05000361/LER-1982-168-03, /03L-0:on 821212,indicated Position for Shutdown Control Element Assembly 12 Went from 148 Inches to 120 Inches Resulting in Reactor Trip.Caused by Failure of Reed Switch.Switch Replaced.No Further Corrective Action Planned

/03L-0:on 821212,indicated Position for Shutdown Control Element Assembly 12 Went from 148 Inches to 120 Inches Resulting in Reactor Trip.Caused by Failure of Reed Switch.Switch Replaced.No Further Corrective Action Planned

ML20028F366
Person / Time
Site:	San Onofre
Issue date:	01/11/1983
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20028F363	List: 05000361/LER-1982-168, Forwards LER 82-168/03L-0.Detailed Event Analysis Submitted 05000361/LER-1982-168-03, /03L-0:on 821212,indicated Position for Shutdown Control Element Assembly 12 Went from 148 Inches to 120 Inches Resulting in Reactor Trip.Caused by Failure of Reed Switch.Switch Replaced.No Further Corrective Action Planned
References
LER-82-168-03L, LER-82-168-3L, NUDOCS 8302010285
Download: ML20028F366 (1)

LER-1982-168, /03L-0:on 821212,indicated Position for Shutdown Control Element Assembly 12 Went from 148 Inches to 120 Inches Resulting in Reactor Trip.Caused by Failure of Reed Switch.Switch Replaced.No Further Corrective Action Planned

Event date:
Report date:
3611982168R03 - NRC Website

text

- coNract stoct t. i I

I I

I o@

mass mir oa rm at uou :s3 mc rio s lil Ic p ls 10 p 12 j@l 0101 -10101010101 -1010 Gi 'l 1111 113 @l g

m.

a uc o

a uca:rm o

6. w o

~

ow T a@l1 1211.12 IR I? @l 01 1l ll 1l8 13 [g 31 1 g go 15 10 [0 [0 l3 16 11 e

av e r oars a

a a noatsave a

a.,7 m EV ENT oESCmtFr:Ge aseo Mboe ASLI CQae5EOJENC15 3,3, ; While in Mode 1, the indicated pos fon for shutdown CEA 12 (Group B) 3 g, went frees 148 inches to 120 inches resulting in a reactor trip due to a high i

g, Local Power Density (LPD)/ low Departure free Nucleate Boiling Ratio g

,,,, (MBR) signal.

Following the reactor trip and concurrent turbine trip, Motor Control,

Center (MCC) 2BC failed to energize, causing several secondary plant steam valves to I

' ' I' I I c. cia gcn ccsul ting in cxccs;ia 5tc. Ja mad and. w.J RC'; vvuldvon.

Thcrc.=

no impact on the health and safety of plant personnel or the public associated

,,,, y with this event.

rrrr1 1 i

E

• $E sees com o.or coas m ",

a lsi,

i t I A l@ [Lj@ [Lj@ l il NI S l Tl R l U lO l.lJ@

z i.

i a

u wT occuaao.ca

,=,

a va,a

= =,oa r.ia

.a.

coa.

m.

1,=v.ua O" ;u.,o I a l 21 l_._j l 11 61 al l-l 10 L3 I

[_LJ

(__l

<ga r

_ a, a

o

=

a sr

=

a a

u a

fa 1 Pt.AmT sieCL. 81 77 we 7p M g

m IAl@lIl@

L. AJ@

LCJO I cl 4l 4l l

lNlg

[ g lNlg lCl I"lDlg u

x u _

a v

.a

.i o

u MSE DE5CAi8TICN ANo Co A AECrl'.E ACTICNS h i:11 The high Lpn/ low CNBR sicnal, resultino in the reactor trip, was caused by failure oj l

j,j,yl a reed switch.

The switch was replaced.

'40 further corrective action is clanned I

for the switch.

This LER will be revised to address the failure of MCC 2BC to L;,UJ l i

energize and will ident'ify 'the' cause and corrective action to be taken to prevent recurrence.

i a e ST

%80eEA ottie(a STAT 1.s ce av

.rtuscos gay :llEscmiaTices

[ T '] [8J @ l 0l Dl 0l g M l

Operational Event I

e,g,,,v, n a

n

- o g.g*g g o,,cT m @,

_=a,,

=

=

=

iT]'T] l 0(( O

'N "

j r

• *,,,%ai,

=,

u es Q lO N["O[gg "

J is go, :n.

l I'I M _s g..aun 8302010285 e30111 l

QDRADOCK 05000361 as sc.,,

PDR mac use ONLv

%.o hO i

liittiliti!!!!

M ILJ 84 i

1 ai pp,y/

y :f::7. -~

9 e. ca

%.ve y u gur.

U