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Determination of Uranium, Thorium,238U/232Th Activity Ratio and Rare Earth Elements Distribution Using Neutron Activation Analysis (NAA)
Authors: Nassef MH and Nawal M. Said
Number of views: 292
In this study, uranium, thorium, cesium concentration and rare earth elements distribution pattern in addition to 238U/232Th activity ratio were determined in 27 collected environmental samples. The samples were analyzed using two different techniques: destructive technique such as neutron activation analysis (NAA) and non-destructive technique such as gamma-ray spectrometry. Concentrations of six rare earth elements were measured using NAA namely: Lu, Ce, Eu, Tb, Yb, and La. The sampling area has different locations across the whole eastern border of Egypt. For NAA technique, the samples were irradiated with neutrons using epithermal neutrons at the Joint Institute of Nuclear Research, Dubna, (Russia). The radioactivity assay was carried out using high-resolution gamma-ray spectrometry. The average concentration in the analyzed samples for 238U, 232Th, and 137Cs was found to be 3.5, 3.93, and 0.83 ppm respectively. The measured values found within the average world range 2.8 (0.81-4.0), 8.6 (1.7-12.3) for 238U and 232Th respectively. The rare earth distribution pattern was determined for the analyzed samples. This distribution pattern is a characteristic signature for the studied area. The area monitored represents a database for any future radiological emergency action outside the country. Also, the obtained results can be used as a useful information data bank for the suggested national nuclear forensic database library and in a nuclear security application.