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MONTHYEARNMP2L2706, License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b.2019-10-31031 October 2019 License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b. Project stage: Request ML19339E8542019-12-0505 December 2019 Supplemental Information Needed for Acceptance of Requested Licensing Action Adoption of Risk-Informed Completion Times Project stage: Acceptance Review NMP2L2718, Supplemental Information No.1 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22019-12-12012 December 2019 Supplemental Information No.1 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 Project stage: Supplement ML20023B1622020-01-21021 January 2020 Acceptance of Requested Licensing Action Use of Risk-Informed Completion Times Project stage: Acceptance Review ML20037B6542020-02-0606 February 2020 Audit Plan Regarding License Amendment Request to Implement Risk-Informed Extended Completion Times 50-410 (L-2019-LLA-0234) Project stage: Other ML20094J1562020-04-22022 April 2020 Audit Plan Supplement in Support of Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times Project stage: Other ML20213A9352020-07-30030 July 2020 Request for Additional Information Review of License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times Project stage: RAI NMP2L2739, Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22020-08-28028 August 2020 Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 Project stage: Request ML20246G6362020-09-0202 September 2020 Request for Additonal Information to Support Review of License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times Project stage: Approval ML20248H5192020-09-28028 September 2020 Changes to Draft Request for Additional Information Regarding Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times Project stage: Draft RAI ML20272A2802020-09-28028 September 2020 Withdrawal and Replacement of Request for Additional Information to Support Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times Project stage: RAI ML20273A2372020-09-28028 September 2020 Request for Additional Information Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times Project stage: RAI NMP2L2745, Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22020-10-0202 October 2020 Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 Project stage: Request NMP2L2746, Supplemental Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22020-10-0202 October 2020 Supplemental Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 Project stage: Supplement NMP2L2749, Responses to Request for Additional Information Questions 17 and 26 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Rev. 22020-10-22022 October 2020 Responses to Request for Additional Information Questions 17 and 26 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Rev. 2 Project stage: Response to RAI ML20351A1642020-12-15015 December 2020 Request for Additional Information Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times Project stage: RAI NMP2L2754, Responses to Request for Additional Information Questions 27 and 28 to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22021-01-0707 January 2021 Responses to Request for Additional Information Questions 27 and 28 to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 Project stage: Response to RAI ML21082A2212021-04-29029 April 2021 Issuance of Amendment No. 186, Adoption of TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4B Project stage: Approval 2020-02-06
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Category:Letter type:NMP
MONTHYEARNMP1L3570, Supplemental Information Letter - Revision to the Technical Specifications Design Features Sections to Remove the Nine Mile 3 Nuclear Project, LLC, Designation2024-02-0101 February 2024 Supplemental Information Letter - Revision to the Technical Specifications Design Features Sections to Remove the Nine Mile 3 Nuclear Project, LLC, Designation NMP1L3569, CFR 50.46 Annual Report2024-01-26026 January 2024 CFR 50.46 Annual Report NMP1L3566, Radiological Emergency Plan Document Revision. Includes EP-AA-1013, Revision 10, Radiological Emergency Plan Annex for Nine Mile Point Station2023-12-14014 December 2023 Radiological Emergency Plan Document Revision. Includes EP-AA-1013, Revision 10, Radiological Emergency Plan Annex for Nine Mile Point Station NMP1L3564, Supplemental Response to Part 73 Exemption Request - Withdrawal of Request for Exemption from 10 CFR 73, Subpart B, Preemption Authority Requirements2023-12-0707 December 2023 Supplemental Response to Part 73 Exemption Request - Withdrawal of Request for Exemption from 10 CFR 73, Subpart B, Preemption Authority Requirements NMP1L3563, Submittal of Relief Request I5R-12, Revision 0, Concerning the Installation of a Full Structural Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208)2023-12-0404 December 2023 Submittal of Relief Request I5R-12, Revision 0, Concerning the Installation of a Full Structural Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208) NMP1L3557, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-11-22022 November 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation NMP1L3554, Submittal of Revision 28 to the Final Safety Analysis Report (Updated), Fire Protection Design Criteria Document, 10CFR50.59 Evaluation Summary Report, 10CFR54.37(b) Aging Management Review, and Technical Specifications with Revised Bases2023-10-0606 October 2023 Submittal of Revision 28 to the Final Safety Analysis Report (Updated), Fire Protection Design Criteria Document, 10CFR50.59 Evaluation Summary Report, 10CFR54.37(b) Aging Management Review, and Technical Specifications with Revised Bases C NMP2L2851, Relief Request Associated with Successive Inspections for Generic Letter 88-01 / BWRVIP-75-A Augmented Examinations2023-08-25025 August 2023 Relief Request Associated with Successive Inspections for Generic Letter 88-01 / BWRVIP-75-A Augmented Examinations NMP1L3534, License Amendment Request - Revision to the Technical Specifications Design Features Sections to Remove the Nine Mile 3 Nuclear Project, LLC, Designation2023-08-18018 August 2023 License Amendment Request - Revision to the Technical Specifications Design Features Sections to Remove the Nine Mile 3 Nuclear Project, LLC, Designation NMP1L3545, Supplemental Information Letter to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 and 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems .2023-08-0404 August 2023 Supplemental Information Letter to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 and 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems . NMP1L3544, Fifth Inservice Inspection Interval, First Inservice Inspection Period 2023 Owner'S Activity Report for RFO-27 Inservice Examinations2023-07-14014 July 2023 Fifth Inservice Inspection Interval, First Inservice Inspection Period 2023 Owner'S Activity Report for RFO-27 Inservice Examinations NMP2L2846, Nine Mire Point Nuclear Station, Units 1 and 2, General License 30-day Cask Registration Notifications2023-07-0505 July 2023 Nine Mire Point Nuclear Station, Units 1 and 2, General License 30-day Cask Registration Notifications NMP1L3539, Day Commitment Response - Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208)2023-06-0909 June 2023 Day Commitment Response - Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208) NMP1L3523, Annual Radioactive Environmental Operating Report2023-05-12012 May 2023 Annual Radioactive Environmental Operating Report NMP1L3522, Independent Spent Fuel Storage Installation (ISFSI) - 2022 Radioactive Effluent Release Report2023-04-30030 April 2023 Independent Spent Fuel Storage Installation (ISFSI) - 2022 Radioactive Effluent Release Report NMP1L3525, Core Operating Limits Report2023-04-19019 April 2023 Core Operating Limits Report NMP1L3526, Submittal of Emergency Relief Request I5R-14 Concerning a Proposed Alternative Associated with N2E Safe End-to-Nozzle Dissimilar Metal Weld Repair with Laminar Indication2023-04-13013 April 2023 Submittal of Emergency Relief Request I5R-14 Concerning a Proposed Alternative Associated with N2E Safe End-to-Nozzle Dissimilar Metal Weld Repair with Laminar Indication NMP1L3520, Supplemental Information for License Amendment Request Application to Partially Adopt Technical Specification Task Force (TSTF) Traveler TSTF-568, Revision 22023-04-0404 April 2023 Supplemental Information for License Amendment Request Application to Partially Adopt Technical Specification Task Force (TSTF) Traveler TSTF-568, Revision 2 NMP1L3519, Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208)2023-03-30030 March 2023 Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208) NMP1L3516, Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208)2023-03-29029 March 2023 Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208) NMP1L3517, Proposed Alternative Associated with a Weld Overlay Repair to the Torus2023-03-29029 March 2023 Proposed Alternative Associated with a Weld Overlay Repair to the Torus NMP1L3518, Proposed Alternative to Utilize Specific Provisions of Code Case N-716-3, Alternative Classification and Examination Requirements Section XI, Division 12023-03-29029 March 2023 Proposed Alternative to Utilize Specific Provisions of Code Case N-716-3, Alternative Classification and Examination Requirements Section XI, Division 1 NMP1L3515, Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208)2023-03-27027 March 2023 Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208) NMP1L3513, Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208)2023-03-24024 March 2023 Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208) NMP1L3499, CFR 50.46 Annual Report2023-01-27027 January 2023 CFR 50.46 Annual Report NMP1L3482, License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b2022-12-15015 December 2022 License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b NMP1L3486, Radiological Emergency Plan Document Revision2022-12-15015 December 2022 Radiological Emergency Plan Document Revision NMP1L3484, Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Reatment of Structures, Systems and Components for Nuclear Power Reactors2022-12-15015 December 2022 Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Reatment of Structures, Systems and Components for Nuclear Power Reactors NMP1L3485, Proposed Alternative Associated with a Weld Overlay Repair to the Torus2022-12-0808 December 2022 Proposed Alternative Associated with a Weld Overlay Repair to the Torus NMP2L2823, Supplemental Information for License Amendment Request Revise Surveillance Requirements to Reduce Excessive Fast Starting of Emergency Diesel Generators2022-10-28028 October 2022 Supplemental Information for License Amendment Request Revise Surveillance Requirements to Reduce Excessive Fast Starting of Emergency Diesel Generators NMP1L3481, Constellation Energy Generation, LLC, 10 CFR 50, Appendix E - Development of Evacuation Time Estimates2022-09-15015 September 2022 Constellation Energy Generation, LLC, 10 CFR 50, Appendix E - Development of Evacuation Time Estimates NMP1L3477, License Amendment Request - Application to Partially Adopt Technical Specification Task Force (TSTF) Traveler TSTF-568, Revision 2, Revise Applicability of BWR/4 TS 3.6.2.5 and TS 3.6.3.2, to Revise.2022-08-12012 August 2022 License Amendment Request - Application to Partially Adopt Technical Specification Task Force (TSTF) Traveler TSTF-568, Revision 2, Revise Applicability of BWR/4 TS 3.6.2.5 and TS 3.6.3.2, to Revise. NMP1L3478, Response to Request for Additional Information - Relief Request Associated with Pump Periodic Verification Tests of Core Spray System Pumps2022-08-0505 August 2022 Response to Request for Additional Information - Relief Request Associated with Pump Periodic Verification Tests of Core Spray System Pumps NMP1L3469, Constellation Energy Company, LLC, Request for Use of Honeywell Mururoa V4F1 R Supplied Air Suits2022-06-30030 June 2022 Constellation Energy Company, LLC, Request for Use of Honeywell Mururoa V4F1 R Supplied Air Suits NMP1L3467, License Amendment Request - Revision to Alternative Source Term Calculation for Main Steam Isolation Valve (MSIV) Leakage and Non-MSIV Leakage2022-06-29029 June 2022 License Amendment Request - Revision to Alternative Source Term Calculation for Main Steam Isolation Valve (MSIV) Leakage and Non-MSIV Leakage NMP1L3465, Independent Spent Fuel Storage Installation - General License 30-day Cask Registration Notifications2022-06-17017 June 2022 Independent Spent Fuel Storage Installation - General License 30-day Cask Registration Notifications NMP1L3462, Independent Spent Fuel Storage Installation, General License 30-day Cask Registration Notifications2022-06-0909 June 2022 Independent Spent Fuel Storage Installation, General License 30-day Cask Registration Notifications NMP2L2799, License Amendment Request - Revise Surveillance Requirements to Reduce Excessive Fast Starting of Emergency Diesel Generators2022-05-24024 May 2022 License Amendment Request - Revise Surveillance Requirements to Reduce Excessive Fast Starting of Emergency Diesel Generators NMP2L2811, Fourth Inservice Inspection Interval, Second Inservice Inspection Period 2022 Owner'S Activity Report for RFO-18 Inservice Examinations2022-05-13013 May 2022 Fourth Inservice Inspection Interval, Second Inservice Inspection Period 2022 Owner'S Activity Report for RFO-18 Inservice Examinations NMP1L3459, 2021 Annual Radiological Environmental Operating Report2022-05-0808 May 2022 2021 Annual Radiological Environmental Operating Report NMP1L3457, 2021 Radioactive Effluent Release Report for Nine Mile Point Units 1 and 22022-04-30030 April 2022 2021 Radioactive Effluent Release Report for Nine Mile Point Units 1 and 2 NMP2L2805, Annual Environmental Operating Report2022-04-23023 April 2022 Annual Environmental Operating Report NMP2L2807, Core Operating Limits Report2022-04-0707 April 2022 Core Operating Limits Report NMP1L3458, Constellation Energy Generation, LLC, Annual Property Insurance Status Report2022-04-0101 April 2022 Constellation Energy Generation, LLC, Annual Property Insurance Status Report NMP1L3454, Relief Request Associated with Pump Periodic Verification Tests of Core Spray System Pumps2022-03-0202 March 2022 Relief Request Associated with Pump Periodic Verification Tests of Core Spray System Pumps NMP1L3447, Constellation Energy Generation, LLC - Response to Request for Additional Information - Proposed Relief Request Associated with Reactor Pressure Vessel Water Level Instrumentation Partial Penetration Nozzle Repairs2022-02-0202 February 2022 Constellation Energy Generation, LLC - Response to Request for Additional Information - Proposed Relief Request Associated with Reactor Pressure Vessel Water Level Instrumentation Partial Penetration Nozzle Repairs NMP1L3444, CFR 50.46 Annual Report2022-01-27027 January 2022 CFR 50.46 Annual Report NMP2L2794, Supplemental Information to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request to Adopt TSTF-582, Revision 02022-01-11011 January 2022 Supplemental Information to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request to Adopt TSTF-582, Revision 0 NMP2L2793, Supplemental Information - Relief Request Associated with Excess Flow Check Valves2021-12-17017 December 2021 Supplemental Information - Relief Request Associated with Excess Flow Check Valves NMP2L2789, Response to Request for Additional Information by the Office of Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-582, Revision 02021-12-16016 December 2021 Response to Request for Additional Information by the Office of Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-582, Revision 0 2024-02-01
[Table view] Category:Response to Request for Additional Information (RAI)
MONTHYEARNMP1L3545, Supplemental Information Letter to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 and 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems .2023-08-0404 August 2023 Supplemental Information Letter to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 and 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems . NMP1L3519, Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208)2023-03-30030 March 2023 Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208) NMP1L3516, Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208)2023-03-29029 March 2023 Submittal of Emergency Relief Request I5R-11 Concerning the Installation of a Weld Overlay on Reactor Pressure Vessel Recirculation Inlet Nozzle N2E Safe End-to-Nozzle Dissimilar Metal Weld (32-WD-208) NMP1L3478, Response to Request for Additional Information - Relief Request Associated with Pump Periodic Verification Tests of Core Spray System Pumps2022-08-0505 August 2022 Response to Request for Additional Information - Relief Request Associated with Pump Periodic Verification Tests of Core Spray System Pumps RS-22-027, Constellation, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated2022-02-23023 February 2022 Constellation, Response to Request for Additional Information Regarding Application to Revise Technical Specifications to Adopt TSTF-541 Revision 2, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated P NMP1L3447, Constellation Energy Generation, LLC - Response to Request for Additional Information - Proposed Relief Request Associated with Reactor Pressure Vessel Water Level Instrumentation Partial Penetration Nozzle Repairs2022-02-0202 February 2022 Constellation Energy Generation, LLC - Response to Request for Additional Information - Proposed Relief Request Associated with Reactor Pressure Vessel Water Level Instrumentation Partial Penetration Nozzle Repairs NMP2L2794, Supplemental Information to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request to Adopt TSTF-582, Revision 02022-01-11011 January 2022 Supplemental Information to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request to Adopt TSTF-582, Revision 0 NMP2L2789, Response to Request for Additional Information by the Office of Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-582, Revision 02021-12-16016 December 2021 Response to Request for Additional Information by the Office of Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-582, Revision 0 NMP2L2787, Response to Request for Additional Information - Relief Request Associated with Excess Flow Check Valves2021-11-15015 November 2021 Response to Request for Additional Information - Relief Request Associated with Excess Flow Check Valves JAFP-21-0087, Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments2021-09-16016 September 2021 Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments NMP2L2773, Company - Response to Request for Additional Information2021-06-30030 June 2021 Company - Response to Request for Additional Information JAFP-21-0044, Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments2021-06-11011 June 2021 Response to Request for Additional Information Regarding Request for Approval of Transfer of Licenses and Conforming Amendments NMP1L3402, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-582, Revision 02021-06-0404 June 2021 Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-582, Revision 0 JAFP-21-0032, Response to Request for Additional Information - Proposed Alternative Concerning ASME Section XI Repair/Replacement Documentation for Replacement of Pressure Retaining Bolting2021-04-20020 April 2021 Response to Request for Additional Information - Proposed Alternative Concerning ASME Section XI Repair/Replacement Documentation for Replacement of Pressure Retaining Bolting NMP1L3376, Supplemental Information to Support Review of Nine Mile Point Nuclear Station, Unit 1, License Amendment Request to Adopt TSTF-334, Revision 22021-01-27027 January 2021 Supplemental Information to Support Review of Nine Mile Point Nuclear Station, Unit 1, License Amendment Request to Adopt TSTF-334, Revision 2 NMP1L3373, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-334, Revision 22021-01-22022 January 2021 Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-334, Revision 2 NMP2L2754, Responses to Request for Additional Information Questions 27 and 28 to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22021-01-0707 January 2021 Responses to Request for Additional Information Questions 27 and 28 to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 NMP2L2749, Responses to Request for Additional Information Questions 17 and 26 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Rev. 22020-10-22022 October 2020 Responses to Request for Additional Information Questions 17 and 26 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Rev. 2 NMP2L2745, Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 22020-10-0202 October 2020 Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2 RS-20-112, Response to Request for Additional Information Related to License Amendment Request to Adopt TSTF-5682020-09-0303 September 2020 Response to Request for Additional Information Related to License Amendment Request to Adopt TSTF-568 NMP2L2742, Response to Request for Additional Information by NRR to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request Re Risk Informed Categorization & Structures, Systems and Components2020-08-28028 August 2020 Response to Request for Additional Information by NRR to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request Re Risk Informed Categorization & Structures, Systems and Components ML20188A2642020-07-0606 July 2020 Clinton Power Station, R.E. Ginna Station, Limerick Station, Nine Mile Point Station & Peach Bottom Station - Proposed Alternative to Utilize Code Case OMN-26 - Response to Request for Additional Information NMP2L2713, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request to Increase Allowable MSIV Leakage Rates2019-11-21021 November 2019 Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request to Increase Allowable MSIV Leakage Rates NMP2L2711, Byron Station; Calvert Cliffs; Clinton Power Station; LaSalle County Station; Limerick Generating Station; and Nine Mile Point Nuclear Station - Proposed Alternative to Utilize Code Case N-8792019-10-16016 October 2019 Byron Station; Calvert Cliffs; Clinton Power Station; LaSalle County Station; Limerick Generating Station; and Nine Mile Point Nuclear Station - Proposed Alternative to Utilize Code Case N-879 JAFP-19-0057, Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-8802019-06-0404 June 2019 Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-880 NMP1L3279, Response to Request for Additional Information - Proposed Alternatives to Utilize Code Cases N-878 and N-880 for Plants2019-05-0101 May 2019 Response to Request for Additional Information - Proposed Alternatives to Utilize Code Cases N-878 and N-880 for Plants NMP1L3264, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 1, License Amendment Request to Revise Technical Specifications 3.3.1 for Primary Contain2019-02-25025 February 2019 Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 1, License Amendment Request to Revise Technical Specifications 3.3.1 for Primary Containm JAFP-19-0006, Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-8802019-01-0808 January 2019 Response to Request for Additional Information - Proposed Alternative to Utilize Code Cases N-878 and N-880 NMP2L2695, Supplement Information and Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of an Emergency License Amendment Request for One Time Extension to The.2018-12-0707 December 2018 Supplement Information and Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of an Emergency License Amendment Request for One Time Extension to The. NMP1L3248, Supplement to the Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 1, License Amendment Request to Apply TSTF-542, Revision 2, Reactor Pre2018-11-0202 November 2018 Supplement to the Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 1, License Amendment Request to Apply TSTF-542, Revision 2, Reactor Pres NMP1L3238, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 1, License Amendment Request to Apply TSTF-542, ...2018-10-0101 October 2018 Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 1, License Amendment Request to Apply TSTF-542, ... NMP1L3233, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 1, Removal of Boraflex Credit License Amendment Request (L-2018-LLA-0039)2018-08-17017 August 2018 Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 1, Removal of Boraflex Credit License Amendment Request (L-2018-LLA-0039) NMP1L3221, Independent Spent Fuel Storage Installation, Nine Mile Point, Units 1 & 2, R. E. Ginna - Response to Request for Additional Information License Amendment Request to Adopt Emergency Action Level Schemes.2018-05-10010 May 2018 Independent Spent Fuel Storage Installation, Nine Mile Point, Units 1 & 2, R. E. Ginna - Response to Request for Additional Information License Amendment Request to Adopt Emergency Action Level Schemes. RS-18-061, Response to Request for Additional Information Regarding Decommissioning Funding Plans for Independent Spent Fuel Storage Installations (Isfsis)2018-05-0202 May 2018 Response to Request for Additional Information Regarding Decommissioning Funding Plans for Independent Spent Fuel Storage Installations (Isfsis) ML18025A7992018-01-25025 January 2018 Response to Request for Additional Information Regarding Generic Letter 2016-01 NMP2L2662, Supplemental Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-542, Reactor Pressure Vessel Water Inventory Control, Revision 22017-12-27027 December 2017 Supplemental Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-542, Reactor Pressure Vessel Water Inventory Control, Revision 2 NMP2L2658, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request to Adopt TSTF-542, Revision 2, Reactor Pressure Vessel Water2017-11-0303 November 2017 Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 2, License Amendment Request to Adopt TSTF-542, Revision 2, Reactor Pressure Vessel Water NMP1L3180, Submittal of Relief Request NMP-RR-001 Concerning Nozzle-to-Vessel Weld and Inner Radii Examinations (Use of Code Case N-702)2017-09-18018 September 2017 Submittal of Relief Request NMP-RR-001 Concerning Nozzle-to-Vessel Weld and Inner Radii Examinations (Use of Code Case N-702) RS-17-053, Response to Request for Additional Information Regarding Generic Letter 2016-012017-04-27027 April 2017 Response to Request for Additional Information Regarding Generic Letter 2016-01 NMP1L3146, Response to Request for Additional Information to Relief to Perform Pressure Isolation Valve Leakage Testing at Frequencies Consistent with 10 CFR 50, Appendix J2017-04-0606 April 2017 Response to Request for Additional Information to Relief to Perform Pressure Isolation Valve Leakage Testing at Frequencies Consistent with 10 CFR 50, Appendix J RS-17-044, Response to Request for Additional Information Regarding Proposed Alternative for the Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography2017-03-13013 March 2017 Response to Request for Additional Information Regarding Proposed Alternative for the Use of Encoded Phased Array Ultrasonic Examination Techniques in Lieu of Radiography RS-17-027, Response to March 12, 2012, Request for Information Enclosure 2, Recommendation 2.1, Flooding, Required Response 3, Flooding Focused Evaluation Summary Submittal2017-03-10010 March 2017 Response to March 12, 2012, Request for Information Enclosure 2, Recommendation 2.1, Flooding, Required Response 3, Flooding Focused Evaluation Summary Submittal ML17037A2652017-02-0606 February 2017 Response to Request for Information Concerning Regional Meteorological Conditions Characterizing Atmospheric Transport Processes within 50 Miles of the Plant RA-16-049, Response to Request for Additional Information Regarding Requests to Withhold Emergency Preparedness Documents from Public Disclosure2016-05-26026 May 2016 Response to Request for Additional Information Regarding Requests to Withhold Emergency Preparedness Documents from Public Disclosure ML16131A6542016-05-0404 May 2016 Response to a Question Raised During the Audit ML16131A6552016-05-0404 May 2016 White Paper Prepared in Response to a Question Raised During the Audit NMP2L2616, Supplemental Response to Request for Additional Information by NRR to Support Review of Relocation of Secondary Containment Bypass Leakage Paths Table from Technical Specifications to the Technical Requirements Manual2016-03-21021 March 2016 Supplemental Response to Request for Additional Information by NRR to Support Review of Relocation of Secondary Containment Bypass Leakage Paths Table from Technical Specifications to the Technical Requirements Manual NMP1L3068, Supplemental Information to Request for Additional Information - Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to A....2016-01-25025 January 2016 Supplemental Information to Request for Additional Information - Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to A.... NMP2L2611, Response to Request for Additional Information by NRR to Support Review of Relocation of Secondary Containment Bypass Leakage Paths Table from Technical Specifications to the Technical Requirements Manual2016-01-0808 January 2016 Response to Request for Additional Information by NRR to Support Review of Relocation of Secondary Containment Bypass Leakage Paths Table from Technical Specifications to the Technical Requirements Manual NMP1L3064, Supplemental Response to Request for Additional Information - Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements....2015-12-22022 December 2015 Supplemental Response to Request for Additional Information - Application for Technical Specification Change Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements.... 2023-08-04
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200 Exelon Way Kennett Square, PA 19348 www.exeloncorp.com 10 CFR 50.90 NMP2L2749 October 22, 2020 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License No. NPF-69 NRC Docket No. 50-410
Subject:
Responses to Request for Additional Information Questions 17 and 26 for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b," Revision 2
References:
- 1. Letter from D. Gudger (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, "Provide Risk-Informed Extended Completion Times -
RITSTF Initiative 4b," dated October 31, 2019
- 2. Letter from M. Marshall (Senior Project Manager, U.S. Nuclear Regulatory Commission) to R. Reynolds (Exelon Generation Company, LLC), "Nine Mile Point Nuclear Station, Unit 2 - Request for Additional Information RE:
Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times (EPID L-2019-LLA-0234)," dated July 30, 2020
- 3. Letter from D. Gudger (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, 'Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b,' Revision 2," dated August 28, 2020
- 4. Letter from M. Marshall (Senior Project Manager, U.S. Nuclear Regulatory Commission) to R. Reynolds (Exelon Generation Company, LLC), "Nine Mile Point Nuclear Station, Unit 2 - Request for Additional Information to Support Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times (EPID L-2019-LLA-0234)," dated September 2, 2020
U.S. Nuclear Regulatory Commission Request for Additional Information TSTF-505, Risk-Informed Extended Completion Times Docket No. 50-410 October 22, 2020 Page 2
- 5. Letter from D. Gudger (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Request for Additional Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, 'Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b,' Revision 2," dated October 2, 2020
- 6. Letter from M. Marshall (Senior Project Manager, U.S. Nuclear Regulatory Commission) to R. Reynolds (Exelon Generation Company, LLC), "Nine Mile Point Nuclear Station, Unit 2 - Withdrawal and Replacement of Request for Additional Information to Support Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times (EPID L-2019-LLA-0234)," dated September 28, 2020
- 7. Letter from M. Marshall (Senior Project Manager, U.S. Nuclear Regulatory Commission) to R. Reynolds (Exelon Generation Company, LLC), "Nine Mile Point Nuclear Station, Unit 2 - Request for Additional Information Re:
Review of License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times (EPID L-2019-LLA-0234)," dated September 28, 2020 By letter dated October 31, 2019 (Reference 1), Exelon Generation Company, LLC (Exelon) requested to change the Nine Mile Point Nuclear Station, Unit 2 (NMP2) Technical Specifications (TS). The proposed amendment would modify TS requirements to permit the use of Risk-Informed Completion Times in accordance with TSTF-505, Revision 2, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b," (ADAMS Accession No. ML18183A493).
In a letter dated July 30, 2020 (Reference 2), the NRC provided a Request for Additional Information (RAI) to support their continued review of Reference 1. The letter contained RAI Questions 1 through 5. Exelon provided the responses to these RAIs in Reference 3.
On September 2, 2020, the NRC provided a second Request for Additional Information (RAI)
(Reference 4) to support their continued review of Reference 1. This request contained RAI Questions 6 through 25. Exelon provided the responses to these RAIs (except for Question
- 17) in Reference 5.
On September 28, 2020, the NRC redacted Question 17 as written and provided a revised Question 17 (ML20272A280) (Reference 6). In addition, the NRC provided a new RAI Question 26 (ML20273A237) (Reference 7). to this letter contains the NRCs RAI Questions 17 and 26 immediately followed by Exelons response.
U.S. Nuclear Regulatory Commission Request for Additional Information TSTF-505, Risk-Informed Extended Completion Times Docket No. 50-410 October 22, 2020 Page 3 Exelon has reviewed the information supporting a finding of no significant hazards consideration and the environmental consideration provided to the NRC in Reference 1. The supplemental information provided in this letter does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration.
Furthermore, the supplemental information provided in this letter does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.
There are no commitments contained in this response.
If you should have any questions regarding this submittal, please contact Ron Reynolds at 610-765-5247.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 22nd day of October 2020.
Respectfully, David T. Gudger Senior Manager - Licensing Exelon Generation Company, LLC : Response to Request for Additional Information cc: USNRC Region I Regional Administrator w/attachments USNRC Senior Resident Inspector - NMP "
USNRC Project Manager, NRR - NMP "
A. L. Peterson, NYSERDA "
ATTACHMENT 1 Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License NPF-69 Docket No. 50-410 Request for Additional Information Adopt Risk-Informed Completion Times Response to Request for Additional Information
Response to Request for Additional Information Attachment 1 Adopt Risk-Informed Completion Times Page 1 of 7 Docket No. 50-410
RAI 17
Section 2.3 of LAR Attachment 1 states that the application of an RICT will be evaluated using the guidance provided in Nuclear Energy Institute topical report (NEI) 06-09, Revision 0-A, "Risk-Informed Technical Specifications Initiative 4b, Risk-Managed Technical Specifications (RMTS) Guidelines, Industry Guidance Document," which was approved by the NRC on May 17, 2007 (ADAMS Accession No. ML071200238). The NRC safety evaluation for NEI 0609, Revision 0-A, states, "The impact of the proposed change should be monitored using performance measurement strategies." NEI 06-09 considers the use of NUMARC 93-01, Revision F (ADAMS Accession No. ML18120A069), as endorsed by Regulatory Guide (RG) 1.160, Revision 4 (ADAMS Accession No. ML18220B281), for the implementation of the Maintenance Rule. NUMARC 93-01, Section 9.0, contains guidance for the establishment of performance criteria.
Furthermore, Section 2.3 of LAR Attachment 1 states:
In addition, the NEI 06-09-A, methodology satisfies the five key safety principles specified in Regulatory Guide 1.177, "An Approach for Plant-Specific, Risk-Informed Decision making: Technical Specifications," dated August 1998 (ADAMS Accession No. ML003740176), relative to the risk impact due to the application of a RICT.
Staff position C.3.2 provided in RG 1.177 for meeting the fifth key safety principle acknowledges the use of performance criteria to assess degradation of operational safety over a period of time. It is unclear to NRC staff how the licensees processes for the RICT application captures performance monitoring for the structures, systems, and components (SSCs) within-scope of the application. In light of these observations, address either (i) or (ii) below:
i) Confirm that the Nine Mile Point 2 Maintenance Rule program incorporates the use of performance criteria to evaluate SSC performance as described in the NRC-endorsed guidance in NUMARC 93-01.
or ii) Describe the approach/method used by Nine Mile Point 2 for SSC performance monitoring as described in Regulatory Position C.3.2 referenced in RG 1.177 for meeting the fifth key safety principle. In the description, include criteria (e.g., qualitative or quantitative) along with the appropriate risk metrics for the RICT application, and explain how the approach and criteria demonstrates the intent to monitor the potential degradation of SSCs for the applicable process of the risk-informed application.
Exelon Response to RAI 17:
Response to 17i:
Nine Mile Point 2 does not use performance criteria as described in NUMARC 93-01.
Response to 17ii:
Nine Mile Point 2 has implemented the guidance in NEI 18-10, Revision 0, "Monitoring the Effectiveness of Nuclear Power Plant Maintenance," as a means of meeting the requirements set in 10 CFR 50.65, "Requirements for monitoring the effectiveness of maintenance at nuclear power plants." The overall purpose of NEI 18-10 is to provide utilities with a risk-informed
Response to Request for Additional Information Attachment 1 Adopt Risk-Informed Completion Times Page 2 of 7 Docket No. 50-410 framework that supports the implementation and monitoring of a maintenance effectiveness program that complies with 10 CFR 50.65, effectively and efficiently leverages utility resources, and is focused on equipment performance commensurate with safety. NEI 18-10 is an alternative to the NUMARC 93-01/RG 1.160 guidance.
Both Regulatory Guide (RG) 1.160, Revision 4, and NUMARC 93-01, Revision 4F (endorsed by RG 1.160) allow for utilities to use alternative methods or approaches to ensure the requirements of 10 CFR 50.65 are being met. RG 1.160, Section D Implementation, Use by Applicants and Licensees:
Applicants and licensees may voluntarily use the guidance in this document to demonstrate compliance with the underlying NRC regulations. Methods or solutions that differ from those described in this regulatory guide may be deemed acceptable if they provide sufficient basis and information for the NRC staff to verify that the proposed alternative demonstrates compliance with the appropriate NRC regulations. Current licensees may continue to use guidance the NRC found acceptable for complying with the identified regulations as long as their current licensing basis remains unchanged.
NUMARC 93-01 Section
2.0 Purpose and Scope
This guideline describes an acceptable approach to meet the Maintenance Rule.
However, utilities may elect other suitable methods or approaches for implementation. This guideline does not address the many industry programs that have been put in place to upgrade maintenance and may be used when implementing the Maintenance Rule. For example, work planning and scheduling, preventive and corrective maintenance, maintenance procedures, training, post maintenance testing, work history, cause determination methods and other maintenance related programs are not discussed.
In accordance with NEI 18-10, Revision 0, all SSC in scope of 10 CFR 50.65 (b)(1) and (b)(2) are evaluated for safety significance. Safety significance is determined by a Maintenance Rule (MR) expert panel informed by importance measures; the following would be considered as potentially high safety significant (HSS) functions.
- 1. FV > 0.005
- 2. RAW > 2.0
- 3. Birnbaum > 1E-05/yr CDF or > 1E-06/yr LERF All other functions in scope of MR are considered low safety significant (LSS).
SSCs that remain capable of performing their intended functions will be retained in (a)(2) status.
If an event or failure occurs and an Issue Report (IR) is generated in the Corrective Action Program (CAP) associated with a scoped in SSC with HSS function(s), the IR will be reviewed for HSS Maintenance Rule Functional Failures (MRFF). Any HSS MRFF will result in an immediate (a)(1) determination (i.e. every HSS function has a performance criterion = 0). All IRs that represent a plant level event (PLE) will result in an immediate (a)(1) determination. For LSS functions the performance criteria is not a set number of MRFFs, but instead is when a trend in system/function performance is observed. This is still performance criteria/monitoring and when reached/observed would drive an immediate (a)(1) determination. Trends will be identified on an ongoing/continuous basis by identification through engineer SSC performance review, through OPEX review, or during the (a)(3) assessment.
Response to Request for Additional Information Attachment 1 Adopt Risk-Informed Completion Times Page 3 of 7 Docket No. 50-410 An aggregate assessment of the balance between reliability and availability with be provided by Core Damage Frequency (CDF) trending. CDF trending looks at the risk impact associated with both planned and unplanned maintenance and considers the impact of failures, as failures that occur at power result in unplanned maintenance. CDF trending also provides an aggregate assessment of maintenance planning and execution. CDF trends will be reviewed during the (a)(3) assessment for a minimum of 1) long unavailability durations, 2) peak periods of risk increase, 3) need to update PRA, and 4) multiple occurrences of the same configuration due to ineffective maintenance. If the assessment determines that the increase in CDF average values was the result of an ineffective maintenance strategy, an immediate (a)(1) determination will be performed for the contributing SSC function(s).
Any SSC function determined to be (a)(1) will result in a CAP causal determination and (a)(1) goals will be established commensurate with the SSCs safety significance and performance and corrective actions will be planned and implemented to correct the cause of the degraded performance. Corrective actions will be tracked to completion. Goals are established to bring about the necessary improvements in performance. Monitoring consists of periodic trending and evaluating performance and/or availability of the SSC function(s) comparing the results with the established (a)(1) goals to verify that the goals are being met. Monitoring also provides a means for determining the effectiveness of the corrective actions. A goal is met and monitoring of SSC function(s) against the specific goal may be discontinued if any of the following criteria are satisfied 1) acceptable performance for three surveillance periods (when periodicity is <= 6 months), 2) acceptable performance for two surveillance periods (when periodicity is >= 6 months but less than 2 cycles), or 3) any approved and documented technical assessment that assures the cause is known and corrected thus monitoring against goals is unnecessary. If any of these conditions are met, the SSC function(s) may be returned to (a)(2) status. If none of these conditions are met then additional causal determination is necessary and new corrective actions, goal setting, and monitoring will be established to drive acceptable SSC performance.
All IRs that represent a PLE and all IRs that were determined to be HSS MRFF will result in an immediate (a)(1) determination.
SSC performance monitoring is performed on an ongoing/continuous basis and if a trend is identified, an (a)(1) determination will be performed. LSS trends and CDF trending are also reviewed during the periodic (a)(3) assessment. If the assessment determines the trends were the result of an ineffective maintenance strategy, an immediate (a)(1) determination will be performed at that time.
The (a)(1) determination will document the basis for remaining in (a)(2) status or the need for goal setting and monitoring under the requirements of (a)(1). For SSC function(s) determined to be (a)(1), goals will be established commensurate with the SSCs safety significance and performance. Monitoring will verify that goals are being met and determine the effectiveness of the corrective actions.
Every IR is reviewed for PLE or HSS MRFF. Every PLE or HSS MRFF will be evaluated to determine if the maintenance strategy is still effective. Events of lower safety significance are reviewed on an ongoing/continuous basis to determine if a trend or correlation exists between the events. If one is identified, the trend will be evaluated to determine if the maintenance strategy is still effective. CDF trending is reviewed periodically to determine the balance between reliability and availability, the effectiveness of maintenance planning and execution, and peak periods of risk increase and multiple occurrences of the same configuration. CDF trending will be used to determine if the maintenance strategy is still effective.
Response to Request for Additional Information Attachment 1 Adopt Risk-Informed Completion Times Page 4 of 7 Docket No. 50-410 Anytime the maintenance strategy is determined to be ineffective, the SSC function(s) will be moved to (a)(1) status and goals will be established such that monitoring can verify performance against goals and determine the effectiveness of corrective actions.
RAI 26
Section 2.3.1, Item 7, of Nuclear Energy Institute (NEI) 06-09, Revision 0-A (ADAMS Accession No. ML12286A322), states, "The impact of other external events risks shall be addressed in the RRMTS [Risk-Managed Technical Specifications] program," and explains that one method to do this is by "performing a reasonable bounding analysis and applying it along with the internal events risk contribution in calculating the configuration risk and the associated RICT [riskinformed completion time] RICT." The NRC staffs safety evaluation for NEI 06-09 (ADAMS Accession No. ML071200238) states, "Where PRA [probabilistic risk assessment]
models are not available, conservative or bounding analyses may be performed to quantify the risk impact and support the calculation of the RICT."
LAR Enclosure 4, Section 3, states that to determine a bounding seismic core damage frequency, the peak ground acceleration hazard curve for the 50th percentile high confidence of low probability of failure (HCLPF) value of 0.42g was used from its individual plant evaluation of external events (IPEEE) seismic margins analysis (SMA). (Note: The SMA HCLPF value of 0.5g is the 84th percentile value). The IPEEE HCLPF value of 0.42g was used rather than the HCLPF value of 0.23g in Table C-2 of Results of Safety/Risk Assessment of Generic Issue 199 (GI-199), "Implications of Updated Probabilistic Seismic Hazard Estimates in Central and Eastern United States on Existing Plants" (ADAMS Accession No. ML100270582). The LAR states that related sensitivity studies were performed on the impact to risk of changing the ground motion frequencies and seismic hazard intervals. The LAR does not describe those sensitivity studies results or how insights from those studies were used. The exception to this is that sensitivity study results are presented in LAR Table E4-4 to justify the defined seismic hazard interval for the highest seismic bin, the %G8 interval (i.e., seismic hazard internal >
1.5g).
a) Explain why the IPEEE HCLPF value of 0.42g was used rather than the HCLPF value of 0.23g in GI-199 and why it is acceptable for this application.
b) Describe the cited sensitivity studies and results.
c) Explain how insights from the sensitivity studies were used to select to a bounding ground motion and to define the seismic hazard intervals.
Exelon Response to RAI 26:
Response to 26a:
Throughout NEI 06-09 Rev 0-A and the NRC SE for that document, reference is made to either a "bounding" or "conservative" analysis, or sometimes to a "reasonable bounding analysis", as being acceptable to account for risk for external hazards when a PRA model is not available.
The estimation of seismic risk results for the NMP2 RICT program are more accurately characterized as a "conservative" analysis that uses an estimated averaged seismic conditional large early release probability (SCLERP) to determine a seismic LERF that is then conservatively used in RICT assessments. A truly bounding analysis would assume characteristics such as SCDF equal to the seismic hazard frequency of the SSE and an estimated averaged seismic conditional large early release probability (SCLERP) of 1.0, both of
Response to Request for Additional Information Attachment 1 Adopt Risk-Informed Completion Times Page 5 of 7 Docket No. 50-410 which are neither reasonable nor useful estimates. The NMP2 evaluation estimates a nominal SCDF, estimates an averaged SCLERP that involves conservative analysis elements in the calculation, and then employs these estimates in a conservative manner in the RICT process by applying the total SCDF and total SLERF as delta SCDF and delta SLERF in each RICT calculation.
The RAI characterizes the 0.23g PGA HCLPF value in Table C-2 of the GI-199 risk assessment (ADAMS Accession No. ML100270582) as a "more recent" value than the NMP2 IPEEE values (SAS-TR-95-001, "Nine Mile Point Station - Unit 2 Individual Plant Examination for External Events (IPEEE)," June 1995). This characterization of a more recent value is not correct. The 0.23g PGA HCLPF value for NMP2 quoted in the 2010 GI-199 risk assessment is the same value as that documented in the 1995 NMP2 IPEEE submittal and it applies to the lowest calculated HCLPF of any item on the NMP2 IPEEE seismic safe shutdown success paths (in this case, the high pressure liquid nitrogen tanks). The 0.23g PGA HCLPF was not used in the NMP2 RICT SCDF seismic penalty calculation because it would result in an overly conservative estimate of SCDF, as discussed below.
The plant HCLPF value of 0.42g PGA used in the SPRA portion of the NMP2 IPEEE was used in the NMP2 RICT LAR seismic penalty calculation to estimate NMP2 seismic CDF rather than the HCLPF of 0.23g PGA identified in GI-199. Based on information in the SPRA portion of the NMP2 IPEEE, the HCLPF of 0.23g PGA is associated with an SSC fragility that does not have a high likelihood of leading directly to core damage. Using a HCLPF of 0.23g PGA would result in an overly conservative estimate of the seismic CDF for the RICT seismic penalty factor.
Pages 3.2-2 and 3.2-3 of the NMP2 IPEEE identify that the HCLPF of 0.23g PGA is associated with the non-safety related (non-seismic qualified) high pressure nitrogen supply. The HCLPF of 0.23g PGA is governed by the fragility of the liquid nitrogen tanks. Page 3.2-8 of the NMP2 IPEEE identifies that "the nitrogen supply was assumed to be required to keep the safety relief valves open in the long term (>24 hours after the seismic event) after emergency depressurization is required to provide low pressure ECCS makeup to the reactor vessel."
However, the NMP2 IPEEE further identifies that two (2) redundant success paths (i.e., RCIC and HPCS for high pressure makeup) remain available as an alternate to the emergency depressurization and low-pressure injection success path. Both of the redundant success paths (i.e., RCIC and HPCS) were assessed to have a HCLPF greater than 0.5g PGA. Although a HCLPF of 0.23g PGA could be identified as the limiting "plant" fragility based on the SMA methodology from the NMP2 IPEEE, use of a HCLPF of 0.23g PGA for the "plant" fragility for the purposes of estimating SCDF for the RICT seismic penalty factor approach is assessed to be overly conservative based on the redundant success paths at NMP2.
The HCLPF value of 0.42g PGA is associated with the screening level for components in the SMA as shown on p. 3.2-9 of the IPEEE. Based on the redundant success paths identified in the IPEEE (i.e., RCIC and HPCS for high pressure makeup), a HCLPF of 0.42g PGA is judged to be a reasonable "plant" fragility for use in calculating an estimate of seismic CDF for the RICT seismic penalty factor approach.
Response to 26b:
The sensitivity studies referenced in LAR Enclosure 4, Section 3 include the following:
- Sensitivity Case 1: Change %G1 hazard interval from 0.09g - 0.3g to 0.09g - 0.2g and then reduce by 0.1g the upper end point (i.e., right hand g-levels) for each of the hazard intervals %G2 through %G8.
Response to Request for Additional Information Attachment 1 Adopt Risk-Informed Completion Times Page 6 of 7 Docket No. 50-410
- Sensitivity Case 2: Change %G1 hazard interval from 0.09g - 0.3g to 0.09g -
0.15g and then make the widths for the lower hazard intervals thinner, while making the higher hazard intervals wider.
- Sensitivity Case 3: Same as base case but create new first interval of 0.03g -
0.09g to capture risk contribution of earthquakes above OBE of 0.075g.
- Sensitivity Case 4: Evaluate risk impact of using 2.5 Hz seismic hazard curve (PGA-based plant HCLPF also adjusted to 2.5 Hz-based HCLPF).
- Sensitivity Case 5: Use all seismic hazard data points from the NMP2 NTTF 2.1 Seismic Hazards Re-evaluation submittal (ML14099A196).
Compared to the base case estimated seismic CDF of 6.4E-7/yr, the sensitivity case results are as follows with identified percent difference from the base case:
- Sensitivity Case 1: 6.9E-7/yr (8% increase)
- Sensitivity Case 2: 6.5E-7/yr (2% increase)
- Sensitivity Case 3: 6.4E-7/yr (negligible change)
- Sensitivity Case 4: 3.7E-8/yr (order of magnitude decrease)
- Sensitivity Case 5: 6.4E-7/yr (negligible change)
Sensitivity Cases 1, 2 and 3 illustrate that the estimated SCDF is not overly sensitive to the interval divisions because sufficient intervals (e.g., 6 or more above the OBE) are already used.
These three sensitivity cases change the widths of the hazard intervals (thinner and larger) as well as modifying the first hazard interval to very low g PGA values. Sensitivity Case 3 illustrates that OBE level earthquakes have a negligible contribution to SCDF and SSE level earthquakes have a minor contribution (i.e., 0.3% contribution) to SCDF.
For Sensitivity Case 4, a hazard curve with a different spectral frequency than PGA is used.
Use of the PGA metric versus a lower spectral acceleration (e.g., in the 1- 10 Hz range) typically results in a higher calculated risk. The 2.5 Hz hazard curve, based on the data in the NMP2 NTTF 2.1 Seismic Hazards Re-evaluation submittal, is selected as it intersects (and drops below) the PGA hazard curve at a comparatively low g level (0.08g); as such, the 2.5 Hz seismic hazard curve was selected for a sensitivity case as it would show a large reduction in calculated risk in the simplified SCDF convolution calculation. This sensitivity case also appropriately scales the PGA-based plant HCLPF to a 2.5 Hz based plant HCLPF for use in the SCDF convolution calculation of this sensitivity case. The calculated SCDF from a simple convolution of the plant HCLPF (in terms of 2.5 Hz) and the 2.5 Hz hazard curve is approximately 4E-08/yr which is significantly less than the base case PGA-based SCDF estimate. This large reduction in calculated SCDF (i.e., using 2.5 Hz vs PGA in a simple plant HCLPF convolution) is likely not what would be shown from a full SPRA.
Sensitivity Case 5 uses all available PGA hazard curve data points and many more hazard intervals (eighteen intervals from 0.0005g to 10g PGA). The resulting SCDF from the use of many more, and thinner, hazard intervals in the calculation is the same result as the base case estimate of 6.4E-7/yr. By using all available data points from the NMP2 NTTF 2.1 Seismic Hazards Re-evaluation submittal, Sensitivity Case 5 provides a more precise convolution calculation, but the result shows what is typical knowledge of seismic risk convolution calculations, i.e., approximately 6-10 hazard intervals of widths of approximately 0.1 to 0.2g is sufficiently accurate.
Response to Request for Additional Information Attachment 1 Adopt Risk-Informed Completion Times Page 7 of 7 Docket No. 50-410 Response to 26c:
PGA is the most common metric used in the NPP seismic PRAs. As can be seen from the response to RAI 26b, the 2.5 Hz metric sensitivity case results in a calculated SCDF over an order of magnitude lower than the base case SCDF calculation using the PGA metric. This large reduction in calculated SCDF (i.e., using 2.5 Hz vs PGA in a simple plant HCLPF convolution) is likely not what would be shown from a full SPRA. Regardless, use of the PGA metric is typical, and in the case of NMP2, assessed to result in the more conservative risk result. As can be seen from the results of the other sensitivity cases discussed above (i.e.,
those related to the number and widths of hazard intervals used in the SCDF convolution), the SCDF convolution result is not overly sensitive to the chosen seismic hazard interval divisions.
Based on the sensitivity case insights, the use of the PGA ground motion and the seismic hazard interval definitions from the base case are judged appropriate to calculate an estimate of seismic CDF for the RICT seismic penalty factor approach.