|
---|
Category:Annual Operating Report
MONTHYEARML24003A7212023-11-27027 November 2023 Independent Safety Committee; Diablo Canyon Nuclear Power Plant Operations, Thirty-Third Annual Report on the Safety July 1, 2022-June 30, 2023 ML23318A2092023-09-13013 September 2023 Thirty-Third Annual Report on the Safety of Diablo Canyon Nuclear Power Plant Operations, July I, 2022 - June 30, 2023 - Volume 1 (Main Report) ML23318A2082023-09-13013 September 2023 Thirty-Third Annual Report on the Safety of Diablo Canyon Nuclear Power Plant Operations, July I, 2022 - June 30, 2023 - Volume 2 (Exhibits) DCL-23-041, 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 20222023-05-22022 May 2023 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2022 ML23037A8312022-09-28028 September 2022 Independent Safety Committee; Thirty-Second Annual Report on the Safety July 1, 2021 - June 30, 2022, Volume II - Exhibits ML23037A8302022-09-28028 September 2022 Independent Safety Committee; Thirty-Second Annual Report on the Safety July 1, 2021 - June 30, 2022, Volume I - Main Report ML23041A3772022-06-30030 June 2022 Independent Safety Committee Thirty-Second Annual Report on the Safety of Diablo Canyon Nuclear Power Plant Operations July 1, 2021-June 30, 2022 DCL-22-033, Annual Report of Occupational Radiation Exposure for 20212022-04-26026 April 2022 Annual Report of Occupational Radiation Exposure for 2021 DCL-2021-514, NPDES Receiving Water Monitoring Program: 2020 Annual Report2021-04-27027 April 2021 NPDES Receiving Water Monitoring Program: 2020 Annual Report DCL-19-078, 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 20182019-10-0303 October 2019 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2018 DCL-18-028, Submittal of 2017 Annual Radioactive Effluent Release Report2018-04-24024 April 2018 Submittal of 2017 Annual Radioactive Effluent Release Report DCL-18-032, Summary Report of 10 CFR 50.59. Changes, Tests, and Experiments, for the Period of January 1, 2016, Through December 31, 20172018-04-18018 April 2018 Summary Report of 10 CFR 50.59. Changes, Tests, and Experiments, for the Period of January 1, 2016, Through December 31, 2017 DCL-17-075, Transmittal of 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 20162017-09-0606 September 2017 Transmittal of 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2016 DCL-16-105, 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 20152016-10-18018 October 2016 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2015 DCL-2016-518, NPDES Receiving Water Monitoring Program: 2015 Annual Report2016-04-25025 April 2016 NPDES Receiving Water Monitoring Program: 2015 Annual Report DCL-16-045, Submittal of 2015 Annual Radiological Environmental Operating Report2016-04-21021 April 2016 Submittal of 2015 Annual Radiological Environmental Operating Report DCL-16-046, Summary Report of 10 CFR 50.59, Changes, Tests, and Experiments, for the Period of January 1, 2014, Through December 31, 20152016-04-18018 April 2016 Summary Report of 10 CFR 50.59, Changes, Tests, and Experiments, for the Period of January 1, 2014, Through December 31, 2015 ML15117A6572015-04-27027 April 2015 2014 Annual Radiological Environmental Operating Report for the Year 2014) - Part 3 of 5 ML15117A6622015-04-27027 April 2015 2014 Annual Radiological Environmental Operating Report for the Year 2014) - Part 5 of 5 ML15117A6602015-04-27027 April 2015 2014 Annual Radiological Environmental Operating Report for the Year 2014) - Part 4 of 5 DCL-15-046, 2014 Annual Radiological Environmental Operating Report for the Year 2014) - Part 1 of 52015-04-27027 April 2015 2014 Annual Radiological Environmental Operating Report for the Year 2014) - Part 1 of 5 ML15117A6562015-04-27027 April 2015 2014 Annual Radiological Environmental Operating Report for the Year 2014) - Part 2 of 5 DCL-13-077, CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 20122013-07-30030 July 2013 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2012 DCL-13-058, Annual Commitment Change Summary Report2013-05-30030 May 2013 Annual Commitment Change Summary Report DCL-13-029, Annual Radiological Environmental Operating Report2013-04-30030 April 2013 Annual Radiological Environmental Operating Report DCL-13-045, Annual Nonradiological Environmental Operating Report2013-04-30030 April 2013 Annual Nonradiological Environmental Operating Report DCL-13-042, Submittal of 2012 Annual Radioactive Effluent Release Report2013-04-30030 April 2013 Submittal of 2012 Annual Radioactive Effluent Release Report DCL-13-022, Annual Report of Occupational Radiation Exposure for 20122013-03-12012 March 2013 Annual Report of Occupational Radiation Exposure for 2012 DCL-12-117, 2011 Annual Commitment Change Summary Report2012-11-20020 November 2012 2011 Annual Commitment Change Summary Report DCL-12-070, 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 20112012-07-19019 July 2012 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2011 DCL-12-040, 2011 Annual Radioactive Effluent Release Report2012-04-30030 April 2012 2011 Annual Radioactive Effluent Release Report ML1120101782011-07-19019 July 2011 Diablo Canyon, 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2010 DCL-11-082, Diablo Canyon, 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 20102011-07-19019 July 2011 Diablo Canyon, 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2010 DCL-11-082, CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 20102011-07-19019 July 2011 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2010 ML11129A0852011-04-28028 April 2011 2010 Annual Radiological Environmental Operating Report DCL-11-049, 2010 Annual Radioactive Effluent Release Report, in Accordance with 10 CFR 50.36a(a)(2) and Section 5.6.32011-04-28028 April 2011 2010 Annual Radioactive Effluent Release Report, in Accordance with 10 CFR 50.36a(a)(2) and Section 5.6.3 DCL-11-051, 2010 Annual Nonradiological Environmental Operating Report2011-04-28028 April 2011 2010 Annual Nonradiological Environmental Operating Report ML1111807472011-04-28028 April 2011 2010 Annual Nonradiological Environmental Operating Report DCL-11-050, Diablo Canyon, Units 1 & 2, 2010 Annual Radiological Environmental Operating Report2011-04-28028 April 2011 Diablo Canyon, Units 1 & 2, 2010 Annual Radiological Environmental Operating Report DCL-10-055, Units, 1 and 2, 2009 Annual Commitment Change Summary Report2010-05-19019 May 2010 Units, 1 and 2, 2009 Annual Commitment Change Summary Report DCL-10-043, Submittal of 2009 Annual Radiological Environmental Operating Report2010-04-28028 April 2010 Submittal of 2009 Annual Radiological Environmental Operating Report DCL-10-039, 10 CFR 50.59 Report of Changes, Tests, and Experiments for the Period January 1, 2008, Through December 31, 20092010-04-19019 April 2010 10 CFR 50.59 Report of Changes, Tests, and Experiments for the Period January 1, 2008, Through December 31, 2009 DCL-10-034, Annual Report of Occupational Radiation Exposure for 20092010-03-26026 March 2010 Annual Report of Occupational Radiation Exposure for 2009 DCL-2009-523, 2008-2009 Annual Report for Storm Water Discharges Associated with Industrial Activities, Diablo Canyon Power Plant (Dcpp), Facility Wdid No. 340I0182482009-06-11011 June 2009 2008-2009 Annual Report for Storm Water Discharges Associated with Industrial Activities, Diablo Canyon Power Plant (Dcpp), Facility Wdid No. 340I018248 DCL-09-031, Submittal of 2008 Annual Commitment Change Summary Report2009-05-0707 May 2009 Submittal of 2008 Annual Commitment Change Summary Report DCL-09-029, 2008 Annual Radiological Environmental Operating Report2009-04-24024 April 2009 2008 Annual Radiological Environmental Operating Report DCL-08-061, CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2007, Affect Peak Cladding Temperature (PCT) Calculations2008-07-23023 July 2008 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2007, Affect Peak Cladding Temperature (PCT) Calculations DCL-08-031, Transmittal of 10 CFR 50.59 Report of Changes, Tests, and Experiments for the Period of January 1, 2006, Through December 31, 20072008-04-17017 April 2008 Transmittal of 10 CFR 50.59 Report of Changes, Tests, and Experiments for the Period of January 1, 2006, Through December 31, 2007 ML0729107542007-10-22022 October 2007 2006 Rulemaking Annual Report DCL-07-071, CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 20062007-07-23023 July 2007 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2006 2023-09-13
[Table view] Category:Letter type:DCL
MONTHYEARDCL-24-010, Nuclear Material Transaction Report for New Fuel2024-01-29029 January 2024 Nuclear Material Transaction Report for New Fuel DCL-24-009, Nuclear Material Transaction Report for New Fuel2024-01-17017 January 2024 Nuclear Material Transaction Report for New Fuel DCL-24-008, Schedule Considerations for Review of the DCPP License Renewal Application2024-01-17017 January 2024 Schedule Considerations for Review of the DCPP License Renewal Application DCL-24-004, Supplement to License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b2024-01-15015 January 2024 Supplement to License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b DCL-23-129, Nuclear Material Transaction Report for New Fuel2023-12-27027 December 2023 Nuclear Material Transaction Report for New Fuel DCL-23-122, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-14014 December 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation DCL-23-128, Emergency Plan Update2023-12-13013 December 2023 Emergency Plan Update DCL-23-125, Core Operating Limits Report for Unit 1 Cycle 252023-12-0606 December 2023 Core Operating Limits Report for Unit 1 Cycle 25 DCL-23-121, Supplement to License Amendment Request 23-03, Revision to Technical Specification3.7.8, Auxiliary Saltwater System2023-11-16016 November 2023 Supplement to License Amendment Request 23-03, Revision to Technical Specification3.7.8, Auxiliary Saltwater System DCL-23-120, License Amendment Request 23-03 Revision to Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System2023-11-14014 November 2023 License Amendment Request 23-03 Revision to Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System DCL-23-118, License Renewal Application2023-11-0707 November 2023 License Renewal Application DCL-2023-520, Discharge Self-Monitoring at Diablo Canyon Power Plant (DCPP)2023-10-19019 October 2023 Discharge Self-Monitoring at Diablo Canyon Power Plant (DCPP) DCL-23-103, Independent Spent Fuel Storage Installation - Withdrawal of License Amendment Request 22-01, Request for Approval of Alternative Security Measures for Early Warning System2023-10-13013 October 2023 Independent Spent Fuel Storage Installation - Withdrawal of License Amendment Request 22-01, Request for Approval of Alternative Security Measures for Early Warning System DCL-23-092, Material Status Report for the Period Ending August 31, 20232023-09-28028 September 2023 Material Status Report for the Period Ending August 31, 2023 DCL-23-077, License Amendment Request 23-02 Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors2023-09-27027 September 2023 License Amendment Request 23-02 Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors DCL-23-083, Upcoming Meeting with Nuclear Security and Incident Response Staff2023-09-13013 September 2023 Upcoming Meeting with Nuclear Security and Incident Response Staff DCL-23-078, Nuclear Material Transaction Report for New Fuel2023-09-0606 September 2023 Nuclear Material Transaction Report for New Fuel DCL-23-070, Withdrawal of Request Regarding Senior Reactor Operator License Application2023-08-16016 August 2023 Withdrawal of Request Regarding Senior Reactor Operator License Application DCL-23-068, Nuclear Material Transaction Report for New Fuel2023-08-0909 August 2023 Nuclear Material Transaction Report for New Fuel DCL-23-066, Nuclear Material Transaction Report for New Fuel2023-08-0303 August 2023 Nuclear Material Transaction Report for New Fuel DCL-23-065, Letter DCL-23-065 Request That Exam Material Be Withheld from Public Disclosure2023-07-27027 July 2023 Letter DCL-23-065 Request That Exam Material Be Withheld from Public Disclosure DCL-23-064, Nuclear Material Transaction Report for New Fuel2023-07-26026 July 2023 Nuclear Material Transaction Report for New Fuel DCL-23-054, License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b2023-07-13013 July 2023 License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b DCL-23-055, Nuclear Material Transaction Report for New Fuel2023-07-0606 July 2023 Nuclear Material Transaction Report for New Fuel DCL-23-042, Independent Spent Fuel Storage Installation, Submittal of Quality Assurance Program Description, Revision 02023-05-24024 May 2023 Independent Spent Fuel Storage Installation, Submittal of Quality Assurance Program Description, Revision 0 DCL-23-032, Independent Spent Fuel Storage Installation Docket No. 72-27, Materials License Number SNM-2514 Humboldt Bay Independent Spent Fuel Storage Installation - NRC Requested Notification of Withdrawal from Voluntary Program2023-05-22022 May 2023 Independent Spent Fuel Storage Installation Docket No. 72-27, Materials License Number SNM-2514 Humboldt Bay Independent Spent Fuel Storage Installation - NRC Requested Notification of Withdrawal from Voluntary Program DCL-23-041, 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 20222023-05-22022 May 2023 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2022 DCL-23-038, Revision to the Unit 1 Reactor Vessel Material Surveillance Program Withdrawal Schedule2023-05-15015 May 2023 Revision to the Unit 1 Reactor Vessel Material Surveillance Program Withdrawal Schedule DCL-23-034, 2022 Annual Nonradiological Environmental Operating Report2023-05-0101 May 2023 2022 Annual Nonradiological Environmental Operating Report DCL-23-036, 2022 Annual Radiological Environmental Operating Report2023-05-0101 May 2023 2022 Annual Radiological Environmental Operating Report DCL-23-025, 2022 Annual Radioactive Effluent Release Report2023-05-0101 May 2023 2022 Annual Radioactive Effluent Release Report DCL-2023-512, Submittal of Receiving Water Monitoring Program 2022 Annual Report2023-04-27027 April 2023 Submittal of Receiving Water Monitoring Program 2022 Annual Report DCL-23-035, Response to Request for Additional Information on Request Regarding Senior Reactor Operator License Application2023-04-24024 April 2023 Response to Request for Additional Information on Request Regarding Senior Reactor Operator License Application DCL-23-028, Technical Specification Bases, Revision 142023-04-24024 April 2023 Technical Specification Bases, Revision 14 DCL-2023-511, Report on Discharge Monitoring for the First Quarter of 20232023-04-20020 April 2023 Report on Discharge Monitoring for the First Quarter of 2023 DCL-23-031, Submittal of Annual Report of Occupational Radiation Exposure for 20222023-04-19019 April 2023 Submittal of Annual Report of Occupational Radiation Exposure for 2022 DCL-23-024, Independent Spent Fuel Storage Installation, Response to Nrg Request for Additional Information for Revision to License Amendment Request 22-01 Request for Approval of Alternative Security Measures for Early Warning System2023-04-0404 April 2023 Independent Spent Fuel Storage Installation, Response to Nrg Request for Additional Information for Revision to License Amendment Request 22-01 Request for Approval of Alternative Security Measures for Early Warning System DCL-23-022, 2023 Annual Statement of Insurance for Pacific Gas and Electric Companys Diablo Canyon Power Plant2023-03-29029 March 2023 2023 Annual Statement of Insurance for Pacific Gas and Electric Companys Diablo Canyon Power Plant DCL-23-023, Decommissioning Funding Report for Diablo Canyon Power Plant, Units 1 and 22023-03-28028 March 2023 Decommissioning Funding Report for Diablo Canyon Power Plant, Units 1 and 2 DCL-23-021, Independent Spent Fuel Storage Installation, Emergency Plan Update2023-03-23023 March 2023 Independent Spent Fuel Storage Installation, Emergency Plan Update DCL-23-020, Responses to NRC Questions Regarding License Renewal Efforts2023-03-17017 March 2023 Responses to NRC Questions Regarding License Renewal Efforts DCL-23-009, Owner'S Activity Report for Unit 2 Twenty-Third Refueling Outage2023-02-22022 February 2023 Owner'S Activity Report for Unit 2 Twenty-Third Refueling Outage DCL-23-008, Request Regarding Senior Reactor Operator License Application2023-02-22022 February 2023 Request Regarding Senior Reactor Operator License Application DCL-2023-503, Annual Sea Turtle Report2023-01-26026 January 2023 Annual Sea Turtle Report DCL-2023-502, (DCPP) 4th Quarter 2022 Report on Discharge Self-Monitoring2023-01-18018 January 2023 (DCPP) 4th Quarter 2022 Report on Discharge Self-Monitoring DCL-22-091, Revised Steam Generator Tube Inspection Report for Twenty-First Refueling Outage2022-12-20020 December 2022 Revised Steam Generator Tube Inspection Report for Twenty-First Refueling Outage DCL-22-089, Core Operating Limits Report for Unit 2 Cycle 242022-12-20020 December 2022 Core Operating Limits Report for Unit 2 Cycle 24 DCL-22-085, Request to Resume Review of the License Renewal Application or, Alternatively, for an Exemption from 10 CFR 2.109(b), Concerning a Timely Renewal Application2022-10-31031 October 2022 Request to Resume Review of the License Renewal Application or, Alternatively, for an Exemption from 10 CFR 2.109(b), Concerning a Timely Renewal Application DCL-22-041, Site-Specific Decommissioning Cost Estimate, Revision 12022-10-12012 October 2022 Site-Specific Decommissioning Cost Estimate, Revision 1 DCL-22-042, Post-Shutdown Decommissioning Activities Report, Revision 12022-10-12012 October 2022 Post-Shutdown Decommissioning Activities Report, Revision 1 2024-01-29
[Table view] |
Text
-PacificElectricGas and Company James R.Becker Site Vice President Diablo Canyon Power Plant Mail Code 104/5/601 P.0. Box 56 Avila Beach, CA 93424 805.545.3462 Internal: 691.3462 July 19, 2011 Fax: 805.545.6445 PG&E Letter DCL-11-082 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 10 CFR 50.46 Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2010
Dear Commissioners and Staff:
Pursuant to 10 CFR 50.46, this letter provides an annual report of changes in the Westinghouse emergency core cooling system (ECCS) evaluation models that affect peak cladding temperature (PCT) calculations for Pacific Gas and Electric Company (PG&E) Diablo Canyon Power Plant (DCPP), Units 1 and 2.
There have been no changes in the small-break loss-of-coolant accident (SBLOCA)
PCT results for either Unit 1 or Unit 2 since the last annual update. The last update was provided in PG&E Letter DCL-10-080, "10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2009," dated July 19, 2010. In support of a prompt operability assessment (POA), the best estimate large-break loss-of-coolant accident (BELOCA) PCT results for both Unit 1 and Unit 2 have assessed a PCT margin allocation since the last update.
A summary of the PCT margin allocations and their bases are provided in the enclosure. The Unit 1 SBLOCA and BELOCA PCT Margin Utilization sheets are provided in Attachment A to the enclosure. The Unit 2 SBLOCA and BELOCA PCT Margin Utilization Sheets are provided in Attachment B to the enclosure. The ECCS evaluation model changes and PCT margin allocations that have occurred since the last annual report are summarized in Attachment C to the enclosure.
The PCT values remain well within the 2200°F limit specified in 10 CFR 50.46.
However, since the Unit 1 BELOCA has a total PCT margin allocation that is currently greater than 50'F, PG&E is proposing a schedule for reanalysis, per 10 CFR 50.46(a)(3)(ii). PG&E has recently initiated a long term: project to implement a transition to a standard fuel design that will require a reanalysis of the Unit 1 BELOCA PCT results. In addition, it is anticipated that BELOCA analysis model changes requiring NRC approval will be required to address the regulation changes A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Diabto Canyon ° Palo Verde
Document Control Desk PG&E Letter DCL-1 1-082 July 19, 2011 Page 2 related to 10 CFR 50.46 that are still in development. In order to accommodate these anticipated changes, PG&E proposes to complete the Unit I BELOCA reanalysis and provide the updated PCT results to the NRC by December 2016.
If you have questions regarding this submittal please contact Mr. Steve Baker at 805-545-6742.
Sinc rely, James ..Becker Site Vice Presidentand Station Director dngd/4955/64041516-0200 Enclosure cc/enc: Elmo E. Collins, NRC Region IV Michael S. Peck, NRC Senior Resident Inspector Alan B. Wang, NRR Project Manager James T. Polickoski, NRR Project Manager Diablo Distribution A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Palo Verde ° South Texas Project
Enclosure PG&E Letter DCL-1 1-082 ANNUAL REPORT OF EMERGENCY CORE COOLING SYSTEM EVALUATION MODEL CHANGES FOR PEAK CLADDING TEMPERATURE Pursuant to 10 CFR 50.46, this enclosure provides an annual report of changes in the Westinghouse emergency core cooling system (ECCS) evaluation models that affect peak cladding temperature (PCT) calculations for Pacific Gas and Electric Company (PG&E) Diablo Canyon Power Plant (DCPP), Units 1 and 2.
This report is based on changes described in the following Westinghouse 10 CFR 50.46 notification letter:
Westinghouse Letter LTR-LIS-11-43, "Diablo Canyon Units 1 and 2 10 CFR 50.46 Annual Notification and Reporting for 2010," dated January 27, 2011.
Attachment A to this enclosure provides DCPP Unit 1 small-break loss-of-coolant accident (SBLOCA) and best estimate large-break loss-of-coolant accident (BELOCA) PCT Margin Utilization Sheets. Attachment B to this enclosure provides DCPP Unit 2 SBLOCA and BELOCA PCT Margin Utilization Sheets.
Attachment C to this enclosure summarizes the ECCS evaluation model changes and PCT margin allocations that have occurred since the last annual report.
There have been no changes in the SBLOCA PCT results for either Unit 1 or Unit 2 since the last annual update. The last update was provided in PG&E Letter DCL-10-080, "10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for 2009" dated July 19, 2010. In support of a prompt operability assessment (POA), the BELOCA PCT results for both Unit 1 and Unit 2 have assessed a PCT margin allocation since the last update.
A summary of the PCT margin allocations and their bases are provided in the attachments. The final net PCT values are listed below for each unit. It should be noted that two PCT values are reported for the Unit 1 BELOCA results. The two BELOCA PCT values are labeled Reflood 1 and Reflood 2, as they represent the two distinctive PCT peaks that occur during the reflood phase for the Unit 1 BELOCA Code Qualification Document (CQD) methodology. The Unit 2 BELOCA reports only one PCT value consistent with the BELOCA Automated Statistical Treatment of Uncertainty Method (ASTRUM) methodology.
Small-Break LOCA Best Estimate Largie-Break LOCA Reflood 1 Reflood 2 Unit 1: 1391°F (no change) 1990°F (no change) 1975 0 F Unit 2: 1288 0 F (no change) 1888 0 F The PCT values remain well within the 2200OF limit specified in 10 CFR 50.46.
However, since the Unit 1 BELOCA has a total PCT margin allocation that is currently greater than 50 0 F, PG&E is proposing a schedule for reanalysis, per 1
Enclosure PG&E Letter DCL-11-082 10 CFR 50.46(a)(3)(ii). PG&E has recently initiated a long term project to implement a transition to a standard fuel design that will require a reanalysis of the Unit 1 BELOCA PCT results. In addition, it is anticipated that BELOCA analysis model changes requiring NRC approval will be required to address the regulation changes related to 10 CFR 50.46 that are still in development. In order to accommodate these anticipated changes, PG&E proposes to complete the Unit 1 BELOCA reanalysis and provide the updated PCT results to the NRC by December 2016.
2
Attachment A PG&E Letter DCL-11-082 DCPP UNIT 1 PEAK CLADDING TEMPERATURE (PCT) MARGIN UTILIZATION SMALL-BREAK LOCA PG&E Letter1 A. ANALYSIS OF RECORD PCT = 1391OF DCL-09-057 B. PRIOR 10 CFR 50.46 ECCS 2 MODEL ASSESSMENTS
- 1. None APCT = 0F C. 10 CFR 50.46 ECCS MODEL ASSESSMENTS THIS YEAR
- 1. None APCT = 0°F D. SUM OF 10 CFR 50.46 CHANGES
- 1. Net Sum of 10 CFR 50.46 PCT Changes APCT = 0°F
- 2. Absolute Sum of 10 CFR 50.46 PCT Changes APCT = 0°F E. Analysis of Record PCT - Line A + Line D.1 Net Sum of 10 1391°F CFR 50.46 PCT Changes The sum of the PCT from the most recent analysis of record using an acceptable evaluation model and the estimates of the net PCT effect for changes and errors identified since this analysis remain less than 2200 0 F.
For those issues that have been previously reported under 10 CFR 50.46, a PG&E letter number is listed.
2 Only permanent assessments of PCT margin are included. Temporary PCT allocations that address current loss-of-coolant accident (LOCA) model issues are not considered with respect to 10 CFR 50.46 reporting requirements.
A-1
Attachment A PG&E Letter DCL-11-082 DCPP UNIT 1 PEAK CLADDING TEMPERATURE (PCT) MARGIN UTILIZATION BEST ESTIMATE LARGE-BREAK LOCA PG&E Letter1 Reflood Reflood 1 2 A. ANALYSIS OF RECORD 1900OF 1860OF DCL-05-146 APCT APCT B. PRIOR 10 CFR 50.46 ECCS MODEL ASSESSMENTS 2
- 1. Revised blowdown heatup 50 F 50 F DCL-05-086 uncertainty distribution.
- 2. HOTSPOT Fuel Relocation 100 F 0°F DCL-07-071 Error.
- 3. Replacement Steam 75 0 F 71 OF DCL-09-057 Generators C. 10 CFR 50.46 ECCS MODEL ASSESSMENTS THIS YEAR
- 1. 230 kV Degraded Voltage 0°F 39 0 F This letter in Event Evaluation Attachment C D. SUM OF 10 CFR 50.46 CHANGES
- 1. Net Sum of 10 CFR 50.46 PCT 90OF 115 0 F Changes
- 2. Absolute Sum of 10 CFR 50.46 90°F 115 0 F PCT Changes E. Analysis of Record PCT - Line A
+ Line D.1 Net Sum of 10 CFR 1990°F 1975 0 F 50.46 PCT Changes The sum of the PCT from the most recent analysis of record using an acceptable evaluation model and the estimates of the net PCT effect for changes and errors identified since this analysis remain less than 2200 0 F.
For those issues that have been previously reported under 10 CFR 50.46, a PG&E letter number is listed.
A-2
Attachment A PG&E Letter DCL-11-082 Only permanent assessments of PCT margin are included. Temporary PCT allocations that address current LOCA model issues are not considered with respect to 10 CFR 50.46 reporting requirements.
A-3
Attachment B PG&E Letter DCL-1 1-082 DCPP UNIT 2 PEAK CLADDING TEMPERATURE (PCT) MARGIN UTILIZATION SMALL-BREAK LOCA PG&E Letter1 A. ANALYSIS OF RECORD PCT = 12880 F DCL-08-061 B. PRIOR 10 CFR 50.46 ECCS 2
MODEL ASSESSMENTS
- 1. None APCT = 0°F C. 10 CFR 50.46 ECCS MODEL ASSESSMENTS THIS YEAR
- 2. None APCT = 0°F D. SUM OF 10 CFR 50.46 CHANGES
- 3. Net Sum of 10 CFR 50.46 PCT Changes APCT = 0°F
- 4. Absolute Sum of 10 CFR 50.46 PCT Changes APCT = 00 F E. Analysis of Record PCT - Line A + Line D.1 Net Sum of 10 1288 0 F CFR 50.46 PCT Changes The sum of the PCT from the most recent analysis of record using an acceptable evaluation model and the estimates of the net PCT effect for changes and errors identified since this analysis remain less than 2200 0 F.
For those issues that have been previously reported under 10 CFR 50.46, a PG&E Letter number is listed.
2 Only permanent assessments of PCT margin are included. Temporary PCT allocations that address current loss-of-coolant-accident (LOCA) model issues are not considered with respect to 10 CFR 50.46 reporting requirements.
B-1
Attachment B PG&E Letter DCL-1 1-082 DCPP UNIT 2 PEAK CLADDING TEMPERATURE (PCT) MARGIN UTILIZATION BEST ESTIMATE LARGE-BREAK LOCA PG&E Letter' A. ANALYSIS OF RECORD PCT= 18720 F DCL-07-071 B. PRIOR 10 CFR'50.46 ECCS MODEL ASSESSMENTS 2
- 1. HOTSPOT Fuel Relocation APCT= 0°F DCL-07-071 Error.
C. 10 CFR 50.46 ECCS MODEL ASSESSMENTS THIS YEAR
- 1. 230 kV Degraded Voltage APCT= 160 F This letter in Event Evaluation Attachment C D. SUM OF 10 CFR 50.46 CHANGES
- 1. Net Sum of 10 CFR 50.46 PCT APCT= 160 F Changes
- 2. Absolute Sum of 10 CFR 50.46 APCT= 160 F PCT Changes E. Analysis of Record PCT - Line A
+ Line D.1 Net Sum of 10 CFR 1888 0 F 50.46 PCT Changes The sum of the PCT from the most recent analysis of record using an acceptable evaluation model and the estimates of the net PCT effect for changes and errors identified since this analysis remain less than 22000 F.
For those issues that have been previously reported under 10 CFR 50.46, a PG&E letter number is listed.
2 Only permanent assessments of PCT margin are included. Temporary PCT allocations that address current LOCA model issues are not considered with respect to 10 CFR 50.46 reporting requirements.
B-2
Attachment C PG&E Letter DCL-11-082 CURRENT EMERGENCY CORE COOLING SYSTEM MODEL CHANGES AND ERRORS 230 kV Degraded Voltage Event Evaluation During an NRC Component Design Basis Inspection it was identified that, contrary to license basis requirements, the 230 kV undervoltage relay delay setpoints are not bound by the current Diablo Canyon Power Plant (DCPP)
FSAR safety analysis. Postulating a sustained 230 kV degraded voltage results in increasing engineered safety feature (ESF) component delay times beyond what has previously been evaluated. The DCPP small-break loss-of-coolant accident (SBLOCA) and best estimate large-break loss-of-coolant accident (BELOCA) safety analyses of record have been evaluated for increased ESF delay times of 5 seconds for the auxiliary feedwater (AFW) and 15 seconds for the emergency core cooling system (ECCS) injection flow as summarized below.
The increased ESF delay times represent a malfunction of a structure, system, or component (SSC) important to safety with a different result than previously evaluated in the Final safety Analysis Report Update (FSARU) per 10 CFR 50.59 and is being submitted for prior NRC approval in License Amendment Request 11-06 as documented in PG&E Letter DCL-11-072.
SBLOCA The core uncovery and peak cladding temperature (PCT) for the limiting Unit 1 and Unit 2 SBLOCA cases occurs at 12 to 15 minutes into the event. The 15 second increase in ECCS flow due delay time was determined to represent a small reduction in the total amount of ECCS injection flow that has entered the reactor coolant system (RCS) up to the time of core uncovery. Similarly, the 5 second increase in the AFW actuation time was determined to have a negligible impact on the thermal hydraulic results since the major source of decay heat removal is due to the RCS flow out of the break. Therefore, it was concluded that there was a 0°F impact on the current SBLOCA Unit 1 and Unit 2 PCT results.
Large-Break Loss-of-Coolant Accident (LBLOCA)
Both Diablo Canyon Unit 1 and Unit 2 use a BELOCA evaluation methodology for the analysis of record. The LBLOCA evaluation considered an increase in ECCS injection flow delay time from 27 seconds to 42 seconds. The primary effect of increasing the ECCS delay time is that it can lead to increased duration of fuel heatup periods during the refill and reflood periods. The blowdown remains unaffected since this phase is over before the ECCS injection flow begins.
Depending on the break size and the accumulator pressure and volume, the end of the refill and periods and the accumulator injection can vary and create periods with significantly different and/or reduced ECCS injection flow.
C-1
Attachment C PG&E Letter DCL-1 1-082 For Unit 1, the evaluation was based on global model runs with an effective break size area greater than the reference transient. These greater break areas will depressurize the RCS faster leading to a more rapid accumulator blowdown and are more likely to result in a delay between the accumulator injection and the start of ECCS injection flow. The cases were selected to evaluate the relative effects of accumulator volume, accumulator pressure, and break size. The limiting evaluation case resulted in a 0°F penalty for the early Reflood 1 period and an estimated 39°F penalty for the Reflood 2 period.
Unit 2 uses the newer Automated Statistical Treatment of Uncertainty Method (ASTRUM) BELOCA methodology which does not track the individual Reflood 1 and Reflood 2 penalties but only reports one overall reflood penalty. For Unit 2, the evaluation was also based on selecting cases with higher break sizes that depressurize faster and lead to a faster accumulator blowdown that create a greater potential for a delay between accumulator injection and ECCS injection.
The evaluation also considered cases with high accumulator pressure or low accumulator volume which could also lead to a faster accumulator blowdown.
The evaluation for the limiting case concluded that there is a net PCT penalty of 16 OF due to the increased ECCS injection flow delay time.
C-2