ML19323C977

LER 80-039/03L-0:on 800417,Channel III Steamline Pressure Protection Bistable for P2-P1 Initiation Failed to Trip & Would Not Respond to Input During Monthly Surveillance Test. Caused by Defective Signal Comparator Card in Loop

ML19323C977
Person / Time
Site:	North Anna
Issue date:	05/14/1980
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19323C967	List: ML19323C966 ML19323C977
References
LER-80-039-03L, LER-80-39-3L, NUDOCS 8005190488
Download: ML19323C977 (2)

Text

_

8005190488

~

$m UCENSEE EVENT REPORT i corao'stocx:I I I l l I l m.sess ==r on rm au. naouinan u ,a==anoen t i e@  !

! o I si el I vi oca Al Nl cco. A l S I 1l@l 0 l 0 l -l0 -l0 l 0 l 0 l 0 l -l Ol 0a l@l

i. is =

4 l-1[rm1l1 ,

l 1(@ s u .@

CON"f (0I Is E I L se@ l 0l SJ 0 J 0 l 0l 3l 3l 8 Ql 0 l4 l1 j.7 l 8 l 0 Qln ( c; j 3 l 4l alnsol@

.. ooc ,7,.ume.n a se avserr oars 1. rs aeroser mars EVENT OMIPTION ANO ,RCSASL3 CQ63eC33 10 l i"TTT1 I On April 17, 1980, the Channel III Steamline Pressure Protection bistable for g ro"TT1 i P:>Pl SI' initiation failed to trip and would not respond to input during the g g I performance of the monthl/ surveillance test. As a result, the channel was g o i left in " Test" and declared inoperable. Since redundant protection channels t I o is i i remained operational to initiate a safety injection if required, the public g I o i 7 I I health and safety we Te not affected. This occurrence is reportable pursuant l s,

i 2 i4 # I to T.S. 6.9.1.9.b. I r as so  ;

'T="= "c 2 sa:E. so r sJ mE  :

13ISI lIlBlg { g g l Il Ng q T l Rl Ul h ll '0.@ 2 h j i a e se is ta na e is

@ Og Lamno

~

8ve'fTEAa l8l q g l 0 l 3l 9l g T Tp l 3l 2 n a an as n a a 2:

NE o"n ruarr W imuns 'b" co'"n"ne'*au's.'"su"r'eu"E inamuracruman

~

@ @ @ l OI 0l0 l l g g g lW lll2]OJg cAusa oescnurTices Amo connective Acncess @

g,,,g;The bistable failed to respond To the input test signal because of a defective ,

g signal comparator (NAL) card. Both the NAL card and the channel test (NCT) card UJ.1.1 we L re replaced and the loop was ' calibrated in accordance with applicable t g ] calibration procedures. The surveillance test was then satisfactorily j iisa I renerformed and the channel was returned to service. t a e m

1. s Tr saamen omenstatus @ onscm.eN ner: wroamenwriose @

lr Isia d @ l 1l Of 0 I@l NA , [ gg Surveillance 'l .st [

g ta ri as e e se

=.sa-o on - uncan @

f i i

• I l,,,,Z,,,( @ Qgl NA m.a-re,.cmery @ l NAl l r a s = se

m. c=NA m @

ii l l 0l Of Q@Q@l l

' passes ==l.'mim E n

- ==cmenen@

t: sil l Of Of Ogl NA l

en ca D D D 't racury g i3is a{J@l NA I N & .  : l p a m NRC USE CNI.Y

• • Eucairieca @ ,

rias @l NA g  ;;g9,y;ggiggl}

,i a a to se se so s suas C7 Pap Ama., W. ' R. Cartwricht g, 703-894-5151' i l

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

Attachment:

Page 1 of I Docket No. 50-338 Report No. LER 80-39/03L-0 Description of Event On April 17, 1980, the P2>P1 SI initiation bistable for Steamline Pressure Protection Channel III did not respond to input test signal and failed to trip during the performance of the monthly channel functional test. The affected channel was left in the " Test" condition and declared inoperable. This event is contrary to T.S. 3.3.2.1 and reportable pursuant to T.S. 6.9.1.9.b.

Probable Consequences of Occurrence The consequences of this event were limited because redundant Steamline Pressure Protection Channels II and IV remained operable to initiate a Safety Injection on a high differential pressure between steamlines 1 and 2 (P2>P1) if required. As a result, the health and safety of the general public were not affected by this occurrence. This event has no generic implications affecting Unit I and 2 process instru-mentation.

Cause of Event The Steamline differential pressure bistable failed to respond to the input test signal and trip when required because of a bad signal l comparator (NAL) card in the instrument loop. l Immediate Corrective Action The signal comparator (NAL) card and the channel test (NCT) card were replaced (the NCT card was replaced as a precaution in case it was the reason for the NAL card failure) and the locp was calibrated in accordance with applicable calibration procedures. The periodic functional test was then satisfactorily reperformed the next day to allow ample burn-in time and the protection channel was returned to service.

Scheduled Corrective Action l

No scheduled corrective action is required. l Actions Taken to Prevent Recurrence Since this is a random event, no further at. ions are required.