ML20032C060
| ML20032C060 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 10/28/1981 |
| From: | Sargent C COMMONWEALTH EDISON CO. |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20032C061 | List: |
| References | |
| NUDOCS 8111060657 | |
| Download: ML20032C060 (2) | |
Text
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- h Commonwealth Edison
) ons Rrst Naticnal Plaze, Chicrgo, filino;s O 7 Address Reply to: Post Office Box 767
/ Chicago, Illinois 60690 October 28, 1981 g
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4 Mr. A. Schwencer, Chief a NOV0 519815 :
Licensing Branch #2 3d u.a.m m Divison of Licening i
Co@UUN.,
8 U.S. Nuclear Regulatory Commission g"[e Washington, D.C.
20555 w
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Subject:
LaSalle County Station Units 1 and 2 Seismic Qualification of Equipment (SQRT)
Summary Report on Valve Flexibility NRC Docket Nos. 50-373/374
Dear Mr. Schwencer:
The purpose of this transmittal is to provide the Summary Report on Valve Flexibility Study which was incomplete at the time Volume 8 was transmitted to you.
This transmittal should be included as Item E of. Volume 8.
This valve flexibility study shows that the use of a 1.5 amplification factor to qualify flexible valves by use of a more elementary model is justified because such a solution is conserva-tive in comparison to the more exact qualificalon via a flexitle valve'model.
The particular samples selected for authentication of the conservatism included roaresentative LaSalle valve-operator combinations with mass ratrus dominated by the valve (Case 1) and dominated by the valve operators (Case 3).
Case 2 represents the majority of applications within the plant.
Solutions were made from the classical response spectra analyses and from ti,ae history analyses also.
The results of this flexibility study are shown in Table I o f the attachment for both analytical methods for each of two load combinations postulated for the study.
The conclusion is esta-blished that the 1.5 multiplication factor used in common practice to increase the acceleration at 'the center of gravity of a valve operator assembly provides a conservative result via the response spectra method of analysis o f a flexible valve - operator assembly.
This conclusion is applicable over the wide-range of valve operator mass-ratios encountered in a typcial power plant like LaSalle.
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Schwencer October 28, 1981 Three (3) copies of the Subject materials are attached for your use.
If there are any questions in this regard, please contact this office.
Very truly yours, es.2,w C. E.
Sa rgent Nuclear Licensing Administrator Attachment cc:
NRC Resident Inspector - LSCS (w/o Att.)
1m 2770N
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