MICRONUC: MICRObial Activity in NUClear waste disposal

The safe storage of nuclear waste in deep geological repositories is a big challenge for our society. Comprehensive understanding of the migration of actinides within the respective host rock and the transport behavior after a possible release from the repository should is urgently needed. Detrimental effects of the radioactive waste on humans and the environment must be avoided over a very long-time period. Microorganisms, which exist in the host rock and backfill material, can survive under extreme conditions over a very long period of time. Their presence therein is of interest because microbial processes can affect the physical and geochemical conditions (e.g. pH, Eh, release of gases) on site. Through their activity, microorganisms can also influence other processes e.g. the corrosion of the container material and migration behavior of actinides, which is caused by the direct or indirect interaction of the microorganisms with the actinides. These processes depend on the type of microbial population, the actinide, and the geochemical circumstances.

The aim of this group is to study the microbial diversity and their activity in the potential host rocks (clay rock, salt rock, crystalline rock) and barrier materials (e.g. bentonite) for nuclear waste disposal and to evaluate their role in respect to the corrosion of container material and the migration of actinides in the geo- and biosphere.

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Current research themes:

• Investigation of the microbial diversity in potential host rocks and barrier materials relevant for a nuclear waste repository in Germany by culture-independent (e.g. DNA/RNA extraction, 16S rRNA gene analysis,) as well as culture-dependent (enrichment and isolation of microorganisms) methods
• Micro- and mesocosm experiments to investigate the microbial activity in the barrier material depending on different repository relevant conditions and their effect on the corrosion of container material
• Characterization of the interaction mechanisms of microorganisms isolated from the different host rocks and barrier materials with actinides on a molecular level by applying a combination of different spectroscopies (e.g. Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLFS), Infrared Spectroscopy (IR) and X-ray absorption spectroscopy) and microscopic techniques such as Scanning Electron Microscopy (SEM) in combination with Energy-Dispersive X-ray spectroscopy (EDX).
• Use of meta-omics techniques to investigate metabolic networks and the influence of the biosphere on the migration behavior of radionuclides

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Team:

Name	Bld./Office	+49 351 260	Email
Cherkouk Dr., Andrea	801/P356	2989	a.cherkoukhzdr.de
Hilpmann, Stephan	801/P306	2860	s.hilpmannhzdr.de
Wei Dr., Ting-Shyang	801/P318	2860	t.weihzdr.de

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Selected publications:

2021

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2020

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2019

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2018

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