SCENARIO ANALYSIS TOOL NUCLEAR FUEL CYCLE SIMULATION SYSTEM (NFCSS): SAFETY ASSESSMENTS IN THE CONTEXT OF SPENT FUEL MANAGEMENT AND DISPOSAL

摘要

For the safety assessment in the context of radioactive wastemanagement and disposal, quantitative evaluation of nuclear fuelcycle system performance is inevitable. In addition, considerationof decay heat and radiotoxicity from spent fuel (SF) are one of themost important factors to promise a safe, and less environmentalload for long-term storage and disposal.In case of looking ahead of future nuclear fuel cyclesystem which intends to reduce plutonium by introduction ofmixed oxide (MOX) fuel together with the UO_2 fuel,understanding decay heat generated from those SFs will help todetermine the occupied area of the geological repository. In thisstudy, heat transfer calculation was carried out to evaluate thetemperature of buffer material in a geological repository basedon the output from scenario-based computer simulation toolNuclear Fuel Cycle Simulation System:NFCSS to show thedifference in the impact to occupied area between those two fuels.