Développement des méthodes de microanalyses par spectrométrie gamma à bas bruit de fond en vue des applications environnementales

Abstract

In this work, The specific activities of naturally occurring radionuclides 226Ra, 232Th and 40K in the phosphate ores and in granular fertilizers have been determined using two gamma spectrometer, a Broad-Energy Germanium (BEGe) detector and well-type HPGe (high-purity germanium detector). The influence of the treatment processes on the radioactivity level in the Djebel Onk phosphate mine, in the dry and humid way has been assessed. The total absorbed dose rates in air (D) and external annual effective dose rates (AED) were calculated from the three radionuclide concentrations. Excess lifetime cancer risks ELCR due to phosphate ores and fertilizers, radiation hazard indices (Raeq, Hex, Hin and Iγr) were also calculated. According to our results, the obtained values are higher than UNSCEAR established standard limits. The findings were discussed and compared to those found in the literature.