Modelling the effects of water chemistry and flowrate on clay erosion

Clay buffer is a key component of the engineered barrier system (EBS) for geological disposal higher activity radioactive waste. Experimental observations indicate possibility erosion at interface with host rock due to interactions groundwater. Existing models clay are very limited in terms addressing hydro-chemical effects, while assessment long-term performance requires robust predictive covering expected environment conditions and multiphysics phenomena involved process. The work presented here step towards such capability, which considers expansion, detachment particles transport detached by groundwater within single modelling framework. effects solution chemistry flowrate on penetration, extruded mass particle release rate investigated this paper. A series experimental data used validate swelling model developed study. results show that extrusion distance, controlled both processes, nearly linearly dependent water irrespective chemistry. Similar linear dependence observed flowrates less than 10?5 m/s. Higher shown induce nonlinearly increasing rates accordance experiments. threshold found above behaviour compacted bentonite can be significantly affected. concept tolerance time introduced as failure criterion. coupled effect velocity further investigation ionic concentrations below 1 mM.