NATURAL RADIOACTIVITY MEASUREMENTS OF SOIL SAMPLES FROM SORAN DISTRICT IN KURDISTAN REGION-IRAQ

Abstract

The amount of radioactivity in soil samples, thirty six samples at different depths (surface, 15cm, 30cm), were collected from twelve different locations at Soran district in the northeastern of Iraqi Kurdistan region. The samples have been studied by using gamma-ray spectrometry, NaI(Tl) Scintillation detector and CR-39 Solid State Nuclear Track Detector (SSNTD) . Activity concentrations of each of K-40, Cs-137, Ra-226 (U-238) , Th-232 (Ac-228) and Radon radionuclides were measured; Radon activity concentration was ranged from (135.301 to 770.727) Bq.m-3. Within the studied area the value of radium equivalent activities Raeq have been calculated and ranged from (0.1130-0.3292) Bq.g-1, these values are below the internationally accepted value of 0.370 Bq.g-1. The value of absorbed dose rate D has been calculated and ranged from (0.0528 to 0.1510) nGyh-1, these calculated values were through the estimate of average global terrestrial radiation of 0.055 nGyh-1. Indoor annual effective dose rate Eied, outdoor annual effective dose rate Eoed, external hazard indices Hex and internal hazard indices Hin have been computed and found to be below the permissible values.