05000346/LER-1978-113-03, /03L-1 on 781110:fluctuating Signals from Absolute Position Indicator for Control Rod 4 of Group 3 Caused Asymmetric Rod Alarms.Caused by Intermittent Failure of Position Indicator Tube.Tube Replaced

/03L-1 on 781110:fluctuating Signals from Absolute Position Indicator for Control Rod 4 of Group 3 Caused Asymmetric Rod Alarms.Caused by Intermittent Failure of Position Indicator Tube.Tube Replaced

ML19259B798
Person / Time
Site:	Davis Besse
Issue date:	12/07/1978
From:	Kovach S TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19259B796	List: 05000346/LER-1978-113, Forwards LER 78-113/03L-1 05000346/LER-1978-113-03, /03L-1 on 781110:fluctuating Signals from Absolute Position Indicator for Control Rod 4 of Group 3 Caused Asymmetric Rod Alarms.Caused by Intermittent Failure of Position Indicator Tube.Tube Replaced
References
LER-78-113-03L, LER-78-113-3L, NP-33-78-135, NUDOCS 7903230170
Download: ML19259B798 (3)

LER-1978-113, /03L-1 on 781110:fluctuating Signals from Absolute Position Indicator for Control Rod 4 of Group 3 Caused Asymmetric Rod Alarms.Caused by Intermittent Failure of Position Indicator Tube.Tube Replaced

Event date:
Report date:
3461978113R03 - NRC Website

text

U.S. NUCLE AR REGULATORY COMMISSION I

NRC FORM 366 i,

(7 77)

LICENSEE EVENT REPORT CONTROL BLOCK: l l

l l

l lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 6 l

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25 26 LICENSE TYPE 40

$7 CAT $8 LICENSE NUMdEH 1

8 9 LICENSEE CODE 14 15 17 l 7 l8 l@

l L j@l 0 ] 5 l 0 l-10 l 3 l 4 \\ 6 @l 11111 l 0 l 7 l 8 l@l1 12 l 0 CON'T 6d 69 EVENT DATE 74 75 REPORT DATE 80 0

1 SOuRC 60 6f DOCKET NUMBER EVENT DESCRIPTION AND PROB ABLE CONSEQUENCES h 1

8 o 2 l On November 10, 1978 and on November 17, 1978, fluctuati.ig signals from the absolute l Abso-l position indicator for Control Rod 4 of Group 3 caused asymmetric rod alarms.

go g3; l each of these times, j lute position indication for this rod was declared inoperable at o

4 l

There

[

in the Action Statement of Technical Specification 3.1.3.3.

1oIsj l placing the unit Relative j I was no danger to the health and safety of the public or to unit personnel.

o 6 j

position indication, as well as zone reference indication for Rod 4, Group 3 was lo l7l l o a i perable.

(NP-33-78-135)

CoVP.

VALVE SYSTEM

CAUSE

CAUSE CODE CODE SU8 CODE COMPONENT CODE SUSCODE SUBCODE l1lFl@ { @ lAj@

El Ll El Cl Cl Nl@ l Z l@ g @

18 19 20 o 3 7

8 9

10 11 12 13 REVISfoN OCCURRENCE REPORT SEQUENTIAL CODE TYPE NO.

REPORT NO.

@ agea; I 71 81 I --I I li ll 31 1/1 10131 S

l-l 111

_EVEf f T YE AR LE R tRO

_ 21 22 23 24 26 27 28 29 30 31 32 KE A

D ON PL T

TET HOURS 22 SB T D FO F B.

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lBl3l6l5 g 33 34 35 J6 3/

40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h

! Af ter access to containment was permitted, investigation of the absolute position in-l i

Oj dication for Control Rod 4 of Group 3 resumed by testing the individual component.s of l Ji j l The cause of the occurrence has been determined to be an intermittent j

1 l: l2] I the PI string.

The position indicator l

f ailure of a component within the position indicator tube.

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iil4l l tube was replaced.

80 1

8 9 DISCOVERY DESCR PTION STA S

% POWER OTHER STATUS IS O RY l

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0l 4 l 9 l@l NA l

A l@l Fluctuating Signals ACTivlTY CO TENT LOCATION OF RELE ASE nELE AsEo OF RELE ASE AMOUNT OF ACTivtTY l

NA l

l NA l 8 l6 l d @ l Zjgl 80 44 45 7

8 9 10,

11 PERSONNEL E XPOSUHES TYPF UESCRIPTION l

l EUYDdH O@L J@l NA l

l l

i i PERSONNE INJURIES OESCH:PTION l

10 lUA'9EH010 l@l N

NA 80 i a 7

8 9 (I

T2 LOSS OF On DAMAGE TO F Actu TY l

TYPE DE SCHIP TION NA 80 b @l i 9 7

il 9 10 NRC USE ONLY

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PUB (lClTY 790323cm gsggr w' ~

80 3 69 69 W-MGM, M. E g

F 11 9 to Susan A. Kovacit y,n,,

pgggg DVR 78-171 &,