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Devi Prasad Mishra - One of the best experts on this subject based on the ideXlab platform.
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A comprehensive review on sources of radon and factors affecting radon concentration in underground Uranium Mines
Environmental Earth Sciences, 2016Co-Authors: Patitapaban Sahu, Durga Charan Panigrahi, Devi Prasad MishraAbstract:This paper presents an extensive literature review on the various sources of radon such as ore body, backfill mill tailings, broken ore and mine water in underground Uranium Mines. This review also comprehensively investigates the influence of intrinsic factors such as ore grade, 226Ra content, water content, porosity and surface area of the materials and the extrinsic factors such as barometric pressure, temperature and ventilation on radon concentration in Uranium Mines. The objectives of this review are to identify the major sources of radon and the parameters significantly affecting radon concentration in underground Uranium mine environment. The review demonstrated that backfill mill tailings are the major source of radon in underground Uranium Mines. A comparison of radon exhalation rates of different rock types and backfill tailings revealed that porosity has more pronounced effect on radon exhalation process than the ore grade/226Ra content of the materials. The radon exhalation rate from the moist materials is comparatively higher than the dry and saturated tailings. Reduction of barometric pressure in mine environment increases the radon exhalation rate from porous rocks, backfill mill tailings and broken ore piles. The contribution of mine water on radon contamination of mine atmosphere mainly depends on the dissolved radon content and flow rate of water. The current knowledge of the factors affecting radon exhalation process has also been reviewed in this paper.
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An improved mathematical model for prediction of air quantity to minimise radiation levels in underground Uranium Mines.
Journal of environmental radioactivity, 2014Co-Authors: Durga Charan Panigrahi, Patitapaban Sahu, Devi Prasad MishraAbstract:Ventilation is the primary means of controlling radon and its daughter concentrations in an underground Uranium mine environment. Therefore, prediction of air quantity is the vital component for planning and designing of ventilation systems to minimise the radiation exposure of miners in underground Uranium Mines. This paper comprehensively describes the derivation and verification of an improved mathematical model for prediction of air quantity, based on the growth of radon daughters in terms of potential alpha energy concentration (PAEC), to reduce the radiation levels in Uranium Mines. The model also explains the prediction of air quantity depending upon the quality of intake air to the stopes. This model can be used to evaluate the contribution of different sources to radon concentration in mine atmosphere based on the measurements of radon emanation and exhalation. Moreover, a mathematical relationship has been established for quick prediction of air quantity to achieve the desired radon daughter concentration in the Mines.
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Sources of Radon and its Measurement Techniques in Underground Uranium Mines – An Overview
Journal of Sustainable Mining, 2014Co-Authors: Patitapaban Sahu, Durga Charan Panigrahi, Devi Prasad MishraAbstract:ABSTRACT Purpose This study aims to identify the potential sources of radon exhalation and its measurement in underground Uranium Mines to control the radiation levels within safe limits and protect miners from radiation hazards. Methods An extensive literature review on radon exhalation in underground Uranium Mines from various sources such as Uranium ore, backfill tailings and mine water has been carried out. The influence of different important factors, viz. ore grade, porosity, grain size and moisture content on radon exhalation has been discussed in depth. Different methods for the measurement of radon exhalation from various sources in Mines have also been presented in this paper. Results The review of literature revealed that the radon exhalation rate in porous Uranium bearing rocks is less affected by the ore grade than in non-porous rocks. The exhalation of radon from backfill tailings is quantitatively more significant than from the Uranium ore itself due to higher bulk porosity and enhanced surface area. Thus, porosity is the dominant factor that affects the rate of radon exhalation from rock surfaces into mine openings. Practical implications The knowledge of the sources of radon and quantitative estimation of radon from various sources will be very much useful in the planning and designing of ventilation systems in underground Uranium Mines. The accurate measurement of radon exhalation in underground Uranium Mines can be made by choosing the optimum size of accumulation chamber and a suitable radon build-up period in the chamber. Originality/value The study portrays the important sources of radon and its measurement techniques in underground Uranium Mines based on an extensive literature review. The methods of measurement of radon exhalation from the ore body and backfill tailings in underground Uranium Mines, used by the authors of this paper, comparatively give more accurate results than previously used methods. Furthermore, the methods are more effective in terms of portability, cost and time for measuring the average radon exhalation across a large.
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sources of radon and its measurement techniques in underground Uranium Mines an overview
Journal of Sustainable Mining, 2014Co-Authors: Patitapaban Sahu, Durga Charan Panigrahi, Devi Prasad MishraAbstract:ABSTRACT Purpose This study aims to identify the potential sources of radon exhalation and its measurement in underground Uranium Mines to control the radiation levels within safe limits and protect miners from radiation hazards. Methods An extensive literature review on radon exhalation in underground Uranium Mines from various sources such as Uranium ore, backfill tailings and mine water has been carried out. The influence of different important factors, viz. ore grade, porosity, grain size and moisture content on radon exhalation has been discussed in depth. Different methods for the measurement of radon exhalation from various sources in Mines have also been presented in this paper. Results The review of literature revealed that the radon exhalation rate in porous Uranium bearing rocks is less affected by the ore grade than in non-porous rocks. The exhalation of radon from backfill tailings is quantitatively more significant than from the Uranium ore itself due to higher bulk porosity and enhanced surface area. Thus, porosity is the dominant factor that affects the rate of radon exhalation from rock surfaces into mine openings. Practical implications The knowledge of the sources of radon and quantitative estimation of radon from various sources will be very much useful in the planning and designing of ventilation systems in underground Uranium Mines. The accurate measurement of radon exhalation in underground Uranium Mines can be made by choosing the optimum size of accumulation chamber and a suitable radon build-up period in the chamber. Originality/value The study portrays the important sources of radon and its measurement techniques in underground Uranium Mines based on an extensive literature review. The methods of measurement of radon exhalation from the ore body and backfill tailings in underground Uranium Mines, used by the authors of this paper, comparatively give more accurate results than previously used methods. Furthermore, the methods are more effective in terms of portability, cost and time for measuring the average radon exhalation across a large.
Pavel Pospisil - One of the best experts on this subject based on the ideXlab platform.
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impact of Uranium Mines closure and abandonment on groundwater quality
Environmental Science and Pollution Research, 2013Co-Authors: Nada Rapantova, Monika Licbinska, Ondrej Babka, Arnost Grmela, Pavel PospisilAbstract:The aim of the study is to assess the evolving mine water quality of closed Uranium Mines (abandoned between 1958 and 1992) in the Czech Republic. This paper focuses on the changes in mine water quality over time and spatial variability. In 2010, systematic monitoring of mine water quality was performed at all available locations of previous Uranium exploitation. Gravity flow discharges (mine adits, uncontrolled discharges) or shafts (in dynamic state or stagnating) were sampled. Since the quality of mine water results from multiple conditions-geology, type of sample, sampling depth, time since mine flooding, an assessment of mine water quality evolution was done taking into account all these conditions. Multivariate analyses were applied in order to identify the groups of samples based on their similarity. Evaluation of hydrogeochemical equilibrium and evolution of mine waters was done using the Geochemist's Workbench and PHREEQC software. The sampling proved that Uranium concentrations in mine waters did not predominantly exceed 0.45 mg/L. In case of discharges from old adits abandoned more than 40 years ago, Uranium concentrations were below the MCL of US Environmental Protection Agency for Uranium in drinking water (0.03 mg/L). Higher concentrations, up to 1.23 mg/L of U, were found only at active dewatered Mines. Activity concentration of 226Ra varied from 0.03 up to 1.85 Bq/L except for two sites with increased background values due to rock formation (granites). Radium has a typically increasing trend after mine abandonment with a large variability. Concerning metals in mine water, Al, Co and Ni exceeded legislative limits on two sites with low pH waters. The mine water quality changes with a focus on Uranium mobility were described from recently dewatered Mines to shafts with water level maintained in order to prevent outflows to surface water and finally to stagnating shafts and discharges of mine water from old adits. The results were in good agreement with published experience on mine water stratification, its disturbance by pumping or natural water decant and the "first flush" phenomenon after mine flooding.
Durga Charan Panigrahi - One of the best experts on this subject based on the ideXlab platform.
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A comprehensive review on sources of radon and factors affecting radon concentration in underground Uranium Mines
Environmental Earth Sciences, 2016Co-Authors: Patitapaban Sahu, Durga Charan Panigrahi, Devi Prasad MishraAbstract:This paper presents an extensive literature review on the various sources of radon such as ore body, backfill mill tailings, broken ore and mine water in underground Uranium Mines. This review also comprehensively investigates the influence of intrinsic factors such as ore grade, 226Ra content, water content, porosity and surface area of the materials and the extrinsic factors such as barometric pressure, temperature and ventilation on radon concentration in Uranium Mines. The objectives of this review are to identify the major sources of radon and the parameters significantly affecting radon concentration in underground Uranium mine environment. The review demonstrated that backfill mill tailings are the major source of radon in underground Uranium Mines. A comparison of radon exhalation rates of different rock types and backfill tailings revealed that porosity has more pronounced effect on radon exhalation process than the ore grade/226Ra content of the materials. The radon exhalation rate from the moist materials is comparatively higher than the dry and saturated tailings. Reduction of barometric pressure in mine environment increases the radon exhalation rate from porous rocks, backfill mill tailings and broken ore piles. The contribution of mine water on radon contamination of mine atmosphere mainly depends on the dissolved radon content and flow rate of water. The current knowledge of the factors affecting radon exhalation process has also been reviewed in this paper.
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An improved mathematical model for prediction of air quantity to minimise radiation levels in underground Uranium Mines.
Journal of environmental radioactivity, 2014Co-Authors: Durga Charan Panigrahi, Patitapaban Sahu, Devi Prasad MishraAbstract:Ventilation is the primary means of controlling radon and its daughter concentrations in an underground Uranium mine environment. Therefore, prediction of air quantity is the vital component for planning and designing of ventilation systems to minimise the radiation exposure of miners in underground Uranium Mines. This paper comprehensively describes the derivation and verification of an improved mathematical model for prediction of air quantity, based on the growth of radon daughters in terms of potential alpha energy concentration (PAEC), to reduce the radiation levels in Uranium Mines. The model also explains the prediction of air quantity depending upon the quality of intake air to the stopes. This model can be used to evaluate the contribution of different sources to radon concentration in mine atmosphere based on the measurements of radon emanation and exhalation. Moreover, a mathematical relationship has been established for quick prediction of air quantity to achieve the desired radon daughter concentration in the Mines.
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Sources of Radon and its Measurement Techniques in Underground Uranium Mines – An Overview
Journal of Sustainable Mining, 2014Co-Authors: Patitapaban Sahu, Durga Charan Panigrahi, Devi Prasad MishraAbstract:ABSTRACT Purpose This study aims to identify the potential sources of radon exhalation and its measurement in underground Uranium Mines to control the radiation levels within safe limits and protect miners from radiation hazards. Methods An extensive literature review on radon exhalation in underground Uranium Mines from various sources such as Uranium ore, backfill tailings and mine water has been carried out. The influence of different important factors, viz. ore grade, porosity, grain size and moisture content on radon exhalation has been discussed in depth. Different methods for the measurement of radon exhalation from various sources in Mines have also been presented in this paper. Results The review of literature revealed that the radon exhalation rate in porous Uranium bearing rocks is less affected by the ore grade than in non-porous rocks. The exhalation of radon from backfill tailings is quantitatively more significant than from the Uranium ore itself due to higher bulk porosity and enhanced surface area. Thus, porosity is the dominant factor that affects the rate of radon exhalation from rock surfaces into mine openings. Practical implications The knowledge of the sources of radon and quantitative estimation of radon from various sources will be very much useful in the planning and designing of ventilation systems in underground Uranium Mines. The accurate measurement of radon exhalation in underground Uranium Mines can be made by choosing the optimum size of accumulation chamber and a suitable radon build-up period in the chamber. Originality/value The study portrays the important sources of radon and its measurement techniques in underground Uranium Mines based on an extensive literature review. The methods of measurement of radon exhalation from the ore body and backfill tailings in underground Uranium Mines, used by the authors of this paper, comparatively give more accurate results than previously used methods. Furthermore, the methods are more effective in terms of portability, cost and time for measuring the average radon exhalation across a large.
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sources of radon and its measurement techniques in underground Uranium Mines an overview
Journal of Sustainable Mining, 2014Co-Authors: Patitapaban Sahu, Durga Charan Panigrahi, Devi Prasad MishraAbstract:ABSTRACT Purpose This study aims to identify the potential sources of radon exhalation and its measurement in underground Uranium Mines to control the radiation levels within safe limits and protect miners from radiation hazards. Methods An extensive literature review on radon exhalation in underground Uranium Mines from various sources such as Uranium ore, backfill tailings and mine water has been carried out. The influence of different important factors, viz. ore grade, porosity, grain size and moisture content on radon exhalation has been discussed in depth. Different methods for the measurement of radon exhalation from various sources in Mines have also been presented in this paper. Results The review of literature revealed that the radon exhalation rate in porous Uranium bearing rocks is less affected by the ore grade than in non-porous rocks. The exhalation of radon from backfill tailings is quantitatively more significant than from the Uranium ore itself due to higher bulk porosity and enhanced surface area. Thus, porosity is the dominant factor that affects the rate of radon exhalation from rock surfaces into mine openings. Practical implications The knowledge of the sources of radon and quantitative estimation of radon from various sources will be very much useful in the planning and designing of ventilation systems in underground Uranium Mines. The accurate measurement of radon exhalation in underground Uranium Mines can be made by choosing the optimum size of accumulation chamber and a suitable radon build-up period in the chamber. Originality/value The study portrays the important sources of radon and its measurement techniques in underground Uranium Mines based on an extensive literature review. The methods of measurement of radon exhalation from the ore body and backfill tailings in underground Uranium Mines, used by the authors of this paper, comparatively give more accurate results than previously used methods. Furthermore, the methods are more effective in terms of portability, cost and time for measuring the average radon exhalation across a large.
Patitapaban Sahu - One of the best experts on this subject based on the ideXlab platform.
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A comprehensive review on sources of radon and factors affecting radon concentration in underground Uranium Mines
Environmental Earth Sciences, 2016Co-Authors: Patitapaban Sahu, Durga Charan Panigrahi, Devi Prasad MishraAbstract:This paper presents an extensive literature review on the various sources of radon such as ore body, backfill mill tailings, broken ore and mine water in underground Uranium Mines. This review also comprehensively investigates the influence of intrinsic factors such as ore grade, 226Ra content, water content, porosity and surface area of the materials and the extrinsic factors such as barometric pressure, temperature and ventilation on radon concentration in Uranium Mines. The objectives of this review are to identify the major sources of radon and the parameters significantly affecting radon concentration in underground Uranium mine environment. The review demonstrated that backfill mill tailings are the major source of radon in underground Uranium Mines. A comparison of radon exhalation rates of different rock types and backfill tailings revealed that porosity has more pronounced effect on radon exhalation process than the ore grade/226Ra content of the materials. The radon exhalation rate from the moist materials is comparatively higher than the dry and saturated tailings. Reduction of barometric pressure in mine environment increases the radon exhalation rate from porous rocks, backfill mill tailings and broken ore piles. The contribution of mine water on radon contamination of mine atmosphere mainly depends on the dissolved radon content and flow rate of water. The current knowledge of the factors affecting radon exhalation process has also been reviewed in this paper.
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An improved mathematical model for prediction of air quantity to minimise radiation levels in underground Uranium Mines.
Journal of environmental radioactivity, 2014Co-Authors: Durga Charan Panigrahi, Patitapaban Sahu, Devi Prasad MishraAbstract:Ventilation is the primary means of controlling radon and its daughter concentrations in an underground Uranium mine environment. Therefore, prediction of air quantity is the vital component for planning and designing of ventilation systems to minimise the radiation exposure of miners in underground Uranium Mines. This paper comprehensively describes the derivation and verification of an improved mathematical model for prediction of air quantity, based on the growth of radon daughters in terms of potential alpha energy concentration (PAEC), to reduce the radiation levels in Uranium Mines. The model also explains the prediction of air quantity depending upon the quality of intake air to the stopes. This model can be used to evaluate the contribution of different sources to radon concentration in mine atmosphere based on the measurements of radon emanation and exhalation. Moreover, a mathematical relationship has been established for quick prediction of air quantity to achieve the desired radon daughter concentration in the Mines.
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Sources of Radon and its Measurement Techniques in Underground Uranium Mines – An Overview
Journal of Sustainable Mining, 2014Co-Authors: Patitapaban Sahu, Durga Charan Panigrahi, Devi Prasad MishraAbstract:ABSTRACT Purpose This study aims to identify the potential sources of radon exhalation and its measurement in underground Uranium Mines to control the radiation levels within safe limits and protect miners from radiation hazards. Methods An extensive literature review on radon exhalation in underground Uranium Mines from various sources such as Uranium ore, backfill tailings and mine water has been carried out. The influence of different important factors, viz. ore grade, porosity, grain size and moisture content on radon exhalation has been discussed in depth. Different methods for the measurement of radon exhalation from various sources in Mines have also been presented in this paper. Results The review of literature revealed that the radon exhalation rate in porous Uranium bearing rocks is less affected by the ore grade than in non-porous rocks. The exhalation of radon from backfill tailings is quantitatively more significant than from the Uranium ore itself due to higher bulk porosity and enhanced surface area. Thus, porosity is the dominant factor that affects the rate of radon exhalation from rock surfaces into mine openings. Practical implications The knowledge of the sources of radon and quantitative estimation of radon from various sources will be very much useful in the planning and designing of ventilation systems in underground Uranium Mines. The accurate measurement of radon exhalation in underground Uranium Mines can be made by choosing the optimum size of accumulation chamber and a suitable radon build-up period in the chamber. Originality/value The study portrays the important sources of radon and its measurement techniques in underground Uranium Mines based on an extensive literature review. The methods of measurement of radon exhalation from the ore body and backfill tailings in underground Uranium Mines, used by the authors of this paper, comparatively give more accurate results than previously used methods. Furthermore, the methods are more effective in terms of portability, cost and time for measuring the average radon exhalation across a large.
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sources of radon and its measurement techniques in underground Uranium Mines an overview
Journal of Sustainable Mining, 2014Co-Authors: Patitapaban Sahu, Durga Charan Panigrahi, Devi Prasad MishraAbstract:ABSTRACT Purpose This study aims to identify the potential sources of radon exhalation and its measurement in underground Uranium Mines to control the radiation levels within safe limits and protect miners from radiation hazards. Methods An extensive literature review on radon exhalation in underground Uranium Mines from various sources such as Uranium ore, backfill tailings and mine water has been carried out. The influence of different important factors, viz. ore grade, porosity, grain size and moisture content on radon exhalation has been discussed in depth. Different methods for the measurement of radon exhalation from various sources in Mines have also been presented in this paper. Results The review of literature revealed that the radon exhalation rate in porous Uranium bearing rocks is less affected by the ore grade than in non-porous rocks. The exhalation of radon from backfill tailings is quantitatively more significant than from the Uranium ore itself due to higher bulk porosity and enhanced surface area. Thus, porosity is the dominant factor that affects the rate of radon exhalation from rock surfaces into mine openings. Practical implications The knowledge of the sources of radon and quantitative estimation of radon from various sources will be very much useful in the planning and designing of ventilation systems in underground Uranium Mines. The accurate measurement of radon exhalation in underground Uranium Mines can be made by choosing the optimum size of accumulation chamber and a suitable radon build-up period in the chamber. Originality/value The study portrays the important sources of radon and its measurement techniques in underground Uranium Mines based on an extensive literature review. The methods of measurement of radon exhalation from the ore body and backfill tailings in underground Uranium Mines, used by the authors of this paper, comparatively give more accurate results than previously used methods. Furthermore, the methods are more effective in terms of portability, cost and time for measuring the average radon exhalation across a large.
A J Cavallo - One of the best experts on this subject based on the ideXlab platform.
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reanalysis of 1973 activity weighted particle size distribution measurements in active u s Uranium Mines
Aerosol Science and Technology, 1998Co-Authors: A J CavalloAbstract:ABSTRACT Activity-weighted particle size distribution data taken with a low-pressure impactor in two working Uranium Mines have been reanalyzed using modern unfolding techniques. Both Mines used diesel engines and were located in the southwestern United States at an elevation of 2120 m; 14 measurements were made in the winter of 1973 at several mine locations and during typical mining activities. The activity median diameter for the principal mode of the distribution determined using these better methods ranged between a minimum of 72 nm and a maximum of 303 nm; the average value was 169 nm (average geometric standard deviation: 2.42), which is significantly smaller than the estimate of 250 nm (geometric standard deviation: 2.5) obtained originally using graphical methods and currently used in some dosimetric calculations. Four samples had secondary modes with more than 20% of the total activity at diameters less than 60 nm; this was possibly a consequence of bimodal diesel emission and/or aerosols genera...
