[1D01-06] Nuclide Migration

[1D06] Laboratory experiments of the swelling behavior of bentonite buffer due to the mechanical interactions between the buffer and backfill materials

*Shun Kimura¹, Kimihiro Kinota¹, Yutaka Sugita¹, Motoki Moriiwa², Sumio Niunoya², Shinichi Takahashi², Tomoyuki Shimura² (1. JAEA, 2. OBAYASHI)

Keywords:Bentonite, Buffer material, Backfill material, Swelling

In vertically emplaced Engineered Barrier System (EBS), the upwards swelling of the buffer material in the disposal pit can decrease its dry density. Consequently, a disposal tunnel above the disposal pit is backfilled to restrict the upwards swelling of the buffer material. In order to evaluate the performance of backfill material, it is essential to understand the swelling behavior of the buffer material due to the mechanical interactions between the buffer and the backfill materials. To this end, laboratory experiments that simulate the buffer and the backfill materials of the vertically emplaced EBS were conducted.