Name of the Project
Kemmerer Unit 1 natrium plant.

Location
Near Kemmerer, Wyoming, in the US, in proximity to the site of a retiring coal-fired power plant. 

Project Owner/s
The project is being developed by TerraPower through the US Department of Energy’s Advanced Reactor Demonstration Program, a public–private partnership. 

Project Description
Kemmerer will be TerraPower’s first natrium plant and the first utility-scale advanced nuclear power plant in the US. 

The plant will feature a 345 MW sodium-cooled fast reactor integrated with a molten-salt-based energy storage system. The storage system will be able to increase output to 500 MW when needed, equivalent to the power required for about 400 000 homes. 

The natrium technology is designed to provide reliable and dispatchable electricity while supporting grids with high levels of renewable energy. 

The plant design separates the energy island from the nuclear island, allowing for significant non-nuclear plant operations, such as steam turbines and salt tanks, to be located outside the nuclear control area. 

Potential Job Creation
The project is expected to require about 1 600 workers during peak construction and employ about 250 full-time staff once operational. 

Capital Expenditure
Not stated. 

Planned Start/End Date
TerraPower broke ground on the greenfield site in June 2024. The US Nuclear Regulatory Commission approved the construction permit for Kemmerer Unit 1 in March 2026, and TerraPower announced the official start of plant construction on April 23, 2026. 

The project is expected to be completed in 2030. 

Latest Developments
TerraPower announced 12 supplier contract awards on August 31, 2026, to support the construction of Kemmerer Unit 1 and the completion of the first-of-a-kind sodium test and fill facility being built at the Wyoming site. TerraPower has said the awards form part of its effort to establish the qualified supply chain required for the first Natrium plant.

Key Contracts, Suppliers and Consultants
Bechtel (engineering, procurement and construction contractor for the Natrium advanced reactor project); Merrick & Company (pin removal cell design and sodium cover-gas monitoring skids design); Mirion Technologies Inc (plant cyber system); BWXT Canada Ltd (control-rod drives design); Teledyne Brown Engineering Inc (sodium cover-gas tag-gas analysis cabinet); Marmen Inc (fuel-transfer lift design for manufacturing); Thermal Engineering International (USA) Inc (air-sodium heat exchanger); Jensen Hughes (drain and expansion tanks design); Boston Government Services, LLC (sodium cover-gas control skids design); James Fisher Technologies LLC (ex-vessel storage tank design); KROHNE Nuclear (intermediate heat-transfer flowmeters); and Valserve (intermediate heat-transfer drain valves).

Contact Details for Project Information
TerraPower, tel +1 425 324 2888 or email press@terrapower.com.