ML19339A311

LER 80-030/03L-0:on 800929,during Two Rod Lock Functional Test on Rod 38-35,position Switch & Rod Block Found Inoperable.Caused by Stuck Position Indicating Switch.Switch Replaced by Changing Control Rod Position Info Probe

ML19339A311
Person / Time
Site:	Vermont Yankee
Issue date:	10/29/1980
From:	Murphy W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19339A308	List: ML19339A307 ML19339A311
References
LER-80-030-03L, LER-80-30-3L, NUDOCS 8011030567
Download: ML19339A311 (1)

Text

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LICENSEE EVENT REPORT LER 80-30/3L O -

CO~1co< <eCx i 1

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,P<ea.E P ,~1 eR 1,P a<t REee,RE. .NPeR Ar.eN, lo li 8l l9 V l YLICENSEE 7

l V ICODE T l s l 1 l@l 14 15 010 l - l 0 l 0 l 0 l 0 l 0 l- l010 LICENSE NUMBER 25 l@l26 4LICENSE Il l1 IlTYPE 11J0l@l$7 CATl Sa l@

CON'T lolil 3o[nc l L l@l 0 ] 5 l 0 l 010 l 2 l 7 Il @l 01912 l9 l g ln @l1 i0121918 l080l@ 74 75 7 8 60 61 DOCK ET NUMSER 68 69 EVENT DATE REPORT DATE EVENT DESCRIPTION AND PROBAB<E CONSEQUENCES h Ioi2l l While performing a Two Rod Interlock Functional Test on rod 38-35, the position switch l Io l3 l l and rod block asacciated with the "one control rod withdrawal permit circuit" was 1

[ol4l lfound to be inoperable. T. S. 3.12. A.1 requires the control rod block interlock to bel lo lsl l operable while in Che Refuel Mode and perform'ing core alterations. Control rod 38-35 I lo ls l lwas returned to position 00 and electrically disarmed. There were no potential l l o l 7 l l Consequences to the health and safety of the public. A similar event was reported l l o 18 I I as RO 76-18 I 7 8 9 90 DE CODE SUSC E CorONENT CODE SU8 COD'E SU E lo191 7 8 l Il E l@ W@ lE l@ l Il Nl Sl Tl Rl Ulh l S l@ l z l@

9 10 11 12 13 18 19 20

._ SEQUENTIAL OCCURRENCE REPORT REVISION LE R 'Ro EVENT YE AR REPORT NO. CODE TYPE NO.

@ REP R l 8l 0l l_l [0 l3 l0 l l/] l0l3l lLl l-l l0l 21 22 23 24 26 27 28 29 30 31 32 K N AC ON ON PL T ME HOURS S8 IT FOR 8. S PPLI MANUFAC RER IAl@(Z_l@ l35Z l@ (Z_j@ l0101010l lHl@ l42 NI@ lN l@ lG l0 18 l047l@

JJ 34 36 37 40 41 43 44 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS 27 l i l o I l An investigation has shown that the position indicatine switch on rod 38-35 at the  !

Ii Ii l [ Full-in interlock position was stuck and remained stuck followine rod withdrawl I

,,,,,lto notch position 02. This provided a false "All Rods In" signal to the Reactor I i,13l l Manual Control System. The defective switch was replaced by replacing control rod l g l 38-35 Position Information Probe. I 7 8 9 80

$A  % PotVER oTHER STATUS 015 O Y OtSCOVERY DESCRIPTION I1 15 l l H l@ 10 l0 l0 lhl NA I l Bl@l Operator observation during funct, test l A TIVITY CO TENT RELEASEo oF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE lil6l 7 8 9 h 10

@l 11 NA 44 l l 45 NA 80 I

PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION li l 7't 'l 010101@l z l@l

NA l l PERSoNNE L ima,ES NUMBER oESCRPfio~@

ITTil 8I 9O I O I O11l@l12 NA l 7 80 Loss OF CR OAMAGE TO FACILITY TYPE DESCRIPTION l i l 91 1 z i@l10 NA I 8 9 80 11080 IN 7

NRC USE ONLY ISSU E DE CRIPTION @

l2lal 7 g 9 hl to NA l 63 69 lll1l!ll!IIllI 80 3 NAME OF PREPARER PHONE: l