Why has Rolls-Royce Selected Amentum for SMR Delivery?

While the Rolls-Royce brand is synonymous globally with luxury automobiles, the company has been a cornerstone of the UK’s nuclear energy infrastructure since 1958. Historically the sole provider of nuclear reactors for the Royal Navy’s submarine fleet, the British engineering giant is now pivoting its expertise toward civil power generation.

Last year marked a significant turning point as the British Government contracted the company to construct a series of small modular reactors (SMRs) in North Wales. Simultaneously, Czech utility company ČEZ enlisted Rolls-Royce for a major project in the Temelín region near the Austrian border.

While the existence of these ambitious projects has been public knowledge for some time, the specifics regarding their construction delivery are now coming into focus. To ensure the successful deployment of these SMRs, Rolls-Royce has appointed US-based Amentum, a global leader in advanced engineering, to handle the planning and day-to-day execution of the programme.

Deploying across two key markets

The focal point of Rolls-Royce’s UK operations will be Wylfa on the Welsh island of Anglesey. This site will host three SMRs expected to deliver up to 1.5GW of low-carbon energy to the national grid. Beyond the energy output, the project is projected to create more than 8,000 long-term jobs, providing a significant boost to the regional economy.

Great British Energy selected the company for this initiative in July 2025, tasking them with the construction of the nation's first-ever small modular reactors.

Meanwhile, the contract in the Czech Republic was solidified in October 2024. Here, Rolls-Royce is working alongside state utility body ČEZ to deploy up to 3GW of electricity generation capacity. The relationship between the two entities was strengthened early last year when ČEZ acquired a 20% stake in Rolls-Royce’s SMR business.

Understanding the technology

The Rolls-Royce SMR utilises a 470MWe design based on a pressurised water reactor, engineered to provide baseload generation for a minimum of 60 years.

A defining feature of this programme is its modular construction method. Approximately 90% of each SMR unit will be built under controlled factory conditions, with the reactors themselves measuring roughly 16 metres by 4 metres.

This approach limits on-site activity to the assembly of pre-fabricated and pre-tested modules. Rolls-Royce states this strategy is intended to reduce project risk and shorten build schedules compared to traditional nuclear construction.

A strategic partnership

Amentum was selected as the delivery partner due to its extensive portfolio in the nuclear sector. The American contractor is currently engaged in the construction of Hinkley Point C and Sizewell C, the first major nuclear plants built in the UK in decades. Furthermore, the firm was tasked with decommissioning the Sellafield site in Cumbria and has worked on nuclear projects across Europe.

John Heller, CEO of Amentum, comments: "The Amentum Rolls-Royce SMR collaboration advances the deployment of this transformational technology, a critical enabler in strengthening energy security in the UK and continental Europe."

Loren Jones, SVP and Head of Amentum's international Energy and Environment business, highlights the economic impact.

"Amentum will support the deployment of a fleet of Rolls-Royce SMRs, contributing to our growth and our plan to create new jobs in the UK over the next four years," Loren explains.

John Heller, CEO of Amentum, comments: "The Amentum Rolls-Royce SMR collaboration advances the deployment of this transformational technology, a critical enabler in strengthening energy security in the UK and continental Europe."

Loren Jones, SVP and Head of Amentum's international Energy and Environment business, highlights the economic impact.

"Amentum will support the deployment of a fleet of Rolls-Royce SMRs, contributing to our growth and our plan to create new jobs in the UK over the next four years," Loren explains.

Executive reaction

The collaboration has been met with enthusiasm from the leadership teams of both organisations.

"By working with Amentum, an established and experienced global nuclear leader, we are combining our skills to build a powerful team that will enable successful delivery on our order commitments in multiple markets," says Chris Cholerton, CEO of Rolls-Royce SMR.

"This partnership plays directly to our strengths – ours in advanced manufacturing and engineering, and theirs in program and construction excellence," Chris adds.

This is not the first interaction between the two firms. Amentum was part of a supply chain consortium that began working with Rolls-Royce in 2016 to develop modular power station concepts. In this new delivery role, Amentum will be supported by partners Turner & Townsend, Hochtief, Mace Consult and Unipart.