Hydrochemical analyses to evaluate groundwater system in Horonobe Area, Hokkaido, Japan

Sakai, Ryutaro; Munakata, Masahiro ; Seguchi, Mariko*; Ooka, Masao*; Ichikawa, Yasuo*; Nakamura, Masaru*; Ishibashi, Junichiro*

In the safety assessment for a geological disposal of radioactive waste, it is important to establish validation methods for deep groundwater flow system to estimate radionuclide migration to human environment through groundwater flow. This study discussed the method which estimates groundwater mixing condition and groundwater flow process using principal component analysis to groundwater chemistry and isotopic compositions in case of Horonobe area. The results demonstrated that there are three component of deep groundwater which has long residence time and surface water derived from meteoric water in this area.