ML20041C165

LER 82-004/01T-0:on 820207,during Routine 115-KV Breaker Exercising,Ground Directional Relay Caused Opening of Breaker Alternate 115-KV.Caused by Momentary Loss Offsite Power.Power Restored After Closing Oswego-NMP1 Breaker

ML20041C165
Person / Time
Site:	Nine Mile Point
Issue date:	02/19/1982
From:	Patrou N NIAGARA MOHAWK POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20041C163	List: ML20041C162 ML20041C165
References
LER-82-004-01T, LER-82-4-1T, NUDOCS 8202260294
Download: ML20041C165 (2)

Text

' NRC FORM 366 U.S. NUCLEA3 REIULATIRY COMMISSION (7-77)

LICENSEE EVENT REPORT-

.CONTF@L BLOCK: l l

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(PLEASE PRINT CR TYPE ALL REIUIRED INFURMATION) l0 ltl 7 -8 9 lN lYLICENSEE lN lM CODE lP l 1 l@l0 l0 l- l0LICENSE 14 15 l0 l0NUMBER l0 l0 l- l 0l 0l@ 25 26 4 l LICENSE 1l ll 1l 1l@l57 CAT TYPE JO l

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[0RT, 60 L l@l0 l 5 l0 61 l0 l0 l2 l2 l068@l69 0l 2l DOCKET NUMBER 0l 7l8 l2 l@l 0l 2l1 EVENT DATE 74 75 REPORT l9DATE l 8l 280l@

EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h lo l2l l During steady state operation and routine 115 KV breaker exercising (South Oswego l gj l Substation), a ground directional relay caused the opening of a breaker on the l l0 l4 l l alternate 115 KV line (Lighthouse Hill Subctation). The coincident opening of these l o 3 l breakers resulted in the removal of all off-site power and placed the plant in a l l0 l6 l l limiting Condition for operation as per Tech. Specs. 3.6.3e(2). Concurrent with the l lo l7l l loss of off-site power, automatic start-up of both diesel generators occurred as l 1018l l designed, followed by the restoration of off-site power approximately @EE ATTACHED SHHET) 80 7 8 9 DE CODE S BC E COMPONENT CODE SU8C DE SU E 7

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_ SEQUENTIAL OCCUR RENCE REPORT REVISION LE R Ro EVENT YE A R R EPORT NO. CODE TYPE No.

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_ 21 22 23 24 26 27 28 29 K N 'ACT ON PL NT ET HOURS 22 SB IT FOR B. SUPPL MA F CTURER IB l@6@

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40 g g 41 lNlg 42 ltig 43 lNl1l2l2lg 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h g l The cause of the start of both diesel generators was the momentary loss of off-site l 3 i l power. Power was restored within approximately 10 seconds and diesel generator l

,,,7; l secured. The loss of the Lighthouse Hill line was later attributed to an open loop l

, 3 l which has been repaired. The removal from service, repair and return to service -

l i 4 l of this line is the subject of LER 82-05. l 7 8 9 80 ST S  % POWER OTH E R STATUS oIS O RY DISCOVERY DESCRIPTION NA Operational Event i s l El@ l 0l 9 l 9 l@l l lA[@l l ACTIVITY CO TENT RELEASED OF RELEASE AMOUNT OF ACTIVtTY LOCATION OF RELEASE NA NA l

( 1 1 6 l W @ l_ Zj g l l l 80 7 8 9 10 11 44 45 1 PERSONNEL EXPOSURES NUMBE R TYPE DESCRIPTION NA l 1 7 l 0 l 0 l 0 l@l Z l@l 80 PERSONNE L INJU IES NUMBER DESCRIPTION NA l 7

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• LOSS OF OR DAMAGE To FACILITY gh 8202260294 020219 TYPE DESCRIPTION U PDR ADOCK 00000220 Q W@l 7 8 9 10 NA S PDR 80 l

PUBLICITY NRC USE ONLY ISSU f D DESCRIPTION A

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NAME OF PREPARER PHONE:

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.LER 82-04 EVENT DESCRIPTION' AND PROBABLE CONSEQUENCES (Continued) 10 seconds after the loss occurred. This' restoration of off-site power came about due to the closing of the Oswego-NMP1 breaker.- Subsequently,.the diesel generators were secured. The safety concerns of this event were minimal since more than the required number of diesel generators came into operation, and because of the very short length of tirse (approx. . 10 seconds) th'at off-site

< power was removed.

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