ML18024A883

LER 79-015/03L-0 on 790607:HPCI Tripped on Mechanical Overspeed.Caused by Damaged Ball & Tappet Assembly Due to Improper Setting of Trip Weight.Ball & Tappet Assembly Replaced & Trip Weight Properly Set

ML18024A883
Person / Time
Site:	Browns Ferry
Issue date:	07/05/1979
From:	TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML18024A882	List: ML18024A881 ML18024A883
References
LER-79-015-03L, LER-79-15-3L, NUDOCS 7907100482
Download: ML18024A883 (4)

Text

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LICENSEE EVENT REPORT CONTROL BLOCK: IPLEASE PRINT OR TYPE ALL REQUIRED INFORhlATION)

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EVENT DESCRIPTION AND PROBABLE CONSEQUENCES QIO DOCKET iNI'V.BER

' i8 69 EVERIT DATE REPORT DATE

'0 83 While performing Sl 4.5.E during normal operation, the HPCX tripped several times on mechanical overspeed. The mechanical overspeed mechanism was re'oved and inspected.

~04 The ball and tappet asse bly was found to have been damaged. This <<as not'in accord-ance with Technical Specification 3.5.E. There were no significant resultirg occur-

~06 rences. There were ro previous events of this nature. There was no hazard to the health or safety of the public.

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~z SEOUEslTIAL OCCURRE'sCE REPORT PEV IS I QN 21 22 23 24 26 27 28 30 3'I 32 ATTACHU=NT hPRQ-Z PRIUE Corso. CosLIPC" i Et4T ACTIQ,sI TAKE's 33 FUTURE ACTION LISLJS L'JS LJS 34 EFFECT ON PLANT 35 SHU i DO's'ri4 METHOD 36 L'uBJ 37 HOURS ~22 40 SUBsSITTED LJS EJS LJS 41 FORSI 5UB. 5 'PPLIER ZIANU A+.URER 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIOtss Q21 0 Inspection of the overspeed trip mechanism revealed the trip weight had bee- improper-ly set causing damage to the ball and tappet assembly. Ball and ta net ass blv --as 2

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~24 R4 OTHER STATUS Q trETHQQ oF DISCOVERY DISCOVERY DESCRIPTION Q32 Precautionary Inspection

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Form BF-17 BF 15.2 6/09/7S LZR SUPPLE~KNTAL INFORMATION BFRO 260 / 7>1> Technical Specification Involved Reported Under Technical Specification 6 7 2.b.2 Date- o. Occurrence ~ / Time of Occurrence Og0o Unit 2 Identification and Descriation of Occurrence:

During unstable operation of b7CI the FPCI turbine tripped on mechanical overspeed several times. As a precautionary measure, the overspeed mechanism was removed and inspected. Ball and tappet assembly ~ms found to have been damaged.

Conditions Prior to Occurrence:

Unit was in normal operation at 74 percent power.

Action specified in the Technical Specification Surveillance Requi"ements me due to inooerable eauioment. De crioe.

EPCI was tagged out for service; RCIC, ADS, CSS, RHR were proven operable.

A arent Cause of Occurrence:

Hechanical overspeed trip weight was improperly set.

Analysis of Occurrence:

There was no damage to plant equipment, no injury to personnel, no danger to health or safety of the public, no reduction in power generation.

Corrective Action:

Ball and tappet assembly was replaced, trip weight properly set, and overspeed tests run to ensure proper operation.

Failure Data:

None Tennessee Valley Authority - Brov:ns Ferry Nuclear Plant

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