Rolls-Royce signs strategic collaboration partnership with Assystem, AtkinsRéalis and Frazer-Nash to support its nuclear growth ambitions
December 5, 2025. Rolls-Royce Submarines has signed an innovative contract with industry experts Assystem, AtkinsRéalis and Frazer-Nash to boost collaboration and gain benefit from the unique nuclear capabilities of each company.
The new Capability Assured Strategic Partnership (CASP) backs UK based businesses and represents a step forward in bringing together nuclear capability to better support the UK Royal Navy’s submarines programme and the wider Defence Nuclear Enterprise.
With a value of up to £400m, this strategic alliance represents one of the largest single supply chain contracts in the history of Rolls-Royce Submarines. Having worked with all three partners for over 20 years, they are uniquely placed to support its future growth ambitions in advanced nuclear technologies.
It represents a long-term commitment from the partners to deliver the collective engineering capabilities, nuclear expertise, and other professional services that Rolls-Royce can utilise to meet growing demand from the Ministry of Defence, and beyond.
In March 2023, it was confirmed that Rolls-Royce Submarines would provide all the nuclear reactor plants that will power new attack submarines as part of the tri-lateral agreement between Australia, the UK and US.
This increase in demand from the Ministry of Defence and the AUKUS agreement means Rolls-Royce plans to double the footprint of its Raynesway site in Derby to support both UK and Australian defence programs. Delivering the Defence Industrial Strategy, the build of new manufacturing and office facilities will create more than 1,000 skilled roles across a range of disciplines, including manufacturing and engineering, plus hundreds more across the supply chain.
Rolls-Royce has powered the UK Royal Navy’s nuclear submarines for over 65 years and is the only private company in the world with the nuclear capability to manage reactor design, manufacture and decommissioning within one single entity.
Chris Walker, Supply Chain Director at Rolls-Royce Submarines said: “We are in a nuclear renaissance across the UK and demand for this expert capability is growing all the time. 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.
“We recognise that if we want to grow our business and maintain our critical commitments to the Ministry of Defence, then we cannot do it alone. 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.”
Keith Beckett, Deputy CEO and AUKUS Director for the Submarine Delivery Agency, the Defence Nuclear Enterprise’s delivery agent for submarines, said: “This partnership exemplifies the Defence Industrial Strategy in action. By uniting leading UK nuclear expertise through CASP, we’re strengthening our industrial base to deliver the submarine capabilities our nation requires.
“The Submarine Delivery Agency welcomes this investment in nuclear skills and collaboration with UK businesses that will enable us to deliver available and capable submarines to the Royal Navy and meet our commitment to our AUKUS partners.”
Chris Conboy, AtkinsRéalis Managing Director – Nuclear EMEA, said: “The UK is investing significantly in its defence capabilities, and nuclear remains at the heart of national security. Through the Capability Assured Strategic Partnership, Rolls-Royce Submarines can draw on deep, multi-disciplinary expertise, including AtkinsRéalis’ end-to-end experience in complex nuclear programmes.
“This partnership builds on our longstanding relationship with Rolls-Royce Submarines, enabling the successful delivery and safe operation of future submarine propulsion capability to the UK and our allies.”
Simon Barber, Assystem UK Managing Director said: “Assystem is proud to strengthen our trusted partnership with Rolls-Royce Submarines through the CASP framework. As a partner to Rolls-Royce for several decades, Assystem, alongside its strategic partners, is providing real value for the successful delivery of their industry commitments and ambitious growth plans.
“The CASP framework will play a key role in the delivery of the UK’s Defence Industrial Strategy for which Assystem is fully supportive.
“As a global nuclear player with 60 years’ experience, Assystem will bring its full life-cycle expertise and capability in engineering, project management, and innovative digital solutions to support the long-term success of the CASP framework.”
Sarah Wilkes, Frazer-Nash Managing Director said: “At Frazer-Nash we talk about solving challenges that matter and there aren’t many more important than national security.
“CASP is an exciting development which will see us working closer and better with RRSL and our partners at AtkinsRealis and Assystem, combining our expertise and specialisms in new ways to help keep the UK safe”.
Rolls-Royce Submarines currently employs more than 5,000 people and designs, manufactures and provides in-service support to the pressurised water reactors that power every boat in the Royal Navy’s submarine fleet.
Rolls-Royce is currently supporting the existing Astute and Dreadnought boat build programmes through the delivery of reactor plant and associated components.
It also provides frontline support across the world for reactor plant equipment from its Operations Centre in Derby and supports the submarines when in the Barrow-in-Furness shipyard and the naval bases at Devonport and Faslane. In addition, there are technical specialists working in offices in Glasgow, Cardiff, and Thurso, Scotland.
