2:30 PM - 2:45 PM
[HCG25-16] A mechanism of container sinking in bentonite buffer hitherto not considered
Keywords:Canister sinking, Chemical deformation, Bentonite, Pressure solution, Engineered barrier, Radioactive waste disposal
In this presentation, a chemical deformation mechanism is presented as another scenario of container sinking, which has not been previously considered in the rad-waste disposal field. Chemical deformation here is the deformation through the pressure solution of minerals constituting the buffer, transportation by diffusion, and precipitation. That such chemical deformation is a ubiquitous phenomenon occurring in various scales in the crust of the earth will be shown through the review of previous works. It will also be shown that such chemical deformation can occur at the range of the pressure and temperature of the geological disposal. It is deduced that container sinking scenario needs to be evaluated also from the viewpoint of chemical deformation of the bentonite, because the sinking distance can be significantly large in the time range of up to a million years for the safety assessment.