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Analytical model for bottom reflooding heat transfer in light water reactors (the UCFLOOD code)

Technical Report ·
DOI:https://doi.org/10.2172/6558445· OSTI ID:6558445
The UCFLOOD code is based on mechanistic models developed to analyze bottom reflooding of a single flow channel and its associated fuel rod, or a tubular test section with internal flow. From the hydrodynamic point of view the flow channel is divided into a single-phase liquid region, a continuous-liquid two-phase region, and a dispersed-liquid region. The void fraction is obtained from drift flux models. For heat transfer calculations, the channel is divided into regions of single-phase-liquid heat transfer, nucleate boiling and forced-convection vaporization, inverted-annular film boiling, and dispersed-flow film boiling. The heat transfer coefficients are functions of the local flow conditions. Good agreement of calculated and experimental results has been obtained. A code user's manual is appended.
Research Organization:
California Univ., Berkeley (USA)
OSTI ID:
6558445
Report Number(s):
EPRI-NP-756
Country of Publication:
United States
Language:
English