Natural Isotopic Activity Ratios as Evidence of Migration and Leaching of Uranium in Egyptian Granitic Rocks | ||||
The International Conference on Chemical and Environmental Engineering | ||||
Volume 11, Issue 11, March 2024, Page 1-9 PDF (1.07 MB) | ||||
Document Type: Original Article | ||||
DOI: 10.1088/1742-6596/2830/1/012022 | ||||
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Authors | ||||
Nahla A. Ismaiel1; Eman Y. Frag2; W. M. Seif3; Hamed I. Mira4; Ahmed M. Shabasy5; Mahmoud R. Khattab4 | ||||
1Radiation Protection Department, Nuclear Power Plants Authority (NPPA), Cairo, Egypt. | ||||
2Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt. | ||||
3Physics Department, Faculty of Science, Cairo University, Giza 12613, Egypt. | ||||
4Geochemical Exploration Department, Nuclear Materials Authority, Cairo, Egypt. | ||||
5Nuclear and Radiological Safety Research Centre (NRSRC), Egyptian Atomic Energy Authority (EAEA), Nasr City, Cairo 11762, Egypt. | ||||
Abstract | ||||
Gamma-spectrometry was utilized to analyse radionuclides in granitic rocks from the El Eridiya area through radiometric measurements. The activity concentration of 238U ranges from 3493±83 to 5209±104 Bq kg-1, while for 234U and its isotope (235U), it varies from 957±32 to 1012±34 Bq kg-1 and 153.0±4.5 to 256.0±5.5 Bq kg-1, respectively. However, for the isotopes 230Th and 232Th, the range is from 11217±254 to 16291±305 Bq kg-1 and 31.0±1.1 to 85.3±0.5 Bq kg-1, respectively. The activity concentration of 40K ranged from 67.9±1.6 to 109.0±2.1 Bq kg-1. The ratios of 234U/238U in the studied granitic rock samples vary from 0.21±0.01 to 0.54±0.03. Due to the current oxidising conditions, most of the rock samples show a higher presence of 234U compared to 238U, with 234U/238U activity ratios below one. Additionally, the activity ratios of 232Th/238U range from 0.006 to 0.019 in the granitic rock samples from the El Eridiya area. Figures 3 and 4 display uranium enrichment, with all samples showing 232Th/238U ratios below one for the earth's crust. Additionally, all samples showed 230Th/238U and 230Th/234U activity levels above one, suggesting preferential leaching of uranium in an oxygen-rich setting. Similarly, the 234U/238U and 230Th/238U activity ratios are below and above one, indicating U-leaching and U-accumulation, respectively. Figure 3 and 4 show uranium enrichment, with all samples having 232Th/238U activity ratios below one for the earth's crust. There were benefits to uranium leaching in an environment with oxidation in all samples, with 230Th/238U and 230Th/234U activity ratios exceeding one. If the 234U/238U activity ratio is lower than one but the 230Th/238U activity ratio is higher than 1, it suggests U-leaching; if the 234U/238U activity ratio is greater than one and the 230Th/238U activity ratio is less than 1, it suggests U-accumulation. | ||||
Keywords | ||||
Granites; Radioactivity; Radionuclides; Migration; Leaching; Isotopes | ||||
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