TXX-4092, Provides Addl Details & Clarifications to Re High/Moderate Energy Pipe Break Analysis.Local Control Station Relocated to Prevent Damage from Flooding.All High Energy Lines Designed to Seismic Category 1 Requirements
| ML20083J870 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/05/1984 |
| From: | Schmidt H TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | Youngblood J Office of Nuclear Reactor Regulation |
| References | |
| TXX-4092, NUDOCS 8401100349 | |
| Download: ML20083J870 (2) | |
Text
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g Log # TXX-4092 TEXAS UTILITIES GENERATING COMPANY File # 903.6 hKY WAY TOWEH
- 4tHB NORTH OLIVE MTHEET L.It. MI
- DALLAM, TEX AM 73201 January 5, 1984 Director of Nuclear Reactor Regulation Attention:
Mr. B. J. Youngblood, Chief Licensing Branch No. 1 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
205_55
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION DOCKET NOS. 50-445 AND 50-446 HIGH/ MODERATE ENERGY PIPE BREAK ANALYSIS
Dear Sir:
This letter provides additional details and clarifications of Texas Utilities letter TXX-4048 dated September 13, 1983.
As per the telephone conversation with Auxiliary Branch Reviewer, Ernest Sylvester on December 19, 1983, the following concerns are addressed:
1.
The moderate energy break of the Safeguards Building auxiliary feedwater pipe supplied by the Condensate Storage Tank was not required to be postulated because the pipe stresses are less than the threshold level specified in BIP MEB 3-1.
The limiting break was determined to be in the 12" safety injection supply 1 *ne from the Reactor Water Storage Tank (RWST).
The break was postulated to occur between the tank and supply valve 1SI-048.
The break flow 3
rate was calculated to be.2457 ft /sec with termination of the Safeguards Building flooding occurring after eight hours.
Termination was by operator action placing sand bags in the pipe tunnel to divert flow. Flooding affected rooms 53, 54, 55, 56-1, 56-2, 57, 58, 59, 61 and 62, with flooding depths rangirig from 8" to 103".
With the exception of a local control station for the ESF fan coil unit to the RHR pumps, no safe shutdown equipment was affected by the flooding. The local control station was relocated.
2.
All high energy lines located in safety related structurcs are designed to seismic category I requirements.
3.
Analyses of flooding effects for the AFW pump rooms and charging pump rooms were performed assuming complete blockage of floor drains.
The flooding from the limiting break in each room is as follows:
8 8401100349 840105 PDR ADOCK 05000445 A
PDR A DEVENION OF TKKA8 l?TILETIEN ELECTRit' COMi%NY
,'A Flooding Accident depth termination Room Line Leak Rate (CFS)
(inches)
(min.)
Charging 199 3"-CS-1-83
.227 9.6" 30 pump 000 4-CS-1-076 1.23 fwd.13 reverse 71" 30 201 4-CS-1-085 1.23 fwd.13 reverse 85" 30 Aux. Feed 72 6"-AF-1-036 2.28 fwd.524 reverse 136" 30 pump 73 6"-AF-1-009 2.28 fwd.524 reverse 144" 30 74 8"-AF-1-011
.524 fwd 3.74 reverse 79" 30 Flooding into adjacent compartments via the common drain header is not analyzed because passive failures (such as drain pipe rupture, or failure of normally closed back water drain valves) are not nostulated in conjunction with the original pipe break.
Should you have additional questions in this matter, please contact this office.
Sincerely, H. C. Schmidt BSD/grr
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