Politicians in many countries, including the UK and Australia, have recently advocated the development of ‘small modular reactors’ (SMRs) as a means to speed up nuclear power production as an alternative to burning fossil fuels. But with the technology still some 15 years from maturity, Ian Lowe argues that SMRs are an expensive and risky distraction from rapidly building safer, cleaner and cheaper renewable energy capacity.
Most governments plan to replace fossil fuel use by renewable energy technologies with storage to reduce greenhouse gas emissions. At this year’s Australian election, the conservative Opposition (Liberal Party) proposed building and operating seven nuclear power stations, five conventional large units and two ‘small modular reactors’ (SMRs). A study by the Australian Academy of Technology and Engineering (ATSE) concluded that there are many questions which would need to be answered for SMRs to be seriously considered as part of the future energy mix. The ATSE report found that the time scale for resolving those issues means that SMRs are very unlikely to help achieve the target of net zero emissions by 2050.
What is a small modular reactor?
Small Modular Reactors (SMRs) are a range of new nuclear reactors that are currently being designed. The aim is to make them easier, cheaper and safer to build and operate than conventional large scale nuclear reactors. They are currently at the design stage in the United States, the UK, Canada and South Korea, with no models yet operating anywhere in the OECD countries. Leveraging its submarine- and ship-based reactor programmes, Russia commissioned an initial floating SMR for power generation in its remote Arctic in 2020 and is reportedly building at least one land-based SMR, also in its Arctic northeast. China also commissioned an initial SMR design in 2021 and is building others.
The proposed designs are smaller in scale than conventional power reactors, typically between 50 and 300 Megawatts (MW), compared to between 2,200 and 3,400 MW for recently proposed UK full-size reactor projects or about 1,100 MW for recently proposed ‘large reactors’ in Australia. That means they would only be ‘small’ by comparison with most recent power reactors. Indeed, the SMRs that Rolls Royce proposes to build in the UK would be 470 MW, much larger than all but the last two of the UK’s 26 Magnox reactors, built in the 1950s and 1960s and now decommissioned. It has been proposed that SMRs would be based on standardised components produced in factories and assembled on site. They could have in-built passive cooling in case of power failure.
There are some key factors driving the development of SMRs around the world:
- Low carbon emissions;
- Ability to back-up intermittent power sources such as renewables;
- Potential for easier and faster construction than conventional nuclear plants on a smaller footprint;
- In some cases, the ability to provide heat as a key input to industrial processes.
Currently, 14 different designs around the world are at a comparatively advanced stage of development. This means they are undergoing detailed simulations, evaluation of components and creation of small-scale replicas for testing and evaluation. However, none has yet been licensed for construction in any OECD country.
How do SMRs stack up?
With renewable and battery technologies getting cheaper every year, expensive new sources of power may well struggle to break in. Since SMRs are still at the design stage, there are no operating data that would allow comparison of the cost of their electricity with the existing low-emissions technologies: solar, wind and hydro.
In Australia, CSIRO’s regular GenCost study illustrates the scale of the challenge. The most recent analysis estimated the 2030 cost of power from solar and wind with storage to be firm capacity in the range A$89-125 per MWh, compared with A$141-233 for large-scale nuclear and A$230-382 for SMRs. So in principle, once the technology is mature enough to enter commercial production, SMRs could supplement supply from renewables, but it is likely there would be a higher cost.
A market for SMRs?
Even on the most optimistic timelines, SMR technology will be installed too late and provide too small a contribution to the energy system to help reach net zero by 2050. Insofar as SMR technology can help support the decarbonisation of energy or heat-intensive industries, the barriers to adoption are substantial. In the particular case of Australia, which has no history of civil or military nuclear production, there are currently bans on nuclear power at the national level and in many states. These would need to be overturned before any work could commence. A regulator would then need to be created to oversee all aspects of the delivery, safety, workforce needs and environmental impact of any SMR installation.
Without a mature SMR market, there would be substantial technical and financial risk in pursuing the technology. The hope is that as the reactors gradually form a market, with increasing expertise and economies of scale, SMRs will gradually decrease in price. There were, of course, similar hopes about large-scale nuclear power reactors, but these have never materialised. All the reactors built in the Western world this century have been well over budget.
First, developers will need to progress their designs and acquire licenses, funding and sites for their construction. Then, they would need to build full-scale working prototypes that they would commission and operate. Current information from developers around the world indicates this is around 10 years away, in the mid-2030s. The third step would involve developers incorporating the knowledge gained from their full-scale prototypes into accepted commercial packages that they could offer the market. It could take 3 to 5 years to reach this stage after prototyping. Finally, developers would become vendors and compete to secure contracts to build SMRs, creating a global SMR market. As such, the evidence suggests that the first commercial releases of SMRs can be expected between the late 2030s and mid-2040s.
A final issue is waste management. Most countries that have been operating nuclear reactors for decades, either for power generation or weapons production, still have no agreed process for managing the radioactive waste for the immense time periods required. While governments have continued to kick this can down the road, there is likely to be public concern about proposals to develop a whole new category of waste without a credible management plan. In the UK, which has had a civil nuclear programme for over 70 years, plans for a safe Geological Disposal Facility for nuclear waste are still at least a decade from even beginning construction; the government’s own project monitoring agency currently rates the scheme as ‘unachievable’.
Questions to be answered
So there are many questions that still need to be answered – cost, construction time, waste disposal, water use, community support and more. Given all these problems, it is hard to see a case for putting public funds into the SMR programme. One motivation for the nuclear power industry is that it otherwise appears to be in terminal decline, given the long delays and hopeless cost blowouts of recent projects like the c.£45 billion, 3,260 MW Hinkley Point C in Somerset. The industry has argued that SMRs could be built much more rapidly than conventional large-scale reactors. While that is true, the other side of that coin is that there genuinely are economies of scale in power station construction, so the SMRs are almost certain to produce even more expensive electricity than the larger design.
From a British, and now Australian, perspective, there might be an argument that there needs to be some sort of civil nuclear programme to develop and maintain the skills that are needed to build and operate nuclear-powered submarines, as well as (in the UK case) to tackle the huge tasks of decommissioning old power stations and managing their waste. However, Australia has until now had no nuclear power plants and many of the most highly credentialed defence experts in Australia have been very critical of the AUKUS agreement to jointly produce nuclear-powered submarines for the Royal Australian Navy, arguing that such vessels would not significantly improve the nation’s capacity to defend its enormous coastline.
While companies around the world are making progress, we would need much more convincing evidence to accept a role for SMRs in electricity supply.
Ian Lowe is an emeritus professor in the School of Environment and Science at Griffith University in Australia. He has published widely and among many advisory roles, he represented the public interest on Australia’s Radiation Health and Safety Advisory Council for fourteen years and was a member of the expert panel advising the South Australia Nuclear Royal Commission. A Fellow of the Australian Academy of Technology and Engineering since 2001, he reviewed their 2024 report on small modular reactors.
The views and opinions expressed in posts on the Rethinking Security blog are those of the authors and do not necessarily reflect the position of the network and its broader membership.
Image Credit: UK Environment Agency. Artist’s impression of Rolls Royce SMR in situ.
