Evaluation of the technical options of radioactive waste management for utilization of MOX fuel: thermal impact of minor actinide separation with geological disposal of high-level waste

The impact of disposal of mixed oxide (MOX) fuel from light water reactors (LWRs) has been considered from the viewpoint of the thermal properties and the number of the vitrified waste for various conditions of the nuclear fuel cycle. In addition, the effect of separation of the minor actinides (MAs) (Np, Am, Cm) that potentially influence the geological disposal area has been evaluated quantitatively. Review of the effect of MAs separation on heat generation in MOX fuel disposal has revealed that dedicated measures for thermal impact reduction need to be developed for the purpose of nuclear-fuel-cycle evaluation from the viewpoint of continuous utilization of Pu. Not only MA separation, but also the nuclear fuel cycle conditions, technical options, waste occupied area per waste package are strongly relevant to the thermal properties of the vitrified waste, and it is necessary to consider the combination of these factors together with the number of waste packages to progress the feasibility studies for geological disposal of MOX-LWR.