ML20127P746
| ML20127P746 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 06/19/1985 |
| From: | Ainger K COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 0283K, 283K, NUDOCS 8507020503 | |
| Download: ML20127P746 (2) | |
Text
. _ _ _ _ _ _ _
Commonwealth E'J: son One First N tion t Pin:. Chicago. Ilknois Address Reply to Post Office Box 767 Chicago. lilinois 60690 June 19, 1985 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Byron Station Units 1 and 2 Braidwood Station Units 1 and 2 Piping Design Criteria NRC Docket Nos. 50-454, 50-455, 50-456 and 50-457 References (a):
January 17, 1985 letter from B. J.
Youngblood to D. L. Farrar (b):
June 18, 1984 letter from T. R. Tramm to H. R. Denton
Dear Mr. Denton:
Reference (b) contained Commonwealth Edison's request for NRC approval to use the Pressure Vessel Research Council (PVRC) recommended damping values on Byron and Braidwood stations.
Reference (a) specified certain limitations that should be followed when applying these revised damping values.
This letter is to confirm that the following conditions specified in Reference (a) will be complied with in our application of these higher damping values:
(1)
Approval is requested for use of the PVRC damping values in accordance with ASME Code Case N-411.
This Code Case will be used in its entirety in any given piping seismic analysis.
Damping values from Code Case N-411 and from Regulatory Guide 1.61 will not be combined in any given analysis.
(2)
The ASME Code Case N-411 damping values will be used only for seismic response spectra analysis and not for time history analysis.
$$0golg4 C
.A H. R. Denton June 19, 1985 (3)
Where pipe supports are modified, moved, or deleted as a result of using the damping values from Code Case N-411, the existing piping displacement limits for the Byron and Braidwood stations will be maintained.
In cases where piping movements exceed the displacement limits, adjacent structures, components, and equipment will be reviewed for adverse effects.
Our commitment to comply with the conditions discussed above should allow prompt NRC approval of this matter.
One signed original and fifteen copies of this letter are provided for NRC review.
Please address any further questions concerning this matter to this office.
Very truly yours, e
cf" K. A. Ainger Nuclear Licensing Administrator im cc:
Byron Resident Inspector Braidwood Resident Inspector 0283K