scholarly journals Validation of Modified ART Mod 2 Code through Comparison with Aerosol Deposition of Cesium Compound in Phébus FPT3 Containment Vessel

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Wasin Vechgama ◽  
Kampanart Silva ◽  
Somboon Rassame
Keyword(s):  
Flow Rate ◽  
Aerosol Deposition ◽  
Radioactive Material ◽  
Brownian Diffusion ◽  
Gravitational Settling ◽  
Containment Vessel ◽  
Cesium Compound ◽  
Turbulent Damping ◽  
Deposition Models ◽  
Calculation Code

Evaluation of aerosol deposition in the containment vessel is an important step for the assessment of radioactive material release to the environment. ART Mod 2 is a calculation code that is used for evaluation of aerosol deposition in the containment vessel. The authors modified aerosol deposition models of ART Mod 2, namely, gravitational settling model, Brownian diffusion model, diffusiophoresis model, and thermophoresis model in order to increase potential of capturing the deposition phenomena. This study aims to compare the simulated results of modified ART Mod 2 with aerosol deposition of cesium compounds in the containment vessel of Phébus FPT3 experiment, in order to validate modified ART Mod 2 code. It is found that aerosol deposition using modified ART Mod 2 agrees with Phébus FPT3. Prediction of Brownian diffusion is significantly improved due to the consideration of turbulent damping process. Cesium mass flow rate and aerosol size are factors that can significantly influence the uncertainty of the results. When conditions of single volumes are carefully selected to match those of the Phébus FPT3 experiment, modified ART Mod 2 can predict aerosol deposition in Phébus FPT3 with relative accuracy.

scholarly journals Effect of gravity on aerosol dispersion and deposition in the human lung after periods of breath holding

2000 ◽  
Vol 89 (5) ◽  
pp. 1787-1792 ◽  
Author(s):  
Chantal Darquenne ◽  
Manuel Paiva ◽  
G. Kim Prisk
Keyword(s):  
Flow Rate ◽  
Turbulent Mixing ◽  
Direct Evidence ◽  
Human Lung ◽  
Hold Time ◽  
Aerosol Deposition ◽  
Breath Holding ◽  
Breath Hold ◽  
Constant Flow Rate ◽  
Aerosol Dispersion

To determine the extent of the role that gravity plays in dispersion and deposition during breath holds, we performed aerosol bolus inhalations of 1-μm-diameter particles followed by breath holds of various lengths on four subjects on the ground (1G) and during short periods of microgravity (μG). Boluses of ∼70 ml were inhaled to penetration volumes (Vp) of 150 and 500 ml, at a constant flow rate of ∼0.45 l/s. Aerosol concentration and flow rate were continuously measured at the mouth. Aerosol deposition and dispersion were calculated from these data. Deposition was independent of breath-hold time at both Vp in μG, whereas, in 1G, deposition increased with increasing breath hold time. At Vp = 150 ml, dispersion was similar at both gravity levels and increased with breath hold time. At Vp = 500 ml, dispersion in 1G was always significantly higher than in μG. The data provide direct evidence that gravitational sedimentation is the main mechanism of deposition and dispersion during breath holds. The data also suggest that cardiogenic mixing and turbulent mixing contribute to deposition and dispersion at shallow Vp.

Research on Deposition of Micro-Nano Aerosols in Rising Bubble Under Pool Scrubbing Condition

2018 ◽  
Author(s):  
Yanmin Zhou ◽  
Haifeng Gu ◽  
Qiunan Sun ◽  
Zhongning Sun ◽  
Jiqiang Su ◽  
...  
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Bubbly Flow ◽  
Aerosol Deposition ◽  
Deposition Efficiency ◽  
Filtration Efficiency ◽  
Liquid Level ◽  
Gas Flow Rate ◽  
Reactor Accident ◽  
Rising Bubble

Aerosols as the main component of radioactive products in migration performance, which is an important factor that a unclear reactor accident present strong diffusion and affects the distributions of source and dose level in reactor containment, and they are therefore expected to be deposited in liquid phase such as in suspension pool and filtered containment venting device. In this paper, the deposition characteristics of micro-nano aerosols in rising bubble under pool scrubbing condition is studied with experiment, the aerosols size in the research range from 20 nm to 600 nm, and the bubble morphology mainly concern homogeneous bubbly flow. The results show that the deposition efficiency and mechanism of aerosol closely relate to gas flow rate, liquid level, particle size and bubbles size and so on. The aerosol deposition near 85nm is proved most difficult because of the convert of deposition mechanisms. In a high liquid level condition, micro-nano aerosol filtration efficiency is enhanced but gradually gradual. Under different gas flow rate, air bubble residence time and the bubble size distributions affect the filtration efficiency of aerosols.

A theory of aerosol deposition in the human respiratory tract

1975 ◽  
Vol 38 (1) ◽  
pp. 77-85 ◽  
Author(s):  
D. B. Taulbee ◽  
C. P. Yu
Keyword(s):  
Particle Size ◽  
Respiratory Tract ◽  
Particle Deposition ◽  
Particle Concentration ◽  
Diffusion Mechanism ◽  
Aerosol Deposition ◽  
Lung Model ◽  
Brownian Diffusion ◽  
Human Respiratory Tract ◽  
Apparent Diffusion

The deposition of inhaled aerosol particles in the human respiratory tract is due to the mechanisms of inertia impaction, Brownian diffusion, and gravitational settling. A theory is developed to predict the particle deposition and its distribution in human respiratory tract for any breathing condition. A convection-diffusion equation for the particle concentration with a loss term is used to describe the transport and deposition of particles. In this equation, an apparent diffusion coefficient due to the velocity dispersion in the lung is present and found to be the dominant diffusion mechanism for the cases considered here. Expressions for deposition by various mechanisms are also derived. The governing equation is solved numerically with Weibel's lung model A. The particle concentration at the mouth is calculated during washin and washout and compared favorably with experimental recordings for 0.5-mum diameter di(2-ethylhexyl) sebacate particles. The total deposition in the lung for particle size ranging from 0.05 to 5 mum is also computed for a 500-cm-3 tidal volume and 15 breaths/min. The results in general agree with recent measurements of Heyder et al. However, a particle size of minimum deposition is found to exist theoretically near 0.3 mum.

scholarly journals Pu/SS Eutectic Assessment in 9975 Packagings in a Storage Facility During Extended Fire

2012 ◽  
Author(s):  
Narendra K. Gupta
Keyword(s):  
Stainless Steel ◽  
Eutectic Temperature ◽  
Radioactive Material ◽  
Interface Temperature ◽  
Fissile Material ◽  
Storage Facility ◽  
Containment Vessel ◽  
Long Term Storage ◽  
Term Storage

In a radioactive material (RAM) packaging, the formation of eutectic at the Pu/SS (plutonium/stainless steel) interface is a serious concern and must be avoided to prevent of leakage of fissile material to the environment. The eutectic temperature for the Pu/SS is rather low (410°C) and could seriously impact the structural integrity of the containment vessel under accident conditions involving fire. The 9975 packaging is used for long term storage of Pu bearing materials in the DOE complex where the Pu comes in contact with the stainless steel containment vessel. Due to the serious consequences of the containment breach at the eutectic site, the Pu/SS interface temperature is kept well below the eutectic formation temperature of 410°C. This paper discusses the thermal models and the results for the extended fire conditions (1500°F for 86 minutes) that exist in a long term storage facility and concludes that the 9975 packaging Pu/SS interface temperature is well below the eutectic temperature.

Dynamic Analysis of a Radioactive Material Package Primary Containment Vessel in a High Pressure Event

2003 ◽  
Author(s):  
Tsu-te Wu ◽  
G. A. Abramczyk ◽  
P. S. Blanton
Keyword(s):  
Dynamic Analysis ◽  
Structural Integrity ◽  
Applied Pressure ◽  
Nonlinear Dynamic Analysis ◽  
Structural Response ◽  
Radioactive Material ◽  
Structural Failure ◽  
Containment Vessel ◽  
Asme Code ◽  
Instantaneous Pressure

This paper discusses the evaluation of the structural integrity of the Primary Containment Vessel (PCV) of a 9975 Shipping Package for radioactive materials subjected to an instantaneously applied pressure load. The instantaneous pressure increase is based on the postulated structural failure of a plutonium oxide container caused by either over pressurization due to detonation or gradual gas buildup. A nonlinear dynamic analysis was performed for a partial 9975 shipping package to evaluate the structural response of the PCV excited by the instantaneous pressurization. The structural integrity of the PCV is justified based on the analytical results in comparison with the stress criteria specified in the ASME Code, Section III, Appendix F for Level D service loads.

Helium Leak Test of a General Purpose Fissile Package (GPFP)

2006 ◽  
Author(s):  
Donald J. Trapp
Keyword(s):  
General Purpose ◽  
Radioactive Material ◽  
Leak Test ◽  
Containment Vessel

The General Purpose Fissile Package (GPFP) is a new package that is designed to safely ship radioactive contents on public highways. The package consists of a specially designed 35 gallon drum which holds a 6-inch diameter containment vessel, which in turn holds the radioactive material that is being transported. The containment vessel must be helium leak tested at fabrication and once per year to ensure it is “leaktight” per ANSI N14.5. To minimize potential leak points, the containment vessel design does not include a port to add helium during the leak test. SRNL designed a helium charging device that the leak test specialist seals inside the vessel and activates at the appropriate time during the leak test.

Dynamic Response Formulation for Pneumatically Driven Liquid in a Pressure Vessel

1991 ◽  
Author(s):  
Richard B. Loucks
Keyword(s):  
Mass Flow Rate ◽  
Aluminum Powder ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Vessel ◽  
Ideal Gas ◽  
Liquid Oxygen ◽  
Mean Flow ◽  
Containment Vessel ◽  
Thermal Output

Abstract The Thermal Radiation Simulator (TRS) at the U.S. Army Ballistic Research Laboratory uses aluminum powder reacting with liquid oxygen to create a large jet like flame. The flame acts as a large thermally radiant wall, exposing targets to a nuclear weapon equivalent. The aluminum powder is driven pneumatically to the combustion chamber from a pressurized containment vessel. Unfortunately the thermal output of the flame oscillates with large amplitude relative to the mean yield. The fluctuating mass flow rate of aluminum powder from the aluminum powder containment vessel seemed the cause of the unstable output. A computer model of the aluminum vessel was constructed to determine the pressure dynamics in the pressure vessel. The aluminum powder was assumed to behave as a Newtonian liquid. The pneumatic fluid was assumed to be an ideal gas. The model concentrated inside the vessel and at the exit. The result was to determine the mass flow rate of aluminum from the exit given the inlet gas pressures. The model did reveal the source of mass flow fluctuations not to be caused directly by the existing pneumatic set-up. The variation was shown to be perturbated by forces outside the pressure vessel. Once the outside influence was eliminated, the model showed a clean mean flow rate of aluminum powder. The results were applied to the TRS and the thermal output was stabilized.

First Results of the Phebus FPT3 Test

2006 ◽  
Author(s):  
Philippe March ◽  
Bruno Biard ◽  
Christelle Manenc ◽  
Fre´de´ric Payot ◽  
Claude Gaillard ◽  
...  
Keyword(s):  
Aerosol Deposition ◽  
Molecular Iodine ◽  
Test Protocol ◽  
Containment Vessel ◽  
Fuel Bundle ◽  
Post Test ◽  
First Results ◽  
Product Test ◽  
On Line

The purpose of this paper is to provide a preliminary overview of the phenomena observed during the experimental phase of the PHEBUS Fission Product Test FPT3. This experiment was the last in the series of 5 in-pile integral experiments performed by IRSN in the PHEBUS facility operated by the CEA on the site of Cadarache. Unlike the previous tests, FPT3 used boron carbide as absorber material instead of silver-indium-cadmium, so varying an important parameter impacting physico-chemical phenomena. FPT3 test course was in agreement with the pre-defined test protocol, including a 8,5-day irradiation phase, a fuel bundle degradation phase which lasted less than 5 hours and a 4-day long-term phase that consisted of an aerosol stage dedicated to the analysis of aerosol deposition mechanisms inside the containment vessel and a chemistry stage devoted to the analysis of the iodine chemistry. During the experiment, both the on-line instrumentation and the periodic samplings worked quite well. The fuel degradation progress could be analysed through both temperatures inside the bundle and gaseous concentration measurements performed in the circuit and inside the containment vessel. Some major events, like fuel clad and absorber rod failures or material relocations, were clearly correlated to both bundle and circuit instrumentation signals. The post test non destructive examinations of the fuel bundle (X-radiography, X- and γ-tomographies and γ-scanning) allowed to compare FPT2 and FPT3 bundle final degradation states. On-line γ-detector measurements coupled with numerous post test gamma-counted sequential samplings help for the characterization of the iodine behaviour inside the containment vessel during the degradation and the long term phases. The whole set of measurements appears self-consistent and provides new data for the iodine solubility inside the sump, the iodine gaseous fraction and the organic versus molecular iodine distribution inside the containment atmosphere.

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