Engineering consultancy Arup has been appointed to carry out early-stage design and engineering work for the UK’s first small modular reactor (SMR), planned for the Wylfa site on Anglesey.
Great British Energy – Nuclear (GBE-N) confirmed that Arup will provide early-phase foundation engineering and design support as the landmark project begins to take shape.
Small modular reactors are designed to accelerate the construction of new nuclear power generation. Their smaller, factory-built components are intended to simplify construction compared with traditional nuclear plants. SMRs are also expected to play a key role in supporting intermittent renewable energy sources such as wind and solar, helping to maintain electricity supply during periods of low generation, sometimes referred to as a dunkelflaute or “dark doldrums”. They could also provide direct power connections for major industrial energy users.
Plans for the Wylfa scheme were confirmed in November 2025, when GBE-N announced proposals to build three reactors at the site in Ynys Môn, Wales, using technology developed by Rolls-Royce. The project is backed by £2.5bn of UK government funding.
Earlier this year, US engineering firm Amentum was selected to lead the delivery programme. It is being supported by a team including Turner & Townsend, Hochtief, Mace Consult and Unipart.
Arup’s appointment brings together a group of specialist partners working on the early stages of the project. Landscape architects and master planners LDA Design are involved in shaping the wider site vision, while nuclear safety specialists TÜV SÜD Nuclear Technologies will provide safety expertise. Gleeds has been appointed to focus on cost engineering during the initial phases of site and infrastructure development.
Simon Roddy, chief executive of GBE-N, said delivering a safe and integrated design for the UK’s first SMR would require close collaboration between engineering and technology partners.
He said the project would rely on strong technical decision-making and innovation, adding that Arup and its partners would play a key role alongside GBE-N and Rolls-Royce SMR.
Jeremy Stain, Arup’s nuclear business lead, said the project represented the first step towards a potential fleet of small modular reactors across the UK.
He said the development aligned with national energy policy and the drive to reduce carbon emissions while strengthening energy security, with nuclear expected to remain a vital part of the future energy mix.
Stain added that Arup was pleased to bring its multidisciplinary engineering expertise and local knowledge to the landmark project.
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