waste management performance assessment of unsaturated clay as a part of radioactive waste disposal site

the disposal concept aims to use a combination of natural and engineered barriers to achieve the necessary degree of long-term isolation and containment of the radioactive wastes. in order to assess the performance of a repository to specified safety targets, it is necessary to consider possible routes in which radionuclides from wastes in the repository might return to the accessible environment. one of the main routes that need to be considered is the unsaturated zone. the unsaturated zone represents a mathematical challenge for modelers due to the dependency of the hydraulic conductivity and its associated gradients on the state of saturation of the soil and the spatial variability in the input parameters through the field . the aim of this study is to simulate the groundwater flow and contaminant transport through the unsaturated zone and perform sensitivity analysis to identify some relationship between the output and the input parameters