ML20206B394
| ML20206B394 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 04/21/1999 |
| From: | Krich R COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20206B396 | List: |
| References | |
| NUDOCS 9904290233 | |
| Download: ML20206B394 (3) | |
Text
I Commonwealth Edimn Company 14@ Opus Place Downers Gmve, IL 60515-5701 April 21,1999 United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Braidwood Station, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50-457 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455
Subject:
Annual and 30-Day Report of the Emergency Core Cooling System Evaluation Model Changes and Errors Required by 10 CFR 50.46 In accordance with 10 CFR 50.46(a)(3)(ii), we are submitting a report of the Emergency Core hf Cooling System (ECCS) Evaluation Model changes and errors for Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2. This report satisfies the 30-day and annual reporting requirements of 10 CFR 50.46. The 30-Day Report is due April 21,1999,30 days from when we approved the greater than 50*F change in calculated Peak Cladding Temperature (PCT) for
>f~d2)j the limiting Small Break and Large Break Loss of Coolant Accident analyses for the Byron and
/
Braidwood Stations. The Annual Report is due April 23,1999. Therefore, this report is being submitted by April 21,1999. provides updated information regarding the PCT for the limiting Small Break and Large Break Loss of Coolant Accident analysis evaluations for the Byron and Braidwood Stations (i.e., PCT rack-up sheets). Attachment 1 includes all assessments as of March 22, 1999. Attachment 2 contains a detailed description for each change or error reported. contains a brief description of other Loss of Coolant Accident assessments, which are not included in the rack-up sheets. In all cases, these assessments resulted in benefits to the calculated PCT but we have conservatively chosen not to credit these PCT benefits, i.e., for
. each change a delta PCT of zero degrees Fahrenheit is assigned.
For all the discrepancies contained in this report, we have determined that these issues do not constitute significant safety concerns, and that the Byron and Braidwood Stations continue to comply with the requirements of 10 CFR 50.46. Compliance with 10 CFR 50.46 is maintained with existing PCT penalties. Therefore, no near-term reanalysis is planned for the Byron and Braidwood Stations, and a proposed schedule for providing a reanalysis is not required.
9904290233 990421 7
{DR ADOCK 05000454?
PDRj A Unicom Company
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~ April 21,1999 U.S. Nuclear Regulatory Commission Page 2 Should you have any questions concerning this letter, please contact Ms. K.M. Root at (630) 663-7292.
1 Respectfully, j
f R.M. Krich Vice President - Regulatory Services - Assessments as of March 22,1999 - Assessment Notes - Assessment Notes Not included in Rack-ups cc:
Regional Administrator-NRC Region Ill NRC Senior Resident inspector - Braidwood Station
}
NRC Senior Resident inspector - Byron Station
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a bec: ' NRC Project Manager-NRR - Braidwood Station
. NRC Project Mansyr-NRR - Byron Station Nicholas Reynolds - Winston & Strawn.
Office of Nuclear Facility Safety-IDNS Site Vice President - Braidwood Station Site Vice President-Byron Station Regulatory Assurance Manager-Braidwood Station Regulatory Assurance Manager-Byron Station Director, Licensing and Compliance -IVidwood and Byron Stations Comed Document Control Desk Licensing (Hard Copy)
Comed Document Control Desk Licensing (Electronic Copy)
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