IFPE/FMDP-MOX4-5, Weapons-Derived MOX Fuel DOE FMDP Test Irradiations Capsules 4 and 5, Advanced Test Reactor (ATR)

Description: Mixed oxide (MOX) test capsules prepared with weapons-derived plutonium have been irradiated to a burnup of 50 GWd/MT. The MOX fuel was fabricated at Los Alamos National Laboratory by a master-mix process and has been irradiated in the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Previous withdrawals of the same fuel have occurred at 9, 21, 30, and 40 GWd/MT. Oak Ridge National Laboratory manages this test series for the Department of Energy's Fissile Materials Disposition Program (FMDP). Description is given of the preparation of the MOX fuel, the equipment design, and the irradiation history of the test capsules, and the significance of the more important observations of the post-irradiation examinations (PIEs) is discussed. Code predictions (Frapcon-3 and TRANSURANUS) are presented and compared with available PIE data for the highest and lowest powered MOX capsules. Fuel performance has been excellent and consistent with code predictions and with existing U.S.and European experience.Pin 7 was irradiated in Capsule 4 and pin 8 was irradiated in capsule 5. These data are restricted to the benchmark participants