Natural radioactivity survey on soils originated from southern part of Thailand as potential sites for nuclear power plants from radiological viewpoint and risk assessment

Natural radioactivity in surface soil samples collected at potential sites from southern part of Thailand to set up nuclear power plants has been investigated. 238U and 232Th were determined by inductively coupled plasma mass spectrometry whereas gamma-ray spectroscopy was used for 40K determination. The activity concentrations for 238U, 232Th and 40K varied in range from 4 to 122, 6 to 170 and 5 to 1,422 Bq kg-1, respectively. The large variation of radionuclide concentrations showed heterogeneous dis-tribution that could be attributed to geological origin. The radiation hazard parameters were estimated from activity concentration of 238U, 232Th and 40K in accordance with the UNSCEAR 2000. Data obtained indicated that soils in the study areas did not pose any significant radiological health hazard to the local population