LONG TERM STORAGE OF NUCLEAR SPENT FUEL AS KEY ROLE OF JAPAN'S NUCLEAR FUEL CYCLE UNTIL 2100: COST AND BENEFIT

摘要

Political and technical advantages to introduce spent nuclear fuel interim storage into Japan's nuclear fuel cycle are examined. Once Rokkasho reprocessing plant starts operation, 80,000 tHM of spent Low Enriched Uranium (LEU) fuel must be stored in an Away From Reactor (AFR) interim storage site until 2100. If a succeeding reprocessing plant starts operating, the spent LEU will reach its peak of 30,000 tHM before 2050, and then will decrease until the end of the second reprocessing plant operation. Throughput of the second reprocessing plant is assumed as twice of that of Rokassho reprocessing plant, indeed 1,600tHM/year. On the other hand, tripled number of final disposal sites for High Level Nuclear Waste (HLW) will be necessary with this condition. Besides, large amount of plutonium surplus will occur, even if First Breeder Reactors (FBR)s consume the plutonium. At maximum, plutonium surplus will reach almost 500 tons. These results indicate that current nuclear policy does not solve the spent fuel problems but rather complicates them. Thus, reprocessing policy could put off the problems in spent fuel interim storage capacity and other issues could appear such as difficulties in large amount of HLW final disposal management or separated plutonium management. If there is no reprocessing or MOX use, the amount of spent fuel will reach over 115,000 tones at the year of 2100. However, the spent fuel management could be simplified and also the cost and the security would be improved by using an interim storage primarily.