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| Purdue used beam geometry in order to produce a preferential (laminar) crack at the location of reinforcement when loaded.During testing, cracks developed and opened to widths exceeding 0.10 inches when approaching the maximum load. These crack widths well exceeded the Shield Building cracks identified and essentially covered the entire test span prior to failure.Each of the beams tested demonstrated two fundamental properties: | | Purdue used beam geometry in order to produce a preferential (laminar) crack at the location of reinforcement when loaded.During testing, cracks developed and opened to widths exceeding 0.10 inches when approaching the maximum load. These crack widths well exceeded the Shield Building cracks identified and essentially covered the entire test span prior to failure.Each of the beams tested demonstrated two fundamental properties: |
| : 1. Each beam developed yielding stress in the reinforcement after the development of laminar cracks, and 2. The load deflection curves for each beam exhibited classic ductile behavior with increasing deflection beyond the yield point.These tests demonstrate that the reinforcement, and therefore the building as a system, retains its strength despite cracking, given the reinforcement was capable of developing yield stress. By exhibiting ductile behavior, the tests confirm that despite the laminar cracking condition, the building system can be expected to demonstrate the classically required deflection and surface cracking indications prior to failure.The University of Kansas also used a large-scale rectangular beam section with #11 rebar splices as noted above; however, the main study beams were cast with a cold joint in the plane of the reinforcement for a length greater than the entire splice length. The University of Kansas tested 6 beams: 3 with 79-inch splices, and 3 with 120-inch splices.These splice lengths correspond to the splice lengths used in the Shield Building.For the beams with the reload cycles, crack widths were at or greater than a width of 0.020 inches prior to unloading. | | : 1. Each beam developed yielding stress in the reinforcement after the development of laminar cracks, and 2. The load deflection curves for each beam exhibited classic ductile behavior with increasing deflection beyond the yield point.These tests demonstrate that the reinforcement, and therefore the building as a system, retains its strength despite cracking, given the reinforcement was capable of developing yield stress. By exhibiting ductile behavior, the tests confirm that despite the laminar cracking condition, the building system can be expected to demonstrate the classically required deflection and surface cracking indications prior to failure.The University of Kansas also used a large-scale rectangular beam section with #11 rebar splices as noted above; however, the main study beams were cast with a cold joint in the plane of the reinforcement for a length greater than the entire splice length. The University of Kansas tested 6 beams: 3 with 79-inch splices, and 3 with 120-inch splices.These splice lengths correspond to the splice lengths used in the Shield Building.For the beams with the reload cycles, crack widths were at or greater than a width of 0.020 inches prior to unloading. |
| This exceeds the crack widths identified in the Shield Building by a factor of approximately | | This exceeds the crack widths identified in the Shield Building by a factor of approximately |
| : 2. These specimens developed capacities near and above yield despite the conservative testing conditions. | | : 2. These specimens developed capacities near and above yield despite the conservative testing conditions. |
| Given the conservative nature of the conditions used in the tests, it is the conclusion of the professors who conducted and evaluated the tests that the reinforcement in the Shield Building experiences little, if any, reduction in strength and capacity due to the laminar cracking condition. | | Given the conservative nature of the conditions used in the tests, it is the conclusion of the professors who conducted and evaluated the tests that the reinforcement in the Shield Building experiences little, if any, reduction in strength and capacity due to the laminar cracking condition. |
| The studies also document that the structure retains its serviceability and ductile behavior. | | The studies also document that the structure retains its serviceability and ductile behavior. |
| The university test findings provide additional confidence in structural adequacy above that already documented in the functionality calculations, and confirmed that the robust design and construction of the Shield Building allow the building to retain significant margin against design loads even with laminar cracking.}} | | The university test findings provide additional confidence in structural adequacy above that already documented in the functionality calculations, and confirmed that the robust design and construction of the Shield Building allow the building to retain significant margin against design loads even with laminar cracking.}} |
Letter Sequence Response to RAI |
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TAC:ME4640, Steam Generator Tube Integrity (Approved, Closed) |
Results
- Approval, Approval, Approval, Approval, Approval, Approval, Approval, Approval, Approval, Approval, Approval, Approval
Other: L-11-114, Drawing No. M-042B, Rev. 35, Sampling System Sh. 2 Local Grab Samples, L-11-131, Drawing No. LR-OS041A2, Revision 1, Operational Schematic Emergency Diesel Generator Systems., L-11-334, Reply to Request Additional Information for the Review of the License Renewal Application Amendment No. 21, L-12-337, Review of the Safety Evaluation Report with Open Items Related to the License Renewal, L-12-444, Submittal of Contractor Equivalent Margins Assessments for Reactor Vessel Welds (Nonproprietary Versions), L-12-456, Notification of Closure of Commitments Related to the Review of the License Renewal Application, L-13-257, Notification of Completion of a License Renewal Commitment Related to the Review of License Renewal Application TAC No. ME4640) and License Renewal Application Amendment No. 45), L-13-330, License Renewal Application Amendment No. 46 - Annual Update, L-13-341, Review of the Safety Evaluation Report Related to the License Renewal of Davis-Besse Nuclear Power Station, L-14-085, License Renewal Application (TAC No. ME4640) Amendment No. 48, L-14-206, License Renewal Application Amendment No. 50 - Annual Update, L-15-120, Notification of Completion of License Renewal Commitments Related to the Review of the Davis-Besse Nuclear Power Station, Unit No. 1, License Renewal Application and License Renewal Application Amendment No. 55, L-15-139, License Renewal Reactor Vessel Internals Inspection Plan, L-15-214, License Renewal Application Amendment No. 59 - Annual Update, L-15-309, License Renewal Application Amendment No. 60, L-15-310, C-CSS-099.20-069, Rev 0, Shield Building Laminar Cracking Limits., ML102450565, ML111050091, ML11110A089, ML11110A091, ML11110A092, ML11110A093, ML11110A094, ML11110A095, ML11110A105, ML11110A106, ML11110A107, ML11122A014, ML11126A017, ML11126A018, ML11126A019, ML11126A020, ML11126A021, ML11126A022, ML11126A023, ML11126A024, ML11126A025, ML11126A026, ML11126A032, ML11126A033, ML11126A034, ML11126A035, ML11126A036, ML11126A037, ML11126A038, ML11126A039, ML11126A040, ML11126A041, ML11126A042, ML11126A043... further results
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MONTHYEARML11126A0882008-01-12012 January 2008 Drawing No. LR-M041B, Revision 1, Piping & Instrument Diagram Primary Service Water System. Job Code 12501 Project stage: Other ML11126A0902008-01-15015 January 2008 Drawing No. LR-OS41A1, Revision 1, Operational Schematic Emergency Diesel Generator Systems. Project stage: Other L-11-131, Drawing No. LR-OS041A2, Revision 1, Operational Schematic Emergency Diesel Generator Systems.2008-01-15015 January 2008 Drawing No. LR-OS041A2, Revision 1, Operational Schematic Emergency Diesel Generator Systems. Project stage: Other ML11126A0682008-05-0505 May 2008 Drawing No. LR-M-037E, Revision 28, Piping & Instrument Diagram Clean Liquid Radioactive Waste System. Project stage: Other ML11126A0652008-08-0606 August 2008 Drawing No. LR-M036B, Revision 1, Piping & Instrument Diagram Component Cooling Water System. Project stage: Other ML11126A0592008-10-0909 October 2008 Drawing No. LR-M033A, Revision 1, Piping & Instrument Diagram High Pressure Injection. Project stage: Other ML11126A0632008-10-10010 October 2008 Drawing No. LR-M033B, Revision 1, Piping & Instrument Diagram Decay Heat Train 1. Project stage: Other ML11126A0702008-10-10010 October 2008 Drawing No. LR-M033C, Revision 1, Piping & Instrument Diagram Decay Heat Train 2. Project stage: Other ML11126A0742008-11-0606 November 2008 Drawing No. LR-M043, Revision 1, Piping & Instrument Diagram Auxiliary Building Chilled Water System. Project stage: Other ML11126A0832008-12-18018 December 2008 Drawing No. LR-M038C, Revision 2, Piping & Instrument Diagram Gaseous Radioactive Waste System. Job Code 12501 Project stage: Other ML11126A0712009-04-0707 April 2009 Drawing No. LR-M034, Revision 1, Piping & Instrument Diagram Emerg. Core Cooling System Ctmt. Spray & Core Flooding Systems. Project stage: Other ML11126A0892009-04-0707 April 2009 Drawing No. LR-OS002, Revision 1, Operational Schematic Makeup and Purification System. Project stage: Other ML1024505652010-08-27027 August 2010 License Renewal Application and Ohio Coastal Management Program Consistency Certification Project stage: Other ML1104500462011-02-17017 February 2011 Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station - Fire Protection Project stage: RAI ML11126A0792011-02-25025 February 2011 Drawing No. LR-M900A, Revision 0, Instrument Air System Piping Schematic. Project stage: Other ML1104205972011-02-28028 February 2011 Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station - Section 2.4 Project stage: RAI ML1106801722011-03-17017 March 2011 Request for Additional Information on the Reactor Vessel Surveillance Aging Management Program, Time-Limited Aging Analyses for Neutron Embrittlement of the Rv and Internals, and Other TLAAs for the Review of the Davis-Besse Nuclear Power S Project stage: RAI ML1107007322011-03-18018 March 2011 Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station-Section 2.2 & 2.3 Project stage: RAI L-11-078, Reply to Request for Additional Information for the Review of License Renewal Application (TAC ME4640) Amendment No. 12011-03-18018 March 2011 Reply to Request for Additional Information for the Review of License Renewal Application (TAC ME4640) Amendment No. 1 Project stage: Response to RAI ML11068A0002011-03-21021 March 2011 Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station - Section 4.7 (TAC Number ME4640) Project stage: RAI L-11-079, Reply to Request for Additional Information for the Review of the License Renewal Application2011-03-23023 March 2011 Reply to Request for Additional Information for the Review of the License Renewal Application Project stage: Response to RAI L-11-089, Reply to Request for Additional Information for the Review License Renewal Application2011-03-23023 March 2011 Reply to Request for Additional Information for the Review License Renewal Application Project stage: Response to RAI ML1108206242011-03-30030 March 2011 Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station-Section 2.1 (Tac No. ME4640) Project stage: RAI ML1109002952011-03-31031 March 2011 Safety Evaluation Report Related to the License Renewal of Salem Nuclear Generating Station Project stage: Approval ML1108204902011-04-0505 April 2011 Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station - Batch 1 Project stage: RAI ML11110A0932011-04-15015 April 2011 Drawing No. M-037D, Rev. 21, Clean Liquid Radioactive Waste System Project stage: Other ML11110A1072011-04-15015 April 2011 Drawing No. M-045, Rev. 56, Chemical Addition Systems Project stage: Other ML11110A1062011-04-15015 April 2011 Drawing No. M-042C, Rev. 33, Sampling System Sh. 3 Project stage: Other ML11110A1052011-04-15015 April 2011 Drawing No. M-040A, Rev. 76, Reactor Coolant System Details Project stage: Other ML11110A0952011-04-15015 April 2011 Drawing No. M-039B, Rev. 18, Miscellaneous Liquid Radioactive Waste Project stage: Other ML11110A0942011-04-15015 April 2011 Drawing No. M-039A, Rev. 33, Miscellaneous Liquid Radioactive Waste Project stage: Other ML11110A0922011-04-15015 April 2011 Drawing No. M-037C, Rev. 30, Clean Liquid Radioactive Waste System Project stage: Other L-11-114, Drawing No. M-042B, Rev. 35, Sampling System Sh. 2 Local Grab Samples2011-04-15015 April 2011 Drawing No. M-042B, Rev. 35, Sampling System Sh. 2 Local Grab Samples Project stage: Other L-11-107, Reply to Request for Additional Information on Reactor Vessel Surveillance Aging Management Program & Time-Limited Aging Analyses for Neutron Embrittlement for Review of License Renewal Application & License Renewal Application...2011-04-15015 April 2011 Reply to Request for Additional Information on Reactor Vessel Surveillance Aging Management Program & Time-Limited Aging Analyses for Neutron Embrittlement for Review of License Renewal Application & License Renewal Application... Project stage: Response to RAI ML11110A0882011-04-15015 April 2011 Reply to Request for Additional Information for the Review of the License Renewal Application, Sections 2.2 & 2.3, License Renewal Application Amendment No. 3, and Revised License Renewal Project stage: Response to RAI ML11110A0912011-04-15015 April 2011 Drawing No. M-011, Rev. 61, Domestic Water System Project stage: Other ML11110A0892011-04-15015 April 2011 Drawing No. M-0060, Rev. 52, Auxiliary Feedwater System Project stage: Other ML1110500912011-04-19019 April 2011 Scoping and Screening Audit Report Regarding the Davis-Besse Nuclear Power Station License Renewal Application Project stage: Other L-11-115, Reply to Request for Additional Information for the Review of the License Renewal Application and License Renewal Application Amendment No. 42011-04-20020 April 2011 Reply to Request for Additional Information for the Review of the License Renewal Application and License Renewal Application Amendment No. 4 Project stage: Response to RAI ML1109807182011-04-20020 April 2011 Request for Additional Information for the Review of the Davis-Bessie Nuclear Power Station - Batch 2 Project stage: RAI ML11126A0362011-04-29029 April 2011 Drawing No. LR-M017D, Revision 1 Piping & Instrument Diagram, Steam Blackout Diesel Generator. Project stage: Other ML11126A0352011-04-29029 April 2011 Drawing No. LR-M017C, Revision 2, Piping & Instrument Diagram, Fuel Oil. Project stage: Other ML11126A0342011-04-29029 April 2011 Drawing No. LR-M017B, Revision 1, Piping & Instrument Diagram, Diesel Generators Air Start. Project stage: Other ML11126A0332011-04-29029 April 2011 Drawing No. LR-M016B, Revision 1, Piping & Instrument Diagram Station Fire Protection System Project stage: Other ML11126A0322011-04-29029 April 2011 Drawing No. LR-M016A, Revision 1, Piping & Instrument Diagram Station Fire Protection System Project stage: Other ML11126A0262011-04-29029 April 2011 Drawing No. LR-M010C, Revision 1, Piping & Instrument Diagram Make-up Water Treatment System Project stage: Other ML11126A0252011-04-29029 April 2011 Drawing No. LR-M010A, Revision 1, Piping & Instrument Diagram Make-Up Water Treatment System Project stage: Other ML11126A0242011-04-29029 April 2011 Drawing No. LR-M009B, Revision 1, Piping & Instrument Diagram Cooling Water System Project stage: Other ML11126A0192011-04-29029 April 2011 Drawing No. LR-M003A, Revision 1, Piping & Instrument Diagram Main Steam and Reheat System. Sheet 1 Project stage: Other ML11126A0452011-04-29029 April 2011 Drawing No. LR-M024H, Revision 1, Piping & Instrument Diagram, No. 2 Main and Auxiliary Turbine Driven Feed Pumps. Project stage: Other 2011-02-25
[Table View] |
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Category:Letter type:L
MONTHYEARL-24-025, Submittal of the Updated Final Safety Analysis Report, Revision 352024-09-25025 September 2024 Submittal of the Updated Final Safety Analysis Report, Revision 35 L-24-188, Submittal of Quality Assurance Program Manual, Revision 302024-08-27027 August 2024 Submittal of Quality Assurance Program Manual, Revision 30 L-24-186, Response to RAI for Exemption Request from 10 CFR 50.71(e)(4) Final Safety Analysis Update Schedule2024-08-15015 August 2024 Response to RAI for Exemption Request from 10 CFR 50.71(e)(4) Final Safety Analysis Update Schedule L-24-032, Cycle 23 and Refueling Outage 23 Inservice Inspection Summary Report2024-07-15015 July 2024 Cycle 23 and Refueling Outage 23 Inservice Inspection Summary Report L-24-063, License Amendment Request to Remove the Table of Contents from the Technical Specifications2024-07-0808 July 2024 License Amendment Request to Remove the Table of Contents from the Technical Specifications L-24-024, Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models2024-06-19019 June 2024 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models L-23-214, Submittal of Relief Request for Impractical American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section XI Examination Requirements2024-06-0505 June 2024 Submittal of Relief Request for Impractical American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section XI Examination Requirements L-24-019, Unit No.1 - Report of Facility Changes, Tests, and Experiments2024-05-22022 May 2024 Unit No.1 - Report of Facility Changes, Tests, and Experiments L-24-072, Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report - 20232024-05-15015 May 2024 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report - 2023 L-24-111, Response to Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations2024-05-15015 May 2024 Response to Regulatory Issue Summary 2024-01, Preparation and Scheduling of Operator Licensing Examinations L-24-031, Unit No.1 - Steam Generator Tube Circumferential Crack Report - Spring 2024 Refueling Outage2024-05-14014 May 2024 Unit No.1 - Steam Generator Tube Circumferential Crack Report - Spring 2024 Refueling Outage L-24-069, Occupational Radiation Exposure Report for Year 20232024-04-30030 April 2024 Occupational Radiation Exposure Report for Year 2023 L-24-018, Submittal of Core Operating Limits Report, Cycle 24, Revision 02024-04-16016 April 2024 Submittal of Core Operating Limits Report, Cycle 24, Revision 0 L-24-013, Annual Notification of Property Insurance Coverage2024-03-26026 March 2024 Annual Notification of Property Insurance Coverage L-23-264, Request for Exemption from 10 CFR 50.71(e)(4) Final Safety Analysis Report Update Schedule2024-02-23023 February 2024 Request for Exemption from 10 CFR 50.71(e)(4) Final Safety Analysis Report Update Schedule L-24-050, Retrospective Premium Guarantee2024-02-22022 February 2024 Retrospective Premium Guarantee L-23-260, Corrections to the 2022 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station2023-12-0707 December 2023 Corrections to the 2022 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station L-23-243, Independent Spent Fuel Storage Installation - Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-0606 December 2023 Independent Spent Fuel Storage Installation - Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation L-23-215, Changes to Emergency Plan2023-10-19019 October 2023 Changes to Emergency Plan L-23-205, Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-09-12012 September 2023 Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments L-23-172, Quality Assurance Program Manual2023-08-31031 August 2023 Quality Assurance Program Manual L-23-188, Energy Harbor Nuclear Corp., Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments2023-08-0707 August 2023 Energy Harbor Nuclear Corp., Supplement to Application for Order Consenting to Transfer of Licenses and Conforming License Amendments L-23-175, Submittal of Fifth Ten Year Inservice Testing Program2023-08-0101 August 2023 Submittal of Fifth Ten Year Inservice Testing Program L-23-034, 2022 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models2023-06-13013 June 2023 2022 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models L-23-135, Response to Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations2023-05-31031 May 2023 Response to Regulatory Issue Summary 2023-01, Preparation and Scheduling of Operator Licensing Examinations L-23-065, Annual Financial Report2023-05-22022 May 2023 Annual Financial Report L-23-101, Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station - 20222023-05-12012 May 2023 Combined Annual Radiological Environmental Operating Report and Radioactive Effluent Release Report for the Davis-Besse Nuclear Power Station - 2022 L-23-131, Readiness for Resumption of NRC Supplemental Inspection2023-05-12012 May 2023 Readiness for Resumption of NRC Supplemental Inspection L-23-092, Occupational Radiation Exposure Report for Year 20222023-04-27027 April 2023 Occupational Radiation Exposure Report for Year 2022 L-23-061, Submittal of the Decommissioning Funding Status Reports2023-03-31031 March 2023 Submittal of the Decommissioning Funding Status Reports L-23-037, and Perry Nuclear Power Plant - Independent Spent Fuel Storage Installation Changes, Tests, and Experiments2023-03-29029 March 2023 and Perry Nuclear Power Plant - Independent Spent Fuel Storage Installation Changes, Tests, and Experiments L-23-066, Annual Notification of Property Insurance Coverage2023-03-21021 March 2023 Annual Notification of Property Insurance Coverage L-23-059, Response to Apparent Violation in NRC Inspection Report 05000346/2022091; EA 23-0022023-03-0909 March 2023 Response to Apparent Violation in NRC Inspection Report 05000346/2022091; EA 23-002 L-22-212, CFR 50.55a Request RP-5 Regarding Inservice Pump Testing2023-03-0606 March 2023 CFR 50.55a Request RP-5 Regarding Inservice Pump Testing L-23-048, Response to Request for Additional Information Regarding Technical Specification 5.6.6 Steam Generator Tube Inspection 180-Day Report2023-03-0101 March 2023 Response to Request for Additional Information Regarding Technical Specification 5.6.6 Steam Generator Tube Inspection 180-Day Report L-23-057, Energy Harbor Nuclear Corp Retrospective Premium Guarantee2023-02-20020 February 2023 Energy Harbor Nuclear Corp Retrospective Premium Guarantee L-22-253, Submittal of Pressure and Temperature Limits Report, Revision 52023-01-10010 January 2023 Submittal of Pressure and Temperature Limits Report, Revision 5 L-22-284, Request for Notice of Enforcement Discretion for Technical Specification 3.7.9, Ultimate Heat Sink (UHS)2022-12-28028 December 2022 Request for Notice of Enforcement Discretion for Technical Specification 3.7.9, Ultimate Heat Sink (UHS) L-22-211, Technical Specification 5.6.6 Steam Generator Tube Inspection 180-Day Report2022-09-29029 September 2022 Technical Specification 5.6.6 Steam Generator Tube Inspection 180-Day Report L-22-216, Submittal of Pressure and Temperature Limits Report. Revision 42022-09-27027 September 2022 Submittal of Pressure and Temperature Limits Report. Revision 4 L-22-213, Occupational Radiation Exposure Report for Year 2021 - Correction2022-09-23023 September 2022 Occupational Radiation Exposure Report for Year 2021 - Correction L-22-129, Submittal of the Updated Final Safety Analysis Report, Revision 342022-09-20020 September 2022 Submittal of the Updated Final Safety Analysis Report, Revision 34 L-22-194, Submittal of Supplemental Information for the Reanalysis for Protection Against Low Temperature Reactor Coolant System Overpressure Events2022-09-19019 September 2022 Submittal of Supplemental Information for the Reanalysis for Protection Against Low Temperature Reactor Coolant System Overpressure Events L-22-203, Submittal of Evacuation Time Estimates2022-09-12012 September 2022 Submittal of Evacuation Time Estimates L-22-050, Summary of Changes to the Energy Harbor Nuclear Corp. Quality Assurance Program Manual2022-08-0909 August 2022 Summary of Changes to the Energy Harbor Nuclear Corp. Quality Assurance Program Manual L-22-152, Response to Request for Additional Information Regarding a License Amendment Request That Revises the Davis-Besse Nuclear Power Station Emergency Plan2022-07-0505 July 2022 Response to Request for Additional Information Regarding a License Amendment Request That Revises the Davis-Besse Nuclear Power Station Emergency Plan L-22-068, Cycle 22 and Refueling Outage 22 Inservice Inspection Summary Report2022-06-30030 June 2022 Cycle 22 and Refueling Outage 22 Inservice Inspection Summary Report L-22-037, 2021 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models2022-06-30030 June 2022 2021 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models L-22-149, Post Accident Monitoring Report2022-06-23023 June 2022 Post Accident Monitoring Report L-22-098, Withdrawal of Proposed Inservice Inspection Alternative RR-A22022-06-22022 June 2022 Withdrawal of Proposed Inservice Inspection Alternative RR-A2 2024-09-25
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FENOCTM FE OC% 5501 North State Route 2 FirstEnergy Nuclear Operating Company Oak Harbor, Ohio 43449 Raymond A. Lieb 419-321-7676 Vice President, Nuclear Fax:419-321-7582 February 28, 2013 L-1 3-098 10 CFR 54 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
Davis-Besse Nuclear Power Station, Unit No. 1 Docket No. 50-346, License Number NPF-3 Revised Reply to Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station, Unit No. 1, License Renewal Application (TAC No. ME4640)By letter dated August 27, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML102450565), FirstEnergy Nuclear Operating Company (FENOC) submitted an application pursuant to Title 10 of the Code of Federal Regulations, Part 54 for renewal of Operating License NPF-3 for the Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse).
By letter L-13-037 dated February 12, 2013, FENOC replied to Nuclear Regulatory Commission (NRC)requests for additional information (RAIs) related to NRC review of the Davis-Besse License Renewal Application (LRA). During a telephone conference with the NRC Project Manager for Davis-Besse License Renewal held on February 19, 2013, the NRC stated that it appeared there was a typographical error in the FENOC response to RAI B.2.43-2a regarding the value for university testing crack size.FENOC performed a review of the response to RAI B.2.43-2a and confirmed that the university testing crack size of 0.20 inches provided in the response was a typographical error. The correct value for the crack size should have been 0.020 inches.FENOC performed a review of the entire response and identified one additional change in the response.
Specifically, in the fourth paragraph of the response, the statement that"[t]wo adjacent splices at 6 inches on center spacing were used" should read "[t]wo adjacent splices at clear spacing of approximately 6 inches were used", since the spacing between the splices was not "on center" spacing. These conditions were entered into the FENOC Corrective Action Program.The Attachment provides the revised FENOC reply to NRC request for additional information B.2.43-2a.
The NRC request is shown in bold text followed by the FENOC response.1W1(45 Davis-Besse Nuclear Power Station, Unit No. 1 L-13-098 Page 2 There are no regulatory commitments contained in this letter. If there are any questions or if additional information is required, please contact Mr. Clifford I. Custer, Fleet License Renewal Project Manager, at 724-682-7139.
I declare und r penalty of perjury that the foregoing is true and correct. Executed on February ;,k, 2013.Sincerely, RayýoA L ie b
Attachment:
Revised Reply to Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse), License Renewal Application (LRA), Section B.2.43 cc: NRC DLR Project Manager NRC Region III Administrator cc: w/o Attachment NRC DLR Director NRR DORL Project Manager NRC Resident Inspector Utility Radiological Safety Board Attachment L-1 3-098 Revised Reply to Request for Additional Information for the Review of the Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse), License Renewal Application (LRA), Section B.2.43 Page 1 of 3 Question RAI B.2.43-2a
Background:
By letter dated November 20, 2012, the applicant responded to a request for additional information (RAI) regarding the proposed monitoring methods for the shield building (SB) cracking.
The RAI response indicates that the proposed inspection sample size of 20 core bores will cover the three areas of cracking (flute shoulders, upper 20 ft of the building, and the steam line penetrations) and is adequate to identify any changes in the laminar cracking, without further impulse response testing during the period of extended operation.
Issue: As part of evaluating the applicant's plan for monitoring the SB cracking with core bores, the staff needs to understand the technical basis for the size of the sample. For example, is the sample based purely on statistics or is it based on the long term effect of the concrete cracks on the ability of the reinforcement to carry design loads and the safety significance of the cracking.
In an earlier RAI response, dated April 5, 2012, it was indicated that the structural impact of the cracking would be determined via testing. A summary description of the test results and discussion of how the test results demonstrate that the sample size is sufficient has not been provided.Request: Provide a discussion of the technical basis for the adequacy of the sample size. If the sample size was based on laboratory testing, provide a summary of the testing. Include an explanation of the testing completed as well as the results, and how this information relates to the structural capacity of the SB and supports the adequacy of the sample size.Telephone Conference Call Summary: The NRC Staff initiated a telephone conference call with FENOC on January 16, 2013, to discuss and clarify NRC follow-up RAIs B.2.43-2a and B.2.43-3a regarding the Davis-Besse Shield Building Monitoring Program. Following discussions, NRC Staff stated that, instead of addressing RAI B.2.43-2a as written, FENOC should respond to the RAI by providing summaries of the laboratory (i.e., university) testing performed and the results of the testing. The summary should address the Attachment L-1 3-098 Page 2 of 3 Shield Building reinforcing bar-concrete bond strength, the assumptions made in the structural operability calculations regarding bond strength, and how the testing performed supports those assumptions.
A copy of laboratory reports is not needed by the NRC Staff.RESPONSE RAI B.2.43-2a Testing was performed at the University of Kansas and at Purdue University to assess the concrete-rebar bond strength of concrete with a laminar crack. Given the conservative nature of the test conditions used in these studies, it is concluded that the reinforcement in the Shield Building experiences little, if any reduction in strength and capacity due to the laminar cracking condition.
During the evaluation of the Shield Building laminar cracking in 2011, FENOC performed calculations to document that the Shield Building remains capable of performing its safety functions despite the presence of laminar cracking.
FENOC assumed in the evaluation calculations that there was no reinforcement capacity in cracked zones where the reinforcing bar included splices. The rationale for the assumption was that unspliced rebar spanning cracked zones retained capacity, while reinforcement capacity with rebar splices could not be quantified, and therefore was considered ineffective in the analysis.It was recognized at the time that follow-up laboratory testing was required to confirm assumptions regarding reinforcement capacity of spliced rebar.FENOC sponsored independent testing programs at Purdue University and the University of Kansas to determine the effects of laminar cracking in the plane of and parallel with reinforcing bar splices (a condition similar to the Shield Building laminar cracking).
The laboratory testing confirmed that the robust design and construction of the Shield Building allow the building to retain significant margin against design loads even with laminar cracking.Both universities conducted testing programs to evaluate the effects of the laminar cracking using large scale rectangular section beams with size #11 tension reinforcement splices. The #11 reinforcement was chosen since it matches the size used in the construction of the Shield Building.
Two adjacent splices at clear spacing of approximately 6 inches were used in all beams to simulate rebar interaction.
The test specimen set-up at both universities was conservative since the Shield Building reinforcement splices are staggered, and not side-by-side, as constructed at both laboratory test facilities.
Both testing programs used materials that were representative of the Shield Building materials with similar strengths.
Concrete strengths of the samples were representative and conservative relative to the strength of the materials in the Shield Building.
Select beams in both the Purdue and Kansas studies were subject to reload cycles. These beams were loaded to develop the crack (at calculated yield), unloaded, and the beams were reloaded to failure. The crack sizes developed exceeded the crack widths identified in the Shield Building.
Attachment L-1 3-098 Page 3 of 3 Purdue University tested six samples with 120-inch splices and six samples with 79-inch splices. These splice lengths correspond to the splice lengths used in the Shield Building.
Purdue used beam geometry in order to produce a preferential (laminar) crack at the location of reinforcement when loaded.During testing, cracks developed and opened to widths exceeding 0.10 inches when approaching the maximum load. These crack widths well exceeded the Shield Building cracks identified and essentially covered the entire test span prior to failure.Each of the beams tested demonstrated two fundamental properties:
- 1. Each beam developed yielding stress in the reinforcement after the development of laminar cracks, and 2. The load deflection curves for each beam exhibited classic ductile behavior with increasing deflection beyond the yield point.These tests demonstrate that the reinforcement, and therefore the building as a system, retains its strength despite cracking, given the reinforcement was capable of developing yield stress. By exhibiting ductile behavior, the tests confirm that despite the laminar cracking condition, the building system can be expected to demonstrate the classically required deflection and surface cracking indications prior to failure.The University of Kansas also used a large-scale rectangular beam section with #11 rebar splices as noted above; however, the main study beams were cast with a cold joint in the plane of the reinforcement for a length greater than the entire splice length. The University of Kansas tested 6 beams: 3 with 79-inch splices, and 3 with 120-inch splices.These splice lengths correspond to the splice lengths used in the Shield Building.For the beams with the reload cycles, crack widths were at or greater than a width of 0.020 inches prior to unloading.
This exceeds the crack widths identified in the Shield Building by a factor of approximately
- 2. These specimens developed capacities near and above yield despite the conservative testing conditions.
Given the conservative nature of the conditions used in the tests, it is the conclusion of the professors who conducted and evaluated the tests that the reinforcement in the Shield Building experiences little, if any, reduction in strength and capacity due to the laminar cracking condition.
The studies also document that the structure retains its serviceability and ductile behavior.
The university test findings provide additional confidence in structural adequacy above that already documented in the functionality calculations, and confirmed that the robust design and construction of the Shield Building allow the building to retain significant margin against design loads even with laminar cracking.