TerraPower Takes First Step Toward Regulatory Approval of the Natrium® Reactor¹ in United Kingdom

Company informs UK regulator that TerraPower intends to submit the Natrium reactor design for review and approval under the Generic Design Assessment process.

Bellevue, WA – April 16, 2025 - TerraPower, a nuclear innovation company, announced today the submittal of a letter to the United Kingdom’s Department for Energy Security and Net Zero (DESNZ) that formally establishes the company’s intention to enter the UK Generic Design Assessment (GDA) process. This is the first step in efforts to deploy the Natrium technology in an international market.

“I am incredibly excited to begin of the process of licensing the Natrium technology in the UK,” said Chris Levesque, TerraPower President and CEO. "TerraPower is committed to deploying Natrium units globally and has been in active discussions in the UK for years. There is immense interest and opportunity for the United States and United Kingdom to cooperate on deploying advanced nuclear plants over the coming decade.”

The UK’s GDA process will build on TerraPower’s successful regulatory endeavors and allow for the company to establish deployment timelines for Natrium sites in the country. TerraPower’s regulatory milestones with its first Natrium plant, currently being developed in the United States, will be used as the basis of its GDA application. These efforts include:

• robust pre-application meetings with the U.S. Nuclear Regulatory Commission (NRC),
• successful submission and acceptance of the construction permit application (CPA) to the NRC,
• over a years’ worth of review with the NRC on the company’s CPA and Topical Report Submittals, with the NRC recently announcing they are ahead of schedule on the review, and
• the successful award of a state-level construction permit from the State of Wyoming; where the first Natrium project is being built.

The Natrium technology features a 345 MWe sodium-cooled fast reactor with a molten salt-based energy storage system. The storage technology can boost the system’s output to 500 MWe for more than five and a half hours when needed. This innovative addition allows a Natrium plant to integrate seamlessly with renewable resources and leads to faster, more cost-effective decarbonization of the electric grid while producing dispatchable carbon-free energy. TerraPower broke ground on the first Natrium project in 2024.

As the UK government and energy providers strategize on how to best meet growing energy demand, innovative solutions like TerraPower’s Natrium technology with baseload power plus gigawatt-scale energy storage will be needed to achieve both a decarbonized and a reliable electric grid.

About TerraPower
TerraPower is a leading nuclear innovation company that strives to improve the world through nuclear energy and science. Since it was founded by Bill Gates and a group of like-minded visionaries, TerraPower has emerged as an incubator and developer of ideas and technologies that offer energy independence, environmental sustainability, medical advancement and other cutting-edge opportunities. It accepts and tackles some of the world’s most difficult challenges. Behind each of its innovations and programs, TerraPower actively works to bring together the strengths and experiences of the world’s public and private sectors to answer pressing global needs. Learn more at terrapower.com.

Media Contacts
press@terrapower.com

¹The Natrium reactor is a TerraPower and GE-Hitachi technology