High background radiation places and spatial distribution of uranium in groundwater of monazite placer deposit in Kanniyakumari district, Tamil Nadu, India

The present investigation deals with gamma radiation survey and analysis of uranium in groundwater samples collected from the Kanniyakumari district. It reveals that gamma dose rate varies from 58 to 3880 nSv/h (mean 276 nSv/h) and uranium concentration varies from <= 0.2 to 10 mu g/L (median 0.4 mu g/L) in the pre-monsoon and <= 0.2 to 14.9 mu g/L (median 0.2 mu g/L) in the post-monsoon seasons. The present study shows that Manavalakurichi and Indranagar junctions have high background radiation due to the monazite placer deposits. The alkaline and reductive nature of groundwater minimizes the leaching of uranium from these monazite placer deposits.