Holtec's image of a two-unit SMR-300 plant
GBN aims to select up to three SMR technologies to support the deployment of multiple units at designated sites. Potential locations include GBN-owned land at Wylfa in Anglesey, North Wales, and Oldbury in Gloucestershire, southwest England, though other sites may be considered.
Holtec’s SMR-300, a pressurized water reactor generating approximately 300 MW of electrical power or 1050 MW of thermal power, has been in development since 2011. Recent design updates include forced flow capability combined with gravity-driven flow in the primary system. In 2023, Holtec announced plans to build two SMR-300 units at the Palisades nuclear power plant site in Michigan, USA, targeting a construction permit application in 2026 and operation by mid-2030, pending regulatory approval.
Holtec Britain stated: “The SMR-300, based on proven pressurised water reactor technology, will support the UK's long-term industrial strategy and clean energy ambitions.” It added: “The UK is also set to benefit from the experience gained through the SMR-300 deployment at Palisades, near Covert, Michigan. As a second-of-a-kind deployment - alongside India and Ukraine - the UK is well positioned to join a global coalition of countries adopting the SMR-300, enabling shared supply chains and driving long-term economic growth.”
In September 2024, Holtec selected South Yorkshire, England, as the preferred site for a proposed SMR factory to serve the UK, Europe, and the Middle East. The company plans to source at least 70% of materials, components, and services from the UK, creating significant supply chain opportunities, particularly in South Yorkshire.
Gareth Thomas, Director of Holtec Britain, stated: “The UK has the opportunity to lead the world in next-generation clean energy. Holtec Britain is ready - with proven technology and established international partners, including Hyundai Engineering & Construction Co Ltd and Mitsubishi Electric, with a clear commitment to supporting economic growth.”
GBN is on track to select the chosen technologies before summer 2025, with a final investment decision expected in 2029. The selection process includes co-funding for design completion, regulatory approvals, and site-specific permissions, with the potential for equipment supply contracts. Each selected technology will be allocated a site capable of hosting multiple SMRs, supporting the UK’s clean energy and economic growth objectives.
