الفهرس 
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Abstract
The thesis aimed to Study the radionuclides determined in metamorphic rock type (granitic gneisses) in order to identify the alteration processes which happened in Abu Rusheid area, South Eastern Desert, Egypt.
The study area was surveyed on a suitable grid pattern. The tectono-stratigraphic sequence of the Precambrian rock units of the studied area are metamorphic rocks, layered metagabbros set in metasediment matrix, granitic genisses and granitic rocks.
A total of 41 points covered the study area and 41 rock samples were taken for radiometric and geochemical analysis.
To achieve this target, we perform measurements in the field and lab.
In the field, ground spectrometric surveying using a portable gamma-ray spectrometer model Rs-230, was carried out over the studied area. The premised area was selected for the details study based on its high radioactivity and mineralization. The obtained results for dose rate, eU, eTh in ppm, K in %, and their ratios eU/eTh, eU/K and eTh/K, where the value of eU/eTh ratio is important for uranium exploration because it depends mainly on the mobility of uranium. Therefore, it outlines the most promising area of uranium migration and accumulation. The resultant of the 3D maps are show different radioactivity levels, which reflect contrasting radioelement contents for the exposed
gneisses granite.
Measurements of radon gas concentration using CR-39 in the cylindrical plastic cup in the field were carried out.
In the lab, radon gas measurements were carried out to determine the radon concentration as well as exhalation rate measurements. The results show the activity concentration of Rn-222, activity concentration of Ra-226, Radon mass and surface exhalation rate and annual absorbed dose equivalent.
The values of radium activity determined in samples are less than the permissible value of 370 Bq/kg. The annual effective dose larger than the normal background level of 5 mSvy-1 for public and 20 mSvy-1 for workers.
The comparison between the measurements of radon concentrations in the field and lab was done. There is a poor correlation between radon gas concentrations in the field and lab, indicating that the geological factors which effect on radon gas emanation is dominating. The great difference between the radon gas concentration in the field and lab may be due to the open system, fractures, permeability of the mineral grains and mass effect that are found in the field than the lab.
For gamma analysis a high resolution gamma detection system (HPGe) detector was used. The natural radionuclides in the samples have been measured. In this work, the activity concentrations of 238U, 226R, 232Th and 40K were higher than the world’s average. Activity ratios of radionuclides for the studied samples238U/235U, 234U/238U, 226Ra / 238U, 226 Ra / 230Th, 230Th/238U, 230Th/234U and 234U/235U were measured to estimate the radioactive equilibrium / disequilibrium in the study area. As well as study hazard indices factors concerning the human beings in this area.
In the present work, the absorbed dose rate (D), the annual effective dose equivalent (AEDE), the excess lifetime cancer risk (ELCR), Annual gonadal dose equivalent (AGDE), radium equivalent (Raeq), external hazard index (Hex), radioactivity level index (I γ), were estimated which indicate that, all the radiation hazard indices factors were higher than the internationally recommended values.
X-ray fluorescence technique (XRF) was used to determine the trace element contents for the granitic rocks. Uranium (U) shows a positive correlation with Cu (0.7), Ni (0.8), Zn (0.7), Y (0.7), V (0.7), Pb (0.7) and Ba (0.7), while U shows a negative correlation with Zr (-0.1), Sr (-0.1), Rb (-0.3), Nb (-0.1) and Th (-0.2).
Thorium (Th) shows a weak correlation with Zr (0.3), Sr (0.3), Rb (0.3) and Nb (0.3), while Th shows a negative correlation with Cu (-0.1), Ni (-0.3), Zn (-0.2), Y (-0.3), V (-0.3), Pb (-0.4) and Ba (-0.1).
According to the trace elements data and the mineralogical studies which have been performed upon granitic gneiss (cataclastic rocks) at Abu Rusheid area, there is an important minerals in the study area.