Natural Radioactivity in Selected Soil Samples from the Archaeological of Ur City in Dhi-Qar Province, Iraq

The specific activity of natural radionuclides in 24 soil samples collected from antiquities area of Ur city in Dhi-Qar province (31.0459863N, 46.2534257E) in southern Iraq have been studied and evaluated. Experimental results were obtained by using a Gamma ray spectrometer analysis system consists of a scintillation detector Sodium Iodide activated by Thallium NaI(Tl) of (3"×3") crystal dimension at the laboratory of radiation detection and measurement in Science Collage, University of Kufa. The spectrometer has been calibrated for energy by acquiring a spectrum from four standard sources of gamma radiations supplied by spectrum techniques (LLC). The measuring time of all soil samples is 18000 seconds; it was found that, the soil specific activity ranges from 29.93±2.97 to 9.99±2.56Bq/kg for 238U, from 25.66±2.55 to 7.77±2.24Bq/kg for 232Th and from 397.38±12.06 to 215.75±8.91Bq/kg for 40K, with mean values of 17.9±3.02Bq/kg, 13.66±2.41Bq/kg and 314.62±11.3Bq/kg, respectively. The results have been compared with the acceptable data of the worldwide literatures. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity (Ra_eq), the gamma absorbed dose rate (AD), the annual effective dose rate and the both (external and internal) hazard index have been calculated and compared with the acceptable values of the worldwide average (UNSCEAR 2000).