Development of rapid evaluation for long-term geomechanical behavior in HLW near-field by centrifugal simulation

Abstract

We evaluate the long-term geomechanical behavior in the near-field of a deep geological disposal repository by the centrifugal model test. The model consisted of a sedimentary rock mass, bentonite buffer, and model overpack, and was enclosed within a pressure vessel. Tests were conducted with a centrifugal force field of 30 G under isotropic stress-constraint conditions with confining pressures and injection of pore water. The temperature conditions of the overpack are constantly 25 °C and 95 °C (normal temperature-and heating-test, respectively). As the result, the values of heating-tests showed similar behaviors to that of the normal temperature tests partially. However, the density of the buffer was lower than that of the normal temperature-tests by X-ray CT imaging in the post-tests.