This article is taken from the monthly journal Sciences et Avenir – La Recherche No. 900 of February 2022.
“An almost inexhaustible, safe source of energy with low environmental impact. The promise, presented as a slogan on the website of the experimental reactor Iter, currently under construction in Saint-Paul-Durance (Bouches-du-Rhone), seems extremely attractive. And it is not for nothing that 35 ITER partner countries will pay 20 billion euros for this gigantic experiment. At the same time, a lot of work is underway in the world to master thermonuclear fusion, including by start-ups.
Technology at the experimental stage
Because on paper this type of reaction has huge advantages. The fusion of deuterium and tritium nuclei, two isotopes of hydrogen (formed from a proton, but also from one and two neutrons, respectively), releases four times more energy than when fissioning uranium into an equal mass of fuel, and eight million times more, than burning oil. It does not pose a risk of runaway or meltdown of reactors, therefore, there is no danger of an accident like the one that occurred at Fukushima (Japan). Fuel is present in abundance in the earth’s crust or oceans. And the main product of the reaction is helium, a non-toxic inert gas. Mostly, “Unlike conventional nuclear processes, fusion does not produce long-lived highly radioactive waste. ” insists Jérôme Boucalossy, director of CEA’s magnetic confinement fusion research institute in Saint-Paul-le-Durance.