​Can nuclear power help the UK reach net zero?

The UK was the first major economy to legally commit to net zero greenhouse gas emissions by 2050, but as the deadline looms, the scale of the task is becoming clearer. As government drives a shift towards low-carbon alternatives to fossil fuels, the electricity network is under mounting pressure to supply clean, reliable power at scale.

With some of Europe’s most reliable wind resources, a long coastline and growing solar output, the UK is well placed to generate renewable electricity. But renewables alone cannot meet our future energy goals. Enter nuclear power. Capable of delivering continuous, low-carbon electricity, nuclear can also support grid stability while supporting our wider decarbonisation efforts.

Nuclear power has been part of the UK’s energy network for more than 60 years. Today, it provides 15% of Britain’s electricity, via nine operational reactors across five sites. These stations generate electricity through nuclear fission; atoms of uranium are split to release heat. This process produces steam, which drives turbines connected to generators. Minimal carbon dioxide is produced over the full lifecycle of a nuclear power plant, from construction to decommissioning.

For plumbing and heating professionals, understanding the role of nuclear energy has never been so important. From powering heat pumps and electric boilers to enabling district heating networks, nuclear energy is closely linked to how our buildings and infrastructure will be heated in the decades to come.

Collaborative approach

Achieving net zero will require a substantial expansion of low-carbon electricity generation. The government’s Electricity Networks Strategic Framework shows that annual electricity demand could more than double by 2050, rising from around 330 TWh to 770 TWh, as heating, transport and industry increasingly switch to electricity on the path to net zero.

Renewables cannot meet demand alone without extensive storage, backup generation and grid reinforcement. “When it comes to decarbonising electricity, the UK’s current strategy is heavily reliant on renewables,” explains Dr William Bodel, a Fellow in Nuclear Energy Policy at the Dalton Nuclear Institute at The University of Manchester. “The problem is renewables are intermittent – the wind isn’t always blowing.

“This isn’t a huge issue when renewables make up a small part of generation, because the shortage can be made up by dispatchable sources elsewhere,” Bodel continues. “Batteries are useful over short periods, but extended periods of low renewable output need dedicated dispatchable supporting generation to keep the country powered. Nuclear energy is an ideal solution.”

Reliable backup

Without substantial nuclear expansion, the UK would need to rely more heavily on gas-fired generation or costly energy storage to maintain security of supply. “If net zero is to be achieved, it will mean changing pretty much everything about our relationship with energy,” says Bodel. “Currently, electricity only comprises about 20% of our energy usage. The other 80% includes things like domestic heating (mostly gas), transport (mostly oil derivatives) and heat for industry. Most of our efforts in decarbonising so far have only really concerned the 20%. The 80% is the hard-to-decarbonise part of the mission.”

Bodel suggests two options when it comes to decarbonising that challenging 80%. “First, electrify everything and power it from the grid,” he says. “The second option is to produce the heat using low-carbon alternatives. This could be dedicated heat piped from a heat source, such as a nuclear reactor, or the development of low-carbon synthetic fuels that require heat in their production.”

“Until now, nuclear has been used almost exclusively for heating water to make electricity,” Bodel continues. “But using that heat for purposes other than electricity has a lot of potential. Almost all reactor designs still involve heating water, but this limits efficiency as temperatures are restricted by the water. But, if direct use of heat for industrial application or synthetic fuel production takes off, new high-temperature reactor designs would become very useful.”

New nuclear build is also critical since most of Britain’s existing nuclear power reactors are due to be decommissioned this decade. Without replacement, the UK risks losing a major source of low-carbon electricity, just as demand is increasing. Building new reactors ensures continuity of clean power, while avoiding a short-term return to fossil fuels during the transition.

Plus, analysis by the Climate Change Committee shows that energy systems combining renewables with firm low-carbon generation, like nuclear, are more cost-effective and resilient than systems relying on renewables alone. Nuclear reduces the need for excessive grid-scale storage, overcapacity and emergency backup, lowering long-term infrastructure costs.

Finally, large-scale nuclear build will strengthen energy security and industrial capability in the UK. Domestic nuclear generation reduces reliance on imported gas and exposure to volatile global energy markets. It also supports skilled engineering jobs, long-term supply chains and technological expertise.

Nuclear now

The UK currently has two major projects in the works: Hinkley Point C in Somerset and Sizewell C in Suffolk. The former is currently under construction and the latter is in the planning and development stage. Once operational, these facilities are expected to provide enough electricity to power six million homes each and operate for at least 60 years. Together, they will play a major role in replacing retiring nuclear stations and supporting the UK’s net zero ambitions.

Alongside these large-scale plants, the government is also backing the development of small modular reactors (SMRs). SMRs are factory-built and assembled on site, allowing greater quality control, shorter construction times and more predictable build costs. “There are high capital costs with nuclear power stations,” says Bodel. “This is largely caused by the build times. Financing becomes very expensive in big projects, as there’s a long time from starting building before revenue can be generated. Smaller reactors are easier and quicker to build, start making money sooner, and stop interest costs ballooning.”

The UK-led Rolls-Royce SMR programme aims to deliver reactors capable of powering around one million homes. These facilities are dispatchable and can be located closer to industrial centres, opening up opportunities for supplying low-carbon heat to manufacturing and district heating networks. “These SMRs are still pretty large in terms of power output (~470 MW compared to our big AGR reactors, which were ~600 MW), but the innovation is the modular nature of the plants,” says Bodel. “The Rolls-Royce SMR is essentially a scaled-down version of what we have at Sizewell B; a pressurised water reactor. Using water as the coolant limits the output temperature of the plant, however (~330°C). Other designs are in the works that use gas as coolant, which allows for higher operating temperatures (high temperature gas-cooled reactors or HTGRs).”

These next-generation designs, sometimes called advanced modular reactors (AMRs) to distinguish them from their water-cooled cousins, have the greatest potential for high-heat applications, with potential operating temperatures upwards of 750°C.

Concerns, costs and debate

No energy source is without controversy and public opinion on nuclear remains mixed. However, independent research from the Nuclear Industry Association found that 72% of the British public believes the UK needs a mix of energy sources, including nuclear, to ensure a reliable electricity supply.

Critics of nuclear point to four key issues: high upfront costs, long construction times, safety concerns and waste disposal. Hinkley Point C has faced delays and budget increases, highlighting the challenges of delivering such complex infrastructure. The station was expected to be completed in 2027 for £26 billion. It is now unlikely to be operational before 2030, with the overall cost revised to between £31 billion and £34 billion. “While relatively cheap over their long lifetimes, the up-front cost for new nuclear is a big problem,” says Bodel. “There are three measures to overcome this. First is fleet-build; building more than one of a given reactor type enables the learnings from the first reactors to be applied in the subsequent ones, bringing down unit costs (e.g. Sizewell C will be a copy of Hinkley Point C).”

Second is modularity; with SMRs and AMRs, much of the build is done in a factory setting for assembly on site. The intention is to decrease build times, bring them online sooner and reduce the large financing costs that build up during several years of construction. “Finally, alternative financing methods offer means to reduce costs,” Bodel explains. “The Regulated Asset Base financing method has been used for other large infrastructure projects and brings down overall costs by providing revenue during construction.”

What’s more, according to the International Energy Agency (IEA) and OECD Nuclear Energy Agency’s (NEA) Projected Costs of Generating Electricity report, electricity from new nuclear power plants is expected to remain the dispatchable low‑carbon technology with the lowest expected costs.

Safety concerns

Public concerns over the safety of nuclear power increased after the Fukushima disaster. In 2011, an earthquake and tsunami struck Japan, triggering a meltdown at the Fukushima Daiichi nuclear plant. The disaster forced tens of thousands to evacuate and highlighted the risks of nuclear power during extreme natural events. However, generally speaking, nuclear power is considered safe.

“Like other high-hazard industries, a large amount of effort goes into risk reduction to ensure safe operation, and the industry is extremely highly regulated,” says Bodel. “This helps in keeping the sector safe and removing the risk to the public.”

The UK operates one of the most robust nuclear regulatory regimes in the world, too, overseen by the Office for Nuclear Regulation and the Environment Agency. Together, they monitor everything from reactor design and construction, to day-to-day operation, waste management and decommissioning. Modern reactors are also designed with multiple independent safety systems and passive safety features that significantly reduce the likelihood of accidents, while continuous monitoring and inspection ensure high levels of operational safety.

Waste management

Of course, there are also concerns around waste disposal. While modern reactor designs and recycling strategies aim to reduce waste, and regulatory frameworks enforce stringent safety measures, the lack of a permanent solution for nuclear waste remains a worry. Deep geological disposal in the form of purpose-built caves hundreds of metres below ground is widely agreed to be the best solution for the final disposal of high-level nuclear waste, but in the UK “we do not have a permanent storage solution, especially if we continue to see significant increases in the amount of nuclear energy being produced”, stated Adrian Ramsay MP, former co-leader of the Green Party, during Centre Think Tank’s ‘Energy dream or nuclear nightmare’ event in 2023. “…the government has tried six times in the last 42 years to find a location where there is local support for actually storing nuclear waste and dealing with it.”

However, the government is progressing plans for a geological disposal facility (GDF), to manage higher-level radioactive waste safely. While the volumes of waste produced by nuclear power are relatively small compared with other industrial wastes, long-term stewardship is essential for maintaining public confidence.

What engineers need to know

While nuclear power may feel far removed from day-to-day plumbing and heating work, its impact on the sector is significant. A reliable supply of low-carbon electricity is fundamental to the:

• rollout of heat pumps
• expansion of district heating networks
• growth of electric and hybrid heating systems
• production of low-carbon hydrogen.

As building services engineers adapt to net zero requirements, upstream energy generation becomes an increasingly important part of the picture. Nuclear power helps create the conditions in which low-carbon heating technologies can operate effectively and at scale.

Both Hinkley Point C and Sizewell C represent a long-term pipeline of work, skills development and employment for engineers. These projects are expected to support thousands of jobs during construction and operation, with a strong emphasis on apprenticeships, training and local supply chains.

Building and operating a modern nuclear plant requires extensive mechanical, pipework, HVAC, water treatment and thermal systems, too, all areas aligned with plumbing and heating expertise. Plus, the reliable, low-carbon electricity generated by both Hinkley Point C and Sizewell C will underpin the wider rollout of heat pumps and electric heating across the UK. Finally, a fleet-based approach to SMRs could create a steady pipeline of work, rather than the peaks and troughs typical of large infrastructure projects, supporting sustained growth in the UK’s nuclear and wider energy workforce.

Reaching net zero is one of the most complex engineering challenges the UK has ever faced. No single technology can deliver it alone. Success depends on a balanced, resilient energy system that combines renewables, storage, flexible demand and firm low-carbon power. Nuclear energy remains a vital part of that mix.

By providing reliable, low-carbon electricity, supporting electrification of heat and enabling hydrogen production, nuclear power underpins many of the changes already reshaping the plumbing and heating sector. For engineers, understanding the role of nuclear has never been so significant.

Nuclear in numbers

• Nuclear power provides around 15% of the UK’s electricity
• Nuclear power has a minimal carbon footprint of around ~15-50g of CO₂ per kilowatt hour (gCO₂/KWh)
• Nuclear currently provides almost 30% of the world’s low-carbon electricity, making it the second largest source after hydropower
• According to the International Energy Agency (IEA), nuclear energy enables about 1.5 gigatonnes (Gt) of global emissions and 180 billion cubic metres (bcm) of global gas demand to be avoided each year
• The UK currently has nine operational nuclear reactors across four sites, consisting of eight aging advanced gas-cooled reactors (AGRs) and one pressurised water reactor (PWR)
• Hinkley Point C will avoid nine million tonnes of CO₂ each year