Russia’s Electrochemical plant (ECP) (part of Rosatom’s fuel company TVEL) said on 7 April that it is building the second depleted uranium hexafluoride (DUHF) processing unit in Zelenogorsk, Krasnoyarsk Territory). The commissioning of the W2- EKhZ unit, scheduled for 2023, will double the capacity of the enterprise for processing DUHF from 10,000 to 20,000 tons a year.
After the completion of the preparatory work, pouring of the foundation of the future premises of the production site will begin. In November 2021, the first batch of the main equipment for the plant is expected to arrive from France, where it is being manufactured at the enterprises of the Orano Projets company. The general contractor for the construction work is TVEL-Stroy and from 2022 Orano Projets specialists will be involved in the installation of technological equipment.
The construction project of the W2-EKhZ unit is being implemented within the framework of the industry programme for the safe handling of depleted uranium hexafluoride. It is aimed at slowing down the accumulation of uranium tails, a waste product of uranium enrichment, and in future, it will undertake stage-by-stage liquidation of all DUHF stocks accumulated at Russian uranium enrichment enterprises. It is planned to multiply the capacity for defluorination of DUHF using such installations which convert uranium hexafluoride into chemically safe uranium oxide powder. In this form, depleted uranium, which is much less radioactive than natural uranium ore, can be stored for a long time in a solid state in containers in open areas without any risks to the environment, and is completely safe for transportation.
Defluorination technologies also make it possible to turn the accumulated reserves of depleted uranium into a valuable raw material for the nuclear power industry of the future. Depleted uranium that is needed to make uranium-plutonium for fast reactors, in particular, mox fuel, currently used in the BN-800 reactor at the Beloyarsk NPP, as well as MNUP fuel for the Brest-OD-300 reactor under construction at the Siberian Chemical Combine (SCC) in Seversk, Earlier this year, Rostekhnadzor issued a licence for the construction of the Brest reactor being built as part of the Proryv (Breakthrough) project to demonstrate a closed fuel cycle. In addition, fluorine-containing products obtained as a result of the defluorination of hexafluoride (hydrofluoric acid and anhydrous hydrogen fluoride) can be marketed as certified chemical products.
“Modern recycling technologies are already making it possible to return DUHF to the fuel cycle and, in the long term, resolve the issue of the resource base of the nuclear power industry for centuries to come,” said Mikhail Zarubin, Senior President for Production at TVEL. “This is relevant primarily for Russia, where the strategy of two-component nuclear power with thermal and fast neutron reactors is being implemented. Our centrifuges re-enrich depleted uranium, the W-EKhZ unit de-fluorinates already “twice depleted” uranium, and the newest fuel fabrication facilities use the uranium oxide for the production of mox fuel assemblies.”
ECP has more than 10 years of experience in processing DUHF. Since 2009, more than 100 thousand tons of DUHF have been processed at the existing W-EKhZ unit. The contract for the supply and installation of equipment for the second similar unit between ECP and Orano Projets was signed at the end of 2019. The W2-EKhZ is being developed jointly by French engineers and ECP specialists.
The sectoral programme for the safe handling of DUHF provides for the commissioning of two units similar to the W-ECP by 2028 at the site of Urals Electro-Chemical Combine (UECC) in Novouralsk with a total capacity of 20,000 tons of DUHF a year, as well as the commissioning of another unit based on domestic technology at JSC SCC with a capacity of up to 12,000 tons a year. Rosatom has set a task to completely process all DUHF stocks at Russian uranium enrichment enterprises by 2057.