ML25273A060
| ML25273A060 | |
| Person / Time | |
|---|---|
| Site: | Kemmerer File:TerraPower icon.png |
| Issue date: | 11/25/2025 |
| From: | NRC/NMSS/DREFS/EPMB3 |
| To: | |
| References | |
| Download: ML25273A060 (0) | |
Text
Enclosure Regulatory Audit Summary Report Kemmerer Power Station Unit 1 Construction Permit Environmental Audit Summary Report
1.0 Background
The U.S. Nuclear Regulatory Commission (NRC) is currently reviewing an application from US SFR Owner, LLC (USO), a wholly owned subsidiary of TerraPower, LLC (TerraPower), for a construction permit (CP) for the Kemmerer Unit 1 reactor project in Kemmerer, Wyoming. As part of its review for Kemmerer Unit 1, the NRC is preparing an Environmental Impact Statement (EIS). An audit was conducted from July 30, 2024, to September 8, 2025, to support the environmental review of the TerraPowers application. This report presents a summary of the audits objectives and activities, and the information obtained from the audit.
1.1 Application Overview By letter dated July 31, 2024, (Agencywide Documents Access and Management System (ADAMS) ML24213A268), the NRC issued its plan for conducting an environmental audit related to the TerraPower CP application for its Kemmerer Unit 1 reactor. The NRC environmental staff reviewed the information in the March 28, 2024, Environmental Report (ER)
(ML24088A072) submitted by TerraPower as a component of its CP Application and other relevant environmental information following procedures in Title 10 of the Code of Federal Regulations (10 CFR) Part 51.
1.2 Project and Site Overview The proposed action is for the NRC to issue a CP to TerraPower authorizing construction of the Kemmerer Unit 1 reactor. The proposed U.S. Department of Energy Federal action is the decision whether to provide financial assistance to USO, through TerraPower, to demonstrate the Natrium advanced reactor. In its CP application, TerraPower proposes to build and operate the Kemmerer pool type sodium fast reactor project to demonstrate the Natrium advanced reactor while ultimately replacing electricity generation capacity in the PacifiCorp service area following planned retirement of existing coal-fired facilities. The proposed site is located approximately 3.8 miles southeast of the existing Naughton Power Plant near Kemmerer, Wyoming. The TerraPower ER provides the applicants analyses of the environmental impacts that could result from construction, operation, and decommissioning of the Kemmerer Unit 1 reactor at the proposed site.
2.0 Audit Scope and Objectives During the audit, the NRC staff discussed environmental matters related to land use and visual resources, air quality and noise, hydrogeology and surface water, terrestrial and aquatic ecology, cultural resources, socioeconomics, human health, non-radiological waste, uranium fuel cycle and radiological waste management, transportation of radioactive material, postulated accidents, and alternatives. The audit allowed the staff to better understand the site, the proposed Kemmerer Unit 1 reactor design, the environmental interfaces of the Kemmerer Unit 1 project, and environmental modeling results in order to make appropriate environmental findings.
In its initial review of data and information within the corresponding context of the ER, the staff identified a list of environmental information needs that would promote a better understanding of the detailed analysis and bases underlying the CP application. The staff provided these
2 information needs to TerraPower in three separate submittals. On August 5, 2024, staff issued batch #1 Information Needs request (ML24285A043) via e-mail (ML24285A044). On September 18, 2024, staff issued batch #2 Information Needs request (ML24289A121) via e-mail (ML24289A120). A third round of information needs was subsequently requested on October 30, 2024, via e-mail (ML24304B068). Environmental audit activities consisted of document and applicant response reviews followed by a sequence of virtual meetings necessary to address specific questions and comments.
All information needs were addressed or resolved prior to the NRC issuance of the draft EIS in June 20, 2025, with the exception of specific issues related to archeological testing. The NRC staff held the audit open until reception of archeological testing results in June 2025 (ML25195A007) and transmittal of an update to the macro-corridor design to avoid potential adverse impacts to cultural resource dated August 20, 2025, (ML25232A002). The Staff subsequently closed out the audit on September 8, 2025.
Table 1 of this report presents a list of the NRC staff and its contractor participating in the audit and their associated environmental review areas. Table 2 presents a list of TerraPower staff and its contractors who participated in the audit.
Table 1. Review Areas with Assigned NRC Staff and PNNL Contract Support Team Member Role/Review Area Joe OHara Environmental Project Manager Pat Vokoun Environmental Project Manager Madelyn Nagel Environmental Project Manager Support William Burris Environmental Project Manager Support Jim Jackson, PNNL PNNL Project Manager, Cumulative, Climate Change Ann Miracle, PNNL PNNL Project Manager Dan Barnhurst Environmental Branch Chief Michelle Rome Environmental Branch Chief Bob Hoffman Peer Review: Cumulative, Air Quality Brad Fritz, PNNL Air Quality Brian Glowacki Peer Review: Hydrogeology and Water Resources, Climate Change, Air Quality Gerry Stirewalt Peer Review: Water Resources and Hydrogeology Rajiv Prasad, PNNL Water Resources - Surface Water Phil Meyer, PNNL Water Resources and Hydrogeology - Groundwater Beau Goldstein Peer Review: Historic and Cultural Resources Cyler Conrad, PNNL Historic and Cultural Resources Peyton Doub Peer Review: Ecology, Land Use, Visual Impacts Caroline Hsu Peer Review: Ecology, Land Use Tracy Fuentes, PNNL Terrestrial Ecology Caitlin Wessel, PNNL Aquatic Ecology Jeffrey Rikhoff Peer Review: Socioeconomics, Environmental Justice, Non-Radiological Health and Waste, Noise Michelle Niemeyer, PNNL Socioeconomics Lin Zeng, PNNL Socioeconomics Kim Leigh, PNNL Non-Radiological Health, Non-Radiological Waste, Noise
3 Team Member Role/Review Area Seema Verma, PNNL Non-Radiological Health, Non-Radiological Waste, Noise Rao Tammara Peer Review: Radiological Human Health and Transportation of Radioactive Materials Zach Gran Safety Donald Palmrose Peer Review: Radiological Materials, Transportation, Fuel Cycle and Radiological Waste Management, and Accidents Jon Napier, PNNL Radiological Human Health, Transportation of Radioactive Materials, Fuel Cycle and Radiological Waste Management, and Accidents Tristan Hay, PNNL Radiological Human Health, Transportation of Radioactive Materials, and Fuel Cycle and Radiological Waste Management Table 2. List of Audit Participants for TerraPower, Bechtel, and Other Contractors (Tetra Tech and General Electric (GE))
TerraPower Bechtel Other Contractors Nick Kellenberger Matthew Waterman Phil Moore (Tetra Tech)
Beth Dalick Periandros Samothrakis Chandler Dangle (Tetra Tech)
Brian Johnson Vince Frasco Lisa Matis (Tetra Tech)
Ethan Graven Lynn Van-Derpoel Mark Karpinski (Tetra Tech)
Erin Wisler Christopher Azmeh Chris Borstel (Tetra Tech)
Jong Chang Megan Brown Eric Pearson (GE)
Barry Mingst Tim Cahill Shane Gardner (GE)
Ethan Graven Rahul Ghosh Sydney Grahovac Ken Jha John Biersdorf Arunika Bhatia Kyra Perkins Eric Riewski Nicole Hill Mary Hoganson Matt Watterman Margaret McCoy Mark Holdsworth Ryan Sell Altheia Wyche Vince Frasco Leo Sanchez Kit Ng 3.0 Summary of Audit Activities and Issues Addressed The audit kickoff meeting was held virtually on July 30, 2024, from 2:30 p.m. to 3:30 p.m. A series of shorter, focused meetings were held virtually as necessary over the remaining course of the audit to address specific information needs. These meetings were attended only by persons specifically interested in the information needs under discussion.
4 Table 3 presents a tabulated summary of how the information needs presented to TerraPower in the audit plan were addressed. In summary, 26 of the 85 audit items were closed through audit discussions. Other items were resolved through the responses provided by TerraPower to the information requests described in Section 2. A final outstanding item regarding cultural resources was resolved by the applicant submission of archeological testing results in June 2025 (ML25195A007) and transmittal of an update to the macro-corridor design to avoid potential adverse impacts to cultural resource dated August 20, 2025, (ML25232A002).
4.0 Audit Closeout Meeting The audit was closed via a virtual meeting between the NRC and TerraPower on September 8, 2024. The staff has determined that the information provided by TerraPower through the audit contains all of the information needed from the applicant to complete the environmental review.
Table 4 presents the attendance list.
Table 3. Summary of Environmental Audit Information Need Resolution Information Need ID ER Section Information Needed Resolution Site and Technical Overview STO-1 3.1 In addition to the water pipeline connecting Naughton Power Plant along the transmission line corridor what construction is necessary for the Cooling Water Intake Structure. Please provide a diagram of system and map of where it will be located onsite (including where the pipeline will run to at Kemmerer Unit 1).
Applicant provided diagram in a submittal of additional information (ML24311A168)
STO-2 Figures 3.1-4 &
3.2-2 What construction is necessary for the discharge structures and where will the discharge outfall be placed? Please provide diagram or schematic and map showing where the various components will be located onsite.
The Figures in the ER do not show locations.
Applicant provided clarification in a submittal of supplemental information (ML25058A220)
STO-3 Please provide an updated table of permits needed for construction and where you are in that process. E.g., Clean Water Act Section 404 permit, a Rivers and Harbors Act Section 10 permit issued by the USACE, Section 401 Water Quality Certification issued by the Department of Natural Resources, and WYPDES Large Construction General Permit for Storm Water Discharges.
Applicant provided additional tables in a submittal of supplemental information (ML24344A002)
Cumulative Impacts (Multiple Review Areas)
CMLT-1 Chapter 7 Per ISG-26, Attachment 4, Does the application include a discussion of the time frames for past, present, and reasonably foreseeable actions? Timeframes are not Resolved through audit activities
5 Information Need ID ER Section Information Needed Resolution addressed in Chapter 7 of the ERs discussion of past, present, and reasonably foreseeable future projects. Please provide.
CMLT-2 Chapter 7 Please provide an update on the status of any of the cumulative projects identified in Chapter 7 of the ER.
Resolved through audit activities CMLT-3 Chapter 7 Will there be any updates, refurbishment, changes made to the Naughton Power Plant intake to support Kemmerer Unit 1 coming online? If there are please provide details of what they are and when they are expected to occur.
Applicant provided updates in a submittal of supplemental information (ML24344A002)
Land Use and Visual Resources LU-1 2.1.1.2 Section 4.1.1 of the ER states that Section 2.1 of the ER notes the zoning of the site as industrial; however, this is not stated in Section 2.1. Please confirm the zoning of the site.
Resolved through audit activities LU-2 2.1.1.1 ESRP 2.2.1 requires that the NRC indicate whether any lands or leased and to whom, for how long, and for what purpose. Section 2.1.1.1 of the ER states that US Sodium Fast Reactor Owner LLC acquired mineral rights within the site. However, the owner of the surface estate is unclear. Please confirm surface ownership.
Resolved through audit activities LU-3 2.1.1.1 ESRP 2.2.1 requires that the NRC identify egress limitations from the area surrounding the site. This information is not available in the ER. Please identify such limitations, if they exist.
Resolved through audit activities LU-4 2.1.1.1 ESRP 2.2.1 requires that the NRC identify prime farmland, unique farmland, and farmland of national or statewide importance on the site.
However, these resources are not discussed in the ER. Please address.
Resolved through audit activities LU-5 NA ESRP 2.2.3 requires that the NRC identify principal agricultural products of the region, including commercial forest products. This is not discussed in the ER. Please include such information.
Resolved through audit activities LU-6 NA Per ESRP 4.1.1, Has the applicant provided an overlay of the proposed construction footprint over the land use maps produced for ESRP 2.2.1? Does the overlay distinguish between permanent versus temporary elements? No overlay of the CP has been included in the ER. Please provide.
Resolved through audit activities
6 Information Need ID ER Section Information Needed Resolution LU-7 4.4.2 Per ESRP 5.1.1, Depending on the site and the level of applicable demographic research, land-use impacts could be projected to result from demand for new housing of operations workers. Only in rare cases would it be expected that enough research would be available to predict the degree that new housing would have land-use impacts in the vicinity. The applicant should acknowledge the operations impact on housing and similar impacts that may occur from outage operations. Section 4.4.2 of the ER describes demographic impacts, such does not tie such impacts back to land use impacts. Please provide such information.
Resolved through audit activities Air Quality AQN-1 2.7.2 Per ESRP 2.7 A description of the regional air quality, including nonattainment or maintenance areas. Most National Ambient Air Quality Standards pollutants are discussed and characterized in the ER. PM-2.5 is not. Please provide a description of PM-2.5 emissions from construction, operation and decommissioning.
Please provide background and/or regional PM-2.5 concentrations. Also please include any additional relevant PM-2.5 information.
Applicant provided description in a submittal of supplemental information (ML24344A002)
Water Resources and Hydrogeology HYD-01 2.2 ESRP 2.3.1 and 2.3.2 require maps of sufficient detail to show the relationship of the site to major hydrological systems that could affect or be affected by plant construction or operation. ESRP 5.2.1 requires identification and description of hydrological alterations resulting from the identified operational activities. ESRP 5.2.2. requires a description of potential impacts to groundwater uses from plant-related operational activities. Section 2.5.3 of the Preliminary Safety Analysis Report (PSAR) identified groundwater surface water interactions along streams and river channels, but this potential interaction between the cooling water source stream and potentially affected groundwater was not discussed in the ER. Provide a description of the potential impacts of cooling water withdrawal due to surface water - groundwater interactions on the alluvial aquifer system.
Applicant provided information in a submittal of supplemental information (ML24344A002)
7 Information Need ID ER Section Information Needed Resolution HYD-02 2.2 ESRP 2.3.3 requires a description of temporal and spatial variations of surface and groundwater-quality characteristics. Section 2.2 of the ER presents limited groundwater quality and surface water results. At minimum, provide a year of quarterly sampling for evaluating potential impacts to the environment that may result from construction or operation.
Resolved through audit activities HYD-03 4.2.4; 5.2.4 ESRP 6.3 and 6.6 require a list of data describing hydrological monitoring, including monitoring locations, frequency, equipment, data analysis procedures, data quality objectives, and aspects related to chemical sampling of water systems. Provide a description of planned groundwater monitoring and surface water monitoring during operations, including water quality parameters, frequencies, types, methods, and other aspects related to monitoring.
Applicant provided data in a submittal of supplemental information (ML24344A002)
HYD-04 1.1.4; 2.2.1.1.8 ER Sections 1.1.4 and 2.2.1.1.8 describe the reactor cooling system and the plant cooling water source, respectively. Provide a description of normal and ultimate heat sinks for the proposed plant. Provide a detailed description of water used for cooling purposes for the proposed plant. Provide a description of thermal discharge to any waterbodies.
Resolved through audit activities HYD-05 2.2.1.1.1 ER Section 2.2.1.1.1 states that stream and reservoir water levels for Hams Fork River are discussed in PSAR Section 2.5.4. PSAR Section 2.5.4 cites PSAR Reference 2.5-102 for flows and withdrawals for the Naughton Plant. Provide PSAR Reference 2.5-102 for review.
Closed by Request for Document (ML25024A131)
HYD-06 2.2.3.1.3 ER Section 2.2.3.1.3 states that surface water quality sampling is planned to occur July 2024 through July 2026. Provide an update on the status of this sampling plan including locations of sampling, water quality parameters, sampling methods, and sampling frequencies.
Applicant provided updates in a submittal of supplemental information (ML24344A002)
HYD-07 2.2.2.1.5 ER Table 2.2-7 uses average monthly Hams Fork discharge from Viva Naughton Reservoir based on 1995-2021 reservoir outflow data.
Provide an update to this data for more recent years, if available.
Resolved through audit activities HYD-08 Provide PacifiCorp Permit #22297 for review.
Closed by Request for
8 Information Need ID ER Section Information Needed Resolution Document (ML25024A133)
HYD-09 3.1, 3.2 Provide greater quality ER Figures 3.1-3, 3.1-4, 3.2-1, and 3.2-2.
Closed by Request for Document (ML25058A220)
HYD-10 5.2.1 Provide a description of post-construction groundwater-surface water interaction.
Applicant provided description in a submittal of supplemental information (ML25076A001)
HYD-11 Based on preliminary design of the cooling system, please provide the following information:
Expected temperature of plant water discharge to North Fork Little Muddy Creek including any seasonal variation.
Brief description of likely discharge structure and discharge port design in relation to the North Fork Little Muddy Creek channel and floodplain.
Applicant provided information in a submittal of supplemental information (ML24344A002)
HYD-12 Please provide a copy of PacificCorp 2018 National Pollutant Discharge Elimination System (NPDES)/ Wyoming Pollutant Discharge Elimination System (WYPDES) permit WY0020311 for review.
Closed by Request for Document (ML25024A135)
HYD-13 4.2.1 The groundwater flow model calculation provided in response to safety information needs 2-3 and 2-4 includes contour maps of groundwater head in each model layer during construction dewatering (Figures 27-31).
Provide a map (or maps) of groundwater drawdown resulting from construction dewatering.
Applicant provided figures in a submittal of supplemental information (ML25076A001)
HYD-14 4.2.1 The groundwater flow model calculation provided in response to safety information needs 2-3 and 2-4 includes mass balance results from the simulation (Figures 16 and 32).
Provide the units for the numbers included in these figures. Provide an explanation for why the construction dewatering results in a decrease in the discharge from North Fork Little Muddy Creek to the groundwater.
Applicant provided figures in a submittal of supplemental information (ML25076A001)
HYD-15 1.14, 2.2.1.1.8 Explain if the underground water sump that would hold treated sanitary wastewater and Applicant provided
9 Information Need ID ER Section Information Needed Resolution cooling tower blowdown is a concrete or lined structure explanation in a submittal of supplemental information (ML24344A002)
HYD-16 1.1.4, 2.2.1.1.8 Explain if the plant effluent would contain any radioactive constituents. Provide a description of planned monitoring of plant effluent for radioactive constituents Applicant provided explanation in a submittal of supplemental information (ML24344A002)
HYD-17 1.1.4, 2.2.1.1.8 Provide estimated dimensions of the rip-rap apron(s) (e.g., number, area and depth of material). Explain if the rip-rap apron and the filter layer would be periodically maintained and provide the expected maintenance frequency.
Applicant provided explanation in a submittal of supplemental information (ML24344A002)
HYD-18 1.1.4, 2.2.1.1.8 Explain if the combined discharge from the underground water sump and outflow from the energy island stormwater detention pond at the NPDES permitted outfall is expected to infiltrate into the floodplain of North Fork Little Muddy Creek.
Applicant provided explanation in a submittal of supplemental information (ML24344A002)
HYD-19 1.1.4, 2.2.1.1.8 Provide a description of the floodplain characteristics where the NPDES permitted discharge will occur (e.g., 1 percent or 0.2 percent-chance floodplain).
Applicant provided description in a submittal of supplemental information n (ML24344A002)
HYD-20 1.1.4, 2.2.1.1.8 Provide a description of expected wintertime conditions near the NPDES permitted outfall and rip-rap apron (e.g., snow and ice conditions)
Applicant provided description in a submittal of supplemental information (ML24344A002)
Aquatic Ecology Resources AECO-1 2.3.2.1 and 2.3.2.2 Aquatic surveys described in the ER were conducted in October 2022 and June 2023, please describe any additional aquatic sampling conducted. RG 4.2 states the applicant should include at least 1 year of baseline data.
Closed by Request for Document (ML25024A095)
10 Information Need ID ER Section Information Needed Resolution AECO-2 Please provide a construction map that shows the areal extent and location of construction activities and water discharge along with aquatic features (ESRP 4.3.2).
Applicant provided supplemental information (ML25058A220)
AECO-3 3.3, Table 3.3-1 Please provide a proposed schedule of construction activities and work windows (ESRP 4.3.2).
Applicant provided schedule in a submittal of supplemental information (ML24344A002)
AECO-4 5.3.2.1.2, 2.2.1.1.2, 2.2.1.1.8 Need additional information on the intake design and how it would affect flow and aquatic species in the Hams Fork River. Will the additional water needed for the plant increase the flow rate at the intake (ESRP 5.3.1.2)? Will the increased water take affect downstream aquatic environments?
Applicant provided information in a submittal of supplemental information (ML24344A002)
AECO-5 5.3.2.2, 3.2.2.12 Need description and or diagram detailing the discharge structure (ex. Where will it enter the stream, info. about the flow reduction system, anticipated discharge flow rate and variations with season, and impacts to biota downstream; ESRP 5.3.2.2)
Resolved through audit activities AECO-6 5.3.2.2.2 Describe aquatic resource impacts related to waste systems (ESRP 5.5.1)
Resolved through audit activities AECO-7 The average high air temperature in Dec, Jan, and Feb is below freezing in Kemmerer, WY.
Please provide information and temperature data about whether North Fork Little Muddy Creek freezes over in the winter. If there is the potential for it to freeze over in the winter how is that expected to impact the planned plant discharge?
Applicant provided information in a submittal of supplemental information (ML24344A002)
AECO-8 The average high air temperature in Dec, Jan, and Feb is below freezing in Kemmerer, WY.
Please provide information and temperature data about whether Hams Fork River freezes over in the winter. If there is the potential for it to freeze over in the winter how is the intake currently kept clear and flowing?
Applicant provided information in a submittal of supplemental information (ML24344A002)
AECO-9 Hargett & ZumBerge 2006 is no longer available on the Wyoming Department of Environmental Quality (WYDEQ) website, please provide new link or copy of document Hargett, E.G. and J.R. ZumBerge.
Closed by Request for Document (ML25024A128)
11 Information Need ID ER Section Information Needed Resolution Redevelopment of the Wyoming Stream Integrity Index for assessing the biological condition of wadeable streams in Wyoming.
WYDEQ, Water Quality Division. Cheyenne and Sheridan, WY.
AECO-10 What other things that could impact aquatic organisms will be built onsite? e.g.discharge outfall, rip rap around outfall, onsite water basins, retaining wall(s) along creek, dock, etc.)
Applicant provided information in a submittal of supplemental information (ML24344A002)
AECO-11 Does TerraPower plan to do any aquatic monitoring during construction?
Applicant provided explanation in a submittal of supplemental information (ML24344A002)
AECO-12 Has TerraPower had any discussions with WYDEQ and Wyoming Game and Fish Department about the projects planned discharge into North Fork Little Muddy Creek and the creeks aquatic habit?
Closed by Request for Document (ML24311A168)
Terrestrial Ecology Resources TECO-1 2.3.1.4, 4.3.1.4, 5.3.1.4 The North American Wolverine (Gulo gulo luscus) is present on the official U.S. Fish and Wildlife Service (USFWS) Information for Planning and Consultation report as a species potentially affected by activities at this location. Please include information on this species, including habitat requirements, life history, and potential project effects. RG 4.2 states that the applicant should include a discussion of each important terrestrial species that has a reasonable likelihood of occurring in the area.
Applicant provided information in a submittal of supplemental information (ML24344A002)
TECO-2 2.7.1.3.5, 2.7.4.1, 4.3.1.3.1 Per RG 4.2, the ER should include a discussion of tall structures that might injure birds and bats. Tall structures with lights and that are guyed are more likely to injure birds and bats. The ER states that the Kemmerer Unit 1 meteorological tower is 197 feet (60 meters) above ground level but does not state whether the tower is guyed or lit. Please state whether the tower is guyed or freestanding and state whether it is lit or unlit. If lit, please state Applicant provided information in a submittal of supplemental information (ML24344A002)
12 Information Need ID ER Section Information Needed Resolution lighting color and whether light is blinking or steady.
TECO-3 2.1.1.1, 2.3.1.2, 2.3.1.4, 4.3.1.4 Please provide copies of the wetland delineation report (Reference 2.1-17, 2.3-39) and surveys for Ute ladies-tresses (Spiranthes diluvialis) in wetlands (References 2.3-42, 9.3-57, 9.3-59) as described in the ER (ESRP 4.1.1; 4.1.2; 4.3.1; 5.1.1; 5.1.2; 5.3.3.2) for NRC staff review. Please state the planned timing of the third year of surveys for Utes ladies-tresses. Three years of surveys are required as stated in USFWS's revised version of the 1992 Interim Survey Requirements for Ute Ladies-tresses Orchid (Spiranthes diluvialis). If year 3 surveys have already been completed for Utes ladies-tresses, please provide survey results for NRC staff review.
Closed by Request for Documents (ML25024A143, ML25024A142, ML25024A138)
TECO-4 2.3.1.1.1, 2.3.1.4, 4.3.1.1.1 The ER states that terrestrial visual surveys were conducted in 2022 and 2023 (Reference 2.3-40, 2.3-41), that raptor nest surveys were conducted in 2023, and that burrowing owl nest-clearing surveys will be conducted 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> before construction in areas of the site with prairie dog burrows. Please provide copies of these surveys for NRC staff review. RG 4.2 states the applicant should include at least 1 year of baseline data.
Applicant provided information in a submittal of supplemental information (ML25024A130)
TECO-5 4.1.1, 4.1.2, 4.3.1, 4.3.2, 4.11 RG 4.2 requires applicants to identify measures and controls to limit adverse impacts during construction activities. Provide copies of such environmental controls and procedures for NRC staff review, including pre-construction nest survey protocols, stormwater pollution prevention plan, spill prevention plan, erosion controls, revegetation plan, and any planned terrestrial resource monitoring.
Closed by Request for Document (ML25024A130, ML25024A136)
TER-6 ER Figure 2.1-7; ER Section 2.3.1.4 Please clarify the number and location of burrowing owl nests. Are the burrowing owl nest(s) within the currently planned macro-corridor? Does the applicant have any other info regarding the known burrowing owl nest(s)? 1) Pg 3 of July 2023 report (response pg. 7) states 1 pair nesting in one prairie dog colony. 2) Figure 1 (response pg. 13) shows 2 burrowing owl nests within TVES survey macro-corridor area. 3) Comparing macro-corridor in ER (Figure 2.-7) and survey report Figure 1 (response pg. 13) appears to show Applicant provided clarification in a submittal of supplemental information (ML24344A002)
13 Information Need ID ER Section Information Needed Resolution nesting owls to be outside of planned macro-corridor.
Historic and Cultural Resources HCR-1 4.6 Provide information about traditional ecological knowledge obtained through coordination, outreach, site visits, communication etc., with Native American Tribes.
Resolved through audit activities HCR-2 4.6 Provide information about the visual impacts analysis for Kemmerer Unit 1 and the utility corridor based on current known facility heights and plumes (as an example for the utility corridor, based on height, structure type, color of transmission structures, etc.).
Applicant provided information in a submittal of supplemental information (ML24344A002)
HCR-3 4.6 Provide a description of the proposed road in the utility corridor in terms of construction disturbance (depth, width, crown/ditch, etc.),
and long-term operations and maintenance.
Applicant provided the description in a submittal of supplemental information (ML24344A002)
HCR-4 4.6 What is the proposed right of way (ROW) width for the utility corridor? This information need is not related to the analyzed/surveyed corridor width, but for the actual negotiated ROW width.
Applicant provided explanation in a submittal of supplemental information (ML24344A002)
HCR-5 4.6 Provide information, including records of past disturbance, regarding the small access road and its impacts to 48LN740 and provide corresponding documentation for staff review.
Resolved through audit activities HCR-6 4.6 Confirm that railroad alignments that cross the direct area of potential effect (APE) represent non-contributing components of National Register of Historic Places (NRHP)-eligible sites and provide documentation of this determination from the State Historic Preservation Office (SHPO).
Applicant provided confirmation in a submittal of supplemental information (ML24344A002)
HCR-7 4.6 Provide information on any updates to identified traditional cultural properties or landscapes within the APE.
Resolved through audit activities
14 Information Need ID ER Section Information Needed Resolution HCR-8 4.6; 5.6; 7.2.6 Provide recommendations for avoiding or mitigating adverse effects to 48LN740 and 48LN8940. Discuss and have construction plans for activities in these areas available for staff review. Provide records of Wyoming SHPO communication and engagement on adverse effects for these historic properties.
Applicant provided information in initial submittal of supplement information (ML25195A006) and subsequent submittals (ML25195A007 and ML25232A002)
HCR-9 4.6 The ER states that 48LN740 is in the indirect APE (page 346/1501 - non-public version);
please confirm.
Applicant provided confirmation in a submittal of supplemental information (ML24344A002)
HCR-10 4.6 The ER Table 2.6-4 (non-public version) describes site eligibility. Are the eligibility determinations listed in this table based on the recommendation of previous recorders or of Karpinski and Karpinski (2023)?
Resolved through audit activities HCR-11 4.6; 7.2.6 The proposed electrical transmission lines, water pipelines, and electrical substation for TerraPower are to be constructed on the historic Naughton Power Plant site. Have these impacts been analyzed? Has the Naughton Power Plant been evaluated for NRHP eligibility? Will facilities/infrastructure at the Naughton Power Plant be affected, such as connection to, altering, replacing, tying-in, demolishing, etc.?
Applicant provided explanation in a submittal of supplemental information (ML24311A168)
HCR-12 4.6; 7.2.6 Are off-site alterations needed to any of PacifiCorps water delivery systems (starting at Lake Viva Naughton) for the TerraPower project to be realized, such as to pipes, pumps, ponds, storage facilities, conveyance facilities, etc.)?
Applicant provided explanation in a submittal of supplemental information (ML24311A168)
HCR-13 4.6 The ER page 760/1501 (non-public version) states that a temporary parking lot will adversely affect 48LN740 - please confirm.
Applicant provided confirmation in a submittal of supplemental information (ML24344A002)
15 Information Need ID ER Section Information Needed Resolution HCR-14 4.6; 5.6 Provide an updated copy of Karpinski and Karpinski (2023) report, A Class III Cultural Resource Inventory for TerraPower, LLCs Natrium Demonstration Project, Lincoln County, Wyoming. Provide records of communication with the Wyoming SHPO, including any eligibility determinations and concurrences.
Applicant provided information in a submittal of supplemental information (ML24311A168)
HCR-15 4.6; 5.6 Provide documentation of any ongoing or completed outreach and communication with Native American Tribes and the Wyoming SHPO, and their responses (in addition to those already provided in the ER).
Applicant provided documentation in a submittal of supplemental information (ML24344A002)
HCR-16 4.6; 5.6; 7.2.6 Provide copies of all procedures that describe protective measures (e.g.,
avoidance/monitoring) and an inadvertent discovery plan for historic and cultural resources during construction, operation and maintenance, and demolition.
Resolved through audit activities Human Health: Non-Radiological No Info Needs Identified Human Health: Radiological HHR-1 2.7.3.2; 5.9; 5.9.1 Per Regulatory Guide 4.2 Rev. 3 Section 5.9.1, the environmental pathways by which radiation from radioactive effluents can be transmitted from the proposed plant to living organisms should be provided. Please provide information that identifies gaseous and liquid effluents pathways, expected rates of emission, annual doses to the public within 50 miles of the site, and the code used to perform the analysis.
Applicant provided information in a submittal of supplemental information (ML24344A002)
HHR-2 5.9.6 Per RG 4.2 Rev 3, Section 5.9.7, the applicant should provide an estimate of the quantity of wastes produced and stored at the facility.
Please provide a subject matter expert (SME) to discuss any potential exposures associated with onsite exposures from solid waste. This includes Class A, B, C, greater than Class C wastes, and spent fuel. The staff notes that there is mention of radioactive waste storage related to Fuel Handling Building in Section 3.1.1.1.2 of the ER.
Resolved through audit activities
16 Information Need ID ER Section Information Needed Resolution HHR-3 2.9.3; 2.9.2 Please provide justification for sample sites.
Please provide lower limits of detection regarding samples (ESRP 6.2).
Resolved through audit activities Fuel Cycle and Radiological/Nonradiological Waste Management FCRW-1 4.10 Per Regulatory Guide 4.2, Revision 3, Section 3.4.3, please provide an estimated yearly amount of solid waste during construction and possible locations of disposal.
Applicant provided estimations in a submittal of supplemental information (ML24344A002)
FCRW-2 6.1.2.6.2 Please provide an SME to discuss the onsite storage of radiological wastes and spent fuel (e.g., a water-based environment). The ER Section 6.1.2.6.2 relies on NUREG-2157 as a bounding analysis of spent fuel storage impacts, however spent fuel generated by liquid metal fast reactors is not within the scope of the analysis in NUREG-2157 because that technology was in commercial use in the United States at the time of publication.
Applicant provided information in a submittal of supplemental information (ML24344A002, ML25037A006)
FCRW-3 6.1.1.4.5 Section 6.1.1.4.5 states that the impacts of fuel fabrication are described in an ER supplement to the GNF-A Wilmington, North Carolina fuel fabrication facility. This supplemental ER has been withdrawn (ML24068A130). Please provide an updated Section 6.1.1.4.5 that addresses the impact of fuel fabrication.
Applicant provided information in a submittal of supplemental information (ML24344A002)
Transportation of Radioactive Material TR-1 6.2 10 CFR 51.52 (a)(3) states that The average level of irradiation of the irradiated fuel from the reactor does not exceed 33,000 megawatt-days per metric ton, and no irradiated fuel assembly is shipped until at least 90 days after it is discharged from the reactor. While the commitment to 90 days has been met, the ER does not specify the expected burnup of spent fuel. Please provide an estimate of the potential.
Applicant provided estimation in a submittal of supplemental information (ML24344A002, ML25037A006)
TR-3 6.2 The NRC staff has identified an issue with the population density values from a WebTRAGIS kml file for use in the RADTRAN Code. Please provide an SME to discuss how this affected TerraPowers analysis in the ER. For reference, please see NUREG-2266 (ML24207A210). Please provide a complete discussion as described in RG 4.2 Rev 3 Section 6.2.1 to allow the staff to make a determination of sufficiency.
Applicant provided discussion in a submittal of supplemental information (ML24344A002)
17 Information Need ID ER Section Information Needed Resolution TR-4 6.2 Provide a knowledgeable expert to discuss the number of shipments of fuel and waste applied in the transportation analysis of ER Section 6.2 and related calculations.
Applicant provided information in a submittal of supplemental information (ML24344A002, ML25037A006)
Accidents ACC-1 5.11.2 Provide an SME to discuss the generation of the accident analysis information, such as that provided in Section 5.11.2, Table 5.11-20, and related material of the ER. The information provided in Table 5.11-20 cannot be traced to identifiable sources in the PSAR. Additionally, the staff needs to confirm the use of recommended MELCOR Accident Consequence Code System input data value in accordance with NUREG/CR-7270 and based on local environmental factors.
Applicant provided confirmation in a submittal of supplemental information (ML24344A002, ML25037A006)
ACC-2 5.11.2 Provide an SME to discuss how Licensing Modernization Project (e.g., NEI 18-04) was factored into the severe accident analysis and severe accident mitigation design alternatives (SAMDAs). The staff needs to discuss this due to the probabilistic risk assessment applied in the CP application is based on preliminary design information that the safety review team is assessing for acceptability at the CP stage.
Please note that as directed by the 1980 Commission Policy Statement on Nuclear power Plant accident considerations under National Environmental Policy Act (45 FR 40101), the ER submitted by applicants for construction permits on or after July 1, 1980, should include a discussion of the environmental risks associated with accidents.
Applicant provided information in a submittal of supplemental information (ML24344A002, ML25037A006)
ACC-3 5.11.3 Provide an SME to discuss the potential application of external events multipliers (e.g.,
NEI 05-01A) in the SAMDA analysis.
Resolved through audit activities Alternatives ALT-1 9.4.2.2 ESRP 9.4.2 states that for discharge systems, the following information should be obtained:
sketches or preliminary designs and operational characteristics of alternative discharge systems showing the discharge design, its location with respect to the receiving Resolved through audit activities
18 Information Need ID ER Section Information Needed Resolution water body, and its relationship to water surface, bottom geometry, intake structure, and shoreline. While discharge system alternatives are proposed in the ER, there are no sketches or preliminary designs included. Please provide such information, as available.
Decommissioning No Info Needs Identified Socioeconomics - Environmental Justice SOCIOEJ-1 4.4.4.1 Section 4.4.4.1 of the ER states a traffic study will inform the design of the US 189 intersection and improvements and include additional recommendations for mitigating traffic congestion. The traffic study considers the peak workforce with two staggered start times, estimating that approximately 60 percent of the workforce and a few truck shipments (an estimated 980 vehicles) would arrive or depart at the peak a.m. and p.m. hours. The ER indicates the traffic study analyzes projected vehicle traffic for 2026, inclusive of Kemmerer Unit 1 construction and Sodium Test and Fill Facility construction. The ER does not provide a title or a reference citation for this traffic study. Please identify the traffic study and provide the source documentation for this information in the ER.
Applicant provided explanation in a submittal of supplemental information (ML25024A137)
SOCIOEJ-2 4.4.3 Section 4.4.3.2.4, Table 4.4-14 and Table 4.4-15 of the ER provides estimated property tax payments for the Kemmerer Unit 1 during construction. The ER states these estimates do not reflect any negotiated property tax agreements, such as payments-in-lieu of taxes or power plant valuation agreements, between tax jurisdictions or the State. Please provide any updated information on estimated property tax payments for the Kemmerer Unit 1 during construction.
Resolved through audit activities SOCIOEJ-3 5.4.3.2.4 Section 5.4.3.2.4 of the ER estimates property tax payments during power plant operation will be approximately $7.5 million. The ER states this estimate does not reflect any negotiated property tax agreements, such as payments-in-lieu of taxes or power plant valuation agreements, between tax jurisdictions or the State. Please provide any updated information Resolved through audit activities
19 Information Need ID ER Section Information Needed Resolution on estimated property tax payment for the Kemmerer Unit 1 during power plant operations.
SOCIOEJ-4 4.4.2; 5.4.2 Section 4.4.2 of the ER states that 37 percent of the construction workers and 80 percent of the operation workers during the construction period are assumed to bring families. Section 5.4.2 of the ER states 100 percent of the operation workers are assumed to bring families. Please resolve this inconsistency.
Resolved through audit activities SOCIOEJ-5 4.4.2; 5.4.2 Workers from the nearby Naughton Power plant are slated to be trained to work at Kemmerer Unit 1, however, Section 4.4.2 of the ER states that 100 percent of operation workers will be relocating to the region. Please clarify the percentage of operations workers expected to move into the region.
Resolved through audit activities Meteorology No Info Needs Identified Table 4. Attendee List for Environmental Audit Close Out Meeting, September 8, 2025 Name Affiliation Nick Kellenberger TerraPower Beth Dalick TerraPower Patricia Vokoun NRC William Burris NRC Ann Miracle PNNL James Jackson PNNL