Relative influence of 129I sources in a sediment core from the Kattegat area

The depth profiles of the 129I concentration and the 129I/127I ratio in a surface sediment core from the Kattegat area have been analyzed in order to obtain information about the different sources of 129I in that core. Therefore, a mathematical model that relates the measured values to the available emission data from the nuclear fuel reprocessing plants and nuclear weapons tests has been applied. Results show that the reprocessing plants at La Hague and Sellafield are the main sources of 129I in the sediment. Results about the transfer from the release points at the reprocessing plants to the sampling zone agree with other literature data. The model calculates quite fast the sedimentation of 129I in the sampling place, probably attached to organic matter. Finally, an estimation of approximately 89 kg of 129I released by Sellafield between 1952 and 1968 has been obtained from the model.