ML20052H662
| ML20052H662 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 05/14/1982 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20052H663 | List: |
| References | |
| NUDOCS 8205210317 | |
| Download: ML20052H662 (2) | |
Text
I T
N
@ ona hrst Nabomt Plaza. Chicago. Ithnois' Commonwealth Edison s
Address Repiy to Post Othee Box 767 f
Chicago, lihnois 60690 May 14, 1982 Mr. Harold R. Denton, Director Of fice of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Byron Station Units 1 and 2 Braidwood Station L%its 1 and 2 Auxiliary Feedwater System Reliability NRC Docket Nos. 50-454, 50-455, 50-456 an d 50-457 References (a):
September 18, 1981, letter from T. R.
Tramm to H. R. Denton.
(b):
October 27, 1981, letter from T. R. Tramm to H. R. Denton.
(c):
October 30, 1981, letter from D. G.
Eisenhut to L. DelGeorge (d):
Novembe r 10, 1981, letter from T. R.
Tramm to H. R. De nton.
(e):
December 15, 1981, letter from T. R. Tramm to H.
R. Denton.
(f):
Janua ry 7, 1982, letter from T. R. Tramm to H. R. Denton.
Dear Mr. Denton:
This is to provide additional information regarding the reliability o f the Byron /Braidwood Auxiliary Feedwater System ( AFWS).
Enclosed is the final report of the reliability analysis f)DOj for the Byron /Braidwood auxiliary feedwater systems.
This report contains the supporting details for the reliability estimate r
reported in reference (f) and referenced in the Byron SER.
It replaces the analyses discussed in references (a), (b), (d) and (e).
f f <r The analysis reported here includes changes in assumptions for the Loss of Offsite Power (LOOP) initiating event and the addition of a fault tree path to evaluate a " failure to supply bus 141 from bus 241".
Those were the final changes requested by the NRC Staf f in their review of the original analysis.
An AFWS unavailability per demand of 9.2 x 10-5 has been demonstrated for the LOOP event.
We understand that with these changes our analysis is acceptable according to the guidance contained in NUREG-0800.
8205210317 820514 PDR ADOCK 05000454 A
~
1 1
H. R. Denton May 14, 1982 The.results of this analysis will be incorporated into the i
FSAR at the earliest opportunity.
Please address questions regarding this matter to this office.
l' One signed original and fif teen copies of this letter are l
provided for your use.
Fif teen copies of the report are also enclosed.
Very truly yours,
&{E rT4n -
T. R. Tramm Nuclear Licensing Administrator 1m f
Enclosure:
" Byron Units 1 & 2, Braidwood Units 1 & 2 Auxiliary Feedwater System Reliability Analysis; Final Report" - Revision 1, l.
April, 1982, Torrey Pines Technology,
GA-C16444 cc:
I. Papazoglou, Brookhaven Nat'l Laboratory 4107N 4
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