ML20197C830
| ML20197C830 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 09/01/1998 |
| From: | Schwartz G COMMONWEALTH EDISON CO. |
| To: | Krich R COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 9809140220 | |
| Download: ML20197C830 (3) | |
Text
Commonwc. tith lilium Company Hraidwood Generating Station Route al, tha H 6 lir.n cs tile, 11.60605*019 Tcl His 658 2801 Memorandum Date:
September 1,1998 To:
R. M. Krich Vice President Regulatory Services
Subject:
Revised Thermo-Lag Ampacity Derating Factor Calculation
Reference:
1.
Teleconference, February 2, 1998, NRC staff with Byron, Braidwood, and Dowers Grove Engineering, "Thermo-Lag Ampacity Derating Factors" 2.
Calculation BYR98-109/BRW-98-339-E, Revision 2, " Base Line Ampacity Values for Standard Fire Wrap Configurations," August 25,1998.
In the Reference I teleconference, the NRC requested Comed to revise the thermal l
analyses models used in the determination of the ampacity derating factors for fire-protected cables at Byron and Braidwood Stations.
The reference 2 calculation documents the revised analysis.
This calculation has been reviewed by Braidwood Site Engineering and fmds it acceptable for transmittal to the NRC staff. It is understood that this submittal should be an acceptable closure to this item. If there are any questions or comments concerning this letter, please contact Richard L. Schliessmann, Regulatory Assurance at extension 2038.
Sincerely, bk4
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/* G. K. Schwanz Station Manager Braidwood Generating Station Ols98029Aie
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Attachment CC:
J.T. Luke I
T.W. Simpkin
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I M. Lesniak 9809140220 990901 PDR ADOCK 05000454 F
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A l'nicom Company
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. August 31,1998 l
United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington. D. C. 20555 - 0001
Subject:
Revised Thermo-Lag Ampacity Derating Factor Calculation Byron Station, Units 1 and 2 Facility Operating Licenses NPF-37 and NPF-66 NRC Docket Nos: STN 50-454 and STN 50-455 Braidwood Station, Units I and 2 Facility Operating Licenses NPF-72 and NPF-77 NRC Docket Nos: STN 50-456 and STN 50-457
Reference:
J. B. Ilosmer (Commonwealth Edison) to US Nuclear Regulatory Commission letter dated September 19,1997.
The referenced letter provided the Commonwealth Edison (Comed) response to an NRC request for additional infonnation (RAI) on the analytical models used to establish the ampacity derating for fire-protected cables at Byron and Braidwood. In a February 2, 1998 telecon the NRC staff noted that all issues addressed in the RAI response were resolved with the exception of one issue (i.e., Comed's use of two different thermal analyses models for the baseline and cladded fire barrier configurations to derive the ampacity derating ratio). In the telecon, the staff requested Comed to revise calculation BYR 96-082/BRW 96-194 to be consistent in the comparison of fire barrier configurations.
Comed has revised the thermal analyses models used in the determination of the ampacity derating factors for fire-protected cables, cable trays, and conduits at Byron and Braidwood Stations. The new calculation, BYR98-109/BRW-98-339-E, that documents the reanalysis is an enclosure to this letter. The reevaluation of fire-protected cables at Byron and Braidwood utilizing the revised ampacity derating factor has determined that all cable routing points aw acceptable.
L Comed strongly encourages a meeting with the NRC staff to explain the analysis and to l
address any staff questions. Such a meeting may provide the best means to expedite the review of this issue and to bring this matter to closure.
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Please address any comments or questions regarding this matter to Mr. David J.
l Chizanowski at (630) 663-7205.
Sincerely, E
R. M. Krich I
Vice President - Regulatory Services I
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Enclosures:
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Regional Administrator-USNRC, RIII NRC Senior Resident inspector-Braidwood Station NRC Senior Resident inspector-Byron Station e
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