Space effect on liquid film flow in a BWR fuel bundle

Conference · Mon Dec 31 23:00:00 EST 1990 · Transactions of the American Nuclear Society; (United States)

OSTI ID:5779158

Nishida, Koji; Kanazawa, Toru; Yokomizo, Osamu ^[1]

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1. Hitachi Ltd., Ibaraki (Japan)

Critical power at boiling transition is an important factor in a boiling water reactor (BWR) fuel bundle design. Boiling transition under high quality accounts for dryout as the result of the complete disappearance of film flow on a fuel rod. This liquid film vanishing process can be calculated by the liquid film model, which takes into account the evaporation due to heat from the rod surface, liquid film entrainment by steam flow, and liquid droplet deposition. It is known that spacers affect liquid film entrainment and liquid droplet deposition, so the detailed study of spacer effects on hydrodynamic characteristics is necessary for critical power prediction based on the film flow model. Many studies have been conducted to examine spacer effects on liquid film flow. However, most of them are restricted to simple test sections such as a rectangular conduit. There are a few reports on fuel bundle geometry; however the bundle studied was only a 3 by 3 rod array. It is known that spacers affect not only deposition and entrainment but also flow distribution among the subchannels. Therefore, in this research, liquid film thickness measurements were performed to clarify the deposition and entrainment at a spacer in a full-sized fuel bundle. Furthermore, critical power predictions on a BWR fuel bundle were carried out with a film flow model that included a spacer model.

• OSTI ID: 5779158
• Report Number(s): CONF-910603--
• Journal Information: Transactions of the American Nuclear Society; (United States), Journal Name: Transactions of the American Nuclear Society; (United States) Vol. 63; ISSN TANSA; ISSN 0003-018X
• 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
42 ENGINEERING
420400 -- Engineering-- Heat Transfer & Fluid Flow
BOILING
BWR TYPE REACTORS
DEPOSITION
DROPLETS
DRYOUT
ENERGY TRANSFER
ENRICHED URANIUM REACTORS
ENTRAINMENT
EVAPORATION
FLUID MECHANICS
FUEL ASSEMBLIES
FUEL CHANNELS
HEAT TRANSFER
HYDRAULICS
MECHANICS
PARTICLES
PHASE TRANSFORMATIONS
POWER REACTORS
REACTOR CHANNELS
REACTOR COMPONENTS
REACTOR CORES
REACTORS
SPACERS
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS