ML20092M799

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Interim Deficiency Rept D/N 52 Re LPSI Pump Failures. Initially Reported on 840523.Corrective Action Will Be Proposed Upon Completion of Investigation.Final Rept Will Be Provided by 850630
ML20092M799
Person / Time
Site: Satsop
Issue date: 06/22/1984
From: Kohler A
WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To: Bishop T
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
D-N-#52, GO3-84-402, NUDOCS 8407020391
Download: ML20092M799 (2)


Text

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liECElVED 0C Washington Public Power Supply System Box 1223 Elma, Washington 98g ppg)gl8g4p810 REG 10N VIM Docket No. 50-503 June 22, 1984 G03-84-402 U.S. Nuclear Regulato.y Commission, Region V .

Office of Inspection and Enforcement 1450 Maria Lane, Suite 260 Walnut Creek, California 94595 - 5368 Attention: Mr. T.W. Bishop, Director Division of Resident Reactor Projects

.and Engineering Programs

Subject:

POTENTIAL 10CFR50.55(e) _"CFICIENCY LOW PRESSURE SAFETY INJECIION PUMP FAILURES D/N #52 On May 23, 1984, The Supply System notified your office of a potential 10CFR50.55(e) deficiency cor.cerning the subject condition. An investigation is in progress; however, sufficient data is not available at this time to determine the cause. Attached is a Supply Systera approved interim report.

It is anticipated that a final report will be provided to your office by June 30, 1985. Should you have any questions or desire fcrther information, please contact me directly.

A.D. Kohler WNP-3 Program Director DRC/mam Attachment cc: Mr. J.A. Adams - BPA Mr. D. Smithpeter - BPA Mr. S.F. Swearngin - BPA Ebasco, Elma Mr. R.D. Hill, Puget Should Power & Light Company Mr. P. Inman, The Washington Water Power Company Mr. B.D. Withers, Portland General Electric Company Mr. E.M. Burton, Pacific Power & Light Company Mr. M.K. Yates, Ebasco, New York Mr. A.A. Tuzes, Combustion Engineering 8407020391 840622 /

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WASHINGTON NUCLEAR PROJECT NO. 3 (DOCKET NO. 50-508) 10CFR50.55(e) DEFICIENCY INTERIM REPORT LOW PRESSURE SAFETY INJECTION (LPSI)

PUMP FAILURES (D/N NO. 52)

Description of Deficiency The Palo Verde Nuclear Generating Station LPSI pumps, as originally supplied, have

- experienced several instances of failure to start when energized. The investigation so far has established the root cause of the problem as excessive shaft deflection due to high magnetic forces in- the motor during start-up. This causes the impeller to co'ntact the casing ring sometimes preventing shaft acceleration. The WNP-3 LPSI pumps may also be subject to this type of failure.

The WNP-3 and PVhGS LPSI motors --have ' identical rotors, bearing systems, and

. electrical characteristics. The hydraulic portions of the pumps are also identical.

Safety ' Implications' .

The LPSI pump provides low pressure injection during a LOCA and also provides reactor coolant system flow to the shutdown heat exchanger during shutdown cooling. There are two LPSI pumps provided per plant. The likelihood of losing two pumps simultaneously by this mode of failure is remote and subsequent restart of a pump after a failure to start has been successful. However, since the potential of this type of failure has been identified, reliability of the ECCS and SDCS can be affected.

Corrective Action When the PVNGS investigation is completed, corrective action will be proposed for the WNP-3 LPSI pumps.

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