ML090080034
| ML090080034 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/08/2009 |
| From: | Moroney B Plant Licensing Branch II |
| To: | Campbell W Tennessee Valley Authority |
| Moroney B, NRR/DORL, 415-3974 | |
| References | |
| TAC MD8898, TAC MD8899, TAC MD8900, TAC ME0190 | |
| Download: ML090080034 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 January 8, 2009 Mr. William R. Campbell, Jr.
Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801
SUBJECT:
SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 - REPORTS OF SIGNIFICANT CHANGES PURSUANT TO 10 CFR 50.46 (TAC NOS. MD8898, MD8899, MD8900 AND ME0190)
Dear Mr. Campbell:
By letter dated June 3,2008, the Tennessee Valley Authority (TVA) submitted a 30-day special report of significant changes to the calculated peak cladding temperature (PCT) resulting from changes to the emergency core cooling system (ECCS) evaluation model for Sequoyah Unit 2.
The report was submitted to satisfy the reporting requirements of Title 10 of the Code of Federal Regulations (10 CFR), Section 50.46(a)(3)(ii). A change in calculated PCT in excess of 50 OF resulted from a reanalysis of the large break loss-of-coolant accident (LBLOCA) using the realistic LBLOCA methodology that was approved for use at Sequoyah Unit 2 by the U.S.
Nuclear Regulatory Commission (NRC) in a license amendment dated April 4, 2008.
Similarly, by letter dated October 29, 2008, TVA submitted a 30-day special report of significant changes to the calculated PCT resulting from changes to the ECCS evaluation model for Sequoyah Unit 1. A change in calculated PCT in excess of 50 OF resulted from a reanalysis of the LBLOCA using the realistic LBLOCA methodology that was approved for use at Sequoyah Unit 1 by the NRC in a license amendment dated September 24, 2008.
Also, by letter dated June 4,2008, TVA submitted a 30-day special report of significant changes to the calculated PCT resulting from changes to the ECCS evaluation model for the small break loss-of-coolant accident (SBLOCA) analysis for Sequoyah Units 1 and 2. For consistency with the LBLOCA analysis, the SBLOCA was analyzed to apply similar changes to the analytical input parameters and the analysis was performed using the same evaluation methodology as the current analysis of record. This resulted in a change in calculated PCT in excess of 50 "F.
Finally, by letter dated November 24, 2008, TVA submitted the annual report of non-significant changes that summarized the changes reported in the previous 30-day special reports and stated that no additional changes had occurred.
W. Campbell, Jr.
- 2 The NRC staff reviewed these reports and concluded that they were appropriately submitted pursuant to 10 CFR 50.46(a)(3)(ii) and the analysis results are acceptable because they are based on updated calculations using NRC-approved methodologies.
If you have any questions, please contact me at (301) 415-3974.
Sincerely,
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Brendan T. Moroney, Project Manhger Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-327 and 50-328 cc: Distribution via Listserv
W. Campbell, Jr.
- 2 The NRC staff reviewed these reports and concluded that they were appropriately submitted pursuant to 10 CFR 50.46(a)(3)(ii) and the analysis results are acceptable because they are based on updated calculations using NRC-approved methodologies.
If you have any questions, please contact me at (301) 415-3974.
Sincerely, Ira!
Brendan 1. Moroney, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-327 and 50-328 cc: Distribution via Listserv Distribution:
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