ML20086G245

Environ RO 76-21:on 760419,two Cooling Towers Became Simultaneously Inoperable.Caused by Broken Gear Reducer Bracket Resulting in Fan Trip Due to High Vibration.Fans E&F Returned to Svc

ML20086G245
Person / Time
Site:	Peach Bottom
Issue date:	04/29/1976
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Stello V Office of Nuclear Reactor Regulation
References
RO-76-21, NUDOCS 8401100173
Download: ML20086G245 (2)

Text

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. O O PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET l PHILADELPHI A. PA.19101 12153 84b40oo

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' #s Apri1 29, 1976 g 4 N ' \"V. ,

Mr. Victor Stello, Jr.

Director 2

Division of Operating Reactors 6,

Np0'ider cS"'* i Office of Nuclear Reactor Regulations United States Nucleer Regulatory Commission 3(A p vi5 f.S /

Washington, D. C. 20555 y j ' ',

SUBJECT:

ENVIRONMENTAL DEVIATION The following deviation was reported to Mr. Walt Baunack, Region 1, Of fice of Inspection and Enforcensent, United States Nuclear Regulatory Commission on April 19, 1976.

Reference:

License Number DPR-44/56 Environmental Technical Specifications: 2.1 Report No. : 50-277/278-76-21 Report Date : April 29,1976 Deviation Date: April 19, 1976 Facility: Peach Bottom Ator.iic Power Station Units 2 and 3 R.D. 1, Delta, rt 17314 Identification of Deviation:

Two cooling towers simultaneously inoperable. I Conditions Prior to Deviation:

Unit 3 was operating at full power and Unit 2 was off for a refueling outage. The "A" cooling tower was out of service due to a previous lift pump failure. The "C" cooling tower was operable during the outage. The "B" cooling tower was operable with 10 of its 11 f ans in service (the E fe.' was out of service due to prestous motor bearing and line bearing iailure) . River flow was about 22,000 CFS. i I

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8401100173 760429 PDR ADOCK 05000277  ;

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00PY SENT REGION a

M . Victor Stollo, Jr. 5 77/278-76-21 ,

April 29,1976 Page 2 Description of Deviation:

The "F" f an on the "B" cooling tower tripped due to high vibration. Since the "E" fan was already out of service for maintenance, the "B" cooling tower became inoperable per Environmental Technical Specification definition.

Designation of Apparent Cause of Deviation:

A broken gear reducer bracket caused the f an to trip due to high vibration.

Analysis of Deviation:

Because of single unit operation and the f act that 9 of the 11 cells of the "B" tower were always in service, the environ-mental impact of this occurrence is minimal.

Corrective Action:

The "F" f an was returned to service on April 21, 1976 thus restoring the cooling tower to operable status. Maintenance on the "E" f an was completed and the f an returned to satisf actory service on 4/27/76.

Failurc, Data Several previous similar occurrences.

Very truly yours, M. . Cooney Su erintendent Generation Division-Nuclear cc: Mr. J. P. O'Reilly NRC, Reg. Office i ,

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