2020 Volume 59 Issue 1 Pages 173-177
Geological disposal of high–level radioactive waste in Japan is based on the concept of a multi–barrier system constituted of the engineered and natural barriers. For the disposal system, the high–level radioactive waste is enclosed in a metal container（overpack, hereafter）fixed in a bentonite buffer. The overpack is aimed at preventing contact of the waste to groundwater during the period longer than 1000 years in which relatively high heat is continuously generated. The overpack, therefore, requires holding corrosion resistivity/prevention and structural stability against mechanical loading at least for 1000 years. In this study, we overviewed bibliographic works on the copper–steel composite containers proposed by the geological disposal organizations in several foreign countries and then suggested for the waste in Japan the preliminary design of the copper coating container that is based on the new copper coating technologies developed by NWMO.
