ML13309B053

Virgil C. Summer, Unit 1 - ECCS Evaluation Model Revisions 30-Day Report

ML13309B053
Person / Time
Site:	Summer
Issue date:	11/04/2013
From:	Gatlin T D South Carolina Electric & Gas Co, South Carolina Public Service Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML13309B053 (12)

Text

Thomas D. Gatlin Vice President, Nuclear Operations 803.345.4342 A SCANA COMPANY November 4, 2013 Document Control Desk U. S. Nuclear Regulatory Commission Washingt6n, DC 20555

Subject:

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT 1 DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 ECCS EVALUATION MODEL REVISIONS 30-DAY REPORT

Reference:

Thomas D. Gatlin, SCE&G, to Nuclear Regulatory Commission DCD,"ECCS Evaluation Model Revisions 30-Day Report," dated October 16, 2012 [ML12293A071]

South Carolina Electric & Gas Company (SCE&G), acting for itself and as agent for South Carolina Public Service Authority, hereby submits information regarding the evaluation, of changes to grid blockage ratio and porosity in Virgil C. Summer Nuclear Station's Best-Estimate (BE) Large-Break Loss-of-Coolant Accident (LBLOCA) analysis.This report is being submitted pursuant to 10 CFR 50.46(a)(3)(ii), which requires licensees to notify the NRC within 30 days of corrections to or changes in the ECCS Evaluation Models of greater than 50 degrees Fahrenheit.

Attachment I documents the 10 CFR 50.46 reporting text. Updated LBLOCA Peak Cladding Temperature (PCT)rack-up slieets are included in Attachment I1.10 CFR 50.46(a)(3)(ii) requires the licensee to provide a report within 30 days, including a propose'd schedule for providing a reanalysis or taking other action as may be needed to show compliance with 10 CFR 50.46. SCE&G has reviewed the information provided by Westinghouse and determined that the adjusted BE LBLOCA PCT values continue to comply wiih the requirements of 10 CFR 50.46. SCE&G previously provided a proposal for BE LBLOCA reanalysis in its October 16, 2012 submittal (Reference).

That reanalysis effort will also address grid blockage ratio and porosity effects.If you have any questions, please call Bruce L. Thompson at (803) 931-5042.Very truly yours, Thomas D. Gatlin TS/TDG/wm Attachments (2)c: K. B. ;Marsh J. W. Williams K. M. Sutton S. A. Byrne W. M. Cherry NSRC J. B. Archie V. M. McCree RTS (CR-13-04243)

N. S. Cams S. A. Williams File (818.02-17)

J. H. Hamilton NRC Resident Inspector PRSF (RC-13-0161)

Virgil C. Summer Station

• Post Office Box 88 -Jenkinsville, SC .29065 .F (803) 941-9776 Document Control Desk Attachment I CR-13-04243 RC-1 3-0161 Page 1 of 2 VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT I DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 ATTACHMENT I VIRGIL C. SUMMER 10 CFR 50.46 REPORTING TEXT FOR CHANGES TO GRID BLOCKAGE RATIO AND POROSITY Document Control Desk Attachment I CR-13-04243 RC-13-0161 Page 2 of 2 Changes to Grid Blockage Ratio and Porosity Background A change in the methodology used to calculate grid blockage ratio and porosity for Westinghouse fuel resulted in a change to the grid inputs used in the V. C. Summer large break loss-of-coolant accident (LBLOCA) analysis.

Grid inputs affect heat transfer in the core during a LBLOCA. This change represents a Non-Discretionary Change in accordance with Section 4.1.2 of Reference 1.Affected Evaluation Model 1996 Westinghouse Best Estimate Large Break LOCA Evaluation Model Estimated Effect The updates to the methodology to calculate grid blockage ratio and porosity used as input in Westinghouse LBLOCA models resulted in degraded heat transfer in the core for the fuel type used in V. C. Summer. The estimated penalty associated with the changes is 24 degrees Fahrenheit for both Reflood 1 and Reflood 2 for 10 CFR 50.46 reporting purposes.References

1. WCAP-1 3451, "Westinghouse Methodology for Implementation of 10 CFR 50.46 Reporting," October 1992.

Document Control Desk Attachment II CR-13-04243 RC-13-0161 Page 1 of 9 VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT I DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 ATTACHMENT II PEAK CLADDING TEMPERATURE (PCT) RACKUP SHEETS Document Control Desk Attachment II CR-13-04243 RC-13-0161 Page 2 of 9 Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large Break Plant Name: Utility Name: V. C. Summer South Carolina Electric & Gas Revision Date: 9/20/2013 Analysis Information EM: CQD (1996) Analysis Date FQ: 2.5 FdH: Fuel: Vantage + SGTP (%): Notes: Delta 75 Replacement Steam Composite 2/3/2003 1.7 10 Limiting Break Size: Guillotine Generator Uprate Core Power 2900 MWt Clad Temp (°F) Ref.Notes LICENSING BASIS Analysis-Of-Record PCT PCT ASSESSMENTS (Delta PCT)1988 1 A. PRIOR ECCS MODEL ASSESSMENTS

1. Backfit Through 2001 Reporting Year 2. Revised Blowdown Heatup Uncertainty Distribution

3. PAD 4.0 Implementation

4. Evaluation of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown 5. Transverse Momentum Cells for Zero Cross-flow Boundary Condition Error B. PLANNED PLANT MODIFICATION EVALUATIONS

1. Fan Cooler Performance Increase 2. Upflow Conversion Evaluation C. 2013 ECCS MODEL ASSESSMENTS

1. Revised Heat Transfer Multiplier Distributions

2. Changes to Grid Blockage Ratio and Porosity D. OTHER 1. None 0 2 5 3-118 5 123 5 (a)0 5 (b)2 2-29 4-35 6 24 7 0 LICENSING BASIS PCT + PCT ASSESSMENTS PCT = 1960 Document Control Desk Attachment II CR-13-04243 RC-13-0161 Page 3 of 9 Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large Break Plant Name: V. C. Summer Utility Name: South Carolina Electric & Gas Revision Date: 9/20/2013 Composite References

1. WCAP-16043, "Best Estimate Analysis of the Large Break Loss of Coolant Accident for the Virgil C. Summer Nuclear Station," June 2003.2. CGE-03-12, "10 CFR 50.46 Annual Notification and Reporting for 2002," March 2003.3. CGE-05-20, "10 CFR 50.46 Annual Notification and Reporting for 2004," April 2005.4. LTR-LIS-08-578, Revision 2, "10 CFR 50.46 Reports for the V. C. Summer (CGE)Upflow Conversion Large Break LOCA Evaluation and Assessment of Transverse Momentum Cells with a Zero Cross-flow Boundary Condition Error," January 2009.5. LTR-LIS-12-372, "V. C. Summer, 10 CFR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown," September 20, 2012.6. LTR-LIS-13-353, "V. C. Summer 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions," July 2013.7. LTR-LIS-1 3-476, "V. C. Summer 10 CFR 50.46 Report for Changes to Grid Blockage Ratio and Porosity," October 2013.Notes: (a) This evaluation credits peaking factor burndown.

See Reference 5.(b) This input error was originally reported in Reference

4. That evaluation is superseded by the report in Reference

5.

Document Control Desk Attachment II CR-1 3-04243 RC-13-0161 Page 4 of 9 Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large Break Plant Name: Utility Name: V. C. Summer South Carolina Electric & Gas Revision Date: 9/20/2013 Analysis Information EM: CQD (1996) Analysis Date: 2/3/2003 FQ: 2.5 FdH: 1.7 Fuel: Vantage + SGTP (%): 10 Notes: Delta 75 Replacement Steam Generator LICENSING BASIS Analysis-Of-Record PCT PCT ASSESSMENTS (Delta PCT)Blowdown Limiting Break Size: Guillotine Jprate Core Power 2900 MWt Clad Temp ('F) Ref. Notes 1860 1 A. PRIOR ECCS MODEL ASSESSMENTS

1. Backfit Through 2001 Reporting Year 2. Revised Blowdown Heatup Uncertainty Distribution

3. PAD 4.0 Implementation

4. Evaluation of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown 5. Transverse Momentum Cells for Zero Cross-flow Boundary Condition Error B. PLANNED PLANT MODIFICATION EVALUATIONS

1. Fan Cooler Performance Increase 2. Upflow Conversion Evaluation C. 2013 ECCS MODEL ASSESSMENTS

1. Revised Heat Transfer Multiplier Distributions

2. Changes to Grid Blockage Ratio and Porosity D. OTHER 1. None 0 2 49 3-83 5 0 5 (a)0 5 (b)0 2-7 4-5 6 0 7 0 LICENSING BASIS PCT + PCT ASSESSMENTS PCT = 1814 Document Control Desk Attachment II CR-1 3-04243 RC-13-0161 Page 5 of 9 Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large Break Plant Name: V. C. Summer Utility Name: South Carolina Electric & Gas Revision Date: 9/20/2013 Blowdown References

1. WCAP-16043, "Best Estimate Analysis of the Large Break Loss of Coolant Accident for the Virgil C. Summer Nuclear Station," June 2003.2. CGE-03-12, "10 CFR 50.46 Annual Notification and Reporting for 2002," March 2003.3. CGE-05-20, "10 CFR 50.46 Annual Notification and Reporting for 2004," April 2005.4. LTR-LIS-08-578, Revision 2, "10 CFR 50.46 Reports for the V. C. Summer (CGE)Upflow Conversion Large Break LOCA Evaluation and Assessment of Transverse Momentum Cells with a Zero Cross-flow Boundary Condition Error," January 2009.5. LTR-LIS-12-372, "V. C. Summer, 10 CFR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown," September 20, 2012.6. LTR-LIS-13-353, "V. C. Summer 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions," July 2013.7. LTR-LIS-1 3-476, "V. C. Summer 10 CFR 50.46 Report for Changes to Grid Blockage Ratio and Porosity," October 2013.Notes: (a) This evaluation credits peaking factor burndown.

See Reference 5.(b) This input error was originally reported in Reference

4. That evaluation is superseded by the report in Reference

5.

Document Control Desk Attachment II CR-13-04243 RC-13-0161 Page 6 of 9 Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large Break Plant Name: V. C. Summer Utility Name: South Carolina Electric & Gas Revision Date: 9/20/2013 Reflood 1 Analysis Information EM: CQD (1996) Analysis Date: 2/3/2003 Limiting Break Size: Guillotine FQ: 2.5 FdH: 1.7 Fuel: Vantage + SGTP (%): 10 Notes: Delta 75 Replacement Steam Generator Uprate Core Power 2900 MWt Clad Temp (°F) Ref. Notes LICENSING BASIS Analysis-Of-Record PCT 1808 1 PCT ASSESSMENTS (Delta PCT)A. PRIOR ECCS MODEL ASSESSMENTS

1. Backfit Through 2001 Reporting Year 0 2 2. Revised Blowdown Heatup Uncertainty Distribution 5 3 3. PAD 4.0 Implementation

-118 5 4. Evaluation of Fuel Pellet Thermal Conductivity 113 5 (a)Degradation and Peaking Factor Burndown 5. Transverse Momentum Cells for Zero Cross-flow 0 5 (b)Boundary Condition Error B. PLANNED PLANT MODIFICATION EVALUATIONS

1. Fan Cooler Performance Increase 1 2 2. Upflow Conversion Evaluation

-44 4 C. 2013 ECCS MODEL ASSESSMENTS

1. Revised Heat Transfer Multiplier Distributions 5 6 2. Changes to Grid Blockage Ratio and Porosity 24 7 D. OTHER 1. None 0 LICENSING BASIS PCT + PCT ASSESSMENTS PCT = 1794 Document Control Desk Attachment II CR-13-04243 RC-13-0161 Page 7 of 9 Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large Break Plant Name: V. C. Summer Utility Name: South Carolina Electric & Gas Revision Date: 9/20/2013 Reflood 1 References

1. WCAP-1 6043, "Best Estimate Analysis of the Large Break Loss of Coolant Accident for the Virgil C. Summer Nuclear Station," June 2003.2. CGE-03-12, "10 CFR 50.46 Annual Notification and Reporting for 2002," March 2003.3. CGE-05-20, "10 CFR 50.46 Annual Notification and Reporting for 2004," April 2005.4. LTR-LIS-08-578, Revision 2, "10 CFR 50.46 Reports for the V. C. Summer (CGE)Upflow Conversion Large Break LOCA Evaluation and Assessment of Transverse Momentum Cells with a Zero Cross-flow Boundary Condition Error," January 2009.5. LTR-LIS-12-372, "V. C. Summer, 10 CFR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown," September 20, 2012.6. LTR-LIS-13-353, "V. C. Summer 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions," July 2013.7. LTR-LIS-13-476, "V. C. Summer 10 CFR 50.46 Report for Changes to Grid Blockage Ratio and Porosity," October 2013.Notes: (a) This evaluation credits peaking factor burndown.

See Reference 5.(b) This input error was originally reported in Reference

4. That evaluation is superseded by the report in Reference

5.

Document Control Desk Attachment II CR-13-04243 RC-13-0161 Page 8 of 9 Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large Break Plant Name: V. C. Summer Utility Name: South Carolina Electric & Gas Revision Date: 9/20/2013 Reflood 2 Analysis Information EM: CQD (1996) Analysis Date: 2/3/2003 Limiting Break Size: Guillotine FQ: 2.5 FdH: 1.7 Fuel: Vantage + SGTP (%): 10 Notes: Delta 75 Replacement Steam Generator Uprate Core Power 2900 MWt Clad Temp (°F) Ref. Notes LICENSING BASIS Analysis-Of-Record PCT 1988 1 PCT ASSESSMENTS (Delta PCT)A. PRIOR ECCS MODEL ASSESSMENTS

1. Backfit Through 2001 Reporting Year 0 2 2. Revised Blowdown Heatup Uncertainty Distribution 5 3 3. PAD 4.0 Implementation

-118 5 4. Evaluation of Fuel Pellet Thermal Conductivity 123 5 (a)Degradation and Peaking Factor Burndown 5. Transverse Momentum Cells for Zero Cross-flow 0 5 (b)Boundary Condition Error B. PLANNED PLANT MODIFICATION EVALUATIONS

1. Fan Cooler Performance Increase 2 2 2. Upflow Conversion Evaluation

-29 4 C. 2013 ECCS MODEL ASSESSMENTS

1. Revised Heat Transfer Multiplier Distributions

-35 6 2. Changes to Grid Blockage Ratio and Porosity 24 7 D. OTHER 1. None 0 LICENSING BASIS PCT + PCT ASSESSMENTS PCT = 1960 Document Control Desk Attachment II CR-13-04243 RC-13-0161 Page 9 of 9 Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large Break Plant Name: V. C. Summer Utility Name: South Carolina Electric & Gas Revision Date: 9/20/2013 Reflood 2 References

1. WCAP-16043, "Best Estimate Analysis of the Large Break Loss of Coolant Accident for the Virgil C. Summer Nuclear Station," June 2003.2. CGE-03-12, "10 CFR 50.46 Annual Notification and Reporting for 2002," March 2003.3. CGE-05-20, "10 CFR 50.46 Annual Notification and Reporting for 2004," April 2005.4. LTR-LIS-08-578, Revision 2, "10 CFR 50.46 Reports for the V. C. Summer (CGE)Upflow Conversion Large Break LOCA Evaluation and Assessment of Transverse Momentum Cells with a Zero Cross-flow Boundary Condition Error," January 2009.5. LTR-LIS-12-372, "V. C. Summer, 10 CFR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown," September 20, 2012.6. LTR-LIS-13-353, "V. C. Summer 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions," July 2013.7. LTR-LIS-13-476, "V. C. Summer 10 CFR 50.46 Report for Changes to Grid Blockage Ratio and Porosity," October 2013.Notes: (a) This evaluation credits peaking factor burndown.

See Reference 5.(b) This input error was originally reported in Reference

4. That evaluation is superseded by the report in Reference 5.