New Rapid Evaluation for Long-Term Behavior in Deep Geological Repository by Geotechnical Centrifuge. Part 1: Test of Physical Modeling in Near Field Under Isotropic Stress-Constraint Conditions

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

“…We adopted a simple near-field model consisting of a single model-overpack, ring-and cylinder-shaped buffers, and a cylindrical rock mass in the present study [6][7][8] (Fig. 1a).…”

“…In the present study, we used Tage tuff, assuming the geological disposal repository composed of sedimentary soft rock. The physical properties of Tage tuff in the laboratory tests are as follows: about 2.6 and 3.6 GPa in the Young's modulus of the uniaxial compressional test under the dry and wet condition, respectively, about 1700 and 2000 kg/m 3 in the density under the dry and wet condition, respectively, and about 10 -9 cm/s in the permeability 8,10,11) .…”

“…(Centrifugal Test equipment for Ultra-long time Range of 5000 Years: simulating coupled Thermal-Hydraulic-Mechanical processes) that enables us to perform a long-term operation of up to six months with maximum payload of 1.5 tons up to 100 G 8,12) (Fig. 2).…”

“…2. Centrifuge test system consists of CENTURY5000-THM, the pressure pumps, the temperature control unit, the data logger, the pressure vessel, and the control and measurement PC 8,12) . Distilled water in the pressure pumps is supplied from the rotary-joint, and the switch of the direction of water flow and the open/close of magnetic valves is controlled by the control and measurement PC through the wireless LAN.…”

“…The schematic of the pressure vessel used in the present study is shown in Fig. 3 6,8,12) . It is a triaxial-type vessel with a maximum hydrostatic pressure loading capacity of 10 MPa for the water-and piston-applied circumferential and axial stress, respectively.…”