Modelling the activity of sulphate-reducing bacteria and the effects on container corrosion in an underground nuclear waste disposal vault

摘要

A mathematical model has been developed to predict the extent of sulphate reduction by sulphate-reducing bacteria (SRB) in an underground nuclear waste disposal vault and the consequences for corrosion of the waste package. The model in based on a series of mass-balance equations that describe the kinetics of sulphate reduction by wo types of SRB (one organotrophic and one chemoheterotrophic), the growth and death of SRB, the supply and consumption of nutrients (acetate and hydrogen) and reactants (SO_4~(2-)) and the consumption of sulphide by precipitation with aqueous Fe (II) or by container corrosion. The disposal vault is described by a series of 1-D mass-transport barriers representing the buffer and backfill materials and fractured rock. The model can also be used to simulate the effects of #gamma# -adiation and desiccation of the buffer and backfill materials on the extent of microbial activity.