TerraPower has begun construction on Kemmerer Unit 1 in Wyoming, a milestone the company describes as the first utility scale advanced nuclear power plant under construction in the United States. The Natrium design uses a sodium cooled fast reactor paired with a molten salt energy storage system, letting the plant run at a steady 345 megawatts while temporarily boosting output to 500 megawatts when the grid needs extra power.
The Nuclear Regulatory Commission issued TerraPower's construction permit earlier this year, marking the first construction permit the agency has granted for a commercial reactor that does not use ordinary water as a coolant. Regulators accelerated their review of the Natrium design as part of a broader push to speed licensing for advanced reactor technologies.
The storage system is designed to let Kemmerer Unit 1 adjust output through the day, complementing wind and solar generation on the surrounding grid while maintaining constant nuclear fuel output at the reactor core. TerraPower, chaired by Bill Gates, has said the project is intended to show that advanced reactor designs can be built on a commercial timeline and budget comparable to conventional power plants.
The Kemmerer project is one of several small modular and advanced reactor designs moving toward construction in the United States as utilities look for firm, dispatchable power to pair with growing electricity demand from manufacturing and data centers.
Source: World Nuclear News - https://www.world-nuclear-news.org/articles/terrapower-starts-construction-of-first-us-utility-scale-advanced-nuclear-plant