05000277/LER-1979-045, Forwards LER 79-045/03L-0

Forwards LER 79-045/03L-0

ML19254E536
Person / Time
Site:	Peach Bottom
Issue date:	10/24/1979
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19254E537	List: 05000277/LER-1979-045, Forwards LER 79-045/03L-0 05000277/LER-1979-045-03, /03L-0:on 790924,E-2 Diesel Tripped,Causing Half Scram & Half Isolation.Caused by Erroneous Shutdown of Emergency Svc Water Sys & Subsequent Rise in Lube Oil Temp in Generator.Control Switch Tagged
References
NUDOCS 7911010443
Download: ML19254E536 (3)

LER-1979-045, Forwards LER 79-045/03L-0

Event date:
Report date:
2771979045R00 - NRC Website

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PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET F'.O. BOX 86 99 PHILADELPHI A. PA.19101 (21510414000 October 24, 1979 Mr. Boyce H.

Grier, Director

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Office of Inspection and Enforcement Region I United States Nuclear Regulatory Commission 631 Park Avenue King of Prussia Pennsylvania 19406

Dear Mr. Grier:

SUBJECT L i c e n s_e c _Ev e n,t. Re p o r t Narrative D e s c r i p_t_i o n The following occurrence was reported to Mr. Greenman Region I,

Office of Inspection and Enforcement on September 25, 1979

Reference:

Docket Number 50-277 Report No.

LER 2-79-45/1T-0 Report Date' October 24, 1979 Occurrence Date.

September 24, 1979 Facility Peach Bottom Atomic Power Station R.D.

1, Delta, PA 17314 Technic _al Specification Reference Technical Specification 3 9.B.4 states that "From and after the date that one of the diesel generators or associated emergency buses and either the emergency or startup power source are made or found to be inoperable for any reason, continued reactor operation is permissible in accordance with Specification 3.5.F provided the other off-site source. startup ' transformer and emergency transformer are availabic and capable of automatically supplying power to the 4 KV emergency buses and the AEC is notified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the occurrence and the plans for restoration of the inoperable components".

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'P43 7911010 1

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Mr.

",o y c e II. Crier Page 2 October 24, 1979 LER 2-79-45/IT-0 Description of the Event:

Prior to the occurrence. Unit 3 was shutdown for a refueling outage and Unit 2 was operating at approximately 100 % p owe r.

The Unit 2 startup source was out of service for relay calibration.

During the period the E-2 diesel was running and supplying one of the emergency buses as a redu". dant source to ensure plant reliability.

Approximately one half h ou r prior to the E-2 diesel trip, the E-3 diesel was started and loaded for a test run.

At 4:46 PM while removing the E-3 diesel from service the operator shutdown the emergency service water system, causing a high lube oil temperature trip on the E-2 diesel at 4:55 PM.

Consequen.ce_s of Event:

The E-2 diesel trip restLted in reactor operation with one diesel and one startup source sut of service.

The trip also caused a half scram and half isolation on Unit 2.

The E-22 bus was immediately re-energized from the remaining off-site power bus-At approximately 5 05 PM the diesel trip was reset and the diesel was restarted.

Because the event was a p e r :ai s s i b l e degraded condition of operation the consequences are considered ninimal.

Cause o f_ E v_e n t '.

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On diesel generator (D/C) starts the Emergency Cooling Water (ECW) pump and both Energency Service Uater (ESW) pumps,1f not

<n a n u a l l y started, start automatically.

The ECW pump automatically shuts down after a time delay when adequate ESW discharge pressure is sensed.

This event was caused by two operating errors.

After the E<

3 diesel was started for test purposes, the

'B' ESW pump was shut down because one pump provides adequate cooling water.

The first error occurred at 4:46 PM when the operator shut down the E-3 D/G and erroneously shut down the ESW pump, failing to recognize that the E-2 D/G was still running.

At 4:54 PM the E-2 D/G trouble alarm annunciated and at 4:55 PM the E-2 D/G tripped on high lube oil temperature caused by lack of cooling water.

The second error resulted in the ECW pump, which can act as a backup to the ESW pump, being iwperable because the control switch was in the

" Pull to Lock" position.

Corrective A c_t i o n :

An operator was immediately dispatched to the E-2 D/G who reset the automatic trip.

The problem was disgnosed and the D/G was restarted within 10 ninutes after che trio.

Within 30 minutes after the trip the E-2 D/G was again supplying power to the E-22 bus.

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Mr. 'syce H.

Grier Page 3 October 24, 1979 LER 2-79-45/1T-0 An information tag has been placed on the control switch for the ECW pump which instructs the operators not to place the switch in the " Pull to Lock" position when performing diesel generator ST's.

The normal practice of not placing controls in " Pull to Lock" mode has been enphasized with operators at shift meetings.

Yours truly,

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<Y ' [g - r c,

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M.

J.

Cooney Superintendent Generation Division-Nuclear Attachment cc:

Director, NRC Office cf Inspection and Enforcement Mr. Norman M.

Haller, NRC - Office of Management &

Program Analysis 1281

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