“In France, we have no oil, but we have ideas,” hammered former president Valéry Giscard d’Estaing. In China, there is a lack of uranium, but we are full of thorium, could be retorted. The reserves of this slightly radioactive metal, which can be used to make nuclear fuel, would even be considerable: according to the Chinese media, they would provide the energy needs of the whole country for sixty thousand years!
In an international context where each nation dreams of energy independence today, the announcement of such a national treasure does not go unnoticed. In the United States, some bosses are already calling for a specific Thorium inventory from the Trump administration. No question of leaving China the slightest technological advantage. However, there is a catch: Thorium has everything of a false good idea. Admittedly, it is three to four times more present on the planet than uranium, estimates the International Energy Agency. But to use it to supply nuclear reactors poses many difficulties.
“It’s a bit like extracting uranium in sea water or sending our nuclear waste on the moon: it is possible, but with a cost and a complexity that does not really make sense”, details Dominique Greneche, doctor of nuclear physics and member of the NGO PNC-France (nuclear heritage and climate). So far, India is the only country to have pushed the experiment, for geopolitical reasons. Following nuclear tests conducted in 1998, the country, banned from the international community, could no longer buy uranium. However, he owned significant thorium deposits.
But after almost thirty years of development, India is still far from mastering this technology. “Currently, it has set up a complex system in three stages. It first produces plutonium using heavy water reactors, a technology different from that which we use, with pressurized water. It then mixes this plutonium with thorium in another type of reactor in order to produce uranium 233 which is ultimately recycled in heavy water reactors”, details Dominique Greneche.
The beginnings of a new nuclear
Operating a power station with only thorium is feasible. But perhaps it would take a century of development before achieving it, assures the specialist. For France, this path seems excluded. In addition to having new reactors, the country should review the entire fuel chain. Upstream, first. “The manufacture would be delicate because of the fairly intense radiation emitted by uranium 232, an isotope associated with the formation of U 233. It would take place” from a distance “, behind thick protective screens, in armored cells”, explains Dominique Greneche. Downstream of the chain, then, the reprocessing of the worn fuels, much more difficult to dissolve, would also pose technical challenges.
Will these barriers discourage China? The moment chosen by Beijing to communicate on his Thorium reserves is not trivial. A shock on the uranium supply is looming by the end of the century. “If the promises to triple the global nuclear capacity are emerging -it was one of the commitments made during COP28 -then we will touch the ‘ceiling’ of the identified resources recoverable from 2040-2050,” warns Claire Kerboul, doctor specializing in nuclear physics and author of The urgency of sustainable nuclear power (Of upper Boeck). However, China builds nuclear power plants at all costs. At the head of a nuclear fleet equivalent to that of France, it has 36 new reactors in its boxes. Beijing therefore has an interest in looking at technologies allowing it, ultimately, to do without the usual fuel. Or save it.
“The best option for China is still the construction of fast neutron reactors (RNR),” says Dominique Greneche. Capable of operating by burning part of the current nuclear waste, it can also offer thousands of years of energy sovereignty. In addition, it is a better controlled technology. Ironically, France was one of the most advanced countries in the world in this field before stopping brutally, in 2018, the Astrid reactor project. China will probably not make the same mistake. It already has an RNR and should put a second in service in 2026. Perhaps the beginnings of a new nuclear.
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