Amentum-Led Consortium Wins $406 Million UK Small Modular Reactor Contract

Great British Energy – Nuclear awarded a $406 million (£300 million) contract to Litmus Nuclear, an Amentum-led joint venture, to serve as owner's engineer for the UK's first small modular reactor deployments at the Wylfa site in North Wales.

The 14-year deal brings together Amentum (NYSE: AMTM), Cavendish Nuclear, and GBE-N under the Litmus Nuclear banner, with the consortium tasked with providing independent technical assurance across design, safety, engineering, construction, and commissioning for the planned Rolls-Royce SMR deployment at Wylfa.

Loren Jones, Amentum's Senior Vice President, said the award "recognizes Amentum's expertise to accelerate the global expansion and revitalization of nuclear energy." The scope covers technical reviews, regulatory support, and construction readiness assessments, functions that directly shape schedule certainty and capital costs before a project sponsor commits to full construction.

The immediate objective is helping GBE-N reach a final investment decision. Owner's engineer services at this stage reduce execution risk by giving the project sponsor a technically independent layer of review over the reactor designer's own submissions, a role that can materially affect regulatory acceptance timelines.

Amentum's selection reflects a demonstrated track record in large UK nuclear programs. The firm has prior involvement at both Hinkley Point C and Sizewell C, giving GBE-N a contractor already familiar with Britain's nuclear regulatory environment and the procurement complexity that comes with major nuclear builds.

Wylfa is one of the UK's flagship clean-energy sites, and the Rolls-Royce SMR deployment there is being watched closely by international nuclear investors and policymakers. At $406 million, this is one of the largest owner's-engineer awards in the emerging SMR market, and it validates the project-delivery model that SMR developers have long argued for: modular reactor design paired with centralized program management and third-party technical assurance.

For the U.S. nuclear supply chain, the award is a concrete signal. Amentum's win on a major foreign SMR program demonstrates that American engineering firms can compete for, and capture, high-responsibility roles in overseas deployments, an important precedent as multiple countries race toward SMR commercialization.