ML20214X090

Forwards Safety Evaluation Re Structural Integrity of Mark I Containment Drywell Vacuum Breakers.Analyses Performed to Predict Breaker Impact Velocities & Verify That Resulting Stresses Used Acceptable Methodology

ML20214X090
Person / Time
Site:	Quad Cities
Issue date:	11/26/1986
From:	Zwolinski J Office of Nuclear Reactor Regulation
To:	Farrar D COMMONWEALTH EDISON CO.
Shared Package
ML20214H117	List: ML20214H115 ML20214X090 ML20214X111
References
GL-83-08, GL-83-8, TAC-57150, TAC-57151, NUDOCS 8612100537
Download: ML20214X090 (3)

Text

i g ab o UNITED STATES

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6 8 n NUCLEAP REGULATORY COMMISSION h  : WASHINGTON, D. C. 20555

% y,,, # November 26, 1986 Docket No. 50-254/265 Mr. Dennis L. Farrar Director of Nuclear Licensing Commonwealth Edison Company Post Office Box 767 Chicago, Illinois 60690

SUBJECT:

SAFETY EVALUATION F0'l STRUCTURAL INTEGRITY OF MARK I CONTAINMENT -

DRYWELL VACUUM BREAKERS (TAC'S 57150, 57151; MPA D-20)

Re: Quad Cities Power Station, Units 1 and 2.

In December of 1979, the General Electric Company (GE) issued Service Information letter (SIL) No. 321 informing customers of unanticipated cycling and damage to drywell vacuum breakers during LOCA tests in a Mark I containment full-scale test _ facility. The SIL addressed the possibility of vacuum breaker failure due to chugging. Failure due to pool swell was determined to be not applicable to Mark I containments.

To assure that drywell vacuum breakers would be capable of withstanding chugging loads, the staff issued Generic Letter 83-08 on February 2, 1983, requesting licensees of Mark I Boiling Water Reactors to submit results of calculations which provide bases for either (1) modifications to the vacuum breakers, or (2) justification that the as-built vacuum breakers are acceptable. In your letter dated July 12, 1983 you provided the requested information describing the results of your analysis.

In SIL No. 321, Supplement 1 of August 24, 1984, GE announced the availability of plant-specific methodology. The plant-specific methodology is described in an enclosure (CDI Report No. 81-21 to a letter from H. C.

Pfefferlen to D. B. Vassallo, dated September 26, 1984. The staff l

evaluation of the plant-specific methodology was completed on December 24, 1984 (letter Vassallo to Pfefferlen dated December 24,1984). The evaluation describes restrictions and conditions on the use of the model.

These conditions and restrictions ensure conservatism in determination of the pallet impact velocity loads on the vacuum breakers during chugging.

On December 26, 1985 NRC staff requested additional information. The purpose of this request was to obtain verification that the pallet impact velocity used in your vacuum breaker stress analysis was eletermined using

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the approved methodology consistent with the conditions and restrictions prescribed by the staff. By letter dated March 17, 1986, you provided the additional information requested.

8612100537 861126 l PDR ADOCK 05000254 P PDR

O Mr. Dennis L. Farrar The staff's technical assistance contractor, Franklin Research Center (FRC1, has reviewed the results of the stress analysis to verify that the vacuum breaker stresses are within the ASME code allowable values for the materials used. Their Technical Evaluation Report is appended to our Safety Evaluation which is enclosed for your information.

Based on our review, NRC staff concludes that the analyses performed to predict the drywell vacuum breaker impact velocities and resulting stresses were performed using acceptable methodology and that the vacuum breakers will not be subjected to excessive stress as a result of LOCA chugging and condensation oscillation loads.

This completes our review of Multiplant Action Item D-20 for Quad Cities Power Station. If you have any questions concerning our review, please contact the NRC Ouad Cities Power Station Project Manager. .

Sincerely, f

. 14 1V John . Zwolinski, Director BWR Pr ject Directorate #1 Division of PWR Licensing

Enclosure:

Safety Evaluation cc w/ enclosure:

See next page

Mr. Dennis L. Farrar Quad Cities Nuclear Power Station Ccomonwealth Edison Company Units 1 and 2 cc:

Mr. R. C. O'Brien President Iowa-Illinois Gas and Electric Company 206 East Second Avenue Davenport, Iowa 52801 Mr. Michael I. Miller Isham, Lincoln & Beale Three First National Plaza Suite 5200 Chicago, Illinois 60602 Mr. Nick Kalivianakis -

Plant Superintendent Quad Cities Nuclear Power Station 22710 - 206th Avenue - North Cordova, Illinois 61242 Resident Inspector U. S. Nuclear Regulatory Commission 22712 206th Avenue North Cordova, Illinois 61242 Chairman Rock Island County Board of Supervisors Rock Island County Court House Rock Island, Illinois 61201 Mr. Michael E. Parker Division of Engineering Illinois Department of Nuclear Safety 1035 Outer Park Drive, 5th Floor Springfield, Illinois 62704 Regional Administrator, Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137