From Energy Crisis to Net Zero: The Promise of SMRs in the UK

Technological and Environmental

Photo: Wix

Throughout the UK, nuclear energy accounts for a relatively small share of the energy mix, with wind providing 36.3%, gas 29.4%, and nuclear only 10.5% as of February 2026. With climate change worsening, nations are transitioning toward sustainable practices, as seen in agreements such as the Paris Agreement. The UK is no different, introducing policies to support sustainable energy, including small modular reactors (SMRs). This essay examines how SMRs—such as those proposed at Wylfa—could support the UK’s net-zero goals, while also considering their limitations and alternatives.

What are SMRs?

Nuclear energy is a reliable low-carbon energy source produced through nuclear fission, where uranium atoms are split by neutrons, releasing heat used to generate electricity. This process occurs in both traditional reactors and SMRs, though SMRs operate on a smaller scale. Conventional reactors produce around 24 million kWh per day, while SMRs produce about 7.2 million kWh. However, SMRs are promoted as quicker, easier, and cheaper to build. Traditional UK projects such as Hinkley Point C have experienced significant delays and cost overruns.

SMRs offer advantages in flexibility, safety, and efficiency. Their smaller size requires less land and allows deployment in more locations. Factory-built modular components reduce construction time by 35–50% and lower emissions. Advanced passive safety systems enable automatic shutdown without human intervention, reducing the risk of disasters.

Economically, SMRs benefit from modular production and standardisation, lowering costs over time. They also require less frequent refuelling, reducing maintenance and downtime. Several SMR types exist, including light-water, gas-cooled, liquid metal, and molten salt reactors, though light-water designs dominate due it being more familair and understood compared to others.

Despite these advantages, SMRs present concerns. They may generate more nuclear waste per unit of energy than large reactors, including higher volumes of long-lived radioactive materials that can contaminate soil and groundwater. SMRs also experience greater neutron leakage, producing more radioactive structural waste.

Environmental impacts extend beyond operation, as increased waste requires expanded transport and disposal infrastructure, raising emissions and affecting land use.

Why are SMRs important for the UK?

The UK faces high electricity costs and an ongoing energy crisis. Despite investment in renewables, prices remain high due to reliance on natural gas and structural issues in the electricity market. Under the marginal pricing system, gas often sets electricity prices, exposing the UK to global market volatility.

This dependence has contributed to rising energy bills, harming both households and energy-intensive industries. Additionally, outdated grid infrastructure limits the distribution of renewable energy, leading to inefficiencies and additional costs.

SMRs could help address these issues. Their geographical flexibility allows deployment closer to demand, reducing reliance on grid expansion. Unlike renewables, nuclear energy provides stable, continuous output, reducing dependence on gas. Increased nuclear capacity could lower electricity prices and improve energy security.

SMRs could also support economic growth by increasing energy availability and reducing reliance on imports, making the UK less vulnerable to geopolitical disruptions such as the conflict between Russia and Ukraine.

However, significant challenges remain. High upfront costs, regulatory delays, and the lack of economies of scale during early days has increased financial risk. The UK’s complex approval processes slow development, while safety, security, and waste management concerns persist. A shortage of skilled workers further complicates deployment.

How can these challenges be addressed?

China provides a key example of successful SMR development, with rapid construction, strong government support, and long-term planning. Its state-backed financing reduces risk and enables lower construction costs and faster deployment.

China’s use of modular construction, standardisation, and consistent policy direction has accelerated innovation and reduced delays. Significant investment in research, development, and workforce training has further strengthened its position.

The UK could adopt similar strategies by providing clear long-term policy direction, increasing government funding, streamlining regulations, and investing in workforce development.

Conclusion

SMRs could play a crucial role in helping the UK achieve net zero while improving energy security and affordability. They offer reliable low-carbon energy, economic benefits, and reduced reliance on gas imports.

However, their success is not guaranteed. High costs, regulatory barriers, waste management challenges, and workforce shortages must be addressed. By adopting stronger government support, clearer policy frameworks, and improved regulation, the UK can better position itself to successfully deploy SMRs.

Ultimately, if these challenges are resolved, SMRs could become a key component of a sustainable, secure, and economically resilient future with energy.