TerraPower

TerraPower, LLC is an American advanced-nuclear reactor design and development engineering company co-founded by Bill Gates in 2008 and headquartered in Bellevue, Washington. Its flagship Natrium reactor is a 345 MW sodium-cooled fast reactor with a molten-salt energy storage system capable of boosting output to 500 MW; it began construction in April 2026 at Kemmerer, Wyoming (the first NRC non-LWR construction permit, issued March 4, 2026). DOE is funding half of the ~$4B project cost.