X-energy has submitted its Xe-100 advanced nuclear reactor for the UK’s Generic Design Assessment, a key licensing step that could clear the way for deployment of the technology in Britain. The filing advances a project the company is developing with Centrica for up to 6 GW of new nuclear capacity in the UK.
The Generic Design Assessment is the UK’s main pre-construction review for new nuclear designs, covering safety, security, safeguards and environmental impact before any site-specific permission is considered. X-energy said the process is expected to run through to the end of 2029, with the review led by UK regulators and supported by a framework that can use technical material already assessed in the US.
The Xe-100 is an 80 MWe high-temperature gas-cooled reactor that can be deployed in four-unit or twelve-unit plants and produce both electricity and industrial heat. X-energy and Centrica signed a joint development agreement in September 2025, with Hartlepool identified as the preferred first site for a 12-unit, 960 MWe plant.
The UK is looking for new sources of firm, low-carbon power as it retires older assets and tries to rebuild industrial capability around nuclear. X-energy says the technology could support energy security, create skilled jobs and offer a route to high-temperature process heat for industry as well as grid electricity.
The company has been in early dialogue with UK regulators since 2024, and has benefited from its US licensing work on the same reactor design. That overlap could shorten review time and reduce duplication, although the UK assessment will still require a full independent examination before the design can move forward.
