ML19253B609

LER 79-085/03L-0:on 790915,while in Mode 1,control Rod Partially Dropped.Cause Unknown.Rod Withdrawn to Group Average Position.No Further Corrective Action Deemed Necessary

ML19253B609
Person / Time
Site:	Crystal River
Issue date:	10/08/1979
From:	Cooper J FLORIDA POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19253B608	List: ML19253B607 ML19253B609
References
LER-79-085-03L, LER-79-85-3L, NUDOCS 7910160488
Download: ML19253B609 (2)

Text

.

unc ronu xs t, u.s. ~uctean necuaronr caus ,ss,on a.m t.lCENSEE EVENT REPORT EXHIBIT A cournot stoc<: 1 I l! I I l@ trtant ena=r on tvrt ALL atouiato NeonMATioN)

FoTO I F vasm) L1 Q Rl Pt 3 lgla0 l0l-lOiuu0l0; ss. OjC s. ,.. .

1 ;0;0;a g a4; lu1l1 g l1 g ,v;.<_-[ g o m .... - s

, . , wa ..

M 3 8 y,g i L gl 01 51 01-1 01 310 t 2 gi ; 9tvterQ414 64 ti CoC4E r %V 3(a em 43 0

t l i Sg7 g9 g j 1,0 jo; 8; 7J 9 [ g 8 'S a t *'JM f 04 8 6 8J

. vent cascnirties arao nacsastt cosstcusNcts @

I g ,$r 1620 in Mode 1, it was reported that control rod 07-07 partially drooped This created an event contrary to Technig

,, ,from 41*. withdrawn to 18% withdrawn.

Redundancy NA. No effect upon the plant or general g cal Specification 3.1.3.1.

o , ,public. This is the fifth occurrence of this type reported. Reference LER's [

, , ,77-34, 43, 47, 135. . f I

a i I I

L2.M.J l .O

' ' ' co . sat.

svsrs.. cause ca si CQct. COCE sLfCO 3 .Cc% t'.? :03! sL3:001 Jac 4

[TT'il l RfB] @ [_XJ

. ,o n

@ al Zl @ lu 5 ,

IZlZIZIZ18 o IZl8 (.J.]@

e, a-St C.'E %rI Ai. Occ ;4 s t a. t ogscer a s sisicas "gvggr vgag at* Car %3. CO t ~584 No

@ l gg; Lie aoIn7 i 91 1-1 10 I81 51 1. ! 10 13I IL [ --J l0I

. a  :. a o a a a .. ..

"i.".'.2T;"

J.'!,.i'r 'W'ir -o..s @ 'sW % ir .s'* S ei5*2s'J.' .

WJO 'FrYls' Lx inBl @ L2J@ I01 01010! l.L.J@ Lsj@ l; J@ lZl919I9IG n J8;a Zl 8 << a,

. v <a < <a <>

cAuss otscaieries n:: matcm E 4: to .s @

, o (The cause of this event is unknown. Reactor power was reduced to 60%. Rod 07-07 was pulled from 10% to 25% and position was verified-by zone reference at 25%.i L'_E.J l

, , g Rod 07-07 was withdrawn to its group average position. No further corrective actt-ion deemed necessary. l

, a I l

.O

, . 9

's'r*.Ts' , ns= or-t= st2res @ EsE:552I  : s:o.in :nr.= r: - @

NA Operator observation i 5

]@ l0 l 712 l@l l l Al@l l agr.gerv CO *1st Loc Ar.ss os =ttaa:a h i e settasa@s

[ZJ LEj@l es ar rut a. :vsrNA:e a:riurv hl l NA l

, 89_ 13 tt esasos.. . gs a isos.a ts 44 4% SO suvet s tvet Ots;e'*t,0s 4-

[T-l l' 10 ] 010 l@[Z_J@l" NA l

. .s:ss,'J m 'i n m e,t. n .... s @

NA l

[TT .l l010 i O ol@lu ..

.C.*.s v 08 Os ris. L av.aa

. - to*3

. 8 40s.o r' 9, I

lll' J 4'I 3/. C, [t NA l f T- .I U, @lu

. W US E G '

n

.,b., 8l ,7'it,';. ,,.es 2

A f

@ / NA l

.. o IIII IfII I f fI l

%2. s er eateht, - J. Cooper . o.4 (904) 745-6466 h .

(SEE ATTAC1ED SUPPLEMENTARY INFORMATION SEEET) f

. g . ..- . .. .

. . 7910160 l t([;(b/ .-

I

SUPPLEMENTARY INFORMATION Report No.: 50-302/79-085/03L-0 Facility: Crystal River Unit #3 Report Date: 8 October 1979 Occurrence Date: 15 September 1979 Identification of Occurrence:

Control rod 07-07 greater than 6.5% (indicated position) away from group average position.

Conditions Prior to Occurrence:

Mode 1 power operation (72%)

Description of 0 warra.ce:

At 1620 it was reported that rod 07-07 had dropped from 41%

withdrawn to 18% withdrawn. This event resulted in a step drop in reactor power of 3%. Reactor power was reduced to 60%. Rod 07-07 was transferred to the auxiliary power supply and withdrawn to 25% by absolute position indication. Rod 07-07 position was verified at 25% on zone reference lamps.

The rod was withdrawn to its average group position and power was returned to its normal supply.

Designation of Apparent Cause:

The cause of this event is unknown. Troubleshooting of the control rod power supply revealed no immediate cause of this event.

Analysis of Occurrence:

No effect upon the plant or general public.

Corrective Action:

No corrective action deemed necessary.

Failure Data:

This is the fifth occurrence of this type reported. Reference LER's 77-34, 43, 47, and 135.

/rc 1!S4 555