ML20086G250

Environ RO 76-14:on 760224,three Cooling Towers Became Simultaneously Inoperative.Caused by Mechanical Failure. Valve Repaired & Tower Returned to Svc

ML20086G250
Person / Time
Site:	Peach Bottom
Issue date:	03/05/1976
From:	Cooney M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Stello V Office of Nuclear Reactor Regulation
References
RO-76-14, NUDOCS 8401100178
Download: ML20086G250 (2)

Text

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O O PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET PHILADELPHIA. PA.19101 .  ;, ,

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Mr. Victor Stello, Jr. ', q 'D% / hf~

Director Division of Operating Reactors Office of Nuclear Reactor Regulations

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United States Nuclear Regulatory Comission Washington, DC 20555

Subject:

Cnvironmental Deviation The following deviation was reported to Mr. Walt Baunack, Office of Inspection and Enforcement, Region 1, United States Nuclear Regulatory Comission on February 24, 1976.

Reference:

License Number DPR-44/56 Environmental Technical Specification: 2.1 Report No.: 50-277/278-76-14 Report Date: March 5,1976 Deviation Date: February 24, 1976 Facility: Peach Bottom Atomic Power Station Units 2 & 3 R. D. 1, Delta, PA 17314 Identification of Deviatien:

Three cooling towers simultaneously inoperative, Conditions Prior to Deviation:

Units 2 and 3 operating at approximately 84% and 58% power, respectively. The "A" cooling tower was out of service due to the previous lift pump failure. The "B" cooling tower was out of service due to a di stribution header f ailure earlier on the same date. River flow was approximitely 150,000 cfs.

Description of Deviation:

Failure of the stem bushing retaining plate on a cell distribution valve on the "C" cooling tower caused excessive water supply to the cell resulting in water overflow and a very large ice buildup on the south side louvers of that cell. The tower was removed from service to

( prevent structural failure.

• t 8401100178 760305 gDRADOCK05000 g SOPY SENT REGION  %

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I Hr. V. Stello 50-277/278-76-14 March 5, 1976 Page 2 Designation of Apparent Cause of Deviation:

l Mechanical failure.

Analysis of Deviation:

Differential temperatures between Pennsylvania-Maryland i

State Line and the Holtwood Dam remained well within the Pennsylvania j State Limits during the period of time the tower was out of service.

The thermal impact of this deviation is .i e. mal due to the reduced plant power production and high river flow.

Corrective Action:

)

i The valve was repaired and the tower was returned to service late on 2/24/76.

Failure Data:

! None similar.

Very truly yours,

. E',/. !N -[, A. f

(hmi /*u /

M. J. Cooney j Superintendent Generation Division - Nuclear cci Mr. J. P. O'Reilly, NRC l

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