TerraPower announced on March 4, 2026, that it received notification from the U.S. Nuclear Regulatory Commission (NRC) that the commissioners voted to award the first Natrium plant, Kemmerer Unit 1 in Kemmerer, Wyo., with a construction permit.
This is the first commercial-scale, advanced nuclear power plant to ever receive the permit, according to the company. The project could cost up to $4 billion for the Bill Gates-backed company.
"Today is a historic day for the United States' nuclear industry," TerraPower President and CEO Chris Levesque said in a statement. "We are beyond proud to receive a positive vote from the Nuclear Regulatory Commissioners to grant us our construction permit for Kemmerer Unit One. This is the first commercial-scale, advanced nuclear plant to receive this permit.
"Our team has worked relentlessly for over four years with the NRC staff to get to this moment. We had extensive pre-application engagement with the NRC, and we submitted a robust and thorough construction permit application almost two years ago. We have spent thousands of manpower hours working to achieve this momentous accomplishment.
"We plan to start construction on the Natrium plant in the coming weeks and look forward to bringing the first Natrium reactor and energy storage system to market in the great state of Wyoming."
TerraPower said its regulatory strategy was built on providing thorough technical content and robust engagement opportunities to discuss the Natrium technology and design with regulators. This includes extensive engagement through both the pre-application and application phases of this permit process.
TerraPower was the first developer to submit a construction permit application for a commercial advanced reactor to the NRC in March 2024, it was docketed by the NRC in May 2024.
The company said that Natrium technology is the first mover in the advanced reactor sector and is well-positioned to support rapidly increasing energy demand.
The Natrium plant design features a 345 MW sodium-cooled fast reactor with a patented molten salt-based energy storage system. The storage technology can boost the system's output to 500 MW of power when needed, as it is designed to keep base output steady, ensuring constant reliability and can quickly ramp up when demand peaks — it is the only advanced reactor design with this feature, according to the company.
The first Natrium plant is being developed through the U.S. Department of Energy's Advanced Reactor Demonstration Program (ARDP), a public-private partnership. The project is expected to be completed in 2030 and will be the first utility-scale advanced nuclear power plant in the United States.
For details, visit terrapower.com.
