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MONTHYEARML15210A7502015-07-29029 July 2015 Proposed Relief Request Associated with the Common Emergency Service Water (ESW) System Piping Project stage: Request ML15216A4912015-08-0404 August 2015 Acceptance Review for TACs MF6551 & MF6552 - Peach Bottom Units 2 and 3 - Relief Request to Defer Repair of Leak in Essential Service Water System Piping Project stage: Acceptance Review ML15223A5152015-08-10010 August 2015 Draft Request for Additional Information Project stage: Draft RAI ML15254A5452015-09-11011 September 2015 Response to Draft Request for Additional Information Regarding Proposed Relief Request Associated with the Common Emergency Service Water (ESW) System Piping Project stage: Draft Request ML15260A5032015-09-17017 September 2015 Summary of Telephone Conference on September 17, 2015, Verbal Authorization of Relief Request for Peach Bottom Atomic Power Station, Units 2 and 3 Project stage: Other 2015-08-04
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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:Response to Request for Additional Information (RAI)
MONTHYEARCCN:23-09, Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information2023-11-10010 November 2023 Supplemental Information Letter for Part 73 Exemption Request - Responses to Request for Confirmatory Information ML22312A3642022-11-0808 November 2022 Response to NRC Inspection Report and Preliminary White Finding ML22145A0852022-05-25025 May 2022 Response to Request for Additional Information - Proposed Relief Request Associated with Reactor Pressure Vessel N-16A Nozzle Repair 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 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 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 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 ML21035A0332021-02-0404 February 2021 Response to Request for Additional Information - 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 ML21029A1662021-01-29029 January 2021 Response to Request for Additional Information - 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 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 ML20224A5302020-08-11011 August 2020 Response to the Order for Implementation of Additional Security Measures and Fingerprinting for Unescorted Access for Wolf Creek Operating Corporation Independent Spent Fuel Storage Installation 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 ML19276F2812019-10-0303 October 2019 Supplemental Response to Request for Additional Information (RAl-1) License Amendment Request to Revise Technical Specifications 3.8.4, DC Sources-Operating ML19241A4652019-08-29029 August 2019 Response to Request for Additional Information (RAl-1) License Amendment Request to Revise Technical Specifications 3.8.4, DC Sources-Operating ML19225B9762019-08-13013 August 2019 Response to NRC Request for Clarification of Information, Dated August 1, 2019 Related to the Peach Bottom Atomic Power Station, Units 2 and 3, Subsequent License Renewal Application ML19206A0562019-07-24024 July 2019 Stations, Units 2 and 3 - Response to Request for Additional Information - License Amendment Request to Revise Technical Specifications 3.8.1, Required Action A.3, for Temporary One-Time Extension of Completion Time ML19163A2232019-06-12012 June 2019 Revised Response to NRC Request for Additional Information, Core Shroud Support Fatigue Analysis Reevaluation, Related to the Subsequent License Renewal Application ML19157A0092019-06-0606 June 2019 Response to NRC Request for Additional Information, Dated May 15, 2019 Related to the Peach Bottom Atomic Power Station, Units 2 and 3, Subsequent License Renewal Application 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 ML19150A2972019-05-30030 May 2019 Revised Responses to NRC Requests for Additional Information, Fire Water System, Related to the Peach Bottom Atomic Power Station, Units 2 and 3, Subsequent License Renewal Application ML19122A2892019-05-0202 May 2019 Response to NRC Requests for Additional Information, Set 1, Dated April 10, 2019 Related to Plant Subsequent License Renewal Application 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 ML19085A3852019-03-26026 March 2019 Response to Second Request for Additional Information - License Amendment Request to Reduce High Pressure Service Water System Design Pressure and Revise Technical Specifications ... ML19065A0082019-03-0505 March 2019 Response to Nrg Audit Review Information Request - Application for Subsequent Renewed Operating Licenses Section 4.6 Primary Containment Fatigue Analyses ML19046A1292019-02-15015 February 2019 Response to RAI - License Amendment Request to Reduce High Pressure Service Water System Design Pressure and Revise Technical Specifications 3.6.2.3, 3.6.2.4, 3.6.2.5, and 3.7.1 for Temporary Extension of Completion Times ML19028A2802019-01-28028 January 2019 Response to NRC Request for Additional Information, Dated December 13, 2018, Regarding Peach Bottom Atomic Power Station, Units 2 and 3, Subsequent License Renewal Severe Accident Mitigation Alternatives Requests for Additional Information 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 ML19007A3262019-01-0707 January 2019 Response to Request Dated December 7, 2018 for Docketing of Additional Documents to Support Nrc'S Environmental Review of the Peach Bottom Atomic Power Station, Units 2 and 3, Subsequent License Renewal Application ML18354B0612018-12-20020 December 2018 Response to NRC Request for Additional Information, Dated November 23, 2018, Regarding the Peach Bottom Atomic Power Station, Units 2 and 3, Subsequent License Renewal Application, Environmental Requests for Additional Information ML18340A1852018-12-0606 December 2018 Response to Request for Additional Information License Amendment Request - Revise Technical Specifications to Allow Two Safety Relief Valves/Safety Valves to Be Out-of-Service with Increased Reactor Pressure Safety Limit RS-18-143, Supplemental Information Supporting License Amendment Requests for Approval of Changes to Emergency Plan Staffing Requirements2018-11-29029 November 2018 Supplemental Information Supporting License Amendment Requests for Approval of Changes to Emergency Plan Staffing Requirements ML18337A2402018-11-28028 November 2018 Response to Request for Additional Information - Relief Requests Associated with the Fifth Inservice Inspection Interval ML18305B2702018-11-0101 November 2018 Response to Request for Additional Information - License Amendment Request for Approval of Changes to Emergency Plan Staffing Requirements ML18257A0172018-09-14014 September 2018 Response to Request for Additional Information Application to Revise Technical Specifications to Adopt Technical Specification Task Force (TSTF)-500, Revision 2, DC Electrical Rewrite Update to ... 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 ... 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. 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) ML17354A3812017-12-20020 December 2017 Supplemental Response Concerning License Amendment Request to Revise Technical Specifications to Adopt TSTF-542, Reactor Pressure Vessel Water Inventory Control, Revision 2 RS-17-149, Spent Fuel Pool Evaluation Supplemental Report, Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from The.2017-12-15015 December 2017 Spent Fuel Pool Evaluation Supplemental Report, Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from The. ML17241A1942017-08-29029 August 2017 License Amendment Request - Revise Technical Specifications Section 3.4.3 (Srvs/Svs) for the Remainder of the Current Operating Cycle for Unit 2 - Supplement 1 Response to Request for Additional Information ML17223A6262017-08-11011 August 2017 Response to Request for Additional Information Application to Revise Technical Specifications to Adopt TSTF-542, Reactor Pressure Vessel Water Inventory Control, Revision 2 ML17220A2142017-08-0808 August 2017 Measurement Uncertainty Recapture License Amendment Request - Supplement 3 Response to Request for Additional Information ML17195A2852017-07-13013 July 2017 Measurement Uncertainty Recapture License Amendment Request - Supplement 2 Response to Request for Additional Information 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 ML16224A3422016-08-11011 August 2016 Response to Request for Additional Information Regarding Proposed License Amendment Concerning Diesel Generator Lube Oil Inventory (TSTF-501-A) for Peach Bottom Atomic Power Station, Units 2 and 3 ML16216A0762016-08-0202 August 2016 Response to Draft Request for Additional Information Regarding the Proposed License Amendment Request Concerning Emergency Diesel Generator Fuel Oil Transfer Surveillance Requirements ML16162A1012016-06-0909 June 2016 Response to Request for Additional Information Regarding Proposed License Amendment Concerning Emergency Diesel Generator Fuel Oil Transfer Surveillance Requirements 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 ML16083A3942016-03-23023 March 2016 Changes to High Pressure Coolant Injection and Reactor Core Isolation Cooling Surveillance Requirements - Supplement 1, Response to Request for Additional Information 2023-11-10
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200 Exelon Way Kennett Square. 'A 19348 Exelon Generation www.exeloncorp.com 10 CFR 50.55a September 11, 2015 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278
Subject:
Response to Draft Request for Additional Information Regarding Proposed Relief Request Associated with the Common Emergency Service Water (ESW) System Piping for Peach Bottom Atomic Power Station, Units 2 and 3
References:
- 1) Letter from D. P. Helker (Exelon Generation Company, LLC) to the U.S.
Nuclear Regulatory Commission, "Proposed Relief Request associated with the Common Emergency Service Water (ESW) System Piping,"
dated July 29, 2015
- 2) E-mail correspondence from R. Ennis (U.S. Nuclear Regulatory Commission) to S. J. Hanson (Exelon Generation Company, LLC),
"Peach Bottom Atomic Power Station - Request for Additional Information Regarding Proposed Relief Request 14R-56 Emergency Service Water Leak Repair Deferral (ML15223A515)," dated August 6, 2015
- 3) Letter from D. P. Helker (Exelon Generation Company, LLC) to the U.S.
Nuclear Regulatory Commission, "Response to Request for Additional Information Regarding Proposed Relief Request associated with the Common Emergency Service Water (ESW) System Piping for Peach Bottom Atomic Power Station, Units 2 and 3," dated August 13, 2015.
- 4) E-mail correspondence from R. Ennis (U.S. Nuclear Regulatory Commission) to S. J. Hanson (Exelon Generation Company, LLC),
"Peach Bottom Atomic Power Station - Draft Request for Additional Information Regarding Proposed Relief Request 14R-56 Emergency Service Water Leak Repair Deferral (NRC TAC Nos. MF6551 and MF6552)," dated September 8, 2015
U.S. Nuclear Regulatory Commission Response to Request for Additional Information Concerning Relief Request 14R-56 September 11, 2015 Page2 By letter dated July 29, 2015, Exelon Generation Company, LLC (Exelon) submitted a Relief Request to the U.S. Nuclear Regulatory Commission (NRC) for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3 (Reference 1). Specifically, Exelon requested that the NRC authorize relief from Code Case N-513-3, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1" of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code) and the condition placed on Code Case N-513-3 as listed in Regulatory Guide 1.147, "lnservice Inspection Code Case Acceptability, ASME Section XI, Division 1," Revision 17, dated August 2014.
In the Reference 2 e-mail correspondence, the U.S. NRC requested additional information.
Reference 3 provided Exelon's response.
In the Reference 4 e-mail correspondence, the U.S. NRC requested additional information.
Attached is our response.
There are no regulatory commitments in this response.
If you have any questions concerning this response, please contact Stephanie J. Hanson at 610-765-5143.
Respectfully, David P. Helker Manager, Licensing and Regulatory Affairs Exelon Generation Company, LLC
Attachment:
Response to Draft Request for Additional Information Regarding Proposed Relief Request 14R-56 cc: USNRC Region I, Regional Administrator USNRC Senior Resident Inspector, PBAPS USNRC Project Manager, PBAPS R. R. Janati, Pennsylvania Bureau of Radiation Protection S. T. Gray, State of Maryland
ATTACHMENT 1 Response to Draft Request for Additional Information Regarding Proposed Relief Request I4R-56
Response to Request for Additional Information Attachment 1 Relief Request Concerning I4R-56 Page 1 of 2 Docket Nos. 50-277 and 50-278 By letter dated July 29, 2015, as supplemented by letter dated August 13, 2015, Exelon Generation Company, LLC (Exelon) submitted a relief request to the U.S. Nuclear Regulatory Commission (NRC) for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3.
Specifically, Exelon requested that the NRC authorize relief from Code Case N-513-3, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1" of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code) and the condition placed on Code Case N-513-3 as listed in Regulatory Guide 1.147, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1," Revision 17, dated August 2014. Relief Request I4R-56 proposes an alternative that allows repair of leaking moderate energy Class 3 Emergency Service Water (ESW) piping during the Unit 2 refueling outage (scheduled to begin in October 2016) in lieu of the Unit 3 outage (scheduled to begin in September 2015).
The NRC staff has determined that additional information is needed to complete its review. The specific request for additional information (RAI) question, which was discussed in a conference call between the NRC staff and Exelon on September 9, 2015, is restated below along with Exelon's response.
Question 1:
Please discuss how the analysis supporting the proposed relief request is consistent with the requirements in Section 3.2(d) of Code Case N-513-3.
Response
The following response discusses how the analysis supporting proposed Relief Request I4R-56 is consistent with the requirements in Section 3.2(d) of ASME Section XI, Division 1 Code Case N-513-3. The text of 3.2(d) is provided below with discussion on how the requirements are satisfied:
- 1. Alternatively, if there is a through-wall opening along a portion of the thinned wall as illustrated in Fig. 5 the flaw may be evaluated as two independent planar through-wall flaws, one oriented in the axial direction and the other oriented in the circumferential direction.
This is also known as the planar characterization approach. This was initially performed by Exelon in support of the Relief Request by evaluating the discovered flaws against the fracture toughness requirements for the material and comparing the results to the allowable values for fracture toughness (KI).
Subsequent to the initial evaluation, per NRC request, Exelon has performed additional evaluations consistent with the original methodology in accordance with the attached spreadsheet (Enclosure 1) where the axial flaw length (Laxial) and circumferential flaw lengths (Lcirc) are compared to the calculated allowable flaw sizes.
- 2. The minimum wall thickness tmin, shall be determined by eq. (4).
This was determined to be 0.0635 inch for design pressure of 150 psig and 0.0246 inch for the maximum operating pressure of 58 psig.
Response to Request for Additional Information Attachment 1 Relief Request Concerning I4R-56 Page 2 of 2 Docket Nos. 50-277 and 50-278
- 3. The allowable through-wall lengths in the axial and circumferential directions shall be determined by varying tadj shown in Fig. 5 from tnom to tmin.
A value of tadj = 0.328 was chosen for the subsequent evaluation. This is 87.5%
of the nominal wall thickness and is, therefore, between tnom and tmin as required.
- 4. The allowable through-wall flaw lengths based on tadj shall be greater than or equal to the corresponding Laxial and Lcirc (see Fig. 5) as determined from CC N-513-3 paragraphs 3.1(a) and 3.1(b) or 3.1(c), as appropriate.
The calculated allowable flaw lengths in the axial and circumferential directions are determined in accordance with 3.1(c) (Enclosure 1). This was the same methodology used in the initial analysis attached to Relief Request I4R-56. Laxial and Lcirc may be conservatively taken to be 4.5 inches from the UT inspections.
This approach takes no credit for any of the material less than tadj (i.e., the structural evaluation assumes a through-wall hole with a diameter of 4.5 inches).
The calculated allowable flaw lengths determined by the additional evaluations and using the maximum operating pressure, as allowed by the Code Case, are 8 inches in the axial direction and 13.5 inches in the circumferential direction.
Therefore, the allowable through-wall flaw lengths based on tadj are significantly greater than Laxial and Lcirc. In addition, the anticipated wear over the temporary acceptance period is not likely to challenge the structural integrity of the piping given the large margin between the conservatively characterized through-wall flaw and the allowable through-wall flaw.
- 5. The remaining ligament average thickness, tc,avg, over the degraded area bounded by Laxial and Lcirc shall satisfy eq. (9).
This requirement was first added to N-513-3 and is also known as the pressure blowout check. It is intended to provide margin against rapid failure of the remaining ligament to prevent personnel injury. Again taking Laxial and Lcirc as 4.5 inches, the required average wall thickness using the maximum operating pressure is 0.1 inch. Note that this calculation results in a larger thickness than the minimum required wall thickness calculated previously. However, based on the UT inspections, the average remaining wall thickness exceeds tc,avg.
Therefore, the requirement of Equation 9 is satisfied. Additionally, based on the corrosion rate of 0.012 inch/year as stated in Relief Request I4R-56, the remaining average wall thickness is also not anticipated to fall below the required tc,avg during the temporary acceptance period.
Response to Request for Additional Information Enclosure 1 Concerning Relief Request 14R-56 Page 1 of 4 Docket Nos. 50-277 and 50-278 Planar Flaw Evaluation in ferritic ninine IA W Code Case N-513-3 PBAPS ESW Min Wall "B" ESW {IR 2494904-03}
I Definitions:
I Flaw depth (lnom . tmin) - Information Only a= 0.047 in I
Pipe wall thickness (lnom) t= 0.375 in I
Maximum assumed circumferential flaw length (dadi): l= 13.500 in I
Pipe outside diameter: D= 12.75 in I
Mean pipe radius: R = D-t R= 6.21 in 2
I I= 7t[D -(D-2t)4 J 4
Piping bending moment of inertia: I= 247.06 in"4 64 I
Flaw half-angle per Figure I, N-513: 0 = 2*R 8= 1.087 rad I
Unit definition for kips: I kip= 1000 lbf I
Unit definition for psi: I ksi = 1000 psi I
Pinine Loads <Moments Increased bv 25% for Uncertainties):
I Maximum operating pressure: OP= 58.00 psi I
POP =7t(~ -t) *OP 2
Maximum operating pressure axial force: Pop= 6662.82 lbs I
Axial load on pipe for Normal/Upset condition forces : Pnu= 957 .00 lbs I
Axial load on pipe for Emergency/Faulted condition forces: Pnf= 1109.00 lbs I
Total axial load on pipe, including pressure from piping analysis for normal/upset condition forces: Pn = Pop+Pnu Pn= 7619.82 lbs I
Total axial load on pipe, including pressure from piping analysis for emergency/faulted condition forces: Pr= Pop+Pnr Pf= 7771.82 lbs I
Applied bending moment on the pipe from piping analysis Mn= 2206.25 ft-lbf for normal/upset condition (SRSS(MA, MB, MC) for WTOl+SEISOB)
I Aoolied bending moment on the pipe from piping analysis Mf= 4328.02 ft-lbf for emergency/faulted condition (SRSS(MA, MB, MC) for WTO I +SEISSS)
I Pipe thermal expansion stress from piping analysis: Pe= 0.000 ksi I
I Adjusted thickness per CC N-513-3, § 3.2(d) tadi = 0.328 in I
Response to Request for Additional Information Enclosure 1 Concerning Relief Request 14R-56 Page 2 of 4 Docket Nos. 50-277 and 50-278 Circumferential Flaw Evaluation Usinl! N-513 Pioinl! Material Prooerties Ref. ASME B31.1):
Young's Modulus: E= 27850 ksi Poisson's Ratio: µ= 0.30 E'= (FJ(I-µ2) E'= 30604.40 ksi Material Prooerties for Flaws oer H-4000:
2 From ASME XI C-8322 J1c = 45 in*lbf/in 5
Allowable Fracture Toughness, Kie: K1c = 37.l 11 ksi*in°*
05 Kie= (CJ1c
- N-513 Annendix I Circumferential Flaw eouations:
Accurate between 5 and 20. Conservative over 20. R/t= 18.936 Acceptable 3
Am= -2.02917 + I.67763*(R/t) - 0.07987*(Rlt/ + O.OOJ 76*(R/t)
Am= 13.05 2 3 Bm = 7.09987 - 4.42394*(R/t) + 0.21036*(R/t) - 0.00463*(R/t)
Bm= -32.68 2
Cm= 7.79661 + 5.16676*(R/t) - 0.24577*(R/t) + 0.00541 *(R/t)3 Cm= 54.24 5 25 Fm= 1.0 + Am*(0ht{ + Bm*(0ht) ' + Cm*(0hr) 3*5 Fm= 2.68 2 3 Ab= -3.26543 + I.52784*(R/t) - 0.072698*(R/t) + 0.0016011 *(R/t)
Ab= 10.47 Bb = l 1.36322 - 3.91412*(R/t) + 0.18619*(R/t/- 0.004099*(R!t}3 Bb= -23.82 2 3 Cb= -3.18609 + 3.84763*(R/t)- O.l8304*(R/t) + 0.00403*(R/t)
Cb= 31.40 5 25 Fb = 1.0 + Ab*(0ht/ + Bb*(0ht) + Cb*(0hr)3- 5 Fb= 2.22
Response to Request for Additional Information Enclosure 1 Concerning Relief Request 14R-56 Page 3 of 4 Docket Nos. 50-277 and 50-278 Annlied Stress Intensitv Factor KI for Circumferential Flaw:
N-513 Appendix I requires that the flaw depth in the C-7300 stress intensity equations be changed to the flaw half-length, c:
Maximum assumed circumferential flaw length: l= 13.500 in Flaw half-length, c = 1/2: c= 6.75 in Note: Units are converted automatically.
NormaVUnset Condition <ref. C-4311):
Kim=( 2.1*Pn }(Jr*c)0.5 *Fm Kim= 19.804 ksi-in° 5
2*Jl'*R*t K lb = ( 2.3
+~ . J( Ji. c )o.s . Fb K1b= 15.646 ksi-in°*
5 Kr= Krm+Krb Kr= 35.450 ksi-in°.s Therefore, Kr< Klc: Acceptable Emer2encv/Faulted Condition <ref. C-4311 ):
K Im
= ( 1.8 P1 *Jl'*c 2 . :Jl'
- R . t J( ) *Fm Krm= 13.466 ksi-in° 5
K lb = ( 1.6 M 2 1
+ Pe ) . (Jr . c )°' . Fb Krb= 21.351 ksi-in°*
5 Jr* R *t 5
K1= K1m+K1b Kr= 34.817 ksi-in° Therefore, K1< Klc: Acceptable
Response to Request for Additional Information Enclosure 1 Concerning Relief Request 14R-56 Page 4 of 4 Docket Nos. 50-277 and 50-278 Axial Throu!!h-walll Flaw Evaluation Usin!! N-513 Stress Intensitv Factor KI for an axial flaw subiect to the boundin!! condition <ref. C-4311):
Axial flaw length: l= 8.000 in Flaw half-length, c = 1/2: c= 4 in Maximum operating pressure: OP= 58 psi Safety Factor for normal/upset conditions from C-2622: SF= 2.7 N-513 Appendix I assigned flaw shape parameter for a through-wall flaw: Q= 1.00
/... = c/(R *t) 0*5 /...= 2.802 Therefore, O<'A.<5: Acceptable Note: Units are converted automatically 2 3 4 F = 1.0 + 0.072449*/... + 0.64856*/... - 0.2327*/... + 0.038154*/... - 0.0023487*/...5 F= 3.122 K
I
= SF. OP. R t
(r 7t.
Q c .F Ki=
Therefore, K1 < Kie:
32.823 Acceptable kSI-In
.. 0.5 END OF ASME CODE CASE N-513-3 EVALUATION