Rolls-Royce SMR has completed Step Two of the Generic Design Assessment carried out jointly by the Office for Nuclear Regulation, the Environment Agency and Natural Resources Wales — confirming its position as the small modular reactor design furthest through regulatory assessment anywhere in Europe. The three-step GDA process examines the safety, security and environmental case for a reactor design before it can be built in Great Britain, and Step Three is expected to conclude by the end of 2026.
The regulatory progress has run alongside real construction commitment. In April, Rolls-Royce SMR and Great British Energy – Nuclear signed a contract enabling site-specific design work to begin at Wylfa on Anglesey, the site confirmed in late 2025 to host the UK's first three SMR units. The agreement allows Rolls-Royce SMR to start ordering critical components from its supply chain ahead of a future final investment decision, backed by a National Wealth Fund loan facility of up to £599 million. The programme is expected to create around 3,000 jobs local to the Wylfa site and a further 5,000 nationally.
The most recent development extends Rolls-Royce's nuclear ambitions beyond the SMR programme itself. In mid-June, Rolls-Royce signed cooperation agreements with the UK National Nuclear Laboratory and the Japan Atomic Energy Agency to jointly develop Advanced Modular Reactor technology and associated coated particle fuel — a different reactor class to the pressurised water SMR design already in GDA, aimed at higher-temperature applications. It signals an intent to build a broader UK nuclear portfolio rather than a single product line.
For the mechanical design and fabrication supply chain, the practical significance is the factory-built, modular delivery model at the centre of the SMR proposition. Standardised, repeatable components built under controlled factory conditions rather than assembled on a single bespoke site is a fundamentally different sourcing pattern to traditional large-scale nuclear new build, and one that rewards suppliers who can demonstrate consistent quality systems, NORSOK/ASME-aligned documentation, and nuclear-grade traceability across repeat production runs rather than one-off projects.