Hydrogeological characterization on surface-based investigation phase in the Mizunami Underground Research Laboratory project, in Japan

Saegusa, Hiromitsu; Onoe, Hironori ; Takeuchi, Shinji; Takeuchi, Ryuji  ; Oyama, Takuya 

The Mizunami Underground Research Laboratory (MIU) project is planned for broad scientific study of the deep geological environment as a basis of research and development for geological disposal of nuclear wastes. One of the main goals of the project is to establish comprehensive techniques for investigation, analysis, and assessment of the deep geological environment. Hydrogeological investigations using a stepwise process in Surface-based Investigation Phase have been carried out in order to obtain information on important properties. Hydrogeological modeling and groundwater flow simulations have been carried out in order to synthesize the investigation results, to evaluate the uncertainty of the model and to identify the main issues for further investigations. Using the stepwise hydrogeological characterization approach and combining the investigation with modeling and simulation, understanding of the hydrogeological environment has been progressively improved.