Decoding: six questions to understand the flow of reprocessed uranium between France and Russia

Since 2018, EDF has decided to restart its reprocessed uranium (RU) recycling from spent fuel in its Cruas reactors. Orano, for its part, had signed a contract to sell part of its RU stocks to be used as fuel in Russia. In both cases, agreements were signed with Russia, which has plants dedicated to the conversion and enrichment of RU. If the French industry were to rethink these agreements, given the geopolitical situation, this would not significantly impact the nuclear power plant.
Has France received Russian uranium?

In early December, France received containers of uranium from Russia. This delivery raised a debate on the alleged dependence of the French nuclear power plant for its fuel needs. This material is enriched reprocessed uranium (RU), owned by EDF, which returns to EDF after conversion and enrichment in Russia. EDF does not import natural uranium from Russia. While some European countries import Russian uranium, Russian exports to France have collapsed since 2016-2017.

What is reprocessed uranium?

RU is the uranium from used nuclear reactor fuel after reprocessing at La Hague. It is a recoverable material that can be converted and enriched for recycling in our current reactors, thus saving resources from the mine. RU contains about 0.9% U235, slightly more than natural uranium (about 0.71%). According to Andra’s material balance, France held about 34,100 metric tons of RU on its territory at the end of 2020. These stocks belong to EDF, Orano, and foreign customers.

Why does EDF need RU?

EDF has a stockpile of about 25,000 tonnes of RU, growing by about 1,045 tonnes per year. In France, only the four reactors at Cruas (Ardèche) are certified to use enriched reprocessed uranium fuel (ERU). The four reactors can operate in a range from 0 to 100% of ERU. EDF’s goal is to increase this rate to the maximum, which will take about four years from 2023. EDF will then consume about 500 tonnes of RU per year. After a call for tenders, the electricity company called on Russian industrial installations to convert and enrich its RU. But this recoverable material remains the property of EDF at all times.

EDF’s ambition is eventually to have the 1300 MW reactors certified to consume RU, which would allow the consumption of about 1,350 tonnes of RU per year (while the 900 MW level will be reserved for Mox). By combining these recycled materials, the national electric utility achieves significant savings on virgin material. Using RU allows for consuming 15% less material and Mox 10% less. For the record, France consumes about 7,000 tons of natural uranium annually.

Why is the conversion and enrichment of RU done in Russia?

In addition to uranium 235, RU also contains many other isotopes. In the book “Histoire et technique des réacteurs nucléaires et de leurs combustibles” (Dominique Grenêche, EDP sciences), one can read for example: “it (RU) also contains a fairly high proportion of U236, which is of the order of 0.5% (…). However, this isotope is a neutron poison since it only captures neutrons without giving rise to a fissile isotope. Moreover, separating it from U235 in an industrial enrichment operation is impossible since the two isotopes have practically the same mass. U232 also poses a problem because it gives rise to descendants that pose radiological constraints.

Thanks to Orano’s industrial installations, France has technical and industrial control of the entire uranium conversion and enrichment chain. But the use of reprocessed uranium would require the deployment of a specific workshop for the conversion of RU. And it would be necessary to reserve a series of dedicated centrifuges in the GBII plant, where 2 of the 14 modules of the present plant are designed to enrich RU. Otherwise, the natural uranium production lines would have contained undesirable isotopes. Before the war in Ukraine, the choice was made to subcontract these operations to Rosatom’s Seversk site, where capacity is available. This choice was dictated by economic and industrial reasons and not by reasons of technological mastery.

Are these RU contracts with Russia indispensable?

In both cases, these contracts were decided before the conflict in Ukraine. Even though they are not necessary to supply France with fuel, the motivation is to include the sector in circular economy practices. France had already conducted an effective RU enrichment campaign between 2000 and 2010. Then it gradually decreased until it completely stopped in 2014. It was decided to restart this option in 2018.

The new geopolitical situation could lead to a rethinking of these contracts without difficulty since France can do without RU to operate its entire fleet. However, Orano could consider building a workshop dedicated to converting RU for enrichment under the condition of assured contracts. However, given the regulatory obligations concerning constructing nuclear facilities in France, such a project would require approximately seven to ten years. Partnerships with other players, such as Westinghouse, could also be envisaged.

What about Orano’s RU stocks?

As interest in using recycled uranium grows with the rising price of uranium, Orano has signed a contract with Rosatom (the Russian operator) to supply 1,150 tons of recycled uranium for conversion and re-enrichment at its Seversk plant in Russia,” Orano said. “The fuel produced from the recycled uranium supplied by Orano will be used in Rosatom’s reactors,” the company said. In this case, the material is sold from France to Russia. This contract signed in 2020 has now been settled. ■

By Ludovic Dupin and Valérie Faudon (Sfen)

Photo: Uranium pellets – @ Areva/US NRC