Lifetimes of Used Fuel Containers Assuming Sulphate-reducing Bacterial Activity

Abstract

There have been several studies that model the mass transport of sulphide from the host rock to used fuel containers (UFCs) inside of a deep geological repository (DGR); however, they do not model directly the production of sulphide. In this work we approximated the reduction of sulphate to sulphide from experiments in the literature. We used a cellular automata (CA) model to estimate the amount of sulphide produced by the activity of sulphate-reducing bacteria (SRB), from those estimates we computed lifetimes of UFCs. Two cases were examined: 1) having SRB active at the rock interface and 2) having SRB active at the rock interface and inside the bentonite clay. We showed that lifetimes of UFCs are around 106 years. We performed a sensitivity analysis for both scenarios.