Nuclear is seen as key to meeting the UK’s rising demand for clean power. Small modular reactors (SMRs) are an alternative to lengthy, expensive mega-projects. But the technology is still in development and political issues remain, argues Sanjoy Sen.
Big news for Anglesey: nuclear is back. Great British Energy-Nuclear has just committed to deliver three Rolls-Royce small modular reactors (SMRs) at the former Wylfa Magnox site. Don’t be misled by the ‘small’. If things come to fruition, this will be a major development for Wales.
Each SMR is designed to generate a constant 470 mega-watts, 24/7. The initial three are sufficient to power 3m households in Wales and there could be up to eight at Wylfa (by comparison, the Gwynt y Môr offshore windfarm nearby generates 576 mega-watts – on a breezy day). This will potentially create 3,000 jobs in a region hit by industrial closures (including the original Wylfa reactor and the nearby aluminium smelter) and it paves the way for advanced manufacturing and AI in North Wales.
SMRs are intended as a quicker, cheaper route to the nuclear power that Westminster considers essential to meeting Britain’s rising demand for low carbon electricity. And they could be particularly well-suited to Wales’s domestic and industrial needs. But the technology isn’t ready yet and political issues remain.
Nuclear: back on the agenda
De-industrialisation has seen UK electricity consumption decline since the 1970s. But new factors are reversing the trend and Wales’s demand could double by 2050. A quarter of new car registrations are now electric. And although only 1% of homes currently have a heat pump, if installation costs fall, these could start to displace gas boilers and ramp up power demand. Heat pumps could play a key role in decarbonising Wales’s housing stock as much of the country is off the gas grid, leaving many properties dependent upon fuel oil.
De-industrialisation has seen UK electricity consumption decline since the 1970s. But new factors are reversing the trend and Wales’s demand could double by 2050.
Although Wales remains a net exporter of electricity, overall UK generation capacity isn’t keeping up. Coal usage ended in 2024 and wind is now the UK’s number one power source. And as UK North Sea production falls (hampered by heavy taxation and the drilling ban), gas-fired power stations are becoming increasingly import-dependent – not just on the still-buoyant Norwegian sector but also on liquefied fracked gas shipped into Milford Haven from North America. To meet the growing deficit, 16% of UK electricity requirements are now sourced from Europe via subsea interconnector cables.
Post-Chernobyl, nuclear fell out of favour. But a generation later, a Westminster consensus has emerged that despite exponential growth in renewables, nuclear is once again essential to deliver national energy security. With no new reactors built since 1995, the Conservative-Liberal Democrat coalition signed off on the giant 3.2 giga-watt Hinkley Point C. Post Ukraine, the Johnson administration raised ambitions to 24 giga-watts by 2050. And Starmer recently committed to a Hinkley copy, Sizewell C.
Syniadau uchelgeisiol, awdurdodol a mentrus.
Ymunwch â ni i gyfrannu at wneud Cymru gwell.
SMRs – what and why?
Big nuclear projects bring big challenges. Hinkley is years late and way over budget. And hosting Europe’s largest construction site has brought challenges to rural Somerset. Sizewell opponents are mobilising in Suffolk.
As an alternative, the SMR concept builds the key elements of a nuclear power station quickly and efficiently in a controlled factory environment. These are then transported to site for relatively painless installation. Rolls-Royce aim to leverage the efficiencies of churning out multiple identical units on a production line whilst generating major export potential. SMRs are designed to be inherently safe to avoid the danger of meltdown.
SMRs could also make nuclear easier to finance. In the Hinkley Contracts for Difference (CFD) model, investors are currently taking the pain of soaring up-front capital costs and will look to offset these via a premium strike price for the power. Sizewell C will instead use a Regulated Asset Base (RAB) model where the taxpayer takes a share of investment risk. Either way, big nuclear is a long, expensive game that only governments and big business can play. By contrast, cheaper SMRs could allow a wider range of investors: Europe’s first privately-financed nuclear power might soon be coming to Teesside.
What are the challenges?
For starters, Rolls Royce need to get their technology ready. SMRs are still relatively unproven – there is a steep learning curve to be climbed. Whilst the first of a kind (FOAK) of anything is expensive, the nth of a kind (NOAK) is potentially much cheaper once design and manufacturing bugs are ironed out. But we have to build several to get to ‘n’: no getting cold feet when the first one over-runs.
Although Wales remains a net exporter of electricity, overall UK generation capacity isn’t keeping up. Coal usage ended in 2024 and wind is now the UK’s number one power source.
It could be a crowded market: Russia and China have rolled out their first SMRs and over a hundred designs now exist worldwide. Nuclear exports also bring political leverage and the Americans see major potential. Following the ‘golden age’ deal signed during the Trump visit, X-Energy (with Centrica) plan up to 12 SMRs for Hartlepool. Meanwhile, Holtec intend to power data centres at a former coal-fired power station in Nottinghamshire. US ambassador Warren Stephens was highly critical of Wylfa SMR, citing Westinghouse’s interest in bringing large-scale nuclear back to the site.
But it’s domestic politics that might yet complicate things.
Whilst Plaid Cymru have historically opposed nuclear, leader (and Ynys Môn Senedd Member) Rhun ap Iorwerth now backs development on former sites, Trawsfynydd and Wylfa. This new flexibility might get tested further if other locations become contenders. With Port Talbot switching its steelmaking to electric arc furnaces, on-site SMRs are already being touted. And micro-modular power is proposed at the former coal-fired Llynfi site in Bridgend. A future Plaid administration could find itself in disagreement with Westminster’s nuclear ambitions and seek devolved powers over large-scale power generation. As a parallel, the SNP has used its planning powers to block Scottish nuclear developments including the SMR at the Grangemouth oil refinery.
Gofod i drafod, dadlau, ac ymchwilio.
Cefnogwch brif felin drafod annibynnol Cymru.
Labour, meanwhile, have had a mixed relationship with nuclear from Blair (“back on the agenda with a vengeance”) to Corbyn’s opposition to Starmer’s recent commitments. The fate of SMRs yet might sit with Ed Miliband, whose future is far from certain with even trade unions opposing his Net Zero ambitions. Andy Burnham has also previously backed nuclear but will have internal factions to appease and economic priorities to balance should he make it to Number 10.
Wylfa is the result of a competition that kicked off almost a decade ago under the Cameron administration. It’s taken a long time to get here and there’s much left to do to unlock the potential of SMRs.
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