The Orano plant in La Hague, in La Manche, is the only one in the world to reprocess, with this level of expertise, used nuclear fuels after their operation. We take stock at the start of 2022.
What is fuel?
The nuclear fuel intended to supply electricity production plants – eighteen sites in France, fifty-six reactors – is enriched in uranium 235 (up to 4 to 4.5%) and uranium 238. Once loaded into the reactor, it is operated on average for four years. It is then unloaded, deposited in a small swimming pool located in the immediate vicinity in the EDF enclosure, where it remains at least six months, as the regulations require, the time that its thermal power decreases sufficiently to allow its transport.
He then left for the Orano factory La Hague (Channel) to be retired. This factory is unique in the world, due to its expertise (Japan, Russia and United Kingdom to a lesser extent). Since its creation in 1966, it has processed 40,000 tonnes of used nuclear fuel (today around 1,000 tonnes per year, which corresponds to French production). As soon as they arrive, the “packages” are immersed for another five years under 9 m of water in large storage pools, so as to keep them at low temperature and time to organize production according to customer orders.
96% recoverable material
How does reprocessing work?
In the nuclear reactor, the fuel is transformed. What remains is composed of 96% of recoverable material (95% of uranium, 1% of plutonium from the original uranium 238 which absorbed the neutrons) and of 4% of what are called the products fission or ultimate waste. The latter are extremely active and represent 99.8% of the total radioactivity of the spent assembly. Orano La Hague, according to a process developed by the Atomic Energy Commission (CEA), vitrifies them: mixed with glass frit, heated to 1,100 ° C, they form a paste poured into containers in stainless steel. Once cooled, the material appears in the form of a kind of obsidian (volcanic stone) which traps radioactive particles for over 100,000 years.
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This is what vitrified waste looks like. Some sort of obsidian. © Orano
Why retreat?
The recoverable 96% of the spent fuel is called upon to return to the electricity production circuit. The plutonium leaves for the Orano group’s Melox plant in Marcoule (Gard). Mixed with depleted uranium, it is part of the composition of MOX. This fuel now represents 10% of nuclear electricity produced in France. Uranium, now that the price of natural ore is soaring again, goes to the Tricastin plant where it is processed. Re-enriched, it becomes usable again by certain reactors.
EDF will use it in its Cruas plant (Ardèche) from 2023. “We will then exceed 20% of nuclear electricity produced in France coming from recycled materials. Ultimately, with EDF, we are aiming for more than 30% material savings ”, declared Philippe Knoche, CEO of Orano, in a interview at Ouest-France on October 20, 2021. The future will consist of “Move towards recycling already recycled fuels”.
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