The nuclear industry in Britain has reached a pivotal moment. Rolls-Royce SMR, the small modular reactor developer, has secured final regulatory approval for its planned factory site in South Wales. The decision, announced by the Welsh Government on Wednesday, clears the path for what would be the first factory-built nuclear power station in the UK.

The site, a 40-hectare plot near the former steelworks at Trostre in Llanelli, will house a dedicated manufacturing facility for the company’s 470-megawatt reactors. The approval covers detailed planning permission and environmental impact assessments. It also includes a Section 106 agreement for local infrastructure contributions.

Chris Cholerton, chief executive of Rolls-Royce SMR, called it “a watershed moment for British energy security.” He told me the company now aims to begin construction within 18 months, subject to final investment decisions. “We have the technology, the site, and the regulator’s nod,” he said. “Now we need the money.”

The facility will produce reactor components in a controlled factory environment. This is a radical departure from traditional nuclear construction, where modules are built on site. The SMR approach reduces build time to around four years, compared to a decade for conventional plants. It also cuts costs, with an estimated £2bn per unit. But critics argue the technology is unproven at scale.

“This is a world-first,” said Professor Andrew Sherry of the University of Manchester’s Dalton Nuclear Institute. “No one has yet delivered a commercial SMR factory. The UK is betting big on first-mover advantage. It could pay off handsomely, or it could become a cautionary tale.”

The approval comes as the UK government pushes to revive nuclear power as part of its net-zero strategy. The Department for Energy Security and Net Zero has committed £210m in early development funding for SMRs. A competition to select the winning technology due next year. But industry insiders say Rolls-Royce is the front-runner, given its existing regulatory clearance and site ownership.

Local reaction is mixed. The Llanelli Chamber of Commerce welcomed the jobs boost: 1,200 direct manufacturing roles and up to 4,000 in the supply chain. But environmental groups remain sceptical. “Small reactors still produce radioactive waste,” said Mari Crighton of Friends of the Earth Cymru. “And we have no long-term disposal plan. Rushing into this is reckless.”

The Welsh Government has attached conditions to the approval. These include a commitment to use local suppliers where possible and a minimum of 500 apprenticeships. “We are not just building a factory,” said Economy Minister Vaughan Gething. “We are building a skills base for the next generation.”

But the biggest challenge remains financing. Rolls-Royce SMR is seeking £2.5bn in private investment to build the first two units. The government has offered a regulated asset base model, similar to that used for the Hinkley Point C reactor. This allows investors to receive a guaranteed return. However, some analysts question whether the returns are sufficient given the technology risk.

“The cost of capital is the Achilles’ heel,” said Tom Greatrex, chief executive of the Nuclear Industry Association. “SMRs need lower financing costs to compete with renewables. The government must step in more forcefully.”

Rolls-Royce SMR hopes to have the first unit generating power by the early 2030s. For a country that has not built a new nuclear power station in nearly three decades, that would be remarkable. But the clock is ticking. The Llanelli site stands ready. The regulatory hurdles are cleared. Now it is a matter of money, and of will.