ML19259B798

LER 78-113/03L-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

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: ML19259B795 ML19259B798
References
LER-78-113-03L, LER-78-113-3L, NP-33-78-135, NUDOCS 7903230170
Download: ML19259B798 (3)

Text

U.S. NUCLE AR REGULATORY COMMISSION I

NRC FORM 366 i,

(7 77)

LICENSEE EVENT REPORT (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

CONTROL BLOCK: l 1

l l l l 6

lh l l@ [

R Tll0lHlDlBlS 1 8 9 LICENSEE CODE 1 14 l@l 15 0 l 0 l - l 0 l 0 LICENSE NUMdEH l N l P l F 25 l-26 l 0 l LICENSE3 }@l TYPE 40 4 $7 l1 l1 CAT $8 l 1 l 1 l@l CON'T 17 l 7 l880l@

0 1 SOuRC l L j@l 0 ] 5 l 0 l- 10 l 3 l 4 \ 6 6d

@l69 11111 EVENT l 0 DATE l 7 l 8 74l@l1 75 12 l 0 REPORT DATE 1 8 60 6f DOCKET NUMBER EVENT DESCRIPTION AND PROB ABLE CONSEQUENCES h o 2 l On November 10, 1978 and on November 17, 1978, fluctuati.ig signals from the absolute l Abso- l go g3; l position indicator for Control Rod 4 of Group 3 caused asymmetric rod alarms.

each of these times, j o 4 l lute position indication for this rod was declared inoperable at There in the Action Statement of Technical Specification 3.1.3.3. [

1oIsj l placing the unit Relative j o 6 I was no danger to the health and safety of the public or to unit personnel.

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

CODE El Ll El Cl Cl Nl@ l Z l@20g @

o 3 12 13 18 19 REVISfoN 9 10 11 REPORT 7 8 SEQUENTIAL OCCURRENCE NO.

CODE TYPE REPORT NO.

@ agea; LE R tRO

_EVEf f T YE AR I 71 81 I --I I li ll 31 1/1 27 10131 28 29 S

30 l-l 31 111 32 23 24 26

_ 21 22 B. St PLIE MANUFACT RER HOURS 22 SB T D FO F KE A D ON PL T TET l43Al@ lBl3l6l5 g l J@ LzJ@ l 0 1 01 S I I L_l@ L_J@ 44 47 LS@l 33 34Cl@ 35 J6 3/ 40 41 42 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h i Oj

! Af ter access to containment was permitted, investigation of the absolute position in-l l Ji j l dication for Control Rod 4 of Group 3 resumed by testing the individual component.s of j

1 l: l2] I the PI string. The cause of the occurrence has been determined to be an intermittent The position indicator l j il3l l f ailure of a component within the position indicator tube.

1 iil4l l tube was replaced. 80 1 8 9 DISCOVERY DESCR PTION OTHER STATUS IS O RY STA S  % POWER l

[Tff] [ Ej@ l A l@l Fluctuating Signals 0l 4 l 9 l@l NA ACTivlTY CO TENT LOCATION OF RELE ASE AMOUNT OF ACTivtTY l nELE AsEo OF RELE ASE l 8 l6 l d @ 10l Zjgl NA l l NA 80 44 45 7 8 9 , 11 PERSONNEL E XPOSUHES TYPF UESCRIPTION l NA i i l EUYDdH l l O@L J@l l

PERSONNE INJURIES N OESCH:PTION l NA 80 i a 10 lUA'9EH010 l@l T2 7 8 9 (I LOSS OF On DAMAGE TO F Actu TY TYPE DE SCHIP TION l NA 7

i 9 b @l il 9 10 NRC USE ONLY 80 PUB (lClTY 790323cm ,,,,,,,,,,,,l}

gsggr w' ~ ,

69 69 W-MGM, M. E 80 3 F 11 9 to pgggg g DVR 78-171 & , , y ,n , ,

Susan A. Kovacit _