ML18113A336

LER 1976-026-00 for St. Lucie Unit 1, During Power Ascension Testing, One of Four Redundant 120 Volt Ac Instrument Power Busses Was Lost Due to Malfunction of 1C Static Inverter

ML18113A336
Person / Time
Site:	Saint Lucie
Issue date:	06/29/1976
From:	Schmidt A Florida Power & Light Co
To:	Moseley N NRC/IE, NRC/RGN-II
References
PRN-LI-76-169 LER 1976-026-00
Download: ML18113A336 (9)

Text

NRC f'cAIM 196 U.so NUCLEAR REGULATORY C iSSION DOCKET NUMBER I2 76l- A 50-335 .

FILE NUMBER

~qNRC DISTRIBUTION FOR PART 50 DOCKET MATERIAL INCIDENT REPORT TO: FROM: DATE OF DOCUMENT Florida'Powys 6 Light Company 6 29 76 Mr, Norman C, Moseley Miami, Florida DATE RECEIVED A D Schmid t 7 12 76 BETTE R ONOTORIZEO PROP INPUT FORM NUMBER OF COPIES RECEIVED Q ORIGINAL @UNCLASSIFIED one copy recvd fiCCOP'Y DESCRIPTION ENCLOSURE L'tr, trans the following: Licensee Event Report (RO 50-335/76-26) on 5/29/76 concerning one of the four redundant 120 volt ac" instrumen power buses, being'ost

'.due to malfunction of the 1C static'inverter.

ACKN %LEDGED (1-P) (2-P)

DO NQT REMOVE PLANT NAME NOTE: IF PERSONNEL EXPOSURE IS INVOLVED SEND DIRECTLY TO KREGER/J..COLLINS St.. Lucie f51 FOR ACTION/INFORMATION ( 12 76 RJL BRANCH CHIEF Ziemann CYS FOR ACTION LIC..ASST.: Di s V CYS ACRS CYS HOLDING S INTERNAL D ISTR I BUTION EG FILE NRC PDR I RE 2 MIPC SCHROEDER IPPOLITO HOUSTON NOVAK CHECK GRIMES CASE HANAUER TEDESCO MACCARY EISENHUT SHAO VOLLMER BUNCH KREGER J. COLLINS EXTERNAL DISTRIBUTION CONTROL NUMBER LPDR: Ft Pierce Fla TIC:

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P.O, IIOX 013100, MIAVI, FLORIDA 3310I

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FLORIDA POWER & LIGHT CO'IPANY June 29, 1976 PRN-LI-76-169 Mr. Norman C. Moseley, Director, Region II Office of Inspection and Enforcement U. S. Nuclear Reg'ulatory Commission 9 fg 230 Peachtree Street, N. N., Suite 818 Atlanta, Georgia, 30303 gf/ypg

Dear Mr.'oseley:

REPORTABLE OCCURRENCE 335-76-26 CP ~~>ISSID~+log~

H ST. LUCIE UNIT 1 DATE OP OCCURRENCE: 'AY 29, 1976 4'C CONVERTER The attached Licensee Event Report is being submitted in accordance with Technical Specification 6.9 to provide 30-day notification of the subject occurrence.

Very truly yours, gpss D. c idt S

)j Vice President Power Resources 4/

MAS/so Attachment CC Jack R. Newman, Esquire Director, Office of Inspection, and Enforcement (30)

Director, Office of Management Information and Program Control (3)

LlCENSEE EVENT REPORT s>>

CONTROL BLOCK: (P e PRINT ALL REQUIRED INFORMATION) 1 6

'UCENSEE LICENSE

[aa~]ELEL5100 NAME 0

UCENSE NUMBER 0 0 0 0 0 0 4 TYPE

~a~

~

7 89 14 15 30 31 32 AEPOAT. AEPOAT

[OD1ICON'T ~L ~L 0 5 0 0 3 . 5 0 5F 5 7 6 0 6 5 5 7 6 7 8 57 58 59 60 61 68 69 74 75 eo EVENT OESCRIPTION

~0 2 During power ascension testing, one of the four redundant 120 volt ac 7 8 9

~03 instrument ower busses was lost due to malfunction of the 1C static 7 8 9 eo

[pP4] inverter. This caused the loss of. one channel of the Reactor Protection 7 8 9 eo Qo 5 and Engineered Safeguards Systems. The bus was returned to service 7 8 9 60 to06 immediately by use of one of. the two redundant. maintenance bypass busses.

7 8 9 PRVIE SYSTEM CAUSE

'UPPLER COMPONENT COMPONENT 7 8 9 10

~zg COOE CAUSE DESCRIPTION

~

COOE 11 12 COMPONENT COOt 0 EIN E RIA 17 '3 ',

~A .

44 G

MANUFAViil 47

'OAVES N

~N 48 Upon investigation, the oscillator circuit board in the 1C inverter was 8 9 60 found to be faulty. The board was replaced and the 1C inverter was 7

Qg s 7 8 9 eo

~co tested satisfactorily.

7 89 FACUTY METHOO OF STATUS POWER OTHER STATUS OISCOVERY OISCOVERY 0ESCRIPTION

~E ~O5 0 N/A N/A 7 8 9 10 12 13 FORM OF ACTlVITY CO@TENT REL~cSEO OF RELEASc AMOUNT OF ACTNITY LOCATION OF RELEASE c a ~a ~Z N/A N/A 7 S 9 10 11 44 45 60 PERSONNEL EXPOSUFIES

~00 0 ~nZ ., N/A 7 8.9 11 12 13 60 PERSONNEL INJURIES NUMBER OESCRIPTION

~00 0 N/A 7 89 11 12 PROBABLE CONSEQUENCES

. N/A Qg8 7 9 I.OSS OR OAMAGF TO FACILITY TYPE OESCRIPTION

~z N/A 7 89 10 PUBLICITY N/A

'7 89

~18 AOOITIONAL EACTORS Fee page 2 for continutation of Event Descrzptxon.

~ ~ ~ ~

i7 89 7 89 M. A. Schoppman 305/552/3779

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REPORTABLE OCCURRENCE 335-76-26 LICENSEE EVENT REPORT PAGE TNO '.

EVENT DESCRIPTION ( Continued' This was the first occurrence 'of this type at St. Lucie Unit, l.

(335-76-26) .

P BOX 013100, MIAMI, FLORIDA 33101 FLORIDA POWER 8( LIGHT COMPANY June 29, 1976 PRN-LI-76-169 Mr. Norman C. Moseley, Director, Region II Office 'of Inspec'tion and Enforcement U. S. Nuclear Regulatory Commission 230 Peachtree'treet, N. N., Suite 818 Atlanta, Georgia 30303

Dear Mr.'Moseley:

REPORTABLE OCCURRENCE 335-76-26 ST. LUCIE UNIT 1 DATE OF OCCURRENCE: MAY 29, 1976 lC 'INVERTER The attached Licensee Event Report is being submitted in accordance with Technical Specification 6.9 to provide 30-day notification of the subject occurrence.

Very truly yours,

~ D. c ddt

~

Vice President Power Resources MAS/so Attachment cc: Jack R. Newman, Esquire Director, Office of Inspection and Enforcement (30)

Director, Office of Management Information and Program Control (3)

HELPING BUILD FLORIDA

~ ~ ~, ~

A 4

4 LlCENSEE EVENT REPORT I

CONTROL BLOCK: (PLEA -

PRINT ALL REQUIRED INFORMATION) 6 UCENSEE UCENSE EVENT NAME LICENSE NUMBER TYPE TYPE toDg F L S L S 1 0 0 0 0 0 0 0 0 0 4 11 11 '~03

,7 89

~

14 15 26 30 31 32 7

[on~] coN7 8

, CATEGORY 57 58 AEPOAT.

59 REPORT TYPE'OURCE 60 61 05003350 OOCKET NUMBER 68 69 a h""3"7 6 74 0

75 4'3'" 0"0 6 80 EVENT DESCRIPTION Qo 2 During power ascension testing, one of the four redundant 120 volt ac 7 8 9 80 Jog instrument ower busses was 'lost due to malfunction of the 1C statio I

7 8 9 80 tOO~] inverter. This caused the loss of one channel of the Reactor Protection 89 80 and Engineered Safeguards Systems. The bus was returned to service 7 8 9 t006 immediately by use of one of.the two redundant. maintenance bypass busses. 80 7 8 9 80 SYSTEM CAUSE SUPPLER MANUFACIURER

~O7 ~ZO COOS COOE GENERA COMPONENT COOE A G 1 9 5 VQIATION N

7 8 9 10 11 12 17 43 44 47 48 CAUSE DESCRIPTION t00I Upon investigation, the oscillator circuit board in the 1C inverter was 7 8 9 80 found to be faulty. The board was replaced. and the 1C inverter was 7 8 9 80 t110 tested satisfactorily.

7 89 80 FACtLITY METHOO OF STATUS POWER OTHER STATUS 'ISCOVEAY OISCOVEAY OESCAIPTION B ~05 0 N/A ~a N/A 7 8 9 10 12 13 44 45 ~

46 80 FOAM OF ACTIVITY COATENT RELEASEO OF RELEASE AMOUNT OF ACTIVITY LOCATION OF AEI.EASE Qaj 4

~Z -N/A N/A 7 8 0 10 11 44 45, 80 PERSONNEL EXPOSURES

~00 0 ~Z . N/A 7 8.9 11 12 13 80 PERSONNEL INJURIES NUMBER OESCAIPTION

~q4 I0000J N/A 7 89 11 12 80 PROBABLE CONSEQUENCES

~15 N/A 7 8 9 80 LOSS OR DAMAGE TO FACIUTY TYPE OESCAIPTION

~z N/A 7 89 10 80 PUBLICITY N/A 7 89 ~ 80 ADDITIONAL FACTORS See page 2 for continutation of Event Description.

7 8 9 80 7 89 80 M. A. Schoppman PHONE:

305/552/3779 CI'0 CAI OST

'EPORTABLE OCCURRENCE 335-76-26 LICENSEE EVENT REPORT PAGE TWO '.

EVENT DESCRI'PTION ( Continued )

This was the first,occurren'ce 'of this type at St. Lucie Unit 1.

(335-76-26).