Present and future studies for geological disposal of long half life radionuclides bearing low feverish radioactive waste

Kuroda, Shigeki*; Kamei, Gento 

Long half-life low heat generating radioactive waste (TRU waste) containing higher amount of radionuclide is considered to be disposed into a geologic formation. As an optimized geologic disposal of the waste, a technical possibility of co-disposal with high-level radioactive waste is being studied. An assessment result shows that a co-disposal is possible in a Japanese representative geologic environment by setting these repositories at a certain distance apart because reciprocal influences can be avoided. Atomic Energy Commission of Japan deliberated on the result and judged that the co-disposal concept described in the 2nd progress TRU report has a technical possibility. On the other side, future studies are required from the view points of (1) more reliable assessment of co-disposal, (2) expansion of generic assessment basis, and (3) flexible correspondence for wide geologic environmental conditions. This article shows a current status of the investigations of TRU waste disposal including an overview of the disposal concept and concrete items for the future studies.