ML20056B490
| ML20056B490 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 08/22/1990 |
| From: | Bradham O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-88-004, IEB-88-4, NUDOCS 9008280351 | |
| Download: ML20056B490 (2) | |
Text
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th C relina Dictric & ois Comptny S Br dhim -
Jenkinsville, SC 2906s.
Nuclear Operations -
(803) 345-4040 r;
'SCE&G
..e-a-o, August 22, 1990 Document Control Desk U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Subject:
Virgil C. Summer Nuclear' Station Docket No. 50/395 Operating License No. NPF-12 NRC Bulletin 88-04 Potential Safety-Related Pump Loss Gentlemen:
In letters dated July 8, and December 20, 1988, South Carolina Electric & Gas Company'(SCf&G)-provided an initial response to two miniflow design concerns addressed in NRC Bulletin 88-04. This correspondence documented the review and acceptability of miniflow design for all active safety-related centrifugal pumps at the Virgil C. Summer Nuclear Station (VCSNS) with the exception of the emergency feedwater (EFW) pumps. As noted in our December 20 letter, the manufacturer's recommended miniflow rates are higher than the curr0nt' design at VCSNS; however, a review of the components' operational history led SCE&G to conclude that a decision on future inspection frequency and/or system modifications should be deferred until the internal components could be inspected.
This inspection was performed by the pump manufacturer..during the recently completed fifth refueling outage. All internal parts were found to be in excellent condition and free from any significant wear fra erosion, cavitation or-internal recirculation.
Since the motor and steam driven EFW pumps have been in service for approximately 10 years without significant deterioration, SCE&G has concluded that modifications to increase the miniflow of these pumps are unnecessary.
Their operation thus far has been typical of that expected during the life of the phr.t; th:rafore, periodic (every three refueling c'Itages) inspectio s of the pump internals are considered to be adequate to detect potential futu e damage from miniflow operation. This inspection frequency is considered to be conservative based on the 10 year wear history for these pumps. The establishment of this inspection frequency is considered to be the final action to be taken by SCE&G in regard to the concerns addressed in the bulletin.
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I'l I declare that the statements ana reatters set forth herein are true and cc. rect to the best of my knowleJge, inf ormation and belief.-
-Should you have any questions, please call at your convenience.
Very truly yours, O. S. Bradham CJM/OSB: led f
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- 0. W, Dixon Jr./1, C. Nichols, Jr.
- t. C. h0berts-
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-R. V.. Tanner l
S. D. Ebneter J.-J. Hayes, Jr.
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General Managers j
C. A.. Price 4
R. J. Wesolus K..E.-Nodland J. C. Snelson-HRC Resident inspector J. B. Knotts, Jr.
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RTS (IEB880004)
File (815.02)
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