ML20093F843
| ML20093F843 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 10/04/1984 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20093F846 | List: |
| References | |
| 9259N, NUDOCS 8410150248 | |
| Download: ML20093F843 (32) | |
Text
.____
. Commonwealth Edison
(
) one r.rst Natenit Plaza. Chicago. Ilhnois i
C 7 Addr:,ss R; ply to: Post Offics Box 767
]
\\
/ Chicago, Illinois 60690 October 4, 1984 Mr. Harold R.-Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555 Sub ject:
Byron Generating Station Units 1 and 2 Braidwood Generating Station Units 1 and 2 Ventilation System Filtration NRC Docket Nos. 50-454/455 and 50-456/457 Reference (a):
June 21, 1983 letter from B. J. Youngblood to D. L. Farrar.
Dear Mr. Denton:
This letter provides information to document the basis for excluding moisture separators and heaters from the design of certain ventilation systems at Byron and Braidwood.
NRC review of this information is necessary.to close Outstanding Item 18 in the Byron SER.
In reference (a) the NRC requested that Commonwealth Edison reexamine the need for moisture separators and heaters in the systems which ventilate the auxiliary building non-accessible areas and the fuel handling building.
The enclosed documents contain calculations, diagrams and other information which demonstrate that such equipment is unnecessary to assure satisfactory operation of the HEPA filters and charcoal adsorbers in these ventilation systems.
Part 4 of the response to FSAR question 311.23 documents an analysis of the relative humidity in the air streams treated by the filter systems serving the fuel handling building.
For a postulated fuel handling accident under a variety of conditions the relative humidity at the charcoal filter is shown to be less than 70%.
FSAR accident analysis assumptions regarding filter efficiency are
-therefore valid.
Attachment A to this letter contains a similar analysis of moisture entrainment and relative humidity at the filters serving non-accessible areas of the auxiliary building.
Responses to NRC Staff questions on this analysis are also included.
For a postula-ted 30 minute 50 gpm leak of an RHR pump seal, it is shown that B410150248 841004 k
PDR ADOCK 05000454 E
~
H. R. Denton October 4, 1984 moisture entrainment will not be a problem and that the relative humidity will be well below 70% for outside air temperatures ranging from 40 - 95% at 90 percent relative humidity.
This analysis provides further validation of the assumptions made in the FSAR analyses.
Please address further questions regarding this matter to this office.
One signed original and fifteen copies of this letter and the attachments are provided for NRC review.
Very truly yours,
[$ rT4W T. R. Tramm Nuclear Licensing Administrator i
1m 9259N 1
l
- - _ -._