ML13331A350
| ML13331A350 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/15/1989 |
| From: | Ornelas R SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-004, IEB-88-4, NUDOCS 8912210041 | |
| Download: ML13331A350 (2) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE. CALIFORNIA 92718 December 15, 1989 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 NRC Bulletin 88-04 San Onofre Nuclear Generating Station Unit 1 This letter completes SCE's response to NRC Bulletin 88-04, Potential Safety Related Pump Loss.
Our response provided to you by letter dated January 5, 1989 identified the need to further evaluate the feedwater pumps in their safety injection mode of operation.
This mode of operation for the feedwater pumps involves the use of a separate miniflow line to the Refueling Water Storage Tank (RWST). The evaluation of the safety-related pumps discussed in the January 5, 1989 response only included the feedwater pumps in the feedwater mode, utilizing the feedwater miniflow line to the condenser.
Further evaluation of the feedwater pumps miniflow in the safety injection mode indicates the miniflow line capacity is adequate for the feedwater pumps.
NRC Bulletin 88-04 was concerned with the potential for dead-heading one or more pumps in safety related systems that have miniflow lines common to two or more pumps.
The Bulletin was also concerned with inadequate miniflow capacity for single pumps.
A hydraulic calculation was performed to determine the flow through the safety injection miniflow lines for each feedwater pump to the RWST with both pumps operating at a shutoff head.
The calculation concluded that there was adequate miniflow for each pump in the safety injection mode since the calculated miniflow in this mode was equivalent to the miniflow in the feedwater mode.
A special test of the feedwater pumps on the safety injection miniflow was performed on May 2, 1989 during the Cycle 10 refueling outage to verify the results of the calculation. The results of the test confirmed that the pumps perform adequately in the safety injection mode with the miniflow to the RWST.
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Document Control Desk December 15, 1989 The test was performed by monitoring pump performance through vibration and bearing oil temperature for a, duration of approximately 5 minutes with the pumps recirculating through the safety injection miniflow to the RWST. The vibration and bearing oil temperature data were within the acceptance criteria for the Inservice Testing Program and the pumps operated with stable discharge pressure and.motor current and no abnormalities in pump operation were noted.
Therefore, the calculation in conjunction with the special test demonstrate that the feedwater pumps operating in the safety injection mode have adequate miniflow.
This completes the actions required by Bulletin 88-04 and no corrective actions are necessary.
As indicated in the January 5, 1989 submittal, the documentation including the calculation and test data will be maintained in the Corporate Document Management System.
If you have any questions regarding this, please let me know.
Respectfully submitted, By:
C c R. Ornelas Supervising Engineer Unit 1 Licensing Subscribed and sworn to before me this
/3S7-A day ofAO,/l A51 1 dayof 9~-~A~w~/9e 9?OFFIGiAL SEAL R.
DeAOMAR V. CLEARY EsNotary Public-Califom-,ia ORANGE COUNTY N ary Public in and for the:/
S ate of California cc: J. B. Martin, Regional Administrator, NRC Region V C. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3