05000368/LER-1981-020-03, /03L-0:on 810520,two Source Range Neutron Flux Monitor Signals Increased Suddenly.Probably Caused by Noise Interference.Investigation Underway.Cables & Connectors to Be Changed During Next Refueling Outage

From kanterella
(Redirected from ML20005A554)
Jump to navigation Jump to search
/03L-0:on 810520,two Source Range Neutron Flux Monitor Signals Increased Suddenly.Probably Caused by Noise Interference.Investigation Underway.Cables & Connectors to Be Changed During Next Refueling Outage
ML20005A554
Person / Time
Site: Arkansas Nuclear Entergy icon.png
Issue date: 06/22/1981
From: Cogburn T
ARKANSAS POWER & LIGHT CO.
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20005A544 List:
References
LER-81-020-03L, LER-81-20-3L, NUDOCS 8106300450
Download: ML20005A554 (1)


LER-1981-020, /03L-0:on 810520,two Source Range Neutron Flux Monitor Signals Increased Suddenly.Probably Caused by Noise Interference.Investigation Underway.Cables & Connectors to Be Changed During Next Refueling Outage
Event date:
Report date:
3681981020R03 - NRC Website

text

-

p,.

Nnc FORM 3E4 U. S. NUCLE AR REGilL ATORY COMMIS$40N LICENSEE EVENT REPORT EXHIBIT A CONTROL BLOCK: l l l l l l l (PLE ASE PRINT OR TYPE ALL REOutRED INFORMATIONI i

foTilIAlRlAlNl012l@ill 0 l0 l - 10 l0 l 0l Oj 0 l-l 0 l0 lg l1 l 1l1 l 1lgl cl4I $4Blg 3

0 9 LIC Nina COD 84 tsC Nss NUMe M 2$

26 4t( NS

,Y,&

JG b3 p'T 0"c' [L_J@l0 l 5 p 10101316 I al@l0 151210 l 8 I ll@l 016 l 21 218 l 11@

CON 8

60 65 ooCaiThuwen.

ene 63 av NY DAT.

34 PS HE,oM T oafi 60 EVENT DESCRIPTION AND PROBA8LE CONSEQUENCES O'o During Mode 6 operation with all core alterations completed and no positive o 2 I reactivity changes in orogress, the twn snurco rango noutrnn finy mnnitnr1 ran I signals increased suddenly by a factor of aDDroximately 1000 indicating i

o.

ITITI I probable noise interference. The RCS bornn enncontration was immediatelyl I verified to be unchanged per T.S. Action 3.9.2.b.

The loa power channels t o.

iremained operable. No similar occurrences.

Reportable per T.S. 6.9.1.9.4 o,

ITTT1 I I

su'EE s"nE

'cS's"

cis' scios cou,owi=T coot t

8 11101@ (BJ@ LCJ@ l ll NI S I TI H Ul@ LE_j@ [lj @

[

i.'#"M a' "E N '"

k ?"'

a...,o vi,Y

@,alg,5, I 8 l 11 L--J l 01210 i Ld I a 31 LL.J L--J L_9

~

25 22 23 24 d6 27 20 29 30 JB 3J AE N Acf O

,L.

T wit MouRs

$0 si D FO UN su Li R MAN FA Tup R LLJ@Lfu@ LZJ@

LZJ@

l 0101010 I LRl@

lJil@ l_tJJ@ l GI 01613 l@

3J 34 33 36 33 40 el 42 43 44 43 CAUSE DESCRIPTION AND CORRECflVE ACTIONS h i o 1The sourco of the nenblom was nnt identified _ as the startun channel I

i indications returned to nomal beforec deteminino cause. However. the i

i I failuro is holieved to ho nniso related duo tn woldor intorforonco (based i i 2 E I on orior exoeriencel.

Efforts are in orogress to evaluate noise I

isusceptibility. A chanaeout' of cables and connectors to improve sianal i

i s,gMelding is planned for theaexL,gfyleing o.itage, a

of ia:Tarus U3u o scovior onsco.,no~ @

iT.ivs v o.ia cmove v La1@ In i nin l@l na i lAJ@l Ooerator observation I

i 5 a

.n,.si@oo,sTi,

'.aiv.1, e

ou~r o,.c1,vuv @ l toc.no,,o,au.se@

a u.s.

l NA l

L2_1 LZJ@l NA i o

,,v so~.!,*t i n ose... onca.1.o @

a xv.i l o l 01 Ol@[Z_J@l NA l

i i

.so.~.~ !',~3u'Anone..,Tio-@

a ou.

lol0101@l NA l

i =

b4?-"'e PIDR ORllilNAL

, o ::.s b.sd@l NA 1 lIIiillllllll 2 o Thomas H_ Cnghnrn 501/968-2519 NAME OF FREPARER

,noN e:

8 see s o oijgo m