ML25344A144

DSEIS

ML25344A144
Person / Time
Site:	Robinson
Issue date:	12/10/2025
From:	Office of Nuclear Material Safety and Safeguards
To:
References
Download: ML25344A144 (0)

Text

Environmental Center of Expertise Division of Rulemaking, Environmental, and Financial Support Office of Nuclear Material Safety and Safeguards ML25344A144 NRC CEQ ID: SEIS-429-00-000-1764730803 Supplement 13, Second Renewal to NUREG-1437 Generic Environmental Impact Statement for License Renewal of Nuclear Plants, Supplement 13, Second Renewal, Regarding Subsequent License Renewal for H.B. Robinson Steam Electric Plant, Unit No. 2 Draft Report for Comment Docket Number: 50-261 Issued: DECEMBER 2025

i COMMENTS ON DRAFT REPORT 1

Proposed Action Issuance of subsequent renewed facility operating license DRP-23 for the 2

H.B. Robinson Stream Electric Plant, Unit 2, in Hartsville, South Carolina 3

4 Type of Statement Draft Supplemental Environmental Impact Statement 5

6 Agency Contact Karen Loomis 7

U.S. Nuclear Regulatory Commission (NRC) 8 Office of Nuclear Material Safety and Safeguards 9

Mailstop T-4B72 10 Washington, DC 20555-0001 11 Email: Karen.Loomis@nrc.gov 12 13 Comments:

14 Any interested party may submit comments on this draft supplemental environmental impact 15 statement. The public commenting process affords an opportunity for public input on the U.S.

16 Nuclear Regulatory Commission (NRC, the Commission) decision-making, including the NRCs 17 analysis of potential environmental effects. Public commenting allows the NRC to make better 18 informed decisions.

19 The deadline for submitting comments on this draft supplemental environmental impact 20 statement is 45 days after the date that it is published in the Federal Register. Comments 21 received after the expiration of the comment period will be considered if it is practical to do so, 22 but assurance of consideration of late comments cannot be given. The NRC encourages 23 electronic comment submission through the Federal Rulemaking website (Regulations.gov).

24 Please include Docket ID NRC-2025-0076 in your comment submission. The NRC cautions you 25 not to include identifying or contact information that you do not want to be publicly disclosed in 26 your comment submission. The NRC will post all comment submissions at Regulations.gov, as 27 well as enter the comment submissions into the NRCs Agencywide Documents Access and 28 Management System (ADAMS). The NRC does not routinely edit comment submissions to 29 remove identifying or contact information.

30 If you are requesting or aggregating comments from other persons for submission to the NRC, 31 then you should inform those persons not to include identifying or contact information that they 32 do not want to be publicly disclosed in their comment submission. Your request should state that 33 the NRC does not routinely edit comment submissions to remove such information before 34 making the comment submissions available to the public or entering the comment into ADAMS.

35

iii COVER SHEET 1

Responsible Agency: U.S. Nuclear Regulatory Commission, Office of Nuclear Material Safety 2

and Safeguards 3

Title:

Generic Environmental Impact Statement for License Renewal of Nuclear Plants, 4

Supplement 13, Second Renewal, Regarding Subsequent License Renewal for Robinson 5

Nuclear Plant, Draft Report for Comment 6

For additional information or copies of this document contact:

7 U.S. Nuclear Regulatory Commission 8

Office of Nuclear Material Safety and Safeguards 9

Mail Stop T-4B72 10 11555 Rockville Pike 11 Rockville, MD 20852 12 Email: Karen.Loomis@nrc.gov 13 ABSTRACT 14 The U.S. Nuclear Regulatory Commission (NRC, the Commission) prepared this supplemental 15 environmental impact statement in response to an application submitted by Duke Energy, LLC 16 to subsequently renew the renewed facility operating license for the H.B. Robinson Steam 17 Electric Plant, Unit 2, for an additional 20 years. This supplemental environmental impact 18 statement, in combination with the Commissions NUREG-1437, Generic Environmental Impact 19 Statement for License Renewal of Nuclear Plants, evaluates the environmental impacts of the 20 proposed action and discusses a reasonable range of alternatives to the proposed action, 21 including an analysis of any negative environmental impacts of not implementing the proposed 22 action.

23 The NRC staffs preliminary recommendation is that the adverse environmental impacts of 24 subsequent license renewal for H.B. Robinson Steam Electric Plant, Unit 2 are not so great that 25 preserving the option of subsequent license renewal for energy-planning decision-makers would 26 be unreasonable.

27

v TABLE OF CONTENTS 1

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

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

LIST OF FIGURES......................................................................................................... ix 4

LIST OF TABLES.......................................................................................................... xi 5

EXECUTIVE

SUMMARY

.............................................................................................. xiii 6

ABBREVIATIONS AND ACRONYMS.......................................................................... xv 7

1 Introduction...................................................................................................... 1-1 8

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

1.2 Purpose and Need for the Proposed Action.......................................................1-1 10 1.3 Major Environmental Review Milestones...........................................................1-2 11 1.4 Generic Environmental Impact Statement.........................................................1-3 12 1.5 Supplemental Environmental Impact Statement................................................1-5 13 1.6 Decision to Be Supported by the Supplemental Environmental Impact 14 Statement..........................................................................................................1-6 15 1.7 Cooperating Agencies.......................................................................................1-6 16 1.8 Required Consultations.....................................................................................1-6 17 1.9 Correspondence................................................................................................1-6 18 1.10 Status of Compliance........................................................................................1-7 19 2

The Proposed Federal Action and the No-Action Alternative...................... 2-1 20 2.1 Description of Nuclear Power Plant Facility and Operation................................2-1 21 2.1.1 External Appearance and Setting.......................................................2-1 22 2.2 Proposed Federal Action...................................................................................2-2 23 2.2.1 Nuclear Power Plant Operations during the Subsequent License 24 Renewal Term....................................................................................2-3 25 2.2.2 Refurbishment and Other Activities Associated with License 26 Renewal.............................................................................................2-3 27 2.2.3 Termination of Nuclear Power Plant Operations and 28 Decommissioning After the Subsequent License Renewal Term.........2-3 29 2.3 Alternatives.......................................................................................................2-4 30 2.4 No-Action Alternative and New Energy Generation...........................................2-4 31 2.5 Comparison of Environmental Impacts of the Proposed Federal Action 32 and the Alternatives...........................................................................................2-5 33

vi 3

Affected Environment and Environmental Consequences.......................... 3-1 1

3.1 Introduction.......................................................................................................3-1 2

3.1.1 Category 1 Issues..............................................................................3-1 3

3.1.2 Category 2 Issues..............................................................................3-4 4

3.2 Surface Water Resources..................................................................................3-5 5

3.3 Groundwater Resources....................................................................................3-9 6

3.3.1 Affected Environment.........................................................................3-9 7

3.3.1.1 Site Geology...................................................................3-9 8

3.3.1.2 Local and Regional Groundwater Resources............... 3-10 9

3.3.1.3 Groundwater Use and Quality...................................... 3-14 10 3.3.1.4 Groundwater Protection Program and Tritium in 11 Groundwater................................................................ 3-15 12 3.3.2 Environmental Consequences: Groundwater Use Conflicts 13 (plants that withdraw more than 100 gallons per minute [gpm])........ 3-16 14 3.3.3 Environmental Consequences: Groundwater Quality 15 Degradation (plants with cooling ponds)........................................... 3-17 16 3.3.4 Environmental Consequences: Radionuclides Released to 17 Groundwater.................................................................................... 3-17 18 3.4 Terrestrial Resources....................................................................................... 3-18 19 3.4.1 Affected Environment....................................................................... 3-18 20 3.4.2 Environmental Consequences: Non-Cooling System Impacts on 21 Terrestrial Resources........................................................................ 3-18 22 3.4.3 Environmental Consequences: Water Use Conflicts with 23 Terrestrial Resources........................................................................ 3-21 24 3.5 Aquatic Resources.......................................................................................... 3-23 25 3.5.1 Affected Environment....................................................................... 3-23 26 3.5.2 Environmental Consequences: Impingement Mortality and 27 Entrainment of Aquatic Organisms (Plants with Once-Through 28 Cooling Systems or Cooling Ponds)................................................. 3-23 29 3.5.2.1 Robinson Cooling Water Intake System....................... 3-23 30 3.5.2.2 Clean Water Act Section 316(b) Requirements for 31 Existing Facilities.......................................................... 3-24 32 3.5.2.3 Impingement Mortality and Entrainment Best 33 Technology Available.................................................... 3-24 34 3.5.2.4 Engineered Designs and Operational Controls............. 3-25 35 3.5.2.5 Impingement and Entrainment Studies......................... 3-26 36 3.5.2.6 Impingement Mortality and Entrainment Conclusion..... 3-28 37 3.5.3 Environmental Consequences: Effects of Thermal Effluents on 38 Aquatic Organisms (Plants with Once-Through Cooling Systems 39 or Cooling Ponds)............................................................................. 3-28 40 3.5.3.1 RNP Effluent Discharge................................................ 3-29 41 3.5.3.2 Clean Water Act Section 316(a) Requirements for 42 Point Source Discharges.............................................. 3-29 43

vii 3.5.3.3 CWA 316(a) Thermal Variance and NPDES Permit 1

Provisions.................................................................... 3-29 2

3.5.3.4 Thermal Studies........................................................... 3-30 3

3.5.3.5 Thermal Impacts Analysis and Conclusion................... 3-30 4

3.5.4 Environmental Consequences: Water Use Conflicts with Aquatic 5

Resources (Plants with Cooling Ponds or Cooling Towers Using 6

Makeup Water from a River)............................................................. 3-33 7

3.6 Federally Protected Ecological Resources...................................................... 3-34 8

3.6.1 Endangered Species Act: Federally Listed Species and Critical 9

Habitats under U.S. Fish and Wildlife Jurisdiction............................. 3-35 10 3.6.2 Endangered Species Act: Federally Listed Species and Critical 11 Habitats under National Marine Fisheries Service Jurisdiction.......... 3-35 12 3.6.3 Magnuson-Stevens Act: Essential Fish Habitat................................ 3-36 13 3.6.4 National Marine Sanctuaries Act: Sanctuary Resources................... 3-36 14 3.7 Historic and Cultural Resources...................................................................... 3-36 15 3.7.1 Environmental Consequences of the Proposed Action:

16 Continued Operations and Refurbishment Activities......................... 3-39 17 3.8 Human Health................................................................................................. 3-39 18 3.8.1 Affected Environment....................................................................... 3-39 19 3.8.2 Environmental Consequences: Microbiological Hazards to the 20 Public............................................................................................... 3-40 21 3.8.3 Environmental Consequences: Electromagnetic Fields.................... 3-41 22 3.8.4 Environmental Consequences: Electric Shock Hazards................... 3-41 23 3.9 Greenhouse Gas Emissions and Climate Change........................................... 3-42 24 3.9.1 Climate Change Impacts on Environmental Resource Areas............ 3-43 25 4

Conclusions..................................................................................................... 4-1 26 4.1 Environmental Impacts of License Renewal......................................................4-1 27 4.2 Comparison of Alternatives................................................................................4-1 28 4.3 Recommendation..............................................................................................4-1 29 5

List of Preparers.............................................................................................. 5-1 30 6

References....................................................................................................... 6-1 31 APPENDIX A COMMENTS RECEIVED ON THE H.B. ROBINSON STEAM 32 ELECTRIC PLANT, UNIT 2 ENVIRONMENTAL REVIEW............... A-1 33 APPENDIX B APPLICABLE LAWS, REGULATIONS, AND OTHER 34 REQUIREMENTS............................................................................. B-1 35 APPENDIX C ECOLOGICAL CONSULTATIONS................................................... C-1 36 APPENDIX D NATIONAL HISTORIC PRESERVATION ACT SECTION 106 37 CONSULTATION.............................................................................. D-1 38

viii APPENDIX E CHRONOLOGY OF ENVIRONMENTAL REVIEW 1

CORRESPONDENCE....................................................................... E-1 2

APPENDIX F AGENCIES, ORGANIZATIONS, INDIAN TRIBES, AND 3

INDIVIDUALS CONTACTED............................................................ F-1 4

ix LIST OF FIGURES 1

Figure 1-1 Environmental Review Process for Subsequent License Renewal of 2

Nuclear Power Plants.......................................................................................1-3 3

Figure 1-2 Environmental Issues Evaluated for Subsequent License Renewal of 4

Nuclear Power Plants.......................................................................................1-5 5

Figure 2-1 Map Showing the H.B. Robinson Steam Electric Plant Layout..........................2-2 6

Figure 3-1 Map of the Vicinity of the H.B. Robinson Steam Electric Plant..........................3-6 7

Figure 3-2 Time Series of Annual Flows Measured Upstream and Downstream of 8

Lake Robinson, 1961-2024..............................................................................3-7 9

Figure 3-3 Average Monthly Upstream Flow and Downstream to Upstream Flow 10 Ratio of Lake Robinson.....................................................................................3-8 11 Figure 3-4 Northwest to Southeast Geologic Cross-Section through the H.B.

12 Robinson Steam Electric Plant Site................................................................. 3-11 13 Figure 3-5 H.B. Robinson Steam Electric Plant Onsite Wells........................................... 3-13 14 Figure 3-6 Vertical Temperature Profile at Transect E Adjacent to the Thermal 15 Discharge Weir, August, 1995......................................................................... 3-30 16 17

xi LIST OF TABLES 1

Table 2-1 Comparison of Environmental Impacts of the Proposed Federal Action 2

and the No-Action Alternative at the H.B. Robinson Steam Electric Plant.........2-6 3

Table 3-1 Applicable Category 1 Issues for the H.B. Robinson Steam Electric Plant........3-2 4

Table 3-2 Applicable Category 2 Issues for the H.B. Robinson Steam Electric Plant........3-4 5

Table 3-3 Thermal Effluent Alternate Thermal Effluent Limits Specified in the H.B.

6 Robinson Steam Electric Plant National Pollutant Discharge Elimination 7

System Permit No. SC0002925...................................................................... 3-29 8

Table 3-4 Lake Robinson Residence Time Calculations Measured from U.S.

9 Geological Survey Gauge No. 02130910, 66 Years of Water Data.................. 3-34 10 Table 3-5 Effect Determinations for Federally Listed Species Under U.S. Fish and 11 Wildlife Jurisdiction for the H.B. Robinson Steam Electric Plant 12 Subsequent License Renewal......................................................................... 3-35 13 Table 5-1 List of Preparers...............................................................................................5-1 14 Table A-1 Individuals Providing Comments During the Scoping Comment Period............ A-2 15 Table A-2 Distribution of Comments by Resource Area or Topic....................................... A-2 16 Table B-1 Operating Permits and Other Requirements for H.B. Robinson Steam 17 Electric Plant, Unit 2......................................................................................... B-2 18 Table C-1 Wetlands and Surface Water Features on the H.B. Robinson Steam 19 Electric Plant Site and within a 6 mi Radius..................................................... C-2 20 Table C-2 State-Listed Terrestrial Species, Potentially Occurring in the Vicinity of the 21 H.B. Robinson Steam Electric Plant Site.......................................................... C-3 22 Table C-3 Environmental Characterization Fish Data Collected via Electrofishing in 23 Lake Robinson, 2012-2019............................................................................. C-9 24 Table C-4 Freshwater Fish Species Present in Lake Robinson...................................... C-10 25 Table C-5 Effect Determinations for Federally Listed Species under U.S. Fish and 26 Wildlife Service Jurisdiction............................................................................ C-13 27 Table C-6 Endangered Species Act Section 7 Consultation Correspondence with the 28 U.S. Fish and Wildlife Service........................................................................ C-13 29 Table D-1 National Historic Preservation Act Section 106 Correspondence for the 30 Subsequent License Renewal of H.B. Robinson Steam Electric Plant, 31 Unit 2............................................................................................................... D-1 32 Table E-1 Environmental Review Correspondence Regarding the Subsequent 33 License Renewal of H.B. Robinson Steam Electric Plant, Unit 2...................... E-1 34 Table F-1 List of Agencies, Organizations, Indian Tribes, and Persons Contacted by 35 NRC during the Environmental Review of the Draft Environmental Impact 36 Statement for the Subsequent License Renewal of H.B. Robinson Steam 37 Electric Plant, Unit 2......................................................................................... F-1 38 39

xiii EXECUTIVE

SUMMARY

1 By letter dated April 1, 2025, Duke Energy, LLC submitted to the U.S. Nuclear Regulatory 2

Commission (NRC, the Commission) an application requesting subsequent renewal of the 3

renewed facility operating license for H.B. Robinson Steam Electric Plant, Unit 2 (Robinson or 4

RNP) for an additional 20-year period (Duke 2025-TN12522). The current facility operating 5

license for RNP expires at midnight on July 31, 2030. The subsequent license renewal 6

application was submitted pursuant to Title 10 of the Code of Federal Regulations Part 54 7

(TN4878), Requirements for Renewal of Operating Licenses for Nuclear Power Plants. The 8

NRC staff found Duke Energy, LLCs application acceptable for docketing as announced in the 9

Federal Register on May 8, 2025 (90 FR 19535-TN12523).

10 On May 22, 2025, in accordance with Title 10 of the Code of Federal Regulations Part 51 11 (TN10253), Environmental Protection Regulations for Domestic Licensing and Related 12 Regulatory Functions, the NRC regulations implementing the National Environmental Policy Act 13 of 1969, as amended (TN661), the NRC staff published in the Federal Register (90 FR 21952-14 TN12524) a notice of intent to conduct an environmental scoping process to gather information 15 to prepare an environmental impact statement to evaluate environmental impacts related to the 16 proposed subsequent license renewal for RNP. This environmental impact statement would be a 17 supplement to the Commissions NUREG-1437, Revision 2, Generic Environmental Impact 18 Statement for License Renewal of Nuclear Plants, Final Report (LR GEIS), dated August 2024 19 (NRC 2024-TN10161).

20 The proposed Federal action is subsequent renewal of the facility operating license for RNP.

21 The purpose and need for the proposed action is to provide an option that allows for power 22 generation capability beyond the term of the current nuclear power plant operating license to 23 meet future system generating needs, as such needs may be determined by authorized Federal 24 (other than the NRC) and State decision-makers, as well as utility stakeholders. For the 25 proposed action, the NRCs decision-making authority is limited to deciding whether to issue the 26 subsequent renewed facility operating license; therefore, there are no alternatives to the 27 proposed action that meet the purpose and need of the proposed action. However, as part of its 28 analysis of any negative environmental impacts of not issuing the subsequent renewed facility 29 operating license (i.e., the no-action alternative), the NRC staff evaluated the environmental 30 impacts of a reasonable range of replacement power alternatives to meet the energy demand 31 currently being met by the power generated by RNP, relying, in part, on the discussion in 32 Appendix D of the LR GEIS of replacement power alternatives and their environmental impacts 33 to each resource area that would be associated with their construction and operation.

34 Based on its review presented in Chapter 2, the NRC staff concluded that the environmentally 35 preferred alternative is the proposed action. With respect to the proposed action, the LR GEIS 36 evaluated 80 environmental issues related to nuclear plant operation and classified each issue 37 as either a Category 1 issue (generic to all or a distinct subset of nuclear plants) or a Category 2 38 issue (specific to individual nuclear plants) (NRC 2024-TN10161). The NRC staff has identified 39 no information that is both new and significant related to Category 1 issues. Thus, the NRC staff 40 relied upon the conclusions of the LR GEIS for all Category 1 issues applicable to RNP 41 subsequent license renewal. Additionally, a summary of the NRC staffs analysis of the 42 Category 2 issues (i.e., plant-specific) applicable to RNP subsequent license renewal is 43 presented in Table 3-2, with more detail presented in Chapter 3. The NRC staff considered 44 mitigation measures for each Category 2 issue, as applicable, and concluded that no additional 45 mitigation measures are warranted.

46

xiv Based on the above, the NRC staffs preliminary recommendation is that the adverse 1

environmental impacts of subsequent license renewal for RNP are not so great that preserving 2

the option of subsequent license renewal for energy-planning decision-makers would be 3

unreasonable.

4

xv ABBREVIATIONS AND ACRONYMS 1

µm micrometer(s) 2

°C degrees Celsius 3

°F degrees Fahrenheit 4

5 ac acre(s) 6 ACHP Advisory Council on Historic Preservation 7

ADAMS Agencywide Documents Access and Management System 8

AGL Above Ground Level 9

APE area of potential effects 10 11 BMP best management practice 12 BTA best technology available 13 14 CFR Code of Federal Regulations 15 cfs cubic foot/feet per second 16 CH4 methane 17 CO carbon monoxide 18 CO2 carbon dioxide 19 CWA Clean Water Act of 1972, as amended 20 CWIS cooling water intake system 21 22 DO dissolved oxygen 23 DOT U.S. Department of Transportation 24 Duke Duke Energy, LLC 25 26 EFH essential fish habitat 27 EIS environmental impact statement 28 EMF electromagnetic field 29 EPA U.S. Environmental Protection Agency 30 ER environmental report 31 ESA Endangered Species Act of 1973, as amended 32 33 FE federally endangered 34 fps foot/feet per second 35 FPD federally proposed designated (critical habitat) 36 FPE proposed for Federal listing as endangered 37 FPT proposed for Federal listing as threatened 38 ft feet/foot 39 FT federally threatened 40 FWS U.S. Fish and Wildlife Service 41 42 GEIS generic environmental impact statement 43

xvi GHG greenhouse gas 1

GPI Groundwater Protection Initiative 2

gpm gallon(s) per minute 3

GPP Groundwater Protection Program 4

GWL global warming level 5

6 ha hectare(s) 7 8

in.

inch(es) 9 10 kg kilogram(s) 11 km kilometer(s) 12 kV kilovolt(s) 13 14 LR license renewal 15 LR GEIS Generic Environmental Impact Statement for License Renewal of Nuclear 16 Plants (NUREG-1437) 17 Lpm liter(s) per minute 18 19 MGD million gallon(s) per day 20 MGM million gallon(s) per month 21 MLD million liter(s) per day 22 MLM million liter(s) per month 23 MT metric ton(s) 24 m

meter(s) 25 mA milliampere(s) 26 mg/L milligram(s) per liter 27 mi mile(s) 28 MSA Magnuson-Stevens Fishery Conservation and Management Act of 1976, 29 as amended 30 MSL mean sea level 31 32 NEPA National Environmental Policy Act of 1969, as amended 33 NESC National Electrical Safety Code 34 NHPA National Historic Preservation Act of 1966, as amended 35 NMFS National Marine Fisheries Service 36 NMSA National Marine Sanctuaries Act 37 NOAA National Oceanic and Atmospheric Administration 38 NPDES National Pollutant Discharge Elimination System 39 NRC U.S. Nuclear Regulatory Commission, the Commission 40 NRHP National Register of Historic Places 41 NUREG NRC technical report designation 42 43

xvii pCi/L picocurie(s) per liter 1

PNNL Pacific Northwest National Laboratory 2

ppb parts per billion 3

4 RCP representative concentration pathway 5

Robinson or RNP H.B. Robinson Steam Electric Plant, Unit 2 6

ROW right-of-way 7

8 SCDES South Carolina Department of Environmental Services 9

SCDNR South Carolina Department of Natural Resources 10 SHPO State Historic Preservation Officer 11 SMR small modular reactor 12 13 USGS U.S. Geological Survey 14 15

1-1 1

INTRODUCTION 1

The U.S. Nuclear Regulatory Commission (NRC, the Commission) environmental protection 2

regulations in Title 10 of the Code of Federal Regulations (10 CFR) Part 51 (TN10253),

3 Environmental Protection Regulations for Domestic Licensing and Related Regulatory 4

Functions, implement the National Environmental Policy Act of 1969, as amended (NEPA) 5 (TN661), as amended. The regulations in 10 CFR Part 51 require, in part, that the NRC staff 6

prepare an environmental impact statement (EIS), which is a supplement to the Commissions 7

NUREG-1437 (NRC 2024-TN10161), Revision 2, Generic Environmental Impact Statement for 8

License Renewal of Nuclear Plants, Final Report (LR GEIS), dated August 2024, for the renewal 9

of a nuclear power plant operating license.

10 The Atomic Energy Act of 1954 (TN663), as amended, specifies that licenses for commercial 11 nuclear power reactors can be granted for up to 40 years. The NRC regulations in 10 CFR 12 Part 54 (TN4878), Requirements for Renewal of Operating Licenses for Nuclear Power Plants, 13 allow for an option to renew such licenses for terms of up to an additional 20 years. The initial 14 40-year licensing period was based on economic and antitrust considerations rather than on 15 technical limitations of the nuclear facility. There are no limitations in the Atomic Energy Act or 16 the NRCs regulations restricting the number of times that a license may be renewed.

17 The decision to seek a subsequent renewed license rests entirely with nuclear power facility 18 owners and, typically, is based on the facilitys economic viability and the investment necessary 19 to continue to meet NRC requirements. The NRC makes the decision to grant or deny a 20 subsequent license renewal application based on whether the applicant has demonstrated that 21 NRC requirements can be met during the subsequent license renewal term.

22 1.1 Proposed Federal Action 23 The proposed Federal action (subsequent renewal of renewed facility operating license DRP-23 24 for the H.B. Robinson Steam Electric Plant, Unit 2 [Robinson or RNP]) was initiated by Duke 25 Energy, LLC (Dukes) submittal to the NRC of a subsequent license renewal application on 26 April 1, 2025 (Duke 2025-TN12522). The current renewed facility operating license for RNP is 27 set to expire at midnight on July 31, 2030. The NRCs Federal action is to determine whether to 28 issue a subsequent renewed facility operating license for RNP for an additional 20 years. If the 29 NRC subsequently renews the renewed facility operating license, Duke would be authorized to 30 operate RNP until midnight on July 31, 2050.

31 1.2 Purpose and Need for the Proposed Action 32 The purpose and need for the proposed action (subsequent renewal of renewed facility 33 operating license) is to provide an option that allows for power generation capability beyond the 34 term of the current nuclear power plant operating license to meet future system generating 35 needs, as such needs may be determined by authorized Federal (other than the NRC) and 36 State decision-makers, as well as utility stakeholders. This definition of purpose and need 37 reflects the Commissions recognition that, absent findings in the safety review required by the 38 Atomic Energy Act of 1954 (TN663), as amended, or in the environmental review required by 39 NEPA that would lead the NRC to reject a subsequent license renewal application, the NRC has 40 no role in the energy-planning decisions of State regulators and utility officials (NRC 2024-41 TN10161).

42

1-2 If the subsequent renewed license is issued, the power plant owners, State regulators, and, in 1

some cases, other Federal agencies will ultimately decide whether the nuclear power plant will 2

continue to operate based on economics, energy reliability goals, and other factors within their 3

jurisdiction or the owners purview. If the subsequent renewed license is not issued, the nuclear 4

power plant must shut down on or before the expiration date of the current renewed license.

5 1.3 Major Environmental Review Milestones 6

The NRC has established a subsequent license renewal process that can be completed in a 7

reasonable period of time with clear requirements to ensure safe plant operation for up to an 8

additional 20 years. The NRC staff conducts a safety review in parallel with an environmental 9

review and documents the findings of the safety review in a safety evaluation report and the 10 findings of the environmental review in a supplemental EIS. The safety evaluation report and the 11 EIS are both factors in the NRCs decision to either grant or deny the issuance of subsequent 12 renewed licenses. The safety evaluation report and the EIS schedules for the RNP subsequent 13 license renewal application are provided at the NRCs project website:

14 https://www.nrc.gov/reactors/operating/licensing/renewal/applications/robinson-subsequent.

15 By letter dated April 1, 2025 (Duke 2025-TN12582), Duke submitted a subsequent license 16 renewal application to the NRC for RNP, which included an environmental report (ER) (Duke 17 2025-TN12518). On May 8, 2025, after reviewing the subsequent license renewal application 18 and ER for sufficiency, the NRC staff published a notice of acceptance for docketing and 19 opportunity to request a hearing in the Federal Register (90 FR 19535-TN12523). On May 22, 20 2025, the NRC staff published a notice of intent to conduct an environmental scoping process 21 which began a 30-day scoping comment period, and to prepare a supplemental EIS (90 FR 22 21952-TN12524). A summary of the scoping process and the comments received during the 23 scoping period is available in Appendix A.

24 To independently verify the information provided in the ER, the NRC staff conducted an 25 environmental audit the week of July 14, 2025 (NRC 2025-TN12525). During the audit, the NRC 26 staff held meetings with nuclear power plant personnel and reviewed plant-specific 27 documentation and photos. The NRC staff captured the findings from the audit in a summary 28 dated August 6, 2025 (NRC 2025-TN12526). Duke provided responses to the NRCs audit 29 requests in a letter dated September 8, 2025 (Duke 2025-TN12519).

30 Upon the completion of the scoping period and the environmental audit, the NRC staff compiled 31 its assessments and initial findings in this draft EIS. This draft EIS is made available for public 32 comment for 45 days. Based on the information gathered, the NRC staff will amend the draft 33 EIS findings, as necessary, and publish a final EIS. Figure 1-1 shows the major milestones of 34 the NRCs subsequent license renewal application environmental review process.

35

1-3 1

Figure 1-1 Environmental Review Process for Subsequent License Renewal of Nuclear 2

Power Plants 3

1.4 Generic Environmental Impact Statement 4

The 2024 LR GEIS was published in August 2024 (NRC 2024-TN10161). The 2024 LR GEIS 5

(Revision 2) updated the issues and findings of the 2013 LR GEIS (Revision 1) (NRC 2013-6 TN2654). Lessons learned and knowledge gained from initial license renewal and subsequent 7

license renewal environmental reviews provided an important source of new information for this 8

assessment. In addition, new research, findings, public comments, changes in applicable laws 9

and regulations, and other information were considered in evaluating the environmental impacts 10 associated with license renewal for the 2024 LR GEIS. The purpose of the 2024 LR GEIS was 11 to identify and evaluate environmental issues for license renewal and determine which issues 12 could result in the same or similar impact at all nuclear power plants or a specific subset of 13 plants (i.e., generic or Category 1 issues) and which issues could result in different levels of 14 impact (i.e., plant-specific or Category 2 issues, or uncategorized). The 2024 LR GEIS also 15 provides descriptions of replacement power alternatives and their environmental impacts to 16 each resource area that would be associated with their construction and operation.

17 On August 6, 2024, the NRC published a final rule (89 FR 64166-TN10321) revising its 18 environmental protection regulations in 10 CFR Part 51. Specifically, the final rule updated the 19 potential environmental impacts associated with the renewal of an operating license for a 20 nuclear power plant for up to an additional 20 years, which could either be an initial or a 21 subsequent license renewal. Table B-1 in Appendix B to Subpart A of 10 CFR Part 51, 22 Environmental Effect of Renewing the Operating License of a Nuclear Power Plant (TN10253),

23 provides a summary of the NRC staffs findings for license renewal environmental issues as 24 evaluated in the 2024 LR GEIS (NRC 2024-TN10161), which provided the technical basis for 25 the final rule. The 2024 LR GEIS and final rule identified 80 environmental issues (i.e., 59 26 Category 1 issues, 20 Category 2 issues, and 1 issue that remains uncategorized) that may be 27 associated with nuclear power plant operations and refurbishment during an initial or a 28 subsequent license renewal term.

29

1-4 Table B-1 of 10 CFR Part 51 (TN10253), Appendix B to Subpart A, defines three levels of 1

significance for potential impact findings for environmental issues: SMALL, MODERATE, and 2

LARGE, which are defined below.

3 SMALL: Environmental effects are not detectable or are so minor that they will neither 4

destabilize nor noticeably alter any important attribute of the resource. For the purposes 5

of assessing radiological impacts, the Commission has concluded that those impacts 6

that do not exceed permissible levels in the Commissions regulations are considered 7

SMALL.

8 MODERATE: Environmental effects are sufficient to alter noticeably, but not to 9

destabilize, important attributes of the resource.

10 LARGE: Environmental effects are clearly noticeable and are sufficient to destabilize 11 important attributes of the resource.

12 These levels are used for describing the environmental impacts of the proposed action as well 13 as the environmental impacts of alternatives to the proposed action. Resource-specific effects 14 or impact definitions from applicable environmental laws and executive orders, other than 15 SMALL, MODERATE, and LARGE, are used instead where appropriate.

16 Issues are assigned a Category 1 (generic to all or a distinct subset of plants) or a Category 2 17 (plant-specific) designation. Category 1 issues are those that meet all the following criteria:

18

• The environmental impacts associated with the issue have been determined to apply either 19 to all plants or, for some issues, to plants having a specific type of cooling system or other 20 specified plant or site characteristic.

21

• A single significance level (i.e., SMALL, MODERATE, or LARGE) has been assigned to the 22 impacts (except for offsite radiological impacts of spent nuclear fuel and high-level waste 23 disposal and offsite radiological impactscollective impacts from other than the disposal of 24 spent fuel and high-level waste).

25

• Mitigation of adverse impacts associated with the issue has been considered in the analysis, 26 and it has been determined that additional plant-specific mitigation measures are not likely 27 to be sufficiently beneficial to warrant implementation.

28 For generic issues (Category 1), an EIS that supplements the LR GEIS (NRC 2024-TN10161) 29 requires no additional plant-specific evaluation unless new and significant information has been 30 identified.

31

• New information can be identified from many sources, including the applicant, the NRC, 32 other agencies, or public comments. If a new issue is revealed, it is first analyzed to 33 determine whether it is within the scope of the license renewal environmental review. If the 34 new issue is in scope, the NRC staff would determine the significance of the issue and 35 document that analysis in the EIS.

36

• New and significant information either identifies an environmental issue that was not 37 covered in the LR GEIS or was not considered in the analysis in the LR GEIS and leads to 38 an impact finding that is different from the finding presented in the LR GEIS.

39

1-5 Plant-specific issues (Category 2) are those that do not meet one or more of the three criteria of 1

Category 1 issues; therefore, an EIS requires plant-specific review for these issues.

2 Figure 1-2 illustrates the subsequent license renewal environmental review process. The results 3

of the plant-specific review are documented in this EIS.

4 5

Figure 1-2 Environmental Issues Evaluated for Subsequent License Renewal of 6

Nuclear Power Plants 7

1.5 Supplemental Environmental Impact Statement 8

This EIS supplements the LR GEIS to present an analysis that considers the environmental 9

effects of the continued operation of RNP during the subsequent license renewal term, 10 alternatives to subsequent license renewal, and mitigation measures for minimizing adverse 11 environmental impacts. Chapter 2 describes the RNP site and its operation, the proposed action 12 (subsequent renewal of the RNP renewed license), and alternatives to the proposed action.

13 Chapter 3 contains an analysis of the potential environmental impacts from the proposed action.

14 Chapter 4 presents the preliminary recommendation of the NRC staff on whether the adverse 15 environmental impacts of subsequent license renewal for RNP are so great that preserving the 16 option of subsequent license renewal for energy-planning decision-makers would be 17 unreasonable. Details regarding any exemptions implemented by the NRC staff as part of this 18 analysis are presented in Appendix B, Applicable Laws, Regulations, and Other Requirements.

19 The NRC staff based its preliminary recommendation on:

20

• the analysis and findings in the 2024 LR GEIS 21

• the applicants ER 22

• the NRC staffs consultation with Federal, State, and local agencies and Indian Tribes 23

• the NRC staffs independent environmental review 24

1-6

• the NRC staffs consideration of public comments received during the scoping process 1

The NRC staffs final recommendation will be made after consideration of public comments 2

received on the draft EIS during the public comment period.

3 1.6 Decision to Be Supported by the Supplemental Environmental Impact 4

Statement 5

The decision to be supported by this EIS supplementing the LR GEIS is whether to 6

subsequently renew the RNP renewed license for an additional 20 years. The regulation in 7

10 CFR 51.103(a)(5) (TN10253) that specifies the NRCs environmental review decision 8

standard states the following:

9 In making a final decision on a license renewal action pursuant to Part 54 of this chapter, 10 the Commission shall determine whether or not the adverse environmental impacts of 11 license renewal are so great that preserving the option of license renewal for energy 12 planning decision-makers would be unreasonable.

13 There are many factors that the NRC takes into consideration when deciding whether to renew 14 the operating license of a nuclear power plant. The analyses of environmental impacts 15 evaluated in the LR GEIS, as supplemented by this EIS, will provide the NRCs decision-maker 16 (i.e., the Commission) with important environmental information for consideration in deciding 17 whether to subsequently renew the RNP renewed license.

18 1.7 Cooperating Agencies 19 During the scoping process, the NRC staff did not identify any Federal, State, or local agencies 20 or Indian Tribes as cooperating agencies for this EIS.

21 1.8 Required Consultations 22 License renewal environmental reviews may require consultation with other Federal, State, 23 regional, and local agencies and Indian Tribes. For license renewal, the NRC staff must 24 consider the effects of its actions on ecological resources protected under Federal statutes, 25 including the Endangered Species Act of 1973 (TN1010), as amended (ESA), and the 26 Magnuson-Stevens Fishery Conservation and Management Act of 1976 (TN9966), as 27 amended. Section 106 of National Historic Preservation Act of 1966 (TN4839), as amended 28 (NHPA) requires Federal agencies to take into account the effects of their undertakings on 29 historic properties. Appendix D presents a list of the agencies and groups with which the NRC 30 staff consulted and a description of the consultations and related correspondence.

31 1.9 Correspondence 32 Appendix D and Appendix E chronologically list correspondence that the NRC staff sent and 33 received with external parties as part of the agencys environmental review of the RNP 34 subsequent license renewal application, excluding the consultation correspondence listed in 35 Appendix C and the public comment discussed in Appendix A.

36

1-7 1.10 Status of Compliance 1

Duke is responsible for complying with all NRC regulations and other applicable Federal, State, 2

and local requirements. Appendix F to the LR GEIS describes some of the major applicable 3

Federal statutes (NRC 2024-TN10161). Numerous permits and licenses are issued by Federal, 4

State, and local authorities for activities at RNP. Appendix B contains further information about 5

Dukes status of compliance.

6

2-1 2

THE PROPOSED FEDERAL ACTION AND THE 1

NO-ACTION ALTERNATIVE 2

This chapter describes (1) RNP and its operation, (2) the proposed Federal action (subsequent 3

renewal of the RNP renewed license), (3) alternatives to the proposed action, (4) the no-action 4

alternative, and (5) the environmental impacts of the proposed action as compared to those of 5

the no-action alternative.

6 2.1 Description of Nuclear Power Plant Facility and Operation 7

The NRC staff incorporates by reference herein the information in Section 2.2 of the ER (Duke 8

2025-TN12518) describing the system and operations of RNP.

9 RNP is a single-unit nuclear power plant located in northeastern South Carolina, approximately 10 5 miles (mi) (8 kilometers [km]) west-northwest of Hartsville. RNP is located on the shore of 11 Lake Robinson, in Darlington County. RNP was originally constructed, licensed, and operated 12 by Carolina Power & Light (CP&L) (NRC 2003-TN7260). CP&L was acquired by Progress 13 Energy, which later merged with Duke, the plants current owner and operator (Duke 2012-14 TN12527).

15 Previously, the RNP site contained two generating units. Unit 1 was a coal plant that began 16 operation in 1960. Unit 1 ceased operation in 2012, and has been undergoing decommissioning 17 with completed demolition and removal of former Unit 1 power block structures (Duke 2025-18 TN12518).

19 Unit 2 is a single-unit nuclear plant. The nuclear steam supply system is a pressurized water 20 reactor with three steam generators. Unit 2 began commerical operation in 1970. The current 21 renewed facility operating license for Unit 2 expires at midnight on July 31, 2030.

22 2.1.1 External Appearance and Setting 23 Chapter 2 of the ER (Duke 2025-TN12518) includes a detailed description of the external 24 appearance and setting of the RNP site. This description includes the following areas: reactor 25 and containment systems, maintenance, inspection, and refueling activities, cooling and 26 auxiliary water systems, power transmission systems, radioactive waste management systems, 27 and non-radioactive waste management systems.

28 RNP is located approximately 5 mi (8 km) west-northwest of Hartsville, South Carolina. The 29 RNP site encompasses approximately 5,900 acres (ac) (2,400 hectares [ha]) of Dukes property 30 in northwestern Darlington and southwestern Chesterfield Counties, including the 2,250 ac 31 (910 ha) Lake Robinson. As a result, the eastern side of Lake Robinson is developed with 32 homes, recreational areas, a marina, and public access points. Duke leases the northern portion 33 of its property to the State of South Carolina, which manages it in conjunction with its adjacent 34 Sandhills State Forest. Duke manages the balance of the undeveloped property for timber 35 production. Figure 2-1 shows the structures within the RNP site boundary.

36 The principal structures at RNP are the following: reactor containment building (Unit 2), turbine 37 building, and switchyards.

38

2-2 1

Figure 2-1 Map Showing the H.B. Robinson Steam Electric Plant Layout. Source: Duke 2

2025-TN12518.

3 2.2 Proposed Federal Action 4

As stated in Section 1.1, the proposed Federal action is to determine whether to issue a 5

subsequent renewed facility operating license for RNP for an additional 20 years, which would 6

authorize Duke to operate Unit 2 from July 31, 2030 to July 31, 2050 (i.e., the subsequent 7

license renewal term). Section 2.2.1 provides a description of normal nuclear power plant 8

operations during the subsequent license renewal term.

9

2-3 2.2.1 Nuclear Power Plant Operations during the Subsequent License Renewal Term 1

Nuclear power plant operations during the subsequent license renewal term would be the same 2

as, or similar to, those occurring during the current renewed license term. Section 2.2 of the ER 3

describes the general types of activities carried out during nuclear power plant operations. The 4

ER states that, There are no plans associated with subsequent license renewal to modify the 5

facility or its administrative controls other than the procedures necessary to implement the aging 6

management programs described in the integrated plant assessment (IPA) (Duke 2025-7 TN12518). Such programs would address structure and component aging in accordance with 8

10 CFR Part 54 (TN4878), Requirements for Renewal of Operating Licenses for Nuclear Power 9

Plants.

10 2.2.2 Refurbishment and Other Activities Associated with License Renewal 11 Refurbishment activities include replacement and repair of major systems, structures, and 12 components. The major refurbishment class of activities characterized in the LR GEIS (NRC 13 2024-TN10161) is intended to encompass actions that typically take place only once in the life 14 of a nuclear plant, if at all. Examples of these activities include, but are not limited to, 15 replacement of turbines and pressurized water reactor steam generators. These actions may 16 have an impact on the environment beyond those that occur during normal operations and may 17 require evaluation, depending on the type of action and the plant-specific design. Section 2.3 of 18 the ER (Duke 2025-TN12518) has identified no subsequent license renewal-related 19 refurbishment or replacement actions needed to maintain the functionality of systems, 20 structures, and components, consistent with the current licensing basis, during the proposed 21 subsequent license renewal operating term. Therefore, such activities are not discussed as part 22 of the analysis of the environmental impacts of the proposed action in Chapter 3.

23 2.2.3 Termination of Nuclear Power Plant Operations and Decommissioning After the 24 Subsequent License Renewal Term 25 NUREG-0586, Supplement 1, Volumes 1 and 2, Generic Environmental Impact Statement on 26 Decommissioning of Nuclear Facilities: Regarding the Decommissioning of Nuclear Power 27 Reactors: Final Report (the Decommissioning GEIS) (NRC 2002-TN665), describes the 28 environmental impacts of decommissioning. The majority of plant operational activities would 29 cease with reactor shutdown. However, some activities (e.g., security and oversight of spent 30 nuclear fuel) would remain unchanged, whereas others (e.g., waste management, 31 administrative work, laboratory analysis, surveillance, monitoring, and maintenance) would 32 continue at reduced or altered levels. Systems dedicated to reactor operations would cease 33 operations. However, if these systems are not removed from the site after reactor shutdown, 34 their physical presence may continue to affect the environment. Impacts associated with 35 dedicated systems that remain in place, or with shared systems that continue to operate at 36 normal capacities, could remain unchanged.

37 Decommissioning will occur whether RNP is shut down at the end of its current renewed license 38 or at the end of the subsequent license renewal term 20 years later. The LR GEIS concludes 39 that subsequent license renewal would have a negligible (SMALL) effect on the impacts of 40 terminating operations and decommissioning on all resources and that this is a Category 1 issue 41 generic to all plants (NRC 2024-TN10161).

42

2-4 2.3 Alternatives 1

NEPA Section 102(2)(C)(iii) requires discussion of a reasonable range of alternatives to 2

the proposed action be included in EISs. These discussions should include an analysis of any 3

negative environmental impacts of not implementing the proposed action (i.e., the no-action 4

alternative) that are technically and economically feasible and meet the purpose and need of the 5

proposal. For license renewal, the NRCs decision-making authority is limited to deciding 6

whether or not to issue renewed licenses for nuclear power plants; therefore, there are no 7

alternatives to that proposed action that meet the purpose and need of the proposed action.

8 However, as part of its analysis of the no-action alternative, the NRC staff evaluates the 9

environmental impacts of a reasonable range of replacement power alternatives. For a 10 replacement power alternative to be considered reasonable, it must be either (1) commercially 11 viable on a utility scale and operational before the reactors operating license expires or 12 (2) expected to become commercially viable on a utility scale and operational before the 13 reactors operating license expires. Comparing the environmental impacts of issuing the 14 subsequent renewed license for RNP to the environmental impacts of the potential 15 consequences of not issuing the license (i.e., the environmental impacts of the construction and 16 operation of reasonable replacement power alternatives under the no-action alternative) helps 17 inform the NRCs determination under 10 CFR 51.103(a)(5) of whether or not the adverse 18 environmental impacts of RNPs subsequent license renewal are so great that preserving the 19 option of subsequent license renewal for energy-planning decision-makers would be 20 unreasonable (TN10253). The ultimate decision about which energy alternative(s) to implement, 21 which may include the continued operation of nuclear power plants that are issued renewed 22 licenses, falls to the power plant owners and State, utility, system, and, where authorized, 23 Federal (other than NRC) energy-planning decision-makers.

24 The no-action alternative and its negative environmental impacts from the shutdown of RNP and 25 from the construction and operation of reasonable replacement power alternatives are 26 described in Section 2.4. For the discussion therein regarding replacement power alternatives, 27 the NRC staff relied upon the description of replacement power sources in Sections 2.3 and 2.4 28 and Appendix D of the LR GEIS (NRC 2024-TN10161) and Sections 2.6.2, 7.2.3, and 8.0 of the 29 ER (Duke 2025-TN12518). Accordingly, that information is incorporated by reference into this 30 EIS. In this manner, this EIS satisfies NEPA Section 102(2)(C)(iii) and supports its dual 31 mandates to foster both informed decision-making and informed public participation.

32 2.4 No-Action Alternative and New Energy Generation 33 Under the no-action alternative, the NRC would not subsequently renew the RNP renewed 34 license, and the reactor unit would shut down on or before the current license expiration date of 35 July 31, 2030.

36 After termination of reactor operations, nuclear power plant operators would initiate 37 decommissioning in accordance with NRC regulations in 10 CFR 50.82 (TN249), Termination 38 of License. The NRCs Decommissioning GEIS (NRC 2002-TN665) describes the 39 environmental impacts of decommissioning activities at a nuclear power plant. The analyses 40 and findings in the Decommissioning GEIS bound the environmental impacts of most of the 41 plant-specific decommissioning activities that would likely take place after Duke terminates 42 reactor operations at RNP. A licensee must also assess in its post-shutdown decommissioning 43 activities report required by the NRCs regulations whether the environmental effects of planned 44 site-specific activities would be bounded by the impacts described in previously issued EISs.

45 Section 2.2.3 describes the incremental environmental effects of subsequent license renewal on 46

2-5 decommissioning activities. As part of its analysis of the negative environmental impacts of the 1

no-action alternative, the NRC staff summarizes in Table 2-1 the Impacts of RNP Shutdown on 2

each applicable resource area.

3 Termination of reactor operations would also result in the total cessation of electrical power 4

generation at RNP. Based on the reasonable assumption that there would be a need to 5

generate power to meet future electrical system needs, the no-action alternative (not 6

subsequently renewing the renewed license) would necessitate the construction and operations 7

of energy alternatives within the RNP service territory to replace the electrical power no longer 8

being generated by RNP. Therefore, as part of its analysis of the negative impacts of the 9

no-action alternative, in addition to the Impacts of RNP Shutdown, the NRC staff evaluated the 10 impacts of the construction and operations of New Energy Generating Assets and summarizes 11 those impacts in Table 2-1.

12 Based on an independent review of the Duke service area, as well as the information in the ER 13 and the LR GEIS, the NRC staff determined which replacement power alternatives would be 14 reasonable and, therefore, appropriate for consideration under the no-action alternative. The 15 NRC staff concluded that for the no-action alternative to RNPs subsequent license renewal, the 16 reasonable replacement power alternatives/new energy generation are new nuclear (e.g., a 17 small modular reactor) or a natural gas combined cycle plant with carbon capture sequestration 18 technology located at the RNP site (Duke 2025-TN12518: Section 2.6.2). These technologies 19 were considered to be reasonable based on the following criteria:

20

• The need to replace the electrical power generation of RNP (approximately 774 megawatts 21 electric annually) for reliable electricity availability to maintain power grid supply reliably.

22

• The need to be fully operational by July 31, 2030, when RNPs current renewed license 23 expires, taking into consideration the development of the technology, permitting, 24 construction of the facility or facilities, and connection to the grid.

25

• The need to be or be expected to be technically feasible and commercially viable on a utility 26 scale.

27 In reaching its conclusion regarding which replacement power alternatives/new energy 28 generation were reasonable and in its evaluation of the negative environmental impacts of those 29 technologies, the NRC staff particularly considered the specific attributes of the replacement 30 power alternatives/new energy generation as described in Sections 2.3 and 2.4 and Appendix D 31 of the LR GEIS (NRC 2024-TN10161).

32 2.5 Comparison of Environmental Impacts of the Proposed Federal Action and 33 the Alternatives 34 Based on the analysis and findings in the LR GEIS; the ER; its consultation with Federal, State, 35 and local government agencies and Indian Tribes; its independent environmental review; and its 36 consideration of public comments, the NRC staff determined the environmental impacts of the 37 proposed Federal action, as described in Chapter 3, and the environmental impacts of the no-38 action alternative (i.e., the environmental impacts of RNP shutdown and the construction and 39 operation of new energy generating assets), including the impacts from new energy generation 40 from alternatives deemed reasonable, on each applicable resource area. For the environmental 41 impacts of the no-action alternative, and new energy generation from alternatives deemed 42 reasonable, the NRC staff specifically relied upon Sections 2.3 and 2.4 and Appendix D of the 43

2-6 LR GEIS (NRC 2024-TN10161) and Sections 2.6.2, 7.2.3, and Chapter 8.0 of the ER (Duke 1

2025-TN12518), incorporated by reference herein.

2 The NRC staff assigned to each resource area an environmental impact significance level of 3

SMALL, MODERATE, or LARGE, as defined in this EIS and in the NRCs regulations, or, as 4

applicable, the appropriate resource specific effects or impact definitions from environmental 5

laws and executive orders. The results of the NRC staffs analysis of the environmental impacts 6

of the proposed action and the no-action alternative, including the impacts from new energy 7

generation from alternatives deemed reasonable are summarized in Table 2-1 and are 8

presented so that they may be compared. This comparison supports both informed 9

decision-making and informed public participation. Descriptions of the resource areas can be 10 found in the LR GEIS (NRC 2024-TN10161).

11 If the NRC does not subsequently renew the RNP renewed operating license (no-action 12 alternative), energy-planning decision-makers would have to choose a replacement power 13 alternative similar to the ones evaluated in this supplemental EIS. Replacement power 14 alternatives have the potential to have greater environmental impacts in any number of the 15 applicable resource areas. Based on the review of the proposed action, the no-action 16 alternative, and replacement power alternatives, the environmentally preferred alternative is the 17 proposed subsequent license renewal action. Therefore, the NRC staffs recommendation is to 18 renew the RNP operating license.

19 Table 2-1 Comparison of Environmental Impacts of the Proposed Federal Action and 20 the No-Action Alternative at the H.B. Robinson Steam Electric Plant 21 Resource Area Proposed Federal Action No-Action Alternative (Impacts of RNP Shutdown)

No-Action Alternative (Impacts of New Energy Generation)

Land Use SMALL SMALL. Onsite land use would remain similar to onsite land use under the proposed SLR.

Plant structures and other facilities would remain in place until decommissioning.

Transmission lines and ROWs would remain in place after the cessation of reactor operations.

SMALL. New energy generating facilities would be placed on the existing RNP site, both requiring under 50 ac (not including construction staging or support infrastructure). For the SMR, no additional offsite transmission lines are required and for the natural gas alternative, an existing pipeline exists and would require an extension thus minimizing impacts from new utility corridors.

Visual Resources SMALL SMALL. Termination of reactor operations because the operating license is not renewed would not immediately change the visual appearance of the RNP site.

The most visible structures would likely remain in place for some time during decommissioning until they are eventually dismantled.

SMALL. New energy generating facilities would be placed on the existing industrial site where the surrounding area is sparsely populated and rural. The tallest structures would be similar to or less than the height of the tallest structures of the existing facility.

2-7 Resource Area Proposed Federal Action No-Action Alternative (Impacts of RNP Shutdown)

No-Action Alternative (Impacts of New Energy Generation)

Air Quality SMALL SMALL. The permanent cessation of RNP operations would reduce overall air emissions from activities related to plant operation, such as from the use of auxiliary boiler and worker vehicles).

SMALL to MODERATE.

Construction of new energy generating facilities would result in temporary air quality impacts.

Depending on the type of new energy generation, air emissions can be considerable.

New natural gas combined cycle units would result in considerable new pollutant emission levels.

Noise SMALL SMALL. The permanent cessation of RNP operations would result in a reduction in noise associated with from onsite sources (e.g., main steam safety relief valves) and vehicle traffic (e.g., workers, deliveries). As site activities are reduced, NRC staff expects the impact on ambient noise levels to be lower than those from current plant operations.

SMALL. Noise associated with new generation would occur during construction. Noise associated with construction activities would be intermittent and temporary. The new facility would be located on the RNP site. Therefore, noise levels associated with operations of a new facility would be similar to noise levels from current plant operations of RNP.

Geologic Environment SMALL SMALL. There would be few or no incremental impacts on site geology and soils associated with the shutdown of RNP. In this case, before beginning decommissioning activities, little or no new ground disturbance would occur at the plant site while operational activities were being reduced and eventually terminated.

SMALL to MODERATE. Ground disturbance would occur during construction of new generating facilities, regardless of whether the new facility is sited on a brownfield or greenfield site.

Depending on the location of the facilities, impacts to prime or important farmlands could occur.

Water Resources SMALL SMALL. Water withdrawals would greatly decrease and eventually cease. Stormwater would continue to be discharged from the site, but wastewater discharges would be reduced considerably.

SMALL to MODERATE.

Impacts would occur associated with construction of all new energy generating facilities.

SMRs and natural gas facilities could have cooling water requirements similar to those of the existing RNP plant. Use of existing infrastructure would minimize construction impacts.

Terrestrial Resources SMALL SMALL. Much of the operational noise and human activity at RNP would cease, thereby reducing disturbances to wildlife in forest cover and other natural vegetation on SMALL to MODERATE.

Impacts would depend on the location and footprint of the new generating facility and would be minimized through the use of best management practices and

2-8 Resource Area Proposed Federal Action No-Action Alternative (Impacts of RNP Shutdown)

No-Action Alternative (Impacts of New Energy Generation) and near the site. Reducing human activity and frequency of operational noise may constitute minor beneficial effects on wildlife inhabiting nearby natural habitats.

adherence to applicable regulations. Use of existing infrastructure would minimize construction impacts.

Aquatic Resources SMALL to MODERATE SMALL. Some withdrawal of water would continue during the shutdown period to provide cooling to spent fuel in the spent fuel pool until that fuel could be transferred to dry storage. The amount of water withdrawn for these purposes would be a small fraction of water withdrawals during operations, would decrease over time, and would likely end within the first several years following shutdown. The reduced demand for cooling water would substantially decrease the effects of impingement, entrainment, and thermal effluent on aquatic organisms, and these effects would entirely cease following the transfer of spent fuel to dry storage.

SMALL to MODERATE.

Impacts would depend on the location and footprint of the new generating facility and would be minimized through the use of best management practices and adherence to applicable regulations. Use of existing infrastructure would minimize construction impacts.

Federally Protected Ecological Resources TBD(a)

Overall, the effects on federally listed species would likely be smaller under the no-action alternative than the effects under continued operation but would depend on the specific shutdown activities as well as the listed species present.

NO EFFECT to NOT LIKELY TO ADVERSELY AFFECT.

Impacts on federally protected species would depend on the location of the new generating facilities, the effects of these facilities on protected species (e.g., cooling water discharges),

and the presence of protected species on such sites.

Consultation with appropriate agencies would be conducted and would minimize impacts.

2-9 Resource Area Proposed Federal Action No-Action Alternative (Impacts of RNP Shutdown)

No-Action Alternative (Impacts of New Energy Generation)

Historic and Cultural Resources No adverse effect on historic properties No effect on historic properties or historic and cultural resources.

Impacts would depend on the presence of historic properties on sites selected for new generating facilities and could be less for brownfield sites.

Compliance with best management practices and Section 106 of the NHPA and consultation with potentially affected Indian Tribes would minimize impacts.

Socioeconomics SMALL SMALL to LARGE. The loss of jobs, income, and tax revenue would have an immediate, noticeable socioeconomic impact. As jobs are eliminated, some, but not all, workers could leave. Income from the buying and selling of goods and services needed to maintain the nuclear power plant would also be reduced.

In addition, loss of tax revenue could affect the availability of public services. If workers and their families move away, increased vacancies and reduced demand for housing would likely cause property values to fall.

SMALL to MODERATE. The closure of RNP would result in a loss of jobs in the surrounding area and potentially adverse indirect impacts on taxes, housing, land use, and public services. Construction and operation of new energy-generating facilities onsite could offset negative impacts as an increased temporary workforce would be needed for construction.

Previous RNP employees could also be hired for new facility operations.

Human Health SMALL and UNCERTAIN(b)

SMALL. Human health risks would be smaller following nuclear power plant shutdown.

The reactor unit, which currently operates within regulatory limits, would emit less radioactive gaseous, liquid, and solid material to the environment. In addition, following shutdown, the variety of potential accidents at the nuclear power plant (radiological or industrial) would be reduced to a limited set associated with shutdown events and fuel handling and storage.

SMALL and UNCERTAIN.

Construction of new generating facilities could result in temporary human health impacts. Operation of these facilities could have human health impacts that would be mitigated by adherence to best management practices, safety standards, and applicable regulations. Given the regulatory oversight exercised by the EPA and State agencies, the NRC staff concludes that the human health impacts from the alternatives presented in the ER, as supplemented, would be SMALL, except for chronic effects of electromagnetic fields (EMFs), for which the impacts are UNCERTAIN. Human health impacts are discussed in

2-10 Resource Area Proposed Federal Action No-Action Alternative (Impacts of RNP Shutdown)

No-Action Alternative (Impacts of New Energy Generation)

Section D.4.8 of the LR GEIS (NRC 2024-TN10161).

Waste Management SMALL(c)

SMALL. The variety of potential accidents at the nuclear power plant (radiological and industrial) would be reduced to a limited set associated with shutdown events and fuel handling and storage.

SMALL. The amount and types of waste generated would depend on the size and type of the new generating facility.

Impacts would be minimized by adherence to best management practices and proper onsite management and offsite disposal management.

Greenhouse Gas Emissions SMALL SMALL. The permanent cessation of RNP operations would reduce overall greenhouse emissions from activities related to plant operation, such as the use of boilers and employee vehicles would occur.

SMALL. Replacement power from a small modular alternative would result in similar greenhouse gas emissions from operation of RNP. The natural gas combined cycle alternative would consist of carbon capture storage technology with a 90 percent capture rate.(d)

EMF = electromagnetic field; EPA = U.S. Environmental Protection Agency; ER = environmental report; LR GEIS= License Renewal Generical Environmental Impact Statement; NHPA = National Historic Preservation Act of 1966; RNP = H.B. Robinson Steam Electric Plant, Unit 2; SLR = subsequent license renewal; SMR = small modular reactor; TBD = to be determined.

(a) The NRC will seek the FWSs concurrence following the issuance of this draft EIS.

(b) The chronic effects of electromagnetic fields on human health associated with operating nuclear power and other electricity generating plants are uncertain as discussed in Section 3.8.3.

(c) NUREG-2157, Generic Environmental Impact Statement for Continued Storage of Spent Nuclear Fuel (NRC 2014-TN4117), discusses the environmental impacts of spent fuel storage beyond reactor operations.

(d) Estimated carbon dioxide emissions for the natural gas combined cycle alternative with carbon capture sequestration technology are presented in Table 7.2-1 of the ER (Duke 2025-TN12518).

1

3-1 3

AFFECTED ENVIRONMENT AND ENVIRONMENTAL 1

CONSEQUENCES 2

3.1 Introduction 3

As outlined in Sections 1.4 and 1.5, this EIS documents the NRC staffs evaluation of the 4

reasonably foreseeable environmental impacts of the proposed Federal action of determining 5

whether to issue a subsequent renewed facility operating license for RNP for an additional 6

20 years. This environmental review is based on the analysis and findings in the LR GEIS; the 7

applicants subsequent license renewal application (Duke 2025-TN12522); the NRC staffs 8

consultation with Federal, State, and local agencies, and Indian Tribes; the NRC staffs 9

independent environmental review; and the NRC staffs consideration of public comments. This 10 EIS is a supplement to the LR GEIS (NRC 2024-TN10161). The LR GEIS identifies 80 issues 11 (divided into 59 Category 1 [generic to all plants], 20 Category 2 [nuclear plant-specific], and 1 12 uncategorized issue) to be evaluated, as applicable, for license renewal of nuclear plants.

13 Those issues applicable to RNP subsequent license renewal are discussed below, either 14 generically or on a site-specific basis, as appropriate, and, based on that discussion, assigned 15 an environmental impact significance level of SMALL, MODERATE, or LARGE, as defined in 16 this EIS and in the NRCs regulations, or, as applicable, the appropriate resource-specific effects 17 or impact definitions from environmental laws and executive orders.

18 3.1.1 Category 1 Issues 19 As explained in Section 1.4, for applicable Category 1 (generic to all or a distinct subset of 20 plants) issues, the NRC staff relies on the analysis presented in the LR GEIS (NRC 2024-21 TN10161), unless new and significant information has been identified.

22 With respect to the proposed action, the NRC staff conducted an independent review consistent 23 with NUREG-1555, Supplement 1, Revision 2, Standard Review Plans for Environmental 24 Reviews for Nuclear Power Plants: Operating License Renewal (NRC 2024-TN10251) for 25 identifying new and significant information, which included, but was not limited to the following:

26

• review of the applicants ER (Duke 2025-TN12518) and the process described therein for 27 discovering and evaluating the significance of new information 28

• audits with the applicant 29

• review of public comments 30

• review of environmental quality standards and regulations 31

• coordination with Federal, State, and local environmental protection and resource agencies 32 and Indian Tribes 33

• review of technical literature 34 As a result of this review, the NRC staff did not identify any new and significant information for 35 applicable Category 1 issues. Therefore, the NRC staff concluded that no additional 36 plant-specific evaluation was required for these issues. These issues, the related sections of the 37 LR GEIS, and the impact findings are provided in Table 3-1. Consistent with its regulations, the 38 NRC staff adopts the conclusions of the LR GEIS for these issues in this EIS.

39

3-2 Table 3-1 Applicable Category 1 (Generic) Issues for the H.B. Robinson Steam Electric 1

Plant 2

Environmental Category - Issue LR GEIS Section Impact Finding Land Use - Onsite land use 4.2.1.1.1 SMALL Land Use - Offsite land use 4.2.1.1.2 SMALL Visual Resources - Aesthetic impacts 4.2.1.2.1 SMALL Air Quality - Air quality impacts 4.3.1.1.1 SMALL Air Quality - Air quality effects of transmission lines 4.3.1.1.2 SMALL Noise - Noise impacts 4.3.1.2.1 SMALL Geologic Environment - Geology and soils 4.4.1.1 SMALL Surface Water Resources - Surface water use and quality (non-cooling system impacts) 4.5.1.1.1 SMALL Surface Water Resources - Altered current patterns at intake and discharge structures 4.5.1.1.2 SMALL Surface Water Resources - Altered Thermal Stratification of Lakes 4.5.1.1.4 SMALL Surface Water Resources - Scouring caused by discharged cooling water 4.5.1.1.5 SMALL Surface Water Resources - Discharge of metals in cooling system effluent 4.5.1.1.6 SMALL Surface Water Resources - Discharge of biocides, sanitary wastes, and minor chemical spills 4.5.1.1.7 SMALL Surface Water Resources - Effects of dredging on surface water quality 4.5.1.1.10 SMALL Surface Water Resources - Temperature effects on sediment transport capacity 4.5.1.1.11 SMALL Groundwater Resources - Groundwater contamination and use (non-cooling system impacts) 4.5.1.2.1 SMALL Groundwater Resources - Groundwater quality degradation resulting from water withdrawals 4.5.1.2.5 SMALL Terrestrial Resources - Exposure of terrestrial organisms to radionuclides 4.6.1.1.2 SMALL Terrestrial Resources - Cooling system impacts on terrestrial resources (plants with once-through cooling systems or cooling ponds) 4.6.1.1.3 SMALL Terrestrial Resources - Bird collisions with plant structures and transmission lines 4.6.1.1.5 SMALL Terrestrial Resources - Transmission line right-of-way (ROW) management impacts on terrestrial resources 4.6.1.1.7 SMALL Terrestrial Resources - Electromagnetic fields effects on terrestrial plants and animals 4.6.1.1.8 SMALL Aquatic Resources - Entrainment of phytoplankton and zooplankton 4.6.1.2.3 SMALL Aquatic Resources - Infrequently reported effects of thermal effluents 4.6.1.2.6 SMALL Aquatic Resources - Effects of nonradiological contaminants on aquatic organisms 4.6.1.2.7 SMALL Aquatic Resources - Exposure of aquatic organisms to radionuclides 4.6.1.2.8 SMALL Aquatic Resources - Effects of dredging on aquatic resources 4.6.1.2.9 SMALL Aquatic Resources - Non-cooling system impacts on aquatic resources 4.6.1.2.11 SMALL Aquatic Resources - Impacts of transmission line right-of-way (ROW) management on aquatic resources 4.6.1.2.12 SMALL Socioeconomics - Employment and income, recreation, and tourism 4.8.1.1 SMALL

3-3 Environmental Category - Issue LR GEIS Section Impact Finding Socioeconomics - Tax revenue 4.8.1.2 SMALL Socioeconomics - Community services and education 4.8.1.3 SMALL Socioeconomics - Population and housing 4.8.1.4 SMALL Socioeconomics - Transportation 4.8.1.5 SMALL Human Health - Radiation exposures to plant workers 4.9.1.1.1 SMALL Human Health - Radiation exposures to the public 4.9.1.1.1 SMALL Human Health - Chemical hazards 4.9.1.1.2 SMALL Human Health - Microbiological hazards to plant workers 4.9.1.1.3 SMALL Human Health - Physical occupational hazards 4.9.4.1.5 SMALL Postulated Accidents - Design-basis accidents 4.9.1.2.1 SMALL Postulated Accidents - Severe accidents 4.9.1.2.1 SMALL Waste Management - Low-level waste storage and disposal 4.11.1.1 SMALL Waste Management - Onsite storage of spent nuclear fuel 4.11.1.2 SMALL Waste Management - Offsite radiological impacts of spent nuclear fuel and high-level waste disposal 4.11.1.3 (a)

Waste Management - Mixed-waste storage and disposal 4.11.1.4 SMALL Waste Management - Nonradioactive waste storage and disposal 4.11.1.5 SMALL Greenhouse Gas Emissions and Climate Change - Greenhouse gas impacts on climate change 4.12.1 SMALL Uranium Fuel Cycle - Offsite radiological impactsindividual impacts from other than the disposal of spent fuel and high-level waste 4.14.1.5 SMALL Uranium Fuel Cycle - Offsite radiological impactscollective impacts from other than the disposal of spent fuel and high-level waste 4.14.1.5 (b)

Uranium Fuel Cycle - Nonradiological impacts of the uranium fuel cycle 4.14.1.5 SMALL Uranium Fuel Cycle - Transportation 4.14.1.5 SMALL Termination of Nuclear Power Plant Operations and Decommissioning 4.14.2.1 SMALL CFR = Code of Federal Regulations; RNP = H.B. Robinson Steam Electric Plant; LR GEIS = License Renewal Generic Environmental Impact Statement; NEPA = National Environmental Policy Act; ROW = right-of-way; EIS = environmental impact statement.

(a) The ultimate disposal of spent nuclear fuel in a potential future geologic repository is a separate and independent licensing action that is outside the regulatory scope of this review. Per 10 CFR Part 51 (TN10253) Subpart A, the Commission concludes that the impacts presented in NUREG-2157 (NRC 2014-TN4117), Generic Environmental Impact Statement for Continued Storage of Spent Nuclear Fuel: Final Report, Volumes 1 and 2 would not be sufficiently large to require the NEPA conclusion, for any plant, that the option of extended operation under 10 CFR Part 54 (TN4878) should be eliminated. Accordingly, while the Commission has not assigned a single level of significance for the impacts of spent nuclear fuel and high-level waste disposal, this issue is considered generic to all nuclear power plants.

(b) There are no regulatory limits applicable to collective doses to the general public from fuel cycle facilities. The practice of estimating health effects on the basis of collective doses may not be meaningful. All fuel cycle facilities are designed and operated to meet the applicable regulatory limits and standards. As stated in the LR GEIS (NRC 2024-TN10161), The Commission concludes that the impacts are acceptable in that these impacts would not be sufficiently large to require the NEPA conclusion, for any plant, that the option of extended operation under 10 CFR Part 54 should be eliminated.

Sources: Table B-1 in Appendix B to Subpart A of 10 CFR Part 51 (TN10253; NRC 2024-TN10161).

3-4 3.1.2 Category 2 Issues 1

For applicable Category 2 (plant-specific) issues, which are not bound or generically 2

dispositioned by the LR GEIS and require a plant-or site-specific review, the applicants ER 3

must contain analyses of the environmental impacts of the proposed action, including the 4

impacts of refurbishment activities, if any, associated with license renewal and the impacts of 5

operation during the renewal term in accordance with 10 CFR 51.53(c) (TN10253). In turn, the 6

NRC staffs supplemental EIS must contain an analysis of those Category 2 issues. Ultimately, 7

the NRC staffs recommendation regarding the environmental acceptability of a license renewal 8

action must be made by integrating the conclusions in the LR GEIS for applicable Category 1 9

issues, considering any new and significant information, as discussed above, with the 10 information developed for applicable Category 2 issues. This ensures both informed 11 decision-making and informed public participation.

12 With respect to the proposed action, the NRC staff evaluated the environmental impacts 13 associated with the applicable Category 2 issues on the affected environment, which is the 14 environment that currently exists at and around the RNP site. Because this environment is at 15 least partially the result of past construction and nuclear power plant operations, the NRC staffs 16 analyses considered the nature and impacts of past and ongoing actions and how, together, 17 these actions shaped the current environment. Where appropriate, the NRC staff also 18 considered reasonably foreseeable actions or projects and relevant ongoing environmental 19 trends. The NRC staffs description of the affected environment and independent evaluation of 20 the environmental consequences to that affected environment associated with applicable 21 Category 2 issues are included in Sections 3.2 through 3.9 and summarized in Table 3-2.

22 NUREG-1555 Supplement 1, Revision 2 (NRC 2024-TN10251), describes in detail the NRC 23 staffs analysis approach for Category 2 issues.

24 Table 3-2 Applicable Category 2 (Plant-specific) Issues for the H.B. Robinson Steam 25 Electric Plant 26 Environmental Category - Issue LR GEIS Section Impact Finding(a)

Surface Water Resources - Surface water use conflicts (plants with cooling ponds or cooling towers using makeup water from a river) 4.5.1.1.9 SMALL Groundwater Resources - Groundwater use conflicts (plants that withdraw more than 100 gallons per minute

[gpm])

4.5.1.2.3 SMALL Groundwater Resources - Groundwater quality degradation (plants with cooling ponds) 4.5.1.2.6 SMALL Groundwater Resources - Radionuclides released to groundwater 4.5.1.2.7 SMALL Terrestrial Resources - Non-cooling system impacts on terrestrial resources 4.6.1.1.1 SMALL Terrestrial Resources - Water use conflicts with terrestrial resources (plants with cooling ponds or cooling towers using makeup water from a river) 4.6.1.1.6 SMALL Aquatic Resources - Impingement mortality and entrainment of aquatic organisms (plants with once-through cooling systems or cooling ponds) 4.6.1.2.1 SMALL

3-5 Environmental Category - Issue LR GEIS Section Impact Finding(a)

Aquatic Resources - Effects of thermal effluents on aquatic organisms (plants with once-through cooling systems or cooling ponds) 4.6.1.2.4 MODERATE Aquatic Resources - Water use conflicts with aquatic resources (plants with cooling ponds or colling towers using makeup water from a river) 4.6.1.2.10 MODERATE Federally Protected Ecological Resources -

Endangered Species Act: federally listed species and critical habitats under U.S. Fish and Wildlife Service jurisdiction(b)(c) 4.6.1.3.1 See Section 3.6 of this EIS Historic and Cultural Resources - Environmental consequences of the proposed action - continued operations and refurbishment activities 4.7.1 See Section 3.7 of this EIS Human Health - Microbiological hazards to the public 4.9.1.1.3 SMALL Human Health - Electromagnetic fields (EMFs)(b) 4.9.1.1.4 Uncategorized (Uncertain Impact)

Human Health - Electric shock hazards 4.9.1.1.5 SMALL Greenhouse Gas Emissions and Climate Change -

Climate change impacts on environmental resources 4.12.2 See Section 3.9 of this EIS EMFs = electromagnetic fields; LR GEIS = License Renewal Generic Environmental Impact Statement; EIS = environmental impact statement.

(a) Impact determinations for Category 2 issues based on findings described in Sections 3.2 to 3.9, as applicable, for the proposed action.

(b) This issue was not designated as Category 1 or Category 2 and is discussed in Section 3.8.

(c) The NRC staff has determined that no federally listed species and critical habitats under the National Marine Fisheries Service jurisdiction occur within the action area; similarly, no Essential Fish Habitat or National Marine Sanctuaries occur near the proposed project.

Sources: Table B-1 in Appendix B to Subpart A of 10 CFR Part 51 (TN10253; NRC 2024-TN10161).

3.2 Surface Water Resources 1

As shown in Figure 3-1, RNP is located along the southwestern corner of Lake Robinson. Lake 2

Robinson is the predominant physical feature in the region covering approximately 2,250 ac 3

(910 ha) and was formed in 1958 by impounding the upper 173 square miles (mi2) (448 square 4

kilometers [km2]) of the Black Creek drainage to provide cooling water for electricity generation.

5 In addition to providing cooling water, Lake Robinson also supports public recreational use.

6 The water level of Lake Robinson is typically maintained between 220.7 feet (ft) and 221.5 ft 7

(67.3 meter [m] and 67.5 m) mean sea level (MSL) with its dam spillway and operation of two 8

tainter gates. A pool level of 220 ft (67 m) MSL provides 31,000 acre-feet (ac-ft) (3.8 x 107 cubic 9

meters [m3]) of storage capacity (Duke 2025-TN12518). If the lake level falls below the top of 10 the spillway, 220 ft (67 m) MSL, Duke can release water from Lake Robinson via spillway 11 valves (Duke 2025-TN12519) but does not have a minimum water release requirement 12 (Duke 2025-TN12519). Duke may also open the spillway valves to assist with meeting RNPs 13 thermal discharge limits (Duke 2025-TN12519).

14 The RNP Unit 2 once-through cooling system withdraws cooling water through an intake 15 structure located on the southwestern shore of Lake Robinson. Additionally, the Unit 1 intake 16 that served the now-retired coal-fired unit operates intermittently to provide water to provide 17 dilution flow during the warmer summer months to assist meeting thermal discharge limits as 18

3-6 well as to maintain flow in the discharge canal during Unit 2 outages. Heated effluent 1

discharged from the plant, typically 20 degrees Fahrenheit (°F) (11.1 degrees Celsius [°C])

2 warmer than the intake temperature, flows northward via a 4.2 mi (6.7 km) long discharge canal 3

and returns to Lake Robinson (Duke 2025-TN12518). Duke does not anticipate changes to the 4

RNP cooling system during the subsequent license renewal period (Duke 2025-TN12518).

5 Additional details regarding the RNP cooling system can be found in ER Section 2.2.3 (Duke 6

2025-TN12518).

7 8

Figure 3-1 Map of the Vicinity of the H.B. Robinson Steam Electric Plant. Source: Duke 9

2025-TN12518.

10 As presented in ER Table 3.6-4a, over the 2019-2023 time period, the average monthly 11 withdrawal was approximately 21,000 million gallons per month (MGM) (80,000 million liter(s) 12 per month [MLM]) with an annual average rate of approximately 690 million gallons per day 13 (MGD). Surface water withdrawal permit No. 16PN001 allows RNP to withdraw a maximum 14 volume of 22,386 MGM from the Unit 2 intake and 3,884 MGM from the Unit 1 intake, for a total 15 maximum withdrawal rate of 26,270 MGM. RNP does not plan to increase water withdrawal 16 rates during the proposed subsequent license renewal term (Duke 2025-TN12518). South 17 Carolina Regulation 61-119 requires permitted surface water users to report the quantity of 18 withdrawals annually to South Carolina Department of Environmental Services (SCDES). RNP 19 purchases water for potable and sanitary use from Darlington County Water and Sewer 20 Authority.

21

3-7 Lake Robinson is supplied by direct precipitation and inflow from Black Creek. Flows on Black 1

Creek approximately 2 mi (3.2 km) upstream of Lake Robinson have been measured at 2

U.S. Geological Survey (USGS) gauging station 02130900 since 1960. The annual average flow 3

at this location over water years 1960 through 2024 is approximately 142 cubic feet per second 4

(cfs) (4.0 cubic meters per second [m3/s]) (USGS 2025-TN12586). Approximately 1,000 ft 5

(305 m) downstream of Lake Robinson dam, stream flows have been measured at USGS 6

gauging station 02130910 since 1961. The annual average flow at this location over water years 7

1961 through 2024 is approximately 201 cfs (5.69 m3/s) (USGS 2025-TN12587). Based on the 8

annual average flow downstream of the dam, the average retention time in Lake Robinson is 9

approximately 75 days. Figure 3-2 shows the annual average flow times series for USGS gages 10 02130900 and 02130910 for water years 1961 to 2024. The higher flows recorded at the 11 downstream gage reflect its 60 percent larger drainage area as compared to the upstream 12 gage. The lower measured flows at both gages in the 2000s and 2010s reflect the drought 13 conditions experienced during those time periods (SCDNR 2023-TN12560). On average, 14 measured flows are highest during the month of March and lowest during the month of July.

15 Monthly minimum flows at the upstream and downstream gages were measured in the summer 16 of 2002 as 16.4 and 26.1 cfs (0.5 and 0.7 m3/s) (USGS 2025-TN12587, USGS 2025-TN12586),

17 respectively.

18 19 Figure 3-2 Time Series of Annual Flows Measured Upstream and Downstream of Lake 20 Robinson, 1961-2024. Sources: USGS 2025-TN12587, USGS 2025-TN12586.

21

3-8 Duke calculated average forced evaporation rates at RNP due to once-through thermal 1

discharge using data from 2016 through 2020. These rates range from 5.6 to 11.6 cfs (0.16 to 2

0.33 m3/s), with the higher rates occurring during the summer months (Duke 2025-TN12518).

3 These evaporation rates represent approximately 3.9 to 8.2 percent of the upstream gages 4

annual mean flow and 10.6 to 21.9 percent of its lowest annual mean flow, in water year 2002 5

(USGS 2003-TN12619). These rates also represent approximately 2.8 to 5.8 percent of the 6

downstream gages annual mean flow and 7.1 to 14.6 percent of its lowest annual mean flow, in 7

water year 2002 (USGS 2003-TN12619). The drainage area for the upstream gage is 8

approximately 65 mi2 (168 km2) less than that of the downstream gage. Given its proximity to 9

the dam (approximately 1,000 ft [305 m] downstream), the drainage area for the downstream 10 gage is approximately equal to that of Lake Robinson and therefore, in NRC staffs view, more 11 representative of flow at RNP. As shown in Figure 3-3, monthly average data indicate that the 12 downstream to upstream flow ratio increases when upstream flows decrease, which typically 13 occurs in the summer months. This flow ratio increase suggests that downstream impacts 14 under lower incoming flow conditions are buffered as result of a higher fraction of downstream 15 flow being derived from reservoir storage.

16 17 Figure 3-3 Average Monthly Upstream Flow and Downstream to Upstream Flow Ratio 18 of Lake Robinson. Sources: USGS 2025-TN12587, USGS 2025-TN12586.

19

3-9 The nearest water user downstream of RNP is the Sonoco Products Company. Sonoco 1

manufactures paper products and withdraws water for industrial use from Prestwood Lake, a 2

smaller impoundment of Black Creek approximately 6 mi (9.7 km) downstream of the Lake 3

Robinson spillway. Surface water use conflicts are mitigated on a continuous basis by SCDES 4

who are required by South Carolina Regulation 61-119 Surface Water Withdrawal, Permitting 5

and Reporting to evaluate the reasonableness of each proposed activity requiring a new or 6

modified surface water withdrawal permit in excess of 3,000,000 gallons (gal) (11,350 m3) per 7

month. In addition, RNPs surface water withdrawal permit requires RNP to maintain an 8

Operational and Contingency Plan to address appropriate standards for water conservation and 9

specify contingency actions if water supplies are threatened (Duke 2025-TN12518). In total, the 10 NRC staff concludes that the potential impacts on surface water resources and downstream 11 water availability from RNPs continued withdrawals and consumptive water use during the 12 license renewal term would be small and therefore the impact of the Category 2 issue related to 13 surface water use conflicts (plants with cooling ponds or cooling towers using makeup water 14 from a river) is SMALL.

15 3.3 Groundwater Resources 16 3.3.1 Affected Environment 17 The NRC staff reviewed Sections 3.5 and 3.6 of the ER (Duke 2025-TN12518) and Chapter 2.5 18 of the updated final safety analysis report (UFSAR) (Duke 2023-TN12561) and evaluated other 19 information related to hydrogeology of the RNP site and groundwater resources during the 20 environmental site audit and review of other available information as cited in this EIS.

21 3.3.1.1 Site Geology 22 The RNP site is located in the South Carolina portion of the upper Atlantic Coastal Plain 23 physiographic province, about 15 mi (24 km) east of the Fall Line (the boundary with the 24 westerly Piedmont province). The coastal plain in South Carolina consists of a wedge of 25 primarily unconsolidated sediments ranging in age from Cretaceous to Pleistocene. These 26 sediments thicken from the Fall Line to the Atlantic Ocean and lie above the Precambrian to 27 Paleozoic crystalline bedrock that outcrops west of the Fall Line (USGS 1990-TN6648). The 28 RNP site is on the southern edge of the Carolina Sandhills, a region characterized by rolling 29 hills, sandy soils, and outcrops of Cretaceous-age deposits identified as the Middendorf 30 Formation in Chesterfield County (Swezey et al. 2023-TN12564). Campbell and Landmeyer 31 (2014-TN12562) identified the Cretaceous geologic units present in Chesterfield and northwest 32 Darlington counties as the Cape Fear formation and members of the Black Creek Group.

33 Middendorf sediments are correlated with units of the Black Creek Group (Campbell and Coes 34 2010-TN6672). Terrain becomes flatter and marshy east and south of the site (Duke 2025-35 TN12518). The UFSAR states that contact between the Middendorf Formation and overlying 36 (younger) Black Creek sediments occurs as close as about 8 mi (13 km) southeast of the site 37 (Duke 2023-TN12561). RNP is adjacent to Lake Robinson, an impoundment of Black Creek, 38 and the plant was constructed within the Black Creek drainage basin. The study area of 39 Campbell and Landmeyer (2014-TN12562) included the RNP site and the upper portion of the 40 Black Creek basin. RNP plant grade elevation is 225 ft (68.6 m) MSL, normal pool elevation of 41 Lake Robinson is 220 ft (67.1 m) MSL, and land elevation along Black Creek below the dam is 42 about 190 ft (57.9 m) MSL.

43

3-10 The natural surficial sediments at the RNP site are about 30 ft (9.1 m) of recent sand and gravel 1

alluvium derived from the underlying Middendorf Formation. The recent surficial sediments are 2

difficult to distinguish from the underlying parent material (Duke 2023-TN12561) but tend to be 3

less compacted (Duke 2025-TN12518). The Middendorf Formation at the RNP site is about 4

400 ft (121.9 m) thick and consists predominantly of highly compacted layers of sand 5

interlayered with lenses of firm to hard clay (Duke 2025-TN12518). The upper surface of the 6

formation is compact and rich in silts and clays (Duke 2025-TN12518). The formation dips at 7

15 to 20 ft/mi (3.8 m/km) (about 0.2 degrees) to the southeast and is underlain by crystalline 8

bedrock. Sediments of the Middendorf Formation comprise the principal aquifer in the region.

9 Excavation during construction extended into the alluvium to elevations from 200 to 216 ft 10 (61.0 to 65.8 m) MSL. Building foundations were supported by piles driven to stiff silty, clayey, 11 and sandy sediments in the Middendorf Formation at about 175 ft (53.3 m) MSL (Duke 2023-12 TN12561). Compacted granular or earthen backfill was used around buildings within the 13 excavation. Sheet piling installed at the intake structure during construction to act as a 14 temporary cofferdam was removed after construction; there is likely no sheet piling remaining in 15 place at the intake structure (Duke 2025-TN12519). Figure 3-4 is a geologic cross-section 16 oriented northwest to southeast through the RNP site that illustrates the occurrence of geologic 17 units, lithologic differences interpreted from boreholes, and building excavation and pile depths.

18 3.3.1.2 Local and Regional Groundwater Resources 19 Groundwater resources in the RNP region include the Crouch Branch and McQueen Branch 20 aquifers in Chesterfield and Darlington Counties, and the deeper Gramling aquifer in Florence 21 County (SCDES 2024-TN12563; Campbell and Landmeyer 2014-TN12562). Low permeability 22 confining units separate the aquifers, but these become thinner to the northwest and may be 23 absent near the Fall Line. The Crouch Branch aquifer hydrogeologic unit is present at the land 24 surface on the RNP site (Campbell and Landmeyer 2014-TN12562); the overlying Crouch 25 Branch confining unit is absent on the site but occurs nearby to the southeast (SCDNR 2021-26 TN12565). Recharge to the Crouch and McQueen Branch aquifers occurs near the Fall Line 27 where the geologic units comprising these aquifers are exposed at the surface; interaction with 28 surface water is also more likely in these areas (SCDES 2024-TN12563). The regional direction 29 of groundwater flow in the Crouch and McQueen Branch aquifers is generally to the southeast 30 in the area of the RNP site with discharge to overlying (or underlying aquifers) and areas of 31 large groundwater withdrawals (USGS 1990-TN6648; SCDNR 2021-TN12565, SCDNR 2023-32 TN12566). No sole source aquifers or recharge source zone for a sole source aquifer have 33 been designated in South Carolina (EPA 2019-TN9022). The RNP site is not located within any 34 designated public water supply groundwater protection zones (SCDHEC 2020-TN12591). As 35 described below, all of Darlington County is in a State-designated Capacity Use Area 36 established for the purpose of managing groundwater resources in the region.

37

3-11 1

Figure 3-4 Northwest to Southeast Geologic Cross-Section through the H.B. Robinson Steam Electric Plant Site.

2 Source: Duke 2025-TN12518.

3

3-12 At the RNP site, the Middendorf formation sediments (see Figure 3-4) are associated with the 1

McQueen Branch aquifer (Duke 2025-TN12518). According to the regional hydrogeologic 2

framework (Campbell and Landmeyer 2014-TN12562), in the vicinity of the RNP site the Crouch 3

Branch aquifer is exposed at the land surface and the McQueen Branch confining unit is 4

continuous. The correlation between the lithologic units shown in Figure 3-4 and the Crouch 5

Branch aquifer is unclear. For example, Well 8 is stated to be 80 ft (24 m) deep and withdrawing 6

water from the Crouch Branch aquifer (Duke 2025-TN12518). This ambiguity does not affect the 7

NRC staffs interpretation of groundwater hydrogeology at the RNP site. Prior to plant 8

construction, groundwater in the recent alluvium likely flowed toward, and discharged to Black 9

Creek, consistent with the conceptual model described in Campbell and Landmeyer (2014-10 TN12562). Impounding the creek to form Lake Robinson altered groundwater levels in the 11 recent alluvium near the lake, but would not change the function of Black Creek as a discharge 12 point for groundwater in the recent alluvium. Fluctuations in Lake Robinson water level may 13 result in temporary recharge from the lake to the adjacent recent alluvium but this would be a 14 local effect. Plant structures with foundations that extend into the recent alluvium will affect 15 groundwater flow paths locally. Groundwater flow paths in the McQueen Branch aquifer will 16 follow the regional gradient but will be affected at the site by withdrawals for plant operations.

17 Information about RNP site groundwater conditions in subsurface hydrogeologic units is obtained 18 from 13 groundwater withdrawal wells and a network of onsite monitoring wells (see Figure 3-5).

19 The majority of wells with known screen depths are screened near the top of the recent alluvium 20 (i.e., near the water table), with several wells screened deeper in the recent alluvium (Duke 21 2025-TN12518). Groundwater elevations in wells near the power block were about 5 ft (1.5 m) 22 below plant grade in July 2020 (Duke 2025-TN12518). Groundwater elevations were lower in 23 wells further south, which the NRC staff attributes to a reduced influence of the lake and a 24 greater influence from water surface elevations in Black Creek below the dam. Groundwater 25 levels in the McQueen Branch aquifer at the RNP site are lower than levels in the recent alluvium 26 due to groundwater withdrawals for plant operations, as illustrated in Figure 3-5. This induces a 27 downward component of groundwater flow between the aquifers. A multi-year decline in 28 groundwater elevations in the recent alluvium was attributed to increased vertical flow in 29 response to groundwater withdrawals from the McQueen Branch aquifer (Duke 2025-TN12519).

30 Groundwater head in the McQueen Branch aquifer trended downward about 10 ft (3 m) from 31 2004 to 2012 based on static head in Well D (Duke 2025-TN12519). When Unit 1 ceased 32 operation and groundwater pumping was reduced (in 2012), groundwater levels in the recent 33 alluvium increased in power block area wells (Duke 2025-TN12519). The hydraulic connection 34 between the two aquifers is limited by the McQueen Branch confining unit, however, which is 35 supported by original well construction logs for the water supply wells showing use of a cement 36 seal to prevent migration along the well boreholes (Duke 2025-TN12519). In addition, when well 37 pumping was altered to change the heads in the McQueen Branch aquifer, no response to the 38 head change was observed in the recent alluvium monitoring wells (Duke 2025-TN12519).

39 Based on water levels in recent alluvium wells (Duke 2025-TN12518), horizontal hydraulic head 40 gradients across the RNP site protected area environs range from about 0.006 to 0.02 ft/ft.

41 Based on the hydraulic head differences between the unconfined and confined aquifers shown 42 in Figure 3-5, the vertical hydraulic head gradient across the McQueen Branch confining unit is 43 about 0.2 to 0.3 ft/ft at the site. Hydraulic conductivity of the recent alluvium was reported to be 44 13.4 ft/d (3.95 x 104 cm/s) (Duke 2025-TN12519). Hydraulic conductivities of the Crouch and 45 McQueen Branch aquifers were calibrated to be about 20 ft/d (7.1 x 103 cm/s) and 45 ft/d 46 (1.6 x 102 cm/s) in the RNP site area (Campbell and Landmeyer 2014-TN12562). Calibrated 47 specific storage for the McQueen Branch aquifer was 1.95 x 104 ft1 (6.40 x 104 m1) 48 (Campbell and Landmeyer 2014-TN12562). Based on aquifer tests for wells in Chesterfield 49

3-13 1

Figure 3-5 H.B. Robinson Steam Electric Plant Onsite Wells. Source: Duke 2025-2 TN12518.

3

3-14 County, the hydraulic conductivity of the McQueen Branch aquifer ranged from 3 to 87 ft/d 1

(1.1 x 103 to 3.1 x 102 cm/s) (Campbell and Landmeyer 2014-TN12562). The calibrated 2

hydraulic conductivity of the McQueen Branch confining unit was about 5 x 104 ft/d 3

(1.8 x 107 cm/s) in the RNP site area (Campbell and Landmeyer 2014-TN12562).

4 Based on groundwater conditions described in the ER and provided to NRC staff during the 5

audit (Duke 2025-TN12518, Duke 2025-TN12519), as summarized in this section, the general 6

direction of groundwater flow in the recent alluvium of the RNP protected area is toward, and 7

discharging into, Black Creek. Groundwater north of the protected area discharges to Lake 8

Robinson. Some leakage occurs from the recent alluvium into the McQueen Branch confining 9

unit. Using the estimated hydraulic conductivity and assuming a porosity value of 0.3 for all 10 sediments, the NRC staff estimated that horizontal groundwater velocities in the recent alluvium 11 could range from about 10 ft/yr (3 m/yr) to about 400 ft/yr (120 m/yr). Downward vertical 12 groundwater flow across the McQueen Branch confining unit would be small and would 13 constitute a minor fraction of plant groundwater withdrawals.

14 3.3.1.3 Groundwater Use and Quality 15 The Crouch and McQueen Branch aquifers are significant sources of water in Chesterfield, 16 Darlington, and Florence Counties. Capacity Use Areas have been established under South 17 Carolinas Groundwater Use and Reporting Act (SC Code 49-5-TN12567) to manage the States 18 groundwater resources. Darlington County is in the Pee Dee Capacity Use Area and 19 groundwater use is managed to ensure sustainable development, protect the groundwater from 20 salt water intrusion, and monitor groundwater quantity and quality (SCDES 2024-TN12563).

21 Groundwater withdrawers covered by a Capacity Use Area are persons withdrawing in excess 22 of 3 million gallons during any 1 month from a single well or from multiple wells under common 23 ownership. Although groundwater levels have declined in many areas of the Pee Dee Capacity 24 Use Area, water levels have remained relatively stable in the western portions of the area where 25 aquifer recharge occurs (SCDES 2024-TN12563).

26 Groundwater use in the Pee Dee Capacity Use Area and in Darlington County have gradually 27 increased since 2001 (SCDES 2024-TN12563). Reported groundwater use in Darlington County 28 during 2023 was over 5 billion gal, with 47 percent for water supply, 28 percent for industrial 29 uses, 17 percent for irrigation, and 7.5 percent for RNP (SCDES 2024-TN12563). All public 30 supply withdrawals in Darlington County were from groundwater sources in 2015 (Dieter et al.

31 2018-TN6681). Groundwater is also widely used for domestic self-supply; total withdrawals for 32 this purpose were 0.91 MGD (3.5 million liter(s) per day [MLD]) in Darlington County during 33 2015 (Dieter et al. 2018-TN6681). Several registered wells are located within 2 mi (3.2 km) of 34 RNP; the closest of these is about 1/2 mi (0.8 km) from the site (Duke 2025-TN12518). Average 35 annual groundwater withdrawals at RNP were about 382 million gallons (1.05 MGD or 4.0 MLD) 36 during 2019 to 2024. About 97 percent of RNP withdrawals are from Wells A, B, C, 1, and 2 37 (Duke 2025-TN12519), which are all located near the power block (see Figure 3.6-5) and 38 withdraw water from the McQueen Branch Aquifer (Duke 2025-TN12518). Wells A, B, and C are 39 sealed to depths of 170 to 172 ft (51.8 to 52.4 m) and are screened at depths of 178 to 220 ft 40 below ground surface (elevation about 5 to 50 ft MSL). Withdrawal of 45 milligal/year (170 41 million liter/year) from Wells D and E, installed in the McQueen Branch aquifer, is authorized for 42 emergency cooling (Duke 2025-TN12518). RNP withdraws a minor amount of water for 43 irrigation use from Well 6 and Well 8 (depth 80 ft [24 m] below ground surface [elevation 145 ft 44 MSL]) installed in the Crouch Branch aquifer.

45

3-15 Groundwater quality in the RNP region is generally good as evidenced by its prevalent use for 1

public supply and other uses. All South Carolina groundwater was classified as Class GB in 2

1985 (SCDES 2024-TN12592). Class GB groundwater is subject to the maximum contaminant 3

levels defined in the state primary drinking water standards (SCDES 2024-TN12603), which 4

include a limit of 20,000 picocuries per liter (pCi/L) for tritium.

5 As described in the ER, there have been past and current groundwater investigation and 6

monitoring activities associated with the management and disposal of coal combustion residuals 7

from Unit 1 (Duke 2025-TN12518). Groundwater monitoring of the ash basin is required as part 8

of the National Pollutant Discharge Elimination System (NPDES) permit (Duke 2025-TN12518).

9 Some metals have been detected in wells monitoring the ash basin (Duke 2025-TN12518). In 10 addition, water from Lake Robinson was used to transport ash to the basin, which resulted in 11 tritium in the lake water being transported to groundwater beneath the basin. Use of lake water 12 for this purpose ceased in 2012 (Duke 2025-TN12518). NPDES groundwater monitoring also 13 includes one well east of the settling ponds.

14 3.3.1.4 Groundwater Protection Program and Tritium in Groundwater 15 Activities were initiated at RNP in 2006 to implement the Industry Groundwater Protection 16 Initiative (GPI) (NEI 2019-TN6775). Six wells between the Unit 2 power block and the discharge 17 canal had been installed in 2006 and 2007 for monitoring a Unit 1 oil spill remediation (Duke 18 2025-TN12519). Well PDW-01 and the four PSW-series wells were installed in 2009 specifically 19 for GPI monitoring (Duke 2025-TN12519). Sentinel wells (100-series) were installed in 2015 20 immediately downgradient of the Unit 2 power block to improve early detection of leaks or spills 21 (Duke 2025-TN12518). Two perimeter wells (MW-110 and MW-112) were installed in 2019 to 22 improve monitor of groundwater pathways likely to lead to offsite private water supply wells 23 (Duke 2025-TN12518). Reviews of the site conceptual model were completed in 2015 and 2020 24 to satisfy requirements of the GPI (Duke 2025-TN12519). The RNP Groundwater Protection 25 Program (GPP) currently includes monitoring of 41 wells, including one off-site confined aquifer 26 well. Monitoring wells are sampled quarterly for tritium and gamma emitters with results reported 27 in the Annual Radiological Effluent Release Reports and publicly available from the NRC (NRC 28 2025-TN12585). Notification of spills, leaks, or discovery of contamination are made to the NRC 29 and other outside agencies when these meet specified criteria.

30 No leaks or spills have occurred at RNP that have resulted in the detection of tritium in 31 groundwater at 20,000 pCi/L or higher during Unit 2 operations (Duke 2025-TN12519). No 32 unplanned radionuclide releases impacting soil or groundwater at the site have occurred in the 33 period 2019 to September 2025 (Duke 2025-TN12519). Tritium detected in groundwater at RNP 34 has been highest at well MW-106 located near the discharge canal. The occurrence of tritium in 35 this well has been attributed to lake water (Duke 2025-TN12518) but may also be from 36 interaction between groundwater and water in the discharge canal. Monthly tritium levels at the 37 R40 sampling location on Black Creek below the Lake Robinson dam during the period of 38 January 2020 through November 2024 ranged from not detected to 7,610 pCi/L (Duke 2025-39 TN12519). Cyclical patterns in the tritium levels coincide with plant outages for refueling, with 40 peak tritium levels in the lake occurring during refueling. The maximum tritium activity in well 41 MW-106 since 2019 was 7,090 pCi/L in 2022 (Duke 2025-TN12518). Tritium has been detected 42 at levels over 1,000 pCi/L in monitoring well MW-108 near the settling ponds. Tritium levels in 43 the settling ponds are regularly monitored but have exceeded the minimum detection activity of 44 4,000 pCi/L in just a few samples (Duke 2025-TN12519). Tritium activity exceeded 1 million 45 pCi/L in a January 2018 sample from the west pond, but no corresponding increase was 46 observed in samples from the downgradient well MW-107 (Duke 2025-TN12519). Tritium has 47

3-16 been detected during 2018 to 2024 in other wells at levels below 1,000 pCi/L, including very low 1

levels (200 to 300 pCi/L) in samples from water supply wells, Well A and Well 1 (NRC 2025-2 TN12585).

3 3.3.2 Environmental Consequences: Groundwater Use Conflicts (plants that withdraw 4

more than 100 gallons per minute [gpm])

5 Section 4.5.1.2.3 of the LR GEIS (NRC 2024-TN10161) provides background information for 6

this Category 2 issue, which is incorporated here by reference. This issue was included in the 7

LR GEIS because overall site pumping rates greater than 100 gpm (378 Lpm) have the potential 8

to create conflicts with other local groundwater users if the reduction in groundwater head 9

induced by pumping extends to offsite wells. The LR GEIS determined that impacts on 10 groundwater use conflicts from withdrawing more than 100 gpm (378 Lpm) could be SMALL, 11 MODERATE, or potentially LARGE depending on the magnitude of pumping, hydrogeologic 12 factors, and the distance to other wells.

13 The issue of groundwater use conflicts was discussed in Section 4.1.2 of the ER (Duke 2025-14 TN12518). This issue is applicable to RNP because average groundwater withdrawals from the 15 McQueen Branch aquifer exceed 700 gpm (2,650 Lpm). RNP withdraws water from the Crouch 16 Branch aquifer also, but these are much less than 100 gpm (378 Lpm) and would have minimal 17 impact on other users of that aquifer. As described above in this section, the McQueen Branch 18 aquifer is a principal source of water for multiple purposes and RNP withdrawals are about 19 7.5 percent of the total withdrawals in Darlington County. The 2024 Pee Dee Capacity Use Area 20 groundwater evaluation reported that groundwater levels in the McQueen Branch aquifer have 21 been stable at a single Darlington County monitoring well but noted that water levels at the well 22 are heavily influenced by the interconnectivity of aquifers and the proximity of the Great Pee 23 Dee River (SCDES 2024-TN12563). Based on a comparison of groundwater hydraulic head 24 maps, the SCDES concluded that groundwater use in the region has not significantly altered 25 McQueen Branch aquifer levels in Darlington County. SCDES recommendations for limiting 26 withdrawal rates or permits for new wells were not aimed at Darlington County water use.

27 As described above in this section, static head in a deep water supply well at RNP showed 28 evidence of decline over an extended period. In addition, groundwater pumping for RNP 29 operations lowers the hydraulic head in the McQueen Branch aquifer to a degree that may 30 induce a downward gradient across the McQueen Branch confining unit. To assess the potential 31 for groundwater use conflicts, the NRC staff completed a confirmatory analysis of the drawdown 32 resulting from plant groundwater withdrawals. The NRC staff used a simplified solution (Theis 33 solution) for drawdown that assumed a constant pumping rate from a single well and a uniform, 34 confined aquifer of constant thickness and infinite extent (Freeze and Cherry 1979-TN3275).

35 Using the hydraulic characteristics of the McQueen Branch aquifer described above in this 36 section, the NRC staff determined that drawdown at the RNP site boundary would be 37 noticeable. Actual drawdown resulting from the pumping is likely to be less than the confirmatory 38 analysis result due to leakage from the Crouch Branch aquifer.

39 Based on the information reviewed, the NRC staff determined that groundwater pumping for 40 RNP operations could result in noticeable offsite drawdown in the McQueen Branch aquifer.

41 However, no significant impacts from McQueen Branch aquifer withdrawals were noted in the 42 recent SCDES groundwater evaluation and no increase in groundwater use is anticipated during 43 the subsequent license renewal term. In addition, no registered wells are located near the RNP 44 site. Therefore, the NRC staff concludes that impacts related to groundwater use conflicts would 45 be SMALL during the RNP subsequent license renewal term.

46

3-17 3.3.3 Environmental Consequences: Groundwater Quality Degradation (plants with 1

cooling ponds) 2 Section 4.5.1.2.6 of the LR GEIS (NRC 2024-TN10161) provides background information for 3

this Category 2 issue, which is incorporated here by reference. This issue was included in the 4

LR GEIS because of the possibility of groundwater quality and beneficial use becoming 5

degraded from the migration into groundwater of contaminants discharged to cooling ponds.

6 The LR GEIS determined that impacts on groundwater quality from the use of cooling ponds 7

could be SMALL or MODERATE depending on the cooling ponds construction and operation, 8

water quality, hydrogeologic factors, and characteristics of any nearby water supply wells 9

(e.g., location, depth, and pumping rate).

10 The issue of groundwater quality degradation was discussed in Section 4.1.4 of the ER (Duke 11 2025-TN12518). This issue is applicable to RNP because, although the plant uses once-through 12 cooling, Lake Robinson operates as a cooling pond (NRC 2024-TN10161). As described above 13 in this section, the Crouch Branch aquifer is present at the surface in the area of Lake Robinson 14 and the unconfined groundwater in the Black Creek basin flows toward, and discharges to, the 15 creek. The presence of the Lake Robinson impoundment does not alter these conditions.

16 Depending on lake water levels, some discharge from the lake into the adjacent groundwater 17 may occur, but this effect would be temporary and localized to the groundwater near the lake.

18 Therefore, the NRC staff concludes that groundwater resources impacts due to the degradation 19 of groundwater quality from the operation of Lake Robinson as a cooling pond would be SMALL 20 during the RNP subsequent license renewal term.

21 3.3.4 Environmental Consequences: Radionuclides Released to Groundwater 22 Section 4.5.1.2.7 of the LR GEIS (NRC 2024-TN10161) provides background information for 23 this Category 2 issue, which is incorporated here by reference. This issue was included in the 24 LR GEIS because of the accidental releases of liquids containing radioactive material into the 25 groundwater at many nuclear power reactor sites (NRC 2024-TN11047). The LR GEIS 26 determined that impacts on groundwater quality from the release of radionuclides could be 27 SMALL or MODERATE depending on magnitude of the leak, radionuclides involved, 28 hydrogeologic factors, distance to receptors, and response time of plant personnel to identify 29 and stop the leak.

30 The issue of radionuclides released to groundwater was discussed in Section 4.1.5 of the ER 31 (Duke 2025-TN12518). Duke monitors groundwater at RNP as part of its GPP, which is 32 implemented to conform with Nuclear Energy Institute 07-07 (NEI 2019-TN6775) and satisfy the 33 requirements of 10 CFR 20.1501 (TN283). Section 3.6.4.2 of the ER describes the historical 34 detection of tritium in the unconfined aquifer at a monitoring well located near the discharge 35 canal, at wells surrounding the ash basin, and a well near the settling ponds. Tritium in 36 groundwater is attributed to groundwater interaction with the discharge canal and the use of 37 Lake Robinson water (which contains tritium from the plant discharge) to transport ash to the 38 ash basin (Duke 2025-TN12518). Tritium detected in groundwater near the settling ponds was 39 not attributed to releases from the settling ponds (Duke 2025-TN12518). However, water levels 40 in these shallow ponds was reported to be 8 to 10 ft (2.4 to 3 m) above the groundwater levels 41 in surrounding wells (Duke 2025-TN12519), which suggests that the ponds could be a source of 42 some discharge to the groundwater and a source of tritium observed at a nearby well. No leaks 43 or spills contributing to significant tritium activity in groundwater have been identified at RNP 44 (NRC 2024-TN11047). Based on information provided in the ER (Duke 2025-TN12518), the 45 annual radiological effluent release reports, and information reviewed by NRC staff during the 46

3-18 environmental site audit, tritium in RNP groundwater during 2018 to 2024 has been below 1

detection limits in most wells and has been above 1,000 pCi/L during this period in only a few 2

wells. Tritium levels during 2018 to 2024 have been highest in well MW-106 near the discharge 3

canal but do not appear to show any consistent trend over this period. Tritium activity in well 4

MW-106 typically fluctuated between about 800 and 6,000 pCi/L with a maximum of 7,500 pCi/L 5

in October 2018. Very low levels of tritium (200 to 300 pCi/L) have been detected in samples 6

from two water supply wells.

7 Based on the information reviewed, the NRC staff determined that low levels of tritium occur in 8

localized areas of the groundwater at RNP, but tritium has not exceeded the drinking water 9

standard (20,000 pCi/L) at any time. Tritium has not been detected at the two downgradient 10 perimeter wells monitoring for offsite migration. Low levels of tritium observed in water supply 11 well samples may be from transport across the McQueen Branch confining unit induced by plant 12 groundwater withdrawals. Any tritium reaching the McQueen Branch aquifer would be captured 13 by the plants water supply wells and not transported offsite. Duke has implemented a GPP to 14 identify potential sources of inadvertent releases to groundwater and procedures to respond to 15 any leaks or spills that occur. The existing monitoring wells appear adequate to provide 16 detection of any releases and the small groundwater velocities in the recent alluvium allow time 17 for an adequate response. Therefore, the NRC staff concludes that groundwater resources 18 impacts due to the release of radionuclides to groundwater would be SMALL during the RNP 19 subsequent license renewal term.

20 3.4 Terrestrial Resources 21 3.4.1 Affected Environment 22 The RNP terrestrial environment is described in the supplemental EIS for the initial license 23 renewal (NRC 2003-TN7260: Section 2.2.6) and in the applicants ER (Duke 2025-TN12518:

24 Section 3.7.1). Those descriptions are incorporated here by reference. Supplemental 25 information describing the terrestrial environment can be found in Appendix C.

26 3.4.2 Environmental Consequences: Non-Cooling System Impacts on Terrestrial 27 Resources 28 Section 4.6.1.1.1 of the LR GEIS (NRC 2024-TN10161) provides background information for 29 this Category 2 issue of non-cooling system impacts on terrestrial resources, which is 30 incorporated here by reference. According to the LR GEIS (NRC 2024-TN10161), non-cooling 31 system impacts on terrestrial resources can include impacts that result from site and landscape 32 maintenance activities, stormwater management, elevated noise levels, and other ongoing 33 operations and maintenance activities that would occur during the subsequent license renewal 34 period on and near a plant site. The NRC staff based its analysis in this section on information 35 derived from the ER (Duke 2025-TN12518) unless otherwise cited. Duke has not identified any 36 refurbishment activities during the proposed subsequent license renewal term (Duke 2025-37 TN12518: Section 2.3). No further analysis of potential impacts from refurbishment activities is 38 therefore necessary.

39 The majority of landscape maintenance activities associated with the subsequent license 40 renewal action are conducted within the industrial portion of the RNP protected area and not 41 within natural areas of the site. The following land management practices occur within the RNP 42 site boundary but are not directly related to the operation of RNP and would continue to occur 43 whether RNP continues operation or not: (1) prescribed fire; (2) tree clearing; (3) planting; 44

3-19 (4) pine straw harvesting; and (5) land clearing for the RNP Solar Farm (Duke 2025-TN12519:

1 TER-04). However, these activities are not associated with the subsequent license renewal 2

action and are not considered further.

3 Landscape Maintenance and Operational Activities 4

Landscape maintenance and operational activities conducted during the subsequent license 5

renewal term would remain similar to ongoing activities. These activities primarily consist of 6

mowing, weed removal, herbicide application, tree trimming, brush removal, debris removal, and 7

the maintenance and repair of plant infrastructure such as roadways, piping installations, 8

fencing, and security-related structures. Typically, only removal of trees and shrubs that pose a 9

safety or security threat are removed from natural areas. The NRC staff expects that physical 10 disturbances would be limited to paved or disturbed areas or to areas of mowed grass or early 11 successional vegetation and not encroach into wetlands or into the remaining areas of forest.

12 The NRC staff concludes that the anticipated activities would have only minimal effects on 13 terrestrial resources, based on information presented in the ER and the staffs independent 14 analysis.

15 Herbicides and pesticides are used on an as-needed basis in areas including security fence 16 lines, along sidewalks and buildings, and in other areas within the security fenced area to 17 maintain compliance with safety and security protocols at RNP. Mowing occurs on the site within 18 the grassy areas of the security fenced portion of the RNP site, including the area surrounding 19 the industrial buildings and along the dam (Duke 2025-TN12519: TER-03).

20 Duke maintains programs to minimize impacts to terrestrial resources on the RNP site including 21 procedures for pesticide compliance, land-disturbing activities, and avian protection. Dukes 22 Pesticide Compliance Procedure contains consideration for endangered species and pollinator 23 protection measures and water quality protection measures. The procedure states that pesticide 24 application around water and sensitive areas generally requires a minimum of 25 ft (7.6 m) 25 buffer from surface waters and areas which could drain to surface water. The procedure also 26 states that pesticides should not be applied immediately prior to or immediately following 27 rainfall, when wind and/or fog conditions are likely to cause drift, or when dew is heavy on 28 vegetation. Dukes Land-Disturbing Activities procedure states that if the land-disturbing work 29 involves tree clearing or takes place in undeveloped areas, then a natural resource evaluation 30 will be conducted. This evaluation will assess potential impacts on state or federally listed 31 species (Duke 2025-TN12519: TER-11).

32 The NRC staff concludes that continued adherence to environmental management procedures 33 already established for RNP would continue to protect terrestrial resources during the proposed 34 subsequent license renewal term.

35 Stormwater Management 36 Stormwater runoff from impervious surfaces can change the frequency or duration of inundation 37 and soil infiltration within wetlands and neighboring terrestrial habitats. Effects of stormwater 38 runoff may include erosion, altered hydrology, sedimentation, and other changes to plant 39 community characteristics. Runoff may contain sediments, contaminants and oils from road or 40 parking surfaces, or herbicides.

41 The stormwater management system at RNP is described in the supplemental EIS for the initial 42 license renewal (NRC 2003-TN7260: Section 2.1.5) and in the applicants ER (Duke 2025-43

3-20 TN12518: Section 3.6.1.2). These descriptions are applicable to the RNP site today and are 1

incorporated by reference. Use of the stormwater conveyance system, which collects 2

stormwater, minimizes the amount of excess runoff that terrestrial habitats would receive and 3

the associated effects.

4 Duke maintains and implements a Stormwater Pollution Prevention Plan that includes best 5

management practices (BMPs) to minimize exposure of industrial activities to stormwater.

6 These BMPs include structural BMPs (buildings, shelters, enclosures, dedicated secondary 7

containments, paved loading/unloading locations, sumps, and oil/water separators) and non-8 structural BMPs (personnel training, facility policy and procedures, environmental awareness, 9

good housekeeping practices, security, preventive maintenance, and spill and emergency 10 response). Duke also maintains a Spill Prevention, Control, and Countermeasure plan that 11 includes practices to minimize hazards to human health and the environment by preventing and 12 controlling oil spills (Duke 2025-TN12518: Section 3.5.3.2).

13 Collectively, these measures ensure that the effects to terrestrial resources from pollutants 14 carried by stormwater would be minimized during the proposed subsequent license renewal 15 term.

16 Noise 17 Elevated noise levels from transformers and other equipment could disrupt wildlife behavioral 18 patterns or cause animals to avoid such areas. However, limited wildlife occurs in areas of the 19 RNP site with elevated noise levels due to the developed nature of those portions of the site, 20 associated lack of high-quality habitat, and regular presence of human activity. Wildlife that 21 does occur in developed areas is likely tolerant of disturbance due to decades of operations.

22 Therefore, noise associated with the continued operation during the proposed subsequent 23 license renewal term is unlikely to create noticeable impacts on terrestrial resources.

24 Undeveloped habitats exist surrounding the industrial portion of the RNP site. Wildlife within 25 these areas may experience elevated noise levels from siren testing, firing range use, or other 26 high decibel activities (Duke 2025-TN12518: Section 3.4). These activities occur infrequently 27 and for short periods. Wildlife may expend additional energy to flee the noise. However, these 28 impacts are not expected to have a noticeable effect on the fitness of wildlife in the vicinity of the 29 site due to the infrequent nature of the events.

30 Conclusion 31 Based on its independent review, the NRC staff concludes that the landscape maintenance 32 activities, stormwater management, elevated noise levels, and other ongoing operations and 33 maintenance activities that Duke might undertake during the subsequent license renewal term 34 would primarily be confined to already disturbed areas of the RNP site. These activities would 35 neither have noticeable effects on terrestrial resources nor would they destabilize any important 36 attribute of the terrestrial resources on or in the vicinity of the site. The NRC staff expects that 37 Duke would continue to comply with the applicable requirements of Federal and State regulatory 38 programs and obtain any needed permits. Accordingly, the NRC staff concludes that 39 noncooling system impacts on terrestrial resources during the subsequent license renewal term 40 would be SMALL.

41

3-21 3.4.3 Environmental Consequences: Water Use Conflicts with Terrestrial Resources 1

Section 4.6.1.1.6 of the LR GEIS (NRC 2024-TN10161) provides background information for 2

this Category 2 issue, which is incorporated here by reference. Water use conflicts occur when 3

the amount of water needed to support riparian communities is diminished because of demands 4

from other users, decreased water availability due to droughts, or a combination of these 5

factors. The 2024 LR GEIS (NRC 2024-TN10161) determined that water use conflicts with 6

terrestrial resources would be SMALL at most nuclear power plants with cooling ponds or 7

cooling towers that withdraw makeup from a river, but a plant-specific review is required 8

because impacts may be MODERATE at some plants.

9 In the 2003 RNP LR EIS (NRC 2003-TN7260), the NRC staff reviewed the available 10 information, including the rate of evaporative water loss associated with the plants operations, 11 maintenance of minimum flow conditions of Black Creek and past operation information, and 12 concluded impacts were SMALL for RNP initial LR. In this EIS, the NRC staff analyzes surface 13 water resource use conflicts in Section 3.2 and water use conflicts regarding aquatic resources 14 in Section 3.5.4. Below, the NRC staff analyzes this plant-specific issue for the subsequent 15 license renewal term in the context of terrestrial resources.

16 RNP utilizes a cooling water system that withdraws water from the southwestern end of Lake 17 Robinson and discharges thermal effluent through a 4.2 mi (6.8 km) discharge canal that runs 18 along the western edge of the lake before emptying into the northern end of the lake, as detailed 19 in Section 3.2 of this EIS and Section 2.2.3 of the ER (Duke 2025-TN12518). As described in 20 Section 3.2, RNP typically consumes approximately 2.8 to 5.8 percent of the downstream 21 gages (USGS station 02130910) annual mean flow and 7.1 to 14.6 percent of its lowest annual 22 mean flow during water year 2002 (USGS 2003-TN12619, USGS 2025-TN12571). As 23 discussed in Section 3.2, the downstream gage is representative of flow at RNP due to similarity 24 in drainage area. In Section 3.2, the NRC staff concluded that surface water use conflicts would 25 be SMALL due to the regulatory and procedural mechanisms in place.

26 The shoreline of Black Creek in the vicinity of RNP is characterized by riparian wetlands.

27 Approximately 15 percent of land within the RNP site boundary and 12 percent of the land within 28 the 6 mi (9.7 km) radius of RNP is classified as either woody or emergent herbaceous wetlands 29 (Duke 2025-TN12518: Table 3.2-1). These wetlands predominantly occur along the shoreline of 30 Black Creek and Lake Robinson (Duke 2025-TN12518: Figures 3.2-1 and 3.2-2). Terrestrial 31 riparian communities onsite and downstream could be impacted by diminished water availability.

32 However, based on the monthly averages of daily mean water height values collected from 33 USGS station 02130900 from 1995 to 2024, the riparian communities of Black Creek upstream 34 of Lake Robinson experienced an average annual surface elevation fluctuation of approximately 35 3 ft (0.9 m) (USGS 2025-TN12620). Downstream of Lake Robinson, the monthly averages of 36 daily mean values collected from USGS station 02130910 from 1996 to 2024 indicate an 37 average annual surface elevation fluctuation of approximately 3.3 ft (1.0 m) (USGS 2025-38 TN12621). Because the upstream average surface elevation fluctuation is not influenced by the 39 consumptive use of plant operations, it can serve as a baseline for the expected natural 40 variability within this system. Therefore, the similarity between the average surface elevation 41 fluctuation downstream of RNP and the upstream baseline indicates that the RNP operation is 42 not substantially altering the natural variability of stream levels within the riparian ecosystem.

43 The consumptive loss caused by RNP operations has the greatest effect on surface elevation 44 during the periods of low flow from June through September. During these months, the average 45 surface elevation downstream of Lake Robinson at USGS station 02130910 over the period of 46

3-22 1996 to 2024 is 3.3 ft (1.0 m). In contrast, during the remaining months, the average surface 1

elevation is 4.5 ft (1.4 m). The downstream shoreline during these periods may be temporarily 2

exposed but would otherwise be inundated during the other months of the year. Vegetation is 3

found at elevations that are not flooded for most of the year by the river. When the river stage is 4

high enough to flood the riparian communities, the impact of consumptive loss from plant 5

operations is negligible.

6 Although the average consumptive loss during lowest annual mean flow ranges from 7.1 to 7

14.6 percent of flows downstream of RNP (Section 3.2), the ratio of downstream to upstream 8

flow increases during these periods (Figure 3-3). This indicates that the reservoir storage is 9

supplementing downstream flows during dry conditions, thereby buffering the effects of the 10 plants consumptive use. However, while the reservoir storage effectively lessens the stress on 11 the downstream system by maintaining flows during typically low flow conditions, it has the 12 potential to alter the riparian community species composition and ecological function 13 downstream. For example, prolonged changes in hydroperiods may favor more drought-tolerant 14 or invasive species over native wetland vegetation.

15 The flow regime in this system has been influenced by RNP in a consistent manner since the 16 last power uprate authorized in 2002. Therefore, the downstream riparian community has been 17 adapting to this altered hydrology since that time and, while we do not have data to evaluate the 18 changes to downstream ecology, it is anticipated that any impacts have likely stabilized and that 19 the terrestrial riparian species composition has adjusted to fit the hydroperiod.

20 RNP plant operation requires the water levels of Lake Robinson to be above 218 ft (66.4 m) 21 ASL. Water levels within Lake Robinson fluctuate minimally, typically maintained between 220.7 22 and 221.5 ft (67.3 and 67.5 m) MSL (Duke 2025-TN12519: TER-01). During low flow events, 23 the dam discharge will remain in the normal spill-over configuration and naturally decrease until 24 the lake level reaches 220 ft (67 m) MSL. At this point, the water will no longer flow over the 25 spillway and will be released via the spillway valves controlled by Duke. The minimum rate of 26 discharge will be set to maintain the Black Creek temperature below 91.4°F (33°C), as required 27 by Dukes NPDES permit (No. SC0002925). This permit does not have a minimum water 28 release requirement from the dam to Black Creek. The lack of a minimum flow requirement 29 could pose a risk to riparian habitats during extended droughts. The NPDES permit also limits 30 the lake drawdown to 2 ft (0.6 m) below normal pool elevation (220 ft or 67.0 m), which is not 31 reported to have been exceeded (Duke 2025-TN12519: AQU-07). Therefore, it is assumed that 32 the flow over the dam has not been completely restricted. Additionally, should water supplies be 33 threatened, Duke implements a drought contingency plan that would go into effect.

34 While the proposed subsequent license renewal for RNP would continue to consume water at 35 current rates with no increase in water withdrawal, the NRC staff acknowledges the potential for 36 continued modification of natural hydroperiods to cause downstream shifts in riparian species 37 community composition. This risk is expected to be minor and localized. RNP has been 38 operating at the current power levels for over 20 years, and any ecological shifts are expected 39 to have already occurred and stabilized. As there are no plans to change consumption rates, the 40 NRC staff assumes that the impacts of continued operation of RNP during the subsequent 41 license renewal term on terrestrial resources would be similar to current operational impacts.

42 Therefore, water use conflicts with terrestrial resources from subsequent license renewal are 43 not expected to destabilize or noticeably alter terrestrial riparian resources. The NRC staff 44 concludes that water use conflicts with terrestrial resources during the RNP subsequent license 45 renewal term would be SMALL.

46

3-23 3.5 Aquatic Resources 1

3.5.1 Affected Environment 2

For the purposes of the following analysis, the NRC staff assumes that the baseline condition of 3

the resource is the freshwater community as it occurs today, which is described in Appendix C.

4 While species richness, evenness, and diversity within the community may change or shift 5

between now and when the proposed subsequent license renewal term would begin, the NRC 6

staff finds the present aquatic community to be a reasonable surrogate in the absence of fishery 7

and species-specific projections.

8 3.5.2 Environmental Consequences: Impingement Mortality and Entrainment of Aquatic 9

Organisms (Plants with Once-Through Cooling Systems or Cooling Ponds) 10 This issue pertains to impingement mortality and entrainment (IM&E) of finfish and shellfish at 11 nuclear power plants with once-through cooling systems or cooling ponds. Sections 4.6.1.2 and 12 4.6.1.2.1 of the LR GEIS (NRC 2024-TN10161) provide background information for this 13 Category 2 issue, which is incorporated here by reference. Specifically, Section 4.6.1.2 14 discusses the following information relevant to this issue:

15

• What IM&E is and how it can affect aquatic ecological communities.

16

• Results of NRC impingement and entrainment analyses at nuclear power plants from 17 2013-2024.

18

• Clean Water Act of 1972, as amended (CWA) Section 316(b) requirements for minimizing 19 IM&E at existing facilities, including best technology available (BTA) standards and 20 ecological study requirements.

21

• The NRC staffs reliance on the expertise and authority of the NPDES permitting authority 22 with respect to the impacts of IM&E.

23

• The NRC staffs analysis approach in the absence of BTA determinations by the NPDES 24 permitting authority.

25 As stated in the LR GEIS, if the NPDES permitting authority has made IM&E BTA 26 determinations and the nuclear power plant has implemented any associated requirements, 27 then the NRC staff assumes that adverse impacts on the aquatic environment would be 28 minimized and that the impacts of IM&E would be SMALL; if this is not the case, impacts could 29 be SMALL, MODERATE, or LARGE. The sections below analyze the impacts of IM&E on 30 aquatic organisms at RNP.

31 3.5.2.1 Robinson Cooling Water Intake System 32 The RNP cooling water intake system (CWIS) impinges and entrains aquatic organisms as it 33 withdraws water from Lake Robinson. The RNP CWIS operates as a closed-cycle recirculating 34 system as defined at 40 CFR 125.92(c) (TN254). Section 3.2 of this EIS and Section 2.2.1 of 35 the applicants ER described the cooling and auxiliary water systems (Duke 2025-TN12518).

36 This section summarizes features of these systems relevant to the impingement and 37 entrainment analysis.

38 RNP utilizes two separate CWISs located on the southwestern shore of Lake Robinson. CWIS 1 39 supports supplemental cooling during warmer summer months. CWIS 2 is the primary 40

3-24 nuclear-fueled unit cooling CWIS. Both intake structures utilize curtain walls to withdraw deeper, 1

cooler water from Lake Robinson. The CWIS 1 curtain wall has a 9.5 ft (2.9 m) opening with a 2

normal approach velocity of 0.35 feet per second (fps) (0.11 m/s) and the CWIS 2 curtain wall 3

has a 21.5 ft (6.55 m) opening at the bottom of the lake, where water is withdrawn for cooling at 4

0.97 fps (0.3 m/s), and then travels to the intake bays. CWIS 1 has two intake bays and CWIS 2 5

has three intake bays, each 11.2 ft (3.41 m) wide.

6 Within the intake bays, water flows through traveling screens, a screen wash system, and a 7

debris trough. The traveling screens are 10 ft (3.05 m) wide and feature mesh openings of 8

0.375 square inches (in2) (2.4 square centimeters [cm2]). Under full flow conditions, velocity 9

at the intake screen racks is 2.1 fps (0.6 mps). During screen cleaning, debris is collected in the 10 debris trough and conveyed through a pipe that discharges into Black Creek approximately 11 400 ft (122 m) downstream of Lake Robinson Dam. Duke uses sodium hypochlorite to 12 control biological fouling within the CWIS.

13 Underground conduit 10.5 ft (3.2 m) in diameter carry cooling water from the intake condensers 14 to the RNP discharge canal. The discharge canal, located on the western shore of the lake, is 15 4.2 mi (6.8 km) in length and is approximately 15 ft (4.6 m) wide by 13 ft (4 m) deep. Discharge 16 canal water travels at approximately 1.75 fps (0.53 m/s). It takes approximately 3.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> for 17 water to travel from the discharge structure to the end of the discharge canal. At the end of the 18 discharge canal, a weir promotes mixing (Duke 2025-TN12518).

19 Organisms small enough to pass through the traveling screen mesh, such as fish eggs, larvae, 20 and other zooplankton, are entrained in the cooling water system. Entrained organisms pass 21 through the entire cooling system, enter the discharge channel, and can either become stranded 22 in the discharge channel or pass through it and re-enter the aquatic environment. During this 23 process, entrained organisms are subject to mechanical, thermal, and toxic stresses.

24 3.5.2.2 Clean Water Act Section 316(b) Requirements for Existing Facilities 25 Under the CWA Section 316(b) regulations, the location, design, construction, and capacity of 26 cooling water intake structures of regulated facilities must reflect the BTA for minimizing 27 impingement and entrainment mortality. Section 4.6.1.2 of the LR GEIS (NRC 2024-TN10161) 28 provides a description of the allowable alternatives to comply with this regulation and is 29 incorporated here by reference.

30 3.5.2.3 Impingement Mortality and Entrainment Best Technology Available 31 The SCDES has not made an impingement mortality or entrainment BTA determination for RNP.

32 The current NPDES permit (SC0002925) was issued on March 8, 2007, with an expiration date 33 of April 31, 2011, was revised on October 15, 2013, and is currently under an administrative 34 extension. As part of the NPDES renewal application, Duke submitted an updated CWA 316(b) 35 report for compliance with impingement and entrainment mortality BTA in June 2022 (Duke 36 2025-TN12518, Duke 2025-TN12519).

37 The SCDES has not yet made a determination, but could determine that RNP operations meet 38 one of the impingement mortality and entrainment mortality compliance alternatives without 39 Duke needing to modify or upgrade any components of the cooling water intake system. When 40 the SCDES makes the impingement and entrainment mortality BTA determinations, it may also 41 impose additional requirements to reduce or mitigate the effects of impingement mortality at 42 RNP. Such requirements from SCDES would be incorporated as conditions of a future renewed 43 NPDES permit.

44

3-25 The NRC staff assumes that any additional requirements that the SCDES imposes would 1

minimize the impacts of impingement and entrainment mortality over the course of the proposed 2

subsequent license renewal term in accordance with CWA Section 316(b) requirements.

3 However, because the SCDES has not made BTA determinations at this time, the NRC staff 4

also considers other lines of evidence below, including the hydraulic zone of influence and 5

results of impingement mortality and entrainment studies, to more fully evaluate the magnitude 6

of impact that impingement and entrainment would represent during the proposed subsequent 7

license renewal period.

8 3.5.2.4 Engineered Designs and Operational Controls 9

In the 2014 final CWA Section 316(b) rule, the U.S. Environmental Protection Agency (EPA) 10 indicates that two basic approaches can reduce impingement mortality and entrainment: (1) flow 11 reduction, and (2) including technologies into the cooling water intake design that gently exclude 12 organisms or collect and return organisms without harm to the water body. The EPA also notes 13 that two additional approaches can reduce impingement and entrainment but that these 14 technologies may not be available to all facilities. The two additional approaches are: relocating 15 the facilitys intake to a less biologically rich area in a water body and reducing the intake 16 velocity. The RNP cooling water intake structure incorporates several of these approaches.

17 Flow Reduction 18 Reducing the amount of water that is withdrawn for cooling purposes from a waterbody reduces 19 the flow rate and thus the number of aquatic organisms that are drawn through the intake 20 structure and subject to impingement or entrainment. Some nuclear power plants have 21 conditions established in NPDES permits or other agreements that require the plant to reduce 22 the volume of water withdrawn under certain conditions or at certain times of the year. For 23 instance, reducing the volume of water withdrawn from a waterbody during peak spawning 24 periods can significantly reduce entrainment. RNP operates as a closed-cooling recirculating 25 system (CCRS) which includes Lake Robinson and two CWISs. On April 11, 2018 the South 26 Carolina Department of Health and Environmental Control (now called SCDES) confirmed that 27 the CWIS is designed and operates as a CCRS and meets the definition of CCRS provided in 28 40 CFR 125.92(c) (Duke 2025-TN12518). The curtain walls on CWIS 1 and 2 (described in 29 Section 3.5.2.1) are also assumed to reduce flow by allowing the CWIS to pull cooler water from 30 the bottom of the reservoir, although this reduction in flow has never been quantified (Duke 31 2025-TN12519). Additionally, CWIS 1 has reduced flow by approximately 41 percent of its total 32 withdrawal capacity of 125.9 MGD (476.6 MLD) since Unit 1 was retired in 2012 (Duke 2025-33 TN12519). From 2016 through 2020 the actual intake flow was 713 MGD (2,699 MLD) which is 34 approximately 83 percent of the plants total design intake flow (Duke 2025-TN12519).

35 Technologies That Exclude or Collect and Return Organisms 36 Several of the RNPs CWIS technologies help exclude organisms from becoming impinged or 37 entrained. As described in Section 3.5.2.1, these include a curtain wall and traveling screens.

38 The EPA indicates that, ideally, traveling screens would be used with a fish handling and return 39 system (79 FR 48300-TN4488). RNP does not have a fish return system (Duke 2025-TN12518).

40 Location of the Facilitys Intake 41 Location of the intake system is another design factor that can affect impingement and 42 entrainment because locating intake systems in areas with high biological productivity or 43

3-26 sensitive biota can negatively affect aquatic life. The RNP intake structures are located at the 1

southwest corner of Lake Robinson near the dam. The curtain wall at CWIS 1 results in a 9.5 ft 2

(2.9 m) opening at the bottom of Lake Robinson, while CWIS 2 leaves a 21.5 ft (6.6 m) opening, 3

allowing water to be drawn from the lower depths of the lake and potentially reducing the 4

number of fish eggs and larvae, which are found in the upper ~18 to 20 ft (5.5 to 6.1 m) of the 5

water column, from entering the CWISs (Duke 2025-TN12518). Redbreasted sunfish, which 6

were often found around the intake during annual environmental monitoring (see 7

Section C.2.2.3) spawn in shallow water ~3 ft (0.9 m) deep, and the bottom dwelling catfish in 8

the lake are cavity spawners. Given the location of the intake, there is a naturally lower risk of 9

affecting aquatic resources since it is pulling deeper benthic water. Therefore, the location of the 10 facilitys intake could be excluding early life stages, and less mobile organisms and life stages.

11 Intake Velocity 12 Water velocity associated with the intake structure greatly influences the rate of impingement 13 and entrainment. The higher the approach velocity, through-screen velocity, or both, the greater 14 the number of organisms that will be impinged or entrained. Most fish can escape impingement 15 by swimming away from a cooling water intake structure if the approach velocity is 0.5 fps 16 (0.15 m/s) or less (79 FR 48300-TN4488). The approach velocity at RNP ranges from 0.35 fps 17 (0.11 m/s) during normal lake level operations (220.7 ft MSL) to 0.4 fps (0.12 m/s) at low water 18 elevation (220.7 ft MSL) at CWIS 1 and 0.97 fps (0.3 m/s) to 1.06 fps (0.32 m/s) at CWIS 2 19 (Duke 2025-TN12518). The area of impact for impingement and entrainment for CWIS 1 is 20 contained within the intake bays but for CWIS 2 it extends ~19 ft (5.8 m) out into Lake 21 Robinson. The design through screen velocity at the traveling screens is 0.66 fps (0.2 m/s) to 22 0.74 fps (0.22 m/s) at CWIS 1 and 1.81 fps (0.55 m/s) to 1.96 fps (0.6 m/s) at CWIS 2 (Duke 23 2025-TN12518). The through screen velocity, which exceeds EPA recommendations of 0.5 fps 24 (0.15 m/s), could adversely affect smaller, slower fish, early life stages, and less mobile 25 organisms and life stages (40 CFR 125.94(c)) (TN254).

26 3.5.2.5 Impingement and Entrainment Studies 27 Impingement 28 In the original CWA Section 316(b) demonstration, impingement of fish was addressed based on 29 studies conducted on a monthly basis (48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> samples) between December 1973 and 30 July 1975 (NRC 2003-TN7260). Sampling continued on a weekly basis (24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> samples) from 31 July 1975 through December 1975. An initial screen washing was followed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by 32 additional screen washes. Fish washed from the screens were identified, weighed, and 33 measured. Impingement of fish at the Unit 2 intake averaged 866 fish per day in 1974 and 291 34 fish per day in 1975. Of these, bluegill made up 74 percent and 57 percent of the biomass in 35 1974 and 1975, respectively. Most bluegill impinged were less than 115 millimeters (mm) 36 (4.5 in.) in length. Chain pickerel (Esox niger) was the next most common species impinged, 37 comprising 14 percent and 28 percent of the biomass in 1974 and 1975, respectively. Maximum 38 impingement occurred during the summer, and minimum impingement occurred during the 39 winter. Fewer fish were impinged on CWIS 1 intake screens compared to those on CWIS 2 40 because Unit 1 draws less water through the intake pumps.

41 For the new CWA Section 316(b) demonstration, researchers monitored impingement at 42 CWIS 1 and CWIS 2 from January to December 2006 (Duke 2025-TN12519). They collected 43 samples twice monthly from March through November and once monthly in January, February, 44 and December. Each 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> sampling event included four, 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> intervals. Seven species of 45

3-27 fish were impinged (bluegill, black crappie, largemouth bass, redbreast sunfish, warmouth, white 1

catfish, and white perch, which was introduced), with bluegill dominating both abundance and 2

biomass at both intakes. At CWIS 1, bluegill made up ~92 percent of abundance and biomass, 3

while at CWIS 2 they accounted for almost 88 percent of individuals and 76 percent of biomass.

4 Impingement peaked at night with sunset to 0100 highest followed by 0100 to dawn. Monthly 5

impingement densities were similar between CWIS 1 and 2 with densities peaking in June, 6

November, and December at both intakes. Young-of year and age-1 bluegill dominated the peak 7

densities and higher impingement rates in November were likely a result of the impingement of 8

fish that had been killed during rotenone sampling in the intake bay (Duke 2025-TN12519).

9 Annual impingement estimates under actual flow volumes were 60,845 fish at CWIS 1 and 10 115,695 fish at CWIS 2, only slightly lower than the estimates at maximum design flow with a 11 reduction of 2 percent at CWIS 1 and 5.5 percent at CWIS 2. The continued abundance of 12 bluegill in the lake indicates that there are no significant impacts to the fish population from 13 impingement on the intake screens (see Section C.2.2.3 for bluegill abundance).

14 Entrainment 15 In the original CWA Section 316(b) demonstration, entrainment of ichthyoplankton was 16 addressed based on studies conducted on a weekly basis between March 1975 and 17 February 1976 (NRC 2003-TN7260). Duplicate samples were collected during day and night 18 using plankton nets. During the study period, no fish eggs were collected, though larval fish 19 were collected during every month but January. Of all the fish collected, 93.8 percent were 20 percids (perch and darters). Other larval fish entrained included 2.6 percent centrarchids 21 (sunfish) and 0.3 percent catastomids (chubsuckers). The remaining fish (3.3 percent) could not 22 be identified to family. None of the species entrained are known to prefer pelagic areas (e.g.,

23 near the intake structure) for spawning. However, based on early CP&L ichthyoplankton 24 sampling conducted in the lower impoundment and discharge areas, there is evidence that 25 darters may move into pelagic areas soon after spawning (CP&L 1976-TN12529). The 26 continued presence and abundance of darters in the lake during early studies (4 years after 27 initial Unit 2 operation) suggested that the effects of entrainment on their population were 28 negligible (CP&L 1976-TN12529).

29 For the CWA Section new 316(b) demonstration, researchers conducted an entrainment 30 characterization study at CWIS 2 in 2016 and 2017 (Duke 2025-TN12519). Samples were 31 collected twice monthly from March through October in 2016 and March through November in 32 2017. They collected 909 organisms from 6 families in 2016 and 1,044 from 5 families in 2017, 33 no Cyprinidaes (minnow and carp) were collected in 2017. Entrainment peaked in April and May 34 both years, dominated by clupeids (shad and herring) in spring and centrarchids (sunfish) in late 35 summer. In 2017, darters also contributed to a smaller October peak. Post yolk-sac larvae 36 accounted for nearly all collections (98 percent in 2016 and 96 percent in 2017), while yolk-sac, 37 young-of-year, and yearlings were rare, and only one egg was collected in 2017. Results show 38 that post yolk-sac shad, sunfish, and darters are most susceptible to entrainment, reflecting the 39 abundance of rocky shoreline habitat near CWIS 2. Entrainment was consistently higher at night 40 than during the day. In 2016, entrainment based on actual water withdrawals totaled an 41 estimated 98.6 million ichthyoplankton, a 9.1 percent reduction in entrainment compared to 42 maximum water withdrawals. In 2017, estimated entrainment at actual water withdrawals rose 43 slightly to 101.8 million ichthyoplankton, representing a 16.7 percent reduction from maximum 44 water withdrawals. Duke also calculated equivalent adult losses in number and biomass due to 45 entrainment, and it varied between years from 32,697 adults (8,303 pounds [lb] or 3,766 46 kilograms [kg]) to 62,462 adults (32,049 lb [28,332 kg]).

47

3-28 3.5.2.6 Impingement Mortality and Entrainment Conclusion 1

The NRC staff reviewed CWA Section 316(b) BTA requirements, engineered designs and 2

operational controls, and the results of impingement and entrainment studies conducted at 3

RNP. These sources of information indicate that impingement at RNP is limited and that 4

entrainment results in a small number of adult equivalent losses. Impingement primarily 5

affects small juveniles of bluegill, white perch, warmouth, and black crappie, while 6

entrainment primarily affects the post yolk-sac larvae and juveniles of sunfish, shad, and 7

darter species. The available information indicates that impingement and entrainment is not 8

destabilizing or noticeably altering any important attributes of the aquatic environment 9

during the current RNP operating license term.

10 The proposed subsequent license renewal would continue with current operating conditions and 11 environmental stressors rather than introduce entirely new impacts. Therefore, the impacts of 12 current operations and subsequent license renewal on aquatic resources would be similar and 13 RNP would be required to abide by any additional restrictions to reduce impingement and 14 entrainment when the new NPDES permit is issued by SCDES. For the reasons described 15 above, the NRC staff finds that the impacts of impingement mortality and entrainment of aquatic 16 organisms resulting from the proposed subsequent license renewal of RNP would be SMALL.

17 3.5.3 Environmental Consequences: Effects of Thermal Effluents on Aquatic 18 Organisms (Plants with Once-Through Cooling Systems or Cooling Ponds) 19 This issue pertains to acute, sublethal, and community-level effects of thermal effluents on 20 finfish and shellfish from operation of nuclear power plants with once-through cooling systems 21 and cooling ponds during an initial or subsequent license renewal term. This includes plants 22 with helper cooling towers that are seasonally operated to reduce thermal load to the receiving 23 water body, reduce entrainment during peak spawning periods, or reduce consumptive water 24 use during periods of low river flow. Sections 4.6.1.2 and 4.6.1.2.4 of the LR GEIS (NRC 2024-25 TN10161) provide background information for this Category 2 issue, which is incorporated here 26 by reference. Specifically, these sections of the LR GEIS discuss the following information 27 relevant to this issue:

28

1. What thermal effects aquatic ecological communities can experience, including acute 29 effects, sublethal effects, and community-level effects.

30

2. Results of NRC thermal impact analyses at nuclear power plants from 2013 through 2024.

31

3. CWA Section 316(a) requirements for assuring the protection and propagation of a 32 balanced, indigenous population of shellfish, fish, and wildlife in and on the receiving body of 33 water (79 FR 48300-TN4488).

34

4. The NRC staffs reliance on the expertise and authority of the NPDES permitting authority 35 with respect to the impacts of thermal effluents.

36

5. The NRC staffs analysis approach in the absence of CWA Section 316(a) variances by the 37 NPDES permitting authority.

38 As stated in the LR GEIS, if the NPDES permitting authority has granted a CWA Section 316(a) 39 variance and the nuclear power plant has implemented any associated requirements, then the 40 NRC staff assumes that adverse impacts on the aquatic environment would be minimized and 41 that thermal impacts would be SMALL; if this is not the case, or the variance is currently under 42 state review, impacts could be SMALL, MODERATE, or LARGE. The sections below analyze 43 the impacts of thermal effluents on aquatic organisms at RNP.

44

3-29 3.5.3.1 RNP Effluent Discharge 1

As described in Section 2.2.3.1 of the ER (2025-TN12518), RNP discharges thermal effluent 2

from the plant down a 4.2 mi (6.8 km) human-made discharge canal on the western side of the 3

lake. The discharge canal is approximately 15 ft (4.6 m) wide by 13 ft (4.0 m) deep. During 4

operation, water velocity in the discharge canal is 1.75 fps (0.53 m/s) with a transit time of 5

3.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> from the plant to the discharge weir. At the end of the discharge canal, a concrete 6

structure with a weir is located to promote mixing of thermal effluent as it enters Lake Robinson.

7 Thermal effluent from both CWIS 1 and 2 enter the discharge canal. Normal circulation patterns 8

of the lake move the water southwards toward the dam (Duke 2025-TN12518).

9 3.5.3.2 Clean Water Act Section 316(a) Requirements for Point Source Discharges 10 Section 4.6.1.2 of the LR GEIS provides an overview of CWA Section 316(a) and its applicability 11 to environmental reviews (NRC 2024-TN10161).

12 3.5.3.3 CWA 316(a) Thermal Variance and NPDES Permit Provisions 13 The SCDES regulates thermal discharge temperatures at RNP through the NPDES Permit No.

14 SC0002925. Pursuant to South Carolina Code of Regulations, R.61-68 (SCDHEC 2014-15 TN6986), Subchapter 61-68-E, water temperature increases for freshwater bodies may not 16 exceed 5°F (2.78°C) above natural conditions, and the temperature shall not go above 90°F 17 (32.2°C), unless site-specific standards, mixing zones, or CWA Section 316(a) Federal 18 determinations apply. Duke identified that there is generally a 20°F (11.1°C) difference between 19 the intake water and the discharge water, therefore, RNP requires an approved alternate 20 thermal effluent limit, which is shown in Table 3-3.

21 The current NPDES permit was issued on March 8, 2007, and expired on April 30, 2011. It was 22 later revised on October 15, 2013. Because a renewal application was submitted before the 23 permit expired, the permit remains in effect under administrative extension in accordance with 24 Section 122.6 of SC Regulation 61-9 (SCDHEC 2019-TN9121). On March 24, 2014, Duke 25 submitted a letter requesting an update to the 2010 NPDES permit renewal application. SCDES 26 is currently reviewing Dukes application (Duke 2025-TN12518).

27 Table 3-3 Thermal Effluent Alternate Thermal Effluent Limits Specified in the H.B.

28 Robinson Steam Electric Plant National Pollutant Discharge Elimination 29 System Permit No. SC0002925 30 Month Permitted Daily Maximum Temperature Monitoring Frequency December-February 90°F Continuous daily March 92°F Continuous daily April 100°F Continuous daily May 106°F Continuous daily June-September 111.2°F Continuous daily October 108°F Continuous daily November 100°F Continuous daily Source: Duke 2025-TN12518: Table 3.6-2, Attachment A (NPDES Permit).

3-30 3.5.3.4 Thermal Studies 1

Duke, or its contractors, have conducted several thermal studies regarding RNP operations. The 2

NRC staff reviewed the following studies and used them in its analysis of this Category 2 issue:

3 CPL 1996, PEC 2005, as well as several RNP Environmental Monitoring Reports 4

(1975-1995, 2012, 2013, 2014-2015, 2016-2019). All of these environmental reports and 5

studies are found in Dukes Request for Additional Information Response and are hereby 6

incorporated by reference (Duke 2025-TN12519).

7 3.5.3.5 Thermal Impacts Analysis and Conclusion 8

A comprehensive review of long-term and recent environmental monitoring data supports a 9

MODERATE thermal impact conclusion. This conclusion is based on multiple lines of evidence 10 showing that while the broader lake ecosystem remains functional and supports a balanced 11 aquatic community, localized and recurring thermal effects are present near the discharge area 12 of the lake. These effects are seasonal, spatially concentrated, and ecologically relevant, 13 particularly during the summer months when water temperatures and thermal stratification are 14 at its peak.

15 During summer months, Lake Robinson presents strong thermal stratification, with temperature 16 gradients reaching approximately 3.6°F (2°C) per meter of depth in the mid-lake areas (Duke 17 2025-TN12519). Figure 3-6, depicts a cross-section of Lake Robinson directly adjacent to the 18 discharge weirs during summer showing water temperatures and thermal stratification (Duke 19 2025-TN12519: pp. 708). Several studies have found that this level of stratification is notable 20 and suggests a stable water column with limited vertical mixing. In limnological literature, 21 thermal gradients exceeding 1.8°F (1°C) per meter are generally classified as strong, and 3.6°F 22 (2°C) per meter gradients reflect a pronounced resistance to vertical mixing (Wetzel 2001-23 TN12530; Kalff 2002-TN12531). In a blackwater system characterized by high dissolved organic 24 carbon, low nutrient levels, and naturally low oxygen levels, such stratification can exacerbate 25 chemical separation within the water column. The lack of vertical mixing restricts oxygen 26 replenishment to bottom waters, promoting hypoxic or anoxic conditions that can lead to the 27 release of nutrients and metals from sediments. These changes can degrade water quality and 28 reduce the availability of suitable habitat for aquatic organisms, particularly in deeper areas of 29 the lake.

30 31 Figure 3-6 Vertical Temperature Profile at Transect E Adjacent to the Thermal 32 Discharge Weir, August, 1995 (Duke 2025-TN12519).

33

3-31 The thermal discharge from RNP enters the lake in the mid to northern portion where water is 1

typically shallower (13.1 to 19.7 ft [~4 to 6 m]) and warmer in the summer months. In contrast, 2

the southern portion of the lake where CWIS 1 and CWIS 2 are located contain deeper and 3

cooler water. As surface temperatures rise and stratification increases, fish and other aquatic 4

organisms may migrate south and deeper in the water column to seek thermal refuge. This 5

behavioral response is common in stratified systems and has been documented in multiple 6

freshwater environments where fish migrate vertically or horizontally to locate cooler, oxygen-7 rich waters during periods of thermal stress (Coutant 1987-TN7736).

8 Thermal stratification, defined as temperature change of at least 3.6°F (2°C) per meter, was 9

observed annually from 2016 through 2019 at multiple test stations throughout Lake Robinson 10 during the 2016-2019 Environmental Monitoring Report (Duke 2025-TN12519). At transect E2 11 immediately adjacent to the discharge weirs, where maximum water depth is 19.7 ft (6 m),

12 dissolved oxygen (DO) concentrations dropped below 5 milligram(s) per liter (mg/L) in the 13 bottom 3.3 to 6.6 ft (1 to 2 m ) during summer months. While surface DO remained above 5 14 mg/L at all stations and the upper 9.8 ft (3 m) of the water column generally stayed above this 15 threshold. In June 2016, DO concentrations at transects E2 and F2 exceeded 5 mg/L only within 16 the upper 6.6 ft (2 m) of the water column. These conditions indicate seasonal habitat 17 compression and potential stress for aquatic organisms sensitive to low oxygen and/or elevated 18 temperatures.

19 The thermal plume from RNPs discharge canal floats in the upper part of the water column 20 (3.3-6.6 ft or 1-2 m) due to density differences which resist vertical mixing (Duke 2025-21 TN12519). Given that the transect of Lake Robinson near the discharge weir has a depth range 22 of 16.4-19.7 ft (5-6 m), both the upper and lower portions of the water column may be 23 unsuitable for aquatic life during warm summer months. The upper layers are unsuitable due to 24 elevated temperatures, and the lower layers due to depleted DO levels. This leaves only a 25 narrow mid-column band as potentially suitable habitat. Such vertical habitat compression can 26 increase competition, predation risk, and physiological stress, particularly for species with 27 limited mobility or environmental tolerances (Duke 2025-TN12519).

28 Dukes 1996 long-term monitoring report adds additional context for thermal impacts on aquatic 29 organisms (Duke 2025-TN12519). It found that spring water temperatures in heated areas may 30 rise by 1.7-2.2°C (3-4°F) under the conservative worse case scenario, potentially advancing 31 fish spawning 1 to 2 weeks earlier in the year. While this may not seem significant, the timing of 32 spawning is tightly linked to food availability for newly hatched fish. If zooplankton populations (a 33 key food source) do not shift in sync with spawning, juvenile fish may experience limited food 34 availability during key developmental stages. This potential temporal mismatch introduces 35 ecological uncertainty, especially for species with narrow spawning periods like the chain 36 pickerel. There are also areas of the lake where surface water temperatures have not dropped 37 low enough to trigger spawning since at least 2012, particularly near the discharge (transect E) 38 and potentially by the intake and just downstream of the dam (transects A and H) (Duke 2025-39 TN12519). This again would negatively impact species like the chain pickerel, which spawn in 40 shallow waters when temperatures approach 45°F (7.2°C), if temperatures never drop below 41 their spawning trigger (SCDNR 2015-TN12569). Other species like bowfin (Amia calva) and 42 eastern creek chubsucker (Erimyzon oblongus) also spawn at cooler temperatures (59-68°F 43

[15-20°C]).

44 Thermal effects are also evident in the phytoplankton and benthos invertebrate communities.

45 Diatoms showed temporary seasonal suppression at the discharge area when water 46 temperatures reached 98.6 to 105.1°F (37 to 40.6°C), although no long-term shifts in 47

3-32 phytoplankton composition were observed from 1985 to 1995 (Duke 2025-TN12519). The 1

benthic invertebrate community remained stable overall, but taxa richness and diversity were 2

reduced at the discharge area during August, with recovery observed by fall. These short-term 3

reductions suggest that thermal conditions periodically disrupt community structure, even if the 4

system recovers seasonally.

5 The fish community, while considered balanced overall, shows noticeable signs of thermal 6

influence. Some species, such as dollar sunfish and lake chubsucker, increased in heated 7

areas, while others, like black banded sunfish have declined (Duke 2025-TN12519). Fish tend 8

to avoid the hottest surface waters near the discharge, which can reach up to 106.7°F (41.5°C),

9 by moving to cooler, oxygenated water less than 13 ft (4 m) deep. This behavior demonstrates 10 the availability of thermal refuge but also confirms that thermal conditions influence fish 11 distribution and habitat use. Historical fishery studies further indicate that some minor fish 12 species are temporarily reduced in number near the discharge during summer but recolonize 13 the area in the fall as temperature drops (Duke 2025-TN12518).

14 Thermal impacts are not limited to the water column. The growth of aquatic plants is also 15 affected. According to Dukes environmental report, the thermal effluent restricts aquatic plant 16 growth along the eastern shores opposite the discharge canal and in the cove directly north of 17 the canal in areas that normally would support aquatic plant growth (Duke 2025-TN12518).

18 While these effects are localized and not considered a threat to the lake-wide aquatic plant 19 population, they further illustrate the localized ecological footprint of the thermal discharge.

20 Although the PEC 2005 report concluded that the thermal plume and associated mixing zone 21 occupies only 1.72 percent of the lakes surface area and 2.65 percent of its volume, the vertical 22 structure of the water column in the affected area is critical (Duke 2025-TN12518). The 23 combination of shallow depth (16.4-19.7 ft [5-6 m]), a floating thermal plume in the upper 6.6 ft 24 (2 m) and DO depletion in the bottom 3.3-6.6 ft (1-2 m) creates a narrow band of space that 25 aquatic organisms can utilize or use to transit between the northern and southern ends of the 26 lake. The spatial constraint, combined with seasonal DO depletion, altered spawning timing, and 27 biological responses across multiple trophic levels, is sufficient to noticeably alter the aquatic 28 ecological environment, however, these changes occur without evidence of destabilizing the 29 overall system.

30 Duke is currently operating under an administrative extension of its NPDES permit, pending 31 review by the SCDES. Historically, the State has established temperature limits under CWA 32 Section 316(a) and South Carolina regulations that are intended to protect aquatic life. Based 33 on this regulatory framework and past implementation, the NRC staff finds that adverse impacts 34 from thermal effluent have been minimized and mitigated. Because the characteristics of the 35 thermal discharge are expected to remain consistent under the proposed subsequent license 36 renewal term, the NRC staff anticipates that similar environmental effects would continue. Given 37 these considerations, the NRC staff concludes that the potential impacts of thermal effluent on 38 the aquatic environment would be MODERATE, as some noticeable, localized and seasonal 39 effects may persist, but they are not expected to destabilize the aquatic ecosystem. SCDES will 40 continue to review the CWA Section 316(a) variance during each NPDES permit renewal and 41 may require additional mitigation or monitoring, if necessary, to ensure the protection and 42 propagation of a balanced, indigenous population of aquatic life in Lake Robinson.

43 For these reasons, the NRC staff finds that thermal impacts during the proposed subsequent 44 license renewal term are sufficient to alter noticeably, but not to destabilize important attributes 45

3-33 of the aquatic environment and would, therefore, result in MODERATE impacts on aquatic 1

resources for thermal effects.

2 3.5.4 Environmental Consequences: Water Use Conflicts with Aquatic Resources 3

(Plants with Cooling Ponds or Cooling Towers Using Makeup Water from a River) 4 Section 4.6.1.2.10 of the LR GEIS (NRC 2024-TN10161) provides background information for 5

this Category 2 issue, which is incorporated here by reference. Water use conflicts occur when 6

the amount of water needed to support aquatic resources is diminished from demand for 7

agricultural, municipal, or industrial use, decreased water availability due to droughts, or a 8

combination of these factors. Section 3.2 of this EIS provides additional information regarding 9

water use conflicts and flow data under the surface water use conflict section.

10 RNP withdraws water from the intake structure located on the southwestern shore of Lake 11 Robinson and discharges to the northern portion of the lake. Black Creek is located both 12 upstream and downstream of RNP and provides makeup water for plant operations.

13 Appendix C.2.1.2 provides information on Black Creek. Additionally, Duke operates and 14 maintains Robinson Dam which is located on the southern shore of Lake Robinson and 15 discharges lake water to downstream Black Creek. Duke does not have a minimum water 16 release requirement from the dam to Black Creek (Duke 2025-TN12519). Duke is permitted by 17 SCDES to withdraw 3,884 MGD (Unit 1) and 22,386 MGD (Unit 2). Duke reports in its 2025 18 environmental report that approximately 3.6 to 7.5 MGD (5.57 to 11.6 cfs) is lost to consumptive 19 use from plant operations (Duke 2025-TN12518). Black Creek and Lake Robinson experience 20 the lowest average monthly flow during the warm summer months of June through September 21 (summer flow), making these 4 months the critical timeframe for potential water use conflicts 22 with aquatic resources to arise.

23 USGS gauge No. 02130900, located approximately 2 mi (3.2 km) upstream from RNP near 24 McBee, South Carolina, provides 65 years of flow data for Black Creek. The average summer 25 flow (June-September) at this location is 101 cfs or ~65 MGD (2.86 m3/s) (USGS 2025-26 TN12570). Downstream of Lake Robinson, USGS gauge No. 02130910 near Hartsville, 27 South Carolina, records an average summer flow of 151 cfs or ~98 MGD (4.28 m3/s) over the 28 same period (USGS 2025-TN12571). These flows include water from upstream in addition to 29 tributary input and runoff from the local water basin.

30 Based on RNP operational data, the facilitys consumptive water use, primarily from evaporative 31 losses and blowdown, ranges from 5.6 to 11.6 cfs (~3.6 to 7.5 MGD or 0.158 to 0.329 m3/s) 32 during summer months. Assuming the higher number, this represents about 11 percent of the 33 average Black Creek inflow to Lake Robinson during the summer months period. While 34 downstream flows are higher due to dam releases and additional tributary inputs, this estimate 35 highlights the potential influence of RNP operations on water availability during low-flow summer 36 conditions.

37 Dukes environmental report states that water within Lake Robinson has an average residence 38 time of approximately 55 days (Duke 2025-TN12518). Calculations based on the reservoirs 39 volume (30,487 ac-feet) and long-term average annual outflow (201 cfs [130 MGD or 5.69 m3/s])

40 from USGS gauge no. 02130910 provide an accurate annual average residence time of 41 approximately 76 days (see Table 3-4 and Section 3.2; Duke 2025-TN12518). During summer 42 months (June through September), when average outflow decreases to 151 cfs (98 MGD or 43 4.28 m3/s), the residence time increases to approximately 102 days. Although the annual 44 residence time remains within the typical range for medium-sized reservoirs 45

3-34 (30-90 days), the extended summer residence time is ecologically significant in this blackwater 1

system as it enhances thermal accumulation and reduces flushing during periods of peak 2

thermal discharge (Thornton et al. 1991-TN12572). The lake receives inflow from Black Creek, 3

which averages 101 cfs (65 MGD or 2.86 m3/s) during summer months (USGS Gauge No.

4 02130900), and discharges over Robinson Dam via a spillway controlled solely by inflow, 5

with no minimum release requirement (Duke 2025-TN12519). During low-flow summer periods 6

(June-September), this passive outflow regime contributes to limited flushing capacity.

7 RNPs consumptive use, estimated at 5.57 to 11.6 cfs (~3.6 to 7.5 MGD or 0.158 to 0.329 m3/s) 8 during summer, represents approximately 5-11 percent of the average summer inflow, a 9

substantial proportion in a system with naturally low dissolved oxygen (blackwater conditions) 10 and thermal inputs from plant operations (Duke 2025-TN12518). Long-term monitoring data 11 from Duke shows that thermal stratification occurs annually and seasonally at Stations E2, F2, 12 and G2, with DO levels falling below 5 mg/L in the bottom 3.3-6.6 ft (1-2 m) of the water 13 column during summer (Duke 2025-TN12519). These conditions are most pronounced at 14 transect E2, where June 2016 showed widespread low DO at the bottom of the lake While 15 surface waters and the upper 9.8 ft (3 m) generally remained above 5.0 mg/L, the persistence of 16 low DO at depth reflects the influence of both thermal inputs and limited vertical mixing.

17 Table 3-4 Lake Robinson Residence Time Calculations Measured from U.S. Geological 18 Survey Gauge No. 02130910, 66 Years of Water Data 19 Flow Basis Lake Robinson Volume Average (mean) Outflow Approximate Residence Time Annual (January-December) 30,487 ac-ft 201 cfs 76 days Summer (June-September) 30,487 ac-ft 151 cfs 102 days Source: Duke 2025-TN12518.

20 The combination of lengthened residence time (102 days), seasonal low inflows, no minimum 21 dam flow release, and the sensitive blackwater characteristics of Lake Robinson supports a 22 MODERATE impact determination. These conditions create a system where even modest 23 consumptive use can contribute to noticeable ecological effects, including reduced flushing, 24 thermal and oxygen stress, and habitat compression for aquatic species during critical summer 25 months. Despite these recurring effects, the aquatic biota communities have remained stable 26 over time, with only temporary seasonal reductions in diversity and abundance near the 27 discharge area (Duke 2025-TN12519). This is indicative that while the system is noticeably 28 altered during critical periods (June through September), it is not ecologically destabilized.

29 Therefore, the available data supports a MODERATE impact determination for aquatic resource 30 water use conflicts.

31 3.6 Federally Protected Ecological Resources 32 The NRC staff must consider the effects of its actions on ecological resources protected under 33 several Federal statutes and must consult with the U.S. Fish and Wildlife Service (FWS) and the 34 National Marine Fisheries Service (NMFS) or the National Oceanic and Atmospheric 35 Administration (NOAA) prior to acting in cases where an agency action may affect those 36 resources. These statutes include the following:

37

• Endangered Species Act of 1973 (TN1010) 38

• Magnuson-Stevens Fishery Conservation and Management Act (TN9966) 39

• National Marine Sanctuaries Act (NMSA) (TN7197) 40

3-35 Sections 3.6.3 and 4.6.1.3 of the LR GEIS (NRC 2024-TN10161) provides background 1

information for this Category 2 issue, which are incorporated here by reference. In the following 2

sections, the NRC staff summarizes its findings with respect to federally protected ecological 3

resources protected under these statutes and the outcome of the related consultations with the 4

FWS, NMFS, and NOAA. Additional information, including the biological evaluation, concerning 5

these resources can be found in Appendix C.

6 3.6.1 Endangered Species Act: Federally Listed Species and Critical Habitats under 7

U.S. Fish and Wildlife Jurisdiction 8

In accordance with 50 CFR 402.08 (TN4312), Federal agencies may designate a non-Federal 9

representative (NFR) to conduct informal consultation. By letter dated 15 May 2025, the NRC 10 notified the FWS of its designation of Duke as its NFR for the RNP subsequent license renewal 11 (NRC 2025-TN12573). In support of the consultation, Duke is preparing a biological evaluation 12 to evaluate the potential impacts of the proposed subsequent license renewal. The biological 13 evaluation will evaluate the impacts of the proposed RNP subsequent license renewal on 14 federally listed species and critical habitats under the FWSs jurisdiction. Appendix C includes 15 the detailed evaluation. Table 3-5 identifies the ESA effect determination for each species, 16 provides a brief justification for the NRC staffs finding, and lists the date of the FWSs 17 concurrence, as applicable.

18 Table 3-5 Effect Determinations for Federally Listed Species Under U.S. Fish and 19 Wildlife Jurisdiction for the H.B. Robinson Steam Electric Plant Subsequent 20 License Renewal 21 Species or Critical Habitat Federal Status(a)

Summary of Effects ESA Effect Determination(b)

FWS Concurrence Date(c) tricolored bat (Perimyotis subflavus)

FPE IP IP TBD red-cockaded woodpecker (Dryobates borealis)

FT IP IP TBD monarch butterfly (Danaus plexippus)

FPT IP IP TBD rough-leaved loosestrife (Lysimachia asperulaefolia)

FE IP IP TBD southern hognose snake (Heterodon simus)

FPT IP IP TBD (a) Indicates protection status under the ESA = Endangered Species Act. FC = candidate for Federal listing; FE = federally endangered; FT = federally threatened; FPE = proposed for Federal listing as endangered; FPT = proposed for Federal listing as threatened; IP = in-progress, pending NFR action.

(b) The NRC staff makes its effect determinations for federally listed species in accordance with the language and definitions specified in the FWS and NMFS Endangered Species Consultation Handbook (FWS and NMFS 1998-TN1031).

(c) TBD = to be determined; the NRC will seek the FWSs concurrence following the issuance of this draft EIS.

3.6.2 Endangered Species Act: Federally Listed Species and Critical Habitats under 22 National Marine Fisheries Service Jurisdiction 23 As part of the environmental review process, the NRC staff evaluated the potential presence of 24 listed species under the jurisdiction of NMFS within the projects action area. This review 25 included reviewing the ERs analysis for Atlantic sturgeon and shortnose sturgeon and querying 26

3-36 for listed species with NMFSs Southeast Region ESA Section 7 Mapper (NOAA 2025-1 TN12622). Upon receiving no results of listed NMFS species or critical habitats within the action 2

area, the NRC staff concludes that no further coordination or consultation under Section 7 of the 3

ESA with NMFS is required for this proposed action.

4 3.6.3 Magnuson-Stevens Act: Essential Fish Habitat 5

Under the provisions of the Magnuson-Stevens Act (TN9966), the Fishery Management 6

Councils and NMFS have designated essential fish habitat (EFH) for certain federally managed 7

species. EFH is defined as the waters and substrate necessary for spawning, breeding, feeding, 8

or growth to maturity (16 U.S.C. 1802(10)) (TN12474). For each federally managed species, the 9

Fishery Management Councils and NMFS designate and describe EFH by life stage (i.e., egg, 10 larva, juvenile, and adult). There is no essential fish habitat within the affected area. Because no 11 EFH occurs within the affected area, the NRC staff concludes that the proposed action would 12 have no effect on essential fish habitat.

13 3.6.4 National Marine Sanctuaries Act: Sanctuary Resources 14 Congress enacted the NMSA (TN7197) in 1972 to protect areas of the marine environment that 15 have special national significance. The NMSA authorizes the Secretary of Commerce to 16 establish the National Marine Sanctuary System and designate sanctuaries within that system, 17 which includes 15 sanctuaries and 2 marine national monuments, encompassing more than 18 600,000 mi2 (1,550,000 km2) of marine and Great Lakes waters from Washington State to the 19 Florida Keys and from Lake Huron to American Samoa. Within these areas, sanctuary 20 resources include any living or non-living resource of a national marine sanctuary that 21 contributes to the conservation, recreational, ecological, historical, educational, cultural, 22 archaeological, scientific, or aesthetic value of the sanctuary. No national marine sanctuaries 23 occur within the affected area for this proposed action. Because no national marine sanctuaries 24 occur within the affected area, the NRC staff concludes that the proposed action would have no 25 effect on sanctuary resources.

26 3.7 Historic and Cultural Resources 27 NEPA (TN661) requires Federal agencies to consider the potential effects of their actions on the 28 affected human environment, which includes aesthetic, historic, and cultural resources as these 29 terms are commonly understood, including such resources as sacred sites. Section 106 of the 30 NHPA (TN4839), requires Federal agencies to consider the effects of their undertakings on 31 historic properties. While NHPA emphasizes impacts on historic properties, for NEPA 32 compliance, impacts on cultural resources that are not eligible for or listed in the National 33 Register of Historic Places (NRHP) would also need to be considered. In accordance with 34 36 CFR 800.8(c) (TN513), the NRC complies with NHPA Section 106 requirements through its 35 NEPA process.

36 Historic and cultural resources are the remains of past human activities and include precontact 37 (i.e., prehistoric) and historic era archaeological sites, districts, buildings, structures, and 38 objects. Historic properties are defined as resources listed on or eligible for listing in the NRHP.

39 The NRHP is the Nations official list of recognized buildings, structures, objects, sites, and 40 districts of national, State, or local historical significance that merit preservation. The criteria for 41 eligibility are listed in the 36 CFR 60.4 (TN1682) and include (a) association with significant 42 events in history; (b) association with the lives of persons significant in the past; (c) embodiment 43

3-37 of distinctive characteristics of type, period, or construction; and (d) sites or places that have 1

yielded, or are likely to yield, important information.

2 In the context of NEPA, the proposed action (i.e., undertaking) is the subsequent license 3

renewal of the current renewed operating license, which would extend the current operating 4

term for an additional 20 years. The direct area of potential effects (APEs) consists of lands 5

within the 5,900 ac (2,400 ha) RNP site and the transmission lines up to the first substation that 6

may be directly or indirectly affected by land-disturbing or other operational activities associated 7

with continued operations and maintenance and/or refurbishment activities. The indirect APE is 8

a 6 mi (10 km) radius of which the centerpoint is located at the RNP. The APEs are defined 9

consistent with the applicants subsequent license renewal ER (Duke 2025-TN12518:

10 Section 3.8).

11 This section describes the cultural background and the historic and cultural resources found at 12 the RNP site and surrounding area. The chronology of the area is divided into the following 13 periods: Paleoindian (prior to 8000 B.C.), Archaic (8000-3000 B.C.), Woodland (3000 B.C.-A.D.

14 1000), Mississippian (A.D. 1000-1520), Exploratory (A.D. 1520-1670), and Historic 15 (A.D. 1670-present). The applicable cultural history background information described in the 16 applicants subsequent license renewal ER, Section 3.8 in Appendix E (Duke 2025-TN12518) 17 remains accurate and is herein incorporated by reference.

18 The RNP initial license renewal supplemental EIS, Section 2.2.9 (NRC 2003-TN7260) and the 19 applicants subsequent license renewal ER (Duke 2025-TN12518: Section 3.8) describe historic 20 and cultural resources at the RNP site and surrounding area, based on historic and 21 archaeological site file searches. In addition to its independent review, the NRC staff used this 22 information to support its NHPA Section 106 obligations and is herein incorporated by reference.

23 A literature review undertaken through the South Carolina Department of Archives and History 24 ArchSite database, South Carolina Institute of Anthropology and Archaeology, National Park 25 Services National Register of Historic Places Information System, Historic American Buildings 26 Survey/Historic American Engineering Record listings, South Carolina Historic Properties 27 Record database for the RNP initial license renewal supplemental EIS (NRC 2003-TN7260),

28 and subsequent license renewal ER (Duke 2025-TN12518) identified no previously recorded 29 archaeological sites within or immediately adjacent to the RNP site. However, the 1840 Wiley 30 Warren Plat map shows the Wiley Warren family farm located on what is now the RNP site. Any 31 structures that were associated with the farm were destroyed before or during construction of 32 RNP. A family cemetery was also reportedly located near the RNP visitor center. No historical 33 sites or cemeteries within the RNP site were identified during the applicants most recent review 34 of the South Carolina Historic Properties Record (SCHPR) database and no physical evidence 35 or remains of the historic Wiley Warren farmstead or cemetery has been identified onsite (Duke 36 2025-TN12519).

37 The NRC staff conducted a literature review to confirm the information available in the 38 subsequent license renewal ER (Duke 2025-TN12518), which clarified historic and cultural 39 resources information regarding site file searches and identified new information regarding 40 evaluation of RNP as a historic property (SCDAH 2025-TN12649; Dorn and Doshier 2025-41 TN12655).

42 The NRC staff conducted background research through the South Carolina Department of 43 Archives and History ArchSite database to cover a 1 mi (1.6 km) buffer around the 5,900 ac 44 (2,400 ha) RNP site and a 6 mi (10 km) radius around the RNP centerpoint. Previously recorded 45

3-38 archaeological sites within a 6 mi (10 km) radius of the RNP centerpoint include 14 1

archaeological sites, while 9 were previously recorded within the RNP site 1 mi (1.6 km) buffer.

2 Of these 23 archaeological sites, 16 date to the precontact period and 7 are historic in age; 3 3

are listed in the database as eligible, 17 are listed as not eligible, and 3 are unevaluated (SCIAA 4

2021-TN6916).

5 Twelve historic buildings have been previously recorded within a 6 mi (10 km) radius of the RNP 6

centerpoint; no historic buildings have been previously identified within the RNP site 1 mi 7

(1.6 km) buffer. Of the 12 previously recorded buildings, 5 are listed in the database as eligible 8

and 7 are listed as not eligible. Twelve properties within the 6 mi (10 km) radius of the RNP 9

centerpoint are NRHP-listed and are located in Hartsville. No such properties were identified in 10 the RNP site 1 mi (1.6 km) buffer. No archaeological sites, historic buildings, or NRHP-listed 11 properties have been identified within the RNP site (SCIAA 2021-TN6916).

12 Six cultural resources surveys have been previously conducted within a 6 mi (10 km) radius of 13 the RNP centerpoint, while 3 were previously conducted within the RNP site 1 mi (1.6 km) 14 buffer. Of those, one survey, for a potential solar project (Wallace and Allen 2024-TN12520),

15 was conducted within the RNP site (Duke 2025-TN12519). The survey was located west of U.S.

16 Highway 151 on approximately 307 ac (124 ha) in an unused portion of the RNP site and 17 identified no cultural resources.

18 On October 7 and 8, 2024, Terracon performed a field investigation to identify and evaluate 19 structures associated with RNP Unit 1 that could be NRHP-eligible. The study was conducted as 20 part of the license renewal process and in response to recommendations provided by the South 21 Carolina State Historic Preservation Officer (SHPO) to Duke. Terracon inventoried a total of 22 55 properties. Of the 55 properties, 18 were recommended to meet the criteria for eligibility 23 under the NRHP. Contributing facilities include the maintenance and tech training center, the 24 technical training facility, containment and associated buildings, secondary sampling building, 25 turbine building, the Lake Robinson Dam and spillway, discharge canal, discharge structure, 26 and intake structure, condensate polisher building, Pap East building, and information center.

27 The nuclear plant and its associated resources was recommended eligible for inclusion in the 28 NRHP under Criteria A and C at the state level. RNP also retains integrity of location, 29 association, design, materials, and workmanship. The applicant submitted the architectural 30 inventory report to the South Carolina SHPO on June 12, 2025; the applicant is currently 31 responding to comments from SHPO (Duke 2025-TN12519). Status of correspondence and 32 concurrence will be updated upon receipt.

33 Duke procedures require an Environmental Requirements Review Checklist to be completed by 34 the project manager during the planning stage of a project. The activity checklist specific to 35 cultural resources (Annex 9.6 of ADMP-ENV-EVS-00021) is currently designed to identify if a 36 planned project has the potential to impact archaeological, historic, or architectural resources 37 regardless of NRHP-eligibility. Additionally, the current Cultural Resources Procedure 38 (ADMPENV-EVS-00095) for facilities operated by Duke identifies the relevant subject matter 39 expert (SME) within the Environmental Health and Safety team as responsible for consulting 40 with the applicable SHPO or Tribal Historic Preservation Officer regarding projects that may 41 impact historic or cultural resources, and notifying the relevant party in the event of a discovery 42 situation. The applicable SME is also responsible for ensuring that historic and cultural 43 resources information and regulatory guidance is provided to facility management, 44 environmental and field support, employees, and contractors. To limit the dissemination of 45 information about historic and cultural resources, only those working at the specific project job 46

3-39 site will be informed about the potential presence of historic and cultural resources (Duke 2025-1 TN12519). The NRC staff reviewed these procedures as part of the confirmatory review.

2 By letters dated May 23, 2025, the NRC initiated NHPA Section 106 consultation by sending 3

letters to the Advisory Council on Historic Preservation and the South Carolina SHPO (NRC 4

2025-TN12511), 16 Federally recognized Indian Tribes (NRC 2025-TN12512), and 13 State 5

recognized Indian Tribes (NRC 2025-TN12514). In these letters, the NRC provided information 6

about the proposed action, defined the APE, and indicated that the NRC would use the process 7

specified in 36 CFR 800.8(c) (TN513) to satisfy NHPA Section 106 requirements. The NRC 8

invited participation in the scoping process. Upon publication, the draft EIS will be made 9

available to the aforementioned parties for review and comment.

10 Responses were received from the Advisory Council on Historic Preservation, South Carolina 11 SHPO, two federally recognized Indian Tribes, and three State recognized Indian Tribes (see 12 Appendix D). See Appendix D for more information.

13 3.7.1 Environmental Consequences of the Proposed Action: Continued Operations and 14 Refurbishment Activities 15 Section 3.7 of the LR GEIS (NRC 2024-TN10161) provides background information for this 16 Category 2 issue, which is incorporated herein by reference. No new construction or 17 modifications are anticipated during the subsequent license renewal term. Any facility operations 18 and maintenance activities necessary to support the continued operation would be limited to 19 previously disturbed areas and would be expected to be similar to current operations.

20 Additionally, Dukes environmental protocols and procedures would be followed to identify and 21 protect historic and cultural resources (Duke 2025-TN12519). Additionally, it does not appear 22 that activities associated with operations and maintenance would directly or indirectly affect the 23 NRHP-eligible structures and buildings at the RNP or aspects of the structures and buildings 24 that contribute to their eligibility.

25 The NRC staff has made a finding that the proposed action will result in No Adverse Effect to 26 historic properties as defined in 36 CFR 800.5(b) (TN513). Further, based on the continuation of 27 operations and maintenance activities and absence of planned refurbishment activities, there 28 would be no impact to historic and cultural resources.

29 3.8 Human Health 30 3.8.1 Affected Environment 31 Section 3.10 of the ER (Duke 2025-TN12518) provides affected environment information 32 pertaining to microbiological hazards (e.g., thermophilic pathogens or etiological agents), and 33 electric shock hazards. This information is incorporated here by reference.

34 Microbiological Hazards to the Public 35 The NRC staff relies upon the information discussed in LR GEIS Sections 3.9.2.2 and 4.9.1.1.3, 36 to provide background information regarding microbiological hazards to the public. RNP uses a 37 once-through cooling system. Information about the once-through cooling system can be found 38 in Section 3.2. Recreational fishing, swimming, water skiing, and boating are publicly available 39 on Lake Robinson; however RNPs discharge canal is not publicly accessible. The applicant 40 stated in ER Section 3.10.1 that RNP discharge temperatures are monitored daily and reported 41

3-40 to SCDES quarterly (Duke 2025-TN12518). The applicant also stated that RNP discharge 1

temperatures for the period from 2019-2023 were approximately between 46°F to 110°F (7.8°C 2

to 43.3°C), with the highest temperatures occurring between June and September for 2019 3

through 2023. The monthly average discharge temperature was limited to between 90°F and 4

111.2°F (32°C to 44°C), which was in accordance with the NPDES permit and did not exceed 5

111.2°F (44°C). The maximum temperature for the period from 2019-2023 was 110.13°F 6

(43.4°C) in which was reported in July 2020.

7 Electromagnetic Fields 8

The NRC staff relies upon the information discussed in LR GEIS Section 3.9.2.3 and 9

Section 4.9.1.1.4 (NRC 2024-TN10161), to provide background information regarding electric 10 fields and magnetic fields, referred to collectively as electromagnetic fields (EMFs), that are 11 produced by any electrical equipment, including operating transmission lines.

12 Scientific consensus on the health implications of EMFs has not been established. The potential 13 health effects from EMF exposure have been the subject of published studies as described in 14 the LR GEIS (NRC 2024-TN10161), but consistent evidence of harmful effects remains 15 inconclusive. The National Institute for Occupational Safety and Health does not consider EMFs 16 to be a proven health hazard (NIOSH 1996-TN6766).

17 Electric Shock Hazards 18 The NRC staff relies upon the information discussed in Sections 3.9.2.4 and 4.9.1.1.5 of the 19 LR GEIS (NRC 2024-TN10161) to provide background information regarding electric shock 20 hazards. Based on its evaluation in the LR GEIS (NRC 2024-TN10161), the NRC staff has 21 found electric shock resulting from direct access to energized conductors or from induced 22 charges in metallic structures to not be a problem at most operating nuclear power plants.

23 Therefore, the NRC staff also does not expect electric shock from such sources to be a human 24 health hazard during continued operation of an existing nuclear power plant following license 25 renewal. However, a plant-specific review is required to determine the significance of the electric 26 shock potential along the portions of the transmission lines that are within the scope of this EIS.

27 Qualified plant personnel may perform electrical work, electric power line maintenance, repair 28 work, and maintenance activities and may be exposed to potential electric shock. Design criteria 29 for nuclear power plants that limit hazards from steady state currents are based on the National 30 Electric Safety Code (NESC) (IEEE SA 2017-TN6762, IEEE 2023-TN10132), which require 31 utility companies to design transmission lines so that the short-circuit current to ground 32 produced from the largest anticipated vehicle or object is limited to less than 5 milliamperes 33 (mA).

34 3.8.2 Environmental Consequences: Microbiological Hazards to the Public 35 The applicant consulted the SCDES, the State agency responsible for environmental health, 36 regarding the potential exposure to thermophilic pathogens (Salmonella sp., Shingella sp.,

37 Pseudomonas aeruginosa, Naegleria fowleri, and Escherichia coli) in Lake Robinson.

38 Correspondence with the SCDES thermal discharge is included in Dukes response to RAIs 39 (Duke 2025-TN12519). The SCDES response to Duke provided general information about the 40 potential widespread of Naegleria fowleri in warm waters throughout the region and would thrive 41 in water at temperatures between 95°F and 100°F (35°C and 38°C). The SCDES concluded 42 that the continued release of cooling water from the RNP is very unlikely to result in propagation 43 of Naegleria fowleri or Pseudomonas aeruginosa to levels that would result in human health 44

3-41 concerns. SCDES regularly monitors levels of Escherichia coli, a thermophilic fecal indicator 1

bacterium in Lake Robinson. There is no evidence that elevated temperatures associated with 2

the RNP have led to an increase in numbers of pathogenic microorganisms. It is stated in the 3

SCDES response that the thermal discharge limit in the RNP NPDES permit (SC0002925) 4 (Duke 2025-TN12518: Attachment A) and the restricted access 2 mi (3.2 km) long discharge 5

serve as protection to any potential recreational exposure to any thermophilic organisms which 6

may be present. It is also stated that cooling water from the RNP has been discharged into the 7

lake for the last 53 years, and no cases of infections from thermophilic organisms associated 8

with recreational activities in Lake Robinson have been reported.

9 Additionally, Duke has not observed algal blooms in Lake Robinson or within the discharge 10 canal. SCDES has not notified RNP of any algal blooms in the vicinity of RNP. The applicant 11 also reviewed SCDESs algal bloom online monitoring tool, which showed no instances of algal 12 blooms in Lake Robinson (Duke 2025-TN12518; SCDES 2025-TN12650).

13 Based on SCDESs conclusion, an independent review of pertinent information in the public 14 domain, and consideration of several factors, such as:

15

• the heated cooling water discharge to Lake Robinson is not accessible to the public, 16

• the discharge temperatures to Lake Robinson are generally below those that would enhance 17 the growth of thermophilic microorganisms, 18

• the river temperature decreases to ambient levels due to mixing, 19

• use of biocides in treating water before discharge, 20

• and very low occurrences of human infections from recreational use, the continuation of 21 RNP's thermal discharge during a 20-year extension of its license would not significantly 22 increase the public health risk posed by etiological agents.

23 The NRC staff finds that the public health risk posed by the etiological agents would remain 24 SMALL.

25 3.8.3 Environmental Consequences: Electromagnetic Fields 26 Given the uncertainty surrounding the health effects of EMPs, the LR GEIS (NRC 2024-27 TN10161) and 10 CFR Part 51 (TN10253), Subpart A, Appendix B, do not designate the health 28 effects of EMFs as either a Category 1 or Category 2 issue, and they remain UNCERTAIN until 29 a scientific consensus is reached on the health implications of EMFs. The NRC staff considers 30 the LR GEIS finding of UNCERTAIN to still be applicable to RNP and will continue to follow 31 developments on this issue.

32 3.8.4 Environmental Consequences: Electric Shock Hazards 33 The in-scope transmission lines meet the NESC definition of an electrical supply station, which 34 includes generating stations inclusive of auxiliaries and equipment required for operation of the 35 generating station and substations. The applicant stated in ER Section 2.2.4.1, that RNP has 36 three in-scope 230 kilovolt (kV) transmission lines that connect the plant to the switchyard 37 where electricity is fed into the regional power distribution system. These three lines are 38 approximately 150 ft (46 m) in length and are above ground in a paved right-of-way. There are 39 also two other lines that normally feed the plant from the grid during outages. One of those lines 40 is 115 kV and approximately 450 ft (137 m) in length. The other line is 230 kV and approximately 41

3-42 150 ft (46 m) in length. Both lines are step-up transformers and are above ground in a paved 1

right-of-way (Duke 2025-TN12518).

2 RNP transmission lines are in accordance with the NESC and industry guidance. In response to 3

NRCs RCI, Duke confirmed that RNP electrical safety procedures are consistent with NESC 4

(2017 or later) and that in-scope transmission lines are not accessible to the public and have 5

limited access by plant personnel (Duke 2025-TN12519). The in-scope transmission lines are 6

located completely within the RNP property boundary and the owner-controlled area. Therefore, 7

they present no electric shock hazard to the public. Duke uses and follows the Occupational 8

Safety and Health Administration standards for electric power generation, transmission, and 9

distribution set in 29 CFR 1910.269 (TN654). Work at RNP is governed by a comprehensive 10 industrial safety program, which would minimize the potential for acute electric shock of workers 11 during the proposed subsequent license renewal term.

12 Based on this information and Dukes ongoing commitment to standards and protocols to 13 minimize hazards to workers from acute electric shock and the inaccessibility of the in-scope 14 transmission lines to the public, the NRC staff concludes that the potential impacts from electric 15 shock hazards, during the subsequent license renewal term, would be SMALL.

16 3.9 Greenhouse Gas Emissions and Climate Change 17 Climate change is the decades or longer change in climate measurements (e.g., temperature 18 and precipitation) that has been observed on a global, national, and regional level (IPCC 2007-19 TN7421; EPA 2016-TN7561; USGCRP 2014-TN3472). Global surface temperature has 20 increased faster since 1970 than in any other 50-year period over at least the last 2,000 years 21 (IPCC 2023-TN8557). From 2011 through 2020, the global surface temperature was 2°F (1.1°C) 22 warmer than that in the preindustrial period (1850-1900) (IPCC 2023-TN8557). From 1901 to 23 2023, global precipitation has increased at an average rate of 0.03 in. (0.08 cm) per decade 24 (EPA 2024-TN10205). From 1901 to 2023, average surface temperature across the contiguous 25 United States has increased by 0.17°F (0.09°C) per decade (EPA 2024-TN10205). From 1901 26 to 2023, total annual precipitation in the contiguous United States has increased at a rate of 27 0.18 in. (0.4 cm) per decade (EPA 2024-TN10205).

28 Climate change and its impacts can vary regionally and seasonally, depending on local, 29 regional, and global factors. Observed climate changes and impacts have not been uniform 30 across the United States. Annual average temperature data in the Southeast (where RNP is 31 located) varies between 2002-2021 (relative to 1901-1960), with South Carolina exhibiting an 32 increase of 0.5-1.5°F (0.28-0.83°C) (USGCRP 2023-TN9762: Figure 2.4). The number of hot 33 days (days at or above 95°F [35°C]) has decreased by 9.7 days, the number of cold days (days 34 at or below 32°F [0°C]) has increased by 3.0 days, and the number of warm nights (nights at or 35 above 70°F [21°C ]) have increased by 7.9 nights in the Southeast from 2002-2021 relative to 36 1901-1960 (USGCRP 2023-TN9762: Figure 2.7). Average annual precipitation from 2002-2021 37 (relative to the 1901-1960 average) for the Southeast exhibits increases and decreases, with 38 the northwestern and southwestern portion of the South Carolina exhibiting a 0-10 percent 39 decrease and the rest of South Carolina exhibiting an increase of 0 to 10 percent (USGCRP 40 2023-TN9762: Figure 2.4). The Southeast has experienced a 37 percent increase in the number 41 of extreme precipitation days (defined as the top 1 percent of heaviest precipitation events) from 42 1958-2021 (USGCRP 2023-TN9762: Figure 2.8).

43 The NRC staff used the NOAA Climate at a Glance tool to analyze temperature and 44 precipitation trends for the 1895-2024 period in Darlington County. A trend analysis shows that 45

3-43 the average annual temperature has increased at a rate of 0.1°F (0.05°C) per decade and 1

average precipitation has decreased by 0.17 in. (0.43 cm) per decade (NOAA 2025-TN12574, 2

NOAA 2025-TN12575).

3 3.9.1 Climate Change Impacts on Environmental Resource Areas 4

Section 4.12.2 of the LR GEIS (NRC 2024-TN10161) provides background information for this 5

Category 2 issue, Climate Change Impacts on Environmental Resources Areas, which is 6

incorporated here by reference. According to the LR GEIS, the impacts of climate change on 7

environmental resources during the subsequent license renewal term are location-specific and 8

cannot be generically evaluated. Changes in climate can have broad implications for certain 9

resource areas. Climate change may impact the affected environment in a way that alters the 10 environmental resources that are impacted by the proposed action. In order for there to be a 11 climate change impact on an environmental resource, the proposed action must have an 12 incremental new, additive, or increased physical effect or impact on the resource or 13 environmental condition beyond what is already occurring. Below, the NRC considers the effects 14 of climate change on environmental resource areas that may also be directly affected by 15 continued operations during the subsequent license renewal term.

16 The effects of climate change on RNP structures, systems, and components are outside the 17 scope of the NRC staffs subsequent license renewal environmental review. The environmental 18 review documents the potential effects from continued nuclear power plant operation on the 19 environment. Plant-specific environmental conditions are considered when siting nuclear power 20 plants. This includes the consideration of meteorological and hydrologic siting criteria as set 21 forth in 10 CFR Part 100 (TN282), Reactor Site Criteria. The NRC regulations require that 22 plant structures, systems, and components important to safety be designed to withstand the 23 effects of natural phenomena, such as flooding, without loss of capability to perform safety 24 functions. Further, nuclear power plants are required to operate within technical safety 25 specifications in accordance with the plants NRC operating license, including coping with 26 natural phenomena hazards. The NRC staff conducts safety reviews before allowing licensees 27 to make operational changes due to changing environmental conditions. Additionally, the NRC 28 staff evaluates nuclear power plant operating conditions and physical infrastructure to ensure 29 safe operation under the plants initial and renewed operating licenses through the NRCs 30 Reactor Oversight Program. If new information about changing environmental conditions that 31 threaten safe operating conditions or challenge compliance with the plants technical 32 specifications becomes available, the NRC staff will evaluate the new information to determine 33 whether any safety-related changes are needed at licensed nuclear power plants. This is a 34 separate and distinct process from the NRC staffs subsequent license renewal environmental 35 review conducted in accordance with NEPA (TN661).

36 The NRC staff considered the best available climate change information from the Fourth and 37 Fifth National Climate Assessment (USGCRP 2017-TN5848, USGCRP 2023-TN9762) as part of 38 the staffs assessment of potential change in climate indicators during the RNP license renewal 39 term (2030-2050). NCA4 (USGCRP 2017-TN5848) primarily relies on representative 40 concentration pathways (RCPs) to describe future climate scenarios. RCPs outline future 41 climate trajectories based on greenhouse gas (GHG) emissions. In contrast, NCA5 (USGCRP 42 2023-TN9762) uses shared socioeconomic pathways (SSP) and global warming levels (GWLs) 43 as its primary framework for assessing potential climate impacts. The five socioeconomic 44 pathway scenarios (SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) cover a range of 45 GHG pathways and climate change mitigation. GWLs quantify changes based on specific global 46 temperature increases relative to preindustrial conditions (e.g., 2.7°F or 1.5°C), providing a 47

3-44 more direct measure of the effects of global temperature shifts (USGCRP 2023-TN9762). The 1

timing of when a GWL is reached will depend on the future GHG emissions.

2 Regional projections for annual mean temperature are available from the Fourth National 3

Climate Assessment based on the RCP 4.5 and RCP 8.5 scenarios for the mid-century 4

(2036-2065) as compared to the average for 1976-2005. The modeling predicts increases of 5

3.4-4.3°F (1.9-2.4°C) across the southeast region by mid-century (USGCRP 2017-TN5848).

6 Under the RCP 8.5 scenario, the coldest and warmest daily temperatures of the year are 7

expected to increase by 4.97°F and 5.69°F (2.76°C and 3.16°C), respectively, in the Southeast 8

by midcentury (USGCRP 2017-TN5848). For the portion encompassing South Carolina, the 9

Fifth National Climate Assessment projects annual temperature increases from 2.0°F-4.0°F 10 (1.1°C-2.2°C) under the 2.7°F (1.5°C) global warming level and 7.0°F-8.0°F (3.9°C-4.4°C) 11 under the 7.2°F (4.0°C) global warming level scenario (USGCRP 2023-TN9762), compared to 12 the period 1851-1900.

13 Climate model simulations suggest spatial differences in annual mean precipitation change 14 across the southeast with some areas experiencing an increase and others a decrease in 15 precipitation. Based on the intermediate (RCP 4.5) emission scenarios for the mid-century 16 (2036-2065), annual mean precipitation is projected to increase up to 2 in. (5.1 cm) relative to 17 1991-2020 in South Carolina (USGCRP 2023-TN9762). Average annual precipitation in South 18 Carolina is projected to increase by 0-5 percent compared with the period 1851-1900 for the 19 2.7°F (1.5°C) and 3.6°F (2°C) global warming levels and 5-10 percent for the 5.4°F (3°C) and 20 7.2°F (4°C) global warming levels (USGCRP 2023-TN9762).

21 The Fifth National Climate Assessment projections include continued increases in the frequency 22 and intensity of heavy or extreme precipitation events across the United States, including across 23 the southeast region (USGCRP 2014-TN3472, USGCRP 2017-TN5848, USGCRP 2018-24 TN5847, USGCRP 2023-TN9762). For the southeast region, models predict up to 15, percent 25 increase in the total precipitation on the heaviest 1 percent of days, 5-year maximum daily 26 precipitation, and annual maximum daily precipitation, respectively, at the 3.6°F (2°C) global 27 warming level in eastern Florida (USGCRP 2023-TN9762).

28 Air Quality: Climate change can impact air quality as a result of changes in meteorological 29 conditions. Air pollutant concentrations are sensitive to winds, temperature, humidity, and 30 precipitation. Ozone levels and particulate matter have been found to be particularly sensitive to 31 climate change influences. Ozone is formed by the chemical reaction of nitrogen oxides and 32 volatile organic compounds in the presence of heat and sunlight. The emission of ozone 33 precursors also depends on the temperature, wind, and solar radiation (NRC 2020-TN7241).

34 Warmer temperatures, air stagnation, droughts, and wildfires are favorable conditions for higher 35 levels of ozone and particulate matter less than 2.5 microns (USGCRP 2023-TN9762). Studies 36 indicate that the position of the Bermuda High in the summer influences surface ozone in the 37 eastern part of the United States (Zhang and Wang 2016-TN10554). RNP is located in 38 Darlington County, which is designated in attainment for all air criteria air pollutants (40 CFR 39 81.341) (TN7226). U.S. Global Change Research Program reports that there is medium 40 confidence that climate change is projected to worsen air quality in many U.S. regions 41 (USGCRP 2023-TN9762). This is due to the uncertainty in how meteorology will respond to 42 climate change and how these meteorological conditions will in turn change air pollutant 43 concentrations. East et al. (2024-TN10550) conducted model simulations using GHG emission 44 scenarios and three climate sensitivities (the change in global average surface temperature for 45 a doubling in atmospheric carbon dioxide). Under the RCP 4.5 emission scenario, the average 46 number of days per year with ozone levels of 70 parts per billion (ppb) or higher for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or 47

3-45 longer in South Carolina increase as climate sensitivity increases. Under a climate sensitivity of 1

8.1°F (4.5°C) the average number of days per year with ozone levels of 70 ppb or higher for 2

8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> increases by 3 days per year. The findings of East et al. (2024-TN10550) suggest that 3

increasing the frequency of high ozone concentrations can increase the risk of not meeting 4

National Ambient Air Quality Standards by mid-century in areas currently attaining them.

5 However, criteria pollutant emissions from RNP are minor, well below 100 tons/year (see 6

Table 3.3-9 of the ER [Duke 2025-TN12518]). Therefore, the NRC staff concludes that any 7

climate change-related deterioration in air quality in Darlington would not exacerbate the minor 8

air quality impacts associated with RNP subsequent license renewal.

9 Surface Water Resources: Observational data and climate model projections both indicate 10 changes in precipitation, runoff, and air temperature in South Carolina and the Southeast region 11 that could influence surface water availability and water quality. Precipitation and air 12 temperature in South Carolina over the last two decades (2002-2021) compared to the 13 1901-1960 period show an increase in average annual temperature of 0.5-1.5°F (0.28-0.83°C) 14 and changes in annual average precipitation up to +/-10 percent greater/lower than the historical 15 baseline (USGCRP 2023-TN9762). Another relevant trend across the broader Southeast region 16 has been a 37 percent increase in extreme precipitation events (top 1 percent of heaviest 17 precipitation events) over 1958-2021 (USGCRP 2023-TN9762: Figure 2.8), and the frequency 18 and severity of extreme precipitation events are projected to continue to increase across the 19 southeast, including South Carolina (USGCRP 2023-TN9762: Figure 2.12). Increases in annual 20 precipitation and heavy precipitation can increase runoff. Increased runoff and high-flow events 21 can result in the transport of a higher sediment load and other contaminants to surface waters 22 with potential degradation of ambient water quality.

23 RNP uses a once-through cooling water system that withdraws water from Lake Robinson to 24 remove heat from the main condensers and other auxiliary equipment. Water is pumped from 25 Lake Robinson at a rate of approximately 506,000 gpm (1,915,418 Lpm]) and returned to Lake 26 Robinson through a discharge canal (Duke 2025-TN12518). Average withdrawal rate by RNP 27 from 2019 through 2023 was approximately 21,000 million gallons per month (MGM) (79,493 28 MLM (Duke 2025-TN12518). RNP holds a surface water withdrawal permit (permit no.

29 16PN001) allowing a maximum volume of 22,386 MGM (84,740 MLM) from the Unit 2 intake 30 and 3,884 MGM (14,700 MLM) from the Unit 1 intake (total maximum permitted withdrawal of 31 26,270 MGM [99,442 MLM]) (Duke 2025-TN12518). Duke calculated average forced 32 evaporation rates at RNP due to once-through thermal discharge using data from 2016 through 33 2020. These rates range from 5.6 to 11.6 cfs (0.16- 0.33 m3/s), with the higher rates occurring 34 during the summer months (Duke 2025-TN12518).

35 The U.S. Global Change Research Program does not identify aridification as a major concern 36 for the Southeast (USGCRP 2023-TN9762: Chapter 2). Changes in the amount and timing of 37 precipitation and seasonal evapotranspiration could alter the seasonal balance of surface water 38 supply and demand (USGCRP 2023-TN9762: Chapter 2). Precipitation projections for mid-39 century (2036-2065) under the intermediate emission scenarios (RCP 4.5) on an average up to 40 2 in. (5.08 cm) increase in annual precipitation compared to 1991-2020 (USGCRP 2023-41 TN9762: Figure 4.3). Projections for runoff show a smaller increase than precipitation, with an 42 estimate of 0-0.5 in. (0-1.27 cm) increase over the mid-century period for the RCP 4.5 43 scenarios and summer (June-August) soil moisture is estimated to slightly decrease 0-0.05 in.

44 (0-0.127 cm) (USGCRP 2023-TN9762: Figures 4.7, 4.6). Under an intermediate scenario (RCP 45 4.5), projected changes for South Carolina by mid-century (2036-2065, relative to 1991-2020) 46 indicate an annual actual evapotranspiration increase of 0.5-2.0 in. (1.3-5.1 cm), average 47 summer soil moisture decrease of 0-0.05 in. (0-0.12 cm), and annual climatic water deficit 48

3-46 (defined as the shortfall of water necessary to fully supply vegetation requirements) increase of 1

0-0.5 in. (0-1.3 cm) (USGCRP 2023-TN9762: Figures 4.4, 4.6, 4.9).

2 Climate change is also expected to increase the number of hot days ( 95°F [35°C]) and the 3

number of warm nights (70°F [21°C]) (USGCRP 2023-TN9762: Figure 2.11), both of which 4

could increase surface water temperatures and evaporation. RNPs NPDES permit sets 5

limitations and monitoring requirements including daily maximum discharge temperature 6

requirements between 90°F and 111.2°F (32°C and 44°C) based on the month of the year 7

(Duke 2025-TN12518). Daily discharge temperatures in 2019 through 2023 ranged from 46°F 8

(8°C) to 110°F (43°C) with the high temperatures occurring between June and September (Duke 9

2025-TN12518). Increased water temperatures could lead to increased volumetric water 10 withdrawal requirements and related increases in discharge. However, average monthly 11 seasonal intake water temperatures at Lake Robinson for the 2014-2024 period have not 12 shown any increasing trends (see Attachment 1 in Duke 2025-TN12519). Furthermore, 13 increases in water temperature can be accommodated by operational changes.

14 Given (1) water withdrawal limits, (2) thermal limits for cooling water discharge; (3) minimal 15 water consumption (4) projected increases in precipitation for South Carolina, the NRC staff 16 concludes that the impacts to water availability and quality from continued operation of RNP 17 would not be exacerbated by the projected changes in climate.

18 Ecological Resources: Changes in water temperature can alter the balance of aquatic 19 ecosystems. Water temperature is an essential physical property of all aquatic environments to 20 which aquatic resources rely on. As discussed above, the southeast is projected to experience 21 an increase in annual mean air temperature and an increase in the number of hot days and the 22 number of warm nights. Higher ambient air temperatures can increase surface water 23 temperatures (USGCRP 2023-TN9762). Temperature directly affects water quality as discussed 24 in Section 3.5.3. Elevated water temperatures prolong the duration of thermal stratification in 25 aquatic environments, resulting in the annual formation of distinct density layers (USGCRP 26 2014-TN3472). Extending thermal stratification in lakes can eliminate or reduce lake circulation 27 and mixing patterns, resulting in reduced dissolved oxygen which can lead to nutrient, heavy 28 metals, and toxin enrichment of the aquatic environment (USGCRP 2014-TN3472). These 29 changes subsequently impact biodiversity and can result in changes to biological productivity.

30 Simultaneously, increased water temperatures could lead to increased volumetric water 31 withdrawal requirements and related increases in heated discharge. This in turn can lead to a 32 proportional increase in the number of aquatic organisms impinged and entrained and may 33 result in a larger area where aquatic organisms could experience elevated temperatures 34 resulting from RNPs thermal effluent discharge. Adherence to permit requirements including the 35 NPDES, which limits the temperature of the thermal discharge, and Surface Water Withdrawal 36 Permit would minimize and not exacerbate climate change-related impacts on the aquatic 37 environment.

38 39

4-1 4

CONCLUSIONS 1

4.1 Environmental Impacts of License Renewal 2

This EIS contains the NRC staffs environmental review of the application to renew the 3

operating license for RNP. The NRC staff identified no information that is new and significant 4

related to Category 1 issues and relied upon the conclusions of the LR GEIS for all Category 1 5

issues applicable to RNP subsequent license renewal. A summary of the NRC staffs analysis of 6

applicable plant-specific (Category 2) environmental issues for RNP can be found in Table 3-2.

7 The NRC staff considered mitigation measures for each Category 2 issue, as applicable and 8

concluded that no additional mitigation measure is warranted.

9 4.2 Comparison of Alternatives 10 In Chapter 3, the NRC staff documents its analysis of the environmental impacts of the 11 proposed action. In Chapter 2, the NRC staff documents its analysis of the environmental 12 impacts of the no-action alternative, which consist of the impacts of RNP shutdown and the 13 impacts of new energy generating assets, and, in Table 2-1, presents those impacts in 14 comparison to the impacts of the proposed action. As shown in Table 2-1, the no-action 15 alternative would have environmental impacts greater than the proposed action. Based on this 16 review, the NRC staff concludes that the environmentally preferred alternative is the proposed 17 action.

18 4.3 Recommendation 19 The NRC staffs preliminary recommendation is that the adverse environmental impacts of 20 subsequent license renewal for RNP are not so great that preserving the option of subsequent 21 license renewal for energy-planning decision-makers would be unreasonable. This preliminary 22 recommendation is based on the following:

23

• the analysis and findings in the LR GEIS (NRC 2024-TN10161) 24

• the ER submitted by the applicant (Duke 2025-TN12518) 25

• the NRC staffs consultation with Federal, State, and local governmental agencies and 26 Indian Tribes 27

• the NRC staffs independent environmental review 28

• the NRC staffs consideration of public comments received during the scoping process 29

5-1 5

LIST OF PREPARERS 1

Table 5-1 List of Preparers 2

Name Education and Experience Mitchell Dehmer, NRC PSM Environmental Science Graduate Certificate in Environmental Management Graduate Certificate in Energy Policy BS Biology 11 years of combined academic and government experience Lloyd Desotell, NRC MS Civil Engineering MS Water Resources Management BA Environmental Studies 20+ years of experience conducting surface and subsurface hydrologic analyses Beau Goldstein, NRC MA Anthropology BA Anthropology Registered Professional Archaeologist 27 years of relevant experience Shannon Healy, NRC MS Environmental Science BS Biology 10 years combined academic and professional experience Caroline Hsu, NRC BS Molecular Biology BA English Literature 13 years of government experience Stephen Koenick, NRC MS Environmental Engineering BS Mechanical Engineering 30+ years of government experience Karen Loomis, NRC MS Environmental Science and Technology BS Environmental Resource Management BS Agriculture and Extension Education 15 years of government experience in project management, program management, and environmental compliance Nancy Martinez, NRC AM Earth and Planetary Science BS Earth and Environmental Science 13 years of experience in environmental impact analysis William Rautzen, NRC MS Health Physics BS Health Physics BS Industrial Hygiene 21 years of government experience including 15 years of environmental impact analysis Gerry Stirewalt, NRC PhD Structural Geology BA Geology and Mathematics Registered Professional Geologist (PG) and Certified Engineering Geologist (CEG) 50+ years of experience in Environmental and Engineering Geology with academia, industry, and the federal government including university teaching; evaluation of high-level radioactive waste disposal sites; characterization of nuclear power sites; 3D geospatial modeling of subsurface stratigraphy, tectonic faults, and groundwater contaminant plumes; and preparation of EIS sections covering geologic environment and groundwater resources

5-2 Name Education and Experience Rao Tammara, NRC MS Chemical and Environmental Engineering BS Chemical Engineering 50 years of experience in Environmental and Nuclear Consulting Teresa Carlon, PNNL BS Information Technology 30 years of experience as SharePoint administrator, project coordinator, reference management, and databases Caitlin Condon, PNNL PhD Radiation Health Physics BS Environmental Health 7 years of experience including health physics, project management, NEPA environmental impact assessments, waste management, radionuclide dispersion and dosimetry modeling Philip Meyer, PNNL PhD Civil Engineering MS Civil Engineering BA Physics 30+ years relevant experience in subsurface hydrology and contaminant transport, including 15+ years of experience in groundwater resource assessment and environmental impacts analysis Dan Nally, PNNL MA Urban and Environmental Policy and Planning BS Biology 13 years of experience in preparation and review of NEPA documents, related regulatory compliance, and conducting public outreach and engagement Mike Parker, PNNL BA English Literature 25 years of experience copyediting, document design, and formatting and 20 years of experience in technical editing Lindsey Renaud, PNNL MA Anthropology BA Anthropology 15 years in cultural resource management, Section 106 and 110 compliance, and NEPA environmental impact assessments. Secretary of the Interior-qualified Registered Professional Archaeologist. Experience in Tribal engagement and Native American Graves Protection and Repatriation Act compliance Caitlin Wessel, PNNL PhD Marine Science MS Coastal, Marine, and Wetland Science BS Biology 12 years of relevant experience in environmental impact assessment and aquatic ecology.

Lin Zeng, PNNL PhD Environmental Science and Engineering BE Civil Engineering 10 years of relevant experience in socioeconomic analysis and environmental impact assessment AM or MA = Master of Arts; BA = Bachelor of Arts; BS = Bachelor of Science; DoD = U.S. Department of Defense; DOI = U.S. Department of Interior; CEG = Certified Engineering Geologist; MBA = Master of Business Administration; MRP = Master of Regional Planning; MS = Master of Science; NEPA = National Environmental Policy Act of 1969; NNSA = National Nuclear Security Administration; NRC = U.S. Nuclear Regulatory Commission; PG = Professional Geologist; PhD = Doctor of Philosophy; PNNL = Pacific Northwest National Laboratory; PSM = Professional Science Masters; PWS = Professional Wetland Scientist

6-1 6

REFERENCES 1

10 CFR Part 20. Code of Federal Regulations, Title 10, Energy, Part 20, Standards for 2

Protection Against Radiation. TN283.

3 10 CFR Part 50. Code of Federal Regulations, Title 10, Energy, Part 50, Domestic Licensing of 4

Production and Utilization Facilities. TN249.

5 10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, Environmental 6

Protection Regulations for Domestic Licensing and Related Regulatory Functions. TN10253.

7 10 CFR Part 54. Code of Federal Regulations, Title 10, Energy, Part 54, Requirements for 8

Renewal of Operating Licenses for Nuclear Power Plants. TN4878.

9 10 CFR Part 100. Code of Federal Regulations, Title 10, Energy, Part 100, Reactor Site 10 Criteria. TN282.

11 29 CFR Part 1910. Code of Federal Regulations, Title 29, Labor, Part 1910, Occupational 12 Safety and Health Standards. TN654.

13 36 CFR Part 60. Code of Federal Regulations, Title 36, Parks, Forests, and Public Property, 14 Part 60, National Register of Historic Places. TN1682.

15 36 CFR Part 800. Code of Federal Regulations, Title 36, Parks, Forests, and Public Property, 16 Part 800, Protection of Historic Properties. TN513.

17 40 CFR Part 81. Code of Federal Regulations, Title 40, Protection of the Environment, Part 81, 18 Designation of Areas for Air Quality Planning Purposes. TN7226.

19 40 CFR Part 125. Code of Federal Regulations, Title 40, Protection of Environment, Part 125, 20 Criteria and Standards for the National Pollutant Discharge Elimination System. TN254.

21 50 CFR Part 402. Code of Federal Regulations, Title 50, Wildlife and Fisheries, Part 402, 22 Interagency CooperationEndangered Species Act of 1973, as amended. TN4312.

23 79 FR 48300. August 15, 2014. National Pollutant Discharge Elimination SystemFinal 24 Regulations to Establish Requirements for Cooling Water Intake Structures at Existing Facilities 25 and Amend Requirements at Phase I Facilities. Federal Register, Environmental Protection 26 Agency. TN4488.

27 89 FR 64166. August 6, 2024. Renewing Nuclear Power Plant Operating Licenses -

28 Environmental Review. Final rule and guidance; issuance, Federal Register, Nuclear 29 Regulatory Commission. TN10321.

30 90 FR 19535. May 8, 2025. Duke Energy Progress, LLC; H.B. Robinson Steam Electric Plant, 31 Unit No. 2; Subsequent License Renewal Application. Federal Register, Nuclear Regulatory 32 Commission. TN12523.

33

6-2 90 FR 21952. May 22, 2025. Duke Energy Progress, LLC; H.B. Robinson Steam Electric Plant, 1

Unit 2; Notice of Intent To Conduct Scoping Process and Prepare Supplemental Environmental 2

Impact Statement. Federal Register, Nuclear Regulatory Commission. TN12524.

3 16 U.S.C. § 1801 et seq. U.S. Code Title 16, Conservation, Chapter 38, Fishery Conservation 4

and Management. TN9966.

5 16 U.S.C. § 1802 et seq. U.S. Code Title 16, Conservation, Chapter 38, Fishery Conservation 6

and Management. TN12474.

7 54 U.S.C. § 306108 et seq. National Historic Preservation Act Section 106, Effect of 8

Undertaking on Historic Property. TN4839.

9 Atomic Energy Act of 1954. 42 U.S.C. § 2011 et seq. Public Law 112-239, as amended. TN663.

10 Campbell, B.G. and A.L. Coes, editors. 2010. Groundwater Availability in the Atlantic Coastal 11 Plain of North and South Carolina. U.S. Geological Survey Professional Paper 1773, Reston, 12 Virginia. Accessed October 19, 2020, at https://pubs.usgs.gov/pp/1773/pdf/pp1773.pdf.

13 TN6672.

14 Campbell, B.G. and J.E. Landmeyer. 2014. Groundwater Availability in the Crouch Branch and 15 McQueen Branch Aquifers, Chesterfield County, South Carolina, 1900-2012. Scientific 16 Investigations Report 2014-5050, U.S. Geological Survey, Reston, Virginia. Available at 17 https://doi.org/10.3133/sir20145050. TN12562.

18 Coutant, C.C. 1987. Thermal Preference: When Does an Asset Become a Liability?

19 Environmental Biology of Fishes 18(3):161-72. DOI:10.1007/BF00000356. Cham, Switzerland.

20 Accessed June 13, 2022, at https://doi.org/10.1007/BF00000356. TN7736.

21 Carolina Power and Light Company (CP&L). 1976. H.B. Robinson Steam Electric Plant, 316 22 Demonstration Summary. Hartsville, South Carolina. ADAMS Accession No. ML022830086.

23 TN12529.

24 Dieter, C.A., M.A. Maupin, R.R. Caldwell, M.A. Harris, T.I. Ivahnenko, J.K. Lovelace, N.L.

25 Barber, and K.S. Linsey. 2018. Estimated Use of Water in the United States in 2015. USGS 26 Circular 1441, U.S. Geological Survey, Reston, Virginia. Accessed October 19, 2020, 27 at https://pubs.usgs.gov/circ/1441/circ1441.pdf. TN6681.

28 Dorn, M. and K. Doshier. 2025. Architectural Survey and National Register Evaluation of the 29 Robinson Nuclear Plant Darlington County, South Carolina, Final Report, Terracon Project No.

30 73247276. Terracon Consultants, Inc., Columbia, South Carolina. ADAMS Accession No.

31 ML25338A243. TN12655.

32 Duke (Duke Energy). 2012. Duke Energy, Progress Energy Complete Merger. Charlotte, North 33 Carolina. Accessed July 22, 2025, at https://news.duke-energy.com/releases/duke-energy-34 progress-energy-complete-merger. TN12527.

35

6-3 Duke (Duke Energy). 2023. H.B. Robinson Steam Electric Plant Unit 2, Revision 30 to Updated 1

Final Safety Analysis Report. Charlotte, North Carolina. ADAMS Accession No. ML23145A162.

2 TN12561.

3 Duke (Duke Energy). 2025. H.B. Robinson Steam Electric Plant, Unit 2, Application for 4

Subsequent Renewed Operating Licenses. Charlotte, North Carolina. ADAMS Accession 5

Package No. ML25091A290. TN12522.

6 Duke (Duke Energy). 2025. Letter from L.A. Basta, Site Vice President, H.B. Robinson Steam 7

Electric Plant, Unit 2, to NRC Document Control Desk, dated April 1, 2025, regarding Duke 8

Energy Progress, LLC (Duke Energy), H.B. Robinson Steam Electric Plant, Unit Number 2, 9

Docket Number 50-261 / Renewed License Number DPR-23, Application for Subsequent 10 Renewed Operating Licenses. Hartsville, South Carolina. ADAMS Accession No.

11 ML25091A291. TN12582.

12 Duke Energy. 2025. Letter from L. Basta, Site Vice President, to NRC Document Control Desk, 13 dated September 8, 2025, regarding Duke Energy Progress, LLC, H.B. Robinson Steam 14 Electric Plant, Unit Number 2, Docket Number 50-261/Renewed License Number DPR-23, 15 Subsequent License Renewal Application Responses to Requests for Additional Information 16 (RAI) and Requests for Confirmation of Information (RCI). Hartsville, South Carolina. ADAMS 17 Accession No. ML25251A097. TN12519.

18 Duke Energy. 2025. Enclosure 3, Attachment 2, H.B. Robinson Steam Electric Plant, Unit 19 Number 2 Subsequent License Renewal Application, Appendix E, Environmental Report.

20 Charlotte, North Carolina. ADAMS Accession No. ML25091A296. TN12518.

21 East, J.D., E. Monier, R.K. Saari, and F. Garcia-Menendez. 2024. Projecting Changes in the 22 Frequency and Magnitude of Ozone Pollution Events Under Uncertain Climate Sensitivity.

23 Earths Future 12, Washington, D.C. Available at https://doi.org/10.1029/2023EF003941.

24 TN10550.

25 Endangered Species Act of 1973. 16 U.S.C. § 1531 et seq. TN1010.

26 EPA (U.S. Environmental Protection Agency). 2016. Climate Change Indicators in the United 27 States 2016. Fourth Edition, EPA 430-R-16-004, Washington D.C. Accessed June 7, 2022, at 28 https://www.epa.gov/sites/default/files/2016-08/documents/climate_indicators_2016.pdf.

29 TN7561.

30 EPA (U.S. Environmental Protection Agency). 2019. Sole Source Aquifers. Washington, D.C.

31 Accessed June 30, 2023, at 32 https://services.arcgis.com/cJ9YHowT8TU7DUyn/arcgis/rest/services/Sole_Source_Aquifers_A 33 ugust_2019/FeatureServer. TN9022.

34 EPA (U.S. Environmental Protection Agency). 2024. Climate Change Indicators in the United 35 States, Fifth Edition. EPA 430-R-24-003, Washington, D.C. TN10205.

36 Freeze, R.A. and J.A. Cherry. 1979. Groundwater. Prentice-Hall, Inc., Upper Saddle River, New 37 Jersey. TN3275.

38

6-4 FWS and NMFS (U.S. Fish and Wildlife Service and National Marine Fisheries Service). 1998.

1 Endangered Species Act Consultation Handbook, Procedures for Conducting Section 7 2

Consultation and Conference. Washington, D.C. ADAMS Accession No. ML14171A801.

3 TN1031.

4 IEEE (Institute of Electrical and Electronics Engineers). 2023. 2023 National Electrical Safety 5

Code (NESC). C2-2023, Piscataway, New Jersey. TN10132.

6 IEEE SA (Institute of Electrical and Electronics Engineers Standards Association). 2017. 2017 7

National Electrical Safety Code. IEEE C2-2017. Piscataway, New Jersey. TN6762.

8 IPCC (Intergovernmental Panel on Climate Change). 2007. Climate Change 2007: The Physical 9

Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the 10 Intergovernmental Panel on Climate Change. New York, New York. ADAMS No. ML112710385.

11 Accessed May 23, 2022, at 12 https://www.ipcc.ch/site/assets/uploads/2018/05/ar4_wg1_full_report-1.pdf. TN7421.

13 IPCC (Intergovernmental Panel on Climate Change). 2023. AR6 Synthesis Report: Climate 14 Change 2023. Intergovernmental Panel on Climate Change, Geneva, Switzerland. TN8557.

15 Kalff, J. 2002. Limnology: Inland Water Ecosystems. Prentice Hall. Upper Sadie River, New 16 Jersey. TN12531.

17 National Environmental Policy Act of 1969 (NEPA), as amended. 42 U.S.C. § 4321 et seq.

18 TN661.

19 National Marine Sanctuaries Act. 2000. National Marine Sanctuaries Act, Title 16, Chapter 32 § 20 1431 et seq. United States Code as amended by Public Law 106-513. Silver Spring, M.D.

21 Available at https://nmssanctuaries.blob.core.windows.net/sanctuaries-22 prod/media/archive/library/national/nmsa.pdf. TN7197.

23 NEI (Nuclear Energy Institute). 2019. Industry Groundwater Protection Initiative - Final 24 Guidance Document, Rev. 1. NEI-07-07, Revision 1, Washington, D.C. ADAMS Accession No.

25 ML19142A071. TN6775.

26 NIOSH (National Institute for Occupational Safety and Health). 1996. EMFs In The Workplace.

27 Washington, D.C. ADAMS Accession No. ML21145A339. TN6766.

28 NOAA (National Oceanic and Atmospheric Administration). 2025. Climate at a Glance, County 29 Time Series, 12-Month Average Temperature Data, Darlington County, South Carolina. Silver 30 Spring, Maryland. Accessed September 19, 2025, at 31 https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/time-series/SC-32 031/tavg/12/12/1895-33 2024?trend=true&trend_base=10&begtrendyear=1895&endtrendyear=2025. TN12575.

34 NOAA (National Oceanic and Atmospheric Administration). 2025. Climate at a Glance, County 35 Time Series, 12-Month Precipitation Data, Darlington County, South Carolina. Silver Spring, 36 Maryland. Accessed September 19, 2025, at 37

6-5 https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/county/time-series/SC-1 031/pcp/12/12/1895-2 2024?trend=true&trend_base=10&begtrendyear=1895&endtrendyear=2025. TN12574.

3 NOAA (National Oceanic and Atmospheric Administration). 2025. ESA Section 7 Mapper, 4

Robinson Southeast Region. Silver Spring, Maryland. Accessed November 11, 2025, at 5

https://noaa.maps.arcgis.com/apps/webappviewer/index.html?id=b184635835e34f4d904c6fb74 6

1cfb00d. TN12622.

7 NRC (U.S. Nuclear Regulatory Commission). 2002. Final Generic Environmental Impact 8

Statement of Decommissioning of Nuclear Facilities (NUREG-0586). NUREG-0586, 9

Supplement 1, Volume 1 and Supplement 1, Volume 2, Washington, D.C. ADAMS Accession 10 Nos. ML023470327, ML023500228. Accessed December 4, 2025, at 11 https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0586/index. TN665.

12 NRC (U.S. Nuclear Regulatory Commission). 2003. Generic Environmental Impact Statement 13 for License Renewal of Nuclear Plants, Supplement 13: Regarding H.B. Robinson Steam 14 Electric Plant, Unit No. 2, Final Report. NUREG-1437, Supplement 13, Washington, D.C.

15 ADAMS Accession No. ML033450517. TN7260.

16 NRC (U.S. Nuclear Regulatory Commission). 2013. Generic Environmental Impact Statement 17 for License Renewal of Nuclear Plants. NUREG-1437, Revision 1, Washington, D.C. ADAMS 18 Accession No. ML13107A023. TN2654.

19 NRC (U.S. Nuclear Regulatory Commission). 2014. Generic Environmental Impact Statement 20 for Continued Storage of Spent Nuclear Fuel. Final Report, NUREG-2157, Washington, D.C.

21 ADAMS Accession No. ML14198A440. TN4117.

22 NRC (U.S. Nuclear Regulatory Commission). 2020. 2020-2021 Information Digest. NUREG-23 1350, Volume 32, Washington, D.C. ADAMS Accession No. ML20282A632. TN7241.

24 NRC (U.S. Nuclear Regulatory Commission). 2024. 2024 List of Leaks and Spills. Washington, 25 D.C. ADAMS Accession No. ML24320A014. TN11047.

26 NRC (U.S. Nuclear Regulatory Commission). 2024. Generic Environmental Impact Statement 27 for License Renewal of Nuclear Plants. NUREG-1437, Volumes 1-3, Revision 2, Washington, 28 D.C. ADAMS Accession No. ML24087A133. TN10161.

29 NRC (U.S. Nuclear Regulatory Commission). 2024. Standard Review Plans for Environmental 30 Reviews for Nuclear Power Plants, Supplement 1: Operating License Renewal, Final Report.

31 NUREG-1555, Revision 2, Washington, D.C. ADAMS Accession No. ML23201A227. TN10251.

32 NRC (U.S. Nuclear Regulatory Commission). 2025. Letter from K.L. Loomis, Environmental 33 Project Manager, Environmental Project Management Branch 1, Division of Rulemaking, 34 Environmental, and Financial Support, Office of Nuclear Material Safety and Safeguards, to L.

35 Basta, Site Vice President, H.B. Robinson Steam Electric Plant, Duke Energy Progress, LLC, 36 dated June 30, 2025, regarding H.B. Robinson Steam Electric Plant, Unit 2 - License Renewal 37 Regulatory Audit Regarding the Environmental Review of the License Renewal Application 38

6-6 (EPID Number: L-2025-SLE-0000) (Docket Number: 50-261). Washington, D.C. ADAMS 1

Accession No. ML25177A046. TN12525.

2 NRC (U.S. Nuclear Regulatory Commission). 2025. Letter from M. Rome, Chief, Environmental 3

Technical Review Branch 1, Division of Rulemaking, Environment, and Financial Support, Office 4

of Nuclear Material Safety and Safeguards, to C. Johnson-Hughes, Project Leader, South 5

Carolina Ecological Services Field Office, U.S. Fish and Wildlife Service, dated May 15, 2025, 6

regarding Designation of Duke Energy Progress, LLC, as the Non-Federal Representative for 7

the Subsequent License Renewal Application for H.B. Robinson Steam Electric Plant, Unit No. 2 8

(Docket Number: 050-261). Washington, D.C. ADAMS Accession No. ML25122A050.

9 TN12573.

10 NRC (U.S. Nuclear Regulatory Commission). 2025. Radioactive Effluent and Environmental 11 Reports for H.B. Robinson 2. Washington, D.C. Accessed August 21, 2025, at 12 https://www.nrc.gov/reactors/operating/ops-experience/tritium/plant-specific-reports/rob2.

13 TN12585.

14 NRC (U.S. Nuclear Regulatory Commission). 2025. Robinson Environmental Audit Summary.

15 Washington, D.C. ADAMS Accession Package No. ML25212A007. TN12526.

16 NRC (U.S. Nuclear Regulatory Commission). 2025. Robinson Scoping-Federally Recognized 17 Tribes Letters. Washington, D.C. ADAMS Package Accession No. ML25126A172. TN12512.

18 NRC (U.S. Nuclear Regulatory Commission). 2025. Robinson Scoping-State Tribes Letters.

19 Washington, D.C. ADAMS Package Accession No. ML25127A106. TN12514.

20 NRC (U.S. Nuclear Regulatory Commission). 2025. Robinson Scoping-Agency Letters.

21 Washington, D.C. ADAMS Package Accession No. ML25127A193. TN12511.

22 SC Code 49-5. Title 49, Waters, Water Resources and Drainage, Chapter 5, Groundwater Use 23 and Reporting Act. South Carolina Code of Laws Unannotated, Columbia, South Carolina.

24 TN12567.

25 SCDAH (South Carolina Department of Archives History). 2025. Email from E.M. Johnson, 26 Director, Historical Services, D-SHPO, State Historic Preservation Office, to B.J. Goldstein, 27 RPA, Environmental Project Manager, Office of Nuclear Materials Safety and Safeguards, U.S.

28 Nuclear Regulatory Commission, dated September 30, 2025, regarding RE: RE: Initiation of 29 Section 106 Consultation and Notification of the Scoping Process for the Environmental Review 30 of the H.B. Robinson Steam Electric Plant, Unit 2, Subsequent License Renewal Application.

31 Columbia, South Carolina. ADAMS Accession No. ML25323A005. TN12649.

32 SCDES (South Carolina Department of Environmental Services). 2024. Pee Dee Capacity Use 33 Area Groundwater Evaluation, Permitting Year 2025. Technical Report Number 005-2024, 34 Columbia, South Carolina. Available at 35 https://des.sc.gov/sites/des/files/Documents/BOW/Water%20Resources/Groundwater/PeeDeeG 36 roundwaterEvaluation_2024_FINAL.pdf. TN12563.

37

6-7 SCDES (South Carolina Department of Environmental Services). 2024. Regulation 61-58, State 1

Primary Drinking Water Regulations. Columbia, South Carolina. Available at 2

https://des.sc.gov/sites/des/files/Library/Regulations/R.61-58.pdf. TN12603.

3 SCDES (South Carolina Department of Environmental Services). 2024. Regulation 61-68 Water 4

Classifications and Standards. Columbia, South Carolina. Available at 5

https://des.sc.gov/sites/des/files/Library/Regulations/R.61-68.pdf. TN12592.

6 SCDES (South Carolina Department of Environmental Services). 2025. Harmful Algal Blooms, 7

Harmful Algal Bloom Monitoring App. Columbia, South Carolina. Accessed December 8, 2025, 8

at https://des.sc.gov/programs/bureau-water/aquatic-science/harmful-algal-blooms. TN12650.

9 SCDHEC (South Carolina Department of Health and Environmental Control). 2014. Regulation 10 61-68, Water Classifications and Standards. Columbia, South Carolina. Accessed March 27, 11 2021, at https://scdhec.gov/sites/default/files/media/document/R.61-68_0.pdf. TN6986.

12 SCDHEC (South Carolina Department of Health and Environmental Control). 2019. Regulation 13 61-9, Water Pollution Control Permits. Columbia, South Carolina. Available at 14 https://scdhec.gov/sites/default/files/Library/Regulations/R.61-9.pdf. TN9121.

15 SCDHEC (South Carolina Department of Health and Environmental Control). 2020. Public 16 Water Supply Groundwater Protection Zones, near H.B. Robinson Unit 2 Area. Columbia, 17 South Carolina. Accessed October 1, 2025, at https://sc-department-of-health-and-18 environmental-control-gis-sc-19 dhec.hub.arcgis.com/datasets/078570d9c90b4cbca64759a50890d770_3/explore?location=34.3 20 96195%2C-80.155903%2C11.82. TN12591.

21 SCDNR (South Carolina Department of Natural Resources). 2015. Freshwater Fish - Species, 22 Chain pickerel (Esox niger) - Native. Columbia, South Carolina. Accessed October 8, 2025, at 23 https://www.dnr.sc.gov/fish/species/chainpickerel.html. TN12569.

24 SCDNR (South Carolina Department of Natural Resources). 2021. Potentiometric Surface of the 25 Crouch Branch Aquifer in South Carolina, November-December 2020. Water Resources Report 26 66, Columbia, South Carolina. Available at 27 https://des.sc.gov/sites/des/files/DNR/Hydrology/pdfs/reports/Report_66_Crouch_Branch_Poten 28 tiometric_Map_2020.pdf. TN12565.

29 SCDNR (South Carolina Department of Natural Resources). 2023. Keystone Drought Events in 30 South Carolina. South Carolina State Climatology Office, Columbia, South Carolina. Available at 31 https://www.dnr.sc.gov/climate/sco/Publications/SCKeystoneDroughtEvents.pdf. TN12560.

32 SCDNR (South Carolina Department of Natural Resources). 2023. Potentiometric Surface of the 33 McQueen Branch and Charleston Aquifers in South Carolina, November-December 2022.

34 Water Resources Report 69, Columbia, South Carolina. Available at 35 https://des.sc.gov/sites/des/files/DNR/Hydrology/pdfs/reports/SCDNR_69_McQueen_Branch_C 36 harleston_2022.pdf. TN12566.

37

6-8 SCIAA (South Carolina Institute of Archaeology and Anthropology). 2021. SC ArchSite.

1 Columbia, South Carolina. Accessed February 17, 2021, at 2

http://www.scarchsite.org/default.aspx. TN6916.

3 Swezey, C.S., B.A. Fitzwater, G.R. Whittecar. 2023. Stratigraphic architecture and fluvial 4

interpretations of the Upper Cretaceous (Turonian?) Middendorf Formation, Chesterfield 5

County, South Carolina, U.S.A. Journal of Sedimentary Research 93(6):327-349, SEPM 6

Society for Sedimentary Geology, Claremore, Oklahoma. Available at 7

https://doi.org/10.2110/jsr.2022.034. TN12564.

8 Thornton, K.W., B.L. Kimmel, F.E. Payne. 1991. Reservoir Limnology, Ecological Perspectives.

9 John Wiley & Sons, Inc., Hoboken, New Jersey. TN12572.

10 USGCRP (U.S. Global Change Research Program). 2014. Climate Change Impacts in the 11 United States: The Third National Climate Assessment. J.M. Melillo, T.C. Richmond, and G.W.

12 Yohe (eds.). U.S. Government Printing Office, Washington, D.C. ADAMS Accession No.

13 ML14129A233. TN3472.

14 USGCRP (U.S. Global Change Research Program). 2017. Climate Science Special Report:

15 Fourth National Climate Assessment. Volume I. Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J.

16 Dokken, B.C. Stewart, and T.K. Maycock (eds.). Washington, D.C. ADAMS Accession No.

17 ML19008A410. doi: 10.7930/J0J964J6. TN5848.

18 USGCRP (U.S. Global Change Research Program). 2018. Impacts, Risks, and Adaptation in 19 the United States: Fourth National Climate Assessment. Volume II. D.R. Reidmiller, C.W. Avery, 20 D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and B.C. Stewart (eds.). Washington, 21 D.C. ADAMS Accession No. ML19008A414. doi: 10.7930/NCA4.2018. TN5847.

22 USGCRP (U.S. Global Change Research Program). 2023. The Fifth National Climate 23 Assessment. A.R. Crimmins, C.W. Avery, D.R. Easterling, K.E. Kunkel, B.C. Stewart, and T.K.

24 Maycock, Eds. Washington, D.C. Available at https://toolkit.climate.gov/NCA5. TN9762.

25 USGS (U.S. Geological Survey). 1990. Ground Water Atlas of the United States: Alabama, 26 Florida, Georgia, and South Carolina. HA 730-G. J.A. Miller (editor), Reston, Virginia. ADAMS 27 Accession No. ML100290484. TN6648.

28 USGS (U.S. Geological Survey). 2003. Pee Dee River Basin, 02130910, Black Creek Near 29 Hartsville, SC. Reston, Virginia. TN12619.

30 USGS (U.S. Geological Survey). 2025. Statistics tables for daily mean (average) data, Black 31 Creek Near Hartsville, SC, USGS-02130910. Reston, Virginia. Accessed November 10, 2025, 32 at https://waterdata.usgs.gov/monitoring-location/USGS-33 02130910/statistics/#selectedDataTypes=f7a134c80a2f4c62901cc887e565d4a0. TN12621.

34 USGS (U.S. Geological Survey). 2025. Statistics tables for daily mean (average) data, Black 35 Creek Near Mcbee, SC, USGS-02130900. Reston, Virginia. Accessed November 10, 2025, at 36 https://waterdata.usgs.gov/monitoring-location/USGS-37 02130900/statistics/#selectedDataTypes=df2696a706ff457395cec003047285cb. TN12620.

38

6-9 USGS (U.S. Geological Survey). 2025. USGS Surface-Water Monthly Statistics for the Nation, 1

USGS 02130900 Black Creek Near McBee, SC, 00060, Discharge, cubic feet per second, 2

Monthly mean in ft3/s (Calculation Period: 1959-10-01 to 2025-06-30). Reston, Virginia.

3 Accessed September 23, 2025, at 4

https://waterdata.usgs.gov/nwis/monthly/?referred_module=sw&site_no=02130900&p 5

or_02130900_124655=1097871,00060,124655,1959-10,2025-6 07&format=html_table&date_format=YYYY-MM-7 DD&rdb_compression=file&submitted_form=parameter_selection_list. TN12570.

8 USGS (U.S. Geological Survey). 2025. USGS Surface-Water Monthly Statistics for the Nation, 9

USGS 02130910 Black Creek Near Hartsville, SC, 00060, Discharge, cubic feet per second, 10 Monthly mean in ft3/s (Calculation Period: 1960-10-01 to 2025-06-30). Reston, Virginia.

11 Accessed September 23, 2025, at 12 https://waterdata.usgs.gov/nwis/monthly/?referred_module=sw&site_no=02130910&p 13 or_02130910_124661=1097873,00060,124661,1960-10,2025-14 07&format=html_table&date_format=YYYY-MM-15 DD&rdb_compression=file&submitted_form=parameter_selection_list. TN12571.

16 USGS (U.S. Geological Survey). 2025. USGS Water Data for the Nation, Black Creek Near 17 Hartsville, SC - USGS - 02130910. Reston, Virginia. Accessed September 30, 2025, at 18 https://waterdata.usgs.gov/monitoring-location/USGS-02130910/#dataTypeId=continuous-19 00065-0&showFieldMeasurements=true&startDT=1961-01-01&endDT=2024-12-31.TN12587.

20 USGS (U.S. Geological Survey). 2025. USGS Water Data for the Nation, Black Creek Near 21 Mcbee, SC - USGS - 02130900. Reston, Virginia. Accessed September 30, 2025, at 22 https://waterdata.usgs.gov/monitoring-location/USGS-02130900/#dataTypeId=continuous-23 00065-0&showFieldMeasurements=true&startDT=1960-01-01&endDT=2024-12-31.TN12586.

24 Wallace, K and D. Allen. 2024. Archaeological Reconnaissance Survey, Robinson Solar Project, 25 Chesterfield and Darlington Counties, South Carolina. Project No. 0697866. Duluth, Georgia.

26 TN12520.

27 Wetzel, R.G. 2001. Limnology: Lake and River Ecosystems (3rd ed.). Elsevier Academic Press.

28 San Diego, California. TN12530.

29 Zhang, Y., and Y. Wang. 2016. Climate-Driven Ground-Level Ozone Extreme in the Fall Over 30 the Southeast United States. In Proceedings of the National Academy of Sciences113(36):

31 10025-10030, National Academy of Sciences, Washington, D.C. TN10554.

32

A-1 APPENDIX A 1

2 COMMENTS RECEIVED ON THE H.B. ROBINSON STEAM ELECTRIC 3

PLANT, UNIT 2 ENVIRONMENTAL REVIEW 4

A.1 Environmental Scoping Summary 5

A.1.1 Introduction 6

The U.S. Nuclear Regulatory Commission (NRC or the Commission) staff began the scoping 7

process for the environmental review of the H.B. Robinson Steam Electric Plant, Unit 2 8

(Robinson or RNP) in May 2025. On May 22, 2025, the NRC published a Notice of Intent in the 9

Federal Register to conduct an environmental scoping process to gather information to prepare 10 an environmental impact statement (EIS) to evaluate environmental impacts related to 11 subsequent license renewal of RNP (90 FR 21952-TN12524). In its Notice of Intent, the NRC 12 staff requested that members of the public and stakeholders submit comments on the scope of 13 the RNP environmental review to the Federal Rulemaking website at Regulations.gov, by email, 14 or postal mail. The scoping process provides an opportunity for members of the public to 15 propose environmental issues to be addressed in the supplemental EIS and to highlight public 16 concerns and issues.

17 During the environmental scoping process, the NRC received one comment. The NRC staff 18 determined the comment to be significant. The comment was reviewed and analyzed in depth 19 by the NRC staff and considered in the appropriate sections in this EIS. Additional information 20 on the comments received can be found below.

21 A.1.2 Objective 22 The objective of this scoping summary is to provide a concise summary of the determinations 23 and conclusions reached during the scoping process, in accordance with Title 10 of the Code of 24 Federal Regulations (10 CFR) Section 51.29(b) (TN10253).

25 There are eight defined tasks that shall be completed in the scoping process as specified in 26 10 CFR 51.29. These tasks are listed below with the location of the resolution within this EIS.

27

1. Define the proposed action that is to be the subject of the EIS. The proposed action is 28 defined in Section 1.2 of this EIS.

29

2. Determine the scope of the EIS and identify the significant issues to be analyzed in depth.

30 Significant issues are discussed in Section A.1.4 of this appendix. The scope of this EIS is 31 listed in Section 2.2.

32

3. Identify and eliminate from detailed study issues that are peripheral or are not significant 33 or that have been covered by prior environmental review. No out of scope comments were 34 identified while preparing this scoping report.

35

4. Identify any environmental assessments and other EISs that are being or will be prepared 36 that are related to but are not part of the scope of this EIS. No additional environmental 37 assessments or EISs were identified while preparing this scoping report.

38

5. Identify other environmental review and consultation requirements related to the proposed 39 action see Chapter 1, Section 1.8, Regulatory Provisions, Permits, and Required 40 Consultations.

41

A-2

6. Indicate the relationship between the timing of the preparation of environmental analyses 1

and the Commissions tentative planning and decision-making schedule, see Chapter 1, 2

Section 1.3, Major Environmental Review Milestones.

3

7. Identify any cooperating agencies and, as appropriate, allocate assignments for preparation 4

and schedules for completion of the EIS to the NRC and any cooperating agencies.

5 Cooperating agencies are identified in Section 1.7.

6

8. Upon completion of the scoping process, the NRC staff compiled its findings in this EIS, see 7

Section A.1.5, Determinations and Conclusions in this appendix.

8 A.1.3 Comments Received During the Scoping Period 9

Table A-1 lists details of the comment received during the scoping process, including 10 commenter name, affiliation, correspondence ID, comment source, and Agencywide Documents 11 Access and Management System (ADAMS) accession number. Table A-2 shows the distribution 12 of comments by resource area.

13 Table A-1 Individuals Providing Comments During the Scoping Comment Period 14 Commenter Affiliation Correspondence ID Comment Source ADAMS Accession Number(a)

Collins, Lisa Chief, Wassamasaw Tribe of Varnertown Indians 1

Email ML25197A054 ADAMS = Agencywide Documents Access and Management System; ID = identification.

(a) Access these documents through the NRCs ADAMS at https://adams-search.nrc.gov/home Table A-2 Distribution of Comments by Resource Area or Topic 15 Resource Area/Topic Number of Comments Received Historic and Cultural Resources 1

A.1.4 Significant Issues Identified from Comments Received 16 The NRC staffs summary and response of the single comment received during the RNP 17 scoping process is provided below.

18 Historic and Cultural Resources 19 Summary: The Wassamasaw Tribe of Varnertown Indians provided five actions for 20 consideration, including consultation with the Tribal Alliance of South Carolina Nations, 21 government-to-government engagement with Indian Tribes in South Carolina, natural and 22 cultural resource assessments conducted in partnership with representatives from the PeeDee 23 Tribe, a thorough evaluation of the plants impacts on water quality, and consideration of 24 cumulative impacts on Tribal communities, ecosystems, and traditional practices beyond the 25 Category 1 and 2 issues that the NRC identifies in its National Environmental Policy Act of 1969 26 (NEPA) reviews. The Tribe specifically requested that the NRC engage with the Tribal Alliance of 27 South Carolina Nation and the Catawba Nation for a joint consultation; provide them with 28 access to NRCs environmental review; include Tribes in any site assessments, hearings, and 29 reviews; and to integrate Traditional Ecological Knowledge and Tribal perspectives into the final 30 EIS.

31

A-3 Response: The NRC staff thanks the Wassamasaw Tribe of Varnertown Indians for their 1

comments, which have been recorded and incorporated into the NRC staffs environmental 2

analysis, as applicable. The NRC publishes all available records relevant to NRC environmental 3

reviews on its website, Agencywide Documents Access and Management System, 4

https://adams-search.nrc.gov/home. Specific information to access and provide comments on 5

this EIS was shared with the appropriate consulting Tribes of South Carolina at the time the 6

draft NEPA document was published.

7 A.1.5 Determinations and Conclusions 8

The significant comment identified in this report was considered in the development of this EIS 9

in accordance with 10 CFR 51.29 (TN10253), Scoping-Environmental Impact Statement and 10 Supplement to Environmental Impact Statement, and 10 CFR 51.70, Draft Environmental 11 Impact StatementGeneral. The NRC staff also follows guidance in NUREG-1555 (NRC 2024-12 TN10251), Supplement 1, Revision 2, Standard Review Plans for Environmental Reviews for 13 Nuclear Power Plants, to ensure compliance with all applicable regulations and NRC policies 14 and procedures. The NRC staff discuss, in Chapters 2 and 3, the topics mentioned in the 15 scoping comment (i.e., historic and cultural resources).

16 The NRC staff compiled its findings in this draft EIS. The draft EIS will be made available for 17 public comment. Once the public comment period is complete, the NRC staff will revise the 18 draft EIS, as appropriate, and will prepare and publish a final EIS.

19 Finally, the NRC will prepare and provide a Record of Decision in accordance with 20 10 CFR 51.102 and 10 CFR 51.103 (TN10253). As a contractor to the NRC, Pacific Northwest 21 National Laboratory is providing technical support throughout the development of the EIS in 22 addition to technical editing and document production tasks.

23 A.2 References 24 10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, Environmental 25 Protection Regulations for Domestic Licensing and Related Regulatory Functions. TN10253.

26 90 FR 21952. May 22, 2025. Duke Energy Progress, LLC; H.B. Robinson Steam Electric Plant, 27 Unit 2; Notice of Intent To Conduct Scoping Process and Prepare Supplemental Environmental 28 Impact Statement. Federal Register, Nuclear Regulatory Commission. TN12524.

29 NRC (U.S. Nuclear Regulatory Commission). 2024. Standard Review Plans for Environmental 30 Reviews for Nuclear Power Plants, Supplement 1: Operating License Renewal, Final Report.

31 NUREG-1555, Revision 2, Washington, D.C. ADAMS Accession No. ML23201A227. TN10251.

32

B-1 APPENDIX B 1

2 APPLICABLE LAWS, REGULATIONS, AND OTHER REQUIREMENTS 3

B.1 Federal and State Requirements 4

Appendix F of the 2024 Generic Environmental Impact Statement for License Renewal of 5

Nuclear Plants (LR GEIS) (NRC 2024-TN10161) discusses Federal laws, regulations, and other 6

requirements that may affect the renewal and continued operation of nuclear power plants 7

licensed by the U.S. Nuclear Regulatory Commission (NRC, the Commission). It provides 8

additional information about environmental laws and regulations that may be applicable to 9

license renewal. These include Federal laws, regulations, and other requirements designed to 10 protect the environment, including land and water use, air quality, aquatic resources, terrestrial 11 resources, radiological impacts, waste management, chemical impacts, and socioeconomic 12 conditions. The NRC staff relies upon and incorporates by reference herein the regulatory 13 discussions and information presented in Appendix F, Sections F.2-F.7 of the LR GEIS (NRC 14 2024-TN10161: pp. F-1-F-24). Therefore, these Federal laws, regulations, and other 15 requirements are not duplicated in this appendix, which instead focuses on facility-specific 16 information.

17 In addition to carrying out some Federal programs, State legislatures develop their own laws.

18 State statutes can supplement, as well as implement, Federal laws for protection of air, surface 19 water, and groundwater. State legislation may also address solid waste management programs, 20 locally rare or endangered species, and historic and cultural resources. Additionally, the Atomic 21 Energy Act of 1954 (TN663), as amended authorizes the NRC to enter into an agreement with 22 any State that allows the State to assume regulatory authority for certain activities (TN10029). A 23 State that enters into such an agreement with the NRC is called an Agreement State, which 24 assumes regulatory responsibility over certain byproduct materials, source materials, and 25 special nuclear materials in quantities not sufficient to form a critical mass. The South Carolina 26 Department of Environmental Services administers the South Carolina Agreement State 27 Program.

28 The U.S. Environmental Protection Agency has the primary responsibility to administer the 29 Federal Water Pollution Control Act of 1972, as amended, herein referred to as the Clean Water 30 Act (CWA) (TN662). The National Pollutant Discharge Elimination System program addresses 31 water pollution by regulating the discharge of potential pollutants to waters of the United States.

32 The CWA allows for primary enforcement and administration through State or Tribal agencies, 33 as long as the State program is at least as stringent as the Federal program. The U.S.

34 Environmental Protection Agency has delegated the authority to issue National Pollutant 35 Discharge Elimination System permits to the South Carolina Department of Environmental 36 Services.

37 B.2 Operating Permits and Other Requirements 38 RNP is subject to various Federal and State requirements. The applicant may prepare and 39 submit for several regulatory approvals or permits prior to the NRC subsequent license renewal 40 approval. As a convenient source of references of environmental requirements, Table B-1 lists 41 the principal permits and licenses issued by Federal, State, and local authorities for activities at 42 RNP, as identified in the environmental report and in response to the NRC staff's environmental 43 audit requests.

44

B-2 Table B-1 Operating Permits and Other Requirements for H.B. Robinson Steam 1

Electric Plant, Unit 2 2

Agency Authority Requirement Facility/ Permit Number Expiration Date Authorized Activity DOT 40 CFR 107 Subpart G Hazardous Materials Certificate of Registration Reg. No.

050923550105F Expiration:

June 06, 2026 Hazardous materials shipments.

FWS 16 U.S.C 703-

712, 50 CFR 13, 50 CFR 16 U.S.C 703-712, 50 CFR 13, 50 CFR, 21.27 Migratory Bird Special Purpose Utility Permit Permit No.

MB000257 Expiration:

March 31, 2028 Permit to handle non-endangered/threaten ed migratory birds.

SCDNR 16 U.S.C 703-

712, 50 CFR 13, 50 CFR 16 U.S.C 703-712, 50 CFR 13, 50 CFR, 21.27 Migratory Bird Special Purpose Utility Permit Permit No. MB-4-24 Expiration:

December 31, 2025 Permit to handle non-endangered/

threatened migratory birds.

SCDNR 16 U.S.C.

1539(a)(I)(B)

Certificate of Inclusion N/A Does not expire.

Certifies that the RNP site is included within the scope of Incidental Take Permit (No. 834071),

issued to the SCDNR by the FWS for the endangered red-cockaded woodpecker.

SCDES SC R.61-62 Title V Operating Permit Permit No. TV-0820-0002 Expiration:

December 31, 2027 Operation of emission units.

SCDES Clean Water Act, Section 402; SC R.61-9 NPDES Wastewater Permit Permit No.

SC0002925 Expiration: April 30, 2011, Administrative extension, effective until issuance of new permit Wastewater discharge to Lake Robinson.

SCDES Clean Water Act, SC Code 48-1-10 NPDES General Stormwater Permit June 30, 2027 SCDES SC R.61-119 Surface Water Withdrawal Permit March 16, 2044

B-3 Agency Authority Requirement Facility/ Permit Number Expiration Date Authorized Activity SCDES Groundwater Use and Reporting Act, Ch 5, Section 49-5-10 et seq. SC R.

61-72 Groundwater Withdrawal Permit October 31, 2025 SCDES Federal Water Pollution Control Act Section 401 Certification of water quality standards Issued November 16, 1972, no expiration SCDES SC R.61-81 Environmental Laboratory Certification January 14, 2027 SCDES SC R.61-81 Environmental Laboratory Certification April 18, 2027 SCDES 40 CFR 280; SC R. 61-92 Underground Storage Tank Registration July 31, 2025 SCDES SC R.61-86.1 Asbestos Abatement Group License September 1, 2025 SCDES SC Radioactive Waste Transportation and Disposal Act, SC R.61-83 South Carolina Radioactive Waste Transport Permit December 31, 2025 SCDES Hazardous waste generator registration Does not expire.

SCDES Class 2 Landfill Post Closure Permit Post-closure period ends November 23, 2030 SCDES Class 2 Landfill Post Closure Permit Post-closure period ends November 29, 2031 SCDES Class 3 Landfill Permit N/A

B-4 Agency Authority Requirement Facility/ Permit Number Expiration Date Authorized Activity SCDES NPDES General Permit for Discharges from the Application of Pesticides March 31,

2021, administratively continued in accordance with R.61-9.122.6 SCDES Licensing for pesticide use Renewed Annually SCDES Permit for Impounded Waters Does not expire.

EPA CWA Section 401(a)(2)

N/A Neighboring jurisdiction process.

EPAs determination of whether the discharge from a federally licensed or permitted activity may affect the water quality of a neighboring jurisdiction (ML25142A199)

Tennessee Department of Environment and Conservation Tennessee Radioactive Waste Transport Permit December 31, 2025 CFR = Code of Federal Regulations; DOT = U.S. Department of Transportation; EPA = U.S. Environmental Protection Agency; FWS = U.S. Fish and Wildlife Service; N/A = not available; NPDES = National Pollutant Discharge Elimination System; SCDES = South Carolina Department of Environmental Services; SCDNR = South Carolina Department of Natural Resources.

- denotes no content in table cell.

B.3 Exemptions 1

Environmental Justice 2

The Title 10 of the Code of Federal Regulations (10 CFR) Part 51 (TN10253), Subpart A, 3

Appendix B, Table B-1, Summary of Findings on NEPA Issues for License Renewal of Nuclear 4

Power Plants, requires an environmental impact statement (EIS) for license renewal to include 5

an analysis for the Category 2 issue of Environmental JusticeImpacts on Minority 6

Populations, Low-Income Populations, and Indian Tribes. Executive Order 14173 (90 FR 8633-7 TN11607), Ending Illegal Discrimination and Restoring Merit-Based Opportunity, issued 8

January 21, 2025, revoked Executive Order 12898 (59 FR 7629-TN1450), Federal Actions to 9

Address Environmental Justice in Minority Populations and Low-Income Populations, issued 10 February 11, 1994, among other things. Staff Requirements Memorandum (SRM)-COMSECY-11 25-0007, Withdrawing the Environmental Justice Policy Statement and Environmental Justice 12

B-5 Strategy, issued April 10, 2025, approved publication of a notice in the Federal Register (90 FR 1

17887-TN11684), which explained that in response to the policies in Executive Order 12898, the 2

NRC had made voluntary commitments on environmental justice in its Policy Statement on the 3

Treatment of Environmental Justice Matters in NRC Regulatory and Licensing Actions 4

(Environmental Justice Policy Statement) and its Environmental Justice Strategy (69 FR 52040-5 TN1009). Accordingly, with the revocation of Executive Order 12898, the NRC also withdrew its 6

Environmental Justice Policy Statement and its Environmental Justice Strategy. Based on 7

Executive Order 14173 and SRM-COMSECY-25-0007, and pursuant to 10 CFR 51.6 8

(TN10253), Specific exemptions, the NRC staff has, upon its own initiative, determined that an 9

exemption from the requirement to address environmental justice in this EIS is authorized by 10 law and otherwise in the public interest. Accordingly, this EIS does not address that issue.

11 Cumulative Effects 12 The NRC regulations at 10 CFR 51.71(d) (TN10253) require that the NRC staff conduct a 13 cumulative effects analysis for draft EISs. Additionally, 10 CFR Part 51, Subpart A, Appendix B, 14 Table B-1, under the Category 2 issue Cumulative Effects, requires inclusion of a site-specific 15 cumulative effects analysis in license renewal EISs. Executive Order 14300, Ordering the 16 Reform of the Nuclear Regulatory Commission, Section 5(c) (90 FR 22587-TN12182), issued 17 May 23, 2025, directs the NRCin consultation with the Council on Environmental Qualityto 18 revise its National Environmental Policy Act of 1969 (NEPA), as amended (TN661) regulations 19 to reflect the Fiscal Responsibility Act of 2023 (TN9775) and Executive Order 14154, 20 Unleashing American Energy (90 FR 8353-TN11916, Jan. 20, 2025). These revisions must 21 align with Section 102 of NEPA (TN661), which requires analysis only of reasonably foreseeable 22 environmental effects and does not include the term cumulative. Despite these changes, 23 current NRC regulations at 10 CFR Part 51 still mandate cumulative effects analysis. However, 24 Executive Order 14154 also directs the Council on Environmental Quality to revoke its NEPA 25 implementing regulations, including the definition of cumulative effects and related guidance.

26 In light of NEPA Section 102, Executive Orders 14154 and 14300, and under 10 CFR 51.6 27 (TN10253), Specific Exemptions, the NRC staff has determined that an exemption from the 28 requirements to perform a cumulative effects analysis in this EIS is authorized by law and 29 otherwise in the public interest. Accordingly, the NRC staff does not perform such an analysis for 30 this EIS. This exemption from cumulative effects analyses only pertains to requirements in the 31 NRCs NEPA implementing regulations in 10 CFR Part 51. This exemption does not affect 32 requirements in other statutes such as the Endangered Species Act of 1973, as amended 33 (TN1010) and the National Historic Preservation Act of 1966, as amended (TN4157).

34 B.4 References 35 10 CFR Part 51. Code of Federal Regulations, Title 10, Energy, Part 51, Environmental 36 Protection Regulations for Domestic Licensing and Related Regulatory Functions. TN10253.

37 59 FR 7629. February 16, 1994. Executive Order 12898 of February 11, 1994: Federal Actions 38 To Address Environmental Justice in Minority Populations and Low-Income Populations.

39 Federal Register, Office of the President. TN1450.

40 69 FR 52040. August 24, 2004. Policy Statement on the Treatment of Environmental Justice 41 Matters in NRC Regulatory and Licensing Actions. Federal Register, Nuclear Regulatory 42 Commission. TN1009.

43

B-6 90 FR 8353. January 29, 2025. Unleashing American Energy. Executive Order 14154. Federal 1

Register, Presidential Documents. TN11916.

2 90 FR 8633. January 31, 2025. Executive Order 14173 of January 21, 2025, Ending Illegal 3

Discrimination and Restoring Merit-Based Opportunity. Federal Register, Presidential 4

Documents. TN11607.

5 90 FR 17887. April 30, 2025. Policy Statement on the Treatment of Environmental Justice 6

Matters in NRC Regulatory and Licensing Actions; Environmental Justice Strategy. Federal 7

Register, Nuclear Regulatory Commission. TN11684.

8 90 FR 22587. May 23, 2025. Ordering the Reform of the Nuclear Regulatory Commission.

9 Executive Order 14300. Federal Register, Presidential Documents. TN12182.

10 42 U.S.C. § 2021 et seq. U.S. Code Title 42, Public Health and Welfare, Section 2021, 11 Cooperation with States. TN10029.

12 Atomic Energy Act of 1954. 42 U.S.C. § 2011 et seq. Public Law 112-239, as amended. TN663.

13 Endangered Species Act of 1973. 16 U.S.C. § 1531 et seq. TN1010.

14 Federal Water Pollution Control Act of 1972 (commonly referred to as the Clean Water Act). 33 15 U.S.C. § 1251 et seq. TN662.

16 Fiscal Responsibility Act of 2023. 2 U.S.C. § 900 et seq. Note. Public Law 118-5. TN9775.

17 National Environmental Policy Act of 1969 (NEPA), as amended. 42 U.S.C. § 4321 et seq.

18 TN661.

19 National Historic Preservation Act. 54 U.S.C. § 300101 et seq. TN4157.

20 NRC (U.S. Nuclear Regulatory Commission). 2024. Generic Environmental Impact Statement 21 for License Renewal of Nuclear Plants. NUREG-1437, Volumes 1-3, Revision 2, Washington, 22 D.C. ADAMS Accession No. ML24087A133. TN10161.

23

C-1 APPENDIX C 1

2 ECOLOGICAL CONSULTATIONS 3

This appendix of the environmental impact statement (EIS) outlines the ecological consultations 4

conducted by the U.S. Nuclear Regulatory Commission (NRC, the Commission) to inform its 5

environmental review under the National Environmental Policy Act of 1969, as amended (NEPA) 6 (TN661), of the subsequent license renewal application for the H.B. Robinson Steam Electric 7

Plant, Unit 2 (RNP). It includes documentation of the NRC staffs compliance with the 8

Endangered Species Act (ESA) (TN1010), the Magnuson-Stevens Fishery Conservation and 9

Management Act (MSA) (TN9966), and the National Marine Sanctuaries Act (NMSA) (TN7197).

10 These consultations assess the potential effects of the proposed action of subsequently 11 renewing the RNP operating license for an additional 20 years on federally listed species, 12 designated critical habitats, essential fish habitats, and marine sanctuary resources.

13 To inform these consultations and the broader NEPA analysis, this appendix begins with 14 information on terrestrial and aquatic resources within the project area. This integrated 15 ecological context provides the scientific basis for evaluating potential environmental impacts, 16 ensuring consistency with applicable Federal statues, and supporting a comprehensive 17 understanding of the affected environment.

18 C.1 Terrestrial Resources 19 C.1.1 Terrestrial Environment 20 The RNP site lies within the Southeastern Plains ecoregion (U.S. Environmental Protection 21 Agency Level III Ecoregion 65) (EPA 2013-TN9981) and the Sand Hills ecoregion subdivision 22 (U.S. Environmental Protection Agency Level IV Ecoregion 65c) (Griffith et al. 2002-TN10429).

23 The Southeastern Plains ecoregion is characterized by irregular plains with a mosaic of 24 cropland, pasture, woodland, and forest. Natural vegetation consists of predominantly longleaf 25 pine, with smaller areas of oak-hickory-pine and Southern mixed forest (EPA 2013-TN8737).

26 The Sand Hills ecoregion is characterized by rolling to hilly topography with vegetation 27 consisting of turkey oak (Quercus laevis), blackjack oak (Quercus marilandica), longleaf pine 28 (Pinus palustris), and wiregrass (Aristida stricta) groundcover in drier sites and shortleaf-loblolly 29 pine (Pinus echinata-P. taeda) forests and other oak-pine forests in fire suppressed and logged 30 areas. Streams in this ecoregion are consistent and seldom flood or dry up due to the sandy soil 31 that dominates the region (Griffith et al. 2002-TN10429).

32 The RNP site encompasses approximately 5,900 ac (2,400 ha) of land in northwestern 33 Darlington and southwestern Chesterfield Counties (Duke 2025-TN12518: Section 3.7.1.2).

34 Approximately 2,250 ac (910.5 ha) of the RNP site consists of Lake Robinson. The remaining 35 area consists predominantly of evergreen forest (28.9 percent), woody wetlands (12.2 percent),

36 and grassland or herbaceous (6.1 percent). The other 11 land use categories each consist of 37 less than 5 percent of the site and total to 19.1 percent of the site (Duke 2025-TN12518:

38 Table 3.2-1).

39 The U.S. Army Corps of Engineers defines wetlands as areas either inundated or saturated by 40 surface or groundwater at a frequency and duration sufficient to support (and that under normal 41 circumstances do support) a prevalence of vegetation typically adapted for life in saturated soil 42 conditions (16 U.S. Code [U.S.C.] § 3902(5) (TN10912). The National Wetland Inventory 43

C-2 features within a 6 mi (9.7 km) radius of RNP as identified in Duke Energy, LLCs (Dukes) 1 environmental report (ER) (Duke 2025-TN12518) are presented in Table C-1.

2 According to National Wetland Inventory data, the RNP site boundaries contain a total of 3

2,703 ac (1,094 ha) of wetlands, ponds, and riverine waters (Duke 2025-TN12518:

4 Section 3.7.1.2.1). Table C-1 summarizes the area and percentage of wetlands and surface 5

water features on the RNP site.

6 Table C-1 Wetlands and Surface Water Features on the H.B. Robinson Steam Electric 7

Plant Site and within a 6 mi Radius 8

Wetland or Water Feature Acres within 6-mi Radius Percent within 6-mi Radius Acres Onsite at RNP Percent Onsite at RNP Freshwater emergent wetlands 230.3 2.32 12.5 0.46 Freshwater ponds 232.8 2.34 29.6 1.10 Freshwater forested/scrub wetlands 6,850.7 68.88 541.6 20.04 Riverine 207.9 2.09 8.2 0.30 Lake 2,424.4 24.38 2,110.9 78.10 Total 9,946.1 100.01 2,702.8 ac 100.0 RNP = H.B. Robinson Steam Electric Plant.

Source: Duke 2025-TN12518: Section 3.7.1.2.1.

Two wetland delineations have been performed on the site, one in 2015 and one in 2023 (Duke 9

2025-TN12518: Section 3.7.1.3.1 and Section 3.7.1.3.2). In 2015, Duke conducted a Natural 10 Resources Investigation to support planning to perform ash basin closure activities near the ash 11 basin at RNP. The study area for this investigation encompassed 1,540 ac (623 ha) and 12 included a wetland and stream delineation. A total of 18 potentially jurisdictional wetlands, 13 including one non-tidal freshwater marsh, two pocosins, and 15 bottomland hardwood forest 14 wetlands, were delineated within the study area. In addition, three potentially jurisdictional open 15 waters and one potentially jurisdictional intermittent stream were also identified within the study 16 area. In 2023, Duke conducted a Wetland Delineation of a portion of Duke owned property in 17 the vicinity of the RNP site. This delineation was conducted in support of the proposed solar 18 project and identified 3.18 ac (1.29 ha) of palustrine forested wetlands.

19 Wildlife species occurring on the RNP site consist of those species typically found in forested 20 habitats of South Carolina. Table 3.7-1 in the ER presents a list of the terrestrial wildlife and 21 vegetative species likely to occur within the vicinity of the RNP site and is incorporated by 22 reference (Duke 2025-TN12518).

23 C.1.2 State-Listed Terrestrial Species 24 The U.S. Nuclear Regulatory Commission (NRC or the Commission) staff independently 25 reviewed the State-protected species list for Chesterfield, Darlington, and Lee Counties.

26 Table C-2 lists four of these species that are terrestrial, State-listed (but not also federally listed 27 or protected), and have potential habitat onsite or within 6 mi (10 km) of RNP. State-listed 28 species that are also federally listed or protected species and may occur onsite include the red-29 cockaded woodpecker (Picoides borealis), southern hognose snake (Heterodon simus), and the 30 bald eagle (Haliaeetus leucocepohalus). Red cockaded woodpeckers and southern hognose 31 snake are discussed in Section C.3 and Bald eagles are discussed in Section C.1.3.

32

C-3 Table C-2 State-Listed Terrestrial Species (That Are Not Also Federally Listed or 1

Protected), Potentially Occurring in the Vicinity of the H.B. Robinson Steam 2

Electric Plant Site 3

Common Name State Legal Status Class Habitat Spotted turtle (Clemmys guttata)

Threatened Reptile Occurs in a variety of wetland types including small ponds, small streams, swamps, flooded forests, and other shallow bodies of water.

Rafinesques big-eared bat (Corynorhinus rafinesquii)

Endangered Mammal Habitat includes swamp forests, hardwood or mixed mature bottomlands, maritime forests and black gum and water tupelo stands. In South Carolina individuals are permanent residents of the coastal plain and hibernate rather than move south during winter months. They characteristically roost in dilapidated buildings or tree cavities near water.

Pine barrens treefrog (Dryophytes andersonii)

Threatened Amphibian Occurs in herb shrub bogs, pocosins and other related communities in the sandhills region. They require open, slow-flowing seeps for breeding habitat.

Carolina gopher frog (Lithobates capito)

Endangered Amphibian Habitat includes forested upland pine and scrub oak habitats with open canopies and herbaceous ground cover and poorly drained longleaf pine flatwoods. Breeding habitat includes ephemeral or seasonal shallow ponds with an open canopy and emergent vegetation.

Sources: Duke 2025-TN12518: Table 3.7-2; iNaturalist 2025-TN12583; SCDNR 2025-TN12577.

Potentially suitable habitat for State-listed species occurs within the vicinity of RNP. The NRC 4

staff reviewed known occurrences of the species listed in Table C-2. Observations of the pine 5

barrens tree frog have been documented since 2020 within a 6 mi (10 km) radius of Lake 6

Robinson (iNaturalist 2025-TN12583). Additionally, Rafinesques big-eared bats have been 7

documented to roost within the 20 mi (32 km). vicinity of RNP (SC Natural Heritage GIS). Duke 8

reports no known observations of the species listed in Table C-2 (Duke 2025-TN12518).

9 C.1.3 Eagles and Migratory Birds 10 The Bald and Golden Eagle Protection Act (BGEPA; TN1447) extends regulatory protections to 11 the bald eagle and the golden eagle (Aquila chrysaetos). The Act prohibits anyone without a 12 permit from the Secretary of the Interior from taking bald eagles (or golden eagles), including 13 their parts, nests, or eggs. The current known range of the bald eagle intersects with the RNP 14 site, however Duke states that there have been no observations of bald eagles at RNP from 15 2019 through 2024 (Duke 2025-TN12518). There is a potential for bald eagles to breed within 16 the vicinity of RNP from September 1 to July 31 (FWS 2025-TN12578), and bald eagles have 17 been observed at Lake Robinson and in its vicinity (SCHTP 2025-TN12579; iNaturalist 2025-18 TN12580). There have been no documented eagle mortalities or injuries at RNP between 2015 19 and 2025 (Duke 2025-TN12519: TER-06).

20

C-4 The Migratory Bird Treaty Act of 1918, as amended (MBTA; TN3331) makes it illegal for anyone 1

to take, possess, import, export, transport, sell, purchase, barter, or offer for sale, purchase, or 2

barter, any migratory bird, or the parts, nests, or eggs of such a bird except under the terms of a 3

valid permit issued pursuant to Federal regulations. The U.S. Fish and Wildlife Service (FWS) 4 designates certain migratory bird species as Birds of Conservation Concern (FWS 2021-5 TN8740), to represent their highest conservation priorities for those birds that are not already 6

designated as federally threatened or endangered.

7 Duke maintains a Migratory Bird Special Purpose Utility Permit (No. MB000257) (Duke 2025-8 TN12519: GEN-01) and a South Carolina Department of Natural Resources Migratory Bird 9

Permit (No. MB-4-24). To ensure compliance with requirements of all bird protection 10 regulations and laws promulgated to reduce avian mortality, including the BGEPA, the MBTA, 11 and the Endangered Species Act, Duke implements an Avian Protection Procedure, as 12 described in Section 3.7.1.4.2 of the ER and incorporated here by reference (Duke 2025-13 TN12518).This procedure contains measures, precautions, and guidance to handle the 14 discovery of dead or injured birds and to handle bird nests within a work zone. Duke maintains a 15 Migratory Bird Hot Line that is contacted upon finding a dead or injured bird and provides 16 guidance for how to proceed to comply with applicable bird regulations and laws (Duke 2025-17 TN12519: TER-11).

18 The FWS Information for Planning and Consultation Report (FWS 2025-TN12578) identified the 19 bald eagle (discussed above), red cockaded woodpecker (discussed in Appendix C.3), and 15 20 other Birds of Conservation Concern species with the potential to occur on the RNP site:

21 American kestrel (Falcosparverius paulus), Bachmans sparrow (Peucaea aestivalis),

22 brown-headed nuthatch (Sitta pusilla), chimney swift (Chaetura pelagica), Chuck-wills-widow 23 (Antrostomus carolinensis), eastern whip-poor-will (Antrostomus vociferus), grasshopper 24 sparrow (Ammodramus savannarum perpallidus), lesser yellowlegs (Tringa flavipes), painted 25 bunting (Passerina ciris), pectoral sandpiper (Calidris melanotos), prairie warbler 26 (Setophaga discolor), prothonotary warbler (Protonotaria citrea), rusty blackbird 27 (Euphagus carolinus), semipalmated sandpiper (Calidris pusilla), and wood thrush 28 (Hylocichla mustelina). Of the Birds of Conservation Concern species, 13 may breed in the area 29 in the spring and summer months and all 15 of these species have been documented within a 30 10 mi (16 km) radius of RNP (iNaturalist 2025-TN12584; eBird 2023-TN8838).

31 Tall structures and buildings can pose a collision hazard to migratory birds. Duke has two 32 structures onsite that are greater than 100 ft (30 m) above ground level (AGL) including the 33 MET tower at 330 ft (100 m) AGL and the containment building at 193.5 ft (59 m) AGL. The 34 containment building is not lit, but the MET tower is lit with a red flashing light. The MET tower is 35 also supported by guy lines (Duke 2025-TN12519: TER-02).

36 Duke has documented 18 avian incidents at the RNP site from 2015 to 2025. Of these incidents, 37 17 of them involved deceased birds and 6 had known causes of death that were due to 38 collisions with buildings or vehicles. No eagles, federally listed birds, Birds of Conservation 39 Concern birds, or State-listed birds were killed or injured in these incidents (Duke 2025-40 TN12519: TER-06).

41 C.1.4 Terrestrial Invasive Species 42 Invasive species are defined as a nonnative organism whose introduction causes or is likely to 43 cause economic or environmental harm, or harm to human, animal, or plant health (81 FR 44 88609-TN8375). Executive Order 13112 directs Federal agencies to not authorize, fund, or 45

C-5 carry out actions likely to cause or promote the introduction or spread of invasive species unless 1

they determine that the benefits of the action clearly outweigh the harm from invasive species 2

and that all feasible and prudent measures to minimize risk of harm are taken (64 FR 6183-3 TN4477: Section 2).

4 Terrestrial invasive species have not been documented at the RNP site and Duke does not 5

manage for invasive species at RNP (Duke 2025-TN12518: Section 3.7.1.2.5). However, 11 6

invasive terrestrial species are known to occur within the vicinity of RNP. These species are 7

presented within Table 3.7-4 of the ER, and the table is incorporated here by reference (Duke 8

2025-TN12518).

9 C.1.5 Important Habitats 10 Important habitats include any wildlife sanctuaries, refuges, preserves, or habitats identified by 11 Federal or State agencies as unique, rare, or of priority for protection; wetlands and floodplains; 12 and land areas identified as critical habitat for species listed by FWS as threatened or 13 endangered. Important habitats in and around RNP include wetlands discussed previously in 14 this section. No designated critical habitat for terrestrial species occurs within the RNP site 15 (FWS 2025-TN12578).

16 In addition to the forests and wetlands described in Section C.1.1, there are three protected 17 wildlife areas in the vicinity of RNP: the Carolina Sandhills National Wildlife Refuge, Sand Hills 18 State Forest, and Kalmia Gardens/Segars-McKinnon Heritage. Descriptions of these areas are 19 presented in Section 3.7.1.2.6 of the ER and are incorporated here by reference (Duke 2025-20 TN12518).

21 C.2 Aquatic Resources 22 This section describes the aquatic environment at the RNP site, as well as relevant ecological 23 studies and surveys conducted at RNP and within the surrounding area. This information 24 supplements and supports the NRC staffs analyses of potential impacts that the aquatic 25 environment may experience as a result of the proposed RNP subsequent license renewal, 26 which are presented in Section 3.5.2 through 3.5.4 of this environmental impact statement 27 (EIS).

28 RNP lies on the southwest side of Lake Robinson in northwest South Carolina. The plant uses a 29 once-through cooling system that withdraws water from the lower, southern end of Lake 30 Robinson and discharges heated effluent to the upper, northern end via a shoreline intake and 31 discharge structures. Water flowing into and out of Lake Robinson is part of Black Creek, which 32 was impounded in 1958 to provide cooling water for power plants. This section describes the 33 aquatic resources of these two ecosystems.

34 The NRC staff previously characterized these resources in Section 2.2.5 of the final EIS that 35 analyzed the initial license renewal (NRC 2003-TN7260). Sections 3.7.2 and 3.7.3 of the ER 36 (Duke 2025-TN12518) also describe aquatic resources. This information is incorporated here by 37 reference, with key, new, and updated information summarized below in the following 38 subsections.

39

C-6 C.2.1 Robinson Freshwater Environment 1

C.2.1.1 Lake Robinson 2

Lake Robinson is a 2,250 ac (910 ha) cooling reservoir that is approximately 7 mi (11 km) long, 3

0.25 to 0.75 mi (0.40 to 1.2 km) wide, and an average of 13.5 ft (4.11 m) deep with a maximum 4

depth of 40.1 ft (12.2 m) at the dam. The lake is part of the PeeDee River Basin which is a 5

dystrophic, blackwater system. Water in the lake and creek are very low in dissolved minerals, 6

have low water hardness, and are tannic and naturally acidic (pH ranged from 4.0 to 6.8 in 7

2019) (Duke 2025-TN12519). There are two primary ecosystem types in the lake, open pelagic 8

zones and littoral areas with submerged and emergent aquatic vegetation.

9 South Carolina Department of Environmental Services regularly monitors surface water at two 10 locations (PD-327 and CL-094) in Lake Robinson and randomly monitors additional sites that 11 vary by year, they also monitor fish tissue at one location north of the discharge (SCDHEC 12 2025-TN12588). The two water monitoring locations consistently record low pH, but this is 13 considered typical for blackwater systems and not a water quality standard violation. At the 14 uplake site, aquatic life uses remain fully supported with significant decreasing trends in pH 15 (expected), turbidity, and total nitrogen concentrations, indicating improving water conditions. At 16 the downlake location, near the RNP intake, aquatic life uses are fully supported, with significant 17 decreasing trends in pH and total nitrogen, however, fecal coliform bacterial show a significant 18 increasing trend. Lake Robinson is still listed as impaired for aquatic life and fish consumption 19 due to elevated copper (measured right below the dam) and mercury levels and there is a fish 20 consumption advisory for the entire lake due to mercury (EPA 2022-TN10535; SCDHEC 2025-21 TN12588). The elevated copper levels are likely due to the brass condenser tubing use at RNP 22 until 1982 when it was replaced with stainless steel tubing (Duke 2025-TN12518).

23 C.2.1.2 Black Creek 24 Black Creek was impounded in 1958 to form Lake Robinson and serve as the cooling water 25 source for Unit 1, which was coal powered and ceased operations in 2012. The creek is also 26 part of the PeeDee River Basin which is a dystrophic, blackwater system with low dissolved 27 minerals, water hardiness and naturally acidic (Duke 2025-TN12519).

28 South Carolina Department of Environmental Services regularly monitors surface water at one 29 location in Black Creek upstream of Lake Robinson near Highway 1 (PD-251) and one site just 30 downstream (PD-159) they also randomly monitor additional sites that vary by year (SCDHEC 31 2025-TN12588). Aquatic life uses remain fully supported, but turbidity, total phosphorus, and 32 fecal coliform concentrations show significant increasing trends (SCDHEC 2015-TN12589).

33 Both routinely monitored sites show low pH which is expected, but the site below Lake 34 Robinson is impaired for aquatic life and fish consumption due to elevated copper (EPA 2022-35 TN10535).

36 C.2.2 Robinson Aquatic Biological Communities 37 The trophic structure of the RNP aquatic environment includes primary producers (plankton, 38 macrophytes, and periphyton), primary consumers (zooplankton and benthic 39 macroinvertebrates), and bottom feeding, planktivorous, and piscivorous fish that serve as 40 secondary and tertiary consumers. Primary producers are organisms that capture the suns 41 energy and synthesize organic compounds from inorganic chemicals. They form the trophic 42 structures foundation by producing the organic nutrients and energy used by consumers.

43

C-7 Primary producers in lake systems include phytoplankton, aquatic macrophytes, and periphyton.

1 Of the three, phytoplankton are the major producers in all but very shallow lakes.

2 C.2.2.1 Primary Producers 3

This section characterizes important RNP aquatic environment primary producers, which 4

include phytoplankton, periphyton, and macrophytes.

5 Phytoplankton and Periphyton 6

Plankton are small and often microscopic organisms that drift or float in the water column.

7 Phytoplankton are single-celled plant plankton and include diatoms (single-celled, yellow algae) 8 and dinoflagellates (single-celled organism with two flagella). Phytoplankton live suspended in 9

the water column and occur in the limnetic (open water) zone of a water body. Periphyton 10 consist of single-celled or filamentous species of algae that attach to benthic or macrophytic 11 surfaces. Periphyton occur in the littoral (nearshore and shallow) zone. They tend to be highly 12 productive because they have more access to nutrients through their roots than do 13 phytoplankton. The phytoplankton community in Lake Robinson is sampled during routine 14 environmental monitoring at the site but samples are only identified if chlorophyll a 15 concentrations are above 40 microgram per liter, which signifies an algae bloom. Common 16 phytoplankton and periphyton found in the RNP freshwater environment include Chlorophyceae 17 (green algae), Chrysophycaece (golden-brown algae), Cryptophycaece (cryptomonads),

18 Myxophycae (blue-green algae), and Bacillariophyceae (diatoms) (Duke 2025-TN12518).

19 Macrophytes 20 Aquatic macrophytes are large plants, both emergent and submerged, that inhabit shallow water 21 areas. Macrophytes occur in the littoral (nearshore and shallow) zone. They tend to be highly 22 productive because they have more access to nutrients through their roots than do 23 phytoplankton. Common aquatic vegetation found in the RNP freshwater environment include 24 broadleaf water-milfoil (Myriophyllum heterophyllum), loose watermilfoil (Myriophyllum laxum),

25 swamp smartweed (Persicaria hydropiperoides), and common water-hyacinth 26 (Eichhornia crassipes) (FWS 2025-TN12590). The last aquatic vegetation surveys conducted at 27 the RNP site were conducted in 1995 and included variable-leaf milfoil 28 (Myriophyllum heterophyllum), fragrant water-lily (Nymphaea odorata), water shield 29 (Brasenia schreberi), slender spikerush (Eleocharis baldwinfi), and spadderdock 30 (Nuphar luteum) (Duke 2025-TN12519).

31 C.2.2.2 Primary Consumers 32 This section summarizes important RNP aquatic environment primary consumers, which include 33 zooplankton and benthic invertebrates.

34 Zooplankton 35 The zooplankton community in Lake Robinson historically shows relatively low taxa richness 36 and diversity but relatively high density and biomass. From 1985 to 1995, rotifer and total 37 zooplankton densities increased significantly, while copepod and total zooplankton biomass 38 decreased (Duke 2025-TN12519). Researchers attributed these changes to the size-selected 39 feeding by fish, particularly young bluegill (Lepomis macrochirus). The bluegill population 40 expanded rapidly throughout the impoundment after the 1982 removal of the brass 41

C-8 condenser tubes, which led to decreased copper levels in the lake. There has not been 1

any zooplankton sampling done since 1995.

2 Benthos (insects, mussel, crayfish, snails) 3 In 1998, researchers collected 75 benthic invertebrate taxa, a number and community 4

composition similar to collections from 1994 to 1997. Naidid worms (Oligochaetes, primarily 5

Pristina aequiseta) and midge larvae (primarily Zalutschia spp. and Parakiefferiella spp.) made 6

up the majority of benthic macroinvertebrates throughout the lake (Duke 2025-TN12519). Taxa 7

richness and diversity remained significantly lower at the discharge than at the upper and lower 8

impoundment sites; however, the discharge population has not changed significantly over the 9

past 20 years, and the benthic invertebrate community across the lake shows little long-term 10 ecological change. Duke conducts annual environmental monitoring, including surveys for 11 Asiatic clams (Corbicula fluminea) and zebra mussels (Dreissena polymorpha), but has not 12 found either species in the lake to date (Duke 2025-TN12519). There have been no recent 13 surveys (since 1998) for benthic invertebrate communities at RNP.

14 C.2.2.3 Secondary and Tertiary Consumers 15 This section characterizes important aquatic environment secondary and tertiary consumers, 16 which include ichthyoplankton, juvenile, and adult fish.

17 Ichthyoplankton 18 As part of their Clean Water Act of 1972 Section 316(b) compliance an entrainment study was 19 conducted in 2016 (March through October) and 2017 (March through November) that sampled 20 ichthyoplankton in the forebay of the plant intake and is incorporated by reference (Duke 2025-21 TN12519). Over the course of the 2-year entrainment study at the RNP, researchers collected a 22 total of 1,953 fish across various sizes, class, and life-stages of ichthyoplankton, with 909 23 specimens gathered in 2016 and 1,044 in 2017. In 2016, 6 families of fish were represented, 24 with Centrarchidae dominating the catch at 40.8 percent, followed by Clupidae at 28.7 percent, 25 and Percidae at 23.7 percent. In 2017, 5 families were collected with Clupidae leading at 26 46.7 percent, followed by Centrarchidae at 24.3 percent, and Percidae at 18.2 percent. These 3 27 families accounted for 89 percent of the total collections in both years, Cyprinidae which made 28 up 0.2 percent of the total in 2016 were not collected during sampling in 2017.

29 At the taxa level, researchers identified eight distinct taxa. In 2016, sunfish species 30 (Lepomis spp.) made up the largest portion of the catch at 38 percent, followed by the shads 31 (gizzard and threadfin, 28 percent), darter species (13 percent), and swamp darter (11 percent).

32 In 2017, the shads dominated at 43 percent, with sunfish species at 23 percent, swamp darter 33 at 11 percent, and white perch at 10 percent. Other taxa contributed less than 7 percent to the 34 total catch.

35 The study found that post yolk-sac larvae overwhelmingly dominated the life stages collected, 36 comprising 98 percent in 2016 and 96 percent in 2017. Only a single shad egg, was collected 37 during the entire study. The lack of eggs and yolk-sac larvae captured by the study could be due 38 to spawning occurring before March or spawning habitat and behavior preferences that put the 39 eggs away from the intake.

40

C-9 Juvenile and Adult Fish 1

Between 1974 and 1993, CP&L studies captured 54 fish species in Lake Robinson using 2

electrofishing, rotenone, and fyke nets (Duke 2025-TN12519). Surveys conducted from 1994 to 3

1998, using only electrofishing and rotenone recorded a total of 32 fish species, with an average 4

of 23 species each year, bluegill dominated the catch comprising 74 percent of the fish collected 5

by electrofishing and 58 to 74 percent of the fish collected with rotenone (NRC 2003-TN7260).

6 Electrofishing and cove rotenone sampling also captured warmouth (Lepomis gulosus),

7 largemouth bass (Micropterus salmoides), and sunfish (Lepomis sp.). More recently, Duke 8

completed environmental monitoring in 2012, 2013, 2014-2015, and 2016-2019, all of the fish 9

surveys were conducted using only electrofishing (Duke 2025-TN12519). During all these 10 sampling years dissolved oxygen and water temperature were the primary environmental 11 variables of biological importance that varied among sites either spatially or temporally.

12 Table C-3 shows an overview of the fish collection data, there is some variation across years.

13 Bluegill was the dominant species every year and at every location, accounting for 41 to 14 67 percent of the fish collected, followed by largemouth bass (6 to 10 percent) and warmouth 15 (5 to 7 percent). Redbreast sunfish (Lepomis auritus) concentrated around the intake and hybrid 16 sunfish occurred in relatively large numbers near the discharge. Redear sunfish 17 (Lepomis microlophus), spotted sucker (Minytrema melanops), lake chubsucker 18 (Erimyzon sucetta), and dollar sunfish (Lepomis marginatus) were also found in higher numbers 19 across the lake. In 2013 and 2014, golden shiner (Notemigonus crysoleucas) was abundant at 20 the uplake location, which is shallower, more riverine, and supports more submerged vegetation 21 than open-water areas. In 2017, threadfin shad (Dorosoma petenense) were abundant at the 22 uplake location. The lowest numbers in both total species and number of fish were found by the 23 discharge every year. Bluegill, largemouth bass, warmouth, golden shiner, and threadfin shad 24 are all pollutant tolerant species, while the sunfish, spotted sucker, and lake chubsucker are 25 more sensitive to water quality.

26 Table C-3 Environmental Characterization Fish Data Collected via Electrofishing in 27 Lake Robinson, 2012-2019 28 Year 2012 2013 2014 2015 2016 2017 2018 2019

1. of Species 23 21 21 23 17 20 18 22

1. of Fish 2,460 2,406 2,859 1,922 1,623 2,515 1,604 1,598 Total biomass (kg) 108.4 128.2 159.8 113.3 98 88.3 83.5 99.1

1. Species, Transect A (intake) 9 11 10 11 7

10 8

8

1. Fish, Transect A (intake, fish/hr) 995 982 963 848 743 712 596 623

1. Species, Transect E (discharge) 10 10 11 13 11 8

8 10

1. Fish, Transect E (discharge, fish/hr) 194 189 229 150 135 175 198 194

1. Species, Transect G (uplake) 21 16 19 16 17 20 16 19

1. Fish, Transect G (uplake, fish/hr) 302 317 463 193 202 587 182 245

1. of Fish Kills 0

0 0

0 0

0 0

0 Source: Duke 2025-TN12519.

C-10 From 1993 to 1998, when fyke net sampling was discontinued, the number of species captured 1

decreased from 54 to 32 (Table C-4). Another decline occurred in 2012, when rotenone 2

sampling was dropped, reducing the number of species captured to 23. Since then, annual 3

species counts during environmental monitoring have ranged between 17 and 23 per year. The 4

changes in species can be seen in Table C-3. Some of this decrease is likely due to using fewer 5

sampling methods, without fyke net sampling nocturnal, less mobile, and smaller species are 6

less likely to be captured, and without rotenone sampling species that hide or are less mobile 7

are unlikely to be detected (Robertson and Smith-Vaniz 2008-TN12593; Ruetz et al. 2007-8 TN12594).

9 Table C-4 Freshwater Fish Species Present in Lake Robinson 10 Common Name Scientific Name 1974-1993 1994-1995 2012-2019 bowfin Amia calva P

P P

American eel Anguilla rostrata P

P eastern mudminnow Umbra pygmaea P

P unidentified pickerel Esox spp.

P redfin pickerel Esox americanus americanus P

P chain pickerel Esox niger P

P P

golden shiner Notemigonus crysoleucas P

P P

unidentified shiner Notropis spp.

P P

ironcolor shiner Notropis chalybaeus P

P dusky shiner Notropis cummingsae P

P unidentified chubsucker Erimyzon spp.

P P

creek chubsucker Erimyzon oblongus P

P P

lake chubsucker Erimyzon sucetta P

P P

spotted sucker Minytrema melanops P

P P

unidentified bullhead Ameiurus spp.

P P

snail bullhead Ameiurus brunneus P

P white catfish Ameiurus catus P

P P

black bullhead Ameiurus melas P

yellow bullhead Ameiurus natalis P

P P

brown bullhead Ameiurus nebulosus P

P flat bullhead Ameiurus platycephalus P

P P

channel catfish lctalurus punctatus P

P unidentified madtom Noturus spp.

P tadpole madtom Noturus gyrinus P

margined madtom Noturus insignis P

P swampfish Chologaster cornuta P

P pirate perch Aphredoderus sayanus P

P P

lined topminnow Fundulus lineolatus P

P P

eastern mosquitofish Gambusia holbrooki P

P P

white perch Marone americana P

P mud sunfish Acantharchus pomotis P

P

C-11 Common Name Scientific Name 1974-1993 1994-1995 2012-2019 flier Centrarchus macropterus P

unidentified pygmy sunfish Elassoma spp.

P P

Everglades pygmy sunfish Elassoma evergladei P

banded pygmy sunfish Elassoma zonatum P

unidentified banded sunfish Enneacanthus spp.

P blackbanded sunfish Enneacanthus chaetodon P

P P

bluespotted sunfish Enneacanthus gloriosus P

P P

unidentified sunfish Lepomis spp.

P P

hybrid sunfish Lepomis (hybrid)

P P

P redbreast sunfish Lepomis auritus P

P P

pumpkinseed Lepomis gibbosus P

warmouth Lepomis gulosus P

P P

bluegill Lepomis macrochirus P

P P

dollar sunfish Lepomis marginatus P

P P

redear sunfish Lepomis microlophus P

P P

largemouth bass Micropterus salmoides P

P P

unidentified crappie Pomoxis spp.

P white crappie Pomoxis annularis P

black crappie Pomoxis nigromaculatus P

P P

unidentified darter Etheostoma spp.

P P

swamp darter Etheostoma fusiforme P

P P

tessellated darter Etheostoma olmstedi P

sawcheek darter Etheostoma serriferum P

P P

Piedmont darter Percina crassa P

threadfin shad Dorosoma petenense P

TOTAL SPECIES 54 32 31(a)

- denotes no content in table cell.

(a) Species varied among years, see Table C-3 for exact number of species collected each year from 2012-2019.

Source: Duke 2025-TN12519.

Important Species 1

There have not been any invasive aquatic species observed in Lake Robinson during annual 2

environmental monitoring, including aquatic vegetation, Asiatic clams (Corbicula fluminea), or 3

zebra mussels (Dreissena polymorpha) (Duke 2025-TN12519). There are two possible 4

State-listed aquatic species listed in Darlington, Chesterfield, and Lee Counties that could be 5

present, but based on habitat preferences and lack of observation in or around RNP it is unlikely 6

that any of them are actually present. These include the shortnose sturgeon 7

(Acipenser brevirostrum) and broadtail madtom (Noturus sp. c.f. leptacanthus) since they are 8

not present at Lake Robinson or in Black Creek they are not considered further (SCHTP 2025-9 TN12579).

10

C-12 C.3 Endangered Species Act Section 7 Consultation 1

As a Federal agency, NRC must comply with the ESA (TN1010), as part of any action 2

authorized, funded, or carried out by the agency. In this case, the proposed agency action is 3

whether to issue subsequent renewed license for the continued operation of RNP. The proposed 4

action would authorize Duke to operate RNP for an additional 20 years beyond the term of the 5

current renewed operating license. Under Section 7 of the ESA, the NRC must consult with the 6

U.S. Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) (the 7

Services [collectively] or Service [individually]), as appropriate, to ensure that the proposed 8

action is not likely to jeopardize the continued existence of any endangered or threatened 9

species or result in the destruction or adverse modification of designated critical habitat.

10 C.3.1 Federal Agency Obligations under Section 7 of the Endangered Species Act 11 The ESA (TN1010) and the regulations that implement ESA Section 7 at Title 50 of the Code of 12 Federal Regulations (50 CFR) Part 402 (TN4312) describe the consultation process that 13 Federal agencies must follow in support of agency actions. As part of this process, the Federal 14 agency shall either request that the Services (1) provide a list of any listed or proposed species 15 or designated or proposed critical habitats that may be present in the action area or (2) request 16 that the Services concur with a list of species and critical habitats that the Federal agency has 17 created (50 CFR 402.12(c)). If any such species or critical habitats may be present, the Federal 18 agency prepares a biological assessment to evaluate the potential effects of the action and 19 determine whether the species or critical habitats are likely to be adversely affected by the 20 action (50 CFR 402.12(a); 16 U.S.C. 1536(c) [TN4459]).

21 Biological assessments are required for any agency action that is a major construction activity 22 (50 CFR 402.12(b)). A major construction activity is a construction project or other undertaking 23 having construction-type impacts that is a major Federal action significantly affecting the quality 24 of the human environment under the NEPA (TN661) (51 FR 19926-TN7600). Federal agencies 25 may fulfill their obligations to consult with the Services under ESA Section 7 and to prepare a 26 biological assessment, if required, in conjunction with the interagency cooperation procedures 27 required by other statutes, including NEPA (50 CFR 402.06(a)) (TN4312). In such cases, the 28 Federal agency should include the results of ESA Section 7 consultation(s) in the NEPA 29 document (50 CFR 402.06(b)).

30 C.3.2 Biological Evaluation 31 Subsequent license renewal does not require the preparation of a biological assessment 32 because it is not a major construction activity. Nonetheless, the NRC staff must consider the 33 impacts of its actions on federally listed species and designated critical habitats. For cases in 34 which the staff finds that license renewal may affect ESA-protected species or habitats, ESA 35 Section 7 requires the NRC to consult with the relevant Service(s).

36 In accordance with 50 CFR 402.08 (TN4312), Federal agencies may designate a non-Federal 37 representative (NFR) to conduct informal consultation. By letter dated May 15, 2025, the NRC 38 notified the FWS of its designation of Duke as its NFR for the RNP subsequent license renewal 39 (NRC 2025-TN12573). In support of the consultation, Duke is preparing a biological evaluation 40 to evaluate the potential impacts of the proposed subsequent license renewal (NRC 2025-41 TN12573).

42

C-13 Duke is structuring its evaluation in accordance with the Services suggested biological 1

assessment contents described at 50 CFR 402.12(f) (TN4312). The results of the analysis are 2

summarized in Table C-5.

3 Table C-5 Effect Determinations for Federally Listed Species under U.S. Fish and 4

Wildlife Service Jurisdiction 5

Species Federal Status(a)

Potentially Present in the Action Area?

Effect Determination(b)

FWS Concurrence Date(c) red-cockaded woodpecker FT IP IP TBD rough-leaved loosestrife FE IP IP TBD tricolored bat FPE IP IP TBD southern longnose snake FPT IP IP TBD monarch butterfly FPT IP IP TBD FPD = federally proposed designated (critical habitat); FE = federally endangered; FPE = proposed for Federal listing as endangered; FPT = proposed for Federal listing as threatened; FT = federally threatened; FWS = U.S. Fish and Wildlife Service; IP = in-progress, pending NFR action; NRC = Nuclear Regulatory Commission; TBD = to be determined.

(a) Indicates protection status under the Endangered Species Act.

(b) The NRC staff makes its effect determinations for federally listed species in accordance with the language and definitions specified in the FWS and NMFS Endangered Species Consultation Handbook (FWS and NMFS 1998-TN1031).

(c) The ESA does not require Federal agencies to seek FWS concurrence for no effect determinations or for NLAA determinations for candidate and proposed species. For species whose FWS concurrence date is listed as N/A or TBD, the NRC will seek the FWSs concurrence following the issuance of this draft EIS.

C.3.3 Chronology of Endangered Species Act Section 7 Consultation 6

C.3.3.1 Endangered Species Act Section 7 Consultation with the U.S. Fish and Wildlife 7

Service 8

Duke, as the designated NFR, will seek concurrence from the FWS for the species for which the 9

proposed action of RNP subsequent license renewal may affect but is not likely to adversely 10 affect (see Table C-1) in accordance with 50 CFR 402.13(c) (TN4312). Table C-6 lists the 11 correspondence relevant to the ESA Section 7 consultation that has transpired to date.

12 Table C-6 Endangered Species Act Section 7 Consultation Correspondence with the 13 U.S. Fish and Wildlife Service 14 Date Description ADAMS Accession No.(a)

May 15, 2025 S. Healy (NRC) to South Carolina Ecological Services Field Office (FWS), Designation of Duke Energy, LLC as the non-Federal representative for the proposed Robinson subsequent license renewal ML25122A050 September 30, 2025 South Carolina Ecological Services Field Office (FWS) to S. Healy (NRC), Official species list for the proposed Robinson subsequent license renewal ML25273A158 ADAMS = Agencywide Documents Access and Management System; FWS = U.S. Fish and Wildlife Service; NRC = U.S. Nuclear Regulatory Commission.

(a)

Access these documents through the NRCs ADAMS at https://adams-search.nrc.gov/home.

C-14 C.3.3.2 Endangered Species Act Section 7 Consultation with the National Marine Fisheries 1

Service 2

As discussed in Section 3.6.2, no federally listed species or critical habitats under NMFS 3

jurisdiction occur within the action area. Therefore, the NRC staff did not engage the NMFS 4

pursuant to ESA Section 7 for the proposed RNP subsequent license renewal.

5 C.4 Magnuson-Stevens Act Essential Fish Habitat Consultation 6

The NRC must comply with the MSA (TN9966), for any actions authorized, funded, or 7

undertaken, or proposed to be authorized, funded, or undertaken that may adversely affect any 8

essential fish habitat (EFH) identified under the MSA. In Section 3.6.3, the NRC staff concludes 9

that the NMFS has not designated any EFH under the MSA within the affected area and that the 10 proposed RNP subsequent license renewal would have no effect on EFH. Thus, the MSA does 11 not require the NRC to consult with the NMFS for the proposed action.

12 C.5 National Marine Sanctuaries Act Consultation 13 The NMSA (TN7197), authorizes the Secretary of Commerce to designate and protect areas of 14 the marine environment with special national significance due to their conservation, recreational, 15 ecological, historical, scientific, cultural, archaeological, educational, or aesthetic qualities as 16 national marine sanctuaries. Under Section 304(d) of the act, Federal agencies must consult 17 with the National Oceanic and Atmospheric Administrations Office of National Marine 18 Sanctuaries if a Federal action is likely to destroy, cause the loss of, or injure any sanctuary 19 resources.

20 No coastal or marine waters or Great Lakes occur near RNP and the RNP subsequent license 21 renewal would have no effect on sanctuary resources. Thus, the NMSA does not require the 22 NRC to consult with the National Oceanic and Atmospheric Administration for the proposed 23 action.

24 C.6 References 25 50 CFR Part 402. Code of Federal Regulations, Title 50, Wildlife and Fisheries, Part 402, 26 Interagency CooperationEndangered Species Act of 1973, as amended. TN4312.

27 51 FR 19926. June 3, 1986. Interagency Cooperation - Endangered Species Act of 1973, as 28 amended. Final Rule, Federal Register, Fish and Wildlife Service, Interior; National Marine 29 Fisheries Service, National Oceanic and Atmospheric Administration, Commerce. TN7600.

30 64 FR 6183. February 8, 1999. Executive Order 13112 of February 3, 1999: Invasive Species.

31 Federal Register, Office of the President. TN4477.

32 81 FR 88609. December 8, 2016. Safeguarding the Nation from the Impacts of Invasive 33 Species. Executive Order 13751. Federal Register, Office of the President. TN8375.

34 16 U.S.C. § 1536. Endangered Species Act, Section 7, Interagency Cooperation. TN4459.

35 16 U.S.C. § 1801 et seq. U.S. Code Title 16, Conservation, Chapter 38, Fishery Conservation 36 and Management. TN9966.

37

C-15 16 U.S.C. § 3901 et seq. U.S. Code Title 16, Conservation, Chapter 59, Wetland Resources.

1 TN10912.

2 Bald and Golden Eagle Protection Act. 16 U.S.C. § 668-668d et seq. TN1447.

3 Duke Energy. 2025. Letter from L. Basta, Site Vice President, to NRC Document Control Desk, 4

dated September 8, 2025, regarding Duke Energy Progress, LLC, H.B. Robinson Steam 5

Electric Plant, Unit Number 2, Docket Number 50-261/Renewed License Number DPR-23, 6

Subsequent License Renewal Application Responses to Requests for Additional Information 7

(RAI) and Requests for Confirmation of Information (RCI). Hartsville, South Carolina. ADAMS 8

Accession No. ML25251A097. TN12519.

9 Duke Energy. 2025. Enclosure 3, Attachment 2, H.B. Robinson Steam Electric Plant, Unit 10 Number 2 Subsequent License Renewal Application, Appendix E, Environmental Report.

11 Charlotte, North Carolina. ADAMS Accession No. ML25091A296. TN12518.

12 eBird. 2023. Species Maps. Cornell Lab of Ornithology eBird Database, Ithaca, New York.

13 Accessed September 5, 2023, at https://ebird.org/map. TN8838 14 Endangered Species Act of 1973. 16 U.S.C. § 1531 et seq. TN1010.

15 EPA (U.S. Environmental Protection Agency). 2013. Level III Ecoregions of the Continental 16 United States. National Health and Environmental Effects Research Laboratory, Corvallis, 17 Oregon. TN9981.

18 EPA (U.S. Environmental Protection Agency). 2013. Primary Distinguishing Characteristics of 19 Level III Ecoregions of the Continental United States. Washington, D.C. TN8737.

20 EPA (U.S. Environmental Protection Agency). 2022. Letter from D. Diaz, Acting Director, Water 21 Division, to J. Hughes, Chief, Bureau of Water, Department of Health and Environmental 22 Control, dated December 28, 2022, regarding South Carolinas 2020 and 2022 303(d) List 23 Submittal. Atlanta, Georgia. TN10535.

24 FWS (U.S. Fish and Wildlife Service). 2021. Birds of Conservation Concern 2021, Migratory 25 Bird Program. Washington, D.C. TN8740.

26 FWS (U.S. Fish and Wildlife Service). 2025. Carolina Sandhills National Wildlife Refuge, 27 Species. Washington, D.C. Accessed September 22, 2025, at 28 https://www.fws.gov/refuge/carolina-sandhills/species. TN12590.

29 FWS (U.S. Fish and Wildlife Service). 2025. Letter from South Carolina Ecological Services, to 30 Whom It May Concern, dated September 30, 2025, regarding List of threatened and 31 endangered species that may occur in your proposed project location or may be affected by 32 your proposed project. Charleston, South Carolina. ADAMS Accession No. ML25273A158.

33 TN12578.

34

C-16 FWS and NMFS (U.S. Fish and Wildlife Service and National Marine Fisheries Service). 1998.

1 Endangered Species Act Consultation Handbook, Procedures for Conducting Section 7 2

Consultation and Conference. Washington, D.C. ADAMS Accession No. ML14171A801.

3 TN1031.

4 Griffith, G.E., J.M. Omernik, J.A. Comstock, M.P. Schafale, W.H. McNab, D.R. Lenat, T.F.

5 MacPherson, J.B. Glover, and V.B. Shelburne. 2002. Ecoregions of North Carolina and South 6

Carolina, (color poster with map, descriptive text, summary tables, and photographs). Reston, 7

Virginia. TN10429.

8 iNaturalist. 2025. Bird Observations, Custom Boundary, Robinson Nuclear Plant, South 9

Carolina. San Rafael, California. Accessed October 15, 2025, at 10 https://www.inaturalist.org/observations?lat=34.40483933966064&lng=-

11 80.1553252859619&radius=16.926787454398276&subview=map&iconic_taxa=Aves. TN12584.

12 iNaturalist. 2025. iNaturalist Observations of Bald Eagle (Haliaeetus leucocephalus),

13 Chesterfield County, South Carolina. San Rafael, California. Accessed October 15, 2025, at 14 https://www.inaturalist.org/. TN12580.

15 iNaturalist. 2025. Observations, Custom Boundary, Robinson Nuclear Plant, South Carolina.

16 San Rafael, California. Accessed October 15, 2025, at 17 https://www.inaturalist.org/observations?lat=34.40483933966064&lng=-

18 80.1553252859619&radius=9.853304042818529&subview=map&threatened. TN12583.

19 Migratory Bird Treaty Act of 1918. 16 U.S.C. § 703 et seq. TN3331.

20 National Environmental Policy Act of 1969 (NEPA), as amended. 42 U.S.C. § 4321 et seq.

21 TN661.

22 National Marine Sanctuaries Act. 2000. "National Marine Sanctuaries Act, Title 16, Chapter 32 § 23 1431 et seq. United States Code as amended by Public Law 106-513." Silver Spring, 24 M.D. Available at https://nmssanctuaries.blob.core.windows.net/sanctuaries-25 prod/media/archive/library/national/nmsa.pdf. TN7197.

26 NRC (U.S. Nuclear Regulatory Commission). 2003. Generic Environmental Impact Statement 27 for License Renewal of Nuclear Plants, Supplement 13: Regarding H.B. Robinson Steam 28 Electric Plant, Unit No. 2, Final Report. NUREG-1437, Supplement 13, Washington, D.C.

29 ADAMS Accession No. ML033450517. TN7260.

30 NRC (U.S. Nuclear Regulatory Commission). 2025. Letter from M. Rome, Chief, Environmental 31 Technical Review Branch 1, Division of Rulemaking, Environment, and Financial Support, Office 32 of Nuclear Material Safety and Safeguards, to C. Johnson-Hughes, Project Leader, South 33 Carolina Ecological Services Field Office, U.S. Fish and Wildlife Service, dated May 15, 2025, 34 regarding Designation of Duke Energy Progress, LLC, as the Non-Federal Representative for 35 the Subsequent License Renewal Application for H.B. Robinson Steam Electric Plant, Unit No. 2 36 (Docket Number: 050-261). Washington, D.C. ADAMS Accession No. ML25122A050.

37 TN12573.

38 Robertson, D.R. and W.F. Smith-Vaniz. 2008. Rotenone: An Essential but Demonized Tool for 39 Assessing Marine Fish Diversity. BioScience 58(2):165-170, Oxford, England. Available at 40 https://doi.org/10.1641/B580211. TN12593.

41

C-17 Ruetz III, C.R., D.G. Uzarski, D.M. Krueger, and E.S. Rutherford. 2007. Sampling a Littoral Fish 1

Assemblage: Comparison of Small-Mesh Fyke Netting and Boat Electrofishing. Muskegon, 2

Michigan. Available at https://scholarworks.gvsu.edu/peerscipub/1/. TN12594.

3 SCDHEC (South Carolina Department of Health and Environmental Control). 2015. Watershed 4

Water Quality Assessment, Pee Dee River Basin. Columbia, South Carolina. Available at 5

https://des.sc.gov/sites/des/files/media/document/Pee%20Dee%20WWQA_2015.pdf. TN12589.

6 SCDHEC (South Carolina Department of Health and Environmental Control). 2025. Watershed 7

Atlas, Robinson; Water Quality Monitoring: Ambient Surface (Fixed), Ambient Surface (Historic),

8 Ambient Surface (Random), Fish Tissue Monitoring, Water Advisories: Freshwater Fish.

9 Columbia, South Carolina. Accessed October 15, 2025, at 10 https://gis.dhec.sc.gov/gisportal/apps/webappviewer/index.html?id=5748b81cf2d84668be4175e 11 ed2511654. TN12588.

12 SCDNR (South Carolina Department of Natural Resources). 2025. South Carolina Department 13 of Natural Resources State Listed Species Protection Guidance. Columbia, South Carolina.

14 Available at 15 https://dnr.sc.gov/environmental/docs/SCDNRStateListedSpeciesProtectionGuidance.pdf.

16 TN12577.

17 SCHTP (South Carolina Heritage Trust Program). 2025. Tracked Species by County, 18 Chesterfield County, Darlington County, and Lee County. Columbia, South Carolina. Accessed 19 April 16, 2025, at https://natural-heritage-program-scdnr.hub.arcgis.com/. TN12579.

20

D-1 APPENDIX D 1

2 NATIONAL HISTORIC PRESERVATION ACT SECTION 106 3

CONSULTATION 4

The National Historic Preservation Act of 1966, as amended (NHPA) (TN4157), requires Federal 5

agencies to consider the effects of their undertakings on historic properties and consult with 6

applicable Federal and State agencies, Indian Tribes, individuals, and organizations with a 7

demonstrated interest in the undertaking before taking an action. Historic properties are defined 8

as resources that are eligible for listing or listed on the National Register of Historic Places. The 9

NHPA Section 106 (TN4839) review process is outlined in regulations issued by the Advisory 10 Council on Historic Preservation in Title 36 of the Code of Federal Regulations (CFR) Part 800, 11 Protection of Historic Properties (TN513). In accordance with 36 CFR 800.8(c), Use of the 12 NEPA Process for Section 106 Purposes, the U.S. Nuclear Regulatory Commission (NRC or 13 the Commission) has elected to use the National Environmental Policy Act of 1969 (NEPA) 14 process to comply with its obligations under Section 106 of the NHPA.

15 Additionally, in accordance with the NRCs January 9, 2017, Tribal Policy Statement (82 FR 16 2402-TN5500), the NRC invited State recognized Tribes to submit any comments or concerns 17 on the scope of the environmental review.

18 Table D-1 lists the chronology of consultation and consultation documents related to the NRCs 19 NHPA Section 106 review of the proposed H.B. Robinson Steam Electric Plant, Unit 2 20 (Robinson or RNP) subsequent license renewal. The NRC staff is required to consult with the 21 noted agencies and organizations in accordance with the laws and regulations listed above.

22 Table D-1 National Historic Preservation Act Section 106 Correspondence for the 23 Subsequent License Renewal of H.B. Robinson Steam Electric Plant, Unit 2 24 Date Description ADAMS Accession No.(a) 05/23/2025 Letter from M. Rome, NRC to J. Loichinger, ACHP - request for scoping comments; notification of Section 106 review ML25127A195 05/23/2025 Letter from M. Rome, NRC to W. Emerson, SC SHPO - request for scoping comments; initiation of Section 106 review ML25127A197 05/23/2025 Letter from M. Rome, NRC to J. Johnson, Governor, Absentee Shawnee Tribe - request for scoping comments; initiation of Section 106 review ML25126A178 05/23/2025 Letter from M. Rome, NRC to B. Harris, Chief, Catawba Indian Nation

- request for scoping comments; initiation of Section 106 review ML25142A339 05/23/2025 Letter from M. Rome, NRC to C. Hoskin, Jr., Principal Chief, Cherokee Nation - request for scoping comments; initiation of Section 106 review ML25142A341 05/23/2025 Letter from M. Rome, NRC to D. Hill, Principal Chief, Muscogee Nation - request for scoping comments; initiation of Section 106 review ML25142A354 05/23/2025 Letter from M. Rome, NRC to B. Anoatubby, Governor, Chickasaw Nation - request for scoping comments; initiation of Section 106 review ML25142A342

D-2 Date Description ADAMS Accession No.(a) 05/23/2025 Letter from M. Rome, NRC to G. Wallace, Chief, Eastern Shawnee Tribe of Oklahoma - request for scoping comments; initiation of Section 106 review ML25142A344 05/23/2025 Letter from M. Rome, NRC to B. Barnes, Chief, Shawnee Tribe -

request for scoping comments; initiation of Section 106 review ML25142A357 05/23/2025 Letter from M. Rome, NRC to L. Johnson, Chief, Seminole Nation of Oklahoma - request for scoping comments; initiation of Section 106 review ML25142A355 05/23/2025 Letter from M. Rome, NRC to J. Bunch, Chief, United Keetoowah Band of Cherokee Indians - request for scoping comments; initiation of Section 106 review ML25142A363 05/23/2025 Letter from M. Rome, NRC to T. Jonathan, Chief, Tuscarora Nation of New York - request for scoping comments; initiation of Section 106 review ML25142A362 05/23/2025 Letter from M. Rome, NRC to T. Cypress, Chairman, Miccosukee Tribe of Florida - request for scoping comments; initiation of Section 106 review ML25142A353 05/23/2025 Letter from M. Rome, NRC to M. Hicks, Principal Chief, Eastern Band of Cherokee Indians - request for scoping comments; initiation of Section 106 review ML25142A343 05/23/2025 Letter from M. Rome, NRC to W. Yargee, Chief, Alabama-Quassarte Tribal Town - request for scoping comments; initiation of Section 106 review ML25142A328 05/23/2025 Letter from M. Rome, NRC to S. Yahola, Town King, Kialegee Tribal Town - request for scoping comments; initiation of Section 106 review ML25142A345 05/23/2025 Letter from M. Rome, NRC to R. Morrow, Town King, Thlopthlocco Tribal Town - request for scoping comments; initiation of Section 106 review ML25142A358 05/23/2025 Letter from M. Rome, NRC to M. Osceola, Jr., Chairman, Seminole Tribe of Florida - request for scoping comments; initiation of Section 106 review ML25142A356 05/23/2025 Letter from M. Rome, NRC to L. Nelson, Chief, Eastern Cherokee, Southern Iroquois and United Tribes of South Carolina - request for scoping comments ML25142A368 05/23/2025 Letter from M. Rome, NRC to P. Parr, Chief, Pee Dee Indian Tribe -

request for scoping comments ML25142A388 05/23/2025 Letter from M. Rome, NRC to E. Pratt, Chief, Santee Indian Organization - request for scoping comments ML25142A391 05/23/2025 Letter from M. Rome, NRC to S. Davis, Chief, Natchez Tribe of South Carolina - request for scoping comments ML25142A371 05/23/2025 Letter from M. Rome, NRC to D. Sharp, Chief, Piedmont American Indian Association Lower Eastern Cherokee Nation of South Carolina

- request for scoping comments ML25142A389 05/23/2025 Letter from M. Rome, NRC to F. Benenhaley, Chief, Sumter Tribe of Cheraw Indians - request for scoping comments ML25142A392

D-3 Date Description ADAMS Accession No.(a) 05/23/2025 Letter from M. Rome, NRC to C. Chavis-Bolton, Chief, Pee Dee Indian Nation of Upper South Carolina - request for scoping comments ML25142A384 05/23/2025 Letter from M. Rome, NRC to J. Creel, Chief, Edisto Natchez Kusso Tribe of South Carolina - request for scoping comments ML25142A369 05/23/2025 Letter from M. Rome, NRC to L. Chavis, Chief, Beaver Creek Indians

- request for scoping comments ML25127A108 05/23/2025 Letter from M. Rome, NRC to J. Tanner, Chief, Chaloklowa Chickasaw Indian People - request for scoping comments ML25142A366 05/23/2025 Letter from M. Rome, NRC to L. Collins, Chief, Wassamasaw Tribe of Varnertown Indians - request for scoping comments ML25142A393 05/23/2025 Letter from M. Rome, NRC to J. Lowery, Chairman, Lumbee Tribe of North Carolina - request for scoping comments ML25142A370 05/23/2025 Letter from M. Rome, NRC to E. Vereen, Chief, Pee Dee Indian Nation of Beaver Creek - request for scoping comments ML25142A374 05/28/2025 Non-public Tribe to B. Goldstein, NRC - project is outside the area of interest ML25192A198 (non-publicly available) 06/03/2025 Letter from R. Mangum, ACHP to M. Rome, NRC - acceptance of 36 CFR 800.8(c) notification ML25192A156 07/03/2025 Email from L. Collins, Chief, Wassamasaw Tribe of Varnertown Indians to B. Goldstein, NRC - scoping comments ML25197A054 07/03/2025 Email from E. Johnson, SC SHPO to B. Goldstein, NRC - status of architectural survey report ML25192A210 07/03/2025 Non-public state recognized Tribe to B. Goldstein, NRC - no comments ML25192A182 (non-publicly available) 07/06/2025 Non-public state recognized Tribe to B. Goldstein, NRC - no comments ML25192A205 (non-publicly available) 07/08/2025 Non-public Tribe to B. Goldstein, NRC - request for hard copies ML25192A172 (non-publicly available) 07/15/2025 Email from B. Goldstein, NRC to L. Collins, Chief, Wassamasaw Tribe of Varnertown Indians - response to comments ML25197A552 09/30/2025 Email from E. Johnson, SC SHPO to B. Goldstein, NRC - revised draft architectural survey report ML25323A005 ADAMS = Agencywide Documents Access and Management System; ACHP = Advisory Council on Historic Preservation; SHPO = State Historic Preservation Office; NRC = U.S. Nuclear Regulatory Commission.

(a) Access these documents through the NRCs ADAMS at https://adams-search.nrc.gov/home.

D-4 D.1 References 1

36 CFR Part 800. Code of Federal Regulations, Title 36, Parks, Forests, and Public Property, 2

Part 800, Protection of Historic Properties. TN513.

3 82 FR 2402. January 9, 2017. Tribal Policy Statement. Federal Register, Nuclear Regulatory 4

Commission. TN5500.

5 54 U.S.C. § 306108 et seq. National Historic Preservation Act Section 106, Effect of 6

Undertaking on Historic Property. TN4839.

7 National Historic Preservation Act. 54 U.S.C. § 300101 et seq. TN4157.

8

E-1 APPENDIX E 1

2 CHRONOLOGY OF ENVIRONMENTAL REVIEW CORRESPONDENCE 3

This appendix contains a chronological listing of correspondence between the U.S. Nuclear 4

Regulatory Commission (NRC or the Commission) and external parties as part of the agencys 5

environmental review of the H.B. Robinson Steam Electric Plant, Unit 2, subsequent license 6

renewal application. This appendix does not include consultation correspondence, or comments 7

received during the scoping process. For a list and discussion of consultation correspondence, 8

see Appendix C and Appendix D. For scoping comments, see Appendix A and the Scoping 9

Summary Report. All documents are available electronically from the NRCs Public Electronic 10 Reading Room found at: http://www.nrc.gov/reading-rm.html. From this site, the public can gain 11 access to Agencywide Documents Access and Management System (ADAMS), which provides 12 text and image files of the NRCs public documents. The ADAMS accession number for each 13 document is included in the following table.

14 E.1 Environmental Review Correspondence 15 Table E-1 lists the environmental review correspondence, by date, beginning with the request by 16 Duke Energy, LLC to renew the operating license for H.B. Robinson Steam Electric Plant, 17 Unit 2.

18 Table E-1 Environmental Review Correspondence Regarding the Subsequent License 19 Renewal of H.B. Robinson Steam Electric Plant, Unit 2 20 Date Correspondence Description ADAMS Accession Number(a) or Federal Register Citing 04/01/2025 H.B. Robinson Steam Electric Plant, Unit 2, Application for Subsequent Renewed Operating Licenses ML25031A290 04/01/2025 H.B. Robinson Steam Electric Plant, Unit 2, Application for Subsequent Renewed Operating Licenses ML25091A291 04/01/2025, Attachment 2 - Subsequent License Renewal Application, Appendix E, Environmental Report ML25091A296 04/08/2025 Robinson subsequent license renewal applicant -

Receipt and Availability - Letter.

ML25077A315 04/28/2025 H.B. Robinson Steam Electric Plant, Unit 2 -

Subsequent License Renewal Application Acceptance Letter ML25106A069 04/29/2025 H.B. Robinson Steam Electric Plant, Unit 2 -

Subsequent License Renewal Application Online Reference Portal ML25113A094 05/08/2025 Duke Energy, LLC; H.B. Robinson Steam Electric Plant, Unit No. 2; Subsequent License Renewal Application 90 FR 19535 05/15/2025 NRC to FWS, Designation of Duke Energy, LLC as the Non-Federal Representative for the Robinson subsequent license renewal ML25122A050 05/19/2025 Clean Water Act Section 401(A)(2) Neighboring Jurisdiction Determination Request for H.B Robinson Steam Electric Plant, Unit 2 ML25142A199

E-2 Date Correspondence Description ADAMS Accession Number(a) or Federal Register Citing 05/22/2025 FRN Robinson Intent to Conduct Scoping and Prepare EIS ML25114A007 05/22/2025 Duke Energy, LLC; H.B. Robinson Steam Electric Plant, Unit No. 2; Notice of Intent To Conduct Scoping Process and Prepare Supplemental Environmental Impact Statement 90 FR 21952 06/30/2025 Robinson Environmental Audit Needs Letter ML25177A046 07/31/2025 Robinson Environmental Audit Summary ML25212A007 07/31/2025 -July 2025 Audit Re the Environmental Review of the H.B. Robinson Steam Electric Plant Subsequent License Renewal Application ML25212A008 08/06/2025 Letter to Applicant-July 2025 Audit Re the Environmental Review of the H.B. Robinson Steam Electric Plant Subsequent License Renewal Application ML25212A010 08/06/2025 -July 2025 Audit Re the Environmental Review of the H.B. Robinson Steam Electric Plant Subsequent License Renewal Application ML25212A009 09/04/2025 H.B. Robinson Steam Electric Plant, Unit Number 2, Subsequent License Renewal Application Responses to Requests for Additional Information (RAI) and Requests for Confirmation of Information (RCI)

ML25251A097 ADAMS = Agencywide Documents Access and Management System; EIS = environmental impact statement; FR = Federal Register; FRN = Federal Registration Number.

(a) Access these documents through the U.S. Nuclear Regulatory Commissions ADAMS at https://adams-search.nrc.gov/home.

1

F-1 APPENDIX F 1

2 AGENCIES, ORGANIZATIONS, INDIAN TRIBES, AND INDIVIDUALS 3

CONTACTED 4

The U.S. Nuclear Regulatory Commission (NRC or Commission) contacted Federal, State, 5

Tribal, regional, and local agencies listed in Table F-1 during the NRC staffs environmental 6

review of the environmental impact statement for the subsequent license renewal of H.B.

7 Robinson Steam Electric Plant, Unit 2.

8 Table F-1 List of Agencies, Organizations, Indian Tribes, and Persons Contacted by 9

NRC during the Environmental Review of the Draft Environmental Impact 10 Statement for the Subsequent License Renewal of H.B. Robinson Steam 11 Electric Plant, Unit 2 12 Name Affiliation Jaime Loichinger Advisory Council on Historic Preservation W. Eric Emerson South Carolina State Historic Preservation Officer Bill Anoatubby, Governor Chickasaw Nation John Raymond Johnson, Governor Absentee Shawnee Tribe Wilson Yargee, Chief Alabama-Quassarte Tribal Town Brian Harris, Chief Catawba Indian Nation Chuck Hoskin, Jr., Principal Chief Cherokee Nation Stephanie Yahola, Town King Kialegee Tribal Town Michell Hicks, Principal Chief Eastern Band of Cherokee Indians Glenna J. Wallace, Chief Eastern Shawnee Tribe of Oklahoma Talbert Cypress, Chairman Miccosukee Tribe of Florida David Hill, Principal Chief Muscogee Nation Lewis J. Johnson, Chief Seminole Nation of Oklahoma Marcellus W. Osceola, Jr., Chairman Seminole Tribe of Florida Ben Barnes, Chief Shawnee Tribe Ryan K. Morrow, Town King Thlopthlocco Tribal Town Tom Jonathan, Chief Tuscarora Nation of New York Joe Bunch, Chief United Keetoowah Band of Cherokee Indians Louie Chavis, Chief Beaver Creek Indians Jeff Tanner, Chief Chaloklowa Chickasaw Indian People Lamar Nelson, Chief Eastern Cherokee, Southern Iroquois and United Tribes of South Carolina John Creel, Chief Edisto Natchez Kusso Tribe of South Carolina John Lowery, Chairman Lumbee Tribe of North Carolina Steve Davis, Chief Natchez Tribe of South Carolina Elizabeth Sky Vereen, Chief Pee Dee Indian Nation of Beaver Creek Carolyn Chavis-Bolton, Chief Pee Dee Indian Nation of Upper South Carolina Pete Parr, Chief Pee Dee Indian Tribe

F-2 Name Affiliation Dexter Sharp, Chief Piedmont American Indian Association Lower Eastern Cherokee Nation of South Carolina Eric Pratt, Chief Santee Indian Organization Francis M. Benenhaley, Chief Sumter Tribe of Cheraw Indians Lisa Collins, Chief Wassamasaw Tribe of Varnertown Indians