Abstract
A survey was carried out to determine terrestrial gamma radiation dose rates, the concentration level of U-238 and Th-232 and alpha and beta activities for the surface soil in Ulu Tiram, Malaysia A 125 measurements were performed using a NaI(TI) gamma-ray detector with crystal size of 1 '' x 1 '' on 15 soil samples collected from the site area about 102 km(2). U-238 Th-232 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 U-238 and Th-232 concentrations in soil samples collected are 3.63 +/- 0.39 ppm within the range of 1.74 +/- 0.20 to 4.58 +/- 0.48 and 43.00 +/- 2.31 ppm within the range of 10.68 +/- 0.76 to 82 10 +/- 4.01 ppm, respectively. The average estimate of alpha and beta activity in soil samples collected are 0.65 +/- 0.09 Bq(.)g (1) and 0.68 +/- 0.08 Bq(.)g (1), respectively. The average of terrestrial gamma-radiation dose rates measured in Ulu Tiram was found to be 200 nGy(.)h (1), within the range of 96 to 409 nGy(.)h (1). The population weighted outdoor annual effective dose was 1.2 mSv.