ML121910319
| ML121910319 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/05/2012 |
| From: | Waldrep B Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML121910319 (7) | |
Text
Benjamin C Waldrep Duke Vice President (akEnergy CorporateGovernance & Operation Support 10 CFR 50.46 Duke Energy Corporation 526 South Church Street Charlotte,NC 28202 MailingAddress:
2012 ECO7H/P. 0. Box 1006 July 5, 201Charlotte, NC 28201-1006 Attention: Document Control Desk 7043828162 U. S. Nuclear Regulatory Commission 704 382 6056 fax Washington, D. C. 20555-001 Benjamin. Waldrep&uke.enerf,.com
Subject:
Duke Energy Carolinas, LLC (Duke Energy)
Oconee Nuclear Station, Units 1, 2, and 3 Docket Numbers 50-269, 50-270, and 50-287 30-Day and Annual Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model 10 CFR 50.46 (a)(3)(ii) requires the reporting of changes to or errors in Emergency Core Cooling System (ECCS) evaluation models (EMs), or in the application of such models that affect the temperature calculation. As such, Duke Energy hereby submits information regarding the results of a full reanalysis of the Loss of Coolant Accident (LOCA) for the Oconee Nuclear Station (ONS), considering a full-core of Mk-B-HTP fuel. ONS Unit 3 Cycle 27 began operation on June 6, 2012, transitioning to loading patterns with a full-core of Mk-B-HTP fuel. ONS Unit 2 transitioned to full-core Mk-B-HTP loading patterns in December 2011, and the resultant impact on ECCS evaluation model results were reported to the NRC on December 8, 2011 [ADAMS Accession No. ML11347A193]. ONS Unit 1 will transition to full-core Mk-B-HTP loading patterns in late 2013. Therefore, at this time, the full-core Mk-B-HTP LOCA analysis results provided herein are only applicable to ONS Units 2 and 3.
The full-core Mk-B-HTP Large Break LOCA PCT result is 1913 0 F, which represents a significant reduction in PCT (absolute value of the PCT change greater than 50 0F), as defined in 10 CFR 50.46 (a)(3)(i), versus the previous analysis of record PCT of 2020°F for a mixed-core of Mk-B1 1 and Mk-B-HTP fuel. The absolute value change in PCT for Large Break LOCA is determined to be 107 0F and is considered to be a significant change per the definition in 10 CFR 50.46 (a)(3)(i).
For the Small Break LOCA, the full-core Mk-B-HTP result is 1598°F. The Small Break LOCA analysis of record PCT for a mixed-core of Mk-B1 1 and Mk-B-HTP fuel was 1397 0 F. In a letter dated August 19, 2010, Duke Energy reported an error associated with this value and applied a 2250 F penalty which resulted in a final Licensing Bases PCT of 1622°F for the mixed-core, thus the Change in PCT for Small Break LOCA is determined to be 23 0F and is not a significant change per the definition in 10 CFR 50.46 (a)(3)(i).
10 CFR 50.46 (a)(3)(ii) also specifies that a proposed schedule for reanalysis is to be included for changes that are determined to be significant. The assessment of the PCT impact is based on a plant specific reanalysis for the applicable core configuration and, therefore, no further analysis is needed. The PCT assessment is derived from input information regarding the fuel type configuration (Mk-B-HTP mixed core opposed to Mk- B-HTP Full-core).
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U.S. Nuclear Regulatory Commission July 5, 2012 Page 2 This information satisfies the 30-day reporting requirements of 10 CFR 50.46 (a)(3)(ii).
During the period from January 1, 2011 to December 21, 2011, there were no errors identified in the application of the large break loss of coolant accident (LBLOCA) EM or the small break loss of coolant accident (SBLOCA) EM. Therefore, this letter also serves as the 2011 annual 10 CFR 50.46 report for ONS.
The new full-core Mk-B-HTP LOCA analyses supports a 24-month fuel cycle with gadolinia as a burnable absorber, and were performed in accordance with the NRC approved LOCA Evaluation Model described in AREVA Topical Report BAW-10192P-A. NRC approval for use of Gadolina fuel at ONS is provided via Safety Evaluation dated July 21, 2011 [ADAMS Accession No. MLI 1137A1 50]. NRC approval for use of 24-month fuel cycles at ONS is provided via Safety Evaluation dated April 20, 2012 [ADAMS Accession No. ML12086A289].
On February 23, 2012, Duke Energy received a letter from AREVA identifying two changes which affect the LBLOCA analysis of record for ONS Units 1, 2, and 3. The first change is an EM application error, and the second change is an EM modeling change. The ONS SBLOCA analyses are not affected by these issues. The impacts to peak cladding temperature (PCT) due to these changes were previously reported to the NRC on March 9, 2012 [ADAMS Accession No. ML12073A354], and are also accounted for in this report.
Included in this report is Mk-B1 1 fuel LOCA PCT summary tables and Mk-B-HTP mixed-core LOCA PCT summary tables for Unit 1, and full-core Mk-B-HTP LOCA PCT summary tables for Units 2 and 3. The LOCA results for Units 1 and 2 remain unchanged from those previously reported on March 9, 2012, and are provided for completeness. The results for the ONS Unit 3, considering a full-core of Mk-B-HTP fuel, resulted in PCT change of minus 107 0 F for a Large Break LOCA.
There are no regulatory commitments associated with this letter.
Please address any comments or questions regarding this matter to Paul Guill at (704) 382-4753 (paul.guill@duke-energy.com).
Sincerely, Benjam ldrep Attachment Table 1: Mk-B1 1 Peak Cladding Temperature Summary - ONS Unit 1 Table 2: Mk-B-HTP Mixed Core Peak Cladding Temperature Summary - ONS Unit 1 Table 3: Mk-B-HTP Full Core Peak Cladding Temperature Summary - ONS Units 2 and 3
U.S. Nuclear Regulatory Commission July 5, 2012 Page 3 xc (with attachment):
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. P. Boska, Senior Project Manager (ONS)
U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 C2 Rockville, MD 20852-2738 A. T. Sabisch, NRC Senior Resident Inspector Oconee Nuclear Station
ATTACHMENT Table 1: Mk-B11 Peak Cladding Temperature Summary- ONS Unit 1 Table 2: Mk-B-HTP Mixed Core Peak Cladding Temperature Summary- ONS Unit I Table 3: Mk-B-HTP Full Core Peak Cladding Temperature Summary - ONS Unit 2 and 3 References for Tables 1, 2, & 3 A) Letter, T. C. Geer (Duke) to USNRC, "Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model", December 18, 2007. [ADAMS ML073580171]
B) Letter, T. C. Geer (Duke) to USNRC, "Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model", July 29, 2008. [ADAMS ML082130096]
C) Letter, T. C. Geer (Duke) to USNRC, "30-Day Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model", August 19, 2010. [ADAMS ML102360485]
D) Letter, G. J. St.Clair (AREVA) to S. B. Thomas (Duke), "10 CFR 50.46 LOCA Report of Two EM Error Corrections (AREVA CR 20120165: ECCS Bypass Mathematical Error and AREVA CR 2012-757: Upper Plenum Column Weldment EM Change)", Dated February 23, 2012, AREVA Letter FAB12-120.
E) Letter, R. M. Glover (Duke) to USNRC, "30-Day Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model", December 8, 2011. [ADAMS ML11347A193]
F) Letter, D. C. Culp (Duke) to USNRC, "30-Day Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model", March 9, 2012. [ADAMS ML12073A354]
Table 1: Mk-B1 1 Peak Cladding Temperature Summary - ONS Unit I LBLOCA PCT(TF) Comments Evaluation model: RELAP5/MOD2-B&W Analysis of record POT 2035 Mark-B 11 (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) References D, F
- 1. Error in ECCS Bypass Calculation -80 Evaluation model changes (APCT) References D, F
- 1. Upper Plenum Column Weldment Modeling +80 Absolute value of errors/changes for this report (APCT) 0 Net change in POT for this report 0 Final PCT 2035 SBLOCA Full Power -100% FP PCT(0 F) Comments Evaluation model: RELAP5/MOD2-B&W Analysis of record POT 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
- 1. Upper Plenum Column Weldment Modeling 0 Absolute value of errors/changes for this report (APCT) 225 Net change in PCT for this report +225 Final POT 1686 SBLOCA Reduced Power- 75% FP [1] PCT(TF) 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. Upper Plenum Column Weldment Modeling 0 Absolute value of errors/changes for this report (APCT) Unknown Net change in PCT for this report Unknown Final POT Unknown Operation Not Justified [2]
Notes
- 1. Partial power SBLOCA analysis with one HPI pump out of service, supports 30 day LCO for TS 3.5.2 Condition B. Also supports TS 3.5.2 Condition C1 and C2.
- 2. Entry to LCO window administratively not allowed. Refer to ONS corrective action program item PIP 0-10-6229 for details.
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Table 2: Mk-B-HTP Mixed Core Peak Cladding Temperature Summary - ONS Unit I LBLOCA PCT(°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) References D, F
- 1. Error in ECCS Bypass Calculation -80 Evaluation model changes (APCT) References D, F
- 1. Upper Plenum Column Weldment Modeling +80 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(°F) Comments Evaluation model: RELAP5/MOD2-B&W Analysis of record PCT 1397 (2 HPI Case) 0.15 ft 2 break Prior errors (APCT)
- 1. None 0 Prior evaluation model changes (APCT)
- 1. None 0 Errors (APCT) Reference C
- 1. Upper Plenum Column Weldment Modeling 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 [1] PCT(°F) Comments Analysis of record PCT 1788 (1 HPI case) 0.075 ft 2 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
- 1. Upper Plenum Column Weldment Modeling 0 Absolute value of errors/changes for this report (APCT) Unknown Net change in PCT for this report Unknown __I Final PCT Unknown Operation Not Justified [2]
Notes
- 1. Partial power SBLOCA analysis with one HPI pump out of service, supports 30 day LCO for TS 3.5.2 Condition B. Also supports TS 3.5.2 Condition C1 and C2.
- 2. Entry to LCO window administratively not allowed. Refer to ONS corrective action program item PIP 0-10-6229 for details.
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Table 3: Mk-B-HTP Full Core Peak Cladding Temperature Summary - ONS Unit 2 & 3 LBLOCA PCT(TF) Comments Evaluation model: RELAP5/MOD2-B&W Analysis of record PCT 1913 Prior errors (APCT)
- 1. None 0 Prior evaluation model changes (APCT)
- 1. None 0 Errors (APCT) References D, F
- 1. Error in ECCS Bypass Calculation -80 Evaluation model changes (APCT) References D, F
- 1. Upper Plenum Column Weldment Modeling +80 Absolute value of errors/changes for this report (APCT) 0 Net change in PCT for this report 0 Final PCT 1913 SBLOCA Full Power -100% FP PCT(°F) Comments Evaluation model: RELAP5/MOD2-B&W Analysis of record PCT 1598 (2 HPI Case) 0.15 ft2 break Prior errors (APCT)
- 1. None 0 Prior evaluation model changes (APCT)
- 1. None 0 Errors (APCT)
- 1. None 0 Evaluation model changes (APCT) Reference D
- 1. Upper Plenum Column Weldment Modeling 0 Absolute value of errors/changes for this report (APCT) 0 Net change in PCT for this report 0 Final PCT 1598 SBLOCA Reduced Power - 50% FP [1] PCT(°F) Comments Analysis of record PCT N/A Will be reported under a separate LAR (Reference E)
Prior errors (APCT)
- 1. N/A Prior evaluation model changes (APCT)
- 1. N/A Errors (APCT)
- 1. N/A Evaluation model changes (APCT) Reference D
- 1. Upper Plenum Column Weldment Modeling 0 Absolute value of errors/changes for this report (APCT) N/A Net change in PCT for this report N/A Final PCT N/A Operation Not Justified [2]
Notes
- 1. Partial power SBLOCA analysis with one HPI pump out of service, supports 30 day LCO for TS 3.5.2 Condition B. Also supports TS 3.5.2 Condition C1 and C2.
- 2. Pending review and approval of separate LAR. Refer to Reference E for additional details.
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