A steel giant shaped like a hamburger, dominated by the red five-star flag. In this sci-fi setting, China has created a world first: to maintain for more than 100 seconds the conditions necessary for nuclear fusion, the grail of renewable energies.
The reactor installed in Hefei (East) carries out experiments within the framework of the Iter project, the huge international work in progress in the south-east of France to control the fusion of the atom.
In 2017, the Chinese machine broke the world record of duration for the maintenance of the conditions necessary for the fusion of atomic nuclei. Then last November, he smashed his own record by reaching the temperature of 100 million degrees, six times the heat produced in the very heart of the sun.
This “Advanced Experimental Tokamak Superconductor” is better known by its acronym “EAST”.
The tokamak, a magnetic containment chamber initially designed in the USSR, generates phenomenal heat for the purpose of melting atomic nuclei.
This “fusion” nuclear (whose principle is already used for the explosion of H bombs) should not be confused with the “fission” (division of atoms) that occurs in conventional nuclear power plants.
Nuclear fusion is considered the energy of tomorrow because it is infinite, like that of the sun, and produces no waste or greenhouse gases.
“With this machine, we hope to bring China’s contribution to the use of nuclear fusion by humanity,” said Song Yuntao, one of the leaders of the experimental reactor project.
Its Like Giant Bike Wheel –
The challenge is of course to keep these temperatures from hell in a sustainable way and to contain them in resistant materials. All this has a cost: more than 12 years after the launch of the project, the budget of Iter for example is estimated at nearly 20 billion euros.
In Hefei, the reactor sits inside a concrete structure. It is connected by cables and pipes to a tangle of measuring devices and other equipment, a decoration that evokes the spokes of a bicycle wheel.
Research on nuclear fusion is not new. According to Iter, the Jet project in the UK is so far the largest and most powerful tokamak ever built.
Other magnetic containment chambers, some of which are now out of service, have been built in Europe, the United States, Japan and South Korea, with sometimes better overall results than EAST, Wu Songtao, a Iter engineer.
“EAST reached 100 million degrees only in the heart of the machine and the temperature was much lower outside the core,” he says. “These parameters are still far from those expected for Iter.”
The reactor under construction in Saint-Paul-lès-Durance, which will be ten times larger than its predecessors, will have to reach 150 million degrees. The first tests are not expected before 2025.
Work Together –
China’s ambition is to build another nuclear fusion reactor which, unlike EAST, would be connected to the electricity grid, which it could begin to supply “around 2040 or 2050”, after the completion of the works in 2030 , according to Song Yuntao.
Budget planned for this post-Iter phase: 6 billion yuan (800 million euros).
These various projects “sit on Iter’s shoulders”, but they nonetheless demonstrate the scientific progress of China, said Mr. Wu.
If the country retains “20 to 30 years behind” the major industrialized nations in nuclear energy, “its capabilities have expanded rapidly over the last 20 years, especially since it got on the train. Iter, “notes the engineer.
Asked in 2017 by the official agency China New, the boss of Iter, Bernard Bigot, estimated the Chinese government “highly motivated” by the nuclear fusion project.
Because of its astronomical costs, “fusion is not something that states can do alone,” says Song. “As for Iter, the people of the world must work together.”