AtkinsRéalis Group Inc. has secured a major multi-year strategic partnership with Rolls-Royce Submarines Limited to support the United Kingdom’s expanding nuclear-powered submarine program. The framework agreement, valued at up to £400 million over five years, includes an option to extend for an additional two years.
Under the agreement, AtkinsRéalis will work alongside engineering partners Frazer-Nash and Assystem to deliver advanced nuclear propulsion, engineering expertise, and professional services to Rolls-Royce Submarines. The collaboration is designed to meet growing demand from the UK Ministry of Defence (MoD) and allied nations, reinforcing the UK’s Defence Nuclear Enterprise.
The partnership operates under the Capability Assured Strategic Partnership (CASP) model, bringing together specialist nuclear capabilities to support the Royal Navy’s submarine fleet and wider defence objectives. It also aligns with the UK Government’s renewed commitment to nuclear power as a cornerstone of national security and its role in enabling the AUKUS trilateral security agreement between the UK, Australia, and the United States.
Through this framework, AtkinsRéalis will provide specialist support in nuclear propulsion systems, safety assurance, systems engineering, and program delivery, which are critical to the design, integration, and lifecycle management of submarine reactor plants. Additional services include consulting, environmental and asset management, cyber resilience, digital solutions, and reactor design and substantiation.
Ian L. Edwards, President and CEO of AtkinsRéalis, said the partnership reflects the company’s ability to deliver highly specialised capabilities amid rising global defence investment. He noted that the collaboration supports the safe and effective operation of future submarine fleets while strengthening defence resilience.
Joe St. Julian, President of Nuclear at AtkinsRéalis, highlighted the company’s 27-year working relationship with Rolls-Royce Submarines, stating that the new agreement builds on decades of experience in nuclear lifecycle management and defence programs.
The appointment follows a January 2025 announcement naming AtkinsRéalis and Mott MacDonald as joint fissile design partners for Rolls-Royce Submarines, supporting plans to significantly expand its Derby submarine site. Together, these appointments underline AtkinsRéalis’ growing role in delivering reliable nuclear propulsion solutions for the UK’s current and next-generation submarine programs, including those supporting the Astute, Dreadnought, and AUKUS submarine fleets.

