Radiological Hazard Resulting from Natural Radioactivity of Soil in East of Shazand Power Plant

Introduction: Nuclear radiation is potentially harmful to humans and soil contamination with radionuclides is the main source of human radiation exposure. These radionuclides can., enter to human body through the food chain. In this study, 34 soil samples were collected from between Arak city and Shazand Power Plant over 20 km length and analyzed. Materials and Methods: The specific activities of 226Ra, 232Th, 40K, and 137Cs were measured in soil samples, using gamma-ray spectrometry and a high-purity germanium (HPGe) detector. For all the samples, we calculated radiological hazards such as radium equivalent (Raeq), dose rate in air (D), internal and external hazard indices (Hin, Hex), annual gonadal dose equivalent (AGDE), and excess lifetime cancer risk. Results: The specific activities of 226Ra, 232Th, 40K, and 137Cs in the soil samples varied from 18.92 to 43.11, 25.31 to 54.27, 230.17 to 728.25, and from in and Hex wereless than unity. Excess lifetime cancer risk of the samples ranged from 0.21×10-3 to 0.31×10-3, which are close to the mean world value (0.29×10-3) butlower than the acceptable value (10-3). Conclusion: The radiological parameters estimated from the specific activities of the radionuclides in soil were within the acceptable range, and therefore, radiation exposure poses no significant risks to the resident population in the vicinity of the power plant.