2-40 Influence of Different Oxidation Temperature on Phase Separation Characteristics of (U1..xNdx)3O8 Solid Solutions

摘要

Rare-earth (RE) elements in spent nuclear fuel are strong neutron absorbers, which affect the fission efficiencyof fissile materials. If some of these fission products (e.g., RE) can be removed by a thermo-mechanical process, itwill greatly improve the burn-up and economics of the recycled fuel in the DUPIC (Direct Use of spent PWR fuelin CANDU Reactors) concept[1;2]. In this work, the phase separation characteristics of the Nd (3%) element from(U1?xNdx)3O8 by high temperature oxidation was investigated in terms of the heat treatment temperature rangebetween 1 000 ?C and 1 700 ?C. The phase separation ratio (wt%) of Nd and U was evaluated using the XRD. Themorphology of the samples were obtained from SEM.