ML20078Q920
| 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 P.O. Box 968 3000 GeorgeWashingtonWay Richland, Washington 9hkS gp09 372-5000 W
D{ Q. 86 November 4, 1983 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
p 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,.
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- 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-turer-for; appropriate repairs. 'The units were completely disassembled, correc-r
- tions made, reassembled and tested in the manufacturer's shop. The units are
..L reinstalled at WNP-2 and are being tested preparatory to performing loss of off-
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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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