Russia’s BN-800: Full mox core planned for 2022

25 February 2021

The first full refuelling of Russia’s BN-800 fast reactor at unit 4 of the Beloyarsk NPP with only uranium-plutonium mixed oxide (mox) fuel was completed during the recent scheduled maintenance outage, fuel company TVEL (part of Rosatom) announced. The unit, which was shut down on 8 January, has been reconnected to the grid and has resumed electricity production. The first 18 serial mox fuel assemblies were loaded into the reactor in January 2020, and another 160 fuel assemblies have now been added to them. Thus, the BN-800 core is now one-third filled with innovative fuel and in future only mox fuel will be loaded into the reactor.

“Beloyarsk NPP is now one step closer to implementation of the strategic direction for the development of the nuclear industry - the creation of a new technological platform based on a closed nuclear fuel cycle,” said Ivan Sidorov, Director of the Beloyarsk NPP. “The use of mox fuel will make it possible to involve in fuel manufacture the isotope of uranium that is not currently used. This will increase the fuel base of the nuclear power industry tenfold. In addition, the BN-800 reactor can reuse used nuclear fuel from other NPPs and minimise radioactive waste by “afterburning” long-lived isotopes from them. Taking into account the planned schedule, we will be able to switch to a core with a full load of mox fuel in 2022.”

The fuel assemblies were manufactured at the Mining and Chemical Combine (MCC, Zheleznogorsk, Krasnoyarsk Territory). Unlike enriched uranium, which is traditional for nuclear power, the raw materials for the production of mox fuel pellets are plutonium oxide produced in power reactors and depleted uranium oxide (obtained by defluorination of depleted uranium hexafluoride - DUHF, the secondary "tailings" of the enrichment plant.

Serial production of mox fuel began at the end of 2018 at MCC. To achieve this, broad industry cooperation was organized under the coordination and scientific leadership of TVEL, which supplies the mox-fuel to Beloyarsk NPP. Initially, the BN-800 reactor was launched with a hybrid core, partly equipped with uranium fuel produced by Mashinostroitelny Zavod and partly with experimental mox assemblies manufactured at the Research Institute of Atomic Reactors (NIIAR).

Photo: Rosenergoatom