What Role Will Amentum Play in Rolls-Royce's SMR Contracts?

While Rolls-Royce is mainly known for making luxury vehicles, it has been one the UK's leading manufacturers of nuclear energy equipment since 1958, when it was the sole provider of nuclear reactors for the Royal Navy's submarine fleet.

Last year, the British company was contracted by the British Government to build a series of small modular reactors in North Wales, and was enlisted by Czech company ČEZ for a project in the Republic's Temelín region, near the country's southern border with Austria.

While these projects have been announced for some time, details of their construction are still only beginning to emerge.

To assist in the delivery of the SMRs, Rolls-Royce has enlisted the help of US-based firm Amentum, a global leader in advanced engineering.

Rolls-Royce has entrusted Amentum with the planning and the day-to-day execution of its SMR programme.

First deployments in two markets

Rolls-Royce's project in the UK is to be located at Wylfa, on the Welsh island of Anglesey. The three SMRs on the site are expected to deliver up to 1.5GW of low-carbon energy to the grid while creating more than 8,000 long-term jobs.

The company was selected for the project by Great British Energy in July 2025 to carry out the construction of the country's first-ever small modular reactors.

Rolls-Royce's contract in the Czech Republic was solidified in October 2024, for which it is working with state utility body ČEZ to deploy up to 3GW of electricity generation capacity.

Early last year, ČEZ acquired a 20% stake in Rolls-Royce's SMR business.

Rolls-Royce's role in nuclear energy

So, how does Rolls-Royce's nuclear energy technology work?

The British firm's SMR is a 470MWe design, based on a pressurised water reactor that will provide baseload generation for at least 60 years.

Around 90% of each SMR unit will be built in factory conditions, with the reactors measuring approximately 16 metres by 4 metres in size.

This factory-based manufacturing approach limits on-site activity mostly just the assembly of pre-fabricated and pre-tested modules.

This, Rolls-Royce says, is intended to reduce project risk and shorten build schedules compared to traditional nuclear construction.

Why has Rolls-Royce chosen Amentum to be its project partner?

Amentum enters this partnership with a great deal of experience in nuclear energy projects.

The American contractor is currently helping to construct Hinckley Point C and Sizewell C, the first major nuclear plants built in the UK for decades.

The firm was also tasked with decommissioning Cumbria's Sellafield site, which stopped producing energy in 2003.

Amentum has also worked on nuclear energy projects across Europe for years, making it a standout choice for Rolls-Royce's work in the Czech Republic too.

The reaction of the executives

Leaders from both Amentum and Rolls-Royce have been enthusiastic about the partnership since it was announced.

John Heller, CEO of Amentum says: "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, who is SVP and Head of Amentum's international Energy and Environment business is excited about both the projects themselves and the jobs they will create.

"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," he explains.

On the other side of the deal, Rolls-Royce's SMR executives are feeling energised by the collaboration.

"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," he adds.

A blossoming relationship

Importantly, this is not the first time that Rolls-Royce and Amentum will be working together.

Amentum was part of a consortium of supply chain companies that began working with Rolls-Royce in 2016 to develop concepts for modular power stations.

In its new role as Rolls-Royce's project delivery partner, Amentum will be supported by supply chain partners Turner & Townsend, Hochtief, Mace Consult and Unipart.

This relationship with Rolls-Royce only serves to cement Amentum's position as a central figure in the UK's energy transition, with the company already supporting the maintenance of the UK's nuclear facilities as part of a Lifetime Enterprise Agreement with EDF.

Ruth Todd, who is Rolls-Royce SMR's Operations & Supply Chain Director, believes the collaboration is an excellent match. 

"This partnership supplements our existing capabilities with specialist expertise, geographical reach and provides access to the breadth of Amentum's wider supply chain," she says.