CHANGES OF O/M, DIMENSION AND MICROSTRUCTURE OF MOX PELLET DURING HEAT TREATMENT

摘要

The oxidation and reduction behaviors of sintered (Pu_(0.3)U_(0.7))O_(2-x) pellets have been studied at 1873 K under a controlled oxygen partial pressure. From the results of O/M ratio changes, dimensional and structural changes, it was concluded that the crack nucleation-propagation and the local density change of pores were caused by the tensile and compressive stresses due to the O/M ratio distribution in the direction of the pellet radius.