Post-Reactor Studies of Fuel Rods with Uranium-Plutonium Nitride Fuel with Gas and Liquid-Metal Sublayer

ETVS fuel assemblies containing nitride fuel rods with different structural implementation and cladding made of different materials are tested in the cores of the BN-600 and BOR-60 reactors in order to substantiate the efficiency of fuel rods with mixed uranium-plutonium nitride fuel used in sodium-cooled (BN-1200) and lead-cooled (BREST-OD-300) reactors. We report here the results of post-reactor studies of BN-600, -800, -1200 and BREST type fuel elements with a helium sublayer after irradiation to maximum burnup 7.5, 6, and 4.5% h.a., respectively, in the composition of 10 ETVS BN-600 fuel assemblies as well BREST type fuel rods with helium and lead sublayer after tests to maximum burnup 5 and 4% h.a. as fuel elements of the BREST type with a helium and lead sublayer after testing to maximum burnup 5 and 4% h.a. in the composition of two ETVS BOR-60 fuel assemblies. The obtained results confirmed that the nitride fuel rods with gas and lead sublayers and EP-823 steel cladding remain efficient at the attained test parameters and, possibly, at higher fuel burnup.