Nuclear’s role in net zero
July 12, 2023

Tim Miles

Nuclear energy doesn’t require the burning of fossil fuels, so it doesn’t directly contribute to carbon emissions. But concerns about the amount of energy necessary for mining and refining – not to mention the overall cost, waste and safety issues – have made the future of nuclear power uncertain. Per the International Energy Agency (IEA), without nuclear power, it will be much harder for the world to achieve net zero.

Grid stability in a net zero world

One of the key challenges for a net zero energy landscape is balancing the grid when most power generation sources are based on renewables. Previous generations could rely on large power stations that are activated and deactivated as needed to maintain grid frequency and resilience, with inertia playing an important role in the process. Energy storage systems form part of the solution, with battery storage playing a major role and other methods – such as gravity storage – also being deployed.

Low carbon energy

The progress being made in the renewables arena is impressive but is it enough to achieve net zero on its own? One key source of low-carbon electricity generation is nuclear power. According to the International Energy Agency (IEA), nuclear accounts for 10% of global electricity generation. With a carbon footprint as low as 15gCO2/KWh, nuclear already plays a major role in the reduction of emissions. Since the 1970s, nuclear power has helped the world to avoid the production of 66Gt of CO2 emissions. In the EU alone, this equates to 40% of total emissions from electricity generation.[1]

Massive increase in demand

Even so, as global demand for electricity is forecast to grow by 250% by 2050 (IEA), there will need to be a corresponding expansion of low-carbon generating capacity. Without nuclear power, this task is harder to achieve. While there are no technical barriers to the development of new sources of nuclear power, there are social and political challenges.

Aging nuclear fleet

The world’s nuclear fleet is aging, with around 25% of nuclear capacity in the world’s advanced economies expected to reach the end of their useful lives by 2025.[2] Yet, the same advanced economies have differing views on nuclear. France, for example, has announced a €50 billion investment in six new nuclear reactors.[3] But in Germany, the country’s final three nuclear power stations were shut down on 15th April this year as it continues to phase out nuclear power from its energy mix.[4] The UK’s Great British Nuclear Initiative aims to champion small modular reactors (SMR) while boosting capacity to 24GW by 2050.[5] The UK, however, has a long history of making ambitious nuclear plans that are later watered down.[6]

Is public opinion changing?

The German policy is the culmination of a policy that began in the German Bundestag’s direct reaction to the Fukushima disaster in Japan more than a decade previously in 2011. German policy is also informed by worries over the safe disposal of nuclear waste and security. The same differences of opinion – from Germany’s ultra-cautious views to the ambitious plans of France – are mirrored across the world. Attitudes are, however, in constant flux. Recent German opinion polls indicate a more positive view of nuclear than in the past.[7] In Finland, the Green Party is supporting nuclear as a sustainable energy choice. And a new breed of environmentalists – “ecomodernists” – are pressing for nuclear electricity generation to be a key part of the overall energy mix.[8]

Delivery and cost

Other challenges to the widespread uptake of nuclear power generation include the industry’s own mixed record on delivery and the cost of investing in the infrastructure. According to the IEA’s Net Zero by 2050 Scenario, annual global investment in nuclear power needs to rise from $30 billion in the period 2010-2020 to $100 billion a year by 2030, with yearly investment remaining above $80 billion through 2050. This is against a track record of projects that are often above budget and behind schedule. The UK’s 3.26MW Hinkley Point C project, for example, has seen estimates rise from £18 billion to £33 billion while the completion date has been postponed from 2025 to 2027.[9]

Thinking small

Small Modular Reactors (SMR) and Micro Modular Reactors (MMR) may form part of the solution. In the UK, Rolls-Royce is developing an SMR with a capacity of up to 470MW that will provide consistent baseload power for up to 60 years.[10] Each module takes up just 10% of the footprint of a conventional nuclear power plant and is designed to be largely factory-built to make it cost-effective and deliverable to reliable time frames. An SMR’s modular design also means that it is scalable simply by adding further modules. The reactors can be used in remote locations, off-grid facilities or as part of the grid.

While the UK Government sees SMRs as “a key part” of their energy strategy, other countries are also developing SMRs. Russia has created a floating 70MW SMR that is sited in the Arctic Ocean. China is building its own SMR fleet and Canada is looking at deploying SMRs in Ontario, New Brunswick and Saskatchewan. In many cases, the technology has grown out of the mini reactors built to power nuclear submarines and other warships. Around 700 of these have been built since the 1950s.[11]

Versatile and cost-effective

Proponents of SMR and MMR say that they are highly versatile and can be used in various applications, from hydrogen production plants to remote locations that are off-grid. Supporters also claim that SMRs and MMRs are safer than their aging larger cousins because they run at a lower core heat and have far fewer components that are subject to potential failure. Skeptics say that the multiplication of reactors also multiplies the risks of catastrophic failure and security problems while still not addressing the challenge of radioactive waste disposal.

The need to modernize

In recent years, China and Russia have dominated the construction of new nuclear power plants. Russia’s dominant position in the export of nuclear power plant design, however, has been severely affected by its invasion of Ukraine. In the rest of the world’s aging fleet, plants are increasingly reaching the end of their operational lives and facing closure or an extension of their lifetime. In the USA, for example, 88 of the country’s 92 reactors have been given a 20-year extension of their operating licenses.[12]

Ultimately, nuclear electricity generation is destined to play a part in the net zero world simply because it’s needed as insurance that baseload will always be available. How that is achieved – whether through large-scale power plants or SMRs and MMRs, or a combination of all these – is up for debate. Until, of course, fusion finally becomes a viable option.[13] But that’s another story.


[1] IEA, Nuclear Power and Secure Energy Transitions, June 2022,

[2] IEA, Nuclear Power in a Clean Energy System, May 2019,

[3] Reuters, Macron bets on nuclear in carbon neutrality push, February 2022,

[4] Federal Office for the Safety of Nuclear Waste Management, The nuclear phase-out in Germany, April 2023,’s%20last%20nuclear%20power%20plants%20to%20go%20off%20the%20grid&text=On%20the%2010th%20anniversary%20of%20the%20decision%20to%20phase%20out,to%20operate%20at%20full%20capacity.

[5] UK Government, Powering Up Britain, March 2023,

[6] Financial Times, After years of false dawns, can Britain realise its nuclear ambitions? January 2023.

[7] Der Spiegel, Germany Sees Tidal Shift in Sentiment Toward Atomic Energy, August 2022,

[8] The Guardian, The UK Greens pushing for the nuclear option, March 2023,

[9] City AM, Inflation drives Hinkley Point C nuclear plant costs, February 2023,

[10] Rolls-Royce SMR,

[11] Asia Times. Tomorrow’s nuclear reactors: small but beautiful, February 2020,

[12] US Office of Nuclear Energy, What’s the Lifespan for a Nuclear Reactor? Much Longer Than You Might Think, April 2020,

[13] BBC, Major breakthrough on nuclear fusion energy, February 2022,