Results of Semiscale Mod-2C feedwater and steam line break (S-FS) experiment series: Main steam line break accident experiments

Technical Report · Tue Mar 01 04:00:00 EST 1988

OSTI ID:6956676

Boucher, T J

This report presents the results of two experiments conducted in the Semiscale Mod-2C facility which simulated main steam line break accidents at high pressure and temperature. Tests S-FS-1 and S-FS-2 simulated double-ended offset shears of the main steam line downstream and upstream, respectively, of the flow restrictor. Initial and boundary conditions were scaled from, and compounding failures and assumptions simulated, those conditions utilized for Final Safety Analysis Report (FSAR) calculations. Primary and secondary thermal-hydraulics responses are characterized (including local secondary convective heat transfer), and the influence of the break size or locations on the responses is discussed. The limiting of primary-to-secondary heat transfer by conduction heat transfer is shown to produce a trend of increased primary cooling with decreased break size, pointing out the need for further analysis for smaller break sizes. The degree of conservatism inherent in FSAR separator performance and break size and location assumptions is shown to be questionable, and the FSAR assumption of a loss of offsite power is shown to be nonconservative. The effectiveness of the recovery operations in regaining and maintaining control of the system is addressed; and main steam line break issues, including the minimum primary fluid temperatures estimated for a full-scale PWR plant, are discussed based on the results of the experiments. Finally, based on the results of the analysis, conclusions are drawn and recommendations are made for further utilization of the data. Future thermal-hydraulic computer code calculations are also considered.

• Research Organization: EG and G Idaho, Inc., Idaho Falls (USA)
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 6956676
• Report Number(s): NUREG/CR-4971; EGG-2516; ON: TI88008581
• Country of Publication: United States
• Language: English

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ACCIDENTS
BOILERS
COOLING SYSTEMS
DATA
ENERGY SYSTEMS
ENERGY TRANSFER
EXPERIMENTAL DATA
FAILURES
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HEAT TRANSFER
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REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR SAFETY
REACTORS
RECOMMENDATIONS
SAFETY
SCALE MODELS
SIMULATION
STEAM GENERATORS
STRUCTURAL MODELS
TEST FACILITIES
VAPOR GENERATORS
WATER
WATER COOLED REACTORS
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