Extralong test study on carbon steel overpack

Wada, Ryutaro*; not registered; Nishimura, Tsutomu*; Fujiwara, Kazuo*; Tateishi, Tsuyoshi*

The overpack for the high-level radioactive waste disposal is expected to maintain the long-term integrity and the corrosion behavior model of the overpack has been developed so far. To verify the adequacy and conservatism of the model, in this study, measurements of hydrogen absorption regarding hydrogen embrittlement of carbon steel, one of the candidate materials, were carried out in the compacted bentonite coexistence environment. The definite research programs to be performed in the future were also established for the important subjects as the extralong tests: (1)The hydrogen penetration-measuring device was designed to measure the penetrated hydrogen caused by the corrosion of carbon steel in the buffer material (compacted bentonite). (2)Out of generated hydrogen by the corrosion of carbon steel in the buffer material, the penetrated hydrogen volumes into carbon steel were measured. (3) Research programs on the four laboratory test themes and the three site test themes were established as the extralong test themes to be performed in the future.