Geophysical Survey Applications in Underground Research Laboratories and Deep Disposal Sites of Spent Nuclear Fuel

To safely dispose high-level radioactive wastes such as spent nuclear fuel in a repository hundreds of meters deep below the earth’s surface, it is critical to verify the disposal process through onsite experiments in an underground research laboratory (URL). From site selection to operational stages, potential pathways for radioactive nuclide leakage into the ecosystem need to be completely delineated considering factors such as fractures and groundwater flow within the bedrock. For this purpose, geophysical survey techniques, which are non-invasive methods, have been actively researched worldwide. Utilization of various geophysical methods can evaluate geological and hydrogeological settings, thermal effects, engineering barriers etc. Analysis on previous geophysical survey cases conducted for URLs as well as repositories showed that geophysical surveys are sufficiently helpful and effective in assessing and managing deep geological repositories. The analysis can be used as fundamental information for the implementation of domestic disposal facilities.