Long term study of 99Tc in brown seaweed from the Swedish coast

Technetium was analysed in brown seaweed samples from Saerdal, located at the Swedish west coast. Since 1967 this location has been used for regular sampling of seaweed (Fucus serratus and Fucus vesiculosus). The activity concentration of 99Tc in seaweed is influenced by the liquid discharge from the nuclear fuel reprocessing plant in Sellafield, UK. Transit time and seasonal variations were estimated by comparing the concentration of technetium in seaweed with the annual discharge of that radionuclide from Sellafield. In this work samples collected from 1994 to 2000 were analysed and the results were combined with data from 1967 to 1993. The concentration of 99Tc in the 1994-2000 seaweed samples varied between 10 and 230 Bq/kg dry weight. The current high values of 99Tc in seaweed samples originate from the increased liquid discharge of technetium starting when the Enhanced Actinide Removal Plant (EARP) at Sellafield came into operation in 1994. (au)