ML19282B808

LER 79-025/03L-0 on 790213:Ohio Edison Relay Testing Actuated Transfer Trip Receiving Relay & Tripped Switchyard Breakers.Caused by Failure of Util to Notify Toledo Edison Before Performing Relay Testing

ML19282B808
Person / Time
Site:	Davis Besse
Issue date:	03/12/1979
From:	Dibert D TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19282B807	List: ML19282B806 ML19282B808
References
LER-79-025-03L, LER-79-25-3L, NUDOCS 7903160210
Download: ML19282B808 (3)

Text

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LICENCEE EVENT REPORT s

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(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 7 0 1 8 9 l0 HlDlBlSl1[gl0 @l-l0j0lNlPlF -l0 3l@l4 1l1l1 1l@l LICENSEE CODE 14 15 LICENSE NUvdER 25 26 LICEB .E T Y FE JO l

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7 8 60 61 DOCKET NU'/8E R 68 69 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h l o l 2 l l At 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br /> on 2/13/79, relay testing at the Beaver Substation of Ohio Edison caused) o 3 l the Davie-Besse Transfer Trip Receiving Relay to actuate. This tripped switchyard l l o l 4 l l breakers 34562 and 34564 and 13.8 KV Breaker HX02B isolating Startup Transf ormer 02 l 10lsl l from "B" Bus. The reactor was tripped by the Reactor Protection System (RPS). Duringl 0 6 l the event, the unit entered the Action Statements of T.S. 3.8.1.1 and 3.4.1. Diesel l 0 7 Generator 02 came on to power Essential Bus D1 and 01 Transf ormer was supplying the o g other 13.8 KV Bus (A Bus) . (NP-33-79-29) l 7 8 9 80 SYSTEM CAUSE CAUSE COVP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE l0l91 7 8 l El Al@ W@ l z l@ l Cl Kl Tl Bl Kl Rl@ lA l@ l Zl@

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_ SE OUENTI A L OCCURRENCE REPORT REVISION LE R RO EVENT YE AR REPORT NO. CODE TYPE N O.

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44 47 CAIJSE DESCRIPTION AND CORRECTIVE ACTIONS i o l The cause of the event was both the f ailure of the Ohio Edison personnel to notify l i i lTECo personnel of the relay testing and the abnormal electrical lineun. "B" Bus is I i 7 l temporarily being powered by Startuo Transformer 02 until desien chances are made to l i 3 l the Aux Transformer to conform to FSAR commitments. TECo re-enchasized the prev _ious__

e li l4 l l request that Ohio Edison Company contact TECo before doine any siniinr testine. l 7 8 9 80 STA S  % POWER OTHER STATUS ISCO RY DISCOVERY DESCRIPTION 5

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1 7 l0 0l 0l l Zl l NA l PERSONNC INJURIES NUYRER DESCRtPTION (

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7 8 9 10 05 69 8J. 5 VR 79-033 NAME OF PREPARER d

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• TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-33-79-29_

DATE OF EVENT: February 13, 1979 FACILITY: Davis-Fesse Unit 1 IDENTIFICATION OF OCCURRENCE:

Relay testing on the Beaver Substation of the Ohio Edison line causing a unit trip on February 13, 1979.

The unit was in Mode 1, with Power (MRT) = 2446, Conditions Prior to Occurrence:

and Load (Gross MWE) = 776.

A reactor / turbine trip occurred at 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br /> on Febru-Description of Occurrence: The ary 13, 1979. The trip followed a loss of two Reactor Coolant Fumps (RCP).

event was initiated by relay testing at the Beaver Substation of the Ohio Edison line which caused our Transfer / Trip Receiving Relay in the Ohio Ed1Jon line panel of Bus lockout that tripped switchyard the Relay House to actuate. This gave a "K" "B" Bus breakers 34562 and 34564, and also isolated Startup Transformer 02 from which it was feeding.

This placed the unit in the Action StatementWith of Technical Specification 3.8.1.l(a)(3)

"B" Bus de-energized, RC? 1-2 and as there was only one operable 13.8 KV Bus.

RCP 2-1 lost power and tripped. With only one RCP running in each loop and power at approximately 87.5% FP, the unit was placed in the Action Statement of Technical Speci-fication 3.4.1, but was immediately remosed from the Action Statement when at 11:30:49 hours, the reactor tripped from a Reactor Protection System (RPS) "Hi Flux /

Number of Pumps" Limit.

Designation of Apparent Cause of Occurrence: The cause of the event was the Ohio .

Bus and isolation Edison Company relay testing which resultedBus in the was lockout of "K" temporarily being powered by of Startup Transf ormer 02 f rom "B" Bus. "B" (FCR)78-486) because design Startup Transf ormer 02 (per Facility Change Request changes (FCR 78-454) must be made to the Auxiliary Transformer to make it meet FSAR Section 8.2.1 commitments.

There was no danger to the health and safety of the public Analysis of Occurrence:

or to unit personnel.

Diesel Generator 2 came on to power Essential Bus "Dl" and The reactor Startup Transf ormer 01 was supplying the other 13.3 KV Bus (A Bus) .

was tripped by the RPS.

Corrective Action: By 1155 hours0.0134 days <br />0.321 hours <br />0.00191 weeks <br />4.394775e-4 months <br />, breakers 34560, 34561, 34562 1145and 34564 hours, were which removed closed. "B" Bus was lined up to Startup Transformer 01 at of Technical Sepcification 3.8.1.1(a)(3), and at the unit from the Action Statement At 1240 hours0.0144 days <br />0.344 hours <br />0.00205 weeks <br />4.7182e-4 months <br />, "Dl" Bus was 1220 hours0.0141 days <br />0.339 hours <br />0.00202 weeks <br />4.6421e-4 months <br /> was switched back to Startup Transfcrmer 02.

LER #79-025 .

4

I a

TOLEDO EDISON COMPANY (

DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE PAGE 2 SUPPLEMENTAL INFORMATION FOR LER NP-33-79-29 transferred to "AC" Transformer and then at 1245 hours0.0144 days <br />0.346 hours <br />0.00206 weeks <br />4.737225e-4 months <br /> Lack to "BD" Transfonner.

RCP 1-2 and RCP 2-1 were restarted at 1241 hours0.0144 days <br />0.345 hours <br />0.00205 weeks <br />4.722005e-4 months <br /> and 1244 hours0.0144 days <br />0.346 hours <br />0.00206 weeks <br />4.73342e-4 months <br />, respectively.

Toledo Edison has re-emphasized a previous request that Ohio Edison personnel contact Toledo Edison personnel before doing any testing which may cause a similar event. to FCR 78-454 had been previously written to revise the present design of the plant meet FSAR co=nitments (Section S.2.1) so house power can be supplied by the auxiliary -

transformer. Presently, both 13.8 KV electrical buses are supplied from "01" trans-former which has a fast transfer capability to provide a uninterruptable source of power.

Failure Data: There has been one previously reported similar occurrence of a fault on the Ohio Edison line de-energizing an essential bus (see Licensee Event Repcrt NP-33-77-106).

LER #79-025

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