InCoManD webinars on microbial activity | Characterization of Complex/Coupled Biogeochemical Processes at the Metal Canister/Bentonite/Radionuclide Interface in Deep Geological repositories
June 15 @ 1:00 pm - 2:30 pm
This talk will examine the role of microorganisms in deep geological repositories (DGRs) for nuclear waste. We will explore who these microbes are, how they survive in extreme environments, and how their activity affects the safety of the repository over thousands of years.
- Microbial Diversity: the key groups of bacteria, fungi, and archaea found in engineered barriers (like bentonite clay) and the surrounding host rock will be identified.
- Environmental Limits Microbial survival is restricted by the harsh conditions inside a repository. We will discuss how high temperatures, radiation, high clay density, and changes in water and oxygen levels control whether microbes stay dormant or become active.
- Impact on Repository Safety Microbial activity can change how well the barrier system works. Key topics include:
- Corrosion: Bacteria causing metal waste containers to rust or degrade.
- Gas: Microbes producing gases that could increase internal pressure.
- Clay Changes: Biological processes altering the protective properties of bentonite.
- Radionuclide mobility: How microbes can either “trap” radioactive elements (like uranium) through biomineralization or help them move through the environment.
- Future Challenges: Finally, we will highlight the need for more long-term experiments in underground labs to help us better predict how biology will interact with nuclear waste barriers over geological timescales.
Learning Outcomes
Upon completion of this session, participants should be able to:
Knowledge
-Evaluate how physicochemical stressors—such as radiation, thermal loads, high bentonite density, and shifting redox potentials—limit or stimulate microbial activity
-Analyze the dual role of microbes in repository performance, specifically their ability to drive Microbiologically Influenced Corrosion (MIC) versus their capacity for radionuclide immobilization through biomineralization
-Recognize current knowledge gaps in the “Safety Case” for deep geological repositories and prioritize future research needs for robust long-term modelling.
Skills
– Competence in determining the “limits of life” based on physical and chemical constraints.
-Ability to evaluate the coupled interactions between microbial metabolism and mineralogical changes
– Proficiency in identifying microbial risks (corrosion, gas buildup) versus biological benefits (immobilization) within a repository’s safety framework
Practical information
Click here to register.
