New Nuclear


Nuclear’s part in a net zero future

Paul Monks

Professor Paul Monks BSc DPhil FRMetS FRSC is Chief Scientific Adviser (CSA) for the Department for Business, Energy and Industrial Strategy (BEIS). His role is to deliver independent and impartial scientific advice to Ministers and policy makers. Prior to joining the department, Professor Paul Monks was Pro-Vice Chancellor and Head of the College of Science and Engineering at the University of Leicester, where he remains a Professor in Atmospheric Chemistry and Earth Observation Science.


  • By 2050, most of the UK’s energy will come from renewable sources
  • Because of its variability, there will need to be a way to load-balance using low carbon energy and storage
  • Nuclear energy can meet that need
  • Nuclear can also provide large quantities of heat for a variety of applications
  • One of the challenges will be ensuring sufficient skilled people and researchers to deliver this agenda

To achieve net zero by 2050, the UK needs to decarbonise its economy, the starting points for which will include reducing demand and increasing the efficiency with which we use energy. There are a number of low carbon solutions available and co-generation is high on the list. Indeed, it is low carbon energy that is important, rather than just electricity, which only accounts for 17% of total energy demand. For comparison, about 40% of the total energy supply is used in transport and 43% in heating.

The British Energy Security Strategy (BESS) speaks about significant investment in new nuclear, but it is not possible to discuss the role of nuclear without thinking about what the rest of that system looks like. The more renewables on the system, the greater the variability. How then, on a winter’s day, can 7TWh of supply be guaranteed? It is forecast that the UK will need to double the amount of electricity as we decarbonise.

The story of BESS started in November 2020 with a template for the Green Industrial Revolution. In October 2020, as part of efforts for COP26, the Government produced the Net Zero Strategy for the UK, which the Committee on Climate Change has described as one of the most comprehensive strategies ever produced by a country. The invasion of Ukraine by Russia then focussed minds on the scale of the ambition, which was brought together in BESS.

This was published as a package of ambitious measures for a secure, clean, and affordable energy system. The Strategy includes an aspiration for 24GW of new nuclear by 2050, which would account for 25% of our projected energy needs. To achieve that, the Strategy establishes Great British Nuclear as the new delivery body for this technology.

However, the Strategy also considers the next generation of nuclear beyond gigawatt stations and has set up the Future Nuclear Enabling Fund. Other ambitions in the Strategy will help drive a more rapid decarbonisation of

our energy system by 2050 and address the demands of changing energy usage. For example, financial models will have to change in order to achieve the required investment in nuclear.

It is not just about building power plants, it is also the way the system as a whole operates in the future. We currently have plans for gigawatt stations and for Small Modular Reactors (SMRs). Looking beyond that, Advanced Modular Reactors (AMRs) are the next generation of small reactors, designed to take forward the promise of cogeneration. In the longer term, there is nuclear fusion and BEIS has been taking this forward through the STEP (Spherical Tokamak for Energy Production) process.

Regarding AMRs, the High Temperature Gas Reactor is our preferred solution as the AMR RD&D programme makes clear. Gas reactors are a well-understood technology, the UK supply chain is familiar with them and has the skills to deliver them. This is existing technology which will need some enhancement. This may take the best part of 20 years, but it is still only changes to an existing technology.

Cogeneration is a critical part of this story. Some 65% of the energy created in a nuclear station is wasted as heat, yet this is a commodity. As we decarbonise, we must become much more efficient in the way that we use that heat.

In the new energy system, base load will be created, essentially, by renewables. Nuclear will be used to balance the load. However, to do so, we will have to invert the accepted way of doing things. There are many other applications for nuclear energy, such as hydrogen production, direct air capture, seawater desalination, and making ammonia for maritime uses.

BEIS has been working on the role of R&D in this area. One of the key challenges will be finding the right people to deliver this programme. There will be a need for skilled people who know how to do nuclear operations, who can research the science and build the plant. There are generations of jobs here. At the same time, it should not be forgotten that some of these skills have been lost as that specialist group of workers has aged and retired. This country will have to make sure it trains the people, delivers the skilled workforce needed and funds the R&D that gives longevity to the nuclear programme.

In terms of cost, there is a tendency to think about nuclear in the wrong way. This must be put in the context of the system cost of electricity, not only the generation cost. We spend billions on load balancing per annum, but that is not yet thought of as a primary cost of the electricity system. We must think about the levelised cost of the total system. Nuclear offers a trade-off between capacity and generation.

The British Energy Security Strategy sets out the scale, magnitude and speed of the Government’s ambition in this area. There is no harm in pushing hard and fast to decarbonise our economy in a world that needs it.