05000324/LER-1980-064-03, /03L-0:on 800905,during Normal Surveillance Reactor Low Water Level Initiation Annunciator Alarmed While All Reactor Level Indications Showed Normal Readings.Caused by Excess Wire Grounded to Switch Housing Cover

/03L-0:on 800905,during Normal Surveillance Reactor Low Water Level Initiation Annunciator Alarmed While All Reactor Level Indications Showed Normal Readings.Caused by Excess Wire Grounded to Switch Housing Cover

ML19351D523
Person / Time
Site:	Brunswick
Issue date:	10/03/1980
From:	Tollison A CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19351D520	List: 05000324/LER-1980-064, Forwards LER 80-064/03L-0 05000324/LER-1980-064-03, /03L-0:on 800905,during Normal Surveillance Reactor Low Water Level Initiation Annunciator Alarmed While All Reactor Level Indications Showed Normal Readings.Caused by Excess Wire Grounded to Switch Housing Cover
References
LER-80-064-03L-01, LER-80-64-3L-1, NUDOCS 8010100332
Download: ML19351D523 (2)

LER-1980-064, /03L-0:on 800905,during Normal Surveillance Reactor Low Water Level Initiation Annunciator Alarmed While All Reactor Level Indications Showed Normal Readings.Caused by Excess Wire Grounded to Switch Housing Cover

Event date:
Report date:
3241980064R03 - NRC Website

text

_ _.

NRC FORM 54 U. C. NUCL2 AM Mitsut A e un f t,ummemun (7 7H LICENSEE EVENT REPORT CONTROL BLOCK: l l

l l

l l lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) l Nl Cl Bl El Pl 2 l@l 0 l 0 l - l 0 l 0 l 0 l 0 l 0 l - l 0 l 0 l@l 4 l 1 l 1 l 1 l 1 l@l l

l@

o i 7

8 9 L CENSEE CODE to in LeCENsE NvMSER 23 26 LICENSE TYPE 40 57 CAT b8 CON'T LolJJ "fRU l L l@l 015101 -l o l 31214 l@l 019 I o 151810 l@l110 lo 1318 lo l@

?

8 60 68 OOCKETNUM8ER 68 69 EVENT DATE 74 76 REPORT DATE 80 EVEf]T DESCRIPTION AND PROB A8LE CONSEQUENCES h M l During T*ormal surveillance. the " Reactor Low tlater Level Initiation" annunciator l

rb T3'l I alarmed while all reactor level indications showed normal readines.

An immediate I

l investigation revealed the annunciator RPS actuation relav. K7A. was nicked un by I

o 4 l 014 I Lrcactor level indication switch, 2-B21-LIS-NO31A-1, therefore the "A" RPS trip channell f5T 1 I was manually tripped as required by technical specifications. This event did not I

g [ affect the health or safety of the public.

l Technical Specifications 3.3.3, 6.9.1.9b I

0 s I OE CODE S 8CO C COMPONENT CODE

$UBCOCE fu E

EE l I I B l@ LB,jh {JLj h l Il Nl S l Tl R l U lh l S lh W h

/

8 9

10 11 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION LER EVENT YE AR REPORT NO.

CODE TYPE NO.

O sgj/RO la 1 01

[- _J l 01 61 4l I/I I0131

(_t j i-l L o_]

n

,a; a

a

_ 26 22 2J 24 26 27

8 29 30 31 32 K N AC C ON PLANT ME HOUR $

S8 iT FORth 8.

SUPPLIE MANUFACTUIER I B l@l Z ]@

lZl@

lZl@

l0l0l0l0l l Y lh l Y lh l N lh l Y l O l 1 l o l@

33 34 2c 36 37 40 43 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h j i g o ; [An extensive investigation revealed that ex: ass wire protruding past the switch I

g,,q g termination was grounded to the switch housing cover. The excess wire was trimmed to I g,,,l prevent contact with the switch housing cover and the switch and the relay were re-l l turned to normal operation.

l l

It 141 [

80 1

8 9 5A S

% POWER OTHER STATUS Di O Ft Y Ot$COVERY DESCRIPTION NA l

[_6]hl Operator Surveillance l

l C l@ l 0l 0l 2l@l i 5 Aaiv,Tv CO#TE~T AMOUNT OF ACTIVtTY LOCATION OF RELE ASE RELE ASED@OF RELE ASE[2J@l n l lu i

(2j i s 1

8 9 10 tt 44 45 80 PERSONNEL EXPOSURES NUMBER TYt2 DESCRtPTION 39 l T71 1010 l 0 !@l2J@l l

m_

13 80

' rERsONNEL iN;UNiEs NUMBER DESCRIPTidN na l

Inl0101@l i a 7

8 9 11 12 T PE DE R PT ON l

Lzj@L i o m

7 8 9 10

.fsu)i"@'0EsCRi, Tion @

NRc use ONtv 8010100

_N l*

332-l l1lllllllllllY NA 2 a

80. h 7

8 9 10 68 69 919-457-9521

{

A. C. TOLLISON, JR.

PHONE:

NAME OF PREPARER.

1.ER ATTACIOfENT - RO #2-80-64 Facility: BSEP Unit No.

2 Event Date:

9-5-80 2

The excess wire protruding past the switch termination of 2-B21-LIS-NO31A-1 was grounded to the switch housing cover.

It is believed a spurious ground in the plant DC electrical system, positive side, produced a closed loop in the relay electrical flowpath th'at allowed a current flow to bypass the switch contacts and pickup the K7A relay.

The K7A relay, which is normally picked up by 2-B21-LIS-N031A, performed all its required functions, therefore this event occurred in the conservative direction.

The calibration P.T. for this type level switch will be revised to inspect for suf ficient clearance between the switch terminal strip and the switch housing cover.

These type switches arc functionally tested on a monthly basis and are cali-brated quarterly to ensure dependable operability.

This instrumentaton is scheduled for replacement with analog-type instru-mentation during a future outage.

2.

Y t

i l

9 l

i'