Influence of pore water vaporization on saturation process in the buffer material coupled Thermo-Hydro-Mechanical analysis

Sato, Shin*; Ono, Hirokazu ; Tanai, Kenji ; Yamamoto, Shuichi*; Fukaya, Masaaki*; Shimura, Tomoyuki*; Niunoya, Sumio*

The saturation process in the buffer material is affected by the heat generated by the vitrified waste in the high-level radioactive waste geological disposal. Especially, the phase changes occurred in the pore water, such as water vaporization and dissolution of the pore air in to the liquid phase affects the water movement in the buffer material. Hence, it is important to evaluate the coupled Thermo-Hydro-Mechanical (THM) behavior considering phase transformation of pore water in the buffer material. Therefore, we carried out the coupled THM analysis to investigate the generation of water vaporization during the saturation process. Additionally, we discussed the influence of relative permeability as one of the gas phase advection properties.