The long-awaited Energy White Paper, Powering Our Net Zero Future, sets out an ambitious pathway to decarbonisation of the UK. It maps out many possible scenarios, with nuclear energy ranging from an irrelevance to a major contributor. Here, Professor Francis Livens from the Dalton Nuclear Institute, looks at what needs to happen in order for nuclear energy to play a significant role in decarbonisation of the UK energy systems.    

• The new White Paper aims to confirm investment for ‘at least one large-scale nuclear project’ by the end of this Parliament.
• This minimum contribution from nuclear energy is entirely achievable with our current technology
• But to make a significant difference to the transformation of our energy system, advanced fission and fusion technologies would need to be deployed.
• To reach the top end of the envisaged contribution, new technology will need to be developed and made commercially viable, deployment needs to be on a large scale and the combination of these two things will be extremely demanding on a traditionally conservative nuclear sector.

Although its first planned publication date was 18 months and two Secretaries of State ago, the Energy White Paper finally emerged on 14 December. While many of its key points were highlighted in last month’s Ten Point Plan, the White Paper seeks to set out the UK’s path to net zero.

The shifts in our energy mix and the associated technological and societal transformations envisaged here will be radical. Large scale replacement of fossil fuels will more or less double electricity demand, and the accompanying shift to low carbon generation will lead, overall, to about a four-fold increase in clean generation. New energy technologies such as energy storage, advanced nuclear fission, nuclear fusion, carbon capture and storage, or use of hydrogen as a fuel, will need to be deployed on a large scale, which brings significant uncertainty.

‘Net Zero by 2050’ is therefore not a matter of choosing this technology or that; it is such a far-reaching change that we need to pursue all options at this stage. Within this uncertain landscape, it is clear that wind and solar will make a large and immediate contribution, but their intermittency has to be compensated by large scale energy storage, hydrogen-fuelled generation, nuclear power, or gas generation with carbon capture. The range of potential contributions to the energy mix is therefore wide:

• Gas with carbon capture and storage 2- 30 GW
• Offshore wind 40 – 120 GW
• Onshore wind 15 – 60 GW
• Solar 15 – 120 GW
• Nuclear 5 – 40 GW

The nuclear contribution

The White Paper very much conforms with the proposition of the Nuclear Innovation and Research Advisory Board (NIRAB), that nuclear fission technologies can be deployed in waves, with each offering greater contributions to decarbonisation. The first comprises large, conventional Pressurised Water Reactors (PWRs), similar to those being built at Hinkley C and proposed for Sizewell C, which produce 1.0 to 1.6 GW each. The second and third waves of nuclear fission reactors offer the prospect of avoiding the difficulties of large PWRs and also open up new decarbonisation options. Smaller, factory-built ‘modular’ designs should allow lower capital costs and quicker construction, with major effects on lifetime costs- the cost of capital is by far the largest single contribution to the cost of electricity from large PWRs, and the White Paper talks about ways in which Government can reduce this cost. ‘Small modular’ PWRs, potentially the second wave, are based on a well established technology. For example, Rolls-Royce, who lead the project, say the first UK small modular reactors (SMR), which produce 440 MW, could be deployed in 10 years, with a build rate of two per year after that. There are many different candidate reactor concepts in the third wave, ‘Advanced Modular’ reactors. Some are quite well established, with prototypes and demonstrators having been built in the past. Others are still very much ‘Powerpoint Reactors’. The White Paper recognises the potential of SMR and advanced modular reactors (AMR), and offers the prospect of a substantial £385 million ‘Advanced Nuclear Fund’ to explore their potential.

A future for fusion?

Nuclear fusion is seen as a potential contributor. The White Paper explicitly sets out the aim to “build a commercially viable fusion power plant by 2040”. The UK Atomic Energy Authority’s (UKAEA) Spherical Tokamak for Energy Production (STEP) aims to build a prototype 100 MW fusion power plant by “around 2040” – but this is not even at the concept stage yet, and a call out just this month for communities to apply to be the host site. As with the more advanced fission reactors, STEP could offer options to produce electricity, hydrogen or synthetic fuels. The UK Government is already supporting the early stages of STEP’s development, with a £220 million fund announced in October 2019.

For all these grand aspirations, the White Paper actually sets out few firm deliverables for the nuclear contribution to the energy mix. The objectives set out in the White Paper are to bring at least one large nuclear project, presumably Sizewell C, to its Final Investment Decision (so still maybe 10 years from generation) by 2024, and also deliver STEP by 2040. And that’s it. If Hinkley C and Sizewell C are the only nuclear projects completed, this would, deliver about 6 GW, at the bottom of the potential range for a nuclear contribution. If Rolls-Royce deliver the UK SMR as they hope, that gives another 7 GW. AMRs and fusion reactors are much further away but, if all goes well, might yield another 5 GW in the 2040s, for a respectable total nuclear contribution of 18 GW by 2050.

Highly ambitious?

The 40 GW top end of the nuclear contribution starts to look extremely ambitious. Continuing production of UK SMRs at the rate of two per year after the initial 16 would give another 24 by 2050, which is 11 GW. Large scale nuclear build could be continued as well. The gap between the Hinkley C and Sizewell C is likely to be about 10 years – assuming that was reduced there would be the potential to generate another 10 GW by the 2050 target – just about achieving the 40 GW ambition.

To sum up, the bottom end of the target contribution for nuclear looks entirely achievable with the current technology available, but, if that is all we do, nuclear will pretty much be an irrelevance to achieving the overall net zero targets. Delivering the top end of the range requires new technologies, new ways of deployment, new uses of nuclear energy, all delivered for less money and in less time. That’s quite a stretching target for a historically conservative sector. This White Paper sounds very much like a gauntlet hitting the floor…

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