Mizunami Underground Research Laboratory project. Compilation of results of geological investigation at the -500m stage

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project, namely the Mizunami Underground Research Laboratory (MIU) Project, in crystalline rock environment in order to construct scientific and technological basis for the geological disposal of High-level Radioactive Waste (HLW). The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). This document presents the data of geological investigations at the -500m stage of the MIU from the 2011 fiscal year to the 2013 fiscal year. At the -500m stage of the MIU, although the Cretaceous Toki granite is distributed, pegmatite, aplite and lampropyre dike are distributed partially. A CD-ROM is atteached as an appendix. (J.P.N.)