ML11207A458
| ML11207A458 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/21/2011 |
| From: | Baxter D Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML11207A458 (5) | |
Text
Dave Baxter Duke 10 CFR 50.46 Vice President (VEnergy Nuclear Engineering Duke Energy Corporation 526 South Church Street Charlotte, NC 28202 Mailing Address:
EC08H / P. 0. Box 1006 Charlotte, NC 28201-1006 July 21, 2011 7043824712 704 382 7852 fax U. S. Nuclear Regulatory Commission Washington, D. C. 20555-001 David.Baxter@duke-energy.com Attention: Document Control Desk
Subject:
Duke Energy Carolinas, LLC (Duke Energy)
Oconee Nuclear Station, Units 1, 2, and 3 Docket Numbers 50-269, 50-270, and 50-287 Report Pursuant to 10 CFR 50.46, Changes to or Errors in an ECCS Evaluation Model 10 CFR 50.46(a)(3)(ii) requires the reporting of changes to or errors in the Emergency Core Cooling System (ECCS) evaluation models (EMs). This report covers the time period from January 1, 2010 to December 31, 2010.
During this time reporting period, there was one error identified in the application of the small break loss of coolant accident (SBLOCA) EM. This error was previously submitted to the NRC as a 30-day report pursuant to 10 CFR 50.46 via Duke Energy letter dated August 19, 2010 (ML102360485). AREVA identified that the SBLOCA axial power shape defined in the applicable ECCS EM may not be bounding for middle-to end-of-cycle conditions. Based on information supplied by AREVA, an assessment of the error results in a peak cladding temperature (PCT) increase of 225 'F from the previously reported full-power SBLOCA analysis PCT values.
The Oconee Units also have a 75% partial-power SBLOCA analysis with one High Pressure Injection (HPI) pump out of service that supports a 30-day LCO operational window, per Oconee Technical Specification 3.5.2. New partial-power SBLOCA analyses to support the 30-day LCO window are being performed by AREVA and will include the revised axial power shape to address the error cited above. At this time, entry into the LCO window is administratively not allowed, pending completion of new SBLOCA analyses that will address this issue. This issue has been entered into Oconee's corrective action system as PIP 0-10-6229.
No errors were identified in the large break loss of coolant accident (LBLOCA) EM during this reporting period.
During 2010, all Oconee Units operated with a mixed-core configuration of Mk-B1 1 fuel and Mk-B-HTP fuel. Separate LOCA analyses have been performed for a full core of Mk-B1 1 fuel, and for Mk-B-HTP fuel in a mixed-core configuration with Mk-B1 1 fuel.
Included in this report are Mk-B1 1 fuel LOCA PCT summary tables and Mk-B-HTP mixed-core LOCA PCT summary tables for Units 1, 2, and 3.
There are no regulatory commitments associated with this letter.
www.duke-energy.com
U.S. Nuclear Regulatory Commission July 21, 2011 Page 2 Please address any comments or questions regarding this matter to L. B. Jones at (704) 382-4753.
Sincerely,Da David A. Baxter Vice President, Nuclear Engineering Attachments Table 1 Mk-B1 1 Peak Cladding Temperature Summary - Oconee Units 1, 2, and 3 Table 2 Mk-B-HTP Mixed Core Peak Cladding Temperature Summary - Oconee Units 1, 2, and 3 xc:
V. M. McCree, Region II Administrator U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Avenue NE, Suite 1200 Atlanta, GA 30303-1257 J. F. Stang, Senior Project Manager (ONS)
U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, MD 20852-2738 A. T. Sabisch NRC Senior Resident Inspector Oconee Nuclear Station
ATTACHMENTS Table 1: Mk-Bl 1 Peak Cladding Temperature Summary Oconee Units 1, 2, and 3 Table 2: Mk-B-HTP Mixed Core Peak Cladding Temperature Summary Oconee Units 1, 2, and 3
Table 1: Mk-B11 I Peak Cladding Temperature Summary - Oconee Units 1, 2, and 3 LBLOCA PCT(°F)
Comments Evaluation model: RELAP5/MOD2-B&W Analysis of record PCT 2035 Mk-B11 (M5), 17.7 kW/ft at 6.021 ft elevation Prior errors (APCT)
References A and B
- 1. Various 0
Prior evaluation model changes (APCT)
- 1. None 0
Errors (APCT)
- 1. None 0
Evaluation model changes (APCT)
- 1. None 0
Absolute value of errors/changes for this report (APCT) 0 Net change in PCT for this report 0
Final PCT 2035 SBLOCA Full Power -100% FP PCT(°F)
Comments Evaluation model: RELAP5/MOD2-B&W Analysis of record PCT 1461 (2 HPI Case) 0.15 ft2 break Prior errors (APCT)
- 1. None 0
Prior evaluation model changes (APCT)
- 1. None 0
Errors (APCT)
Reference C
+225 Evaluation model changes (APCT)
- 1. None 0
Absolute value of errors/changes for this report (APCT) 225 Net change in PCT for this report
+225 Final PCT 1686 SBLOCA Reduced Power - 75% FP PCT(-F)
Comments Analysis of record PCT 1774 (1 HPI case) 0.075 ft2 break Prior errors (APCT)
- 1. None 0
Prior evaluation model changes (APCT)
- 1. None 0
Errors (APCT)
Reference C
- 1. None 0
Absolute value of errors/changes for this report (APCT)
Unknown Net change in PCT for this report Unknown Final PCT Unknown Operation Not Justified Reference A) Letter, T. C. Geer (Duke Energy) to USNRC, "Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model," December 18, 2007 (ML073580171)
B) Letter, T. C. Geer (Duke Energy) to USNRC, "Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model," July 29, 2008 (ML082130096)
C) Letter, T. C. Geer (Duke Energy) to USNRC, "30-Day Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model," August 19, 2010 (ML102360485)
Page 1
Table 2: Mk-B-HTP Mixed Core Peak Cladding Temperature Summary - Oconee Units 1, 2, and 3 LBLOCA PCT(0 F)
Comments Evaluation model: RELAP5/MOD2-B&W Analysis of record PCT 2020 Prior errors (APCT)
- 1. None 0
Prior evaluation model changes (APCT)
- 1. None 0
Errors (APCT)
- 1. None 0
Evaluation model changes (APCT)
- 1. None 0
Absolute value of errors/changes for this report (APCT) 0 Net change in PCT for this report 0
Final PCT 2020 SBLOCA Full Power -100% FP PCT(0 F)
Comments Evaluation model: RELAP5/MOD2-B&W Analysis of record PCT 1397 (2 HPI Case) 0.15 ft2 break Prior errors (APCT)
- 1. None 0
Prior evaluation model changes (APCT)
- 1. None 0
Errors (APCT)
Reference C (per Table 1)
+225 Evaluation model changes (APCT)
- 1. None 0
Absolute value of errors/changes for this report (APCT) 225 Net change in PCT for this report
+225 Final PCT 1622 SBLOCA Reduced Power - 75% FP PCT(0 F)
Comments Analysis of record PCT 1788 (1 HPI case) 0.075 ft2 break Prior errors (APCT)
- 1. Not Applicable (New Analysis performed in 2008)
N/A Prior evaluation model changes (APCT)
- 1. Not Applicable (New Analysis performed in 2008)
N/A Errors (APCT)
Reference C (per Table 1)
- 1. None 0
Absolute value of errors/changes for this report (APCT)
Unknown Net change in PCT for this report Unknown Final PCT Unknown Operation Not Justified Page 2