Counter Current Flow Limitation (CCFL) was observed in the pressurizer surge line of
the Oregon State University APEX facility during test NRC-10. This test simulated a one-inch
diameter cold leg break with a failure of three of four of the fourth-stage Automatic
Depressurization System (ADS) valves. The result was a high vapor flow rate through
ADS 1-3, that caused CCFL in the pressurizer surge line and liquid holdup in the
pressurizer. Because this liquid was not available for core cooling, further study of the
passive safety systems in the AP600 under Mode 5 Cold Shutdown conditions was
deemed necessary. An analysis of the AP600 geometry and the existing CCFL database
determined that Kutateladze scaling is appropriate for the APEX and AP600 surge lines.
The Kutateladze CCFL correlation was used to assess CCFL in the APEX and AP600
pressurizer surge lines under Mode 5 Cold Shutdown conditions. The results indicate that
CCFL would be expected in the pressurizer surge lines at low pressures and decay powers
prior to ADS 4 actuation. Test NRC-35 examined CCFL and provided data to benchmark
NRC's thermal hydraulic analysis codes. This thesis presents the results of test NRC-35
and the supporting CCFL calculations. / Graduation date: 1999
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/33578 |
| Date | 09 March 1999 |
| Creators | Colpo, Sarah E. |
| Contributors | Reyes, Jose N. Jr |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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