Monitoring of infiltration of saline water in fractures using ground penetrating radar

Masumoto, Kazuhiko*; Matsushita, Tomoaki*; Takeuchi, Ryuji  

The monitoring of groundwater condition in fractures around the rock cavern is important for safety assessment for high level radioactive waste. The GPR (Ground Penetrating Radar) method is unique technique to survey the water condition in fractures, indirectly, and with no disturbance of original groundwater condition. The authors conducted the GPR monitoring of infiltration of saline water on the side wall of the 500m access tunnel of Mizunami Underground Research Laboratory. The results showed that the difference of saline concentration in fractures caused the change of the reflection wave form and the intense of spectrum due to the results of spectrum analysis of reflection wave.