ML20078Q920

Final Deficiency Rept,Condition 277 Re Emergency Diesel Generators 1A & 1B W/High Out of Spec Vibration Readings & Bearing Failure.Initially Reported on 830802.Generators Returned to Manufacturer

ML20078Q920
Person / Time
Site:	Columbia
Issue date:	11/04/1983
From:	Carlisle C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50.55E, 276, GO2-83-1019, NUDOCS 8311140218
Download: ML20078Q920 (2)

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. Washington Public Power Supply System W gp09 372-5000 P.O. Box 968 3000 GeorgeWashingtonWay Richland, Washington 9hkS November 4, 1983 D{ Q. 86 G02-83-1019

. , SggfgMy Mr. J. B. Martin Regional Administrator U.S. Nuclear Regulatory Commission Region V .-

l',50 Maria Lane, Suite 210 Walnut Creek, California 94596

Subject:

10CFR50.55(a) CONDITION #276 DGlA & DGlB BEARING FAILURE

References:

1. Telecon QA2-83-184, dated August 2, 1983, R.T. Johnson to D. Haist, same subject.

2. Letter G02-83-742, dated August 18, 1983, C.S. Carlisle to J.B. Martin, same subject.

3. Telecon QA2-83-214, dated September 30, 1983, W.W. Willier to B. Dodds, same subject.

In accordance with the provisions of 10CFR50.55(e), your office was informed by the above ' references of the subject condition. Attachment I provides the Project's revised final report on the Condition #276.

If you have any questions, contact Roger Johnson, WNP-2 Project QA Manager, at (509) 377-2501, extension 2712.

Program Director, WNP-2 JGT/kd

Attachment:

As stated cc: W.S. Chin, BPA N.D. Lewis, EFSEC A. Toth, NRC Resident Inspector Document Control Desk, NRC 8311140218 831104 PDR ADOCK 05000397 S PDR n 7/97

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. WASHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT N0.-2

-DOCKET ~NO. 50-397

. LICENSE'NO.-CPPR-93 10CFR50.55(e) CONDITION #276-DGlA AND'lB BEARING FAILURE REVISED FINAL' REPORT Description of-Deficiency Emergency Diesel Generator lA:h'ad, high, out-of specification vibration readings

- accompanied by rumbling and sparks being emitted from the south end generator-

-bearing. Disassembly of generator _per SLT-547.1-10 determined that a_ shim

'(spacer) required to maintain clearance at the thrust bearing was missing The

. unit was returned to the factory.and repaired. While these repairs were being performed Unit 1B was also corrected on-site.

On September 28,1983, Unit'1B experienced the failure of an insulated bearing

- seat thus removing the unit from service.

Safety Implication The existence.in redundant safety-related equipment (DG-GEN-1A and 1B) of defects

'which could render.them simultaneously-inoperable, could impair event mitigation,.

F - and_ safe shutdown under a design base. accident coincident with loss of off-site power. The condition _is considered to-be reportable under 10CFR50.55(e) criteria.

1 Cause of the Deficiency-i

. Both generators failed for'different reasons. Diesel generator'lA failed because

.of excessive end-clearance caused by a missing shim,-resulting in a breakdown of bearing insulation.; This same condition did not exist on Diesel Generator

- 1B._ Unit.1B failed because it had been improperly assembled at the Vendor's-plant following a line bearing failure. . The reassembly placed an incorrect shim between the shaft-and the insulation. The manufacturer attempted to correct this_ condition'by applying-a .100 inch thrust on the bearing. While generator

.. lB was being. inspected by the Supply System the thrust was removed, thus allowing

,  ; the shim to move, thus damaging the insulation. Both 1A and-1B generator bearing-ends have been reworked, therefore, a similar problem does not exist in the lA

generator.

-Actions to Prevent-Recurrence

.Startup Testing remains the most currently _ effective method of identifying opera-tional equipment defects since the equipment'has been manufactured and delivered for a considerable period of time.

~ The quality'of vendor work was and should continue to be covered by approved'

QA programs-for equipment procured _in the future.

- Corrective Action DG-GEN-1A and.lB were both removed from the plant and returned to the manufac-r turer-for; appropriate repairs. 'The units were completely disassembled, correc-

- tions made, reassembled and tested in the manufacturer's shop. The units are reinstalled at WNP-2 and are being tested preparatory to performing loss of off-

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..L site' power tests requiring full utilization of this equipment. Removal and re-placement of the equipment is documented in SLT-S47.1-10 and SLT-547.1-ll.

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