Op-Ed on Small Modular Reactors in Britain

Steve Thomas, Emeritus Professor of Energy Policy at the University of Greenwich provided an excellent opinion column on the SMR programme on the Business Green website. Steve has been a researcher in the area of energy policy for over twenty-five years. He specialises in the economics and policy of nuclear power. What are your views?

 

The UK SMR programme

1.   Introduction

Small Modular Reactors (SMRs) are claimed to be cheaper and easier to build, safer, generate less waste and will create many jobs compared to existing large reactor designs. If the UK pursues this technology, it will regain its position as a world leader in civil nuclear technology. These claims are unproven, misleading, or just plain wrong. Worldwide, no commercial design of SMR has even received a firm order yet.

2.   What are SMRs?

SMRs are defined as producing 30-300MW of power compared to the 1200+MW produced by large reactor designs. The SMRs under development are at least 75MW, most are around 300MW and the largest, the Rolls Royce SMR, nearly 500MW. This would make the Rolls Royce SMR larger than all the UK’s Magnox reactors except Wylfa and about the same size as the UK’s AGRs.

SMRs encompass a range of technologies but the ones closest to being available are those based on the dominant reactor types, Pressurised Water and Boiling Water Reactors. There is also interest in High Temperature Gas-Cooled Reactors (HTGR), because of the hope they might be able to operate at a high enough temperature, 900+C, to allow production of hydrogen using an efficient catalytic process. In March 2023, the UK government opened a competition for £60m specifically for HTGRs, but if this programme bears fruit, deployment will be two decades away.[1]

3.   What are the claims for SMRs?

The claims on cost are based on modular construction with parts produced in factories on production lines and delivered as modules with only assembly needed on-site. This is claimed to reduce costs because production lines are cheaper than one-off fabrication of parts, and time and quality control is easier in factories than on-site.

In the past, reactor vendors have scaled up reactors when the economics of existing designs appeared poor. This scaling up failed to make large reactors economic. But while it is clear there were scale economies, these were counterbalanced by cost-increasing factors such as increased safety requirements. Unless scaling down is accompanied by a significant reduction in the safety features required, logically, it will increase costs.

The claims on production lines, meant to suggest assembly plants with cars moving down a line, are misleading. Rolls Royce expects its production lines to produce only 2-4 reactors per year. Components would be produced by specialist suppliers, e.g., pump manufacturers and shipped to a central location where modules would be assembled for shipping to the site. A problem with production lines is inflexibility. If they cannot be kept fully loaded the savings will be lost.

The claims on modularity are meant to suggest an ‘IKEA flat pack’ with only bolting the modules together needed at the site. This is also misleading. The reactors would still need substantial site-work such as foundations and cooling systems. The difference between SMRs and traditional reactors is only one of the extent of site-works, it is not a radically different method of construction. The large Westinghouse AP1000 reactor design (1170MW) is modular and factory produced, but this has not prevented all eight orders for this design going way over cost and budget.

The claims on safety are based on features such as passive safety (not requiring engineered systems to control the reactor in an accident), integral design (all major systems housed in the reactor vessel), and siting below surface in a pool of water. Not all reactors have these features, the Rolls Royce design has none. These features have apparent attractions, but they have not been assessed in depth by credible safety regulators much less proven in operation.

The claims on waste volumes for PWRs and BWRs appear inaccurate. Researchers led by Alison MacFarlane, a former Commissioner at the US Nuclear Regulatory Commission, calculated that the waste from SMRs would be between 2-30 times as much as for the equivalent capacity of large reactors.[2]

4.   The UK SMR programme

The UK’s pursuit of SMRs dates back to 2014 and has been characterised by false starts: budgets not spent,[3] roadmaps not produced,[4] and reactor designs receiving public money not pursued.[5]

In 2017, Rolls Royce announced its SMR, which is still the only credible UK-based SMR design. Rolls Royce’s status as a ‘national champion’ meant it was seen as the front-runner for deployment. In 2019, the government awarded Rolls Royce £18m,[6] and in 2020, a further £210m to be matched by £250m of private sector funding to allow the design sufficiently to be developed sufficiently to get it through a comprehensive safety review,[7] the Generic Design Assessment. This started in March 2022 and is expected to take at least four years.

The Rolls Royce design appears to be ‘old school’, a fact that it tries to make a virtue of. It claims there is no need for a prototype (or demonstration) plant. “We do not need a prototype. This is a standard pressurised water reactor” and “no innovation in the nuclear technology part.”[8] Given its large size, logically, the expensive safety features required for large reactors such as a core-catcher or equivalent, would also be required for the Rolls Royce SMR.

Since 2020, there has been no further public funding for Rolls Royce. With the expensive stages of development remaining, the government must commit money soon if the project is not to collapse. Current funds will run out at the end of 2024,. Rolls Royce cannot justify to its shareholders the cost of developing the design to commercial status, perhaps in excess of £1bn, and equipping factories to produce the components based on a hope that it would win orders with the design. It can only proceed with financial support from the British public. Rolls Royce made the scale of backing needed clear in evidence to a UK Parliamentary Committee in 2017. Among the nine guarantees it required, the most extraordinary was a government guarantee of 7GW (16 reactors) of orders, on Rolls Royce’s optimistic cost estimate, £30bn.[9]

In March 2023, the government announced a contest, to be carried out by Great British Nuclear (GBN) to identify designs that would be given public funds for development to provide ‘a programme of new nuclear projects beyond Sizewell C’.[10] The objective would be to reach a Final Investment Decision for one or more designs by 2029,[11] implying that the first capacity might only come online in the mid-2030s, by which time the electricity generation sector should already be decarbonised.

In October 2023, GBN identified six designs including the Rolls Royce SMR that would be supported. This represents all the credible PWR and BWR designs worldwide, but it is not clear what the extent of the financial support would be and Rolls Royce’s position as the likely choice appears in doubt.

5.   Conclusions

It is extraordinary that the government is gambling on SMRs providing a significant element in its decarbonisation strategy despite it being a set of technologies that has not won a commercial order worldwide, much less having its costs and reliability being proven. At best, SMRs will only be commercially available after the last fossil-fired generation has been phased out in the UK. Claims on job-creation and making the UK a world leader in nuclear technology are fanciful.

As with previous ambitious UK nuclear targets, the 2022 Johnson target of 24GW of new nuclear capacity by 2050 including a substantial number of SMRs will not be met. The problem is the time and opportunity cost of pursuing the nuclear option, at the expense of cheaper, quicker to deploy and less prone to delay and failure options such as renewables and energy efficiency programmes.

 

[1] https://www.gov.uk/government/publications/advanced-modular-reactor-amr-research-development-and-demonstration-programme-phase-b-competition

[2] https://www.pnas.org/doi/10.1073/pnas.2111833119

[3] In 2015, the government announced a budget of £250m to be spent by 2020 to assist development of SMR designs https://www.theguardian.com/environment/2015/nov/24/mini-nuclear-reactors-answer-to-climate-change-crisis

[4] In 2016, it announced it would produce a roadmap for the deployment of SMRs

[5] The U-Battery HTGR and the Westinghouse LFR received public funds in 2021 but they appear to no longer be considered

[6] https://www.rolls-royce.com/media/press-releases/2019/23-07-2019-commitment-to-initial-funding-for-smr-welcomed-by-consortium.aspx

[7] https://www.rolls-royce.com/media/press-releases/2021/08-11-2021-rr-announces-funding-secured-for-small-modular-reactors.aspx

[8] https://committees.parliament.uk/oralevidence/10083/html/

[9] https://www.parliament.uk/business/committees/committees-a-z/lords-select/science-and-technology-committee/news-parliament-2015/nuclear-research-technology-report-published/

and https://www.laka.org/docu/boeken/pdf/6-01-3-60-08.pdf#page=2

[10] https://www.find-tender.service.gov.uk/Notice/020640-2023

[11] https://namrc.co.uk/industry/great-british-nuclear-july23/