الفهرس 
Introduction and Literature ReviewOnly 14 pages are availabe for public view
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Abstract
Eighteen samples 0f sediments from Um Bogma, South western Sinai and twelve granite samples collected and from Gabal Gattar, N0rth Eastern Desert in Egypt have been investigated. This work has stressed on the distribution of radionuclides and their ratios in the three phases; original sample, leachate and residual. The concentrati0ns of trace and major elements were determined to c0mpare with the radionuclide, distribution. These have been done thr0w three stages:
- First stage; radiometric analysis using Hyper Pure Germanium detector for different radionuclides and their isotopes and daughters.
- Second stage; chemical analyses of uranium after Leaching experiments for the choice samples to f0llow the behavior of radionuclides in different media (0riginal, leachate and residual).
- Third stage; determination 0f trace elements using X-ray fluorescence.
In first stage: C0ncentrations of radionuclides in sediment and granite samples were determined by γ-ray spectrometer using HPGe detect0r with a specially designed shield. The value 0f uranium was high in sediments and granite samples where the value of 40K in granite was higher than that in sediments where it depends on the chemical c0mposition of rock types. The abs0rbed dose rate ranged from (419 to 3908) nGy/h f0r sediment samples and from (1002 to 1307) nGy/h for granite samples. The representative external hazard index values (Hex) f0r sediment and granite samples were estimated. In the present w0rk, the state of radioactive disequilibrium in the U-series at Um B0gma and Gabal Gattar area were studied. The activity ratios between 214Pb/226Ra, 214Pb/214Bi and 226Ra/238U were calculated. The th0rium to uranium concentration ratios (Clark value) was als0 estimated. The total excess life-time cancer risk (ELCR) was measured.
In sec0nd stage: The residual, pr0duced from leaching processes, constitute most of the original r0ck materials and contain most of the radi0activity emitted from 226Ra and its daughters 222Rn, 214Pb and 214Bi. Six different rock samples (four sediments and two granites) were subjected to sulfuric acid leaching with the same parameters of solid-liquid fluid ratio (S / L), acid c0ncentration and leaching time. After the leaching pr0cess, the solution was separated from the residue and the latter was dried. The two units, namely the soluti0ns (leachate), and residues were measured by the germanium detector to determine the activity concentration (Bq / kg) of different radionuclides in the two units of the six samples. The results showed that the relationship between the total activities of solution and the residual have three categories. In the first 0ne for sediment samples, the activity of solution + residual was 72.37% from the original of siltstone (3S), the activity of solution + residual was 90.02% from the original claystone sample (17S), the activity of soluti0n + residual was 92.6% from original of shale (2S), the activity of solution + residual was 74.07% from 0riginal claystone (7S). In the second for granite samples, the activity of solution + residual was 130.39% from original (2G) and the activity of solution + residual was 142.3% from 0riginal (5G). These variations depend mainly on the grain surfaces in the different rock types. This phenomenon varied in magnitude within the different radionuclides in each sample. Also the leachability of U by the chemical analysis using several acidic leaching experiments f0r uranium have been perf0rmed by sulfuric acid. The measurements of leaching efficiency% of uranium by using HPGe detector, we found the values of leachability are alm0st equality.
In third stage; Trace elements in the studied samples were determined, by using a Philips X-ray unit. These analyses have revealed the presence 0f interesting values of REEs and U; namely m0re than 500 and 250 ppm respectively. While the uranium chemically recorded about 240 ppm for (3S), the values of REEs and U which present in the sample (17S) are m0re than 1000 and 1020 ppm respectively, and the uranium chemically recorded about 420 ppm, for (2S) namely more than 500 and 1050 ppm respectively, while the uranium chemically rec0rded about 600 ppm, and finally (7S) m0re than 1000 and 300 ppm respectively, while the uranium chemically recorded about 300 ppm.