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The UK’s Reinvigoration of Nuclear Energy

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The volatility of energy prices following recent geopolitical challenges has brought a renewed focus on domestic energy security. Because of the risks associated with weather-dependent energy solutions, a revival of nuclear energy appears to be forthcoming. Indeed, at COP 28, no less than 22 countries committed to triple global nuclear power capacity by 2050, and the UK Government has announced plans to increase the contribution of nuclear power to 25% of the UK’s electricity supply by 2025.1

In 2022, 13 countries already produced at least a quarter of their electricity from nuclear energy. Of those, France generated up to 70% of its electricity from nuclear energy, while Ukraine, Slovakia, Belgium and Hungary generated about 50% from nuclear.2 The UK meanwhile generated about 15% of its electricity from nuclear, and almost all of the UK’s existing nuclear reactors are operating with a lifespan which will end within the decade. It is unclear, therefore, how exactly the UK Government plans to achieve its target.

One path which the UK Government appears to be investigating is that of small modular reactors (“SMRs”). In the Spring Budget 2024, the UK government announced that it would buy two sites (the Wylfa site in Ynys Môn and the Oldbury-on-Severn site in South Gloucestershire) for two new nuclear power plants. Towards the end of 2023, it also announced that it would be proceeding to the next stage in its quest to find SMRs which could be used at the UK’s nuclear sites. Now, six companies have been invited to submit their initial tenders by June 2024, with the UK’s Energy Secretary, Claire Coutinho, recently proclaiming SMRs as “the future of nuclear technology, and key to quadrupling the UK’s nuclear capacity by 2050 as part of the biggest expansion in 70 years”.3

Traditional nuclear power plants (“NPPs”) often come with very large capacities, and are intended to power large cities. They are also traditionally very complex in design. SMRs, on the other hand, are much smaller and adopt a (comparatively) more simplified reactor design, meaning that they can be deployed more flexibly in response to demand. For example, SMRs generally have <300 MW(e) per unit, which is approximately one third of the capacity of an NPP, making them better placed to meet local energy needs in remote areas with more modest power requirements. In fact, SMRs can be designed to have capacities as low as 10MW(e) (“Microreactors”) meaning a (comparatively) tiny footprint. Alternatively, they can be deployed in clusters to power larger communities which might not have land to spare for a large NPP to be built. The SMRs’ size also means that they are well-suited to being connected to a larger plant, and can make use of the outputs and convert those into further useful energy, such as heating for various industrial processes, district heating systems, or desalination plants.

NPPs also require substantial upfront capital investment, often resulting in long payback periods. SMRs, on the other hand, by virtue of their modular nature and also their more simplistic design, are easier to build in factories, which in turn can achieve economies of scale and standardisation, driving down overall costs. This means that SMRs usually require a lower upfront investment, and also means that SMRs can be fabricated offsite with much shorter construction timelines, once again saving costs.

One of the main draws of SMRs, however, is their reliability. Renewables like wind and solar are heavily dependent on the weather, and can consequently produce energy intermittently. SMRs are not so dependent, making them more consistent, and also a good option to integrate into existing grid networks to complement or boost existing intermittent energy sources and even out any drops in coverage, operating, for example, overnight, on cloudy days, or on days without wind.

However, the existing regulatory framework surrounding nuclear energy in the UK was designed with large nuclear plants in mind, built in the traditional way. As a result, the existing framework will likely need to evolve with a move toward SMRs. Some steps have already been taken. For example, there are currently six National Policy Statements (“NPSs”) in the UK which provide a framework for energy projects; one general overarching energy NPS (EN-1) and five technology-specific NPSs (EN-2 to EN-6). These statements set out the government’s policy for the delivery of energy infrastructure and provide the legal framework for planning decisions for ‘Nationally Significant Infrastructure’ such as energy generation projects under the Planning Act 2008. The government has recently closed a consultation to produce a new nuclear NPS,4 which sought feedback on proposed material updates to the existing policy for siting nuclear power stations. The results of this consultation are intended to be enshrined in a new EN-7, which seeks to provide a more appropriate planning framework for future nuclear energy projects, and a draft EN-7 is intended to be circulated for further consultation later in 2024.

These are very exciting developments for the UK, and no doubt other countries will also be looking to take advantage of the benefits offered by SMRs. In this series, we will explore how the adoption of SMRs may impact existing energy sources and the future development of traditional and renewable energy sources, how existing regulatory and planning structures sit alongside an energy matrix that includes SMRs and will also investigate potential design and constructability matters.




4 The consultation was run by the Department for Energy Security and Net Zero, called “Approach to siting new nuclear power stations beyond 2050”. It can be accessed at the following link:

This information is provided by Vinson & Elkins LLP for educational and informational purposes only and is not intended, nor should it be construed, as legal advice.