Nuclear technology company TerraPower announced that it has officially started construction on Kemmerer Unit 1, anticipated by the company to be the first utility-scale advanced nuclear power plant in the U.S.

Launched in 2008 by Bill Gates, Nathan Myhrvold and John Gilleland, TerraPower is a nuclear innovation company aimed at developing technologies to provide safe, affordable and abundant carbon-free energy. Bill Gates currently serves as chair of TerraPower’s board.

The company’s “Natrium” system is designed to integrate into electricity grids with high levels of variable renewable generation, combining a 345 MW sodium fast reactor with a molten salt energy storage system capable of retaining large amounts of energy that can be used to power the grid during periods of peak demand when weather or darkness reduce renewable output. While providing a baseload output of 345 MW, each plant’s built-in storage system can boost energy delivery to up to 500 MW for more than five hours.

The first planned reactor, Kemmerer Unit 1, is located near the site of a retiring coal facility in Kemmerer, Wyoming. Earlier this year, TerraPower and Meta signed an agreement to build up to eight advanced nuclear reactors in the U.S.

The launch of construction follows the issuance of a construction permit by the U.S. Nuclear Regulatory Commission (NRC), the first-ever issued by the Commission for a commercial-scale advanced nuclear power plant.

The first Natrium plant is being developed through the U.S. Department of Energy’s Advanced Reactor Demonstration Program (ARDP), a public-private partnership. TerraPower initially broke ground on the site in 2024, and began construction on non-nuclear support facilities. The company recently said that it expects the project to be completed in 2030.

With the construction permit in place, TerraPower said that it is mobilizing a workforce of approximately 1,600 workers to begin plant construction. Once operational, the plant is expected to employ approximately 250 full-time staff.

Chris Levesque, President and CEO of TerraPower, said:

“This is the moment our industry has been working toward for a generation. We’re not just breaking new ground on a first-of-a-kind nuclear plant in Wyoming; we’re building the next generation of America’s energy infrastructure. The Natrium plant will deliver reliable and dispatchable power to the grid and Kemmerer Unit 1 serve as a commercial blueprint to mobilize a fleet of Natrium plants across the country and around the world.”