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A new test facility has gone into operation in Japan. The reactor is of the same type as a plant in southern France that has been under construction since 2007.
What is it about? The world’s largest test facility for a nuclear fusion reactor has officially been put into operation in Japan. The JT-60SA plant in Naka, north of Tokyo, is a Japanese-European cooperation project. Until the European Iter reactor under construction in Cadarache, southern France, goes into experimental operation, the Japanese plant will be the largest of its kind of the tokamak type. Switzerland is also indirectly involved in the JT-60SA through the Iter project.
What is nuclear fusion? Nuclear fusion involves fusing atomic nuclei together at extremely high temperatures. Enormous amounts of energy are released – but comparatively little radioactive radiation. The radioactive waste from a fusion reactor will one day be correspondingly small and relatively short-lived. Conventional nuclear power plants, on the other hand, obtain their energy from the splitting of atomic nuclei. A lot of radioactive radiation is released – and a lot of very strong and very long-lasting nuclear waste is generated.
The difficulties with the fusion reactor are fairly well recognized – and I’m confident we can do it.
How does the tokamak reactor work? The facility in Japan – like Iter in southern France – consists of a donut-shaped container, the tokamak, in which plasma held in orbit by immensely powerful electromagnets is heated to 100 million degrees Celsius. The aim is to cause hydrogen nuclei to fuse and release energy – like in the sun. In order to bring about nuclear fusion, a considerable amount of energy is initially required. In Japan, plasma operation should now be able to be examined in more detail than before.
Why this expensive fusion research? “Fusion is the ideal energy source – safe, clean and practically unlimited,” says Christian Theiler. He is an assistant professor of physics at the ETH Lausanne, where nuclear fusion research is also carried out. “We need such an energy source – in conjunction with other energy sources – in a future energy mix.” Theiler expects that fusion power plants could go into operation from around 2050: “The difficulties are pretty well recognized – and I am confident that we can do it.”
Is this the solution to the energy problem? In the long term, fusion power plants could become a clean alternative to burning fossil fuels and the controversial nuclear energy, say their supporters. For critics and environmentalists, however, fusion technology is far too inefficient, complex and expensive. Above all, nuclear fusion is at least decades away from being ready for the market – that’s why renewable energies such as wind and sun are better alternatives for a rapid energy transition, say the critics.