ML17195A950

Forwards Two Safety Evaluations Approving Util plant-unique Analysis Rept on Pool Dynamic Loads for Mark I Containment & Mods on Containments & Torus Attached Piping.Bnl Technical Evaluation of plant-unique Analysis Rept Encl

ML17195A950
Person / Time
Site:	Dresden
Issue date:	09/18/1985
From:	Zwolinski J Office of Nuclear Reactor Regulation
To:	Farrar D COMMONWEALTH EDISON CO.
Shared Package
ML17195A951	List: ML17195A950 ML17195A952 ML17195A953 ML20204G817 ML20205B027
References
LS05-09-014 LSO5-85-09-014, LSO5-85-9-14, NUDOCS 8509230613
Download: ML17195A950 (3)

Text

• UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555

,September 18, 1985 Docket Nos. 50-?.37/?49 LS05-85-09-014 Mr. Dennis L. Farrar Director of Nuclear Licensing Commonwealth Edison Company Post Office Box 767 Chicago, Illinois 60690

SUBJECT:

MARK I CONTAINMENT LONG TERM PROGRAM Re: Dresden Nuclear Power Station, Unit Nos. 2 and 3 The staff has completed a post-implementation audit review of the Dresden, Unit Nos. 2 and 3, Plant Unique Analysis Report (PUAR) for the Mark I containment long term program. Enclosed are the staff's Safety Evaluations for the pool dynamic and structural load aspects of this program. Technical assistance was provided by Brookhaven National Laboratory for the pool dynamic load audit review and by Franklin Research Center for the structural audit review. Copies of their technical evaluations are also enclosed.

The staff has determined that all but a few of the modifications made by Commonwealth Edison (CECo) are in accordance with the generic acceptance criteria contained in Appendix A of NUREG-0661, Mark I Containment long Term Program and its supplement. Where deviations from the acceptance criteria specified in NUREG-0661 have been taken, they have been found acceptable. Therefore, the staff has concluded that CECo's PUAR analysis verified that the containment modifications made have restored the original design safety margin to the Mark I containments at Dresden, Units 2 and 3.

This action completes the staff's review of this issue.

The vacuum breakers on Mark I containments, which were the subject of Generic letter 83-02, are not considered within the scope of the Mark I containment long term program. This issue will be reviewed independently at a later date.

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• 1 '

Mr. Dennis L. Farrar September 18, 1985 Within 90 days of receipt of this letter it is requested that you submit any Technical Specification changes required as a result of* the Mark I containment modifications you have made; (i.e., torus temperature monitoring system changes, torus to drywell differential pressure control changes, torus water level changes).

Sincerely, John A. Zwolinski, Chief Operating Reactors Branch #5 Division of Licensing

Enclosures:

1. Safety Evaluation - Pool Dynamics Load

2. Safety Evaluation - Structural Review

3. BNL Technical Evaluation Report

4. FRC Technical Evaluation Report cc w/enclosures:

See next page DISTRIBUTION Docket OELD NRC PDR EL.Jordan Local PDR BGrimes NSIC ACRS ( 10)

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Mr. Dennis L. Farrar Dresden Nuclear Power Station Commonwealth Edison Company Units 1, 2 arid 3 cc:

Robert G. Fitzgibbons Jr.

Isham, Lincoln &Beale Three First National Plaza Suite 5200 Chicago, Illinois 60602 Mr. Doug Scott Plant Superintendent Dresden Nuclear Power Station Rural Route #1 Morris, Illinois 60450 U. S. Nuclear Regulatory Commission Resident Inspectors Office Dresden Station Rura 1 Route #1 Morris, Illinois 60450 Chairman Board of Supervisors of Grundy County Grundy Countv Courthouse Morris, Illinois 60450 Regional Administrator Nuclear Regulatory Commission, Region III 799 Roosevelt Road Glen Ellyn, Illinois 6n137 Gary N. Wright, Manager Nuclear Facility S~fety Illinois Department of Nuclear Safety 1035 Outer Park Drive, 5th Floor Springfield, Illinois 62704