ML20084H501

AO BFAO-7441W:on 740618,during Performance of Surveillance Instruction on Core Spray Sys Loop II Logic,Pumps 1B & 1D Failed to Start.Caused by Bent Contact Arm on Relay.Arm Repaired & Checked for Adequate Wipe

ML20084H501
Person / Time
Site:	Browns Ferry
Issue date:	06/27/1974
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084H502	List: ML20084H501 ML20084H504
References
AO-BFAO-7441W, NUDOCS 8305040370
Download: ML20084H501 (2)

Text

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'Mr. John F. O' Leary, Director Y ) !y;pa ~,/

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Office of Regulation N U.S.- Atomic Energy Comission ;p[ C//

Washington, DO 20545 ~

Dear Mr. O' Leary:

TEINESSEE VALLEY AUTHORITY - BROWS FERRY UUCLEAR PINiT UNIT 1 -

DOCKET no. 50-259 - FACILITY OPERATING LICENSE DPR ABRORMAL OCCURRENCE REPORT BFAO-7441W The enclosed report is to provide details concerning core spray systen pu=ps 13 cnd 1D which failed to start during routine surveillance testing on unit 1 and is submitted.in accordonce with r p endix A to Regulatory Guide 1.16, Revision 1, October 1973 This event occurred on Browns Ferry Nuclear Plant unit 1 on June 18, 1974.

Very truly yours, TENNESSEE VALLEY AUTHORITY E. F. Thomas Director of Pouer Production Enclosure CC (Enclosure):

Mr. Norman C. Moseley, Director Region II Regulatory Operations.0ffice, USAEC 230 Peachtree Street, L"cT. , Suite 818 Atlanta, Geor61a 30303 l

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O ABNORMAL OCCURRENCE REPORT

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Report Ho.: BFAO-7441U Report 1Date: June 28, 1974

' Occurrence Date: June 18, 1974 Facility: Browns Ferry Nuclear Flert unit 1

, Identification of Occurrence Core spray system pumps 1B cnd ID failed to start during routine surveillnnee testing on unit 1.

Conditions Prior to Occurrence The unit was at 100-percent power.

Description of Occurrence During the perforrance of a surveillence instruction on core sprey system loop II logic, purps 13 and 1D failed to start when called upon by a simulated automatic initiation signal.

Designation-of Anuarent Cause of Occurrence A bent contact arm on a relay that permits initiation of the loop II core sp"ev zumnn unn e n nnr. niinu +.na con nnr. nn rwor. om en heya en 9eq,29re eye,. int er np2 to perform its intended function. This relay is one of two relays which actuate on decreasing reactor pressure to allow the core spray system loop II pumps to start if called upon by automatic initiation.

Analysis of Occurrence The failure of the relay contact would not have inhibited the core spray system 4

loop II pu ps from stcrting had they been automatical3y initiated. The contact that failed has another contact in parallel with it that actuates from a redundant signal to perform the same function.

Corrective Action The bent contact arm uns imediateAv repaired and checked for adequate wipe.

The surveillance instruction was completed uith satisfacto./ results.

Failure Data

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The relay on which the bent contact arm is ' located is a 250V de, type HFA51A,

., manufactured by General Electric Co=pany.

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