Study on long-term stability of geological environment. Annual report of fiscal year 2001

The Tono Geoscience Center has progressed the study on long-term stability of geological environment, as a part of the scientific study on deep stratum (geoscientific science) shown in the national plan, in the study on geological disposal technology for safe disposal of the high level radioactive wastes. On this study, together with elucidating characteristics of the phenomena (regularity, scale of changes, and so on based on action histories from past to present), at an object of natural phenomena such as earthquake/fault, volcanic action, upheaval/erosion, sea water quasi-change, and so on, assumed by feasibility to affect to the geological disposal system, survey and study to elucidate their effects on geological environment (groundwater flow, water quality, rock mechanics, and so on) are progressed. Concretely, to concretely and demonstratively evaluate general forecastings that 'some geological environments capable of regarding to be stable at long-term are also present in Japan' shown in the Second Progress Report on R and D of geological disposal, not only development on a forecasting model to mainly predict future natural phenomena and survey technology systematized to obtain data on site, but also R and D centering accumulation of scientific data required for safety evaluation and so on, have been progressed. (G.K.)