ML19254F267

LER 79-023/03X-1:on 790803,seismic Bracings for Cells in 201A & B Batteries Removed to Allow Insp.Batteries Declared Inoperable.Caused by Reduction in Cell Voltages. Replacement of 201A Battery complete;201B Work in Progress

ML19254F267
Person / Time
Site:	Millstone
Issue date:	11/01/1979
From:	NORTHEAST UTILITIES
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19254F266	List: ML19254F265 ML19254F267
References
LER-79-023-03X, LER-79-23-3X, NUDOCS 7911070445
Download: ML19254F267 (2)

Text

'" ' ' ' ""

• JRC FORM 3GG LICENSEE EVENT REPORT Update Report - Previous report date 3/30/79 CONTnOL BLCCK: l l l l l l l (PLE ASE PnlNT On TYPE ALL REQUlnED INFORMATION) i e l

o l1] l C l LICENSEE T l M CODE I N l 514l 215l@l 0l Ol -lLICENSE 0 l 0NUMSCH l 0 l 0 l - l 0 l 2b0 LoJ@l 26 411 IyPC LiCLt.3L 11 3011 11 I 57 CA l@l I 58 l@

8 9 CON'T o i B

"*","Jl_Lj@l015 s

60 61 0l0l013l316l@{0l8l0l317l9l@lll1lol1l719l@

DOC K E T nut.*D E H 68 03 EVENT DATE 74 75 HEPOaTDATE LG EVENT DESCntPTION AND PnOBABLE CONCEGUENCES h o 2 l During steady state power operation, the seismic bracing for various cells in the  ;

201 A and B batteries was removed to allow for cell inspection and/or replacement. l 1 o l31 1 o 4 l This resulted in the batteries being declared inoperable in accordance with Section I o s l 3.8.2.3.b of the Technical Specifications. Upon completion of the inspections or l

@] cell replacements, the seismic bracing was reinstalled and the battery declared I o 7 l operable within two (2) hours in each case. I o a l

I .

C DE CO E S DCC E COVPONENT CODE SUSC dE S C E

~

7 o 9 8

l E lC l@ l Bl@ l Al@ 1B l Al Tl TlR l YlO l Zl@ l 207 l@

9 10 11 12 13 18 19 SEQUE NTI AL OCCURRENCE REFORT REVislON EVENT YE AR REPORT NO; CODE T\PE NO.

L E R/RO

@ gEP,gT, {} 9 l l-l l 0 l2 l 3 l l/l l 0131 28 23 lXl 33 l-l 31 ll]

32

_ 21 22 23 24 26 27 AKE ATO ON PL fT f ET O HOURS S C IT E F 1 US. PLIE I MAN F/ TUHER l33A l@l34 Cl@ L7J@

35 171@

36 101 01 01 01 3/ 43 lY 43 l@ (Y 42 l@ l43A l@ LC 44 l l 7131@ 47 CAUSE DESCniPTION AND CONNECTIVE ACTIONS lTTin i The cell inspections and replacements were the result of a reduction in individual i 11lil I cell voltages, although the cells were still operable. This condition was the I iti7; l subject of an informational letter to the Office of Inspection and Enforcement on [

lilal 1 8/20/79. The comDlete 201 A battery replacerent was comoleted on 10/30/79 and the f i 4 l 2018 replacement is expected in the next several weeks. l 7 8 9 63 STA  % POWER OTH ER STATUS iSC RY DISCOVERY DESCRIPTION "A Surveillance Testino j 1 s (J_J @ l ll 01 Ol" @ l "

l l" B l@l "

ACTIVITY COMTENT nEtEASEn Or attASE

",0UNT As Or ACuviTY @I tOCAuON Or nEttASE @

nA I NA I li Ic I8 L7_.J 7 9

@ toL7J@l11 44 45 80 FERSONNEL EXPOSURES tsuYHE R TYPE DESCRIPTION l

li l 71 l o l o l o 'l@l z l@l NA PEnSOm/t imu'JiES NU'.*B F A DESCRIP TION l ,., ,, , ,) .

[ -

l 7

i a 8 9 l010101@l12 11 NA EJ h iol8L7_J@l TYPE E C I PT Or FA ILI" @

nA rgg33070 { 63 l

7 9 10 ESCHIP TlON 2 a l'.SUEl@l LB nA I I111111111111? 03* L I B 9 to 68 09 r;

• ,'

• Attachment LER 79-23/03X-1 tiillstone Unit 2 Docket flo. 50-336 EVEllT DESCRIPTI0fl During steady state power operation, the seismic bracing for various cells in the 201A and B batteries were removed to allow for cell inspection and/or replacement as outlined below.

BATTERY EV0LUTION DATE 201B Cell inspection 10/2/79 201A Cell inspection 10/3/79 201B Replacement of cell 28 10/5/79 ,

10/11/79 201B Replacenent of cell 43 201B Replacement of cell 41 10/17/79 10/21/79 201B Replacement of cell 15 T:iese cell inspections and/or replacements resulted in the batteries being declared inoperable in accordance with Section 3.8.2.3.b of the Technical Specifications. Upon the completion of each inspection and/or cell replacement, the seismic bracing was reinstalled and the battery declared operable within two (2) hours in each case.

CAUSE DESCRIPTIO!!

The cell inspections and replacements are the result of a reduction in individual cell voltages, although the cells were still operable. This condition was the subject of an informational Mtter to the Office of Inspection and Enforcement on 8/20/79 which discussed the cause of cell deterioration. The replacement of the 201A battery utilizing temporary seismic bracing was completed on 10/25/79. The replacement of the 201B battery is expected in the next several weeks.

I'"'2 230