X-energy Submits UK Generic Design Assessment Application for Xe-100 Advanced Modular Reactor, Advancing 6 GW Centrica Partnership

Advanced nuclear reactor developer X-energy has submitted an application for the UK's Generic Design Assessment (GDA) — the country's established regulatory licensing pathway for new nuclear reactor technologies — for its Xe-100 high-temperature gas-cooled reactor. The Xe-100 is an 80-MWe (megawatt electrical) advanced modular reactor (AMR) that can be deployed in four- or twelve-unit plants and is capable of producing both electricity and high-temperature industrial heat. The GDA is administered jointly by the UK Office for Nuclear Regulation (ONR), the Environment Agency, Natural Resources Wales, and the Department for Energy Security and Net Zero (DESNZ), and is expected to conclude by the end of 2029. The GDA submission advances X-energy's Joint Development Agreement with UK energy company Centrica, signed in September 2025, which targets up to 6 GW of Xe-100 capacity across the United Kingdom. The GDA process is a prerequisite for deployment of any new reactor design in the UK: until a design has cleared the GDA, it cannot be licensed for construction at a specific site. Progressing through the GDA therefore represents the critical regulatory gating event for the entire Centrica-X-energy partnership's UK ambitions.

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