Study on geology on the Mizunami Underground Research Laboratory Project; Geology and geological structure from G.L. -300m to G.L. -500m

Tsuruta, Tadahiko  ; Sasao, Eiji   ; Kawamoto, Koji; Kuboshima, Koji; Ishibashi, Masayuki

JAEA is performing the Mizunami Underground Research Laboratory (MIU) Project in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in the fractured crystalline rock. The Project has three overlapping phases with a total duration of about 20 years, and is under the Phase II (Construction phase) and the Phase III (Operation phase). One of the Phase II goals is set up to develop and revise models of the geological environment using the investigation results, and to determine and assess changes in the geological environment in response to excavation. This report aims compiling the study on geology and geological structure from G.L. -300m to G.L. -500m, excavated in the fiscal years from FY2008 to FY2012, and provides the fundamental information on the geology and geological structure for future study and modelling of geological environment. The compiling data are utilized in the updating of the geological models.