The new project will be delivered through Great British Energy’s nuclear arm (GBE-N), in partnership with Rolls-Royce SMR, and will form the cornerstone of the UK government’s £2.5bn SMR programme. Subject to final contracts, construction is expected to begin in 2026, with the first reactors generating power by the mid-2030s.

Initially, three reactors will be built at the former Wylfa nuclear power station site, which closed in 2015. The Rolls-Royce SMR’s are designed to provide 470 MW of power per unit, roughly one-third the size of a large-scale nuclear plant. However, GBE-N has confirmed the location could ultimately host up to eight SMRs.

UK Prime Minister Sir Keir Starmer described the announcement as a turning point for the nation’s industrial and energy strategy. ‘Britain was once a world leader in nuclear power, but years of neglect and inertia meant places like Anglesey were left behind,’ he said. ‘Today, that changes. We’re cutting red tape, changing planning laws and backing growth to deliver the country’s first SMR in North Wales.’

Chancellor of the Exchequer Rachel Reeves called it ‘a nuclear revival [that] will fire up the Welsh economy, marking the start of a new era in British innovation and energy security’. She added: ‘Wylfa will revitalise local communities, attract major investment and open up exciting opportunities for young people – creating world-class training and apprenticeships in North Wales for the next generation of engineers, technicians and innovators.’

The three Rolls-Royce SMRs could provide clean electricity for around three million homes, contributing to Britain’s wider goal of achieving net zero by 2050, according to the government. The project forms part of its broader modern industrial strategy, with nuclear positioned as a key pillar of the UK’s clean energy mix alongside renewables. The government’s recent Spending Review confirmed multi-billion-pound backing for both SMRs and large-scale reactors such as Hinkley Point C, which is currently under construction in Somerset and expected to power six million homes.

For the nuclear industry, Wylfa’s revival represents the start of a new phase of development. Simon Bowen, Chair of GBE-N, called the decision ‘historic’. ‘These first SMRs at Wylfa will lay the groundwork for a fleet-based approach to nuclear development, strengthening the UK’s energy independence and bringing long-term investment to the local economy,’ he said.

Chris Cholerton, Chief Executive of Rolls-Royce SMR, said the announcement marked ‘the first step in a 100-year commitment to clean energy, innovation and community partnership’. He also noted that by ‘delivering nuclear power very differently’ by utilising modularisation and a high level of factory build, it would be possible to minimise the impact of infrastructure delivery on local communities while also creating jobs and growth. (A video about how that might work was recently published by the company; see below).

Earlier this year the UK government announced a shake-up of planning rules to allow new nuclear projects, including SMRs, to be built in a range of sites across England and Wales.

Alongside the Wylfa announcement, the government has tasked GBE-N with identifying further sites for new nuclear plants across the UK (including Scotland), including potential large-scale gigawatt reactors similar to Sizewell C that is being built on the Suffolk coast. Like its 1,650 MW sister facility Hinkley Point C, Sizewell C will provide clean power to six million homes. Recommendations are expected by autumn 2026. The former Oldbury nuclear site in Gloucestershire, which missed out on being selected as the location for the UK’s first SMR, is expected to be considered.

International and domestic dissent

While the Wylfa news was widely welcomed by the UK energy sector, it also sparked a complaint from the US, with whom the UK government has been working closely on nuclear.  

In a rare public rebuke, US Ambassador to the UK Warren Stephens criticised the decision to back SMRs at Wylfa rather than a large-scale reactor proposal reportedly put forward by US firm Westinghouse. Posting on X, Stephens said: ‘We are extremely disappointed by this decision, not least because there are cheaper, faster and already-approved options to provide clean, safe energy at this same location.’ He added that if the UK wanted to address energy costs and availability quickly, ‘there is a different path, and we look forward to decisions soon on large-scale nuclear projects'.

The BBC reported that Downing Street had responded by insisting that the Wylfa project ‘doesn’t close the door’ to a US manufacturer working on a future project.

Rolls-Royce SMR was announced in June as Great British Energy-Nuclear’s preferred bidder to partner with to build the UK’s first small modular reactors, subject to final government approvals and contract signature, expected later this year.

The two countries recently unveiled a major agreement between regulators making it easier to fast-track new nuclear power station developments in both countries. They also announced major commercial deals such as X-Energy and Centrica’s plans to build up to 12 advanced modular reactors in Hartlepool, UK.

Trade unions, too, expressed mixed views. While the GMB union welcomed the return of nuclear to Anglesey, National Officer Charlotte Brumpton-Childs said Wylfa ‘was ready for – and deserved – a large-scale reactor’. She continued: ‘We look forward to working with Rolls-Royce and the government to deliver trade-union-organised construction of the SMRs,’ adding that the GMB would hold ministers to account on their pledge to continue developing large gigawatt-scale reactors elsewhere.

Environmental groups also voiced concerns. The People Against Wylfa B campaign argued that the new SMR project represented ‘an unnecessarily big development of an unproven technology’, suggesting that investment in renewables like wind, wave and tidal power was what Anglesey really needed.

Advocates believe that a successful Wylfa deployment could anchor a fleet of SMRs across the UK, forming the basis of a new export industry.

The UK and Czechia have already signed a civil nuclear cooperation agreement, with ČEZ, the Czech energy company, acquiring a 20% stake in Rolls-Royce SMR. This international partnership could pave the way for SMR exports from the UK to central Europe and beyond.