Modelling of the spent fuel heat-up in the spent fuel pools using one-dimensional system codes and CFD codes
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A. Graževičius
Abstract
The main functions of spent fuel pools are to remove the residual heat from spent fuel assemblies and to perform the function of biological shielding. In the case of loss of heat removal from spent fuel pool, the fuel rods and pool water temperatures would increase continuously. After the saturated temperature is reached, due to evaporation of water the pool water level would drop, eventually causing the uncover of spent fuel assemblies, fuel overheating and fuel rods failure. This paper presents an analysis of loss of heat removal accident in spent fuel pool of BWR 4 and a comparison of two different modelling approaches. The one-dimensional system thermal-hydraulic computer code RELAP5 and CFD tool ANSYS Fluent were used for the analysis. The results are similar, but the local effects cannot be simulated using a one-dimensional code. The ANSYS Fluent calculation demonstrated that this three-dimensional treatment allows to avoid the need for many one-dimensional modelling assumptions in the pool modelling and enables to reduce the uncertainties associated with natural circulation flow calculation.
Kurzfassung
Die Hauptfunktion von Abklingbecken ist es, die Restwärme abgebrannter Brennelemente zu verringern und gleichzeitig die Brennelemente abzuschirmen. Im Falle eines Verlusts der Wärmeabfuhr würden die Temperatur der abgebrannten Brennelemente und die Wassertemperatur kontinuierlich ansteigen. Nach Erreichen der Sättigungstemperatur würde der Wasserstand im Pool aufgrund der Verdampfung sinken, die abgebrannten Brennelemente wären nicht mehr bedeckt und würden überhitzen. Dieser Beitrag präsentiert die Analyse eines Störfalls mit Ausfall der Kühlung in einem Abklingbecken des SWR 4 und ein Vergleich zweier verschiedener Modellierungsansätze. Dazu wurde der thermohydraulische Rechencode RELAP5 und der CFD-Code ANSYS-Fluent verwendet. Die Ergebnisse sind ähnlich, aber lokale Effekte können mit dem eindimensionalen Code nicht simuliert werden. Die ANSYS-Fluent-Berechnung zeigt, dass durch die dreidimensionale Behandlung viele Annahmen bei der eindimensionalen Modellierung entfallen und damit die Unsicherheiten bei der Berechnung der natürlichen Zirkulationsströmung verringert werden.
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© 2017, Carl Hanser Verlag, München
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- SIMULATE-3 K coupled code applications
- Application of the new IAPWS Guideline on the fast and accurate calculation of steam and water properties with the Spline-Based Table Look-Up Method (SBTL) in RELAP-7
- Simulation of water hammer phenomena using the system code ATHLET
- New version of the reactor dynamics code DYN3D for Sodium cooled Fast Reactor analyses
- Sensitivity analysis for thermo-hydraulics model of a Westinghouse type PWR: verification of the simulation results
- Calculation of the fuel temperature coefficient of reactivity considering non-uniform radial temperature distribution in the fuel rod
- The effect of boron dilution transient on the VVER-1000 reactor core using MCNP and COBRA-EN codes
- Modelling of the spent fuel heat-up in the spent fuel pools using one-dimensional system codes and CFD codes
- Optimization and analysis of the effects of physical parameters in a TRIGA-ADSR
- A comparison study for mass attenuation coefficients of some amino acids using MCNP code
- Validation of radioactive isotope activity measurement in homogeneous waste drum using Monte Carlo codes
- Study of the response reduction of LiF:Mg, Ti dosimeter for high dose dosimetry
- Non-contact micro mass evaluation method using an X-ray microscope
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- SIMULATE-3 K coupled code applications
- Application of the new IAPWS Guideline on the fast and accurate calculation of steam and water properties with the Spline-Based Table Look-Up Method (SBTL) in RELAP-7
- Simulation of water hammer phenomena using the system code ATHLET
- New version of the reactor dynamics code DYN3D for Sodium cooled Fast Reactor analyses
- Sensitivity analysis for thermo-hydraulics model of a Westinghouse type PWR: verification of the simulation results
- Calculation of the fuel temperature coefficient of reactivity considering non-uniform radial temperature distribution in the fuel rod
- The effect of boron dilution transient on the VVER-1000 reactor core using MCNP and COBRA-EN codes
- Modelling of the spent fuel heat-up in the spent fuel pools using one-dimensional system codes and CFD codes
- Optimization and analysis of the effects of physical parameters in a TRIGA-ADSR
- A comparison study for mass attenuation coefficients of some amino acids using MCNP code
- Validation of radioactive isotope activity measurement in homogeneous waste drum using Monte Carlo codes
- Study of the response reduction of LiF:Mg, Ti dosimeter for high dose dosimetry
- Non-contact micro mass evaluation method using an X-ray microscope
