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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
[Table view] |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 14, 2014 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 NO. 2-RELIEF REQUEST NDE-PNS-U2, ASSOCIATED WITH THE THIRD INSERVICE INSPECTION
- INTERVAL, REGARDING PRESSURIZER NOZZLE-TO-HEAD WELD EXAMINATIONS (TAC NO. MF2441)
Dear Mr. Halpin:
By letter dated July 10, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 13192A082),
Pacific Gas and Electric Company (PG&E, the licensee) submitted a relief request for U.S. Nuclear Regulatory Commission (NRC) approval.
In the relief request, PG&E identifies the limited examination of three pressurizer relief nozzle welds at Diablo Canyon Power Plant, Unit 2 (DCPP-2) for the third inservice inspection (lSI) interval.
According to the licensee, the achievable coverage for the welds in question ranges from 65-71 percent, as compared to a specification of essentially 100 percent, in accordance with provisions of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, "Rules for lnservice Inspection of Nuclear Plant Components."
This request was submitted pursuant to Title 10 of the Code of Federal Regulations (1 0 CFR) paragraph 50.55a(g)(5)(iii) on the basis that conducting the examinations as required by the ASME Code would be impractical.
The NRC staff has completed its review of the relief request as discussed in the enclosed safety evaluation.
The NRC staff review concludes that the ASME Code examination coverage requirements are impractical for the subject welds, and imposition of the ASME Code requirements would create a burden on the licensee.
Accordingly, the NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(g)(5)(iii).
- Further, the NRC staff concludes that the examinations performed, as described in the request for relief, provide reasonable assurance of the structural integrity and leak tightness of the subject welds. Therefore, pursuant to 10 CFR 50.55a(g)(6)(i),
the NRC staff grants relief for the subject examinations of the items contained in NDE-PNS-U2, as requested, at DCPP-2, for the third 1 0-year lSI interval, which ends on March 12, 2016. No alternative requirements beyond those specified in the request for relief are being imposed by the NRC staff.
E. Halpin If you have any questions, please contact the NRC Project Manager, Mr. Peter J. Bamford, at 301-415-2833 or via e-mail at Peter.Bamford@nrc.gov.
Docket No. 50-323
Enclosure:
Safety Evaluation cc w/encl: Distribution via ListServ Sincerely, Michael T. Markley, Chief Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST ASSOCIATED WITH THE THIRD INSERVICE INSPECTION INTERVAL PRESSURIZER NOZZLE-TO-HEAD WELD EXAMINATIONS.
REQUEST NO. NDE-PNS-U2 PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON POWER PLANT, UNIT NO. 2 DOCKET NO. 50-323
1.0 INTRODUCTION
By letter dated July 10, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 13192A082),
Pacific Gas and Electric Company (PG&E, the licensee) submitted a relief request for U.S. Nuclear Regulatory Commission (NRC) approval.
In the request, PG&E identified the limited examination of three pressurizer relief nozzle welds at Diablo Canyon Power Plant, Unit 2 (DCPP-2) for the third inservice inspection (lSI) interval.
According to the licensee, the coverage for the welds in question ranges from 65-71 percent, as compared to a specification of essentially 100 percent, in accordance with provisions of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, "Rules for lnservice Inspection of Nuclear Plant Components."
This request was submitted pursuant to Title 10 of the Code of Federal Regulations (1 0 CFR) paragraph 50.55a(g)(5)(iii) on the basis that conducting the examinations as required by the ASME Code would be impractical.
2.0 REGULATORY EVALUATION The lSI of ASME Code Class 1, 2, and 3 components is to be performed in accordance with the applicable edition and addenda of ASME Code,Section XI, as required by 10 CFR 50.55a(g),
except where specific relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i).
Pursuant to 10 CFR 50.55a(g)(4),
ASME Code Class 1, 2, and 3 components (including supports) must meet the requirements set forth in the 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 1 0-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 lSI Code of record for the Enclosure third 1 0-year lSI inspection interval at DCPP-2 is the 2001 Edition, 2003 Addenda, of the ASME Code,Section XI. The third 1 0-year lSI interval began on January 1, 2006, and is planned to end (nominally) on March 12, 2016. 3.0 TECHNICAL EVALUATION The licensee's request for relief and the NRC staff evaluation is described below. The request is proposed to apply through the end of the DCPP-2 third lSI interval.
3.1 ASME Code Component Affected and ASME Code Requirement The three pressurizer nozzle-to-head welds affected by this relief request are listed in the following table. The last column of the table shows the average combined coverage that was actually achieved by the licensee for each weld using ultrasonic testing (UT). ASME Code,Section XI, Examination Category B-D Pressurizer Nozzle-to-Head Welds ASME Code Item Weld Identifier ASME Coverage Obtained 63.110 WIB-346 66% 63.110 WIB-422A 71% 63.110 WIB-368 65% The ASME Code,Section XI, Table IWB-2500-1, Category B-0, Item 63.110 requires that pressurizer nozzle-to-head welds be volumetrically examined once during each 1 0-year lSI interval.
Essentially 100 percent of the weld and adjacent base material is to be examined in accordance with the requirements of Appendix I, 1-2100. The applicable examination volume is defined by Figure IWB-2500-7(b) and the examination is performed per the rules of the ASME Code,Section V, Article 4. 3.2 Licensee's Proposed Alternative and Basis The licensee proposed the following alternative examination:
PG&E proposes that the alternative ultrasonic examinations conducted to the maximum extent practicable provide reasonable assurance that the structural integrity of the subject welds remains intact. In order to support its determination of impracticality, the licensee's application includes the following excerpts:
The Unit 2 pressurizer nozzle-to-head weld configurations are such that essentially 100 percent coverage of the ASME Code required examination volume is not practicable, as determined during the third 1 0-year lSI interval examinations conducted in the DCPP Unit 2 sixteenth and seventeenth refueling outages (2R16 and 2R17). An inherent design characteristic of the DCPP nozzle configuration is that there is insufficient setback distance for the radial-out scan beam to reach the inside surface of the exam area. The nozzle reinforcement also prevents the positioning of circumferential scan search units to allow full coverage of the exam volume in the nozzle base material.
Additionally, the WIB-346 weld reinforcement causes search unit lift-off resulting in small reductions in coverage, primarily in the upper region of the examination volume. "Essentially 100 percent" coverage of the exam volume would require redesign of the pressurizer to (a) machine away the nozzle reinforcement, (b) move the weld farther back from the nozzle reinforcement, or (c) eliminate the weld by integrally incorporating the nozzle into the head. Either of the latter two modifications would effectively result in having to replace the entire pressurizer to accommodate full coverage of the exam area as specified by ASME Code. In addition to the potential modifications noted above, the licensee also stated that: Removing the weld reinforcement on WIB-346 would result in only small incremental increases in exam volume coverage at the cost of reducing the pressurizer head structural margin, and significant personnel exposure.
It is estimated that 20-30 man hours would be required to remove the reinforcement and produce a surface contour required to prevent lift-off of the search units. This effort in a 20 millirem (mR) dose rate field would result in total exposure of 400-600mR.
3.3 NRC Staff Evaluation The ASME Code,Section XI requires 100 percent volumetric examination of pressurizer to-head welds. As indicated in the above table, the licensee was unable to obtain the volumetric code coverage of 100 percent of the subject welds. The licensee stated that examinations of the ASME Category B-0, Full Penetration Welds of Nozzles in Vessels listed were limited due to the nozzle geometry/configurations.
The NRC staff evaluated the relief request determination in accordance with 10 CFR 50.55a(g)(6)(i),
which permits relief pursuant to impracticality under 10 CFR 50.55a(g)(5)(iii).
Based on the licensee's assessment that to accommodate full coverage of the examination area as specified by the ASME Code could result in having to machine away nozzle reinforcements or perform modifications that would result in having to replace the entire pressurizer, the NRC staff concluded that it is impractical for the licensee to comply with these specific ASME Code requirements, and imposing them would be a burden on the licensee.
The licensee obtained 65-71 percent volumetric examination coverage for the three pressurizer nozzles.
The NRC staff examined the schematics of the pressurizer nozzle geometry and the areas covered by the 45 degree n and 60 o UT radial and circumferential scans from both directions as shown in Figures 1 to 15 of the submittal for the three nozzles and verified that this coverage is the best that can be achieved practically without altering the nozzle geometries.
Since the coverage is more than 65 percent and the volume examined for all of the subject nozzle-to-head welds includes the most vulnerable locations for crack initiation based on stresses and environment (i.e., the weld and base material near the inside surface of the nozzles),
the NRC staff concluded that the coverage achieved is sufficient to detect any existing patterns of degradation.
Hence, it is reasonable to expect that if significant service-induced degradation had occurred, evidence would have been detected by the UT examinations that were performed.
This conclusion is supported by prior inspection results which showed no flaw indications.
- Finally, in addition to the examinations
- proposed, the affected welds are subject to the pressure testing requirements of the ASME Code,Section XI, which provides an independent means to evaluate structural integrity and leak tightness.
The NRC staff concludes that the licensee has acceptably demonstrated that the essentially 100 percent ASME Code-required examination requirement is impractical for these welds. Further, based on the above, the NRC staff concludes that there is reasonable assurance that the structural integrity and leak tightness of the subject welds will be maintained by the alternative examinations proposed.
Therefore, the NRC staff concludes that 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 could result if the requirements were imposed on the facility.
4.0 CONCLUSION
The NRC staff has reviewed the licensee's submittal and concludes that ASME Code examination coverage requirements are impractical for the subject welds, and imposition of the ASME Code requirements would create a burden on the licensee.
Accordingly, the NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(g)(5)(iii).
- Further, the NRC staff concludes that the examinations performed, as described in the application, provide reasonable assurance of the structural integrity and leak tightness of the subject welds. Therefore, the NRC staff grants relief for the subject examinations of the items contained in relief request NDE-PNS-U2, as requested, at DCPP-2 for the third 1 0-year lSI interval, which ends (nominally) on March 12, 2016. No alternative requirements beyond those specified in the relief request are being imposed by the NRC staff. 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.
Principal Contributor:
S. Sheng, NRR Date: May 14, 2014 E. Halpin If you have any questions, please contact the NRC Project Manager, Mr. Peter J. Bamford, at 301-415-2833 or via e-mail at Peter.Bamford@nrc.gov.
Docket No. 50-323
Enclosure:
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