ML19261A705

LER 79-001/03L-0 on 790105:during Normal Operation,Failure of Inverter 4 Interrupted 120V Vital AC Power to Channel D Components.Inverter Malfunction Caused by Failure of Several Capacitors (C1) & Oscillator Board (SC1-PL-1163)

ML19261A705
Person / Time
Site:	Millstone
Issue date:	02/02/1979
From:	Bates R NORTHEAST UTILITIES
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19261A702	List: ML19261A701 ML19261A705
References
LER-79-001-03L, LER-79-1-3L, NUDOCS 7902060296
Download: ML19261A705 (1)

Text

< 77)

LICENSEE EVENT REPORT (PLE ASE PRINT OR TYi'E alt. REQUIRED INFORMATIONS CONTROL BLOCK: l 1

l 1 l l l lh 6

[.) i l Cl TtsCENSEE l M lCODE N l S l 2 l@l 010 l- 101010 l0 l 01 -l 0l 250 l@l 26 4LICENSE

[ 1 [ 1T YPE l1 JG

[1 J@l [

SI CAI Lu

[g 8 9 le 15 LICENSE Nu?/tsEH COWT

'0 i SER$

l L l@l 015 l 010101313 1668 l@l 63 0l 1EVENT l 0DATEl 5 l 7 l 149 l@l 75 0 REPORT l 210DATE

[2 l7 l 809 [g 8 60 61 OOCKET NUMBER EVENT DESCRIPTION AND PROBAOLE CONSEQUENCES h Ia 2 l During routine power operation, the failure of inverter No. 4 resulted in an The ,

,o 3 l interruption of 120 volt vital AC power to channel D RPS and ESAS cc -ponents.

g io a l channel D RPS trips for High Power, local Power Density, High Pressurizer Pressure I and High Containment Pressure, and the ESAS trip for High Containment Pressure were ,

'o s

.o 3 disabled, were subsequently inhibited and operation continued in accorJance with _ ,

3 action 3.3.2.1, ia 7 l Technical Specifications Section 3.3.1.1, Table 3.3-1, Action 2b, and Inverter: Solid State Controls, Inc.; Model SV12150/TS-150NB.

o g  ; Table 3.3-2, Action 7.

' C$$" *#$E C0 su' sci $t COvPor.ENT CODE F

stsEde s$$E to 9 lE ID l @ LEj @ lA l @ l Gl El NI E Rl A[@ y@ l20Z @

13 18 19 F 8 9 10 11 12 EVENT YE AR RE b T JO COO 5 N LER O agg'RO y 17191 l- 10 10 11 I lel 10131 [L_j [--j l 0l 23 24 26 27 28 29 30 31 32

_.21 22 O PL PT MET HOUAS 22 58 IT D F B. $ PPLt MAN FA TURER KE ACTO l33A l@l34Z l@ lZl@ lZl@ 10'10 10 l0 l l41 Hj@ lYl@ l43A [@ lS [2 l5 l 0l; 44 47 35 36 32 40 42 CAUSE DESCRIPYlON AND CORRECTIVE ACTIONS li o l The malfunction of the inverter was caused by the failure of several capacitors (Cl) g i- 1 i I and an oscillator board (SCl-PL-ll63) which also prevented the static switch from trans y

, , l ferring .the vital AC to the alternate source, until th'e inverter was fully deenergized. ,

1 3 l The voltage surge following the delayed transfer caused failures of several components ;

i 4 I in the channel D RPS and ESAS cabinets which were replaced and operation continued. g 80 7 8 9 STA US  % POWER OTHER STATUS IS OV RY DISCOVERY OESCRIPTION i 5 LE_j@ l 1 l 0 l 0 l@l NA l [A_j@l Operator observation [

' ' N ACTIVITY COrTENT AMOUNT OF ACTivlTY LOCATION OI: RELE ASE i o NA l NA (

1 RELE 8 9

[Z_] A!ED@OF RELEASEZl@l 10 11 44 45 6G PERSONNEL FXPOSUAES NUMBE R TYPE DESCRIPTION i 7 101010 l@Lz_j@l n  !

PEnSONuf L ,N;URiE:.

N UU B E R DESCRIPTION f

ITlTlI0IoIol@l i 8 9 11 12 NA 60 YPE DESC PT ON J

f i <>

R LzJ8I

'J 10 NA

, Y) 1 StJE E CHiPTION 7QQ a 68 69 CO-e 8 9 10 R. U. Bates . 203/447-1791