Central Research Institute of Electric Power Industry - Japan Atomic Energy Agency Joint Research; A Study of the hydraulic properties and transport characteristics around the Mizunami Underground Laboratory Project

Hasegawa, Takuma*; Nakata, Kotaro*; Tomioka, Yuichi*; Goto, Kazuyuki*; Kashiwaya, Koki*; Hama, Katsuhiro 

The groundwater flow velocity is one of the important items in the safety assessment for the HLW disposal. Generally, it is too difficult to measure the groundwater flow velocity directly. Therefore, to determine the groundwater age by radio active isotopes are effective. However, there are some problems to apply the metrology to the natural samples. For example, because the ratio of Carbon isotope changes by dissolving of the carbonate mineral and resolving the organic materials, the development of the technique for correcting this is needed. In this study, the groundwater ages are measured by He and C, etc. and compared these results as a joint research with Central Research Institute of Electric Power Industry.