CP-202200003, (CPNPP) - Annual Report of Changes in Peak Cladding Temperature
| ML22136A303 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 05/16/2022 |
| From: | Hicks J Luminant, Vistra Operations Company |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| CP-202200003, TXX-22001 | |
| Download: ML22136A303 (14) | |
Text
II Luminant CP-202200003 TXX-22001 May 16, 2022 Jack C. Hicks Manager, Regulatory Affairs Comanche Peak Nuclear Power Plant (Vistra Operations Company LLC)
P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 T 254.897.6725 A TIN: Document Control Desk Ref 10 CFR 50.46(a)(3)(ii)
U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
References:
Comanche Peak Nuclear Power Plant (CPNPP)
Docket Nos. 50-445 and 50-446 Annual Report of Changes in Peak Cladding Temperature
- 1.
Letter TXX-12146, dated October 18, 2012, from Rafael Flores of Luminant Power to the NRC regarding "30-Day Report for Significant Change in Peak Clad Temperature"
- 2.
Letter logged TXX-14058, dated April 22, 2014, from Rafael Flores of Luminant Power to the NRC regarding "30-Day Report for Significant Change in Peak Clad Temperature"
Dear Sir or Madam:
Pursuant to 10CFR50.46(a)(3)(ii), Vistra Operations Company LLC (Vistra OpCo) hereby submits the attached peak cladding temperatures (PCT) for Comanche Peak Nuclear Power Plant (CPNPP), Units 1 and 2. The Large-Break Loss-of-Coolant-Accident (LBLOCA) and Small-Break Loss-of-Coolant Accident (SBLOCA) analyses for Units 1 and 2 were performed for CPNPP with the approved Westinghouse methodologies listed in Technical Specification 5.6.5. Per Reference 1, Luminant Power previously submitted information regarding fuel pellet thermal conductivity with fuel burnup in the Westinghouse Best Estimate LBLOCA analysis methodology for CPNPP Units 1 and 2. Also, per Reference 2, Luminant Power submitted information regarding an evaluation of revised Heat Transfer Multiplier Distributions, changes to Grid Blockage Ratio and Porosity, and application of a corrected Burst Strain in the Westinghouse Best Estimate LBLOCA analysis methodology for CPNPP Unit 2 and its effect on Peak Cladding Temperature (PCT).
Vistra OpCo has reviewed the notification of 10CFR50.46 reporting information pertaining to the Emergency Core Cooling System (ECCS) Evaluation Model changes that were implemented by Westinghouse. The review concludes that the effect of additional changes to, or errors in, the Evaluation Models on the limiting transient PCT were not significant. provides an assessment of the specific changes and enhancements to the Westinghouse Evaluation Models for 2021.
TXX-22001 Page 2 of 2 provides the calculated LBLOCA and SBLOCA PCT margin allocations in effect for the 2021 Comanche Peak Units 1 and 2 Evaluation Models. There were no changes, error corrections, or enhancements to the 1985 Westinghouse Small Break Loss-of-Coolant Accident Evaluation Model with NOTRUMP. The PCT values determined in the LBLOCA analysis of record, combined with all of the PCT allocations, remain well below the 10CFR50.46 regulatory limit of 2200 degrees Fahrenheit.
Therefore, CPNPP Units 1 and 2 are in compliance with 10CFR50.46 requirements and no other action is required.
This communication contains no new commitments regarding CPNPP Units 1 and 2.
Should you have any questions, please contact Ken Vehstedt at (254) 897-6296 or ken.vehstedt@luminant.com.
Sincerely, Attachments
- 1.
Assessments of Specific Changes and Enhancements to the Westinghouse Evaluation Models c (email) -
- 2.
CPNPP Units 1 and 2 Peak Cladding Temperatures Scott Morris, Region IV [Scott.Morris@nrc.gov]
Dennis Galvin, NRR [Dennis.Galvin@nrc.gov]
John Ellegood, Senior Resident Inspector, CPNPP [John.Ellegood@nrc.gov]
Neil Day, Resident Inspector, CPNPP [Neil.Day@nrc.gov]
to TXX-22001 Page 1 of 1 GENERAL CODE MAINTENANCE
Background
Assessments of Specific Changes and Enhancements to the Westinghouse Evaluation Models Various changes have been made to enhance the usability of codes and to streamline future analyses.
Examples of these changes include 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 forward-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 2004 Westinghouse Realistic Large Break LOCA Evaluation Model Using ASTRUM 2016 Westinghouse FULL SPECTRUM' LOCA Evaluation Model Estimated Effect The nature of these changes leads to an estimated Peak Gadding Temperature (PCT) impact of 0°F.
REDUCTION IN FLOW AREA TO THE BOTTOM OF THE BARREi/BAFFLE REGION
Background
For plants without holes in the edge of the lower core plate, the flow area from the bottom of the core to the barrel/baffle region has historically been modeled as the gap between the baffle plate and the lower core plate, and this flow area did not consider the reduced flow area due to the presence of the bottom nozzle flow skirt. The impact of reducing the flow area between the core and barrel baffle region due to including the bottom nozzle flow skirt has been qualitatively evaluated. This item 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 Estimated Effect The evaluation determined that considering a reduced flow area from the bottom of the core to the barrel/baffle region when considering the bottom nozzle flow skirt has a negligible effect on the SBLOCA analysis results, leading to an estimated peak cladding temperature (PCT) impact of 0°F.
COMANCHE PEAK UNIT 2 CYCLE 20 PBOT/PMID VIOLATIONS
Background
The Comanche Peak Unit 2 Cycle 20 reload core design resulted in several violations of the PBOT/PMID box used in the Large Break LOCA analysis. These violations were evaluated for Comanche Peak Unit 2 Cycle 20 operation. This item represents a change in plant configuration or associated set points, distinguished from an evaluation model change in Section 4 of WCAP-13451.
Affected Evaluation Model(s) 2004 Westinghouse Realistic Large Break LOCA Evaluation Model Using ASTRUM Estimated Effect The impact of the PBOT /PMID violations for Comanche Peak Unit 2 Cycle 20 was determined via a plant-specific evaluation to be 0°F.
to TXX-22001 Page 1 of 11 CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 1 EM:
NOTRUMP AOR
Description:
Appendix K Small Break Summary Sheet Status: Current PCT (°F) 1013 Reference#
ANALYSIS-OF-RECORD 1
AOR + ASSESSMENTS PCT=
1013.0 °F REFERENCES Note#
1 WCAP-16840-P, "Comanche Peak Nuclear Power Plant Stretch Power Uprate Licensing Report," August 2007.
NOTES:
(a) None to TXX-22001 Page 2 of 11 CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 1 EM:
ASTRUM (2004)
Description:
Best Estimate Large Break Summary Sheet Status: Current PCT {°F) 1492 Reference#
ANALYSIS-OF-RECORD ASSESSMENTS*
- 1.
Evaluation of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown
- 2.
Revised Heat Transfer Multiplier Distributions
- 3.
Error in Burst Strain Application AOR + ASSESSMENTS Delta PCT
{°AF) 122
-6 21 1
Reference#
2 3
4 PCT=
1629.0 °F Note#
Note#
(a)
Reporting Year**
2012 2013 2013 The licensee should determine the reportability of these assessments pursuant to 10 CFR 50.46.
- The "Reporting Year" refers to the annual reporting year in which this assessment was included.
REFERENCES 1
WCAP-16762-P, Revision 1, "Best-Estimate Analysis of the Large-Break Loss-of-Coolant Accident for the Comanche Peak Nuclear Power Plant Unit 1 Using the ASTRUM Methodology," March 2009.
2 LTR-LIS-12-410, "Comanche Peak Units 1 and 2 10 CFR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown," September 2012.
3 LTR-LIS-13-359, "Comanche Peak Units 1 and 2 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions," July 2013.
4 LTR-LIS-14-43, "Comanche Peak Units 1 and 2 10 CFR 50.46 Report for the HOTSPOT Burst Strain Error Correction," January 2014.
NOTES:
(a) This evaluation credits peaking factor burndown, see Reference 2.
to TXX-22001 Page 3 ofll CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 1 EM:
ASTRUM (2004)
Description:
Best Estimate Large Break Summary Sheet Status: Cycle 22 ANALYSIS-OF-RECORD ASSESSMENTS*
- 1.
Evaluation of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown
- 2.
Revised Heat Transfer Multiplier Distributions
- 3.
Error in Burst Strain Application
- 4.
PBOT/PMID Violation PCT {°F) 1492 Delta PCT
( 0 AF) 122
-6 21 0
Reference#
Note#
1 Reporting Reference#
Note#
Year**
3 (a) 2012 4
2013 5
2013 2
2020 AOR + ASSESSMENTS PCT=
1629 °F The licensee should determine the reportability of these assessments pursuant to 10 CFR 50.46.
- The "Reporting Year" refers to the annual reporting year in which this assessment was included.
REFERENCES 1
WCAP-16762-P, Revision 1, "Best-Estimate Analysis of the Large-Break Loss-of-Coolant Accident for the Comanche Peak Nuclear Power Plant Unit 1 Using the ASTRUM Methodology," March 2009.
2 L TR-LIS-20-233, "10 CFR 50.46 Reporting Text and LBLOCA PCT Summary Sheet Update for the Evaluation of the Comanche Peak Unit 1 Cycle 22 PBOT/PMID Violations," September 2020.
3 LTR-LIS-12-410, "Comanche Peak Units 1 and 2 10 CFR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown," September 2012.
4 LTR-LIS-13-359, "Comanche Peak Units 1and210 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions," July 2013.
5 LTR-LIS-14-43, "Comanche Peak Units 1 and 2 10 CFR 50.46 Report for the HOTSPOT Burst Strain Error Correction," January 2014.
NOTES:
(a) This evaluation credits peaking factor burndown, see Reference 3.
to TXX-22001 Page 4 of 11 CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 2 EM:
NOTRUMP AOR
Description:
Appendix K Small Break Summary Sheet Status: Current PCT {°F) 1210 Reference#
ANALYSIS-OF-RECORD 1
AOR + ASSESSMENTS PCT=
1210.0 °F REFERENCES Note#
1 WCAP-16840-P, "Comanche Peak Nuclear Power Plant Stretch Power Uprate Licensing Report," August 2007.
NOTES:
(a)
None to TXX-22001 Page 5 of 11 CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 2 EM:
ASTRUM (2004)
Description:
Best Estimate Large Break Summary Sheet Status: Current ANALYSIS-OF-RECORD ASSESSMENTS*
- 1.
Evaluation of Fuel Pellet Thermal Conductivity Degradation and Pealdng Factor Burndown
- 2.
Revised Heat Transfer Multiplier Distributions
- 3.
Changes to Grid Blockage Ratio and Porosity
- 4.
Error in Burst Strain Application PCT{°F) 1632 Delta PCT
{°AF) 190
-17 24 21 Reference#
1 Reference#
2 3
4 5
AOR + ASSESSMENTS PCT=
1850.0 °F Note#
Note#
(a)
The licensee should determine the reportability of these assessments pursuant to 10 CFR 50.46.
Reporting Year**
2012 2013 2013 2013
- The "Reporting Year" refers to the annual reporting year in which this assessment was included.
REFERENCES 1
WCAP-16763-P, Revision 1, "Best-Estimate Analysis of the Large-Break Loss-of-Coolant Accident for the Comanche Peak Nuclear Power Plant Unit 2 Using the ASTRUM Methodology," March 2009.
2 LTR-LIS-12-410, "Comanche Peak Units 1and210 CFR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Bumdown," September 2012.
3 LTR-LIS-13-359, "Comanche Peak Units 1and210 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions," July 2013.
4 LTR-LIS-13-472, "Comanche Peak Units 1 and 2 10 CFR 50.46 Reports for Changes to Grid Blockage Ratio and Porosity," October 2013.
5 LTR-LIS-14-43, "Comanche Peak Units 1 and 2 10 CFR 50.46 Report for the HOTSPOT Burst Strain Error Correction," January 2014.
NOTES:
(a) This evaluation credits peaking factor burndown, see Reference 2.
to TXX-22001 Page 6 of 11 CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 2 EM:
ASTRUM (2004)
Description:
Best Estimate Large Break Summary Sheet Status: Retired Cycle 19 Reference#
Note#
ANALYSIS-OF-RECORD PCT {°F) 1632 1
Delta PCT Reporting ASSESSMENTS*
{°AF)
Reference#
Note#
Year**
- 1.
Evaluation of Fuel Pellet Thermal Conductivity Degradation and 190 3
(a) 2012 Peaking Factor Bumdown
- 2.
Revised Heat Transfer Multiplier Distributions
-17 4
2013
- 3.
Changes to Grid Blockage Ratio and Porosity 24 5
2013
- 4.
Error in Burst Strain Application 21 6
2013
- 5.
PBOTIPMID Violation 0
2 2020 AOR + ASSESSMENTS PCT=
1850 °F The licensee should determine the reportability of these assessments pursuant to 10 CPR 50.46.
- The "Reporting Year" refers to the annual reporting year in which this assessment was included.
REFERENCES 1
WCAP-16763-P, Revision 1, "Best-Estimate Analysis of the Large-Break Loss-of-Coolant Accident for the Comanche Peak Nuclear Power Plant Unit 2 Using the ASTRUM Methodology," March 2009.
2 LTR-LIS-20-116, "10 CPR 50.46 Reporting Text and LBLOCA PCT Summary Sheet Update for the Evaluation of the Comanche Peak Unit 2 Cycle 19 PBOTIPMID Violations," April 2020.
3 LTR-LIS-12-410, "Comanche Peak Units 1 and 2 10 CPR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Bumdown," September 2012.
4 LTR-LIS-13-359, "Comanche Peak Units 1and210 CPR 50.46 Report for Revised Heat Transfer Multiplier Distributions," July 2013.
5 LTR-LIS-13-472, "Comanche Peak Units 1and210 CPR 50.46 Reports for Changes to Grid Blockage Ratio and Porosity," October 2013.
6 LTR-LIS-14-43, "Comanche Peak Units 1 and 2 10 CPR 50.46 Report for the HOTSPOT Burst Strain Error Correction," January 2014.
NOTES:
(a)
This evaluation credits peaking factor bumdown, see Reference 3.
to TXX-22001 Page 7 of 11 CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 2 EM:
ASTRUM (2004)
Description:
Best Estimate Large Break Summary Sheet Status: Cycle 20 Reference#
Note#
ANALYSIS-OF-RECORD PCT (°F) 1632 Delta PCT Reporting ASSESSMENTS*
( 0 AF)
Reference#
Note#
Year**
- 1.
Evaluation of Fuel Pellet Thermal Conductivity Degradation and 190 3
(a) 2012 Peaking Factor Burndown
- 2.
Revised Heat Transfer Multiplier Distributions
-17 4
2013
- 3.
Changes to Grid Blockage Ratio and Porosity 24 5
2013
- 4.
Error in Burst Strain Application 21 6
2013
- 5.
PBOT/PMID Violation 0
2 2021 AOR + ASSESSMENTS PCT=
1850 °F The licensee should determine the reportability of these assessments pursuant to 10 CPR 50.46.
- The "Reporting Year" refers to the annual reporting year in which this assessment was included.
REFERENCES 1
WCAP-16763-P, Revision 1, "Best-Estimate Analysis of the Large-Break Loss-of-Coolant Accident for the Comanche Peak Nuclear Power Plant Unit 2 Using the ASTRUM Methodology," March 2009.
2 TCX-LOCA-TM-A5-000001, "10 CPR 50.46 Reporting Text and LBLOCA PCT Summary Sheet Update for the Evaluation of the Comanche Peak Unit 2 Cycle 20 PBOT/PMID Violations," September 2021.
3 LTR-LIS-12-410, "Comanche Peak Units 1and210 CPR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown," September 2012.
4 LTR-LIS-13-359, "Comanche Peak Units 1and210 CPR 50.46 Report for Revised Heat Transfer Multiplier Distributions," July 2013.
5 LTR-LIS-13-472, "Comanche Peak Units 1 and 2 10 CPR 50.46 Reports for Changes to Grid Blockage Ratio and Porosity," October 2013.
6 LTR-LIS-14-43, "Comanche Peak Units 1and210 CPR 50.46 Report for the HOTSPOT Burst Strain Error Correction," January 2014.
NOTES:
(a)
This evaluation credits peaking factor bumdown, see Reference 3.
to TXX-22001 Page 8 ofll CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 1 EM:
FSLOCA' AOR
Description:
FULL SPECTRUM LOCA EM Large Break Summary Sheet Status: Future ANALYSIS-OF-RECORD AOR + ASSESSMENTS REFERENCES PCT (°F) 1566 PCT=
1566.0 °F Reference#
1 Note#
(a) 1 WCAP-18417-P, "Engineering Summary Report of the Comanche Peak Unit 1 Loss-of-Coolant Accident (LOCA) Analysis with the FULL SPECTRUM LOCA (FSLOCA) Methodology," February 2019.
NOTES:
(a)
The analysis-of-record PCT reflects the uncertainty analysis that included the error in gamma energy redistribution uncertainty (1546°F) as well as the correction of the error (20°F).
to TXX-22001 Page 9 of 11 CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 1 EM:
FSLOCA AOR
Description:
FULL SPECTRUM LOCA EM Small Break Summary Sheet Status: Future ANALYSIS-OF-RECORD AOR + ASSESSMENTS REFERENCES PCT {°F) 1032 PCT=
1032.0 °F Reference#
Note#
(a) 1 WCAP-18417-P, "Engineering Summary Report of the Comanche Peak Unit 1 Loss-of-Coolant Accident (LOCA) Analysis with the FULL SPECTRUM LOCA (FSLOCA) Methodology," February 2019.
NOTES:
(a)
The analysis-of-record PCT reflects the uncertainty analysis that included the error in gamma energy redistribution uncertainty (1017°P) as well as the correction of the error (15°F).
to TXX-22001 Page 10 ofll CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 2 EM:
FSLOCA AOR
Description:
FULL SPECTRUM LOCA EM Large Break Summary Sheet Status: Future ANALYSIS-OF-RECORD AOR + ASSESSMENTS REFERENCES PCT {°F) 1610 PCT=
1610.0 °F Reference#
Note#
(a) 1 WCAP-18418-P, "Engineering Summary Report of the Comanche Peak Unit 2 Loss-of-Coolant Accident (LOCA) Analysis with the FULL SPECTRUM LOCA (FSLOCA) Methodology," March 2019.
NOTES:
(a) The analysis-of-record PCT reflects the uncertainty analysis that included the error in gamma energy redistribution uncertainty (1579°F) as well as the correction of the error (31 °F).
to TXX-22001 Page 11 ofll CPNPP Units 1 and 2 Peak Cladding Temperatures LOCA Peak Cladding Temperature (PCT) Summary Plant Name:
COMANCHE PEAK 2 EM:
FSLOCA AOR
Description:
FULL SPECTRUM LOCA EM Small Break Summary Sheet Status: Future ANALYSIS-OF-RECORD AOR + ASSESSMENTS REFERENCES PCT{°F) 1116 PCT=
1116.0 °F Reference#
1 Note#
(a) 1 WCAP-18418-P, "Engineering Summary Report of the Comanche Peak Unit 2 Loss-of-Coolant Accident (LOCA) Analysis with the FULL SPECTRUM LOCA (FSLOCA) Methodology," March 2019.
NOTES:
(a) The analysis-of-record PCT reflects the uncertainty analysis that included the error in gamma energy redistribution uncertainty (1113 °F) as well as the correction of the error (3°F).