Effect of water vapor on re-saturation process in EBS performance of re-saturation process by Thermo-Hydro-Mechanical coupled analysis

The coupled Thermo – Hydro – Mechanical behavior of a radioactive waste disposal facility during its re-saturation is affected by water vapor generated by the heating of pore water. In this study, a Thermo – Hydro – Mechanical coupled analysis of a confirmation test being conducted at the Horonobe Underground Research Center was performed, and how the increase in pore pressure caused by the generation of the water vapor affects the engineering barrier performance was discussed. As a result, by considering the water vapor in the analysis, the evaporation of the moisture content around the heater led to the increase in porosity by about 10% and the decrease in saturation by about 15% as the air pressure in the voids increased. Therefore, it was necessary to consider the effect of the water vapor generation due to the temperature rise near the heater in order to simulate re-saturation behavior in the long-term behavior evaluation of the buffer materials.