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MONTHYEARNL-16-2382, License Amendment Request to Modify Approved 10 CFR 50.69 Categorization Process2017-06-22022 June 2017 License Amendment Request to Modify Approved 10 CFR 50.69 Categorization Process Project stage: Request ML17319A3252017-12-0404 December 2017 Audit Plan Regarding Incorporate Seismic Probabilistic Risk Assessment Into the 10 CFR 50.69 Categorization Process (CAC Nos. MF9861 and MF9862; EPID L-2017-LLA-0248) Project stage: Other ML17354A7822018-01-0505 January 2018 Request for Additional Information Incorporate Seismic Probabilistic Risk Assessment Into the 10 CFR 50.69 Categorization Process (CAC Nos. MF9861 and MF9862; EPID L-2017-LLA-0248) Project stage: RAI NL-18-0188, License Amendment Request to Incorporate Seismic Probabilistic Risk Assessment Into the 10 CFR 50.69 Categorization Process, Response to Request for Additional Information (RAIs 4-11)2018-02-21021 February 2018 License Amendment Request to Incorporate Seismic Probabilistic Risk Assessment Into the 10 CFR 50.69 Categorization Process, Response to Request for Additional Information (RAIs 4-11) Project stage: Response to RAI ML18054A0662018-03-0808 March 2018 Summary Report for NRC Audit for Vogtle Electric Generating Plant, Units 1 and 2, Amendment Request to Incorporate Seismic Probabilistic Risk Assessment Into 10 CFR 50.69 Categorization Process (CAC Nos. MF9861 and MF9862; EPID L-2017-LLA-0 Project stage: Other ML18079A9572018-03-28028 March 2018 Request for Additional Information Incorporate Seismic Probabilistic Risk Assessment Into the 10 CFR 50.69 Categorization Process (CAC Nos. MF9861 and MF9862; EPID L-2017-LLA-0248) Project stage: RAI NL-18-0597, Units 1 & 2, License Amendment Request to Incorporate Seismic Probabilistic Risk Assessment Into the 10 CFR 50.69 Categorization Process Response to Request for Additional Information (RAIs 3b-1, 8-1, & 9b-1)2018-04-26026 April 2018 Units 1 & 2, License Amendment Request to Incorporate Seismic Probabilistic Risk Assessment Into the 10 CFR 50.69 Categorization Process Response to Request for Additional Information (RAIs 3b-1, 8-1, & 9b-1) Project stage: Response to RAI NL-18-1043, License Amendment Request: Supplement to Request to Incorporate Seismic Probabilistic Risk Assessment Into the Categorization Process2018-08-0606 August 2018 License Amendment Request: Supplement to Request to Incorporate Seismic Probabilistic Risk Assessment Into the Categorization Process Project stage: Supplement ML18180A0622018-08-10010 August 2018 Issuance of Amendment Nos. 196 and 179 Regarding Application of the Seismic Probabilistic Risk Assessment Into the Previously Approved 10 CFR.50.69. Categorization Process Project stage: Approval 2018-03-28
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Category:Letter
MONTHYEARML24243A0072024-09-10010 September 2024 – Correction of Amendment Nos. 223 and 206 Regarding Revision to Technical Specifications to Adopt TSTF-339-A, Relocate Technical Specification Parameters to the COLR Consistent with WCAP-14483 NL-24-0337, Interim 10 CFR 21.21(a)(2) Report Regarding Operation Technology, Inc., ETAP Software Error in Transient Stability Program2024-09-0909 September 2024 Interim 10 CFR 21.21(a)(2) Report Regarding Operation Technology, Inc., ETAP Software Error in Transient Stability Program ML24102A2642024-09-0909 September 2024 – Exemption Request Regarding Final Safety Analysis Report Update Schedule (EPID L-2024-LLE-0013) - Letter ML24249A2942024-09-0606 September 2024 Correction of Amendment Nos. 218 and 201 Regarding Revision to Technical Specifications to Use Online Monitoring Methodology 05200025/LER-2024-002, (Vegp), Unit 3, Manual Reactor Protection System and Automatic Safeguards Actuation Due to an Unexpected Change in Position of a Main Feedwater Pump Minimum Flow Control Valve2024-09-0505 September 2024 (Vegp), Unit 3, Manual Reactor Protection System and Automatic Safeguards Actuation Due to an Unexpected Change in Position of a Main Feedwater Pump Minimum Flow Control Valve IR 05000424/20240052024-08-26026 August 2024 Updated Inspection Plan for Vogtle Electric Generating Plant, Units 1 and 2 - Report 05000424/2024005 and 05000425/2024005 ML24235A1952024-08-22022 August 2024 Updated Inspection Plan for Vogtle Electric Generating Plant, Units 3 and 4 - Report 05200025/2024005 and 05200026/2024005 IR 05000424/20244012024-08-15015 August 2024 4 - Security Baseline Inspection Report 05000424-2024401, 05000425-2024401, 05200025-2024402, and 05200026-2024403 - Cover Letter NL-24-0299, Exemption Request: Final Safety Analysis Report Update Schedule, Response to Request for Additional Information2024-08-14014 August 2024 Exemption Request: Final Safety Analysis Report Update Schedule, Response to Request for Additional Information 05000425/LER-2024-001, (Vegp), Unit 2, Manual Actuation of the Reactor Protection System Due to a Rod Control Fuse Opening Causing a Misaligned Shutdown Rod2024-08-0909 August 2024 (Vegp), Unit 2, Manual Actuation of the Reactor Protection System Due to a Rod Control Fuse Opening Causing a Misaligned Shutdown Rod ML24218A1842024-08-0707 August 2024 Examination Report and Cover Letter 05200026/LER-2024-001, (Vegp), Unit 4, Manual Reactor Protection System Actuation Due to Procedure Not Optimally Sequenced to Reset the Rapid Power Reduction Signal2024-08-0606 August 2024 (Vegp), Unit 4, Manual Reactor Protection System Actuation Due to Procedure Not Optimally Sequenced to Reset the Rapid Power Reduction Signal ML24212A1442024-08-0101 August 2024 Integrated Inspection Report 05200025/2024002 and 05200026/2024002 IR 05000424/20240022024-07-29029 July 2024 Integrated Inspection Report 05000424/2024002 and 05000425/2024002 IR 05000424/20244042024-07-26026 July 2024 Material Control and Accounting Program Inspection Report 05000424/2024404 and 05000425/2024404 (Cover Letter) NL-24-0282, License Amendment Request and Exemption Request: Remove Tier 1 and Tier 2* Requirements2024-07-25025 July 2024 License Amendment Request and Exemption Request: Remove Tier 1 and Tier 2* Requirements NL-24-0126, – Units 3 and 4, License Amendment Request: Changes to Technical Specification 3.7.6, Main Control Room Emergency Habitability System (Ves) Action a and SR 3.7.6.62024-07-25025 July 2024 – Units 3 and 4, License Amendment Request: Changes to Technical Specification 3.7.6, Main Control Room Emergency Habitability System (Ves) Action a and SR 3.7.6.6 ML24204A0722024-07-23023 July 2024 Issuance of Amendment No. 225, Regarding LAR to Revise TS 3.7.9 for a one-time Change to Support Nuclear Service Cooling Water Transfer Pump Repairs - Emergency Circumstances NL-24-0286, Emergency Request to Revise Technical Specification 3.7.9 for a One-Time Change to Support a Unit 1 Nuclear Service Cooling Water Transfer Pump Repair2024-07-20020 July 2024 Emergency Request to Revise Technical Specification 3.7.9 for a One-Time Change to Support a Unit 1 Nuclear Service Cooling Water Transfer Pump Repair NL-24-0261, 10 CFR 50.46 ECCS Evaluation Model Annual Report for 20232024-07-19019 July 2024 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2023 ML24191A4562024-07-19019 July 2024 Request for Relief and Alternative Requirements for Squib (Explosively Actuated) Valves First Test Interval ML24194A0342024-07-12012 July 2024 Review of the Refueling Outage 1R24 Steam Generator Tube Inspection Report ML24191A3792024-07-10010 July 2024 – Initial Test Program and Operational Programs Inspection Report 05200026/2024011 NL-24-0227, Proposed Inservice Inspection Alternative GEN-ISI-AL T-2024-03 for Pressurizer Welds in Accordance with 10 CFR 50.55a(z)(1)2024-07-0303 July 2024 Proposed Inservice Inspection Alternative GEN-ISI-AL T-2024-03 for Pressurizer Welds in Accordance with 10 CFR 50.55a(z)(1) NL-24-0234, Application to Revise Technical Specifications to Adopt TSTF-589, Eliminate Automatic Diesel Generator Start During Shutdown2024-06-28028 June 2024 Application to Revise Technical Specifications to Adopt TSTF-589, Eliminate Automatic Diesel Generator Start During Shutdown NL-24-0143, Proposed Alternative to Use ASME Code Case N-752, Risk-Informed Categorization and Treatment for Repair/ Replacement Activities in2024-06-27027 June 2024 Proposed Alternative to Use ASME Code Case N-752, Risk-Informed Categorization and Treatment for Repair/ Replacement Activities in NL-24-0087, License Amendment Request: Changes to Technical Specification 3.7.6, Main Control Room Emergency Habitability System (Ves) Air Storage Tanks2024-06-21021 June 2024 License Amendment Request: Changes to Technical Specification 3.7.6, Main Control Room Emergency Habitability System (Ves) Air Storage Tanks NL-24-0201, Proposed Inservice Inspection Alternative GEN-ISI-ALT-2024-002 for Steam Generator Welds in Accordance with 10 CFR 50.55a(z)(1)2024-06-18018 June 2024 Proposed Inservice Inspection Alternative GEN-ISI-ALT-2024-002 for Steam Generator Welds in Accordance with 10 CFR 50.55a(z)(1) NL-24-0243, Registration of Spent Fuel Cask Use2024-06-18018 June 2024 Registration of Spent Fuel Cask Use ML24163A0632024-06-12012 June 2024 2024 Licensed Operator Re-qualification Inspection Notification Letter Vogtle, Units 3 & 4 ML24155A1772024-06-0505 June 2024 Regulatory Audit in Support of Review of the LAR to Revise Emergency Diesel Generator Frequency and Voltage Ranges for Technical Specification 3.8.1, Surveillance Requirements NL-24-0202, SNC Response to Regulatory Issue Summary 2024-01: Preparation and Scheduling of Operator Licensing Examinations2024-05-24024 May 2024 SNC Response to Regulatory Issue Summary 2024-01: Preparation and Scheduling of Operator Licensing Examinations ML24141A0482024-05-17017 May 2024 EN 56958_1 Ametek Solidstate Controls, Inc ML24094A1402024-05-16016 May 2024 Staff Response to Request for Revision to NRC Staff Assessment of Updated Seismic Hazard Information and Latest Understanding of Seismic Hazards at the Vogtle Plant Site Following the NRC Process for the Ongoing Assessment of Natural Hazard ML24130A2412024-05-13013 May 2024 Integrated Inspection Report 05200025/2024001 and 05200026/2024001 ML24120A1812024-05-13013 May 2024 Request for Withholding Information from Public Disclosure Responses to NRC Request for Additional Information for Refueling Outage IR24 Steam Generator Tube Inspection Report – Enclosure 2 ML24101A2112024-05-11011 May 2024 Expedited Issuance of Amendment No. 198 Change to Technical Specification 5.5.13, Ventilation Filter Testing Program (VFTP) NL-24-0191, Annual Radiological Environmental Operating Reports for 20232024-05-10010 May 2024 Annual Radiological Environmental Operating Reports for 2023 ML24127A2372024-05-0909 May 2024 Initial Test Program and Operational Programs Inspection Report 05200026/2024010 NL-24-0194, Revised Request for Relief and Alternative Requirements for Squib Valves First Test Interval (V34-IST-ALT-03-R1)2024-05-0707 May 2024 Revised Request for Relief and Alternative Requirements for Squib Valves First Test Interval (V34-IST-ALT-03-R1) IR 05000424/20244032024-05-0101 May 2024 Cyber Security Inspection Report 05000424/2024403 and 05000425/2024403 Public ML24120A2832024-04-30030 April 2024 Project Manager Reassignment NL-24-0170, Responses to Second Round NRC Request for Additional Information for Refueling Outage 1 R24 Steam Generator Tube Inspection Report2024-04-25025 April 2024 Responses to Second Round NRC Request for Additional Information for Refueling Outage 1 R24 Steam Generator Tube Inspection Report NL-24-0165, Annual Non-Radiological Environmental Operating Reports and Annual Radioactive Effluent Release Reports for 20232024-04-25025 April 2024 Annual Non-Radiological Environmental Operating Reports and Annual Radioactive Effluent Release Reports for 2023 IR 05000424/20240012024-04-23023 April 2024 –Integrated Inspection Report 05000424/2024001 and 05000425/2024001 NL-24-0154, Preservice Inspection Progam Owners Activity Report2024-04-16016 April 2024 Preservice Inspection Progam Owners Activity Report ML24030A9092024-04-10010 April 2024 Issuance of Amendment Nos. 224 and 207, Regarding Revision to Technical Specification 3.4.14 (Reactor Coolant System) Pressure Isolation Valve Leakage Surveillance Requirement 3.4.14.1 ML24079A0062024-04-10010 April 2024 – Proposed Alternative to the Requirements of ASME Code of Operation and Maintenance of Nuclear Power Plants for Pressure Isolation Valve Testing Frequency ML24096A1322024-04-0505 April 2024 Individual Notice of Consideration of Issuance of Amendment to Facility Operating License and Opportunity for Hearing and Order (EPID L-2024-LLA-0043) - Letter NL-24-0128, License Amendment Request: Technical Specification 5.5.13, Ventilation Filter Testing Program (VFTP) Testing Frequency2024-04-0404 April 2024 License Amendment Request: Technical Specification 5.5.13, Ventilation Filter Testing Program (VFTP) Testing Frequency 2024-09-09
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML24199A1592024-07-17017 July 2024 NRR E-mail Capture - Request for Additional Information - Vogtle 3 and 4 - Exemption for the Requirements in 10 CFR 50.71 Pertaining to the Submittal of Updated Final Safety Analysis Report ML24100A7842024-04-0909 April 2024 NRR E-mail Capture - for Your Action - Request for Additional Information (RAI) - Vogtle, Units 3 and 4 - Alternative Request for Explosively Actuated Valves (L-2023-LLR-0016) ML24072A3982024-03-12012 March 2024 NRR E-mail Capture - for Your Action - Second Round Request for Additional Information (RAI) - Vogtle, Unit 1 - SG Tube Inspection Report - 1R24 (L-2023-LRO-0067) ML23341A2042024-01-12012 January 2024 Request for Additional Information Exemption Requests for Physical Barriers (EPID L-2023-LLE-0018 & L-2023-LLE-0021) ML23342A0802023-12-0808 December 2023 NRR E-mail Capture - Request for Additional Information (RAI) - Vogtle, Unit 1 - Review of SG Tube Inspection Report for Refueling Outage 24 (L-2023-LRO-0067) ML23279A2082023-10-0505 October 2023 Issuance of Formal RAIs - Vogtle, Units 1 and 2 - Proposed LAR and Proposed Alternative Request to Revise TS 3.4.14.1 and IST ALT-VR-02 (EPIDs L-2023-LLA-0061 and L-2023-LLR-0023) ML23257A2092023-09-14014 September 2023 NRR E-mail Capture - Formal Issuance of 2nd Round RAIs for Surry Units 1&2 and North Anna Units 1&2 Emergency Plans LAR ML23248A3482023-09-0505 September 2023 NRR E-mail Capture - for Your Action - Request for Additional Information (RAI) 6 - Vogtle - TSTF-339 LAR (L-2023-LLA-0053) ML23243A9862023-08-31031 August 2023 NRR E-mail Capture - Draft RAIs for EP Staff Augmentation Times LAR (L-2022-LLA-0166) ML23188A1512023-08-0909 August 2023 Round 2 RAIs for LAR 22-002 TS 3.8.3 Inverters-Operating, Completion Time Extension ML23200A0112023-07-18018 July 2023 Document Request for Vogtle Unit 3 RP Inspection ML23198A1552023-07-17017 July 2023 NRR E-mail Capture - for Your Action - Request for Additional Information (RAI) - Hatch, Farley, and Vogtle, Units 1 and 2 Quality Assurance Topical Report (QATR) Submittal Dated June 15, 2023 ML23193A7832023-07-12012 July 2023 NRR E-mail Capture - for Your Action - Request for Additional Information (RAI) - Vogtle - TSTF-339 LAR (L-2023-LLA-0053) ML23065A0612023-03-0303 March 2023 NRR E-mail Capture - for Your Action - Request for Additional Information (RAI) 14 - Vogtle - AST, TSTF-51, TSTF-471, and TSTF-490 LAR (L-2022-LLA-0096) ML23006A0882023-01-0606 January 2023 NRR E-mail Capture - for Your Action - Request for Additional Information (RAI) - Vogtle - Accident Source Term (Ast), TSTF-51, TSTF-471, and TSTF-490 LAR (L-2022-LLA-0096) ML22348A0332022-12-13013 December 2022 NRR E-mail Capture - for Your Action - RAI - Vogtle, Unit 2 - Steam Generator Tube Inspection Report (L-2022-LRO-0120) ML22192A1042022-08-0101 August 2022 Acceptance of Requested Licensing Action Amendment Request Application to Allow Use of Lead Test Assemblies for Accident Tolerant Fuel with Request for Additional Information ML22157A0902022-06-0606 June 2022 NRR E-mail Capture - RAIs - Vogtle, Unit 1 - Refueling Outage (RFO) 1R23 Steam Generator (SG) Tube Inspection Report ML22104A1312022-04-14014 April 2022 NRR E-mail Capture - Request for Additional Information - Farley and Vogtle - Relocate Piping Inspection License Amendment Request (L-2021-LLA-0235) ML22026A3942022-01-26026 January 2022 NRR E-mail Capture - Request for Additional Information - Vogtle, Units 1 and 2, TS 3.7.2 LAR ML21350A1032021-12-16016 December 2021 NRR E-mail Capture - Request for Additional Information - Vogtle, Units 1 and 2, TS 3.7.2 LAR ML21321A3762021-11-15015 November 2021 NRR E-mail Capture - Request for Additional Information - Vogtle, Units 1 and 2, TS 3.7.2 LAR ML21075A0032021-03-12012 March 2021 Emergency Preparedness Exercise Inspection Request for Information for - Brunswick, Catawba, North Anna, Oconee, Vogtle 1 & 2 ML21033B1072021-02-0202 February 2021 NRR E-mail Capture - RAI - Vogtle Unit 1 - SG Report (L-2020-LRO-0059) ML20338A1512020-12-0303 December 2020 NRR E-mail Capture - RAIs for Vogtle GSI-191 LAR (L-2020-LLA-0182) ML20325A0432020-11-20020 November 2020 NRR E-mail Capture - for Your Review - Draft RAIs for Vogtle GSI-191 LAR (L-2020-LLA-0182) ML20297A3052020-10-22022 October 2020 NRR E-mail Capture - RAIs for Vogtle Relief Request - EPRI Report (L-2020-LLR-0109) ML20293A0752020-10-14014 October 2020 NRR E-mail Capture - RAIs for SNC Fleet EP LAR (L-2020-LLA-0150 and L-2020-LLA-0151) ML20149K6252020-05-27027 May 2020 NRR E-mail Capture - RAIs for SNC Fleet Fire Protection Exemption Requests ML19263A6432019-09-19019 September 2019 NRR E-mail Capture - RAI - Vogtle End State License Amendment Request (LAR) to Revise the Technical Specifications (Tss) for Vogtle, Units 1 and 2 (L-2019-LLA-0148) ML19156A1872019-06-0505 June 2019 NRR E-mail Capture - Request for Additional Information (RAI) for Vogtle Unit 2 Core Operating Limits Report, Cycle 21 ML19105B1632019-04-15015 April 2019 NRR E-mail Capture - Request for Additional Information (RAI) for Voglte TSTF-412 Adoption LAR (L-2018-LLA-0731) ML18355A4772019-01-0404 January 2019 Request for Additional Information Revise TS 5.2.2.g and Update Emergency Plan Minimum On-Shift Staff Tables ML18337A4032018-12-0606 December 2018 Request for Additional Information Revise Technical Specification 5.2.2.G and Updating Emergency Plan Minimum On-Shift Staff Tables ML18236A4452018-08-30030 August 2018 Review of Response to RAI License Amendment Request for Approval to Utilize the Tornado Missile Risk Evaluator to Analyze Tornado Missile Protection Non-Conformances ML18227A0222018-08-15015 August 2018 Notification of Inspection and Request for Information ML18225A3362018-08-13013 August 2018 NRR E-mail Capture - Request for Additional Information Regarding Relief Request VEGP-ISI-RR-03 ML18197A0602018-07-13013 July 2018 Us NRC Final RAI No. 1 for Vogtle 3 and 4 LAR-18-015, Fire Protection System Non-Safety Cable Spray Removal ML18197A1882018-07-13013 July 2018 Us NRC Final Request for Additional Information (Final RAI) No. 4 on Vogtle LAR-17-024, Technical Specification Updates for Reactivity Controls and Other Miscellaneous Changes ML18197A1052018-07-13013 July 2018 Us NRC Final Request for Additional Information (Final RAI) No. 1 on Vogtle 3 and 4 LAR-17-043, Containment Pressure Analysis ML18192B7692018-07-11011 July 2018 Us NRC Draft Request for Additional Information (Draft RAI) No. 4 on Vogtle LAR-17-024, Technical Specification Updates for Reactivity Controls and Other Miscellaneous Changes ML18192C0782018-07-11011 July 2018 RAI (LAR 18-009) - Vogtle Electric Generating Plant, Unit 3 and 4 ML18136A4972018-06-0101 June 2018 Request for Additional Information, License Amendment Request to Incorporate Tornado Missile Risk Evaluator Methodology Into Licensing Basis ML18109A1152018-05-0101 May 2018 Request for Additional Information ML18079A9572018-03-28028 March 2018 Request for Additional Information Incorporate Seismic Probabilistic Risk Assessment Into the 10 CFR 50.69 Categorization Process (CAC Nos. MF9861 and MF9862; EPID L-2017-LLA-0248) ML18058A0812018-02-27027 February 2018 Enclosurequest for Additional Information(Rai for Review of Southern Nuclear Operating Company'S Decommissioning Funding Plan Updates for Joseph M. Farley,Unit 1 and 2;Edwin I. Hatch,Units 1 and 2; and Vogtle Electric Generating Plant, Unit ML18030B0622018-02-0808 February 2018 Request for Additional Information Reverse Technical Specification 5.5.17 for Permanent Extension of Type a and Type C Leak Rate Test Frequencies (CAC Nos. MG0240, MG0241; EPID L-2017-LLA-0295) ML17355A1012018-01-11011 January 2018 Request for Additional Information (CAC Nos. MF9685 and MF9686; EPID L-2017-TOP-0038) ML17354A7822018-01-0505 January 2018 Request for Additional Information Incorporate Seismic Probabilistic Risk Assessment Into the 10 CFR 50.69 Categorization Process (CAC Nos. MF9861 and MF9862; EPID L-2017-LLA-0248) ML17318A0352017-11-22022 November 2017 Request for Additional Information 2024-07-17
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. James J. Hutto Regulatory Affairs Director Southern Nuclear Operating Co., Inc. P.O. Box 1295, Bin 038 Birmingham, AL 35201-1295 March 28, 2018
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2-REQUEST FOR ADDITIONAL INFORMATION RE: INCORPORATE SEISMIC PROBABILISTIC RISK ASSESSMENT INTO THE 10 CFR 50.69 CATEGORIZATION PROCESS (CAC NOS. MF9861 AND MF9862; EPID L-2017-LLA-0248)
Dear Mr. Hutto:
By letter dated June 22, 2017, the Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request regarding the Vogtle Electric Generating Plant, Units 1 and 2 (VEGP). The proposed amendment would modify the licensing basis to implement a change to the approved voluntary implementation of the provisions of Title 10 of the Code of Federal Regulations (10 CFR), Part 50.69, "Risk-informed categorization and treatment of structures, systems, and components for nuclear power reactors." The proposed amendment would incorporate the use of the VEGP seismic probabilistic risk assessment into the previously approved 10 CFR 50.69 categorization process. The Nuclear Regulatory Commision (NRC) staff issued a request for additional information by letter dated January 5, 2018. SNC responed by letters dated February 6 and February 21, 2018. The NRC staff has reviewed the responses and has determined that additional information is needed for the staff to complete its evaluation.
During a clarification call on March 28, 2018, Mrs. Burns agreed that SNC respond within 30 days of the date of this letter. The NRC staff's review is continuing and further requests for information may be developed.
Docket Nos. 50-424 and 50-425
Enclosure:
Request for Additional Information cc w/enclosure:
Listserv Sincerely, Michael Orenak, Project Manager Plant Licensing Branch, 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST INCORPORATE SEISMIC PROBABILISTIC RISK ASSESSMENT INTO 10 CFR 50.69 CATEGORIZATION PROCESS SOUTHERN NUCLEAR OPERA TING COMPANY, INC. VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 DOCKET NOS. 50-424 AND 50-425 By letter dated June 22, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 17173A875), the Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) regarding the Vogtle Electric Generating Plant, Units 1 and 2 (VEGP). The proposed amendment would modify the licensing basis to implement a change to the approved voluntary implementation of the provisions of Title 10 of the Code of Federal Regulations (10 CFR), Part 50.69, "Risk-informed categorization and treatment of structures, systems, and components for nuclear power reactors." The proposed amendment would incorporate the use of the VEGP seismic probabilistic risk assessment (SPRA) into the previously approved 10 CFR 50.69 categorization process. The U.S. Nuclear Regulatory Commission (NRC) staff issued a request for additional information (RAI) by letter dated January 5, 2018 (ADAMS Accession No. ML 17354A782).
SNC responded by letters dated February 6, 2018 (ADAMS Accession No. ML 180378121), and February 21, 2018 (ADAMS Accession No. ML 180528342).
The NRC staff has reviewed the responses and has determined that additional information is needed for the staff to complete its evaluation.
RAI 3b-1 In letter dated January 5, 2018, the NRC requested in RAI 3b that the licensee demonstrate how the limitations and conditions in the NRC staff's safety evaluation for PWROG-14001-P, Revision 1, "PRA Model for the Generation Ill Westinghouse Shut-Down Seal," (ADAMS Accession No. ML 17200C876) are being met. The licensee's response stated, in part, that the Limitation and Condition 2 ( demonstration of seal operation subsequent to exceedance of a particular cold leg temperature) is addressed "probabilistically" in the VEGP SPRA but did not provide supporting information.
It is, therefore, not apparent how the licensee addressed Limitation and Condition 2 probabilistically.
Furthermore, the licensee's response does not describe whether and how the VEGP SPRA addresses the impact of asymmetric reactor coolant system (RCS) cooling on seal operation.
- i. Please describe how the VEGP SPRA addresses Limitation and Condition 2 "probabilistically".
Enclosure ii. Please discuss how the VEGP SPRA addresses the impact of asymmetric RCS cooling on seal operation.
RAI 8-1 In RAI Ba, the NRC requested to justify how the required risk sensitivity study outlined in Section 8 of Nuclear Energy Institute (NEI) 00-04, "10 CFR 50.69 SSC [Structures, Systems, and Components]
Categorization Guideline," dated July 2005 (ADAMS Accession No. ML052910035), will be performed for categorization using the SPRA. In its response to RAI Ba, the licensee states that the risk sensitivity study is not intended to be mechanistic and is a test to determine that an adequate margin to risk acceptance guidelines exist. Furthermore, the response stated that no changes other than that the factor of three change in unreliability and unavailability for low safety significance (LSS) components is required, because the factor of three increase addresses "any failure mechanism" of the modeled component.
The response to RAI 8b also states that the validity of modeling inputs would be maintained by periodic updates to the SPRA model. The responses to RAls Ba and 8b appear to justify keeping the seismic capacity of LSS components unchanged as part of the risk sensitivity study outlined in Section 8 of NEI 00-04. It appears that the proposed approach to performing the risk sensitivity study for categorization using the SPRA may not be sufficient to ensure that an adequate margin to risk guidelines exist if seismic capacities are affected, specifically when components do not have associated random failures or seismic failures dominate the random failures.
Please describe how the risk sensitivity study approach addresses the potential impact on seismic capacities.
Alternatively, please discuss why seismic capacities will not be affected by the categorization program such that changing the seismic capacity of LSS components as a part of the risk sensitivity study described in Section 8 of NEI 00-04 analysis would not be warranted.
RAI 9b-1 In RAI 9b, the NRC requested that the licensee describe how the SPRA importance measures will be used to calculate the integrated importance measures and justify any impact of the approach for calculating the SPRA importance measures on the integral assessment.
The licensee's response stated that the formulae in NEI 00-04 for integrated importance measures will be used to "combine the seismic importance measures with the internal events and fire importance measures." It is not apparent from the licensee's response and the NEI 00-04 guidance how the integrated importance measures are calculated for certain SPRA basic events that may not align with basic events in other PRA models. Examples of such SPRA basic events include SPRA basic events that are specific to the SPRA model or SPRA basic events that represent a subcomponent modeled within the boundary of an internal events PRA component.
Please describe and justify how the integrated importance measures are calculated for SPRA basic events that may not align with basic events in other PRA models.
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 -REQUEST FOR ADDITIONAL INFORMATION RE: INCORPORATE SEISMIC PROBABILISTIC RISK ASSESSMENT INTO THE 10 CFR 50.69 CATEGORIZATION PROCESS (CAC NOS. MF9861 AND MF9862; EPID L-2017-LLA-0248)
DATED MARCH 28, 2018 DISTRIBUTION:
PUBLIC PM Reading File RidsAcrsAcnw_MailCTR Resource RidsNrrDorlLpl2-1 Resource RidsNrrLAKGoldstein Resource RidsNrrPMVogtle Resource RidsNrrDraAplb Resource RidsNrrDeSCPB Resource RidsRgn2MailCenter Resource JBettle, NRR DNold, NRR CTilton, NRR THilsmeier, NRR ADriver, NRR ADAMS Accession No. ML 18079A957 OFFICE DORL/LPL2-1
/PM NAME MOrenak (SWilliams for) DATE 03/22/18 OFFICE DORL/LPL2-1/BC NAME MMarkley DATE 03/23/18 DORL/LPL2-1
/LA KGoldstein 03/20/18 DORL/LPL2-1
/PM MOrenak (SWilliams for) 03/28/18 OFFICIAL RECORD COPY *Via e-mail DRA/APLA/ABC*
CFong 03/19/18