Report

Up and atom: Unlocking SMRs and large nuclear

This report from UK think tank Onward argues that Britain faces a firm-power crunch.

Up and Atom argues that Britain faces a firm-power crunch: firm generation capacity has fallen by about 24 GW over twenty years, four of the five remaining nuclear stations (the AGRs) are due to close by 2030, and much of the gas fleet is over twenty years old. Nuclear can supply clean, reliable power at scale, but UK and Western projects have become far slower and costlier.

Hinkley Point C is expected to take around twelve years at roughly three times Sizewell B’s cost per kW. The report traces this to two problems. The first is scale: atrophied supply chains after a 23-year build hiatus, no standardised repeated designs (worsened by around 7,000 UK-specific changes to the EPR), and no organisation retaining lessons between projects. The second is incentives: poor risk allocation (Sizewell C leaves taxpayers and billpayers with most of the financial risk but little delivery control), weak cost-control incentives, lost competitive tension (including picking only Rolls-Royce SMR rather than two vendors), and the regulatory risk aversion identified by the Fingleton Review.

It holds up Sizewell B, Heysham B and Torness as proof that a publicly owned utility with an empowered, well-incentivised project leader can deliver on time and budget.

The report backs SMRs as a bet that “economies of volume” can offset lost economies of scale, while stressing that this is unproven and that large reactors shouldn’t be abandoned. Its target is “nth of a kind” reactors at £7,500/kW or less, within about ±10% on cost and schedule.

It proposes three parallel pathways and five recommendations:

Keep Wylfa viable for eight reactors, not just the initial three.

Build a fleet of fifteen Rolls-Royce SMRs owned and delivered by GBE-N. This comes with strong accountability measures, including a named project leader, a completion-based £100m bonus pool, pay flexibility, no rushing to FID, performance-conditional expansion, and Critical National Importance designation.

Open a competitive private route for SMRs and advanced reactors, using state-acquired legacy nuclear sites and CfD allocation.

Run a Barakah-style vendor competition for future gigawatt-scale plants, weighing EPR/EPR2, AP1000, APR1400 or even a repeat of Sizewell B.

Give the ONR proper core funding so it can scale ahead of demand.

The report concludes that with Fingleton implemented in full and a new generation of empowered, well-rewarded project leaders, Britain can once again lead in clean, reliable nuclear power.