Scientific Foresight (STOA) By / July 7, 2023

What if we could make nuclear fusion work? [Science and Technology Podcast]

If it is to achieve the Paris Agreement objective of keeping the rise in global temperature well below 2° C, the EU must consider every possible technology to decarbonise energy production.

© Culham Centre for Fusion Energy

Written by Antonio Vale with Clemens Weichert.

If it is to achieve the Paris Agreement objective of keeping the rise in global temperature well below 2° C, the EU must consider every possible technology to decarbonise energy production. Nuclear fusion is the process that powers the sun and it can be reproduced on Earth. However, even once the considerable engineering challenges of designing a fusion power plant are overcome, there are major constraints inherent in upscaling fusion power.

The basic function of a nuclear fusion reactor is to combine two hydrogen nuclei into a single helium nucleus with slightly less mass then the sum of the two original nuclei. The lost mass is converted into energy. This process is the power source behind both the sun and the hydrogen bomb.

The physics are known and the fuel is readily available. When harnessed in a controlled reaction, fusion power can provide low‑carbon electricity. Research into such civilian use cases has been ongoing since the 1950s. In facilities like the Joint European Torus (JET) near Oxford, scientists are able to heat up plasma to the necessary temperatures, 10 times as hot as the core of the sun. However, heating the plasma and keeping it confined in the reactor requires energy-intensive magnets, or lasers, that use a great deal more energy than the fusion reaction generated. This is a major engineering challenge.

While most approaches use magnetic confinement and a mixture of two fuels – deuterium and tritium – there are numerous variations in fuels and confinement methods. US researchers at the National Ignition Facility (NIF) use inertial confinement, and in 2022, for the first time, they achieved ignition: a net energy gain from a fusion reaction, though not nearly enough to account for the electricity demand of operating their equipment.

Nuclear fusion research has so far relied on purpose-built, state-funded research facilities such as JET and NIF. A next generation facility – the result of an international cooperation project called ITER – is being built in southern France. The EU is funding 45 % of the project, which is set to produce its first plasma in 2025 and start full operation in 2035. Once results are in, ITER is to be followed by a prototype plant with a capacity of 1 GW – powerful enough to cover half of Berlin’s electricity consumption in 2022 – to demonstrate operational viability. However, according to the generally accepted timetable for this pathway, fusion energy will not be on the grid until long after 2050, too late for the green transition.

Nevertheless, some private companies, such as Commonwealth Fusion Systems, are promising a working power plant before 2040. Although the probability of these companies meeting their ambitious goals should not be overstated, they are using the insights generated by JET to improve on the formula in a number of ways, such as using high-end magnets. Should one of them achieve a breakthrough – that is, a self-sustaining fusion reaction with a significant net energy gain – a fusion power plant might be able to feed electricity into the electricity grid much sooner than currently predicted.

Potential impacts and developments

Once the scientific and engineering challenges are overcome, the construction of the first fusion power plants can start. In this scenario, the availability of raw materials, fuels, and qualified workers would represent hard constraints on scaling up the technology. Capital costs and regulations pose soft constraints. Building a fusion reactor requires rare earth elements such as neodymium for the magnets. These are already at a very high supply risk because of their use in wind turbines and electric vehicles, as well as the dominant role China plays in their extraction and processing. For fuel, ITER-style reactors require tritium, which is only commercially produced by nuclear power plants of the CANDU type, all of which will retire in the coming decades. In theory, fusion power plants should be able to ‘breed’ their own fuel supply, but this has not yet been achieved. Securing the initial amount to start the reaction will prove to be a ‘make or break’ criterion for the industry. While some approaches circumvent this problem by using a different fuel mix, most public and private funding goes to start-ups using deuterium and tritium, as the most efficient mix.

Building and operating a fusion power plant would require a large workforce of nuclear engineers, metal‑workers, and electricians. While these are well-paid jobs, the difficulty currently being experienced in France with staffing new conventional nuclear plants gives an idea of some of the problems a fusion power project would run into. Just like nuclear fission plants, which gain energy from splitting atoms, nuclear fusion plants will take a long time to plan and build. For a fission plant, construction normally takes 5 to 10 years; similar timeframes would apply to fusion plants. Depending on the tritium breeding rate of a future power plant, scaling up could take decades. On top of these hard constraints, soft constraints come into play. More specifically, the upfront capital costs of construction will presumably be very high. By way of comparison, recent fission plants have cost over €10 billion to build.

However, the rewards of achieving fusion power would be considerable. Proponents highlight the low carbon emissions, the availability of deuterium fuel extracted from sea water, and the small land-use footprint as advantages of fusion power. Though some radioactive waste is produced, it poses little danger given the small quantities and short half-life. The main promise is that fusion power will produce a constant supply of cheap electricity for the decarbonisation of industry, transport and heating. Furthermore, falling electricity prices might also enable other future technologies such as vertical agriculture, desalination – an energy intensive technology to provide water for agriculture and utilities – or even direct carbon capture and storage from the atmosphere. Although fusion power plants could provide a constant baseload of electricity, they would not be able to adjust quickly to fluctuating supply and demand.

Anticipatory policy-making

The EU has two major programmes in place in the field of fusion energy. One is its contribution to ITER, the other is the Euratom research and training programme. ITER, meaning ‘the way’ in Latin, will be the largest fusion reactor of its kind upon completion. The EU contribution to ITER is managed by Fusion for Energy, which is responsible to Euratom and its Member States. Over the 2014-2027 period, the EU will spend €8 billion on the project. The 2016 roadmap schedules the beginning of operations for 2025. In the same timeframe, €1.5 billion – close to half of Euratom’s research and training budget – will go to fusion research. These funds go to organisations such as Eurofusion, a consortium that works within the official fusion roadmap towards the success of fusion energy, for example by funding young researchers in fusion training and education. In this way, the EU is already addressing the workforce challenges that a commercial fusion project will bring. The Union is therefore taking a leading role in fusion research worldwide.

Implementing the proposed EU regulation on critical raw materials would significantly improve the security of supply of some elements that are crucial for any fusion reactor, such as rare earths and lithium. Appropriate safety regulations should take into account the far lower risks compared with fission plants. With regard to the high capital costs of a fusion power plant, some degree of state funding might be considered, since even scientists who are convinced of the feasibility of building a fusion power plant have been voicing concern about their profitability since the 1970s.

Even under the most optimistic scenario for developments in fusion energy research and development and in a favourable political environment, the hard constraints of tritium supply, construction times, and workforce availability make fusion energy a long-term prospect. Entering a future electricity market dominated by renewables, fusion plants will not be able to provide flexible electricity at times of peak demand. Their production costs will therefore be the decisive factor in market entry, determining whether they can provide baseline power to the grid at a price that can compete with renewables-charged energy storage options. Nevertheless, with a variety of actors pursuing a wide range of approaches to fusion, one of them might just find a solution to these problems.

Read this ‘at a glance’ on ‘What if we could make nuclear fusion work?‘ in the Think Tank pages of the European Parliament.

Listen to podcast ‘What if we could make nuclear fusion work?’ on YouTube.

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