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Category:Meeting Briefing Package/Handouts
MONTHYEARML24037A0252024-02-0808 February 2024 Pre-Submittal Presentation - 02/08/2024 - Proposed License Amendment Request Change to the Sequoyah Nuclear Plant Technical Specifications 3.8.1 and 3.8.2 ML23345A1662023-12-13013 December 2023 Tennessee Valley Authority - Pre-submittal Meeting for Conversion of Nuclear Quality Assurance Plan from ANSI N45.2-1971 to ASME NQA-1-2015 (EPID L-2023-LRM-0103) - Slides ML23291A1562023-10-18018 October 2023 NRC Pre-Submittal Meeting Watts Bar & Sequoyah LAR, TVA Presentation Slides ML23128A2882023-05-0808 May 2023 TVA Nuclear Plants -2022 EOC Media Slides ML22157A4132022-06-0606 June 2022 Plants - Pre-Submittal Teleconference for Proposed Amendment Request Regarding the Change for the Sequoyah and Watts Bar Nuclear Plants Technical Specification 3.4.12 Meeting Slides ML22080A1662022-03-21021 March 2022 TVA Nuclear Plants -2021 EOC Media Loop Slides for Automatic Play ML21308A4932021-11-0808 November 2021 Pre-submittal Meeting Presentation - License Amendment Request to Revise Sequoyah Operating License to Use Fire and Seismic PRA Models for 10 CFR 50.69 Risk-Informed Categorizations (EPID L-2021-LRM-0109) (Slides) ML21281A2282021-10-13013 October 2021 Tennessee Valley Authority Fleet Pre-Submittal Meeting for License Amendment Request to Change Emergency Action Level Scheme Presentation - October 13, 2021 (EPID L-2021-LRM-0096) (Slides) ML21252A3632021-09-15015 September 2021 Pre-Submittal Meeting for License Amendment Request to Eliminate the High Negative Flux Rate Trip ML21061A0892021-03-0202 March 2021 TVA Presentation Slides for March 2, 2021, Public Meeting to Discuss Sequoyah Alternative Request ML20203M0572020-07-16016 July 2020 Updated TVA Non-Proprietary Slides for Open Session of July 16, 2020, Partially Closed Public Meeting to Discuss Sequoyah License Amendment Request ML20196L7922020-07-16016 July 2020 Corrected TVA Non-Proprietary Slides for Open Session of July 16, 2020, Partially Closed Public Meeting to Discuss Sequoyah License Amendment Request ML20196L6892020-07-16016 July 2020 TVA Non-Proprietary Slides for Open Session of July 16, 2020, Partially Closed Public Meeting to Discuss Sequoyah License Amendment Request ML20175A0552020-06-23023 June 2020 TVA Slides for June 23, 2020, Emergency Plan Change Presubmittal Meeting ML20163A6952020-06-12012 June 2020 Bpg Presentation on TVA SCWE Final 2 ML20108E9082020-04-16016 April 2020 Presentation Slides for Sequoyah Nuclear Plant, Unit 2 - Exigent License Amendment Request TS 4.2.2, Control Rod Assemblies, Pre-Submittal Conference Call - April 16, 2020 ML20050C8662020-02-20020 February 2020 February 20, 2020 - Pre-Submittal Meeting Presentation - Permanent Operation with Control Rod H8 Removed ML20049G1822020-02-18018 February 2020 February 20, 2020 - Pre-submittal Meeting Presentation - Transition to Westinghouse Fuel ML20024D2112020-01-27027 January 2020 Pre-Submittal Meeting for License Amendment Request (LAR) Revised Steam Generator (SG) Inspection Intervals - January 27, 2020 ML19325C7142019-12-0202 December 2019 November 15,2019, Summary of Conference Call with Tennessee Valley Authority to Discuss Submittal of Exigent License Request (EPID L-2019-LLA-0239) for Sequoyah Nuclear Plant, Unit 1 ML19323D8882019-11-15015 November 2019 TVA Pre-submittal Presentation Slides - Exigent Amendment ML19161A2392019-06-10010 June 2019 Plants Pre-Submittal Meeting for Proposed License Amendments Hydrological Analysis Updates June 10, 2019 ML19142A2772019-05-21021 May 2019 Summary of Public Meeting - Sequoyah Nuclear Plant ML18312A3502018-11-14014 November 2018 Meeting to Discuss Proposed Technical Specification Changes Needed of Associated with the Use of Westinghouse Robust Fuel Assemblies at Sequoyah Nuclear Plant Units 1 & 2 - November 14, 2018 ML18164A3092018-06-13013 June 2018 June 6, 2018 Summary of Public Meeting - Sequoyah Nuclear Plant - Docket Nos. 50-327 and 50-328 ML17342A3642017-12-0808 December 2017 Enclosure 2, Handouts and Presentations Discussed During the November 16, 2017 ROP Working Group Public Meeting NEI 09-07, Enclosure 2, Handouts and Presentations Discussed During the November 16, 2017 ROP Working Group Public Meeting2017-12-0808 December 2017 Enclosure 2, Handouts and Presentations Discussed During the November 16, 2017 ROP Working Group Public Meeting ML17271A0162017-09-28028 September 2017 Meeting Slide for Tennessee Valley Authority (TVA) Hydrology Precipitation Model Topical Report Review Status ML17212A8432017-08-0101 August 2017 Meeting Slides for Pre-submittal Meeting with Tennessee Valley Authority on Unbalanced Voltage License Amendment Request for TVA Nuclear Plants ML17053A0232017-02-22022 February 2017 Slides for Meeting with Tennessee Valley Authority to Discuss HEC-RAS Flood Model Project: Seismic Dam Failure Methodology ML16102A3302016-04-0404 April 2016 Presentation Slides for 04042016 Public Meeting on Resolution of TVA Flood Model Issue ML14259A1662014-09-17017 September 2014 Meeting Slides for the September 17, 2014 Public Meeting to Discuss the Dseis for License Renewal of Sequoyah Units 1 and 2 ML14262A3302014-09-16016 September 2014 9/16/2014 Meeting Slide for Sequoyah Nuclear Plant, Units 1 and 2 Regarding AST Presentation ML14107A3352014-04-16016 April 2014 Summary of Meeting with Tennessee Valley Authority to Discuss Nrc'S Reactor Oversight Process (ROP) and Nrc'S Annual Assessment of Plant Safety Performance for Period of January 1, 2013, to December 31, 2013 for Sequoyah Bar Nuclear Plant ML14101A1522014-04-11011 April 2014 Summary of Public and Closed Meeting for Tennessee Valley Authority 2013 Synergy Safety Culture Survey Results ML14090A4582014-03-31031 March 2014 Public Meeting Summary TVA Synergy Safety Culture Survey Results ML14071A1522014-03-13013 March 2014 Slide, ITS Project Electrical Systems Presentation March 13, 2014 ML14049A3372014-02-18018 February 2014 2/4/2014 - Summary of Public Meeting for Sequoyah Nuclear Plant, Docket No. 50-327, and 50-328 ML13361A0212013-12-27027 December 2013 License Renewal IP71002 Exit Meeting Slides and Notes from December 17, 2013 ML13210A4042013-07-30030 July 2013 Meeting Slide for 7/30-31/2013 Meeting Re. Hydrology License Amendment Requests ML13189A1352013-07-0101 July 2013 Progress Update on Improved Flood Mitigation System Project ML13182A0872013-06-27027 June 2013 Plants - 1st Quarterly Update for NTTF Recommendation 2.1, Flooding Hazard Reevaluation Report (Hrr) Extension Request ML13182A0662013-06-27027 June 2013 Plants - 1st Quarterly Update for the Improved Flood Mitigation System ML13156A0462013-06-0404 June 2013 NRC Pre-Submittal Meeting, Improved Technical Specification Conversion ML13120A1322013-04-29029 April 2013 Plants, Units 1 and 2 - NTTF Recommendation 2.1, Flooding Hazard Reevaluation Report Extension Request ML12352A2082012-12-17017 December 2012 December 3, 2012 Summary of Public Meeting Flood Mode Operation Improvement Strategy for Watts Bar and Sequoyah ML12215A4252012-09-0505 September 2012 Meeting Slides with Tennessee Valley Authority Regarding Sequoyah Nuclear Plant, Units 1 and 2 Multiple Circuit Failure Modifications Appendix R (Fire Protection) ML12214A1992012-07-16016 July 2012 7/16/12 Slides of Public Meeting with TVA Regarding the Use of the Unit Station Service Transformers as a Power Supply to an Offsite Circuit for Sequoyah Nuclear Plant ML12156A0762012-05-31031 May 2012 TVA Slides for Nrc/Tva Public Meeting on May 31, 2012 ML12128A0632012-05-0303 May 2012 EOC Meeting Summary 2024-02-08
[Table view] Category:Slides and Viewgraphs
MONTHYEARML24037A0252024-02-0808 February 2024 Pre-Submittal Presentation - 02/08/2024 - Proposed License Amendment Request Change to the Sequoyah Nuclear Plant Technical Specifications 3.8.1 and 3.8.2 ML23345A1662023-12-13013 December 2023 Tennessee Valley Authority - Pre-submittal Meeting for Conversion of Nuclear Quality Assurance Plan from ANSI N45.2-1971 to ASME NQA-1-2015 (EPID L-2023-LRM-0103) - Slides ML23291A1562023-10-18018 October 2023 NRC Pre-Submittal Meeting Watts Bar & Sequoyah LAR, TVA Presentation Slides ML23128A2882023-05-0808 May 2023 TVA Nuclear Plants -2022 EOC Media Slides ML22201A1262022-07-20020 July 2022 July 20, 2022 - Pre-submittal Meeting for Inservice Testing (IST) Program Request for Alternative for the Centrifugal Charging Pump 1B-B Testing Per ISTB-3310 (RP-12) ML22157A4132022-06-0606 June 2022 Plants - Pre-Submittal Teleconference for Proposed Amendment Request Regarding the Change for the Sequoyah and Watts Bar Nuclear Plants Technical Specification 3.4.12 Meeting Slides ML22103A0852022-04-14014 April 2022 and Watts Bar Plant Pre-submittal Meeting for Inservice Testing (IST) Program Request for Alternative for the Motor Driven Auxiliary Feedwater Pump Testing Following Maintenance During an Outage Per ISTB-3310 ML22080A1662022-03-21021 March 2022 TVA Nuclear Plants -2021 EOC Media Loop Slides for Automatic Play ML22046A2932022-02-15015 February 2022 Pre-submittal Meeting Presentation - Request for Alternative to ASME OM Code ISTC-3630 Regarding Leakage of Pressure Isolation Valves ML21308A4932021-11-0808 November 2021 Pre-submittal Meeting Presentation - License Amendment Request to Revise Sequoyah Operating License to Use Fire and Seismic PRA Models for 10 CFR 50.69 Risk-Informed Categorizations (EPID L-2021-LRM-0109) (Slides) ML21281A2282021-10-13013 October 2021 Tennessee Valley Authority Fleet Pre-Submittal Meeting for License Amendment Request to Change Emergency Action Level Scheme Presentation - October 13, 2021 (EPID L-2021-LRM-0096) (Slides) ML21252A3632021-09-15015 September 2021 Pre-Submittal Meeting for License Amendment Request to Eliminate the High Negative Flux Rate Trip ML21197A0022021-08-0505 August 2021 N-769-6 Relief Pre-Submittal TVA Presentation August 2021 ML21111A0202021-04-21021 April 2021 TVA Slides for April 21, 2021 Public Meeting to Discuss Planned Sequoyah Amendment Request ML21096A1002021-04-0606 April 2021 Annual Assessments ML21061A0892021-03-0202 March 2021 TVA Presentation Slides for March 2, 2021, Public Meeting to Discuss Sequoyah Alternative Request ML20196L7922020-07-16016 July 2020 Corrected TVA Non-Proprietary Slides for Open Session of July 16, 2020, Partially Closed Public Meeting to Discuss Sequoyah License Amendment Request ML20203M0572020-07-16016 July 2020 Updated TVA Non-Proprietary Slides for Open Session of July 16, 2020, Partially Closed Public Meeting to Discuss Sequoyah License Amendment Request ML20196L6892020-07-16016 July 2020 TVA Non-Proprietary Slides for Open Session of July 16, 2020, Partially Closed Public Meeting to Discuss Sequoyah License Amendment Request ML20175A0552020-06-23023 June 2020 TVA Slides for June 23, 2020, Emergency Plan Change Presubmittal Meeting ML20163A6952020-06-12012 June 2020 Bpg Presentation on TVA SCWE Final 2 ML20112F5302020-04-21021 April 2020 TVA Nuclear Plants -2019 EOC Media Loop Slides for Automatic Play (Final) ML20108E9082020-04-16016 April 2020 Presentation Slides for Sequoyah Nuclear Plant, Unit 2 - Exigent License Amendment Request TS 4.2.2, Control Rod Assemblies, Pre-Submittal Conference Call - April 16, 2020 ML20050C8662020-02-20020 February 2020 February 20, 2020 - Pre-Submittal Meeting Presentation - Permanent Operation with Control Rod H8 Removed ML20049G1822020-02-18018 February 2020 February 20, 2020 - Pre-submittal Meeting Presentation - Transition to Westinghouse Fuel ML20024D2112020-01-27027 January 2020 Pre-Submittal Meeting for License Amendment Request (LAR) Revised Steam Generator (SG) Inspection Intervals - January 27, 2020 ML19325C7142019-12-0202 December 2019 November 15,2019, Summary of Conference Call with Tennessee Valley Authority to Discuss Submittal of Exigent License Request (EPID L-2019-LLA-0239) for Sequoyah Nuclear Plant, Unit 1 ML19323D8882019-11-15015 November 2019 TVA Pre-submittal Presentation Slides - Exigent Amendment ML19161A2392019-06-10010 June 2019 Plants Pre-Submittal Meeting for Proposed License Amendments Hydrological Analysis Updates June 10, 2019 ML19164A2032019-05-30030 May 2019 OEDO-19-00288-TVA Sequoyah Leadership Forum Power Point ML19142A2772019-05-21021 May 2019 Summary of Public Meeting - Sequoyah Nuclear Plant ML18312A3502018-11-14014 November 2018 Meeting to Discuss Proposed Technical Specification Changes Needed of Associated with the Use of Westinghouse Robust Fuel Assemblies at Sequoyah Nuclear Plant Units 1 & 2 - November 14, 2018 ML18164A3092018-06-13013 June 2018 June 6, 2018 Summary of Public Meeting - Sequoyah Nuclear Plant - Docket Nos. 50-327 and 50-328 ML17271A0162017-09-28028 September 2017 Meeting Slide for Tennessee Valley Authority (TVA) Hydrology Precipitation Model Topical Report Review Status ML17212A8432017-08-0101 August 2017 Meeting Slides for Pre-submittal Meeting with Tennessee Valley Authority on Unbalanced Voltage License Amendment Request for TVA Nuclear Plants ML17053A0232017-02-22022 February 2017 Slides for Meeting with Tennessee Valley Authority to Discuss HEC-RAS Flood Model Project: Seismic Dam Failure Methodology ML16102A3302016-04-0404 April 2016 Presentation Slides for 04042016 Public Meeting on Resolution of TVA Flood Model Issue ML14259A1662014-09-17017 September 2014 Meeting Slides for the September 17, 2014 Public Meeting to Discuss the Dseis for License Renewal of Sequoyah Units 1 and 2 ML14262A3302014-09-16016 September 2014 9/16/2014 Meeting Slide for Sequoyah Nuclear Plant, Units 1 and 2 Regarding AST Presentation ML14101A1522014-04-11011 April 2014 Summary of Public and Closed Meeting for Tennessee Valley Authority 2013 Synergy Safety Culture Survey Results ML14071A1522014-03-13013 March 2014 Slide, ITS Project Electrical Systems Presentation March 13, 2014 ML14049A3372014-02-18018 February 2014 2/4/2014 - Summary of Public Meeting for Sequoyah Nuclear Plant, Docket No. 50-327, and 50-328 ML13361A0212013-12-27027 December 2013 License Renewal IP71002 Exit Meeting Slides and Notes from December 17, 2013 ML13210A4042013-07-30030 July 2013 Meeting Slide for 7/30-31/2013 Meeting Re. Hydrology License Amendment Requests ML13189A1352013-07-0101 July 2013 Progress Update on Improved Flood Mitigation System Project ML13156A0462013-06-0404 June 2013 NRC Pre-Submittal Meeting, Improved Technical Specification Conversion ML13120A1322013-04-29029 April 2013 Plants, Units 1 and 2 - NTTF Recommendation 2.1, Flooding Hazard Reevaluation Report Extension Request ML13115A0202013-04-23023 April 2013 Public Meeting Summary - Regulatory Conference / Enforcement Conference Sequoyah Nuclear Plant ML12352A2082012-12-17017 December 2012 December 3, 2012 Summary of Public Meeting Flood Mode Operation Improvement Strategy for Watts Bar and Sequoyah ML12215A4252012-09-0505 September 2012 Meeting Slides with Tennessee Valley Authority Regarding Sequoyah Nuclear Plant, Units 1 and 2 Multiple Circuit Failure Modifications Appendix R (Fire Protection) 2024-02-08
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HEC-RAS Flood Model Project:
Seismic Dam Failure Methodology February 22, 2017
Outline
- Hydrologic & Hydraulic Models
- Schedule HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 2
=
Background===
In the March 12, 2012, 50.54(f) letter submitted to licensees, re-evaluation of flood hazard is requested. Interim Staff Guidance, JLD-ISG-2013-01, provides guidance to perform flood hazard due to dam failure.
- TVA submits Updated Flood Hazard March 12, 2015.
- TVA re-evaluates stability of 27 upstream dams to current TVA dam safety standards for flood and seismic loading as outlined in JLD-ISG-2013-01.
- Assumptions of failure are made for additional upstream dams (conservative assumption for the flood hazard at nuclear power plants)
HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 3
Updating Licensing Basis Proposed Update Current Basis HEC-RAS model SOCH model Current dam stability Deterministic nuclear methodology using power plant seismic input probabilistic site-specific for dam stability seismic hazard analysis evaluation for dam stability evaluation Multiple dam failure considerations using Multiple dam failure attenuation equations considerations through deaggregation of seismic hazard Use of the completed updated flood hazard for seismic dam failures aligns with current standards for both dam stability and hydraulic analysis. Planned hydrology license amendment requests will require review criteria other than SRP.
HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 4
Overview of Methodology Detailed Analysis per JLD-ISG-2013-01 When dam failure is not assumed, detailed analysis of the dams are made.
Detailed analysis on 27 upstream dams/dikes Seismic Source Model, CEUS-SSC [EPRI/NRC/DOE 2012]
Ground Motion Attenuation, Ground Motion Prediction Equations [EPRI 2004/2006]
Site Amplification, Site Response Analysis included detailed field investigation and laboratory test reports Detailed Analysis of Seismic Capacity of the Dam, Post-seismic dam stability with detailed field investigation and laboratory reports [TVA Dam Safety Criteria]
HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 5
Probabilistic Seismic Hazard Analysis 6
Inputs 5
Seismic source model: 2012 EPRI/DOE/NRC CEUS-SSC model 4
Ground motion prediction models: EPRI (2004, 2006) Series 1 3
Series 2 Series 3 2
Shown to the right are 10,000 year return period, 5% damped mean UHRS 1 No RLMEs located within about 200 km of the dam sites; however New Madrid fault 0 system, Reelfoot Rift, and Charleston Category 1 Category 2 Category 3 Category 4 source added to model HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 6
Seismic Source Catalog Updates Seismic Source Recently for seismic PRA work, catalog updates for the region have been completed Plot to the right shows predicted vs. observed earthquake counts for catalog updates to 4/30/2016 HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 7
Ground Motion Model Update Comparison Ground Motion Models EPRI 2013 vs. EPRI 2004/2006 Recently for seismic PRA work, ground motion models comparisons have been completed HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 8
SSE comparison 1.6 1.4 1.2 1
Acceleration, g SSE 0.8 Douglas E-4 Guntersville E-4 0.6 South Holston SD1 E-4 0.4 Wheeler E-4 0.2 0
0.1 1 10 100 Frequency, Hz HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 9
OBE comparison 0.8 0.7 0.6 0.5 Acceleration, g OBE 0.4 Douglas 1/2 E-4 Guntersville 1/2 E-4 0.3 South Holtson SD1 1/2 E-4 0.2 Wheeler 1/2 E-4 0.1 0
0.1 1 10 100 Frequency, Hz HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 10
Controlling Earthquake RG 1.208, Appendix D with following exceptions:
- Deagreggation at 1 and 10 Hz instead of 1 to 2.5 Hz and 5 to 10 Hz
- 10 Hz spectral frequency of interest, concrete dam
- 1 Hz spectral frequency of interest, earthen dam
- Modal magnitude and distance instead of mean magnitude and distance
- 1 Hz controlling earthquake, distant large magnitude New Madrid
- 10 Hz controlling earthquake, local moderate event in Eastern Tennessee Seismic Zone HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 11
Time histories Time History Development 1 Hz Controlling 1 1999 Chi Chi, Taiwan Earthquake 6 sets of time histories developed 2 2002 Denali, AK 3 1992 Landers, CA 3 sets for 1 Hz 3 sets for 10 Hz 4 1987 Superstition Hills, CA Spectrally matched per SRP 3.7.1 criteria 10 Hz Controlling Earthquake 5 2011 Mineral, VA Time History Use
- 1. Dynamic stability analyses of dams if 6 1988 Saguenay, Quebec founded on hard rock, or
- 2. Site response analysis to develop ground motions at foundation level beneath dam if dam not founded on hard rock HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 12
Dam Site Response Analysis
- Site-specific exploration and testing completed
- Time history sets developed for each dam at frequency of interest
- Response analysis software used to perform the wave propagation analysis to define seismic response at dam foundation for condition other than hard rock
- Foundations considered massless but with stiffness
- Hydrodynamic masses representing the upstream normal pool reservoir are computed and applied to upstream face HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 13
Dam Stability Analysis Concrete Updated Current Licensing Basis 2-D or 3-D finite element analyses of dams 2-D rigid body analyses of critical locations prior including modifications to current modifications Headwater and tailwater - normal pool Headwater and tailwater - 25 year flood and 1/2 PMF flood without tailwater reduction Dynamic analysis of seismic loading and reservoir effects performed to define damaged Pseudo-static analysis with hydrodynamic state pressures
- Cohesion at rock-concrete interface neglected,
- Silt pressure not considered conservatively
- Cohesion at rock-concrete interface applied
- Degradation of friction angle
- Friction angle, no degradation
- Silt pressure effect included
- Increased uplift due to degraded drains and
- Increased uplift due to degraded drains and base base cracking not considered cracking Acceptance criteria - sliding FS=1.0 and If damaged state, no rock-concrete tensile resultant within dam base strength Acceptance criteria - sliding FS=1.3 and Resultant within dam base HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 14
Dam Stability Analysis Earthen Updated Current Licensing Basis Pseudo-static method of seismic coefficient Pseudo-static, standard slip circle method generally used Headwater and tailwater - normal pool Headwater and tailwater - 25 year flood and 1/2 Dynamic analysis for applied ground motion PMF without tailwater reduction with in-situ soil properties Amplification assumed based on nuclear plant Evaluation of liquefaction potential and studies (dam dynamic soil properties not reservoir effects available)
Post-seismic stability
- If FS < 1.1, seismic deformation analysis is conducted
- Seismic deformation limited to < 2 feet and 1/2 filter thickness
- Seepage evaluations included HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 15
Hydrologic & Hydraulic Models Updated Current Licensing Basis Hydrologic Hydrologic Precipitation - 25 year flood updated with Precipitation - 1/2 PMF (Vintage HMR) additional gauge data Precipitation - 500 year flood Hydraulic Hydraulic Simulated Open Channel Hydraulics (SOCH)
HEC-RAS model model Debris fields not utilized Debris fields utilized HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 16
Simplified Screening
- Inconsequential dam failure combinations assessment based on reservoir volumes
- Entire volume transferred downstream to next reservoir, carried throughout system
- Outlet structures of stable dams assumed closed HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 17
Screening - Watts Bar HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 18
Screening - Sequoyah HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 19
Screening Results
- Possible Consequential Results (Single Failure)
- South Holston
- Watauga
- Chatuge
- Cherokee
- Fontana
- Norris
- Nottely
- Watts Bar HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 20
Seismic Single Dam Failure Updated Current Licensing Basis One half 10-4 AFE ground motion + 500 year flood OBE + 1/2 PMF Watts Bar Norris Chatuge Cherokee Douglas 10-4 AFE ground motion + 25 year flood Fontana No additional; above cases govern SSE + 25 year flood Watts Bar HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 21
Considerations of Multiple Dam Failures From Single Seismic Event (Updated)
JLS-ISG-2013-01 Section 5.5 Seismic influence refinement completed through deaggregation of hazard.
Frequency of Interest Concrete dams, 10 Hz Earthen dams, 1 Hz HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 22
Seismic Influence Deaggregation 10 Hz at 10-4 AFE HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 23
Seismic Influence Deaggregation 10 Hz at one half ground motion 10-4 AFE HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 24
Seismic Influence Deaggregation 1 Hz at 10-4 AFE & 1 Hz at one half ground motion 10-4 AFE
- All dams evaluated have large portion of 1 Hz seismic hazard influenced by the New Madrid Fault Zone. Therefore, events contributing to the hazard of one dam are likely to be a major contributor to the hazard at all the other dams.
HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 25
Multiple Dam Failure Combinations From Single Seismic Event Updated Current Licensing Basis OBE + 1/2 PMF 10-4 AFE eq + 500 year flood Fontana and Tellico Apalachia, Blue Ridge, Chatuge, Fort Norris and Tellico Loudoun, Fontana, Melton Hill, Tellico and Watts Bar Dams Fontana, Tellico, Hiwassee, Apalachia, Blue Ridge 1/2 10-4 AFE eq + 25 year flood Cherokee, Douglas and Tellico Apalachia, Blue Ridge, Chatuge, Fort SSE + 25 year flood Loudoun, Melton Hill, Tellico and Watts Bar Dams Norris, Cherokee, Douglas, Tellico HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 26
Results - SQN FHRR+ Current Licensing Basis Failure SQN Elevation (ft) Failure SQN Elevation (ft)
Combination Grade elevation 705 Combination Grade elevation 705 1/2 10-4 AFE eq + 500 year flood OBE+1/2 Probable Maximum Flood Douglas Centered 705.3 Norris, Tellico 706.3 (Apalachia, Blue Ridge, Fontana, Tellico 702.2 Chatuge, Fort Loudoun, Fontana, Tellico, 706.3 Fort Patrick Henry, Hiwassee, Apalachia, Melton Hill, Tellico, Blue Ridge Watts Bar) Cherokee, Douglas, 708.6 10-4 AFE eq + 25 year flood Tellico Fort Loudoun Centered 703.0 SSE+25 year flood (Apalachia, Blue Ridge, Cherokee, Douglas, 706.0 Chatuge, Fort Loudoun, Tellico, Norris Fontana, Melton Hill, Tellico, Watts Bar)
+FHRR shown only as an indication of expected updated results; HEC-RAS ineffective flow area issue requires addressing in updated HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 27
Results - WBN FHRR+ Current Licensing Basis Failure WBN Elevation (ft) Failure WBN Elevation (ft)
Combination Grade elevation 728 Combination Grade elevation 728
-4 1/2 10 AFE eq + 500 year flood OBE+1/2 Probable Maximum Flood Douglas Centered 729.9 Norris, Tellico 728.7 (Apalachia, Blue Ridge, Fontana, Tellico 720.7 Chatuge, Fort Loudoun, Fontana, Tellico, 722.0 Fort Patrick Henry, Hiwassee, Apalachia, Melton Hill, Tellico, Blue Ridge Watts Bar) Cherokee, Douglas, 729.1 10-4 AFE eq + 25 year flood Tellico Fort Loudoun Centered 727.7 SSE+25 year flood (Apalachia, Blue Ridge, Cherokee, Douglas, 731.2 Chatuge, Fort Loudoun, Tellico, Norris Fontana, Melton Hill, Tellico, Watts Bar)
+FHRR shown only as an indication of expected updated results; HEC-RAS ineffective flow area issue requires addressing in updated HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 28
Schedule - Planned Path HEC-RAS FLOOD MODEL PROJECT: SEISMIC DAM FAILURE METHODOLOGY l 29