05000259/LER-1980-001-01, /01T-0:on 800107,in Cold Shutdown While Performing Tests Per IE Bulletin 79-28,speed Control on Diesel Generator 3A Was Lost.Caused by Broken Coupling Which Connects Speed Pickup to Generator Shaft.Coupling Replaced

/01T-0:on 800107,in Cold Shutdown While Performing Tests Per IE Bulletin 79-28,speed Control on Diesel Generator 3A Was Lost.Caused by Broken Coupling Which Connects Speed Pickup to Generator Shaft.Coupling Replaced

ML19291C210
Person / Time
Site:	Browns Ferry
Issue date:	01/18/1980
From:	TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19291C208	List: 05000259/LER-1980-001-01, /01T-0:on 800107,in Cold Shutdown While Performing Tests Per IE Bulletin 79-28,speed Control on Diesel Generator 3A Was Lost.Caused by Broken Coupling Which Connects Speed Pickup to Generator Shaft.Coupling Replaced
References
LER-80-001-01T, LER-80-1-1T, NUDOCS 8001230140
Download: ML19291C210 (2)

LER-1980-001, /01T-0:on 800107,in Cold Shutdown While Performing Tests Per IE Bulletin 79-28,speed Control on Diesel Generator 3A Was Lost.Caused by Broken Coupling Which Connects Speed Pickup to Generator Shaft.Coupling Replaced

Event date:
Report date:
2591980001R01 - NRC Website

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00 61 DOCK E T NU'.aB E H 68 69 EVENT DATE 74 lb REPOR T DATE 83 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h l With unit 3 in cold shutdown while performin. tests in accordance with IE 79-23 speed l o

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, Tennessee Valley Authority Form BF-17

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Browns Ferry Nuclear Plant BF 15.2 1/10/79 LER SUPPLEMENTAL INFORMATION BFRO 259 /

801 Technical Specification Involved NA Reported Under Technical Specification 6.7.2.A.9 Date of Occurrence 1-7-80 Time of Qccurrence 11:00 p.m. Unit 3

Identification and Description of Occurrence:

Speed control on the 3A diesel generator was lost during the performance of 8TER 7902 per IE Bulletin 79-23.

Conditions Prior to Occurrence:

Unit I was in scheduled refueling outage.

Unit 2 was at reduced power at 840 MWe.

Unit 3 was in cold shutdown.

Action specified in the Technical Specification Surveillance Requirements met due to inoperable equipment. Describe.

N/A Apparent Cause of Occurrence: The elastomer spider coupling had deteriorated and failed causing metal to metal contact of the coupling halves. This caused the speed pick-up coupling half to fail. Apparently the material used in the spider is vulnerable to attack by the heat and oil present in the environment. The deterioration eventually caused the spider to fracture when subjected to the loading of the coupling half.

Analysis of Occurrence:

There was no danger to health or safety of the public.

Corrective Action

The spider coupling has replaced on units 1 and 2, and unit 3 diesel generators. The spider on 3C diesel generator was also found to be defective. No significant, deterioration was observed on other units. To preclude. recurrence, the couplings will be inspected annually.

Failure Data:

179) 342 NA

• Retention :

eriod - Lifetime; Responsibility - Administrative Supervisor

• Revision : W l