On 7 September 2023 the House of Lords will debate a motion by Lord Howell of Guildford (Conservative) that “this House takes note of the role of nuclear energy in securing the future energy supply”.

1. The role of nuclear in the UK’s energy mix

In 2022, nuclear power provided 13.9% of total electricity supplied in the UK. However, as the table below illustrates, its contribution has fallen significantly since the 1990s, when it provided around a quarter of the UK’s total electricity supply. Since 1995 there have been eight nuclear plant closures, with no new plants coming online, reducing installed nuclear capacity reducing by more than a quarter. Declining nuclear capacity has been (more than) compensated for by the rise of renewable energy, whose share of electricity generation rose from 3% in 2000 to 42% in 2022.

Figure 1. Nuclear share of electricity supply

1960s 1970s 1980s 1990s 2000s 2010s 2020–22
6.6% 11.1% 17.1% 24.5% 19.1% 18.3% 14.4%

(Source: Department for Energy Security and Net Zero, ‘Historical electricity data’, updated 27 July 2023.)

As reported by the House of Commons Science, Innovation and Technology Committee, nuclear power output is due to decrease further over the coming years. The committee notes that the contribution of nuclear to the UK’s energy mix will “fall substantially by 2028, when all plants bar Sizewell B are scheduled to come to the end of their lives”. The capacity increase offered by the Hinkley Point C plant—currently under construction and due to come online later in the decade—will be outweighed by these upcoming retirements.

2. The government’s objectives for nuclear energy

2.1 British energy security strategy

In recent years the government has outlined its ambition to reverse the trend of declining nuclear power capacity, particularly in context of the requirement to achieve net zero carbon emissions by 2050. For example, “delivering new and advanced nuclear power” was one of the ten points in the government’s ‘Ten point plan for a green industrial revolution’ published in November 2020. These ambitions were then set out more explicitly in April 2022 when the government published its ‘British energy security strategy’. The strategy aimed to set out “how Great Britain will accelerate homegrown power for greater energy independence” in the wake of significant turbulence in global energy markets following the pandemic and Russia’s full-scale invasion of Ukraine.

The strategy described nuclear energy as “the only form of reliable, low carbon electricity generation which has been proven at scale” and that drawing on nuclear was the only way to secure “a big enough baseload of reliable power for our island”. The strategy set a target for nuclear energy to generate 24 GW (gigawatts) of power by 2050. The government estimated that this would be “three times more than now and [represent] up to 25% of our projected electricity demand”.

Within this overall ambition, the strategy outlined the government’s intention take at least one nuclear project to final investment decision (FID) during this parliament—stating that the government had committed £1.7bn of direct funding to help achieve this—and to take two projects to FID in the next parliament. More generally, the government summarised its ambitions as wanting to “improve our track record to deliver the equivalent of one reactor a year, rather than one a decade”.

2.2 Great British Nuclear

To help achieve the objectives outlined, the energy security strategy proposed the establishment of a ‘Great British Nuclear Vehicle’, to be tasked with “helping projects through every stage of the development process and developing a resilient pipeline of new builds”. This vehicle, ‘Great British Nuclear’ (GBN), was officially launched as an arm’s-length body on 18 July 2023.

The government states that companies will be able to register their interest with GBN to “participate in a competition to secure funding support to develop their products”. At GBN’s launch the secretary of state for energy security and net zero, Grant Shapps, claimed that “we are seeing the first brush strokes of our nuclear power renaissance to power up Britain and grow our economy for decades to come”.

2.3 Small modular reactors

One of the main forms of “new and advanced nuclear power” that the government has expressed an interest in supporting is small modular reactors (SMRs).

In November 2021 the government provided £210m of grant funding to Rolls-Royce SMR to support the development of its SMR design, with the then Business and Energy Secretary Kwasi Kwarteng claiming that SMRs “offer exciting opportunities to cut costs and build more quickly”. In April 2022 the government said it would “collaborate with other countries to accelerate work on advanced nuclear technologies” as part of its energy security strategy. £157m of further grant funding to support the development of advanced nuclear technologies, such as SMRs, accompanied the launch of GBN.

SMRs represent a new approach for civil nuclear power generation. They are smaller and produce less power than conventional nuclear reactors. They are expected to generate electric power up to 300 MW (megawatts), in comparison to the 1,000–1,400 MW generated by the current generation of nuclear reactors operating in the UK. However, the construction process for SMRs is reportedly more flexible, with the reactors able to be fabricated largely in a factory environment and transported to site, unlike existing nuclear power plants which require a large amount of on-site fabrication.

In an interview with the Financial Times, Mr Shapps said that SMRs would contribute towards meeting the targets outlined in the energy security strategy, but that he did not expect SMRs to be online and producing energy until the 2030s.

3. Debate and commentary on nuclear power expansion

On 31 July 2023, the House of Commons Science, Innovation and Technology Committee published its report on ‘Delivering nuclear power’. The report said the government was “right to identify nuclear power as an important contributor to meeting our future electricity needs” but argued there were significant challenges in achieving the government’s “ambitious” aim of 24 GW of nuclear capacity by 2050. The report noted that this would be three times current levels and “almost double the highest nuclear installed capacity the UK has ever achieved”. Furthermore, it said that “targets are not a strategy” and that the energy security strategy resembled something more like a “wish list”. It recognised that the government had published an ‘Energy security plan’ in March 2023 to supplement the strategy, but said that this “did not include much further information about how the energy security strategy would be implemented”.

In a Financial Times article accompanying the release of the report, the chair of the committee, former secretary of state for business, energy and industrial strategy Greg Clark, highlighted what he called the “energy security case for nuclear power under our own control” and argued that the push for nuclear made sense in the context of the UK’s “legal requirement” of net zero carbon emissions by 2050. However, Mr Clark also highlighted the deliverability challenges of nuclear energy:

… expansive ambition will not get nuclear power built. Much more than with other energy technologies, the scale, financial demands, workforce planning and—in the case of advanced nuclear technologies—research and development needed for new nuclear requires a dependable strategic plan if hopes are to have any chance of being turned into reality.

Mr Clark said that “witness after witness” who appeared before the committee’s enquiry highlighted the lack of a strategic plan for nuclear. He said that “the government’s stated aim to deploy a nuclear reactor a year is not grounded in any explanatory detail”. He added that it was unclear whether the 24 GW target was “intended to be met by gigawatt-scale plants like Hinkley Point C, or smaller, more distributed nuclear reactors such as small modular reactors”.

Furthermore, despite the government’s intentions to support the development of SMR technology, it remains uncertain whether SMRs will ever be commercially viable. As outlined in the committee report, SMRs are expected to be “quicker and cheaper” to build, but the “full extent of the proposed cost savings including cost of construction and cost per megawatt-hour remains unknown”. Prospective SMR manufacturers report that the UK market alone is unlikely to be large enough for them to make a return on their investment, with exports sales likely to be necessary if SMR manufacturing is to be a commercially viable venture.

The chief scientist of Greenpeace UK, Dr Doug Parr, said that the nuclear industry was making “speculative claims” regarding the proposed benefits of SMRs relative to conventional nuclear power. He said that “SMRs have no track record, but initial indications are that the familiar problems of cost overruns and delays will be repeated”. In addition to these concerns, Steve Thomas, an emeritus professor of energy policy at the University of Greenwich, suggests that the focus on SMRs will divert time and resources away from energy efficiency and renewables which he believes are the “answers” to net zero electricity generation.

Professor Thomas’s position is in line with that of the Green Party, the Liberal Democrats, and the Scottish National Party. The co-leader of the Green Party Adrian Ramsey has described nuclear as an “expensive distraction”, arguing that renewable energy technologies and energy efficiency are “cleaner and cheaper solutions that can be delivered far quicker than nuclear ever can”. Wera Hobhouse, the Liberal Democrat energy and climate change spokesperson, has also criticised the expense of nuclear power relative to renewables. Referring to the Nuclear Energy (Financing) Act 2022, she argued it was “madness” that the government had “recently passed a new law that will allow them to add levies to energy bills to fund new nuclear plants”. Scotland’s last remaining nuclear power plant in Torness is due close in 2028 and SNP energy spokesperson Alan Brown has said that the UK government should be focussing its efforts on Scotland’s “renewable energy potential” rather than attempting to build more nuclear power stations.

The Labour Party has, in contrast, expressed support for nuclear power, with Labour leader Keir Starmer describing it as a “critical part of the UK’s energy mix”. As part of its proposed ‘mission’ to decarbonise the electricity system by 2030 Labour has said that in government it would “get new nuclear projects at Hinkley and Sizewell over the line, extending the lifetime of existing plants, and [back] new nuclear including small modular reactors”.

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Cover image by Max Lederer on Unsplash.