ML24212A221

License Renewal Regulatory Audit Regarding the Environmental Review of the License Renewal Application (EPID Number: L-2024-LNE-0000) (Docket Number: 50-461)

ML24212A221
Person / Time
Site:	Clinton
Issue date:	08/02/2024
From:	Ashley Waldron NRC/NMSS/DREFS/EPMB1
To:	Wilson C Constellation Energy Generation
References
EPID L-2024-LNE-0000)
Download: ML24212A221 (1)

Text

Christopher D. Wilson Director, License Renewal Constellation Energy Generation, LLC 200 Exelon Way Kennett Square, PA 19348

SUBJECT:

CLINTON POWER STATION, UNIT 1 - LICENSE RENEWAL REGULATORY AUDIT REGARDING THE ENVIRONMENTAL REVIEW OF THE LICENSE RENEWAL APPLICATION (EPID NUMBER: L-2024-LNE-0000) (DOCKET NUMBER: 50-461)

Dear Christopher D. Wilson:

By letter dated February 14, 2024, (Agencywide Documents Access and Management System ML24045A024), Constellation Energy Generation, LLC submitted to the U.S. Nuclear Regulatory Commission (NRC) an application for license renewal of Facility Operating License No. NPF-62 for Clinton Power Station (CPS), Unit 1.) pursuant to Section 103 of the Atomic Energy Act of 1954, as amended, and Part 54 of Title 10 of the Code of Federal Regulations, Requirements for renewal of operating licenses for nuclear power plants.

The NRC staff has initiated the environmental review for the application. A virtual environmental audit will be conducted the week of August 26, 2024, and September 3 and 4 by the NRC staff (see Enclosure 1). In addition, the NRC staff will conduct a site-visit the week of September 23, 2024.

To the extent possible, the NRC staff requests the information identified in the Environmental Audit Needs List (Enclosure 2) be made available on the CPS online reference portal prior to the audit. A draft schedule of tours and meetings is provided in Enclosure 3.

August 2, 2024 C. Wilson 2 If you have any questions, please contact me via email at Ashley.Waldron@nrc.gov.

Sincerely, Ashley N. Waldron Environmental Project Manager Environmental Project Management Branch 1 Division of Rulemaking, Environmental, and Financial Support Office of Nuclear Material Safety and Safeguards Docket No. 50-461

Enclosures:

As stated Signed by Waldron, Ashley on 08/02/24

ML24212A221 OFFICE NE/PM:EPMB1 LA:REFS BC:EPMB1 NE/PM:EPMB1 NAME AWaldron AWalker-Smith SKoenick AWaldron DATE 7/30/2024 7/30/2024 8/1/2024 8/1/2024

Audit Plan

License Renewal Environmental Review Clinton Power Station, Unit 1

August 2024

Enclosure 1 License Renewal Environmental Review Clinton Power Station Unit 1

1. Background

By letter dated February 14, 2024, (Agencywide Documents Access and Management System ML24045A024), Constellation Energy Generation, LLC submitted to the U.S. Nuclear Regulatory Commission (NRC) an application for license renewal of Facility Operating License No.

NPF-62 for Clinton Power Station (CPS), Unit 1 pursuant to Section 103 of the Atomic Energy Act of 1954, as amended. A Federal Register (FR) Notice (89 FR 16591) dated March 7, 2024, noted the receipt and availability of the application, including the environmental report (ER).

The NRC staff is conducting an environmental audit of the CPS site to improve understanding, to verify information, and to identify information for docketing to support the preparation of an environmental impact statement (EIS). Specifically, the NRC staff will be identifying pertinent environmental data, reviewing the facility, and seeking clarifications regarding information provided in the ER.

2. Environmental Audit Bases

License renewal requirements for environmental reports are specified in Title 10 of the Code of Federal Regulations (10 CFR) Part 51, Postconstruction environmental reports. As specified by 10 CFR 51.53(c): Operating license renewal stage, (1) Each applicant for renewal of a license to operate a nuclear power plant under Part 54 of this chapter shall submit with its application a separate document entitled "Applicant's Environmental ReportOperating License Renewal Stage." Review guidance for the staff is provided in NUREG-1555, Supplement 1, Revision 1, Standard Review Plans for Environmental Reviews for Nuclear Power Plants: Supplement 1 -

Operating License Renewal.

The NRC staff is required to prepare a site-specific supplement to NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants. During the scoping process required in 10 CFR 51, the NRC staff is required to define the proposed action, identify significant issues which must be studied in depth, and to identify those issues that can be eliminated from further study.

3. Environmental Audit Scope

The scope of this environmental audit is to identify new and significant issues and issues which can be eliminated from further study. The NRC staff will also identify environmental resources that must be described and evaluated in the Supplemental EIS. Audit team members will review the documents and other requested information made available on the CPS online reference portal identified on the environmental audit needs list (Enclosure 2) and discuss any questions and additional information needs with the applicants subject matter experts.

4. Information and Other Material Necessary for the Environmental Audit

As identified on the environmental audit needs list (Enclosure 2).

5. Environmental Audit Team Members and Resource Assignments

2 The environmental audit team members and their assignments are shown in the table below.

Discipline Team Members Environmental Review Supervisor Steve Koenick Environmental Project Manager Ashley Waldron Backup Environmental Project Manager Karen Loomis Air Quality Nancy Martinez Aquatic Resources Mitchell Dehmer Cumulative Impacts Jeff Rikhoff Environmental Justice Caroline Hsu Federally Protected Ecological Resources Mitchell Dehmer Geologic Environment Gerry Stirewalt Greenhouse Gases/Climate Change Nancy Martinez Groundwater (Hydrology and Hydrogeology) Gerry Stirewalt Historic and Cultural Resources Jennifer Davis Human Health Donald Palmrose Land Use and Visual Resources Caroline Hsu Meteorology and Climatology Nancy Martinez Noise Nancy Martinez Postulated Accidents Jerry Dozier/Elijah Dickson Replacement Power Alternatives Jeff Rikhoff Severe Accident Mitigation Alternatives (SAMA) Jerry Dozier/Elijah Dickson Socioeconomics Caroline Hsu Spent Nuclear Fuel Leah Parks Surface Water Lloyd Desotell Termination of Operations and Decommissioning Rao Tammara Terrestrial (Land Cover and Habitat) Caroline Hsu Uranium Fuel Cycle Rao Tammara Waste Management (rad and non-rad) Leah Parks

6. Logistics

An environmental audit will be conducted by the NRC staff virtually the week of August 26, 2024, followed by a site-visit the week of September 23, 2024. The SAMA portion will be conducted virtually the week of September 3, 2024. An entrance meeting will be held with plant management at the beginning of the environmental audit and an exit meeting will be held following the site visit.

7. Special Requests

Constellation staff and contractors who are subject matter experts in the disciplines identified on

3 the environmental audit needs list should be available for interviews and tours.

8. Deliverables

An audit summary report will be issued by the NRC staff within 90 days from the end of the environmental audit.

4 Clinton Power Station Audit and Information Needs

Described below in three categories (i.e., tours, meetings, and information needs) are the information needs of the U.S. Nuclear Regulatory Commission (NRC) staff, supported by Pacific Northwest National Laboratory (PNNL), Clinton Power Station, Unit 1 (CPS). Information needs are identified as either resource-specific questions or document requests. Please arrange for the tours and meetings specified below to occur during either the virtual environmental audit or site visit as noted. Additionally, we ask that you provide responses to the information needs on the electronic portal and make subject matter experts available to discuss these items with the NRC staff.

Virtual Tours

Please arrange for, and provide appropriate subject matter experts to contribute to, the following virtual tours. For the virtual tours, please provide photographs, diagrams, location maps, and/or callouts for specific components that would be of interest for the features noted.

Number and Features Observed NRC Participants PNNL Title Participants

1. General Virtual walk-through of the following via All All Available site photographs and/or diagrams:

• Exterior grounds

• Transmission lines

• Historic and cultural sites

• Possible alternative power generation locations

• Independent Spent Fuel Storage Installation (ISFSI)

• Plant views from publicly accessible areas

2. Plant intake Virtual walk-through of the following via Ashley Waldron Rajiv Prasad and discharge photographs and/or diagrams (details Karen Loomis Stephen Ferencz vary by location): Lloyd Desotell Philip Meyer

• Intake surrounding area views Mitchell Dehmer Rebecka Bence

• Intake bays Caitlin Wessel

• Intake traveling screens & trash baskets

• CWIS system pathway from intake to discharge

• Discharge flume (beginning, overview of flume, and ending at Clinton Lake)

• Discharge terminus (grates, gating, mesh)

• Discharge surrounding area views

• Onsite IDNR hatchery ponds

5 Number and Features Observed NRC Participants PNNL Title Participants

• Mechanical draft Cooling Towers

• Unit 2 pit discharge pipe location to Lake Clinton

• NPDES outfall

3. Radwaste Virtual walk-through of the following via Ashley Waldron Philip Meyer photographs and/or diagrams: Karen Loomis Rebecka Bence

• Liquid radwaste system - discharge Leah Parks locations

• Gaseous radwaste system - discharge locations

• Low-Level Radioactive Waste (LLW)

Storage Area (Radwaste Building)

4. Virtual walk-through of the following via Ashley Waldron Philip Meyer Groundwater photographs and/or diagrams (details Karen Loomis Rebecka Bence Resources vary by location): Gerry Stirewalt

• Retention Ponds

• Sedimentation Ponds

6 In-person Tours

Please arrange for, and provide appropriate subject matter experts to contribute to, the following in-person tours as part of the NRCs site visit.

Number and Title Features Observed NRC PNNL Participants Participants

1. General site

• Exterior grounds All Dan Nally tour

• In-scope transmission lines Rajiv Prasad Rebecka Bence

• Possible alternative power generation Lindsey Renaud locations

• ISFSI

• Plant views from publicly accessible areas

2. Plant intake

• Salt Creek North Fork Ashley Waldron Dan Nally and discharge

• CWIS Intake surrounding area views Karen Loomis Rajiv Prasad tour Lloyd Desotell Rebecka Bence

• CWIS Intake bays Mitchell Dehmer

• CWIS Intake traveling screens

• CWIS system pathway from intake to discharge

• Discharge flume

• Discharge terminus

• Discharge surrounding area views

• Unit 2 pit discharge pipe pathway and terminus

• Clinton Lake Dam

• Ultimate heat sink

• NPDES outfall

3. Groundwater

• Monitoring wells and piezometers Lloyd Desotell Dan Nally tour

• Sedimentation ponds Ashley Waldron Rajiv Prasad Karen Loomis Rebecka Bence

• Retention ponds

4. Historic and

• Tour grounds and facilities, Jennifer Davis Lindsey Renaud Cultural specifically where any cultural/historic artifacts have been identified

7 Meetings

Please be prepared to schedule breakout meetings with the appropriate subject matter expert(s) and/or contractor(s) concerning the following topics. Those in attendance should be prepared to discuss the corresponding questions as described in the Information Needs and Document Requests section below. The staff intends to use these breakout meetings, as needed, to resolve or clarify any outstanding data needs or questions arising from the environmental audit. The NRC intends to leverage virtual breakouts to the extent possible. Any in-person breakouts are specified.

• General Topics

• Replacement Energy Alternatives

• Land Use and Visual Resources

• Air Quality

• Meteorology and Climatology

• Noise

• Geologic Environment

• Water Resources (Surface and Groundwater)

• Ecological Resources (Terrestrial, Aquatic, and Federally Protected Ecological Resources)

• Historic and Cultural Resources

• Socioeconomics

• Human Health

• Environmental Justice

• Waste Management

• Greenhouse Gas and Climate Change

• Cumulative Impacts

• Postulated Accidents/SAMA

8 Information Needs and Document Requests

Information needs and document requests are identified below by resource area.

General (All)

The following requests are generic to more than one environmental resource area. Issues applicable to these questions are provided below along with the responsible NRC and PNNL subject matter expert, as appropriate.

GEN-1Section 2.2.3.1 of the environmental report (ER) states that mechanical draft cooling towers were installed in 2018 and 2019. Please indicate whether any changes to the surrounding environment have been observed with installation of the towers, such as changes in the condition of vegetation, or drift or plume impacts.

GEN-2Please provide any relevant updates to Table 9.1-1 in the Environmental Report. If any authorizations have expired since Constellation Energy Generation, LLCs (CEGs)

Application for Subsequent Renewed Operating License, dated February 14, 2024 (Agencywide Documents Access and Management System (ADAMS) ML24045A023),

please provide the status of those permits and/or renewals.

Topic-specific The following requests are specific to a single environmental review area. If a topic is not provided below, the discussions held in response to the generic requests above are expected to fully cover that topic.

Replacement Energy Alternatives (Jeff Rikhoff, NRC; Dave Goodman, PNNL)

Audit Needs

ALT-1 Section 7.2.3.2.1 of the ER states that 1,610 acres would be needed to construct 652 MW of wind installations onsite. Per Department of Energy (DOE) estimates of 2.47 acres per MW for construction footprint (~1,610 acres) and 0.74 acres per MW for permanent structures (~480 acres within the 1,610 acres), and 85 acres per MW for wind farm boundaries cited in Section 7.2.2.4 of the ER, approximately 55,400 acres of land would be needed or affected based on the boundaries estimate. Please explain how the DOE boundaries estimate in the ER can be met. Would there be offsite or adjacent land use impacts? If, so, what would be the effects?

Document Needs

None anticipated.

Enclosure 2 Land Use and Visual Resources (Caroline Hsu, NRC; Dave Goodman, PNNL)

Audit Needs

None anticipated.

Document Needs

None anticipated.

Air Quality (Nancy Martinez, NRC)

Audit Needs

AQN-1Section 3.3.3 of the ER states that there have been no notices of violation or non-compliance associated with Clinton air emissions from 2018 through 2022. Have there been any notices of violation or non-compliance associated with Clinton air emissions since 2022?

AQN-2Table 3.3-10 of the ER provides annual air emissions. PM, PM 2.5 and PM10 quantified emissions are the same. Discuss why the annual quantified emissions are the same.

AQN-3Clarify if emissions presented in Table 3.3-10 of the ER accounts for all the emission sources listed in Table 3.3-9 of the ER.

AQN-4Section 3.3.3 of the ER states Clintons cooling towers are exempted from statement permit requirements. Does CEG have estimated annual particulate matter emissions for the cooling towers? If so, please provide.

Document Needs

AQN-5Provide a copy of the annual air emission reports submitted to the Illinois Environmental Protection Agency (IEPA) for the last 5 years.

AQN-6Provide a copy of Air Emission Permit No. 039804AAC.

Noise (Nancy Martinez, NRC)

Audit Needs

NOI-1Section 3.4 of the ER states that CEG conducted a noise survey to determine sounds levels of the cooling towers:

• Were sound levels taken at nearby offsite noise sensitive receptors (e.g.,

nearest resident, resident that raised the noise complaint) while the cooling towers were in operation?

• The noise survey recorded a maximum reading of 83 A-weighted decibels which the ER states does not violate local ordinances or zoning regulations.

Please identify the local ordinances and zoning regulations.

2

• Identify the nearest resident to the cooling towers and the distance between them?

NOI-2Section 3.4 of the ER states that CEG monitors noise at and around the station for occupational and ambient effects on an as needed basis. Have any noise surveys been conducted in the immediate vicinity of the site (i.e., outside the site boundary)?

NOI-3Section 3.4 of the ER identifies that on August 12, 2021, a nearby resident shared a noise complaint with a Clinton representative regarding the sound level generating from the helper cooling towers. The ER further identifies that the cooling towers typically operate between May and September, operation is triggered by a flume temperature of 109 °F, and are turned on to reduce the average daily discharge temperature below 99

°F.

• If available, please provide additional details regarding the August 12, 2021, complaint (e.g., was the complaint with respect to day or night noise levels).

• Were the results of the noise survey shared with the resident that made the complaint?

NOI-4Has CEG received any noise complaints with respect to operations of Clinton since 2022?

Document Needs

None

Geologic Environment (Gerry Stirewalt, NRC; Phil Meyer, PNNL)

Audit Needs

None anticipated.

Document Needs

None anticipated.

Water Resources - Surface Water (Lloyd Desotell, NRC; Rajiv Prasad, PNNL)

Audit Needs

SW-1Have there been any violations associated with CPS wastewater discharges since 2022? If yes, please describe all notices of violations including dates, any corrective actions taken, and resolutions.

SW-2Have there been any reportable spills at CPS since 2022?

SW-3Provide monthly and annual surface water withdrawals (ER table 3.6-4a and Table 3.6.4-b) for 2023, if available.

SW-4ER Section 3.6.4.1 mentions that there were no detections of tritium in surface water samples associated with the radiological environmental monitoring program (REMP) surface water sampling between 2018 and 2022. Have there been any detections of tritium or gamma-emitting radionuclides in surface water samples since 2022?

3 SW-5U.S. Geological Survey (USGS) gauge 05578500 is cited as having data from October 1942 to 1976. However, the USGS webpage for gauge 05578500 reports discharge data from 1987 to present. Clarify what the period of record and gauge location the flow statistics reported in ER Section 3.6.1.1 are based on.

SW-6Discuss the current IEPA issued National Pollutant Discharge Elimination System (NPDES) permits and Clean Water Act (CWA) Section 401 certification waiver for CPS and their expiration dates, if any.

SW-7Confirm the datum used for all elevations in the ER Section 3.6 is the mean sea level.

SW-8Discuss water systems described in ER Section 2.2.3 associated with CPS operations.

Discuss the stormwater system and the sanitary wastewater system described in ER Section 3.6.1.2.

SW-9ER Section 3.6.1 states that the IEPA requires a minimum release of 5 cfs from the Clinton Lake Dam, pursuant to the NPDES permit. NRC review of the NPDES permit did not find this requirement. Please provide a current reference for this requirement.

SW-10ER Page 9-16 states: As discussed in Section 3.6.3.1, CPSs water is sourced from Clinton Lake, Water System No. IL3112201, and the State of Illinois does not require a surface water withdrawal permit for CPS. Please provide correspondence from the State of Illinois or other documentation to support this statement.

SW-11ER Figure 3.6-4 shows significant interannual discharge temperature variability. Please describe the source of this variability with particular attention to why the 2022 discharge temperatures are lower than other years.

SW-12ER Section 4.5.4.4 states: CPS uses a once-through cooling system and Mechanical Draft Cooling Towers (MDCTs) but does not use cooling ponds. Therefore, this issue is not applicable and further analysis is not required. NUREG -1437 Volume 1, Revision 1 identifies the Clinton cooling system as Once-through (cooling pond).

Section 4.4.1.1 of the 1996 revision of NUREG-1437 states that the Clinton cooling system meets the definition of cooling pond. Please address this apparent discrepancy and provide revised ER discussions as applicable.

Document Needs

SW-13Provide a copy of the current spill prevention, control, and countermeasure (SPCC) plan.

SW-14Provide a copy of the current stormwater pollution prevention plan (SWPPP).

SW-15Provide a copy of the NPDES Permit No. IL0036919 Public Notice/Fact Sheet (the link provided in in the references did not work).

SW-16Provide a copy of the General NPDES permit No. 1LG870019.

SW-17Provide a copy of water permit system Nos. IL3111153 and IL3112201.

SW-18Provide a copy of Illinois Department of Transportation (IDOT) Permit No. 18199.

SW-19Provide a copy of the last 5 years of NPDES annual inspection reports.

SW-20Provide a copy of annual water withdrawal reports sent to the state, if applicable.

4 Water Resources - Groundwater Resources (Gerry Stirewalt, NRC; Phil Meyer, PNNL)

Audit Needs

GW-1Clarify any differences between the evaluation program for groundwater impacts initiated in 2006 and the corporate radiological groundwater protection program (RGPP), as discussed in Section 3.6.2.4 of the ER.

GW-2State if a 5-year update to the hydrogeologic investigation first conducted in 2006 was done more recently than 2018. If not, state when the next 5-year update is planned.

GW-3ER Section 3.6.2.4 states 14 shallow and intermediate monitoring wells were installed following a hydrologic investigation conducted in 2006. It is also states that 17 wells are currently monitored for the RGPP. Clarify when the 3 additional monitoring locations were installed and the purpose for the additional locations, (for example, if the three additional wells targeted a specific system, structure, or component).

GW-4Clarify the purpose of the groundwater wells and piezometers listed in Table 3.6-3 of the ER that are not part of the RGPP.

GW-5The 2023 annual radiological environmental operating reports (AREOR) states wells MW-CL-1 and MW-CL-2 are sampled as part of the RGPP and are included in reported results. The applicants ER does not include MW-CL-1 or MW-CL-2 in Section 3.6.2.4, Table 3.6-3, or Figure 3.6-7. Explain this discrepancy.

GW-6Provide a description/diagram of the Unit 2 pit passive drainage system. Include estimated flow rates, water monitoring/sampling (frequency and analytes), and any permit requirements related to the discharge of this water to Clinton Lake.

GW-7Confirm there have been no releases of non-radiological material to groundwater since November 2023.

GW-8Confirm there have been no releases of radiological material to groundwater since November 2023.

Document Needs

GW-9Provide a copy of the RGPP and the most recent 5-year update to the hydrologic investigation report.

GW-10Figures 3.5-3 a, b and c of the ER are blurry/contain unreadable text. Provide these figures in a higher resolution format so all labelling is readable.

Terrestrial Resources (Caroline Hsu, NRC; Tracy Fuentes, PNNL)

Audit Needs

TER-1Birds and bats can collide with telecommunication towers. Collision risk is higher for taller towers, for guyed towers, and for different lighting regimes. ER Section 2.2.4 states that CPS has one meteorological (MET) tower and a microwave tower that is 250 feet tall. Section 3.2.1 states that there is a lease for a cell tower. Please confirm the height above ground level of the MET tower, the microwave tower, and the cell tower. State whether they are lit or unlit, and guyed or not guyed. If lit, please state lighting colors and whether lights are steady or blinking. If any towers are registered with the Federal Aviation Administration (FAA), please provide the link to the FAA obstruction database for the registered tower.

5 TER-2Please provide the height above ground level for all other tall buildings/structures on the CPS site ( 100 feet above ground level). If any buildings or structures are registered with the FAA, please provide the link to the FAA obstruction database for the registered building/structure.

TER-3ER Section 4.6.6.4.2 states that avian nests, bird interactions, and mortalities in the past 5 years have been that of the Canada goose and that there was also an osprey nest. Please provide the following: 1) a summary of bird mortalities or injuries (species, date, cause if known) in chronological order from 2013-2024, 2) any detailed reports for each incident, if any, and 3) a map and details of osprey nests on the CPS site.

TER-4ER Section 3.7.2.6 states CEG has undertaken a transmission right-of-way (ROW) grasslands restoration project, including the in-scope transmission lines in 2017.

Please provide the following information: 1) clarification as to whether this restoration project applies to in-scope transmission lines, given that the majority of the ground beneath them appears to be paved, 2) a map of areas on site that have been restored under this project, 3) acres restored on site.

TER-5ER Section 3.7.8.4 states that Agrilaser bird repellent systems were installed at CPS in 2020. ER Section 4.6.6.4 states that CPS installed two automated intelligent laser bird repellent units which continuously scans the areas where they are installed and prevent nesting during the breeding season. Please provide the following: 1) maps showing locations of installed Agrilaser bird repellent systems; 2) targeted species; 3) effectiveness of system; 4) explain need for installation; 5) when and how long are the systems active each year; 6) Agrilaser model and system specifications used on site; and 7) any protocols, procedures, or best management practices related to Agrilaser use on CPS.

TER-6ER Section 2.2.5.3 states that CEG promotes protection of migratory, threatened, and endangered birds through a corporate avian and wildlife protection plan and that it incorporates industry best management practices (BMPs) for birds. Please provide a copy of the corporate avian and wildlife protection plan and the avian BMPs for NRC staff review.

TER-7ER Sections 3.7.6 and 9.5 states that CEG administrative controls to ensure operational changes or construction activities reviewed. Please provide copies of corporate and site -specific environmental administrative procedures, controls, and best management practices, if not already covered.

Document Needs

TER-8ER Section 3.7.8.3 and 4.6.6.4 states that a 2020 survey of birds occurred in the Clinton Lake area. Please provide a copy of this survey for NRC staff review.

TER-9ER Section 3.7.7.1.6 and 4.6.6.2 discusses a herpetofauna survey conducted in 2019 for Kirtlands snake and a snake monitoring and conservation plan. Please provide a copy of these surveys and conservation plans for NRC staff review.

TER-10ER Section 3.7.2.4 states that two wetland delineations were performed at the CPS site: one in 2014 and one in 2018. Please provide copies of these wetland delineations for NRC staff review.

6 Aquatic Resources (Mitchell Dehmer/Briana Arlene, NRC; Caitlin Wessel, PNNL)

Audit Needs AQU-1ER Section 2.2.3.1 states, Mechanical Draft Cooling Towers (MDCTs) were installed along the discharge flume in 2018 and 2019 to provide additional cooling seasonally for the water discharge to ensure compliance with National Pollutant Discharge Elimination System (NPDES) permit temperature limits. Were there instances prior to this where the discharge was regularly exceeding the NPDES permit temperature limits? If yes, please summarize.

AQU-2ER Section 2.2.3.1 talks about the MDCTs and how they are triggered. How many days each year from 2020 - 2023 and so far, this year (2024) has the thermal discharge daily average been greater than 99°F? How many days each year do the MDCTs run?

AQU-3What is the average temperature decrease at the discharge when the MDCTs are running vs when they are not?

AQU-4What are the dimensions of 1) intake bays, 2) intake screens (and screen mesh size),

3) intake pipe diameter?

AQU-5Confirm the temperatures in ER Figure 3.6-4 are correct and where in the discharge flume this data is collected (pg. 181)

AQU-6Is there any more recent data for Asian Clams near or in the intake? If yes, please provide. (ER Section 3.7.1.2, pg. 192)

AQU-7Have any Zebra or Quagga mussels been found during intake monitoring and diver inspections? If yes, please provide details on years and amounts observed.

AQU-8ER Sections 3.7.5.1 and 3.7.5.2 describe numerous invasive aquatic plants and animals. Which of these species are known to occur, or are likely occur, on the CPS site?

AQU-9What is the through screen velocity at the cooling water intake structure?

AQU-102005-2007 Impingement Monitoring Study mentions that there are seasonal conditions in the lake that may trigger fungal growth and increase infection rates within the lake.

What are these conditions? (ER Section 4.6.1.4).

AQU-11Discuss the results of the 2019-2020 entrainment study and how this information will be used to support a best technology available (BTA) decision in the new NPDES permit; has that new permit request been submitted yet and if not when do you anticipate submitting it?

AQU-12Have you gotten a response from Illinois Department of Natural Resources (IDNR) from your January 18th letter requesting Listed Species and Sensitive Habitats (ER Appendix C)? If yes, please provide that information.

AQU-13Please clarify planned or anticipated dredging to occur during the license renewal term.

If so, how often does CEG anticipate dredging? When was the last time dredging occurred in the ultimate heat sink (UHS)? What is the current level or accumulated sediment.

AQU-14ER Section 4.6.2 states that no fish kills have occurred on Lake Clinton in the past 5 years. Is CEG aware of any fish kills related to CPS operations since the plant began operating?

AQU-15Please describe the location of the onsite IDNR hatchery ponds referred to in Section 3.7.1.2 of the ER and provide additional details on their use in stocking Clinton Lake.

7 Document Needs

AQU-162015 Thermal Survey (mentioned in ER Section 3.6.1.2.6, pg 150)

AQU-17If available, Phytoplankton survey data from 1983-1991 (discussed in ER Section 3.7.1.2, pg 189)

AQU-18If available, Zooplankton survey data from 1983-1991 (discussed in ER Section 3.7.1.2, pg 190)

AQU-191992 CPS Biological Report (discussed in ER Section 3.7.1.2, pg 190)

AQU-20ER Section 3.7.1.2 under Mussels and Other Shellfish cites the reference SEA 2003, but this reference is not included the reference list in Chapter 10. Please provide a full citation for this reference, as well as a copy of this reference for NRC staff review.

AQU-21ER Section 3.7.1.2 under Fish Communities states that the Illinois Natural History Survey conducts periodic creel surveys of Clinton Lake. Provide a copy of the last 5 years of these surveys or information on how to access these reports if available online.

AQU-22316(a) Demonstration Report mentioned in ER Section 3.7.1.2 under Mussels and Other Shellfish.

AQU-23CEGs Avian and Wildlife Management Plan as described in ER Section 2.2.5.3 AQU-242019 and 2020 Entrainment Abundance Characterization Study (discussed in ER Section 3.7.7.1.1, pg 220)

AQU-251987-1988 Impingement Study described in ER Sections 3.7.7.1.2 and 4.6.1.4 and cited in the NRCs 2006 EIS for the Clinton early site permit as:

Pallo, M.S. 1988. Clinton Power Station Fish Impingement Report, April 1987 - May 1988. Illinois Power Company, Environmental Affairs Department, Field Biology Laboratory, Decatur, Illinois.

AQU-262005-2007 Impingement Monitoring Study (discussed in ER Section 3.7.7.1.3, pg 223)

AQU-272005-2007 Clinton Lake electrofishing, beach seining, and gill netting studies conducted by Strategic Environmental Actions, Inc. described in ER Section 3.7.7.1.4 AQU-28Any fish studies / surveys / reports that are available; Environmental Science &

Engineering Inc. (ER Section 3.7.7.1.4)

AQU-29Thermal modeling study (ER Section 3.7.7.1.5, pg 228)

AQU-30ER Section 3.6.1.2.4 refers to a January 25, 2019, letter from U.S. Army Corps of Engineers (USACE) that states that a Section 404 permit is not required for dredging of Clinton Lake. Please provide a copy of this letter for NRC staff review.

AQU-31ER Section 3.7.7.1.4 cites the reference IPC 1988b, but this reference is not included the reference list in Chapter 10. Please provide a full citation for this reference, as well as a copy of this reference for NRC staff review.

AQU-32Any correspondence or supporting documentation from the IEPA related to Special Condition 10 in the NPDES permit and the IEPAs CWA 316(b) BTA determination for impingement mortality.

8 Federally Protected Ecological Resources (Mitchell Dehmer/Briana Arlene, NRC, Tracy Fuentes, PNNL, Caitlin Wessel, PNNL)

Audit Needs

FPE-1Please describe the Endangered Species Act (ESA) action area for the proposed CPS license renewal. The implementing regulations for Section 7(a)(2) of the ESA define action area as all areas affected directly or indirectly by the Federal action and not merely the immediate area involved 16 in the action (50 CFR 402.02). The action area effectively bounds the analysis of federally listed species and critical habitats because only species and habitats that occur within the action area may be affected by the Federal action.

FPE-2ER Section 3.7.8.1 states that suitable roosting and maternity habitat for the Indiana bat (Sodalis myotis) and northern long-eared bat (S. septentrionalis) occurs on the CPS site. Please describe where this habitat occurs and/or depict the location(s) of this habitat on a map.

FPE-3The U.S. Fish and Wildlife Service (FWS) has developed a Northern Long-eared Bat Rangewide Determination Key (DKey) to streamline the process of determining whether a project may affect this species. The DKey requires Federal action agencies to answer a series of questions to support this determination. Please answer the following questions, which the NRC staff obtained from the DKey. A simple yes/no response will suffice for most questions. Supplementary information on this DKey can be obtained at: https://www.fws.gov/library/collections/northern-long-eared-bat-assisted-determination-key-supplementary-information.

a. Does the proposed project include, or is it reasonably certain to cause, intentional take of the northern long-eared bat or any other listed species?

b. The action area does not overlap with an area for which FWS currently has data to support the presumption that the northern long-eared bat is present. Are you aware of other data that indicates that northern long-eared bats (NLEB) are likely to be present in the action area?

Bat occurrence data may include identification of NLEBs in hibernacula, capture of NLEBs, tracking of NLEBs to roost trees, or confirmed NLEB acoustic detections.

Data on captures, roost tree use, and acoustic detections should post-date the year when white-nose syndrome was detected in the relevant state. With this question, we are looking for data that, for some reason, may have not yet been made available to FWS.

c. Is the action area located within 0.5 miles of a known northern long-eared bat hibernaculum?

d. Does the action area contain any caves (or associated sinkholes, fissures, or other karst features), mines, rocky outcroppings, or tunnels that could provide habitat for hibernating northern long-eared bats?

e. Does the action area contain or occur within 0.5 miles of (1) talus or (2) anthropogenic or naturally formed rock crevices in rocky outcrops, rock faces or cliffs?

f. Is suitable summer habitat for the northern long-eared bat present within 1000 feet of project activities? (If unsure, answer "Yes.")

9

g. Does the action include the intentional exclusion of northern long-eared bats from a building or structure?

h. Does the action involve removal, modification, or maintenance of a human-made structure (barn, house, or other building) known or suspected to contain roosting bats?

i. Will the action result in herbicide use that may affect suitable summer habitat for the northern long-eared bat?

j. Will the action include or cause the application or drift of pesticides other than herbicides (e.g., fungicides, insecticides, or rodenticides) into forested areas that are suitable summer habitat for the northern long-eared bat? Answer "Yes" if the application may result in transport (e.g., in water) or aerial drift of the pesticide into forested areas that are suitable summer habitat for the northern long-eared bat.

k. Will the action include or cause activities that are reasonably certain to cause chronic nighttime noise in suitable summer habitat for the northern long-eared bat?

Chronic noise is noise that is continuous or occurs repeatedly again and again for a long time.

l. Does the action include, or is it reasonably certain to cause, the use of artificial lighting within 1000 feet of suitable northern long-eared bat roosting habitat?

m. Will the action include tree cutting or other means of knocking down or bringing down trees, tree topping, or tree trimming?

n. Has a presence/probable absence summer bat survey targeting the northern long-eared bat following the Services Range-wide Indiana Bat and Northern Long-Eared Bat Survey Guidelines been conducted within the project area? If unsure, answer No.

o. Does the action include emergency cutting or trimming of hazard trees in order to remove an imminent threat to human safety or property? Note: A "hazard tree" is a tree that is an immediate threat to lives, public health and safety, or improved property and has a diameter breast height of six inches or greater.

p. Are any of the trees proposed for cutting or other means of knocking down, bringing down, topping, or trimming suitable for northern long-eared bat roosting (i.e., live trees and/or snags 3 inches dbh that have exfoliating bark, cracks, crevices, and/or cavities)?

q. Will the action cause noises that are louder than ambient baseline noises within the action area?

FPE-4The FWS published a proposed rule to list the tricolored bat (Perimyotis subflavus) as endangered under the ESA on September 14, 2022 (87 FR 56381). This species range includes DeWitt County. Please provide an analysis of the potential impacts of the proposed license renewal on tricolored bat. This analysis should address (1) mortality or injury from collisions with plant structures and vehicles; (2) habitat loss, degradation, disturbance, or fragmentation, and associated effects; and (3) behavioral changes resulting from refurbishment or other site activities, among other impacts relevant to this species that CEG may identify.

FPE-5The FWS published a proposed rule to list the salamander mussel (Simpsonaias ambigua) as endangered under the ESA and to designate critical habitat for this species on August 22, 2023 (88 FR 57223). This species range includes DeWitt County. Please discuss whether any aquatic surveys in Lake Clinton have detected this

10 species (including individuals not identified to the species level that may have been salamander mussels) and provide an analysis of the potential impacts of the proposed license renewal on the salamander mussel. This analysis should address (1) impingement of fish species that early life stages of salamander mussels use as hosts; (2) impacts related to water quality, including chemical and thermal effluents; and (3) dredging, among other impacts relevant to this species that CEG may identify.

FPE-6Is the salamander mussel (or either state listed mussel) looked for during CWIS monitoring? Pg. 3-128 of the ER states that half a dozen Unionidae family mussels were collected. What species were they? The salamander mussel is a part of this family.

FPE-7The U.S. Fish and Wildlife Services Information for Planning and Conservation (IPaC) database (https://ipac.ecosphere.fws.gov/) indicates that the whooping crane (Grus americanus) may occur in the action area. Please provide an analysis of the potential impacts of the proposed license renewal on whooping crane. This analysis should address (1) mortality or injury from collisions with plant structures and vehicles; (2)habitat loss, degradation, disturbance, or fragmentation, and associated effects; and (3) behavioral changes resulting from refurbishment or other site activities, among other impacts relevant to this species that CEG may identify.

Document Needs FPE-8Please provide a copy of CEGs Wildlife and Avian Management Plan.

FPE-9Please provide any additional correspondence between CEG and the FWS.

FPE-10Provide a response, if available, from FWS from your January 18 th letter requesting Listed Species and Sensitive Habitats (ER Appendix C).

Historic and Cultural Resources (Jenny Davis, NRC; Lindsey Renaud, PNNL)

Audit Needs HCR-1 Provide information on how much of the 13,626-acre area of potential effects (APE) has been surveyed for archaeological and architectural resources. Confirm how much of the area has been disturbed by construction and other ground-disturbing activities.

HCR-2 Confirm the acreage of the built facility area within the Exclusion Area Boundary (EAB).

Is the EAB the only location within the 13,626-acre area that has facilities?

HCR-3 If available, the staff would like to view any historic photo documentation of the site prior to construction commencing, during construction, and post construction.

HCR-4 ER Table 3.8-1 indicates that the last archaeological survey within the APE was completed around 2008. ER Section 3.8 does not mention any recent in-field surveys to identify previously unknown historic properties. Describe what steps were taken to identify historic properties within the archaeological APE. Additionally, confirm if any Traditional Cultural Properties are within the APE.

HCR-5 ER Section 3.6.1.2.4 specifies that dredging would likely be required during the license renewal term. Provide additional information on dredging, including where the 1991 dredging took place, whether the future dredging is anticipated to occur in the same location, and where the sediment spoils would be placed (beyond onsite south of the station).

Further, ER Section 3.8 does not mention anything about dredging or describe any

11 potential impacts to historic properties. Clarify if any previously recorded sites are within the probable dredging area and discuss any potential impacts, if applicable.

HCR-6 How is cultural resources information safeguarded? For the 172 known archaeological sites within the APE, who is responsible for the safeguarding and management of the information? Describe any cultural resources databases, best management practices, and other applicable mechanisms for the dissemination of known resources within project areas.

HCR-7 Confirm if CEG has an inadvertent discovery protocol (IDP) for the inadvertent discovery of human remains. Describe what procedures would be followed if such an occurrence were to happen, including coordination with the local coroners office and the Illinois State Historic Preservation Office. Provide the IDP for NRC staffs review.

HCR-8 Attachment D, Cultural Resources Consultation Letters, provided copies of letters CEG sent to Tribes seeking input on the current license renewal. Provide all correspondence and other communication documents CEG has received from Tribes since January 18, 2023.

HCR-9 Provide Geographic Information System (GIS) shapefiles for the following features as shown on Figure 3.1-1 of the ER: CPS Site Boundary and Building/Structure

Document Needs HCR-10Excavation, Trenching, and Shoring procedure HCR-11Excavation permit HCR-12Inadvertent Discovery Protocol for Human Remains (if available)

Socioeconomics (Caroline Hsu, NRC; Dave Anderson, PNNL)

Audit Needs None anticipated.

Document Needs

SOC-1Provide updates to ER Tables 3.9-2a and 3.9-2b for the years 2022 and 2023, if available. Provide the updated link to the source for these tables as the referenced link appears to be broken.

Human Health (Donald Palmrose, NRC)

Audit Needs

HH-1Please provide an overview of the radiation control program with emphasis on the as low as reasonably achievable (ALARA) program to control worker radiation exposure (annual dose goals and status). Are there any proposed changes or upgrades to the program being considered during the license renewal term?

HH-2Please provide any updates concerning waterborne diseases in the vicinity of the plant since the submission of the subsequent license renewal environmental report, including any updates from Centers for Disease Control and Prevention National Outbreak Reporting System Dashboard and/or subsequent local information as discussed in 3.10.1 and 4.9.1.4.

12 HH-3Section 2.2.3.1 states that Clinton added two MDCTs in 2018 and 2019 along the discharge flume to provide additional cooling to ensure water discharge temperatures are in compliance with the NPDES permit temperature limits. It notes that the cooling towers are triggered by a flume temperature of 109 degrees Fahrenheit and typically operate May to September. Please walk through the occupational safety program to limit exposure to microbiological hazards for workers and any contractors, as noted for performing maintenance, along with any results of the Occupational Safety and Health Administration (OSHA) inspection discussed in the ER or the anticipated date of the inspection as discussed in Section 3.10.1.

HH-4Discuss the electrical safety program along with related OSHA regulations as implemented at the site under the industrial safety program. Plan to discuss the safety specific policies for work conducted at electrical transmission locations as noted in 2.2.5 and 3.10.2 and a walk-through of the workplace hazards identification process and jobsite analysis noting how change evaluations would identify electric shock hazards or potential human error to eliminate risk during work on the in-scope transmission lines. In addition, Section 3.10.2 discusses the in-scope transmission lines and points to Figure 2.2-2. Figure 2.2-2 shows the lines to and from the 345-kV switchyard noted as the 345-kV transmission corridor and the 138-kV transmission corridor. Please clarify the number of in-scope transmission lines and be prepared to discuss the control of the of the 138-kV lines by Ameren within the owner-controlled area.

Document Needs

HH-5Section 3.10.2 describes the in-scope transmission lines and discusses in detail the 138-kV line related to clearance standards within National Electrical Safety Code National Electrical Safety Code (NESC) but is silent on the review of clearances with respect to the 345-kV lines. Please provide a copy of the study and/or analysis findings used to determine compliance with the current NESC guidance for the 345-kV lines.

When providing a copy of the study, ensure that the conclusion of no clearance issues and that NESC clearance requirements are met as stated in the ER.

Environmental Justice (Jeff Rikhoff, NRC; Dave Anderson, PNNL)

Audit Needs

None anticipated.

Document Needs

None anticipated.

Waste Management (Leah Parks, NRC)

Audit Needs

WM-1As part of the effluent control systems, plan to discuss the provisions made to sample and analyze fluids before discharge as discussed in 2.2.6.1. In addition, plan to discuss how the plant processes radioactive effluents to maintain radiation doses to the public to levels that are ALARA. Are there any proposed changes or upgrades to the program

13 being considered during the license renewal term?

WM-2Section 2.2.6.5 notes that CPS does not currently generate or store mixed waste on site. Section 9.5.13.3 states CPS rarely generates mixed waste, and the last shipment of mixed waste was in 2020. It also states that CEG has a conditional exemption from IEPA for low-level mixed waste in accordance with 40 CFR 266, Subpart N, in place for any mixed waste placed in storage at CPS storage units listed under the exemption.

Please discuss where mixed waste is stored if it is generated.

WM-3Section 2.2.6.5 discusses low-level radioactive waste, including greater than Class C waste. What are the plans to store or ship low-level waste (e.g., are there minimum quantity shipment plans or procedures for decision making)? In addition, plan to discuss how the plant plans to handle low-level radioactive waste (Class A, B, and C, Greater-than-Class C) during the license renewal term (onsite storage, potential expansion of storage facilities, and disposal options). Are there any proposed changes or upgrades to the program being considered during the license renewal term?

WM-4Clinton Power Station is subject to the reporting provisions of 40 CFR Part 110 as it relates to the discharge of oil in such quantities as may be harmful pursuant to Section 311(b)(4) of the Federal Water Pollution Control Act. In section 9.5.3.6 of the ER, the applicant discusses reportable spills and states that for the period of 2018-2022, there were no reportable releases at CPS that have triggered this notification requirement. If there have been any reportable releases which would trigger this notification requirement since the ER was written, please provide a description of the releases.

WM-5If there have been any reportable unplanned releases of radioactive materials (unplanned/inadvertent radioactive liquid or gaseous releases) which would trigger a notification requirement since the ER was written, please provide a description of the releases. Please be prepared to discuss your plan to handle unplanned releases of radioactive materials.

WM-6If there have been any reportable inadvertent releases or spills of nonradioactive contaminants which would trigger a notification requirement since the ER was written, please provide a description of spills/releases. Please be prepared to discuss your plan to handle inadvertent nonradioactive releases.

Document Needs:

WM-7Provide procedures related to the radioactive and nonradioactive Waste Management Program, Waste Minimization Program, and Stormwater Pollution Prevention Plan.

WM-8Drawings and photos that are highlighted/marked showing the flow paths for releases for both radiological and non-radiological waste paths. Please have subject matter experts available to discuss the flow paths.

WM-9Provide the log of approved waste vendors used to manage and dispose of hazardous and non-hazardous waste as discussed in Section 2.2.7 of the ER.

14 (Leah Parks, NRC)Spent Nuclear Fuel

Audit Needs

SNF-1Section 2.2.6.4 of the ER states that It is anticipated that the CPS ISFSI may need to be expanded during the LR period of extended operation if the DOE has not taken ownership of the spent nuclear fuel prior to the ISFSI reaching capacity. It is expected that there is enough previously disturbed land area available for this expansion within the site boundary. Please discuss the storage plans for the spent fuel produced during the license renewal term, including any plans for expansion or additional storage locations necessary for capacity for license renewal term.

Document Needs None

Uranium Fuel Cycle (Rao Tammara, NRC)

Audit Needs

None

Termination of Operations and Decommissioning (Rao Tammara, NRC)

Audit Needs

None

Greenhouse Gas and Climate Change (Nancy Martinez, NRC; GHG - Julia Flaherty, Lexi Goldberger, PNNL; Climate Change - Ravij Prasad, Stephen Ferencz, PNNL)

Audit Needs

GHG-CC-1 ER Section 2.2.3.1 states that mechanical draft cooling towers were installed along the discharge flume in 2018 and 2019 to provide additional seasonal cooling to ensure compliance with NPDES permit temperature limits. Provide a time series figure of the monthly average intake cooling water temperature for the available period of record. Additionally, provide a discussion and any relevant information as to whether a warming trend has been observed in Clinton Lake GHG-CC-2 Table 3.3-11 of the ER provides quantified annual greenhouse gas emissions (GHG) emissions from direct sources, purchased electricity, and workforce commuting.

• For direct emissions, provide the relative percentage each source (stationary combustion sources, sulfur hexafluoride, process CO2 and ozone depleting compounds refrigerants) contributed to the annual total.

• Provide additional information regarding how direct emissions were estimated.

As part of the response provide the emission factors, global warming potentials, fuel usage, fugitive emissions, and/or any assumptions used to quantify emissions.

• Section 3.3.4 of the ER lists that fugitive SF 6 emissions are included in the estimate of direct GHG emissions at Clinton. Provide additional information about where SF6 is used (identify the sources/equipment) and if and how fugitive emissions of SF6 are mitigated. If CEG has site procedures that address 15 the handling of sulfur hexafluoride to prevent or reduce fugitive emissions, please provide a copy.

• Table 3.3-11 identify that process CO 2 was considered in the Clinton GHG emissions inventory. Identify the sources/equipment that use CO2?

• If 2023 GHG emission data is available, please provide.

Document Needs

None anticipated.

Cumulative Impacts (Jeff Rikhoff, NRC; Dave Goodman, PNNL)

Audit Needs

CI-1 Per 10 CFR 51.53(c)(3)(ii)(O), please provide information about other past, present, and reasonably foreseeable future actions occurring in the vicinity of the nuclear plant that may result in a cumulative effect that may have occurred since the ER was submitted.

Document Needs

None anticipated.

Postulated Accidents/SAMA (Jerry Dozier/Elijah Dickson NRC; Bill Ivans/Steve Short PNNL)

GENERAL

Review of severe accident mitigation analysis (SAMA) analysis and results as documented in CEGs License Renewal ER and supporting documents. Review of Level 1, 2 and 3 probabilistic risk analysis (PRA) as described in the ER and supporting documents. See below for specific questions to be discussed and/or addressed at the audit. Note that additional questions may be developed and provided several days before the audit or during the audit.

DOCUMENTS REQUESTED TO BE AVAILABLE FOR REVIEW

Please make the following documents available on the portal:

1. The most recent PRA peer review reports, and/or self-assessment reports, and Facts and Observations (F&O) closure review reports for all hazards (i.e., internal events, including internal flooding and fire).

2. Documentation associated with the Level 2 and 3 PRA model reviews.

3. Available documentation of the review of the results of the CPS Level 2 PRA by the team of CPS experts representing various site organizations (e.g. Operations, System Engineering, Mechanical/Safety Analysis, PRA and License Renewal) to confirm that the model is representative of the plant and the results are reasonable.

16

4. PRA notebooks for the CPS PRA model (CL122A/CL122AF0) used in the SAMA analysis that document the quantification results and which provide the breakdown of the contributors to core damage frequency (CDF), including, but not limited to:

o CPS PRA Summary Notebook (PRA FPIE 2020) o CPS Fire PRA Summary & Quantification Notebook (PRA Fire 2020)

5. Documentation of updated analysis for seismic and other external events.

6. Documentation of the containment event trees (CETs) developed to produce results for each of the CET end states or source term categories (STCs) reported in the ER.

7. Documentation of the Level 3 analysis and the core inventory.

8. Documentation of the identification and disposition of SAMAs identified from the review of SAMAs from other SAMA analyses and from other sources.

APPLICANT STAFF TO BE AVAILABLE DURING THE AUDIT

CEG and contractor personnel knowledgeable of the CPS Level 1, 2 and 3 PRA development and results as well as SAMA identification and evaluation. Discussion will focus on the attached questions (draft audit questions) and any other questions that may arise from the material reviewed during the audit.

Audit Needs

1. Provide the following information regarding the Level 1 PRA used for the SAMA analysis. The basis for this request is as follows: Applicants for license renewal are required by Title 10 of the Code of Federal Regulations (10 CFR) Part 51.53(c)(3)(ii)(L) to consider SAMAs if not previously considered in an environmental impact assessment, related supplement, or environmental assessment for the plant. As part of its review of the CPS SAMA analysis, NRC staff evaluates the applicants treatment of internal events and calculation of core damage frequency in the Level 1 PRA model. The requested information is needed in order for the NRC staff to reach a conclusion on the sufficiency of the applicants Level 1 PRA model for supporting the SAMA evaluation.

a. Discuss any major plant modifications or plant changes made since the release of the CPS PRA (CL122A/CL122AF0) used in the SAMA analysis in Addendum 2 to Attachment F of the CPS ER and the impact of these modifications/changes on the SAMA analysis. Also, clarify if there are any planned major plant modifications or changes that could adversely impact the SAMA analysis, and assess the impact of these modification/changes on the SAMA analysis.

b. Section 2.5 of Addendum 2 to Attachment F of the CPS ER summarizes self-assessments and peer reviews underwent by the CPS PRA. It is indicated that for the Internal Events PRAs, an independent review was conducted in December 2018 and November 2019 on the resolutions to all F&Os from the October 2009 peer review. This same closure review also addressed resolutions to F&Os generated from the April 2018 Fire PRA peer review. Address the following with respect to the F&O closure process:

17

i. Clarify that the F&O closure reviews were conducted in accordance with NRC letter dated May 1, 2017, U.S. Nuclear Regulatory Commission Staff Expectations for an Industry Facts and Observations Independent Assessment Process (ML17121A271), and NRC letter dated May 3, 2017, U.S. Nuclear Regulatory Commission Acceptance on Nuclear Energy Institute Appendix X to Guidance 05-04, 07-12, and 12-13, Close-Out of Facts and Observations (ML17079A427). If the F&O closure reviews were not conducted in accordance with this guidance, assess the impact of any deviations from this guidance on the SAMA analysis.

ii. Discuss whether the scope of the F&O closure reviews included all finding-level F&Os (for the internal events and fire PRAs), including those finding-level F&Os that are associated with Met Supporting Requirements, from the October 2009 and April 2018 peer reviews. If not, identify and provide the complete text of the original peer review findings and recommendations for any F&Os that were excluded from the F&O closure review scope, and their associated disposition for the SAMA analysis.

iii. Confirm that the closure review team for each review was provided with a written assessment and justification of whether the resolution of each F&O, within the scope of the independent assessment, constitutes a PRA upgrade or maintenance update, as defined in ASME/ANS RA-Sa-2009, Addenda to ASME/ANS RA-S-2008, Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications, as qualified by Regulatory Guide 1.200, Revision 2, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, (ML090410014). If the written assessment and justification for the determination of each F&O was not performed and reviewed by the F&O closure review team, discuss how this aspect of the F&O closure process was met consistent with the staffs acceptance as discussed in the May 3, 2017, letter.

iv. Confirm that the CPS PRA (CL122A/CL122AF0) used in the SAMA analysis in Addendum 2 to Attachment F of the CPS ER incorporates the dispositions to all the formally closed F&Os.

v. Section 2.5.2 of Addendum 2 to Attachment F of the CPS ER indicates that two F&Os related to the IEPRA were not fully resolved by the December 2018 and November 2019 F&O closure reviews. Additionally, one Fire PRA F&O remains open from the 2022 focused-scope peer review, which was performed after the F&O closure reviews. While the CPS ER dispositions these F&Os in Tables 2.5-1 and 2.5-2 of Addendum 2 to Attachment F, formatting issues prevent these tables from being fully and effectively reviewed. Provide re-formatted tables such that the information within these tables is fully visible and can allow for the review of all open F&Os.

c. Various sections within Addendum 2 to Attachment F of the CPS ER refer to Diverse and Flexible Mitigation Capability (FLEX) strategies credited within the CPS PRA (e.g.,

Section 6.0). In an NRC memorandum dated May 30, 2017 (ML17031A269), the NRC staffs positions and conclusions are provided regarding use of guidance in Nuclear Energy Institute (NEI) 16-06, Crediting Mitigating Strategies in Risk-Informed Decision Making. In an NRC memorandum dated May 6, 2022, Updated Assessment of 18 Industry Guidance for Crediting Mitigating Strategies in Probabilistic Risk Assessments (ML22014A084), the NRC staff identified challenges and strategies for incorporating FLEX equipment into a PRA model in support of risk-informed decision-making when using additional industry guidance issued after NEI 16-06. Specifically, over-crediting FLEX in the PRA model could underestimate the potential benefit of SAMAs. Address the following:

i. Describe the FLEX strategies that were credited in the CPS PRA model (inclusive of internal events and fire) used to support the SAMA analysis.

Include identification of discussion of the FLEX equipment that was credited and whether that equipment is portable or permanently installed and identification of the operator actions that are credited.

ii. Clarify the guidance used to model FLEX strategies within the CPS PRA model, identify the NRC memorandum that is applicable to the modeling of FLEX in the CPS PRA model, and explain how each of the 13 NRC staff conclusions are addressed in the PRA.

iii. If the FLEX modeling is not in accordance with the applicable NRC memorandum, describe and provide the results of a sensitivity study that assesses the impact on the SAMA analysis of not crediting FLEX strategies.

2. Provide the following information relative to the Level 2 PRA analysis. The basis for this request is as follows: Applicants for license renewal are required by 10 CFR 51.53(c)(3)(ii)(L) to consider SAMAs if not previously considered in an environmental impact assessment, related supplement, or environmental assessment for the plant. As part of its review of the CPS SAMA analysis, NRC staff evaluates the applicants treatment of accident propagation and radionuclide release in the Level 2 PRA model. The requested information is needed in order for the NRC staff to reach a conclusion on the adequacy of the applicants Level 2 PRA model for supporting the SAMA evaluation.

a. Section 2.5 of Addendum 2 to Attachment F of the CPS ER summarizes the PRA model development and peer review process, which for the Level 2 analysis only addresses (partially) large early release. In Section 2.3.2, the ER provides only a high-level description of the Level 2 analysis that was developed and applied to produce the results for the CET end points or source term categories and release categories reported in the ER. Address the following:

i. Explain how the Level 2 post-core damage accident response analysis is linked to the Level 1 PRA model, including addressing how the Level 1 core damage sequences were binned into plant damage states (PDSs), describing each of the PDSs, and providing the results of this binning process.

ii. Summarize the CET(s) developed to produce results for each of the CET end states or STCs reported in the ER and the process for progressing each PDS through the CET(s). Include in the response a description of the modeled branch points (both system failures and phenomenological).

iii. Describe the logic and criteria used in the selection of the representative Modular Accident Analysis Program (MAAP) case for each release category, or source term category, and provide justification that the selected cases are reasonable for the SAMA analysis (e.g., does not underestimate the estimated benefits of SAMAs).

19 iv. Summarize the independent and/or peer reviews performed to provide confidence in the Level 2 analysis, summarize the results of these reviews, and summarize any unresolved independent/peer review comments and their impact on the SAMA analysis.

v. Sections 2.3.2 and 2.4.2 of Addendum 2 to Attachment F of the CPS ER report Large Early Release Frequency (LERF) estimates of 7.31E-08/year and 2.40E-06/year for the Internal Events and Fire PRA models used in the SAMA analysis.

As a comparison, Table 3-1 reports a frequency of 8.74E-07/year for ST2 (High/Early) from the Level 2 analysis developed for the SAMA analysis. Explain the reasons for this difference and provide an assessment of the impact of this difference on the SAMA analysis.

b. Section 2.3.2.3 of Addendum 2 to Attachment F of the CPS ER indicates that Table 2.3.2-1 provides a frequency matrix of the radionuclide release categories and the Level 1 accident classes. However, formatting issues prevent this table from being fully and effectively reviewed. Similar issues also apply to Table F.2.3.2-1. Provide re-formatted tables such that the information within these tables is fully visible and can allow for their review.

3. Provide the following information with regard to the treatment and inclusion of external events in the SAMA analysis. The basis for this request is as follows: Applicants for license renewal are required by 10 CFR 51.53(c)(3)(ii)(L) to consider SAMAs if not previously considered in an environmental impact assessment, related supplement, or environmental assessment for the plant. As part of its review of the CPS SAMA analysis, NRC staff evaluates the applicants treatment of external events in the PRA models. The requested information is needed in order for the NRC staff to reach a conclusion on the sufficiency of the applicants PRA models for supporting the SAMA evaluation.

a. Confirm the freeze date" or the date which corresponds to the CPS design and operation incorporated into the CPS Fire PRA (CL122AF0) used for the SAMA analysis in Addendum 2 to Attachment F of the CPS ER.

b. The basis of the applicants Seismic CDF estimate presented in Section 4.1.2 of Addendum 2 to Attachment F of the CPS ER does not appear to be discussed; however, the documented estimate of 6.4E-06/year is numerically equivalent to that presented in Section 3.2.4.1.3 of the NRC staff safety evaluation of the license amendment request (LAR) for CPS to adopt Technical Specifications Task Force (TSTF) Traveler TSTF-505 (ML21132A288). Confirm that the basis of the applicants proposed Seismic CDF estimate remains the same, and if not, provide the basis for the approach used to estimate seismic risk used in the SAMA analysis in Addendum 2 to Attachment F of the CPS ER.

c. NRC Regulatory Issue Summary 2015-06, while not requiring regulatory action, identified several instances in which nuclear power plants were determined to not conform with their tornado-generated missile licensing basis. Discuss any changes to the CPS site or surrounding environment or to CPS that would change the conclusions of the individual plant examination for external events (IPEEE) regarding tornado-generated missiles and which could impact the SAMA analysis.

20

d. Section 4.1.2 of Addendum 2 to Attachment F of the CPS ER explains that other external events, apart from seismic events, were assessed in 2020 using a progressive screening approach. However, related hazards appear to be screened based on an assumption that reflects considerations that are unstated in the ER and were made in support of referenced LARs, specifically 10 CFR 50.69 (ML21090A193) and TSTF-505 (ML21132A288). Summarize the screening assessment that was used to address these other external hazards and that forms the basis for the ER conclusion. In the response, discuss the screening criteria used and their applicability to the SAMA analysis, and, specifically, whether changes to the plant, the plant site, or the area surrounding the plant site made since the IPEEE have impacted the conclusions of the IPEEE.

e. Section 2.5.2 of Addendum 2 to Attachment F of the ER indicates that a focused-scope peer review was performed on the Fire Scenario Selection technical element; however, the standard and process guidelines applied are not discussed. Clarify the standard and process guidelines used and justify that the peer review is reasonable for the SAMA analysis.

4.Please provide the following information regarding the Level 3 PRA used in the SAMA analysis. The basis for this request is as follows: Applicants for license renewal are required by 10 CFR 51.53(c)(3)(ii)(L) to consider SAMAs, if not previously considered, in an environmental impact assessment, related supplement, or environmental assessment for the plant. As part of its review of the CPS SAMA analyses, NRC staff evaluates the applicant's analysis of accident consequences in the Level 3 PRA. The requested information is needed in order for the NRC staff to reach a conclusion on the sufficiency of the applicant's Level 3 PRA model for supporting the SAMA evaluations.

a. Table F.3-19 of the CPS ER provides the base case mean Population Dose Risk (PDR) and Offsite Economic Cost Risk (OECR) results using the 2017 CPS PRA model (CL117B/CL117BF0). While Table 3-1 of Addendum 2 to Attachment F provides updated release category frequencies for the 2022 CPS PRA model (CL122A/CL122AF0), updated base case mean PDR and OECR results do not appear to be provided. Moreover, Section 3.0 of Addendum 2 to Attachment F summarizes the base case results for the 2022 CPS PRA model that are equivalent to the 2017 CPS PRA model (i.e., PDR of 68.1 person-rem/year and OECR of $963,000/year), whereas the Phase 2 SAMA analysis in Section 6.0 makes use of different figures (i.e., PDR of 27.2 person-rem/year and OECR of $404,403/year). Provide a breakdown of the base case mean PDR and OECR results by release category for the 2022 CPS PRA model, and address discrepancies, if any, that exist with the SAMA analysis performed in Addendum 2 to Attachment F.

b. Section F.3.7 states that the 2020 meteorological data set was used to support the Level 3 model. However, atmospheric mixing height values appear to be based on historical values from a 1972 Environmental Protection Agency publication. Explain why the selected data is reasonable for the SAMA analysis (e.g., does not underestimate the estimated benefits of SAMAs), or alternatively provide the results of a sensitivity analysis.

c. Section 7.3.2 of Addendum 2 to Attachment F acknowledges that NUREG/CR-7270 provides updated technical bases for input parameters used in MACCS (MELCOR Accident Consequence Code System) modeling applications and provides a sensitivity study that was performed to assess the impact of this new information on 21 decontamination modeling performed to support the SAMA analysis. This study showed an increase in the PDR of approximately 4% and an increase in OECR of approximately 61%. It is noted that for most of the parameters addressed as part of the sensitivity study and identified in Table 7.3-1 of Addendum 2 to Attachment F, the technical bases documented within NUREG/CR-7270 represent modeling choices that are considered reasonable generic choices and are expected to be applicable for most U.S. locations per Appendix C to NUREG/CR-7270. Given this, justify why the updated technical bases documented within NUREG/CR-7270 for parameters related to decontamination modeling should not be incorporated into the base case used to support the SAMA analysis, examine the impact of uncertainty, and support other documented sensitivity studies.

5. Provide the following information with regard to the selection and screening of Phase I SAMA candidates. The basis for this request is as follows: Applicants for license renewal are required by 10 CFR 51.53(c)(3)(ii)(L) to consider SAMAs if not previously considered in an environmental impact assessment, related supplement, or environmental assessment for the plant. As part of its review of the CPS SAMA analysis, NRC staff evaluates the applicants basis for the selection and screening Phase I SAMA candidates. The requested information is needed in order for the NRC staff to reach a conclusion on the adequacy of the applicants Phase I SAMA selection and screening process for the SAMA evaluation.

a. Sections F.5.1.1 and F.5.1.2 of the ER describes what cutoff values were assumed in determining dominant risk contributors within the Level 1 and Level 2 importance analyses, respectively. However, the rationale for the cutoff value applied (i.e., a Fussell-Vesely of 0.05) is not clear. For internal events risk, this cutoff value is correlated to an averted cost-risk of $29,000, but a similar comparison is not done to address other hazards (e.g., fire and seismic) and uncertainty. If such a comparison were made, the resulting averted cost-risk (i.e., 0.05 x $11,635,329, without uncertainty, or

$35,836,813, with uncertainty) would appear to exceed the implementation costs of many SAMAs identified addressed in Addendum 2 to Attachment F, including those found to be potentially cost-beneficial in Section 8.0. Justify the rationale for the cutoff value used to determine what is a dominant risk contributor in the context of the SAMA analysis. In doing so, explain why SAMAs identified for contributors below the applied cutoff values would be not cost-beneficial.

b. Section F.6 provides only a brief description of the cost estimating process for determining the implementation cost for the various SAMAs, and some implementation costs within Table 5-3 of Addendum 2 to Attachment F simply reference non-CPS estimates without discussion as to the scope and applicability of the associated modifications/changes. Provide a more detailed description of the cost estimating process and bases used to develop the implementation cost estimate for SAMA candidates, including whom or what organization performed the estimate (or assessed the applicability thereof), what costs are included in the estimate (e.g., procurement, installation, long-term maintenance, surveillance, calibration, and training), and conservatisms in the cost estimates, whether specific to CPS or not. Additionally, this description should speak to how the applicability of non-CPS-specific implementation costs was determined.

6. Provide the following information with regard to the Phase II cost-benefit evaluations. The basis for this request is as follows: Applicants for license renewal are required by 10 CFR 51.53(c)(3)(ii)(L) to consider SAMAs if not previously considered in an environmental impact assessment, related supplement, or environmental assessment for the plant. As part of its 22 review of the CPS SAMA analysis, NRC staff evaluates the applicants cost-benefit analysis of Phase II SAMAs. The requested information is needed in order for the NRC staff to reach a conclusion on the acceptability of the applicants cost estimations for individual SAMAs and cost-benefit evaluation.

a. Section 6.2 of Addendum 2 to Attachment F of the CPS ER indicates that the benefit of SAMA 3 is at least partially derived from the RCIC (Reactor Core Isolation Cooling) storage tank being protected; however, it is not clear what this protection entails and how it addresses associated dominant contributors in Tables 5-1 and 5-2. Clarify what modifications/changes are being proposed to protect the RCIC storage tank and summarize how they serve to address identified dominant contributors.

b. Section 6.4 of Addendum 2 to Attachment F of the CPS ER indicates that SAMA 5 is modeled by reducing the HEP (Human Error Probability) associated with bus realignment and that it is assumed that SAMA 5 reduces the execution time for bus realignment from 60 to 30 minutes. However, the cost estimate for SAMA 5 within Table 5-3 suggests that this SAMA would eliminate the need for local breaker manipulation and provide the main control room with remote alignment capability.

Provide further justification for HEP-related modeling assumptions or demonstrate that such assumptions do not impact the results of the SAMA analysis.

c. Section 6.25 of Addendum 2 to Attachment F of the CPS ER indicates that risk-significant conduits are re-routed from Fire Zone CB-5A to Fire Zone CB-1G but that these conduits are then assumed to be failed for all fires originating in Fire Zone CB-1G. Provide further justification for this modeling assumption or demonstrate that it does not impact the results of the SAMA analysis.

7. For certain SAMAs considered in the CPS ER, there may be lower cost or more effective alternatives that could achieve much of the risk reduction. In this regard, provide an evaluation of the following SAMA. The basis for this request is as follows: Applicants for license renewal are required by 10 CFR 51.53(c)(3)(ii)(L) to consider SAMAs if not previously considered in an environmental impact assessment, related supplement, or environmental assessment for the plant. As part of its review of the CPS SAMA analysis, NRC staff considers additional SAMAs that may be more effective or have lower implementation costs than the other SAMAs evaluated by the applicant. The requested information is needed in order for the NRC staff to reach a conclusion on the adequacy of the applicants determination of cost-beneficial SAMAs.

a. Table 5-3 of Addendum 2 to Appendix F of the CPS ER cost estimate indicates that SAMA 5, which addresses the installation of an emergency tie line from the switchyard to an emergency bus, is based on an estimate developed for a potentially cost beneficial SAMA at Wolf Creek Generating Station (WCGS). It is noted that given the

$400,000 cost estimate and scope of SAMA 5, the WCGS SAMA upon which the estimate is based appears to be SAMA 2 from the Supplement 32 to NUREG-1437 (ML081260608), which includes, among other changes, hardware modifications to allow the remote start and alignment of ten diesel generators at a local generating station. Confirm the WCGS SAMA upon which the SAMA 5 cost estimate is based and justify how its scope is appropriate for SAMA 5 (e.g., does not overestimate the implementation cost).

b. Section 8.0 of Addendum 2 to Attachment F of the CPS ER identifies ten potentially cost-beneficial SAMAs based on the SAMA analysis using the 2022 CPS PRA model (CL122A/CL122AF0); however, there appears to be no discussion indicating whether 23 these SAMA candidates will be formally evaluated for potential implementation at the plant. Clarify that these potentially cost-beneficial SAMAs will be formally evaluated for potential implementation at the plant.

24 Clinton Power Station, Unit 1 Environmental Audit Schedule Virtual Audit Tuesday, August 27, 2024 START END ACTIVITY 9:00 am ET 9:30 am ET Entrance meeting between U.S. Nuclear Regulatory Commission (NRC), Constellation and contractors 9:30 am ET 3:00 pm ET Virtual tours/virtual meetings between NRC, Constellation, and contractor subject matter experts (SMEs)

Wednesday, August 28, 2024 START END ACTIVITY 9:00 am ET 3:00 pm ET Virtual meetings between NRC, Constellation, and contractor SMEs

Thursday, August 29, 2024 START END ACTIVITY 9:00 am ET 3:00 pm ET Virtual meetings between NRC, Constellation, and contractor SMEs

Tuesday, September 3, 2024 START END ACTIVITY 9:00 am ET 4:00 pm ET Virtual meetings between NRC, Constellation, and contractor SMEs

Wednesday, September 4, 2024 START END ACTIVITY 9:00 am ET 4:00 pm ET Virtual meetings between NRC, Constellation, and contractor SMEs

In-Person Audit Tuesday, September 24, 2024 START END ACTIVITY 9:00 am ET 4:00 pm ET NRC site visit

Thursday, September 26, 2024 START END ACTIVITY 10:00 am ET 10:30 am ET Virtual exit meeting between NRC, Constellation, and contractors

Enclosure 3