05000296/LER-1996-008, Forwards LER 96-008,providing Details Concerning Loss of Instrumentation Input Logic for Plants Division II ECCS Due to Cleared Fuse & Shorted Silicon Controlled Rectifier in Atu Inverter

Forwards LER 96-008,providing Details Concerning Loss of Instrumentation Input Logic for Plants Division II ECCS Due to Cleared Fuse & Shorted Silicon Controlled Rectifier in Atu Inverter

ML18038B805
Person / Time
Site:	Browns Ferry
Issue date:	01/15/1997
From:	Machon R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML18038B806	List: 05000296/LER-1996-008, Forwards LER 96-008,providing Details Concerning Loss of Instrumentation Input Logic for Plants Division II ECCS Due to Cleared Fuse & Shorted Silicon Controlled Rectifier in Atu Inverter 05000296/LER-1996-008-03, :on 961217,loss of ECCS Division II Instrumentation Caused ECCS Equipment to Be Inoperable. Replaced Cleared Fuse & Shorted SCR
References
NUDOCS 9701210379
Download: ML18038B805 (6)

LER-1996-008, Forwards LER 96-008,providing Details Concerning Loss of Instrumentation Input Logic for Plants Division II ECCS Due to Cleared Fuse & Shorted Silicon Controlled Rectifier in Atu Inverter

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
2961996008R00 - NRC Website

text

REGULATOINFORMATION DISTRIBUTION TEM

('RIDE)

ACCESSION NBR:9701210379

'DOC.DATE: 97/01/15 NOTARIZED:

NO DOCKET FACIL:50-296 Browns Ferry Nuclear Power Station, Unit 3, Tennessee 05000296 AUTH.NAME AUTHOR AFFILIATION MACHON,R.D.

Tennessee, Valley Authority RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Forwards LER 96-008,providing details concerning loss of instrumentation input logic for plants Division II ECCS due to cleared fuse

& shorted silicon controlled rectifier in ATU, inverter.

DISTRIBUTION CODE:

IE22T COPIES RECEIVED:LTRl ENCLj SIZE: ~+

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:

E RECIPIENT ID CODE/NAME PD2-3-PD INTERNAL: ACRS AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DET/EIB EXTERNAL: L ST LOBBY WARD NOAC MURPHYFG A NRC PDR COPIES LTTR ENCL 1

1 1

1 2

2 1

1 1

1 1

1 1

1 1

1 1

1 1

1 1

1 1

1 RECIPIENT ID CODE/NAME WILLIAMS,J.

MEME NRR/DE/EELB NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN2 FILE 01 LITCO BRYCE,J H

NOAC POORE,W.

NUDOCS FULL TXT COPIES LTTR ENCL 1

1 2

2 1

1 1

1 1

1 1

1 1

1 1

1 1

1 1

1 1

1 1

1 0

Y D

0 C

N NOTE 'TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE!

CONTACT THE DOCUMENT CONTROL DESK, ROOM OWFN SD-5(EXT. 415-2083)

TO ELIMINATE YOUR NAME FROM DISTRIBUTION L1STS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL 'NUMBER'F COPIES REQUIRED:

LTTR 26 ENCL 26

Il I

Tet~~see Ve~ Au'.ttonty. Post Otftoe Sox 2000, Decatur. Mos~ 35569 ".000 January 15, 1997 R.,D. (Rick) Machon Vce PtesoettlSr<was Fery N~Cteat Pteot U.S. Nuclear Regulatory Commission ATTN:

Document Control Desk Washington, D.C.

20555

Dear Sir:

10 CFR 50.73 BROWNS FERRY NUCLEAR PLANT (BFN) - UNITS 3 - DOCKET NOS.

50-296

- FACILITY OPERATING LICENSE DRP-68

- LICENSEE EVENT REPORT 50-296/96008 The enclosed report provides details concerning the loss of instrumentation input logic for the plant's Division II Emergency Core Cooling Systems (ECCS) due to a cleared fuse and shorted Silicon Controlled Rectifier in the ATU inverter.

This is the fourth Unit 3 inverter failure (the first was reported in LER 50-296/96004),

but it was the first Unit 3 Division II inverter failure.

The root cause analysis resul'ts and corrective actions to preclude recurrence will be included in a LER 50-296/96004 supplemental report.

This report is submitted in accordance with 10 CFR 50.73 (a) (2) (vii) and (a) (2) (i) (B).

Sincerely, WzxrXI~I>~~-.

R.

D. Hachon Enclosure cc:

See page 2

9701210379 970115 PDR ADOCK 05000296

'S PDR

il I

U.S. Nuclear Regulatory Commission Page 2

January 15, 1997 Enclosure cc (Enclosure):

Mr. Mark S. Lesser, Branch Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900

Atlanta, Georgia 30323 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road

Athens, Alabama 35611 Mr. J.

F. Williams, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852

4l