US-based TerraPower has submitted its Natrium reactor and energy storage system to undergo the UK Generic Design Assessment (GDA) process. TerraPower formally notified UK regulators of its plans to begin the GDA review process in May, and in September, announced plans to evaluate potential UK sites for the Natrium reactor in partnership with KBR Inc.
Through the GDA, UK regulators assess the safety, security and environmental implications of new reactor designs. The three-step process is carried out by the Office for Nuclear Regulation (ONR), the Environment Agency (EA) and Natural Resources Wales (NRW). Successful completion of the process results in the issue of a Design Acceptance Confirmation from the ONR and a Statement of Design Acceptability from the EA.
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 of power when needed as it is designed to keep base output steady, ensuring constant reliability and can quickly ramp up when demand peaks. TerraPower says the decoupled design separates major structures into two independent islands – nuclear and energy, which significantly reduces the quantity of specialised materials, cutting plant costs and accelerating construction timelines.
“This submission marks a substantial step towards bringing the revolutionary Natrium reactor and energy storage system to the United Kingdom,” said Chris Levesque, TerraPower President & CEO. “TerraPower is committed to delivering Natrium units across the globe, and our industry-leading regulatory team is setting the standard on how to license and deploy advanced nuclear technologies. We look forward to working with the UK government as we work through the review process.”
TerraPower has been working through the regulatory requirements in the US, where the first Natrium plant is being constructed. This includes the recent finalisation of the Environmental Impact Statement for the Nuclear Regulatory Commission.
TerraPower broke ground on the Natrium project in 2024 at its site in Kemmerer in Wyoming and immediately began construction efforts for the non-nuclear parts of the plant. TerraPower is building its first plant through a public-private partnership with the Department of Energy’s (DOE) Advanced Reactor Demonstration Program (ARDP). This authorises a 50/50 cost share and up to $2bn for the Natrium project.
