Specific Activities and Radioactive Contour Maps of Natural (238U, 232Th, 226Ra and 40K ) and Anthropogenic (137Cs) Radionuclides in Beach Sand Samples Collected from Nai Yang Beach of Phuket Province After Tsunai Disaster

Full text: Specific activities of natural (238U, 232Th, 226Ra and 40K) and artificial anthropogenic (137Cs) radionuclides in 50 beach sand samples collected from Nai Yang beach in Phuket province which was effected from 2004 tsunami disaster, have been studied and measured. Experimental results were obtained by using a high-purity germanium (HPGe) detector and gamma spectrometry analysis system and also evaluated by using the standard reference materials IAEA/RGU-1, IAEA/RGTh-1, KCL and SL-2 which were obtained from Department of Physics, Faculty of Science, Prince of Songkhla University Hat Yai Campus. Experimental set-up and measurements were operated and carried out at Nuclear and Material Physics Laboratory in Department of Physics, Faculty of Science, Thaksin University Songkhla Campus. It was found that, the beach sand specific activity ranges from 862.50 to 3,356.35 Bq/kg for 40K, 3.51- 28.58 Bq/kg for 226Ra, 10.15 to 30.22 Bq/kg for 232Th and 0.00 to 2.39 Bq/kg for 137Cs with mean values of 1,843.03 ± 152.49 Bq/kg, 14.88 ± 3.30 Bq/kg, 19.19 ± 2.80 Bq/kg and 0.14 ± 0.11 Bq/kg, respectively. Furthermore, the results were also used to evaluate the absorbed dose rates in air (D), the radium equivalent (Raeq), the external hazard index (Hex) and the annual effective dose rate (AED) in all beach area. Moreover, experimental results were also compared to the Office of Atoms for Peace (OAP) research data, Thailand and global radioactivity measurements and evaluation, the recommended values which were proposed by the Organization for Economic Cooperation and Development (OECD, 1979) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 1988, 1993, 2000). Specific activities of natural and artificial anthropogenic radionuclides in all of Nai Yang beach sand samples could be also used to create the radioactive contour maps