Decision marks the first construction permit ever issued by the NRC for a commercial non-light-water power reactor.
March 9, 2026
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The U.S. Nuclear Regulatory Commission (NRC) just announced the approval of a construction permit for TerraPower’s Natrium advanced reactor project in Kemmerer, Wyoming.
This is the first construction permit ever issued by the NRC for a commercial non-light-water power reactor and represents a historic step toward deployment of a new generation of advanced reactors in the United States.
History in the Making
TerraPower submitted its construction permit application in March 2024 to build Kemmerer Power Station Unit 1 on a site near an existing coal-fired power plant.
The application was accepted by the NRC in May 2024, marking the first time in more than 40 years that the agency docketed an application for a commercial non-light-water reactor. The NRC completed its safety review of the Kemmerer project in December 2025, ahead of schedule and 11 percent under budget.
TerraPower broke ground on non-nuclear construction to prepare the Kemmerer site in June 2024.
The company now has the green light to commence building its Natrium reactor, which could become America’s first commercial-scale next-generation nuclear power plant.
Natrium in Focus
The Natrium reactor is a 345-megawatt electric sodium-cooled fast reactor with a molten salt energy storage system that can quickly boost the system’s output to 500 megawatts for increased flexibility and reliability.
Its simplified design and use of advanced construction methods will make it faster and more affordable to build, and its constant high operating temperature can be used to generate heat or electricity to drive other energy-intensive manufacturing processes.
Natrium is one of two projects supported by the U.S. Department of Energy (DOE) through the Advanced Reactor Demonstration Program to demonstrate first-of-a-kind reactor technologies.
The project was awarded cost-shared funding from DOE to advance the reactor design and licensing, fuel development and qualification, and construction of two supporting facilities to fabricate fuel and test the reactor’s sodium coolant technology, respectively.
What’s Next?
With the construction permit approved, TerraPower will now need to submit a separate operating license application to the NRC before it can operate the facility.
Once operational, Natrium will become the first commercial reactor ever in the state of Wyoming and is anticipated to bring jobs, economic benefits, and a valuable source of reliable energy to the state.
The Natrium project is expected to be completed in 2030.