Treat modular nuclear reactor costs with pinch of salt, warns academic

Estimates of small modular reactor (SMR) costs should be treated with scepticism until the first few of the mini-nuclear power plants have been built, a leading energy academic has warned.

Professor Jim Watson of University College London (UCL) sounded the warning during a House of Commons energy security and net zero committee meeting.

He said while large scale nuclear reactors, like EDF’s Hinkley C project, are not going to be delivered very quickly and will always be expensive, the true costs of building SMRs will only be realised after they starting being built.

Therefore, Watson – who is director of the UCL’s Institute for Sustainable Resources and the former head of the UK Energy Research Centre – urged estimates of their costs to be treated with a pinch of salt.

“We have to be very careful not to believe the estimates of how much they are going to cost until we have built one, or two or three,” he added.

Advocates of SMRs have argued that the cost of delivering the small reactors should be cheaper than those for larger GW-scale reactors because they can be fabricated using modular components and require less of the on-site construction and engineering that has fuelled the succession of cost over-runs plaguing Hinkley.

Professor Rob Gross, Watson’s successor as director of the UK Energy Research Centre, said that while there is “a place for nuclear”, more than “one or two” reactors per decade cannot be expected.

The government committed to increase nuclear generation to 24GW by 2050 within its Civil Nuclear Roadmap to 2050, published in January.

However, last month the Environmental Audit Committee told the government that its plan for SMRs lacks clarity and therefore risks increasing costs to the taxpayer.

The committee made the assertion within a strongly-worded letter sent to energy secretary Claire Coutinho.

It states that despite pledging £215 million to advance SMRs, government policy on the role of the technology in Great Britain’s energy mix remains unclear.

The committee is particularly concerned about the government’s timeline for SMR deployment.

It points out that as a final investment decision on the first SMR is not expected until 2029, it is unlikely that the reactor project will be contributing generating capacity to the grid in 2035.

With the government aiming to have decarbonised the grid by 2035, the cross-bench group of MPs raise concerns about the role that SMRs will therefore play.

Great British Nuclear (GBN) has subsequently delayed a decision on where the first SMRs will be built until after the next election.

A decision was originally earmarked for spring with the plan to award contracts for development by the summer.

However, in this month’s Budget announcement, it emerged the selection has now been pushed back to June at the very earliest, meaning contracts are unlikely to be awarded before a general election.