Letter Sequence RAI |
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EPID:L-2017-LLA-0281, Provide RISK-INFORMED Extended Completion Times - RITSTF Initiative 4B (Approved, Closed) |
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MONTHYEARML17086A4512017-02-21021 February 2017 02-21-17 NRC Final Revision of Appendix X to NEI 05-04, 07-12, 12-16, Close-Out of Facts and Observations (F&Os) Project stage: Request ML17243A0142017-08-30030 August 2017 Application to Adopt 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Reactors. Project stage: Request ML17272B0162017-10-10010 October 2017 Supplemental Information Needed for Acceptance of Requested Licensing Action Adoption of Title 10 of the Code of Federal Regulations Section 50.69 (CAC Nos. MG0181-82; EPID L-2017-LLA-0281) Project stage: Acceptance Review ML17297B5212017-10-24024 October 2017 Supplement to Application to Adopt 10CFR50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors Project stage: Supplement ML17300A2762017-10-27027 October 2017 Acceptance Review - Peach Bottom Units 2 and 3 - License Amendment Request to Adopt 10 CFR 50.69 (CAC Nos. MG0181 and MG0182; EPID L-2017-LLA-0281) Project stage: Acceptance Review ML18005A0772018-01-0909 January 2018 Regulatory Audit Plan Regarding License Amendment Request to Adopt 10 CFR 50.69 (CAC Nos. MG0181 and MG0182; EPID L-2017-LLA-0281) Project stage: Other ML18096B5062018-04-0606 April 2018 Request for Additional Information Exelon Generation Company, LLC Requested Amendment to Adopt 10 CFR 50.69 for Risk-informed Categorization and Treatment of Structures, Systems and Components Project stage: RAI ML18072A3722018-04-10010 April 2018 Regulatory Audit Summary Regarding License Amendment Request to Adopt Title 10 of the Code of Federal Regulations Section 50.69 Project stage: Other ML18128A0092018-05-0707 May 2018 Response to Request for Additional Information Application to Adopt 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Plants. Project stage: Response to RAI ML18157A2602018-06-0606 June 2018 Supplemental Information to Support Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Plants. Project stage: Supplement ML18178A4772018-06-27027 June 2018 Request for Additional Information 2nd Round - Adopt 50.69 License Amendment Project stage: RAI ML18192A1192018-07-10010 July 2018 Request for Additional Information 2nd Round (Final) - Adopt 50.69 License Amendment Project stage: RAI ML18200A2742018-07-17017 July 2018 Request for Additional Information 2nd Round (Final) - Adopt 50.69 License Amendment Project stage: RAI ML18222A3872018-08-10010 August 2018 Response to Request for Additional Information and Supplemental Information - Application to Adopt 1 O CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems, and Components ... Project stage: Supplement ML18234A1872018-08-22022 August 2018 Supplemental Information - Application to Adopt 10 CFR 50.69, Risk Informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Plants Project stage: Supplement ML18263A2322018-10-25025 October 2018 Issuance of Amendment Nos. 321 and 324 to Adopt 10 CFR 50.69 (CAC Nos. MG0181 and MG0181; EPID L-2017-LLA-0281) Project stage: Approval ML18302A2572018-11-0101 November 2018 Correction to Amendment Nos. 321 and 324 to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structure, Systems and Components (CAC Nos. MG0181 and MGO182; EPID L-2017-LLA-0281) Project stage: Other 2018-04-10
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Category:Letter
MONTHYEARML24022A2262024-01-22022 January 2024 (PBAPS) Unit 3 - Submittal of the Inservice Inspection (ISI) Owner'S Activity Report (OAR) for the 24th Refueling Outage for Unit 3 ML23346A2412024-01-17017 January 2024 Staff Assessment of Updated Seismic Hazards Following the NRC Process for the Ongoing Assessment of Natural Hazards Information (EPID L-2019-PMP-0061) - Letter IR 05000277/20234022024-01-11011 January 2024 Security Baseline Inspection Report 05000277/2023402 and 05000278/2023402 and Independent Spent Fuel Storage Installation Security Inspection 07200029/2023401 ML23354A1922024-01-0505 January 2024 Exemption from Select Requirements of 10 CFR Part 73 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting) ML23355A0622023-12-18018 December 2023 Independent Spent Fuel Storage Installation (Isfsi), Security Plan, Training and Qualification Plan, and Safeguards Contingency Plan ML23278A1292023-12-14014 December 2023 Units 1 & 2; Limerick, Units 1 & 2; Nine Mile Point, Units 1 & 2; and Peach Bottom, Units 2 & 3 -Revision to Approved Alternatives to Use Boiling Water Reactor Vessel and Internals Project Guidelines ML23305A1402023-12-13013 December 2023 Units 1 & 2; Nine Mile Point, Unit 2; Peach Bottom, Units 2 & 3; and Quad Cities, Units 1 and 2 - Issuance of Amendments to Adopt Traveler TSTF-580 ML23334A2502023-11-30030 November 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation ML23270C0072023-11-29029 November 2023 Notice of Proposed Amendment to Decommissioning Trust Agreement ML23317A1192023-11-10010 November 2023 Constellation Energy Generation, LLC - 2023 Annual Report - Guarantees of Payment of Deferred Premiums ML23305A3472023-11-0101 November 2023 Revision of One Form That Implements the Radiological Emergency Response Plan (RERP) IR 05000277/20230032023-10-30030 October 2023 Integrated Inspection Report 05000277/2023003 and 05000278/2023003 and Exercise of Enforcement Discretion ML23286A0012023-10-13013 October 2023 Reply to a Notice of Violation (NOV) - NOV 05000277, 05000278/2023010-01 RS-23-097, Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans2023-10-12012 October 2023 Constellation Energy Generation, LLC, Advisement of Leadership Changes and Submittal of Updated Standard Practice Procedures Plans ML23271A1342023-10-11011 October 2023 Dtf Analysis Letter IR 05000277/20244012023-10-0505 October 2023 Information Request for the Cybersecurity Baseline Inspection, Notification to Perform Inspection 05000277/2024401 and 05000278/2024401 ML23265A1502023-09-22022 September 2023 License Amendment Request Revise a License Condition and Certain Technical Specifications to Remove Restrictions in Support of Decommissioning Activities ML23264A8682023-09-21021 September 2023 Independent Spent Fuel Storage Installation Registration of Dry Storage Canister WC-EOS-37PTH-008-B4L, WC-EOS-37PTH-007-B4L, and WC-EOS-37PTH-002-B4L IR 05000277/20230102023-09-15015 September 2023 Biennial Problem Identification and Resolution Inspection Report 05000277/2023010 and 05000278/2023010 and Notice of Violation ML23251A2022023-09-11011 September 2023 Cover Letter W/Report LR-N23-0045, and Peach Bottom Atomic Power Station, Units 2 and 3 - Notice of Proposed Amendment to Decommissioning Trust Agreement2023-09-0808 September 2023 and Peach Bottom Atomic Power Station, Units 2 and 3 - Notice of Proposed Amendment to Decommissioning Trust Agreement IR 05000277/20230052023-08-31031 August 2023 Updated Inspection Plan for Peach Bottom Atomic Power Station, Units 2 and 3 (Report 05000277/2023005 and 05000278/2023005) ML23158A1952023-08-30030 August 2023 R. E. Ginna - Issuance of Amendments to Adopt TSTF-273-A, Revision 2, Safety Function Determination Program Clarifications ML23232A0012023-08-19019 August 2023 Revision of One Procedure That Implements the Radiological Emergency Response Plan (Rerp). Includes EPP 06-009, Rev. 13 IR 05000277/20230112023-08-15015 August 2023 Comprehensive Engineering Team Inspection Report 05000277/2023011 and 05000278/2023011 ML23226A1112023-08-14014 August 2023 10 CFR 50.46 Annual Report IR 05000277/20230022023-08-0808 August 2023 Integrated Inspection Report 05000277/2023002 and 05000278/2023002 RS-23-087, Revision to Approved Alternatives Associated with the Use of the BWRVIP Guidelines in Lieu of Specific ASME Code Requirements on Reactor2023-08-0404 August 2023 Revision to Approved Alternatives Associated with the Use of the BWRVIP Guidelines in Lieu of Specific ASME Code Requirements on Reactor IR 05000277/20230402023-07-17017 July 2023 95001 Inspection Supplemental Report 05000277/2023040 and Follow-Up Assessment Letter ML23188A0532023-07-0707 July 2023 Registration of Use of Independent Spent Fuel Storage Installation (ISFSI) Casks ML23186A1272023-07-0606 July 2023 Response to Disputed Non-Cited Violation Documented in Peach Bottom Atomic Power Station, Units 2 and 3, Inspection Report 05000277/2022004 and 05000278/2022004 ML23178A0352023-06-27027 June 2023 Senior Reactor and Reactor Operator Initial License Examinations RS-23-077, Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations2023-06-16016 June 2023 Response to NRC Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations ML23151A4162023-05-31031 May 2023 Revision of One Form That Implements the Radiological Emergency Response Plan (RERP) for Wolf Creek Generating Station (WCGS) ML23150A2052023-05-30030 May 2023 Independent Spent Fuel Storage Installation (Isfsi), Annual Radiological Environmental Operating Report 80 January 1, 2022 Through December 31, 2022 RS-23-042, Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling2023-05-25025 May 2023 Application to Revise Technical Specifications to Adopt TSTF-580, Provide Exception from Entering Mode 4 with No Operable RHR Shutdown Cooling ML23142A1602023-05-23023 May 2023 Summary of April 11, 2023, Public Observation Meeting with Constellation Energy Generation, LLC Re Proposed Exemption Request from Work Hour Requirements ML23132A1582023-05-18018 May 2023 Correction to Technical Specification 3.4.7 (Page 3.4-16) Issued in Amendment No. 337 ML23132A1532023-05-12012 May 2023 Transmittal of 2022 Annual Financial Reports WM 23-0009, Financial Assurance Requirements for Decommissioning Nuclear Power Reactors 10 CFR 50.75(f)(1)2023-05-10010 May 2023 Financial Assurance Requirements for Decommissioning Nuclear Power Reactors 10 CFR 50.75(f)(1) IR 05000277/20230012023-05-0808 May 2023 Integrated Inspection Report 05000277/2023001 and 05000278/2023001 ML23114A2522023-04-28028 April 2023 Request to Use a Provision of a Later Edition of the ASME Boiler & Pressure Vessel Code, Section XI 2024-01-05
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARIR 05000277/20244012023-10-0505 October 2023 Information Request for the Cybersecurity Baseline Inspection, Notification to Perform Inspection 05000277/2024401 and 05000278/2024401 ML23264A7992023-09-21021 September 2023 NRR E-mail Capture - Final RAI - Constellation Energy Generation, LLC Fleet Request License Amendment Request to Adopt TSTF-580, Revision 1 ML22118A3312022-04-28028 April 2022 NRR E-mail Capture - Peach Bottom - Formal RAI for Proposed Alternative I5R-14, Revision 1 ML22041B5362022-02-10010 February 2022 NRR E-mail Capture - Constellation Energy Generation, LLC - Request for Additional Information Regarding Fleet License Amendment Request to Adopt TSTF-541 ML22021A5692022-01-21021 January 2022 Information Request for the Cyber Security Baseline Inspection, Notification to Perform Inspection 05000277/2022403 and 05000278/2022403 ML22020A0642022-01-13013 January 2022 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding Proposed Fleet Alternative for Repair of Water Level Instrumentation Partial Penetration Nozzles ML21256A1902021-09-10010 September 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding License Transfer Application ML21144A2132021-05-24024 May 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding License Transfer Application ML21062A0652021-03-0101 March 2021 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding Proposed Fleet Alternative to Documentation Requirements for Pressure Retaining Bolting ML21049A2572021-02-18018 February 2021 Request for Additional Information Byron/Dresden Proposed Changes to Site Emergency Plans to Support Post-Shutdown and Permanently Defueled Conditions (EPID-2020-LLA-0240 & EPID-2020-LLA-0237) ML21035A2222021-02-0404 February 2021 Notification of Conduct of a Fire Protection Team Inspection ML21091A1782021-02-0202 February 2021 Ti 2515/194 Inspection Documentation Request ML21012A1302021-01-12012 January 2021 Request for Additional Information - TSTF-505 ML20357A0972020-12-21021 December 2020 Request for Additional Information - TSTF-505 ML20296A3342020-10-21021 October 2020 ISI Remote Inspection - Supplemental Request for Information ML20239A7982020-08-25025 August 2020 NRR E-mail Capture - Exelon Generation Company, LLC - Fleet License Amendment Request to Adopt TSTF-568, Revision 2 ML20153A7042020-06-0101 June 2020 NRR E-mail Capture - Preliminary RAI for Fleet Request to Use Alternative OMN-26 ML20135H1972020-05-14014 May 2020 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding Request to Extend Safety Relief Valve Test Interval ML20070R2282020-03-10010 March 2020 Request for Additional Information - RR ML19303D1662019-10-31031 October 2019 Requests for Additional Information for the Environmental Review of the Peach Bottom Subsequent License Renewal Application - Set 2 (EPID No. L-2018-RNW-0013)- RAIs ML19232A1752019-08-20020 August 2019 Request for Additional Information - TSTF-500 Implementation LAR ML19140A2832019-05-15015 May 2019 Email - Peach Bottom Atomic Power Station, Units 2 and 3 Second Round RAI Request - Set 1 ML19140A2822019-05-15015 May 2019 027 Pb FU RAI Subsequent to Clarification Call - Cu Greater than 15 Zn Holston (Jg) ML19253D2932019-05-0707 May 2019 002 Attachment 4D Confirmation Water Chemistry Chereskin Revised (002) ML19249C7252019-05-0303 May 2019 SLRA Requests for Additional Information - Set 2 May 3, 2019 ML19108A4282019-04-10010 April 2019 RAIs SLRA Set 1_ERO(Rev 1) ML19079A0232019-03-19019 March 2019 Licensed Operator Positive Fitness-For-Duty Test ML19058A2902019-02-27027 February 2019 Request for Additional Information - High Pressure Service Water One Time TS Change ML19037A4832019-02-0606 February 2019 NRR E-mail Capture - Clarification Questions Associated with Staff Assessment of Peach Bottom Seismic Probabilistic Risk Assessment Report Dated August 28, 2018 ML19028A0062019-01-25025 January 2019 Secondary Containment LAR Requests for Additional Information ML19017A0472019-01-16016 January 2019 Request for Additional Information - High Pressure Service Water One Time TS Change ML18348B0292018-12-13013 December 2018 Subsequent License Renewal Severe Accident Mitigation Alternatives Requests for Additional Information ML19010A3832018-12-0707 December 2018 Additional Documents Needed for Peach Bottom SLR Environmental Review ML18324A6742018-11-15015 November 2018 Request for Additional Information (FINAL)- LAR to Allow 2SRV/SVs OOS at High Pressure ML18312A4072018-11-0808 November 2018 Request for Additional Information (Public) - LAR to Allow 2SRV/SVs OOS at High Pressure ML18276A0202018-10-0202 October 2018 NRR E-mail Capture - Exelon Generation Company, LLC - Request for Additional Information Regarding License Amendment Request to Revise Emergency Plan for Limerick and Peach Bottom ML18240A1742018-08-28028 August 2018 Request for Additional Information (Final) - Adopt TSTF-500 Battery TS Changes LAR ML18239A1322018-08-27027 August 2018 Request for Additional Information Final - Relief Request I5R-04 ML18228A6762018-08-14014 August 2018 Request for Additional Information - Adopt TSTF-500 Battery TS Changes LAR ML18226A2012018-08-14014 August 2018 Request for Additional Information - Relief Request I5R-05 ML18214A2812018-08-0202 August 2018 Request for Additional Information Draft - Relief Request I5R-02 ML18200A2742018-07-17017 July 2018 Request for Additional Information 2nd Round (Final) - Adopt 50.69 License Amendment ML18192A1192018-07-10010 July 2018 Request for Additional Information 2nd Round (Final) - Adopt 50.69 License Amendment ML18178A4772018-06-27027 June 2018 Request for Additional Information 2nd Round - Adopt 50.69 License Amendment ML18096B5062018-04-0606 April 2018 Request for Additional Information Exelon Generation Company, LLC Requested Amendment to Adopt 10 CFR 50.69 for Risk-informed Categorization and Treatment of Structures, Systems and Components ML18094B0832018-04-0505 April 2018 Enclosurequest for Additional Information (Letter to P. Duke RAI Regarding Entergy Operations, Inc.'S Decommissioning Funding Plan Update for Salem and Hope Creek, and Peach Bottom ISFSIs Docket Nos. 72-48 and 72-29) ML18067A1482018-03-0808 March 2018 Enclosurequest for Additional Information (Letter to P. R. Simpson Request for Additional Information Regarding Exelon Generating Company, Llc'S Decommissioning Funding Plan Update for Independent Spent Fuel Storage Installation) ML17317B5502017-11-0909 November 2017 Licensed Operator Positive Fitness-For-Duty Test ML17240A0062017-08-24024 August 2017 Request for Additional Information Regarding License Amendment Request for Measurement Uncertainty Recapture Power Uprate ML17222A0962017-08-10010 August 2017 Request for Additional Information - Amendment Request Regarding Safety Relief Valve and Safety Valce Operability for Cycle 22 2023-09-21
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From: Tobin, Jennifer To: Helker, David P:(GenCo-Nuc)
Cc: "Gropp Jr, Richard W:(GenCo-Nuc)"
Subject:
Peach Bottom Units 2 and 3 - Request for Additional Information 2nd Round - Adopt 50.69 License Amendment (EPID L-2017-LLA-0281)
Date: Tuesday, June 26, 2018 4:46:00 PM Attachments: Peach Bottom 50-69 2nd Round RAIs.docx
Dear Mr. Helker,
By letter dated August 30, 2017 (Accession No. ML17243A014), as supplemented by letter dated October 24, 2017 (ADAMS Accession No. ML17297B521), Exelon Generation Company, LLC requested an amendment to the facility operating license for Peach Bottom Atomic Power Station Units 2 and 3 to adopt 10 CFR 50.69 for Risk-informed Categorization and Treatment of Structures, Systems and Components.
The Nuclear Regulatory Commissions (NRC) staff is reviewing your submittal and has determined that additional information is needed to complete its review. The specific request for additional information (RAI) questions are provided below. These DRAFT questions are being sent to ensure that the questions are understandable, the regulatory basis for the questions is clear, and to determine if the information was previously docketed. A clarification phone call to discuss the DRAFT RAIs will be scheduled, if needed.
If you have any questions, please contact me at (301) 415-2328. A copy of this e-mail will be made publicly available in ADAMS.
- Thanks, Jenny Jenny Tobin Project Manager NRR/DORL/LPL-1 Office O9-C12 Phone 301-415-2328 REQUEST FOR ADDITIONAL INFORMATION (DRAFT)
APPLICATION TO ADOPT 10 CFR 50.69 RISK-INFORMED CATEGORIZATION OF STRUCTURES, SYSTEMS, AND COMPONENTS EXELON GENERATION COMPANY PEACH BOTTOM ATOMIC POWER STATION (PBAPS), UNITS 2 AND 3 DOCKET NOS. 50-277 AND 50-278 Title 10, of the Code of Federal Regulations, Part 50, Section 69 (10 CFR 50.69), Risk-Informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Reactors, allows licensees to use a risk-informed process to categorize systems, structures, and components (SSCs) according to their safety significance in order to remove SSCs of low safety significance from the scope of certain identified special
treatment requirements. Regulatory Guide (RG) 1.201, Revision 1, Guidelines for Categorizing Structures, Systems, and Components in Nuclear Power Plants According to their Safety Significance (Agencywide Documents Access and Management System (ADAMS) Accession No. ML061090627) endorses, with regulatory positions and clarifications, the Nuclear Energy Institute (NEI) guidance document NEI 0004, Revision 0 10 CFR 50.69 SSC Categorization Guideline, (ADAMS accession No. ML052910035) as one acceptable method for use in complying with the requirements in 10 CFR 50.69. Both RG 1.201 and NEI 0004 cite RG 1.200, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, (ADAMS Accession No. ML040630078) which endorses industry consensus probabilistic risk assessment (PRA) standards, as the basis against which peer reviews evaluate the technical adequacy of a PRA. Revision 2 of RG 1.200 is available at ADAMS Accession No. ML090410014.
By letter dated August 30, 2017 (ADAMS Accession No. ML17243A014), as supplemented by letters dated October 24, 2017 (ADAMS Accession No. ML17297B521), May 7, 2018 (ADAMS Accession No. ML18128A009), and June 6, 2018 (ADAMS Accession No. ML18157A260), Exelon Generation Company, LLC (Exelon, the licensee) submitted a license amendment request (LAR) to adopt the regulation in 10 CFR 50.69 at the Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. Section 3.1.1 of the LAR states that Exelon will implement the risk categorization process of 10 CFR 50.69 in accordance with NEI 0004, Revision 0, as endorsed by RG 1.201. However, the licensees LAR as supplemented does not contain enough information for the Nuclear Regulatory Commission (NRC) staff to determine if the licensee has implemented the guidance in NEI 0004, as endorsed by RG 1.201, appropriately as a means to demonstrate compliance with all of the requirements in 10 CFR 50.69. The following requests for additional information (RAIs) outline the specific issues and information needed to complete the NRC staffs review:
RAI 03.c.01 - Follow-up to Licensee Response to NRC RAI 03.c regarding Fire Modeling The disposition to partially resolved Fact and Observation (F&O) 2012-1-40 states that detailed two-point fire modeling was not been performed for all risk significant scenarios but this treatment did not have a significant impact on the application. In RAI 03.c, the NRC staff requested that the licensee justify its statement that not fully resolving the F&O has a minimal impact on the application or to provide a mechanism that ensures that the two-point fire modeling is applied to risk significant fire scenarios prior to implementing the 10 CFR 50.69 categorization process. The response to RAI 03.c states that this finding will be resolved prior to implementing 10 CFR 50.69. The licensee stated that risk significant fire PRA scenarios capable of being modeled using a two-point modeling approach will be updated using a two (or more) point fire modeling approach prior to implementation of the 50.69 process.
- i. Explain what the phrase capable of being modeled using a two-point modeling approach means and what type of fire scenarios will not be modeled using this approach.
ii. Justify how supporting requirement (SR) FSS-C1 will be met at Capability Category (CC) II after the update is performed.
iii. If SR FSS-C1 will not be met at CC-II, justify why not using a two-point model for all risk significant scenarios has no impact on the application.
RAI 05.b.01 - Follow-up to Licensee Response to NRC RAI 05.b regarding Uncoordinated Breakers in the Fire PRA The disposition to open F&O 2012-5-1 states that if the licensee identifies uncoordinated circuits, then the uncoordinated circuits will be modeled in the fire PRA. In RAI 05.b.ii, the NRC staff requested description of how modeling of uncoordinated circuits will be performed. The response to RAI 05.b proposed an implementation item stating that the uncoordinated circuits will be modelled or additional analysis will be performed to show that the circuits are coordinated. Confirm that any additional analysis performed to determine that circuits are coordinated will be performed in accordance with guidance in NUREG/CR-6850 on breaker coordination studies.
RAI 08.d.01 - Follow-up to Licensee Response to NRC RAI 08.d regarding the RCIC and HPCI Turbine Failure Probabilities In RAI 08.d.ii the NRC staff requested the licensee to provide justification for the nominal failure probability assigned to the failure of the Reactor Core Isolation Cooling (RCIC) and High Pressure Coolant Injection (HPCI) turbines to run after passing liquid. The licensees response to RAI 08.d states that failure of the HPCI and RCIC turbines to start were assigned a nominal value of 0.05 based on operator and system manager interviews, and based on engineering judgement. However, the licensee stated that the HPCI and RCIC turbines are not specifically designed to continue running while passing liquid and there was no industry failure data or valid testing under accident conditions cited in the RAI response. Provide the following:
- i. A sensitivity study or other quantitative justification which demonstrates that that the 10 CFR 50.69 categorization results are not sensitive to the assumed 0.05 failure probability, or ii. Propose a mechanism that removes credit for the 0.05 failure to start probability for HPCI and RCIC turbines in the internal event and fire PRAs prior to implementation of the 10 CFR 50.69 risk informed categorization process.
RAI 10.b.01 - Follow-up to Licensee Response to NRC RAI 10.b regarding External Flood Hazard Screening In RAI 10.b, the NRC staff requested the licensee to identify any structures, systems or components (SSCs), passive and/or active, which are credited in the screening of external flood hazards. The licensees response to RAI 10.b states that a recently issued NRC staff assessment of the Peach Bottom external flooding evaluation in a letter dated November 6, 2017 (ADAMS Accession No. ML17292B763) indicates that there are no SSCs credited in the screening of external flooding. In addition, the response states that either available physical margin exists or, where water ingress is expected, all external flood mechanisms resulted in water surface elevations below the design basis protection of the plant.
However, the evaluation letter refers to flood protection features that are credited to reliably maintain key safety functions identified in Appendix B of NEI 16-05, Revision 1
(ADAMS Accession No. ML16165A178). These features seem to be passive features such as doors. Provide the following:
- i. Clarify whether the flood protection features are SSCs, passive or active, that are credited in the external flood hazard screening.
ii. If the flood protection features are SSCs that are credited in the external flood hazard screening, then confirm that the guidance in NEI 00-04 Figure 5-6 will be followed for those SSCs (i.e. if the removal of the SSC would cause a screened scenario to become unscreened, then that SSC would be designated high-safety-significant).