Uranium Isotopes in the Mahanadi River-Estuarine System, India

Extensive measurements of uranium isotopes in dissolved form during different seasons and in suspended form during the monsoon season are reported for the Mahanadi river-estuarine system on the east coast of peninsular India. Beyond the very low chlorinity (0•2 g l−1) region, uranium isotopes behave conservatively in the Mahanadi estuary. The discharge weighted mean uranium input to the Bay of Bengal is 36 tons year−1, out of which the dissolved uranium input is only 18•3%, that is, 6•6 tons year−1. Of the dissolved flux, only 27% (i.e. 1•8 tons year−1) occurs during the monsoon season whereas 99% of the input of uranium in suspended form takes place during the same season