Development of geological models in the Mizunami Underground Research Laboratory project. Updating from 'Shaft180 geological model' to 'Stage300 geological model' in phase II

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named the Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase I), Construction Phase (Phase II) and Operation Phase (Phase III). Currently, the project is under the Construction Phase and the Operation Phase. In the phase II, the geological models has been updated four times (Shaft180 geological model, Pilot500 geological model, Substage200 geological model and Stage300 geological model) based on the increasing data of geological mapping and borehole investigations at the shafts and research galleries. These geological models represent distributions of lithofacies and geological structures based on each geological investigation. In order to evaluate relationship between understanding of geological environments and progress of investigations, to organize the history of geological models updating is important. Thus this document describes the history of geological models at the Phase II. A CD-ROM is attached as an appendix. (author)