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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
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Pacifc Gas and Electric Company James R. Becker Diablo Canyon Power Plant Vice President-Diablo Canyon PO. Box 56 Operations and Station Director Avila Beach, CA 93424 July 24, 2003 805.545.3462 Fax: 805.545.4234 PG&E Letter DCL-03-091 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 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 Emergence Core Cooling System Evaluation Model Chanaes
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 evaluation models that affect peak cladding temperature (PCT) calculations for Diablo Canyon Power Plant (DCPP), Units 1 and 2. There has been no change in the small-break loss of coolant accident (SBLOCA) PCT results or evaluation model since the last annual report submitted via PG&E Letter DCL-02-089, dated July 26, 2002.
Per the commitment identified in PG&E Letter DCL-00-1 34, dated October 19, 2000, PG&E has performed a reanalysis for the best estimate large-break loss of coolant accident (BELOCA). The reanalysis was performed using the Westinghouse superposition step methodology, which is currently being reviewed (WCAP-12945 revision) by the NRC. The reanalysis will not be established as the analysis of record per 10 CFR 50.46 until after NRC acceptance of the methodology, which is anticipated later this year. However, the superposition step methodology represents an appropriate ECCS evaluation model for the purpose of performing PCT assessments and updating the PCT margin allocations for both DCPP Units 1 and 2.
The summary of the updated PCT margin allocations and their bases are provided in the enclosure, and the final net PCT values are listed below for each Unit.
It should be noted that two PCT values are reported for the BELOCA consistent with the current Westinghouse PCT tracking methodology. The 2 large-break PCT values are labeled Reflood 1 and Reflood 2, as they represent the 2 distinctive PCT peaks that occur during the reflood phase for the BELOCA methodology.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance CatLaway
P _p Document Control Desk PG&E Letter DCL-03-091 A July 24, 2003 Faage 2 Small-Break LOCA Best Estimate Large-Break LOCA Reflood 1 Reflood 2 Unit 1 (no change): 1317 OF 1976 OF 1964 OF Unit 2 (no change): 1306 OF 1976 OF 1964 OF The PCT values remain within the 22000 F limit specified in 10 CFR 50.46. The Unit 1 SBLOCA and BELOCA PCT Margin Utilization sheets are provided in Attachment A of the enclosure. The Unit 2 SBLOCA and BELOCA PCT Margin Utilization Sheets are provided in Attachment B of the enclosure.
PG&E will update the DCPP Unit 1 large break analysis of record PCT value once the NRC acceptance of the Westinghouse superposition step reanalysis methodology is obtained. Since acceptance is anticipated later this year, PG&E is also providing a draft Unit 1 PCT margin allocation sheet for information. This Unit 1 PCT margin allocation sheet is labeled "Pending Analysis of Record" and is provided in Attachment C of the enclosure. In addition, as discussed in the enclosed report, PG&E will perform a plant specific BELOCA analysis for Unit 2 using the accepted methodology established in WCAP-12945-P-A, "Code Qualification Document for Best Estimate LOCA Analysis," Bajorek, S. M. et. al., 1998. This analysis will be completed to support design changes to be implemented during the Unit 2 twelfth refueling outage, which is currently scheduled for the fall of 2004.
Sincerely, James R. Becker Vice President, DCPP Operations and Station Director mjr/A0494471 E2/R0236364 Enclosure cc/enc: Thomas P. Gwynn David L. Prouix Girija S. Shukla Diablo Distribution A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
ENCLOSURE PG&E Letter DCL-03-091 ANNUAL REPORT OF EMERGENCY CORE COOLING SYSTEM EVALUATION MODEL CHANGES THAT AFFECT 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 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 letters:
Westinghouse Letter PGE-03-16, dated March 11, 2003, "Diablo Canyon Units 1 and 2, 10 CFR 50.46 Annual Notification and Reporting for 2002."
Westinghouse Letter PGE-03-33, dated June 6, 2003, "Diablo Canyon Unit 1 BELOCA Reanalysis Final Engineering Report."
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.
There has been no change in the SBLOCA PCT results or evaluation model since the last annual report submitted via PG&E Letter DCL-02-089, dated July 26, 2002.
Per the commitment identified in PG&E Letter DCL-00-1 34, dated October 19, 2000, PG&E has performed a reanalysis for the BELOCA. The reanalysis was performed using the Westinghouse superposition step methodology, which is currently being reviewed (WCAP-12945 revision) by the NRC. The reanalysis will not be established as the analysis of record per 10 CFR 50.46 until after NRC acceptance of the methodology, which is anticipated later this year. However, the superposition step methodology represents an appropriate ECCS evaluation model for the purpose of performing PCT assessments and updating the PCT margin allocations for both DCPP Units 1 and 2.
PG&E will update the Unit 1 large-break analysis of record PCT value once the NRC acceptance of the Westinghouse superposition step reanalysis methodology is obtained. Since acceptance is anticipated later this year, PG&E is also providing a draft Unit 1 PCT margin allocation sheets for NRC information.
This Unit 1 PCT margin allocation sheet is labeled "Pending Analysis of Record" and is provided as Attachment C to this enclosure.
It should also be noted that during the BELOCA reanalysis, Westinghouse identified that due to ECCS model changes, the Unit 2 PCT exceeded that of Unit 1 for several comparative cases. The current BELOCA analysis of record is based on a bounding plant methodology that established Unit 1 as the limiting plant, and the Unit I PCT results as bounding when applied to Unit 2.
ENCLOSURE PG&E Letter DCL-03-091 Based on the reanalysis results with several comparative cases showing Unit 2 PCTs exceeding those of Unit 1, PG&E has determined that the bounding plant methodology is no longer appropriate for establishing the Unit 2 BELOCA analysis of record. Therefore, PG&E will perform a plant-specific BELOCA analysis for Unit 2 using the accepted methodology established in WCAP-12945-P-A, "Code Qualification Document for Best Estimate LOCA Analysis," Bajorek, S. M. et. al., 1998.
The Unit 2 BELOCA analysis will be completed in support of design changes to be implemented during the Unit 2 twelfth refueling outage. This outage is currently scheduled for the fall of 2004. These Unit 2 design changes include modifying the reactor vessel internals to provide baffle region core bypass flow in the upward direction instead of the current downward direction, and reducing the reactor coolant temperature in the upper head region.
In the interim period until the NRC approves the Westinghouse superposition step reanalysis methodology and the Unit 2 analysis is completed, an appropriately conservative PCT margin is established by maintaining the current analysis of record PCT value for DCPP Units 1 and 2. This is conservative since the comparative case results generated as part of the Unit 1 reanalysis show a significant decrease in the overall PCT values relative to the current analysis for both DCPP Units 1 and 2 when the appropriate code corrections and ECCS model changes are implemented. The Unit 1 final PCT at the ninety-fifth percentile is significantly reduced compared with the current value (1900 OF, reanalysis vs. 1976 OF, original analysis). The Unit 2 comparative case results indicate that the revised Unit 2 PCT at the ninety-fifth percentile will be comparably reduced. Therefore, the PCT results of the current analysis of record remain conservative for both DCPP Units 1 and 2.
The final net PCT values that are reflected in Attachments A and B are listed below. It should be noted that two PCT values are reported for the BELOCA consistent with the current Westinghouse PCT tracking methodology. The 2 large-break PCT values are labeled Reflood 1 and Reflood 2, as they represent the 2 distinctive PCT peaks that occur during the reflood phase for the BELOCA methodology.
Small-Break LOCA Best Estimate Large-BreakBLOCA Reflood 1 Reflood 2 Unit 1 (no change): 1317 OF 1976 OF 1964 OF Unit 2 (no change): 1306 OF 1976 OF 1964 OF
ATTACHMENT A PG&E Letter DCL-03-091 DCPP UNIT I PEAK CLADDING TEMPERATURE MARGIN UTILIZATION SMALL-BREAK LOCA PG&E Letter' A. ANALYSIS OF RECORD PCT= 13040F DCL-99-096 B. PERMANENT 10 CFR 50.46 ECCS MODEL ASSESSMENTS 2
- 1. NOTRUMP Mixture Level APCT = 130 F DCL-00-107 Tracking/Region Depletion Errors C. 10 CFR 50.59 AND 10 CFR 50.92 SAFETY EVALUATIONS
- 1. None APCT = 0F D. OTHER MARGIN ALLOCATIONS
- 1. None APCT = 0F LICENSING BASIS PCT + MARGIN ALLOCATION PCT = 1317 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 LOCA model issues are not considered with respect to 10 CFR 50.46 reporting requirements.
A-I
ATTACHMENT A PG&E Letter DCL-03-091 DCPP UNIT 1 PEAK CLADDING TEMPERATURE MARGIN UTILIZATION BEST ESTIMATE LARGE-BREAK LOCA PG&E Lefter' Reflood Reflood 1 2 A. ANALYSIS OF RECORD 19760 F 19640 F DCL-00-1 07 APCT APCT B. PERMANENT 10 CFR 50.46 ECCS MODEL ASSESSMENTS 2
- 1. None OOF 0F C. 10 CFR 50.59 AND 10 CFR 50.92 SAFETY EVALUATIONS
- 1. None OOF OOF D. OTHER MARGIN ALLOCATIONS
- 1. None 0F OOF LICENSING BASIS PCT + MARGIN 1976 0F 1964 0F ALLOCATION PCT 1 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.
A-2
f ATTACHMENT B PG&E Letter DCL-03-091 DCPP UNIT 2 PEAK CLADDING TEMPERATURE MARGIN UTILIZATION SMALL-BREAK LOCA PG&E Letter' A. ANALYSIS OF RECORD PCT = 1293 0F DCL-99-096 B. PERMANENT 10 CFR 50.46 ECCS MODEL ASSESSMENTS 2
- 1. NOTRUMP Mixture Level APCT = 13 OF DCL-00-1 07 Tracking/Region Depletion Errors C. 10 CFR 50.59 AND 10 CFR 50.92 SAFETY EVALUATIONS
- 1. None APCT = 0 OF D. OTHER MARGIN ALLOCATIONS
- 1. None APCT = 0 OF LICENSING BASIS PCT + MARGIN ALLOCATION PCT = 1306 0F 1 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-1
ATTACHMENT B PG&E Letter DCL-03-091 DCPP UNIT 2 PEAK CLADDING TEMPERATURE MARGIN UTILIZATION BEST ESTIMATE LARGE-BREAK LOCA PG&E Letter' Reflood Reflood 1 2 A. ANALYSIS OF RECORD 19760F 19640 F DCL-00-1 07 APCT APCT B. PERMANENT 10 CFR 50.46 ECCS MODEL ASSESSMENTS 2
- 1. None 0F 0F C. 10 CFR 50.59 AND 10 CFR 50.92 SAFETY EVALUATIONS
- 1. None 0F 0F D. OTHER MARGIN ALLOCATIONS
- 1. None 0F 0F LICENSING BASIS PCT + MARGIN 19760 F 19640 F ALLOCATION PCT 1 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
I e ATTACHMENT C PG&E Letter DCL-03-091 Pending Analysis of Record DCPP UNIT I PEAK CLADDING TEMPERATURE MARGIN UTILIZATION BEST ESTIMATE LARGE-BREAK LOCA Reflood Reflood 1 2 A. ANALYSIS OF RECORD 1900OF 18600 F Reference 1 APCT APCT B. PERMANENT 10 CFR 50.46 ECCS MODEL ASSESSMENTS 2
- 1. None 0F 0F C. 10 CFR 50.59 AND 10 CFR 50.92 SAFETY EVALUATIONS
- 1. None 0F 0F D. OTHER MARGIN ALLOCATIONS
- 1. None 0F 0F LICENSING BASIS PCT + MARGIN 1900 0F 1860 0F ALLOCATION PCT Reference 1: Westinghouse Letter PGE-03-33, 'Diablo Canyon Unit I BELOCA Reanalysis Final Engineering Report," June 6, 2003 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.
C-1