ML20040B194

Updated 81-028/03X-1:on 811017,field Breaker Failed to Open, Effectively Disabling Rrmg Set Recirculation Pump Trip Instrumentation.Caused by Binding of Operating Mechanism.New Breaker Installed

ML20040B194
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	12/30/1981
From:	Murphy W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20040B188	List: ML20040B187 ML20040B194
References
LER-81-028-03X, LER-81-28-3X, NUDOCS 8201250258
Download: ML20040B194 (1)

Text

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I RRC FORM 366 U. S. RUCLEAR REGULATORV COMMISSION (7 77) '

UPDATE REPORT - Previous Report Date 11/11/81 ,

l LICENSEE EVENT REPORT LER 81-28/3X (Rev. 1) l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATIONI lh CONTROL BLOCK: l l l l l l I d

) l0 l t8 l9 l Vl UCENSEE 7

Tl Vl COOE Yl Sl 1l@l 010 l - l 0 uCENSE 4 15 l 0 l 0NUMSER l 0 l 0 l -l 0 l 250 l@l 26 4 uCENSE l 1l llTYPE 1l 1l@l JG $7 UAT $8 l l@ L CON'T lOlil l',"c' l L }@l 0 l 5 l 0 l 0 l 0 l 2 l 7 l 1 @l l l 0 l l l 7 l 8 l l }@l1 l 2 l 3 l 0 l 8 l180l@ ,

7 8 60 61 DOCK ET NUMBER 6d 69 EVENT DATE 74 75 REPORT DATE EVENT DESCRIPTION AND PROBA8LE CONSEQUENCES h Io12l lDuring routine shutdown operations, when B RRMG set was shut down, the field breaker i  !

[ o 131 l failed to open. This ef fecti"ely disabled the recirc pump trip instrumentation for l l l o 14 I lB RRMG se t . T. S. Section 3.2.I requires this instrumentation to be operable durinn l l l

l o i s l Ipower operation. There were no significant occurrences as a result of this event, I l l

1016 I h1or were there any adverse effects to public health or safety. A previous similar I l 0 l 7 ] [ occurrence was reported as LER 81-10/3L. I 10181I l 7 8 9 80 SYSTEu CAUSE CAusE COMP. VA LV E ,

CODE CODE SUSCODE COMPONENT CODE SU8 CODE SUSCODE l0l9l 7 6 lI lB lh Wh Wh Ic lK lT lB lR lK lh l A lh l7. lh 9 10 11 12 13 Id 19 2U r

_ SEQUE N TI A L OCCURRENCE REPORT R EVISION I LER RO EVENT YE AR REPOHT NO. COCE TYPE NO.

a O'7 .&Tr 1811l l-l I 01 21 al I/I 10 13 I lx I l-l 111 4

_2' 22 23 24 26 27 28 29 Ju 31 32 ,

ACTION FUTURE EFFECT SHUTOOWN ATT ACHV ENT NP R O-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT VETHOO , HOURS 4 $US Mt TTE D PORMdV8. SUPPU E R MANUPACTURER Icl@lzl@ LIJ@ Izl@ lo 1010101 IN I@ INI@ b'l@ 1 c1018101@

JJ 34 JS 36 3' 40 41 42 4J 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS

[TTF1 Irhe cause of occurrence was binding of the operating mechanism. A stud which oper- i ,

i ji l i ; E'_es a shorting disc on the center contact was found to be too long, causine over- 1 i1 ;7i i stress of the crossbar assembly when locking the breaker into its housinn. A new I  ;

l .

t l31l breaker, with the stud trimmed, was installed and successfully tested. The breaker l I1 I A 1 1 In a CE Mode l AKF-2-2 5. l -

7 8 9 80 I

's'T'4ES  % POWER OTHER STATUS OSO Rv DISCON ERY DESCRIPTION

, y lDlh l0l0l0]@l NA l y@l Bkr failed to func when RRMG shutdown l f A TIVITY CONTENT i RETE ASEO OPREtE.SE LOCATION OF RELEASE I i Io 8l 9L7.J @ l10z I@l 7 ft Av00~NATOP .CTmTv 44 l

45

@l No 80 I  !

I PERSONNEL f *POSURES {

NUYBER TvPf DE SCRIPTION liI7llO!0l0l@ d hl 7 8 9 11 12 13 NA NA 80 l l PERSONNE t. INJuniES ,

NUMBER DESCRiPfiON +

W l 309 l O l 0l@l

• 11 12 NA 80 l

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toss rv E cF OEsCRca 04uacE PfiON TO PaciuTv ( O3> g20125025g a1123005000271 '

NA pDR ADOCK pDR i 9 4 9 W @l10 s l

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PU B L IC4 TV l

NRC USE ONLY

• l IssufD DESCRIPTION , l 121011Nlhl 7 4 3 to NA l 68 69

[l l l !Il I I I I I II 80 5 I

NAME OF PREPARER IJa rren P. Murphy PHONE.

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