Flow instability and flow reversal in heated annular multichannels with initial downward flow

Conference · Thu Dec 31 04:00:00 EST 1992

OSTI ID:10121744

Guerrero, H N; Hart, C M

Experimental and theoretical results are presented regarding the stability of initial downward flow of single phase water in parallel annular channels of the Savannah River Site (SRS) fuel assembly. The test was performed on an electrically heated prototypic mockup of a Mark-22 fuel assembly. The test conditions consisted of mass fluxes, from 98--294 kg/m{sup 2}-sec, and inlet water temperatures of 25{degrees}C and 40{degrees}C. With increased power to the heaters, flow instability was detected, characterized by flow fluctuations and flow redistribution among subchannels of the outer flow channel. With increased power, a condition was observed indicating local subchannel flow reversals where certain subchannel fluid temperatures were high at the inlet and low at the exit. With additional power increased, a critical heat flux condition was observed indicating local subchannel flow reversals where certain subchannel fluid temperatures were high at the inlet and low at the exit. With additional power increases, a critical heat flux condition was reached in the outer channel.

• Research Organization: Westinghouse Savannah River Co., Aiken, SC (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC09-89SR18035
• OSTI ID: 10121744
• Report Number(s): WSRC-MS--92-388; CONF-930830--2; ON: DE93006164
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220600
CRITICAL HEAT FLUX
FLOW MODELS
FLUID FLOW
FUEL ASSEMBLIES
HEAT TRANSFER
HYDRAULICS
PRODUCTION REACTORS
REACTOR CHANNELS
RESEARCH
TEST
TRAINING
PRODUCTION
IRRADIATION
MATERIALS TESTING REACTORS
SAVANNAH RIVER PLANT
STABILITY