Study on trend of volumetric shrinkage and water content depression of bentonite-based buffer under dry condition

Abstract

  In high-level radioactive wastes geological disposal, an engineered barrier by bentonite which is called buffer around a waste package is built. When the buffer suffers high temperature by generation of heat from wastes for long term, the heat may deteriorate barrier performance of the buffer material. In order to evaluate suitable heat influence for design of the repository, behavior of buffer under high temperature needs to be clarified. In this research, dry shrinkage examinations of bentonite-based buffer were carried out, and the tendency of the relations between specification of buffer, temperature and water ratio depression, dry shrinkage were clarified.