Analysis of BWR out-of-phase instabilities in the frequency domain

Conference · Wed Jan 01 04:00:00 EST 1992 · Transactions of the American Nuclear Society; (United States)

OSTI ID:6663045

Farawila, Y M; Pruitt, D W ^[1]; Kreuter, D ^[2]

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1. Siemens Nuclear Power Corp., Richland, WA (United States)
2. Siemens AG KWU Group, Offenbach (Germany)

During startup or because of an inadvertent recirculation pump trip, a boiling water reactor (BWR) may operate at relatively low flow and high power conditions. At these conditions, a BWR is susceptible to coupled flow and power oscillations that could result in undesirable reactor scram unless appropriate countermeasures are taken. This contribution to analytical methods has been developed to address in part a general industrywide and regulatory concern about BWR stability initiated by the LaSalle 2 instability event in March 1988. This work is designed to extend the capability of the one-dimensional parallel channel frequency domain code STAIF to predict the regional oscillation decay ratio. The basic theory follows that developed by March-Leuba and Blakeman, where the oscillation mechanism is identified as the excitation of a subcritical neutronic mode with a constant core pressure drop boundary condition. The improvements to the basic theory include applying the theory to one-dimensional neutronics instead of point kinetics and taking account of the actual three-dimensional harmonic flux distribution.

• OSTI ID: 6663045
• Report Number(s): CONF-921102--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 66
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100* -- Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
ANALYTIC FUNCTIONS
BWR TYPE REACTORS
COMPUTER CODES
ENRICHED URANIUM REACTORS
FUNCTIONS
KINETICS
ONE-DIMENSIONAL CALCULATIONS
OSCILLATIONS
POWER REACTORS
REACTOR KINETICS
REACTOR STABILITY
REACTORS
S CODES
STABILITY
THERMAL REACTORS
TRANSIENTS
WATER COOLED REACTORS
WATER MODERATED REACTORS