ASTEC, COCOSYS, and LIRIC Interpretation of the Iodine Behavior in the Large-Scale THAI Test Iod-9

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
G. Weber ◽  
L. Bosland ◽  
F. Funke ◽  
G. Glowa ◽  
T. Kanzleiter
Keyword(s):  
Mass Transfer ◽  
Large Scale ◽  
Saint Paul ◽  
Molecular Iodine ◽  
Severe Accident ◽  
Research Network ◽  
Lumped Parameter ◽  
Post Test ◽  
Iodine Test ◽  
Iodine Transport

The large-scale iodine test Iod-9 of the German Thermal hydraulics, Hydrogen, Aerosols, Iodine (THAI) program was jointly interpreted by means of post-test analyses within the THAI Circle of the Severe Accident Research NETwork (SARNET)/Work Package 16. In this test, molecular iodine (I2) was injected into the vessel dome of the 60 m3 THAI vessel to observe the evolution of its distribution between water, gas, and surfaces. The main processes addressed in Iod-9 are (a) the mass transfer of I2 between the gas and the two sumps, (b) the iodine transport in the main sump when it is stratified and then mixed, and (c) the I2 adsorption onto, and desorption from, the vessel walls in the presence and absence of wall condensation. The codes applied by the THAI Circle partners were the Accident Source Term Evaluation Code (ASTEC)-IODE (IRSN, Saint Paul Lez Durance, France), Containment Code System (COCOSYS)-Advanced Iodine Model (AIM) (GRS, Garching, Germany), and Library of Iodine Reactions in Containment (LIRIC; AECL, Chalk River, ON, Canada). ASTEC-IODE and the Advanced Iodine Model (AIM) are semi-empirical iodine models integrated in the lumped-parameter codes ASTEC and COCOSYS, respectively. With both codes multicompartment iodine calculations can be performed. LIRIC is a mechanistic iodine model for single stand-alone calculations. The simulation results are compared with each other and with the experimental measurements. Special issues that were encountered during this work were studied in more details: I2 diffusion in the sump water, I2 reaction with the steel of the vessel wall in gaseous and aqueous phases, and I2 mass transfer from the gas to the sump. Iodine transport and behavior in THAI test Iod-9 are fairly well simulated by ASTEC-IODE, COCOSYS-AIM, and LIRIC in post-test calculations. The measured iodine behavior is well understood and all measured data are found to be consistent. The very slow iodine transport within the stratified main sump was simulated with COCOSYS only, in a qualitative way. Consequently, this work highlighted the need to improve modeling of (a) the wet iodine adsorption and the washdown from the walls, (b) the I2 mass transfer between gas and sump, and (c) the I2/steel reaction in the gaseous and aqueous phases. In any case, the analysis of the large-scale iodine test Iod-9 has been an important validation step for the codes applied.

ASTEC, COCOSYS, and LIRIC Interpretation of the Iodine Behaviour in the Large-Scale THAI Test Iod-9

2009 ◽  
Author(s):  
G. Weber ◽  
L. Bosland ◽  
F. Funke ◽  
G. Glowa ◽  
T. Kanzleiter
Keyword(s):  
Mass Transfer ◽  
Large Scale ◽  
Molecular Iodine ◽  
Measured Data ◽  
Lumped Parameter ◽  
Post Test ◽  
Iodine Test ◽  
Iodine Transport ◽  
Semi Empirical ◽  
Water Gas

The large-scale iodine test Iod-9 of the German THAI programme was jointly interpreted by means of post-test analyses within the THAI Circle of the SARNET/WP16. In this test, molecular iodine (I2) was injected into the vessel dome of the 60 m3 THAI vessel to observe the evolution of its distribution between water, gas, and surfaces. The main processes addressed in Iod-9 are (a) mass transfer of I2 between the gas and the two sumps, (b) iodine transport in the main sump when it is stratified and then mixed, and (c) I2 adsorption onto, and desorption from, the vessel walls in the presence and absence of wall condensation. The codes applied by the THAI Circle partners were ASTEC-IODE (IRSN), COCOSYS-AIM (GRS) and LIRIC (AECL). IODE and AIM are semi-empirical iodine models integrated in the lumped-parameter codes ASTEC and COCOSYS respectively. With both codes multi-compartment iodine calculations can be performed. LIRIC is a mechanistic iodine model for single stand-alone calculations. The simulation results are compared with each other and with the experimental measurements. Special issues that were encountered during this work were studied in more detail: I2 diffusion in the sump water, I2 reaction with the steel of the vessel wall in gaseous and aqueous phases, and I2 mass transfer from the gas to the sump. Iodine transport and behaviour in THAI test Iod-9 are fairly well simulated by ASTEC-IODE, COCOSYS-AIM and LIRIC in post-test calculations. The measured iodine behaviour is well understood and all measured data are found to be consistent. The very slow iodine transport within the stratified main sump was simulated with COCOSYS only, in a qualitative way. Consequently, this work highlighted the need to improve modelling of (a) the wet iodine adsorption and the washdown from the walls, (b) the I2 mass transfer between gas and sump, and (c) the I2/steel reaction in the gaseous and aqueous phases. In any case, the analysis of the large-scale iodine test Iod-9 has been an important validation step for the codes applied.

COCOSYS and ASTEC Analyses of Iodine Multi-Compartment Tests in the ThAI-Facility

2006 ◽  
Author(s):  
G. Weber ◽  
H.-J. Allelein ◽  
F. Funke ◽  
T. Kanzleiter
Keyword(s):  
Relative Humidity ◽  
Large Scale ◽  
High Relative Humidity ◽  
Severe Accident ◽  
Experimental Investigations ◽  
Post Test ◽  
Steel Surfaces ◽  
Accident Conditions ◽  
Adsorption Desorption ◽  
Desorption Model

Post test calculations with the accident codes COCOSYS-AIM and ASTEC-IODE were performed on the iodine multi-compartment tests of the German ThAI program (Thermal hydraulics, Aerosols, Iodine). In the tests transport and adsorption/desorption behavior of gaseous I2 were measured in the 60 m3 vessel with a five-compartment configuration under severe accident conditions. The thermal hydraulic modules in COCOSYS and in the containment part of ASTEC (CPA) are nearly identical but not the iodine modules AIM and IODE. The adsorption/desorption model in AIM is based on ThAI data whereas in IODE correlations derived from laboratory-scale tests are used. A 50-zone nodalisation of the ThAI vessel was used with both codes. COCOSYS-AIM and ASTEC-IODE describe qualitatively correctly the I2 concentration differences of several orders of magnitude in periods with stratified atmosphere and the slow homogenization in a convective mixed atmosphere. However, both codes overestimate the gaseous I2 concentration at high relative humidity. The most likely reason is a slow reaction of deposited I2 to the non-volatile FeI2 on the steel surfaces, which has not been modeled sufficiently yet. Further experimental investigations in the ThAI facility are envisaged. A considering of the ThAI data in the I2 adsorption/desorption correlations may improve future ASTEC-IODE results. Nevertheless, the analyses of the large-scale ThAI iodine tests have been an important validation step for COCOSYS-AIM and ASTEC-IODE demonstrating the capability of multi-compartment I2 treatment.

Simulation of a Containment Spray System Test With the European Lumped-Parameter Codes ASTEC and COCOSYS

2012 ◽  
Author(s):  
Tobias Risken ◽  
Marco K. Koch
Keyword(s):  
Droplet Surface ◽  
Severe Accident ◽  
Test Facility ◽  
High Agreement ◽  
Spray System ◽  
Lumped Parameter ◽  
Post Test ◽  
Temperature And Pressure ◽  
Accident Scenarios ◽  
Increasing Temperature

The presented post-test calculations of the test PACOS Px2.2 performed at Ruhr-Universität Bochum (RUB) regard the predictability of the containment spray system’s effect using the lumped parameter codes ASTEC and COCOSYS. The focus of the calculations is set on the decrease of temperature and pressure in case of severe accident scenarios in light water reactor containments. The comparison of the simulation results to experimental data shows, that pressure and temperature during spraying can be simulated satisfactorily with ASTEC and COCOSYS. While calculating the results of the pressure with high agreement to the experiment, both codes underestimate the temperature more and more with increasing distance along the spray path, as the increasing temperature caused by a moving steam cushion is underestimated. The steam cushion is caused by spray induced convection pushing the warmer atmosphere of the upper test facility compartments into the cooler lower compartments. The temperature increase in the lower zones resulting from the establishing flows cannot be simulated properly, as both codes are not fully capable of calculating the occurring forces between dynamic atmosphere and droplet surface.

Post test calculations of a severe accident experiment for VVER-440 reactors by the ATHLET code

Kerntechnik ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. 362-370
Author(s):  
H. György ◽  
I. Trosztel
Keyword(s):  
Severe Accident ◽  
Post Test

Design methodology for mass transfer-enhanced large-scale electrochemical reactor for CO2 reduction

2021 ◽  
pp. 130265
Author(s):  
Byungchan Jung ◽  
Seongho Park ◽  
Chulwan Lim ◽  
Woonghee Lee ◽  
Youngsub Lim ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Design Methodology ◽  
Large Scale ◽  
Co2 Reduction ◽  
Electrochemical Reactor

scholarly journals Trace element catalyses mineral replacement reactions and facilitates ore formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yanlu Xing ◽  
Joël Brugger ◽  
Barbara Etschmann ◽  
Andrew G. Tomkins ◽  
Andrew J. Frierdich ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Trace Elements ◽  
Fluid Flow ◽  
Large Scale ◽  
Metal Accumulation ◽  
Nucleation And Growth ◽  
Reaction Interface ◽  
Ore Formation ◽  
Key Factor ◽  
Mineral Replacement

AbstractReaction-induced porosity is a key factor enabling protracted fluid-rock interactions in the Earth’s crust, promoting large-scale mineralogical changes during diagenesis, metamorphism, and ore formation. Here, we show experimentally that the presence of trace amounts of dissolved cerium increases the porosity of hematite (Fe2O3) formed via fluid-induced, redox-independent replacement of magnetite (Fe3O4), thereby increasing the efficiency of coupled magnetite replacement, fluid flow, and element mass transfer. Cerium acts as a catalyst affecting the nucleation and growth of hematite by modifying the Fe2+(aq)/Fe3+(aq) ratio at the reaction interface. Our results demonstrate that trace elements can enhance fluid-mediated mineral replacement reactions, ultimately controlling the kinetics, texture, and composition of fluid-mineral systems. Applied to some of the world’s most valuable orebodies, these results provide new insights into how early formation of extensive magnetite alteration may have preconditioned these ore systems for later enhanced metal accumulation, contributing to their sizes and metal endowment.

An Efficient Preconditioner for Linear System Solution in Multi-Domain Modeling of the Circulatory System

2013 ◽  
Author(s):  
Mahdi Esmaily Moghadam ◽  
Yuri Bazilevs ◽  
Tain-Yen Hsia ◽  
Alison Marsden
Keyword(s):  
Strong Coupling ◽  
Large Scale ◽  
Computational Cost ◽  
Circulatory System ◽  
Flow Simulation ◽  
Global Dynamics ◽  
Domain Modeling ◽  
Computationally Efficient ◽  
Lumped Parameter ◽  
System Solution

A closed-loop lumped parameter network (LPN) coupled to a 3D domain is a powerful tool that can be used to model the global dynamics of the circulatory system. Coupling a 0D LPN to a 3D CFD domain is a numerically challenging problem, often associated with instabilities, extra computational cost, and loss of modularity. A computationally efficient finite element framework has been recently proposed that achieves numerical stability without sacrificing modularity [1]. This type of coupling introduces new challenges in the linear algebraic equation solver (LS), producing an strong coupling between flow and pressure that leads to an ill-conditioned tangent matrix. In this paper we exploit this strong coupling to obtain a novel and efficient algorithm for the linear solver (LS). We illustrate the efficiency of this method on several large-scale cardiovascular blood flow simulation problems.

Numerical modeling of large-scale bubble plumes accounting for mass transfer effects

2002 ◽  
Vol 28 (11) ◽  
pp. 1763-1785 ◽  
Author(s):  
Gustavo C. Buscaglia ◽  
Fabián A. Bombardelli ◽  
Marcelo H. Garcı́a
Keyword(s):  
Mass Transfer ◽  
Numerical Modeling ◽  
Large Scale ◽  
Transfer Effects ◽  
Bubble Plumes

scholarly journals Carbothermic Reduction of Zinc Containing Industrial Wastes: A Kinetic Model

2021 ◽  
Author(s):  
M. Leuchtenmueller ◽  
C. Legerer ◽  
U. Brandner ◽  
J. Antrekowitsch
Keyword(s):  
Mass Transfer ◽  
Zinc Oxide ◽  
Kinetic Model ◽  
Large Scale ◽  
Industrial Wastes ◽  
Oxide Reduction ◽  
Transfer Coefficients ◽  
Metallothermic Reduction ◽  
Metal Bath ◽  
Zinc Recovery

AbstractEffective recycling of zinc-containing industrial wastes, most importantly electric arc furnace dust, is of tremendous importance for the circular economy of the steel and zinc industry. Herein, we propose a comprehensive kinetic model of the combined carbothermic and metallothermic reduction of zinc oxide in a metal bath process. Pyro-metallurgical, large-scale lab experiments of a carbon-saturated iron melt as reduction agent for a molten zinc oxide slag were performed to determine reaction constants and accurately predict mass transfer coefficients of the proposed kinetic model. An experimentally determined kinetic model demonstrates that various reactions run simultaneously during the reduction of zinc oxide and iron oxide. For the investigated slag composition, the temperature-dependent contribution of the metallothermic zinc oxide reduction was between 25 and 50 pct of the overall reaction mechanism. The mass transfer coefficient of the zinc oxide reduction quadrupled from 1400 °C to 1500 °C. The zinc recovery rate was > 99.9 pct in all experiments.

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