Partitioning of high-level waste as pretreatment in waste management

Removal of the long-lived radionuclides from high-level waste (HLW) is a potential means not only for making wastes more acceptable in terms of long term hazards, but also for alleviating storage requirement. From these points a method is developed of partitioning actinides, Sr-90 and Cs-137 from HLW. A chemical flow-sheet has been constructed and experiments with actual HLW were initiated in 1982. Through the partitioning, active elements in HLW can be fractionated into 3 groups. Total volume of the solid materials of the 3 groups was calculated and found to be reduced to less than one-third of the volume of the vitrified material containing 10 wt% of fission products as oxide. Such volume reduction seems to facilitate the long term storage or the deep geological disposal of HLW. 7 references, 7 figures, 1 table