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UK: Power from SMRs 30% more expensive than large reactors

Nuclear Monitor Issue: 
Jim Green ‒ Nuclear Monitor editor

Electricity from the first small modular reactor (SMR) in Britain would be 30% more expensive than power from large reactors according to a report by the consultancy Atkins for the UK Department for Business, Energy and Industrial Strategy, because of reduced economies of scale and the costs of deploying first-of-a-kind technology.1,2

The Atkins report said there is "a great deal of uncertainty with regards to the economics" of the smaller reactors.2 The report estimates that the levelized cost of electricity for an SMR based on a pressurized water reactor design would be £86‒124/MWh with a central estimate of £101/MWh, and adds this caveat: "However it is recognised that SMR is a new technology and there is a substantial risk that these costs will be higher than this if costs accumulate during development or if financing costs are initially higher than they are for large nuclear."2

Chris Lewis from the consultancy EY said: "While the study recognises that the economics to build SMRs are challenging, measures can be taken to achieve greater cost reduction through the standardisation of technology, greater modularisation, and the ability to standardise design and repeat manufacturing."1

The Department for Business, Energy and Industrial Strategy announced on December 7 that it is making available up to £56 million over the next three years to support R&D into SMRs and to assess their feasibility and accelerate the development of promising designs.3

The government support is a small fraction of the funding required to develop SMRs. Nearly US$500 million was wasted on the mPower SMR project in the US ‒ including US$111 of government funding ‒ before the project was abandoned.4

And the £56 million on offer in the UK is a small fraction of support promised in 2015, when chancellor George Osborne said that at least £250m would be spent by 2020 on an "ambitious" programme to "position the UK as a global leader in innovative nuclear technologies".5

Industry sources told the Guardian that the government funding is a relatively small sum and they are unsure whether it will be enough to make a difference. "It's a pretty half-hearted, incredibly British, not-quite-good-enough approach," one said.4 An energy industry source questioned how credible most of the SMR developers were: "Almost none of them have got more than a back of a fag packet design drawn with a felt tip."5

Paul Dorfman, a research fellow at University College London, said: "The real question the government must ask is this: given the ongoing steep reduction in all renewable energy costs, and since SMR research and development is still very much ongoing, by the time SMRs comes to market, can they ever be cost competitive with renewable energy? The simple answer to that is a resounding no."5

Pete Roche wrote in September:6

"We now know thanks to Andy Stirling and Philip Johnstone of Sussex University that the government wants to use the civilian nuclear programme to generate expertise, and technology, for military use, especially reactors for Trident nuclear submarines. Lord Hutton gave the game away in his introduction to the SMR Consortium report when he wrote: 'A UK SMR programme would support all 10 'pillars' of the Government's Industrial Strategy and assist in sustaining the skills required for the Royal Navy's submarine programme.'

"Senior civil servants revealed that the government's decision to build a new generation of civil nuclear power stations starting with Hinkley Point is linked to maintaining enough skills to keep Britain's nuclear deterrent. The disclosure came at a hearing of the Commons Public Accounts Committee looking at the huge cost of building Hinkley Point power station which critics see as uneconomic and not properly costed.

"Stephen Lovegrove told the committee 'I was in regular discussion with Jon Thompson, former Permanent Secretary at the MOD, to say that as a nation we are going into a fairly intense period of nuclear activity … We are building the new SSBNs (nuclear armed nuclear submarines) and completing the Astutes … We are completing the build of the nuclear submarines which carry conventional weaponry. We have at some point to renew the warheads, so there is very definitely an opportunity here for the nation to grasp in terms of building up its nuclear skills.'

"With regard to Hinkley, Stirling and Johnstone say there is a 'remarkable persistence and intensity of UK Government attachments to what is increasingly recognised as an economically untenable project.' The persistence of this nuclear attachment looks to be at least partly due to a perceived need to subsidise the costs of operating and renewing the UK nuclear-propelled submarine fleet."


1. Adam Vaughan, 8 Dec 2017, 'Power from mini nuclear plants 'would cost more than from large ones'',

2. Atkins, 21 July 2016, 'SMR Techno-Economic Assessment Project 1: Comprehensive Analysis and Assessment Techno-Economic Assessment, Final Report, Volume 1, For The Department of Energy and Climate Change',

See also UK Department for Business, Energy & Industrial Strategy, 'Small Modular Reactors: Techno-Economic Assessment',

3. World Nuclear News, 7 Dec 2017, 'UK to support 'next-generation' nuclear technology',

4. Nuclear Monitor #840, 21 March 2017, 'U.S. small reactor project just got smaller',

5. Adam Vaughan, 4 Dec 2017, 'UK government to release funding for mini nuclear power stations',

6. Pete Roche, Nov 2017, 'SMRs', NuClear News, No.101,