ML20084H305

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Informs That Circulating Water Pumps Not Designed to Operate Below 590-ft Elevation (Top of 30-day Emergency Water Supply of Uhs).In Event of Dike Failure,Pumps Will Be Manually Tripped Before Level Reaches 590-ft Elevation
ML20084H305
Person / Time
Site: Braidwood  Constellation icon.png
Issue date: 04/26/1984
From: Swartz E
COMMONWEALTH EDISON CO.
To: Harold Denton
Office of Nuclear Reactor Regulation
References
8529N, NUDOCS 8405080010
Download: ML20084H305 (2)


Text

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f N Commonwe:lth Edison

[ ) One First National Plaza. ChrCago, lihnois

't - " ? Address Reply to. Post Office Box 767

'(p/ Chicago. Illinois 60690 April 26, 1984 Mr. Harold R. Denton, Director Of fice of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Braidwood Station Units 1 and 2 Circulating Water Pump Trip NRC Docket Nos. 50-456/457

Dear Mr. Denton:

On December 27, 1983 and January 9, 1984, the Commonwealth Edison Company held teleconferences with Ms. Janice A. Stevens and other NRR staff members to discuss our circulating water pump _ trip set point in relation to our thirty day Ultimate Heat Sink (UHS) water supply given a dike failure at Braidwood Station. The purpose of this letter is to document our intentions in thiV matter.

At Braidwood Station the normal cooling lake water level is at elevation 595'. There exists a lake level indicator OLI-CWO41 within the main control room along with its associated low lake level alarm OLSL-CWO41 with set point at 594'. Additionally, there exists circulating water pump discharge pressure indication in the control room indicative of satisfactory pump operating conditions.

The circulating water pumps art not designed to operate below the 590' elevation, which is the top of the thirty daf emergency water supply of the UHS. In the unlikely event of a dike failure, the pumps will be manually tripped before the lake water level reaches the 590' elevation to avoid damage to the pumps. The operator actions necessary to accomplish this utilizing the above instrumentation will be defined in applicable Braidwood Station emergency operating procedures when written.

Please address any questions concerning this matter to this office.

One (1) signed original and fifteen (15) copies of this letter are provided for your use.

Very truly you ,

E. Douglas Swa t Nuclear Licensing Administrator cc: RIII Inspector - Braidwood i 8405080010 840426

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590' minimum CW pump submergence lake level (2 feet above discharge pipe centerline 8588' per the pump curve) i.

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