Axial-power-shape induced frequency shifts in BWR stability measurements
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H. Nylén
Abstract
Higher reactor-core-resonance frequency than expected was recognised at the 1800 MWt BWR Barsebäck 2 in Sweden during stability measurements in 2004, and has subsequently been analysed in some detail. Estimation of the void velocity was made by analysing the phase shift between two levels in the LPRM-detector strings, and compared to calculations. Discrepancies in calculated frequency response between simulated perturbation and results from noise analysis were observed, whereas good agreement between calculated and measured void transport was found. The observed deviations in frequency calculations are most likely affected by the pronounced downward shift in power during the stability measurements, and in such circumstances, the shift in reactor-core-resonance frequency can be estimated from void transport calculations.
Kurzfassung
Eine höhere Kern-Resonanzfrequenz als erwartet wurde an dem 1800 MWt BWR Barsebäck 2 in Schweden während Stabilitätsmessungen in 2004 festgestellt und im Anschluss daran detailiert analysiert. Die Voidgeschwindigkeit wurde bestimmt durch die Analyse der Phasenverschiebung zwischen den zwei Level im LPRM-Detektor Strang und verglichen mit Berechnungen. Unterschiede im berechneten Frequenzverhalten zwischen einer simulierten Störung und den Ergebnissen der Rauschanalyse wurden festgestellt, während eine gute Übereinstimung zwischen berechnetem und gemessenem Voidtransportwerten beobachtet wurde. Die beobachteten Abweichungen bei den Frequenzberechnungen werden höchstwahrscheinlich durch eine starke Verschiebung der Leistung nach unten während der Stabilitätsmessungen beeinflusst. Unter diesen Umständen kann die Verschiebung der Kern-Resonanzfrequenz aus den Voidtransportberechnungen abgeschätzt werden.
References
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© 2010, Carl Hanser Verlag, München
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Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Numerical simulation on a HPLWR fuel assembly flow with one revolution of wrapped wire spacers
- Axial-power-shape induced frequency shifts in BWR stability measurements
- Numerical investigation of heat transfer in the vertical annulus between pressure tube and calandria tube of the advanced water cooled reactor
- Uncertainty analysis for fission products transport in CANDU primary heat transport during a severe accident
- Definition of conservative conditions for RIA analysis in the modernized RBMK reactor core
- Assessment of different mechanisms of C-14 production in irradiated graphite of RBMK-1500 reactors
- In-pile measurements of the fission gas pressure and comparison with ROFEM code results
- The time-dependent P1 model for the neutronics of multiplying systems: a review
- Efficiency of reflection coefficients in the isotropic neutron transport equation and computation of the critical-half thicknesses
- Finite differences with exponential filtering in the calculation of reactivity
- Asymptotic solution of critical thickness with direct second kind Chebyshev polynomial approximation in forward and backward scattering
- Interactions of radionuclides in solution with ions and with trace concentrations of solid phase
