Geomicrobiology.co.uk

The Website of the University of Manchester Geomicrobiology Group

        The UK nuclear waste legacy consists of complex and heterogeneous wastes contaminated with both radioactive isotopes and toxic, stable co-contaminants. Microbial metabolism has the potential to drastically alter the chemistry of radioactively contaminated environments, altering the structure of nuclear waste storage materials and controlling radionuclide speciation and mobility. However, we currently know almost nothing about the microbial diversity of nuclear waste forms of relevance to the UK, the processes that microbial communities can catalyse, and the mechanisms by which these organisms potentially tolerate the extreme environments that exist at these sites.

   In my studentship, which is part of the EPSRC DIAMOND (Decommissioning, Immobilisation and Management of Nuclear wastes for Disposal) consortium, I am examining the biogeochemistry of extreme environments in radioactive waste forms such as high radiation flux and extremes in pH. The aim of my project is to assess the microbial community of key nuclear sites using targeted molecular ecology techniques; use culture and modelling experiments with analogue materials to assess the range of biogeochemical processes that are feasible in such environments; and to also determine the impact of the key microbial processes identified on materials performance and radionuclide speciation, with a view to controlling and/or exploiting biotransformations.

    Overall, the results from this study will lead to an improved understanding of the fundamental role of microorganisms in controlling the environmental behaviour of radionuclides in key UK waste forms, and ultimately to help improve management practices for these problematic materials.

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