Amentum-Led Joint Venture Secures $406 Million Contract as Owner’s Engineer for UK’s First Small Modular Reactors
CHANTILLY, VA., April 1, 2026 — Great British Energy – Nuclear (GBE-N) has selected a joint venture between Amentum (NYSE: AMTM) and Cavendish Nuclear as Owner’s Engineer for its flagship small modular reactor (SMR) project in the UK.
The contract, which has a maximum value of $406 million (£300 million) and a duration of up to 14 years, covers work to deploy GBE-N’s preferred reactor technology from Rolls-Royce SMR at the Wylfa site in North Wales.
The ‘Litmus Nuclear’ joint venture, led by Amentum, will provide essential independent assurance and expert technical advice including design, safety, engineering, construction and commissioning to support GBE-N’s goal of reaching a final investment decision for the SMR program at Wylfa.
“This award recognizes Amentum’s expertise in accelerating the global expansion and revitalization of nuclear energy and also underlines our central role in the UK’s nuclear ambitions, alongside our work at Hinkley Point C and Sizewell C,” said Loren Jones, senior vice president and head of Amentum’s Energy & Environment-International business. “We will draw upon our deep technical nuclear knowledge to provide independent technical and delivery assurance so that GBE-N can progress the SMR program and make a vital contribution to strengthening energy security and the UK’s industrial base.”
The joint venture partners will ensure that the SMR program is robust, meets regulatory requirements and can deliver reliable, low-carbon power for decades to come.
Simon Roddy, Chief Executive of GBE-N added: “As we continue to bring together the coalition required to deliver the UK’s first SMRs, I’m pleased to welcome Amentum and Cavendish to the team. Their valuable expertise will be instrumental in assuring GBE-N’s project moves with pace and determination, and I look forward to working with them over the coming years.”
In November 2025, the UK’s Department for Energy Security and Net Zero announced that Wylfa, on the island of Anglesey/Ynys Môn had been selected as the site for the UK’s first SMRs, a planned fleet of 470MWe reactors which are smaller and designed to be built more quickly than some traditional nuclear power stations.
About Amentum
Amentum is a global leader in advanced engineering and innovative technology solutions, trusted by the United States and its allies to address their most significant and complex challenges in science, security and sustainability.
About Amentum in the United Kingdom
With more than 6,000 people in the UK, Amentum is the delivery partner for project and construction management services at Hinkley Point C; sole program and project management delivery partner at Sizewell C; and also supports the UK’s existing nuclear power stations under a Lifetime Enterprise Agreement with EDF. It is a major supplier of engineering design, safety case and project management at Sellafield and other UK nuclear decommissioning sites and operates the country’s largest private sector complex of nuclear laboratories and engineering test facilities in Warrington.
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