ML18038B766

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: ML18038B766 ML18038B768
References
NUDOCS 9610090124
Download: ML18038B766 (6)

Text

REGUZ ACCESSION NBR:9610090124 CATEGORY 1'ORY INFORMATION DOC.DATE:

FACIL:50-.296 Browns Ferry 'Nuclear Power 96/09/30 i

DISTRIBUTION SYSTEM (RIDS)

NOTARIZED: NO Station, Unit 3, Tennessee 05000296 DOCKET 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 (

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

SZEE: 2 NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCE PD2-3-PD 1 1 WILLIAMSEJ~ 1 1 INTERNAL: AC 1 1 AEOD/SPD/RRAB 2 2 ENTE 1 1 NRR/DE/ECGB 1 1 EELB 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1' NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 1 NOAC MURPHY,G.A 1 1 NOAC POORE,W. 1 1 D

NRC PDR . 1 1 NUDOCS FULL TXT' 1 1 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 10 CFR 50.73 ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:

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 actions previous similar events. TVA believes that corrective 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 101 II

.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

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