Sensitivity analysis on the thermal-hydraulic parameters governing the saturation of an engineered clay barrier system

In this paper, we study the impact a heat source makes on the thermo-hydraulic behaviour of a system composed of an engineered clay barrier and a host rock, namely an argillite. We first perform a benchmark test case with code CAST3M and code ASTER. The results of the calculations are in good agreement, except for the gas pressure. Nevertheless, gas pressure does not seem to influence the saturation process, although the saturation kinetics is governed by the darcean water flow. The saturation process is accelerated when the heat source is taken into account. More precisely, this acceleration is due to dynamic viscosity increase with heating. In a second time, five other heating sources have been tested in code ASTER. Compared with the reference calculations, some give an identical response. However, the highest heating sources provoke a desaturation phenomenon because of the air pressure increase with temperature. The liquid saturation of the engineered barrier is then delayed.