A survey of possible microbiological effects within shallow land disposal sites designed to accept intermediate-level radioactive wastes

A literature survey was conducted to assess the current knowledge on microbial activity that may occur within a shallow intermediate-level waste disposal trench. Relatively little published information exists that is directly based on intermediate radioactive wasteforms, but relevant work was identified from other scientific fields. The likely environmental conditions within a disposal trench and their influence on microbial activity are considered. Also discussed are specific microbiological effects on waste packagings, backfill materials and concrete structures. Overall, it is unlikely that there will be extensive activity within the trenches and little evidence exists to suggest microbiologically-enhanced radionuclide migration,. The quantitative effect of microbial action is not possible to ascertain from the literature, but the general impression is that it will be low. Physical or chemical degradation processes are likely to predominate over those of a microbiological nature. Areas where further research would be valuable are also recommended. (author)