05000318/LER-1979-036-03, /03L-0:on 791004,control Element Assembly 1 Dropped to Bottom of Core.Caused by Oscillation in 15-volt Power Supply,Resulting in Dip of Output Voltage & Decreasing Holding Current of Upper Grimper

/03L-0:on 791004,control Element Assembly 1 Dropped to Bottom of Core.Caused by Oscillation in 15-volt Power Supply,Resulting in Dip of Output Voltage & Decreasing Holding Current of Upper Grimper

ML19256E030
Person / Time
Site:	Calvert Cliffs
Issue date:	10/19/1979
From:	Bauer E, Lagiewski J BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19256E024	List: 05000318/LER-1979-036, Forwards LER 79-036/03L-0 05000318/LER-1979-036-03, /03L-0:on 791004,control Element Assembly 1 Dropped to Bottom of Core.Caused by Oscillation in 15-volt Power Supply,Resulting in Dip of Output Voltage & Decreasing Holding Current of Upper Grimper
References
LER-79-036-03L-01, LER-79-36-3L-1, NUDOCS 7910250322
Download: ML19256E030 (1)

LER-1979-036, /03L-0:on 791004,control Element Assembly 1 Dropped to Bottom of Core.Caused by Oscillation in 15-volt Power Supply,Resulting in Dip of Output Voltage & Decreasing Holding Current of Upper Grimper

Event date:
Report date:
3181979036R03 - NRC Website

text

NHC F OHM JG6 v. d. 3.ULLean net.auta a un LUM...su um (7-7))

l]{

~

l 3

8

}

LICENSEE EVENT REPORT CONTROL BLOCK: []

l l

l l

lh (PLEASE PRINT OR TYPE ILL EO L !

1 6

IO l i l I M I D I c l C l N l 2 l@l 010 - l0 l0 01010l-1010l@l4l1 1 Il 11 @l l

l@

7 8 9 LICENSEE COOE 14 tS LICENSE NuvdER 25 Ib LICE'eSE T Y PE JO 57 C A T $8 CON'T s',$

L l@l Q 51010101311 18 }@l1 1010 la 1719 l@ 1 In 11 19 (7 la l@

O i

7 8

60 61 DOCKET NuveER 68 69 EVENT DATE 14 75 REPORT DATE

'O EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h 101 1 l Durina routine oneration control element asso-bly-01 dennend tn thn 1

0 3i [ bottom of the core at 0228. Per the reouirements of T.S. 3.1.3.1.f.

I l 0 l41 ] reactor cower was reduced to 4 70% at 0310.

At 0328, control i

IOlsi eierent assembly-01 was restored to alianment with other CEA's I

iOisi lof its crouo. LER's 79-24 (U-2) and 78-48 (U-1) describe similiar 1

0 7

levents.

I I

o a

• $'o'E

'^'!E s '8C$$E su8C7of sEEE

^'

C CO CevPONENT COoE O

9 lR18 @ lX l@

Z l@ l I l N l S l T l R l U l@ I P l@ [Z_j @

7 8

9 10 11 12 13 18 19 20 S E QU E N TI AL OCCURAENCE REPORT REVISION LER RO EVENT YE AR R EPORT NO.

CODE TYPE NO.

@, reg l217191 1-1 LO ' '_6J l/l 0l3l lL l

[-j l0 l 22 23 24

.?

27 28 29 30 31 32 TAE N ACT ON ON PLANT ME H HOu15 S 8 D

FOR9 B.

SL PPLI E R VANUFACTuRER lZ l@lF l@

B @

[_Zj@

l 01010]_01 1 NJ@

W@

W@

l Fi 3 l_1 l 4 l@

33 34 35 36 JJ

.-s 4 '.

42 43 44 47 CAUSE DESCRIPTION AND CORREC'IVE ACTIONS lit is surroised that a t'orentarv oscillation in the reculatorv rortion of tha i

o i, i, i [15V power sucolv cau3,{the outout voltaae of the oower suoplv to din somewhat I

ii,, j lbelcw 15V D.C. thus decreasino the "holdino" curren+ nf the rFa 'e I

n n n o,-

larioper. At this t;jme FCR 78-72 which adds redundant nnwer eunnlie<: with w I

3 lauctioneerina circuit, is in croaress and has been coroleted on linit I.

I 7

8 9 80 ST

% PCWER OTHE R ST ATUS DISCO RY O'SCOVERY OESCRIPTION

(_E_J @ l l l 0 Ol@l N/A l

W@l Onerator Observation l

i s

ACTIVITY CONTENT AMOUNT OF ACTIVITY @ l LOCATION OF RELE ASE @

RELEASED OF RELE ASE li l6 l W @ l Zl@l N/A lN/A l

7 8 9 10 11 A4 45 83 PERSONNEL E XPCsynES NU98 E R TYPE

DESCRIPTION

l010l0l@lZl@lN/A I

1 7

PERsONNEt mu' des NUMBER DESCRIPTICN li l-l l0 l 010 l@l N/A vnn glU

.) U /

83 7

3 9 11 12 LOSS OF CA OAYAGE TO FACILETV i

TYPE D E SCRIPTION li191lZl@lN/A l

7 8 9 10 83 PL8t f C" NRC USE ONLY r m T i e illl! "' '

79'02503 z z i iiiiiiiiiiiili 7

8 9 10 68 69 8S. ;

duer P-O*.E I W I

• 700 "Q3 N A*.'E OF PRE P AR E R