Small Modular Reactors and the Future of Nuclear Power

Keir Starmer has recently announced that the government will be upturning ‘archaic’ rules on nuclear power planning, in order to build small modular reactors (SMRs) to grow the UK grid’s power output. Similar plans are being made worldwide as governments turn to nuclear as a reliable method of generating power.

The government plans to scrap the eight-site list, which has restricted the commissioning of nuclear reactors to eight locations in the country. With demand increasing and reactors in these areas reaching the ends of their lifetimes, Starmer emphasises that there is a need to find new sources of power quickly. Around 15% of the UK’s grid comes from nuclear power, which, given that there are only eight sites, proves its ability to generate massive amounts of power. All the while, the country is under pressure to build more domestic power stations and untether itself from Russia, who supplied £4.5 billion worth of gas, oil, and coal in 2021 – fossil fuel imports decreased significantly after Russia’s invasion of Ukraine in 2022 and have since stopped.

Nuclear power comes from firing neurons at rods of uranium in a chamber, and harnessing the energy released from the chain reaction of collisions. One kilogram of uranium-235 has the potential to generate 24,000MWh of power, which is about two million times more the equivalent energy generated by the same quantity of oil or coal. Nuclear is also a popular choice because it is reliable – as long as there is a supply of radioactive material and conditions in the reaction chamber are controlled, the reactor will be able to constantly generate power while operational. No external conditions are needed, unlike in solar, wind or tidal power stations. 

Since nuclear fuel is finite, it cannot be called a renewable source of energy. It is, however, considered carbon neutral, because the process does not release carbon dioxide and therefore does not directly cause global warming. This explains why many UN countries are pledging to produce more nuclear energy globally, as they move away from fossil fuels and towards “cleaner” sources of energy to achieve net-zero emissions by 2050. Supporters of nuclear power deem it a necessary energy source to replace fossil fuel generators and be used along with renewable power stations. People also like that it brings new high-skill jobs to rural areas, with potential for earning higher wages than those in other energy technologies. The government anticipates that these new builds will lead to cheaper electricity bills for the nation in the long term, and that those who live near the builds may be eligible to pay less for electricity.

New jobs and lower energy rates would be great outcomes for the public, but there is concern as to whether these new SMRs will ever be built. The most recently built nuclear reactor, Sizewell B, finished construction 30 years ago and faced significant delays due to opposition groups – often residents opposing factors such as noise pollution, land loss and aesthetic disruption. Complaints and legal action have prevented and delayed further nuclear builds since then and are likely to delay new ones, meaning that developers must be prepared to face similar levels of blocking and public scrutiny if the government pushes through with these plans. It will slow down the expansion process as a result and waste time and money that could have been spent on renewable energy projects. For nuclear energy to be a viable option, it is imperative that the government convinces the general public, looks to fix budgets and prepares solid plans that consider the wider implications of the reactor’s developments.

A non-renewable and wasteful form of generation, nuclear energy is inevitably a divisive subject. The various political parties have long had their own stances, with the Green Party being especially opposed to nuclear power. In their 2024 Manifesto, the group said that it wants to see a ‘phase-out’ of nuclear energy in favour of renewables. Here in Scotland, the amount of renewable energy being generated has been steadily increasing over the last twenty years, and in 2023, 70% of energy generated in the country came from renewable sources, compared to 19% nuclear and 8% fossil fuels. This sets Scotland apart from the UK as a whole, in which only 46% of energy generated comes from renewable sources. As a result, the SNP is also resisting nuclear developments. When asked at First Minister’s Questions in parliament, First Minister John Swinney said he would not support these builds in Scotland, saying that renewables have proven to be beneficial for Scotland. The disparity will mean that further nuclear development in Scotland will be slow, if it ever happens at all.

Assurances that SMR technology can be realised to produce energy for the country is essential. More research will be needed to prove the viability of nuclear SMRs. Capacity, usually given in megawatts (MW), describes the maximum power output of a generator operating at peak efficiency. SMRs are nuclear reactors with a capacity of up to 300MW, while a large, conventional reactor has a power capacity of over 700MW. Although a very new technology, there are about 80 SMR projects developing worldwide. China is increasing its nuclear output through SMRs, with ACP100, a 125MW reactor, being the first SMR design to pass a safety review by the International Atomic Energy Agency. However, most global SMR projects are still in the design stages and have not even begun construction. Meanwhile in the UK, there are currently no SMRs operating anywhere. The UK’s most recently built reactor, Sizewell B, is also its most powerful, with a capacity of 1,198MW, while the country’s smallest reactor has a capacity of 575MW, which is about twice as much as an SMR. By investing in physically smaller, lower capacity reactors, the aim is to supply electricity in high-demand areas. They are also meant to be faster and therefore cheaper to build than large reactors.

The Labour government’s announcement fails to outline a reactor decommissioning and waste management strategy for the proposed new reactors, decommissioning being a careful deconstruction of the station, the removal of nuclear waste, and the restoration of the land for other uses. This process is navigated by the Office for Nuclear Regulation (ONR) who work with the Nuclear Decommissioning Authority (NDA) to ensure that decommissioning strategies meet national and international safety guidelines. The stringency of this process means that it could take decades and cost billions in taxpayer money. As SMRs are supposed to be built faster and use less fuel, the decommissioning process is presumed to also be faster but remains unknown for now.

Radioactive nuclear waste is a huge safety and environmental concern. The current waste management process overseen by the NDA involves shipping radioactive waste to Sellafield, Cumbria where it is stored in containers until it is safe enough to be buried deep underground, in a process called geological disposal. Also, while low-level nuclear waste can be processed at other sites, Sellafield remains the only place in the UK that has been prepared to safely store highly radioactive nuclear waste. The government has said a Nuclear Regulatory Taskforce will be formed to oversee new nuclear developments, but it remains to be seen what changes the taskforce may make to current decommissioning and waste management policy. What is clear, however, is that new methods to reduce waste from the previous reactors, and to minimise future output will be vital if more plants are to be built.While regulations indicate that SMRs in the UK will be built safely, they remain experimental developments. Large companies like Rolls Royce are keen to invest in the projects and reap the rewards of the extra power, but the processes of planning and building will be slow. It’s also only a temporary fix – the country will eventually need to find a sustainable replacement for nuclear power that can still meet growing demand for energy. The decommissioning process for nuclear developments will need further consideration by the new Nuclear Regulatory Taskforce, to give timelines of when sites can be fully restored after reactor shutdown. The problem of waste must also be tackled through a long-term plan that goes beyond Sellafield, considering the effects on people and the environment. Ultimately, it’s clear that the proposed SMR builds should only go ahead if the costs can be outweighed by their net benefit for the nation.