The Nuclear Regulatory Commission has authorized NRC staff to issue TerraPower’s subsidiary, US SFR Owner, a construction permit for the company’s Kemmerer Power Station Unit 1 commercial nuclear power plant in Kemmerer, Wyoming.
“This is a historic step forward for advanced nuclear energy in the United States and reflects our commitment to delivering timely, predictable decisions grounded in a rigorous and independent safety review,” NRC Chairman Ho Nieh said.
This is the first commercial reactor the NRC has approved for construction in nearly a decade and the first approval for a non-light water reactor in more than 40 years.
NRC staff finished their technical review of this new design in less than 18 months. Following a streamlined mandatory hearing process, the Commission authorized its Office of Nuclear Reactor Regulation to issue the permit, having found the staff’s review of the Kemmerer application adequate to make the necessary regulatory safety and environmental findings.
The staff expects to issue the permit soon. TerraPower filed the application in March 2024, requesting a permit to build the sodiumcooled, advanced reactor design on a site near an existing coal-fired power plant.
The NRC staff accepted the application and began formal review in May 2024. The 345-megawatt electric (MWe) plant includes an energy storage system to temporarily boost output up to 500 MWe when needed.
US SFR Owner would need to submit a separate operating license application, and the NRC staff would need to approve it before the facility could operate.
The NRC staff issued its safety evaluation for the permit in December 2025, and the final environmental impact statement for the site in October 2025.
