Microbiology of Barrier Components of a Deep Geological Repository for Used Nuclear Fuel

Explore the critical role of microorganisms in engineered barrier systems designed for deep geological repositories storing used nuclear fuel in this comprehensive webinar. Learn how microbial activity, particularly sulfide production by sulfate-reducing bacteria, poses potential corrosion risks to copper containers surrounding nuclear fuel. Discover the research methodology combining cultivation and molecular analyses to characterize microbial communities in bentonite clays and deep geological repository environments. Examine how dry compacted bentonites at high densities and low water activity effectively limit microbial growth, serving as biological barriers. Review field study results from the Grimsel Underground Research Laboratory's MaCoTe experiment, which demonstrated microbial community stability over a decade under repository-like conditions. Understand laboratory enrichment findings that recovered various microbial taxa, including aerobic heterotrophs and sulfate-reducing bacteria, but only under specific permissive conditions. Analyze subsurface rock and groundwater samples, revealing the presence of low-abundance microbial communities including CPR and DPANN lineages. Gain insights into how water availability, density, and swelling pressure control microbial survival in these extreme environments. Apply this knowledge to microbial risk assessment and long-term safety evaluations for deep geological repository systems in Canada and internationally.