Rolls-Royce Submarines has awarded a contract worth up to £400m ($533m) to Assystem, AtkinsRéalis, and Frazer-Nash to deliver engineering expertise, nuclear capabilities, and other professional services.
Under the five-year Capability Assured Strategic Partnership (CASP), Assystem, AtkinsRéalis, and Frazer-Nash aim to consolidate their respective nuclear capabilities to support the Royal Navy’s submarines programme and Defence Nuclear Enterprise.
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Rolls-Royce Submarines said that the contract to Assystem, AtkinsRéalis, and Frazer-Nash is among the largest supply chain agreements in its history.
Rolls-Royce Submarines supply chain director Chris Walker said: “The intent behind this strategic alliance is to harness the collective capabilities of each party to successfully deliver complex nuclear programmes and explore advanced nuclear technologies.
“Our decades-long relationships with Assystem, AtkinsRéalis and Frazer-Nash see the partners ideally placed to support us, bringing unique insight across the capability landscape.”
AtkinsRéalis will provide specialist support in nuclear propulsion systems, safety assurance, systems engineering, and programme delivery. It will also deliver consulting, environmental services, asset management, cyber resilience, digital solutions, and reactor design and substantiation.
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By GlobalDataAssystem will expand its existing engineering, project management, and digital services to help Rolls-Royce Submarines transform how it works with its supply chain, enabling a more agile, capability-driven operating model and strengthening the UK’s nuclear future.
Frazer-Nash, on its part, will deliver submarine nuclear reactor design, analysis, manufacture, assurance, and in-service support to help ensure safe and efficient submarine operations.
In March 2023, authorities confirmed that Rolls-Royce Submarines would supply all nuclear reactor plants for the new Australia, the UK and the US (AUKUS) attack submarines.
The AUKUS agreement, alongside increasing the UK Ministry of Defence (MoD) requirements, has prompted Rolls-Royce to plan an expansion at its Raynesway site in Derby.
The planned development at Raynesway will double the facility’s size, thereby increasing submarine production.
Rolls-Royce is responsible for supplying reactor plants and technical support for all submarines in the Royal Navy’s fleet.
Currently, more than 5,000 employees of Rolls-Royce Submarines are engaged in designing, manufacturing and providing operational support for pressurised water reactors used by the Royal Navy.
The company supports both ongoing Astute and Dreadnought class submarine build programmes by delivering reactor plant components and related equipment.
In addition, Rolls-Royce Submarines offers direct support for reactor plant equipment internationally from its Operations Centre in Derby, and assists submarines located at the Barrow-in-Furness shipyard as well as the naval bases in Devonport and Faslane.
In October 2025, Rolls-Royce Submarines inaugurated a new office in Cardiff, bringing more than 100 job opportunities to the area.
In January 2025, Rolls-Royce Submarines won the eight-year Unity contract, worth around £9bn from the UK MoD. This contract will consolidate all aspects of research and technology, design, manufacture, and in-service support for the nuclear reactors that power the Royal Navy’s submarine fleet.
