HNP-07-083, Emergency Core Cooling System Evaluation Changes
| ML071580199 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 06/01/2007 |
| From: | Corlett D Progress Energy Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| HNP-07-083 | |
| Download: ML071580199 (5) | |
Text
Progress Energy JUN 01 207 SERIAL: HNP-07-083 10 CFR 50.46 U. S. Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO. NPF-63 EMERGENCY CORE COOLING SYSTEM EVALUATION CHANGES Ladies and Gentlemen:
In accordance with the Code of Federal Regulations, Title 10, Part 50.46, "Acceptance.
criteria for emergency core cooling systems for light-water nuclear power reactors,"
paragraph (a)(3)(ii), the Harris Nuclear Plant (HNP), of Carolina Power & Light Company doing business as Progress Energy Carolinas, Inc., submits its annual report regarding the effect of changes or errors in the application of the Emergency Core Cooling System (ECCS) evaluation models.
The HNP ECCS performance following a large break loss of coolant accident (LBLOCA) is calculated for HNP by AREVA NP using the SEM/PWR-98 ECCS Evaluation Model for PWR LBLOCA Applications. The ECCS performance following a small break loss of coolant accident (SBLOCA) is calculated for HNP by AREVA NP using the EXEM PWR Small Break Model.
The previous HNP annual report to the NRC was provided by letter dated May 24, 2006, which documented a SBLOCA peak clad temperature (PCT) of 1701OF and a LBLOCA PCT of 21020F. Since that report, no errors or changes in the LOCA models or results have been made that would require a 30-day report under 10 CFR 50.46.
The new value for the SBLOCA PCT is 1658 0F, and the LBLOCA PCT value remains unchanged at 21020F. provides a summary of the impact of errors on PCT since the May 2006 report. provides a summary of the errors associated with the SBLOCA model since the May 2006 report. provides a summary of the errors associated with the LBLOCA model since the May 2006 report.
Progress Energy Carolinas, Inc.
Harris Nuclear Plant P. 0. box 165 New Hill, NC 27562
Page 2 Serial: HNP-07-083 This letter contains no new regulatory commitments. Please contact me if you have any questions regarding this submittal at (919) 362-3137.
Sincerely, L-0 D. H. Corlett Supervisor, Licensing - Regulatory Programs Harris Nuclear Plant DHC/jpy Attachments:
- 1. Summary of the Impact of Errors on Peak Clad Temperature
- 2. Summary of the Errors Associated with the Small Break LOCA Model
- 3. Summary of the Errors Associated with the Large Break LOCA Model c: Mr. P. B. O'Bryan, NRC Sr. Resident Inspector Ms. L. M. Regner, NRC Project Manager Dr. W. D. Travers, NRC Regional Administrator to SERIAL: HNP-07-083 Summary of the Impact of Errors on Peak Clad Temperature Harris Nuclear Plant Small Break LOCA Peak Clad Temperature Summary Peak Clad Temperature (CF)
Value Reported 5/24/2006 Reported Error Impact New SBLOCA PCT Value 1701
-43 1658 Harris Nuclear Plant Large Break LOCA Peak Clad Temperature Summary Peak Clad Temperature (*F)
Value Reported 5/24/2006 Reported Error Impact New LBLOCA PCT Value 2102 None 2102 Page Al-1 of 1 to SERIAL: HNP-07-083 Summary of the Errors Associated With the Small Break LOCA Model AREVA NP (the HNP nuclear fuel and safety analysis vendor) determined that the modeling of the HNP core exit was incorrect. The error was discovered as part of an extent of condition review of an error in the analysis of a non-Progress Energy facility.
The ANF-REFAP countercurrent flow limitation correlation already included a reduction that accounts for the decrease in the flow area from the core exit to the upper tie plate (UTP). However, the model for HNP used the UTP flow area instead of the core exit flow area. Therefore, the model included an additional, unnecessary penalty. The estimated change in PCT is -43 OF. There are no immediate plans to re-run the SBLOCA analysis because of the conservative nature of this error and the large amount of PCT margin for SBLOCA.
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