Implementation of In-DEBS (In-situ Demonstration of Engineered Barrier System)

The paper describes the process of developing and implementing In-DEBS (In-situ Demonstration of Engineered Barrier System) for analyzing thermal-hydraulic-mechanical (THM) coupled behavior characteristics of an engineered barrier system in a high-level waste disposal system. The engineered barrier system is composed of a disposal canister, buffer, and near field rock. In-DEBS is designed to analyze the THM coupled behavior due to the inflow of underground water and the heat of disposal canisters in the buffer and near field rock. Since it is difficult to assemble the buffer block while installing sensors and heaters in a disposal hole, the buffer blocks were assembled from the outside. OBPA (One-Body Pre-Assembly) assembled with buffer blocks, sensors and heater requires special transport equipment to accurately insert it into the disposal hole because the total weight is about three tones. In this study, the fully assembled buffer block was inserted by developing a crane exclusively for In-DEBS, which can be moved into an accurate position by lifting more than five tones. To analyze the THM coupled behavior of the near field rock, 4 test holes were cored around In-DEBS and a total of 40 temperature sensors and 5 pore pressure sensors were installed in the test hole. A total of 185 sensors for temperature, relative humidity, pressure and displacement sensors were installed in the In-DEBS. All sensors were connected to a multichannel measuring system that stores field data in real time.