Spatial weighting of Doppler reactivity feedback

Technical Report · Thu Dec 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/6803075· OSTI ID:6803075

Carew, J F; Diamond, D J; Todosow, M

The spatial weighting of the local Doppler feedback implicit in the determination of the core Doppler feedback reactivity has been investigated. Using a detailed planar PDQ7-II PWR model with local fuel-temperature feedback, the core Doppler spatial weight factor, S, has been determined for various control patterns and power levels. Assuming power-squared weighting of the local Doppler feedback, a simple analytic expression for S has been derived and, based on comparison with the PDQ7-II results, provides a convenient and accurate representation of the Doppler spatial weight factor. The sensitivity of these results to variations in the fuel rod heat transfer coefficients, fuel loading and the magnitude of the Doppler coefficient has also been evaluated. The dependence of the local Doppler coefficient on moderator temperature, boron concentration and control rod density has been determined and found to be weak. Selected comparisons with vendor analyses have been made and indicate general agreement.

• Research Organization: Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: EY-76-C-02-0016
• OSTI ID: 6803075
• Report Number(s): BNL-NUREG-23709
• Country of Publication: United States
• Language: English

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FUNCTIONS
MATHEMATICAL MODELS
P CODES
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