Opportunities, Costs and Challenges of Small Modular Reactors (SMRs)

I am not an advocate for nuclear power but we should be assessing it as an option in the mix, especially with the UK’s military expertise in submarine power plants there must be some advantage in looking at this technology to be harnessed on dry land for the benefit of the power grid.??

As the UK aims to achieve a net-zero energy future, nuclear power is increasingly being proposed as a key player in providing reliable, low-carbon electricity. However, large-scale nuclear projects, like the construction of Hinkley Point C, face challenges related to cost overruns, lengthy construction times and local opposition (￡46bn and 4 years behind schedule ). In this context, Small Modular Reactors (SMRs) are seen as a promising alternative, offering a more flexible, scalable and cost-effective approach to nuclear energy.?

SMRs, typically generating between 10 MW and 300 MW, are far smaller than traditional nuclear power plants, which often exceed 1,000 MW in capacity, (Hinkley C 3,200MW). Their modular nature and factory-based construction promise significant advantages in terms of cost, construction time and deployment flexibility. But as with any new technology, there are both benefits and challenges associated with scaling SMRs to meet the UK's grid needs.?

Building on the UK’s Submarine Reactor Expertise?

The UK's existing expertise in small nuclear reactors - particularly through Rolls-Royce , which has been building compact nuclear reactors for submarines for decades - provides a strong foundation for SMR development. Rolls-Royce is now spearheading the development of SMRs for civilian power generation, drawing on its technical know-how in designing compact, safe and efficient reactors for military applications.?

The ability to build small reactors in modular form could revolutionise how nuclear power is deployed in the UK. Submarine reactors are designed to operate in harsh, confined conditions for long periods without refueling, which means they are optimised for efficiency, compactness and safety - qualities that could be transferred to SMRs for civilian use. These reactors are designed with inherent safety features and robust engineering, which makes the transition to SMRs a natural extension of existing technological expertise.?

However, it’s important to recognise that while the technical know-how is transferable, there are significant differences between building military reactors and scaling up SMRs for grid-level energy generation. Civilian reactors must comply with different regulatory standards, be optimised for economic efficiency, and integrate into the existing power infrastructure.?

Potential Sites for SMRs in the UK?

Several potential sites for SMR deployment have already been earmarked across the UK, particularly focusing on existing nuclear sites where public acceptance of nuclear technology is higher, and where grid connections are already in place. Locations like Trawsfynydd, Wylfa and Sellafield are front-runners, as they have previously hosted or continue to host nuclear facilities.?

• Trawsfynydd (Wales): A decommissioned nuclear site, ideal for early SMR deployment.?

• Wylfa (Anglesey): A large nuclear site with existing infrastructure but stalled large-scale projects.?

• Sellafield (Cumbria): Home to a significant nuclear workforce, ideal for diversifying into SMRs.?

Other sites where decommissioned coal or gas power stations are located are also possible.???

Leveraging these sites is a strategic move that addresses some of the transmission and infrastructure challenges that come with building new nuclear capacity. Existing grid connections at these sites make SMR deployment faster and cheaper, as new infrastructure wouldn’t need to be developed from scratch. Additionally, there is already a nuclear-skilled workforce in place, reducing the need for extensive new training programs and community outreach.?

Benefits of SMRs for the UK Grid?

1. Cost and Construction Efficiency?

One of the biggest challenges with traditional nuclear plants is the high upfront capital cost and the risk of delays in construction. For example, the costs of large nuclear plants like Hinkley Point C are set to exceed ￡46 billion, with timelines stretching to 10-15 years from approval to operation. SMRs, however, could help address these issues:?

• Factory-built modules: SMRs are designed to be built in factories, allowing for mass production and standardized components, leading to cost reductions through economies of scale.?

• Faster deployment: Because SMRs are modular, they can be assembled more quickly on-site, reducing the risk of cost overruns.?

• Incremental investment: Instead of investing in a massive plant upfront, SMRs allow for smaller, more gradual investments. This can help reduce financial risk and allow more flexible project financing.?

Rolls-Royce projects that each SMR could cost around ￡2 billion—a significant reduction compared to large nuclear plants—although this figure is still speculative until SMRs are more widely deployed.??

2. Grid Flexibility and Decentralisation?

Traditional large-scale nuclear plants require substantial grid infrastructure and are typically connected to large transmission hubs. SMRs, however, could provide more distributed power generation, reducing reliance on a few large plants and helping to decentralise the energy system. This has several potential benefits:?

• Increased grid resilience: Smaller, distributed power plants are less vulnerable to failure. If one SMR goes offline, it doesn’t have the same large-scale impact as losing a large nuclear power station.?

• Strategic deployment: SMRs can be built near industrial hubs or in areas of high energy demand, providing localized power and reducing transmission losses.?

3. Low-Carbon, Reliable Power?

SMRs offer a low-carbon alternative to fossil fuels, which is critical for the UK to meet its Net Zero 2050 targets. They provide baseload power, which is essential for balancing intermittent renewable energy sources like wind and solar. This means SMRs could complement renewable energy sources, offering 24/7 reliable power to fill gaps when renewables are not generating.?

Challenges and Issues to Address?

3.1. Economic Viability and Cost?

While SMRs promise lower costs, the economic viability of SMRs is still uncertain, especially in the early stages of deployment. The first SMRs will face the "first-of-a-kind" costs, which are typically higher than later iterations. For SMRs to truly reduce costs, they need to achieve mass production, which requires significant upfront investment and regulatory approval.?

• Cost per MW: Although SMRs are cheaper to build, they also generate less electricity compared to large nuclear plants. To meet the UK's growing energy needs, many SMRs would need to be built, which could offset the initial cost benefits.?

3.2. Regulatory and Safety Concerns?

Adapting the regulatory framework for SMRs is critical. Although submarine reactors have a proven safety record, civilian nuclear safety standards are far more stringent. Ensuring that SMRs meet these requirements while keeping costs down is a major challenge.?

• Public perception: While SMRs are designed with inherent safety features, public skepticism towards nuclear energy persists, particularly in the wake of accidents like Fukushima. Robust safety protocols and transparent communication will be essential in gaining public acceptance.?

3.3. Transmission and Integration?

While SMRs can provide more localized power, integrating them into the existing power grid requires careful planning. SMRs will need to be strategically sited to ensure they can easily connect to the grid without incurring excessive transmission costs. Building SMRs in remote locations, for example, could involve significant additional costs for connecting them to the national grid.?

Conclusion: A Possible Path Forward for SMRs in the UK?

SMRs offer a promising alternative solution to the challenges facing the UK’s nuclear energy sector, combining the country’s existing expertise in submarine nuclear reactors with new approaches to modular construction. They present a potential pathway for delivering cost-effective, reliable, low-carbon energy, which is critical for meeting the UK's Net Zero 2050 targets.?

However, the successful deployment of SMRs will depend on addressing several key challenges, including achieving economic viability, securing public trust and ensuring they can be effectively integrated into the national grid. By leveraging existing nuclear sites and infrastructure, the UK can accelerate the deployment of SMRs and realize their potential as a cornerstone of its future energy strategy.?

This is a positive case for nuclear energy, but uranium is still a finite resource, so is it still not better use of taxpayers' money to improve energy efficiencies in transport, domestic heating, etc to reduce overall energy consumption. Installation of rooftop PV where possible also reduces the need for upgrading transmission lines which is necessary for large scale windfarms etc.??

Disclaimer: I am not an expert in nuclear power development, this is what I can glean from moderate research online. Happy to have more evidenced detail from better sources develop the arguments for or against SMRs.