Current status and future prospects of the Horonobe International Project (HIP), 4; Task C: Full-scale Engineering Barrier System (EBS) dismantling experiment

Ono, Hirokazu 

In the geological disposal of high-level radioactive waste, after emplacement of an EBS, the near-field environment is affected by processes such as heat release from the waste, groundwater infiltration into the EBS, swelling and deformation of the buffer material, and chemical reactions between groundwater and minerals. It is crucial to develop simulation codes to evaluate such coupled thermal-hydraulic-stress-chemical (THMC) processes for safety assessment of geological disposal. The full-scale vertical-emplacement EBS experiment (Horonobe EBS experiment) has been undertaken in the 350 m gallery of the Horonobe Underground Research Laboratory (URL) with the Horonobe geological environment. In the Horonobe EBS experiment, various sensors were installed in the buffer and backfill material to obtain the data required to evaluate coupled THMC processes in near-field. In Task C of the Horonobe International Project (HIP), the dismantling experiment of the Horonobe EBS experiment will be carried out and the data obtained from this experiment will be used to understand the coupled processes and to evaluate the simulation code.