New theoretical prediction of swelling characteristics of bentonite-based buffer

Bentonite is currently planned for use as buffer for repositories of high-level nuclear waste because it must have swelling characteristics to seal the waste. It is necessary to choose the appropriate bentonite from among many kinds of bentonite in the design of buffer. For this purpose, the author proposes a new prediction method for swelling characteristics of bentonite-based buffer. The prediction method comprises some equations that were previously developed for repulsive and attractive forces between two montmorillonite layers; others included in the method are the author's previously proposed equations for (1) the swelling volumetric strain of montmorillonite, and (2) the influences of pore water chemistry and specific surface of bentonite. (authors)