Controlling ionizing radiation exposures during chemical treatments of Egyptian black sands minerals / Amal Saeed Nasr Ahmed Nasr ; Supervised Anwar Abdulazim Elsayed , Haitham Sharaf Eldin Mohamed , Yassin Abdulazim Mohammad

Thesis (Ph.D.) - Cairo University - Faculty of Science - Department of Biophysics

For the purpose of radiation protection, proper measures and parameters should be established and clarified to control the occupational or public exposures to ionizing radiation. The laboratories of chemical processing of Egyptian black sand minerals "monazite, zircon, ilmenite and rutile" at the Nuclear Materials Authority (NMA), were selected to evaluate the radiation exposure of the workers at these laboratories.The physical radiation quantities; equivalent dose as a measure of the external exposure to gamma rays and the concentrations of radon and thoron gases beside the concentration of uranium in the air and dust were measured to calculate internal exposure. These measurements were carried out during the chemical processing of 200 gm monazite, 2.5kg zircon, 2.5 kg ilmenite and 10 kg rutile. The effective dose due to external exposure was calculated assuming whole body irradiation while the factors obtained by the biokinetic models were employed to calculate the internal effective doses. This study introduced a new measure to control the effective doses during the chemical processing of the radioactive minerals. It was named " Batch Dosimetry" which depends on the estimation of the effective doses during the real time of the chemical batches as an alternative of the individual dosimetry. The total effective dose during the batches for monazite, zircon, ilmenite and rutile were 1.88, 10.54, 8.06, 10.52 (oSv), respectively.The total annual effective doses for minerals of monazite, zircon, ilmenit, and rutile were 0.19, 1.79, 0.37, 1.17 (mSv), respectively

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