Keywords:HLW Geological Disposal, Natural Phenomena, Geological Environment, Evaluation Model / Scenario, Argument diagram
Regarding the selection of suitable geological environment for geological disposal, it is not only necessary to evaluate characteristic of natural phenomena currently occurred, but also to predict the long-term occurrence and changes of natural phenomena over tens of thousands of years after disposal. Moreover, it is essential properly to assess the potential impacts of natural phenomena on the geological environmental conditions. For the appropriate assessment of the impacts, impact assessment model and scenario will be developed. In order to ensure their reliability, validity of scientific evidences should be clarified based on the results of case studies. As a method to demonstrate the validity, a method based on argument diagram has been proposed. In this study, we devised its simplified argument diagram, set the theme then organized the flow of information. As a result, it has made it possible to define the research contents and results information on the natural phenomena and geological environmental conditions that required for the setting theme, and to clarify the flow of the results information for constructing conceptual models and scenarios that adopted as the impact assessment. In addition, since the evaluation scenario was constructed based on the demonstrated conceptual model, we obtained the prospect that we will be able to objectively judge the validity of the scenario. Acknowledgements: This study was carried out under a contract with METI (Ministry of Economy, Trade and Industry) as part of its R&D supporting program for developing geological disposal technology.