Investigation of the EDZ using high-resolution GPR with modulating frequency

Suyama, Yasuhiro*; Toida, Masaru*; Masumoto, Kazuhiko*; Takeuchi, Shinji

The EDZ is considered to be a fast transport pathway and provides a boundary condition for transport in bentonite buffers in groundwater scenarios for the geological disposal of radioactive waste. The distribution of the EDZ obtained through in-situ measurements, is important for safety assessments. High-resolution Ground Penetrating Radar (HGPR) with modulating frequency functions as a wide-angle measurement technique. It is one of the advanced techniques that can be used to investigate the EDZ of a radioactive waste disposal tunnel. Verification tests of the HGPR were carried out using a model and in-situ, in the gallery of Tono mine in central Japan. In summary, it is shown that the investigation technique was able to detect underground structures with a resolution of less than 0.1m.