General: While I am not an associate involved with, on a scope like this, I am 

a local resident. I am a tournament fisherman, and I enjoy the benefits of Lake Braidwood. We 

have, as an organization, the Illinois B.A.S.S. Nation. We consist of approximately bass clubs 

distributed throughout the State of Illinois. There are four clubs here locally that participate in 

tournaments here on Lake Braidwood. Starting back in about 2002, I believe, there was a 

tournament held here called fishing for a cure. Where a lot of us guys came in, and it was a well 

organized tournament group. And the proceeds from the tournaments went to all of the local 

type charities. We’ve had for multiple sclerosis, for the people that were affected by the 

tornados just recently and a couple years ago. And what it demonstrates is what a good 

neighbor Exelon has been to us as local people.

In their process of recognizing the impact to the environment, starting back in the year 2007, 

through meeting us fisherman through their fishing for a cure tournaments, we were approached 

as a group to help along with the Illinois Department of Natural Resources to place habitats into 

the Braidwood Lake. And we’re happy to say that, in retrospect of those being planted, that we 

have seen a remarkable improvement in the fishery here in Braidwood. With the impact of the 

hot water and that, some things changed, and Braidwood Exelon’s response was let’s put some 

habitats in. And the habitats create areas where these items have been placed that allow fish to 

be able to hide for nurseries for freshly spawned fish. And as a result of that, we’re seeing good 

recruitment starting to develop. It shows in the tournaments that are held in that the average 

size of the fish has increased tremendously over the years. And it’s not uncommon now to see 

five or six-pound fish weighing in at the tournament. Prior to putting the habitats in, there were 

points in time where we didn’t see that. A two-pound bass would have been a great thing. Not 

only did it impact the bass, it’s impacted the catfish and the bluegills. There’s a fabulous picture 

here. It brings in people from throughout the community; even from the City ofChicago. It’s 

bringing in revenues. The gas stations are selling bait and fishing licenses and gasoline to us 

boaters. Just in respect to that, we’d like to share that with you. And in regards to the fishing 

for a cure tournament, we have one coming up May 2nd. And the tournament which has all 

turned around the monies back into the community, we have raised over $365,000 for local, 

not-for-profit organizations. We appreciate that, and we appreciate the fact that they care about 

the environment.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.7 Oral Comments From Chris Rosso (from afternoon public meeting transcripts)

Comment 007-1-General: I want to talk a little bit about, expand on the impact of losing 

Braidwood Station as a low carbon, a zero-carbon energy provider to the state, in light of 

coming EPA and Illinois guidelines. So others have talked about the carbon emission impact, 

how many cars come off the roads, how many tons of CO2 would need to be provided by other 

easily accessible sources of power such as coal or natural gas. But one of the other major 

resources that we have in Illinois and the whole Midwest that’s often overlooked is Grade A 

farmland. And what some of the other alternative fuel sources, such as solar and wind, offer as 

far as zero carbon production, they lack in energy density and efficiencies in that manner. So 

what if we lose Braidwood Station and other nuclear power plants, and replace them with the 

solar grids such as the one that Exelon invested in the South Side of Chicago, or the swarms of 

wind turbines in the cornfields south of Braidwood and right around LaSalle Station? So do a 

little quick research, based on energy efficiencies, when you gather as many of these sources in 

one area as possible, so big solar plants such as those going out in California, next generation 

solar, some of the most efficient, the most efficient types of “renewable” energy in the country 

and in the world. And looking at one of the newest solar plants that went up in San Bernardino 

County in California, it’s a whopping 392 megawatts. It uses 3,500 acres. So what do you get 

from that? You get 9.8 acres per megawatt. That’s a thermal solar unit. That’s the most 

efficient type of solar right now. It’s not the black panels that you see. Those are photovoltaic 

panels, which also in California, in San Luis Obispo County is the Topaz Solar Farm that’s 

550 megawatts, but that uses nine-and-a-half square miles. It’s over 6,000 acres. And that 

gets you 11 acres per megawatt.

Comment 007-2-General: Looking at Braidwood Station, it uses a cooling lake, which makes 

up a large majority of the footprint of the power plant. We’re at about, based on our website, a 

little over 4,400 acres for our 2,300 megawatts. And that’s 1.9 acres per megawatt. So if we 

start looking at the economic impact of taking away those nuclear power plants, from an energy 

density standpoint, you’re not only giving up potentially prime land that could be used to invest 

in other businesses closer to Chicago, but you’re talking about stripping potential for Grade A 

farmlands to be cultivated and used further out in the state. So that’s something, even though I 

wasn’t part of putting together this document for the license renewal for Braidwood, something I 

think I haven’t heard a lot in these public meetings is what’s the land use impact of losing these 

stations.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.8 Oral Comments From Bob Tovey (from afternoon public meeting transcripts)

Comment 008-1-General: And I was asked to speak here by one of our business 

representatives, Donald Gregory, who is also the president of the Will County Building Trades. 

I’ve worked in these plants, on the construction of them, from 1968 when I returned from 

Viet Nam out of the service, up until 2009, when I retired six years ago. And I was, I worked in 

over 30 plants from the east coast to the west coast. And there was a time when Exelon wasn’t 

at the top of the rock. But when it kind of started, I was working at Braidwood when they were 

getting ready to fire up in ’87. And the things that were done at Braidwood, like color coding the 

units so people didn’t mess up operating and stuff like that, that went on through the whole 

Exelon fleet. And it just like made a change in the fleet. Make it much, much more safe, much 

more efficient. And I just, in my opinion, I feel that Braidwood’s been operating over 20 years 

now. And I think may they had one little hiccup. But I think that their performance record 

proves that they should be allowed a license for another 20 years. They, and Exelon, Dresdan’s 

been running over two, over 40 years. And everybody else has talked about all the 

environmental and the economic impact, which is great. But I feel that, you know, the 

performance deserves something.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.9 Oral Comments From Angie Hutton (from both afternoon and evening public 

meeting transcripts)

Comment 009-1-General: And everyone else has talked about the economics, but just a 

statement from us, or a couple. Braidwood Station is a good neighbor to the City of Braidwood. 

The communication between them and the city is ongoing. There are fliers, and the e-mails that 

are sent, the community information nights. And there’s also a citizen’s advisory panel, which I 

am part of. And at that meeting, we can ask any question we want. It doesn’t matter what it is. 

If they don’t have an answer that evening, it is either e-mailed to us or brought out at the next 

meeting. So there’s, citizens in town can ask, and then we can bring it down there. So they are 

very open in everything that they’re doing.

Comment 009-2-General: There was an event recently that provided information on 

Braidwood, Dresden and LaSalle Stations. They do try to get the information out to the

residents. Being transparent, the Braidwood has a good rapport with the citizens of Braidwood. 

They provide about 864 jobs and over $27 million annually to the local tax base. But with that 

said, they also provide immense to out not-for-profits. And there’s, you know, can somebody 

say oh, they should give more, of course. But I know from, of course, with the CAP meetings 

that they do provide a lot to our not-for-profits. And without that, like our food pantry in town, it 

just couldn’t exist. We do need that. And a lot of that, I know, is done by the employees, too, of 

the plant. So the employees, too, when they do the turnarounds, I mean, they’re impacting our 

gas stations, our grocery store, anything that we have when they can come into town definitely 

helps our citizens and our local business. So it is a win/win for us all the time. And the clean, 

reliable energy, it is important for the future. And Braidwood is a bit part of our future. So the 

Braidwood Chamber does support the license renewal.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.

Comment 009-3-General: Angie Hutton, President of the Braidwood Chamber and I spoke 

earlier, so I would just like to say that that’s on record. But the Chamber would like to say, you 

know, we do support the renewal of the license for the Braidwood Station.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.10 Oral Comments From Dean Rankovich (from afternoon public meeting transcripts)

Comment 010-1-General: On behalf of the Operating Engineers Local 150. We come from 

South Bend, Indiana to the west side of the Mississippi River. We have 23,000 members, which 

2,000 of them live in Will County. We maintain every one of the plants that Exelon has in our 

geographical jurisdiction. Braidwood and other nuke plants are a very positive impact to our 

overall environment. We’re able to provide huge amounts of electricity for our homes and 

business, without creating carbon emissions. But the environmental benefits depend on plants 

operating safely. Thousands of building trades members work at the Braidwood plant and all 

other Exelon plants across our area, providing important maintenance and improving the plants, 

in addition to having built the plants in the first place. We don’t know from experience, we do 

know from experience that Braidwood Plant has a strong record of safe operation. If we didn’t 

believe it, we wouldn’t be working in there. And those jobs, and the thousands more that the 

Braidwood supports, gives us a better quality of life in Will County. It provides tax dollars that 

protect our homes and families and invest in our communities. When you look at the energy 

provided, the environmental benefits, and the positive impacts on jobs and our community, you 

see the huge positive affect of Braidwood. On behalf of the Operating Engineers Local 150, 

23,000 members, and 2,000 that live in Will County, and our families, we strongly encourage 

you to provide the renewal of the plant’s operating license.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.11 Oral Comments From Dave Schultz (from evening public meeting transcripts)

Comment 011-1-General: I’m Dave Schultz, I’m a local resident and I am avid tournament 

bass fisherman, I’m here tonight to speak on behalf of Exelon and some of the affects it has on 

the environment, namely fishing and so forth. As we can see, we’ve got a local pond here, 

Exelon provides a tremendous amount of sportsmanship and opportunities for local people of 

all ages, especially the kids, also adult tournament fisherman, adult pleasure fisherman and not 

only here in the State of Illinois, but also they travel from states like Indiana and would have 

even had people from Wisconsin come and fish Braidwood Lake. Because it is a well-known 

lake across the communities. Anyway, the, Exelon has provided many, many things to improve 

their environment such as they have a habitat program that we’re involved in and they’ve been 

doing that for years now. I think there’s something like almost 700 habitat items that have been 

purchased by Exelon and some of the local fisherman come out on certain days and we actually 

put them in specific areas in the lake to help with the fish and their habitat and their survival and 

so forth. Where there’s one plan here for, it’s coming up here actually in a couple of weeks I 

believe. But already some people have made plans to come and participate in that. The other 

thing is Exelon also provides many things for the non-for-profit organizations. And for the last 

14 years they have provided, they have put on a charity tournament that I’m personally part of, 

and I’m considered a charity boat.

So, therefore I fish with a partner that they provide for me and we go out and have a great time 

and any winnings that we have will be donated back to the charities. There’s many charities 

that they benefitted over the years. And this year they are going to benefit three different 

hospices which are, I’m sure they’re very grateful for, they raise quite a bit of money for them. 

And actually that’s been close to $400,000, they’ll probably hit that this year I would imagine 

with their thing. The wildlife we, I just locally, I have just recently finished a tournament on 

Saturday here and there is actually bass that are spawning and doing their nature thing and 

they do not seem to be affected whatsoever. You can actually see these fish taking care of their 

business. So, but it’s a good thing and many people in the area just enjoy the lake and so forth. 

So, that’s really probably about it.

Response: These comments are general in nature, did not impact the environmental analysis, 

and support the license renewal. No changes were made in the SEIS text as a result of these 

comments.
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A.2.12 Written Comments From Lindy Nelson, U.S. Department of the Interior

Comment 012-1-Special Status Species and Habitats: The DSEIS lists the northern 

long-eared bat (Myotis septentrionalis) as a proposed species. The northern long-eared bat 

is now listed as threatened under the Endangered Species Act (ESA). This change should be 

reflected in the Final SEIS.

Response: The staff revised the text in Sections 3.8 and 4.8. to reflect the threatened status of 

the northern long-eared bat (NLEB). 

Comment 012-2-Special Status Species and Habitats: The DSEIS describes that the sauger 

(Sander canadense) is the only known fish host for sheepnose mussel (Plethobasus cyphyus) 

glochidia. This should be changed to: “the sauger is the only known natural host for the 

sheepnose.” According to the 2012 Federal Register Final Rule (77 FR 14914): “little is known 

regarding host fish of the sheepnose. Until recently the only cited host for this species came 

from a 1914 report that found glochidia naturally attached to sauger (Sander canadense) in the 

wild. No confirmation of successful transformation was recorded in this early report 

(Surber 1913, p. 110; Wilson 1914, pp. 338–340). However, recent laboratory studies at the 

Genoa National Fish Hatchery, the University of Minnesota, and Ohio State University have 

successfully transformed sheepnose glochidia on fathead minnow (Pimephales promelas), 

creek chub (Semotilus atrromaculatus), central stoneroller (Campostoma anomalum), and brook 

stickleback (Culaea inconstans) (Watters et al. 2005, pp. 11–12; Brady 2008, pers. comm.; 

Watters 2008, pers. comm.). Although these are identified as suitable hosts in laboratory 

studies, natural interactions between the aforementioned fishes and the sheepnose seem 

rare and infrequent due to habitat preferences. Fish that frequent medium to large rivers near 

mussel beds, like the sauger, may act as hosts in the natural environment.” Additionally, the 

Genoa National Fish Hatchery has identified the golden shiner (Notemigonus crysoleucas) as 

another host fish of the sheepnose in laboratory studies and has propagated the sheepnose and 

raised the golden shiner for possible reintroduction of the sheepnose in its natural habitat. This 

section of the Final SEIS should be changed to reflect other potential hosts for the sheepnose.

Response: The staff modified the text in Sections 3.8 and 4.8 to identify other potential hosts 

for sheepnose including sauger and golden shiner. Specifically, the NRC staff referenced 

reports cited in FWS (77 FR 14914) reporting that in laboratory studies, sheepnose glochidia 

successfully transformed on several other species, including fathead minnow (Pimephales 

promelas), creek chub (Semotilus atromaculatus), central stoneroller (Campostoma anomalum), 

and brook stickleback (Culaea inconstans), although interactions between these species and 

sheepnose may be rare and infrequent in nature due to habitat preferences.

Comment 012-3-Special Status Species and Habitats: This section discusses impingement

and entrainment of aquatic organisms. The DSEIS concludes that: “No noticeable changes in 

the mussel community have occurred since Braidwood began operating. Thus, impingement 

and entrainment of mussel glochidia through impingement of host fish appears to have a 

SMALL impact on the mussel community in the vicinity of Braidwood.” The DSEIS notes that 

the sauger has not been collected as part of past impingement studies. The DSEIS also notes 

that the golden shiner and fathead minnow have been collected as part of past impingement 

studies. The Final SEIS should account for the possibility of the sheepnose using the golden 

shiner or fathead minnow as host species.
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Response: The staff revised Section 4.8 to reflect the possibility of sheepnose using the 

golden shiner and fathead minnow as host species. Specfically, the NRC staff referenced the 

FWS (77 FR 14914) reports that state that, in laboratory studies, sheepnose glochidea have 

successfully transformed on several other species, including fathead minnow (Pimephales 

promelas), creek chub (Semotilus atromaculatus), central stoneroller (Campostoma anomalum), 

and brook stickleback (Culaea inconstans), although interactions between these species and 

sheepnose may be rare and infrequent in nature due to habitat preferences.

Comment 012-4-Special Status Species and Habitats: The U.S. Nuclear Regulatory 

Commission (NRC) used the DSEIS to fulfill its obligation to prepare a biological assessment

under section 7 of the ESA. The NRC concluded that the proposed action would have no effect 

on the following species: snuffbox mussel (Epioblasma triquetra), Hine’s emerald dragonfly 

(Somatochlora hineana), eastern prairie fringed orchid (Platanthera leucophaea), lakeside daisy 

(Hymenopsis herbacea), leafy-prairie clover (Dalea foliosa), and Mead’s milkweed (Asclepias 

meadii). Effect determinations were not made for the two candidate species: 

rattlesnake-master borer moth (Papaipema eryngii) and the eastern massasauga (Sistrurus 

catenatus); however, determinations should be made in the Final SEIS. Based on the 

information provided in the DSEIS, we conclude that the project is expected to have no effect on 

these species.

Response: In response to FWS’s comment, the staff added determinations of “no effect” for 

rattlesnake-master borer moth to Section 4.8. After FWS submitted these comments, FWS 

proposed listing the massasauga as a threatened species. NRC staff revised text in 

Sections 3.8 and 4.8 to reflect the change in status of this species from a candidate to 

a proposed species. The staff then added a finding of “no effect” for the proposed 

species massasauga.

Comment 012-5-Special Status Species and Habitats: We do not concur with NRC’s 

determination of “may affect, not likely to adversely affect” for the endangered sheepnose 

(Plethobasus cyphyus). At this time we cannot concur that the project would not adversely 

affect the sheepnose mussel, due to the lack of recent survey information in the project area 

and because other potential host species (i.e., golden shiner and fathead minnow) were not 

considered as part of the impact analysis for the sheepnose. In order for the Department to 

assess potential impacts to the sheepnose, we recommend that mussel surveys be conducted 

to assess current presence and status of the endangered mussel in the project area. Mussel 

surveys should be coordinated with the U.S. Fish and Wildlife Service’s (Service) Chicago 

Illinois Field Office. The mussel survey report should be submitted to the Service for their 

review.

The DSEIS states that: “Sheepnose larvae are indirectly susceptible to impingement and 

entrainment of host fish, and the only known host species for sheepnose is sauger. Juvenile 

and adult sauger were not reported in surveys of the Kankakee River near the Braidwood intake 

or impingement collections in 1988 and 1989, and eggs and larvae were not reported from 

samples in the river or from entrainment collections in the same years (EA Engineering 1990). 

Monitoring studies of fish in the Kankakee River near Braidwood in the last 5 years also has not 

reported sauger in the collections (e.g., HDR 2009, 2013, 2014). Assuming that the results 

reflect future conditions, the indirect effect of impingement and entrainment on sheepnose host 

species from now until 20 years beyond the expiration of Braidwood’s present operating 

licenses is likely to be insignificant. Some unionid species may have one host species, and 

others more than one, and future studies may identify additional sheepnose host species that 
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might modify this conclusion. Sheepnose are also susceptible from direct and indirect effects 

(through host fish species) of Braidwood’s effluent due to temperature and current alterations 

and to chemical contaminants.

The IEPA, not the NRC, regulates the discharge through its Illinois NPDES permitting program 

to insure protection of aquatic species, and Braidwood must have an Illinois NPDES permit to 

operate. In view of these observations, the NRC staff concludes that snuffbox may occur near

Braidwood but that the continued operation of Braidwood may, but is not likely to, adversely 

affect the species.” Mussel surveys for the Braidwood Station were most recently conducted in 

2009 by Ecological Specialists, Inc. (ESI). Initial surveys were conducted by HDR Engineering 

(HDR) in 2008 (when a fresh dead sheepnose was collected in the Kankakee River in the 

vicinity of the Braidwood discharge diffuser). Due to the lack of recent survey information in the 

project area, we cannot concur with the applicant’s effect determination of “may affect, not likely 

to adversely affect.” We recommend that mussel surveys be conducted in the areas covered by 

the past HDR and ESI studies to determine if the sheepnose may be adversely affected by the 

proposed project. The NRC should also supplement its impact analysis for the sheepnose to 

include the golden shiner and fathead minnow as potential natural host species.

Response: Exelon committed to do a mussel survey in the Kankakee River and provide to the 

NRC and U.S. Fish and Wildlife Service (FWS) for review. Exelon submitted the results of the 

survey to NRC and FWS on September 30, 2015. After considering the results of that recent 

information, the NRC staff did not change its preliminary biological assessment that the 

operation of Braidwood’s cooling water intake system “may, but is not likely to, adversely affect” 

sheepnose. Following FWS review of the mussel survey, the NRC and FWS may either enter 

into formal section 7 consultation or conclude the present consultation. The NRC staff revised

text of the Chapter 4 to include the aforementioned discussion. The result of the consultation

will be included in the Record of Decision for the proposed Braidwood license renewal.

Comment 012-6-Special Status Species and Habitats: The NRC concluded that the project 

“may affect, but is not likely to adversely affect” the northern long-eared bat. The DSEIS 

indicates that: “Over the duration of the proposed license renewal term, Exelon (2013c) reports 

no plans for landscape-altering activities, such as those that might adversely affect northern 

long-ear bats.” If no tree clearing is proposed as part of the proposed action, the applicant 

should make a “no effect” determination for the species. If tree clearing is proposed, Exelon 

should quantify the amount of tree clearing and provide that information to the Service. Recent 

mist-net surveys have captured the northern long-eared bat in close proximity to the 

Braidwood Station.

Response: The NRC staff requested and received additional information from Exelon and 

revised the text in Section 4.8 to reflect that Exelon does not expect tree clearing to be recurring 

activity at the Braidwood site.
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A.2.13 Written Comments From Kenneth Westlake, U.S. Environmental 

Protection Agency

Comment 013-1-Special Status Species and Habitats: The Northern Long-Eared Bat (Myotis 

septentrionalis) (NLEB) was Federally-listed as a threatened species in April 2015. USFWS 

reports that surveys in Shawnee National Forest in Illinois, about 300 miles south of Braidwood, 

consistently catch NLEBs, and USFWS states they may be found on the Braidwood site. 

USFWS has also indicated that winter hibernacula are not located on the Braidwood site; 

however, when NLEBs forage at night and roost during daylight in small numbers in live and 

dead trees, they change roosts often. The Draft Supplemental EIS indicates “This site would 

probably not provide prime habitat for long-ear bats even though they are more opportunistic 

than Indiana bats in roost selection.”

Recommendation: U.S. EPA recommends NRC consult with USFWS to determine the 

following: 1) what type(s) of non-winter habitat NLEBs use, 2) if such habitat exists at the 

Braidwood site, what protocol should be used and what time of year is best to survey for 

NLEBs, and 3) if NLEBs are captured at the Braidwood site, what effect license renewal will 

have on NLEBs. U.S. EPA recommends consultation with USFWS under Section 7 of the 

Endangered Species Act regarding the NLEB occur before the Final Supplemental EIS is 

published. If USFWS concurs that license renewal would have no effect on the NLEB, USFWS 

may propose technical assistance to the applicants to ensure any NLEB habitat located on the 

Braidwood site remains viable for the NLEB. If technical assistance is provided, we strongly 

recommend the applicant commit to including the provisions of the technical assistance in its 

management plans. All correspondence regarding consultation and coordination with USFWS 

should be included as an appendix to the Final Supplemental EIS and the results of that 

consultation should be included the Final Supplemental EIS.

Response: The NRC staff consulted the FWS, as requested, regarding NLEB three items 

listed above and received additional information from Exelon regarding potential tree-clearing 

activities. The staff revised the text of Section 4.8 to include the recent listing of NLEB as 

endangered, and updated information on the consultation between NRC and FWS.

Comment 013-2-Special Status Species and Habitats: As stated in the Draft Supplemental 

EIS, sheepnose mussels (Plethobasus cyphyus) are susceptible to direct and indirect effects 

(through host fish species) of Braidwood’s effluent, due to temperature and current alterations 

and to chemical contaminants. USFWS’ 2013 letter to NRC notes the possible presence of the 

Federally-listed sheepnose mussel and requested NRC pay particular attention “to potential 

impacts from water quality (including temperature) and water quantity that may result from 

proposed operations” on those species. Mussel surveys were conducted near Braidwood in 

2008 and 2009. The most recent survey was conducted in 2012 and sampled 20 sites in the 

Kankakee River. Sheepnose were found at two sites in the Kankakee River. However, it is not

clear from reviewing the Draft Supplemental EIS where the sheepnose were found in relation to 

the project area.

Recommendation: The mussel surveys conducted in the project area are several years old. 

U.S. EPA recommends NRC consult with USFWS to determine if these surveys are still valid or 

whether additional mussel surveys are needed before a license renewal decision is made. All 

correspondence regarding consultation and coordination with U.S. FWS should be included as 

an appendix to the Final Supplemental EIS and the results of that consultation should be 

included in the body of the Final Supplemental EIS.
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Response: Exelon committed to do a mussel survey in the Kankakee River, FWS has 

reviewed the study design, and Exelon completed the survey and submitted results to FWS and 

NRC on September 30, 2015. Following FWS review of the mussel survey, the NRC and FWS 

may either enter into formal section 7 consultation or conclude the present consultation. The 

NRC staff revised text of Chapter 4 to include the aforementioned discussion. The result of the 

consultation will be included in the Record of Decision for the proposed Braidwood license 

renewal.

Comment 013-3-Aquatic: As stated in the Draft Supplemental EIS, the Illinois Department of 

Natural Resources (IDNR) lists 14 State-endangered or threatened species (9 fish, 5 mussels) 

in Will County, and available aquatic surveys (ESI 2009; HDR 2008, 2014; IDNR 1998; Price 

et al. 2012) indicate that 10 of these species (5 fish, 5 mussels) occur within the Kankakee River 

and its tributaries. In December 2009, the IDNR (2009) issued an incidental take permit to the 

applicant for State-listed species (western sand darter, pallid shiner, river redhorse, purple 

wartyback, spike, black sandshell, and sheepnose) that had the potential to be affected by the 

replacement of the discharge channel. The incidental take permit prohibited construction 

activities from occurring during the spring spawning season and required relocation of 

state-listed freshwater mussels prior to the commencement of construction. In July 2010, 

Ecological Specialists collected and relocated 911 live mussels within the area that had the 

potential to be impacted by construction. Relocated mussels included 16 State-listed mussels 

(8 purple wartyback and 8 black sandshell). The 2009 incidental take permit also requires the 

applicant to complete a follow-up survey of fish and mussels near the construction area 5 years 

after completion of construction. The Draft Supplemental EIS indicates this survey will be 

undertaken in 2016.

Recommendation: U.S. EPA recommends NRC conduct the follow-up survey of fish and 

mussels in the project area and consult with IDNR before a license renewal decision is made. 

All correspondence regarding consultation and coordination with IDNR should be included as an 

appendix to the Final Supplemental EIS and the results of that consultation should be included 

in the body of the Final Supplemental EIS.

Response: The commenter recommends that the NRC conduct followup mussel and fish 

surveys related to the discharge channel replacement project described in the DSEIS and 

document the surveys and any relevant correspondence with the IDNR in the Final 

Supplemental Environmental Impact Statement (FSEIS). However, the discharge channel 

replacement project was completed in December 2010 and is not part of the proposed action. 

Exelon is required to comply with the Illinois Endangered Species Protection Act in its 

operations, and it sought an incidental take authorization from the IDNR prior to commencing 

that project. The incidental take authorization specifies that Exelon is responsible for 

conducting any followup aquatic surveys and for coordinating with the IDNR regarding effects to 

State-listed species that may have resulted from the discharge channel replacement. Exelon 

conducted the mussel portion of the follow-up survey in September 2015, and the NRC has 

updated Sections 3.7, 3.8, 4.7, and 4.8 of the SEIS to reflect the results of the survey.

Comment 013-4-Terrestrial Resources: Bald Eagles

A stated in Section 3.6.3.3, Important Species and Habitat, “The bald eagle, which is 

Federally-protected under the Bald and Golden Eagle Protection Act (BGEPA) and the 

Migratory Bird Treaty Act (MBTA), has nested on one of the cooling pond islands in the past. 

The BGEPA and MBTA provide certain protections to bald and golden (Aquila chrysaetos) 

eagles and migratory birds, respectively. USFWS Chicago Ecological Services Field Office 

provided technical assistance to the applicant to ensure that eagles were protected and the 
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applicant appropriately complied with the BGEPA. In its Environmental Report, the applicant 

indicated that bald eagles have not nested on the cooling pond in recent years.” The Draft 

Supplemental EIS is not clear regarding the time period during which bald eagles have been 

nesting on the islands in the cooling ponds.

Recommendation: U.S. EPA recommends the Final Supplemental EIS indicate if bald eagles 

had been observed nesting during the 2014 nesting season and whether it appears that a 

nest(s) on the cooling pond islands are or will be occupied during the 2015 nesting season, 

which can begin in January or February1. If bald eagles are observed nesting on cooling ponds 

islands during the 2015 nesting season, we recommend a discussion be added to the EIS 

concerning the applicant’s plans to adhere to USFWS’ 2007 National Bald Eagle Management 

Guidelines and details of any technical assistance provided by the USFWS. Lastly, passing any 

information about bald eagle sightings to USFWS helps the agency maintain its sightings 

database.

1 http://www.fws.gov/southeast/eslbaldeagle/baea_nhstry_snstvtv.html

Response: The commenter requests that the FSEIS address whether bald eagles have been 

observed nesting on cooling pond islands in 2014 or 2015 and how the applicant intends to 

adhere to the 2007 National Bald Eagle Management Guidelines. The commenter also 

encourages the NRC and Exelon to inform FWS of bald eagle sightings to help the FWS 

maintain its sighting records. In e-mail correspondence to NRC dated June 23, 2015 

(ADAMS Accession No. ML15180A391), Exelon states that it has not observed any bald 

eagles nesting on the cooling pond islands during the 2014 nesting season or in 2015 to date. 

Regarding adherence to the 2007 Bald Eagle Management Guidelines, most of the islands in 

the Braidwood cooling pond are within areas leased and managed by the IDNR as part of the 

Mazonia–Braidwood State Fish and Wildlife Area. The lease requires that IDNR assure 

compliance with all environmental laws, including those that protect wildlife. Accordingly, if 

Exelon personnel observe nesting bald eagles in the leased area of the cooling pond, Exelon 

will inform IDNR of the observation and request that IDNR undertake its responsibilities in 

accordance with the lease. If Exelon personnel observe nesting bald eagles in the restricted 

access portion of the cooling pond, Exelon will notify the FWS and coordinate with the agency 

to ensure adherence to the Bald Eagle Management Guidelines. The NRC staff updated 

Section 3.6.3.3 of the FSEIS to reflect the information stated in this comment response.

Comment 013-5-Terrestrial Resources: The applicant maintains a Wildlife Habitat Council 

(WHC)-certified Wildlife Management Plan for the Braidwood site. The plan outlines the goals 

and projects of the applicant’s Wildlife at Work program, which includes ecological management 

of the cooling pond (referred to as “Braidwood Lake” in the plan) through fish population 

management, underwater habitat restoration, and shoreline habitat restoration. The plan 

indicates that the applicant will consider planting other native shoreline plants, in consultation 

with IDNR in the future. The applicant will also evaluate the potential for controlling and 

removing some of the non-native invasive common reed (Phragmites australis) with mechanical 

methods and aquatic-safe herbicides. Non-native species are not currently being controlled).”

Recommendation: The Draft Supplemental EIS indicates that the applicant intends to seek 

WHC recertification and continue to implement wildlife protection programs during the term of 

the proposed re-licensing. U.S. EPA commends the applicant and the Braidwood staff in 

conducting these activities. We encourage incorporation of additional native shoreline plantings 

and removal of terrestrial and aquatic non-native, invasive species in the Wildlife Management 

Plan.
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Response: The commenter generally commends Exelon for maintaining a Wildlife 

Management Plan for the Braidwood site and provides several specific recommendations 

for future updates to the plan. Section 3.6.3 of the SEIS has been revised to include the 

commenter’s recommendation to Exelon regarding incorporation of additional native shoreline 

plantings and removal of non-native invasive species into the Braidwood Wildlife 

Management Plan.

Comment 013-6A-Water Resources: Surface Water Section 3.5.1.3, Surface Water Quality 

and Effluents, provides locations of the Braidwood National Pollution Discharge Elimination 

System (NPDES) outfalls in Figure 3-8 and Table 3-6 lists a brief description of each outfall. 

The discussion of the NPDES permit limits with the associated outfalls that follows is 

ambiguous.

Recommendation: A table with each NPDES outfall with corresponding monitoring and 

effluent limits for each would provide the reader with a clearer description of pollutants that 

could potentially be released from the facility. This information would make the public aware of 

potential exposures or water quality impacts that may impair or restrict designated uses of that 

water body.

Response: NPDES permit requirements are set and enforced by the U.S. EPA or the State (if 

EPA has delegated its CWA Section 402 permit authority to the State, as is the case in Illinois). 

As discussed in Section 3.5.1.3 of the SEIS, the NPDES permit specifies the discharge

standards and monitoring requirements for effluent chemical and thermal quality and for 

stormwater discharges through the plant’s outfalls. Depending on the outfall monitored, 

constituents include temperature, pH, chlorine, total suspended solids, oil, and grease. No 

discharge of polychlorinated biphenyl compounds is allowed. The NPDES permit for Braidwood 

is attached to an Exelon letter dated August 15, 2014 (ADAMS No. ML14227A712). In 

response to this comment, the NRC staff revised Table 3–6 of the SEIS to list NPDES permit 

limits for monitored constituents for each outfall. The staff also revised Section 3.5.1.3 of the 

SEIS to identify NPDES permit noncompliance occurrences, limits that were exceeded, and to 

discuss corrective actions.

Comment 013-6B-Water Resources: Section 3.5.1.3, Surface Water Quality and Effluents, 

page 3-31 starting on line 3 mentions that the applicant has prepared a Storm Water Pollution 

Prevention Plan (SWPPP). Section 3.13.2, Nonradioactive Waste, also discusses the SWPPP 

and that it “identifies potential sources of pollution that may affect the quality of storm water

discharges from each permitted outfall”.

Recommendation: The Final Supplemental EIS should provide more discussion on these 

sources of pollution that potentially could be discharged from the facility into the storm water

outfall. The Final Supplemental EIS should contain, at minimum, impacts on the environment 

with respect to quantities released and the effects of those releases on water quality and 

public exposure.

U.S. EPA acknowledges the discussion beginning on page 4-61 regarding the recently updated 

requirements under the Clean Water Act Section 316(b) on impingement and entrainment of 

aquatic organisms. We appreciate the inclusion of this information and note that specific 

upgrades to the cooling water system, if any, will be identified during the facility’s next NPDES

permit in July 2019.
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Response: The SEIS states that Exelon is required to maintain and update an SWPPP 

per Braidwood NPDES permit. The SWPPP for Braidwood is provided at ADAMS 

No. ML14030A264. In response to this comment, the NRC staff added a description of the 

stormwater outfalls and monitored outfalls to Table 3–6 of the SEIS and added information on 

potential pollutant sources from Braidwood’s SWPPP Section3.5.1.3. Potential pollutant 

sources that could affect stormwater discharge include diesel and gasoline storage tanks, 

the lime silo, oil storage tanks, the sodium hypochlorite tank, the sodium bromide tank, and 

transformer areas. Engineering controls are employed to prevent pollutant spills, such as 

double wall tanks with leak detection instrumentation, underdrain systems to direct flow to oil 

separator prior to entering outfalls, and berms to retain potential leakage. Inspections by plant 

personnel are routinely conducted to identify leaks or hazards. Discharge monitoring data are 

reported in monthly Discharge Monitoring Reports and submitted to the State.

Surface water impacts are analyzed in accordance with 10 CFR Part 51 and described in 

Section 4.5.1.1. of the SEIS. Table 4–5, in Section 4.5.1.1, lists NEPA issues considered in 

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

(NUREG-1437, Volume 1, Revision 1, ADAMS No. ML13106A241). In the GEIS, impacts on 

surface water quality from NPDES permitted and other stormwater discharges subject to the 

SWPPP evaluated under the issue, “Surface water use and quality (non-cooling system

impacts),” are considered to be SMALL and are classified as a Category 1 issue. For 

Category 1 issues, no additional plant-specific analysis is required unless new and significant 

information is identified. The environmental review of the Braidwood site did not discover any 

new and significant information with respect to this issue. Therefore, the NRC staff concludes 

that the impacts are SMALL.

Comment 013-7-Water Resources: Global Climate Change - Aquatic Resources U.S. EPA

notes that there has been one requested and approved variance to the NPDES permit regarding 

temperature in the past five years2. The Draft Supplemental EIS includes some information on 

discharge and withdrawal rates, but not temperature data for the cooling pond and the 

Kankakee River, near the outfall. Further, there is no conclusion about whether anticipated 

increases in water temperature will change the way the plant operates. We are interested in 

a discussion of both impacts from withdrawal of water (that might be too warm to adequately 

serve as cooling water) and discharge of water (that might be too warm to discharge per the 

NPDES permit).

Recommendation: U.S. EPA recommends NRC and the applicant come to a conclusion about 

whether there is a trend in increasing water temperatures in the cooling pond and the Kankakee 

River. The Final Supplemental EIS should also identify any potential impacts to operation from 

increasing water temperatures, in terms of both water withdrawal and water discharge. 

2 Page 4-65, lines 9-12: In the past 5 years, Braidwood has reported one noncompliance with Special Condition 4 to the EPA. In 

March 2012, blowdown water discharged as effluent to the Kankakee River at Outfall 001 exceeded the permitted temperature 

limits at points beyond the mixing zone edge due to a period of extremely warm weather and little to no precipitation in Illinois 

(Exelon 2014l).

Response: The commenter suggests that the FSEIS include (1) temperature data for 

Braidwood’s cooling pond and the Kankakee River (near the discharge outfall) and conclude 

whether there is a trend of increasing water temperatures in both the cooling pond and 

Kankakee River and (2) a discussion of how potential increases in water temperature will 

impact plant operations.
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Cooling Pond and Kankakee River Temperature Data

As part of the NRC’s environmental review, NRC staff issued requests for additional information 

(RAIs) asking Exelon to provide Kankakee River and cooling pond water temperatures and 

information as to whether any warming trends have been observed during the period of plant 

operations (ADAMS No. ML13350A512). In response to the RAIs, Exelon provided the NRC 

with temperature data measured at the Braidwood River Screen House intake structure for the 

2002 through 2008 and 2011 through 2013 (ADAMS No. ML14030A266) time period and from 

the cooling pond for the 2004 through 2013 time period (ADAMS No. ML14030A264). 

Section 4.11 of the SEIS includes the cooling pond’s annual average temperature data and 

average maximum monthly temperatures of water discharged to the Kankakee River in the 

summer months (ADAMS No. ML14030A266). Section 4.16.3.1 of the SEIS states that the data 

obtained do not display an increasing trend in cooling pond temperatures. In response to this 

comment, the NRC staff expanded the discussion of climate change impacts to water resources 

in Section 4.16.3.1 to consolidate the data presented in Section 4.11.

Water Temperature Impacts to Plant Operations

Section 4.16.3.1 of the SEIS addresses the impacts of climate change on plant operations and 

on surface water resources. Higher air surface temperatures can lead to higher cooling pond 

temperatures and an increase in evaporation from Braidwood’s cooling pond; this can 

subsequently result in additional makeup water withdrawals from the Kankakee River and 

higher temperature discharges to the Kankakee River. Higher cooling water temperatures, as a 

result of increased cooling pond and Kankakee River water temperatures, decrease the cooling 

efficiency of thermoelectric power generating facilities and electricity production. As intake 

water temperatures warm, cooling water makeup requirements increase. The warming of lake 

waters would lead to an increase in the average monthly use of cooling water and could 

potentially result in a slightly larger volume of heated water discharged back to the river. Any 

increases in makeup water withdrawals for Braidwood’s cooling pond would need to be in 

compliance with Braidwood’s maximum makeup withdrawal rate and provisions specified in 

its 1977 construction permit from the Illinois Department of Transportation (IDOT), Division of 

Water Resources (now the IDNR). As discussed in Section 3.5.1.2, Braidwood has operating 

procedures to comply with the provisions of makeup water withdrawals and actions that plant 

personnel must follow. Furthermore, thermal discharges would be required to meet 

Braidwood’s applicable NPDES permit (No. IL0048321) temperature limit requirements, and any 

departure from such requirements will require IEPA approval. As discussed in Section 3.5.1.3 

of the SEIS, surface water discharge is regulated by the IEPA via the NPDES program, and 

NPDES permits are issued by the IEPA. Additionally, plant operations are dictated by 

NRC-issued operating license technical specifications which ensure that plants operate safely 

at all times, to include ensuring that adequate cooling water is available and maintained. 

Specifically, technical specifications and operating procedures provide assurance that optimal 

water levels in reservoirs and cooling ponds are maintained and that cooling water intakes are 

protected for safe operation of the facility. If not, the plant would have to reduce power or shut 

down. If a licensee proposes physical alterations to its plants or proposes changes in operating 

conditions contrary to operating license technical specifications, NRC would conduct safety and 

environmental reviews of such requests. This is a separate process from the license renewal 

review. No changes were made to the SEIS in response to the comment.
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Comment 013-8-Greenhouse Gas Emission and Climate Change: Global Climate Change 

and Greenhouse Gases

On December 18, 2014, the Council on Environmental Quality released revised draft guidance 

for public comment that describes how Federal departments and agencies should consider the 

effects of greenhouse gas (GHG) emissions and climate change in their NEPA reviews. The 

revised draft guidance supersedes the draft GHG and climate change guidance released by 

CEQ in February 2010. This guidance explains that agencies should consider both the potential 

effects of a proposed action on climate change, as indicated by its estimated GHG emissions, 

and the implications of climate change for the environmental effects of a proposed action.

Section 4.15.3 details potential GHG emissions and impacts related to climate change, 

concluding that GHG emissions would be lower for activities associated with license renewal 

than for fossil-fuel based energy production, as analyzed in the Draft Supplemental EIS.

Recommendation: We recommend that the Final Supplemental EIS identify opportunities to 

minimize GHG emissions associated with operation of the facility to the extent feasible during 

the license renewal period. For example, clean energy options, such as energy efficiency and 

renewable energy, can be considered in the purchase of maintenance equipment, new 

equipment and vehicles. See also, U.S. EPA’s diesel emission reduction strategies, below, for 

options to consider. In addition, U.S. EPA recommends that the applicant consider the need to 

develop adaptation measures to address impacts from climate change on the facility, such as 

increased intensity and frequency of storm and flood events.

Response: The commenter recommends that the FSEIS identify (1) opportunities to minimize 

GHG emissions associated with operation of Braidwood (e.g., energy efficiency and renewable 

energy in the purchase of maintenance equipment and vehicles) and (2) adaptation measures 

to address impacts from climate change on the facility from increases in intensity and frequency 

of storm and flood events.

Opportunities to minimize GHG emissions associated with operation of the facility during the 

license renewal period were not identified or evaluated in the SEIS for the following reasons. 

Section 4.15.3 of the SEIS identifies that annual GHG emissions from continued operation from 

Braidwood are several orders of magnitude lower than GHG emissions from the integrated 

gasification combined cycle (IGCC), natural-gas-fired combined-cycle (NGCC), Combination, 

and Purchased Power Alternatives. GHG emissions from Braidwood are below EPA’s threshold 

of 25,000 MT of carbon dioxide equivalents (CO2e), which requires facilities to report GHG 

emissions to the EPA annually in accordance with 40 CFR Part 98. Furthermore, GHG 

emissions from Braidwood are minor relative to various GHG inventories presented in 

Section 4.16.11. Section 4.16.11 concludes that the incremental impacts from the contribution 

of GHG emissions from continued operation of Braidwood on climate change would be SMALL.

Additionally, the NRC staff did not identify or evaluate potential mitigation strategies to reduce 

GHG emissions since the licensee, not the NRC, is responsible for the purchase of 

maintenance equipment and vehicles. Based on its limited statutory authority under the Atomic 

Energy Act of 1954 (AEA), the NRC cannot impose requirements on its nuclear power plant 

licensees that are not related to protection of public health and safety from radiological hazards 

or protection of common defense and security, such as clean energy options for maintenance 

equipment and vehicles. Nevertheless, licensees are required to comply with all applicable 

Federal, State, and local permit requirements relevant to their activities.

Adaptation of a facility to address impacts from climate change on the facility is outside the 

scope of the NRC’s license renewal environmental review and was not specifically evaluated 

in the development of the Braidwood SEIS. General Design Criteria in 10 CFR Part 50, 
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Appendix A, require that plant structures, systems, and components important to safety be 

designed to withstand the effects of natural phenomena, such as flooding, without loss of 

capability to perform safety functions. Plants are required to operate within NRC-issued 

operating license technical specifications which ensure safe operations or require a plant to shut 

down, including coping with natural phenomena hazards. Any proposed climate or adaption 

change that is contrary to the terms of operating license or technical specifications would 

require prior NRC review and approval before it could be implemented. Additionally, the NRC 

inspects nuclear power plant operating conditions and physical infrastructure to ensure 

continued safe operations through its reactor oversight program.

If new information becomes available, the NRC would evaluate the new information to 

determine if any changes are needed at existing plants or to its regulations. This oversight 

of current operations is a separate and distinct process from NRC’s license renewal NEPA

reviews. For example, as part of the NRC’s lessons-learned activities resulting from the 

March 2011 earthquake and tsunami in Japan, the NRC issued orders under 10 CFR 50.54 

requesting, in part, that licensees conduct flooding reevaluations at existing nuclear power 

plants (see ADAMS No. ML12053A340). The NRC will evaluate information submitted in 

response to the order and will take action, as necessary, to protect public health and safety.

Comment 013-9-Air Quality: EPA notes the only proposed refurbishment activities proposed 

at Braidwood are the steam generator replacement for Unit 2 and reactor pressure vessel head 

replacement for one or both units. Refurbishment activities are expected to take place during 

normal outage schedules and will be limited to already disturbed areas, therefore impacts are 

expected to be minimal.

However, U.S. EPA recommends the applicant commit to the following diesel emission 

reduction strategies to further reduce impacts to air quality as a result of the proposed 

construction activities associated with the license renewal process.

 Use low-sulfur diesel fuel (15 ppm sulfur) in construction vehicles 

and equipment.

 Retrofit engines with an exhaust filtration device to capture diesel particulate 

matter before it enters the construction site.

 Position the exhaust pipe so that diesel fumes are directed away from the 

operator and nearby workers, reducing the fume concentration to which 

personnel are exposed.

 Use catalytic converters to reduce carbon monoxide, aldehydes, and 

hydrocarbons in diesel fumes. These devices must be used with low 

sulfur fuels.

 Use enclosed, climate-controlled cabs pressurized and equipped with high 

efficiency particulate air (HEPA) filters to reduce the operators’ exposure to 

diesel fumes. Pressurization ensures that air moves from inside to outside. 

HEPA filters ensure that any incoming air is filtered first.

 Regularly maintain diesel engines, which is essential to keep exhaust 

emissions low. Follow the manufacturer’s recommended maintenance 

schedule and procedures. Smoke color can signal the need for maintenance. 

For example, blue/black smoke indicates that an engine requires servicing or 

tuning.
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 Reduce exposure through work practices and training, such as turning off 

engines when vehicles are stopped for more than a few minutes, training 

diesel-equipment operators to perform routine inspection, and maintaining 

filtration devices.

 Repower older vehicles and/or equipment with diesel- or alternatively-fueled 

engines certified· to meet newer, more stringent emissions standards. 

Purchase new vehicles that are equipped with the most advanced emission 

control systems available.

 Use electric starting aids such as block heaters with older vehicles to warm 

the engine reduces diesel emissions.

 Use respirators, which are only an interim measure to control exposure to 

diesel emissions. In most cases, an N95 respirator is adequate. Workers 

must be trained and fit-tested before they wear respirators. Depending on 

work being conducted, and if oil is present, concentrations of particulates 

present will determine the efficiency and type of mask and respirator. 

Personnel familiar with the selection, care, and use of respirators must 

perform the fit testing. Respirators must bear a NIOSH approval number.

 Per Executive Order 13045 on Children’s Health3, EPA recommends 

operators and workers pay particular attention to worksite proximity to 

places where children live, learn, and play, such as homes, schools, and 

playgrounds. Diesel emission reduction measures should be strictly 

implemented near these locations in order to be protective of 

children’s health.

3 Children may be more highly exposed to contaminants because they generally eat more food, drink more water, and have higher 

inhalation rates relative to their size. Also, children’s normal activities, such as putting their hands in their mouths or playing on the 

ground, can result in higher exposures to contaminants as compared with adults. Children may be more vulnerable to the toxic

effects of contaminants because their bodies and systems are not fully developed and their growing organs are more easily 

harmed. EPA views childhood as a sequence of lifestages, from conception through fetal development, infancy, and adolescence.

Response: The comment recommends that the applicant commit to diesel emission reduction 

strategies to reduce impacts to air quality as a result of activities associated with potential 

refurbishment (steam generator replacement and reactor pressure vessel head replacement) 

and suggests how Exelon could minimize diesel emissions.

Based on its limited statutory authority under the AEA, NRC cannot impose mitigation measures 

or standards on its nuclear power plant licensees that are not related to public health and safety 

from radiological hazards or common defense and security. The actions and recommendations 

identified are outside the NRC’s statutory authority. Nevertheless, licensees are required to 

comply with all applicable Federal, State, and local permit requirements relevant to their 

activities. For example, the commenter identifies actions to minimize worker exposure to diesel 

fumes (e.g., use of respirators, work practices and training, exhaust positioning). As discussed 

in Section 3.11.5 of the SEIS, Exelon maintains a worker safety program at Braidwood, and the 

Occupational Safety and Health Administration (OSHA) is responsible for developing and 

enforcing workplace safety regulations; implementation of Exelon’s worker safety program 

and OSHA regulations safeguard the health of workers. Furthermore, use of diesel fueled 

equipment and operation of vehicles must comply with air pollution regulations for the State 

of Illinois and applicable air permits from the IEPA and could include the reduction measures 

described in the comment.
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A.2.14 Written Comments May 12, 2015, From Michael Gallagher, Exelon 

Generation Company

Comment 014-1-Surface Water Resourcers: The DSEIS states that “the IDNR regulates 

Exelon’s operation and maintenance of the cooling pond through Permit No. NE2000125 

(IDNR 2000).” This is not correct. The IDNR permit referenced in this text is a permit for 

Cooling Pond dam operation and maintenance only, not for operation and maintenance of 

the Cooling Pond more generally.

Response: The NRC staff corrected the reference to IDNR Permit No. NE2000125 to clarify 

that it applies to cooling pond dam operation and maintenance rather than operation and 

maintenance of the cooling pond as a whole.

Comment 014-2-Aquatic: The DSEIS states that in the FES-O in 1984, the:

NRC determined that the effects of thermal additions to the cooling pond were discountable 

because the State had not identified the pond as a fishery resource and because the applicant 

had indicated that the pond would only be used for cooling purposes [emphasis added]. 

However, since that time, the IDNR has regularly stocked the lake with game fish and the pond 

is managed as part of the Mazonia-Braidwood State Fish and Wildlife Area. The pond also 

provides quality habitat, food, and water to waterfowl and migrating birds. The NRC, therefore, 

no longer considers effects to the cooling pond to be discountable.

Thus, the DSEIS concludes that a material change in circumstances has occurred since the 

Braidwood Operating License Final Environmental Statement was issued that now, at the 

License Renewal stage, compels a NEPA assessment by NRC of the effects of thermal 

additions to the cooling pond, whereas one was not needed at the Operating License Stage. 

Exelon Generation objects to this conclusion for the following reasons:

1. The Braidwood Cooling Pond is a “wastewater treatment system” and, therefore, is not 

a “water of the United States” under the Clean Water Act. Because it is not a water of 

the United States, the NRC should not be evaluating impacts on the Cooling Pond from 

Braidwood’s thermal additions to the cooling pond water.

2. Section 316(a) of the CWA, as its title states, provides “Effluent limits that will assure 

protection and propagation of balanced, indigenous population of shellfish, fish, and 

wildlife.” The CWA, however, does not apply to influents into the Braidwood Cooling 

Pond. Accordingly, there is no need to ensure protection and propagation of a 

balanced, indigenous population of shellfish, fish, and wildlife in the Braidwood Cooling 

Pond. To suggest otherwise through a NEPA analysis, would be to impermissibly 

impose an environmental standard on a wastewater treatment system that is itself 

exempt from that standard.

3. The NRC acknowledges, in its “Summary of Thermal Impacts Conclusion” on DSEIS 

page 4-67, that Illinois considers the Braidwood Cooling Pond to be a “wastewater

treatment facility” that “is not subject to the limitations of the CWA.” As a wastewater 

treatment facility, there are no limits on thermal additions to the Cooling Pond from the 

Braidwood circulating water system; whereas if the Cooling Pond was subject to the 

CWA, thermal additions might be regulated differently. As a result, there is no federal 

or state requirement to protect the fish that might be present in the Cooling Pond. 

Even being part of a “Fish and Wildlife Area” does not change that result.

4. The lease between Exelon and the State of Illinois Department of Natural Resources

recognizes that the Cooling Pond’s primary purpose is to provide cooling water to 
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Braidwood, and that all other purposes identified in the lease may be overridden to 

meet that need. Recital B of the lease states: “The Leased Premises is a part of 

Braidwood Generating Station owned by [Exelon] (“Braidwood Generating Station”).” 

Recital C states: “It is essential that [Exelon] continue to have the use of the waters of 

the Leased Premises for cooling water and other purposes for the Braidwood 

Generating Station, and that its continued operation of the Braidwood Generating 

Station be without interference from [Illinois] or anyone using the Leased Premises.” 

Finally, Recital D states: “The parties recognize that public use of the Leased 

Premises must be restricted and regulated in order that such public use hereunder 

shall not conflict or interfere with the present and future operation and use of the 

Braidwood Generating Station.” Inherent in these recitals is Illinois’ acknowledgement 

that plant operations must take precedence over the viability of fish that Illinois 

artificially stocks in the Cooling Pond. Indeed, by signing the lease, Illinois agreed that 

it “shall not pursue . . . any action or proceeding which might result in claims, fines, 

judgments or damages against [Exelon] arising from or related to fish or other aquatic 

life being killed during the term of this Lease.” Similarly, recreation is permitted in 

designated areas only; access by the public since the Cooling Pond was created has 

not been allowed to approximately 760 acres. If the parties to the lease understand 

that any fish stocked in the Cooling Pond are for limited recreational purposes, and that 

significant fish kills or unnatural fish population trends are anticipated due to water 

discharges at elevated temperatures, then the NRC should not skew its environmental 

impacts analysis by considering the “effects” to the Cooling Pond by Braidwood’s 

extended operation.

Response: In items 1, 2, 3, and 4 above, the commenter objects to the NRC’s assessment 

of thermal impacts on aquatic resources in the cooling pond because (a) such effects were not 

considered in the 1984 Final Environmental Statement (FES) for operation of Braidwood; (b) the 

cooling pond is not subject to effluent limitations under the CWA; (c) the State of Illinois 

considers the cooling pond to be a wastewater treatment facility; and (d) the lease agreement 

between Exelon and the IDNR for management of the cooling pond recognizes that the primary 

purpose of the pond and significant fish kills and unnatural fish population trends are anticipated 

as a result of elevated water temperatures.

The NRC staff differs with the commenter’s view that aquatic resources in the cooling pond 

should not be considered in the staff’s analysis of the potential effects of license renewal on 

aquatic resources. The NRC’s regulations at 10 CFR 51 concerning license renewal reviews 

and the Generic Environmental Impact Statement for License Renewal of Nuclear Plants, 

NUREG–1437 (GEIS) direct the NRC to consider all aquatic resources that may be affected by 

plant operations regardless of the type of water body in which such resources reside as noted in 

Appendix B, Table B-1 . For instance, Section 4.2.2 of the 1996 GEIS specifically notes that 

aquatic biota of cooling ponds may be affected by thermal discharges and that these effects 

should be considered the same as those considered for once-through cooling systems except 

that such effects mainly influence aquatic communities that did not exist before the creation of 

the cooling pond. The 2013 GEIS did not identify new information that would alter this 

methodology or alter any conclusions regarding impacts to aquatic populations in cooling ponds. 

The NRC, therefore, addresses the potential effects of license renewal on aquatic resources in 

the Kankakee River as well as the Braidwood Cooling Pond. This treatment of aquatic 

resources in cooling ponds is consistent with previous NRC license renewal reviews, including 

the NRC’s license renewal SEISs for Wolf Creek Generating Station, Unit 1, and South Texas 

Project, Units 1 and 2. In response to this comment, the NRC staff added a discussion of why 

the NRC considers aquatic resources in cooling ponds in its discussion of thermal impacts to 

aquatic organisms in Section 4.7.1.3 of the SEIS.
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5. The NRC also should not assess the impact of plant operations on fish that are 

manually placed in the Cooling Pond because there is no current mechanism for Illinois 

to stock fish in the Cooling Pond during the period of extended operation (PEO). The 

current lease between Exelon and Illinois is dated December 16, 2002, and it expires 

October 26, 2026. This is essentially coincident with the expiration of the existing 

Braidwood licenses on October 17, 2026 and December 18, 2027. Accordingly, there 

is no current mechanism for Illinois to stock the Cooling Pond during the PEO.

6. Because the lease expires in October 2026, for purposes of assessing the aquatic 

impacts of license renewal, the NRC should consider that under the No-Action 

Alternative, Illinois may not stock the Cooling Pond, thereby eliminating the fishing 

resource and eliminating its benefits. Thus, the NRC should consider the overall 

aquatic impacts from this baseline, not from the assumption that the Cooling Pond 

will be fully stocked by the State of Illinois during the proposed PEO.

Response: In items 5 and 6 of the comment, the commenter objects to consideration 

of stocked fish populations in the cooling pond in NRC’s assessment of thermal impacts on 

aquatic organisms because the current lease between Exelon and IDNR will expire in 2026, 

and, therefore, there is no assured mechanism for stocking to continue during the entirety of the 

proposed license renewal term. The NRC staff disagrees that stocked fish populations should 

not be considered, because stocking could cease. As previously noted, NRC’s regulations and 

the GEIS direct the NRC staff to consider all aquatic resources that may be affected by plant 

operations regardless of the type of water body in which such resources reside. The 

Environmental Standard Review Plan for license renewal (NUREG-1555, Supplement 1, 

Revision 1) directs NRC staff to focus its aquatic assessments on representative and important 

species, which include important recreational or commercial fish such as those in the Braidwood 

cooling pond that are stocked by the IDNR. The NRC staff concludes that it is reasonable to 

assume that stocked fish species would continue to inhabit the cooling pond throughout the 

proposed license renewal period for the following reasons. If Exelon and IDNR renew the lease 

to manage and stock the cooling pond, stocked species would continue to occur in the cooling 

pond because IDNR would continue to stock those species. If Exelon and IDNR do not renew 

the lease to manage and stock the cooling pond, stocked species would continue because the 

IDNR currently stocks the cooling pond with game species that can tolerate warmer water 

temperatures, including largemouth bass, channel catfish, blue catfish, bluegill, hybrid striped 

bass, and redear sunfish. Although these species occasionally appear in fish kills (see 

Section 3.7.4 of the SEIS), the primary negative pressure on these populations is recreational 

fishing, which would stop in the scenario in which the lease is not renewed. Although the 

distribution of species and population sizes may change without artificial replenishment, it is 

likely that the majority of stocked species that can tolerate warmer water temperatures would 

continue to occur in the cooling pond during the proposed license renewal term regardless of 

whether the lease to manage and stock the cooling pond is renewed. In Section 4.7 of the 

SEIS, the NRC staff does not address impacts to aquatic resources in the cooling pond 

separately under the two scenarios (i.e., lease expiration or lease renewal), because neither 

scenario would materially change the NRC’s assessment of impacts or conclusions regarding 

impacts to aquatic resources during the proposed license renewal term. The NRC staff added a 

description to Section 4.7.1.3 of the SEIS stating that the lease between Exelon and IDNR may 

expire during the proposed license renewal term but that the NRC staff assumes stocked fish 

species will remain in the cooling pond throughout the license renewal period for purposes of its 

impact assessment.
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7. The fish species that are stocked in the Cooling Pond are skewed towards those that 

will thrive in elevated temperatures. As such, failure to renew the plant’s license would 

result in a cessation of the thermal discharge and likely the death of these fish.

Response: The NRC staff recognizes that certain stocked recreational species that thrive in 

warmer waters may experience population declines or cease to occur in the cooling pond under 

the No-Action Alternative. The NRC has revised Section 4.7.2 to include this potential impact.

8. The suggestion that “the pond is managed as part of the Mazonia-Braidwood State 

Fish and Wildlife Area” is misleading without further context. Access by the public 

since the Cooling Pond was created has not been allowed to approximately 760 acres 

which comprise the intake and discharge channels in the immediate vicinity of 

Braidwood Station. Furthermore, the lease agreement allows Exelon, upon reasonable 

notice to IDNR, to restrict public access to the entire leased area at any time to 

accommodate operation and security of the plant.

Response: The NRC staff amended the referenced sentence in Section 4.7.1.3 to state that 

the IDNR manages a portion of the cooling pond (beyond the immediate vicinity of Braidwood) 

as part of the Mazonia–Braidwood State Fish and Wildlife Area.

Comment 014-3-Aquatic: Lines 25 to 28 on page 4-66 contain the following text: “Information 

on fish kills in the cooling pond indicates noticeable effects that are likely to persist while 

Braidwood is operational. This LOE does not provide enough information to determine if fish 

kills have destabilized any important attribute of the resource. Therefore, this LOE indicates 

that the effects of the thermal discharge on cooling pond aquatic biota are MODERATE.

Exelon Generation submits that the above-quoted conclusion fails to take account of the actual 

baseline aquatic environment in the Cooling Pond. If thermal impacts in the Cooling Pond are 

to be assessed, then the analysis should take account of the nature of the existing fish 

population, which is not naturally occurring. Because of IDNR’s goal for the fishery in the 

Cooling Pond to provide a desirable recreational fishing experience for anglers and Exelon’s 

desire to maximize the tolerance of fish to the thermal environment in the Cooling Pond, the fish 

populations in the Cooling Pond are artificially adjusted each year through stocking. Therefore, 

even if a fish kill occurs during a particular year, effects on the fish populations may only be 

observable at the time of the event because stocking can replace the losses. It should be 

recognized that in a closed system, such as the Cooling Pond, with a heavily managed fish 

population and the expectation of occasional fish kills, the impacts of thermally induced fish kills 

are essentially unnoticeable except at the time of the event, and hence, the impacts should be 

characterized as SMALL.

Response: The commenter states that the thermal impacts on aquatic organisms in the cooling 

pond under Line of Evidence 4 (LOE 4) are SMALL because the cooling pond is a heavily 

managed system and the effects of fish kills are essentially unnoticeable due to the stocking 

that replaces losses from such events. The NRC staff disagrees that the impacts are SMALL. 

While stocked species’ populations will rebound upon restocking, nonstocked species could 

experience noticeable declines as a result of fish kills. As indicated in Section 3.7.3.2, gizzard 

shad, one of the most frequently affected species during periods of elevated pond temperatures, 

have decreased in abundance dramatically in recent years. Threadfin shad are also often 

affected by elevated pond temperatures and have been present in a number of the fish kills 

described in Section 3.7.4. Accordingly, the NRC staff did not revise its conclusion of 

MODERATE for LOE 4 in Section 4.7.1.3 of the SEIS. The NRC staff did, however, revise 
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its impact assessment in this section of the SEIS to describe the highly managed nature of the 

cooling system and the differences in expected impacts to managed and nonmanaged species.

Comment 014-4-Global Climate Change: The evaluation of cumulative impacts of 

greenhouse gas (GHG) emissions from continued operation of Braidwood on Global Climate 

Change could leave the reader with the mistaken impression that Braidwood’s GHG emissions 

would have some measurable impact on global climate change, when they could not.

To start, the only table in the Executive Summary (Table ES-1) declares through its title that the 

“Site-Specific Impacts of [Braidwood’s] License Renewal” include MODERATE cumulative 

impacts to Global Climate Change. This is an unsupportable conclusion for a proposed action 

involving renewal of a nuclear power plant operating license, because nuclear power plants 

have virtually no GHG emissions, and nuclear power is one of the solutions that can decrease 

GHG emissions.

Under draft guidance recently published by the Council on Environmental Quality (CEQ), 

Federal agencies are asked to consider the cumulative impacts “of a proposed action’s 

reasonably foreseeable emissions and effects,” with cumulative impacts defined as the 

“incremental impact[s] of the action when added to other past, present, and reasonably 

foreseeable future actions . . . .” CEQ, Revised Draft Guidance for Federal Departments and 

Agencies on Consideration of Greenhouse Gas Emissions and the Effects of Climate Change in 

NEPA Reviews, 79 Fed. Reg. 77,802, 77,802, 77,826 (Dec. 24, 2014) (emphasis added). Thus, 

the cumulative impacts assessment should not be an assessment of the general impacts of all 

projects, but an assessment of the incremental contributions of the proposed project 

under consideration.

As shown in Table 4-29 of the DSEIS, the incremental addition of CO2 emissions from the 

continued operation of Braidwood would be extraordinarily small in comparison to global, U.S., 

and Illinois state emissions. According to that table, Braidwood would emit nearly 30 times less 

CO2 than the next lowest emitter on the table. Thus, the conclusion that “the cumulative impact 

of GHG emissions on climate change is noticeable but not destabilizing” and therefore 

MODERATE, is misleading in that it fails to clearly distinguish between Braidwood’s impact and 

the impact of all other sources. The conclusion does not lead to more informed decisionmaking, 

which is the purpose of NEPA and the draft CEO Guidance, because it fails to focus on 

Braidwood’s incremental contribution and to acknowledge that continued operation would in 

fact be beneficial for Global Climate Change. Indeed, all of the alternatives to license renewal 

considered in depth in the DSEIS involve significantly greater levels of CO2 emissions from 

fossil fuel generation.

NRC should revise Table ES-1 to indicate that the effects from the plant are SMALL, and to 

make conforming changes in the cumulative impacts section that discusses GHG emissions 

and Global Climate Change.

Response: The commenter expresses concern that the MODERATE conclusion reached in the 

cumulative impacts to Global Climate Change analysis of the SEIS is misleading as it does not 

distinguish between Braidwood’s incremental impact and the impact from other sources; states 

that the MODERATE conclusion is not supported since nuclear power plants have virtually no 

GHG emissions; believes that the cumulative impacts assessment should only be an 

assessment of the incremental contributions of the proposed action, not of the impacts of all 

projects; and requests that Table ES–1 and Section 4.16.11 of the SEIS be revised to conclude 

that impacts on climate change from Braidwood operation are SMALL.
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Regarding the commenter’s concern of a MODERATE cumulative impact conclusion not 

distinguishing Braidwood’s incremental impact, Section 4.16.11 of the SEIS clarifies that the 

NRC staff concludes that the impacts from the contribution of GHG emissions from continued 

operation of Braidwood on climate change would be SMALL. It is the cumulative impact of GHG 

emissions resulting from continued operation of Braidwood on global climate change when 

added to the aggregate effects of other past, present, and reasonably foreseeable future actions 

on climate change that is MODERATE. The SEIS also states that GHG emissions from 

Braidwood are minor relative to various GHG inventories presented in Section 4.16.11. 

Furthermore, Section 4.15.3.9 of the SEIS compares GHG emissions from continued operation 

of Braidwood and Alternatives and concludes that GHG emissions from the IGCC, NGCC, 

combination, and purchased power alternatives can be higher by several orders of magnitude 

than the proposed action.

Contrary to the commenter’s statement that the MODERATE conclusion in the SEIS analysis 

of cumulative impacts to Global Climate Change is not supported, Section 4.16.11 of the SEIS 

presents scientific research that supports this conclusion. As discussed in Section 4.16.11, 

climate change research and climate models indicate that short-term climate change is 

projected to occur with or without present and future GHG emissions. In other words, if GHG 

emissions were to be completely eliminated, Earth’s average surface temperature will continue 

to increase and climate-related changes will persist over the next few decades. The magnitude 

of continued increase in GHG emission rates will determine the amount of additional future 

warming and long-term (beyond 2030) climate change. Since climate change and 

climate-related changes have been observed on a global level (see Section 4.15.13.10 of the 

SEIS) and climate models indicate that future climate change will continue, the cumulative 

impact of GHG emissions on global climate is MODERATE (i.e., the cumulative impact of GHG 

emissions on climate change is noticeable but not destabilizing).

As defined by the Council on Environmental Quality (CEQ) in 40 CFR 1508.7, a cumulative 

impact is an “impact on the environment which results from the incremental impact of the action 

when added to other past, present, and reasonably foreseeable future action....” Therefore, the 

Global Climate Change cumulative impacts assessment (Section 4.16.11 of the SEIS) 

addresses the incremental impact of GHG emissions resulting from continued operation of 

Braidwood on global climate change when added to the aggregate effects of other past, 

present, and reasonably foreseeable future actions, not just the incremental impacts of 

continued operation of Braidwood on climate change. Furthermore, as discussed in the SEIS, 

GHGs are transported by wind and become well-mixed in the atmosphere as a result of their 

long atmospheric time, and their impact on climate is global. Therefore, it is appropriate for the 

cumulative impact assessment to include the aggregate effects of additional actions.

Thus, the MODERATE conclusion presented in Table ES–1 and Section 4.16.11 is specific 

to the cumulative impacts of GHG emissions on climate change and is supported by climate 

change research and climate models. The MODERATE conclusion with respect to climate 

change is the result of all aggregated GHG contributors. The NRC staff added text in 

Section 4.16.11 and a footnote to Table ES–1 of the SEIS to distinguish between the 

incremental impact from Braidwood on climate change and cumulative impact from past, 

present, and reasonably foreseeable projects.
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A.2.15 Historic and Cultural Resources: Written Comments From Rachel Leibowitz, 

Illinois Historic Preservation Agency

Comment 015-1-General: We have reviewed the documentation submitted for the referenced 

project in accordance with 36 CFR Part 800.4. Based upon the information provided, no historic 

properties are affected. We, therefore, have no objection to the undertaking proceeding as 

planned.

Response: This letter states that the State of Illinois concludes that no historic properties are 

affected and that the NRC complied with Section 106 of the National Historic Preservation Act

of 1966, as amended. No changes were made to the SEIS as a result of this letter.
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A.2.16 Written Comments From Nathan Grider, Illinois Department of Natural Resources

Comment 016-1-Aquatic: The Department is concerned about impingement and entrainment

of state-listed species, which can occur when makeup water is drawn from the Kankakee River 

into the cooling pond or from the cooling pond into the Braidwood station. The Department has 

no record of Incidental Take Authorization (ITA) being granted to the Braidwood facility for 

state-listed species suffering mortality as a result of impingement and entrainment. Currently, 

Exelon Generation Company, LLC. may be at risk of penalties under the Illinois Endangered 

Species Protection Act [520 ILCS 10/11]. The document clearly indicates that “take” has and 

likely is still occurring for the state-endangered pallid shiner (Hybopsis amnis) and 

state-threatened river redhorse (Moxostoma carinatum), and likely for other state-listed 

species as described in the following comments:

Comment 016-3-Aquatic: No entrainment or impingement studies have been conducted at the 

cooling pond intake (page 4-40). Older records exist in the cooling pond for pallid shiner (1989) 

and river redhorse (1999). However, according to the Department’s Fisheries Division, these 

species have not been collected during routine samples of the cooling pond in recent years. 

These species may have been impinged or entrained in the past and some risk may still exist as 

individuals are entrained from the Kankakee River intake and established in the cooling pond. 

Older records for western sand darter (1992, Ammocrypta clarum) also exist in the project area. 

An ITA was secured for this species in 2009 when Braidwood installed a discharge diffuser in 

the Kankakee River. Some risk of mortality may exist for this species as a result of entrainment 

and impingement. Exelon Generation Company, LLC. should evaluate potential impacts to the

western sand darter and consider ITA. The Department recommends Exelon Generation

Company, LLC. apply for ITA for the pallid shiner and river redhorse for the reasons stated

above. Please direct all matters pertaining to ITA to Jenny Skufca (Jenny.Skufca@illinois.gov) 

with the Department’s Office of Resource Conservation.

Comment 016-5-Aquatic: Mussels - Recent records exist in the Kankakee River near the 

intake for the state and federally-endangered sheepnose mussel (2008, Plethobasus cyphyus), 

as well as state-threatened black sandshell (2010, Ligumia recta), spike (2008, Elliptio dilatata ), 

and purple wartyback (2010, Cyclonaias tuberculata ). The Department notes that ITA was 

granted to Exelon Generation Company, LLC. for these four mussel species in 2009 for the 

construction of the discharge diffuser in the Kankakee River.

The only known host for sheepnose glochidia is the sauger ( Stizostedion canadense). 

Glochidia hosts for the black sandhell include bluegill (Lepomis macrochirus), largemouth bass 

(Micropterus salmoides), sauger, and white crappie (Pomoxis annularis). Glochidia hosts for 

the spike mussel include gizzard shad (Dorosoma cepedianum), flathead catfish (Pylodictis 

olivaris), white crappie, black crappie (P. nigromaculatus), and yellow perch (Perca flavescens). 

Glochidia hosts for the purple wartyback include channel catfish (Ictalurus punctatus), yellow 

bullhead (Ameiurus natalis), flathead catfish, and black bullhead (A. melas).

When comparing the glochidia hosts information to data collected from all three impingement

studies (pages 4-40 through 4-50), fishes which serve as glochidia host to black sandshell, 

spike, and purple wartyback mussels were known to be impinged at the Kankakee River intake. 

These fishes were also collected in Kankakee River monitoring samples from 2009 through 

2013 (pages 3-59 through 3-61) Therefore, individuals of these mussel species are likely being 

taken as a result of host mortality. It appears no saugers were collected in previous 

impingement studies or the recent Kankakee River samples. However, due to records of 

this mussel species in the vicinity, the host fish must also be present and subject to certain 

impingement risks. The Department recommends Exelon Generation Company, LLC. apply 
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for ITA for the sheepnose, black sandshell, spike, and purple wartyback mussels for the reasons 

stated above.

Comment 016-6-Aquatic: Mentioned on page 3-65 is: “[Mussel] species abundance, 

however, appears to be lower in the vicinity of Braidwood than in other regions of the Kankakee 

River ... HDR (2008) indicates that the lower species abundance near Braidwood is likely the 

result of unsuitable or marginal habitat.”

The Department is concerned that the lower mussel species abundance, as mentioned 

above, may be directly correlated to the operation of the Braidwood facility. The Department 

recommends this issue be investigated further and mitigation measures adopted if correlations 

exist to the facilities operations.

Response: Comments 016-1, 016-3, 016-5, and 016-6 concern the potential for Braidwood 

to impinge or entrain State-listed species, including pallid shiner, river redhorse, western sand 

darter, American eel, sheepnose, black sandshell, spike, and purple wartyback. The 

commenter recommends that Exelon coordinate with the IDNR regarding the potential for 

impingement and entrainment of these species and apply for an incidental take authorization 

under the Illinois Endangered Species Protection Act. The commenter also recommends that 

Exelon investigate whether lower mussel abundance in the vicinity of Braidwood is correlated 

with Braidwood operation and that Exelon consider mitigation measures if a correlation exists. 

As indicated in an e-mail correspondence to the NRC dated June 23, 2015 (ADAMS Accession 

No. ML15180A391), Exelon intends to submit information to the IEPA characterizing 

impingement and entrainment with the Braidwood NPDES permit renewal application in 

accordance with 40 CFR § 122.21(r)(1)(ii). The renewal application must be submitted on or 

before January 31, 2019, the date on which the current permit expires. During conversations 

between Exelon personnel and Nathan Grider of IDNR, IDNR agreed that concerns regarding 

possible impingement and entrainment of State-listed species as well as investigation and 

mitigation measures could be addressed in the context of the Braidwood NPDES permit renewal 

process and that, if appropriate, Exelon would apply for an incidental take authorization under 

the Illinois Endangered Species Protection Act at that time. The NRC staff made no changes to 

the SEIS text as a result of this comment.

Comment 016-2-Aquatic: Fishes - Three impingement studies have been conducted at the 

Kankakee River intake: Commonwealth Edison Company conducted a study during 1980 

through 1981, EA Engineering during1988 through 1989, and again during 1991. Based on 

these studies, the state-endangered pallid shiner and state-threatened river redhorse were 

being impinged at the Kankakee River intake. Impingement (and possibly entrainment) is likely 

ongoing based on recent records near the Kankakee River intake for pallid shiner (2013) and 

river redhorse (2014). Larvae of pallid shiner and river redhorse may also be entrained. The 

Department notes from page 4-56 that entrained pallid shiner larvae may have been collected, 

but misidentified as cyprinids. It is unclear from the document if river redhorse larvae are being 

entrained.

Mentioned on page 4-47 is:

“However, in its Kankakee River Area Assessment, the IDNR (1998) indicates that the pallid 

shiner is “on the verge of extinction” in Illinois and that the Kankakee River population is the only 

large population remaining in the state. Based on this information, any losses of pallid shiner to 

impingement at Braidwood could result in a decreased ability for the Illinois population to survive 

and reproduce.”
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Further, page 4-48 explains potential impacts to the river redhorse as:

“If the [river redhorse] species’ status changes during the proposed license renewal term, 

impingement at Braidwood could contribute more significantly to endangering the Illinois 

population’s continued existence.

Catosomids (sucker family, including redhorse spp.) appear to have decreased alarmingly from 

the 1980’s to present in monitoring samples taken in the vicinity of the Braidwood intake and 

discharge (pages 3-58 & 3-62). The Department has not observed a similar decline in other 

parts of the Kankakee River. The Braidwood station came online in the late 1980’s and the 

decline in catostomids could be correlated to impingement, entrainment, and thermal discharge 

from the facility. The Department recommends this issue be investigated further and mitigation

measures adopted if correlations exist to the facilities operations.

Response: The commenter is concerned that the decrease in catostomids in the vicinity of 

Braidwood since the facility began operating is correlated with impingement, entrainment, and 

thermal effects of the facility. The commenter recommends further investigations of this 

potential issue and adoption of mitigation measures, as appropriate, to address such effects. 

Under the provisions of the CWA and through the NPDES process, the IEPA, and not the NRC, 

is responsible for addressing impacts to aquatic organisms resulting from impingement, 

entrainment, and thermal effluent. As described in Section 4.7.1.2 of the SEIS, as a result of 

the 1988-1989 impingement study at Braidwood, the IEPA determined that pumping restrictions 

were appropriate to address entrainment effects. In 1991, IEPA incorporated a condition 

(Special Condition 8) into Braidwood’s NPDES permit that limits Kankakee River makeup water 

withdrawals during the peak entrainment period (the last 3 weeks in May and the first week in 

June). During this period, the NPDES permit restricts withdrawals to only those needed to fill 

the freshwater holding pond and to maintain efficient operation of the cooling pond. 

Withdrawals are prohibited during night hours (1 hour before sunset through 1 hour after 

sunrise). The IEPA most recently renewed the Braidwood NPDES permit in 2014. Further 

aquatic studies or mitigation measures would be addressed by the IEPA during a future NPDES 

permit renewal process. The NRC staff did not change the SEIS in response to this comment.

Comment 016-4-Aquatic: Additionally, the catadromous American eel (Anguilla rostrate) 

was recently approved by the Illinois Endangered Species Protection Board to be added as a 

state-threatened species. This change will take affect once published in the Illinois Register. 

This species is known to be vulnerable to impingement and entrainment. Exelon Generation 

Company, LLC. should evaluate potential impacts to this species and consider ITA.

Comment 016-7-Aquatic: Amphibians - Recent records also occur near the Kankakee River 

intake for the state-threatened mudpuppy (2012, Necturus maculosus). It unclear if this species 

is subject to impingement and entrainment risks at the Kankakee River intake. Exelon 

Generation Company, LLC. should evaluate potential impacts to this species and consider ITA

Response: Comments 016-4 and 016-7 concern the potential for the State-threatened 

American eel and State-threatened mudpuppy to be affected by impingement and entrainment

at Braidwood. The NRC staff reviewed the available preoperational and operational monitoring 

and impingement and entrainment studies associated with Braidwood; neither species appeared 

in any of these studies. In e-mail correspondence dated June 23, 2015 (ADAMS Accession 

No. ML15180A391), Exelon confirmed that it is not aware of the mudpuppy and American eel 

occurring in the vicinity of Braidwood. The NRC staff made no changes to the SEIS in response 

to this comment.
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Appendix A

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Appendix A

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Appendix A

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Appendix A

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A.2.17 Written Comments From Anonymous

Comment 017-1-Aquatic: Your statement re the Kankakee River near Braidwood Nuclear G S 

shows the negative impacts: “EPT taxa are generally considered to be intolerant of 

environmental stress. Thus, a relatively high EPT richness typically represents a high quality 

benthic community. In 1979, 29 EPT taxa were collected, while in 2011, only 11 EPT taxa were 

collected. The change in EPT richness appears to contradict EA Engineering’s (2012) 

conclusions because it signals a possible degradation in water quality.” p. 3-55 While you imply 

mercury caused the problem, the US started being strict on mercury prior to the opening of 

Braidwood & the timeline indicates that the problem started with the nuclear reactor. There 

were coal mines here but the drop in species richness came with the reactor. You fail to give 

water sampling or species sampling for radionuclides & mercury to better judge. You have not 

updated phytoplankton zooplankton studies. You have not updated amphibian-reptile studies, 

even though they are sentinels and should thrive with the new pond, if it were non-radioactive. 

Because no amphibians or reptiles survived the radiation? Mussels are a sentinel species so 

this is telling: “No juveniles or other indications of recruitment were observed during the survey, 

which suggests that the mussels in the vicinity of Braidwood likely come from larger, stable, and 

reproducing upstream populations... Species abundance, however, appears to be lower in the 

vicinity of Braidwood than in other regions of the Kankakee River. During the hand-picking 

portion of the August 2008 survey (HDR 2008), 192 individuals were collected in 15 man-hours, 

which yields a catch-per-unit-effort (CPUE) of 12.8. Suloway (1981) collected 1,006 individuals 

in 37 man-hours, which yields a 27 CPUE of 27.2, and Price et al. (2012) reported a CPUE of 

40.0 at mainstem locations. HDR (2008) indicates that the lower species abundance near 

Braidwood is likely the result of unsuitable or marginal habitat.” (See pp. 3-62 to 3-65) This 

study is methodologically flawed: the vast majority - 74% of the mussels, which were alive, 

were found upstream from the nuclear reactor discharge. The rest were either from the center 

of the river OR downstream. For all we know zero were found alive downstream. Upstream 

should be the control and the study should be downstream. This shows how bad the impacts 

are - even by including those upstream, which should be the control, together with downstream, 

the impacts of Braidwood Nuclear are terrible. We aren’t able to tell if it is due to heat, 

radionuclides, entrainment into the water intake or, most likely, all of the above, because this 

EIS doesn’t tell us. Where’s the radionuclide amount & type in the water, air, plants & animals? 

Where is health status of plants & animals? Tumors? Gray feathers, etc? Where is 

consideration of the impacts of a 50 mile radius of fallout between suburban Chicago & 

Bloomington-Peoria? Where is the econ impact on Chicago? This is supposed to be an EIS 

but your alternatives are a poorly done SEIS, rather than EIS. How about over 15 million acres 

which Chernobyl teaches us can be contaminated - useless for agriculture, habitation? The EIS 

for Texas? For transport? All of this must be included in THIS.

Response: The commenter states that the NRC did not adequately address the impacts to the 

aquatic environment resulting from impingement, entrainment, and radionuclide exposure. The 

aquatic environment and the impacts to aquatic resources are discussed in Sections 3.7 and 

4.7, respectively. The NRC staff evaluated impacts from impingement and entrainment on 

aquatic resources at Braidwood in Section 4.5. Based on an evaluation of available aquatic 

studies, the NRC staff concluded that the impacts would be SMALL to MODERATE for 

Braidwood license renewal. The NRC staff has identified no new and significant information 

since the issuance of the DSEIS that would alter this conclusion in the FSEIS. Regarding 

impacts from radionuclides, the NRC staff found no new and potentially significant information 

that would alter the GEIS’s conclusion that the impact to aquatic resources from radionuclides 

would be SMALL. This conclusion is supported by the discussion in Section 3.1.4 of radioactive 

effluents discharged by Braidwood into the environment and the data from Braidwood’s 
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radiological environmental monitoring program. The NRC staff found that all radioactive 

effluents were within NRC and EPA limits and that there was no measurable impact to the 

environment from those radioactive effluents. No SEIS text was changed in response to 

this comment.

Comment 017-2-Alternatives/Wind: On pp. 2-18 to 2-19 you have typically NRC outrageous 

nonsensical contradictions. You pretend that wind power cannot come up to speed, all while 

showing that the estimated amount of wind power needed can & has been achieved in the past 

and could quickly be in the future. Batteries have long existed. There is no reason that solar 

panels and/or wind cannot be used with individual home batteries. It’s only the utilities & their 

research institute EPRI who think that the production must be big so that they can control. 

Additionally, if the sun is not shining there, the wind is probably blowing and/or raining. Rain 

can run mini-hydro. There should be plenty of farm & city waste to make biofuel. There is no 

reason for nuclear even subtracting a recent advance in energy storage.

Where is the cost-benefit analysis that tells us that choosing nuclear electricity & killing off 

everyone and everything; destroying the land is better than safe solar, wind, biofuels, hydro? 

Solar, wind and hydro can be mini in size. Did you know that plenty of people still alive today 

lived healthy, happy lives without electricity? There was almost no cancer ca 1900 & that 

probably came from poor usage of x-rays, radium & uranium dyes in false teeth & dishes & 

mining. By what right are you killing the present and future for nuclear electricity that you can 

get from elsewhere and actually could live without if you had to. By what right do you cause 

miscarriages-kill unborn children, frogs, other animals & plants?

Response: The purpose and need for NRC’s proposed action is to provide an option to 

continue plant operations beyond the current licensing term to meet future system generating 

needs, as such needs may be determined by State, utility, system, and, where authorized, 

Federal (other than NRC) decisionmakers. Unless there are findings in the safety review 

required by the AEA or in the NEPA environmental review that would lead the NRC to reject

a license renewal application, the NRC has no role in the energy-planning decisions of power 

plant owners, State regulators, system operators, and, in some cases, other Federal agencies 

as to whether the plant should continue to operate. Alternatives that could not replace 

Braidwood’s current generating capacity and whose costs or benefits do not justify their 

inclusion in the range of reasonable alternatives were eliminated from detailed study in the 

SEIS. The reasons why these alternatives were eliminated are explained in Section 2.3 of 

the SEIS.

While a range of replacement power alternatives is discussed in the SEIS, the only alternative 

to license renewal within NRC’s decisionmaking authority is to not issue a renewed operating 

license. The NRC has no authority or regulatory control over the selection of replacement 

power alternatives. In addition, the NRC cannot ensure that the most environmentally 

preferable replacement power alternatives are selected. This comment provided no new 

and significant information. No SEIS text was changed in response to this comment.
Appendix A

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Appendix A

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Appendix A

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A.2.18 Oral Comments From Mike Gorga (from April 21, 2015, afternoon public 

meeting transcripts)

Comment 018-1-General: I am an employee from Exelon Braidwood. I do live in Will County. 

I’m 50 miles, within 50 miles of three nuclear plants. The people who came up before me spoke 

about the larger impacts; the $26 million in tax revenue, the millions and millions of tons of 

carbon emissions. But I was going to talk a little bit more locally and more specific to the 

community around us. So, you know, along with the nuclear power plants in Illinois, we do 

have the greatest carbon emission portfolio. But we also are committed to being a good 

environmental steward. So within Braidwood Station, we do have an environmental 

stewardship committee. And within that committee, we do environmental discussions with the 

local schools; grade schools, high schools. And we ask them to provide us proposals for our 

grant. We call it the Gabby Green Grant, where we provide thousands of dollars to the 

neighborhood schools to work on their environmental projects. So we’ve funded greenhouses. 

We’ve funded outdoor classrooms, and other environmental educational topics in the local 

schools. Additionally, we’re currently working with the IDNR to construct osprey nests to 

support that aquatic bird of prey that we need to see in the area. And additionally, one of the 

facts that we’ve got here is that we’ve talked about CO2, but also with regards to other ozone 

depleting and greenhouse gases, 74 tons of nitrogen oxide and 176,000 tons of sulfur dioxide 

were also prevented from being entered into our atmosphere through the operation of the 

nuclear plant.

Response: These comments are general in nature, support the license renewal, and do not 

inform the environmental impact analysis. No text was changed in the SEIS as a result of 

these comments.
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Appendix A

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Appendix A

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A.2.19 Written Comments May 15, 2015, From Michael Gallagher, Exelon 

Generation Company

Comment 019-1-Terrestrial: In line 19 on page 3-43, change the text as follows;

“... and eastern cottonwood (Hibiscus tiliacous Populus deltoides) trees ...”

This change is needed because the correct scientific name for Eastern cottonwood is Populus 

deltoides. Hibiscus tiliaceus is the coastal cottonwood.

Response: The commenter notes that the SEIS lists the wrong species name for the 

eastern cottonwood. The NRC staff updated the SEIS to reflect the correct species name.

Comment 019-2-Aquatic: There are many mistakes in Table 3-9 on pages 3-57 to 3-58 in 

terms of how species are classified and grouped, which means that the number of individuals 

collected (by family) and relative abundance values (by family) are also wrong. For example:

 Moxostoma spp/redhorse are catastomids, not cyprinids

 Ambloplites rupestris/ rock bass is a centrarchid, not a catastomid

 Esox lucius is an esocid, not a catastomid

 Noturus flavus is an ictalurid, not a catastomid

 Lythrurus/redfin shiner is a cyprinid, not a centrarchid

 M. dolomieu is a centrarchid, not a percid

 Ameiurus natalis is an ictalurid, not a moronid

 Catastomus commersoni is catastomid, not a moronid

 Campostoma/stoneroller is a cyprinid, not an ictalurid

The implications of misclassifying species are quickly apparent. One example: because 

100 smallmouth bass were misclassified, they were added to the perch family total. As a result, 

the relative abundance of perch is greatly inflated and the relative abundance of centrarchids is 

substantially reduced.

Consider correcting the errors in classification and grouping of species in Table 3-9. Also 

consider revisiting and revising any analyses of impacts that are based on the erroneous 

classifications and groupings.

Comment 019-3-Aquatic: The comparisons between years/time periods in lines 1 to 7 on 

page 3-58 are based on the values in Table 3-9, which contain mostly wrong information. 

Consider revisiting and revising such comparisons after correcting the information.

Comment 019-4-Aquatic: There are many mistakes in Table 3-10 on pages 3-59 to 3-60 in 

terms of how species are classified and grouped, which means that the number of individuals 

collected (by family) and percentages (by family) are also wrong. For example:

 Lepomis microlophus/ redear sunfish is a centrarchid, not a cyprinid

 Minytrema melanops is a catastomid, not a cyprinid

 lctiobus bubalus is a catastomid, not a centrarchid

 Et cetera (9 more mis-classifications) 
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One consequence: when rock bass and smallmouth bass (both misclassified) are placed 

(where they should be) in the centrarchid group, the number of centrarchids collected is 

increased by 588.

Consider correcting the errors in classification and grouping of species in Table 3-10. Also 

consider revisiting and revising any analyses of impacts that are based on the erroneous 

classifications and groupings.

Comment 019-5-Aquatic: The comparisons in Figure 3-16 (histograms) are based on data in 

Table 3-10, which is fundamentally flawed: species were assigned to wrong families, thus 

aggregate number collected by family is wrong in almost every case. Consider revisiting and 

revising such comparisons after correcting the data.

Comment 019-10-Aquatic: The analysis and discussion in lines 9 to 18 on page 4-58 are 

based on faulty data presented in Section 3.7.3.1 as indicated above in comments regarding 

that section. 

Comment 019-11-Aquatic: The analysis and discussion in lines 1 to 18 on page 4-59 are 

based, in part, on faulty data presented in Section 3.7.3.1 as indicated above in comments 

regarding that section designated as Item #2 through Item #5.

Comment 019-12-Aquatic: The conclusion in lines 4 to 10 on page 4-60 (LOE 3 Conclusion) is 

based on erroneous information presented in Section 3.7.3.1, as indicated above in comments 

regarding that section.

Response: Comments 019-2-Aquatic, 019-3-Aquatic, 019-4-Aquatic, and 019-5-Aquatic 

identify a number of fish species that are listed in the wrong family in the tables that appear in 

Section 3.7 of the SEIS. Comments 019-10-Aquatic, 019-11-Aquatic, and 019-12-Aquatic note 

that the analysis of impingement and entrainment impacts is in part affected by the 

misclassifications in Section 3.7. The NRC staff corrected these formatting and indexing 

changes and revised the affected tables, figures, and text. As recommended by the 

commenter, the NRC staff revised its analysis of impingement and entrainment impacts in 

Section 4.7.1.2 that were affected by the misclassifications.

Comment 019-6-Terrestrial: As indicated in line 27 on page 4-25, Section 4.5.1.1 relies on 

data about surface water from the USGS gage located at Wilmington (miles below Braidwood) 

for water years 1934 to 2012. The analysis results in a rate of consumption by Braidwood of 

0.9% to 2.9% of the Kankakee River’s average and low-water flows, respectively. However, in 

the section on Water Use Conflicts with Terrestrial Resources (Section 4.6.1.3, on page 4-33), 

the DSEIS relies on data about surface water from the USGS gage located at Momence for 

water years 2002 to 2012. This results in a rate of consumption by Braidwood of 3.0% to 6.6% 

of the Kankakee River’s average and low-water flows. For consistency and the reasons set 

forth in the comment designated as Item #7, below, consider using the Wilmington gaging 

station data set for both sections.

Comment 019-7-Terrestrial: The nearest USGS gaging station to the Braidwood makeup 

water intake and blowdown is at Wilmington (8.3 mi downstream), not Momence (33.7 mi 

upstream). Using river flow values from Momence to calculate the percentage of river flow 

represented by Braidwood’s makeup water withdrawal ignores the substantial contribution to 

river flow of the Iroquois River, a major tributary that enters the Kankakee at Aroma Park, 

approximately 23 miles upstream of the Braidwood makeup water intake. Consider using river 

flow data from the Wilmington USGS gaging station as a basis instead of the Momence 

gaging station.
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Comment 019-8-Terrestrial: In lines 22 to 23 on page 4-33, the DEIS states that 48,000 gpm 

is normally withdrawn from the Kankakee as cooling pond makeup, and compares this value to 

the conservative river discharge (flow) values from Momence to calculate consumptive losses 

as a percentage of river flow. However, Section 3.5.1.2 of the DEIS indicates that 

46 mgd/71.2 cfs/32,000 gpm are withdrawn as makeup and 23 mgd/35.6 cfs/16,000 gpm are 

returned to the river as blowdown. Consider using Braidwood’s net river water withdrawal rate 

(i.e., makeup pumping rate minus blowdown discharge rate), rather than its gross withdrawal 

rate, to calculate consumptive losses based on data from the Wilmington gaging station, rather 

than the Momence gaging station.

Comment 019-9-Terrestrial: Because very conservative values (from Momence USGS 

station) were used to characterize base river flows and these base flows were compared to 

the makeup withdrawal rate (48,000 gpm) rather than the net river water withdrawal rate, 

16,000 gpm (which represents the water lost to seepage and evaporation), the estimated 

percentages of river flow consumed (3 to 6.6 percent) are too high. Consider using Braidwood’s 

net river water withdrawal rate (i.e., makeup pumping rate minus blowdown discharge rate), 

rather than its gross withdrawal rate, to calculate consumptive losses based on data from the 

Wilmington gaging station, rather than the Momence gaging station.

Comment 019-14-Aquatic: The comments above designated as Item #7 through Item #9 

regarding Section 4.6.1.3 (lines 18 through 24 on page 4-33) also apply to the paragraph in 

lines 22 to 32 on page 4-67, which repeats the information presented in Section 4,6.1.3.

Response: Comments 019-6-Terrestrial and 019-7-Terrestrial note that the NRC staff did 

not use the nearest U.S. Geological Survey (USGS) gaging station in its analysis of water use 

conflicts with terrestrial and aquatic resources in Sections 4.6.1.3 and 4.7.1.4, respectively. 

Comment 019-8-Terrestrial and Comment 019-9-Terrestrial suggest that the NRC staff use 

Braidwood’s net river water withdrawal rate rather than gross withdrawal rate to calculate 

consumptive losses of water. Comment 019-14-Aquatic notes that Comments 19-7 through 

19-9 also apply to water use conflicts with aquatic resources. In response to these comments, 

the NRC staff has revised Sections 4.6.1.3 and 4.7.1.4 of the SEIS to be consistent with the 

discussion of consumptive water use in Section 4.5.1.1 and to reflect the Wilmington 

gaging station.

Comment 019-13-Aquatic: In lines 35 to 43 on page 4-62, a summary of the NRC’s 

conclusion that impingement and entrainment impacts in the Kankakee River from Braidwood 

license renewal would be SMALL to MODERATE is presented. Lines 38 to 43 state the 

following:

“MODERATE impacts would primarily result from the following:

 impingement of the State-endangered pallid shiner (LOE 1) and clupids [sic] 

(LOE 3);

 entrainment of common carp, cyprinids, and darter eggs (LOE 2, 3); and

 entrainment of Percina, darter, pallid shiner, and other less common cyprinid 

larvae (LOE 2).”

Regarding the first bullet, Exelon submits that additional and more recent aquatic resources 

information than were considered by NRC contradicts NRC’s findings regarding the pallid shiner 

population in the lower Kankakee River and northern Illinois. The assertions that pallid shiner is 

susceptible to being extirpated from Illinois and that further impingement of pallid shiner at 

Braidwood could contribute to the loss of this species in Illinois suggests that the numbers of 
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pallid shiner in the Kankakee River are decreasing and the range of pallid shiner is, at best, 

static. On the contrary, studies in the Kankakee and Des Plaines Rivers indicate that not only 

have pallid shiner numbers increased since 1998 but that its range has expanded as well during 

the past 15 years. Routine fish monitoring conducted in the vicinity of Dresden Nuclear Station 

on the Des Plaines, Kankakee, and Illinois Rivers shows an increase in the number of pallid 

shiner specimens observed. From 1991 through 2000, no pallid shiners were observed. Since 

2001, pallid shiner captures have increased from 12 individuals to as many as 165 specimens in 

2007 with an average of 82 specimens between 2001 and 2014 (EA 2015). The majority of 

these captures were observed in the Kankakee River between Grundy County Line Road bridge 

and the confluence with the Des Plaines River, approximately 12 river miles downstream of the 

Braidwood Station makeup water intake. In addition, as part of routine fish monitoring 

conducted since 1977 for NRG Midwest Generation, LLC. (formerly Commonwealth Edison), 

pallid shiner were first observed in the Des Plaines River, upstream of the confluence with the 

Kankakee River in 2000 (EA 2014). Pallid shiners have been observed during 12 of the 

14 sampling years between 2000 and 2013. Despite the fact that these results were observed 

in areas well downstream of the Braidwood Station makeup water intake, the presence of palid 

shiner in multiple new locations within the Kankakee River and Illinois River watersheds are 

contradictory to the assertion that the species is on the verge of extirpation from Illinois. 

Furthermore, the increased number of pallid shiners over more than a decade indicates that 

impingement and entrainment by the Braidwood Station makeup water intake are not having 

noticeable or adverse effects on the pallid shiner population in the Kankakee River or 

northern Illinois.

Regarding the second and third bullets, common carp is not a species belonging to the 

taxonomic family Catostomidae. As such, entrainment of common carp eggs by Braidwood 

cannot result in the decline of catostomids. Furthermore, common carp are an invasive species

that is excluded from all other Cyprinidae species that may be most likely impacted by 

entrainment because the abundance of common carp is disproportionately high in the 

entrainment samples. Therefore, the entrainment of common carp eggs and larvae is, at best, 

inconsequential with respect to any decline of cyprinids. Finally, While the number of fish eggs 

and larvae entrained at the Braidwood makeup water intake is a large number, relative to the 

90.2 to 94.9 percent ichthyoplankton production within the Kankakee River in Illinois that is 

outside of the area of influence, the amount of Kankakee River ichthyoplankton potentially 

entrained is comparatively very small.

References

EA Engineering, Science, & Technology, Inc., PBC (EA). 2015. Draft Dresden Nuclear Station 

316(a) Demonstration, Appendix B Information Supporting Representative Important Species 

Rationale: Biothermal Assessment - Predictive Demonstration. Exelon Corporation.

_________. 2014. 2013 Upper Illinois Waterway Fisheries Investigation RM 274.4-296.0. 

NRG Midwest Generation, LLC.

Response: The commenter states that recent findings on the Kankakee River pallid shiner 

population contradict NRC findings regarding this species, that the NRC impingement and 

entrainment conclusions are flawed because the common carp was incorrectly identified as a 

catostomid, and that the number of fish eggs and larvae entrained at Braidwood is small when 

compared to the ichthyoplankton production within the Kankakee River in Illinois outside the 

area of Braidwood’s influence. Regarding the first part of the comment, the NRC staff 

recognizes that the information presented in the SEIS regarding the State-endangered pallid 

shiner is a static “snapshot” of the species’ status at the time of the referenced studies. The 

NRC has updated its discussion of impacts to this species throughout Section 4.7.1.2 to state 
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that the specific impact of Braidwood’s continued operation on this species’ population will vary 

based on the Kankakee River population’s overall recovery or decline during the proposed 

license renewal period. The commenter cites two studies that it states indicate an increasing 

trend in the size of the pallid shiner population in the Kankakee River. The NRC staff reviewed 

these studies and included the studies’ findings regarding the pallid shiner in Section 4.7.1.2 of 

the SEIS. Regarding the second portion of the comment, as stated in the response to 

Comments 019-2-Aquatic, 019-3-Aquatic, 019-4-Aquatic, 019-5-Aquatic, 019-10-Aquatic, 

019-11-Aquatic, and 019-12-Aquatic, the NRC staff revised its analysis of impingement and 

entrainment impacts in Section 4.7.1.2 that was affected by the misclassification of several fish 

species. As a result of this revision, common carp no longer appears in the conclusion of this 

section. The commenter’s final statements appear to support the NRC staff conclusion of 

SMALL for entrainment effects to Kankakee River aquatic resources as a whole in Line of 

Evidence 2 (LOE 2) in Section 4.7.1.2. The comment does not provide any evidence that would 

contradict the NRC’s conclusion in LOE 2 of MODERATE for Percina spp., cyprinids, and 

darters. Changes were made in the SEIS as noted above.

Comment 019-15-Historic and Cultural Resources: In lines 34 to 35 on page 4-78, the 

DSEIS notes (in the context of its review of historic and cultural resources)·that “the first 

substation is located on-site at the 345-kV Braidwood Station switchyard (emphasis added).” 

This statement is not consistent with DSEIS Section 3.11.4 (and possibly other DSEIS 

sections), which was not updated to account for the NRC’s 2013 Final Rule and GEIS. The 

2013 GEIS changed the definition of “in-scope” transmission lines, and Exelon described the 

effect this would have for Braidwood “in-scope” transmission lines in its response to Request for 

Additional Information CR-7 (January 21, 2014, ADAMS Accession No. ML14030A264).

Consider harmonizing all sections in the DSEIS that address impacts to resources from 

“in-scope” transmission lines with the 2013 Final Rule’s definition as applied to 

Braidwood Station.

Response: The NRC staff revised Section 3.11.4 of the SEIS to clarify that Braidwood has 

no offsite transmission lines within the scope of the license renewal environmental review.

Comment 019-16-Historic and Cultural Resources: Section 4.9.2 (lines 20 to 21 on 

page 4-80) states that a separate environmental review would be needed to assess 

decommissioning impacts on cultural resources for the No Action alternative to Braidwood 

license renewal. Exelon Generation notes that such an environmental review has been 

completed and recommends that Section 4.9.2 be revised to incorporate by reference the 

conclusions from NUREG-0586 (NRC 2002, GEIS on Decommissioning of Nuclear Facilities). 

NUREG-0586 concludes that for all nuclear plant sites at which decommissioning will not 

require disturbing lands beyond existing site boundaries, impacts to cultural resources would 

be SMALL. For nuclear plants where decommissioning would disturb land beyond existing site 

boundaries, impacts would have to be assessed on a case-by-case basis and might be SMALL, 

MODERATE or LARGE. Exelon Generation submits that the existing Braidwood site is 

sufficiently large that explicit justification is warranted before concluding in Section 4.9.2 that the 

generic finding in NUREG-0586 of SMALL impacts to cultural resources from decommissioning 

would not apply to Braidwood.

Response: This comment recommends better aligning Section 4.9.2 to the decommissioning

GEIS. In response to this comment, the NRC staff updated Section 4.9.2 to include a 

discussion of the NUREG-0586 conclusions regarding decommissioning impacts on historic and 
Appendix A

A-123

cultural resource. The NRC staff also included a discussion of the post-shutdown 

decommissioning activities report (PSDAR) to indicate when the extent of land disturbing 

activities would be known. Finally, the NRC staff revised Table 2–2 to reflect the NRC staff’s 

revised determination of a SMALL to LARGE impact on historic and cultural resources for the 

no-action alternative because the extent of land disturbing activities would be unknown until the 

NRC receives the PSDAR after plant shutdown.

Comment 019-17-Historic and Cultural Resources: The IGCC impact to cultural resources

is characterized in Section 4.9.4 as SMALL. The NGCC impact to cultural resources is 

characterized in Section 4.9.5 as SMALL to MODERATE. Each plant is assumed to be sited 

on the approximately 67 acres of undisturbed land on the Braidwood site, and the difference 

between the projects in impacts to cultural resources is attributed to the new gas pipeline that 

would need to be constructed for the NGCC. However, given that the IGCC alternative requires 

2,000 acres and the NGCC alternative requires 94 acres including pipelines (see Table 2-1 on 

page 2-9), the conclusions are inconsistent. There is not that much difference in the uncertainty 

of the cultural resource richness of the new pipeline compared to undisturbed area of the 

existing site, and the IGCC would consume more undisturbed acres than the NGCC. Therefore, 

Exelon Generation recommends reconsideration of the impact findings in sections 4.9.4 and 

4.9.5 for the IGCC and NGCC alternatives.

Response: This comment suggests that the conclusions for the IGCC and the NGCC are 

inconsistent with regard to the impacts to historical and cultural resources. The NRC staff 

revised Section 4.9.5 to reflect the NRC staff’s revised determination of a SMALL impact on

historic and cultural resources for the NGCC alternative. 

Comment 019-18-Historic and Cultural Resources: The impact from the Purchased Power 

alternative to cultural resources is described in Section 4.9.7 (pages 4-82 [lines 39 to 47] to 4-83 

[lines 1 to 8]) as SMALL to LARGE. The description of the activities under this alternative is 

inconsistent with the description given in Section 2.2.2.5. According to section 2.2.2.5, “facilities 

from which power would be purchased would not likely be constructed solely to replace 

Braidwood” although “[p]urchased power may require new transmission lines.” Section 2.2.2.5 

further states, “Impacts to other resource areas [such as cultural resources] from the operation 

of existing power plant facilities would likely be less than those for new plants because existing 

facilities would not require new construction.” Given that the New Nuclear alternative, which 

requires construction of new facilities, was evaluated to have SMALL impacts on cultural 

resources (see section 4.9.3, page 4-80), it is difficult to understand the basis for NRC’s 

conclusion that Purchased Power, for which no construction is likely except possibly 

transmission lines, would have SMALL to LARGE impacts. Therefore, Exelon Generation 

recommends reconsideration of the impact findings in section 4.9.7 for the Purchased Power 

alternative taking into account the probability that new generating facilities would not be needed.

Response: This comment states that “The description of the activities under [Purchased 

Power] is inconsistent with the description given in Section 2.2.2.5.” The NRC staff revised 

Section 2.2.2.5 to clarify that impacts are SMALL to LARGE because construction of new 

facilities may occur.

Comment 019-19-Socioeconomic: The description of the Purchased Power Alternative in 

Section 4.10.7 is different from that in Section 2.2.2.5. According to Section 2.2.2.5 (page 2-17, 

line 20 to 21), “facilities from which power would be purchased would not likely be constructed 
Appendix A

A-124

solely to replace Braidwood.” Yet, Section 4.10.7 bases its conclusions about impacts to 

socioeconomics and transportation resources on the possibility that new electrical power 

generating facilities would be needed to supply purchased power. Therefore, Exelon 

Generation recommends reconsideration of the impact findings in section 4.10.7 for the 

Purchased Power alternative taking into account the probability that new generating facilities 

would not be needed.

Response: This comment states that the description of the Purchased Power Alternative in 

Section 4.10.7 is different from that in Section 2.2.2.5, which defines the Purchased Power 

Alternative for this environmental review. The NRC staff differs with this analysis. The 

discussion in Section 4.10.7 does not state that new electrical power would be constructed to 

replace Braidwood, but discusses the indirect effects of purchased power. Increased demand 

for power as a result of losing the Braidwood generation could cause suppliers to consider 

constructing new (merchant) power plants or peaking stations to take advantage of increased 

power sales in order to increase revenue. This would be an indirect effect of purchased power 

because the NRC staff does not consider the discussion in Section 4.10.7 to be in conflict with 

the discussion in Section 2.2.2.5. The staff made no changes to the SEIS text as a result of 

this comment.
Appendix A

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Appendix A

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A.2.20 Minor Edits Submitted by Michael Gallagher, Exelon Generation Company

Editorial comments that are accepted as recommended (020-1, 020-2, 020-3, 020-4, 020-5, 

020-6, 020-7, 020-8, 020-9, 020-11, 020-12, 020-12, 020-14, 020-15, 020-16, 020-18, 020-19, 

020-20, 020-22, 020-23, 020-25, 020-26, 020-28, 020-29, 020-30, 020-31, 020-32, 020-33, 

020-34, 020-35, 020-36, 020-37, 020-38, 020-39, 020-41, 020-40, 020-42, 020-43, 020-44, 

020-45, 020-46, 020-47, 020-48, 020-49, 020-50, 020-52, 020-53, 020-54, 020-55, 020-56, 

020-57, 020-58, 020-59, 020-60, 020-61, 020-62, 020-63, 020-64, 020-67, 020-68, 020-69, 

020-70, 020-71, 020-72, 020-73, 020-74, 020-75, 020-76, 020-77, 020-78, 020-79, 020-80, 

020-81, 020-82, 020-83, 020-84, 020-85) are not considered substantive and therefore not 

included in the list below. They mainly consist of typos, spelling, revising numbers in charts, 

and modifying acroynms. Changes to the SEIS text are indicated by change bars in the margin 

of each page.

Comment 020-10-Introduction: Consider adding the Native American Graves Protection 

and Repatriation Act to the Federal laws listed in lines 5 to 10 on page 1-6 that direct Federal 

agencies to consult with one another regarding proposed agency actions. Otherwise, it is not 

clear why only Native American tribes were consulted – “based on historic cultural ties” could 

include non-Native Americans who settled the land centuries ago, but there is no requirement 

to consult with their descendants.

Response: Native American Graves Protection and Repatriation Act (NAGPRA) does not 

direct Federal agencies to consult with one another regarding proposed agency actions. 

NAGPRA sets requirements for managing Native American human remains and artifacts 

when discovered or in the possession of Federal agencies. License renewal is not an activity 

that could result in the NRC possessing remains discovered on licensee property. No changes 

to the SEIS were made as a result of this comment. See 

http://www.nps.gov/archeology/tools/Laws/nagpra.htm. 

Comment 020-17-Alternatives: For completeness, consider adding a column in Table 2-1 on 

page 2-7 for “Purchased Power.” Although the characteristics of purchased power are different 

than those of the technology alternatives, the exclusion of purchased power from Table 2-1 

could lead the reader to believe it was not analyzed in detail. Identifying the key characteristics 

of purchased power, although different in nature from those of the technologies, could be 

informative.

Response: Because purchased power characteristics are sufficiently different from technology 

alternatives, their inclusion in Table 2–1 would likely be more confusing than helpful to the 

reader. Added explanatory footnote to table consistent with Byron FSEIS edits, which stated 

that, given the speculative nature of using purchased power to replace Braidwood and the 

difficulty addressing each row heading, the purchased power alternative is not included in 

the table.

Comment 020-21-Alternatives: Consider adding a column in Table 2-2 on page 2-25 for 

“Special Status Species and Habitats,” which is discussed as a separate resource in Chapter 4 

of the Draft SEIS.

Response: The NRC cannot forecast a particular level of impact for these alternatives as 

discussed on pages 4-77 & 4-78 which consist of Natural Gas Combined Cycle Alternative 

and Combination of Interconnected Wind Farms, Solar Photovoltaic, and Natural Gas.
Appendix A

A-134

Comment 020-24-Affected Environment: Consider marking the makeup water pipeline on 

Figures 3-4 and 3-5.

Response: Amending Figures 3–4 and 3–5 to show the makeup water pipeline does not 

impact the environmental analysis of the SEIS. Therefore, Figures 3–4 and 3–5 were not 

updated to show the water pipeline.

Comment 020-27-Land Use: In lines 9 to 10 on page 3-18, the DEIS states:

“...strip mined spoils on the site were flooded to create a 2,540 ac (1,028-ha) artificial 

cooling pond, which provides Braidwood with a source of cooling water.”

Consider replacing the above-quoted phrase with the following text:

“...cooling pond, which has a total surface area of 1,028 ha (2,540 ac), was created by flooding 

portions of a former strip mine and provides Braidwood with a source of cooling water. Spoil 

piles/spoil areas associated with the former strip mine became islands, berms, wetlands, and 

uplands within the cooling pond.”

Response: The comment recommends word changes to the description of the cooling ponds. 

The staff has determined that the recommended text changes do not provide new and 

significant information. Therefore, no change to the text is needed or was made.

Comment 020-51-Environmental Consequences: The definition of the No-Action Alternative 

that is assumed in Section 4.2.2.1 on page 4-2 is inconsistent with the assumed definition for 

the No-Action Alternative in Section 4.3.2.1 on pages 4-6 to 4-7. As an example, the impacts 

for land use under “no-action” in Section 4.2.2.1 acknowledge that impacts could occur if new 

generation capacity is constructed to replace the lost generation of Braidwood. However, on air 

quality (Section 4.3.2.1) the “no-action” analysis is based on an assumption of no replacement 

power. 

Response: The No-Action alternative is generically described in Section 2.2 of the GEIS and 

more specifically described in Section 2.2.1 of the Braidwood SEIS. The assessment of impacts 

to land use and air quality in Sections 4.2.2.1 and 4.3.2.1, respectively, of the Braidwood SEIS 

is consistent with the No-Action alternative as described in the GEIS, Section 2.2, and the 

Braidwood SEIS, Section 2.2.1. No changes were made to the SEIS as a result of this 

comment.

Comment 020-65-Greenhouse: In lines 14 to 17 on page 4-122, revise the text as follows to 

avoid suggesting that Braidwood’s GHG emissions and climate change are significantly linked 

in some way: “The following sections discuss: (a) GHG emissions released from operation of 

Braidwood and alternatives and (b) the environmental impacts that could generally occur from 

changes in climate conditions, although the significant contributory effects would come 

from other sources independent of Braidwood.” 

Response: This additional language is not necessary since Section 4.16.11 of the SEIS 

concludes that the incremental impact from Braidwood on climate change is SMALL. No 

change was made to the SEIS to include the revised text on page 4-122.
Appendix A

A-135

Comment 020-66-Cumulative Impacts: Although Section 4.8 describes impacts to threatened 

and endangered species, Section 4.16 (cumulative impacts) does not include a summary 

discussion of threatened and endangered species. This omission is inconsistent with the 

treatment in Section 4.16 of other resource areas.

Response: Cumulative Effects to Special Status Species and Habitats are analyzed 

differently from, and are not included in, Section 4.16. This issue of impacts to threatened and 

endangered species usually is addressed in a Cumulative Effects subsection in Section 4.8.1, 

which appears to have been omitted in the Braidwood DSEIS, but is included in the FSEIS.

Comment 020-71-Global: Consider clarifying the conclusion in lines 28 to 29 on page 4-150 

as follows: “The NRC staff concludes that the cumulative impacts from the proposed license 

renewal and other past, present, and reasonably foreseeable projects would be MODERATE, 

although the impacts will be overwhelmingly due to other projects around the world, 

independent of Braidwood.” 

Response: Additional language is not necessary. The NRC staff revised Section 4.16.11 

to clarify that the incremental impacts from Braidwood on climate change are SMALL.
Appendix A

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Appendix A

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Appendix A

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Appendix A

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Appendix A

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Appendix A

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Appendix A

A-150
APPENDIX B 

APPLICABLE REGULATIONS, LAWS, AND AGREEMENTS

B-1 

B.APPLICABLE REGULATIONS, LAWS, AND AGREEMENTS

The Atomic Energy Act of 1954 (AEA) authorizes the U.S. Nuclear Regulatory Commission 

(NRC) to enter into agreement with any state to assume regulatory authority for certain 

activities. For example, in accordance with Section 274 of the AEA, as amended, the State 

of Illinois assumed regulatory responsibility over the following nuclear material usages:

 byproduct materials as defined in Section 11e.(1) of the Act,

 byproduct materials as defined in Section 11e.(2) of the Act,

 source materials, and

 special nuclear materials in quantities not sufficient to form a critical mass.

The Illinois Emergency Management Agency (IEMA) administers the Illinois Agreement State 

Program. In addition to implementing some Federal programs, state legislatures develop state 

laws, which are subject to applicable Federal statutes and regulations. State laws supplement, 

as well as implement, Federal laws for protection of air, water quality, and groundwater. State 

legislation may address solid waste management programs, locally rare or endangered species, 

and historic and cultural resources. 

The Clean Water Act of 1972 (CWA) allows for primary enforcement and administration through 

state agencies, provided the state program is at least as stringent as the Federal program. The 

state program must conform to the CWA and to the delegation of authority for the Federal 

National Pollutant Discharge Elimination System (NPDES) Program from the 

U.S. Environmental Protection Agency (EPA) to the state. In accordance with the CWA, for 

surface water, the primary mechanism to control water pollution is the requirement that directs 

dischargers (e.g., point source dischargers) to obtain an NPDES permit or, in the case of states 

where the authority has been delegated from EPA, a State Pollutant Discharge Elimination 

System (SPDES) permit.

B.1 Federal and State Environmental Requirements

Certain environmental requirements may have been delegated to state authorities for 

implementation, enforcement, or oversight by the applicable Federal agencies in exercising the 

agencies’ regulations. Table B-1 provides a list of Braidwood licenses and permits needed for 

compliance with the major requirements of the Illinois environmental laws that affect the license 

renewal of Braidwood Station (Braidwood). These licenses and permits are addressed in this 

supplemental environmental impact statement (SEIS), pursuant to the NRC Environmental 

Standard Review Plan, including applicable Tribal consultation.
Appendix B

B-2 

Table B–1. Federal, State, and Local Laws and Other Requirements

Braidwood is subject to other requirements regarding various aspects of their environmental 

program. Representative examples of those requirements are briefly described below.

License, Permit, or Other 

Required Approval (or 

Submittal)

Responsible 

Agency Authority Relevance

Air Quality Protection

Required for sources that are not 

exempt and are major sources, 

affected sources subject to the 

Acid Rain Program, sources 

subject to new source 

performance standards, or 

sources subject to National 

Emission Standards for 

Hazardous Air Pollutants

U.S. EPA or 

IEPA

Federal 

Clean Air Act

(42 USC 7401), 

40 CFR 70, and 

Illinois 

Administrative 

Code 35 IAC 201

Nuclear power plants are 

subject to 40 CFR Part 61, 

Subpart H, “National Emissions 

Standards for Emissions of 

Radionuclides,” which is 

included in the terms and 

conditions of the Title V 

Operating Permit.

Water Resources Protection

NPDES Permit—Construction 

Site Stormwater—required before 

making point source discharges

of storm water from a 

construction project that disturbs 

more than 2 ha (5 ac) of land

U.S. EPA or 

IEPA

CWA 

(33 USC 1251 

et seq.); 40 CFR 

Part 122; Illinois 

Administrative 

Code, Title 35, 

Part 309

Any plant refurbishment

involving construction of more 

than 2 ha (5 ac) of land would 

require a Stormwater Pollution 

Prevention Plan and 

Construction Site Storm 

Water Discharge Permit.

NPDES Permit—Industrial Facility 

Stormwater—required before 

making point source discharges

of storm water from an 

industrial site

U.S. EPA

or IEPA

CWA 

(33 USC 1251 

et seq.); 40 CFR 

Part 122; Illinois 

Administrative 

Code Title 35, 

Part 309

Stormwater would be 

discharged from the nuclear 

power plants during operations. 

Stormwater would discharge

through existing outfalls 

covered by the permit.

NPDES Permit—Process Water 

Discharge—required before 

making point source discharges 

of industrial process wastewater

U.S. EPA

or IEPA

CWA 

(33 USC 1251 

et seq.); 40 CFR 

Part 122; Illinois 

Administrative 

Code Title 35, 

Part 309

Processed industrial 

wastewater would be 

discharged through existing 

outfalls covered by the permit.

Spill Prevention Control and 

Countermeasures Plan—required 

for any facility that could 

discharge diesel fuel in harmful 

quantities into navigable waters 

or onto adjoining shorelines

U.S. EPA

or IEPA

CWA 

(33 USC 1251 

et seq.); 

40 CFR Part 112

A Spill Prevention Control and 

Countermeasures Plan is 

required at nuclear power 

plants storing large volumes of 

diesel fuel or other petroleum 

products or both.
Appendix B

B-3 

License, Permit, or Other 

Required Approval (or 

Submittal)

Responsible 

Agency Authority Relevance

CWA, Section 401, Water Quality 

Certification—required to be 

submitted to the agency 

responsible for issuing any 

Federal license or permit to 

conduct an activity that may 

result in a discharge of pollutants 

into waters of a state

U.S. EPA

or IEPA

CWA, 

Section 401 

(33 USC 1341)

Certification for operation of 

a nuclear power plant may 

require a Federal license or 

permit (e.g., a CWA, 

Section 404, Permit or a CWA, 

Section 401, Water Quality 

Certification).

New Underground Storage Tanks 

System Registration—required 

within 30 days of bringing a new 

underground storage tank system 

into service

U.S. EPA

or IEPA

Resources 

Conservation 

and Recovery 

Act (RCRA), as 

amended, 

Subtitle I 

(42 USC 

6991a-6991i); 

40 CFR §280.22

This registration is required if 

new underground storage tank 

systems would be installed 

during refurbishment at a 

nuclear power plant.

Above Ground Storage Tank 

Permit—required to install, 

remove, repair, or alter any 

stationary tank for the storage of 

flammable or combustible liquids

Applicable 

State Fire 

Marshal

This permit is required if new 

above-ground diesel fuel 

storage tanks would be 

installed during refurbishment

at a nuclear power plant. In 

accordance with Braidwood 

Environmental Report (ER), 

there is no plan for new diesel 

fuel storage.
Appendix B

B-4 

License, Permit, or Other 

Required Approval (or 

Submittal)

Responsible 

Agency Authority Relevance

Waste Management & Pollution Prevention

Registration and Hazardous 

Waste Generator Identification 

Number—required before a 

person who generates over 

100 kg (220 lb) per calendar 

month of hazardous waste ships 

the hazardous waste off site

U.S. EPA or 

IEPA

RCRA, as 

amended 

(42 USC 6901 

et seq.), 

Subtitle C 

Generators of hazardous waste

must notify EPA that the wastes 

exist and require management 

in compliance with RCRA.

Hazardous Waste Facility 

Permit—required if hazardous 

waste will undergo nonexempt 

treatment by the generator; be 

stored on site for longer than 

90 days by the generator of 

1,000 kg (2,205 lb) or more of 

hazardous waste per month; be 

stored on site for longer than 

180 days by the generator of 

between 100 and 1,000 kg (220 

and 2,205 lb) of hazardous waste 

per month; be disposed of onsite; 

or be received from off site for 

treatment or disposal

U.S. EPA

or IEPA

RCRA, as 

amended 

(42 USC 6901 

et seq.), 

Subtitle C 

Hazardous wastes are usually 

not disposed of on site at 

nuclear power plants. 

Hazardous wastes generated 

on site are not generally stored 

for more than 90 days. 

However, should a nuclear 

power plant store wastes on 

site for greater than 90 days for 

characterization, profiling, or 

scheduling for treatment or 

disposal, a Hazardous Waste 

Facility Permit would be 

required.
Appendix B

B-5 

License, Permit, or Other 

Required Approval (or 

Submittal)

Responsible 

Agency Authority Relevance

Emergency Planning & Response

List of Material Safety Data 

Sheets—submission required for 

hazardous chemicals (as defined 

in 29 CFR Part 1910) that are 

stored on site in excess of their 

threshold quantities

State and 

local 

emergency 

planning 

agencies 

(IEMA)

Emergency 

Planning and 

Community 

Right-to-Know 

Act of 1986 

(EPCRA), 

Section 311 

(42 USC 11021); 

40 CFR §370.20

Nuclear power plant operators 

are required to submit list of 

Material Safety Data Sheets to 

state and local emergency 

planning agencies.

Annual Hazardous Chemical 

Inventory Report—submission 

required when hazardous 

chemicals have been stored at a 

facility during the preceding year 

in amounts that exceed 

threshold quantities

State and 

local 

emergency 

response 

agencies 

(IEMA); local 

fire 

department

EPCRA, 

Section 312 

(42 USC 11022); 

40 CFR §370.25

If hazardous chemicals have 

been stored at a nuclear power 

plant during the preceding year 

in amounts that exceed 

threshold quantities, plant 

operators would be required to 

submit an Annual Hazardous 

Chemical Inventory Report.

Notification of Onsite Storage 

of an Extremely Hazardous 

Substance—submission required 

within 60 days after onsite 

storage begins of an extremely 

hazardous substance in a 

quantity greater than the 

threshold planning quantity

State and 

local 

emergency 

response 

agencies 

(IEMA)

EPCRA, 

Section 304 

(42 USC 11004); 

40 CFR §355.30

If an extremely hazardous 

substance stored at a nuclear 

power plant in a quantity 

greater than the threshold 

planning quantity, plant 

operators would prepare and 

submit the Notification of Onsite 

Storage of an Extremely 

Hazardous Substance.

Annual Toxics Release Inventory 

Report—required for facilities that 

have 10 or more full-time 

employees and are assigned 

certain standards

U.S. EPA

or IEPA

EPCRA, 

Section 313 

(42 USC 11023); 

40 CFR Part 372

If required, nuclear power plant 

operators would prepare and 

submit a Toxics Release 

Inventory Report to EPA.

Industrial Classification codes

Transportation of Radioactive 

Wastes and Conversion Products 

Packaging, Labeling, and Routing 

Requirements for Radioactive 

Materials—required for packages 

containing radioactive materials 

that will be shipped by truck or 

rail

U.S. 

Department of 

Transportation

Hazardous 

Material 

Transportation 

Act (HMTA) 

(49 USC 1501 

et seq.); AEA, 

as amended 

(42 USC 2011 

et seq.); 

49 CFR 

Parts 172, 173, 

174, 177, and 

397

When shipments of radioactive 

materials are made, nuclear 

power plant operators would 

comply with U.S. Department 

of Transportation packaging, 

labeling, and routing 

requirements.
Appendix B

B-6 

License, Permit, or Other 

Required Approval (or 

Submittal)

Responsible 

Agency Authority Relevance

Biotic Resource Protection

Threatened and Endangered 

Species Consultation—required 

between the responsible Federal 

agencies and affected states to 

ensure that the project is unlikely 

to jeopardize the continued 

existence of any species listed 

at the Federal or state level as 

endangered or threatened or 

result in destruction of critical 

habitat of such species

U.S. Fish and 

Wildlife 

Service

(FWS) and 

other 

applicable 

state 

agencies 

(listed in 

Appendix D 

of this SEIS)

Endangered 

Species Act of 

1973, as 

amended 

(16 USC 1531 

et seq.)

The NRC would consult with 

the FWS and state agencies 

regarding the impact of license 

renewal on threatened or 

endangered species or their 

critical habitat.

CWA, Section 404, (Dredge and 

Fill) Permit—required to place 

dredged or fill material into waters 

of the U.S., including areas 

designated as wetlands, unless 

such placement is exempt or 

authorized by a Nationwide 

permit or a regional permit (a 

notice must be filed if a 

Nationwide or regional 

permit applies.)

USACE CWA 

(33 USC 1251 

et seq.); 33 CFR 

Parts 323 and 

330

Any dredging or placement of 

fill material into wetlands within 

the jurisdiction of the USACE at 

a nuclear power plant would 

require a Section 404 permit.

Cultural Resources Protection

Archaeological and Historical 

Resources Consultation—

required before a Federal agency 

approves a project in an area 

where archaeological or historic 

resources might be located

State Historic 

Preservation 

Officer or 

Tribal Historic 

Preservation 

Officer or 

both (listed in 

Appendix D 

of this SEIS)

National Historic 

Preservation Act

of 1966, as 

amended 

(16 USC 470 

et seq.); 

Archaeological

and Historical 

Preservation Act 

of 1974 (16 USC 

469–469c-2); 

Antiquities Act 

of 1906 

(16 USC 431 

et seq.); 

Archaeological 

Resources 

Protection Act 

of 1979, as 

amended 

(16 USC 

470aa-mm)

The NRC would consult with 

the State or Tribal Historic 

Preservation Officers or both 

and applicable Indian tribes

(e.g., tribes that have historical 

ties to the land) regarding the 

impacts of license renewal and 

the results of archaeological

and architectural surveys of 

nuclear power plant site.
Appendix B

B-7 

Table B–2. Licenses and Permits

Permit Number Dates Responsible Agency

License to operate 

Braidwood, Unit 1 NPF-72 Issued: 07/02/1987Expires: 10/17/2026 NRC

License to operate 

Braidwood, Unit 2 NPF-77 Issued: 05/20/1988Expires: 12/18/2027 NRC

Hazardous materials 

shipments registration

040801750001SU

051713550083VX

Issued: 06/09/2010

Expired: 06/30/2013

Issued: 05/17/2013

Expires: 06/30/2016

U.S. Department of 

Transportation, Pipeline 

and Hazardous 

Materials Safety 

Administration

Shipments of low-level 

radioactive waste IL0106 Issued: Not applicableExpires: Not applicable

Illinois Emergency 

Management Agency, 

Division of Nuclear 

Safety

License to deliver 

radioactive material to 

processing facility in 

Tennessee

T-IL005-L11

Issued: 01/1/2011

Expires: (Renewed 

Annually)

Tennessee Department 

of Environment and 

Conservation

Permit to deliver 

radioactive material to 

disposal facility in Utah

0110000031

Issued: 05/21/2011

Expires: (Renewed 

Annually)

Utah Department of 

Environmental Quality

Illinois Pollutant 

Discharge Elimination 

System Permit

IL0048321 

(IEPA 1997 and 

ComEd 2000)

Issued: 07/31/2014

Expires: 07/31/2019

Illinois Environmental 

Protection Agency,

Division of Water 

Pollution Control

Air Permit (auxiliary 

boilers and 

emergency generators)

Application 

#79020011

ID# 197816AAB

Issued: 05/29/2001

Expired: 04/29/2007 

Renewal submitted: 

10/30/2006

Illinois Environmental 

Protection Agency,

Division of Air 

Pollution Control

Registration of Industrial 

and Hazardous Waste ILD000806505 Issued: Not applicableExpires: Not applicable

Illinois Environmental 

Protection Agency,

Bureau of Land 

Potable Water System IL3081869 Issued: Not applicable

Expires: Not applicable

Illinois Department 

of Health, Division of 

Environmental Health

Source: Braidwood License Renewal Application (Exelon 2010)

APPENDIX C 

CONSULTATION CORRESPONDENCE

C-1 

C.CONSULTATION CORRESPONDENCE

C.1 National Historic Preservation Act of 1966 Consultation

The National Historic Preservation Act (NHPA) requires Federal agencies to consider the 

effects of their undertakings on historic properties and consult with applicable state and Federal 

agencies, tribal groups, and individuals and organizations with a demonstrated interest in the 

undertaking before taking action. Historic properties are defined as resources that are eligible 

for listing on the National Register of Historic Places. The historic preservation review process 

(Section 106 of the National Historic Preservation Act of 1966, as amended) is outlined in 

regulations issued by the Advisory Council on Historic Preservation (ACHP) in Title 36 of Code 

of Federal Regulations (CFR), Part 800. In accordance with 36 CFR 800.8(c), the U.S. Nuclear 

Regulatory Commission (NRC) has elected to use the National Environmental Policy Act

(NEPA) process to comply with its obligations under Section 106 of the NHPA.

Table C–1 lists the chronology of consultations and consultation documents related to the NRC 

Section 106 review. The NRC staff is required to consult with the noted agencies and 

organizations in accordance with the statutes listed above.
Appendix C

C-2 

Table C–1. NHPA Correspondence

Date Sender and Recipient Description

ADAMS 

Accession 

No.(a)

8/8/13

M. Wong (NRC) to A. Haaker, 

Illinois Historic Preservation 

Agency

Request for scoping comments/notification 

of Section 106 review ML13191B089

8/8/13 M. Wong (NRC) to R. Nelson, 

ACHP

Request for scoping comments/notification 

of Section 106 review ML13186A174

8/13/13 M. Wong (NRC) to J. Greendeer, 

Ho-Chunk Nation

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13 M. Wong (NRC) to D. Lankford, 

Miami Tribe of Oklahoma

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13

M. Wong (NRC) to J. Froman, 

Peoria Tribe of Indians in 

Oklahoma

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13 M. Wong (NRC) to J. Barrett, 

Citizen Potawatomi Nation

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13

M. Wong (NRC) to A. Sanache, 

Sac and Fox Tribe of the 

Mississippi in Iowa/Meskwaki

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13

M. Wong (NRC) to M. Dougherty, 

Sac and Fox Nation of Missouri 

in Kansas and Nebraska

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13 M. Wong (NRC) to G. Thurman, 

Sac and Fox Nation

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13 M. Wong (NRC) to M. Wesaw, 

Pokagon Band of Potawatomi

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13 M. Wong (NRC) to H. Frank, 

Forest County Potawatomi

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13

M. Wong (NRC) to 

K. Meshigaud, Hannahville 

Indian Community, Band 

of Potawatomi

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13

M. Wong (NRC) to S. Ortiz, 

Prairie Band of 

Potawatomi Nation

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13 M. Wong (NRC) to J. Blackhawk, 

Winnebago Tribe of Nebraska

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13 M. Wong (NRC) to S. Cadue, 

Kickapoo Tribe in Kansas

Request for scoping comments/notification 

of Section 106 review ML13227A388

8/13/13 M. Wong (NRC) to G. Salazar, 

Kickapoo Tribe of Oklahoma

Request for scoping comments/notification 

of Section 106 review ML13227A388

9/4/13

A. Haaker, Illinois Historic 

Preservation Agency, to 

C. Bladey (NRC)

Section 106 determination ML13269A369

9/16/13 K. Collier, Kickapoo Tribe of 

Oklahoma to M. Wong (NRC)

Statement of No Objection to 

Braidwood License Renewal Application ML13274A239
Appendix C

C-3 

Date Sender and Recipient Description

ADAMS 

Accession 

No.(a)

3/23/15

D. Wrona (NRC) to 

J. Greendeer, Ho-Chunk Nation

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to D. Lankford, 

Miami Tribe of Oklahoma

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to J. Froman, 

Peoria Tribe of Indians of

Oklahoma

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to J. Barrett, 

Citizen Potawatomi Nation

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to J. Bender, 

Sac and Fox Tribe of the 

Mississippi in Iowa/Meskwaki

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to B. Robidoux, 

Sac and Fox Nation of Missouri 

in Kansas and Nebraska

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to G. Thurman, 

Sac and Fox Nation

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to J. Warren, 

Pokagon Band of Potawatomi

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to H. Frank, 

Forest County Potawatomi

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to 

K. Meshigaud, Hannahville 

Indian Community, Band 

of Potawatomi

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to S. Ortiz, 

Prairie Band of Potawatomi 

Nation

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to 

J. Blackhawk, Winnebago 

Tribe of Nebraska

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159
Appendix C

C-4 

Date Sender and Recipient Description

ADAMS 

Accession 

No.(a)

3/23/15

D. Wrona (NRC) to S. Cadue, 

Kickapoo Tribe in Kansas

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to G. Salazar, 

Kickapoo Tribe of Oklahoma

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A159

3/23/15

D. Wrona (NRC) to R. Nelson, 

Advisory Council on Historic 

Preservation

Notice of Availability of the Draft 

Supplemental Environmental Impact 

Statement for License Renewal of Braidwood 

Station, Units 1 and 2, for Public Comment

ML15008A145

3/23/15

D. Wrona (NRC) to A. Haaker, 

Illinois Historic Preservation 

Agency

Braidwood Station, Units 1 and 2, License 

Renewal Application Review ML15007A509

4/15/15

R. Leibowitz, Illinois Historic 

Preservation Agency, to 

C. Bladey (NRC)

Statement of No Objection to Braidwood 

NHPA Undertaking and Evidence of 

Compliance with NHPA Section 106 

consultation

ML15124A026

(a) These documents can be accessed through the NRC’s Agencywide Documents Access and Management System 

(ADAMS) at http://adams.nrc.gov/wba/. 

C.2 Endangered Species Act of 1973 and Magnuson–Stevens Fisheries 

Management Act of 1996 Consultation

The NRC must comply with the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 

et seq., herein referred to as ESA) when authorizing, funding, or carrying out Federal actions, 

such as the proposed action that this supplemental environmental impact statement (SEIS) 

addresses, which is whether to issue a renewed license for the continued operation of 

Braidwood Station, Units 1 and 2 (Braidwood), for an additional 20 years beyond the current 

license terms. Under the ESA, the NRC must consult under section 7 of the ESA with the 

U.S. Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS), as 

appropriate, to ensure the protection of listed species and designated critical habitat. The 

regulations that implement section 7 (50 CFR 402) describe the consultation procedures that 

Federal agencies must follow in order to fully comply with the act. Depending on the project, the 

NRC may need to consult with the FWS, NMFS, or both. In the case of Braidwood, no species 

under NMFS’s jurisdiction occur within the action area, and so the NRC staff consulted only with 

the FWS.

The ESA section 7 implementing regulations at 50 CFR 402.06 allow Federal agencies to fulfill 

their obligations under section 7 of the ESA in conjunction with the requirements of the National 

Environmental Policy Act of 1969, as amended (NEPA). In such cases, the Federal agency 

must include the results of its consultation with FWS or NMFS in the NEPA document (i.e., this 

SEIS). A chronology of the section 7 consultation is provided below, and Table C–2 lists the 

correspondence related to the NRC’s review of the Braidwood license renewal application 
Appendix C

C-5 

pursuant to section 7 of the ESA. This table will be updated upon issuance of the final SEIS, as 

applicable, to include correspondence between the issuance of the draft and final SEISs.

Additional information regarding Federally listed species appears in Chapters 3 and 4 of this 

SEIS. Section 3.8 describes the action area and the Federally listed species and habitats that 

have the potential to occur in the action area. Section 4.8 provides an assessment of the 

potential effects of the proposed license renewal on each of these species and the NRC’s effect 

determinations, which are consistent with those identified in Section 3.5 of Endangered Species 

Consultation Handbook (FWS and NMFS 1998).

Chronology of Section 7 Consultation

After receiving the license renewal application, the NRC staff considered whether any Federally 

listed species or habitats occur within the vicinity of Braidwood that could be affected by the 

proposed license renewal. The NRC staff compiled a list of these species and habitats and 

requested the FWS’s concurrence with this list in accordance with the ESA section 7 regulations 

at 50 CFR 402.12(c) in a letter dated September 11, 2013 (NRC 2013). On 

September 24, 2013, FWS (2013b) replied with a letter that included scoping comments 

and comments on the NRC’s list of Federally-listed species for Braidwood. Following this 

correspondence and during the NRC staff’s determination of the action area (described in 

Section 3.8), the NRC has further refined the list of species that may be affected by the 

proposed Braidwood license renewal. Because the FWS’s Rock Island Field Office no longer 

responds to species list requests (FWS 2013a), NRC staff did not send a revised species list 

request to FWS. The NRC compiled the list of species from the FWS’s Endangered Species 

Program online database (FWS 2014a, 2014b). Since publishing the draft supplemental 

environmental impact statement (DSEIS), NRC staff updated the species list to reflect the 

change of status of northern long-eared bat from proposed to threatened species and 

massasauga from candidate to proposed threatened species.

In comments on the DSEIS, FWS (DOI 2015) did not concur with NRC’s initial determination of 

"may affect, not likely to adversely affect" for the endangered sheepnose, because insufficient 

recent information was available to adequately determine the nature of effects and to determine 

the possible occurrence of sheepnose in the action area. After FWS’s non-concurrence, the 

ESA section 7 consultation regarding sheepnose entered a “technical assistance” phase until 

FWS and NRC could evaluate the results of Exelon’s proposed mussel survey. Exelon 

proposed to conduct a mussel survey in the Kankakee River (ESI 2015; Exelon 2015c). The 

FWS (2015) reviewed the proposal and indicated no concerns with the proposed survey. 

Exelon (2015b) forwarded the completed mussel survey report (Belt and Dunn 2015) to both 

FWS and NRC, which NRC staff then reviewed. Following FWS’s review of the mussel survey, 

the NRC and FWS may either enter into formal section 7 consultation or conclude the present 

consultation. The NRC plans to present the final result of that consultation in the Record 

of Decision for the proposed renewal of Braidwood’s operating licenses.

NRC staff presents an assessment of the effects of the proposed action on Federally listed 

species in Sections 3.8 and 4.8 of this SEIS and intends to send FWS a copy of this SEIS when 

it is issued.
Appendix C

C-6 

Table C–2. Section 7 Consultation Correspondence

Date

Sender and 

Recipient Description ADAMS No.(a)

9/11/13 M. Wong (NRC) to 

T. Melius (FWS)

Request for Concurrence with List of Federally-listed 

Species and Habitats for the Proposed Braidwood 

Station, Units 1 and 2, License Renewal

ML13226A549

9/24/13 L. Clemency (FWS)

to C. Bladey (NRC)

No subject. Included comments on NRC’s preliminary 

List of Federally listed Species and Habitats for the 

Proposed Braidwood Station, Units 1 and 2, 

License Renewal

ML13269A373

5/8/15 L. Nelson (FWS) to 

D. Wrona (NRC)

Comments on the DSEIS for the proposed license 

renewal of Braidwood ML15131A004

6/23/15 N. Ranek (Exelon) 

to R. Baum (NRC)

Subject: 2 of 2 Emails -- Exelon Responses to 

Questions dated June 19, 2015 on Braidwood DSEIS ML15189A157

9/29/15 M. Gallagher 

(Exelon) to NRC

Subject: Braidwood, Units 1 and 2 - Transmittal of 

Report Titled "Five Year Post-Construction Monitoring 

of the Unionid Community Near the Braidwood Station 

Kankakee River Discharge Location," Dated 

September 2015

ML15274A093

(a) These documents can be accessed through the NRC’s Agencywide Documents Access and Management System 

(ADAMS) at the following URL: http://adams.nrc.gov/wba/. 

C.3 References

36 CFR Part 800. Code of Federal Regulations, Title 36, Parks, Forests, and Public Property, 

Part 800, “Protection of historic and cultural properties.”

50 CFR Part 402. Code of Federal Regulations, Title 50, Wildlife and Fisheries, Part 402, 

“Interagency Cooperation—Endangered Species Act of 1973, as amended.”

Belt E, Dunn H. 2015. Final Report: Five Year Post-Construction Monitoring of the Unionid 

Community Near the Braidwood Station Kankakee River Discharge. Braidwood, IL: 

Exelon Nuclear. September 2015. 42 p. ADAMS No. ML15274A088.

[DOI] Department of the Interior. 2015. Letter from L. Nelson, Regional Environmental Officer, to 

D. Wrona, U.S. Nuclear Regulatory Commission. May 8, 2015. ADAMS No. ML15131A004.

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

[ESI] Ecological Specialists, Inc. 2015. Letter from E. Belt, Senior Malacologist, to J. Petro, 

Exelon Generation. Subject: Mussel survey. February 24, 2015. ADAMS No. ML15180A037.

[Exelon] Exelon Generation Company, LLC. 2015a. E-mail from N. Ranek, License Renewal 

Environmental Lead, to R. Baum, U.S. Nuclear Regulatory Commission. Subject: 2 of 

2 emails—Exelon responses to questions dated June 19, 2015 on Braidwood DSEIS. 

June 23, 2015. ADAMS No. ML15189A157.
Appendix C

C-7 

[Exelon] Exelon Generation Company, LLC. 2015b. Letter from M. Gallagher, Vice President—

License Renewal Projects, to Document Control Desk, U.S. Nuclear Regulatory Commission. 

Subject: Report Titled “Five Year Post-construction Monitoring of the Unionid Community near 

the Braidwood Station Kankakee River Discharge Location,” dated September 2015. 

September 29, 2015. ADAMS No. ML15274A087.

[FWS] U.S. Fish and Wildlife Service. 2013a. E-mail from J. Duyvejonck, Rock Island Field 

Office, to B. Grange, U.S. Nuclear Regulatory Commission. Subject: Byron Illinois license 

renewal. August 30, 2013. ADAMS No. ML13246A385.

[FWS] U.S. Fish and Wildlife Service. 2013b. Letter from L. Clemency, Field Supervisor, to 

C. Bladey, Chief, Rules, Announcements, and Directives Branch, U.S. Nuclear Regulatory 

Commission. Subject: NOI comments. September 24, 2013. ADAMS No. ML13269A373.

[FWS] U.S. Fish and Wildlife Service. 2014a. “Illinois Threatened and Endangered Species; 

Illinois County Distribution; Federally Endangered, Threatened, and Candidate Species.” 

October 2013. Available at <http://www.fws.gov/midwest/endangered/lists/illinois-cty.html> 

(accessed 24 February 2014).

[FWS] U.S. Fish and Wildlife Service. 2014b. Information, Planning, and Conservation 

System (IPaC), Version 1.4. Natural Resources of Concern. (Accessed 24 February 2014).

[FWS] U.S. Fish and Wildlife Service. 2015. E-mail from S. Cirton, Fish and Wildlife Biologist, to 

N. Ranek, License Renewal Environmental Lead, Exelon Generation, LLC. Subject: 

Exelon Generation—Braidwood Station mussel survey. June 18, 2015. 

ADAMS No. ML15189A172.

[FWS and NMFS] U.S. Fish and Wildlife Service and National Marine Fisheries Service. 1998. 

Endangered Species Consultation Handbook: Procedures for Conducting Consultation and 

Conference Activities Under Section 7 of the Endangered Species Act. March 1998. 315 p. 

Available at <http://www.fws.gov/endangered/esa-library/pdf/esa_section7_handbook.pdf> 

(accessed 8 July 2013).

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

[NHPA] National Historic Preservation Act of 1966, as amended. 54 U.S.C. §100101 et seq.

[NRC] U.S. Nuclear Regulatory Commission. 2013. Letter from M. Wong, Branch Chief, to 

T. Melius, Midwest Regional Director, U.S. Fish and Wildlife Service. Subject: Request for 

concurrence with list of Federally-listed species and habitats for the proposed Braidwood 

Station, Units 1 and 2, license renewal. September 11, 2013. ADAMS No. ML13226A549.

APPENDIX D 

CHRONOLOGY OF ENVIRONMENTAL REVIEW CORRESPONDENCE

D-1 

D.CHRONOLOGY OF ENVIRONMENTAL REVIEW CORRESPONDENCE

This appendix contains a chronological listing of correspondence between the U.S. Nuclear 

Regulatory Commission (NRC) and external parties as part of its environmental review for the 

Braidwood Station (Braidwood). All documents, with the exception of those containing 

proprietary information, are available electronically from the NRC’s Public Electronic Reading 

Room, which is found on the Internet at the following web address: 

http://www.nrc.gov/reading-rm.html. From this site, the public can gain access to the NRC’s 

Agencywide Documents Access and Management System (ADAMS), which provides text and 

image files of NRC’s public documents. The ADAMS accession number for each document is 

included below.

D.1 Environmental Review Correspondence

Table D–1 lists the environmental review correspondence in date order beginning with the 

request by Exelon Generation Company, LLC (Exelon), to renew the operating licenses for 

Braidwood.
Appendix D

D-2 

Table D–1. Environmental Review Correspondence

Date Correspondence Description ADAMS No.

05/29/13 Braidwood, Units 1 and 2 - Environmental Report, Part 1 ML13155A424

05/29/13 Braidwood and Byron, Units 1 and 2 - Application for Renewed 

Operating Licenses ML13155A387

05/29/13 Braidwood, Units 1 and 2 - Environmental Report, Part 2 ML13155A426

05/29/13 Braidwood and Byron, Units 1 and 2 - Information to Support NRC Staff 

Review of the Application for Renewed Operating Licenses ML13155A388

06/06/13 Letter—Receipt and Availability of the LRA for the Byron and Braidwood 

Nuclear Stations ML13144A099

06/10/13 Press Release-13-051: NRC Announces Public Availability of License 

Renewal Application for Braidwood and Byron Nuclear Power Plants in Illinois ML13161A381

06/24/13 Advisement of Leadership Changes for Exelon Generation Company ML13177A019

07/16/13

Determination of Acceptability And Sufficiency for Docketing, Proposed 

Review Schedule, and Opportunity for a Hearing Regarding the Application 

From Exelon Generation Company, LLC, for Renewal of the Operating 

Licenses for Byron Nuclear Station, Unit 1

ML13134A142

07/18/13 FRN - License Renewal Application; Notice of Docketing and Opportunity to 

Request a Hearing and to Petition for Leave to Intervene ML13134A156

07/24/13 Press Release-13-062: NRC Announces Hearing Opportunity on License 

Renewal Application for Byron and Braidwood Nuclear Plants in Illinois ML13207A291

07/24/13 Braidwood notice of intent to prepare environmental impact statement ML13178A244

08/05/13

08/21/2013 Forthcoming Meeting to Discuss the License Renewal Process 

and Environmental Scoping for Exelon Generation Company, LLC, 

Braidwood Nuclear Station Units 1 and 2

ML13193A361

08/06/13 Braidwood, Units 1 and 2, Notification of Intent to Prepare an Environmental 

Impact Statement and Conduct Scoping Process for License Renewal ML13193A299

08/08/13 Braidwood Station, Units 1 and 2, License Renewal Application Review ML13191B089

08/12/13 Press Release-13-066: NRC Public Meetings to Discuss Environmental 

Reviews of Byron, Braidwood Nuclear Plant License Renewals ML13224A318

08/13/13 Request for Scoping Comments Concerning the Braidwood Nuclear 

Generating Station, Units 1 and 2, License Renewal Application Review ML13227A388

08/16/13 Braidwood Station Units 1 and 2, License Renewal Process and 

Environmental Scoping Meeting ML13227A249

08/21/13 Comment (3) by Sue Rezin Supporting Extension of Braidwood Nuclear 

Generating Station License ML13248A271

08/27/13

Comment (1) of Nancy Schultz Voots & Lawrence M. Walsh on Behalf of 

the County Board Will County, Illinois, Supporting of the Renewal of the 

Operating License of the Exelon Generation Braidwood Nuclear 

Generating Station

ML13247A009

08/28/13 Comment (2) of Tom Zimmer Opposing Braidwood Nuclear Plant License 

Extension for 20 Years Due to Environmental and Health Issue Hazardous ML13263A219

09/04/13 Comment (00004) of Anne E. Haaker, on Behalf of IL Historic Preservation 

Agency on License Renewal for Braidwood Station ML13269A369

09/05/13 0821NRC2-154-Afternoon ML13247A541

09/11/13 Braidwood, FWS Letter Scoping and Species List ML13226A549

09/16/13

Comment (6) of Kent Collier on Behalf of Kickapoo Tribe of Oklahoma 

Supporting the Renewal Application of Braidwood Station, Units 1 and 

2 License

ML13274A239
Appendix D

D-3 

Date Correspondence Description ADAMS No.

10/29/13

License Renewal Environmental Site Audit re Byron and 

Braidwood Stations - Severe Accident Mitigation Alternative (TAC 

Nos. MF1834/1835, MF1790/1791, MF1832/1833, and MF1792/1793)

ML13270A116

11/07/13 License Renewal Environmental Site Audit Regarding Braidwood Station 

(TAC Nos. ME1832/1833, MF1792/1793) ML13270A126

12/03/13

Summary of Site Audit Related to the Review of the License Renewal 

Application for Braidwood Station, Units 1 and 2 (TAC Nos. MF1832, 

MF1833, and MF1792, MF1793)

ML13318A238

12/13/13 Audit Trip Report SAMA ML13312A317

12/18/13 Draft Byron and Braidwood SAMA RAIs E-mail ML14002A472

12/18/13 Draft Byron and Braidwood SAMA RAIs ML14002A473

12/21/13 RAI Braidwood Nuclear Station ML13354B937

01/07/14

Request for Additional Information for the Review of the Byron and 

Braidwood Application - Severe Accident Mitigation Alternative Review 

(TAC Nos. MF1790, MF1791, MF1792, & MF1793).

ML13318A208

01/21/14

Braidwood Station, Units 1 and 2, Response to NRC Request for Additional 

Information, Dated December 20, 2013, Related to Byron and Braidwood 

Station, Units 1 and 2 License Renewal Application, Braidwood Station 

Applicant's Environmental Report

ML14022A132

01/24/14 Byron and Braidwood SAMA RAI Conference Call Summary ML14007A240

01/31/14

Braidwood Station Kankakee River Fish Monitoring Program, 1991–2013 -

Tables Requested by the NRC to Describe the Number of Fish Caught by 

Sampling Gear and Species at Each Monitoring Location

ML14030A269

02/04/14

Braidwood, Units 1 & 2 and Byron Units 1 & 2, Response to NRC Requests for 

Additional Information for the Severe Accident Mitigation Alternatives Review, 

dated January 6, 2014 License Renewal Application

ML14035A512

03/04/14

Summary Of Telephone Conference Call Held On February 12, 2014, 

Between The U.S. Nuclear Regulatory Commission And Exelon Generation 

Company, LLC, Concerning Requests For Additional Information Pertaining To 

The Braidwood Station License Renewal Application

ML14050A101

03/31/14 Requests for Additional Information for Review of Braidwood Station, License 

Renewal Application ML14079A617

04/02/14 Requests For Additional Information For The Review Of The Braidwood 

Station License Renewal Application Environmental Report ML14087A432

04/03/14

Issuance of Environmental Scoping Summary Report Associated with the 

Staff's Review of the Application By Exelon Generation Company, LLC, for 

Renewal of the Operating Licenses for Braidwood Station, Units 1 and 2, 

(TAC No. MF1832, MF1833, MF1792)

ML13337A506 

(package)

04/15/14

Summary Of Telephone Conference Call Held On March 31, 2014 Between 

The U.S. NRC And Exelon Generation Company, LLC, Concerning Requests 

For Additional Information Pertaining To The Braidwood Station, License 

Renewal Application

ML14092A356

04/30/14

Response to NRC Request for Additional Information dated April 2, 2014, 

Related to the Byron and Braidwood Stations, Units 1 and 2 License Renewal 

Application, Braidwood Station Applicant's Environmental Report

ML14122A065

05/01/14

Summary of Telephone Conference Call Held on April 16, 2014, Between the 

U.S. Nuclear Regulatory Commission & Exelon Generation Company, LLC, 

Concerning Requests for Additional Information Pertaining to the Braidwood 

Station, License Renewal Application

ML14114A671
Appendix D

D-4 

Date Correspondence Description ADAMS No.

05/05/14

Schedule Revision for Environmental Review of Byron and Braidwood Nuclear 

Stations License Renewal Application - Environmental Review Schedule (TAC 

Nos. MF1790, MF1791, MF1792, And MF1793)

ML14104B131

05/12/14 Update to Chapter 9 of Byron and Braidwood Stations, Units 1 and 2 License 

Renewal Application, Braidwood Station Applicant's Environmental Report ML14132A140

08/15/14 Braidwood, Units 1 and 2 - Renewal of National Pollutant Discharge 

Elimination System (NPDES) Permit No. IL0048321 ML14227A712

10/08/14

Amendment to Exelon Generation, LLC Response dated April 30, 2014 to 

NRC Request for Additional Information dated April 2, 2014, related to Byron 

& Braidwood Units 1 & 2 License Renewal Application, Braidwood Station 

Applicant's Environmental Report

ML14281A019

10/17/14

Schedule Revision for the Environmental Review of the Byron Station and 

Braidwood Station License Renewal Application Environmental Review 

Schedule (TAC Nos. MF1790, MF1791, MF1792, and MF1793)

ML14275A003

03/18/15

Letter to Michael Gallagher, Vice President, License Renewal Projects, Exelon 

Generation Company - Notice of Availability of the Draft Plant-Specific 

Supplement 55 to the Generic Environmental Impact Statement for License 

Renewal of Nuclear Plants regarding Braidwood Station, Units 1 and 2

ML14351A455

03/18/15 FRN on Braidwood - Docket Nos. 50-456 and 50-457; NRC-2013-0169 ML15020A390

03/27/15 Letter to Elizabeth Poole, EPA, on availability of Braidwood DSEIS ML15014A168

05/08/15

Lindy Nelson on Behalf of U.S. Department of the Interior on Draft 

Plant-Specific Supplement 55 to the Generic Environmental Impact Statement

for License Renewal of Nuclear Plants Regarding Braidwood Station, Units 1 

and 2

ML15154A510

05/12/15

Michael P. Gallagher on Behalf of Exelon Generation Company, LLC; 

Braidwood Station, Units 1 and 2; on Draft Supplemental Generic 

Environmental Impact Statement for License Renewal

ML15138A082

05/12/15

Unknown Individual on NRC-2013-0169-0014, Exelon Generation Company, 

LLC; Braidwood Station, Units 1 and 2; Draft Supplemental Generic 

Environmental Impact Statement

ML15138A083

05/12/15

Nathan Grider on NRC-2013-0169-0014, Exelon Generation Company, LLC; 

Braidwood Station, Units 1 and 2; Draft Supplemental Generic Environmental 

Impact Statement

ML15138A081

05/12/15

Kenneth A. Westlake on Behalf of U.S. EPA on Draft Plant-Specific 

Supplement 55 to the Generic Environmental Impact Statement for License 

Renewal of Nuclear Plants Regarding Braidwood Station, Units 1 and 2

ML15154A508

05/15/15 Nancy L. Ranek on Behalf of Exelon Generation, LLC, on Draft NUREG-1437 

Supplement 55 for the Braidwood Station License Renewal ML15154A509

05/15/15

Michael P. Gallagher on Behalf of Exelon Generation Company, LLC, on Draft 

Generic Environmental Impact Statement for License Renewal of Nuclear 

Plants Supplement 55 Regarding Braidwood Station

ML15146A058

06/23/15

Exelon Generation—Permit Application for Maintenance Dredging of the 

Braidwood Nuclear Station Intake to the U.S. Army Corps of Engineers, 

Chicago District

ML15174A109

08/05/15

Response to NRC Request for Additional Information dated August 5, 2015, 

Related to Braidwood Stations, Units 1 and 2 License Renewal

Schedule Time for Fish and Mussel Survey

ML15218A631

08/31/15 Email from Nancy Ranek (Exelon) to Rick Baum (NRC) regarding schedule 

change for Braidwood Station Mussel Survey ML15244A329
Appendix D

D-5 

Date Correspondence Description ADAMS No.

09/14/15 Schedule Revision for the Review of the Braidwood Stations, Units 1 and 2, 

License Renewal Application (TAC Nos. MF1832 and MF1833) ML15243A358

09/29/15

Transmittal of Report Titled “Five Year Post-Construction Monitoring of the 

Unionid Community Near the Braidwood Station Kankakee River Discharge

Location,” Dated September 2015

ML15274A093

APPENDIX E 

ACTIONS AND PROJECTS CONSIDERED IN CUMULATIVE ANALYSIS

E-1 

E.ACTIONS AND PROJECTS CONSIDERED IN CUMULATIVE IMPACT 

ANALYSIS 

Table E–1 identifies projects considered in the U.S. Nuclear Regulatory Commission (NRC) 

staff’s analysis of cumulative impacts related to the environmental analysis of the continued 

operation of Braidwood. Potential cumulative impacts associated with these actions and 

projects are addressed in Section 4.16 of this supplemental environmental impact statement. 

However, not all projects listed in this appendix are considered in each resource area, as 

appropriate (i.e., due to the uniqueness of the resource and its geographic area of 

consideration).
Appendix E

E-2 

Table E–1. Projects Considered in Cumulative Impact Analysis

Project Name Summary of Project Location Status

Nuclear Projects

Clinton Power Station, 

Unit 1 

Nuclear power plant, 

1 1,067-MWe 

General Electric Type 6 

reactor

DeWitt County, 

IL, approximately 

77 mi (124 km) 

southwest. 50-mi 

radius overlaps 

with Braidwood.

Operational 

(NRC 2014a)

Byron Station, Units 1 

and 2 

Nuclear power 

plant, 2 1,121-MWe 

Westinghouse 

4-loop reactors

Ogle County, 

IL, approximately 

80 mi (129 km) 

northwest. 50-mi 

radius overlaps 

with Braidwood.

Operational (NRC 2014b, 

2014c)

LaSalle County Station, 

Units 1 and 2

Nuclear power plant, 

2 1,200-MWe 

General Electric Type 5 

reactors

LaSalle County, 

IL, approximately 

23 mi (37 km) 

west

Operational (NRC 2014d, 

2014e)

Dresden Nuclear Power 

Station, Units 2 and 3

Nuclear power 

plant, 2 867-MWe 

General Electric Type 3 

reactors

Grundy County, 

IL, approximately 

12 mi (20 km) 

north

Operational (NRC 2014f, 

2014g)

Dresden Nuclear Power 

Station, Unit 1 

Nuclear power plant

NA (not applicable 

or available)

Grundy County, 

IL, approximately 

12 mi (20 km) 

north

Shut down in 

October 1978 and is 

currently in SAFSTOR. 

No dismantlement 

activities are under way. 

All spent fuel from DNPS 

Unit 1 transferred to the 

onsite Independent 

Spent Fuel Storage 

Installation (NRC 2014h)

Wind Projects

Top Crop I Wind Farm 68-unit wind farm with 

102 MW generating 

capacity

Grundy, LaSalle 

and Livingston 

Counties, IL, 

approximately 

20 mi (33 km) 

west

Operational 

(EDPR 2014)

Top Crop II Wind Farm 132-unit wind farm with 

198 MW generating 

capacity

Grundy County, 

IL, approximately 

17 mi (28 km) 

west

Operational 

(EDPR 2014)

Grand Ridge Wind Farm 66-unit wind farm with 

99 MW generating 

capacity

Marseilles, IL, 

approximately 

26 mi (42 km) 

northwest

Operational (Boldt 2014)
Appendix E

E-3 

Project Name Summary of Project Location Status

Fossil Fuel Projects

Joliet Station 3-unit 1,358-MW coal 

and natural gas facility

Joliet, IL, 

approximately 

22 mi (35 km)

north

Operational, NPDES

Permit Nos. IL0002216 

and IL0064254 

(EPA 2014a)

Will County Station 4-unit 1,092-MW coal 

facility

Romeoville, IL, 

approximately 

30 mi (48 km) 

north

Operational, NPDES

Permit No. IL0002208 

(IEPA 2013)

Landfills

Prairie View Landfill Permitted landfill area of 

631 ac and a permitted 

disposal area of 223 ac. 

Design capacity of 

30,196,438 yd3.

Wilmington, IL, 

approximately 

7 mi (11 km) 

northeast

Operational until 

2027, NPDES Permit 

No. IL0078662 (Will 

County 2010)

Laraway Recycling and 

Disposal Facility

Permitted landfill area of 

225 ac and a permitted 

disposal area of 32.2 ac. 

Design capacity of 

1,185,400 yd3.

Joliet, IL, 

approximately 

22 mi (35 km) 

north

Operational until 

2045, NPDES Permit 

No. IL0063479 

(IEPA 2010)

Water Supply and Treatment Facilities

City of Godley, 

wastewater treatment

Water treatment with 

discharge to Mazon 

River, tributary of 

Illinois River

Approximately 

1 mi (2 km) 

southwest

Operational, NPDES

Permit No. IL0078816 

(EPA 2014b)

City of Godley, water 

supply

Withdraws groundwater

from Ancell aquifer 

St. Peter Sandstone

Approximately 

1 mi (2 km) 

southwest

Operational (EPA 2014c)

City of Braidwood, 

water supply

Withdraws groundwater

from Ironton–Galesville 

deep sandstone aquifer

Approximately 

1.4 mi (2.2 km) 

north-northeast

Operational (EPA 2014c)

City of Braidwood, 

wastewater treatment

Water treatment with 

discharge to a tributary 

of Claypool Ditch, with 

drainage to the Mazon 

River, a tributary of the 

Illinois River

Approximately 

1.4 mi (2.2 km) 

north-northeast

Operational, NPDES

Permit No. IL0054992 

(EPA 2014b)

Various minor NPDES

wastewater discharges

Various businesses 

with smaller wastewater

dischargers to Kankakee 

River Basin

Within 50 mi 

(31 km)

Operational (EPA 2014b)

Transportation

South Suburban Airport Proposed 809-ha 

(2,000-ac) commercial 

service airport

Peotone, IL, 

approximately 

24 mi (39 km) 

southwest

Components of master 

plan and environmental 

analysis submitted to the 

State. Construction 

expected sometime 

during the license 

renewal term for 

Braidwood (SSA 2013).
Appendix E

E-4 

Project Name Summary of Project Location Status

Remediation Sites

Joliet Army Ammunition 

Plant

14-ha (36-ac) facility 

used from early 1940s 

through 1977 to load, 

assemble, and package 

high-explosive artillery 

shells, bombs, mines, 

and small-arms 

ammunition. Other 

activities on site included 

testing of ammunition, 

washout and renovation 

of shells, and burning 

and demolition of 

explosives.

Joliet, IL, 

approximately 

22 mi (35 km) 

northeast

Ongoing remediation 

under the purview of the 

U.S. Army. Land use 

controls are restricting 

land uses; portions are 

now under productive 

reuse by the U.S. Forest 

Service (Midewin 

National 

Tallgrass Prairie), the 

Veteran’s Administration 

(Abraham Lincoln 

National Cemetery), the 

County of Will (500-ac 

landfill), and productive 

uses through 

commercial and 

industrial redevelopment 

(EPA 2013).

Parks and Recreation Sites

Braidwood Dunes and 

Savanna Nature Preserve

127 ha (315 ac) near 

Braidwood, IL, part of 

Kankakee Sands 

preservation system and 

protects a diversity of 

habitats, including 

prairie, savanna, 

and wetland.

Approximately 

4 mi (6 km) 

northeast

Operational. Managed 

by Forest Preserve 

District of Will County 

(IDNR 2014a).

Mazonia State Fish and 

Wildlife Area

447 ha (1,107 ac) 

contains more than 

200 water impoundments 

ranging from 0.3 ha 

(0.75 ac) to 12 ha (30 ac) 

in size for recreational 

fishing. Managed 

primarily for sport fish 

and waterfowl. Includes 

Braidwood Lake, owned 

by Commonwealth 

Edison, a partially 

perched, cooling lake.

Approximately 

2 mi (4 km) 

southwest

Operational. Managed 

by Illinois Department of 

Natural Resources

(DNR); Braidwood Lake 

is leased to the Illinois 

DNR by Commonwealth 

Edison (IDNR 2014b).

Midewin National 

Tallgrass

7,689 ha (19,000 ac) 

federal tallgrass prairie 

preserve east of the 

Mississippi River. 

Located on former Joliet 

Army Ammunition Plant.

Near Wilmington, 

IL, approximately 

7 mi (11 km) 

northeast

Operational. Managed 

by U.S. Department of 

Agriculture Forest

Service (USFS 2014).

Kankakee River 

State Park

1,618 ha (4,000 ac) 

along the Kankakee 

River. Hiking, fishing, 

and camping occur 

within the park.

Approximately 

12 mi (19 km) 

west

Operational. Managed 

by Illinois Department of 

Natural Resources

(IDNR 2014c).
Appendix E

E-5 

Project Name Summary of Project Location Status

Braidwood Projects

Unit 2 steam generator 

replacement

Assumed to occur during 

normal refueling outage. 

500 additional workers 

specific to replacement. 

All work to occur on 

previously disturbed 

land on site.

Braidwood site Assumed to occur prior 

to the end of the 40-year 

initial license term 

(Exelon 2013)

Units 1 and 2 reactor

pressure vessel 

head replacement

Assumed to occur during 

normal refueling outage. 

340 additional workers 

specific to replacement.

Braidwood site Assumed to occur 

during licensing term 

(Exelon 2013)

Other Projects

Future Urbanization Construction of housing 

units and associated 

commercial buildings; 

roads, bridges, and rail; 

and water and/or 

wastewater treatment 

and distribution facilities 

and associated pipelines 

as described in local 

land-use planning 

documents

Throughout region Construction would 

occur in the future, as 

described in State and 

local land-use 

planning documents.

Sources: Boldt 2014; EDPR 2014; EPA 2013, 2014a, 2014b, 2014c; Exelon 2013; IDNR 2014a, 2014b, 

2014c; IEPA 2010, 2013; NRC 2014a, 2014b, 2014c, 2014d, 2014e, 2014f, 2014g, 2014h; SSA 2013; 

USFS 2014; Will County 2010

E.1 References

[Boldt] The Boldt Company. 2014. “Grand Ridge Energy, LLC.” 2014. Available at 

<http://www.theboldtcompany.com/project/grand-ridge-energy-llc-grand-ridge-wind-farm/> 

(accessed July 2014).

[EDPR] EDP Renewables. 2014. “EDPR Wind Farms: About.” 2014. Available at 

<http://www.edprwindfarms.com/about> (accessed July 2014).

[EPA] U.S. Environmental Protection Agency. 2013. “Region 5 Cleanup Sites: Joliet Army 

Ammunition Plant.” November 14, 2013. Available at 

<http://www.epa.gov/region05/cleanup/jolietarmy/index.html> (accessed July 2014).

[EPA] U.S. Environmental Protection Agency. 2014a. “Joliet Generating Station (#9 and #29).” 

Available at <http://iaspub.epa.gov/triexplorer/

release_fac_profile?TRI=60436JLTGN1800C&year=2011&trilib=TRIQ1&FLD=&FLD=RELLBY

&FLD=TSFDSP&OFFDISPD=&OTHDISPD=&ONDISPD=&OTHOFFD=> (accessed July 2014).

[EPA] U.S. Environmental Protection Agency. 2014b. “Envirofacts: Home: search results: 

Facilities with permits and discharges to waters of the United States.” July 15, 2014. Available 

at <http://www.epa.gov/enviro/index.html> (accessed June 2014).
Appendix E

E-6 

[EPA] U.S. Environmental Protection Agency. 2014c. “Envirofacts: SDWIS Search: Safe 

Drinking Water Search for the State of Illinois – Will and Grundy Counties.” July 15, 2014. 

Available at <http://oaspub.epa.gov/enviro/sdw_form_v2.create_page?state_abbr=IL> 

(accessed July 2014).

[Exelon] Exelon Generation Company, LLC. 2013. Appendix E – Applicant’s Environmental 

Report – Operating License Renewal Stage Braidwood Station, Units 1 and 2, Facility Operating 

License Nos. NPF-72 and NPF-77, Braidwood, Illinois. May 29, 2013. 3,503 p. Agencywide 

Documents Access and Management System No. ML131550528. 

[IDNR] Illinois Department of Natural Resources. 2014a. “Illinois Nature Preserves and 

Commission: Braidwood Dunes and Savanna.” 2014. Available at 

<http://www.dnr.illinois.gov/inpc/pages/area3willbraidwooddunesandsavanna.aspx>(accessed 

July 2014).

[IDNR] Illinois Department of Natural Resources. 2014b. “Mazonia–Braidwood State Fish & 

Wildlife Area.” 2014. Available at 

<http://www.dnr.state.il.us/lands/landmgt/parks/r2/mazonia.htm>(accessed July 2014).

[IDNR] Illinois Department of Natural Resources. 2014c. “Kankakee River State Park.” 2014. 

Available at <http://dnr.state.il.us/lands/landmgt/parks/r2/kankakee.htm> (accessed July 2014).

[IEPA] Illinois Environmental Protection Agency. 2010. National Pollutant Discharge Elimination 

System Permit Program - NPDES Permit No. IL0063479. Springfield, IL: IEPA. October 8, 2010. 

16 p. Available at 

<http://www.epa.state.il.us/public-notices/2010/waste-management-laraway/index.pdf> 

(accessed July 2014).

[IEPA] Illinois Environmental Protection Agency. 2013. National Pollutant Discharge Elimination 

System Permit Program - NPDES Permit No. IL0002208. Springfield, IL: IEPA. 

February 20, 2013. 17 p. Available at 

<http://www.epa.state.il.us/public-notices/2013/midwest-generation-will-county/index.pdf> 

(accessed July 2014).

[NRC] U.S. Nuclear Regulatory Commission. 2014a. “Clinton Power Station, Unit 1.” 

May 8, 2014. Available at <http://www.nrc.gov/info-finder/reactor/clin.html> (accessed 

July 2014).

[NRC] U.S. Nuclear Regulatory Commission. 2014b. “Byron Station, Unit 1.” May 8, 2014. 

Available at <http://www.nrc.gov/info-finder/reactor/byro1.html> (accessed July 2014).

[NRC] U.S. Nuclear Regulatory Commission. 2014c. “Byron Station, Unit 2.” May 8, 2014. 

Available at <http://www.nrc.gov/info-finder/reactor/byro2.html> (accessed July 2014).

[NRC] U.S. Nuclear Regulatory Commission. 2014d. “LaSalle County Station, Unit 1.” 

May 8, 2014. Available at <http://www.nrc.gov/info-finder/reactor/lasa1.html> (accessed 

June 2014).

[NRC] U.S. Nuclear Regulatory Commission. 2014e. “LaSalle County Station, Unit 2.” 

May 8, 2014. Available at <http://www.nrc.gov/info-finder/reactor/lasa2.html> (accessed 

June 2014).

[NRC] U.S. Nuclear Regulatory Commission. 2014f. “Dresden Nuclear Power Station, Unit 2.” 

April 23, 2014. Available at <http://www.nrc.gov/info-finder/reactor/dres2.html> (accessed 

June 2014).
Appendix E

E-7 

[NRC] U.S. Nuclear Regulatory Commission. 2014g. “Dresden Nuclear Power Station, Unit 3.” 

April 23, 2014. Available at <http://www.nrc.gov/info-finder/reactor/dres3.html> (accessed 

June 2014).

[NRC] U.S. Nuclear Regulatory Commission. 2014h. “Dresden – Unit 1.” February 20, 2014.

Available at <http://www.nrc.gov/info-finder/decommissioning/power-reactor/ 

dresden-nuclear-power-station-unit-1.html> (accessed June 2014).

[SSA] South Suburban Airport. 2013. “Master Plan.” Available at 

<http://www.southsuburbanairport.com/MasterPlan/MP-home.htm> (accessed July 2014).

[USFS] U.S. Forest Service. 2014. “Midewin National Tallgrass Prairie—Home.” 2014. 

Available at <http://www.fs.usda.gov/main/midewin/home> (accessed July 2014).

Will County. 2010. “Will County Green: Prairie View Landfill.” Available at 

<http://www.willcountygreen.com/initiatives/prairie_view_landfill.aspx> (accessed July 2014)

APPENDIX F 

U.S. NUCLEAR REGULATORY COMMISSION STAFF EVALUATION 

OF SEVERE ACCIDENT MITIGATION ALTERNATIVES FOR 

BRAIDWOOD STATION, UNITS 1 AND 2, 

IN SUPPORT OF LICENSE RENEWAL APPLICATION REVIEW

F-1 

F.U.S. NUCLEAR REGULATORY COMMISSION STAFF EVALUATION OF 

SEVERE ACCIDENT MITIGATION ALTERNATIVES FOR BRAIDWOOD 

STATION, UNITS 1 AND 2, IN SUPPORT OF LICENSE RENEWAL 

APPLICATION REVIEW

F.1 Introduction

Exelon Generation Company, LLC (Exelon), submitted an assessment of severe accident

mitigation alternatives (SAMAs) for the Braidwood Station, Units 1 and 2 (Braidwood), as part of 

the Environmental Report (ER) (Exelon 2013a). This assessment is based on the most recent 

Braidwood probabilistic risk assessment (PRA) available at that time, a plant-specific offsite 

consequence analysis performed using the MELCOR Accident Consequence Code System 2 

(MACCS2) computer code, and insights from the Braidwood individual plant examination (IPE) 

(ComEd 1994, 1997a) and individual plant examination of external events (IPEEE) 

(ComEd 1997b). In identifying and evaluating potential SAMAs, Exelon considered SAMAs that 

addressed the major contributors to core damage frequency (CDF) and release frequency at 

Braidwood, as well as SAMA candidates for other operating plants that have submitted license 

renewal applications. Exelon initially identified 35 potential SAMAs. This list was reduced to 

34 unique SAMA candidates by eliminating SAMAs that are not applicable to Braidwood due to 

design differences, that have already been implemented at Braidwood or the intent achieved by 

other means, or that have excessive implementation costs. One additional candidate SAMA 

was also further evaluated after accounting for analysis uncertainties. Exelon assessed the 

costs and benefits associated with each of the 35 potential SAMAs and concluded in the ER 

that 26 of the candidate SAMAs evaluated are potentially cost-beneficial. Exelon has submitted

all 26 potentially cost-beneficial SAMAs to the Braidwood Plant Health Committee for further 

implementation consideration in accordance with current Braidwood processes and procedures 

for evaluating possible plant modifications. 

Based on a review of the SAMA assessment and plant audit trip conducted November 4, 5, and 

6, 2013, the U.S. Nuclear Regulatory Commission (NRC) staff issued requests for additional 

information (RAIs) to Exelon by letter dated January 6, 2014 (NRC 2014). Key questions 

concerned: (a) the disposition of internal and external review comments on the PRA model, 

(b) the modeling of systems shared between units, (c) additional details on the Levels 2 and 3 

PRA models, (d) the scope and status of the Braidwood fire PRA model, (e) the estimated 

seismic CDF, (f) the identification of candidate SAMAs, (g) the basis for the SAMA cost 

estimates, and (h) the results of the uncertainty analysis. Exelon submitted additional 

information by letter dated February 4, 2014 (Exelon 2014). In the responses, Exelon provided 

a discussion of the conduct of the PRA model self-assessment and the resolution of review 

findings, a discussion of the modeling of shared systems and the incorporation of opposite unit 

equipment unavailability, clarification of Levels 2 and 3 PRA modeling details and assumptions, 

further details on the Braidwood fire PRA, analysis of additional SAMAs, updated SAMA cost 

information, and revised SAMA benefit analyses to fully account for seismic events and 

uncertainty. Exelon’s responses addressed the NRC staff’s concerns and did not result in the 

identification of additional potentially cost-beneficial SAMAs.

An assessment of SAMAs for Braidwood is presented below.
Appendix F

F-2 

F.2 Estimate of Risk for Braidwood

Exelon’s estimates of offsite risk at Braidwood are summarized in Section F.2.1. The 

summary is followed by the NRC staff’s review of Exelon’s risk estimates in Section F.2.2.

F.2.1 Exelon’s Risk Estimates

Exelon combined two distinct analyses to form the basis for the risk estimates used in the 

SAMA analysis: (1) the Braidwood Levels 1 and 2 PRA models (both are essentially new 

models developed since the IPE models) and (2) a supplemental analysis of offsite 

consequences and economic impacts (essentially a Level 3 PRA model), developed specifically 

for the SAMA analysis. The SAMA analysis is based on the most recent Braidwood Level 1 and 

Level 2 PRA model, available at the time of the ER, which is referred to as the Braidwood PRA 

(Revision BB011b1). The scope of this Braidwood PRA includes internal floods but does not 

include external events.

The Braidwood CDF is approximately 3.6×10−5 per year for Unit 1 and 3.5×10−5 per year for 

Unit 2 (Exelon 2013a). Exelon did not explicitly include the contribution from external events 

within the Braidwood SAMA risk estimates; however, it did account for the potential risk 

reduction benefits associated with external events by multiplying the estimated benefits for 

internal events by a factor of 2.8. This is discussed further in Sections F.2.2 and F.6.2.

The breakdown of CDF by initiating event is provided in Table F–1 (Exelon 2013a). As shown 

in this table, events initiated by loss of essential service water (SX), small loss-of-coolant 

accident (LOCA), and internal flooding are the dominant contributors to the CDF for both units.

Table F–1. Braidwood Core Damage Frequency (CDF) for Internal Events

Initiating Event

Unit 1 CDF

(per year)

Unit 1

Percent CDF

Contribution

Unit 2 CDF

(per year)

Unit 2 

Percent CDF

Contribution

Loss of Essential Service Water (SX) 1.3×10−5 36 1.3×10−5 37

Small Loss-of-Coolant Accident

(LOCA) 6.4×10−6 18 6.3×10−6 18

Internal Flooding 5.7×10−6 16 5.6×10−6 16

Loss of Component Cooling Water 

(CCW) 3.2×10−6 9 3.2×10−6 9 

Loss of Auxiliary Power (AP) 2.1×10−6 6 1.4×10−6 4

Other Initiating Events 1.8×10−6 5 1.8×10−6 5

Medium LOCA 1.4×10−6 4 1.4×10−6 4

Steam Generator Tube Rupture 

(SGTR) 1.4×10−6 4 1.8×10−6 5 

General Transient and Loss of 

Main Feedwater 7.1×10−7 2 7.0×10−7 2 

Total (Internal Events)(a) 3.6×10−5 100 3.5×10−5 100

(a) Column totals may be different due to round off.

In addition, in the ER, Exelon identified that station blackout (SBO) contributes (a) 7.1×10−7 per 

year, or 2.0 percent, for Unit 1 and (b) 1.1×10−6 per year, or 3.0 percent, for Unit 2, to the total 

internal events CDF. In response to the NRC staff RAI, Exelon identified that anticipated 
Appendix F

F-3 

transients without scram (ATWS) contribute 1.6×10−7 per year or 0.4 and 0.5 percent of the total 

CDF for Units 1 and 2, respectively (Exelon 2014).

The Braidwood Level 2 PRA model that forms the basis for the SAMA evaluation is a new 

model and stated by Exelon to represent the current state of the art (Exelon 2013a). The 

Level 2 model utilizes a single containment event tree (CET) to assess the accident progression 

following a core damage event and contains both phenomenological and systemic events. The 

Level 1 core damage sequences are binned into plant damage states (PDSs). These PDSs 

provide the interface between the Level 1 and Level 2 CET analysis. Each PDS bin is then 

entered into the CET. The CET is linked directly to the Level 1 event trees and CET nodes are 

evaluated using supporting fault trees and logic rules.

The result of the Level 2 PRA is a set of 13 release or source term categories, with their 

respective frequency and release characteristics. The results of this analysis for Braidwood are 

provided in Table F.2-8 of the ER (Exelon 2013a). The categories were defined based on the 

similarity of scenario release characteristics and ultimate containment failure mode. This 

resulted in six release categories with large early releases (LERs), four with late releases, two 

with small early releases, and one for an intact containment. The frequency of each release 

category was obtained by summing the frequency of the individual accident progression CET 

endpoints binned into the release category. Source terms were developed for each of the 

13 release categories using the results of Modular Accident Analysis Program (MAAP) 

Version 4.0.6 computer code calculations (Exelon 2013a).

The offsite consequences and economic impact analyses use the MACCS2 (NRC 1998) code to 

determine the offsite risk impacts on the surrounding environment and public. Inputs for these 

analyses include plant-specific and site-specific input values for core radionuclide inventory, 

source term and release characteristics, site meteorological data, projected population 

distribution (within a 80-km (50-mi)) radius) for the year 2047, emergency response evacuation 

modeling, and economic data. The core radionuclide inventory corresponds to the end-of-cycle 

values for Braidwood operating at 3,645 megawatts thermal (MWt). The magnitude of the 

onsite impacts (in terms of cleanup and decontamination costs and occupational dose) is based 

on information provided in NUREG/BR–0184 (NRC 1997a).

In the ER, Exelon estimated the dose to the population within 80 km (50 mi) of the Braidwood 

site to be approximately 1.14 person-sieverts (Sv) (114 person-roentgen equivalents man (rem)) 

per year (Exelon 2013a). In addition, Exelon estimated the annual offsite economic cost impact 

to be $810,000 per year. The breakdown of the total population dose and offsite economic cost 

by containment release mode is summarized in Table F–2. Late failures due to containment 

overpressure events (such as loss of containment heat removal due to loss of power or cooling 

water) and large early release frequency (LERF) accidents caused by unisolated 

interfacing-systems loss-of-coolant accident (ISLOCA) dominate the population dose risk (PDR) 

at Braidwood. Late containment overpressure failures are dominant in the offsite economic 

cost impact.
Appendix F

F-4 

Table F–2. Breakdown of Population Dose and Offsite Economic Cost by Containment 

Release Mode (a)

Containment Release Mode

Population Dose

(Person-rem (b)

Per Year)

Percent 

Contribution

Offsite 

Economic 

Cost

($/yr)

Percent 

Contribution

Containment overpressure (late) 87.3 77 687,000 83

ISLOCA 15.5 14 54,400 7

SGTR 9.05 8 61,800 8

Containment isolation failure 1.18 1 3,800 <1

Containment intact 0.33 <1 300 <1

Early containment failure 0.29 <1 2,000 <1

Basemat melt-through (late) 0.06 <1 62 <1

Total (c) 114 100 810,000 100

(a) Values in table derived from Table F.3-9 of the ER

(b) One person-rem = 0.01 person-Sv 

(c) Column totals may be different due to round off.

F.2.2 Review of Exelon’s Risk Estimates

Exelon’s determination of offsite risk at the Braidwood site is based on the following three major 

elements of analysis:

(1) the Level 1 risk model that supersedes the 1994/1997 IPE submittals (ComEd 1994, 

1997a), a new interim internal fire analysis (approved by Exelon for interim use) and 

the seismic and other external event analyses of the 1997 IPEEE submittal 

(ComEd 1997b);

(2) the new Level 2 risk model; and

(3) the MACCS2 analyses performed by Exelon to translate fission product source 

terms and release frequencies from the Level 2 PRA model into offsite consequence 

measures.

Each of these analyses was reviewed by NRC staff to determine the acceptability 

of Braidwood’s risk estimates for the SAMA analysis, as summarized below.

F.2.2.1 Internal Events CDF Model

The NRC staff’s review of the Braidwood IPE is described in an NRC letter dated 

December 3, 1997 (NRC 1997b). Based on a review of the original and modified IPE submittal, 

the NRC staff concludes that the Braidwood IPE has met the intent of generic letter (GL) 88-20 

(NRC 1988). The NRC staff review indicated that while no definition of a vulnerability was 

provided by the staff or Exelon, Exelon did identify one potential vulnerability (used by Exelon 

for plant management) and one enhancement. These are discussed in Section F.3.2.

There have been numerous revisions to the Braidwood PRA since the original 1994 IPE 

submittal. A listing of the complete revision history of the Braidwood PRA since the original IPE 

submittal was provided in the ER (Exelon 2013a) and is summarized in Table F–3 below. A 

comparison of the internal events CDF between the 1997 modified IPE and the current PRA 
Appendix F

F-5 

model indicates there has been very little change in the total CDF (from 3×10−5 per year for both 

units to 3.6×10−5 per year for Unit 1 and 3.5×10−5 per year for Unit 2).

Table F–3. Summary of Major PRA Models and Corresponding CDF and LERF Results (a)

PRA Model Summary of Significant Changes From 

Prior Model

CDF (per year) LERF (per year)

Unit 1 Unit 2 Unit 1 Unit 2

Original IPE

(6/1994) • IPE submittal

2.7×10−5

(same model)

2.6×10−6

(same model)

Modified IPE (b)

(3/1997)

• Numerous modifications based on NRC concerns on 

Braidwood IPE similar to those on other Commonwealth Edison 

IPEs

3.0×10−5

(same model) Not Available

Revision 0

(10/1999)

• Changed PRA model from support state model to linked fault 

tree model involving extensive changes to all event trees and 

fault trees

• Updated all data

4.9×10−5 4.9×10−5 3.8×10−6 3.8×10−6 

Revision 1

(10/2000)

• Changed SX pump success criterion from two pumps to 

one pump

4.6×10−5 4.6×10−5 4.9×10−6 4.9×10−6

Revision 3a

(8/2001)

• Revised loss of offsite power (LOOP)/DLOOP Event Tree

• Internal flooding analysis incorporated

• Incorporation of plant mods to CV pump lube oil cooler

• Incorporation of plant mod that removed auxiliary feedwater 

(AFW) pump 1B dependency on instrument air

3.2×10−5 3.1×10−5 4.6×10−6 4.6×10−6

Revision 4

(2/2002)

• Significant model enhancements to the following systems: 

reactor protection system, engineered safety features actuation 

system (ESFAS), CCW, power-operated relief valves (PORVs), 

AFW and instrument power

• Updated containment failure likelihood

3.1×10−5 3.1×10−5 4.6×10−6 4.9×10−6

Revision 5

(12/2002)

• Changed small LOCA and transient accident modeling

• Addressed miscellaneous model issues

• Incorporated updated failure and unavailability data, HEPs and 

support system initiating event frequencies

3.8×10−5 3.8×10−5 4.2×10−6 4.5×10−6

Revision 5B

(6/2003)

• Reevaluated the plant-specific data

• Performed full convergence analysis and a human failure 

dependency analysis

• Incorporated new SX success criteria

• Revised the model so that automatic quantification can be 

performed using ORAM-Sentinel and PSALINK program

5.4×10−5 5.4×10−5 4.7×10−6 5.4×10−6

Revision 5F

(12/2006)

• Model revised to incorporate conditional dual unit LOOP for 

most initiators

• Updated some LERF binning

• Changed modeling of ESFAS testing

• Added RWST switchover channel testing and common cause

5.4×10−5 5.4×10−5 5.0×10−6 5.8×10−6

Revision 6C

(5/2008)

• Extensive model update including changes to AFW success 

criteria, revisions to human error probability to reflect procedure 

changes and operator interviews, revised internal flooding 

analysis, updated data analysis, and changes to emergency 

service water and CCW modeling

3.6×10−5 3.5×10−5 2.9×10−6 3.4×10−6

Revision 6E3

(5/2010)

• Revised RCP seal LOCA model

• Incorporated revised feed and bleed success criteria

• Incorporated AFW unit crosstie modification

• Revised human reliability assessment

1.6×10−5 1.5×10−5 1.4×10−6 1.6×10−6

Revision BB011a

(6/2012)

• Updated internal flooding analysis

• Incorporated new data analysis

• Incorporated new human reliability dependency and 

preinitiator analysis

• Removed credit for AFW unit crosstie modification

4.3×10−5 4.3×10−5 2.7×10−6 3.3×10−6

Revision BB011b

(11/2012)

• Improved modeling of ESW and CCW systems

• Incorporated new operator actions for use of emergency 

service water and CCW systems

3.6×10−5 3.5×10−5 2.5×10−6 3.1×10−6

Revision BB011b1

(12/2012)

• LERF model replaced with Level 2 model based on 

methodology of WCAP-16341-P 3.6×10−5 3.5×10−5 1.1×10−6 1.0×10−6

(a) Except for Modified IPE information, information in table is based on ER Table F.2-1 with some intermediate models not included.

(b) Information from ComEd 1997a.
Appendix F

F-6 

The CDF value from the 1997 modified IPE (3×10−5 per year) is in the middle range of the CDF 

values reported in the IPEs for Westinghouse four-loop plants. Figure 11.6 of NUREG-1560 

shows that the IPE-based total internal events CDF for Westinghouse four-loop plants ranges 

from 2×10−6 per year to 2×10−4 per year, with an average CDF for the group of 6×10−5 per year 

(NRC 1997c). It is recognized that other plants have updated the values for CDF subsequent to 

the IPE submittals to reflect modeling and hardware changes. The current internal events CDF 

results for Braidwood (3.6×10−5 per year for Unit 1 and 3.5×10−5 per year for Unit 2) are 

comparable to those results for other plants of similar vintage and characteristics.

The NRC staff considered the peer review performed for the Braidwood PRA and the potential 

impact of the review findings on the SAMA evaluation. In the ER (Exelon 2013a), Exelon briefly 

described the results of the 1999 Westinghouse Owners Group peer review of Revision 0 of the 

Braidwood PRA. Exelon stated that the 27 significance-level A (expected impact to be 

significantly nonconservative) and level B (expected impact to be nonconservative but small) 

facts and observations (F&Os) generated during the peer review have been closed out. In 

response to an NRC staff RAI to describe (a) what is meant by “closed out,” (b) how this is 

verified, and (c) if these F&Os were considered in the 2012 self-assessment and the corrections 

incorporated in the PRA that was used for the SAMA analysis, Exelon provided a description of 

the process used to track and close out F&Os as well as other potential model changes. In the 

ongoing model-update process, the model and document changes associated with each F&O, 

as well as the decision to not change the model or documentation, are reviewed and approved 

with each official model approval in accordance with Exelon procedures. The approved 

dispositions of all peer review F&Os were incorporated in the SAMA PRA. Exelon stated 

that “changes due to the peer review F&Os were fully considered as part of the 2012 

self-assessment” (Exelon 2014).

The NRC staff has determined that Exelon’s disposition of the peer review findings is consistent 

with the guidance in Nuclear Energy Institute (NEI) 05-01 (NEI 2005) and that the final 

resolution of the findings provides reasonable assurance of minimal impact to the results of the 

SAMA analysis.

The NRC staff noted in an RAI that ER Table F.2-1 (describing changes made to each PRA 

revision) states PRA Revision 5A “[r]evised the model and data to address the PRA quality 

issues raised by CR#00142080 (1/30/03) against Rev. 5 model,” and requested Exelon to 

identify the underlying quality-process issues and the corrective actions taken (NRC 2014). 

In response to the RAI, Exelon stated:

The underlying process issue that allowed these technical quality issues to occur 

was a premature approval of the model prior to full review as required by the 

work process procedure. Exelon T&RM ER-AA-600-1015, ‘FPIE PRA Model 

Update,’ provides specific process and review criteria for a new model to be 

officially approved. [Exelon 2014]

Further:

This process was not followed adequately for Revision 5, resulting in the CR. 

To help ensure that the review items are performed prior to model approval, the 

Quantification Notebook for each official model of record (including the current 

model of record) now includes confirmation that the reviews required by 

ER-AA-600-1015 were performed to check for these and other quality issues. 

The Quantification Notebook documenting the listed reviews is internally 

independently reviewed. Signatures of the author, reviewers, and approver 

confirm this review has been performed, and approval of the Quantification 

Notebook signifies official approval of the updated model. [Exelon 2014]
Appendix F

F-7 

Exelon indicated that there had been several self-assessments of the Braidwood PRA, with the 

latest in 2012 of Revision BB011a against the Capability Category II requirements of the 2009 

revision of the American Society of Mechanical Engineers (ASME) and American Nuclear 

Society (ANS) PRA standard (ASME and ANS 2009). Exelon further clarified in its response to 

an RAI that the self-assessment considered the guidance in Regulatory Guide 1.200, Revision 2 

(NRC 2009), and it was performed consistent with the NEI 00-02 (NEI 2006) self-assessment 

process (Exelon 2014).

This self-assessment identified 2 supporting requirements (SRs) that were classified as not 

being met and 22 that were considered as meeting only the Capability Category I requirements. 

The ER provided a tabulation of the issues related to the SRs that did not meet Capability 

Category II and the potential impact on the SAMA analysis. All but four of the SRs not meeting 

Capability Category II were associated with requirements for the LER analysis. This was a 

result of the self-assessment being performed on the BB011a LERF-only model. These LER 

issues were addressed in a subsequent assessment as discussed in Section F.2.2.3 below. For 

the four non-LER issues identified in the self-assessment, Exelon concluded that not meeting 

the Capability Category II requirements would have no meaningful impact on the SAMA 

analysis. The NRC staff concurs with this conclusion.

The NRC staff noted in an RAI that the list of CDF contribution by initiating event (see Table F–1 

above) included a contribution due to loss of AP but did not explicitly include a contribution due 

to a LOOP (NRC 2014). Exelon indicated that the loss of AP is a loss of an internal AP bus and 

is modeled the same as the loss of any other support system. The LOOP contribution is 

included in the “Other” category and is 0.9 percent and 1.0 percent of the total internal events 

CDF for Units 1 and 2, respectively. These values are for the LOOP initiating event only and do 

not include the contribution from LOOP that are the consequences of other initiating events. 

Both single unit and dual unit loss of offsite power (DLOOP) events are included in the 

Braidwood PRA (Exelon 2014).

The freeze date for the inclusion of plant specific data for the model was December 2010. In 

response to an NRC staff RAI concerning actual or planned changes to Braidwood hardware or 

operation since the freeze date, Exelon listed a number of modifications being considered, all of 

which were considered as SAMAs in the license renewal analysis. In addition Exelon stated 

that “no potential changes in fuel cycle or fuel management are known that would affect the 

SAMA analysis” (Exelon 2014).

To confirm as-built modeling in Exelon’s analysis, the NRC staff notes that, as indicated at the 

November 2013 audit and stated in an RAI response (Exelon 2014), Exelon is planning to install 

no-leakage reactor coolant pump (RCP) seals at Braidwood. The staff confirmed that this 

planned change is not included in the baseline SAMA analysis, but is evaluated appropriately 

as a candidate SAMA.

In response to an NRC staff RAI to identify the systems that are shared or can be crosstied 

between units and describe the modeling including the treatment of unavailability during 

outages of the other unit, Exelon indicated that the service water (SW), CCW, AFW, AP direct 

current power, and instrument air/service air systems are shared or could be crosstied between 

Braidwood units and stated that:

The Braidwood PRA is a fully integrated two-unit model, so all components from 

each unit and those shared between units are explicitly modeled. Unit-specific 

components which can be used by the opposite unit are linked into the opposite 

unit’s fault tree logic structure.

Further, it is indicated that unavailability is modeled with both normal maintenance terms as well

as outage maintenance terms for all shared components except those needed during normal full 
Appendix F

F-8 

power and outage operations. The normal unavailability is based on unavailable hours during 

normal power operation while the outage unavailability is based on unavailable hours (a) during 

an outage and (b) during total time as defined by the event progression (Exelon 2014).

During the reviews of the Braidwood ER SAMA analysis and that from the similar Byron Station 

analysis (Exelon 2013b), the NRC staff noted some differences in PRA results between the 

two sites and asked Exelon, in an RAI, to explain the reasons for these differences. The staff 

asked if the reasons suggest design or operating changes that might be cost-beneficial for 

one site or the other (NRC 2014). For sequences resulting from RCP seal LOCAs following 

Loss of CCW with failure to establish emergency core cooling system (ECCS) recirculation 

cooling but with successful cooldown and depressurization, for which the Byron CDF is 

considerably larger than that for Braidwood, Exelon indicated that the difference is due to 

a different normal valve alignment at Byron which requires additional operator actions 

(NRC 2014). For sequences resulting from random nonisolable small LOCAs with failure to 

establish ECCS recirculation cooling but with successful cooldown and depressurization, for 

which the Braidwood CDF is considerably larger than that for Byron, Exelon indicated that the 

difference is primarily because at Braidwood Station, SX007 SW valves must be throttled open 

to establish an appropriate flow rate through the component cooling heat exchangers (HXs). 

This requirement for Braidwood results from Braidwood SW being taken from the Braidwood 

cooling pond (lake), whose water temperature varies throughout the year. At Byron, the 

SX007 valves do not need manipulation during an accident (Exelon 2014). The potential 

for SAMAs suggested by these differences is discussed in Section F.3.2.

Given the following current conditions—(a) an early revision of the Braidwood internal 

events PRA model has been peer-reviewed, (b) a more recent revision was subjected to a 

self-assessment using the 2009 revision of the ASME PRA standard and the guidance in 

Regulatory Guide 1.200, Revision 2, (c) the assessment was performed consistent with the 

NEI 00-02 self-assessment process and the review findings were adequately resolved, and 

(d) Exelon has satisfactorily addressed NRC staff questions regarding the PRA—the NRC staff 

concludes that the internal events Level 1 PRA model is of sufficient quality to support the 

SAMA evaluation.

F.2.2.2 External Events

As indicated above, the Braidwood PRA used for the SAMA analysis does not include external 

events. In the absence of such an analysis, Exelon used the Braidwood IPEEE and other 

analyses to identify the highest risk accident sequences and the potential means of reducing the 

risk posed by those sequences and to estimate the benefit of potential SAMAs, as discussed 

below and in Section F.3.2.

The Braidwood IPEEE was submitted in June 1997 (ComEd 1997b), in response to 

Supplement 4 of GL 88-20 (NRC 1991a), which requested that each power reactor licensee 

identify and report to the NRC plant-specific vulnerabilities to severe accidents caused by 

external events. The submittal included a seismic margin assessment (SMA), a fire assessment 

using the Electric Power Research Institute (EPRI) fire-induced vulnerability evaluation (FIVE) 

guidance (EPRI 1992), and a screening analysis for other (high winds, floods, and other (HFO)) 

external events. Commonwealth Edison Company (ComEd) did not explicitly provide a 

definition of a vulnerability and did not identify any vulnerabilities in the seismic, fire, or HFO 

areas. However, a number of seismic issues were identified during ComEd’s IPEEE 

development, which were identified as “outliers” (related to statistical likelihood). As indicated 

in the ER, for example, these are generally items with potential seismically induced interaction 

issues for which it was difficult to calculate a High Confidence of Low Probability of Failure 

value; therefore, these require further evaluation. In its safety evaluation report (NRC 2001), 
Appendix F

F-9 

the NRC staff concludes that the applicant’s IPEEE process is capable of identifying the most 

likely severe accidents and severe accident vulnerabilities for external events and, therefore, 

that the Braidwood IPEEE has met the intent of Supplement 4 to GL 88-20.

The Braidwood IPEEE seismic analysis was a focused-scope SMA following NRC guidance 

(NRC 1991a, 1991b). The SMA approach is deterministic in nature and does not result in 

probabilistic risk information. The SMA was performed using a Safe Shutdown Equipment List 

(SSEL) with plant walkdowns in accordance with the guidelines and procedures documented in 

EPRI Report NP-6041-SL (EPRI 1991). Two success paths, each capable of mitigating the 

effects of a seismically induced small break LOCA, were identified based on a review of the 

guidance and plant documentation. The components on the SSEL were then evaluated for 

seismic capacity.

The components and associated structures in which they are housed were evaluated based on 

the screening criteria of NP-6041-SL. The review of major structures was based primarily on a 

review of the design bases augmented by a walkdown to identify any anomalous conditions. 

Masonry block walls were evaluated and qualified to the seismic design basis loads in 

compliance with the plant’s seismic evaluation criteria. Mechanical and electrical equipment 

that did not meet the screening criteria were considered SMA outliers. If the equipment had 

anchorage that was not judged robust by the walkdown team, the high confidence in low 

probability of failure (HCLPF) anchorage evaluation was calculated to obtain an anchorage 

seismic capacity.

A number of outliers were identified. The majority of the outliers involved seismic interaction 

concerns that were resolved through licensee corrective actions. Others were resolved either 

by conservative deterministic failure margin capacity analysis that showed that the seismic 

capacity substantially exceeded the review-level earthquake demand, or by 

maintenance/modifications. These outliers were considered further in the Phase I SAMA

identification discussed in Section F.3 below.

For the purposes of the SAMA evaluation, Exelon assumed a seismic CDF of 1×10−6 per year 

in the development of the external events multiplier (Exelon 2013a). Since the SMA approach 

used in the IPEEE does not involve the determination of seismic CDF and Exelon did not 

provide a basis for the value used, the NRC staff asked Exelon to consider the impact on the 

SAMA analysis if a seismic CDF from the generic issue (GI) 199 risk assessment (NRC 2010a) 

for the Braidwood site was used instead of the assumed seismic CDF of 1×10−6 per year. 

Exelon indicated that using the “weakest link” (bounding scenario) seismic CDF value (7.3×10−6

per year) from GI 199, the external events multiplier would increase from 2.8 to 3.0. Exelon 

reevaluated the SAMAs using this larger multiplier (Exelon 2014). This is discussed in more 

detail below.

The Braidwood IPEEE included an internal fire analysis employing EPRI’s FIVE methodology 

(EPRI 1992). However, this has been superseded by the 2008 Braidwood Fire PRA, which is 

stated by Exelon to be an interim implementation of NUREG/CR–6850 (EPRI and NRC 2005). 

Interim implementation status is because not all needed analyzing tasks are completely 

addressed or implemented in the model. The 2008 Braidwood fire PRA was used in the SAMA

analysis for determining the fire contribution to the external events multiplier as well as for 

identifying potential SAMAs to mitigate the internal fire risk.

While the Braidwood fire PRA is a risk assessment as compared to the IPEEE fire analysis, 

which is a screening analysis, it was not used directly in the SAMA analysis quantification. 

Exelon indicated that this was due to the fire model’s not being fully integrated with the most 

recent Levels 2 and 3 analyses and the fire model’s being based on Revision 6C of the internal 
Appendix F

F-10

events PRA rather than the current Revision BB11b1 model used for the internal events 

SAMA analysis.

In response to an NRC staff RAI (request) to provide more information on the quality and 

development of the 2008 Braidwood Fire PRA, Exelon indicated that the fire PRA development 

tasks do not have any specific quality assurance activities (Exelon 2014). However, there are 

internal processes that are used to ensure that the tasks are being performed and reviewed by 

knowledgeable personnel. This is accomplished by the use of certification guides for analysis in 

addition to each document’s having three levels of signatures—preparer, reviewer, and 

approver—commensurate with quality assurance expectation for PRA. In addition, Exelon 

briefly discussed several conservatisms and nonconservatisms in the current model. The major 

conservatism identified is in the fire modeling task, which uses generic treatments of the zone of 

influence and no credit is given for fire severity. The nonconservatisms identified include not 

accounting for the effects of hot gas layers and the limited modeling of multiple spurious 

operations. The human reliability analysis (HRA) is identified as having potentially both 

conservative and nonconservative impacts on the results. A flow chart method is used for 

determining the human error probabilities (HEPs). The HEPs are generic in nature and 

modified based on certain parameters that may not be accurate given the actual fire.

In addition, the HEPs may be higher due to the unavailability of cues to give the operators 

a chance to respond to the event or, in some cases, timing constraints (Exelon 2014).

The NRC staff notes that, while the 2008 Braidwood Fire PRA is still under development and 

has not been peer reviewed, the SAMA evaluation should be performed using the best available 

information (consistent with NEPA requirements) on risk insights. Considering that the 2008 

Braidwood Fire PRA model is a more current analysis of the fire risk at Braidwood than the 

IPEEE fire analysis and therefore is the best currently available fire risk information, the NRC 

staff concludes that the use of the fire PRA model provides an acceptable basis (best available 

information) for identifying and evaluating SAMA candidates.

The major (CDF greater than 1×10−6 per year) fire core damage contributors for each unit are 

listed in Tables F–4(a) and F–4(b). This information was used by Exelon to identify potential 

SAMAs for the fire events and to evaluate the benefit of any SAMA uniquely directed at 

reducing the fire risk. This is discussed in Sections F.3 and F.4 below.

As seen in Table F–4(b), the Unit 2 results include a CDF for fire in the Unit 1 containment. It 

is stated in the ER that the fire-induced failures are Unit 1 equipment and the fire is modeled as 

requiring a Unit 2 shutdown without the availability of untraced equipment, such as the main 

feedwater (FW) system. In response to an NRC staff RAI which noted that Unit 2 containment 

fires did not appear in the Unit 1 results, Exelon explained that the fire model considers the 

impact of a fire in each of the site’s fire zones for each unit, even if the fire zone is in the 

opposite unit. The Unit 1 results also include Unit 2 containment fires as contributors, but these 

fires were below the review threshold used in the ER. The Braidwood fire PRA, which is an 

interim model, conservatively assumes failure of the equipment for which the cable routing is 

not known, which includes the main FW system (Exelon 2014).

The ER indicated that the 2008 Braidwood fire PRA utilized fire ignition frequencies from 

NUREG/CR–6850 rather than the later data from EPRI 1016735 (EPRI 2008). The NRC staff 

notes that the use of the updated fire ignition frequencies in EPRI 1016735 is endorsed by the 

NRC in NUREG/CR–6850 Supplement 1 (EPRI and NRC 2010). To account for this, the results 

of the 2008 Braidwood fire PRA were reduced by a factor of 1.262, which was obtained from the 

results of a sensitivity study performed for the Byron fire PRA. The total fire CDF for Braidwood 

is then 7.5×10−5 per year (for Braidwood Unit 2), the higher of the two units, divided by 1.262 or 

5.94×10−5 per year (Exelon 2013a).
Appendix F

F-11

Table F–4(a). Major Braidwood Unit 1 Contributors to Fire CDF

Fire Zone Fire Zone Description CDF

(per year)

1-1 Unit 1 containment 7.0×10−6

11.3-1 Unit 1 containment pipe penetration area 5.7×10−6

11.3-0 Auxiliary building general area, Elevation (Elv.) 364 5.7×10−6

11.4c-0 Radwaste and remote shutdown panel control room 5.3×10−6

11.6-1 Division 12 containment electrical penetrations area 3.7×10−6

5.2-1 Division 11 engineered safety feature (ESF) switchgear room 3.2×10−6

5.6-1 Division 11 miscellaneous electric equipment room and 

battery room

3.2×10−6

5.5-1 Unit 1 auxiliary electric equipment room 2.5×10−6

5.6-2 Division 21 Miscellaneous electric equipment room and 

battery room

2.1×10−6

5.1-1 Division 12 ESF switchgear room 1.5×10−6

11.6c-0 Auxiliary building laundry room 1.5×10−6

18.12-0 Lake screen house 1.3×10−6

11.6-0 Auxiliary building general area, Elv. 426 1.2×10−6

11.5a-1 Division 11 containment electrical penetrations area 1.1×10−6

In response to an NRC staff RAI concerning the applicability of the Byron sensitivity study result 

to Braidwood, Exelon indicated that this reduction factor was applied to the total fire CDF but not 

to the individual fire zone results listed in Table F–4. Exelon also provided the results of a 

sensitivity study of the impact of the EPRI 1016735 fire ignition frequencies on the CDF for each 

of the Braidwood major fire zones identified in Table F–4. This study indicated that, for Unit 2, 

the total CDF for the major fire zones was reduced from 4.89×10−5 per year to 3.54×10−5 per 

year or a reduction factor of 1.38 while a reduction factor of 1.37 was similarly found for Unit 1 

(Exelon 2014). Both of these reduction factors are higher than the 1.262 reduction factor used 

in the SAMA evaluation.

While the above Braidwood sensitivity study was only performed on the major fire zones 

representing about 65 percent of the total fire CDF, the NRC staff considers these results to 

provide a reasonable representation of the significant contributors to fire CDF at Braidwood and 

therefore sufficient to support the use of the 1.262 reduction factor for the total Braidwood fire 

CDF. Considering that a SAMA evaluation should be performed using the best available risk 

information, the NRC staff concurs that the use of the 2008 Braidwood fire PRA adjusted as 

described above rather than the IPEEE fire analysis for the development of the external events 

multiplier in the SAMA evaluation is appropriate. The NRC staff also concludes that the use of 

the individual fire zone results without adjustment for ignition frequency is conservative and 

acceptable for SAMA identification and cost-benefit evaluation purposes.

The Exelon IPEEE analysis of high winds and tornadoes, external floods, and transportation 

and other nearby facility accidents (HFO events) followed the screening and evaluation 

approaches specified in Supplement 4 to GL 88-20 (NRC 1991a). For these events, the IPEEE 

concluded that the Braidwood design conforms to the 1981 Standard Review Plan criteria 

(NRC 1981) and therefore the contribution to CDF from these events meets the IPEEE 

screening criterion of 1×10−6 per year in NUREG–1407 (NRC 1991b). The IPEEE did not 

identify any vulnerabilities or enhancements.
Appendix F

F-12

Table F–4(b). Major Braidwood Unit 2 Contributors to Fire CDF

Fire Zone Fire Zone Description CDF

(per year)

5.2-2 Division 21 ESF switchgear room 7.8×10−6

11.4C-0 Radwaste and remote shutdown panel control room 6.1×10−6

1-2 Unit 2 containment 4.9×10−6

5.6-1 Division 11 Miscellaneous electric equipment room and 

battery room

4.6×10−6

5.6-2 Division 21 Miscellaneous electric equipment room and 

battery room

3.7×10−6

11.6-2 Division 22 containment electrical penetrations area 3.4×10−6

5.5-2 Unit 2 auxiliary electric equipment room 3.1×10−6

5.2-1 Division 11 ESF switchgear room 2.2×10−6

11.6-0 Auxiliary building general area, Elv. 426 1.7×10−6

11.5A-2 Division 21 containment electrical penetrations area 1.6×10−6

11.4-0 Auxiliary building general area, Elv. 383 1.4×10−6

18.12-0 Lake screen house 1.3×10−6

11.5-0 Auxiliary building general area, Elv. 401 1.2×10−6

1-1 A Unit 1 Containment 1.2×10−6

11.6C-0 Auxiliary building laundry room 1.2×10−6

18.10E-2 System auxiliary transformers 242-1 and 242-2 1.1×10−6

8.10E-1 System auxiliary transformers 142-1 and 142-2 1.1×10−6

8.6-0 Turbine building operating floor 1.0×10−6

Based on the aforementioned results, Exelon indicated in the ER that the total external events 

CDF is approximately 6.3×10−5 per year. This value is based on a seismic CDF of 1.0×10−6 per 

year, a fire CDF of 5.9×10−5 per year, a high wind CDF of 1.0×10−6 per year, an external 

flooding CDF of 1.0×10−6 per year, and a transportation and other nearby accidents CDF of 

1.0×10−6 per year. The total external events CDF of 6.3×10−5 per year is 1.8 times the Unit 2 

internal events CDF of 3.5×10−5 per year. The total CDF (internal and external events) is then 

9.8×10−5 per year or 2.8 times the Unit 2 internal events CDF.

Therefore, the ER used an external events multiplier of 2.8 in the SAMA analysis to account 

for the impact of external events on the benefits determined from the internal events PRA.

As discussed above, the GI 199 risk assessment gives a seismic CDF for Braidwood of 

7.3×10−6 per year. Use of this value yields a total external events CDF of 7.0×10−5 per year 

and a total internal plus external events CDF of approximately 1.05×10−4 per year, which is 

approximately 3.0 times the Unit 1 internal events CDF. In response to an NRC staff RAI, 

Exelon used this higher external events multiplier to update a cost-benefit analysis 

(Exelon 2014).

The NRC staff: (a) agrees with the applicant’s overall conclusion concerning the use of a 

multiplier to represent the impact of external events and (b) finds that the applicant’s use of a 

multiplier of 3.0 in response to an NRC staff RAI will reasonably account for external events in

the SAMA evaluation. This is discussed further in Section F.6.2.
Appendix F

F-13

F.2.2.3 Level 2 Fission Product Release Analysis

The NRC staff reviewed the general process used by Exelon to translate the results of the 

Level 1 PRA into containment releases, as well as the results of the Level 2 analysis, as 

described in the ER and in response to NRC staff RAIs (Exelon 2014). The results of the 

Level 2 analysis are provided in ER Table F.2-8 (release category frequencies) and Table F.2-7 

(timing and magnitude of release).

The current Level 2 model is essentially a completely new model, replacing the prior LERF 

model, and was developed specifically for the SAMA analysis. Exelon stated that the current 

Braidwood Level 2 model is a state-of-the-art Level 2 analysis structure designed to address the 

Category II requirements of Regulatory Guide 1.200 (NRC 2009) and the ASME PRA Standard 

(ASME and ANS 2009).

Exelon stated that the Level 2 model is generally consistent with the “Simplified Level 2 

Modeling Guidelines,” Westinghouse Commercial Atomic Power (WCAP)-16341-P 

(Westinghouse 2005). This WCAP provides a common and standardized method for 

pressurized-water reactors (PWRs) with large dry containments to produce an analysis that 

generally meets Capability Category II of the ASME PRA standard. The guidance particularly 

addresses the latest understanding for induced SGTRs, direct containment heating, and other 

important Level 2 phenomena. While the WCAP is focused on modeling the LERF for the 

ASME standard, it includes guidance for including intact, small, and late releases to provide 

a more complete, though still standardized, Level 2 analysis. 

In response to an NRC staff RAI to identify areas where the Braidwood model differs from that 

in WCAP-16341-P, Exelon indicated that the differences include (Exelon 2014):

• No credit for recovery of alternating current power or diesel generator 

repair after core damage.

• Modeling of potential hot leg rupture following an induced tube rupture, such 

that the release to the environment is substantially reduced, based on recent 

research results from the State-of-the-Art Reactor Consequence Analyses 

(SOARCA) project (Bixler et al. 2013).

• Use of a combined CET rather than separate SBO and non-SBO CETs. This 

is a modeling choice and has no effect on the overall model since recovery of 

offsite power is not credited.

• Crediting a human action to maintain a sufficient water pool over the 

steam generator (SG) tubes to scrub releases in SGTR events. While not 

specifically included in the WCAP methodology, WCAP-16341-P does 

identify that this type of scrubbing is possible.

Plant damage states provide the interface between the Level 1 and Level 2 analyses. Each 

Level 1 accident sequence that leads to core damage consists of a unique combination of an 

initiating event followed by the success or failure of various plant systems (including operator 

actions). The Level 1 sequences that result in core damage are grouped into PDS bins. Each 

bin collects all of those sequences for which: (a) the progression of core damage, (b) the 

release of fission products from the fuel, (c) the status of the containment and its safeguards 

systems, and (d) the potential for mitigating the potential radiological source terms are similar.

The PDS bins for Braidwood are characterized by the status of containment bypass due to 

SGTR or ISLOCA, reactor coolant system (RCS) pressure, and the availability of 

feedwater (AFW).
Appendix F

F-14

For Braidwood a single detailed CET evaluates the accident progression following a core 

damage event and analyzes each PDS bin as a group. The Braidwood CET (shown in ER 

Figure F.2-4) is stated to be based on the CETs provided in WCAP-16341-P. While the function 

of the CET is essentially the same as the WCAP CETs, some changes were made to 

accommodate the capabilities and features of the Braidwood PRA model. The event tree 

begins with one or more core damage sequences. The CET then asks a number of questions 

to determine the characteristics of a release if one were to occur. Each question is modeled as 

a top event in the event tree and the outcome is based on previous work for Braidwood 

(including logic taken from the existing model), recent accident progression research, and 

the guidance provided in the WCAP.

The NRC staff noted in an RAI that ER Section F.2.3.2 indicated that containment failure due to 

direct containment heating is “0.000” and asked to clarify how this, and other early containment 

failure (CFE) probabilities, are included in the Level 2 models (NRC 2014). In response to the 

RAI, Exelon indicated that the “0.000” containment failure probability is not a typo but is the 

value reported from WCAP-16341-P, which in turn quotes the value from NUREG/CR-6338, 

“Resolution of Direct Containment Heating Issue for all Westinghouse Plants with Large Dry 

Containments or Subatmospheric Containments.” The WCAP notes that the NUREG provides 

only three significant digits. The 0.000 value applies to all sequences and all combinations of 

hydrogen burns, steam explosion, or direct containment heating—or some combination of the 

three. Therefore, the probability of CFE at Braidwood is negligible for any sequence. However, 

in order to maintain flexibility in the model for sensitivity analyses, the CFE probability is 

maintained in the model and assigned a probability of 0.001 for any cause or combination 

of causes (Exelon 2014).

Each CET end state represents a radionuclide release to the environment and is assigned to 

a release category. Four general release categories were defined: intact, late release, small 

early release, and LER. Because there are a large number of Level 2 sequences that contribute 

to each general release category with varying release characteristics, the general release 

categories were then subsequently subdivided into 13 detailed release categories.

The LER categories are for the containment bypass or failure conditions that lead to the release. 

These are unisolated ISLOCAs, containment isolation failures, CFEs, noninduced SGTRs with 

and without FW, and pressure or thermal induced SGTRs. The late release categories are for 

containment overpressure failure and “basemat” melt through, each with or without FW. The 

small early release categories are for SGTRs with FW available resulting in water level above 

the SG tubes and thermally induced SGTRs shortly followed by hot-leg failure.

Exelon developed the accident progression and associated release characteristics for each 

release category by using the results of MAAP Version 4.0.6 computer code calculations. A 

representative sequence was selected for each detailed release, considering both the likelihood 

of the scenario and its potential consequences. Since source terms are not always available for 

each sequence making up a release category, the selection of the representative sequence was 

based on judgment as to the potential consequences. Exelon stated that the sequence that is 

judged to be associated with a higher potential source term is used as the representative 

sequence unless there is: (a) another sequence that accounts for a majority of the release 

category frequency and (b) the sequence with the “higher” source term that accounts for less 

than about 10 percent of the release category frequency. In those cases, the “majority” 

sequence would be chosen as representative (Exelon 2013a). Table F.2-6 of the ER describes 

the representative sequence used for each release category. Table F.3-8 of the ER describes 

and justifies the MAAP case for each representative sequence and provides the resulting key 

event timings. In response to an NRC staff RAI, Exelon stated that the input for the MAAP 
Appendix F

F-15

cases specified the fission product masses (as opposed to radionuclide activity values), as 

recommended by the MAAP Users Group Bulletin, “MAAP-FLASH #68” (Exelon 2014).

The above listed tables indicate that for several release categories, the run duration of the 

MAAP analysis was quite long (200, 800, and 1,600 hours). Exelon stated that this duration 

was necessary to achieve a plateau of the release fractions, with primary attention paid to 

cesium iodide (CsI) and cesium hydroxide (CsOH) release fractions. In response to NRC staff 

RAIs as to the reason this was necessary and to identify conservatisms in the analysis, Exelon 

indicated that the run time for various MAAP calculations was established based on: (a) the 

timing for the onset of core damage, (b) the timing for either containment failure or containment 

bypass, and (c) consideration of revaporization of fission products that initially deposited within 

the RCS (particularly on the SG tubes where, after the SG dries out and the tube temperature 

increases, the deposited fission products become available for release late in the event). The 

run times were selected to make sure to capture this revaporization phenomenon 

(Exelon 2014).

Exelon provided plots of the CsI release as a function of time for a number of release categories 

by Exelon in response to the RAI. In many cases, the plots show a stable (steady state) total 

release from the containment is achieved well before the end of the run. For the dominant 

release category (LATE-CHR-NOAFW), which contributes 58 percent of the PDR and 

79 percent of the offsite economic cost risk (OECR), the CsI reaches a stable value at 

600 hours. For CsOH (which is stated by Exelon to be the primary driver for long-term dose and 

costs), the release is slower and the release fraction is still increasing at a slow rate even at 

1,600 hours.

The NRC staff notes that the above cited times of 600 hours (25 days) and 1,600 hours 

(67 days) are relatively long, compared with the time that is expected for additional onsite and 

offsite resources (mitigation measures) to be available to mitigate the releases. This has a 

significant impact on the release fractions. For example, for the dominant release category, 

at 72 hours or 3 days after declaration of a general emergency, the CsI release fraction is 

37 percent of the value used in the consequence analysis, while the CsOH release fraction is 

only 7 percent of the value used in the consequence analysis. Alternatively, if the releases were 

terminated at 144 hours or 6 days after declaration of a general emergency, the CsI release 

would be 63 percent and the CsOH release would be 16 percent of the values used in the 

consequence analysis for the dominant release category. Use of these lower release fractions 

would result in a significant reduction in both PDR and OECR.

In response to the NRC staff’s RAI to identify the major factors that contribute to the OECR and 

to discuss their realism (or conservatism), in addition to discussing the conservatism involved in 

using the release fractions for very long run times, Exelon identified conservative modeling 

involving the chemical form of cesium (Cs). NUREG/CR–7110 (Bixler et al. 2013) indicates that 

only a small fraction of the Cs is in the form of CsI and that the dominant chemical form will be 

cesium molybdate (a compound containing an oxoanion with molybdenum) with the remaining 

Cs in the form of CsOH. The Braidwood SAMA analyses conservatively assume that the 

dominant Cs chemical form is CsOH. Cesium molybdate has a very low vapor pressure and 

would therefore be expected to remain deposited (retained) on structures (e.g., the tubes in an 

SG, instead of being released) for a longer time, relative to CsOH. The result of this assumption 

is a conservative SAMA assessment (Exelon 2014).

The NRC staff noted in an RAI that the analysis of sequences involving containment isolation 

failure did not allow for CFE due to such phenomenology as hydrogen explosion or direct 

containment heating (NRC 2014). In response to the RAI, Exelon indicated that, while hydrogen 

explosion and direct containment heating are potential failure modes for the containment 
Appendix F

F-16

isolation failure sequences (Release Category LERF-CI), the probability of CFE due to these 

mechanisms is 1×10−3

. While the CFE CsI release fraction may be about 20 times larger than

the CsI release fraction for containment isolation, the frequency is 1,000 times less. 

Furthermore, the potential contribution from the fraction of isolation failures that result in CFE 

represents only about 1 percent of the other CFE frequency (Release Category LERF-CFE). 

Rebinning the CFE contributions from the LERF-CI release category into the LERF-CFE release 

category results in no measurable change to the reported PDR and OECR values and, 

therefore, would have no impact on the SAMA analysis (Exelon 2014).

In response to an NRC staff RAI to describe the steps taken to ensure the technical adequacy 

of the revised Braidwood Level 2 PRA model, Exelon indicated that for the initial completion of 

the updated Level 2 model included in Revision BB011b1 of the PRA, an internal review was 

conducted examining accident sequence modeling, fault tree modeling, and cutset reviews. 

The documentation of the BB011b1 model also includes a self-assessment (roadmap) against 

Capability Category II of the ASME PRA Standard. This self-assessment (roadmap) concluded 

that all applicable LER (or LERF) SRs were met at Capability Category II. The signatures of the 

preparer and the reviewer confirm the internal review and agreement with the conclusion of the 

self-assessment (roadmap). The new Level 2 model replaced the simplified (generally 

conservative) previous LERF model. Reductions in LERF come from several improvements, 

including credit for: (a) an operator action to keep an SG full to scrub a release from a SGTR 

and (b) reduced CFE probabilities (Exelon 2014).

The NRC staff has reviewed the Level 2 methodology and determined that: (a) Exelon has 

satisfactorily addressed NRC staff RAIs and (b) the Level 2 model was assessed by Exelon 

against the LER safety requirements of the ASME PRA standard and found to meet the 

Capability Category II requirements. Therefore, the NRC staff concludes that the Level 2 PRA 

is of sufficient quality to support the SAMA evaluation.

F.2.2.4 Level 3 Offsite Consequence Analysis

The NRC staff reviewed the process used by Exelon to extend the containment performance 

(Level 2) portion of the PRA to an assessment of offsite consequences (Level 3 PRA). This 

included consideration of the source terms used to characterize fission product releases for the 

applicable containment release categories and the major input assumptions used in the offsite 

consequence analyses. The MACCS2 code (Version 1.13.1) was utilized to estimate offsite 

consequences (NRC 1998). Plant-specific input to the code includes: (a) the source terms for 

each source term category and the reactor core radionuclide inventory (both discussed above), 

(b) site-specific meteorological data, (c) projected population distribution within an 80-km 

(50-mi) radius for the year 2047, (d) emergency evacuation modeling, and (e) economic data. 

As indicated in the ER, the reactor core radionuclide inventory used in the consequence 

analysis was based on end-of-cycle power of 3,645 MWt. The current rated power for 

Braidwood is 3,586.6 MWt and the core radionuclide inventory was based on this power 

(Exelon 2008). Exelon has submitted a license amendment requesting a Measurement 

Uncertainty Recapture (MUR) power uprate from 3,586.6 MWt to 3,645 MWt (Exelon 2011). 

The proposed uprate was included in the MACCS2 analysis by scaling the base core inventory 

by the power uprate ratio (1.0163). This information is provided in Section 3.5 of Attachment F 

to the ER (Exelon 2013a). Exelon performed a sensitivity study assuming the current rated 

power of 3,586.6 MWt. The decrease in power of 1.63 percent resulted in a decrease in both 

PDR and cost risk of 1 percent each.

Exelon modeled all releases as being from midheight of the reactor containment building and at 

1×107 (10 megawatts) thermal content, except for intact containment (which maintained zero 

energy for the purpose of release height analysis). Exelon performed sensitivity studies using 
Appendix F

F-17

zero plume energy (Exelon 2013a). With zero plume heat, the dose risk and cost risk decrease 

by 3 percent and 8 percent, respectively. Exelon performed sensitivity studies for plume release 

height and deposition velocity (Exelon 2013a). Release height set to ground level resulted in a 

decrease in dose risk of 2 percent and a decrease in cost risk of 4 percent. Release height set 

to the top of containment resulted in an increase in dose risk of 2 percent and an increase in 

cost risk of 2 percent. The deposition velocity was reduced from 0.01 meters per second (m/s) 

(0.03 foot per second (fps)) to 0.005 m/s (0.016 fps) (a factor of 2), which resulted in a decrease 

in PDR of 10 percent and decrease in cost risk of 21 percent. In response to an NRC staff RAI, 

Exelon provided additional values and assumptions associated with the MACCS2 model input, 

including: rainfall, mixing height, building wake effects, plume energy, land fraction, region 

index, watershed index, growing season, fraction of farmland, and shielding and protection 

factors (Exelon 2014). Based on the information provided, the staff concurs and concludes 

that the release parameters used are acceptable for the purposes of the SAMA evaluation,

consistent with the review criteria in the standard review plan.

Exelon used site-specific meteorological data for the 2010 calendar year as input to the 

MACCS2 code. The development of the meteorological data is discussed in Section 3.7 

of Attachment F to the ER. The data were collected from onsite and local meteorological 

monitoring systems. In response to an NRC staff RAI (Exelon 2014), Exelon clarified that only 

mixing layer height was based on other meteorological data. The mixing layer height was

based on a U.S. Environmental Protection Agency study (Holzworth 1972); this is identified 

in Section F.3.7 of the ER. Missing data were filled in by substituting data from a different 

elevation, interpolation, power law, or substituting data from the previous or subsequent day. 

Sensitivity analyses were performed using MACCS2 and the meteorological data for the years 

2008 and 2009 (Exelon 2013a). The year 2008 data resulted in a decrease in dose risk of 

2 percent and a decrease in cost risk of 3 percent. The year 2009 data resulted in a decrease 

in dose risk of 3 percent and no change in cost risk. The NRC staff notes that previous SAMA

analyses overall results have shown little sensitivity to year-to-year differences in meteorological 

data; therefore, the NRC staff concludes that the use of the 2010 meteorological data in the 

SAMA analysis is reasonable.

The population distribution used as input to the MACCS2 analysis was estimated for the 

year 2047 using year 2000 census data as accessed by SECPOP2000 (Sector Population, 

Land Fraction, and Economic Estimation Program) (Bixler et al. 2003) as a starting point. The 

transient population was included in the 16-km (10-mi) emergency planning zone (EPZ), and in 

the population projection from years 2000 to 2047. In addition, special facilities population was 

also included in the initial year 2000 population estimate. In response to an NRC staff RAI, 

Exelon provided the year 2000 transient, special facility, and residential population distributions 

(Exelon 2014). These are presented in Tables 4b-1 and 4c-1 of the RAI response. A 30-year 

population growth rate was estimated using the year 2000 SECPOP2000 data and population 

growth estimates from the Illinois (DCEO 2012) and Indiana (IBRC 2012) county population 

projections to year 2030. The year 2030 population estimate was then scaled to year 2046 

using this growth rate to obtain the population distribution in 2046. The NRC staff noted that 

Section 2.6.1 of the ER contained year 2010 census population, but the SAMA analysis used 

year 2000 census data for estimating population growth. In response to an NRC staff RAI, 

Exelon compared a projected year 2010 population to the recently available year 2010 census 

population for result sensitivity determination. The projected population within the 80-km 

(50-mi) radius was approximately 6 percent higher than the census population (Exelon 2014). 

The baseline population was determined for each of 160 sectors, consisting of 16 directions for 

each of 10 concentric distance rings to a radius of 80 km (50 mi) surrounding the site. Individual 

county growth rates were applied at each grid element. Some grid elements include land from 

multiple counties. A weighted growth rate was used for those grid elements based on the 
Appendix F

F-18

fraction of land in that grid element associated with each county. Counties that were projected 

to have negative growth rates were conservatively assumed to have zero growth rates. In 

response to an NRC staff RAI, Exelon stated that three recently publicized SECPOP2000 code 

errors were accounted for in the Braidwood analysis (Exelon 2014). Exelon performed a 

sensitivity study for the year 2047 population by increasing the population by 30 percent 

(uniformly). The resulting dose risk increased by 30 percent and cost risk increased by 

29 percent. The NRC staff concurs with the results and considers the methods and 

assumptions for estimating population reasonable and acceptable (within acceptable sensitivity) 

for purposes of the SAMA evaluation, consistent with the review criteria in the standard review 

plan.

The emergency evacuation model was modeled as a single evacuation zone and stated to 

extend out 16 km (10 mi) from the plant (the EPZ) (ET 2003). Exelon assumed that 95 percent 

of the population would evacuate. This assumption is conservative relative to the 

NUREG–1150 study (NRC 1990) that assumes evacuation of 99.5 percent of the population 

within the EPZ. The evacuated population was assumed to move at an average radial speed of 

approximately 4.2 m/s (9.4 miles per hour (mph)) with a delayed start time of 115 minutes after 

declaration of a general emergency (Exelon 2013a). The evacuation speed is a time-weighted 

average value accounting for season, day of week, time of day, and weather conditions 

(ET 2003). A general emergency declaration was assumed to occur when plant conditions 

degraded to the point when it was judged that there was a credible risk to the public. In 

response to an NRC staff RAI, Exelon clarified that the evacuation study (ET 2003) does not 

associate specific events with the evacuation time study (Exelon 2014). Exelon performed 

sensitivity studies for the evacuation speed and delay time to evacuation. The evacuation 

speed was reduced by 67 percent to 1.4 m/s (3.1 mph). The resulting dose risk increased by 

5 percent and the change in cost risk was negligible. The evacuation delay time was increased 

by a factor of 2 to 230 minutes. The resulting dose risk increased by 0.7 percent and the 

change in cost risk was negligible. The NRC staff concurs and concludes that the evacuation 

assumptions and analysis are reasonable and acceptable for the purposes of the SAMA

evaluation.

Site-specific agriculture and economic parameters were developed manually using data in the 

2007 National Census of Agriculture (USDA 2009) and 2007 data from the Bureau of Economic 

Analysis (BEA 2012) for each of the 21 counties surrounding Braidwood, to a distance of 80 km 

(50 mi). Economic values were updated to July 2012 using the consumer price index from the 

Bureau of Labor Statistics (BLS 2012). The values used for each of the 160 sectors were the 

data from each of the surrounding counties multiplied by the fraction of that county’s area that 

lies within that sector. Food ingestion was modeled using the new MACCS2 ingestion pathway 

model COMIDA2 (NRC 1998). For Braidwood, approximately 1.4 percent of the total PDR is 

due to food ingestion (1.6 person-rem/year) (Exelon 2013a). In response to an NRC staff RAI, 

Exelon stated that input parameters used were based on food production parameters derived 

from annual food consumption of an average individual, and that food ingestion dose limits were 

based on 1998 Food and Drug Administration Guidance (Exelon 2014). Certain standardized 

economic parameter input values that may be applied to the region as a whole (e.g., for 

parameters describing the cost of evacuating and relocating people, land decontamination, 

and property condemnation) were obtained from NUREG–1150 (NRC 1990) (and a related

MACCS2 User’s Guide sample problem). Those values were adjusted to account for cost 

escalation since 1986 (the year that input values were first specified) using the U.S. Consumer 

Price Index (CPI) method. Specifically, a factor of 2.09 (CPI of 229.1 divided by CPI of 109.6), 

representing cost escalation from 1986 (CPI index of 109.6) to July 2012 (CPI index of 229.1), 

was applied to the NUREG–1150/MACCS2 sample problem values. 
Appendix F

F-19

Exelon performed a sensitivity study for the economic rate of return, resettlement planning, and 

generic economic inputs. The rate of return was modified to 3 percent and 12 percent (from 

7 percent). The decrease in rate of return (by approximately 57 percent) resulted in an increase 

in population dose of 1 percent and a decrease in cost risk of 9 percent. The increase in rate of 

return (by approximately 71 percent) resulted in a decrease in population dose of 1 percent and 

an increase in cost risk of 11 percent. In response to an NRC staff RAI, Exelon provided 

clarification that the rate of return on property impacts the estimated property that is condemned 

(or reclaimed) (Exelon 2014). Changes in property reclamation will result in changes in dose 

consequences to those who occupy the property after it has been reclaimed. Resettlement 

planning was modified assuming: (a) no “Intermediate Phase” and (b) a 1-year “Intermediate 

Phase” (in lieu of 6 months). No “intermediate phase” resulted in an increase in dose risk of 

17 percent and a decrease in cost risk of 40 percent. A 1-year “intermediate phase” resulted in 

a decrease in dose risk of 13 percent and an increase in cost risk of 41 percent. Key generic 

economic input parameters to MACCS2 were modified as shown in Table F.7-1 of the ER. In 

general the input variables were increased by a factor of 2. The increase in these economic 

parameters resulted in a decrease in dose risk of approximately 4 percent and an increase in 

cost risk of approximately 52 percent.

The NRC staff concludes that the methodology used by Exelon to estimate the offsite 

consequences for Braidwood provides an acceptable basis from which to proceed with an 

assessment of risk reduction potential for candidate SAMAs. Accordingly, the NRC staff based 

its independent assessment of offsite risk on the CDF and offsite population doses and offsite 

economic costs reported by Exelon.

F.3 Potential Plant Improvements

The process for identifying potential plant improvements, an evaluation of that process, and the 

improvements evaluated in detail by Exelon are discussed in this section.

F.3.1 Process for Identifying Potential Plant Improvements

Exelon’s process for identifying potential plant improvements (SAMAs) consisted of the 

following elements:

• review of the most significant basic events from the current, plant-specific 

PRA including the 2008 Braidwood fire analysis;

• review of selected cost-beneficial SAMAs from selected plants;

• review of potential plant improvements identified in the Braidwood IPE and 

IPEEE; and

• insights from the PRA group.

Based on this process, an initial set of 35 candidate SAMAs, referred to as Phase I SAMAs, was 

identified. In Phase I of the evaluation, Exelon performed a qualitative screening of the initial list 

of SAMAs and eliminated SAMAs from further consideration using the following criteria:

• The SAMA is not applicable to Braidwood plant design.

• The SAMA has already been implemented or its intent met at Braidwood.

• The SAMA has estimated implementation costs that would exceed the dollar 

value associated with completely eliminating all severe accident risk at 

Braidwood.
Appendix F

F-20

Based on this screening, one SAMA was eliminated leaving 34 for further evaluation. The 

results of the Phase I screening analysis are provided in Table F.5-3 of the ER (Exelon 2013a). 

The remaining SAMAs, referred to as Phase II SAMAs, are listed in Table F.6-1 of the ER 

(Exelon 2013a). In Phase II, a detailed evaluation was performed for each of the 34 SAMA 

candidates, as discussed in Sections F.4 and F.6 below. To account for the potential impact 

of external and internal flooding events, the estimated benefits based on internal events were 

multiplied by a factor of 2.8 as discussed in Section F.2.2.2. Also as discussed in 

Section F.2.2.2, this multiplier was increased to 3.0 in response to an NRC staff RAI 

(Exelon 2014).

F.3.2 Review of Exelon’s Process

Exelon’s efforts to identify potential SAMAs focused primarily on areas associated with internal 

initiating events. The initial list of SAMAs generally addressed the accident sequences 

considered to be important to CDF (i.e., importance list review) from functional, initiating 

event, and risk reduction worth (RRW) perspectives at Braidwood.

Exelon provided in the ER a tabular listing of the Level 1 PRA basic events sorted according 

to their RRW (Exelon 2013a). The RRW is the factor by which the risk would decrease if the 

component, train, system, function, initiating event, or HEP is assumed to be perfectly reliable 

(i.e., if its probability of failure were zero). The SAMAs impacting these basic events would 

have the greatest potential for reducing risk. In the ER, Exelon indicates that the review of 

these events down to an RRW of 1.006 would correspond to a potential benefit of $100,000 if a 

SAMA to mitigate this event were 100 percent effective. This value is Exelon’s estimate of the 

cost of a procedure change along with any necessary engineering analysis and training. As 

Exelon noted, this value of the RRW does not include the potential impact of external events. 

This was stated as not included because the Braidwood fire results were reviewed separately 

for potential SAMAs and the fire model is in an interim state. Exelon used an RRW cutoff of 

1.005 based on the availability of an earlier SAMA review that used this as a cutoff.

The RRW cutoff of 1.005 corresponds to about a half percent change in CDF given 100-percent 

reliability of the SAMA. The NRC staff estimates that this equates to a benefit of approximately 

$249,000 (after the benefits have been multiplied by a factor of 3.0 to account for external 

events).

In response to an NRC staff RAI to justify not extending the review down to an RRW value 

which would encompass failures whose mitigation would have a benefit, accounting for both 

internal and external events, of $100,000 as determined in the Braidwood Phase II cost-benefit 

analysis, Exelon discusses the guidance given in NEI’s SAMA guidance document (NEI 2005). 

This document, which is endorsed by the NRC, indicates that the SAMA analysis should use the 

Probabilistic Safety Analysis importance to “identify plant-specific SAMA candidates by 

reviewing dominant risk contributors (to both CDF and population dose) in the Level 1 and 

Level 2 PSA models.” While acknowledging that the definition of “dominant risk contributors” is 

open to interpretation, Exelon indicates that the guidance does not indicate that the identification 

process should be an exhaustive search for all plant enhancements that might be 

cost-beneficial. Exelon points out that the PRA Applications Guide (EPRI 1995) defines 

risk-significant events to be those events with RRW values of 1.010 and greater. As indicated 

above, the Braidwood importance review was carried out down to an RRW value of 1.005 

(Exelon 2014).

Relative to the use of RRW cutoff criterion in SAMA analysis, the NRC staff disagrees with the 

practice of reviewing basic events down to an RRW of 1.005 based solely on the definition of 

risk-significant events from the PRA Applications Guide (EPRI 1995). Rather, the intent of the
Appendix F

F-21

SAMA analysis, as discussed in NEI 05-01 (NEI 2005), is to perform a review of the 

risk-significant contributors to the level necessary to identify potential cost-beneficial 

enhancements. The minimum cost of a potentially cost-beneficial enhancement was 

determined by Exelon to be $100,000 for Braidwood and, hence, this should be the basis for the 

importance review. Based on additional explanation provided by Exelon, the NRC staff notes 

(as discussed above) that Exelon performed a separate review of the important contributors to 

fire risk. Hence, the staff agrees that the RRW cutoff for the internal events Level 1 and Level 2 

importance review need not consider the contribution from fire events. The NRC staff estimates 

that an RRW of 1.005 equates to a benefit of approximately $108,000 (after the benefits have 

been multiplied by a factor of 1.3 to account for nonfire external events only). Exelon also notes 

in the ER that this benefit would be further reduced with implementation of SAMA 15 (cross-tie 

AFW between Units 1 and 2 to provide steam generator makeup), which Exelon states is 

currently being implemented at Braidwood (Exelon 2013a). Based on Exelon’s separate review 

of the significant contributors to fire risk, and Exelon’s implementation of SAMA 15 at 

Braidwood, the NRC staff concludes that Exelon’s review of Braidwood’s PRA importance 

analysis down to an RRW of 1.005 is adequate for the purpose of the SAMA assessment.

Exelon also provided in the ER tabular listings of the Level 2 PRA basic events for the combined 

LERF categories and the combined Late Release categories, which in total account for 

approximately 95 percent of the estimated PDR and OECR. Exelon used an RRW cutoff of 

1.005 when reviewing these basic events for SAMA candidates. The Level 2 sequences for 

the intact release category were not included in the review so as to prevent high frequency–low 

consequence events from biasing the importance listing.

Exelon’s review of the Level 1 and Level 2 importance lists resulted in the identification of 

25 SAMA candidates. Exelon used the importance list review to identify the equipment failure 

scenarios most important to Braidwood risk, by examining the reasons for the importance 

through sequence and system analysis.

Although not identified to mitigate any specific Level 2 basic event, Exelon identified an 

additional SAMA candidate (SAMA 25 Install a Filtered Containment Vent) as a “General 

Late Release Mitigation Method” (Exelon 2013a).

The Exelon review of the late release categories importance list identified SAMA 24, to provide 

a reactor vessel cooling system to prevent vessel melt through, as a means of mitigating 

basemat melt through. The NRC staff noted that based on the Braidwood IPE (ComEd 1994), 

plant procedures were implemented to direct reactor cavity flooding in core damage scenarios 

to provide a means of exterior vessel cooling (NRC 1997b). Based on the IPE implementation 

of cavity flooding, the NRC staff requested in an RAI clarification on why the additional cooling 

system in SAMA 24 was required to perform this function (NRC 2014). Exelon noted that for 

cases where core damage occurred, there was a concern that it might not be possible to 

perform cavity flooding in the time available to prevent vessel failure. Preventing reactor vessel 

melt through not only prevents basemat melt through but also prevents CFEs such as that due 

to direct containment heating. A fast-acting system might therefore have added benefit. These 

additional failures were assumed to be mitigated by SAMA 24 in the ER cost-benefit analysis. 

The NRC staff considers this description of SAMA 24 and explanation of its potential benefit 

reasonable.

Exelon reviewed the cost-beneficial Phase II SAMAs from prior SAMA analyses for 

six Westinghouse PWR sites to aid in the identification of additional SAMA candidates. Many 

of the industry Phase II SAMAs were already represented by other SAMAs in the Braidwood list, 

were known not to impact important plant systems or be relevant to the Braidwood design, or 

were judged not to have the potential to be close contenders for Braidwood. As a result, most 
Appendix F

F-22

of the SAMAs in these prior analyses were not added to the Braidwood SAMA list. 

However, Exelon’s review resulted in the identification of one additional SAMA candidate.

The NRC staff noted in an RAI that the NRC staff’s evaluation of the Indian Point, Units 2 and 

3, SAMA analysis (NRC 2010b) identified 13 potentially cost-beneficial SAMAs, whereas the 

Braidwood review considered only 7 of the 13 SAMAs (NRC 2014). In response to the RAI, 

Exelon assessed the additional six Indian Point SAMAs and concluded that each was either not 

applicable to the Braidwood design, has been implemented at Braidwood, or is already 

addressed by a Braidwood candidate SAMA (Exelon 2014).

In its review of industry cost-beneficial SAMAs, Exelon noted that two Vogtle SAMAs (SAMAs 6 

and 16) (NRC 2008) that were originally cost-beneficial were, upon further evaluation of the cost 

and benefit, judged not to be cost-beneficial at Vogtle. In response to an NRC staff RAI to 

consider if these SAMAs would be applicable or potentially cost-beneficial at Braidwood, Exelon 

determined that the failure being mitigated by Vogtle SAMA 6 (involving adding a bypass line 

around the cooling tower return valve) is not a significant risk contributor for Braidwood and the 

SAMA would not be cost-beneficial. For Vogtle SAMA 16 (involving nonexplicit improvements in 

ISLOCA procedures), Exelon determined that the intent of this SAMA is already met by existing 

Braidwood ISLOCA procedures that are constantly trained on and improved by the plant staff 

(Exelon 2014). Based on this additional information, the NRC staff finds Exelon’s explanation to 

be acceptable and concludes that Vogtle SAMAs 6 and 16 have been adequately considered for 

applicability and are unlikely to be cost-beneficial at Braidwood.

Exelon considered the potential plant improvements described in the IPE in the identification 

of plant-specific candidate SAMAs for internal events. As described in the ER, while the 

Braidwood IPE did not identify any vulnerabilities or provide a definitive list of enhancements, 

the report did describe a multisite review of IPE and Accident Management insights. The ER 

indicated that the IPE did discuss two enhancements, both of which have been implemented at 

Braidwood (Exelon 2013a).

The NRC staff noted in an RAI that, according to the NRC staff safety evaluation report for 

the IPE (NRC 1997b), the transmittal of the modified Braidwood IPE indicated that a potential 

vulnerability involving a unit loss of emergency service water (ESW) due to internal flooding had 

been identified and that a modification was being considered (NRC 2014). In response to the 

RAI, Exelon indicated that this modification had not been implemented but is included as 

SAMA 10, alter the ductwork between the auxiliary building sump drain room and the SX pump 

room, in the SAMA analysis (Exelon 2014).

In response to an NRC staff RAI, Exelon indicated that as part of routine work, PRA groups 

identify major contributors to plant risk and, in some cases, the groups have identified specific 

changes that could reduce risk. As part of the SAMA identification process, the site PRA group 

was questioned to determine if they have identified any such changes. For Braidwood, the PRA 

group did not identify any plant enhancements that were not already identified by the SAMA 

identification process (Exelon 2014).

In response to an NRC staff RAI to describe the steps taken to identify SAMAs involving 

improvements in procedures, training or available cues for the important human errors, Exelon 

indicated that the HRA quantifications are reviewed to identify the major contributors to the HEP 

and to determine if there are any practical means of reducing those contributors. Braidwood 

SAMAs 7 and 8 are examples of the results of this process (Exelon 2014).

As discussed above in Section F.2.2.1, the NRC staff noted some differences in PRA results 

for the Braidwood site compared to the Byron site. Exelon indicated that for certain sequences 

resulting from random nonisolable small LOCAs with failure to establish ECCS recirculation 
Appendix F

F-23

cooling but with successful cooldown and depressurization, for which the Braidwood CDF is 

considerably larger than that for Byron, the difference is primarily because at Braidwood the 

SX007 SW valves must be throttled open to establish an appropriate flow rate through the 

component cooling HXs. This requirement results from SW’s being taken from the Braidwood 

cooling pond (lake), whose water temperature varies throughout the year. At Byron, the 

SX007 valves do not need manipulation during an accident. In response to an NRC staff RAI, 

Exelon pointed out that a low-cost potentially cost-beneficial SAMA, SAMA 6, was developed to 

address the SX007 valve throttling issue (Exelon 2014).

Based on this information, the NRC staff concludes that the set of SAMAs evaluated in the ER, 

together with those identified in response to NRC staff RAIs, adequately addresses the major 

contributors to internal event CDF. 

As discussed above, risk insights from the 2008 Braidwood Fire PRA were used to identify 

SAMA candidates. Since the fire model was not fully integrated with the most recent Levels 2 

and 3 analyses and the model was based on Revision 6C of the internal events PRA rather than 

the current Revision BB11b1 model, it could not be used directly in the identification of SAMAs. 

However, the fire contributors that are potentially significant to risk were reviewed to identify 

potential SAMAs. In the ER Exelon considered and evaluated the fire zones with a CDF

contribution greater than the IPEEE screening threshold of 1.0×10−6 per year for potential 

SAMAs. These fire zones are listed in Table F–4.

The major fire scenario results for each zone were reviewed and grouped together to help 

identify target equipment that is common to multiple scenarios in a given fire zone. In response 

to an NRC staff RAI, Exelon defined major fire scenarios as those contributing 10 percent or 

more to the fire zone frequency (Exelon 2014). The major scenarios of each of the important 

fire zones are described and potential SAMAs identified in Section F.5.1.6.1 of the ER. This 

review indicated that a number of the previously identified internal events SAMAs would also 

mitigate fire-initiated accidents. In addition, Exelon’s review resulted in the identification of 

eight additional SAMA candidates. One SAMA—SAMA 30, automate swap to recirculation 

mode, previously identified from the Level 1 importance review—was also identified to mitigate 

fire-initiated accidents.

The NRC staff noted in an RAI that the 1.0×10−6 per year screening threshold used in the fire 

SAMA identification review corresponds to a benefit threshold of $474,000 (NRC 2014). In 

response to the RAI to provide assurance that use of this threshold does not result in missing 

some potentially cost-effective SAMAs, Exelon provided the results of an assessment of the 

impact of lowering the threshold to that corresponding to a fire RRW of 1.01. Based on the fire 

ignition frequency adjusted total Braidwood fire CDF of 5.9×10−5 per year, an RRW of 1.01 

corresponds to a fire CDF of 5.9×10−7 per year. Based on this lower threshold, Exelon identified 

three additional Unit 2 fire zones to be considered for potential SAMAs. No additional Unit 1 fire 

zones were above this threshold. For the first two Unit 2 fire zones, Exelon discussed the fire 

scenarios and noted that previously identified candidate SAMAs would mitigate the fire risk from 

these zones. For the third zone, fire zone U2:3.4A-2, Unit 2 Cable Riser Area, Elv. 451′, having 

a fire CDF of 6.5×10−7 per year, one additional SAMA candidate to install a low-flow seal 

injection pump, or to install cable wrap or fire barriers, was identified and evaluated and 

determined to not be cost-beneficial (Exelon 2014). This is discussed further in Section F.6.2.

The staff considered the best available information for its independent analysis. While the fire 

PRA model is still under development, it is the best available information at the time of this 

review. Therefore, the NRC staff concludes that the screening RRW of 1.01 for identifying 

potential fire-mitigating SAMAs reasonable.
Appendix F

F-24

Regarding fire zone 11.6c-0 (the auxiliary building laundry room), the NRC staff asked Exelon to 

consider a SAMA to move the laundry to another facility if the fire source in the fire zone is due 

to laundry room operation (NRC 2014). In response to the RAI, Exelon indicated that the 

laundry equipment has been removed from that room and this room no longer serves that 

function (Exelon 2014).

In response to an NRC staff RAI to describe the extent to which new or improved Braidwood fire 

procedures to mitigate the important fires have been considered in the SAMA analysis, Exelon 

responded that review of the fire procedures to identify improvements in the fire response is an 

iterative task that is performed as part of the fire PRA development process and is not within the 

scope of the SAMA analysis. Unlike SAMAs to modify Abnormal Operating Procedures and 

Emergency Operating Procedures, the identification of fire response enhancement requires 

coordination with the fire modeling team and procedure writers to ensure the actions are 

consistent with existing procedures and that the proposed changes are appropriate for the 

failure modes caused by the fire events (Exelon 2014). Although the NRC staff does not agree 

that identifying improvements to the fire procedures is beyond the scope of a SAMA analysis, 

since the applicant’s fire PRA model is still under development and will be separately approved, 

as appropriate, the NRC staff concludes that further enhancement to the fire procedures is not 

necessary for the Braidwood SAMA evaluation for license renewal.

As discussed in Section F.2.2.2, although the IPEEE did not identify any fundamental 

vulnerabilities or weaknesses related to external events, a number of “outliers” were identified 

from the IPEEE seismic assessment (ComEd 1997b). These “outliers” were addressed in the 

ER and described as “generally items with potential seismically induced interaction issues for 

which it was difficult to calculate a High Confidence of Low Probability of Failure value” 

(Exelon 2013a). Exelon described each of the items and their disposition concluding that 

no additional SAMAs were needed to address these items.

As stated earlier, the Exelon IPEEE analysis of other external hazards (high winds, tornadoes, 

external floods, and other external events) did not identify opportunities for improvements for 

these events.

The NRC staff notes that the Braidwood external flooding design and capability, seismic design 

and capability, and the IPEEE seismic “outliers” were assessed in the engineering walkdowns 

and evaluations required for the response to the Fukushima Near-Term Task Force’s 

Recommendation 2.3 (Exelon 2012a, 2012b; NRC 2012).

The NRC staff questioned Exelon about potentially lower cost alternatives to some of the 

SAMAs evaluated, as listed in an RAI (NRC 2014), including:

• A SAMA to modify procedures to avoid clearing of RCS cold leg water seals 

in the event of core damage. In response to the RAI, Exelon explained that 

this improvement has already been implemented at Braidwood because the 

Braidwood procedures direct an “RCP bump” to inject reactor coolant line 

water into the reactor vessel only if the SG level is greater than 10 percent, 

which avoids the clearing of the RCS cold leg seal (Exelon 2014).

• An SG PORV gagging device for use after an SGTR and stuck-open SG 

PORV as an alternate to SAMA 14. In response to the RAI, Exelon explained 

that the Braidwood design includes isolation valves with manual handwheels 

upstream of the SG PORVs, hence the ability to stop flow through a 

stuck-open PORV exists without the need for the gagging device 

(Exelon 2014).
Appendix F

F-25

• Install “reduced leakage” RCP seals similar to those evaluated for Vogtle 

SAMA 7 (NRC 2008) as an alternative to the “no-leakage” seals evaluated as 

Braidwood SAMA 4. In response to the RAI, Exelon explained that this is not 

a viable alternative for Braidwood because a decision has already been made 

to implement SAMA 4 at Braidwood, Exelon has already made awards for the 

replacement of the RCP seals, and the cost of engineering and analysis has 

already exceeded the cost given for the Vogtle “reduced leakage” RCP seals 

(Exelon 2014).

• Installation of additional flood alarms to assist in mitigating important internal 

flood scenarios. In response to the RAI, Exelon reviewed the internal 

flooding events and determined that internal flooding alarms already existed, 

were evaluated in an existing SAMA (SAMA 16), or determined that the 

flooding sequences are not risk significant (Exelon 2014).

The NRC staff notes that the set of SAMAs submitted is not all-inclusive and that additional less 

expensive, design alternatives can be postulated. Based on the best available information and 

its independent review, the NRC staff concludes that the benefits of any additional modifications 

are unlikely to exceed the benefits of the modifications evaluated and that the alternative 

improvements would not likely cost less than the least expensive alternatives evaluated, when 

the subsidiary costs associated with maintenance, procedures, and training are considered.

In summary, the NRC staff concludes that Exelon used a systematic and comprehensive 

process for identifying potential plant improvements for Braidwood, and that the set of potential 

plant improvements (SAMA) identified by Exelon is reasonably comprehensive and, therefore,

acceptable. The SAMA search included reviewing insights from the plant-specific risk studies 

and reviewing plant improvements considered in previous SAMA analyses. While explicit 

treatment of external events in the SAMA identification process was limited, the NRC staff has 

determined that the prior implementation of plant modifications and the absence of external 

event vulnerabilities reasonably justifies examining primarily the internal events risk results for 

this purpose.

F.4 Risk Reduction Potential of Plant Improvements

Exelon evaluated the risk-reduction potential of the 35 SAMAs retained for the Phase II 

evaluation in the ER (Exelon 2013a). The SAMA evaluations were generally performed by 

Exelon in a realistic or conservative fashion that overestimates the benefit of the SAMA. In 

most cases the failure likelihood of the added equipment is taken to be optimistically low, 

thereby overestimating the benefit of the SAMA. In other cases it was assumed that the SAMA 

eliminated all of the risk associated with the proposed enhancement. The NRC staff notes that 

this bounding approach overestimates the benefit and is conservative.

Exelon used model requantification to determine the potential benefits for most of the SAMAs. 

The CDF, population dose reductions, and offsite economic cost reductions were estimated 

using the Braidwood PRA model. The changes made to the model to quantify the impact of 

each SAMA are described in Section F.6 of the ER for each SAMA. Table F–5 summarizes the 

assumptions used to estimate the risk reduction for each of the evaluated SAMAs, the 

estimated risk reduction in terms of percent reduction in CDF, population dose, and offsite 

economic cost, and the estimated total benefit (present value) of the averted risk. The 

determination of the benefits for the various SAMAs is further discussed in Section F.6.

The NRC staff reviewed the assumptions used in evaluating the benefit or risk reduction 

estimate of each of the SAMAs as described in the ER Section F.6. In response to an NRC 
Appendix F

F-26

staff RAI, Exelon clarified that for SAMA 14, automating the refueling water storage tank 

(RWST) makeup, it is conservative to assume, for both SGTR and non-SGTR sequences, 

that transitioning to recirculation mode and terminating break flow (i.e., controlled cooldown) is 

required. The human errors associated with both of these scenarios are reduced by a factor of 

10 as a result of the additional time available due to this SAMA (Exelon 2014). In response to 

another NRC staff RAI, Exelon clarified that for SAMA 15, inter-unit AFW crosstie, no credit is 

taken for this during dual-unit events since each unit may require the use of its own AFW pump, 

realistically (Exelon 2014). The NRC staff considers the assumptions, as clarified, to be 

reasonable and acceptable for purposes of the SAMA evaluation.

For those SAMAs identified in the ER which specifically mitigate fire risk (i.e., SAMAs 27, 28, 

29, 31, 32, 33, 34, and 35), a bounding estimate of the SAMA benefits was made. Exelon 

conservatively assumed that all of the fire risk, or fire CDF, associated with the fire zones 

affected by the SAMA is eliminated. (Because PDR and OECR were not directly calculated, this 

is noted as “Not Estimated” in Table F–5). These SAMAs were assumed to have no additional 

benefits in internal events. The NRC staff notes that this approach is not necessarily 

conservative for SAMAs, in which the benefit is dominated by the reduction in PDR or OECR 

and not CDF. However, the NRC staff concludes that since all of the fire mitigating SAMAs 

identified in the ER were determined by Exelon to be potentially cost-beneficial, further 

evaluation of these SAMAs is not necessary.

The NRC staff has reviewed Exelon’s bases for calculating the risk reduction for the various 

plant improvements and concludes that the rationale and assumptions for estimating risk 

reduction are reasonable and generally conservative (i.e., the estimated risk reduction is higher 

than what would actually be realized). Accordingly, the NRC staff based its independent 

estimates of averted risk for the various SAMAs on Exelon’s risk reduction estimates.
F-27

Table F–5. SAMA Cost and Benefit Screening Analysis for Braidwood Station (a)

Analysis Case and Applicable SAMAs(a) Modeling Assumptions

% Risk Reduction Total Ben

CDF

Population 

Dose OECR

Baseline 

(Internal + 

External)

1 – Diesel Driven SX Pump

Reduce the probability of RCP 

seal failure on loss of SX. 

Auto-start failure of diesel pump 

is 1×10−2.

55 78 87 41M 

2 – Replace the Positive Displacement 

Pump with a Self-Cooled, Auto-Start 

Pump

Reduce the probability of RCP 

seal failure on loss of SX. Seal 

injection pump failure is 1×10−3; 

transfer switch is 100% reliable.

46 19 6 5.4M 

3 – Auto-Start of Standby SX Pump

Reduce the probability of loss of 

cooling to critical loads on failure 

of standby SX to start. Auto-start 

failure is 1×10−4.

20 12 6 4.1M 

4 – Install “No Leak” RCP Seals

Reduce the probability of RCP 

seal for loss of seal cooling. Seal 

failure probability is reduced by a 

factor of 1,000.

47 20 7 6.1M 

5 – Modify the Startup Feedwater Pump 

to Start Using the ATWS Mitigating 

System Actuation Circuitry (AMSAC) SG 

Low-Low-Low Level Signal to Mitigate 

AFW Failure

Modify FW pump start logic 

to require failure of both the 

automated start function and 

manual operator action. 

Auto-start failure is 1×10−4.

11 29 39 18M 

6 – Enhance Plant Procedures to 

Explicitly Confirm Adequate 

_SX007 Throttling

Reduce HEP for verification of 

adequate RHR (to 6×10−4). Joint 

human error probability (JHEP) is 

reduced by about a factor of 5.

15 <1 <1 673K 

7 – Establish Flow to the Residual Heat 

Removal (RHR) Heat Exchanger (HX) on 

RHR Pump Start

Modify procedures to preclude 

the need for continuous action 

statement to protect RH pumps. 

Reduce HEP from 7.3×10−4 to 

1.4×10−4.

3 <1 <1 118K 

8 – Install Kill Switches for the Fire 

Protection Pumps in the Main Control 

Room (MCR)

Reduce the HEP for termination 

of fire pump flow. Action time is 

assumed to be 1 minute per 

pump.

4 2 1 784K 
F-28

Analysis Case and Applicable SAMAs(a) Modeling Assumptions

% Risk Reduction Total Ben

CDF

Population 

Dose OECR

Baseline 

(Internal + 

External)

9 – Install Flow Restrictors in Fire 

Protection Pipes

Aux building fire break flow is 

reduced to 1,000 gpm 

(4,000 L/min), and is adequate 

to meet fire suppression 

requirements. The increase in 

available time to terminate flow 

reduces the flood mitigation

factor to 1.2×10−4.

9 5 2 1.7M 

10 – Alter Ductwork Between the Aux 

Building (BLDG) Room and the SX Pump 

Room

Completely eliminate the 

“T1” flooding scenario. Flood 

mitigation factors for normal 

service water (SW) and SX floods 

are simplified to HEP for 

termination of flooding before 

reaching Elv. 364′.

13 12 11 5.5M 

11 – Implement diverse mitigation

system (DMS)

A portable 480-V generator is 

aligned to support diesel driven 

AFW makeup or a portable SG 

makeup pump. Failure probability 

for this function is 1×10−2. 

Cognitive failure to diagnose the 

need for secondary cooling, and 

any dependent combinations, are 

assumed to fail DMS.

70 77 84 41M 

12 – Modify Practices for System Auxiliary 

Transformer (SAT) Maintenance or 

Enhance Procedures

Completely eliminate risk of dual 

SAT out of service. 4 12 16 7.1M 

13 – Alternate AFW Cooling with 

Seal Protection 

Eliminate SX dependence 

for motor driven AFW pump 

operation. Reduce the probability 

of RCP seal failure on loss of SX. 

Seal injection pump failure is 

1×10−3; transfer switch is 

100% reliable.

66 77 85 41M 
F-29

Analysis Case and Applicable SAMAs(a) Modeling Assumptions

% Risk Reduction Total Ben

CDF

Population 

Dose OECR

Baseline 

(Internal + 

External)

14 – Automating RWST Makeup

Reduce HEPs for transition to 

recirculation mode and terminate 

break flow on SGTR by a factor of 

10. Reduce impacted JHEPs to 0 or 

by a factor of 10.

1 <1 <1 161K 

15 – Resolve Regulatory Issues and 

Complete Implementation of the 

Inter-Unit AFW Cross-tie

The AFW crosstie action 

execution failure probability 

is reduced to 2.4×10−2.

3 2 3 1.3M 

16 – Install High Flow Sensors on the 

Non-Essential Service Water System

Completely eliminate all risk 

associated with SW flood 

event scenarios.

2 6 8 3.5M 

17 – Use AMSAC for Alternate Low SG 

Level AFW Initiation

Eliminate the independent manual 

AFW initiation human failure events 

(HFEs) in conjunction with all 

associated JHEPs. The AMSAC 

logic is 100% reliable.

<1 <1 <1 57K 

18 – Automate Refill of the Diesel 

Driven AFW Pump Fuel Oil Day Tank

Eliminate the independent HFE and 

all dependent combinations to refill 

the AFW pump fuel oil day tank.

1 <1 <1 330K 

19 – Replace Motor-Operated Valves 

(MOVs) in the RHR Discharge Line with 

Valves That Can Isolate an ISLOCA Event

Completely eliminate all risk from 

the ISLOCA events occurring in 

the RHR discharge lines.

<1 10 5 2.9M 

20 – Disallow On-line RHR HX Maintenance

Completely eliminate all risk 

associated with RHR HX 

maintenance.

<1 0 <1 49K 

21 – Install an Emergency Isolation Valve in 

Each of the RHR Suction Lines

Completely eliminate all risk from 

the ISLOCA events occurring in the 

RHR discharge lines.

<1 3 1 745K 

22 – Install the Same High Flow Isolation 

Logic Used on Valve_CC685 on 

Valve_9438

Completely eliminate all risk from 

the ISLOCA events occurring in 

the RCP thermal barrier cooling 

HXs.

0 <1 <1 170K 

23 – Install a Passive Hydrogen 

Ignition System

Completely eliminate all containment 

failures due to hydrogen detonation. 0 <1 <1 116K 
F-30

Analysis Case and Applicable SAMAs(a) Modeling Assumptions

% Risk Reduction Total Ben

CDF

Population 

Dose OECR

Baseline 

(Internal + 

External)

24 – Provide a Reactor Vessel Exterior 

Cooling System

Completely eliminate relocation of 

the core to the containment floor, 

and eliminate all CFEs. Allow 

scrubbing to maximize averted cost.

0 <1 <1 124K 

25 – Install a Filtered Containment Vent

The filtered vent reduces the 

consequential dose and offsite 

economic cost associated with 

containment overpressure 

failures by a factor of 10.

0 72 76 35M 

26 – DMS Using a Dedicated Generator, 

Self Cooled Charging Pump, and a 

Portable AFW Pump

Indefinite AFW makeup capability 

and an alternate high-pressure 

injection function capable of 

providing alternate seal injection 

to prevent RCP seal LOCAs. The 

frequency of seal LOCA 

sequences is reduced by a factor 

of 100.

69 77 84 41M 

27 – Protect RH Safety Injection (SI) and 

Chemical and Volume Control System 

(CVCS) Cubicle Cooling Fan Cables in 

Fire Zone 11.3-0

Completely eliminate all of 

the risk associated with fire 

zone 11.3-0.

(b) 16 Not Estimated 2.6M 

28 – Install Fire Barriers Around 

MCC 134X

Completely eliminate all of 

the risk associated with fire 

zone 11.6-0.

(b) 10 Not Estimated 1.7M 

29 – Seal the Inverter 111 Panel and 

Install Fire Barriers to Protect 

Nearby Equipment

Completely eliminate all of 

the risk associated with fire 

zone 5.6-1.

(b) 9 Not Estimated 1.5M 

30 – Automate Swap to Recirculation Mode

Completely eliminate the 

contribution from the failure to 

swap to recirculation mode.

1 <1 <1 90K 

31 – Install Fire Barriers Around 

MCCs 132X5 and 134X

Completely eliminate all of 

the risk associated with fire 

zone 11.6-0.

(b) 3 Not Estimated 557K 

32 (d) – Install Fire Barriers Around 

MCC 132X5

Completely eliminate all of the risk 

associated with fire zone 11.5a-1.

(b) 3 Not Estimated 488K 
F-31

Analysis Case and Applicable SAMAs(a) Modeling Assumptions

% Risk Reduction Total Ben

CDF

Population 

Dose OECR

Baseline 

(Internal + 

External)

33 – Install Cable Wrap on the 141 to 241 

4-kV Cross-Tie Cable in the Division 11 

ESF Switchgear Room

Completely eliminate all of the 

risk associated with fire 

zone 5.2-1 (Unit 2).

(b) 6 Not Estimated 1M 

34 – Install Cable Wrap on the 141 to 241 

4-kV Cross-Tie Cable in the Aux Building 

Elevation 426′ of the General Area

Completely eliminate all of 

the risk associated with fire 

zone 11.6-0 (Unit 2).

(b) 5 Not Estimated 813K 

35 – Install Cable Wrap to Protect 

2AF005A, B, C and D in the Division 21 

Containment Electrical Penetrations Area

Completely eliminate all of 

the risk associated with fire 

zone 11.5a-2 (Unit 2).

(b) 5 Not Estimated 761K 

(a) SAMAs in bold are potentially cost-beneficial.

(b) The risk reduction for fire-mitigating SAMAs was estimated by the NRC staff, utilizing information provided in the ER, as the ratio of th

divided by the total fire CDF of 5.94×10−5 per year.

(c) The estimated benefits and implementation costs were revised in response to NRC staff RAIs 3.d, 6.a, and 6.f (Exelon 2014).

(d) SAMA 32 was determined to be potentially cost-beneficial in the ER (Exelon 2013a), but was subsequently determined to not be cost-

NRC staff RAI 3.d (Exelon 2014).

Sources: Exelon 2013a, 2014
Appendix F

F-32

F.5 Cost Impacts of Candidate Plant Improvements

In the ER, Exelon estimated the costs of implementing the candidate SAMAs through the 

development of Braidwood-specific cost estimates, the use of industry estimates, and, in some 

cases, combinations of these two sources. It was also noted that Braidwood-specific 

implementation costs do include contingency costs for unforeseen difficulties, but do not 

account for any replacement power costs (RPCs) that may be incurred due to consequential 

shutdown time unless specifically noted. In response to an NRC staff RAI, Exelon stated that 

a consulting firm was used to develop “order of magnitude” cost estimates for the SAMA 

implementation (Exelon 2014). Details such as cost of equipment, demolition, scaffolding, 

overtime, consumables, freight, engineering, etc. were used to develop the costs. Exelon 

provided the components of the cost estimates associated with: (a) developing supporting 

procedures, (b) providing lifelong training, and (c) applicable simulator updates.

Exelon also identified in the RAI response that the cost estimates for several SAMAs (2, 3, 4, 5, 

8, 9, 10, 11, 13, 16, 17, and 18) were for both Units 1 and 2 rather than for a single unit 

(Exelon 2014). Revised implementation cost estimates for each of these SAMAs was provided 

on a per unit basis. The corrected implementation costs were utilized in an updated cost-benefit 

analysis and are reflected in Table F–5. Detailed cost estimates were not developed for SAMAs 

that were judged to have implementation costs that far exceeded the estimated benefit.

In response to an NRC staff RAI concerning savings due to sharing of costs between units and 

between the Byron and Braidwood sites, Exelon clarified that since implementation costs were 

developed on a “per site” basis, cost sharing between units was accounted for in the updated 

analysis by dividing the “per-site” costs in half to obtain the “per-unit” costs (Exelon 2014). Cost 

sharing, however, was not considered between sites. Exelon explained that if cost sharing 

between sites was possible, engineering costs at the first sister plant are estimated to be 

generally 75 percent to 80 percent of the original costs if the modifications are identical. Exelon 

indicated that sharing of costs between sites is not appropriate because:

• It is not necessarily true that a SAMA implemented at one site will necessarily 

be implemented at the other site.

• While cost sharing between sites could reduce some implementation costs, 

any reductions in cost would be offset if other costs were also accounted for, 

such as inflation and RPCs.

• The SAMA designs are conceptual, and the cost estimates provided are 

“order of magnitude” estimates. Changes in the per-site engineering costs of 

12 percent to 13 percent are expected to be within the margin of error.

• Actual installation costs are generally larger than estimated installation costs.

• The impact of accounting for inter-site cost sharing is bounded by the results 

of the CDF uncertainty analysis, which is discussed in Section F.6.2.

The NRC staff agrees that the amount of cost savings due to sharing of cost between sites is 

highly uncertain. For its independent analysis, the NRC staff also considers the potential cost 

savings due to SAMA implementation at more than one site (in the cost-benefit analysis). For 

this consideration, the results of the cost-benefit analysis summarized in Table F–5 indicate 

that, if the amount of savings suggested by Exelon is realized, SAMA 21 and possibly SAMA 18 

would become cost-beneficial. However, considering the above points (high uncertainty in the 

data) and in particular that both of these SAMAs are shown not cost-beneficial at Byron (similar 

reactor design except for the cooling tower instead of cooling pond) and hence no inter-site cost 
Appendix F

F-33

savings would be realized, the NRC staff concludes that further consideration of these 

two SAMAs is not warranted.

Exelon estimated the minimum cost of making a change to a procedure and for conducting the 

necessary training on a procedure change to be $100,000. In response to an NRC staff RAI, 

Exelon stated that, although potentially lower cost estimates could be developed for procedure 

changes, all SAMAs associated with procedure changes were found to be cost-beneficial 

(Exelon 2014). Since all SAMAs associated with procedure change were found to be potentially 

cost-beneficial, reducing the cost of a procedure change to less than $100,000 would have no 

impact on the SAMA analysis results, and, based on this, the NRC staff finds this RAI 

response acceptable.

For SAMAs 12 and 20, the NRC staff requested in an RAI additional explanation for why the 

implementation cost estimates for these SAMAs assumed an extended outage time rather than 

assuming maintenance was performed in parallel with other outage activities (NRC 2014). For 

SAMA 12, Exelon responded that the SAT is the primary source of power to systems supporting 

spent fuel pool cooling when the fuel is in the spent fuel pool (Exelon 2014). At Braidwood, SAT 

work has not been performed during refueling outages as the refueling unit’s SAT is protected 

during the entire outage. Shutdown risk procedures do not allow for SAT work any time fuel is 

in the reactor vessel. The SAT protection could be removed during defueled conditions when 

the core fuel is in the spent fuel pool. However, the standard template for the defueled window 

is only 32 hours. The proposed SAT maintenance typically requires approximately 14 days to 

complete, requiring the outage to be extended. In addition, non-ESF buses are powered by the 

SAT that is needed during the outage. Reconfiguration of the SAT would hamper the ability to 

perform other normal outage work. For SAMA 20, Exelon responded that the primary driver is 

that any work on an RH train be performed during the defueled window (Exelon 2014). When 

fuel is in the reactor vessel, both RH trains are desired to be in service. In addition, while pump 

suction and HX work could be done on line, the inability to vent the RH pump discharge requires 

that this work be performed during an outage. However, the standard template for the defueled 

window is only 32 hours. The proposed RH maintenance typically requires approximately 4 to 

5 days to complete, requiring the outage to be extended. Based on this additional information, 

the NRC staff considers the estimated costs for SAMAs 12 and 20 to be reasonable and 

acceptable for purposes of the SAMA evaluation.

For certain improvements, the NRC staff compared the cost estimates to estimates developed 

elsewhere for similar improvements, including estimates developed as part of other licensees’ 

analyses of SAMAs for operating reactors. 

For SAMA 1, install a dedicated diesel-driven SX pump, the NRC staff noted that the cost 

estimate from the Limerick SAMA analysis used as the basis for the cost estimate included 

large HXs and safety-related equipment (PECO 1989). The NRC staff questioned in an RAI 

whether non-safety-grade equipment could be considered, and that large HXs significantly 

increase cost but are not needed in SAMA 1 (NRC 2014). In response to the RAI, Exelon

reevaluated the cost estimate for SAMA 1, and provided the updated cost, which is included in 

Table F–5.

Given that Exelon followed the guidance in NEI 05-01 (NEI 2005) and satisfactorily addressed 

NRC questions regarding cost estimates, the NRC staff concludes that the cost estimates 

provided by Exelon are sufficient and appropriate for use in the SAMA evaluation.
Appendix F

F-34

F.6 Cost-Benefit Comparison

Exelon’s cost-benefit analysis and the NRC staff’s review are described in the 

following sections.

F.6.1 Exelon’s Evaluation

The methodology used by Exelon was based primarily on NRC’s guidance for performing 

cost-benefit analysis, (i.e., NUREG/BR-0184, Regulatory Analysis Technical Evaluation 

Handbook) (NRC 1997a). The guidance involves determining the net value for each SAMA, 

according to the following formula:

Net Value = (APE + AOC + AOE + AOSC) – COE, where

APE = present value of averted public exposure ($)

AOC = present value of averted offsite property damage costs ($)

AOE = present value of averted occupational exposure costs ($)

AOSC = present value of averted onsite costs ($)

COE = cost of enhancement ($)

If the net value of a SAMA is negative, the cost of implementing the SAMA is larger than the 

benefit associated with the SAMA and it is not considered cost-beneficial. Exelon’s derivation 

of each of the associated costs is summarized below.

NUREG/BR-0058 has recently been revised to reflect the agency’s policy on discount rates. 

Revision 4 of NUREG/BR-0058 states that two sets of estimates should be developed, one at 

3 percent and one at 7 percent (NRC 2004). Exelon provided a base set of results using the 

3-percent discount rate and sensitivity studies using the 7-percent discount rate (Exelon 2013a).

Averted Public Exposure (APE) Costs

The APE costs were calculated using the following formula:

APE = Annual reduction in public exposure (Δ person-rem/year)

× monetary equivalent of unit dose ($2,000 per person-rem)

× present value conversion factor (15.04 based on a 20-year period with a 

3-percent discount rate)

As stated in NUREG/BR-0184 (NRC 1997a), the monetary value of the public health risk after 

discounting does not represent the expected reduction in public health risk due to a single 

accident. Rather, it is the present value of a stream of potential losses extending over the 

remaining lifetime (in this case, the renewal period) of the facility. Thus, it reflects the expected 

annual loss due to a single accident, the possibility that such an accident could occur at any 

time over the renewal period, and the effect of discounting these potential future losses to 

present value. For the purposes of initial screening, which assumes elimination of all severe 

accidents, Exelon calculated an APE of approximately $3,420,000 for the 20-year license 

renewal period (Exelon 2013a).
Appendix F

F-35

Averted Offsite Property Damage Costs (AOC)

The AOC were calculated using the following formula:

AOC = Annual CDF reduction

× offsite economic costs associated with a severe accident (on a per-event basis)

× present value conversion factor

This term represents the sum of the frequency-weighted offsite economic costs for each release 

category, as obtained for the Level 3 risk analysis. For the purposes of initial screening, which 

assumes elimination of all severe accidents caused by internal events, Exelon calculated an 

OECR of about $810,000 based on the Level 3 risk analysis (Exelon 2013a). This results in a 

discounted value of approximately $12,200,000 for the 20-year license renewal period.

Averted Occupational Exposure (AOE) Costs

The AOE costs were calculated using the following formula:

AOE = Annual CDF reduction

× occupational exposure per core damage event

× monetary equivalent of unit dose

× present value conversion factor

Exelon derived the values for AOE from information provided in Section 5.7.3 of the regulatory 

analysis handbook (NRC 1997a). Best estimate values provided for immediate occupational 

dose (3,300 person-rem) and long-term occupational dose (20,000 person-rem over a 10-year 

cleanup period) were used. The present value of these doses was calculated using the 

equations provided in the handbook in conjunction with a monetary equivalent of unit dose 

of $2,000 per person-rem, a real discount rate of 3 percent, and a time period of 20 years to 

represent the license renewal period. For the purposes of initial screening, which assumes 

elimination of all severe accidents caused by internal events, Exelon calculated an AOE of 

approximately $22,100 for the 20-year license renewal period (Exelon 2013a).

Averted Onsite Costs

Averted onsite costs (AOSC) include: (a) averted cleanup and decontamination costs (ACC) 

and (b) averted power replacement costs. Repair and refurbishment costs are considered for 

recoverable accidents only and not for severe accidents. Exelon derived the values for AOSC 

based on information provided in Section 5.7.6 of NUREG/BR-0184, the regulatory analysis 

handbook (NRC 1997a).

Exelon divided this cost element into two parts—the onsite cleanup and decontamination cost, 

also commonly referred to as ACC, and the RPC.

ACC were calculated using the following formula:

ACC = Annual CDF reduction

× present value of cleanup costs per core damage event

× present value conversion factor

The total cost of cleanup and decontamination subsequent to a severe accident is estimated in 

NUREG/BR-0184 to be $1.5 billion (undiscounted). This value was converted to present costs 

over a 10-year cleanup period and integrated over the term of the proposed license extension. 

For the purposes of initial screening, which assumes elimination of all severe accidents caused 
Appendix F

F-36

by internal events, Exelon calculated ACC of approximately $696,000 for the 20-year license 

renewal period.

Long-term RPCs were calculated using the following formula:

RPC = Annual CDF reduction

× present value of replacement power for a single event

× factor to account for remaining service years for which replacement power

is required

× reactor power scaling factor

Exelon based its calculations on a Braidwood net output of 1,197 megawatts electrical (MWe) 

and scaled up from the 910 MWe reference plant in NUREG/BR-0184 (NRC 1997a). Therefore, 

Exelon applied a power scaling factor of 1197⁄910 to determine the RPCs.

For the purposes of initial screening, which assumes elimination of all severe accidents caused 

by internal events, Exelon calculated an RPC of approximately $259,000 and AOSC of 

approximately $955,000 for the 20-year license renewal period.

Using the above equations, Exelon estimated the total present dollar value equivalent 

associated with completely eliminating severe accidents from internal events at Braidwood to 

be about $16,575,743, also referred to as the maximum averted cost-risk (MACR). The internal 

events MACR is rounded to next highest thousand ($16,576,000) for SAMA calculations. Use 

of a multiplier of 2.8 to account for external events increases the value to $46.4 million and 

represents the dollar value associated with completely eliminating all internal and external event 

severe accident risk for Braidwood. This is referred to as the modified MACR.

Exelon’s Results

If the implementation costs for a candidate SAMA exceeded the calculated benefit, the SAMA 

was considered not to be cost-beneficial. In the baseline analysis contained in the ER (using a 

3-percent discount rate), Exelon identified 18 potentially cost-beneficial SAMAs (SAMAs 3, 5, 6, 

7, 8, 9, 10, 11, 13, 15, 16, 19, 25, 26, 27, 28, 29, and 33). Based on consideration of 

uncertainty analysis, Exelon identified an additional eight potentially cost-beneficial SAMAs 

(SAMAs 1, 2, 4, 22, 31, 32, 34, and 35), resulting in 26 SAMAs in total. In response to NRC 

staff RAIs, Exelon provided the results of revised baseline and uncertainty analyses to account 

for: (a) updated SAMA implementation cost estimates, (b) a revised multiplier of 3.0 to account 

for external events, and (c) revisions to the uncertainty analysis (Exelon 2014). Exelon did not 

identify any additional cost-beneficial SAMAs as a result of the revised baseline and 

uncertainty analyses.

The potentially cost-beneficial SAMAs for Braidwood are as follows:

• SAMA 1 – Diesel Driven SX Pump

• SAMA 2 – Replace the Positive Displacement Pump with a Self Cooled, Auto 

Start Pump

• SAMA 3 – Auto Start of Standby SX Pump

• SAMA 4 – Install “No Leak” Seals

• SAMA 5 – Modify the Startup Feedwater pump to Start Using the AMSAC SG 

Low-Low-Low Level Signal to Mitigate AFW Failure
Appendix F

F-37

• SAMA 6 – Enhance Plant Procedures to Explicitly Confirm Adequate 

_SX007 Throttling

• SAMA 7 – Establish Flow to the RH HX on RH Pump Start

• SAMA 8 – Install Kill Switches for the Fire Protection Pumps in the MCR

• SAMA 9 – Install Flow Restrictors in Fire Protection Pipes

• SAMA 10 – Alter Ductwork Between the Aux BLDG Room and the SX Pump 

Room

• SAMA 11 – Implement DMS

• SAMA 13 – Alternate AFW Cooling with Seal Protection

• SAMA 15 – Resolve Regulatory Issues and Complete Implementation of the 

Inter-Unit AFW Cross-tie

• SAMA 16 – Install High Flow Sensors on the Non-Essential Service 

Water System

• SAMA 19 – Replace MOVs in the RHR Discharge Line with Valves That Can 

Isolate an ISLOCA Event

• SAMA 22 – Install the Same High Flow Isolation Logic Used on Valve_CC685 

on Valve_CC9438

• SAMA 25 – Install a Filtered Containment Vent

• SAMA 26 – DMS Using a Dedicated Generator, Self Cooled Charging Pump, 

and a Portable AFW Pump

• SAMA 27 – Protect RH SI and CVCS Cubicle Cooling Fan Cables in Fire 

Zone 11.3-0 

• SAMA 28 – Install Fire Barriers Around MCC 134X

• SAMA 29 – Seal the Inverter 111 Panel and Install Fire Barriers to Protect 

Nearby Equipment

• SAMA 31 – Install Fire Barriers Around MCCs 132X5 and 132X

• SAMA 32 – Install Fire Barriers Around MCC 131X2

• SAMA 33 – Unit 2 SAMA - Install Cable Wrap on the 141 to 241 

4-kV Cross-tie Cable in the Division 11 ESF Switchgear Room

• SAMA 34 – Unit 2 SAMA - Install Cable Wrap on the 141 to 241 4-kV 

Cross-tie Cable in the Aux Building Elevation 426′ of the General Area

• SAMA 35 – Unit 2 SAMA - Install Cable Wrap to Protect 2AF005A, B, C, 

and D in the Division 21 Containment Electrical Penetrations Area

The potentially cost-beneficial SAMAs and Exelon’s plans for further evaluation of these SAMAs 

are discussed in more detail in Section F.6.2.
Appendix F

F-38

F.6.2 Review of Exelon’s Cost-Benefit Evaluation

The cost-benefit analysis performed by Exelon was based primarily on NUREG/BR–0184 

(NRC 1997a) and discount rate guidelines in NUREG/BR-0058 (NRC 2004) and was executed 

consistent with this guidance.

The NRC staff noted that SAMAs identified primarily on the basis of the internal events analysis 

could provide benefits in certain external events, in addition to their benefits in internal events 

(internal flooding events were included in the PRA model). Exelon accounted for the potential 

risk reduction benefits associated with external events by applying a multiplier to the estimated 

benefits for internal events. In the analysis reported in the ER, Exelon multiplied the estimated 

benefits for internal events by a factor of 2.8, incorporating an external events multiplier of 1.8 to 

account for external events (Exelon 2013a). As discussed above, 18 SAMAs were determined 

to be potentially cost-beneficial in Exelon’s baseline analysis (SAMAs 3, 5, 6, 7, 8, 9, 10, 11, 13, 

15, 16, 19, 25, 26, 27, 28, 29, and 33). As discussed in Section F.2.2.2, in response to an NRC 

staff RAI, Exelon provided a revised baseline evaluation by applying a multiplier of 3.0 [(fire 

CDF of 5.94×10−5 per year + seismic CDF of 1.0×10−6 per year + external flooding CDF of 

1.0×10−6 per year + high winds CDF of 1.0×10−6 per year + transportation and nearby facility 

accident CDF of 1.0×10−6 per year) ⁄ (internal events CDF of 3.50×10−5 per year) + 1] to account 

for external events (Exelon 2014). The results of this revised evaluation are provided in 

Table F–5. No additional potentially cost-beneficial SAMAs were identified as a result of this 

revised evaluation (using a multiplier of 3.0 and a 3-percent discount rate), which incorporated 

the revised SAMA implementation costs discussed in Section F.5.

Exelon considered the impact that possible increases in benefits from analysis uncertainties 

would have on the results of the SAMA assessment. In the ER, Exelon presents the results of 

an uncertainty analysis of the internal events CDF, which indicates that the 95th percentile value 

is a factor of 2.29 times the point estimate CDF for Braidwood. Exelon considered whether any 

additional Phase I SAMAs might be retained for further analysis if the benefits from internal and 

external events were increased by a factor of 2.29. One additional SAMA (SAMA 12) was 

identified. Exelon also considered the impact on the Phase II screening if the estimated benefits 

from internal and external events were increased by a factor of 2.29. As discussed above (with 

these considerations), 8 additional SAMAs (SAMAs 1, 2, 4, 22, 31, 32, 34, and 35) were 

determined to be potentially cost-beneficial in Exelon’s analysis.

In an RAI, the NRC staff noted that the mean CDF (for BB011a) was lower than the point 

estimate (usually the mean CDF is greater than the point estimate due to the correlation of 

uncertainties) (NRC 2014). In response to the NRC staff RAI, Exelon responded that many of 

the largest contributors to the Braidwood PRA results are human probabilities related, JHEPs, 

or flood mitigation events (including operator errors) that are not correlated events. In addition, 

several contributors with large failure probabilities were assigned lognormal distributions with 

relatively high error factors. These factors can act to reduce the mean relative to the point 

estimate. Exelon recalculated the uncertainty analysis using revised error factors for selected 

events and determined that the revised 95th percentile value is a factor of 1.97 times the point 

estimate CDF for Braidwood. Since all Phase I SAMAs were retained in the Phase I analysis in 

the ER (after considering analysis uncertainties), the revised uncertainty analysis was 

performed for all SAMAs identified in the ER. Exelon also considered the impact on the 

Phase II screening if the estimated benefits from internal and external events were increased by 

this uncertainty factor of 1.97 (in addition to the multiplier of 3.0 for external events and revised 

SAMA implementation costs discussed in Section F.5). No additional SAMAs were found to be 

cost-beneficial as a result of this revised evaluation (using a 3-percent discount rate), although 

one SAMA, SAMA 32, was found to no longer be cost-beneficial (Exelon 2014). Although 
Appendix F

F-39

determined to no longer be cost-beneficial in this revised evaluation, Exelon did not withdraw 

this SAMA from further implementation consideration in the RAI response. The results of this 

revised evaluation are provided in Table F–5.

Exelon provided the results of additional sensitivity analyses in the ER, including the use of a 

7-percent discount rate and variations in MACCS2 input parameters (as discussed in 

Section F.2.2.4). Exelon determined that these analyses did not identify any additional 

potentially cost-beneficial SAMAs (Exelon 2013a). In an RAI, the NRC staff requested Exelon 

to explain why the MACCS2 sensitivity case for economic rate of return resulted in a change in 

dose consequence (NRC 2014). In response to the RAI, Exelon provided clarification that the 

rate of return on property impacts the estimated property that is condemned (or reclaimed). 

Changes in property reclamation will result in changes in dose consequences to those who 

occupy the property after it has been reclaimed (Exelon 2014). The NRC staff considers this 

explanation reasonable.

Exelon stated in the ER that SAMA 15, Resolve Regulatory Issues and Complete 

Implementation of the Inter-Unit AFW Cross-Tie to Improve AFW Reliability, was in the final 

stages of implementation at Braidwood at the time of the ER submittal and was, therefore, 

included as a SAMA rather than being included in the base PRA model. A sensitivity analysis 

was provided in the ER in which SAMA 15 was incorporated into the base PRA model and the 

Phases I and II SAMAs were reevaluated. This reevaluation did not alter the conclusions of 

either the Phase I screening analysis or the Phase II cost-benefit analysis.

Exelon also stated in the ER that many of the SAMAs address similar areas of plant risk and 

that implementation of one SAMA may result in other SAMAs no longer being cost-beneficial. 

Exelon further noted that SAMA 11, Implement diverse mitigation system or DMS, would 

mitigate many of the largest contributors to Braidwood risk, and that it may be fully or partially 

implemented at Braidwood for reasons other than the results of the SAMA analysis (specifically, 

it includes capabilities to address insights from the Fukushima Dai-ichi accident). Exelon 

reevaluated the cost-beneficial SAMAs assuming both SAMA 15 and SAMA 11 are 

implemented in an attempt to optimize a reduced set of SAMAs that would address the largest 

risk contributors. As a result, 15 SAMAs were determined to no longer be cost-beneficial 

(SAMAs 1, 2, 3, 4, 8, 9, 10, 13, 16, 25, 26, 27, 31, 32, and 35) (Exelon 2013a). The NRC staff 

notes that SAMA 4 is effectively implemented in this analysis since installing “no leak” RCP 

seals is one element of SAMA 11.

As discussed in Section F.3.2, in response to an NRC staff RAI, Exelon identified one additional 

SAMA candidate to install a low-flow seal injection pump to mitigate both a fire-induced RCP 

seal LOCA and a head vent LOCA, or to install cable wrap or fire barriers to prevent the fire 

damage, due to a transient fire in fire zone U2:3.4A-2 (Unit 2 Cable Riser Area, Elv. 451). 

Exelon estimated the implementation cost to be: (a) at least $2.9 million to install a low-flow 

seal injection pump (same as SAMA 2, which was to mitigate the RCP seal LOCA only) or 

(b) about $1 million to install cable wrap or fire barriers (same as SAMA 35). The risk reduction 

benefit from eliminating all fire risk in fire zone U2:3.4A-2, which has a fire CDF of 6.5×10−7 per 

year, was estimated by Exelon to be about $302,000 in the baseline and $595,000 after 

accounting for uncertainties. Based on this result, Exelon concluded that this SAMA was 

not cost-beneficial in either the baseline or uncertainty analysis.

As discussed above, the determination of risk reduction for a fire-specific SAMA from the 

mitigated fire CDF is not necessarily conservative since it is possible that a SAMA could have a 

greater impact on person-rem and OECR than on the CDF. The description of the fire scenario 

in fire zone U2:3.4A-2 indicates that the ignition source is a transient fire with the largest 

contributor from welding and cutting activities. The fire results in failure of a number of 
Appendix F

F-40

Division 1 systems including a seal LOCA. Based on this description, the NRC staff noted 

the use of updated ignition frequencies would reduce the fire CDF for this zone as would the 

planned installation of the “no leak” RCP seals. Considering this as well as the previously 

discussed conservatism in the Level 2 fission product release fractions for the risk-dominant 

release categories, the NRC staff concludes that it is unlikely that the new SAMA candidate for 

fire zone U2:3.4A-2 would be cost-beneficial, even after accounting for the potential 

nonconservatism in the analysis.

Exelon stated in the ER that the 26 SAMAs (SAMAs 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 16, 

19, 22, 25, 26, 27, 28, 29, 31, 32, 33, 34, and 35) determined to be cost-beneficial in the ER 

baseline and uncertainty evaluations have been submitted to the Braidwood Plant Health 

Committee for further implementation consideration (Exelon 2013a).

Given that Exelon has satisfactorily addressed the NRC staff questions regarding Exelon’s 

cost-benefit evaluations, the NRC staff concludes that the cost-benefit evaluations are of 

sufficient quality to support the SAMA evaluation. For the SAMA evaluation, the NRC staff 

concurs and concludes that, with the exception of the potentially cost-beneficial SAMAs 

discussed above (SAMAs 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 16, 19, 22, 25, 26, 27, 28, 29, 

31, 32, 33, 34, and 35), the costs of the other SAMAs evaluated would be higher than their 

associated benefits.

F.7 Conclusions

Exelon initially compiled a list of 35 SAMAs based on a review of: (a) the most significant basic 

events from the plant-specific PRA and insights from the Braidwood PRA group, (b) insights 

from the plant-specific IPE and IPEEE, and (c) Phase II SAMAs from license renewal 

applications for other plants. An initial qualitative screening removed SAMA candidates that: 

(a) are not applicable to Braidwood due to design differences, (b) have already been 

implemented at Braidwood or the intent achieved by other means, or (c) have excessive 

implementation costs. Based on this screening, one SAMA was eliminated leaving 

34 candidate SAMAs for evaluation. The one candidate SAMA initially screened was 

further evaluated after accounting for analysis uncertainties.

For all 35 SAMA candidates, benefit and cost estimates were developed as shown in Table F–5. 

The cost-benefit analyses in the ER showed that 18 of the SAMA candidates were potentially 

cost-beneficial in the baseline analysis (SAMAs 3, 5, 6, 7, 8, 9, 10, 11, 13, 15, 16, 19, 25, 26, 

27, 28, 29, and 33). Exelon performed additional analyses to evaluate the impact of parameter 

choices and uncertainties and in response to NRC staff RAIs on the results of the SAMA 

assessment. As a result, eight additional SAMAs were identified as potentially cost-beneficial 

(SAMAs 1, 2, 4, 22, 31, 32, 34, and 35). Exelon has indicated that all 26 potentially 

cost-beneficial SAMAs will be submitted to the Braidwood Plant Health Committee for further 

implementation consideration in accordance with current Braidwood processes and procedures 

for evaluating possible plant modifications. 

The NRC staff reviewed the Exelon analysis and concludes that the methods used and the 

implementation of those methods were sound. The treatment of SAMA benefits and costs 

supports the general conclusion that the SAMA evaluations performed by Exelon are 

reasonable and sufficient for the license renewal submittal. Although the treatment of SAMAs 

for external events was somewhat limited, the NRC staff determined that the likelihood of 

additional cost-beneficial enhancements in this area was minimized by: (a) utilization of an 

interim Braidwood fire PRA to identify SAMA candidates, (b) resolution of suggested plant 

improvements that were identified as a result of the IPEEE process, and (c) inclusion of a 

multiplier to account for external events.
Appendix F

F-41

Based on the NRC staff’s review of Exelon’s SAMA evaluations, including Exelon’s response to 

NRC staff questions regarding the evaluations, the NRC staff concludes that Exelon has 

adequately identified areas in which risk can be further reduced in a cost-beneficial manner 

through the implementation of the identified and potentially cost-beneficial SAMAs. Given the 

potential for cost-beneficial risk reduction, the NRC staff agrees that further evaluation by 

Exelon of the 26 candidate SAMAs identified by Exelon as being potentially cost-beneficial 

in the ER is warranted.

Additionally, the NRC staff evaluated the identified potentially cost-beneficial SAMAs

to determine if they are in the scope of license renewal, (i.e., they are subject to aging 

management). This evaluation considers whether the systems, structures, and components 

associated with these SAMAs: (1) perform their intended function without moving parts or 

without a change in configuration or properties and (2) are not subject to replacement based on 

qualified life or specified time period. The NRC staff determined that these SAMAs do not relate 

to adequately managing the effects of aging during the period of extended operation. 

Therefore, they need not be implemented as part of license renewal in accordance with Title 10 

of the Code of Federal Regulations (CFR), Part 54, “Requirements for renewal of operating 

licenses for nuclear power plants.”

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NUREG-1437

Supplement 55

Final

Generic Environmental Impact Statement for License Renewal of Nuclear Plants 

Regarding Braidwood Station, Units 1 and 2