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 D Florida Power & Light Co
To:	Moseley N C 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 I2 76l-A~qNRC DISTRIBUTION FOR PART 50 DOCKET MATERIAL DOCKET NUMBER 50-335.FILE NUMBER INCIDENT REPORT TO: Mr, Norman C, Moseley FROM: Florida'Powys 6 Light Company Miami, Florida A D Schmid t DATE OF DOCUMENT 6 29 76 DATE RECEIVED 7 12 76 BETTE R Q ORIGINAL fiCCOP'Y DESCRIPTION ONOTORIZEO

@UNCLASSIFIED PROP INPUT FORM ENCLOSURE NUMBER OF COPIES RECEIVED one copy recvd L'tr, trans the following:

Licensee Event Report (RO 50-335/76-26) on 5/29/76 concerning one 120 volt ac" instrumen'.due to malfunction of of the four redundant power buses, being'ost the 1C static'inverter.

ACKN%LEDGED (1-P)(2-P)DO NQT REMOVE PLANT NAME St..Lucie f51 NOTE: IF PERSONNEL EXPOSURE IS INVOLVED SEND DIRECTLY TO KREGER/J..COLLINS BRANCH CHIEF CYS FOR ACTION LIC..ASST.:

V CYS ACRS CYS HOLDING S Ziemann Di s FOR ACTION/INFORMATION (12 76 RJL 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 LPDR: Ft Pierce Fla TIC: EXTERNAL DISTRIBUTION CONTROL NUMBER "Jl'o p~~'I'N 4 I-A.'lf f p II/h P.O, IIOX 013100, MIAVI, FLORIDA 3310I%I~~'I+//jpg>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 230 Peachtree Street, N.N., Suite 818 Atlanta, Georgia, 30303

Dear Mr.'oseley:

REPORTABLE OCCURRENCE 335-76-26 ST.LUCIE UNIT 1 DATE OP OCCURRENCE:

'AY 29, 1976 9 fg gf/ypg CP~~>ISSID~+log~

H 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, D.c idt Vice President Power Resources gpss 4/S)j MAS/so Attachment CC Jack R.Newman, Esquire Director, Office of Inspection, and Enforcement (30)Director, Of f ice of Management Information and Program Control (3) s>>CONTROL BLOCK: 1'UCENSEE NAME[aa~]ELEL5100 14 15 7 89 6 UCENSE NUMBER-0 0 0 0 0-0 0 4 LICENSE TYPE~a~30 31 32 LlCENSEE EVENT REPORT (P e PRINT ALL REQUIRED INFORMATION)

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

maintenance bypass busses.7 8 9 PRVIE SYSTEM CAUSE COMPONENT COMPONENT COOE COOE COMPONENT COOt'UPPLER MANUFAViil

~zg~0 EIN E RIA~A.G 7 8 9 10 11 12 17'3',44 47 CAUSE DESCRIPTION Upon investigation, the oscillator circuit board'OAVES N~N 48 in the 1C inverter was 7 8 9 Qg s found to be faulty.The board was replaced and the 1C inverter was 7 8 9~co tested satisfactorily.

60 eo OTHER STATUS N/A AMOUNT OF ACTNITY N/A PROBABLE CONSEQUENCES Qg 7 8 9 I.OSS OR OAMAGF TO FACILITY TYPE OESCRIPTION

~z 7 89 10 PUBLICITY 7 89 FACUTY STATUS POWER~E~O5 0 7 8 9 10 12 13 FORM OF ACTlVITY CO@TENT REL~cSEO OF RELEASc c a~a~Z 7 S 9 10 11 PERSONNEL EXPOSUFIES

~00 0~nZ 7 8.9 11 12 13 PERSONNEL INJURIES NUMBER OESCRIPTION

~00 0 7 89 11 12 METHOO OF OISCOVERY 44 45., N/A N/A.N/A N/A N/A OISCOVERY 0ESCRIPTION N/A LOCATION OF RELEASE N/A 60 60'7 89 AOOITIONAL EACTORS~~Fee page 2 for continutation of Event Descrzptxon.

~~~18 i7 89 7 89 M.A.Schoppman 305/552/3779

~~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 I CONTROL BLOCK: LlCENSEE EVENT REPORT 6 (PLEA-PRINT ALL REQUIRED INFORMATION)

EVENT TYPE UCENSE TYPE UCENSEE NAME toDg F L S L S 1 0 ,7 89 14 15 LICENSE NUMBER 0-0 0 0 0 0-0 0 4 11 11'~03 26 30 31 32 a h""3"7 6 0 4'3'" 0"0 6 80 AEPOAT.REPORT , CATEGORY TYPE'OURCE

[on~]coN7~7 8 57 58 59 60 61 OOCKET NUMBER 05003350 68 69 74 75 EVENT DESCRIPTION Qo 2 During power ascension testing, one of the four redundant 120 volt ac 7 8 9 80 tOO~]inverter.This caused the loss of one channel of the Reactor Protection 7 8 9 80 Jog instrument ower busses was'lost due to malfunction of the 1C statio 89 I and Engineered Safeguards Systems.The bus was returned to service 80 7 8 9 80 t006 immediately by use of one of.the two redundant.

maintenance bypass busses.7 8 9 SYSTEM CAUSE COOS COOE~O7~ZO 7 8 9 10 11 12 CAUSE DESCRIPTION t00I Upon investigation, COMPONENT COOE GENERA SUPPLER MANUFACIURER VQIATION A G 1 9 5 N 17 43 48 the oscillator circuit board in the 1C inverter was 44 47 7 8 9 found to be faulty.The board was replaced.and the 1C inverter was 80 80 METHOO OF OTHER STATUS'ISCOVEAY N/A~a 44 45~46 AMOUNT OF ACTIVITY-N/A 44 45,.N/A N/A N/A N/A N/A 7 8 9 t110 tested satisfactorily.

7 89 FACtLITY STATUS POWER B~05 0 7 8 9 10 12 13 FOAM OF ACTIVITY COATENT RELEASEO OF RELEASE Qaj 4~Z 7 8 0 10 11 PERSONNEL EXPOSURES~00 0~Z 7 8.9 11 12 13 PERSONNEL INJURIES NUMBER OESCAIPTION

~q4 I0000J 7 89 11 12 PROBABLE CONSEQUENCES

~15 7 8 9 LOSS OR DAMAGE TO FACIUTY TYPE OESCAIPTION

~z 7 89 10 PUBLICITY OISCOVEAY OESCAIPTION N/A LOCATION OF AEI.EASE N/A 80 80 80 80 80 80 80 80 7 89 ADDITIONAL FACTORS See page 2 for continutation of Event Description.

7 8 9~80 80 7 89 M.A.Schoppman 305/552/3779 PHONE: 80 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).