الفهرس 
صفحة العنوانOnly 14 pages are availabe for public view
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Abstract
Uranium is the most used element in the nuclear fuel cycle. Worldwide, different techniques have been used to analyze the isotopic composition of uranium. For efficient control of nuclear material, a precise determination of uranium isotopic ratios is a critical factor. In this work, the current Eichrom method for the radiochemical chromatographic separation of uranium was modified to achieve efficient extraction of uranium for the preparation of very thin alpha sources. Measurements of different types of natural, depleted and enriched uranium samples for nuclear safeguards purposes were performed using alpha spectrometry. For that purpose and after samples digestion, uranium element was extracted from other interfering radionuclides, purified, electrodeposited on a stainless-steel disc, and measured using alpha-spectrometer, then the isotopic ratios were calculated. For comparison purposes, the samples were also measured using a hyper pure germanium (HPGe) spectrometer and the uranium isotopic ratios were obtained.
Quality assurance parameters were followed through the use of blanks, certified reference materials and the estimation of the combined uncertainty. Also, the accuracy and reliability of the radiochemical procedure were confirmed by participation in the International Atomic Energy Agency (IAEA) proficiency tests. The results obtained by both techniques were in agreement within difference ranged from -8.7 to 12%. It was concluded that alpha spectrometric measurement of uranium isotopes preceded by efficient radiochemical separation process using the modified extraction chromatography method is a fast and reliable technique for safeguard purposes.