ML20084H746

AO BFAO-7430W:on 740513,reactor Bldg Closed Cooling Water Backup Cooling Water Supply Valve FCV 67-50 Failed to Open. Caused by Plugged Strainer in Water Supply Line.Strainer Changed & Mod Approved

ML20084H746
Person / Time
Site:	Browns Ferry
Issue date:	05/23/1974
From:	Eric Thomas TENNESSEE VALLEY AUTHORITY
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084H749	List: ML20084H746 ML20084H751
References
AO-BFAO-7430W, NUDOCS 8305050002
Download: ML20084H746 (3)

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TENNESSEE VALLh AUTHOAITV tm CHAs 4 ANCOGA, TENNESSEE i

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,-4 . ' fp ' v' ,L X N Mr. John F. O' Leary, Director q'

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Office of Regulation \; N.' AQ/

U.S. Atomic Energy Co=aission '4- '2 md \/

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Dear Mr. O' Leary:

TENITESSEE VALLEY AUTHORITY - BROWNS FERRY UUCLEAR PLANT UNIT 1 -

DOCKET NO. 50-259 - FACILITY OPERATING LICENSE DPR ABNORMAL OCCURR3!CE REPORT BFAO-7430U The enclosed report is to provide details concerning a reactor building closed cooling water (R3CCU) backup cooling water supply valve FCV 67-50 which was inoperable and is submitted in accordance with Appendix A to Regulatory Guide 1.16, Revision 1, Octcber 1973 This event occurred on Brouns Ferry nuclear Plant unit 1 on May 13,1974.

Very truly yours, ,

TEIGESSEE VALLEY AUTHORITI

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' 7* E. . Tho=as Director of Power Production Enclosure CC (Enclosure):

Mr. Norren C. Ibseley, Director Region II Regulatorf Operations Office, USAEC 230 Peachtree Street, IDI. , Suite 818 Atlanta, Georgia 30303 l

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.. ABNORIML OCCURRENCE REPORT l Report No.: BFAO-7430W Report Date: May 23, 1974 Occurrence Date: May 13, 1974-l Facility: Browns Ferr/ Nuclear Plant unit 1 Identification of Occurrence Reactor building closed cooling water (RECCW) backup cooling water supply valve FCV 67-50 inoperable.

Conditions Prior to Occurrence The unit 1 reactor was in the cold shutdown condition. Routine surveillance testing of the F2CW system was in progress.

Description of Occurrence RBCCW backup cooling water supply valve FCV 67-50 was closed and would not open.

Designation of Antarent Cause of Occurrence FCV 67-50 is a nomany closed diaphragm operated valve requiring water pressure on the diaphragn to open the valve. A strainer in the water supply line to the diaphragm becane plugged and prevented the valve fro openirg.

Ane. lysis of Occurrence With FCV 67-50 inoperabic, the other RBCCW backup cooling water supply valve ,

(FCV 67-51) would have opened and supplied water to the RBCCW heat exchsngers had the nomal raw cooling water pressure dropped to a predetemined value.

Corrective Action The strainer in the waterline to the diaphragm operator was changed. A modifi-cation change request has been approved to modify this system and eliminate the need for frequent strainer changes. At the present time, the strainer on this valve is changed once a nonth. Until the modification is inplemented, the strainer change frequency wiu. be once ever/ two weeks.

Failure Data Nameplate data for FCV 67-50 is as follows:

Fisher Controls S/N .5442452 Type - 657-8-UR Size - 46 Spring Set - 7 .

PSIInitialTravel-41/8 30 FSI To open

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Failure Data (continued) >

Valve Body Size - 8

, Rating - 150 Body Material - WCB Steel Trim - 317 Chror.e -

Seal Construction - 316sS Order No. - 72C33-75133-1 Bushing - Stainless f

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