05000296/LER-1996-004-01, Forwards LER 96-004-01,clarifying Analysis of Event Section Which Div I & II ECCS Equipment Remained Operable for Automatic Initiation

Forwards LER 96-004-01,clarifying Analysis of Event Section Which Div I & II ECCS Equipment Remained Operable for Automatic Initiation

ML18038B766
Person / Time
Site:	Browns Ferry
Issue date:	09/30/1996
From:	Machon R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML18038B767	List: 05000296/LER-1996-004-01, Forwards LER 96-004-01,clarifying Analysis of Event Section Which Div I & II ECCS Equipment Remained Operable for Automatic Initiation
References
NUDOCS 9610090124
Download: ML18038B766 (6)

LER-1996-004, Forwards LER 96-004-01,clarifying Analysis of Event Section Which Div I & II ECCS Equipment Remained Operable for Automatic Initiation

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
2961996004R01 - NRC Website

text

CATEGORYi REGUZ 1'ORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9610090124 DOC.DATE: 96/09/30 NOTARIZED: NO DOCKET FACIL:50-.296 Browns Ferry 'Nuclear Power Station, Unit 3, Tennessee 05000296 AUTH.NAME AUTHOR AFFZLIATZON MACHON,R.D.

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

SUBJECT:

Forwards LER 96-004-0l,clarifying analysis of event section which Div I

& II ECCS equipment remained operable for automatic initiation.

DZSTRZBDTZON CODE:

ZE22T COPZES RECEZVED:LTR L ENCL

(

SZEE: 2 TITLE: 50.73/50.9 Zicensee Event Report (LER), Incident Rpt, etc.

NOTES:

RECIPIENT ID CODE/NAME PD2-3-PD INTERNAL: AC ENTE EELB NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN2 FILE 01 COPIES LTTR ENCL 1

1 1

1 1

1 1

1 1

1 1

1' 1

1 1

1 1

RECIPIENT ID CODE/NAME WILLIAMSEJ~

AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DSIR/EIB COPIES LTTR ENCE 1

1 2

2 1

1 1

1 1

1 1

1 1

1 1

1 EXTERNAL: L ST LOBBY WARD 1

1 NOAC MURPHY,G.A 1

1 NRC PDR 1

1 LITCO BRYCE,J H

NOAC POORE,W.

NUDOCS FULL TXT' 1

1 1

1 1

D U.

Mi E

N NOTE TO ALL NRIDS N RECIPIENTS PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR'ORGANIZATION, CONTACT"THE DOCUMENT CONTROL DESK (DCD)

ON EXTENSION 415-2083 FULL TEXT CONVERSION REQUIRED TOTAL 'NUMBER OF COPIES REQUIRED:

LTTR 24 ENCL 24

Teririessee va~ Authority, post cÃce Box 2000. Decatur. Aaoarria 356c9.2000 September 30, 1996 R. D. (Rick) Machon Vice Pres>cent. Brovms Ferry Nuclear Past U.S. Nuclear Regulatory Commission ATTN:

Document Control Desk Washington, D.C.

20555 Gentlemen:

10 CFR 50.73 BROGANS FERRY NUCLEAR PLANT (BFN) - UNITS 1~

2q AND 3 - DOCKET NOS ~ 50-259~

260~

AND 296 - FACZLZTY OPERATING LZCENSE DPR-33'2'ND 68 - LZCENSEE EVENT REPORT 50-296/96004+

REVISION 1 This revision to LER 50-296/96004 is to clarify in the Analysis of the Event section which Division I and Division II ECCS equipment remained operable for automatic initiation, and which Division I ECCS equipment would be required to be manually initiated.

The initial report also provided details concerning the loss of instrumentation input logic for the plant's Division I Emergency Core Cooling Systems (ECCS).

The July 17,

1996, ev resumed to be caused by a failed control board in the D1vision I Analog Trip Unit Inverter.

On August 6,

1996, a similar event occurred.

When TVA has determined the root causes and has taken appropriate corrective actions for both events to preclude recurrence of this type of an event, TVA will submit a supplemental report.

In addition, the initial report noted that TVA has had

previous similar events

TVA believes that corrective actions taken to resolve those events would not have precluded this event.

However, due to the aggregate of these

events, TVA is conducting a broader evaluation of inverter problems.

Consequently, TVA's current presumption that past inverter problems were separate and isolated may change.

This evaluation result will be addressed in another supplemental report.

96i0090i24 960930 PDR ADQCK 05000296 8

PDR

'0 0

4I

U.S. Nuclear Regulatory Commission Page 2

September 30, 1996 Finally, the initial report was submitted in accordance 'with 10 CFR 50.73 (a) (2) (vii).

Sincerely, R.

D.

M hon Enclosure cc (Enclosure):

INPO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 Paul Krippner American Nuclear Insurers Town Center, Suite 300S 29,South Main Street West Hartford, Connecticut 06107 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road

Athens, Alabama 35611 Regional Administrator Region II 101.Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. J.

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

II Ik