What is the role of nuclear power in the energy mix and in reducing greenhouse gas emissions?

  1. How much nuclear energy is currently produced in the UK and worldwide?

The UK has 15 nuclear reactors, which generated about 21 per cent of its electricity in 2016. Almost half of that capacity will no longer be in use by 2025 as old plants are taken offline, although this will be partly offset by the construction of the first new nuclear power station to be built in a generation, the Hinkley Point C project in Somerset. In 2017 UK regulators also approved the design of Horizon Nuclear Power’s plant at Wylfa, in Wales, which will now have to obtain planning permission. The UK imports some nuclear energy from France and the Netherlands.

The Nuclear Energy Institute reports that in April 2017, 30 countries worldwide were operating 449 nuclear reactors for electricity generation, with 60 new nuclear plants under construction in 15 countries. Together, nuclear plants provided 11 per cent of the world’s electricity production in 2014. France relies the most heavily on nuclear power, which supplied 72.3 per cent of its electricity in 2016, while nuclear energy supplied at least a quarter of electricity in a further 12 countries in that year. Total nuclear capacity has declined since the Fukushima disaster in Japan in March 2011, which prompted nuclear power plants to be taken offline in several countries.

  1. What role could nuclear power play in fighting climate change?

Nuclear power, which currently means energy derived from fission (splitting the uranium atom), has a minimal carbon footprint of around 15–50 gCO2/KWh. By comparison, the average footprint of gas power generators is around 450 gCO2/KWh and that of coal power generators around 1,050 gCO2/KWh. It can therefore be part of a global decarbonisation process, with some countries depending on nuclear more heavily than others to cut their emissions. The 10 largest emitters of greenhouse gases globally all have plans to use nuclear power in some way to reduce their carbon footprint. Nuclear is currently the largest source of low-carbon electricity in OECD countries.

According to the International Energy Agency (IEA), nuclear energy currently contributes to CO2 emissions reductions from the power sector of about 1.3 to 2.6 gigatonnes each year, assuming it replaces either gas- or coal-fired generation. The IEA’s 2015 Technology Roadmap report states that to meet the Paris Agreement target of not exceeding a 2°C rise in temperature, global nuclear capacity would need to more than double from current levels to reach 930 GW in 2050.

But nuclear is unlikely to be the answer on its own. Aside from controversies over safety and cost, this is because while nuclear power is well suited for providing base power, it is ‘poorly suited for dealing with power fluctuations on the grid (in either supply or demand)’. Nor are nuclear power plants able to provide backup power to deal with rapid fluctuations, notably to complement intermittent renewable sources such as offshore and onshore wind, as they do not ‘have the capability for fast ramp up/ramp down’.

China is building 24 new reactors, which will contribute to a reduction in coal-fired generation, with consequent cuts in emissions. In the EU, the European Sustainable Nuclear Industrial Initiative (ESNII) is being developed as part of the European Strategic Energy Technology Plan (SET-Plan), which aims to accelerate the development and deployment of low-carbon technologies. The boom in cheap gas supplied from fracking in the United States is reducing the profitability of nuclear power, prompting concerns that nuclear plants will be decommissioned prematurely, negatively affecting CO2 emission reduction targets.

In the UK, the Committee on Climate Change has stated that new nuclear power plants – as well as carbon capture and storage – will be necessary in order to achieve sufficient cuts in annual emissions to meet the Fifth Carbon Budget reduction targets.

  1. What are the main controversies surrounding nuclear power?

Safety and cost concerns around nuclear energy persist.

Public concern over the safety of nuclear power increased after the Fukushima Daiichi accident triggered by the Japanese tsunami of March 2011. The accident prompted safety reviews and pledges to move away from nuclear in some countries (e.g. Germany announced its plans to phase out nuclear by 2022, and is investing heavily in renewables). The long-term storage of nuclear waste can also raise safety concerns. Currently only a handful of countries, including Finland, Sweden, France and the US, have started building permanent storage facilities in purpose-built caves hundreds of metres below ground (deep geological disposal).

Nuclear power is expensive for a number of reasons. Developing new safety requirements has been costly, as is the shift towards building new Generation III reactors, such as those fuelling the Hinkley Point C power station in the UK. And the global financial crisis has made financing big infrastructure projects including nuclear power stations more challenging. Critics argue that as the cost of renewable energy falls, the case for nuclear power is being weakened. However, the World Nuclear Association argues that although nuclear plants are expensive to build, they are ‘relatively cheap to run’ and that the energy produced is competitive with fossil fuels in many places.

In the UK the National Audit Office criticised the Government in June 2017 for its ‘risky and expensive’ deal with French company EDF to build Hinkley Point C. However, earlier analysis by the Committee on Climate Change showed that electricity generated by Hinkley Point C is likely to be cheaper than electricity supplied by coal- or gas-fired power plants, assuming there is a carbon price consistent with the UK’s emissions reduction targets – and that Hinkley Point C is therefore still likely to be cost-effective compared with alternatives for electricity generation.