Research and development of new technology for the immobilization of TRU-rich wastes. Applicability of yttria-stabilized zirconia for TRU-rich wastes

The purpose of this study is to clarify the performance of yttria-stabilized zirconia (YSZ) as a waste form for geological disposal of TRU-rich wastes, for example, the TRU waste arising from 4-group partitioning of HLLW (High-Level Liquid Wastes). By immobilizing the actinides in stable ceramic waste forms for a long time, imposition of the other multi-barrier materials can be reduced qualitatively and quantitatively, further, this leads to decrease a total cost of waste disposal. From property evaluations of phase stability, chemical durability, mechanical property and stability for change of waste composition by disintegration, YSZ is good enough as a host material to immobilize the TRU-rich wastes. (author)