SAMPLING DEVICE FOR TRITIUM ASSESSMENT IN SOLID-WASTE MATERIALS

A technique for tritium extraction, coupled with Liquid Scintillation Counting (LSC), has been developed to be applied to the declassificati on of the tritiated waste to non radioactive waste status in complianc e with limits established by regulatory bodies. An experimental rig ha s been developed which enables tritiated water extraction from waste s amples by heating in a stream of humidified nitrogen avoiding combusti on. The resultant tritiated water vapour is condensed, collected and p resented for LSC to determine the tritium specific activity of the tes t materials. The feasibility and the reproducibility of the method has been demonstrated by performing tests with samples of representative waste material labelled with an HTO reference standard resulting in a high extraction efficiency and a limit of detection of tritium in the test material lower than 0.01 Bq/g.