The dependence of pool scrubbing decontamination factor on particle number density: modeling based on bubble mass and energy balances
25 Apr 2021-Journal of Nuclear Science and Technology (Taylor & Francis)-Vol. 58, Iss: 9, pp 1048-1057
TL;DR: Pool scrubbing is one of the promising means for mitigating radioactive aerosol release into the environment in nuclear severe accident scenarios as discussed by the authors, however, the influence of operational conditions on its percolation is unknown.
Abstract: Pool scrubbing is one of the promising means for mitigating radioactive aerosol release into the environment in nuclear severe accident scenarios. The influence of operational conditions on its per...
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TL;DR: In this article , the authors investigated the hydrodynamics in two typical pool scrubbing experiments with the two-fluid model, and the influence of some key factors including bubble diameter, nozzle submergence as well as interaction models are analyzed.
Abstract: Abstract Pressure relief by blowdown is one of the most important measures to prevent excessive pressures in the primary circuit or containment in severe nuclear accidents. Pool scrubbing can significantly reduce the release of radioactive materials, e.g., aerosols, to the environment during the pressure relief. The decontamination factor indicating the particle retention efficiency depends, among other factors, on the hydrodynamic conditions of the gas-liquid two-phase flow inside the pool. In the present work, the hydrodynamics in two typical pool scrubbing experiments is investigated with the two-fluid model, and the influence of some key factors including bubble diameter, nozzle submergence as well as interaction models are analysed. One case is a rectangular pool and the other is a cylindrical column, and their injection Weber number is around 2×10 3 and 4×10 5 , respectively. The numerical results show that as the distance from the nozzle exit increases, the void fraction and velocity field expand from the central region, where the nozzle is located, to the whole cross section. The profile and its development depends largely on the bubble size and the interaction force model. It reveals that in the monodisperse simulation, the tuning of bubble diameter is necessary for achieving good agreement, although it is difficult for high velocity gas injection. More information is required to properly describe the bubble size distribution as well as its evolution in pool scrubbing conditions. Furthermore, the experimental data show clear drag reduction in the bubble swarm generated by the gas jet, and the mechanism and model improvement possibilities need to be investigated.
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TL;DR: In this article , Lagrangian simulations of particles advected by steady internal circulation in a spherical bubble are used to show that particle centrifugal velocity becomes scale invariant for low-Stokes numbers (St≤10-2) when the characteristic timescale is chosen to be that for transversal particle motion at the Stokes terminal velocity corresponding to the local fluid acceleration.
TL;DR: In this paper , a simplified radionuclide transport scrubbing code utilizes classical aerosol scrubbing mechanisms to model this phenomenon and predict aerosol masses reaching the cover gas region, and the experimental results were found to match the trends found in the scrubbing model closely, but significantly more scrubbing was seen experimentally.
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27 Jul 1982
TL;DR: Properties of Gases Uniform Particle Motion Particle size Statistics Straight-Line Acceleration and Curvilinear Particle motion Adhesion of Particles Brownian Motion and Diffusion Thermal and Radiometric Forces Filtration Sampling and Measurement of Concentration Respiratory Deposition Coagulation Condensation and Evaporation Atmospheric Aerosols Electrical Properties Optical Properties Bulk Motion of aerosols Dust Explosions Bioaerosols Microscopic measurement of Particle Size Production of Test aerosols Appendices Index Index
Abstract: Properties of Gases Uniform Particle Motion Particle Size Statistics Straight-Line Acceleration and Curvilinear Particle Motion Adhesion of Particles Brownian Motion and Diffusion Thermal and Radiometric Forces Filtration Sampling and Measurement of Concentration Respiratory Deposition Coagulation Condensation and Evaporation Atmospheric Aerosols Electrical Properties Optical Properties Bulk Motion of Aerosols Dust Explosions Bioaerosols Microscopic Measurement of Particle Size Production of Test Aerosols Appendices Index
5,208 citations
Book•
01 Jan 1999
TL;DR: Aerosol Technology, Second Edition as mentioned in this paper is the #1 guide to aerosol science and technology and has been the text of choice among students and professionals who need to acquire a thorough working knowledge of modern aerosol theory and applications.
Abstract: The #1 guide to aerosol science and technology -now better than everSince 1982, Aerosol Technology has been the text of choice among students and professionals who need to acquire a thorough working knowledge of modern aerosol theory and applications. Now revised to reflect the considerable advances that have been made over the past seventeen years across a broad spectrum of aerosol-related application areas - from occupational hygiene and biomedical technology to microelectronics and pollution control -this new edition includes:* A chapter on bioaerosols* New sections on resuspension, transport losses, respiratory deposition models, and fractal characterization of particles* Expanded coverage of atmospheric aerosols, including background aerosols and urban aerosols* A section on the impact of aerosols on global warming and ozone depletion.Aerosol Technology, Second Edition also features dozens of new, fully worked examples drawn from a wide range of industrial and research settings, plus new chapter-end practice problems to help readers master the material quickly.
3,237 citations
TL;DR: An overview of the challenges and progress associated with the task of numerically predicting particle-laden turbulent flows is provided and suggestions are made for improving closure modelling of some important correlations.
Abstract: The paper provides an overview of the challenges and progress associated with the task of numerically predicting particle-laden turbulent flows The review covers the mathematical methods based on turbulence closure models as well as direct numerical simulation (DNS) In addition, the statistical (pdf) approach in deriving the dispersed-phase transport equations is discussed The review is restricted to incompressible, isothermal flows without phase change or particle-particle collision Suggestions are made for improving closure modelling of some important correlations
1,328 citations