ULNRC-05769, Callaway Plant - 10 CFR 50.46 Annual Report, ECCS Evaluation Model Revisions

Callaway Plant - 10 CFR 50.46 Annual Report, ECCS Evaluation Model Revisions

ML110601271
Person / Time
Site:	Callaway
Issue date:	03/01/2011
From:	Maglio S Ameren Missouri
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
ULNRC-05769
Download: ML110601271 (13)

Text

WAmeren MISSOURI Callaway Plant :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

March 1, 2011 ULNRC-05769 u.s. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Ladies and Gentlemen:

10 CFR 50.46 DOCKET NUMBER 50-483 CALLA WAY PLANT UNION ELECTRIC COMPANY 10 CFR 50.46 ANNUAL REPORT ECCS EVALUATION MODEL REVISIONS

References:

1) ULNRC-05260 dated 3-9-06 2) ULNRC-05378 dated 3-7-07 3) ULNRC-05475 dated 3-4-08 4) ULNRC-05600 dated 3-4-09 5) ULNRC-05683 dated 3-1-10 Ameren Missouri hereby submits the annual report required per 10 CFR 50.46(a)(3) for Callaway Plant. Attachment 1 to this letter describes changes to the Westinghouse ECCS Large Break and Small Break Loss of Coolant Accident (LOCA) Evaluation Models which have been implemented for Callaway during the time period from March 2010 to March 2011. Attachment 2 provides an ECCS Evaluation Model Margin Assessment which accounts for all peak cladding temperature (PCT) changes resulting from the resolution of prior issues as they apply to Callaway.

No new PCT penalties are included in these attachments.

References 1 through 5 provided annual 10 CFR 50.46 reports that were issued after the LOCA analyses were revised to reflect the installation of the replacement steam generators in 2005. The PCT values determined in the Large Break and Small Break LOCA analyses of record, when combined with all PCT margin allocations, remain below the 2200°F regulatory limit. As such, no reanalysis is planned by Ameren Missouri.

PO Box 620 Fulton, MO 65251 AmerenMissouri.com VLNRC-05769 March 1, 2011 Page 2 This letter does not contain any new commitments.

If you have any questions on this report, please contact Mr. Tom Elwood at (314) 225-1905.

GGY/nls Enclosure Very truly yours, J1bort 2 Scott Maglio Regulatory airs Manager ULNRC-05769 March 1, 2011 Page 3 cc: Mr. Elmo E. Collins, Jr. Regional Administrator U.S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 Senior Resident Inspector Callaway Resident Office U. S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Mohan C. Thadani (2 copies) Senior Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 0-8G 14 Washington, DC 20555-2738 Mr. James Polickoski Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 0-8B IA Washington, DC 20555-2738 ULNRC-05769 March 1, 2011 Page 4 Index and send hardcopy to QA File A160.0761 Hardcopy:

Certrec Corporation 4200 South Hulen, Suite 630 Fort Worth, TX 76109 (Certrec receives ALL attachments as long as they are non-safeguards and may be publicly disclosed.)

Electronic distribution for the following can be made via Responses and Reports ULNRC Distribution:

A. C. Heflin F. M. Diya C. O. Reasoner III L. S. Sandbothe S. M. Maglio T. B. Elwood S. L. Gallagher T. L. Woodward (NSRB) G. G. Yates Mr. Paul Parmenter, Director (SEMA) Mr. Thomas Mohr, Senior REP Planner (SEMA) Mr. John Campbell, REP Planner (SEMA) Ms. Diane M. Hooper (WCNOC) Mr. Tim Hope (Luminant Power) Mr. Ron Barnes (APS) Mr. Tom Baldwin (PG&E) Mr. Wayne Harrison (STPNOC) Ms. Linda Conklin (SCE) Mr. John O'Neill (Pillsbury Winthrop Shaw Pittman LLP) Mr. Dru Buntin (DNR)

Enclosure to ULNRC-05769 Page 1 of 9 Westinghouse Non-Proprietary Class 3 (8 Westinghouse Westinghouse Electric Company Nuclear Services 1000 Westinghouse Drive Cranberry, Pennsylvania 16066 USA Direct tel: (412) 374-5241 Direct fax: (724) 720-0857 e-mail: valerijd@westinghouse.com Ourref: LTR-L/S-11-40 January 26, 2011 Callaway 10 CFR 50.46 Annual Notification and Reporting for 2010

Dear Sir or Madam:

This is a notification of 10 CFR 50.46 reporting information pertaining to the Westinghouse Electric Company Evaluation Models/analyses.

As committed to in WCAP-13451, Westinghouse Methodology for Implementation of 10 CFR 50.46 Reporting, Westinghouse is providing an Annual Report for Emergency Core Cooling System (ECCS) Evaluation Model changes and errors for the 2010 model year. Standardized reporting pages for all changes and errors for the Evaluation Models utilized for your plant(s) are enclosed, consistent with the commitment following the NUPIC audit in early 1999. Peak Clad Temperature (PCT) sheets are enclosed.

All necessary revisions for any non-zero, non-discretionary, PCT change to Section C have been included.

Non-discretionary PCT impacts of OaF will generally not be presented on the PCT sheet. Any plant-specific errors in the application of the model for 2010 will also be provided in Section C with discussion enclosed or cited. The Evaluation Model changes and errors (except any plant-specific errors in the application of the model) will be provided to the NRC via Westinghouse letter. This information is for your use in making a determination relative to the reporting requirements of 10 CFR 50.46. The information that is provided in this letter was prepared in accordance with Westinghouse's Quality Management System (QMS). Author: (Electronically Approved)*

J. D. Valeri LOCA Integrated Services I Verified: (Electronically Approved)*

L. Nguyen LOCA Integrated Services I Approved: (Electronically Approved)*

A. J. Colussy Attachment Manager, LOCA Integrated Services I *Electronically approved records are authenticated in the electronic document management system. © 2011 Westinghouse Electric Company LLC All Rights Reserved Enclosure to ULNRC-05769 Page 2 of 9 Attachment to L TR-LlS-11-40 January 26, 2011 URANIA-GADOLINIA PELLET THERMAL CONDUCTIVITY CALCULATION (Non-Discretionary Change) Background Two errors were discovered in the pellet thermal conductivity calculation for urania-gadolinia pellets in the SBLOCTA code. First, the calculation did not include the terms required to adjust for pellet densities other than 95% of the theoretical density. Second, the conversion from Fahrenheit to Rankine used an adder of 459 instead of 459.67. These errors have been corrected and evaluated for impact on existing Small Break LOCA analysis results. These changes represent a closely-related group of Discretionary Changes in accordance with Section 4.1.2 of WCAP-13451.

Affected Evaluation Model(s) 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP Estimated Effect SBLOCT A sensitivity calculations led to an estimated PCT effect of OaF for existing Small Break LOCA analysis results.

Enclosure to ULNRC-05769 Page 3 of 9 Attachment to L TR-LlS-11-40 PELLET CRACK AND DISH VOLUME CALCULATION (Non-Discretionary Change) Background January 26, 2011 Two errors were discovered in the calculation of the normalized pellet crack and dish volumes in the SBLOCT A code. First, an incorrect operator was used to select between two tables of normalized volume vs. linear heat generation rate. Second, the normalized volume at 18 kW 1ft was incorrectly programmed in one of the tables as 1.58 instead of 1.59. These errors have been corrected in the SBLOCTA code and will be corrected (where applicable) in future versions of the BASH and LOCBART codes. These changes represent a closely-related group of Non-Discretionary Changes in accordance with Section 4.1.2 of WCAP-13451.

Affected Evaluation Model(s) 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP 1981 Westinghouse Large Break LOCA Evaluation Model with BASH Estimated Effect A combination of SBLOCT A sensitivity calculations and engineering judgment led to an estimated peT effect of OaF for existing Large and Small Break LOCA analysis results.

Enclosure to ULNRC-05769 Page 4 of 9 Attachment to L TR-LlS-11-40 TREATMENT OF VESSEL AVERAGE TEMPERATURE UNCERTAINTY (Non-Discretionary Change) Background January 26, 2011 Historically, the overall vessel average temperature uncertainty calculated by Westinghouse considered only "-" instrument uncertainties, corresponding to the indicated temperature being lower than the actual temperature.

This uncertainty was then applied as a "+/-" uncertainty in some LOCA analyses, rather than using specific "+" and "-" uncertainties.

This discrepancy has been evaluated for impact on existing Large and Small Break LOCA analysis results, and its resolution represents a Non-Discretionary Change in accordance with Section 4.1.2 of WCAP-13451.

Affected Evaluation Model(s) 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP 1996 Westinghouse Best Estimate Large Break LOCA Evaluation Model 1999 Westinghouse Best Estimate Large Break LOCA Evaluation Model, Application to PWRs with Upper Plenum Injection 2004 Westinghouse Realistic Large Break LOCA Evaluation Model Using ASTRUM Estimated Effect This issue was judged to have a negligible impact on existing Large and Small Break LOCA analysis results, leading to an estimated PCT impact ofO°F.

Enclosure to ULNRC-05769 Page 5 of 9 Attachment to LTR-LlS-11-40 GENERAL CODE MAINTENANCE (Discretionary Change) Background January 26, 2011 Various changes have been made to enhance the usability of the codes and to help preclude errors in analyses.

This includes items such as modifying input variable definitions, units, and defaults; improving the input diagnostic checks; enhancing the code output; optimizing active coding; and, eliminating inactive coding. These changes represent Discretionary Changes that will be implemented on a fit basis in accordance with Section 4.1.1 of WCAP-13451.

Affected Evaluation Model(s) 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP Estimated Effect The nature of these changes leads to an estimated PCT impact ofO°F.

Enclosure to ULNRC-05769 Page 6 of 9 Attachment to L TR-LlS-11-40 CONSIDERATION OF SAFETY INJECTION PUMP HEAT (Discretionary Change) Background January 26, 2011 SCP-IO-21 (Reference I) is a Westinghouse issued Technical Bulletin documenting an evaluation for the consideration of the addition of auxiliary feedwater (AFW) pump heat on various non-LOCA transients.

The Callaway plant has subsequently requested that Westinghouse also address the impact of Safety Injection (SI) pump heat addition on their Appendix K Small Break LOCA (SBLOCA) and Appendix K Large Break LOCA (LBLOCA) analyses of record. Affected Evaluation Model(s) 1981 Westinghouse Large Break LOCA Evaluation Model with BASH 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP Estimated Effect The effect of SI pump heat was considered for the Callaway Appendix K SBLOCA and Appendix K LBLOCA analyses.

It was determined that the inclusion of SI pump heat will produce a negligible effect on the results of the large break and small break LOCA analyses, leading to an estimated PCT impact of OaF for 10 CFR 50.46 reporting purposes.

Reference

1. SCP-IO-21, "TB-09-4, Rev. I -Impact of Auxiliary Pump Heat on Westinghouse and Combustion Engineering Analyses/Methodologies," April 13, 2010.

Enclosure to ULNRC-05769 Page 7 of 9 Attachment to L TR-LlS-11-40 January 26, 2011 Westinghouse LOCA Peak Clad Temperature Summary for Appendix K Large Break Plant Name: Callaway Ameren UE 1 114111 Utility Name: Revision Date: Analysis Information EM: FQ: Fuel: Notes: BASH 2.5 Vantage 5 Analysis Date: FdH: SGTP (%): 6/6/03 1.65 5 Limiting Break Size: Cd=0.6 Clad Temp (OF) Ref. Notes LICENSING BASIS Analysis-Of-Record PCT PCT ASSESSMENTS (Delta PCT) 1939 1,4,5 A. PRIOR ECCS MODEL ASSESSMENTS

• LOCBART Pellet Volumetric Heat Generation Rate B. PLANNED PLANT MODIFICATION EVALUATIONS

• Fuel Rod Crud 2 . Increased Sump Screen Metal Mass C. 2010 ECCS MODEL ASSESSMENTS

• None D.OTHER*

• None LICENSING BASIS PCT + PCT ASSESSMENTS 14 0 3 0 0 PCT= 1956 It is recommended that the licensee determine if these PCT allocations should be considered with respect to 10 CFR S0.46 reporting requirements.

7 2,3 (a) 6

References:

Notes: 1 . SCP-04-73/SCP-RSG-04-30, "Transmittal of Final Engineering Report for NSSS RSG Analyses," July 16,2004. 2 . SCP-99-111, "Ameren U. E., Callaway Project, 10 CFR SO.46 Annual Notification and Reporting for 1998," March S, 1999. 3 . SECL-99-036, "Safety Evaluation for Cycle 10 Axial Offset Anomaly at Callaway," April 1999. 4 . SCP-OS-44, "L TR-MPG-OS-69 P-Attachment (Proprietary)

& LTR-MPG-OS-69 NP-Attachment (Non-Proprietary), "Responses to NRC Request for Additional Information on WCAP-1626S-P, Rev. 0, 'Callaway Replacement Steam Generator Program NSSS Licensing Report,"'" June IS, 200S. S . NF-SCP-OS-49, Rev. I, "Cycle IS Final RSE with Revised PCT Rackup," July 27, 200S. 6 . SCP-07-27, Rev. I, "Large Break LOCA Evaluation for Increased Sump Screen Mass," March 2007. 7 . LTR-LlS-07-313, "10 CFR S0.46 Reporting Text for LOCBART Version 37.0 Issues and Revised PCT Rackup Sheets for Callaway," May 2007. (a) This 0 OF has been assessed for 4.0 mils of crud.

Enclosure to ULNRC-05769 Page 8 of 9 Attachment to L TR-LlS-11-40 January 26, 2011 Westinghouse LOCA Peak Clad Temperature Summary for Appendix K Small Break Plant Name: Utility Name: Revision Date: Callaway Ameren UE 1114/11 Analysis Information EM: NOTRUMP 2.5 Analysis Date: 10/8/03 1.65 Limiting Break Size: 4 inch FQ: FdH: Fuel: Vantage 5 SGTP (%): 5 Notes: LICENSING BASIS Analysis-Of-Record PCT PCT ASSESSMENTS (Delta PCT) A. PRIOR ECCS MODEL ASSESSMENTS 1 . None B. PLANNED PLANT MODIFICATION EVALUATIONS 1 . None C. 2010 ECCS MODEL ASSESSMENTS 1 . None D.OTHER* 1 . None LICENSING BASIS PCT + PCT ASSESSMENTS Clad Temp (OF) 1043 0 0 0 0 PCT= 1043

• It is recommended that the licensee determine if these PCT allocations should be considered with respect to 10 CFR 50.46 reporting requirements.

References:

Ref. 1 . SCP-04-73/SCP-RSG-04-30, "Transmittal of Final Engineering Report for NSSS RSG Analyses," July 16,2004. Notes: None Notes Enclosure to ULNRC-05769 Page 9 of 9 Attachment to L TR-LlS-11-40 RACKUP eRoom Check: EMs applicable to Callaway:

Appendix K Large Break -BASH Appendix K Small Break -NOTRUMP 2010 Issues Transmittal Letter Issue Description L TR-LIS-l 0-304 Consideration Of Safety Injection Pump Heat -Appendix K Small Break LOCA And Appendix K Large Break LOCA Evaluation LTR-LIS-IO-708 Treatment of Vessel Average Temperature Uncertainty January 26, 2011