ML20073G944
| ML20073G944 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 04/12/1983 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8304180441 | |
| Download: ML20073G944 (1) | |
Text
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One First National Plaza. Ch>Cago. Illinois Address Reply to: Post Office Box 767 Chicago. Illinois 60690 April 12, 1983 1
Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 I
Subj ect:
Byron Generating Station Units 1 and 2 Braidwood Generating Station Units 1 and 2 Steam Generator Tube Vibration NRC Docket Nos. 50-454, 50-455, 50-456, and 50-457.
Reference (a): February 9, 1983 letter from T. R. Tramm to H. R. Denton
Dear Mr. Denton:
This letter will document our present intentions with regard to modification of the Byron /Braidwood steam generators to minimize tube degradation associated with flow-induced vibration. We are revising the position taken in reference (a) with regard to the timing of these i
modifications.
On March 23, 1983, Westinghouse updated the NRC on the status of the engineering efforts underway to develop modifications for their D-4, D-5, and E types steam generators. Test data and analyses were presented to demonstrate that a combination of expanding selected tubes at two tube support plates in the pre-heater section and the bypassing of 10% of the main feedwater flow to the auxiliary feedwater nozzle would solve the flow-induced tube vibration problem.
In reference (a), Commonwealtt: Edison previously indicated that such modifications would be installed on the Byron /Braidwood steam generators prior to fuel loading if it was practical to do so.
Otherwise, authorization was requested to operate unmodified steam generators at a reduced power level. Upon review of the present status of engineering and schedules, it appears that we will be able to implement the planned modifications on all steam generators prior to fuel loading. Approval of the interim power restriction for unmodified steam generators is, therefore, no longer necessary. The request in reference (a) for this approval is hereby withdrawn.
Please contact this office if additional information is needed.
Very truly yours,
/d" T. R. Tramm Nuclear Licensing Administrator 8304180441 830412 dl i
PDR ADOCK 05000454 A
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