Determination of actinides in samples obtained during dismantling activities

At present, some of the nuclear and radioactive facilities from CIEMAT employed in the past to perform activities related to the production of nuclear energy have been decommissioned as part of a more global on-going dismantling project. During the radiological characterization of a former laboratory a significant contamination of actinide elements in the old liquid effluents system was found. Samples obtained from two different locations (pipes and deposit) were measured by gamma- and alpha-spectrometry to quantify the contamination of the system. A quick and simple method using Actinide resin coupled with liquid scintillation counting (LSC) was employed for the determination of gross-alpha activity. The samples were also analyzed using a sequential leaching procedure to obtain information about the actinide association to certain geochemical phases with different solubilities such as carbonates, oxides, organic matter, etc., and thus, to choose the most appropriate clean-up method. Finally, the results obtained by the different techniques mentioned are compared and discussed.