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MONTHYEARML16123A3582016-05-0202 May 2016 NRR E-mail Capture - Acceptance Review - Request for Relief NDE-SIF-U1, Diablo Canyon Power Plant, Unit 1 Project stage: Acceptance Review 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 Project stage: Other 2016-05-02
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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
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
[Table view] Category:Safety Evaluation
MONTHYEARML24099A2192024-05-29029 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 ML23199A3122023-07-20020 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 2024-05-29
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Mr. Edward D. Halpin UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 27, 2016 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. 1 -RELIEF REQUEST NDE-SIF-U1 TO ALLOW USE OF ALTERNATE AMERICAN SOCIETY OF MECHANICAL ENGINEERS BOILER AND PRESSURE VESSEL CODE SECTION XI EXAMINATION REQUIREMENTS FOR THE THIRD INSERVICE INSPECTION INTERVAL (CAC NO. MF7552)
Dear Mr. Halpin:
By letter dated March 31, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 16091A238), Pacific Gas & Electric Company (the licensee) submitted relief request (RR) NDE-SIF-U1 for relief from the requirements set forth in American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI "Rules for lnservice Inspection of Nuclear Power Plant Components," for the Diablo Canyon Power Plant (DCPP), Unit 1, Class 2 seal injection filter pressure vessel welds. Specifically, the ASME Code requires that essentially 100 percent of each subject weld and adjacent base metal be volumetrically examined once during each inservice inspection ISi interval in accordance with the requirements of Appendix I, 1-2210. Pursuant to Title 10 of the Code of Federal Regulations (1 O CFR), paragraph 50.55a(g)(5)(iii), the licensee requested relief on the basis that meeting the Code requirement would be impractical for the facility.
The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the licensee's submittal and determined that the ASME Code examination coverage requirements for the subject seal injection filter shell-to-flange and shell-to-head welds are impractical and considered the burden upon the licensee if the ASME Code requirement was imposed. Accordingly, the NRC staff evaluated the licensee's submittal in accordance with the provisions set forth in 10 CFR 50.55a(g)(6)(i) and found that the licensee complied with the regulation.
Furthermore, the NRC staff concludes that the examinations performed by the licensee 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-SIF-U1, as requested for DCPP, Unit 1, for the third 10-year ISi interval, which ended on November 6, 2015. 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.
E. Halpin If you have any questions, please contact the Senior Project Manager, Balwant K. Singal, at 301-415-3016 or via e-mail at Balwant.Singal@nrc.gov.
Docket No. 50-275
Enclosure:
Safety Evaluation cc w/encl: Distribution via ListServ Sincerely, Robert J. Pascarelli, 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 NDE-SIF-U1 SEAL INJECTION FILTER VESSEL SHELL-TO-HEAD AND SHELL-TO-FLANGE WELD TO ALLOW USE OF ALTERNATE EXAMINATION VOLUME COVERAGE REQUIREMENTS PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON POWER PLANT. UNIT NO. 1 DOCKET NOS. 50-275
1.0 INTRODUCTION
By letter dated March 31, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 16091A238), Pacific Gas & Electric Company (the licensee) submitted relief request (RR) NDE-SIF-U1 for relief from the requirements set forth in American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI "Rules for lnservice Inspection of Nuclear Power Plant Components," for the Diablo Canyon Power Plant (DCPP), Unit 1, Class 2 seal injection filter pressure vessel welds. Specifically, the ASME Code requires that essentially 100 percent of each subject weld and adjacent base metal be volumetrically examined once during each inservice inspection (ISi) interval in accordance with the requirements of Appendix I, 1-2210. Pursuant to Title 10 of the Code of Federal Regulations (1 O CFR), paragraph 50.55a(g)(5)(iii), the licensee requested relief on the basis that meeting the Code requirement would be impractical for the facility.
2.0 REGULATORY EVALUATION
lnservice inspection of ASME Code Class 1, 2, and 3 components is to be performed in accordance with Section XI of the ASME Code and applicable addenda as a way to detect anomaly and degradation indications so that structural integrity of these components can be maintained.
lnservice inspection is required by 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).
The regulations in 10 CFR 50.55a(g)(5)(iii) state that the licensee must notify the NRC and submit information to support its determinations that conforming with an ASME Code requirement is impractical for its facility.
Determinations of impracticality in accordance with this section must be based on the demonstrated limitations experienced when attempting to comply with the Code requirements during the ISi interval for which the request is being submitted.
Enclosure Pursuant to 10 CFR 50.55a(g)(4), components (including supports) that are classified as ASME Code Class 1, Class 2, and Class 3 must meet the requirements, except design and access provisions and preservice examination requirements, set forth in Section XI of editions and addenda of the ASME Code, that become effective subsequent to editions specified in paragraphs (g)(2) and (3) of this section, 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 successive 120-month inspection intervals (following the initial 120-month inspection interval) must comply with the requirements in the latest edition and addenda of the ASME Code, which was incorporated by reference in 10 CFR 50.55a(a) 12 months before the start of the 120-month interval (or the optional ASME Code Cases listed in NRC Regulatory Guide 1.14 7, Revision 17, "lnservice Inspection Code Case Acceptability, ASME Section XI, Division 1," August 2014; ADAMS Accession No. ML 13339A689), subject to the conditions listed in 10 CFR 50.55a(b).
3.0 TECHNICAL
EVALUATION
- 3. 1 Affected Components The following table lists the two affected Unit 1, ASME Section XI, Code Class 2 seal injection filter pressure vessel welds that are addressed in the relief request. Both welds were examined in the DCPP Unit 1 19th refueling outage (1R19). Code Item Number Description Weld Number Category C-A C1.10 Seal Injection Filter Shell-to-Flange Weld GA C-A C1.20 Seal Injection Filter Shell-to-Head Weld GB 3.2 ASME Code Requirement In its letter dated March 31, 2016, the licensee stated that: ASME Section XI, Table IWC-2500-1, Category C-A, Item No. C1 .10 and Item No. C 1.20 each require that seal injection filter vessel welds be volumetrically examined once during each ISi interval.
Essentially 100 percent of the full volume of the weld and adjacent base material is to be examined in accordance with the requirements of Appendix I, 1-2210. The applicable examination volume is identified in Figure IWC-2500-1 and the examination is to be performed per the rules of ASME Section XI, Appendix 111, as supplemented by Table 1-2000-1.
The DCPP Unit 1 third interval ISi program is based on the 2001 Edition through 2003 Addenda of the ASME Code,Section XI. 3.3 Reason for the Request In its letter dated March 31, 2016, the licensee stated that, The Unit 1 seal injection filter vessel shell-to-head and shell-to-flange weld configurations are such that essentially 100 percent coverage of the ASME Code required examination volume from the outside diameter is not feasible, as determined during the third interval examinations conducted in the DCPP Unit 1 nineteenth refueling outage (1R19). 3.4 Licensee's Proposed Alternative and Basis The licensee proposed that performing the ultrasonic (UT) examinations to the maximum practical extent provides reasonable assurance that the structural integrity of the subject welds is maintained.
The licensee provided graphics and a detailed explanation as to why the DCPP Unit 1 seal injection filter shell-to-flange and shell-to-head weld configurations prevent examination of essentially 100 percent coverage of the ASME Code-required examination volume as determined during the third interval examinations conducted in the DCPP Unit 1 19th refueling outage (1R19), in support of the claim of impracticality.
For the shell-to-flange weld GA, the proximity of the weld to the transition in the flange creates geometric restrictions that prevents both axial examination from the flange side of the weld outward as well as scanning back from the weld with skewing during circumferential scans on the flange side. Additionally, examination of the full circumference of this weld was limited due to a nameplate and a support for the lid davit arm which are welded to the shell. Axial examination from the head side of the shell-to-head weld GB was limited due to the transition of the seal injection filter vessel to the curvature of the head which results in a loss of contact for the transducer and an accompanying change in sound angle. Furthermore, three support legs and an inlet nozzle that are welded to the vessel limit examination of the total circumference.
The licensee discussed the impracticality of obtaining additional coverage by referring to the difficulties in performing further outer and inner surface examinations.
Meeting the ASME Code requirement of "essentially 100 percent" coverage of the exam volume from the outer surface would require either replacement or redesign and rework of the seal injection filter vessel to move the shell-to-flange welds farther from the flange and head or eliminate the weld by integrally incorporating the flange into the shell. Furthermore, the welded supports and the inlet nozzle would require relocation.
Performing examinations from the inside of the seal injection filter would require accessing the 10-inch nominal diameter vessel below an external shielding structure and work in a high-contamination, high-risk, foreign material exclusion area. Additionally, an internal filter support structure limits access to the shell-to-head weld. 3.5 Duration of Proposed Relief Relief is requested for the DCPP, Unit 1, third ISi interval, which ended on November 6, 2015, coincident with the completion date of 1R19 in accordance with ASME Code,Section XI, Paragraph IWA-2430(d)(1).
3.6 NRC Staff Evaluation Section XI of the ASME Code requires essentially 100 percent volumetric examination of all seal injection filter shell-to-flange welds and adjacent base metal. The licensee made the claim that obtaining the volumetric requirements for the subject welds at DCPP Unit 1 was impractical.
Pursuant to 10 CFR 50.55a(g)(4), the licensee attributed the inability to achieve the required examinations to the geometry/configuration of the seal injection filter vessel. Therefore the NRC staff evaluated the licensee's relief request in accordance with 10 CFR 50.55a(g)(6)(i), which permits the NRC staff to grant such relief and impose such alternative requirements as it determines are authorized by law, will not endanger life or property or the common defense and security, and are 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.
Based on the licensee's assessment that obtaining essentially 100 percent examination volume coverage would ultimately require redesign and replacement of the entire seal injection filter vessel and considering the burden upon the licensee if the requirement were to be imposed, the NRC staff concluded that it is impractical for the licensee to comply with this ASME Code requirement.
In its letter dated March 31, 2016, the licensee provided Figures 1 through Figure 5 to further support the argument of impracticality.
Figure 1 provided a detailed schematic of the full seal injection filter layout. The Figures 2 and 3 focused on the aerial and side views of subject welds and surrounding appurtenances that precluded certain exam coverages.
Figures 4 and 5 provided detailed drawings of the subject welds and their surrounding base metals, along with an image representing full examination coverage as required by the ASME Code, and images of the actual coverages obtained via the axial and circumferential 60 degree longitudinal wave and 45 degree shear wave UT examinations.
Furthermore, the licensee included measurements and calculations to demonstrate that, from the combined average of the various UT exams, the licensee was able to obtain 55.4 and 52.4 percent volumetric coverage for welds GA and GB, respectively.
The licensee also noted that no reportable flaws were found during the examinations.
The NRC staff verified that the licensee achieved the maximum coverage practical without unnecessary alterations based on its evaluation of the licensee's schematics and calculations.
The licensee stated that the worst possible scenario would be a 360 degree circumferential crack of the weld which would result in a loss of seal injection water. In this case, the licensee would be able to isolate this seal injection filter manually and send water through the second redundant seal injection filter vessel. A flaw leading to this outcome would likely be detected under the examinations performed.
Furthermore the affected welds are also subject to the pressure testing requirements of the ASME Code,Section XI, Table IWC-2500-1, Examination Category C-H, which provides an independent means to evaluate structural integrity and leak tightness; no flaws were detected when these tests were performed.
Therefore, the NRC staff concludes that the coverage achieved is sufficient to detect any existing patterns of degradation. The NRC staff concludes that the licensee adequately demonstrated that the essentially 100 percent ASME Code-required examination requirement is impractical for the subject seal injection filter shell-to-flange and shell-to-head welds and surrounding base metal. Furthermore, based on the above, the NRC staff concludes that there is reasonable assurance that the structural integrity and leak tightness of the welds will be maintained by the examination coverage achieved.
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 reviewed the licensee's submittal and concludes that the ASME Code examination coverage requirements for the subject seal injection filter shell-to-flange and shell-to-head welds are impractical and considered the burden upon the licensee if the ASME Code requirement was imposed. Accordingly, the staff evaluated the licensee's submittal in accordance with the provisions set forth in 10 CFR 50.55a(g)(6)(i) and found that the licensee complied with the regulation.
Furthermore, the NRC staff concludes that the examinations performed by the licensee 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-SIF-U1, as requested for DCPP Unit 1 for the third 10-year ISi interval, which ended on November 6, 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:
Austin Young Date: July 27, 2016 E. Halpin If you have any questions, please contact the Senior Project Manager, Balwant K. Singal, at 301-415-3016 or via e-mail at Balwant.Singal@nrc.gov.
Docket No. 50-275
Enclosure:
Safety Evaluation cc w/encl: Distribution via ListServ DISTRIBUTION:
PUBLIC LPL4-1 R/F RidsACRS_MailCTR Resource RidsNrrDeEvib Resource RidsNrrDorlDpr Resource RidsNrrDorlLpl4-1 Resource RidsNrrLAJBurkhardt Resource RidsNrrPMDiabloCanyon Resource RidsRgn4MailCenter Resource JBowen, EDO RIV AYoung, NRR/DE/EVIB ADAMS Accession No. ML 16207 A397 Sincerely, /RA/ Robert J. Pascarelli, Chief Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
- SE via email dated July 6, 2016 OFFICE NRR/DORL/LPL4-1
/PM N RR/DORL/LPL4-1
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/BC NAME BSingal JBurkhardt JMcHale RPascarelli DATE 07/26/16 07/26/16 07/06/16 07/27/16 OFFICIAL RECORD COPY