Experimental studies on the coupled THMC processes by couple equipment

Fujisaki, Kiyoshi; Suzuki, Hideaki*; Fujita, Tomoo ; Ito, Akira*; Oda, Yoshihiro 

An important part of the safety assessments of near field in a geological disposal system of high-level radioactive waste consists an assessment of the coupled thermal-hydraulic-mechanical and chemical (THMC) phenomena. In order to validate the newly developed THMC model, the engineered scale experimental studies on the coupled THMC processes by COUPLE equipment have been carried out with a simulated engineered barrier surrounded by a mortar block. In this experiment, temperature at heater and side surface of mortar block was controlled at constant temperature, respectively. And high-pH water reacted with mortar infiltrates into the buffer material. This paper presents the results of measured data by various sensors during the experiment and sampling data of pH and leaching cations in buffer material after the experiment, in COUPLE equipment. And also the results of preliminary simulations on coupled T-H processes and chemical process in the experiment are described.