Radioactive nuclides are mainly brought by the groundwater flow from the high-level radioactive waste (HLW) disposal facility constructed in deep underground. It is very important to evaluate fractures developed in deep underground, which is thought to be a main groundwater flow path.
Borehole Television (BTV) System can get a variety of 3 dimentional geological information such as strike/dip of bedding and fractures, aperture, spacing, shape and filling minerals of fractures.
Based on the information obtained by BTV, fracture network modelling can be established and finally the mechanism of fracture development will be discussed.
Rock permeability can be discussed with regard to a fracture parameter obtained by BTV observation.
By combining the BTV observation with the core logging and other geophysical measurements, geological and geohydrological information in deep underground could be obtained in detail.
By developing the system, the BTV will be useful technique to explore in deep underground.