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. GatlinVice President, Nuclear Operations 803.345.4342 A SCANA COMPANYNovember 4, 2013Document Control DeskU. S. Nuclear Regulatory Commission Washingt6n, DC 20555

Subject:

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

Reference:

Thomas D. Gatlin, SCE&G, to Nuclear Regulatory Commission DCD,"ECCS Evaluation Model Revisions 30-Day Report,"

datedOctober 16, 2012 [ML12293A071]

South Carolina Electric

& Gas Company (SCE&G),

acting for itself and as agent forSouth Carolina Public Service Authority, hereby submits information regarding theevaluation, of changes to grid blockage ratio and porosity in Virgil C. Summer NuclearStation'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 requireslicensees to notify the NRC within 30 days of corrections to or changes in the ECCSEvaluation Models of greater than 50 degrees Fahrenheit.

Attachment I documents the10 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 neededto show compliance with 10 CFR 50.46. SCE&G has reviewed the information providedby Westinghouse and determined that the adjusted BE LBLOCA PCT values continue tocomply wiih the requirements of 10 CFR 50.46. SCE&G previously provided a proposalfor BE LBLOCA reanalysis in its October 16, 2012 submittal (Reference).

Thatreanalysis 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. GatlinTS/TDG/wm Attachments (2)c: K. B. ;Marsh J. W. Williams K. M. SuttonS. A. Byrne W. M. Cherry NSRCJ. 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 DeskAttachment ICR-13-04243 RC-1 3-0161Page 1 of 2VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT IDOCKET NO. 50-395OPERATING LICENSE NO. NPF-12ATTACHMENT IVIRGIL C. SUMMER 10 CFR 50.46 REPORTING TEXT FOR CHANGES TO GRIDBLOCKAGE RATIO AND POROSITY Document Control DeskAttachment ICR-13-04243 RC-13-0161 Page 2 of 2Changes to Grid Blockage Ratio and PorosityBackground A change in the methodology used to calculate grid blockage ratio and porosity forWestinghouse fuel resulted in a change to the grid inputs used in the V. C. Summer large breakloss-of-coolant accident (LBLOCA) analysis.

Grid inputs affect heat transfer in the core during aLBLOCA. This change represents a Non-Discretionary Change in accordance with Section 4.1.2of Reference 1.Affected Evaluation Model1996 Westinghouse Best Estimate Large Break LOCA Evaluation ModelEstimated EffectThe updates to the methodology to calculate grid blockage ratio and porosity used as input inWestinghouse LBLOCA models resulted in degraded heat transfer in the core for the fuel typeused in V. C. Summer. The estimated penalty associated with the changes is 24 degreesFahrenheit 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 DeskAttachment IICR-13-04243 RC-13-0161 Page 1 of 9VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT IDOCKET NO. 50-395OPERATING LICENSE NO. NPF-12ATTACHMENT IIPEAK CLADDING TEMPERATURE (PCT) RACKUP SHEETS Document Control DeskAttachment IICR-13-04243 RC-13-0161 Page 2 of 9Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large BreakPlant Name:Utility Name:V. C. SummerSouth Carolina Electric

& GasRevision Date: 9/20/2013 Analysis Information EM: CQD (1996) Analysis DateFQ: 2.5 FdH:Fuel: Vantage + SGTP (%):Notes: Delta 75 Replacement SteamComposite 2/3/20031.710Limiting Break Size: Guillotine Generator Uprate Core Power 2900 MWtClad Temp (°F) Ref.NotesLICENSING BASISAnalysis-Of-Record PCTPCT ASSESSMENTS (Delta PCT)1988 1A. PRIOR ECCS MODEL ASSESSMENTS

1. Backfit Through 2001 Reporting Year2. Revised Blowdown Heatup Uncertainty Distribution

3. PAD 4.0 Implementation

4. Evaluation of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown5. Transverse Momentum Cells for Zero Cross-flow Boundary Condition ErrorB. PLANNED PLANT MODIFICATION EVALUATIONS

1. Fan Cooler Performance Increase2. Upflow Conversion Evaluation C. 2013 ECCS MODEL ASSESSMENTS

1. Revised Heat Transfer Multiplier Distributions

2. Changes to Grid Blockage Ratio and PorosityD. OTHER1. None0 25 3-118 5123 5 (a)0 5 (b)2 2-29 4-35 624 70LICENSING BASIS PCT + PCT ASSESSMENTS PCT = 1960 Document Control DeskAttachment IICR-13-04243 RC-13-0161 Page 3 of 9Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large BreakPlant Name: V. C. SummerUtility Name: South Carolina Electric

& GasRevision Date: 9/20/2013 Composite References

1. WCAP-16043, "Best Estimate Analysis of the Large Break Loss of Coolant Accidentfor 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 FuelPellet 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 TransferMultiplier Distributions,"

July 2013.7. LTR-LIS-1 3-476, "V. C. Summer 10 CFR 50.46 Report for Changes to Grid BlockageRatio 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 DeskAttachment IICR-1 3-04243RC-13-0161 Page 4 of 9Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large BreakPlant Name:Utility Name:V. C. SummerSouth Carolina Electric

& GasRevision Date: 9/20/2013 Analysis Information EM: CQD (1996) Analysis Date: 2/3/2003FQ: 2.5 FdH: 1.7Fuel: Vantage + SGTP (%): 10Notes: Delta 75 Replacement Steam Generator LICENSING BASISAnalysis-Of-Record PCTPCT ASSESSMENTS (Delta PCT)BlowdownLimiting Break Size: Guillotine Jprate Core Power 2900 MWtClad Temp ('F) Ref. Notes1860 1A. PRIOR ECCS MODEL ASSESSMENTS

1. Backfit Through 2001 Reporting Year2. Revised Blowdown Heatup Uncertainty Distribution

3. PAD 4.0 Implementation

4. Evaluation of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown5. Transverse Momentum Cells for Zero Cross-flow Boundary Condition ErrorB. PLANNED PLANT MODIFICATION EVALUATIONS

1. Fan Cooler Performance Increase2. Upflow Conversion Evaluation C. 2013 ECCS MODEL ASSESSMENTS

1. Revised Heat Transfer Multiplier Distributions

2. Changes to Grid Blockage Ratio and PorosityD. OTHER1. None0 249 3-83 50 5 (a)0 5 (b)0 2-7 4-5 60 70LICENSING BASIS PCT + PCT ASSESSMENTS PCT = 1814 Document Control DeskAttachment IICR-1 3-04243RC-13-0161 Page 5 of 9Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large BreakPlant Name: V. C. SummerUtility Name: South Carolina Electric

& GasRevision Date: 9/20/2013 BlowdownReferences

1. WCAP-16043, "Best Estimate Analysis of the Large Break Loss of Coolant Accidentfor 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 FuelPellet 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 TransferMultiplier Distributions,"

July 2013.7. LTR-LIS-1 3-476, "V. C. Summer 10 CFR 50.46 Report for Changes to Grid BlockageRatio 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 DeskAttachment IICR-13-04243 RC-13-0161 Page 6 of 9Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large BreakPlant Name: V. C. SummerUtility Name: South Carolina Electric

& GasRevision Date: 9/20/2013 Reflood 1Analysis Information EM: CQD (1996) Analysis Date: 2/3/2003 Limiting Break Size: Guillotine FQ: 2.5 FdH: 1.7Fuel: Vantage + SGTP (%): 10Notes: Delta 75 Replacement Steam Generator Uprate Core Power 2900 MWtClad Temp (°F) Ref. NotesLICENSING BASISAnalysis-Of-Record PCT 1808 1PCT ASSESSMENTS (Delta PCT)A. PRIOR ECCS MODEL ASSESSMENTS

1. Backfit Through 2001 Reporting Year 0 22. Revised Blowdown Heatup Uncertainty Distribution 5 33. PAD 4.0 Implementation

-118 54. Evaluation of Fuel Pellet Thermal Conductivity 113 5 (a)Degradation and Peaking Factor Burndown5. Transverse Momentum Cells for Zero Cross-flow 0 5 (b)Boundary Condition ErrorB. PLANNED PLANT MODIFICATION EVALUATIONS

1. Fan Cooler Performance Increase 1 22. Upflow Conversion Evaluation

-44 4C. 2013 ECCS MODEL ASSESSMENTS

1. Revised Heat Transfer Multiplier Distributions 5 62. Changes to Grid Blockage Ratio and Porosity 24 7D. OTHER1. None 0LICENSING BASIS PCT + PCT ASSESSMENTS PCT = 1794 Document Control DeskAttachment IICR-13-04243 RC-13-0161 Page 7 of 9Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large BreakPlant Name: V. C. SummerUtility Name: South Carolina Electric

& GasRevision Date: 9/20/2013 Reflood 1References

1. WCAP-1 6043, "Best Estimate Analysis of the Large Break Loss of Coolant Accidentfor 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 FuelPellet 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 TransferMultiplier Distributions,"

July 2013.7. LTR-LIS-13-476, "V. C. Summer 10 CFR 50.46 Report for Changes to Grid BlockageRatio 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 DeskAttachment IICR-13-04243 RC-13-0161 Page 8 of 9Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large BreakPlant Name: V. C. SummerUtility Name: South Carolina Electric

& GasRevision Date: 9/20/2013 Reflood 2Analysis Information EM: CQD (1996) Analysis Date: 2/3/2003 Limiting Break Size: Guillotine FQ: 2.5 FdH: 1.7Fuel: Vantage + SGTP (%): 10Notes: Delta 75 Replacement Steam Generator Uprate Core Power 2900 MWtClad Temp (°F) Ref. NotesLICENSING BASISAnalysis-Of-Record PCT 1988 1PCT ASSESSMENTS (Delta PCT)A. PRIOR ECCS MODEL ASSESSMENTS

1. Backfit Through 2001 Reporting Year 0 22. Revised Blowdown Heatup Uncertainty Distribution 5 33. PAD 4.0 Implementation

-118 54. Evaluation of Fuel Pellet Thermal Conductivity 123 5 (a)Degradation and Peaking Factor Burndown5. Transverse Momentum Cells for Zero Cross-flow 0 5 (b)Boundary Condition ErrorB. PLANNED PLANT MODIFICATION EVALUATIONS

1. Fan Cooler Performance Increase 2 22. Upflow Conversion Evaluation

-29 4C. 2013 ECCS MODEL ASSESSMENTS

1. Revised Heat Transfer Multiplier Distributions

-35 62. Changes to Grid Blockage Ratio and Porosity 24 7D. OTHER1. None 0LICENSING BASIS PCT + PCT ASSESSMENTS PCT = 1960 Document Control DeskAttachment IICR-13-04243 RC-13-0161 Page 9 of 9Westinghouse LOCA Peak Clad Temperature Summary for Best Estimate Large BreakPlant Name: V. C. SummerUtility Name: South Carolina Electric

& GasRevision Date: 9/20/2013 Reflood 2References

1. WCAP-16043, "Best Estimate Analysis of the Large Break Loss of Coolant Accidentfor 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 FuelPellet 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 TransferMultiplier Distributions,"

July 2013.7. LTR-LIS-13-476, "V. C. Summer 10 CFR 50.46 Report for Changes to Grid BlockageRatio 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.