Letter Sequence Supplement |
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TAC:ME9631, BWR Technical Specification Changes That Implement the Revised Rule for Combustible Gas Control (Approved, Closed) |
Initiation
- Request, Request, Request, Request, Request, Request, Request, Request, Request
- Acceptance
- Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement
Administration
- Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance
- Meeting, Meeting
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MONTHYEARML12286A0122012-09-28028 September 2012 License Amendment Request - Extended Power Uprate Project stage: Request ML12286A0112012-09-30030 September 2012 License Amendment Request - Extended Power Uprate, Attachment 4, NEDO-33566, Rev. 0, Safety Analysis Report, Constant Pressure Power Uprate, Page 2-488 Through End, and Attachments 5 and 7 Through 9 Project stage: Request ML12279A2852012-10-22022 October 2012 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML12279A2902012-10-22022 October 2012 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit 2 Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13042A0962013-02-0808 February 2013 Completed Evaluation of Part 21 Potentially Reportable Condition Notification: Error in Main Steam Line High Flow Calculational Methodology Project stage: Request ML13051A0322013-02-15015 February 2013 Supplemental Information & Corrections Supporting Request for License Amendment Request - Extended Power Uprate - Supplement No. 1 Project stage: Supplement ML13056A4822013-03-0808 March 2013 Acceptance Review Regarding Proposed Extended Power Uprate Project stage: Acceptance Review ML13052A8532013-03-11011 March 2013 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13052A8562013-03-11011 March 2013 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13081A7052013-03-28028 March 2013 Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: RAI ML13106A1262013-04-26026 April 2013 Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: RAI ML13129A1432013-05-0707 May 2013 Extended Power Uprate, Supplement 2 - Response to Request for Additional Information Project stage: Supplement ML13149A1452013-05-24024 May 2013 Extended Power Uprate License Amendment Request - Supplement 3 Response to Request for Additional Information - Extended Power Uprate Project stage: Supplement ML13156A3682013-06-0404 June 2013 Extended Power Uprate License Amendment Request Supplement 4 Response to Request for Additional Information - Extended Power Uprate Project stage: Supplement ML13134A3842013-06-10010 June 2013 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13161A3972013-06-26026 June 2013 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13182A0252013-06-27027 June 2013 Supplemental Information Supporting Request for License Amendment Request - Extended Power Uprate - Supplement No. 5 Project stage: Supplement ML13178A3312013-07-0101 July 2013 Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: RAI ML13183A1992013-07-0303 July 2013 Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: RAI ML13203A1142013-07-23023 July 2013 Non-Proprietary - Request for Additional Information Regarding Proposed License Amendment Extended Power Uprate Project stage: RAI ML13203A1002013-07-23023 July 2013 Request for Additional Information Regarding License Amendment Request for Extended Uprate Project stage: RAI ML13211A4032013-07-30030 July 2013 EPU LAR Supplement 6 Attachment 2 - Response to Request for Additional Information - Snpb Project stage: Supplement ML13211A4022013-07-30030 July 2013 Extended Power Uprate License Amendment Request - Supplement 6 Response to Request for Additional Information - Extended Power Uprate Project stage: Supplement ML13213A2852013-07-31031 July 2013 Extended Power Uprate License Amendment Request - Supplement 7, Response to Request for Additional Information - Extended Power Uprate Project stage: Supplement ML13217A4312013-08-0505 August 2013 Extended Power Uprate License Amendment Request - Supplement 8 Response to Request for Additional Information - Extended Power Uprate Project stage: Supplement ML13221A0642013-08-15015 August 2013 Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: RAI ML13240A0022013-08-22022 August 2013 Extended Power Uprate License Amendment Request - Supplement 9 Response to Request for Additional Information Project stage: Supplement ML13232A2772013-08-26026 August 2013 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13232A2902013-08-26026 August 2013 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13241A4182013-08-29029 August 2013 Extended Power Uprate License Amendment Request - Supplement 10 Response to Request for Additional Information Project stage: Supplement ML13253A4162013-09-11011 September 2013 Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: RAI ML13260A0762013-09-13013 September 2013 Extended Power Uprate License Amendment Request - Supplement 11 Response to Request for Additional Information Project stage: Supplement ML13247A7692013-09-18018 September 2013 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13261A0432013-09-18018 September 2013 Requesty for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: Other ML13242A0902013-10-0101 October 2013 Draft Environmental Assessment and Finding of No Significant Impact Related to the Proposed Extended Power Uprate Project stage: Draft Other ML13242A1082013-10-0101 October 2013 Draft Environmental Assessment and Finding of No Significant Impact Related to the Proposed Extended Power Uprate Project stage: Draft Other ML13268A4002013-10-0101 October 2013 Enclosure 2 - Peach Bottom Atomic Power Station, Units 2 and 3 - Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: RAI ML13268A2632013-10-0101 October 2013 Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: RAI ML13289A1912013-10-11011 October 2013 Extended Power Uprate License Amendment Request - Supplement 12, Response to Request for Additional Information Project stage: Supplement ML13289A3002013-10-15015 October 2013 Extended Power Uprate License Amendment Request - Supplement 13 Response to Request for Additional Information Project stage: Supplement ML13308A3312013-10-31031 October 2013 Extended Power Uprate License Amendment Request - Supplement 14, Response to Request for Additional Information Project stage: Supplement ML13291A1222013-11-0606 November 2013 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13339A8072013-11-22022 November 2013 Comment (1) of Kevin Borton on Behalf of Exelon Generation Co. LLC, on Proposed License Amendment to Increase the Maximum Reactor Power Level Project stage: Other ML13338A2502013-12-0404 December 2013 Notice of Forthcoming Closed Meeting with Exelon Generation Company, LLC (Exelon) to Discuss Steam Dryer Analysis Related to Proposed Extended Power Uprate (EPU) for Peach Bottom Atomic Power Station (Pbaps), Units 2 and 3 Project stage: Request ML13345A6872013-12-0606 December 2013 Supplement 15 Response to Request for Additional Information Extended Power Uprate License Amendment Request Project stage: Supplement ML13308C4412013-12-11011 December 2013 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML13351A3902013-12-19019 December 2013 Summary of Closed Meeting with Exelon Generation Company, LLC, to Discuss Steam Dryer Analysis Related to Proposed Extended Power Uprate for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Meeting ML13358A0832013-12-20020 December 2013 Extended Power Uprate License Amendment Request- Supplement 16 Corrections, Clarifications and Additional Information - Extended Power Uprate Project stage: Supplement ML13345B3102014-01-0808 January 2014 Request for Withholding Information from Public Disclosure for Peach Bottom Atomic Power Station, Unit Nos. 2 and 3 Project stage: Withholding Request Acceptance ML14002A1762014-01-15015 January 2014 Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Project stage: RAI 2013-05-24
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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
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10 CFR 50.90 March 17, 2014 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:
Extended Power Uprate License Amendment Request- Supplement 23 Response to Request for Additional Information- Extended Power Uprate
Reference:
- 1. Exelon letter to the NRC, "License Amendment Request- Extended Power Uprate," dated September 28, 2012 (ADAMS Accession No.
ML122860201)
- 2. Letter from K. F. Borton (Exelon Generation Company, LLC) to U.S.
Nuclear Regulatory Commission, "Extended Power Uprate License Amendment request- Supplement 12 Response to Request for Additional Information," dated October 11, 2013 (ADAMS Accession No.
ML13289A191)
In accordance with 10 CFR 50.90, Exelon Generation Company, LLC (EGC) requested amendments to Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS) Units 2 and 3, respectively (Reference 1).
Specifically, the proposed changes would revise the Renewed Facility Operating Licenses to implement an increase in rated thermal power from 3514 megawatts thermal (MWt) to 3951 MWt.
The attachment to this letter provides EGC's response to the Mechanical and Civil Engineering Branch (EMCB) Request for Additional Information No. 37.
EGC has reviewed the information supporting a finding of no significant hazards consideration and the environmental consideration provided to the U. S. Nuclear Regulatory Commission in Reference 1. The supplemental information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration. Further, the additional information provided in this submittal 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.
U. S. Nuclear Regulatory Commission EPU LAR Supplement 23 Response to EMCB-RAI-37 March 17, 2014 Page2 In accordance with 10 CFR 50.91, "Notice for public comment; State consultation,"
paragraph (b), EGC is notifying the Commonwealth of Pennsylvania and the State of Maryland of this application by transmitting a copy of this letter along with the attachments to the designated State Officials.
There are no regulatory commitments contained in this letter.
Should you have any questions concerning this letter, please contact Mr. David Neff at (610) 765-5631 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 1ih day of March 2014.
Kevin F. Borton Manager, Licensing - Power Uprate Exelon Generation Company, LLC -Response to Mechanical and Civil Engineering Branch Request for Additional Information No. 37 cc: USNRC Region I, Regional Administrator w/attachments USNRC Senior Resident Inspector, PBAPS w/attach ments USNRC Project Manager, PBAPS w/attachments R. R. Janati, Commonwealth of Pennsylvania w/attachments S. T. Gray, State of Maryland w/attachments
Attachment 1 Peach Bottom Atomic Power Station Units 2 and 3 NRC Docket Nos. 50-277 and 50-278 Response to Mechanical and Civil Engineering Branch Request for Additional Information No. 37
EPU LAR Supplement 23 Attachment 1 Response to EMCB RAI-37 Page 1 of 3 Response to Request for Additional Information Mechanical and Civil Engineering Branch (EMCB)
By letter dated September 28, 2012, Exelon Generation Company, LLC (EGC) submitted a license amendment request for Peach Bottom Atomic Power Station (PBAPS}, Units 2 and 3.
The proposed amendment would authorize an increase in the maximum power level from 3514 megawatts thermal (MWt) to 3951 MWt. The requested change, referred to as an extended power uprate (EPU), represents an increase of approximately 12.4 percent above the current licensed thermal power level. Supplement 12 to the license amendment request, submitted to the NRC on October 11, 2013, (ADAMS Accession No. ML13289A191) provided responses to EMCB RAI Nos. 1 through 24. In an email dated February 27, 2014, from the NRC (Rick Ennis) to Exelon (Kevin Borton and Dave Neff), the NRC provided an RAI seeking information related to the response to EMCB-18 in Supplement 12. This attachment provides the response to that RAI.
EMCB-RAI-37 The licensee's response to NRC request for additional information (RAJ) EMCB-RAI-18 in Supplement 12 to the EPU license amendment request dated October 11, 2013, stated, in part that:
Vibration susceptibility assessments of small bore branch piping in systems experiencing significant flow increases due to EPU are being completed prior to EPU power ascension. These assessments identify potentially susceptible configurations using various screening criteria and are supplemented by walkdowns to confirm the small bore line configurations. Initial assessments and confirmatory walkdowns have been completed for the Unit 2 small bore piping.
Based on the results of these assessments and walkdowns, a large majority of the small bore lines were determined to be not susceptible to increased header-induced vibrations based on the established screening criteria and require no further action. For the remaining small bore lines, further evaluations are now being performed to better determine vibration susceptibility and the need for any support and/or piping modifications. The additional evaluations and development of any required modification designs will be completed in time to support installation of the modifications prior to EPU power ascension. The initial assessments and confirmatory walkdowns for the Unit 3 small bore lines are currently in progress. Based on the work completed to date, the Unit 3 results are expected to be similar to those for Unit 2.
The necessary monitoring, analyses and modifications to address potential piping vibration vulnerabilities are being performed to ensure there will be no adverse effects at EPU operating conditions.
With respect to the work being performed by the licensee to evaluate the potential impact of flow-induced vibration for small bore piping, as a result of the proposed EPU, please provide the following information:
a) List the systems of the small bore branch piping that were selected for screening and walkdowns.
EPU LAR Supplement 23 Attachment 1 Response to EMCB RAI-37 Page 2 of 3 b) Discuss the method and the screening criteria established to assess vibration susceptibility of small bore piping.
c) How does the screening indicate that further evaluations are required and what methodology do the additional evaluations employ?
d) Have the additional evaluations, mentioned in the EMCB-RAI-18 response, been completed? What modifications, if any, were required as a result of these evaluations?
RESPONSE
a) The following systems were selected for screening and walkdowns to evaluate the potential impact of flow-induced vibration (FIV) for small bore piping, due to the system's increased flow rates as a result of the proposed EPU:
- 1) Main Steam,
- 2) Feedwater,
- 3) Condensate,
- 4) Extraction Steam, and
- 5) Heater Drain.
b) A systematic process to assess vibration susceptibility of the small branch lines in the selected systems was performed for PBAPS Unit 2 and Unit 3. The assessment was conducted separately for Unit 2 and Unit 3. The lines were categorized into various configuration types and then evaluated using specific screening criteria. The EPRI Fatigue Management Handbook (Reference 37-1) was used as a basis for this assessment.
Verification walkdowns to confirm the configurations of the small bore piping in the selected systems were conducted on Unit 2 and Unit 3 during outages in 2012 and 2013, respectively.
The small bore lines were categorized as either cantilevered or complex configurations and then grouped into subcategories within those two configuration types. Cantilevered branch lines include one or more isolation valves or other masses that terminate a short distance from the large bore header without additional support. Complex branch lines feature spans that are supported in one or more additional locations beyond the large bore takeoff.
The following screening criteria were used to assess vibration susceptibility of the small bore branch lines as a result of EPU implementation:
- 1) Branch Lines Mounted to Well-Restrained Components or Piping (Cantilevered and Complex Configurations). A number of the identified small bore lines in the scope of this assessment are mounted near the inlet or outlet nozzles of pumps and heat exchangers.
These components are rigidly anchored to the plant structure, and should not experience increased FIV during EPU operation, regardless of their configuration type. Thus, implementation of EPU will not impact the vibration susceptibility of these lines.
- 2) Branch Lines on Header Piping with Minimal Predicted Flow Increase (Cantilevered and Complex Configurations). For individual large bore lines that do not experience an appreciable change in flow rate as a result of EPU, levels of FIV are expected to be nearly identical to present operation. Thus, implementation of EPU will not impact the vibration susceptibility of these lines.
EPU LAR Supplement 23 Attachment 1 Response to EMCB RAI-31 Page 3 of 3
- 3) Non-Susceptible Cantilevered Configurations. Cantilevered lines are most susceptible to vibration when they contain large unsupported masses or feature long spans of piping. Cantilevered branch lines that are short and/or support little suspended mass will not experience vibration-related failures. Thus, implementation of EPU will not impact the vibration susceptibility of these lines.
- 4) Cantilevered Lines with High Natural Frequencies. Cantilevered lines that did not fall within the non-susceptible configurations of item 3) above were evaluated on the basis of their calculated natural frequency. Cantilevered lines with natural frequencies above anticipated header vibration frequencies are considered to be not susceptible to EPU-related FIV concerns.
- 5) Complex Lines with Minimal Suspended Mass. Complex lines that do not support additional mass between the branch connection and the first support are not a concern for resonant excitation and are considered to be not susceptible to EPU-related FIV concerns.
- 6) Complex Lines with Balanced Support Configuration. Assessment of these lines was performed by qualitatively assessing their support configuration and verifying a balance between flexibility and rigidity. Balanced configurations are considered to be not susceptible to EPU-related FIV concerns.
Each small bore branch line was evaluated against the above screening criteria and assigned an EPU FIV susceptibility rating. Lines that met one or more of the screening criteria were considered to have a low probability of vibration susceptibility. Lines that did not meet at least one of the screening criteria were considered to have a higher probability of vibration susceptibility and warranted further evaluation.
c) Small bore lines with high EPU FIV susceptibility ratings were subjected to additional evaluations that included detailed focused reviews of the specific configurations, the creation of detailed piping models of representative (bounding) versions of the lines, and/or modal analyses to more accurately determine the first mode frequency.
d) The additional evaluations have been completed. Minor modifications are being implemented as a result of the evaluations. For Unit 2, two small bore branch line configurations, corresponding to eight individual lines, are being modified to include tie-back supports and/or other modifications to increase the natural frequency of the small bore lines.
For Unit 3, four small bore branch line configurations, corresponding to 15 individual lines, are being modified. The modifications being made to Unit 3 are similar to those being made to Unit 2.
Reference 37-1 Materials Reliability Program: Fatigue Management Handbook, Revision 1 (MRP-235).
EPRI, Palo Alto, CA: 2008. EPRI Proprietary Licensed Material.