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

摘要

Natural radioactivity in surface soil samples collected at potential sites from southern part of Thailand to set up nuclear power plants has been investigated. U-238 and Th-232 were determined by inductively coupled plasma mass spectrometry whereas gamma-ray spectroscopy was used for K-40 determination. The activity concentrations for U-238, Th-232 and K-40 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 distribution that could be attributed to geological origin. The radiation hazard parameters were estimated from activity concentration of U-238, Th-232 and K-40 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.