Mizunami Underground Research Laboratory project. Plan for fiscal year 2013

The Mizunami Underground Research Laboratory (MIU) project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host crystalline rock at Mizunami City in Gifu, central Japan. The project proceeds in three overlapping phases, 'Phase I: Surface-based investigation Phase', 'Phase II: Construction Phase' and 'Phase III: Operation Phase'. The present report summarizes the research and development activities planned for fiscal year 2013 based on the MIU Master Plan updated in 2010. The long-term monitoring of hydraulic pressure and groundwater chemistry at the existing boreholes are continued. The borehole investigation in order to characterize rock mechanical properties will be carried out at the GL-500m stage. As study on engineering technologies for deep underground, validation and evaluation of design methodology, existing and supplementary excavation methods, countermeasures during excavation and safe construction will be carried out based on data obtained during shafts and galleries construction. As the part of the Phase III investigations, the geological environment models around the gallery are constructed by using geological, hydrogeological and geochemical data obtained through the field investigations. Groundwater recovery experiment in tunnel is started at the GL-500m stage. As collaboration studies, various experiments and researches are planned to carried out with CRIEPI (Central Research Institute of Electric Power Industry), AIST (National Institute of Advanced Industrial Science and Technology), Nagra (National Cooperative for the Disposal of Radioactive Waste), KAERI (Korea Atomic Energy Research Institute) and other research organizations. Furthermore, as utilization of the MIU, the galleries have been used with TRIES (Tono Research Institute of Earthquake Science) and Nagoya University. (author)