Evaluation of Long-term behavior of bentonite buffer based on Molecular Dynamics and Homogenization Analysis

Abstract

To show the long-term stability of bentonite buffer is one of important matter in HLW disposal. We have applied the unified MD/HA method and in-situ XRD measurement of basal spacing of clay minerals to find out the micro-mechanism of mechanical behavior of bentonite. As a result, it was assumed that the cause of secondary compression of bentonite was drainage from interlayer of clay minerals, so it could be deemed the very slow consolidation. We constructed analysis code for the micro-scale mechanism and simulated long-term consolidation test by the analysis code. As a result, it was confirmed that the analysis method could follow the secondary compression well. After that, long-term behavior of bentonite buffer for HLW disposal was evaluated.