Relationships between Degree of Saturation, Total Suction, and Electrical and Thermal Resistivity of Highly Compacted Bentonite

Abstract

Bentonite clay is a component of an engineered barrier system that is highly compacted around nuclear waste bundles in deep geological repositories (DGR). The bentonite is subject to both thermal and hydraulic gradients that may cause the barrier system to fail, compromising the stability of the deep geological repository. Regularly monitoring and assessing the condition of the highly compacted bentonite (HCB) is key to the long-term safe storage of nuclear waste bundles. The degree of saturation of the bentonite is the most critical parameter considered when assessing the performance of the material. The thermal and electrical resistivities of highly compacted bentonite samples were measured and a relationship was developed between the resistivities and the degree of saturation of the material. In addition, this study presented a relationship between total suction and electrical resistivity.