The U.S. Nuclear Regulatory Commission (NRC) has issued a final environmental impact statement (EIS) for the construction permit application of Kemmerer Power Station Unit 1, a proposed Natrium advanced reactor in Lincoln County, Wyoming. This development marks a key step in reviewing TerraPower's plan, submitted on behalf of US SFR Owner, LLC (USO), to build an innovative sodium-cooled fast reactor. The EIS, designated as NUREG-2268, evaluates the potential environmental impacts of issuing the permit, as well as alternatives. Released on October 23, 2025, the document stems from an application filed in March 2024 and reflects collaboration with the U.S. Department of Energy (DOE). Its significance lies in advancing advanced nuclear technology under DOE's Advanced Reactor Demonstration Program, while addressing the retirement of coal-fired power plants in the PacifiCorp service area. By providing a comprehensive environmental review, the EIS informs the NRC's decision on whether to allow construction of this 840-megawatt thermal reactor, which includes a molten salt energy storage system for variable output up to 500 megawatts electric net.
Background and Application Process
TerraPower, acting for USO—a wholly owned subsidiary—submitted the construction permit application on March 28, 2024, under section 103 of the Atomic Energy Act of 1954 and 10 CFR part 50. The application seeks approval to construct Kemmerer Unit 1 as part of DOE's program to demonstrate advanced reactors. Supplements were provided on May 2 and May 9, 2024, refining details of the project. The NRC published a notice of receipt in the Federal Register on May 14, 2024 (89 FR 42004), followed by a notice of intent to prepare an EIS and conduct scoping on June 12, 2024 (89 FR 49917). This process aligns with the National Environmental Policy Act (NEPA) requirements, as outlined in 10 CFR 51.20(b), which mandates an EIS for nuclear power reactor construction permits. The NRC also used the EIS to fulfill obligations under section 106 of the National Historic Preservation Act, integrating cultural resource considerations into the environmental review.
The proposed reactor is a pool-type, sodium-cooled fast reactor designed to generate electricity while storing energy in molten salt for flexible output. This setup aims to replace generation capacity lost from retiring coal facilities, supporting grid reliability in the region. The site's location in Lincoln County positions it to integrate with existing infrastructure, potentially minimizing new environmental disruptions.
Key Environmental Analysis and Findings
The final EIS assesses impacts across various categories, including land use, water resources, air quality, ecology, and socioeconomics. It weighs the benefits—such as clean energy production and economic development—against costs like construction-related disturbances and waste management. The document concludes that, after evaluating these factors, the recommendation is to issue the construction permit unless safety issues arise. This is based on the application details, an environmental audit, agency consultations, and public input.
Notably, the EIS identifies no environmentally preferable alternatives that fully meet the project's purpose of demonstrating the Natrium technology and offsetting coal retirements. Alternatives considered likely included other sites, energy sources, or no-action scenarios, though specifics are detailed in the full NUREG-2268 report. The analysis incorporates comments from the draft EIS public period, which ran from June 20, 2025 (90 FR 26333) to August 4, 2025. These comments, addressed in the final version, came from Federal, State, Tribal, and local stakeholders, ensuring a broad perspective.
As stated in the EIS, "after weighing the environmental, economic, technical, and other benefits against environmental and other costs, and considering reasonable alternatives, the recommendation is, unless safety issues mandate otherwise, that the NRC issue the requested CP to USO." This reflects an independent review process that prioritizes verifiable data over speculation.
Involved Parties and Regulatory Context
Key players include the NRC as the lead agency, with DOE as a cooperating partner due to its Advanced Reactor Demonstration Program funding. TerraPower and USO drive the private sector effort, building on prior nuclear innovations. The project aligns with broader federal goals for low-carbon energy, though it operates within strict regulatory bounds.
Relevant precedents include past EIS processes for advanced reactors, such as those under the Energy Policy Act of 2005, which encouraged demonstration projects. No direct court cases are cited in the notice, but the approach follows established NEPA guidelines and NRC precedents like the review for the Vogtle Electric Generating Plant expansions. Political forces include support for nuclear energy as a climate solution, balanced against local concerns about safety and environmental risks. Perspectives vary: proponents highlight job creation and emissions reductions, while critics may emphasize waste concerns or water usage in arid Wyoming. The EIS presents these without bias, relying on data from consultations.
Implications and Broader Context
Short-term implications involve potential construction starting if the permit is granted, leading to immediate economic boosts in Lincoln County through jobs and infrastructure. Long-term effects could include advancing sodium-cooled reactor technology, influencing future designs and contributing to national energy security. Challenges persist in areas like supply chain for advanced components and public acceptance of nuclear power.
Different viewpoints emerge from stakeholders. Environmental groups might advocate for renewable alternatives, citing lower risks, while industry supporters argue nuclear's reliability complements intermittency in wind and solar. Tribal consultations, as part of the historic preservation compliance, address cultural impacts, ensuring indigenous perspectives are integrated.
In summary, the final EIS provides a thorough foundation for the NRC's decision, emphasizing balanced environmental stewardship. Potential next steps include the NRC's safety evaluation report and a final permitting decision. Ongoing debates may focus on scaling advanced reactors amid evolving energy policies, with challenges in regulatory efficiency and technological maturation. These trajectories highlight the need for continued monitoring and adaptive management in nuclear development.