Radioactivity levels of super(238)U and super(232)Th, the alpha and beta activities and associated dose rates from surface soil in Ulu Tiram, Malaysia

• Published in: Journal of radioanalytical and nuclear chemistry Vol. 273; no. 3; pp. 653 - 657
• Main Authors: Abdul Rahman, AT, Ramli, A T
• Format: Journal Article
• Language: English
• Published: 01-09-2007
• Subjects: Malaysia
• ISSN: 0236-5731
• DOI: 10.1007/s10967-007-0926-2

A survey was carried out to determine terrestrial gammaradiation dose rates, the concentration level of super(238)U and super(232)Th and alpha and beta activities for the surface soil in Ulu Tiram, Malaysia A 125 measurements were performed using a NaI(T1) gamma-ray detector with crystal size of 1 double prime x 1 double prime on 15 soil samples collected from the site area about 102 km super(2) super(238)U and super(232)Th concentrations were determined in soils by using hyper pure germanium (HPGe) gamma-ray spectrometry. The activity of alpha and beta from the surface soil was counted by using alpha beta counting system. The average value of super(238)U and super(232)Th concentrations in soil samples collected are 3.63 plus or minus 0.39 ppm within the range of 1.74 plus or minus 0.20 to 4.58 plus or minus 0.48 and 43.00 plus or minus 2.31 ppm within the range of 10.68 plus or minus 0.76 to 82 10 plus or minus 4.01 ppm, respectively. The average estimate of alpha and beta activity in soil samples collected are 0.65 plus or minus 0.09 Bqg super(-1) and 0.68 plus or minus 0.08 Bqg super(-1), respectively. The average of terrestrial gamma-radiation dose rates measured in Ulu Tiram was found to be 200 nGy h super(-1), within the range of 96 to 409 nGy h super(-1). The population weighted outdoor annual effective dose was 1.2 mSv.