Annual report for research on long-term stability of geological environment in FY2005

The Japanese islands are located in the tectonically active Circum-Pacific Mobile Belt. As a result, Japan has a high frequency of earthquakes and eruptions. The concept of geological disposal of HLW in Japan is based on a multi-barrier system which combines a stable geological environment with an engineered barrier system. Therefore, special consideration is given to the long-term stability of the geological environment, taking into account volcanism, faulting, uplift, denudation, climatic change and sea-level change in Japan. Development of research/prediction technologies for geotectonic events has been carried out to evaluate the long-term stability of the geological environment in Japan. Until fiscal year 2005, to confirm existence of phenomena that have a influence on geological disposal system (e.g. active fault or Quarternary volcanoes), to confirm that there was not the trace that the phenomena occurred in the past, to predict/evaluate possibility of the phenomena and to develop the research/prediction techniques for geotectonic events (e.g. research techniques for earthquake source faults, research techniques for detecting magmas and high-temperature fluids, three-dimensional landform development simulator) were carried out. In a natural analog study, a systematization of the information and maintenance of the scientific grounds to do collaborating evidence of long-term safety of geological disposal were carried out. This report describes our efforts of these technologies based on its R and D program until fiscal year 2005. (author)