Corrosion of Copper in Anoxic Ground Water in the Presence of SRB

Copper is used in various applications in environments favoring and enabling formation of biofilms bynaturally occurring microbes. Copper is also the chosen corrosion barrier for nuclear waste in Finland. Thecopper canisters should have lifetimes of 100,000 years. Copper is commonly considered to be resistantto corrosion in oxygen-free water. This is an important argument for using copper as a corrosion protectionin the planned canisters for spent nuclear-fuel encapsulation. However, microbial biofilm formation on metalsurfaces can increase corrosion in various conditions and provide conditions where corrosion would nototherwise occur. Microbes can alter pH and redox potential, excrete corrosion-inducing metabolites, directlyor indirectly reduce or oxidize the corrosion products, and form biofilms that create corrosive microenvironments. Microbial metabolites are known to initiate, facilitate, or accelerate general or localized corrosion, galvaniccorrosion, and intergranular corrosion, as well as enable stress-corrosion cracking. Sulfate-reducing bacteria(SRB) are present in the repository environment. Sulfide is known to be a corrosive agent for copper. Here we show results from corrosion of copper in anoxic simulated ground water in the presence of SRBenriched from the planned disposal site. KCI Citation Count: 0