Microbially induced corrosion of steel and copper materials in deep geological repositories

Microbially induced corrosion in deep bedrock is important when evaluating long-term safety of disposal of radioactive waste. In oxygen-free water, corrosion of metals is low. Microorganisms however, are able to accelerate several types of corrosion. The groundwater at the repository depth contains up to 105 microbial cells mL-1 with considerable diversity1. The activity of microorganisms attached to the surfaces and the properties of formed biofilms are essential factors when considering the possibility of microbially induced corrosion. Under the biofilm the conditions may differ remarkably from the surrounding environment and thus induce circumstances where the corrosion is locally increased. As a consequence of corrosion of the metallic waste or capsule material, radioactive nuclides may be released into groundwater and transferred to neighbouring areas of the repository. The aim of research is to characterize microbial biofilms associated with corrosion, study the ability of the indigenous groundwater microbes to produce aggressive corrosive agents and in addition to this the ability of microorganisms from deep terrestrial biosphere to benefit from these metallic material.