ML19316A466

LER 78-004/01T-0:on 780301,1B Circuit Breaker Closed During Shift to High Speed.Caused by Improperly Adjusted Instantaneous Trip Setpoint.Breaker Reset & Setpoint Adjusted

ML19316A466
Person / Time
Site:	Oconee
Issue date:	03/15/1978
From:	Ken Wilson DUKE POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19316A461	List: ML19316A460 ML19316A464 ML19316A466
References
LER-78-004-01T, LER-78-4-1T, NUDOCS 7912110779
Download: ML19316A466 (2)

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Nac acau ses u. s. NUCLEA3 f;ECU1.ATORY CCMutssioM tr.rn LICENSEE EVENT REPORT EXHIBIT A ccNTmet stoce l l l I I I l (PLEAss ra:NT on fyrs ALL arousato inacauATiom

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7. 75 atPC.Toart so EVENT DESCalFTICN ANQ *RCB ASLE CON $EQUENCES l'o # 21 i After the performance of an in rument channel on-line test the ,

EI 1B RBCU circuit breaker closed as the unit was being shifted to high 9 Lo.1*.! I speed. This left two RCBU's out-of-service contrary to T.S.3.3.1 since ,

gi 1C was already out for repairs to a related valve. The breaker was ,

Al reset within 5 minutes restoring redundancv within the RBCU systems.  ;

gi Since both building spray systems were available and sufficient cooling ,

t o ta l I capacity uas available, public health and safety were not endangered. ,

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d'ggj",'0 g cAuss cescaiencN AND COAREC'nVE Ac*lCNS h gi The cause of the breaker closure was the failure of the instantaneous 1

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_ trio setooint to be properly adjusted. The breaker tripped when the i gi current surged as the unit went to high speed. Had it been properly 1

mI adiusted, the breaker would not have tripped. The breaker was reset  ; l wl i

and its setpoint was adjusted. ,

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• a * 'e l [g9g9g,,,,9,g Neue os ensp4nen K. R. Wilson (704.e) 373-8197 2119777

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Toa M t. FRA N u, 3*R P s WILES b- 703

'OCONEE NEC/OIE PRINCIEAL INSPECTOR r .

mKE POWER COMPANY l OCONEE_hYgLEAR STATION mzPomT wuxnem Ro -269 4 TIME /DATE OF INCIDENI 13F7 - Eli117 TIME /DATE OF DISCOVERY f.7.S~7 - 7/l17f UMTI(S) I _ UNIT STATUS AT TIME OF INCIDENT too % FP DESCKIPTION OF INCIDENT: FOL L Ot,a t h! 6 T~k m PEEfo 2MA *J C C CV 2 Mas s, EM c 'r C o o s.s a n, AHb 3'Pl0lAl2 toll 2cilic - WB I 5 o L A Ts O N Lo 6e c c HAMMEL S 5" $ 6 CAJ LsMe TarsT ;

"IB' R B C LA. PO tasG A SM. PP L V RAGAMEK TRIffEO IDN sL G

__SHI P rih & FR O M L -om T~o HI SPsED W s Toe ** 1 c 4 R 2Cs s.

o ss,.T BF K G Aus cai O s<,f 1"O Lfs ta - 2,4 8&s4 6 AEPAcdfD-HOW INCIDEh*I WAS DISCOVERED: O A> LOSS OF t f # d C t.4. P'o us E m tads e n Tt ow s s! C apTR o t R oam ta r< s t. a Se r PYs4 6 _

FR o m L e su 'ro Ms S fgED DTEDIATE CORRECTIVE ACTION: " l 8 '# RRCA P8WE4 844.89LN 8AEAKER uJ h 5 I M M aT DI MiE s.1 kES ET ; Masc a4 G **1 B

R Be t r. Ava r n. n e t a von L os > .staeO o paa.A n on or en 25 c on b o 'rs a ns . \

REPORTABLE FURSUANT TO TECiDsICAL SPECIFICATION 6.4, L I,A,(2) h 3.7.'f[h DATE REPORT DUE TO NRC/0IT. 3'/ IS/7 P' IIME/DATE TELECOPIED OK OIKERVISE TRANSMII' RED TO NRC/0IE doeo - 7 /2 /7 F PREPARED BY PHONE (803) 882-5363

n. D Aved ratwa -

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