Mechanism development of the spent fuel dry pulverizing/mixing device

The spent fuel dry pulverizing/mixing device mechanism is used to deal with the spent fuels for the safe disposal. The separated pellets from hulls by a slitting device are put and oxidized from UO2 solid pellet to U3O8 powder in the device. The device have been developed based on a voloxidation method which is one of several dry de-cladding methods. We have benchmarked dry de-cladding methods, analyzed applicability to the advanced spent fuel management process, integrated and compared several configuration, and finally derived detailed specifications proper to requirements for the device. Also, thermal characteristics of the device such as thermal stress and strain have been analyzed by the commercial software, I-DEAS, and the reliability of the results have been verified by the KOLAS(KOrea Laboratory Accreditation Scheme). The UO2 solid pellets are put in the device which has a capacity of 20 kgHM per a batch, heated up about 600 .deg. C in the air environment. Then, the UO2 solid pellets are oxidized into the U3O8 powder, and the powder is collected in a special vessel. The device has been development as follows: the multi-staged fine hole meshes are used to reduce the size of the powder gradually, heat and air(oxygen) are supplied continuously to reduce the reaction time, and slight vibration effect are applied to collect powder cling to the device