Optimization of waste management for mixed oxide fuel in light-water reactors: Evaluation of the effectiveness of blending spent uo2 and mixed oxide fuels in reprocessing

•Disposal of blended UO2–MOX HLW glass (blended HLW) could become a reasonable option for waste management.•Reprocessing MOX with a shorter cooling period is the key to minimize the heat effects due to 241Am.•Increasing the UO2 content is effective for reducing the heat generation of blended HLW. This study evaluated the impact of using mixed oxide fuel in light- water reactors (MOX-LWRs) from the viewpoint of waste management. As one of the challenges of MOX-LWR fuel is the high decay heat, one reasonable option for waste management may be to reduce the heat generation of high-level radioactive waste (HLW) glass by blending spent MOX and UO2 fuels. Both the thermal properties of the HLW glass and the thermal impact on the repository are examined. The results indicate that introducing blended UO2–MOX HLW glass (blended HLW) as a technical option can control the heat generation of the HLW glass and the thermal impact on the repository, which then lead to a reduction of 5–30% in the emplacement area. The obtained results demonstrate the viability of a future alternative approach for the management of MOX-LWR.