Experimental Data Analysis During Initial In-DEBS Operation

This paper is intended to describe the field experimental data obtained from the initial operation of In-DEBS (Engineering scale in-situ demonstration of engineered barrier system), which is installed to analyze the THM (thermal, hydro, and mechanical) coupled behavior of engineered barrier system. On the top, which is plugged with concrete, heat is generated during the curing process of concrete. The heat affects the buffer and the near-field rock. The temperature of the buffer and the near field rock becomes less and less farther away from the plugging. Sensors and measurement system were verified using these phenomena. To protect the measurement system, the heater temperature was gradually increased to 100°C over one week, and the temperature of the heater surface was maintained at the target temperature. After heater operation, the temperature of the buffer reached the steady state in about four days, and the relative humidity increased and gradually decreased after a certain period of time. Also, the total pressure of the buffer was increased by swelling due to groundwater saturation. After the heater was started, it was observed that the temperature and displacement of the near-field rock continued to increase.