Tashkent, Uzbekistan (UzDaily.com) -- Power unit No. 4 of the Beloyarsk NPP with the BN-800 reactor has been connected to the grid and resumed operations upon completion of the scheduled maintenance.

For the first time the refueling has been carried out with uranium-plutonium fuel only. The first batch of 18 MOX fuel assemblies was loaded into the reactor core in January 2020, and now 160 assemblies more with fresh MOX fuel have been added (replacing the assemblies with enriched uranium). Thus, the BN-800 core is now one-third filled with innovative fuel. From now on, only MOX fuel will be loaded into this reactor.

“Beloyarsk NPP has become one step closer to implementing the strategic goal of the nuclear industry development - the new technological platform based on closed nuclear fuel cycle. This means that using MOX fuel will make it possible to involve the uranium that is not currently used in the fuel manufacturing and expand the resource feed-stock of the nuclear power industry. In addition, the BN-800 reactor can re-use spent nuclear fuel from other NPPs and minimize radioactive waste by “afterburning” long-lived isotopes from them. Taking into account the schedule, we will be able to switch to the core fully loaded with MOX fuel already in 2022”, Ivan Sidorov, Director of the Beloyarsk NPP, commented.

The fuel assemblies were manufactured at the Mining and Chemical Combine (MCC, Zheleznogorsk, Krasnoyarsk region). Distinct from traditional nuclear fuel with enriched uranium, MOX fuel pellets are based on the mix of nuclear fuel cycle derivatives, such as oxide of plutonium bred in commercial reactors, and oxide of depleted uranium which comes from defluorination of depleted uranium hexafluoride (UF6), the so-called secondary tailings of uranium enrichment facilities.

“In parallel with loading the BN-800 core with MOX fuel, the team of Rosatom specialists continues developing the technologies of such fuel fabrication at the MCC site. In particular, manufacturing of fresh fuel with high-background plutonium extracted from the irradiated fuel of VVER reactors has been mastered. All technological operations are fully automated and are performed without staff presence in vicinity. The first 20 MOX assemblies with high-background fuel have already been manufactured, passed acceptance, and are scheduled to be loaded in 2022. Advanced technologies of fissile materials recycling and re-fabrication of nuclear fuel in the future will make it possible to process irradiated fuel instead of storing it, as well as to reduce the accumulated volumes of waste”, said Alexander Ugryumov, Vice President for Research, Development and Quality at TVEL JSC.

The BN-800 reactor was initially launched with a hybrid core, partially loaded with uranium fuel produced by Elemash, TVEL’s fabrication facility in Elektrostal (Moscow region), and partially with experimental MOX fuel bundles manufactured at the Research Institute of Atomic Reactors in Dimitrovgrad, Ulyanovsk region (NIIAR).

Serial batch-production of MOX fuel started in late 2018 at the site of the Mining and Chemical Combine. The launch of this unique highly automatized fabrication shop-floor had been provided due to the broad cooperation of Russian nuclear industry enterprises with the coordination role of TVEL Fuel Company, which is also the official supplier of the MOX fuel to Beloyarsk NPP.