A Review of Contamination of Metallic Surfaces within Aqueous Nuclear Waste Streams

Metallic plant infrastructure (e.g. pipework, vessels and structural materials) is often subjected to extreme environments within nuclear facilities such as acidic spent fuel reprocessing and fuel storage ponds. Exposed surfaces can become contaminated with a wide range of radioactive contaminants, including high yield fission products and actinides. Identification of the mechanisms by which radionuclides interact with metallic surfaces, such as stainless steel, is a crucial factor during decontamination strategy development. Once contamination mechanisms are fully understood, careful selection of tailored decontamination approaches will lead to both primary and secondary waste volume reduction, subsequently reducing the economic and environmental burdens associated with disposal, allowing for recycling or re-use of the material. This review of the literature provides a summary of work accumulated in the field of radionuclide contamination of stainless steel surfaces. Trends with respect to contamination mechanisms, as well as the factors contributing to contamination such as surface chemistry and corrosion, are presented. The outstanding research needs to further develop our understanding of contamination mechanisms have been identified, including the advanced materials characterisation techniques likely to play a significant role in contaminant identification.