NATURAL RADIOACTIVITY MEASUREMENT AND DOSE ASSESSMENT OF BEACH PLACER SANDS IN THE COASTAL REGION OF TAMIL NADU (INDIA)

摘要

A preliminary study was carried out to determine the radioactivity concentration of Th-232, Ra-226 and K-40 in beach placer sands from 13 locations along the coast line of Tamil Nadu state, India. The ambient dose rates varied from 9 to 467 nGy h(-1). The activity concentrations of radionuclide Th-232, Ra-226 and K-40 ranged from 5.2 to 683 Bq kg(-1), 13 to 198 Bq kg(-1) and 107 to 421 Bq kg(-1), respectively. The annual effective dose rate ranges from 27 to 620 mu Sv y(-1) and was higher at seven beaches in comparison to the UNSCEAR annual worldwide average value.