ML20210F303
| ML20210F303 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 07/22/1999 |
| From: | Herron J TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9907300006 | |
| Download: ML20210F303 (3) | |
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.l Tennessee Valley Authority, Post Offee Box 2000, Decatur, Alabama 35609-2000 l
i John T. Herrca -
l Interirn Vee President, Browns Ferry Nuclear Plant July 22, 1999 i
U.S. Nuclear Regulatory Commission 10 CFR 50.46 ATTN: Document Control Desk Washington, DC 20555 Gentlemen:
In the Matter of
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Docket Nos. 50-259 Tennessee Valley Authority
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50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) - EMERGENCY CORE COOLING SYSTEM (E;CS) EVALUATION MODEL CHANGES - ANNUAL REPORT The purpose of this letter is to report, in accordance with 10 CFR 50.46 (a) (3) (ii), the impact of chat.ges or errors in the methodology used to demonstrate compliance with the ECCS requirements of 10 CFR 50.46.
This submittal covers the period from June 1998 to June 1999.
One reportable non-significant error, as described below, was found during this time period.
On June 25, 1999, General Electric (GE) notified TVA of an error in the modeling of the counter current flow limiting O
(CCFL) coefficient used in the SAFER code.
This error affects the CCFL calculations used for GE8, GE9, GE10, and Siemens fuel types, and is associated with the CCFL w
correlation at the upper tie plate of the subject fuel bundle p types.
GE reported that the error results in a 25 F increase in the calculated peak clad temperature (PCT) calculations for BFN impacted fuel bundle types.
GE8, GE10, and Siemens fuel bundles have not been used in any of the BFN units.
BFN Unit 2 currently has 48 GE9 fuel bundles loaded and, therefore, is the only unit whose calculations are affected by the CCFL error.
9907300006 990722 ^
PDR ADOCK 05000259 P
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U.
S. Nuclear Regulatory Commission Page 2 July 22, 1999 The BFN Loss-of-Coolant Accident (LOCA) analysis for Gell and earlier fuel types is documented in NEDC-32484P, " Browns Ferry Nuclear Plant Units 1, 2,
and 3, SAFER /GESTR-LOCA Loss-of-Coolant Accident Analysis", Revision 2, December 1997, which was submitted to NRC July 24, 1998, in conjunction with the Power Uprate project.
As shown in the NEDC, the limiting fuel type for BFN is BP/P8X8R fuel which has a calculated licensing basis PCT of 1590"F.
BP/P8X8R fuel is not subject to the CCFL error.
As stated previously, the only fuel type used at BFN whose PCT calculations are affected by the CCFL coefficient error is GE9 in Unit 2.
When the 25 F adjustment for the CCFL error is included for the GE9 PCT calculations, a maximum licensing basis PCT of 1495 F results, which remains well below the limiting fuel type (BP/P8X8R) PCT determination.
Therefore, the CCFL coefficient error does not have a significant impact on the LOCA calculations PCT limits.
l If you have any questions regarding this report, please contact Tim Abney at (256) 729-2636.
Sincerely, A-Nw hn T. Herron I 1terim Site Vice President l
cc: See page 3 l
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U. S. Nuclear Regulatory Commission Page 3 July 22, 1999 cc:
Mr. Paul Frederickson, Branch Chief U.S. Nuclear Regulatory Commission Region II 61 Forsyth Street, S.W..
Suite 23T85 Atlanta, Georgia 30303 Mr. William O. Long, Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611 I
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