Micro X-ray Diffraction Analysis for Spent Fuel of Burn-up 41,000 MWd/tU

With the development of high burn-up fuels, the microstructural changes like as the formation of the many pores and the small grains and the change of the UO2 lattice size in a periphery of a fuel pellet have been observed. Even though a periphery (rim) of a fuel pellet has thin layer within a few hundred micrometers in thickness, affects the thermal conductivity of the nuclear fuel. Therefore, the microstructural characters in a rim have investigated by many researchers. In this study, the lattice parameter change was investigated for a spent nuclear fuel pellet of average burn-up 41,000 MWd/tU involving a rim and the diffraction pattern was measured for a pellet/clad interface by a radiation shielded micro-XRD