ML20097B834

Lists Planned Mods to Restore Drywell Cooling Redundancy, Including Addition of Six New Upper Area Drywell Fan Coil Cooling Units.Mods Will Be Completed by End of First Refueling Outage

ML20097B834
Person / Time
Site:	LaSalle
Issue date:	09/04/1984
From:	John Marshall COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
9132N, NUDOCS 8409140168
Download: ML20097B834 (2)

Text

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N Commonwealth Edison

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LkNy} Address Reply to: Post Office Box 767 Chicago, Illinois 60690 September 4, 1984

- Mr.' James G. Keppler Regionel Administrator ~

'U.S.

Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL. 60137

Subject:

LaSalle County Station Units 1 and 2 High Orywell Temperature Long Term Corrective Actions NRC Docket Nos. 50-373 and 50-374 References (a):- LER No. 83-143/OlT-0

-(b):

LER No. 83-145/03L-0 (c):

A. B. Davis letter P,o Cordell Reed dated December 2, 1984, Inspection Report Nos. 50-373/33-50 and 50-374/83-53.

(d):

C.

W. Schroeder letter to J. G. Keppler dated December 22, 1983.

(e):

C. E. Norelius letter dated January 13, Cordell Reed.

(f):

Inspection Report No. 373/84-02.

Dear Mr. Denton:

This letter addresses planned modifications to LaSalle County Station, Units 1 and 2, to restore drywell cooling redundancy.

These long term corrective modifications to ensure continued operation for both units over the full license life of the units have now been determined.

These actions / modifications are as follows:

1)

For each unit add six new upper area drywell fan coil cooling units.

2)

For each unit add a new Carrier Corp. 400 Ton Drywell Water Chiller to supply chilled water to the new upper area drywell. fan coil cooling units.

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-J.

G. Keppler' September 4, 1984

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Five of the six new area coolers in parallel operation with one of the two existing drywell cooler units have been designed to provide a

-15% margin over the expected long term heat load in the drywell.

Insulation degradation over the life of the plant has been taken into consideration in thel design margin.

The installation of the new fan coil cooling units and drywell chillers will restore drywell cooling redundancy and.thereby meet our commitment to the NRC (letter to J. G. Keppler from C.W. Schroeder dated December 22, 1983).

.The-scheduled completion dates for these modifications are tha end of the first refueling outage for each unit.

If you have any further questians or concerns, please contact this office.

Very truly yours,

.% N J. G. Marshall Nuclear Licensing Administrator lm ec:

Region III Inspector - LSCS 9132N

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