05000302/LER-1979-010-03, /03L-0 on 790125:during Routine Operations,Air Handling Fan Failed to Start.Caused by Faulty Overcurrent Timing Relay

/03L-0 on 790125:during Routine Operations,Air Handling Fan Failed to Start.Caused by Faulty Overcurrent Timing Relay

ML19274D851
Person / Time
Site:	Crystal River
Issue date:	02/15/1979
From:	Cooper J FLORIDA POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19274D849	List: 05000302/LER-1979-010, Forwards LER 79-010/03L-0 05000302/LER-1979-010-03, /03L-0 on 790125:during Routine Operations,Air Handling Fan Failed to Start.Caused by Faulty Overcurrent Timing Relay
References
LER-79-010-03L, LER-79-10-3L, NUDOCS 7902260457
Download: ML19274D851 (2)

LER-1979-010, /03L-0 on 790125:during Routine Operations,Air Handling Fan Failed to Start.Caused by Faulty Overcurrent Timing Relay

Event date:
Report date:
3021979010R03 - NRC Website

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75 mg.Omigarg 30 EVEN.' OESCRIPTION AND PROSA8LE CONSEcutNCE3 h 1 At 1620, during routine operations, air handling fan (AHF-14C) failed to i

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'rhis created an event contrary to Technical Specification 3. 7.8.1.

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SUPPLEMENIARY INFORMATION Report No. 50-302/79 - 010/03L-0 Facility: Crystal River Unit #3 Report Date: 15 February 1979 Occurrence Date:

25 January 1979 Identification of Occurrence: One pair of Auxiliary Building exhaust fans operable contrary to Technical Specification 3.7.8.1.

Conditions Prior to Occurrence: Mode 1 power operation (1007.)

Description of Occurrence: At 1620, air handling fan (AHF-14C) failed to start.

Subsequent investigation by an electrician revealed that the overcurrent timing relay had " hung up".

The relay was inspected, reset and the fan returned tc operable status at 1800 on 26 January 1979.

Designation of Apparent Cause: The probable cause of the relay failure is attributed to foreign particles restricting the timing relay disc.

Analysis of Occurrence: There was no hczard to the plant or general public as redundant fans AHF-14 B & D were operable.

Corrective Action

Further investigation by the relay maintenance section will follow. A preventive maintenance program for switchgear relays is being implemented to act on a two year cycle.

Failure Data: Eight previous occurrences reported. First occurrence of this type for AHF-14C.