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| | number = ML15239B212 | | | number = ML15239B212 |
| | issue date = 09/03/2015 | | | issue date = 09/03/2015 |
| | title = Davis-Besse Nuclear Power Station, Unit 1 - Interim Staff Response to Reevaluated Flood Hazards Submitted in Response to 10 CFR 50.54(f) Information Request - Flood-Causing Mechanism Reevaluation | | | title = Interim Staff Response to Reevaluated Flood Hazards Submitted in Response to 10 CFR 50.54(f) Information Request - Flood-Causing Mechanism Reevaluation |
| | author name = Uribe J F | | | author name = Uribe J |
| | author affiliation = NRC/NRR/JLD | | | author affiliation = NRC/NRR/JLD |
| | addressee name = Boles B D | | | addressee name = Boles B |
| | addressee affiliation = FirstEnergy Nuclear Operating Co | | | addressee affiliation = FirstEnergy Nuclear Operating Co |
| | docket = 05000346 | | | docket = 05000346 |
| | license number = | | | license number = |
| | contact person = Uribe J F, NRR/JLD, 415-3809 | | | contact person = Uribe J, NRR/JLD, 415-3809 |
| | case reference number = TAC MF3721 | | | case reference number = TAC MF3721 |
| | package number = ML15239B210 | | | package number = ML15239B210 |
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| =Text= | | =Text= |
| {{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Brian D. Boles Site Vice President FirstEnergy Nuclear Operating Company c/o Davis-Besse NPS 5501 N. State Route 2 Oak Harbor, OH 43449-9760 September 3, 2015 | | {{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 3, 2015 Mr. Brian D. Boles Site Vice President FirstEnergy Nuclear Operating Company c/o Davis-Besse NPS 5501 N. State Route 2 Oak Harbor, OH 43449-9760 |
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| ==SUBJECT:== | | ==SUBJECT:== |
| DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1-INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) INFORMATION REQUEST-CAUSING MECHANISM REEVALUATION (TAC NO. MF3721) | | DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1- INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) INFORMATION REQUEST- FLOOD-CAUSING MECHANISM REEVALUATION (TAC NO. MF3721) |
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| ==Dear Mr. Boles:== | | ==Dear Mr. Boles:== |
| The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRC) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 11, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 14070A 108), flood hazard reevaluation report (FHRR) submitted by FirstEnergy Nuclear Operating Company (FENOC, the licensee) for the Davis-Besse Nuclear Power Station, Unit 1 (Davis-Besse), as well as supplemental information resulting from requests for additional information and audits. By letter dated March 12, 2012, the NRC issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f) (hereafter referred to as the 50.54(f) letter) (ADAMS Accession No. ML 12053A340). The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance. Concurrently, with the reevaluation of flooding hazards, licensees were required to develop and implement mitigating strategies in accordance with NRC Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 12054A735). On March 30, 2015, the Commission provided Staff Requirements Memoranda (SRM) (ADAMS Accession No. ML 15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards," dated November 21, 2014 (ADAMS Accession No. ML 14309A256), affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events. The NRC staff has reviewed the information submitted by the licensee and has summarized the results of the review in the table provided as an Enclosure to this letter. Table 1 provides the current design-basis flood hazard mechanisms. Table 2 provides reevaluated flood hazard mechanisms; however, reevaluated flood hazard mechanisms bounded by the current basis (Table 1) are not included B. Boles The NRC staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information described in guidance documents currently being finalized by the industry and NRC staff) for Davis-Besse. Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding". The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time. In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised. This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards. Once this methodology is endorsed by the NRC, flood duration parameters and applicable associated effects should be considered as part of the Davis-Besse MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and related associated effects developed by the licensee during the NRC staff's review of the MSA. As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis. In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 15174A257). This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan for the Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML 15209A682). | | |
| B. Boles If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov. Docket No. 50-346 | | The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRC) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 11, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14070A108), flood hazard reevaluation report (FHRR) submitted by FirstEnergy Nuclear Operating Company (FENOC, the licensee) for the Davis-Besse Nuclear Power Station, Unit 1 (Davis-Besse), as well as supplemental information resulting from requests for additional information and audits. |
| | By letter dated March 12, 2012, the NRC issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f) (hereafter referred to as the 50.54(f) letter) |
| | (ADAMS Accession No. ML12053A340). The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance. Concurrently, with the reevaluation of flooding hazards, licensees were required to develop and implement mitigating strategies in accordance with NRC Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML12054A735). On March 30, 2015, the Commission provided Staff Requirements Memoranda (SRM) (ADAMS Accession No. ML15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards," dated November 21, 2014 (ADAMS Accession No. ML14309A256), affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events. |
| | The NRC staff has reviewed the information submitted by the licensee and has summarized the results of the review in the table provided as an Enclosure to this letter. Table 1 provides the current design-basis flood hazard mechanisms. Table 2 provides reevaluated flood hazard mechanisms; however, reevaluated flood hazard mechanisms bounded by the current design-basis (Table 1) are not included |
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| | B. Boles The NRC staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information described in guidance documents currently being finalized by the industry and NRC staff) for Davis-Besse. Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding". The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time. |
| | In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised. This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards. Once this methodology is endorsed by the NRC, flood duration parameters and applicable associated effects should be considered as part of the Davis-Besse MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood-related associated effects developed by the licensee during the NRC staff's review of the MSA. |
| | As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis. In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML15174A257). This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan for the Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML15209A682). |
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| | B. Boles If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov. |
| | Juan F. ribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket No. 50-346 |
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| ==Enclosure:== | | ==Enclosure:== |
| Summary of Results of Flooding Hazard Re-Evaluation Report -ML 15238B865 cc w/encl: Distribution via Listserv Juan F. ribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation ENCLOSURE: SUMMARY TABLES OF REEVALUATED FLOOD HAZARD LEVELS Davis-Besse, Unit 1 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism I Stillwater Waves/ Design Basis Reference I I Elevation Run up Hazard Elevation Local Intense Precipitation LIP -Turbine Building 584.5 ft Minimal 584.5 ft FHRR Section 2.1.1 IGLD55 IGLD55 Streams and Rivers i River and Streams 579.0 ft Not 579.0 ft FHRR Section 2.1.2 IGLD55 applicable IGLD55 Failure of Dams and Onsite I Water Control/Storage Structures Dam Failure No Impact No Impact No Impact FHRR Section 2.1.3 Identified Identified Identified Storm Surge Storm Surge 583.7 ft 6.6 ft 590.3 ft FHRR Section 2.1.4 IGLD55 IGLD55 FHRR Section 2.1.8 ' Seiche Seiche Not included Not included Not included FHRR Table 3 in DB in DB in DB Tsunami 1 Not included Not included Not included FHRR Table 3 in DB in DB in DB I Ice-Induced Flooding No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Channel Migrations/Diversions No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Note: Reported values are rounded to the nearest one-tenth of a foot.
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| Davis-Besse, Unit 1 Table 2. Reevaluated Flood Hazards for Flood-Causing Mechanisms for Use in the MSA Mechanism Stillwater Waves/ Reevaluated Reference Elevation Run up Hazard Elevation Local Intense Precipitation Turbine Building 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Intake Structure 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Auxiliary Buildings 585.4 ft Minimal 585.4 ft FHRR Table 1 IGLD55 IGLD55 Storm Surge 585.8 ft 0.1 ft 585.9 ft FHRR Section 3.7.4 IGLD55 IGLD55 i Note 1: The licensee is expected to develop flood event duration parameters and applicable flood associated effects to conduct the MSA. The staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood associated effects during its review of the MSA. Note 2: Reevaluated hazard mechanisms bounded by the current design basis (see Table 1) are not included in this table. Note 3: Reported values are rounded to the nearest one-tenth of a foot.
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| PKG ML 152398210 LTR: ML 152398212 ENCL: ML 152388865 *via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA N RO/DSEA/RH M2/TR* NAME JUribe Slent Mlee DATE 8127 /15 8 / 27 /15 8 / 26 /15 OFFICE NRO/DSEA/RHM2/BC* NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME CCook MShams JUribe DATE 8 / 26 /15 8 / 28 /15 9 / 3 /15}} | | Summary of Results of Flooding Hazard Re-Evaluation Report - ML15238B865 cc w/encl: Distribution via Listserv |
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| | ENCLOSURE: |
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| | ==SUMMARY== |
| | TABLES OF REEVALUATED FLOOD HAZARD LEVELS |
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| | Davis-Besse, Unit 1 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism I Stillwater Waves/ Design Basis Reference I |
| | I Elevation Run up Hazard Elevation Local Intense Precipitation LIP - Turbine Building 584.5 ft Minimal 584.5 ft FHRR Section 2.1.1 IGLD55 IGLD55 Streams and Rivers i River and Streams 579.0 ft Not 579.0 ft FHRR Section 2.1.2 IGLD55 applicable IGLD55 Failure of Dams and Onsite I Water Control/Storage Structures Dam Failure No Impact No Impact No Impact FHRR Section 2.1.3 Identified Identified Identified Storm Surge Storm Surge 583.7 ft 6.6 ft 590.3 ft FHRR Section 2.1.4 IGLD55 IGLD55 FHRR Section 2.1.8 Seiche Seiche Not included Not included Not included FHRR Table 3 in DB in DB in DB Tsunami Not included Not included Not included FHRR Table 3 in DB in DB in DB 1 |
| | I Ice-Induced Flooding No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Channel Migrations/Diversions No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Note: Reported values are rounded to the nearest one-tenth of a foot. |
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| | Davis-Besse, Unit 1 Table 2. Reevaluated Flood Hazards for Flood-Causing Mechanisms for Use in the MSA Mechanism Stillwater Waves/ Reevaluated Reference Elevation Run up Hazard Elevation Local Intense Precipitation Turbine Building 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Intake Structure 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Auxiliary Buildings 585.4 ft Minimal 585.4 ft FHRR Table 1 IGLD55 IGLD55 Storm Surge 585.8 ft 0.1 ft 585.9 ft FHRR Section 3.7.4 IGLD55 IGLD55 i |
| | Note 1: The licensee is expected to develop flood event duration parameters and applicable flood associated effects to conduct the MSA. The staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood associated effects during its review of the MSA. |
| | Note 2: Reevaluated hazard mechanisms bounded by the current design basis (see Table 1) are not included in this table. |
| | Note 3: Reported values are rounded to the nearest one-tenth of a foot. |
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| | PKG ML152398210 LTR: ML152398212 ENCL: ML152388865 *via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA NRO/DSEA/RH M2/TR* |
| | NAME JUribe Slent Mlee DATE 8127 /15 8 / 27 /15 8 / 26 /15 OFFICE NRO/DSEA/RHM2/BC* NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME CCook MShams JUribe DATE 8 / 26 /15 8 / 28 /15 9 / 3 /15}} |
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Category:Graphics incl Charts and Tables
MONTHYEARL-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 ML20142A3972020-05-0505 May 2020 Annual Radiological Environmental Operating Report, Figure 32, Wind Rose Annual Average 10M ML20142A3982020-05-0505 May 2020 Annual Radiological Environmental Operating Report, Figure 31, Wind Riose Annual Average 75M ML20142A3992020-05-0505 May 2020 Annual Radiological Environmental Operating Report, Figure 30, Wind Rose Annual Average 100M ML16056A1392016-03-11011 March 2016 Correction to the U.S. Nuclear Regulatory Commission Analysis of Licensees' Decommissioning Funding Status Reports ML15239B2122015-09-0303 September 2015 Interim Staff Response to Reevaluated Flood Hazards Submitted in Response to 10 CFR 50.54(f) Information Request - Flood-Causing Mechanism Reevaluation ML15238B8652015-09-0303 September 2015 FHRR MSFHI Tables 1 and 2 ML14307B7072014-12-10010 December 2014 Supplemental Information Related to Development of Seismic Risk Evaluations for Information Request Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Seismic Hazard Reevaluations for Recommendation 2.1 of the Near-T 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)2013-07-23023 July 2013 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) ML12167A2622012-05-29029 May 2012 Enclosure - Davis-Besse 17RFO License Condition 2.C(7) SG Circumferential Crack Report ML1214500142012-05-23023 May 2012 NFPA 805 LAR Status Matrix - May 2012 ML1015201172010-05-28028 May 2010 Nozzle 4 - 52M Deposit Depth ML1005396232010-02-22022 February 2010 Lessons Learned Task Force Action Plan Regarding Stress Corrosion Cracking Dec 2009 (Final Update) ML0824902892008-10-0202 October 2008 ITSB Draft L, to Davis-Besse Amendment Conversion Improved Technical Specifications with Beyond Scope Issues ML0824903002008-10-0202 October 2008 ITSB Draft R, to Davis-Besse Amendment Conversion Improved Technical Specifications with Beyond Scope Issues ML0824902952008-10-0202 October 2008 ITSB Draft M, to Davis-Besse Amendment Conversion Improved Technical Specifications with Beyond Scope Issues ML0824902752008-10-0202 October 2008 Draft a, Attachment to Davis Besse Amendment Conversion Improved Technical Specifications with Beyond Scope Issues ML0824902802008-10-0202 October 2008 ITSB Draft La, to Davis Besse Amendment Conversion Improved Technical Specifications with Beyond Scope Issues L-08-094, Response to Request for Additional Information Regarding Measurement Uncertainty Recapture Power Uprate Amendment Application2008-03-12012 March 2008 Response to Request for Additional Information Regarding Measurement Uncertainty Recapture Power Uprate Amendment Application ML0727405102008-02-11011 February 2008 Lltf Action Plan Feb 2008 Update - Public ML0803700812008-02-0101 February 2008 Lltf Status of Recommendations February 2008 ML0728203072007-10-11011 October 2007 Electronic Distribtion Initiative Letter, Licensee List, Electronic Distribution Input Information, Division Plant Mailing Lists ML0708602822007-03-15015 March 2007 Review and Analysis of the Davis-Besse March 2002 Reactor Pressure Vessel Head Wastage Event, Appendix B, Crack Driving Force and Growth Rate Estimates ML0708602812007-03-15015 March 2007 Review and Analysis of the Davis-Besse March 2002 Reactor Pressure Vessel Head Wastage Event, Appendix a, Finite Element Stress Analysis of Davis-Besse CRDM Nozzle 3 Penetration ML0708602712007-03-15015 March 2007 Review and Analysis of the Davis-Besse March 2002 Reactor Pressure Vessel Head Wastage Event, Section 8. Stress Analysis and Crack Growth Rates for Davis-Besse CRDM Nozzles 2 and 3 ML0708602682007-03-15015 March 2007 Review and Analysis of the Davis-Besse March 2002 Reactor Pressure Vessel Head Wastage Event, Section 7. FENOC/Davis-Besse Response to CRDM Cracking and Boric Acid Corrosion Issues ML0708602642007-03-15015 March 2007 Review and Analysis of the Davis-Besse March 2002 Reactor Pressure Vessel Head Wastage Event, Section 6. Boric Acid Wastage of Carbon Steel Components in Us PWR Plants ML0708602612007-03-15015 March 2007 Review and Analysis of the Davis-Besse March 2002 Reactor Pressure Vessel Head Wastage Event, Section 5. Worldwide Industry Response to CRDM and Other Alloy 600 Nozzle Cracking ML0708602532007-03-15015 March 2007 Review and Analysis of the Davis-Besse March 2002 Reactor Pressure Vessel Head Wastage Event, Section 3. Background ML0702603952007-01-31031 January 2007 Summary of Conference Telephone Call Regarding the Spring 2006 Steam Generator Inspections - Handouts ML0618002582006-06-27027 June 2006 Closure of Davis-Besse Operational Improvement Plan ML0611401302006-03-16016 March 2006 Ltr Fm J. Gutierrez, Morgan Lewis to S. Brock Requesting to Withhold Materials from Public Disclosure Which Was Submitted by FENOC - Affidavits of Terry Young and Warren Bilanin ML0525707982005-09-12012 September 2005 Documentation of Completed Post-Restart Process Plan for Transition of Davis-Besse from the IMC 0350 Oversight Process to the Reactor Oversight Program (ROP) ML0523801412005-08-31031 August 2005 Status of Davis-Besse Lessons Learned Task Force Recommendations - Last Update: August 31, 2005 ML0411301992004-04-21021 April 2004 Oversight Panel Final Restart Checklist Public Release Memo ML0414503382004-02-13013 February 2004 Oversight Panel Open Action Item List ML0414503372004-02-13013 February 2004 IMC 0350 Panel Process Plan ML0414503262004-02-13013 February 2004 Restart Action Matrix - Open Items Only ML0308000432003-01-0101 January 2003 Firstenergy Nuclear Operating Company, NRC Allegations and Employee Concerns Program Contact Trends, January 2002 - January 2003 ML0224601492002-08-29029 August 2002 Undated Data Chart, CDF, LERF, Rem ML0224601482002-08-29029 August 2002 Heat 69 Crack Growth - Bounding Weibull with 1.5 Shape Facto with Handwritten Notes ML0224601422002-08-29029 August 2002 Chart, Long-Term Results for Integrated Model with Handwritten Notes ML0224003452002-08-27027 August 2002 Failure Frequency Curve for Davis-Besse Conditions ML0224003402002-08-27027 August 2002 Draft Graphs for Flaw Curves and Stress Intensity Factors ML0530703682002-03-13013 March 2002 Timeline of Key Events Related to Reactor Vessel Head Boric Acid Wastage Rev.3, 3-13-02 ML0530704022001-04-20020 April 2001 Normal Sump Pump Samples 2024-06-19
[Table view] Category:Letter
MONTHYEARIR 05000346/20244032024-09-27027 September 2024 Security Baseline Inspection Report 05000346/2024403 L-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 05000346/LER-2021-001, Emergency Diesel Generator Speed Switch Failure Due to Direct Current System Ground2024-09-19019 September 2024 Emergency Diesel Generator Speed Switch Failure Due to Direct Current System Ground ML24134A1522024-09-17017 September 2024 Exemption from the Requirements of 10 CFR 50.71(e)(4) Final Safety Analysis Report Update Schedule (EPID L-2024-LLE-0005) - Letter ML24260A2382024-09-16016 September 2024 Notification of an NRC Biennial Licensed Operator Requalification Program Inspection and Request for Information ML24255A8032024-09-11011 September 2024 Technical Specification 5.6.6 Steam Generator Tube Inspection 180-Day Report ML24255A8642024-09-0606 September 2024 Rscc Wire & Cable LLC Dba Marmon Industrial Energy & Infrastructure - Part 21 Retraction of Final Notification ML24249A1602024-09-0505 September 2024 Information Request to Support Upcoming Material Control and Accounting Inspection at Davis-Besse Nuclear Power Station L-24-188, Submittal of Quality Assurance Program Manual, Revision 302024-08-27027 August 2024 Submittal of Quality Assurance Program Manual, Revision 30 ML24239A3972024-08-23023 August 2024 Rssc Wire & Cable LLC Dba Marmon - Part 21 Final Notification - 57243-EN 57243 IR 05000346/20240052024-08-22022 August 2024 Updated Inspection Plan for Davis-Besse Nuclear Power Station (Report 05000346/2024005) 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 IR 05000346/20240022024-08-0101 August 2024 Integrated Inspection Report 05000346/2024002 IR 05000346/20244012024-07-30030 July 2024 Security Baseline Inspection Report 05000346/2024401 ML24208A0962024-07-25025 July 2024 57243-EN 57243 - Rssc Wire & Cable LLC, Dba Marmon - Part 21 Notification 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 - 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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 3, 2015 Mr. Brian D. Boles Site Vice President FirstEnergy Nuclear Operating Company c/o Davis-Besse NPS 5501 N. State Route 2 Oak Harbor, OH 43449-9760
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1- INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) INFORMATION REQUEST- FLOOD-CAUSING MECHANISM REEVALUATION (TAC NO. MF3721)
Dear Mr. Boles:
The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRC) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 11, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14070A108), flood hazard reevaluation report (FHRR) submitted by FirstEnergy Nuclear Operating Company (FENOC, the licensee) for the Davis-Besse Nuclear Power Station, Unit 1 (Davis-Besse), as well as supplemental information resulting from requests for additional information and audits.
By letter dated March 12, 2012, the NRC issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f) (hereafter referred to as the 50.54(f) letter)
(ADAMS Accession No. ML12053A340). The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance. Concurrently, with the reevaluation of flooding hazards, licensees were required to develop and implement mitigating strategies in accordance with NRC Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML12054A735). On March 30, 2015, the Commission provided Staff Requirements Memoranda (SRM) (ADAMS Accession No. ML15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards," dated November 21, 2014 (ADAMS Accession No. ML14309A256), affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events.
The NRC staff has reviewed the information submitted by the licensee and has summarized the results of the review in the table provided as an Enclosure to this letter. Table 1 provides the current design-basis flood hazard mechanisms. Table 2 provides reevaluated flood hazard mechanisms; however, reevaluated flood hazard mechanisms bounded by the current design-basis (Table 1) are not included
B. Boles The NRC staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information described in guidance documents currently being finalized by the industry and NRC staff) for Davis-Besse. Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding". The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time.
In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised. This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards. Once this methodology is endorsed by the NRC, flood duration parameters and applicable associated effects should be considered as part of the Davis-Besse MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood-related associated effects developed by the licensee during the NRC staff's review of the MSA.
As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis. In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML15174A257). This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan for the Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML15209A682).
B. Boles If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov.
Juan F. ribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket No. 50-346
Enclosure:
Summary of Results of Flooding Hazard Re-Evaluation Report - ML15238B865 cc w/encl: Distribution via Listserv
ENCLOSURE:
SUMMARY
TABLES OF REEVALUATED FLOOD HAZARD LEVELS
Davis-Besse, Unit 1 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism I Stillwater Waves/ Design Basis Reference I
I Elevation Run up Hazard Elevation Local Intense Precipitation LIP - Turbine Building 584.5 ft Minimal 584.5 ft FHRR Section 2.1.1 IGLD55 IGLD55 Streams and Rivers i River and Streams 579.0 ft Not 579.0 ft FHRR Section 2.1.2 IGLD55 applicable IGLD55 Failure of Dams and Onsite I Water Control/Storage Structures Dam Failure No Impact No Impact No Impact FHRR Section 2.1.3 Identified Identified Identified Storm Surge Storm Surge 583.7 ft 6.6 ft 590.3 ft FHRR Section 2.1.4 IGLD55 IGLD55 FHRR Section 2.1.8 Seiche Seiche Not included Not included Not included FHRR Table 3 in DB in DB in DB Tsunami Not included Not included Not included FHRR Table 3 in DB in DB in DB 1
I Ice-Induced Flooding No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Channel Migrations/Diversions No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Note: Reported values are rounded to the nearest one-tenth of a foot.
Davis-Besse, Unit 1 Table 2. Reevaluated Flood Hazards for Flood-Causing Mechanisms for Use in the MSA Mechanism Stillwater Waves/ Reevaluated Reference Elevation Run up Hazard Elevation Local Intense Precipitation Turbine Building 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Intake Structure 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Auxiliary Buildings 585.4 ft Minimal 585.4 ft FHRR Table 1 IGLD55 IGLD55 Storm Surge 585.8 ft 0.1 ft 585.9 ft FHRR Section 3.7.4 IGLD55 IGLD55 i
Note 1: The licensee is expected to develop flood event duration parameters and applicable flood associated effects to conduct the MSA. The staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood associated effects during its review of the MSA.
Note 2: Reevaluated hazard mechanisms bounded by the current design basis (see Table 1) are not included in this table.
Note 3: Reported values are rounded to the nearest one-tenth of a foot.
PKG ML152398210 LTR: ML152398212 ENCL: ML152388865 *via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA NRO/DSEA/RH M2/TR*
NAME JUribe Slent Mlee DATE 8127 /15 8 / 27 /15 8 / 26 /15 OFFICE NRO/DSEA/RHM2/BC* NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME CCook MShams JUribe DATE 8 / 26 /15 8 / 28 /15 9 / 3 /15