The UK government-owned Great British Energy Nuclear (GBEN) has designated Rolls-Royce SMR as the preferred supplier for its small modular reactor (SMR) programme, marking a decisive step in our nuclear ambitions. The winning technology will receive substantial government backing, with the first units expected to come online by the mid-2030s. This announcement coincides with the Treasury committing over £14 billion to support the construction of Sizewell C, which will feature two French EPR reactors, underscoring the government’s dual-track approach to nuclear expansion.
The two-year tender process saw Rolls-Royce’s 470 MWe pressurised water reactor compete against GE-Hitachi’s BWRX-300 and Holtec’s SMR-160 design. Industry sources confirm the selection criteria prioritised deployability and compatibility with Britain’s existing nuclear infrastructure. GBEN, formerly Great British Nuclear, will now spearhead site development, having already secured two key locations – Oldbury and Wylfa – former Magnox sites purchased from Hitachi for £160 million in 2024 after previous development attempts collapsed.
Jeremy Stain, head of nuclear energy at engineering firm Arup, explained that GBEN’s immediate priorities include finalising technology specifications, expanding the site portfolio, and assembling specialist teams. He emphasised that while the financing model remains under development, the government has earmarked £2.5 billion over four years to de-risk early-stage projects. This approach aims to attract institutional investors by guaranteeing returns during construction rather than postponing profitability until operational commencement.
The financial architecture deliberately targets pension funds and long-term investors, with Stain noting that billions in private capital will be required despite substantial government underwriting. Industry analysts highlight this as a necessary intervention, given the £20-30 billion estimated cost for a full SMR fleet. The Czech energy group ČEZ’s acquisition of a 20% stake in Rolls-Royce SMR in 2025 demonstrates growing international confidence in the technology, alongside major shareholders including Qatar’s sovereign wealth fund and US energy giant Constellation.
Critics question whether the mid-2030s timeline is achievable, pointing to regulatory hurdles and supply chain constraints. However, with energy security concerns outweighing fiscal caution, the government appears determined to position Britain as a leader in next-generation nuclear technology, even as it maintains reliance on traditional large-scale projects like Sizewell C. The coming years will test whether this twin-track approach can deliver on its promise of affordable, low-carbon baseload power.
