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Rajendra Prasad - One of the best experts on this subject based on the ideXlab platform.
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measurement of natural radioactivity and Radon Exhalation rate in fly ash samples from a thermal power plant and estimation of radiation doses
Radiation Measurements, 2013Co-Authors: A. K. Mahur, Rajendra Prasad, R G Sonkawade, Mamta Gupta, Rati Varshney, K D VermaAbstract:Abstract Fly ash produced by coal-burning in thermal power station has become a subject of world wide interest in recent years because of its diverse uses in construction activities and considerable economic and environmental importance. Fly ash is used in the production of bricks, sheets, cement and also in land filling etc. Indian coals used in thermal power plants are found to have high ash contents, resulting in the production of large amount of fly ash. Coal contains radionuclides including uranium (the source of inert gas Radon), Th and K. Thus coal combustion results in enhanced concentration of natural radionuclides 226 Ra, 232 Th and 40 K. Since these radionuclides concentration in fly ash plays an important role in health physics it is important to measure radionuclides concentration in fly ash. In the present work enhanced radioactivity and Radon Exhalation rate from fly ash samples collected from a thermal power plant of NTPC (National Thermal Power Corporation), Dadri (U.P.) India, have been measured. A high resolution gamma ray spectroscopic system has been used for the measurement of natural radioactivity ( 226 Ra, 232 Th and 40 K). Gamma spectrometric measurements were carried out at Inter-University Accelerator Centre, New Delhi using a coaxial n-type HPGe detector (EG&G, ORTEC, Oak Ridge, USA). Activity concentration of 226 Ra varies from 81.8 ± 2.2 to 177.3 ± 10.0 Bq kg −1 with an average value of 118.6 ± 7.4 Bq kg −1 and of 232 Th from 111.6 ± 3.2 to 178.5 ± 3.9 Bq kg −1 with an average value of 147.0 ± 3.4 Bq kg −1 . 40 K activity was found to be below detection limit in some samples while other samples have shown potassium activity to vary from 365.9 ± 4.8 to 495.9 ± 6.2 Bq kg −1 with an average value of 352.0 ± 4.5 Bq kg −1 . Surface Radon Exhalation rates ( E A ) and Mass Exhalation rates ( E M ) in these samples were measured by “Sealed can technique” using LR-115 type II track detectors. E A is found to vary from 80.1 ± 9.3 to 242.7 ± 16.3 mBq m −2 h −1 with an average value 155.5 ± 12.8 mBq m −2 h −1 , while E M varies from 3.1 ± 0.4 to 9.3 ± 0.6 mBq kg −1 h −1 with an average value of 6.0 ± 0.5 mBq kg −1 h −1 . Radium equivalent activity ( Ra eq ), related to the external gamma dose and internal dose due to Radon and its daughters range from 283.2 to 422.4 Bq kg −1 with an average value of 353.9 Bq kg −1 . The calculated values of external hazard index ( H ex ) vary from 0.77 to 1.87 with an average value of 1.03. Most of the samples show the value of Ra eq close to the allowed upper limit of 370 Bq kg −1 and H ex close to unity respectively except in two samples. Annual effective dose varies from 0.15 to 0.23 mSv y −1 with an average value 0.19 mSv y −1 .
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Radon Exhalation and gamma radioactivity levels in soil and radiation hazard assessment in the surrounding area of national thermal power corporation dadri u p india
Radiation Measurements, 2013Co-Authors: A. K. Mahur, Rajendra Prasad, R G Sonkawade, Mamta Gupta, Rati Varshney, K D VermaAbstract:Abstract In the present study soil samples were collected from the region around a National Thermal Power Corporation (NTPC) at Dadri (U.P.), India. Radon activity and Radon Exhalation rates were measured by using “sealed can technique” using LR 115-type II nuclear track detectors. Radon activities are found to vary from 177.5 ± 23.1 to 583.4 ± 4.9 Bq m −3 with an average value of 330.5 ± 30.4 Bq m −3 . Surface Exhalation rates in these samples vary from 63.9 ± 8.3 to 210.2 ± 15.1 mBq m −2 h −1 with an average value of 119.1 ± 11.1 mBq m −2 h −1 , whereas mass Exhalation rates vary from 2.5 ± 0.3 to 8.1 ± 0.6 mBq kg −1 h −1 with an average of 4.6 ± 0.4 mBq kg −1 h −1 . Activity concentrations of naturally occurring radionuclides ( 226 Ra, 232 Th and 40 K) were also measured in these soil samples using high resolution γ–ray spectroscopic system. Activity concentrations of 226 Ra, 232 Th, and 40 K vary from 32.2 ± 6.0 to120.9 ± 4.5 Bq kg −1 , 19.3 ± 0.9 to 44.6 ± 1.5 Bq kg −1 and 195.4 ± 2.8 to 505.4 ± 6.3 Bq kg −1 with overall mean values of 70.0 ± 8.9 Bq kg −1 , 34.8 ± 1.2 Bq kg −1 and 436.1 ± 5.6 Bq kg −1 respectively. From the activity concentrations of 226 Ra, 232 Th and 40 K, radium equivalent activity ( Ra eq ) and the external hazard index ( H ex ) were calculated and found to vary from 73.4 to 214.7 Bq kg −1 and from 0.2 to 0.6 respectively.
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estimation of Radon Exhalation rate natural radioactivity and radiation doses in fly ash samples from durgapur thermal power plant west bengal india
Journal of Environmental Radioactivity, 2008Co-Authors: A. K. Mahur, D Sengupta, Rajesh Kumar, Rajendra PrasadAbstract:Abstract Coal and its by products often contain significant amounts of radionuclides, including uranium which is the ultimate source of the radioactive gas Radon. Burning of coal and the subsequent emission to the atmosphere cause the re-distribution of toxic trace elements in the environment. Due to considerable economic and environmental importance and diverse uses, the collected fly ash has become a subject of worldwide interest in recent years. In the present study, Radon Exhalation rate and the activity concentration of 238 U, 232 Th and 40 K radionuclides in fly ash samples from Durgapur thermal power plant (WB) have been measured by “Sealed Can technique” using LR-115 type II detectors and a low level NaI (Tl) based gamma ray spectrometer, respectively. Radon Exhalation rate varied from 360.0 to 470.0 mBq m −2 h −1 with an average value of 406.8 mBq m −2 h −1 . Activity concentrations of 238 U ranged from 84.8 to 126.4 Bq kg −1 with an average value of 99.3 Bq kg −1 , 232 Th ranged from 98.1 to 140.5 Bq kg −1 with an average value of 112.9 Bq kg −1 and 40 K ranged from 267.1 to 364.9 Bq kg −1 with an average value of 308.9 Bq kg −1 . Radium equivalent activity obtained from activity concentrations is found to vary from 256.5 to 352.8 Bq kg −1 with an average value of 282.5 Bq kg −1 . Absorbed gamma dose rates due to the presence of 238 U, 232 Th and 40 K in fly ash samples vary in the range 115.3–158.5 nGy h −1 with an average value of 126.4 nGy h −1 . While the external annual effective dose rate varies from 0.14 to 0.19 mSv y −1 with an average value of 0.15 mSv y −1 , effective dose equivalent estimated from Exhalation rate varies from 42.5 to 55.2 μSv y −1 with an average value of 47.8 μSv y −1 . Values of external hazard index H ex for the fly ash samples studied in this work range from 0.69 to 0.96 with a mean value of 0.77.
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measurement of natural radioactivity and Radon Exhalation rate from rock samples of jaduguda uranium mines and its radiological implications
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2008Co-Authors: A. K. Mahur, D Sengupta, Rajesh Kumar, R G Sonkawade, Rajendra PrasadAbstract:Abstract The Singhbhum shear zone is a 200 km long arcuate belt in Jharkhand state situated in eastern India. The central part between Jaduguda–Bhatin–Nimdih, Narwapahr–Garadih–Turamdih is rich in uranium. Presence of uranium in the host rocks and the prevalence of a confined atmosphere within mines could result in enhanced concentration of Radon ( 222 Rn) gas and its progeny. Inhalation of Radon daughter products is a major contributor to the radiation dose to exposed subjects. By using high resolution γ-ray spectroscopic system various radionuclides in the rock samples, collected from different places of Jaduguda uranium mines have been identified quantitatively based on the characteristic spectral peaks. The activity concentrations of the natural radionuclides, uranium ( 238 U), thorium ( 232 Th) and potassium ( 40 K) were measured in the rock samples and radiological parameters were calculated. Uranium concentration was found to vary from 123 ± 7 Bq kg −1 to 40,858 ± 174 Bq kg −1 . Activity of thorium was not significant in the samples, whereas, few samples have shown potassium activity from 162 ± 11 Bq kg −1 to 9024 ± 189 Bq kg −1 . Radon Exhalation rates from these samples were also measured using “Sealed Can technique” and found to vary from 4.2 ± 0.05 to 13.7 ± 0.08 Bq m −2 h −1 . A positive correlation was found between the Radon Exhalation rate and the uranium activity. The absorbed dose rates vary from 63.6 to 18876.4 nGy h −1 , with an average value of 7054.2 nGy h −1 . The annual external effective dose rates vary from 0.7 to 23.2 mSv y −1 . Radium equivalent activities (Ra eq ) varied from 134.3 to 40858.0 Bq kg −1 . Value of external hazard index ( H ex ) varied from 0.4 to 110.4 with an average value of 41.2.
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an investigation of Radon Exhalation rate and estimation of radiation doses in coal and fly ash samples
Applied Radiation and Isotopes, 2008Co-Authors: A. K. Mahur, D Sengupta, Rajesh Kumar, Meena Mishra, Rajendra PrasadAbstract:Coal is a technologically important material used for power generation. Its cinder (fly ash) is used in the manufacturing of bricks, sheets, cement, land filling etc. Coal and its by-products often contain significant amounts of radionuclides, including uranium which is the ultimate source of the radioactive gas Radon. Burning of coal and the subsequent atmospheric emission cause the redistribution of toxic radioactive trace elements in the environment. In the present study, Radon Exhalation rates in coal and fly ash samples from the thermal power plants at Kolaghat (W.B.) and Kasimpur (U.P.) have been measured using sealed Can technique having LR-115 type II detectors. The activity concentrations of 238U, 232Th, and 40K in the samples of Kolaghat power station are also measured. It is observed that the Radon Exhalation rate from fly ash samples from Kolaghat is higher than from coal samples and activity concentration of radionuclides in fly ash is enhanced after the combustion of coal. Fly ash samples from Kasimpur show no appreciable change in Radon Exhalation. Radiation doses from the fly ash samples have been estimated from Radon Exhalation rate and radionuclide concentrations.
Konstantin Kovler - One of the best experts on this subject based on the ideXlab platform.
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legislative aspects of radiation hazards from both gamma emitters and Radon Exhalation of concrete containing coal fly ash
Construction and Building Materials, 2011Co-Authors: Konstantin KovlerAbstract:Abstract Utilization of coal fly ash in concrete construction has clear environmental, technological and economical advantages. At the same time, fly ash is known to have enhanced concentrations of Naturally Occurring Radioactive Materials (NORM). Legislative issues related to the utilization of coal fly ash in concrete construction are analyzed. Different approaches implemented in standards regulating gamma radiation and Radon emanation of concrete and other building materials are reviewed. Although Radon Exhalation rate of concrete containing coal fly ash can be sometimes slightly higher than that of the reference concrete, Radon emanation coefficient is usually lower. In view of this, the standards regulating radioactivity of building materials, but not addressing Radon emanation properly could be detrimental to the utilization of fly ash in concrete. At the same time, the evaluation of the excess dose caused by building materials for the Radon pathway is complicated, and much more research work is required to justify the assumptions of the physical models in the future standards.
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Radon Exhalation of hardening concrete monitoring cement hydration and prediction of Radon concentration in construction site
Journal of Environmental Radioactivity, 2006Co-Authors: Konstantin KovlerAbstract:Abstract The unique properties of Radon as a noble gas are used for monitoring cement hydration and microstructural transformations in cementitious system. It is found that the Radon concentration curve for hydrating cement paste enclosed in the chamber increases from zero (more accurately – background) concentrations, similar to unhydrated cement. However, Radon concentrations developed within 3 days in the test chamber containing cement paste were ∼20 times higher than those of unhydrated cement. This fact proves the importance of microstructural transformations taking place in the process of cement hydration, in comparison with cement grain, which is a time-stable material. It is concluded that monitoring cement hydration by means of Radon Exhalation method makes it possible to distinguish between three main stages, which are readily seen in the time dependence of Radon concentration: stage I (dormant period), stage II (setting and intensive microstructural transformations) and stage III (densification of the structure and drying). The information presented improves our understanding of the main physical mechanisms resulting in the characteristic behavior of Radon Exhalation in the course of cement hydration. The maximum value of Radon Exhalation rate observed, when cement sets, can reach 0.6 mBq kg −1 s −1 and sometimes exceeds 1.0 mBq kg −1 s −1 . These values exceed significantly to those known before for cementitious materials. At the same time, the minimum ventilation rate accepted in the design practice (0.5 h −1 ), guarantees that the concentrations in most of the cases will not exceed the action level and that they are not of any radiological concern for construction workers employed in concreting in closed spaces.
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Radon Exhalation of cementitious materials made with coal fly ash part 1 scientific background and testing of the cement and fly ash emanation
Journal of Environmental Radioactivity, 2005Co-Authors: Konstantin Kovler, A Perevalov, V Steiner, L A MetzgerAbstract:Increased interest in measuring radionuclides and Radon concentrations in fly ash, cement and other components of building products is due to the concern of health hazards of naturally occurring radioactive materials (NORM). The current work focuses on studying the influence of fly ash (FA) on Radon-Exhalation rate (Radon flux) from cementitious materials. The tests were carried out on cement paste specimens with different FA contents. The first part of the paper presents the scientific background and describes the experiments, which we designed for testing the Radon emanation of the raw materials used in the preparation of the cement-FA pastes. It is found that despite the higher (226)Ra content in FA (more than 3 times, compared with Portland cement) the Radon emanation is significantly lower in FA (7.65% for cement vs. 0.52% only for FA).
Daniel Hatungimana - One of the best experts on this subject based on the ideXlab platform.
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compressive strength water absorption water sorptivity and surface Radon Exhalation rate of silica fume and fly ash based mortar
Journal of building engineering, 2019Co-Authors: Daniel Hatungimana, Caner Taskopru, Mutlu Ichedef, Muslim Murat Sac, şemsi YaziciAbstract:Abstract In this study, the effect of partial cement replacement with silica fume and fly ash on the compressive strength, water absorption, volume of permeable pore, water sorptivity, Radon content and surface Radon Exhalation rate of mortar mixtures were investigated. It was observed that the compressive strength of mortar mixtures containing silica fume as partial cement replacement increased as the amount of silica fume content increased while the water absorption, volume of permeable pore, water sorptivity and Radon Exhalation rate of mortar mixtures decreased. The decrease in surface Radon Exhalation rate was ranged between 23% and 43% while that of mortar mixtures containing fly ash increased up to 15% of the rate of the control mortar mixture. Results showed that silica fume addition decreased the Radon concentration and surface Radon Exhalation rate while fly ash showed a detrimental effect.
A. K. Mahur - One of the best experts on this subject based on the ideXlab platform.
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measurement of natural radioactivity and Radon Exhalation rate in fly ash samples from a thermal power plant and estimation of radiation doses
Radiation Measurements, 2013Co-Authors: A. K. Mahur, Rajendra Prasad, R G Sonkawade, Mamta Gupta, Rati Varshney, K D VermaAbstract:Abstract Fly ash produced by coal-burning in thermal power station has become a subject of world wide interest in recent years because of its diverse uses in construction activities and considerable economic and environmental importance. Fly ash is used in the production of bricks, sheets, cement and also in land filling etc. Indian coals used in thermal power plants are found to have high ash contents, resulting in the production of large amount of fly ash. Coal contains radionuclides including uranium (the source of inert gas Radon), Th and K. Thus coal combustion results in enhanced concentration of natural radionuclides 226 Ra, 232 Th and 40 K. Since these radionuclides concentration in fly ash plays an important role in health physics it is important to measure radionuclides concentration in fly ash. In the present work enhanced radioactivity and Radon Exhalation rate from fly ash samples collected from a thermal power plant of NTPC (National Thermal Power Corporation), Dadri (U.P.) India, have been measured. A high resolution gamma ray spectroscopic system has been used for the measurement of natural radioactivity ( 226 Ra, 232 Th and 40 K). Gamma spectrometric measurements were carried out at Inter-University Accelerator Centre, New Delhi using a coaxial n-type HPGe detector (EG&G, ORTEC, Oak Ridge, USA). Activity concentration of 226 Ra varies from 81.8 ± 2.2 to 177.3 ± 10.0 Bq kg −1 with an average value of 118.6 ± 7.4 Bq kg −1 and of 232 Th from 111.6 ± 3.2 to 178.5 ± 3.9 Bq kg −1 with an average value of 147.0 ± 3.4 Bq kg −1 . 40 K activity was found to be below detection limit in some samples while other samples have shown potassium activity to vary from 365.9 ± 4.8 to 495.9 ± 6.2 Bq kg −1 with an average value of 352.0 ± 4.5 Bq kg −1 . Surface Radon Exhalation rates ( E A ) and Mass Exhalation rates ( E M ) in these samples were measured by “Sealed can technique” using LR-115 type II track detectors. E A is found to vary from 80.1 ± 9.3 to 242.7 ± 16.3 mBq m −2 h −1 with an average value 155.5 ± 12.8 mBq m −2 h −1 , while E M varies from 3.1 ± 0.4 to 9.3 ± 0.6 mBq kg −1 h −1 with an average value of 6.0 ± 0.5 mBq kg −1 h −1 . Radium equivalent activity ( Ra eq ), related to the external gamma dose and internal dose due to Radon and its daughters range from 283.2 to 422.4 Bq kg −1 with an average value of 353.9 Bq kg −1 . The calculated values of external hazard index ( H ex ) vary from 0.77 to 1.87 with an average value of 1.03. Most of the samples show the value of Ra eq close to the allowed upper limit of 370 Bq kg −1 and H ex close to unity respectively except in two samples. Annual effective dose varies from 0.15 to 0.23 mSv y −1 with an average value 0.19 mSv y −1 .
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Radon Exhalation and gamma radioactivity levels in soil and radiation hazard assessment in the surrounding area of national thermal power corporation dadri u p india
Radiation Measurements, 2013Co-Authors: A. K. Mahur, Rajendra Prasad, R G Sonkawade, Mamta Gupta, Rati Varshney, K D VermaAbstract:Abstract In the present study soil samples were collected from the region around a National Thermal Power Corporation (NTPC) at Dadri (U.P.), India. Radon activity and Radon Exhalation rates were measured by using “sealed can technique” using LR 115-type II nuclear track detectors. Radon activities are found to vary from 177.5 ± 23.1 to 583.4 ± 4.9 Bq m −3 with an average value of 330.5 ± 30.4 Bq m −3 . Surface Exhalation rates in these samples vary from 63.9 ± 8.3 to 210.2 ± 15.1 mBq m −2 h −1 with an average value of 119.1 ± 11.1 mBq m −2 h −1 , whereas mass Exhalation rates vary from 2.5 ± 0.3 to 8.1 ± 0.6 mBq kg −1 h −1 with an average of 4.6 ± 0.4 mBq kg −1 h −1 . Activity concentrations of naturally occurring radionuclides ( 226 Ra, 232 Th and 40 K) were also measured in these soil samples using high resolution γ–ray spectroscopic system. Activity concentrations of 226 Ra, 232 Th, and 40 K vary from 32.2 ± 6.0 to120.9 ± 4.5 Bq kg −1 , 19.3 ± 0.9 to 44.6 ± 1.5 Bq kg −1 and 195.4 ± 2.8 to 505.4 ± 6.3 Bq kg −1 with overall mean values of 70.0 ± 8.9 Bq kg −1 , 34.8 ± 1.2 Bq kg −1 and 436.1 ± 5.6 Bq kg −1 respectively. From the activity concentrations of 226 Ra, 232 Th and 40 K, radium equivalent activity ( Ra eq ) and the external hazard index ( H ex ) were calculated and found to vary from 73.4 to 214.7 Bq kg −1 and from 0.2 to 0.6 respectively.
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estimation of Radon Exhalation rate natural radioactivity and radiation doses in fly ash samples from durgapur thermal power plant west bengal india
Journal of Environmental Radioactivity, 2008Co-Authors: A. K. Mahur, D Sengupta, Rajesh Kumar, Rajendra PrasadAbstract:Abstract Coal and its by products often contain significant amounts of radionuclides, including uranium which is the ultimate source of the radioactive gas Radon. Burning of coal and the subsequent emission to the atmosphere cause the re-distribution of toxic trace elements in the environment. Due to considerable economic and environmental importance and diverse uses, the collected fly ash has become a subject of worldwide interest in recent years. In the present study, Radon Exhalation rate and the activity concentration of 238 U, 232 Th and 40 K radionuclides in fly ash samples from Durgapur thermal power plant (WB) have been measured by “Sealed Can technique” using LR-115 type II detectors and a low level NaI (Tl) based gamma ray spectrometer, respectively. Radon Exhalation rate varied from 360.0 to 470.0 mBq m −2 h −1 with an average value of 406.8 mBq m −2 h −1 . Activity concentrations of 238 U ranged from 84.8 to 126.4 Bq kg −1 with an average value of 99.3 Bq kg −1 , 232 Th ranged from 98.1 to 140.5 Bq kg −1 with an average value of 112.9 Bq kg −1 and 40 K ranged from 267.1 to 364.9 Bq kg −1 with an average value of 308.9 Bq kg −1 . Radium equivalent activity obtained from activity concentrations is found to vary from 256.5 to 352.8 Bq kg −1 with an average value of 282.5 Bq kg −1 . Absorbed gamma dose rates due to the presence of 238 U, 232 Th and 40 K in fly ash samples vary in the range 115.3–158.5 nGy h −1 with an average value of 126.4 nGy h −1 . While the external annual effective dose rate varies from 0.14 to 0.19 mSv y −1 with an average value of 0.15 mSv y −1 , effective dose equivalent estimated from Exhalation rate varies from 42.5 to 55.2 μSv y −1 with an average value of 47.8 μSv y −1 . Values of external hazard index H ex for the fly ash samples studied in this work range from 0.69 to 0.96 with a mean value of 0.77.
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measurement of natural radioactivity and Radon Exhalation rate from rock samples of jaduguda uranium mines and its radiological implications
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2008Co-Authors: A. K. Mahur, D Sengupta, Rajesh Kumar, R G Sonkawade, Rajendra PrasadAbstract:Abstract The Singhbhum shear zone is a 200 km long arcuate belt in Jharkhand state situated in eastern India. The central part between Jaduguda–Bhatin–Nimdih, Narwapahr–Garadih–Turamdih is rich in uranium. Presence of uranium in the host rocks and the prevalence of a confined atmosphere within mines could result in enhanced concentration of Radon ( 222 Rn) gas and its progeny. Inhalation of Radon daughter products is a major contributor to the radiation dose to exposed subjects. By using high resolution γ-ray spectroscopic system various radionuclides in the rock samples, collected from different places of Jaduguda uranium mines have been identified quantitatively based on the characteristic spectral peaks. The activity concentrations of the natural radionuclides, uranium ( 238 U), thorium ( 232 Th) and potassium ( 40 K) were measured in the rock samples and radiological parameters were calculated. Uranium concentration was found to vary from 123 ± 7 Bq kg −1 to 40,858 ± 174 Bq kg −1 . Activity of thorium was not significant in the samples, whereas, few samples have shown potassium activity from 162 ± 11 Bq kg −1 to 9024 ± 189 Bq kg −1 . Radon Exhalation rates from these samples were also measured using “Sealed Can technique” and found to vary from 4.2 ± 0.05 to 13.7 ± 0.08 Bq m −2 h −1 . A positive correlation was found between the Radon Exhalation rate and the uranium activity. The absorbed dose rates vary from 63.6 to 18876.4 nGy h −1 , with an average value of 7054.2 nGy h −1 . The annual external effective dose rates vary from 0.7 to 23.2 mSv y −1 . Radium equivalent activities (Ra eq ) varied from 134.3 to 40858.0 Bq kg −1 . Value of external hazard index ( H ex ) varied from 0.4 to 110.4 with an average value of 41.2.
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an investigation of Radon Exhalation rate and estimation of radiation doses in coal and fly ash samples
Applied Radiation and Isotopes, 2008Co-Authors: A. K. Mahur, D Sengupta, Rajesh Kumar, Meena Mishra, Rajendra PrasadAbstract:Coal is a technologically important material used for power generation. Its cinder (fly ash) is used in the manufacturing of bricks, sheets, cement, land filling etc. Coal and its by-products often contain significant amounts of radionuclides, including uranium which is the ultimate source of the radioactive gas Radon. Burning of coal and the subsequent atmospheric emission cause the redistribution of toxic radioactive trace elements in the environment. In the present study, Radon Exhalation rates in coal and fly ash samples from the thermal power plants at Kolaghat (W.B.) and Kasimpur (U.P.) have been measured using sealed Can technique having LR-115 type II detectors. The activity concentrations of 238U, 232Th, and 40K in the samples of Kolaghat power station are also measured. It is observed that the Radon Exhalation rate from fly ash samples from Kolaghat is higher than from coal samples and activity concentration of radionuclides in fly ash is enhanced after the combustion of coal. Fly ash samples from Kasimpur show no appreciable change in Radon Exhalation. Radiation doses from the fly ash samples have been estimated from Radon Exhalation rate and radionuclide concentrations.
şemsi Yazici - One of the best experts on this subject based on the ideXlab platform.
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compressive strength water absorption water sorptivity and surface Radon Exhalation rate of silica fume and fly ash based mortar
Journal of building engineering, 2019Co-Authors: Daniel Hatungimana, Caner Taskopru, Mutlu Ichedef, Muslim Murat Sac, şemsi YaziciAbstract:Abstract In this study, the effect of partial cement replacement with silica fume and fly ash on the compressive strength, water absorption, volume of permeable pore, water sorptivity, Radon content and surface Radon Exhalation rate of mortar mixtures were investigated. It was observed that the compressive strength of mortar mixtures containing silica fume as partial cement replacement increased as the amount of silica fume content increased while the water absorption, volume of permeable pore, water sorptivity and Radon Exhalation rate of mortar mixtures decreased. The decrease in surface Radon Exhalation rate was ranged between 23% and 43% while that of mortar mixtures containing fly ash increased up to 15% of the rate of the control mortar mixture. Results showed that silica fume addition decreased the Radon concentration and surface Radon Exhalation rate while fly ash showed a detrimental effect.
