| dc.description.abstract |
For high-level waste (HLW) disposal, the HLW is isolated from natural environment by multi-barrier systems including engineering and natural barriers in the deep ground. The disposal holes would be drilled in host rock and set up with canister and buffer. Then the canister is not easily affected by natural operation, humanity activities and tectonic movement with high stability. However, Taiwan is located at Circum - Pacific seismic zone which earthquake occurs frequently. As a result, the effect of earthquake-induced vibration on the canister, buffer and disposal hole is needed to be investigated.
This research assumes that the deposition is set up in granite layer at certain depth. The disposal hole is regard as an entire intact space without deformation and cracks. Referring to KBS-3V concept and geometry, the test model is built with 1/10 scale of prototype. Through the centrifuge modeling, 10 g artificial acceleration field is created to simulate in situ stress of canister from buffer material. Seismic events is input by shaking table with 15-cycle sinusoidal waves. During shaking, acceleration, pore water pressure and total pressure histories are measured in order to realize the seismic behavior of canister and buffers in the disposal hole.
Considering different states of buffer material and conditions, in total, 6 dynamic models are conducted. In buffer at 17% water content condition, large acceleration and contact pressure is measured at the surface of canister. When water invades to buffer at 17% water content and close to saturated conditions, the acceleration and the contact pressure on the canister are both reduced. After the test, cracks were found on the surrounding buffer materials for the model buffer at 17% water content condition without water invasion and water invasion cases. | en_US |