Study of distribution of 226Ra, 232Th and 40K in different rock formations and their dose estimation in and around Chickmagalur, India
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S. Manjunatha , A. Jayasheelan , P. Venkataramanaiah |
Department of Physics, PES Institute Technology and Management, Shimoga, 577204, India , manjunatha_s@yahoo.com |
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Abstract: (9081 Views) |
Background: The concentrations of radionuclides like 226Ra, 232Th and 40K and the dose rate are measured in igneous and metamorphic rock formations in and around Chickmagalur. A total of 236 samples from 13 different locations around study area were analyzed. Materials and Methods: The activity concentrations of the three radioactive elements were determined for mean period of 25000 s using HPGe (GMX - 10190) detector and the dose calculations were made using standard formulae. Results: The mean activity concentrations in igneous rocks recorded were 36.6 Bqkg-1, 73.2 Bqkg-1 and 992.3 Bqkg-1 for 226Ra, 232Th and 40K respectively. The mean activity concentrations in metamorphic rocks were 17.2 Bqkg-1, 28.1 Bqkg-1 and 617.8 Bqkg-1 for 226Ra, 232Th and 40K respectively. Assuming 20% occupancy factor, the corresponding mean annual effective dose due to igneous and metamorphic rocks were 169.6 µSv and 90 µSv respectively. Conclusion: The concentrations of radionuclides were found to be in similar with global and Indian average (1-3). |
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Keywords: Radionuclides, Igneous rock, metamorphic rock and effective dose. |
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Full-Text [PDF 919 kb]
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Type of Study: Original Research |
Subject:
Medical Physics
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