Radiological risk assessment of 238U, 232Th and 40K in Thailand coastal sediments at selected areas proposed for nuclear power plant sites

This paper reports on the distribution of three natural radionuclides 238U, 232Th and 40K in marine sediments long the Gulf of Thailand to establish baseline data for future environmental monitoring. Sediments were collected from five potential sites selected for nuclear and thermal power plants commission as well as heavy industry development. Concentration of uranium and thorium were determined using inductively coupled plasma mass spectrometry (ICP-MS) as well as activity of 238U series (226Ra), 232Th series (228Ac) and 40K by γ-spectroscopy. The radiation hazard parameters were calculated based on United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Variation in concentration of natural radionuclides at different sampling areas could be attributed to organic matter content and sediment particle size. The radiological health hazards to the people living nearby sampling areas and the people who handle the marine sediments are within limits recommended by UNSCEAR