SCC has manufactured 1000 experimental MNUP nuclear fuel aseemblies (Credit: TVEL)Russia’s Siberian Chemical Combine (SCC – part of Rosatom’s TVEL Fuel Company) said that it had produced more than 1000 experimental fuel elements based on mixed uranium-plutonium nitride fuel (MNUP fuel) during its eight years of participation in the Proryv (Breakthrough) project.

Fuel elements of various standard sizes and structural materials were manufactured in order to find and justify the optimal configuration.

Experimental fuel elements and fuel assemblies are being tested in the BN-600 fast reactor at the Beloyarsk NPP to obtain the most complete experimental data on the properties and behaviour of pellet MNUP fuel in a steel cladding. They will form the basis for the experimental substantiation of the fuel element design, based on which fuel elements for the lead-cooled fast neutron BREST-OD-300 reactor will be developed.

The BREST-OD-300 is part of the Pilot Demonstration Energy Complex (ODEK), which is under construction at SCC as part of the Proryv project. ODEK will include three linked facilities: a fuel fabrication/re-fabrication unit, the  300MW BREST-OD-300 reactor, and a unit for used fuel reprocessing.

Irradiation of experimental fuel assemblies began in the spring of 2014. The assemblies remained in the reactor until autumn 2016 and the research is now complete. The experts confirmed that all the fuel elements retained their original shape during the irradiation period, and no structural element defects were identified. In the spring of 2020, new batches of experimental fuel assemblies were loaded, each containing 61 fuel elements.

“Tests of the innovative MNUP fuel are continuing successfully. More than 21 experimental assemblies were irradiated directly in the BN-600 reactor, the serviceability of this fuel has been proven”, said the chief technologist of the "Breakthrough" project Yuri Mochalov.

Photo: SCC has produced some 1000 MNUP fuel assemblies (Credit: TVEL)