[2C05-09] Material 2

[2C06] Fundamental research on alternative clay materials used for backfill in geological disposal

*Takafumi Iwatani¹, Masahiro Kawakubo² (1. Nishimatsu construction, 2. Radioactive Waste Management Funding and Research Center)

Keywords:geological disposal, clay materials, backfill material, hydraulic conductivity, plasticity index

At geological disposal in Finland and Sweden, it is considered to set different requirements for backfill material depending on place and depth. In geological disposal in Japan, a large amount of bentonite will be used as buffer and backfill materials. To confirm applicability of the clay materials other than bentonite for the backfill material, it will be possible to correspond flexibly to short supply. In this study, compaction and permeability tests were conducted using mixture of clay and crashed rock.From the results of these tests, hydraulic conductivity of the mixed soils was 1.0×10^-11-1.0×10^-8 m/s, it was confirmed that these clay materials might be possible as the backfill material depending on design requirements of the backfill.