Study on evaluation methodology for groundwater flow based on geochemical data, 2; Case study for Horonobe area (Contract research)

Sakai, Ryutaro; Takeda, Seiji ; Munakata, Masahiro ; Kimura, Hideo

In the safety assessment for a geological disposal of radioactive waste, it is important to establish validation methods for deep groundwater flow to estimate radionuclide migration to human environment through groundwater flow. Costal sedimentary rocks in our country provide dominant fossil water formed during sub-seabed sedimentation and chemical compositions of the water mixed with meteoric water and fossil water depend on the initial fossil water composition and groundwater flow conditions. Analytical study on the effects of groundwater flow on the mixed water quality as a indicator of its Cl/O ratios was carried out in case of Horonobe district, where geochemical data is now being stored.