ML19263E207

LER 79-063/03L-0 on 790501:during Startup Operation,Rods A06,F08,K08,H10,C07,C09,E05 & L11 Observed to Have 12-step Disagreement Between Various Rod Position Indications.Caused by Electronic Drift in RPI Circuitry.Rpis Recalibrated

ML19263E207
Person / Time
Site:	North Anna
Issue date:	05/31/1979
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19263E199	List: ML19263E198 ML19263E200 ML19263E203 ML19263E207
References
LER-79-063-03L, LER-79-63-3L, NUDOCS 7906050303
Download: ML19263E207 (2)

Text

O . * *

(7 77)

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

CONTROL BLOCK: l I

l l l l l lh 6

7 o i 8 9 IvIAlNlAlSl1 lh! O ! 0l - n!nln!0ln!-ln!n!@l4l1l1l1l1lh!

LICENSEE CODE 14 15 LICEN5E NubdER h 26 LICEN>E 14 PE JO l

$1 CA I Sd l@

CON'T o i  %",aN I Ll@l0 i s 10 10 10 13 13 8  !@l 0 5101 il 7191@ln is I, li 17 lo l@ 15 HEPOR T DATE 80

/ 8 f,'J 61 DOCKET NUMBER 63 69 EVENT DATE #4 EVENT DESCRIPTION AND PROBAHLE CONSEQUENCES h O 2 lDurine Startuo Ooerarions rho f n11 nut n o rnda (Un6 Fnq vna _1rin en7_ rno FO% ,nA l 0 3 lL11), were chserved to t we a 12 sten disagreennnt herveen rhn vnrfnns rnd nnairfnn I o 4 lindications. at various t imes dur f nc rho Sr, reno. Thnan unr enerocend ne chov no n,,rr l O  !> led and all RPT's were in specification within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The health and safory of tho I l o 16 ! ineneral public was noe nf fncend. Thin ovone in ronnrenk1n ,e nnr 'r _ s _ A _ o _1 o_h_

O 7 I I O s I 30 7 8 9 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SU9 CODE COMPONEN T CODE SU9 CODE SUSCODE l0l91 7 8 lI lE @ ]@ l 1]@ lIlNlSlTlRlUl@ I l@ ] @

9 10 11 12 13 13 13 20 SEQUENTI AL OCCURRENCE REPOHT REVISION

_ EVENT YEAH REPORT NO. CODE TYPE NO.

b "LEUQEE R.RO 7 9l _l l 0l6 3l j ,,,-l l0l3l lL l g l 0l

_ 21 22 23 24 26 27 23 23 30 31 32 ACTION FUTURE EFFECT SHUTDOWN A TT ACHV E N T NPR D-4 PRIME COMP. COYPON EN T TAKEN ACTION ON Pl.AN T METHOD H O' :RS SUSYlTTED FORMdUB. SUPPLIEH MANUFACTURER lE 33 l@lZl@

34 l35Z l@ W@

36 3 l0l0l0 0l 40 l41Y l@ lNl@

42 43 Nl@ lWl1l2l0l@

44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS 1 O lThe cause of this indicator disaereement was due to electronic drift in the RPI circ- l 1 i juritv. Corrective action was to recalibrain the affected RPT'n_ l I

11 171 l 1 3 l 1 4 l 7 8 9 80 F ACILt Tv METHOD OF STATUS S MWER OTHER STATUS DISCOV E R Y DISCOVERY DESCRIPTION 1 5 [C_j @ l d d0l@ N/A l lBl@l Operator Observation AC TIVI TY CC TENT RELEASED OF PELE ASE AYOt,NT 08 ACTIVITY LOCATION OF RELEASE li ls l8 LLJ @ I10z l@l v4 I I N/A 1 9 11 44 45 80 PERSONNEL E

• 2OSURES

%Y4P 7 28 26 MON 1 / l0 l0 l Distyl 7. Q3,l N/A l 7 8 9 11 12 TJ 80 PERSONNELF. M IES ,,

i 8 10 NUYBE R 0 !0 l@l DESCR!D TIOY

• N/A 2294 08 i 7 8 9 11 12 LOSS OF OR DAMAGE TO FACILITV .

TYPE D E SCRIP TIO N 7

1 9 8 9 d @l N/A 10 "

l NRC Use oNLv ISSU E O DESCRIP TIO*J 7 9 0 6 0 5 0 a 303 ll(([ll4 l2l0l[N_l@l N/A l lllll 7 8 9 'o 68 69 80i NAME OF PREPARER W. R. Cartwright pnoug: 703-894-5151 {

Virginia Electric and Power Company North Anna Power Station, Unit 1 Attachment 1 Page 1 of 1 Dacket No: 50-333 Report No: 79-063/03L-0 Description of Event During normal startup a greater than 12 step disagreement was noted for rods H06, F08, K08, H10, C07, C09, E05 and L11. These rods were noted at various times during the startup and were corrected as they occurred. All RPI's were returned to service within one hour. Reactor power was less than 5% at the time of this event, therefore, the requirements of action statement A2 were met.

Probable Consequence of Occurrence Operability of the control rod position indication is required to determine control rod position and thereby ensure compliance with the control rod alignment and insertion limits.

Since reactor power was below 50% there was no effect on the safe operation of the plant and the health and safety of the general public was not affected.

This event has no direct affect on Unit #2 since Unit #2 is not operational at this time. Since identical RPI circuity exists for Unit #2, this problem of voltage drift may occur when Unit #2 does become operational.

Cause of Occurrence This cause of the indicator disagreement was due to the electronic drif t in the RPI circuity. The exact cause was volta re drif t in the ass ociated signal condi-tioning card.

Immediate Corrective Action Recalibration and functional check were performed on rods H06, F08, K03, H10, C07, C 9, E05, and L11 individual rod position indicators.

Scheduled Corrective Action An engineering study of IRPI drif t is already in progress .

Action Taken To Prevent Recurrence No further action required at this time.

2294 J09