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It’s official: the design of a European nuclear fusion power plant has now begun, with the aim of commercializing this “clean” electricity by 2054. The first phase, lasting five years, will be devoted to key technology decisions that will help move fusion power from concept to commercial exploitation. The demonstration plant, dubbed DEMO, should provide power of 300 to 500 megawatts.
Research in the field of nuclear fusion is going well. It is indeed one of the best solutions envisaged for producing energy without CO2 emissions or radioactive waste. Because it relies on almost inexhaustible resources and presents no risk (for humans or the environment), nuclear fusion is considered a safe and sustainable source of energy. Many physicists are trying to design the ideal reactor capable of producing more energy than is needed to initiate and sustain the fusion reaction.
Records in terms of plasma efficiency and lifetime are becoming more and more frequent – proof that we are getting ever closer to the goal. Most of the projects use tokamaks, machines designed to confine burning plasma using powerful magnets. The DEMO plant will be no exception: it too will rest on a tokamak, then collect the heat of the reaction to transform it into electricity. But many parameters remain to be defined before considering its construction.
A project that brings together nearly 5,000 experts from all over Europe
The EUROfusion research consortium unites nearly 5000 experts from across Europe around the largest and most comprehensive fusion R&D program in the world. Earlier this year, EUROfusion researchers already demonstrated the potential of fusion by setting a world record of 59 megajoules of sustained fusion energy at the Joint European Torus (JET) in Culham, UK — currently the largest and most powerful tokamak in the world.
This recent record reinforces the credibility of the ITER project, currently under construction in the south of France – whose first plasma production is scheduled for December 2025 – and also stands in favor of the development of the DEMO plant. The JET, like all the other existing tokamaks, serves as a sort of test bed; they are an opportunity to test different materials and containment devices to determine the best way to produce energy. But so far, the “net gain” in energy has never been achieved.
The plant will need to be able to control and sustain the plasma much longer than the experiments performed so far. Until then, several problems remain to be elucidated, starting with the breeding of tritium – one of the two fuels necessary for the reaction. The fusion of deuterium and tritium (which are two isotopes of hydrogen) will produce a helium nucleus and a neutron. Deuterium can be obtained from water, so it is almost inexhaustible. Tritium will be produced during the fusion reaction, when the generated neutrons interact with the lithium modules covering the vacuum chamber.
It is still necessary that the neutrons can escape from the plasma to come and strike the walls of the tokamak and that these are able to resist this influx of neutrons! This is also valid not only for the demonstration plant, but also for all the other fusion reactors, such as ITER. The shape of the tokamak, elongated or spherical, must also be carefully considered.
A state of the art shared with the entire scientific community
The team gathered around DEMO presented the results of its pre-conceptual phase (2014-2020) in a special issue of the journal Fusion engineering and design. It thus shares the state of the art in the design of demonstration power plants, through 25 peer-reviewed open access scientific publications. The design of magnets, the choice of materials, the production of tritium, the extraction of heat, nuclear safety, … absolutely all critical points are addressed.
” DEMO’s design and R&D activities in Europe benefit greatly from the experience gained during the design, licensing and construction of ITER underline Gianfranco Federici, Head of the Fusion Technology Department at EUROfusion, and Tony Donné, EUROfusion Program Director. Both are a reminder, however, that uncertainties in fusion science and engineering will persist throughout the design and engineering phases.
The two researchers also specify that the work of DEMO cannot wait for the completion of ITER: “ If DEMO engineering design efforts begin too long after ITER delivery, a highly skilled and experienced workforce will be lost to other industries, with an inevitable brain drain and loss of lessons learned. they write at the conclusion of the series of articles, insisting that education and training programs dedicated to nuclear fusion will be essential to support its development and deployment.
The conceptual design is expected to be completed in 2027, but DEMO is unlikely to be the world’s first nuclear fusion power plant. Indeed, several private companies in the sector, such as Tokamak Energy and First Light Fusion, in the United Kingdom, plan to commission a power plant in the 2030s. China has announced that its Fusion Engineering Test Reactor in China (CFETR) will produce up to 2 gigawatts when completed around 2035. The UK is also said to be about to launch its first fusion power station, dubbed STEP (for Spherical tokamak for power generation), whose construction will be completed around 2040.