Specialists at Russia’s AA Bochvar Research Institute of Inorganic Materials (VNIINM), part of the Rosatom’s Fuel Company TVEL, have developed a technical design for a fuel element based on uranium-plutonium nitride fuel (MNUP fuel) for the BREST-OD-300 fast breeder reactor. This will form the basis for the industrial production of MNUP-fuel, which will be launched as part of the Experimental Demonstration Energy Complex (ODEK), which is being built at the Siberian Chemical Combine (SCC) in Seversk, as part of the Proryv (Breakthrough) project.
TVEL is also developing second-generation fuel elements for BREST-OD-300 with a higher burnup level. These will be used when the production of MNUP fuel moves from fabrication refabrication: that is, when MNUP-fuel initially loaded into the BREST reactor has been reprocessed and is re-used to make a second load.
“Experimental fuel assemblies with MNUP fuel have been tested since 2014 in the BN-600 reactor at the Beloyarsk NPP,” said Mikhail Skupov, Deputy General Director of VNIINM and head of the joint industry project “Development of fuel rods and fuel assemblies with MNUP-fuel”. “Although a fuel burnup level of 6% is sufficient for the initial load in the BREST reactor, experiments indicate that it has already reached 9%. This makes it possible to put the life tests of the fuel rods at a burnup level of 9-10%.” [For comparison, burn-up in light water reactors is around 4-5%]
Alexander Ugryumov, Vice President for Scientific and Technical Activities and Quality at TVEL said: “The results of research work on MNUP fuel for the BREST reactor will significantly accelerate the development of fuel for the nitride version of the core for the next generation of BN-1200M fast reactors. In 2022, it is planned to load experimental fuel assemblies with fuel elements of the BN-1200M type into BN-600 for endurance tests.”
Currently construction of a module for fabrication/refabrication of MNUP-fuel is nearing completion at SCC as part of the ODEK. In February, Russian regulator Rostekhnadzor issued a licence to SCC for the construction of the BREST-OD-300 reactor. The Breakthrough project aims to create a new technological platform for the nuclear industry with a closed nuclear fuel cycle to solve the problems of handling and storing used nuclear fuel and radioactive waste.