Sensitivity study with respect to direction of ADI method during re-flooding in AHWR
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M. Kumar
Abstract
The Advanced Heavy water Reactor (AHWR) is a natural circulation vertical pressure tube type boiling light water cooled and heavy water moderated reactor. As the AHWR fuel bundle quenching under accident condition is designed primarily with radial jets at several axial locations, bottom re-flooding still remain open as another option. Radial direction injection of emergency core cooling leads to rewetting of AHWR fuel cluster in circumferential direction. A 3D fuel pin model has been developed by using Finite Difference Method (FDM) of transient heat conduction equation. Alternating Direction Implicit technique of Finite Difference Method (FDM) has been used for discretisation of numerical equation in different time step at different direction. Sensitivity numerical study with respect to direction of ADI method has been carried out to optimize the time step during the transient as well as steady state and is found that it is insensitivity with direction of solution. Further, to assess influence of circumferential rewetting vis-à-vis axial rewetting. Both the analyses are carried out with same fluid temperature and heat transfer coefficients as boundary conditions. It has been found from the analyses that for radial jet, the circumferential conduction is significant and overall the fuel temperature falls in the quench plane with the initiation of quenching event. The paper discusses the sensitivity study with respect to direction of ADI solution and comparison of numerical results for circumferential and axial rewetting for single pin.
Kurzfassung
Der fortgeschrittene Schwerwasserreaktor AHWR ist ein Leichtwasser gekühlter, Schwerwasser moderierter Reaktor mit Naturumlauf. Das AHWR-Brennstoffgebinde ist so konstruiert, dass im Störfall bei Wiederbenetzung mit radialen Wasserstrahlen an verschiedenen axialen Stellen die Wassereinspeisung von unten eine weitere Option bleibt. Die Einspritzung in radialer Richtung bei Notfallkühlung des Kerns führt zur Wiederbenetzung der Brennstoffelemente in umlaufender Richtung. Ein 3D-Brennelementemodell wurde mit Hilfe der Finite-Differenzen-Methode (FDM) entwickelt. Die Alternating Direction Implicit (ADI)-Methode wurde für die Diskretisierung von numerischen Gleichungen in verschiedenen Zeitschritten und verschiedenen Richtungen verwendet. Eine Sensitivitätsstudie wurde durchgeführt in Hinblick auf die Richtung der ADI-Methode, um somit die Zeitschritte sowohl während des transienten als auch während des stabilen Zustands zu optimieren. Des Weiteren wurde der Einfluss der umlaufenden gegenüber der axialen Wiederbenetzung untersucht. Beide Analysen wurden bei gleicher Flüssigkeitstemperatur und gleichen Wärmetransferkoeffizienten als Randbedingung durchgeführt. Dabei wurde festgestellt, dass für den radialen Wasserstrahlanalyse die umlaufende Leitung wesentlich ist und die Brennelementtemperatur bei der Initiierung der Wiederbenetzung. Die Sensitivitätsstudie wird in diesem Beitrag mit Blick auf die Richtung der ADI-Lösung diskutiert und die numerischen Ergebnisse für umlaufende und axiale Wiederbenetzung für ein einzelnes Element verglichen.
References
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© 2015, Carl Hanser Verlag, München
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Evaluation of A-dependence of cross-sections for light charged particle production in proton induced reactions at intermediate energies
- Sensitivity study with respect to direction of ADI method during re-flooding in AHWR
- Experimental investigation of thermal mixing phenomena in a tee pipe
- Flow impinging effect of critical heat flux and nucleation boiling heat transfer on a downward facing heating surface
- Operating experience feedback from safety significant events at research reactors
- Review of regulatory requirements relevant to calibration of monitoring instruments in research reactors
- The dust characteristics in the collisional plasma sheath at the presence of external magnetic field
- Shamir Secret Sharing Scheme with Dynamic Access Structure (SSSDAS): case study on nuclear power plant
- Criticality calculations with PN approximation for certain scattering parameters of Anlı-Güngör and Henyey-Greenstein phase functions in spherical geometry
- An analytical approach for a nodal formulation of a two-dimensional fixed-source neutron transport problem in heterogeneous medium
- Evaluation of gross radioactivity in foodstuffs
- Development of gamma spectroscopy employing NaI(Tl) detector 3 inch × 3 inch and readout electronic of flash-ADC/FPGA-based technology
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Evaluation of A-dependence of cross-sections for light charged particle production in proton induced reactions at intermediate energies
- Sensitivity study with respect to direction of ADI method during re-flooding in AHWR
- Experimental investigation of thermal mixing phenomena in a tee pipe
- Flow impinging effect of critical heat flux and nucleation boiling heat transfer on a downward facing heating surface
- Operating experience feedback from safety significant events at research reactors
- Review of regulatory requirements relevant to calibration of monitoring instruments in research reactors
- The dust characteristics in the collisional plasma sheath at the presence of external magnetic field
- Shamir Secret Sharing Scheme with Dynamic Access Structure (SSSDAS): case study on nuclear power plant
- Criticality calculations with PN approximation for certain scattering parameters of Anlı-Güngör and Henyey-Greenstein phase functions in spherical geometry
- An analytical approach for a nodal formulation of a two-dimensional fixed-source neutron transport problem in heterogeneous medium
- Evaluation of gross radioactivity in foodstuffs
- Development of gamma spectroscopy employing NaI(Tl) detector 3 inch × 3 inch and readout electronic of flash-ADC/FPGA-based technology
