ML100830121

Submittal of Annual Report of Emergency Core Cooling System (ECCS) Model Changes

ML100830121
Person / Time
Site:	Wolf Creek
Issue date:	03/16/2010
From:	Flannigan R Wolf Creek
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RA 10-0024
Download: ML100830121 (6)

Text

WLF CREEK

'NUCLEAR OPERATING CORPORATION March 16, 2010 Richard D. Flannigan Manager Regulatory Affairs RA 10-0024 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

Reference:

Westinghouse Letter LTR-LIS-1 0-108, dated February 3, 2010, Wolf Creek 10 CFR 50.46 Annual Notification and Reporting for 2009

Subject:

Docket No. 50-482: 10 CFR 50.46 Annual Report of Emergency Core Cooling System (ECCS) Model Changes Gentlemen:

This letter provides the annual report for the Emergency Core Cooling System (ECCS)

Evaluation Model changes and errors for the 2009 model year that affect the Peak Cladding Temperature (PCT) for Wolf Creek Generating Station (WCGS). This letter is provided in accordance with the criteria and reporting requirements of 10 CFR 50.46(a)(3)(ii), as clarified in Section 5.1 of WCAP-13451, "Westinghouse Methodology for Implementation of 10 CFR 50.46 Reporting." Regulation 10 CFR 50.46(a)(3)(ii) states, in part, "For each change to or error discovered in an acceptable evaluation model or. in the applicationof such a model that affects the temperature calculation, the applicant or holder of a construction permit, operating license, combined license, or manufacturing license shall report the nature of the change or error and its estimated effect on the limiting ECCS analysis to the Commission .at least annually as specified in section 50.4 or section 52.3 of this chapter, as applicable. If the change or error is significant, the applicant or licensee shall provide this report within 30 days and include with the report a proposed schedule for providing a reanalysis or taking~other action as may be needed to show compliance with section 50.46 requirements.".

Wolf Creek Nuclear Operating Corporation (WCNOC) has reviewed the notification of 10 CFR 50.46 reporting information pertaining to the ECCS Evaluation Model changes that were implemented by Westinghouse for 2009 as described in the above Reference. The review concludes that the effect of changes to, or errors in, the Evaluation Models on the limiting transient PCT is not significant for 2009. Therefore, the report of the ECCS Evaluation Model changes is provided on an annual basis.

Attachment I provides an assessment of the specific changes and enhancements to the Westinghouse Evaluation Models for 2009. These model changes and enhancements do not have impacts on the PCT and, generally, will not be presented on the PCT rackup forms.

P.O. Box 411 / Burlington, KS 66839 / Phone: (620) 364-8831 fr .

An Equal Opportunity Employer M/F/HCNET

RA 10-0024 Page 2 of 2 Attachment II provides the calculated Large Break Loss of Coolant Accident (LOCA) and Small Break LOCA PCT margin allocations in effect for the 2009 WCGS evaluation models. The PCT values determined in the Small Break and Large Break LOCA analysis of. record, combined with all of the PCT allocations, remain well below the 10 CFR 50,46 regulatory limit of 2200 degrees Fahrenheit. Therefore, WCGS is in compliance with 10 CFR 50.46 requirements and no reanalysis or other action is required.

No commitments are identified in this correspondence.

If you have any questions concerning this matter, please contact me at (620) 364-4117, or Diane Hooper at (620) 364-4041.

Sincerely, Richard D. Flannigan RDF/rlt Attachment I - Assessment of Changes to the Westinghouse Emergency Core Cooling System (ECCS) Evaluation Models for Large and Small Break Loss of Coolant Accidents (LOCA)

Attachment II - Emergency Core Cooling System (ECCS) Evaluation Model Peak Cladding Temperature (PCT) Margin Utilization cc: E. E. Collins (NRC), w/a G. B. Miller (NRC), w/a B. K. Singal (NRC), w/a Senior Resident Inspector (NRC), w/a

Attachment I to RA 10-0024 Page 1 of 1 ASSESSMENT OF CHANGES TO THE WESTINGHOUSE EMERGENCY CORE COOLING SYSTEM (ECCS) EVALUATION MODELS FOR LARGE AND SMALL BREAK LOSS OF COOLANT ACCIDENTS (LOCA)

Non-Discretionary Changes With Peak Cladding Temperature (PCT) Impact None Non-Discretionary Changes With No PCT Impact None Enhancements/Forward-Fit Discretionary Changes None Editorial Chanaes None Summary 1981 WESTINGHOUSE LARGE BREAK LOCA EVALUATION MODEL WITH BASH There were no changes, error corrections, or enhancements to the 1981 Westinghouse Large Break LOCA Evaluation Model with BASH. Therefore, there is no associated reporting text related to the 1981 Westinghouse Large Break LOCA Evaluation Model with BASH for 2009.

1985 WESTINGHOUSE SMALL BREAK LOCA EVALUATION MODEL WITH NOTRUMP There were no changes, error corrections, or enhancements to the 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP. Therefore, there is no associated reporting text related to the 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP for 2009.

Attachment II to RA 10-0024 Page 1 of 3 EMERGENCY CORE COOLING SYSTEM (ECCS) EVALUATION MODEL PEAK CLADDING TEMPERATURE (PCT) MARGIN UTILIZATION LARGE BREAK LOCA PEAK CLAD TEMPERATURE (PCT) MARGIN UTILIZATION ***

Evaluation Model: 1981 EM with BASH Fuel: 17x17 V5H w/IFM, non-IFBA, 275 psig Peaking Factor: FQ=2.50, FdH=1.65 SG Tube Plugging: 10%

Power Level: 3565 MWth Limiting transient: Cd=0.4, Min. SI, Reduced Tavg LICENSING BASIS Clad Temp (*F) Ref. Notes Analysis of Record PCT 1916°F I (a)

MARGIN ALLOCATIONS (APCT)

A. PRIOR PERMANENT ECCS MODEL ASSESSMENTS

1. Structural Metal Heat Modeling -25 8

2. LUCIFER Error Corrections -6 10

3. Skewed Power Shape Penalty 152 11

4. Hot Leg Nozzle Gap Benefit -136 11

5. SATAN-LOCTA Fluid Error 15 2

6. LOCBART Spacer Grid Single-Phase Heat Transfer Error 15 9

7. LOCBART Vapor Film Flow Regime Heat Transfer Error 9 12

8. LOCBART Cladding Emissivity Errors 6 13

9. LOCBART Radiation to Liquid Logic Error Correction 17 14

10. LOCBART Pellet Volumetric Heat Generation Rate 45 15 B. PLANNED PLANT CHANGE EVALUATIONS

1. Loose Parts Evaluation 20 3

2. Effects of Containment Purging 0 4

3. Cycle 10 Fuel Assembly Design Changes 95 5

4. Fuel Rod Crud 0 6 C. 2009 PERMANENT ECCS MODEL ASSESSMENTS

1. None 0 D. TEMPORARY ECCS MODEL ISSUES 0 E. OTHER

1. Cold Leg Streaming Temperature Gradient 0 8 (b)

2. Rebaseline of AOR (12/96) -63 9 (c)

3. LOCBART Zirc-Water Oxidation Error 28 7 (d)

LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 2088°F CUMULATIVE ABSOLUTE MAGNITUDE OF PCT CHANGES E I APCT = 0°F SINCE LAST 30-DAY REPORT (LETTER ET 07-0021)

Attachment II to RA 10-0024 Page 2 of 3

References:

1. Westinghouse Topical Report WCAP-13456, "Wolf Creek Generating Station NSSS Rerating Licensing Report," October 1992.

2. Westinghouse to WCNOC letter SAP-97-102, "Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, 10 CFR 50.46 Annual Notification and Reporting," February 17, I

1997.

3. Westinghouse to WCNOC letter SAP-90-148, "Wolf Creek Nuclear Operating Corporation, RCS Loose Parts Evaluation," April 18, 1998.

4. Westinghouse to WCNOC letter SAP-94-102, "Containment Mini Purge Isolation Valve Stroke Time Increase," January 12, 1994.

5. Westinghouse to WCNOC letter 97SAP-G-0009, "Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, Safety Assessment for the Wolf Creek Generating Station with ZIRLO TM Fuel Assemblies," February 7, 1997.

6. Westinghouse to WCNOC letter 97SAP-G-0075, "Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, Wolf Creek Crud Deposition/Axial Offset Anomaly Safety Evaluation," September 29, 1997.

7. Westinghouse to WCNOC letter OOSAP-G-0006, "Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, Wolf Creek Cycle 12 LOCA Current Limits," February 10, 2000.

8. Westinghouse to WCNOC letter SAP-93-701, "Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, 10 CFR 50.46 Notification and Reporting Information," January 25, 1993.

9. Westinghouse to WCNOC letter SAP-99-148, "Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, 10 CFR 50.46 BART/BASH Evaluation Model, Mid-Year Notification and Reporting for 1999," September 22, 1999.

10. Westinghouse to WCNOC letter SAP-94-703, "Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, 10 CFR 50.46 Notification and Reporting Information," February 8, 1994.

11. Westinghouse to WCNOC letter SAP-95-716, "Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, LOCA Axial Power Shape Sensitivity Model," August 14, 1995.

12. Westinghouse to WCNOC letter SAP-00-1 18, "Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, 10 CFR 50.46 Appendix K (BART/BASH/NOTRUMP) Evaluation Model, Mid-Year Notification and Reporting for 2000," June 30, 2000.

13. Westinghouse to WCNOC letter SAP-00-1 50, ,"Wolf Creek Nuclear Operating Corporation, Wolf Creek Generating Station, 10 CFR 50.46 BART/BASH Evaluation Model Mid-Year Notification and Reporting for 2000," December 2000.

14. Westinghouse to WCNOC letter SAP-02-32, "10 CFR 50.46 BART/BASH Evaluation Model Mid-Year Notification and Reporting for 2002," June 2002.

15. LTR-LIS-07-312, "10 CFR 50.46 Reporting Text for LOCBART Version 37.0 Issues and Revised PCT Rackup Sheets for Wolf Creek," May 2007.

Notes:

(a) An evaluation was performed to support removal of the transition core penalty for Cycle 12 (Ref. 7).

(b) A PCT benefit of < 2.5°F was assessed, however, a benefit of 0°F will be tracked for reporting purposes.

(c) This previously unclaimed benefit was realized through prior rebaseline of the limiting case.

(d) This assessment is a function of analysis PCT plus certain margin allocations and as such may increase/decrease with margin allocation changes.

Attachment II to RA 10-0024 Page 3 of 3

• • • SMALL BREAK LOCA PEAK CLAD TEMPERATURE (PCT) MARGIN UTILIZATION Evaluation Model: 1985 EM with NOTRUMP Fuel: 17x17 RFA-2 w/IFM Peaking Factor: FQ=2.50, FdH=1.65 SG Tube Plugging: ,10%

Power Level: 3565 MWth,;

Limiting transient: 4-inch Break LICENSING BASIS Clad Temp (°F) Ref. Notes Analysis of Record PCT 936 I MARGIN ALLOCATIONS (APCT)

A. PRIOR PERMANENT ECCS MODEL ASSESSMENTS

1. None 0 B. PLANNED PLANT CHANGE EVALUATIONS

1. Loose Part Evaluation 45 2 (a)

C. 2009 PERMANENT ECCS MODEL ASSESSMENTS

1. None 0 D. TEMPORARY ECCS MODEL ISSUES

1. None 0 E. OTHER

1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 981°F CUMULATIVE ABSOLUTE MAGNITUDE OF PCT CHANGES E IAPCT = 0-F

References:

1. WCAP-16717-P, Rev. 0, "Wolf Creek Generating Station (SAP), MSIV/MFIV Replacement Project, Small Break Loss of Coolant Accident Analysis Engineering Report," January 2007.

2. SAP-90-148/NS-OPLS-OPL-I-90-239, "Wolf Creek Nuclear Operating Corporation, RCS Loose Part Evaluation," April 1990.

Notes:

(a) This penalty will be carried to track the loose part which has not been recovered.