Determination of natural radioactive elements in Abo Zaabal, Egypt by means of gamma spectroscopy

The natural nuclide gamma-ray activities and their respective annual effective dose rates, produced by U-238, Th-232, K-40 and Ra-226, are determined for 10 different natural samples (soil-plant-water) from Abo Zaabaal Lake. This lake is located very close to the Egyptian reactors. The gamma spectra analysis indicates that the photo-gamma lines represent ten radioactive nuclides Th-234, Pu-239, Ac-228, Ra-226, Pb-212, Pb-214, Tl-208 Bi-212, Bi-214 and K-40. These nuclides represent the daughters of the natural radioactive series U-238 and Th-232 with K-40. The mean activity concentration of 238U was found to be 6.57, 10.16 and 5.44 Bq kg(-1) for (soil-plant-water); 8.46, 8.33 and 6.04 Bq kg(-1) of Th-232, and 136.3, 216.8 and 119.2 Bq kg(-1) of K-40 respectively. The mean activity concentrations of Ra-226 were obtained which help to evaluate the radiation hazard indices as radium equivalent, internal and external hazard indices. In addition, to assess the radiation risk to a biosystem, the annual effective dose rate, the absorbed dose in human and the absorbed dose outdoor are also evaluated. (C) 2012 Elsevier Ltd. All rights reserved.