Understanding waste phenomenology to reduce the amount of sampling and analysis required to resolve Hanford waste tank safety issues

Safety issues associated with Hanford Site waste tanks arose because of inadequate safety analyses and high levels of uncertainty over the release of radioactivity resulting from condensed phase exothermic chemical reactions (organic solvent fires, organic complexant-nitrate reactions, and ferrocyanide-nitrate reactions). The approach to resolving the Organic Complexant, Organic Solvent, and Ferrocyanide safety issues has changed considerably since 1990. The approach formerly utilized core sampling and extensive analysis of the samples with the expectation the data would provide insight into the hazard. This resulted in high costs and the generation of a large amount of data that was of limited value in resolving the safety issues. The new approach relies on an understanding of the hazard phenomenology to focus sampling and analysis on those analytes that are key to ensuring safe storage of the waste