Studies on design of the engineered barrier system and mechanical stability of rock based on surfaced-based investigation of the Horonobe URL project

Aoyagi, Shigeo; Tanai, Kenji ; Matsui, Hiroya ; Kawakami, Susumu; Yui, Mikazu

This paper presents the design of the disposal design based on surface-based investigations in Horonobe URL project with a focus on the engineered barrier system (EBS) and the estimation of mechanical stability of rock. The purpose of this study is as follows.[1]Establishment of the overall design methodology on engineered barrier system and repository based on the results of surface-based investigation in sedimentary rock.][2]Extraction of issues to be solved in the construction phase of URL through studies based on surface-based investigation.]The applied methods on this study are based on the second progress report (H12)(1999) published by JNC. As results of this study,the design flow shown in H12 report is revised under the consideration of correlation with each field. The typical specification of buffer and overpack (iron) in the geological environment in Horonobe are the same specification as H12 report. The rock around a dry pit at the depth of 450m in Horonobe is expected more stable in long-term than SR-C in H12 report.