ML19290E695

LER 80-023/03L-0:on 800208,during Monthly Surveillance Test, Trip Bistable for Containment hi-hi Pressure Channel 2 Failed to Trip.Caused by Short in Card Component T-31-1-C. Nal Card Replaced & Recalibr

ML19290E695
Person / Time
Site:	North Anna
Issue date:	03/07/1980
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19290E691	List: ML19290E690 ML19290E695
References
202, LER-80-023-03L, LER-80-23-3L, NUDOCS 8003140393
Download: ML19290E695 (2)

Text

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMI'*JON rA m .

E.lCENSEE EVENT REPORT CONTROL BLOCK: l i

l l 1 l l lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

FITl8 9I v I A l N l A l S l 1l@l0l0l-l0l0l0l0l0l-l010l@l4l1l111l1l@l 7 LICENSEE CODE 14 15 UCENSE NUMMEM 2*A Me UCOnt 1YPE JO l

67 L.A l tid l@

CON'T O i l'"C'L l@lols 101010 1,1 a l a l@l 012 l 01 R I R I O l@l 34 i%

0I ,101,1 o f nl@ 80

? 8 60 61 DOCK ET NUMBER 6s 6"J EVEN T DATE ftEPOH T DATE EVENT DESCRIPTION AND PROB ABLE CONSEQUENCES h 10121lOn Fohru,rv R. 10RO with the ro,ctnr ,e 100* nn nv tho tefn hve+ > bio e nr enn* > < - 1.I O 3 1111 Ili Pressure Channel II failed to trip during the performance of the nonthly survoli-

[TTTl llance test. %e af fected channel was lef t in the blocked condition and declared in-lo isl loperable. Since redundant Containment 111 111 Fressuro .' h a n n e l s T. ITT. and TV romained

[TTTI loperable to initiato a en i f roont rod . the health and c,rorv of the noner,1 nnhite i 10171 lwere not af fected . This event is recortable nurs",nt to T.9. 6.4.1 o_h I O a l  !

7 8 9 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SU8 CODE COM*0NENT CODE SuuCODE SusCODE O 9 I T i n l@ Lg_]@ L.nl@ l "I si TI RI nl@ LeJ@ 12@

7 8 9 10 ' 11 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REvtSaON LER/RO EVE NT YE A R R EPORT NO. CODE TYPE Mk

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36 31 0I 0 01 01 40 Lxi@ l_al@ Ld@ l el il ,1 cl@

41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h i O 1%e histable failed to trip hocause card co-nenent T-31-1-C. which reen1, ton thn 1sv l 1 1 loower sonplv. had shorted. %e N AL c a rd v,9 ren1nced nna roc,14hr,enr1 fn ,rrnv>,rrn I m brith nonlicable calibration proceduros. The norindic toct o,c thon c , + 4 c f , r e n ,- 41 7

W lrenerfor-od nnd the chnnnot ",n returnod en corvico I L'_l.* ] I I 7 8 9 80 ST  % POWER OTHER STATUS D4 0 RY DISCOVERY DESCRtPTION i s [,iLJ@ li lo 10 l@l NA l l4.B- l@l Surveillance Tost 8 4,,,, ,gg7, -u u. +4 48 _

8.

R u uSEO 0,R ufASE LOCAnO~ 0, rue SE @

7 1 6 8 9

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11 NAAMOU~T OP ACuvirY 44 l

45 NA @l l 40 PERSONNEL. E X POSUR ES NUMBER DESCRIPTION 1 7 l0 l0 10 lh[ TYPE,Zjhl NA I PERSONN E L INJURIES NUMSEM DESCRtPTION 1 a lo lo 0 l@l12 NA l 7 8 9 11 80 LOSS OP OR DAMAGE TO FACILITY TYPE DESCRIPTION L'.J.SJ 7 8 9 Iz_l@l10 NA -

l GO ISSUE 1.2 L,) [3._,f@lDEnsCRIPTION [dd3/ []h $ I [llll1Ill11Il; 7 8 9 10 68 69 80. r.

NAME OF PREPARER PHONE: __.-

Virginia Electric and Power Company North Anna Power Station, Unit #1

Attachment:

Page 1 of 1 Dockot No. 50-338 Report No. LER 80-23/03L-0 Description of Event On February 8, 1980, the Containment Ili-Hi Pressure Channel II bistabic failed to trip during the performance of the monthly surveillance test and, as a result, left in the blocked condition and declared inoperable.

Probable Consequences of Occurrence The consequences of this event were limited because redundant containment Hi-Hi Pressure Channels, I, III, and IV remained operable to initiate a containment depressurization actuation on a 2 out of 3 logic if required.

As a result, the health and safety of the general public wer. not jeopardized.

This event has no generic implications affecting Unit I and Unit 2 instrumen-tation.

Cause of Event The bistable failed to trip during the performance of the test because the transistor which regulates the NAL card 15 volt power supply (component T-31-1-C) had shorted.

Immediate Corrective Action The NAL card was replaced and the new card was calibrated in accordance with applicable calibration procedures. The surveillance test was then reperformed satisfactorily and the channel was returned to its normal condition.

Scheduled Corrective Action No scheduled corrective action is required.

Actions Taken To Prevent Recurrence No further actions are required.

.