Computational fluid dynamics validation study of steam condensation on the containment walls
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B. Gera
Abstract
In water cooled power reactors, significant quantities of hydrogen could be produced following a severe accident (loss-of-coolant-accident along with non availability of emergency core cooling system). A sound understanding of dispersion, stratification and diffusion of released hydrogen during severe accidents is, therefore, of practical importance and use to better understand the possibility of ignition, combustion and explosion of such releases within the context of containment safety. The presence of air and steam in the containment atmosphere also affects the hydrogen distribution as steam condensation takes place at containment walls in presence of non condensable and bulk of the mixture diffuses towards wall. The application of general purpose CFD codes for the analysis of the hydrogen behaviour within NPP containments during severe accidents has been increasing over past few years. The commercial CFD codes generally do not have built-in steam condensations models. In the present work, the adaptation of a commercial multi-purpose code to this kind of problem is explained, i.e. by the implementation of models for steam condensation onto walls in presence of non-condensable gases. Steam condensation was modeled using the Uchida correlation, which was originally developed to be used for “lumped” (volume-averaged) modeling of steam condensation in the presence of non-condensable gases. The Uchida correlation is based on experiments on natural convection from relatively small vertical plates. The present methodology has been validated against experimental data from the TOSQAN and COPAIN experimental facilities.
Kurzfassung
In Wasser-gekühlten Leistungsreaktoren können signifikante Mengen Wasserstoff nach einem schweren Unfall (Kühlmittelverluststörfall und fehlendes Kernkühlungssystem) erzeugt werden. Deshalb ist ein fundiertes Verständnis von Dispersion, Stratifikation und Diffusion des während eines schweren Unfalls freigesetzten Wasserstoffs von praktischer Bedeutung, um die Möglichkeiten von Zündung, Verbrennung und Explosion solcher Freisetzungen im Rahmen der Containmentsicherheit besser zu verstehen. Das Vorhandensein eines Luft-Dampf-Gemischs in der Containmentatmosphäre beeinflusst die Wasserstoffverteilung, da der Dampf an den Containmentwänden kondensiert und der Großteil des Gemischs sich zu den Containmentwänden hin ausbreitet. Vermehrt werden in letzten Jahren CFD Codes zur Analyse des Wasserstoffverhaltens innerhalb des Containments verwendet. Die kommerziellen CFD Codes haben im allgemeinen keine integrierten Dampfkondensationsmodelle. In der vorliegenden Arbeit wird über die Anpassung eines kommerziellen Mehrzweckcodes an diese Art Probleme durch die Implementierung von Dampfkondensationsmodellen berichtet. Dazu wurde die Uchida-Korrelation verwendet, die ursprünglich für volumengemittelte Modelle der Dampfkondensation entwickelt worden war. Die jetzige Methode wurde validiert mit Hilfe experimenteller Ergebnisse aus den TOSQAN und COPAIN Testanlagen.
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© 2012, Carl Hanser Verlag, München
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Analytical assessment for stress corrosion fatigue of CANDU fuel elements under load following conditions
- Development of a thermal-hydraulic analysis code for annular fuel assemblies
- Reduction of fluid property errors of various thermohydraulic codes for supercritical water systems
- Computational fluid dynamics validation study of steam condensation on the containment walls
- CFD analysis of a hydraulic valve for cavitating flow
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- 124I production for PET imaging at a cyclotron
- Investigation of ground state features of some medical radionuclides
- Solution of the radiative transfer equation with the successive order scattering transport approximation and its application to a biological medium
- Solving the constant source problem for the quadratic anisotropic scattering kernel using the modified FN method
- Application of the Laplace transform method for computational modelling of radioactive decay series
- A standing wave reactor by continuous radial fuel shuffling
- Technical Notes/Technische Mitteilungen
- On the radial flux shape of a fast standing wave reactor operated by radial fuel shuffling
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Analytical assessment for stress corrosion fatigue of CANDU fuel elements under load following conditions
- Development of a thermal-hydraulic analysis code for annular fuel assemblies
- Reduction of fluid property errors of various thermohydraulic codes for supercritical water systems
- Computational fluid dynamics validation study of steam condensation on the containment walls
- CFD analysis of a hydraulic valve for cavitating flow
- Thermal plume behaviour in the Kadra reservoir at Kaiga atomic power station – Part 2: studies for the case of four and six units in operation
- 124I production for PET imaging at a cyclotron
- Investigation of ground state features of some medical radionuclides
- Solution of the radiative transfer equation with the successive order scattering transport approximation and its application to a biological medium
- Solving the constant source problem for the quadratic anisotropic scattering kernel using the modified FN method
- Application of the Laplace transform method for computational modelling of radioactive decay series
- A standing wave reactor by continuous radial fuel shuffling
- Technical Notes/Technische Mitteilungen
- On the radial flux shape of a fast standing wave reactor operated by radial fuel shuffling
