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<SUP>−1</SUP>) region, uranium isotopes behave conservatively in the Mahanadi estuary. The discharge weighted mean uranium input to the Bay of Bengal is 36 tons year<SUP>−1</SUP>, out of which the dissolved uranium input is only 18.3%, that is, 6.6 tons year<SUP>−1</SUP>. Of the dissolved flux, only 27% (i.e. 1.8 tons year<SUP>−1</SUP>) occurs during the monsoon season whereas 99% of the input of uranium in suspended form takes place during the same season