The UK has committed to a net zero 2050 target, but what place does nuclear energy have in meeting this ambition? In this blog, Professor Francis Livens from the Dalton Nuclear Institute outlines the recommendations of a new roadmap for the UK’s nuclear sector, including its role in hydrogen production, and what steps are needed to make the UK a key-player in the next generation of nuclear reactors.

• There is a role for nuclear power in meeting the UK’s net zero targets, but policymakers must move quickly to implement it.
• Advanced nuclear reactors could be used to cleanly produce hydrogen fuel for use in other hard-to-decarbonise sectors.
• With clear leadership, the UK has the potential to be a global hub in advanced reactor production and fuel recycling.

Last year’s Energy White Paper set out a very stark challenge for the UK’s nuclear sector– ‘show that you can play a safe, economic part in helping reach our net zero ambitions, and you have a future; fail to do so, and you don’t’. Net zero, and particularly the potential role of hydrogen in achieving it, has been the subject of much discussion recently, and our recent position paper, Nuclear energy for net zero: a strategy for action, specifically explores the relationship between nuclear energy and hydrogen.

The first point to make is that Net Zero is a massive challenge – electricity production, where the UK has made good progress with decarbonisation, is only about 20% of total UK energy demand, and complete replacement of carbon fuels requires enormous change in the whole energy system. The White Paper starts to recognise this and spells out possible roles for renewables, gas with carbon capture and storage, and nuclear, but the reality is that the scale of the problem is so huge that the UK has to explore all these options. Indeed, as the report was in the final stages of preparation, EDF announced their decision not to re-start the Dungeness B nuclear plant in Kent. Whilst it was never credible or intended that Dungeness B would remain in operation until 2050, this decision makes the challenge of continual progress in UK emissions reduction all the harder in the coming years.

As these technologies become better understood, their significance may change, and ruling out potentially useful options would hinder progress unnecessarily. The UK must urgently develop the ability to compare honestly and objectively different technologies, both nuclear and non-nuclear, across their whole life cycle.

Nuclear Power and hydrogen

Hydrogen is attractive for the decarbonisation of some energy sectors where electric power is unsuitable, and could have a large role in the decarbonisation of transport, industry, and domestic heating. Electrolysis (using electricity to split water into hydrogen and oxygen) is one route. The better established electrolysis processes are, however, pretty inefficient and expensive, particularly if you are switching your plant between electricity generation when demand is high and hydrogen production when there is an electricity surplus. Although conventional nuclear energy is optimised for the production of electricity, advanced nuclear reactors, which can produce much higher temperatures than the 300°C or so of conventional ones, have a unique attraction since you can avoid the inefficiencies of electricity generation and, instead, use the reactor heat to drive processes like thermal decomposition of water directly, which is much more efficient than electrolysis. To develop this radical option, we need clear leadership and a strong focus on the feasibility of these technologies, followed by rapid development if they do turn out to have a part to play.

Delivering

Time is critically short. You do not demonstrate a nuclear technology, license it and deploy it quickly, so if advanced nuclear is to play a part, development needs to start now, to give enough time to demonstrate it for rapid deployment by the early 2030s. The very recent opening up of the regulatory assessment process to advanced nuclear technologies is a welcome first step. Nonetheless, this compressed timescale severely limits our choice of nuclear technology and we conclude that only the High Temperature Gas-cooled Reactor (HTGR) is a realistic option, not least because there is the possibility of international collaboration to speed things up. Delivering this requires consistent leadership and commitment comparable to that shown in the fusion arena by the UKAEA.

HTGR technology uses different fuels from conventional reactors and, although the UK actually has quite a good understanding of HTGR fuel, it needs to be able to manage and operate the whole fuel cycle. In particular, HTGR fuel is unlikely to be recycled, even though only around 1% of the total energy potential of the fuel is used. While the economics of recycling nuclear fuel are unfavourable at present, fuel recycling might be something the UK wants to do in the second half of this century if the world goes nuclear in a big way.

There are, however, major challenges in deploying HTGRs. High operating temperatures stress the reactor materials so there is a tension between seeking ever higher temperatures and the design challenges, particularly in materials selection and performance. Beyond these technical issues, HTGRs will also be deployed in new ways, potentially close to towns and cities, or major industrial plants, or collocated with hydrogen production facilities. The societal and regulatory aspects of using nuclear energy in this way are likely to be some of the most difficult aspects of deployment.

The opportunity

HTGRs, with hydrogen, could be game-changing, or could be an irrelevance, and the UK needs to answer this question honestly and urgently. Government needs to have access to competent advice, not just on nuclear energy, but on all aspects of the energy system and, in the case of HTGRs, there is an urgent need for evaluation and a decision.

If HTGRs have a part to play, then the relative immaturity of the technology actually presents an opportunity for the UK. Building maybe tens of HTGRs in the UK is a strong foundation for a UK industry – the country has the R&D base, can make fuel, and has the chance to reinvigorate the high quality manufacturing needed, all capabilities currently focused in NW England and North Wales. While the potential impact of HTGR has not been quantified, the proposed and complementary UK SMR programme, which is comparable in scale, is estimated to offer as many as 40,000 high quality jobs.

The UK needs to move fast to resolve the question of whether or not it is willing to go forward with HTGRs and hydrogen, and if so, to take any opportunity which is there. If it continues to prevaricate, any opportunity will certainly be lost.

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Energy is one of The University of Manchester’s research beacons. Our energy and climate change researchers are at the forefront of the energy transition, collaborating with governments, businesses and institutions to develop innovative, real world solutions to drive a green recovery and help achieve next zero. As the UK prepares to host the COP26 climate summit, read our collection of blogs on climate change for more evidence-based policy solutions.