Fabrication of Uranium-Plutonium Mixed Carbide Fuel Pins for Irradiation Tests

Nine pins containing uranium-plutonium mixed carbide fuel were fabricated for irradiation tests in JRR-2 and JMTR to examine the fuel behavior under irradiation and to test the performance of advanced FBR fuels. Two kinds of fuels with the different compositions of (U, Pu) C1.0 and (U, Pu) C1.1 were prepared by the carbothermic reduction of the oxides followed by sintering. The basic designs of carbide fuel pins, fabrication procedures and the results of characterization tests are described in this paper. The irradiations of eight encapsuled fuel pins were completed up to the burn-ups of about 5a/0 at the linear heat rates of 42-64kW/m without any fuel pin failure. A final fuel pin containing thermally stabilized pellets is under irradiation in JMTR.