Bio-deconstruction of cementitious materials by sulfur-oxidizing microorganisms - a first proof of concept for use in the abrasion of radioactive contaminated concrete

At the end of a nuclear power plant's operating life, controlled dismantling of radioactively contaminated concrete structures is necessary. A biological degradation process using sulfur-oxidizing microorganisms (SOB) could be an interesting alternative to established mechanical demolition methods. A related biological process is biogenic sulfuric acid corrosion (BSC), which occurs during the deterioration of concrete in sewage pipes. In this study, the BSC process was investigated using SOB treated with radioactive radiation. The SOB were irradiated with Co-60 gamma at 5 and 10 kGy and as a reference without irradiation. Concrete specimens were exposed to the BSC process using the treated SOB and showed comparable damage patterns and mass losses at the end of weathering, regardless of the pretreatment. After 363 days of weathering the mass loss was approximately 30%. These results show the resilience of SOB to radioactive radiation and could form the basis of a biodeterioration process.