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MONTHYEARDCL-08-103, ASME Section XI Inservice Inspection Program Relief Request NDE-Leak Path for the Unit 1, Fifteenth Refueling Outage, Third Ten-Year Inspection Interval to Allow Use of the Rules of the NRC First Revised Order, EA-03-009.2008-12-0404 December 2008 ASME Section XI Inservice Inspection Program Relief Request NDE-Leak Path for the Unit 1, Fifteenth Refueling Outage, Third Ten-Year Inspection Interval to Allow Use of the Rules of the NRC First Revised Order, EA-03-009. Project stage: Request ML0834002822008-12-0404 December 2008 Acceptance Review E-mail Project stage: Acceptance Review ML0907509232009-04-0808 April 2009 Relief Request NDE-Leak Path, Proposed Alternative to ASME Code Case N-729-1 as Conditioned by 10 CFR 50.55(g)(6)(ii)(D)(3), Demonstrated Volumetric or Surface Leak Path Assessment for Spring 2009 Refueling Outage, ME0200 Project stage: Other 2008-12-04
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Category:Inservice/Preservice Inspection and Test Report
MONTHYEARDCL-24-014, Owners Activity Report for Unit 1 Twenty-Fourth Refueling Outage2024-02-12012 February 2024 Owners Activity Report for Unit 1 Twenty-Fourth Refueling Outage 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-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-22-060, Owner'S Activity Report for Unit 1 Twenty-Third Refueling Outage2022-07-21021 July 2022 Owner'S Activity Report for Unit 1 Twenty-Third Refueling Outage ML22138A4362022-05-18018 May 2022 ASME Section XI Inservice Inspection Program Plan - Fourth 10-Year Inspection Interval, Revision 1 ML21307A0012021-11-15015 November 2021 Review of the Fall 2020 Steam Generator Tube Inservice Inspection Report DCL-21-055, Owner'S Activity Report for Unit 2 Twenty-Second Refueling Outage2021-07-19019 July 2021 Owner'S Activity Report for Unit 2 Twenty-Second Refueling Outage DCL-21-008, Owner'S Activity Report for Unit 1 Twenty-Second Refueling Outage2021-01-27027 January 2021 Owner'S Activity Report for Unit 1 Twenty-Second Refueling Outage DCL-20-039, One Hundred Eighty Day Steam Generator Report for Diablo Canyon Power Plant Unit 2 Twenty-First Refueling Outage2020-05-13013 May 2020 One Hundred Eighty Day Steam Generator Report for Diablo Canyon Power Plant Unit 2 Twenty-First Refueling Outage ML20064F5782020-03-0404 March 2020 Owner'S Activity Report for Unit 2 Twenty-First Refueling Outage DCL-19-084, ASME Section XI Lnservice Inspection Program Request for Alternative NDE-RCSSE-2R22 Use of Alternate Sizing Qualification Criteria Through a Protective Clad Layer2019-10-31031 October 2019 ASME Section XI Lnservice Inspection Program Request for Alternative NDE-RCSSE-2R22 Use of Alternate Sizing Qualification Criteria Through a Protective Clad Layer DCL-19-049, Owner'S Activity Report for Unit 1 Twenty-first Refueling Outage2019-06-13013 June 2019 Owner'S Activity Report for Unit 1 Twenty-first Refueling Outage DCL-18-105, Submittal of the Fourth Ten-Year Interval Inservice Testing (1ST) Program Plan, Revision 12018-12-0505 December 2018 Submittal of the Fourth Ten-Year Interval Inservice Testing (1ST) Program Plan, Revision 1 DCL-18-048, Owner'S Activity Report for Unit 2 Twentieth Refueling Outage2018-06-19019 June 2018 Owner'S Activity Report for Unit 2 Twentieth Refueling Outage DCL-17-028, ASME Section XI Inservice Inspection Program Plan - Fourth 10-Year Inspection Interval2017-04-18018 April 2017 ASME Section XI Inservice Inspection Program Plan - Fourth 10-Year Inspection Interval DCL-16-116, ASME Section XI Inservice Inspection Program Relief Request NDE-SIF-U2 Due to Impracticality of Full Examination Volume Coverage Requirements2016-11-10010 November 2016 ASME Section XI Inservice Inspection Program Relief Request NDE-SIF-U2 Due to Impracticality of Full Examination Volume Coverage Requirements DCL-16-115, ASME Section XI Inservice Inspection Program Relief Request NDE-RCS-SE-1R20 to Allow Use of Alternative Depth Sizing Criteria2016-11-10010 November 2016 ASME Section XI Inservice Inspection Program Relief Request NDE-RCS-SE-1R20 to Allow Use of Alternative Depth Sizing Criteria DCL-16-086, Owner'S Activity Report for Unit 2 Nineteenth Refueling Outage2016-08-31031 August 2016 Owner'S Activity Report for Unit 2 Nineteenth Refueling Outage DCL-16-056, One Hundred Eighty-Day Steam Generator Report for Nineteenth Refueling Outage2016-05-0202 May 2016 One Hundred Eighty-Day Steam Generator Report for Nineteenth Refueling Outage DCL-16-024, Submittal of the Fourth Ten-Year Interval Inservice Testing (IST) Program Plan2016-03-0202 March 2016 Submittal of the Fourth Ten-Year Interval Inservice Testing (IST) Program Plan DCL-16-018, Owner'S Activity Report for Nineteenth Refueling Outage2016-02-0303 February 2016 Owner'S Activity Report for Nineteenth Refueling Outage DCL-15-116, Submittal of 10 CFR 50.55a Request FLIG-U1, Request for Extension of Third Lnservice Inspection Interval for Performing Reactor Vessel Stud Hole Ligament Examinations2015-10-0707 October 2015 Submittal of 10 CFR 50.55a Request FLIG-U1, Request for Extension of Third Lnservice Inspection Interval for Performing Reactor Vessel Stud Hole Ligament Examinations DCL-15-106, ASME Section XI Inservice Inspection Program Request for Relief NDE-FWNS-U1/U2 to Allow Use of Alternate Examination Volume Coverage Requirements2015-09-0303 September 2015 ASME Section XI Inservice Inspection Program Request for Relief NDE-FWNS-U1/U2 to Allow Use of Alternate Examination Volume Coverage Requirements DCL-15-054, One Hundred Eighty-Day Steam Generator Report for Diablo Canyon Power Plant, Unit 2, Eighteenth Refueling Outage2015-04-29029 April 2015 One Hundred Eighty-Day Steam Generator Report for Diablo Canyon Power Plant, Unit 2, Eighteenth Refueling Outage DCL-15-048, ASME Section XI Inservice Inspection Program Request for Relief NDE-PNS-U2A to Allow Use of Alternate Examination Volume Coverage Requirements2015-04-0909 April 2015 ASME Section XI Inservice Inspection Program Request for Relief NDE-PNS-U2A to Allow Use of Alternate Examination Volume Coverage Requirements DCL-14-053, Owner'S Activity Report for Eighteenth Refueling Outage2014-06-11011 June 2014 Owner'S Activity Report for Eighteenth Refueling Outage DCL-14-027, Request for Relief from the Requirements of Appendix IX of ASME Section XI, 2001 Edition with 2003 Addendum2014-03-28028 March 2014 Request for Relief from the Requirements of Appendix IX of ASME Section XI, 2001 Edition with 2003 Addendum DCL-13-063, Inservice Inspection Report for Seventeenth Refueling Outage2013-06-13013 June 2013 Inservice Inspection Report for Seventeenth Refueling Outage DCL-12-089, Inservice Inspection Report for Unit 1 Seventeenth Refueling Outage2012-09-13013 September 2012 Inservice Inspection Report for Unit 1 Seventeenth Refueling Outage DCL-12-007, Request for Approval of an Alternative to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section XI Examination Requirement for Class 1 and 2 Piping Welds2012-01-20020 January 2012 Request for Approval of an Alternative to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section XI Examination Requirement for Class 1 and 2 Piping Welds ML12025A3032011-12-28028 December 2011 Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Page 101 Through Page 200 ML12025A3042011-12-28028 December 2011 Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Page 201 Through Drawing No. 102028, Sheet 38 ML12025A3022011-12-28028 December 2011 Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Cover Page Through Page 100 ML12025A3052011-12-28028 December 2011 Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Drawing No. 102028, Sheet 39, Through Drawing No. 104628, Sheet 46 DCL-12-006, Diablo Canyon - Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Drawing No. 102028, Sheet 39, Through Drawing No. 104628, Sheet 462011-12-28028 December 2011 Diablo Canyon - Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Drawing No. 102028, Sheet 39, Through Drawing No. 104628, Sheet 46 DCL-12-006, Diablo Canyon - Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Page 201 Through Drawing No. 102028, Sheet 382011-12-28028 December 2011 Diablo Canyon - Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Page 201 Through Drawing No. 102028, Sheet 38 DCL-12-006, Diablo Canyon - Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Page 101 Through Page 2002011-12-28028 December 2011 Diablo Canyon - Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Page 101 Through Page 200 DCL-12-006, Diablo Canyon - Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Cover Page Through Page 1002011-12-28028 December 2011 Diablo Canyon - Inservice Inspection Program Plan, Third 10-Year Inspection Interval, Revision 1, Cover Page Through Page 100 DCL-11-093, Inservice Inspection Report for Sixteenth Refueling Outage2011-09-0101 September 2011 Inservice Inspection Report for Sixteenth Refueling Outage DCL-11-053, One Hundred Eighty-Day Steam Generator Report - Sixteenth Refueling Outage2011-04-21021 April 2011 One Hundred Eighty-Day Steam Generator Report - Sixteenth Refueling Outage DCL-10-157, Snubber Visual Examination and Functional Testing Related to the Inservice Inspection Program Third 10-Year Interval2010-12-21021 December 2010 Snubber Visual Examination and Functional Testing Related to the Inservice Inspection Program Third 10-Year Interval DCL-10-051, ASME Section XI Inservice Inspection Program Relief Request NDE-RCS-SE-1R16 to Allow Use of Alternate Sizing Qualification Criteria2010-05-17017 May 2010 ASME Section XI Inservice Inspection Program Relief Request NDE-RCS-SE-1R16 to Allow Use of Alternate Sizing Qualification Criteria ML1005005362010-02-0808 February 2010 Inservice Inspection Report for Fifteenth Refueling Outage DCL-09-046, Submittal of Fifteenth Refueling Outage Inservice Inspection Report2009-06-22022 June 2009 Submittal of Fifteenth Refueling Outage Inservice Inspection Report DCL-08-103, ASME Section XI Inservice Inspection Program Relief Request NDE-Leak Path for the Unit 1, Fifteenth Refueling Outage, Third Ten-Year Inspection Interval to Allow Use of the Rules of the NRC First Revised Order, EA-03-009.2008-12-0404 December 2008 ASME Section XI Inservice Inspection Program Relief Request NDE-Leak Path for the Unit 1, Fifteenth Refueling Outage, Third Ten-Year Inspection Interval to Allow Use of the Rules of the NRC First Revised Order, EA-03-009. DCL-08-058, Transmittal of Inservice Inspection Report, Fourteenth Refueling Outage2008-07-10010 July 2008 Transmittal of Inservice Inspection Report, Fourteenth Refueling Outage DCL-07-099, ASME Section XI Inservice Inspection Program Relief Request REP-1 U2, Revision 1, and Response to Request for Additional Information2007-10-22022 October 2007 ASME Section XI Inservice Inspection Program Relief Request REP-1 U2, Revision 1, and Response to Request for Additional Information DCL-07-084, Inservice Inspection Report for Fourteenth Refueling Outage2007-08-27027 August 2007 Inservice Inspection Report for Fourteenth Refueling Outage DCL-06-099, ASME Section XI Inservice Inspection Program Relief Requests NDE-SLH U2 and NDE-LSL U22006-08-24024 August 2006 ASME Section XI Inservice Inspection Program Relief Requests NDE-SLH U2 and NDE-LSL U2 DCL-06-101, Inservice Inspection Report for Plant Thirteenth Refueling Outage2006-08-23023 August 2006 Inservice Inspection Report for Plant Thirteenth Refueling Outage 2024-02-12
[Table view] Category:Letter
MONTHYEARML24260A1222024-09-14014 September 2024 14 Sept 2024 Ltr - California Coastal Commission to Pg&E, Incomplete Consistency Certification for Requested Nuclear Regulatory Commission License Renewal for Diablo Canyon Power Plant DCL-24-087, License Renewal - Historic and Cultural Resources Reference Documents (Redacted)2024-09-12012 September 2024 License Renewal - Historic and Cultural Resources Reference Documents (Redacted) ML24262A2462024-09-11011 September 2024 10 CFR 2.206 - Diablo Canyon Units 1 and 2 Seismic - Petitioner Response to Acknowledgement Letter - DCL-24-083, CFR Part 21 Notification: Commercially Dedicated Snubber Valve Not Properly Heat Treated2024-09-0909 September 2024 CFR Part 21 Notification: Commercially Dedicated Snubber Valve Not Properly Heat Treated DCL-24-078, Pre-Notice of Disbursement from Decommissioning Trust2024-09-0303 September 2024 Pre-Notice of Disbursement from Decommissioning Trust DCL-24-082, Decommissioning Draft Biological Assessment and Draft Essential Fish Habitat Assessment2024-08-28028 August 2024 Decommissioning Draft Biological Assessment and Draft Essential Fish Habitat Assessment ML24205A0662024-08-27027 August 2024 OEDO-24-00083 - 10 CFR 2.206 - Ack Letter - Diablo Canyon Units 1 and 2 Seismic Core Damage Frequency - IR 05000275/20243012024-08-26026 August 2024 NRC Examination Report 05000275/2024301; 05000323/2024301 IR 05000275/20240052024-08-22022 August 2024 Updated Inspection Plan for Diablo Canyon Power Plant, Units 1 and 2 (Report 05000275/2024005 and 05000323/2024005) DCL-24-077, Responses to NRC Requests for Additional Information on Diablo Canyon Power License Renewal Application Severe Accident2024-08-15015 August 2024 Responses to NRC Requests for Additional Information on Diablo Canyon Power License Renewal Application Severe Accident DCL-24-075, Response to Request for Additional Information for 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 React2024-08-0808 August 2024 Response to Request for Additional Information for 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 React IR 05000275/20240022024-08-0606 August 2024 Integrated Inspection Report 05000275/2024002 and 05000323/2024002 DCL-24-070, License Amendment Request 24-03 Revision to Technical Specification 5.5.16 for Permanent Extension of Type a and Type C Leak Rate Test Frequencies2024-07-31031 July 2024 License Amendment Request 24-03 Revision to Technical Specification 5.5.16 for Permanent Extension of Type a and Type C Leak Rate Test Frequencies DCL-24-071, Core Operating Limits Report for Unit 2 Cycle 252024-07-22022 July 2024 Core Operating Limits Report for Unit 2 Cycle 25 DCL-2024-523, Submittal of Report on Discharge Self-Monitoring2024-07-18018 July 2024 Submittal of Report on Discharge Self-Monitoring ML24187A1352024-07-16016 July 2024 Letter to Paula Gerfen - Diablo Canyon Units 1 and 2 - Summary of June 2024 Audit Related to the License Renewal Application Severe Accident Mitigation Alternatives Review IR 05000275/20240142024-07-11011 July 2024 Age-Related Degradation Inspection Report 05000275/2024014 and 05000323/2024014 IR 05000275/20244012024-07-0808 July 2024 Security Baseline Inspection Report 05000275/2024401 and 05000323/2024401 (Full Report) IR 05000323/20240112024-07-0303 July 2024 License Renewal Phase Report 05000323/2024011 DCL-2024-527, Sea Turtle Stranding Report (Loggerhead Sea Turtle) Diablo Canyon Power Plant2024-07-0101 July 2024 Sea Turtle Stranding Report (Loggerhead Sea Turtle) Diablo Canyon Power Plant DCL-24-066, Request to Extend the Nrg Approval of Alternative for Use of Full Structural Weld Overlay, REP-RHR-SWOL2024-06-27027 June 2024 Request to Extend the Nrg Approval of Alternative for Use of Full Structural Weld Overlay, REP-RHR-SWOL ML24155A2182024-06-18018 June 2024 OEDO-23-00350-NRR - (LTR-23-0228-1) - Closure Letter - 10 CFR 2.206 Petition from Mothers for Peace and Friends of the Earth Regarding Diablo Canyon ML24129A1762024-06-14014 June 2024 National Historic Preservation Act Section 106 Consultation – Results of Identification and Evaluation (Docket Number: 72-026) ML24200A2052024-06-0707 June 2024 Fws to NRC, List of Threatened and Endangered Species That May Occur in Your Proposed Project Location or May Be Affected by Your Proposed Project for Diablo Canyon License Renewal ML24099A2192024-05-29029 May 2024 Issuance of Amendment Nos. 245 and 247 Revision to TSs to Adopt TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b ML24117A0132024-05-20020 May 2024 Letter to Paula Gerfen-Diablo Canyon Units 1 and 2-Regulatory Audit Regarding Severe Accident Mitigation Alternatives for the License Renewal Application DCL-24-054, LCO 3.0.3 Completion Time Limits2024-05-17017 May 2024 LCO 3.0.3 Completion Time Limits DCL-24-052, Responses to NRC Requests for Additional Information on the Diablo Canyon Power Plant License Renewal Application Environmental Report2024-05-16016 May 2024 Responses to NRC Requests for Additional Information on the Diablo Canyon Power Plant License Renewal Application Environmental Report DCL-24-051, One Hundred Eighty Day Steam Generator Report for Twenty-Fourth Refueling Outage2024-05-0808 May 2024 One Hundred Eighty Day Steam Generator Report for Twenty-Fourth Refueling Outage ML24127A2042024-05-0202 May 2024 02May2024 Ltr - California Coastal Commission to Pg&E, Coastal Development Permit Needed for Pg&E’S Proposed Relicensing of Diablo Canyon Nuclear Power Plant DCL-24-047, 2023 Annual Non-radiological Environmental Operating Report2024-05-0101 May 2024 2023 Annual Non-radiological Environmental Operating Report DCL-24-049, 2023 Annual Radiological Environmental Operating Report2024-05-0101 May 2024 2023 Annual Radiological Environmental Operating Report L-24-004, Independent Spent Fuel Storage Installation - Responses to NRC Requests for Additional Information on the Diablo Canyon Independent Spent Fuel Storage Installation License Renewal Application (Cac/Epid 001028/L-2022-RNW-0007)2024-04-30030 April 2024 Independent Spent Fuel Storage Installation - Responses to NRC Requests for Additional Information on the Diablo Canyon Independent Spent Fuel Storage Installation License Renewal Application (Cac/Epid 001028/L-2022-RNW-0007) DCL-24-048, O CFR 50.59 and 1 O CFR 72.48 Summary Report for the Period of January 1, 2022, Through December 31, 20232024-04-30030 April 2024 O CFR 50.59 and 1 O CFR 72.48 Summary Report for the Period of January 1, 2022, Through December 31, 2023 DCL-24-027, 2023 Annual Radioactive Effluent Release Report2024-04-28028 April 2024 2023 Annual Radioactive Effluent Release Report DCL-24-045, Annual Report of Occupational Radiation Exposure for 20232024-04-24024 April 2024 Annual Report of Occupational Radiation Exposure for 2023 IR 05000275/20240012024-04-23023 April 2024 Integrated Inspection Report 05000275/2024001 and 05000323/2024001 ML24114A2032024-04-22022 April 2024 Request for Information for EP Program and Performance Indicator Verification Inspection (Wolf Creek Nuclear Generating Station) Inspection Report 05000482/2024003 ML24106A2882024-04-18018 April 2024 License Renewal Application Environmental Review RCIs and RAIs ML24106A2892024-04-18018 April 2024 Letter to Paula Gerfen - Diablo Canyon Units 1 and 2 - Summary of March 2024 Audit Regarding the Environmental Review of the License Renewal Application DCL-24-042, Response to NRC Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations2024-04-17017 April 2024 Response to NRC Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations ML24108A1122024-04-15015 April 2024 License Amendment Request 24-02 Request for Approval of DCPP Early Warning System to Meet 10 CFR 73.55(i)(2) and 10 CFR 73.55(e)(9)(vi)(A) DCL-24-022, Notification of Changes to Decommissioning Schedule2024-04-0202 April 2024 Notification of Changes to Decommissioning Schedule DCL-24-023, Revised Certification of Permanent Cessation of Power Operations2024-04-0202 April 2024 Revised Certification of Permanent Cessation of Power Operations DCL-24-031, Decommissioning Funding Report2024-03-27027 March 2024 Decommissioning Funding Report DCL-24-032, 2024 Annual Statement of Insurance for Pacific Gas and Electric Company’S Diablo Canyon Power Plant2024-03-27027 March 2024 2024 Annual Statement of Insurance for Pacific Gas and Electric Company’S Diablo Canyon Power Plant ML24082A2592024-03-25025 March 2024 Notice of Enforcement Discretion for Diablo Canyon Power Plant, Unit 2 (EPID L-2024-LLD-0002) - March 25, 2024 ML24081A0462024-03-22022 March 2024 Audit Summary in Support of the License Amendment Request to Adopt TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b DCL-24-028, Request for Enforcement Discretion Regarding Compliance with Technical Specification 3.0.3, Limiting Condition for Operation Applicability2024-03-21021 March 2024 Request for Enforcement Discretion Regarding Compliance with Technical Specification 3.0.3, Limiting Condition for Operation Applicability ML24081A4052024-03-21021 March 2024 Request for Enforcement Discretion Regarding Compliance with Technical Specification 3.0.3, Limiting Condition for Operation Applicability 2024-09-09
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Pacific Gas and Electric Company'Diablo Canyon Power Plant R 0. Box 56 Avila Beach, CA 93424 December 4, 2008 PG&E Letter DCL-08-103 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Diablo Canyon Unit 1 ASME Section XI Inservice Inspection Program Relief Request NDE-Leak Path for the Unit 1, Fifteenth Refueling Outage, Third Ten-Year Inservice Inspection Interval to Allow Use of the Rules of the NRC First Revised Order, EA-03-009 for Performance of Volumetric Leak Path Assessment of Reactor Head Penetration Nozzles Dear Commissioners and Staff: Pursuant to 10 CFR 50.55a(a)(3)(ii), Pacific Gas and Electric Company (PG&E)hereby requests NRC approval for Inservice Inspection (ISI) Relief Request NDE-Leak Path.This request for relief proposes an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, Code Case N-729-1 as conditioned by 10 CFR 50.55a(g)(6)(ii)(D)(3) for "demonstrated volumetric or surface leak path assessment through all J-groove welds." The proposed alternative is the continued use of the volumetric leak path assessment process used to satisfy the requirements of the First Revised NRC Order EA-03-009.
The duration of the proposed alternative applies only to the reactor head penetration nozzle examinations to be performed in the Diablo Canyon Unit 1 Fifteenth Refueling Outage (1R15), scheduled to begin January 26, 2009. The Unit 1 reactor head is scheduled to be replaced in the sixteenth refueling outage.Enclosed is Relief Request NDE-Leak Path, including the basis for the proposed alternative.
To support the implementation of the proposed changes in 1 R1 5, PG&E requests approval of Relief Request NDE-Leak Path by January 26, 2009.Approval of this relief request will allow DCPP to continue to utilize the existing First Revised NRC Order EA-03-009 requirements to govern volumetric leak path assessment during 1R15.A member of the STARS (Strategic Teaming and Resource Sharing) Alliance , a Catlaway
- South Texas Project .Wolf Creek f Document Control Desk December 4, 2008 Page 2 PG&E Letter DCL-08-103 PG&E makes no regulatory commitments (as defined by NEI 99-04) in this letter.If you have any questions or require additional information, please contact Stan Ketelsen at (805) 545-4720.tcg/50042807 Enclosures cc: Diablo Distribution cc/enc: Elmo E. Collins, Regional Administrator, NRC Region IV Michael S. Peck, NRC Senior Resident Inspector Alan B. Wang, Project Manager, Office of Nuclear Reactor Regulation State of California, Pressure Vessel Unit A member of the STARS (Strategic Teaming and Resource Sharingi AlLiance Callaway
- Wolf Creek Enclosure PG&E Letter DCL-08-103 Request for Relief NDE-Leak Path for Inservice Inspection of Reactor Head Penetration Nozzles at the Diablo Canyon Power Plant Unit 1, Fifteenth Refueling Outage Enclosure PG&E Letter DCL-08-103 Code of Federal Regulation 10 Part 50.55a Relief Request NDE-Leak Path Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
--Hardship or Unusual Difficulty without a Compensating Increase in Level of Safety or Quality--1. ASME Code Component(s)
Affected Diablo Canyon Power Plant (DCPP) Unit 1 reactor vessel closure head four-inch diameter control rod drive mechanism (CRDM) penetrations, instrument nozzle penetrations and their corresponding J-weld connections to the head. The four-inch penetrations are numbered one through seventy-nine.
This request for relief does not include the three-quarter-inch diameter reactor head vent line penetration.
- 2. Applicable Code Edition and Addenda American Society of Mechanical Engineering (ASME) Boiler and Pressure Vessel Code,Section XI, 2001 Edition through 2003 Addenda as augmented by Code Case N-729-1 with conditions for use stated in 10 CFR 50.55a(g)(6)(ii)(D)(3).
- 3. Applicable Code Requirement An alternative is requested to the requirement for "demonstrated volumetric or surface leak path assessment through all J-groove welds" as applied to reactor vessel closure head nozzle examinations performed in accordance with ASME Code Case N-729-1 as conditioned by 10 CFR 50.55a(g)(6)(ii)(D)(3).
Code of Federal Regulation 10 Part 50.55a(g)(6)(ii)(D)(3) states in part,"Instead of the specified
'examination method' requirements for volumetric and surface examinations in Note 6 of Table 1 of Code Case N-729-1, the licensee shall perform volumetric and/or surface examination of essentially 100 percent of the required volume or equivalent surfaces of the nozzle tube, as identified by Figure 2 of ASME Code Case N-729-1.A demonstrated volumetric or surface leak path assessment through all J-groove welds shall be performed." 1 Enclosure PG&E Letter DCL-08-103
- 4. Reason for Request The requirement to execute a "demonstrated volumetric or surface leak path assessment through all J-groove welds" during the DCPP Unit I fifteenth refueling outage (1 R1 5) scheduled for January 2009 poses a hardship due to the expedited implementation requirement for demonstrated volumetric leak path assessment and personnel exposure associated with alternative surface examinations.
PG&E requests approval to use the proposed alternative described below in accordance with the provisions of 10 CFR 50.55a(a)(3)(ii).
Although the industry has initiated efforts to accomplish a volumetric leak path demonstration, the extent of remaining tasks will likely preclude successful completion in time to support the 1 R1 5 January outage start date. Fabrication of mockups to represent the various postulated nozzle conditions, demonstration protocol development, testing, documentation, blind demonstrations and evaluation of results are examples of outstanding activities that are expected to be necessary to complete the demonstration.
Inspection vendor resources are currently challenged by the Fall 2008 outage campaign and preparations for the Spring 2009 outages.The optional surface examination of the J-welds is a hardship due to the greatly increased personnel radiation exposure associated with this examination technique.
The supplementary scans and additional robotic tool reconfigurations required to accomplish surface examinations result in a significant extension to the examination duration and concomitant increase in the total dose received.More importantly, the complicated geometry of the J-weld surface, particularly on penetrations other than those very close to the reactor head center, poses an extremely difficult challenge for remote inspection.
Furthermore, the guide funnels attached to the outside diameter (OD) of the nozzles obstruct access to the J-weld surface on the five instrument penetrations.
It is known that the requisite surface examination coverage for all DCPP Unit 1 J-welds can not be obtained using current robotic inspection technology.
Incomplete remote inspections would need to be supplemented with under head entries to manually perform surface examinations to obtain complete coverage.2 Enclosure PG&E Letter DCL-08-103 Dose rates adjacent to the reactor head where the tool reconfiguration and maintenance is performed are approximately 500mRPhour while dose rates under the head near the J-weld areas are expected to be in the 2 to 4 Rem/hour range based on previous survey data. In addition, high contamination levels in excess of one Rad/hour have been documented on under head surfaces.The hazardous radiological conditions coupled with difficult access and challenging working environment result in excessive (undue) personnel exposure and potential contamination to accomplish surface examination of the J-welds.5. Proposed Alternative and Basis for Use In lieu of implementing the "demonstrated volumetric or surface leak path assessment through all J-groove welds" as required by ASME Code Case N-729-1 as conditioned by 10 CFR 50.55a(g)(6)(ii)(D)(3), PG&E proposes that a volumetric leak path assessment be performed in 1 R1 5 that meets the requirements of the First Revised NRC Order EA-03-009, IV.C.(5)(b)(i).
The proposed volumetric leak path examination area will extend to a minimum of 2 inches above the highest point of the root of the J-groove weld (on a horizontal plane perpendicular to the nozzle axis) on each of the four-inch penetrations.
The combination of volumetric leak path assessment and bare metal visual examination of the reactor closure head outside surface provides a comprehensive approach for detection of leakage past the J-weld.Background The Westinghouse designed Diablo Canyon Unit 1 reactor vessel closure head was fabricated by Combustion Engineering.
The reactor head contains seventy-nine, four-inch outside diameter CRDM and instrument nozzle penetrations and a single three-quarter-inch diameter vent line penetration.
The seventy-nine, four-inch diameter nozzles are installed with a maximum specified diametrical interference fit of three mils.The Diablo Canyon Unit 1 reactor vessel closure head is scheduled to be replaced in the sixteenth refueling outage.3 Enclosure PG&E Letter DCL-08-103 Basis The Code Case N-729-1 bare metal visual examination combined with a volumetric, leak path assessment in accordance with Order EA-03-009, IV.C.(5)(b)(i) provides assurance that reactor closure head penetration nozzle leakage will be detected.The efficacy of the bare metal visual examination is addressed in MRP 117 "Materials Reliability Program Inspection Plan for Reactor Vessel Closure Head Penetrations in U.S. PWR Plants" section 3.4,"Protection Against Significant Boric Acid Wastage of the Low Alloy Steel Head," which states in part: "Section 7 of the top-level safety assessment report (MRP-1 10 [5]) describes the evaluations that verify that protection against boric acid wastage is provided by the bare metal visual examinations for evidence of leakage required by Sections 5 and 6 of this document.
This conclusion is supported by the experience with over 50 leaking CRDM nozzles, including the observation that the large wastage cavity at one plant would have been detected relatively early in the wastage progression had bare metal visual examinations been performed at each refueling outage, and likely even if performed less frequently, with appropriate corrective action. In addition, the wastage modeling presented in M RP-1 10 supports the adequacy of bare metal visual examination performed according to the sensitivity and coverage requirements of Section 5.1 and at the frequency defined in Section 6." PG&E will perform a bare metal visual examination in 1IRI 5. Previous Unit I bare metal visual examination results are available for comparison and demonstrate that essentially 100 percent inspection coverage of the penetration to top of interface can be achieved on all of the seventy-nine four-inch nozzles.The volumetric (ultrasonic) leak path assessment technology used on the four-inch nozzles at DCPP to satisfy the First Revised NRC Order EA-03-009 requirements employs a zero degree incidence longitudinal wave introduced from the tube inside diameter (ID). The response from the tube OD in the interference fit region is monitored for changes in amplitude due to variations in reflected versus transmitted energy.Because the tube OD is in intimate contact with the reactor head base material as a result of the interference fit, a portion of the ultrasonic energy is transmitted through this interface.
In the case that leakage into the annulus area between the tube and head base material results in steam cutting, the intimate contact is disturbed in a localized area. This condition is detected by distinguishing variation in tube OD response signal amplitude in the reduced intimate contact area as compared to the surrounding areas. Redundantly, leakage resulting in steam cutting would also be detectable by a bare metal visual examination since flow to the atmosphere is inherent.4 Enclosure PG&E Letter DCL-08-103 PG&E's inspection vendor, WesDyne International, manufactured a mockup for leak path technique development that simulates the steam cutting condition.
The mockup consists of a sleeve with machined ID grooves and holes that is installed over a section of penetration tube with a two mil interference fit. Test results demonstrate that the machined areas in the sleeve are readily detectable using the zero degree amplitude discrimination methodology described above when imaged by the analysis software.
Filling the machined loss of fit areas with water resulted in no affect on detectability.
Further details of the mockup configuration and test results are included in reference 8.4.PG&E has previously completed two volumetric leak path examinations in accordance with the NRC Order on all of the seventy-nine four-inch penetration nozzles. The digitally recorded examination results from those examinations provide an excellent baseline for comparison with thel R1 5 findings.
Moreover, current appraisals indicate that the existing technology used to perform the volumetric leak path assessment in accordance with the First Revised NRC Order EA-03-009 will not need to be significantly altered to meet the new demonstration obligation.
The three-quarter-inch diameter vent line penetration is inspected using eddy current to examine the J-weld and remaining wetted surfaces within the specified examination area. The eddy current surface examination is supplemented by low frequency eddy current designed to detect wastage of the reactor head surrounding the penetration.
The vent line examination meets the Code Case N-729-1 requirements, as conditioned by 10 CFR 50.55a(g)(6)(ii)(D)(3), for leak path assessment.
Conclusion The proposed alternative examination, volumetric leak path assessment performed in accordance with the First Revised NRC Order EA-03-009, when combined with a bare metal visual examination provides confidence that leakage past the J-weld into the annulus region would be detected.These techniques provide a defense-in-depth leak path assessment approach that assures the structural integrity of the reactor head remains intact.Consequently, performing a "demonstrated volumetric or surface leak path assessment through all J-groove welds" as required by ASME Code Case N-729-1 as conditioned by 10 CFR 50.55a(g)(6)(ii)(D)(3), would result in hardship as the default surface examination will result in undue personnel radiation exposure without providing a compensating increase in the level of quality and safety.5 Enclosure PG&E Letter DCL-08-103
- 6. Duration of Proposed Alternative The duration of the proposed alternative applies only to the reactor head penetration nozzle examinations scheduled to be performed in 1 R1 5 in accordance with Code Case N-729-1 as conditioned by 10 CFR 50.55a(g)(6)(ii)(D)(3).
The Unit 1 reactor head is scheduled to be replaced in the sixteenth refueling outage.Diablo Canyon Unit 1 is in the Third Ten-Year Inservice Inspection Interval.7. Precedent Leak path assessment is addressed by the First Revised NRC Order EA-03-009, IV.C.(5)(b)(i), which states "In addition an assessment shall be made to determine if leakage has occurred into the annulus between the RPV head penetration nozzle and the RPV head low-alloy steel." 8. References
8.1 First
Revised NRC Order EA-03-009 (ADAMS Accession Number ML040220181).
8.2 "Materials Reliability Program Reactor Vessel Closure Head Penetration Safety Assessment for U.S. Pressurized Water Reactor (PWR) Plants (MRP-110)." 8.3 "Materials Reliability Program Inspection Plan for Reactor Vessel Closure Head Penetrations in U.S. PWR Plants" Section 3.4,"Protection Against Significant Boric Acid Wastage of the Low Alloy Steel Head (MRP-1 17)." 8.4 WDI-TJ-006-03-P, Revision 3 "Ultrasonic Testing of Interference Fit Samples for Leak Path Detection" (ADAMS Accessibn Number ML040490495).
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