The Interaction Between Bentonite and Silica Sol™
Silica Sol is proposed as sealing agent to inject in small fractures in the foreseen deep bedrock repository of spent nuclear fuel. Silica Sol has been used in different tunnels very successfully. When Silica Sol is injected with saline solutions in the fractures, the solution will gel and build up a hydrological barrier. Thanks to the small particle size distribution the sealing agent can be injected long into the fractures and also in very small fractures. Except for the fracture sealing, the Silica Sol can be used for sealing between the bentonite barrier and the surrounding bedrock. The interaction between Silica Sol has to be investigated to see if the wanted properties of the bentonite will change. To start the interactions on the micro scale will be studied and the colloidal characteristics of the Silica Sol and mixtures of Silica Sol and bentonite will be determined. Colloidal characteristics such as surface charge, size and conformation will be studied.