الفهرس 
Natural RadioactivityOnly 14 pages are availabe for public view
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Abstract
The main target of this study is the assessment of the radiation hazards for 33 represented samples collected from rare metals albite granite from four areas Abu Rusheid, Abu Dabbab, Nuweibi and Um Naggat areas in the Eastern Desert, Egypt. That enriched with economic rare-metals; Sn-Nb-Ta. These rare metals are important for manufactures of electronics like mobile phone, laptop computers, digital camera as well as automotive and medical electronic equipment.
The sample locations, collection methods and preparation procedures have been discussed. Thirty-three samples of albite granite were collected from different four areas: 9 samples from Abu Rusheid area, 8 samples from Um Naggat area, 9 samples from Nuweibi area and 7 samples from Abu Dabbab area.
The concentration of the terrestrial radionuclides is measured in all the studied samples to estimate the specific radioactivity of 238U-series, 232Th-series and 40K by using a high resolution hyper pure germanium (HPGe) gamma ray spectrometer. The analysis of data is completed by using a computerized analyzer fitted with a high multichannel analyzer with high level software programs. The radionuclide concentrations in the different samples are compared with the world-wide average reported in the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), this comparison is of scientific interest to health physics. Estimation the values of the radon emanation coefficient of the rocks at these areas, have been also accomplished.
The average activity concentrations are estimated for 238U (501.8, 447.5, 60.6 and 89.3 Bq/kg), 226Ra (577.8, 520.4, 74.8 and 105.8 Bq/kg), 235U (23.5, 20.8, 2.8 and 4.2 Bq/kg), 232Th (692, 234.9, 84.5 and 51.6 Bq/kg) and 40K (1352.6, 1134.6, 1155.6 and 914.5 Bq/kg) for Abu Rusheid, Um Naggat, Nuweibi and Abu Dabbab areas respectively. from the result analysis, the specific activities of 238U and 232Th were found to be higher than the world-wide average. Also, the activity ratio 226R/238U was estimated to identify the U equilibrium/ disequilibrium for the four areas. The clark’s ratios were calculated to determine any U-enrichment in the albite granite of the studied areas. Abu Rusheid and Um Naggat areas under investigation are classified as having high levels of terrestrial radioactivity concentration. However, the decision to use the materials containing terrestrial radioactive elements is established not only on the evaluation of the activity concentrations of these elements but also on the possible or suggested configuration of radiation exposures.
On the other side, these areas are characterized by high concentrations of heavy minerals and rare-metal elements in granitic plutons and its content of radioactive elements. Therefore, the present study would recommend exploiting economic the radioactive elements existing in granitic rocks and how to use the economically rare metals. So, in the present work we have measured also these concentrations in samples using XRF technique.
The concentrations of trace elements have been measured using XRF technique for albite granite samples of Abu Rusheid area (in ppm) in decreasing order, are: Zr (2722.7) ˃ Rb (1653.2) ˃ Nb (481) ˃ Y (305.6) ˃ Zn (269.8) ˃ Pb (140.3) ˃ Sr (89.2) ˃ Ba (40.8) ˃ Cr (27.2) ˃ Cu (13.7) > Ni (11.1). The trace elements concentrations (in ppm) at Um Naggat area in decreasing order, are: Zr (1365.1) ˃ Rb (1138.6) ˃ Zn (303.5) ˃ Y (294.6) ˃ Nb (241.3) ˃ Pb (56) ˃ Sr (45.1) ˃ Ba (35.4) ˃ Cr (31.9) ˃ Cu (10.1) >Ni (9.9). The trace elements concentrations (in ppm) at Nuweibi area, are: Rb (930.7) ˃ Zr (226.4) ˃ Zn (201) ˃ Y (142) ˃ Pb (45.2) ˃ Nb (40.7) ˃ Cr (28.8) ˃ Ni (9.4) ˃ Cu (8.9) ˃ Sr (7.7) >Ba (3.9). The trace elements concentrations (in ppm) at Abu Dabbab area, are: Rb (1043.1) ˃ Zn (585.3) ˃ Zr (197) ˃ Y (157) ˃ Nb (34.9) ˃ Cr (28.3) ˃ Pb (12) ˃ Ni (11.9) ˃ Ba (9.6) ˃ Cu (6.9) >Sr (6.7).
CR-39 SSNTD fixed at the top of a radon chamber filled with a crushed sample was employed to estimate the values of the radon emanation coefficient for the studied areas. The results averaged the values of the emanation coefficient into two categories; one of them includes the rocks from Abu Dabbab and Nuweibi with value of 0.027 and the other includes the rocks from Um Naggat and Abu Rusheid with value of 0.008. The difference in the values of the emanation coefficient may be ascribed to the difference in the other properties of the rock grains. However, the isolation of these parameters may reveal experimentally a reciprocal relationship between the emanation coefficient and the radium activity in the rocks. This indicate that Abu Rusheid and Um Naggat areas are enriched with uranium and consequently radium and radon contents are more than that of Abu Dabbab and Nuweibi areas.