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Category:Code Relief or Alternative
MONTHYEARML20249C8502020-10-22022 October 2020 Proposed Alternative NDE-RCS-SE-2R22 to the Requirements of the ASME Code ML19176A0082019-06-28028 June 2019 Request for Relief from the Inservice Inspection Program Requirements of ASME Code, Section XI, for Steam Generator and Pressurizer Nozzle Inside Radius Sections ML19023A0262019-01-25025 January 2019 Request for Alternative from Volumetric/Surface Examination Frequency Requirements of ASME Code Case N-729-4 ML17263A0592017-10-0606 October 2017 Diablo Canyon Power Plant, Unit 2 - Relief Requests to Allow Use of Proposed Alternatives to Implement Requirements of ASME Code, for Reactor Pressure Vessel Welds for the Third ISI Interval (CAC Nos. MF9386, MF9387, MF9388, MF9389, and MF9390) ML17138B1152017-05-18018 May 2017 10 CFR 50.55a Request for Approval of Alternative - RI-ISI-2 ML17037D2672017-03-0909 March 2017 Relief Request NDE-RCS-SE-1R20 to Allow Use of Alternate Depth Sizing Criteria for the Fourth Inservice Inspection ML16207A3972016-07-27027 July 2016 Relief Request NDE-SIF-U1, Allow Use of Alternate Examination Volume Coverage Requirements, Class 2 Seal Injection Welds, for the Third 10-Year Inservice Inspection Interval ML16056A5132016-03-0707 March 2016 Relief Request FLIG-U1, Request to Extend Third 10-Year Inservice Inspection Interval for Reactor Vessel Stud Hole Ligament Examinations ML16055A2812016-02-26026 February 2016 Relief Request NDE-FWNS-U1/U2 to Allow Use of Alternate Examination Volume Coverage Requirements, Third 10-Year Inservice Inspection Interval ML16013A3402016-01-27027 January 2016 Relief Request NDE-PNS-U2A, ASME Code Section XI Requirements to Allow Use of Alternate Exam Volume Coverage Requirements, for the Third 10-year Inservice Inspection Interval ML15337A0212015-12-0808 December 2015 Relief Request NDE-SG-MS-IR - Relief from Exam Requirements for Main Steam Nozzles in Replacement Steam Generators, Third 10-Year Inservice Inspection Interval ML15299A0342015-11-0404 November 2015 Relief Request NDE-RCS-SE-2R19, Use of Alternate Sizing Qualification Criteria Through a Protective Clad Layer, Third 10-Year Inservice Inspection Interval DCL-15-118, Response to NRC Request for Additional Information Regarding Relief Request FLIG-U12015-10-12012 October 2015 Response to NRC Request for Additional Information Regarding Relief Request FLIG-U1 ML15261A0072015-09-18018 September 2015 Request for Relief PRS-3, Proposed Alternative to Requirements for System Leakage Testing Class 1 Piping Vent, Drain, and Test Isolation Devices, for the Third 10-year Inservice Inspection Interval (TAC MF6520-MF6521) DCL-15-086, ASME Section XI Inservice Inspection Program Request for Relief PRS-32015-07-28028 July 2015 ASME Section XI Inservice Inspection Program Request for Relief PRS-3 ML15187A0352015-07-15015 July 2015 Relief Request REP-SI, Revision 2, Proposed Alternative for Repair/Replacement Activities for Certain Safety Injection Pump Welded Attachments, Remaining Useful Life +20 Years ML15168A0242015-06-19019 June 2015 Request for Alternative RPV-U1 - Extension to Allow Use of Alternate Reactor Inspection Interval Requirements for the Third 10-Year Inservice Inspection Interval DCL-15-075, Relief Request REP-SI - Supplement2015-06-18018 June 2015 Relief Request REP-SI - Supplement ML14251A4682014-09-16016 September 2014 Relief Request NDE-SFW-13, ASME Code Section XI, Request for Alternative to Allow Use of Alternate Examination Requirements, Third 10-Year Inservice Inspection Interval ML14196A0952014-08-0404 August 2014 Request for Relief from ASME Code Requirements for Mechanical Clamping Devices for Class 2 and 3 Piping Pressure Boundary ML14104B6132014-05-14014 May 2014 Relief Request NDE-PNS-U2, Requirements for Examination Coverage of ASME Class 1 Pressurizer Nozzle-to-Head Welds, Third 10-Year Inservice Inspection Interval ML13350A1512014-01-0303 January 2014 Relief Request NDE-RCS-SE-1R18, Alternative to ASME Code, Section XI, App. Viii, Suppl. 2 and 10 as Modified by CC N-695 and CC N-696, to Allow Use of Alternative Depth-Sizing Criteria ML13192A3542013-09-12012 September 2013 Relief Request RVFLNG-INT3 - Alternative to ASME Code Pressure Test Requirements for Class 1 Reactor Vessel Flange Leakoff Lines, Third 10-Year Inservice Inspection Interval (TAC MF0408-MF0409) ML13232A3082013-08-28028 August 2013 Relief Request REP-1 U2, Revision 2, Alternative to Code Requirements for Pressurizer Structural Weld Overlays, for the Third 10-Year Inservice Inspection Interval DCL-13-038, ASME Section XI Inservice Inspection Program Relief Request NDE-RCS-SE-1R18 to Allow Use of Alternative Depth Sizing Criteria2013-04-11011 April 2013 ASME Section XI Inservice Inspection Program Relief Request NDE-RCS-SE-1R18 to Allow Use of Alternative Depth Sizing Criteria ML1106003562011-03-29029 March 2011 Relief Request NDE-RCS-SE-2R16, Alternative to Requirements of ASME Code, Section XI, Supplement 10 as Modified by Code Case N-695, Qualification Requirements for Dissimilar Metal Piping Welds ML0801100012008-02-0606 February 2008 Approval of Relief Request REP-1 U2, Revision 1, for the Application of Weld Overlay on Dissimilar Metal Welds of Pressurizer Nozzles ML0716200722007-06-25025 June 2007 Relief Requests NDE-SLH U2 and NDE-LSL U2 for Second 10-year Inservice Inspection Interval Re Reactor Vessel Shell Weld Inspections ML0707803692007-03-29029 March 2007 Relief Request NDE-SBR for the Second 10-Year Interval Inservice Inspection and Examination Program for Snubbers DCL-07-032, Response to NRC Request for Additional Information Regarding ASME Section XI Inservice Inspection Program Relief Requests NDE-SLH U2 and NDE-LSL U22007-03-23023 March 2007 Response to NRC Request for Additional Information Regarding ASME Section XI Inservice Inspection Program Relief Requests NDE-SLH U2 and NDE-LSL U2 ML0621200382006-09-20020 September 2006 Relief, Relief Request for Relief NDE-SLH (TAC No. MC9474) - Reactor Pressure Vessels Welds DCL-06-069, Residual Heat Removal Weld RB-119-11 - Flaw Analytical Evaluation Results2006-06-0606 June 2006 Residual Heat Removal Weld RB-119-11 - Flaw Analytical Evaluation Results ML0608203592006-04-0404 April 2006 Relief, Relief Request for Second Inservice Inspection Interval for Steam Generator Welds, MC9473 ML0603302512006-01-30030 January 2006 Relief Requests 1, 2, and 3 Approval ML0526603312005-10-26026 October 2005 Diablo Canon Pp, Units 1 & 2 - Approval of Requests for Relief from the (ASME) Boiler and Pressure Vessel Code (Code) Section XI Inservice Inspection Program Requirements (Tac Nos MC6693 & MC6694) ML0208502842002-04-11011 April 2002 Relief, Approval of Inservice Inspection Relief Request - Use of ASME Code Case N-597 (TAC MB1693 and MB1694) 2020-10-22
[Table view] Category:Letter
MONTHYEARIR 05000275/20230042024-02-0909 February 2024 Integrated Inspection Report 05000275/2023004 and 05000323/2023004 ML24002B1802024-01-29029 January 2024 LRA Audit Plan DCL-24-010, Nuclear Material Transaction Report for New Fuel2024-01-29029 January 2024 Nuclear Material Transaction Report for New Fuel ML24018A0152024-01-29029 January 2024 License Renewal Application Review Schedule Letter ML24017A2492024-01-24024 January 2024 Letter to Neil Peyron, Chairman, Tule River Tribe, Re. Diablo Canyon ML24024A1752024-01-24024 January 2024 Letter to Tribal Council San Luis Obispo County Chumash Indians on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24003A8902024-01-24024 January 2024 Letter to P. Gerfen - Diablo Canyon Notice of Intent to Conduct Scoping and Prepare an Environmental Impact Statement ML24012A1582024-01-24024 January 2024 Letter to Hon. Violet Sage Walker, Chairwoman Northern Chumash Tribal Council on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24012A0062024-01-24024 January 2024 Achp Scoping Letter for Diablo Canyon License Renewal ML24012A0552024-01-24024 January 2024 Letter to J. Polanco, Shpo, on Request to Initiate Section 106 Consultation and Scooping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24024A1562024-01-24024 January 2024 Letter to Hon. Gabe Frausto, Coastal Band of Chumash Indians on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24024A1652024-01-24024 January 2024 Letter to Hon. Mona Olivas Tucker, Yak Tityu Tityu Yak Tilhini Northern Chumas Indians on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24024A1612024-01-24024 January 2024 Letter Hon. Gary Pierce, Salian Tribe of Monterey and San Luis Obispo Counties on Section 106 Consultation and Scoping Process for the Environmental Review of Diablo Canyon Nuclear Plant, Unit 1 and 2 License Renewal Application ML24012A0362024-01-24024 January 2024 Request to Initiate Section 106 Consultation and Scoping Process for the Environmental Review License Renewal Application 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 IR 05000275/20230112024-01-12012 January 2024 NRC License Renewal Phase 1 Inspection Report 05000275/2023011 DCL-23-129, Nuclear Material Transaction Report for New Fuel2023-12-27027 December 2023 Nuclear Material Transaction Report for New Fuel ML23326A0122023-12-21021 December 2023 12-21-23 Letter to the Honorable Byron Donalds from Chair Hanson Responds to Letter Regarding 2.206 Petition to Close Diablo Canyon Nuclear Power Plant, Unit 1 ML23341A0042023-12-19019 December 2023 LRA Acceptance Letter ML23352A2342023-12-18018 December 2023 Notification of Age-Related Degradation Inspection (05000275/2024014 and 05000323/2024014) and Request for Information 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 ML23355A0952023-12-0808 December 2023 License Renewal Application Online Reference Portal 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 ML23291A2702023-11-28028 November 2023 Letter to Nakia Zavalla, Shpo, the Santa Ynez Band of Chumash Indians; Re., Diablo Canyon ISFSI Initiating Section 106 Consultation ML23320A2442023-11-28028 November 2023 Letter to Kerri Vera, Director of Department of Environmental Protection, Tule River Tribe; Re., Diablo Canyon ISFSI Initiating Section 106 Consultation ML23325A1382023-11-27027 November 2023 ISFSI Tribal Letter to San Luis Obispo County Chumash Indians ML23325A1322023-11-27027 November 2023 ISFSI Tribal Letter to Salian Tribe of Montgomery, San Luis Obispo ML23325A1332023-11-27027 November 2023 ISFSI Tribal Letter to Yak Tityu Tityu Northern Chumash Indians ML23307A0062023-11-27027 November 2023 ISFSI Tribal Letter to Northern Chumash Tribal Council ML24003A7242023-11-27027 November 2023 Independent Safety Committee; Diab Lo Canyon Nuclear Power Plant Operations, Thirty-Third Annual Report on the Safety ML23325A1292023-11-27027 November 2023 ISFSI Tribal Letter to Coastal Band of Chumash ML23320A1502023-11-17017 November 2023 Individual Notice of Consideration of Issuance of Amendment to Facility Operating License, Proposed No Significant Hazards Consideration Determination, & Opportunity for Hearing (Exigent Circumstances) (EPID L-2023-LLA-0155) - LTR 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 ML23296A0982023-11-15015 November 2023 Notification and Request for Consultation Regarding Pacific Gas and Electric Diablo Canyon Independent Spent Fuel Storage Installation Material License Renewal Request (Docket Number: 72-26) 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 ML23293A1052023-11-14014 November 2023 Receipt and Availability of License Renewal Application IR 05000275/20230032023-11-13013 November 2023 Integrated Inspection Report 05000275/2023003 and 05000323/2023003 ML23311A2082023-11-0909 November 2023 Reassignment of U.S. Nuclear Regulatory Commission Branch Chief in the Division of Operating Reactor Licensing for Plant Licensing Branch IV DCL-23-118, License Renewal Application2023-11-0707 November 2023 License Renewal Application ML23318A2102023-10-31031 October 2023 Independent Safety Committee; Thirty-Third Annual Report on the Safety of Diablo Canyon Nuclear Power Plant Operations 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 IR 05000275/20240152023-10-10010 October 2023 Information Request for the Cybersecurity Baseline Inspection, Notification to Perform Inspection (050002752024015 and 050003232024015) 2024-02-09
[Table view] Category:Safety Evaluation
MONTHYEARML23199A3122023-07-20020 July 2023 Revision to the Reactor Vessel Material Surveillance Capsule Withdrawal Schedule ML22340A6752023-03-0606 March 2023 Approval of Certified Fuel Handler Training and Retraining Program ML23012A2172023-02-0909 February 2023 Issuance of Amendment Nos. 244 and 245 Revision to Technical Specifications to Adopt TSTF-569, Revision 2, Revise Response Time Testing Definition ML21242A2162022-12-21021 December 2022 Issuance of Amendment Nos. 243 and 244 Technical Specifications and Revised License Conditions for the Permanently Defueled Condition (EPID: L-2020-LLA-0261 ML22334A0822022-12-0101 December 2022 Correction to Issuance of Amendment Nos. 242 and 243 Revision to Emergency Plan for Post-Shutdown and Permanently Defueled Condition ML22187A0252022-11-16016 November 2022 Issuance of Amendment Nos. 242 and 243 Revision to Emergency Plan for Post-Shutdown and Permanently Defueled Condition ML22221A1682022-09-0606 September 2022 Issuance of Amendment Nos. 241 and 242 Revision to Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspection ML21160A1742021-09-0202 September 2021 Issuance of Amendment Nos. 239 and 240 Revising Technical Specification 3.2.1, Heat Flux Hot Channel Factor (Fq(Z)), to Implement Methodology from WCAP-17661, Revision 1 ML21188A3452021-07-0808 July 2021 Issuance of Amendment No. 238 Revision to TS 3.7.8, Auxiliary Saltwater (Asw) System (Emergency Circumstances) ML20249C8502020-10-22022 October 2020 Proposed Alternative NDE-RCS-SE-2R22 to the Requirements of the ASME Code ML20218A2762020-09-11011 September 2020 Issuance of Amendment Nos. 237 and 239 to Relocate Technical Specification 5.3, Unit Staff Qualifications, to Updated Final Safety Analysis Report ML20235R6352020-08-31031 August 2020 Issuance of Amendment Nos. 236 and 238 Revision to Technical Specification 3.7.5, Auxiliary Feedwater (AFW) System, Exigent Circumstances ML19274B0822019-10-0707 October 2019 Correction to Issuance of Amendment Nos. 233 and 235 to Revise the Emergency Plan to Change Staffing and Extend Staff Augmentation Times for ERO Positions ML19196A3092019-08-21021 August 2019 Issuance of Amendment Nos. 233 and 235 Regarding Revision to Emergency Plan to Change Staffing and Extend Staff Augmentation Times for Emergency Response Organization Positions ML19176A0082019-06-28028 June 2019 Request for Relief from the Inservice Inspection Program Requirements of ASME Code, Section XI, for Steam Generator and Pressurizer Nozzle Inside Radius Sections ML19023A0262019-01-25025 January 2019 Request for Alternative from Volumetric/Surface Examination Frequency Requirements of ASME Code Case N-729-4 ML17263A0592017-10-0606 October 2017 Diablo Canyon Power Plant, Unit 2 - Relief Requests to Allow Use of Proposed Alternatives to Implement Requirements of ASME Code, for Reactor Pressure Vessel Welds for the Third ISI Interval (CAC Nos. MF9386, MF9387, MF9388, MF9389, and MF9390) ML17212A3792017-09-25025 September 2017 Diablo Canyon Power Plant, Units 1 and 2 - Issuance of Amendment Nos. 231 and 233 Re: Emergency Action Level Scheme Change (CAC Nos. MF8528 and MF8529) ML17132A2312017-05-16016 May 2017 Diablo Canyon Power Plant, Units 1 and 2 - Correction Letter Regarding Amendment Nos. 230 and 232 to Adopt Alternative Source Term (CAC Nos. MF6399 and MF6400) ML17012A2462017-04-27027 April 2017 Issuance of Amendments Revise Licensing Bases to Adopt Alternative Source Term ML17037D2672017-03-0909 March 2017 Relief Request NDE-RCS-SE-1R20 to Allow Use of Alternate Depth Sizing Criteria for the Fourth Inservice Inspection ML17018A3412017-02-23023 February 2017 Issuance of Amendments Revise Technical Specification 3.4.12, Low Temperature Overpressure Protection (LTOP) System, ML16349A3862016-12-28028 December 2016 Safety Evaluation Regarding Implementation of Mitigating Strategies and Reliable Spent Fuel Pool Instrumentation Related to Orders EA-12-049 and EA-12-051 ML16139A0082016-12-21021 December 2016 Issuance of Amendment Nos. 227 and 229, Digital Replacement of the Process Protection System Portion of the Reactor Protection System and Engineered Safety Features Actuation System ML16207A3972016-07-27027 July 2016 Relief Request NDE-SIF-U1, Allow Use of Alternate Examination Volume Coverage Requirements, Class 2 Seal Injection Welds, for the Third 10-Year Inservice Inspection Interval ML16117A2522016-05-19019 May 2016 Issuance of Amendment Nos. 226 and 228, Revise Minimum Flow Value Specified in Technical Specification 3.4.1, RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits ML16035A4412016-04-14014 April 2016 Issuance of Amendment Nos. 225 and 227, Adopt National Fire Protection Association NFPA 805, Performance-Based Standard for Fire Protection for LWR Generating Plants (2001 Edition) ML16055A3592016-03-0909 March 2016 Issuance of Amendment Nos. 224 and 226, Revise Updated Final Safety Analysis Report for Beacon Power Distribution Monitoring System Methodology and TS 5.6.5 (COLR) Paragon and Nexus Methodologies ML16056A5132016-03-0707 March 2016 Relief Request FLIG-U1, Request to Extend Third 10-Year Inservice Inspection Interval for Reactor Vessel Stud Hole Ligament Examinations ML16055A2812016-02-26026 February 2016 Relief Request NDE-FWNS-U1/U2 to Allow Use of Alternate Examination Volume Coverage Requirements, Third 10-Year Inservice Inspection Interval ML16032A0062016-02-19019 February 2016 Redacted, Issuance of Amendment Nos. 223 and 225, Revise UFSAR Section 15.4.2.2 to Incorporate Pressurizer Filling Analysis for Major Rupture of a Main Feedwater Pipe Accident Into Licensing Basis ML16013A3402016-01-27027 January 2016 Relief Request NDE-PNS-U2A, ASME Code Section XI Requirements to Allow Use of Alternate Exam Volume Coverage Requirements, for the Third 10-year Inservice Inspection Interval ML15037A0062016-01-0505 January 2016 ISFSI - Safety Evaluation, Encl. 4, Amendment Nos. 222, 224, and 4 - Authorize Use of Preemption Authority Granted Under Provisions of Section 161A of the Atomic Energy Act of 1954, as Amended (CAC MF2809, MF2810, and L24991) ML15029A1732016-01-0505 January 2016 ISFSI - Issuance of Amendment Nos. 222, 224, and 4, Authorize Use of Preemption Authority Granted Under Provisions of Section 161A of the Atomic Energy Act of 1954, as Amended (CAC MF2809, MF2810, and L24991) ML15337A0212015-12-0808 December 2015 Relief Request NDE-SG-MS-IR - Relief from Exam Requirements for Main Steam Nozzles in Replacement Steam Generators, Third 10-Year Inservice Inspection Interval ML15281A1642015-12-0303 December 2015 Issuance of Amendment Nos. 221 and 223, Revise Updated Final Safety Analysis Report and Approval to Perform Fuel Assembly Structural Analyses That Considers Application of Leak Before Break ML15299A0342015-11-0404 November 2015 Relief Request NDE-RCS-SE-2R19, Use of Alternate Sizing Qualification Criteria Through a Protective Clad Layer, Third 10-Year Inservice Inspection Interval ML15245A5422015-09-30030 September 2015 Issuance of Amendment Nos. 220 and 222, Request to Revise Operating License Condition Related to Cyber Security Plan Milestone H Full Implementation Date ML15261A0072015-09-18018 September 2015 Request for Relief PRS-3, Proposed Alternative to Requirements for System Leakage Testing Class 1 Piping Vent, Drain, and Test Isolation Devices, for the Third 10-year Inservice Inspection Interval (TAC MF6520-MF6521) ML15204A2222015-08-27027 August 2015 Issuance of Amendment Nos. 219 and 221, Adopt Technical Specifications Task Force Traveler TSTF-432, Revision 1, Change in Technical Specification End States (WCAP-16294) ML15187A0352015-07-15015 July 2015 Relief Request REP-SI, Revision 2, Proposed Alternative for Repair/Replacement Activities for Certain Safety Injection Pump Welded Attachments, Remaining Useful Life +20 Years ML15162A8822015-07-0101 July 2015 Issuance of Amendment Nos. 218 and 220, Revise Surveillance Requirements in TS 3.8.1, AC Sources, Related to Diesel Generator Testing ML15168A0242015-06-19019 June 2015 Request for Alternative RPV-U1 - Extension to Allow Use of Alternate Reactor Inspection Interval Requirements for the Third 10-Year Inservice Inspection Interval ML14251A4682014-09-16016 September 2014 Relief Request NDE-SFW-13, ASME Code Section XI, Request for Alternative to Allow Use of Alternate Examination Requirements, Third 10-Year Inservice Inspection Interval ML14196A0952014-08-0404 August 2014 Request for Relief from ASME Code Requirements for Mechanical Clamping Devices for Class 2 and 3 Piping Pressure Boundary ML14104B6132014-05-14014 May 2014 Relief Request NDE-PNS-U2, Requirements for Examination Coverage of ASME Class 1 Pressurizer Nozzle-to-Head Welds, Third 10-Year Inservice Inspection Interval ML14042A1932014-02-27027 February 2014 Issuance of Amendment Nos. 217 and 219, Editorial and Clarifying Changes to Technical Specification (TS) 3.7.10, Control Room Ventilation System (CRVS) and TS 5.6.5, Core Operating Limits Report (COLR) (TAC MF1959-MF1960) ML13192A3542013-09-12012 September 2013 Relief Request RVFLNG-INT3 - Alternative to ASME Code Pressure Test Requirements for Class 1 Reactor Vessel Flange Leakoff Lines, Third 10-Year Inservice Inspection Interval (TAC MF0408-MF0409) ML13178A0052013-09-0505 September 2013 Issuance of Amendment Nos. 216 and 218, Adoption of TSTF-421-A, Revision to RCP Flywheel Inspection Program (WCAP-15666), Using Consolidated Line Item Improvement Process ML13232A3082013-08-28028 August 2013 Relief Request REP-1 U2, Revision 2, Alternative to Code Requirements for Pressurizer Structural Weld Overlays, for the Third 10-Year Inservice Inspection Interval 2023-07-20
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 February 26, 2016 Mr. Edward D. Halpin Senior Vice President and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Power Plant P.O. Box 56, Mail Code 104/6 Avila Beach, CA 93424
SUBJECT:
DIABLO CANYON POWER PLANT, UNIT NOS. 1 AND 2 - AMERICAN SOCIETY OF MECHANICAL ENGINEERS SECTION XI INSERVICE INSPECTION PROGRAM RELIEF REQUEST NDE-FWNS-U1/U2 TO ALLOW USE OF ALTERNATE EXAMINATION VOLUME COVERAGE REQUIREMENTS (CAC NOS. MF6689 AND MF6690)
Dear Mr. Halpin:
By letter dated September 3, 2015 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML15246A244), as supplemented by letter dated January 27, 2016 (ADAMS Accession No. ML16027A358), Pacific Gas & Electric Company (the licensee) submitted a request for relief (NDE-FWNS-U1/U2) from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components," non-destructive examination requirements applicable to the Diablo Canyon Power Plant (DCPP), Unit Nos. 1 and 2, steam generator (SG) feedwater (FW) nozzle-to-shell welds. ASME Code,Section XI, Table IWC-2500-1, Code Category C-B, Item Number C2.21, requires that surface and volumetric examinations of the nozzle-to-shell weld of nozzles at terminal ends of piping runs be performed in accordance with Figure IWC-2500-4(a), (b), or (d) during each inspection interval. The licensee requested relief from the ASME Code,Section XI requirement for an essentially 100 percent volumetric examination of the inner one-third volume of the welds of the DCPP, Unit Nos. 1 and 2, SG FW nozzle-to-shell welds because compliance with the requirement is impractical and the configuration of the nozzles precludes obtaining complete volumetric examination coverage.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensee's submittal and concludes, as set forth in the enclosed safety evaluation, that compliance with the ASME Code,Section XI, Table IWC-2500-1, Examination Category C-B, Item No. C2.21 nozzle-to-shell weld volumetric examination requirement to examine essentially 100 percent of the inner one-third volume of the SG FW nozzle-to-shell welds for DCPP, Unit Nos. 1 and 2, is impractical because the configuration of the nozzles precludes obtaining 100 percent volumetric examination coverage. The volumetric examination coverages achieved for the DCPP, Unit Nos. 1 and 2, FW nozzle-to-shell welds (84 percent and 79 percent, respectively), combined with the complete surface examinations of these welds, as well as the periodic visual [VT-2]
examinations of the SGs performed during each refueling outage in conjunction with the system leakage test, provide reasonable assurance of structural integrity of the SG FW nozzle-to-shell welds. Therefore, the NRC staff grants relief for the subject examinations of the items contained in relief request NDE-FWNS-U1/U2, as requested for DCPP, Unit Nos. 1 and 2, for
E. Halpin the third 10-year inservice inspection intervals, which nominally ended on May 6, 2015, for Unit No. 1, and is nominally scheduled to end on March 12, 2016, for Unit No. 2.
All other ASME Code,Section XI requirements for which relief was not specifically requested and approved in the subject request for relief remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector.
If you have any questions, please contact the Project Manager, Siva P. Lingam, at 301-415-1564 or via e-mail at Siva.Lingam@nrc.gov.
Sincerely, Robert J. Pascarelli, Chief Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323
Enclosure:
Safety Evaluation cc w/encl: Distribution via Listserv
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST NDE-FWNS-U1/U2 FOR FEEDWATER NOZZLE-TO-SHELL WELD TO ALLOW USE OF ALTERNATE EXAMINATION VOLUME COVERAGE REQUIREMENTS PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON POWER PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-275 AND 50-323
1.0 INTRODUCTION
By letter dated September 3, 2015 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML15246A244), as supplemented by letter dated January 27, 2016 (ADAMS Accession No. ML16027A358), Pacific Gas & Electric Company (PG&E, the licensee) submitted a request for relief (NDE-FWNS-U1/U2) from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components," non-destructive examination requirements applicable to the Diablo Canyon Power Plant (DCPP), Unit Nos. 1 and 2, steam generator (SG) feedwater (FW) nozzle-to-shell welds. ASME Code,Section XI, Table IWC-2500-1, Code Category C-B, Item Number C2.21, requires that surface and volumetric examinations of the nozzle-to-shell weld of nozzles at terminal ends of piping runs be performed in accordance with Figure IWC-2500-4(a), (b), or (d) during each inspection interval. The licensee requested relief from the ASME Code,Section XI requirement for an essentially 100 percent volumetric examination of the inner one-third volume of the welds of the DCPP, Unit Nos. 1 and 2, SG FW nozzle-to-shell welds because compliance with the requirement is impractical and the configuration of the nozzles precludes obtaining complete volumetric examination coverage.
Volumetric examination to the maximum extent possible coupled with complete surface examination of the subject welds are proposed to provide reasonable assurance of the structural integrity of the welds.
The request is for the third 10-year inservice inspection (ISi) interval for both units. For DCPP, Unit No. 1, the ISi interval began on January 1, 2006, and nominally ended on May 6, 2015; for DCPP, Unit No. 2, the ISi interval began on July 1, 2006, and is nominally scheduled to end on March 12, 2016. Actual end dates of the intervals are dependent on the completion dates of the 19th refueling outages for each unit, in accord with ASME Code,Section XI, Paragraph IWA-2430(d)(1).
Enclosure
2.0 REGULATORY EVALUATION
The ISi of ASME Code Class 1, 2, and 3 components is to be performed in accordance with Section XI of the ASME Code and applicable edition and addenda as required by Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g), except where specific relief has been granted by the U.S. Nuclear Regulatory Commission (NRC) pursuant to 10 CFR 50.55a(g)(6)(i).
Pursuant to 10 CFR 50.55a(z), alternatives to the requirements of paragraph (g) may be used, when authorized by the Commission, if (i) the proposed alternatives would provide an acceptable level of quality and safety or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) must meet the requirements, except design and access provisions and preservice examination requirements, set forth in ASME Code,Section XI to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 10-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The regulations in 10 CFR 50.55a(g)(4)(iv) states that inservice examination of components and system pressure tests may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph 10 CFR 50.55a(a), subject to the limitations and modifications listed in 10 CFR 50.55a(b) and subject to Commission approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met.
The ASME Code of record for the third 10-year ISi interval at DCPP, Unit Nos. 1 and 2, is the 2001 Edition with Addenda through 2003.
3.0 TECHNICAL EVALUATION
3.1 Affected Components The component affected by this request is the SG FW nozzle. The SG FW nozzle is an ASME Code,Section XI, Class 2 component. The four figures on pages 6 through 9 of PG&E's September 3, 2015 submittal show the general configuration and examination coverage illustrations for the DCPP SG FW nozzles.
3.2 ASME Code Requirements (as stated by the licensee)
ASME [Code,] Section XI, Table IWC-2500-1, Examination Category C-B, Item No. C2.21 requires that SG feedwater nozzle-to-shell welds be volumetrically examined once during the ISi interval. Essentially 100 percent of the inner one-third volume of the weld, and adjacent base material, is to be examined in accordance with the requirements of [ASME Code,Section XI,] Appendix I,
[Paragraph] 1-2120. The applicable examination volume is defined by [ASME Code,Section XI,] Figure IWC-2500-4(a) and the examination is performed per
the rules of ASME [Code,] Section V, Article 4, as supplemented by [ASME Code,Section XI, Appendix I,] Table 1-2000-1.
3.3 Licensee's Basis for Requesting Relief (as stated by the licensee)
Pursuant to 10 CFR 50.55a(g)(5)(iii), Pacific Gas and Electric Company (PG&E) hereby requests NRC approval of lnservice Inspection Request for Relief NDE-FWNS-U1/U2 for the Diablo Canyon Power Plant Unit No. 1 and Unit No. 2 third lnservice Inspection Interval. Relief is requested from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, for examination coverage of Class 2 feedwater nozzle-to-vessel welds. The details of the proposed request are enclosed [in the licensee's September 3, 2015 submittal].
"Essentially 100 percent" coverage of the exam volume from the outside surface would require redesign of the SG to move the weld farther back from the nozzle reinforcement or eliminate the weld by integrally incorporating the nozzle into the shell. Either of these two modifications would effectively result in performing major redesign and rework or replacement of the entire SG to accommodate full coverage of the exam area as specified by [the ASME] Code.
Performing examinations from the inside diameter of the SGs would require accessing the secondary side of the generators which involves substantial effort to remove the manway cover, making provisions for personnel access into a confined space, and work in a high risk foreign material exclusion area.
These efforts required to attain a small incremental increase in coverage would incur increased personnel radiation exposure and an increase in personnel safety risk due to work in a difficult to access and highly constrained work environment without a commensurate increase in examination effectiveness.
PG&E proposes that the alternative ultrasonic examinations conducted to the maximum extent practicable from the outside surface provide reasonable assurance that the structural integrity of the subject welds remains intact.
The [DCPP, Unit Nos. 1 and 2, seventeenth refueling outages] 1R17 and 2R17 examinations were implemented to the extent practicable using manual scan techniques and small footprint search units in effort to attain the greatest possible coverage of the required examination volume. The volume examined on both of the subject feedwater nozzle-to-shell welds includes the weld and surrounding base material near the inside surface of the weld joint, which are typically the highest stress regions and where degradation would likely manifest, should it occur.
The radial-in and circumferentially oriented angle beam scans fully interrogated the ASME [Code, Section] XI Code exam volume, whereas, the radial-out scans covered a portion of the volume. Examination of ferritic materials from a single
side of the weld has been demonstrated as effective in studies (Reference 1 [of the licensee's September 3, 2015 submittal]) and by successful single side ferritic ASME [Code, Section] XI, Appendix VIII qualifications per the Performance Demonstration Initiative program. Therefore, it is expected that the ultrasonic techniques employed on the DCPP FW nozzle-to-shell welds would have detected structurally significant flaws if extant within the examination area.
The 1R17 and 2R 17 ultrasonic examinations with combined coverage values of approximately 84 percent and 79 percent for the selected Unit No. 1 and Unit No. 2 subject welds, respectively, provide reasonable assurance that the structural integrity of these welds remains intact and provide an acceptable level of quality and safety.
Potential Failure Consequences A failure of the- feedwater nozzle-to-shell weld could result in a loss of feedwater to a SG. Depending on the size of the postulated break (leak) the specific consequences will vary. At the smallest end of the break size spectrum, the feedwater system would be capable of maintaining SG level through normal makeup. Larger break sizes would result in depressurization of the SG and loss of heat transfer capability. The worst case consequence would occur if the nozzle-to-shell weld was to suffer 360 degree circumferential cracking. In this case, the break is bounded by the feedwater line break assumed in the DCPP design basis analysis.
Essentially no change to overall plant safety is expected due to implementation of the proposed alternative in lieu of the [ASME] Code [, Section XI] requirement.
This assumption is based on the effectiveness of ultrasonic examination on ferritic material as previously described, and little or no historical occurrence of large service induced planar flaws in this type of weldment.
3.4 NRC Staff Evaluation During a telephone call with the licensee on September 23, 2015 (ADAMS Accession No. ML15267A387), the NRC staff requested the following clarification regarding the licensee's September 3, 2015, relief request (RR):
- The RR submittal requests relief under the provisions of Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 50.55a(g)(5)(iii),
"IS/ program update: Notification of impractical IS/ Code requirements."
However, the submittal also discusses and requests approval for "proposed alternatives." Proposed alternatives are addressed under the provision of 10 CFR 50.55a(z), "Alternatives to codes and standards requirements." Clarify whether or not an alternative pursuant to 10 CFR 50.55a(z) is also being requested in this RR.
During the call, the licensee clarified that the request is solely for relief under the provisions of 10 CFR 50.55a(g)(5)(iii), and that no proposed alternatives under 10 CFR 50.55a(z) are requested. In response to this clarification, the NRC staff sent an e-mail to the licensee on September 24, 2015 (ADAMS Accession No. ML15267A387), stating that the licensee's submittal would be reviewed in accordance with the provisions of 10 CFR 50.55a(g)(6), "Actions by the Commission for evaluating impractical and augmented /SI Code requirements."
During its review, the NRC staff noted that according to Appendix 9.5A of Revision 20 to the DCPP Final Safety Analysis Report Update (November 2011 ), the SGs were replaced in 2008 and 2009 at DCPP, Unit Nos. 1 and 2, respectively. Therefore, similar requests for the DCPP SG FW nozzles for relief during previous 10-year ISi intervals were not available to the staff for comparison during its review of PG&E's submittal. However, precedent requests for similar relief for DCPP dated September 29, 1999 (ADAMS Legacy Library Accession No. 9902220262), and the Calvert Cliffs Nuclear Power Plant dated July 27, 2001 (ADAMS Accession No. ML011860464), were identified in PG&E's September 3, 2015, submittal, and were reviewed by the staff for consistency.
In its September 3, 2015, submittal, the licensee identified that the DCPP replacement SG shell and nozzle forgings are fabricated from SA-508 Grade 3 Class 2 material with a nominal shell thickness of approximately 3.50 inches. The FW nozzles intersect the shell cylinder at a right angle and are joined by a weld extending concentrically around the nozzle forging and through the full thickness of the shell. The weld joint design is an unequal depth double U-groove design with an included groove angle of 7 degrees. The nozzle-to-shell welds were made using high strength filler metals (i.e., E9018M, ER80S-2, and S3NiMo1) whose composition and mechanical properties are similar to the joined base metals.
The licensee also identified that the subject welds were examined in the 1R17 and 2R 17 refueling outages to the extent practicable using a combination of 35-, 45-, and 60-degree angled shear waves and zero degree longitudinal waves. The 35- and 45-degree angles were used for radial-out examinations in order to achieve the maximum possible coverage of the ASME Code specified examination volume. The 60-degree angle was not able to interrogate the ASME Code examination volume in the radial-out direction due to the restricted setback caused by the nozzle boss configuration. Forty-five and 60- degree angles were used for radial-in and circumferential scan examinations. No flaws were detected in any of the examinations of the subject welds.
The licensee identified that the combined examination volume coverage attained for the DCPP, Unit Nos. 1 and 2, welds was 84 percent and 79 percent, respectively. Although the entire ASME Code examination volume was interrogated by the zero degree longitudinal wave scan, these coverage values were based on the 35-, 45-, and 60-degree angles since they would be expected to detect service-induced planar flaws emanating from the inside surface. The licensee provided four figures that illustrate the coverage for each of the inspection angles and directions used to determine the coverage values.
The compound curvature of the nozzle forging boss to shell contour transition zone and the forging design diameter constitute geometric restrictions that preclude full examination volume coverage from the outside surface. The coverage limitations are associated with the radial-out
oriented scans. An inherent design characteristic of the flange type nozzle configuration is that there is often insufficient setback distance for the radial-out scan beams to cover the entire ASME Code specified examination area at the inside surface of the weld.
In a request for additional information (RAI) dated December 15, 2015 (ADAMS Accession No. ML15350A039), the NRC staff noted that the licensee's submittal did not identify whether the surface examinations required by ASME Code,Section XI, Table IWC-2500-1, Code Category C-B, Item Number C2.21 were performed. Therefore, in the RAI, the staff requested the licensee (1) to identify whether the surface examinations required by ASME Code,Section XI, Table IWC-2500-1, Code Category C-B, Item Number C2.21 were performed for the SG FW nozzle-to-shell welds; (2) to provide a summary of the results for any surface examinations performed for the SG FW nozzle-to-shell welds; (3) to identify whether relief is also being requested from any of the applicable ASME Code,Section XI surface examination requirements for the SG FW nozzle-to-shell welds; and (4) to provide a description of the impact of any surface examinations performed for the SG FW nozzle-to-shell welds on the burden and bases assessments included in the RR.
In its RAI response dated January 27, 2016, the licensee stated that the surface examinations required by the ASME Code,Section XI, Table IWC-2500-1, Code Category C-B, Item Number C2.21 were performed forthe SG FW nozzle-to-shell welds, and that 100 percent coverage was achieved. Additionally, the licensee stated that the surface examinations did not detect any relevant indications and that no defects were noted. The licensee noted that the magnetic particle examination used is sensitive to defects that initiate or propagate to the outside surface of the weld and adjoining examination area and provides assurance that no surface breaking flaws exist on these nozzle welds.
ASME Code,Section XI also requires that the SGs receive a visual (VT-2) examination during each inspection period. The VT-2 examinations of the SGs, which will continue to be performed during each refueling outage in conjunction with the system leakage test, will provide reasonable assurance of the leak tightness of the SG FW nozzle-to-shell welds because the system leakage test will provide for detection of flaws when they are small and can be repaired prior to the SG FW nozzle-to-shell welds losing their ability to perform their intended function.
Based on the volumetric examination coverage achieved, as well as the complete surface examinations that were performed, the NRC staff concludes that there is reasonable assurance that degradation of the SG FW nozzle-to-shell welds is unlikely to occur. With the limited inaccessibility of the FW nozzle-to-shell welds for volumetric examination and the full access of the FW nozzle-to-shell welds for surface examination, the replacement of the SG FW nozzle design with a design that is conducive to essentially 100 percent volumetric examination is impractical. Furthermore, the periodic VT-2 examinations performed on the SGs provide reasonable assurance of structural integrity of the SG FW nozzle-to-shell welds for DCPP, Unit Nos. 1 and 2.
4.0 CONCLUSION
Based on the above, the NRC staff concludes that compliance with the ASME Code,Section XI, Table IWC-2500-1, Examination Category C-B, Item No. C2.21 nozzle-to-shell weld volumetric
examination requirement to examine essentially 100 percent of the inner one-third volume of the SG FW nozzle-to-shell welds for DCPP Unit Nos. 1 and 2 is impractical because the configuration of the nozzles precludes obtaining 100 percent volumetric examination coverage.
The volumetric examination coverages achieved for the DCPP, Unit Nos. 1 and 2, FW nozzle-to-shell welds (84 percent and 79 percent, respectively), combined with the complete surface examinations of these welds, as well as the periodic VT-2 examinations of the SGs performed during each refueling outage in conjunction with the system leakage test, provide reasonable assurance of structural integrity of the SG FW nozzle-to-shell welds.
Therefore, pursuant to 10 CFR 50.55a(g)(6)(i), request for relief NDE-FWNS-U1/U2 is granted to DCPP, Unit Nos. 1 and 2, for the third 10-year ISi intervals, which nominally ended on May 6, 2015, for Unit No. 1, and is nominally scheduled to end on March 12, 2016, for Unit No. 2. Granting relief pursuant to 10 CFR 50.55a(g)(6)(i) is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that would result if the requirements were imposed on the facility.
All other ASME Code,Section XI requirements for which relief was not specifically requested and approved in the subject request for relief remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector.
D~e: February 26, 2016
ML16055A281 *SE via email OFFICE NRR/DORL/LPL4-1/PM NRR/DORL/LPL4-1/LA NRR/DE/EVIB/BC* NRR/DORL/LPL4-1/BC NAME Slingam JBurkhardt JMcHale RPascarelli DATE 2/26/2016 2/26/2016 2/08/2016 2/26/2016