[3C01-05] Simulation

[3C03] Analyses of Coupled Thermo-Hydro-Mechanical (T-H-M) Processes in Buffer Material

*Daiko Okajima¹, Haruo Sato¹ (1. Okayama University)

Keywords:geological disposal, buffer material, bentonite, temperature, Thermo-Hydro-Mechanical coupled processes, swelling stress, diffusion equation, difference method

In geological disposal of a high-level radioactive waste, engineered barrier systems need to maintain their function over a long period of time under the combined influence from the waste and the surrounding rock mass. In this study, we performed a long-term analysis of the effect of thermal conductivity and specific heat on the thermal diffusivity as a function of volumetric water content and temperature in buffer material. Based on the results, we analyzed the effect of volumetric water content in buffer material on swelling stress. We compared the analytical data with measured data to evaluate the applicability of the analytical method to the evolution of temperature, moisture content, and swelling stress distribution.