Key Parameters for Retrieval of Radioactive Waste

Management of radioactive legacy wastes is complicated by difficulties of access for sampling and measurement. Some wastes were laid down before systems were put in place to properly document their constituents while others have consolidated into sludge layers with poorly understood yield properties below supernatant liquids. The primary challenge is therefore to gain enough knowledge about the contents of tanks and silos to facilitate mobilisation, retrieval, transportation and buffer storage. For example the extent of the settled layer, its size consist, particle density and the precise position of large objects which have been discarded into the same space should be known before specialised technology can brought to bear. Expensive sampling campaigns have indicated partial answers to some of these questions, but do not have the advantages of reliable on-line visualisation and remote measurement (or inference) of key variables.