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| {{#Wiki_filter:SNCDegradedGridDesignCriteria SNC Degraded Grid Design Criteria 1 April 23, 2014 Agenda *Purpose*Back g round g*New SNC Degraded Grid Relaying Design Criteria | | {{#Wiki_filter:SNC Degraded Grid Design Criteria April 23, 2014 1 |
| *Methodology*Comments and Questions 2
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| Purpose Review the design criteria being used by Southern Nuclear for the new degraded grid voltage protective relaying at Hatch Nuclear Plant and Farley Nuclear plant. These criteria draw from previous industry guidance and ourownexperiencebutarenotintendedasacommitment our own experience , but are not intended as a commitment to any particular existing guidance document.Obtain NRC feedback on the criteria to help ensure that the implemented solutions meet NRC expectations for automaticprotectionforpotentialdegradedgrideventsand automatic protection for potential degraded grid events and resolve NRC findings from the related CDBIs.
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| 3 Background For a potential degraded grid event, previous designs:*Relied on manual actions b y the transmission s y stem yyand plant operators to prevent an occurrence.*Some required Class 1E loads were not automatically ttdftidltid pro t ec t e d f rom a sus t a i ne d vo lt age i na d equacy.Therearecurrentlytwosubmittalsonthedocketonefor There are currently two submittals on the docket , one for Plant Farley and one for Plant Hatch, that include a schedule for the degraded grid modification projects. The LARbittlihlttilit LAR su b m itt a l s rev ise eac h p l an t s opera ti ng li cense t o include completion dates, by unit, for the modifications.
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| 4 Background -Scope of Modifications *FNP:-Replacement of the existing degraded voltage relays-Raising the existing voltage setpoints.*HNP:Rltfthitidddltlildi-R ep l acemen t o f th e ex i s ti ng d egra d e d vo lt age re l ays i nc l u di ng change from 2 relays to 3 relays (2 of 3 logic). -Raising the existing voltage setpoints.-Replacement of 4 existing startup auxiliary transformers
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| -Addition of 2 new startup auxiliary transformers and 230KV breakers including associated relaying, fire protection, etc.-Upgrade of 4.16KV bus short circuit capability for 10 buses (breakers and bus bracing).
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| 5 Background -Farley Schedule*January 2015 -Submit Farley License Amendment Request(LAR)
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| Request (LAR)*January 2016 -NRC approval of Farley LAR
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| *SpringOutage2016(U2R24)
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| -Designimplementation Spring Outage 2016 (U2R24) Design implementation begins on U2*Fall Outage 2016 (U1R27) -Design implementation biU1 b eg ins on U1*Fall Outage 2017 (U2R25) -Design implementation completedonU2 completed on U2*Spring Outage 2018 (U1R28) -Design implementation completed on U1 6
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| Background -Hatch Schedule*December 2015 -Submit Hatch License Amendment Request(LAR)
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| Request (LAR)*December 2016 -NRC approval of Hatch LAR
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| *SpringOutage2017(U2R24)
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| -Designimplementation Spring Outage 2017 (U2R24) Design implementation begins on U2*Spring Outage 2018 (U1R28) -Design implementation biU1 b eg ins on U1*Spring Outage 2019 (U2R25) -Design implementation completedonU2 completed on U2*Spring Outage 2020 (U1R29) -Design implementation completed on U1 7
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| Definitions & Acronyms*DVR -Degraded Voltage Relaying*MEV -Minimum Ex p ected Volta g e -The stead y state pg yvoltage level at the 4.16kV buses that is expected when the 230kV switchyard is at the minimum voltage based oncontingencystudiesdefinedbytheFSAR on contingency studies defined by the FSAR.*MRV -Minimum Required Voltage -The steady state voltage level at a Class 1E 4.16kV bus that is required for its safety-related loads to accomplish their safety functions. The safety-related motors shall be able to start successfullywiththe pre-startsteady
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| -statebusvoltage successfully with the pre start steady state bus voltage at the MRV.
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| 8 Design Criteria -Voltage*The DVR shall be set such that offsite power will be automatically disconnected and transferred to onsite power during an extended degraded grid
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| condition (any voltage dip having a longer durationthanexpectedfornormaloraccident duration than expected for normal or accident operations). *The DVR on the Class 1E 4.16KV bus will be set so that, including tolerances, voltage dropout value will be above the MRV value.ThDVRlt tlildi*Th e DVR vo lt age rese t va l ue , i nc l u di ng tolerances, will be set below the MEV.
| | Agenda |
| 9 Design Criteria -Time Delay*The DVR minimum time delay will be set such that, with tolerances, it will delay actuation to prevent a spurious trip due to motor starting or
| | * Purpose |
| | * g |
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| other momentary transient events.
| | ===Background=== |
| *TheDVR maximumtimedelaywillbesetsuch | | * New SNC Degraded Grid Relaying Design Criteria |
| *The DVR maximum time delay will be set such that, with tolerances, it will: | | * Methodology |
| -be less than the maximum time allowed for the diesel generator to start and obtain rated speed and voltage.-prevent loss of Class 1E functions when the voltage is inadequatebyactuationpriortoatripofloadson inadequate by actuation prior to a trip of loads on overload.10 Voltage Setpoint Methodology *Part 1 -Using maximum expected non-accident bus loading, determine minimum acceptable steady-state voltage for normal operation.*Part 2 -Using maximum expected accident loading, determinetheminimum pre-startvoltagethatprovides determine the minimum pre-start voltage that provides acceptable Class 1E motor starting (e.g. during LOCA
| | * Comments and Questions 2 |
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| block motor starting)*Part 3 -Using maximum expected accident loading, determine the minimum steady-state voltage that providesacceptableClass1Emotoroperationand provides acceptable Class 1E motor operation and starting for individual motors.*The maximum voltage of Parts 1-3 determines the MRV 11(i.e. analytical limit). | | Purpose Review the design criteria being used by Southern Nuclear for the new degraded grid voltage protective relaying at Hatch Nuclear Plant and Farley Nuclear plant. |
| DVR Voltage Setpoint ExampleSetting for normal steady state Setting to detect inadequate LOCA starting voltage prior to startsteadystate requirementSetting for LOCAsteady state requirement 12Colored bar represents the DVR voltage setting uncertainty & reset requirement DVR Voltage Setpoint Example Limiting PartSetting for normal steady state Setting to detect inadequate LOCA starting voltage prior to startsteadystate requirementSetting for LOCAsteady state requirement 13Colored bar represents the DVR voltage setting uncertainty & reset requirement DVR Time Delay Setpoint Example *Minimum Delay:-At MEV, LOCA block motor starting voltage transient lasts for 7 seconds (i.e. recovers above the DVR voltage reset value).-The duration of all other motor starting or fault transient events is less than 7 seconds.*Maximum Delay:-Upon a LOCA, the diesel must start and be at normal voltage andfrequency(iereadyforloading)at15seconds and frequency (i.e. ready for loading) at 15 seconds.-With inadequate voltage, motors cannot stall for greater than 12 seconds without tripping on overload.CidiDVRidlihi | | These criteria draw from previous industry guidance and our own experience, experience but are not intended as a commitment to any particular existing guidance document. |
| *C ons id er i ng DVR t i me d e lay uncerta i nty, t h e sett i ng must be between 7 and 12 seconds. | | Obtain NRC feedback on the criteria to help ensure that the implemented solutions meet NRC expectations for automatic protection for potential degraded grid events and resolve NRC findings from the related CDBIs. |
| 14 LAR Submittal Content*Calculations (portions) demonstrating the use of the methodology and the setpoint results.-Criteria, methodology and assumptions-Steady-state and starting cases for the MEV and the DVR setting part of the anal y sis showin g volta ges for each Class 1E bus and pyggits required loads.-Setpoint uncertainty calculationsBasisfor setpoints-Basis for setpoints*List of the most limiting components for each study case. | | 3 |
| 15 Comments or Questions? | | |
| | ===Background=== |
| | For a potential degraded grid event, previous designs: |
| | y |
| | * Relied on manual actions byy the transmission system and plant operators to prevent an occurrence. |
| | * Some required Class 1E loads were not automatically protected t t d from f a sustained t i d voltage lt inadequacy. |
| | i d There are currently two submittals on the docket docket, one for Plant Farley and one for Plant Hatch, that include a schedule for the degraded grid modification projects. The LAR submittals b itt l revise i each h plants l t operatingti lilicense tto include completion dates, by unit, for the modifications. |
| | 4 |
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| | Background - Scope of Modifications |
| | * FNP: |
| | - Replacement of the existing degraded voltage relays |
| | - Raising the existing voltage setpoints. |
| | * HNP: |
| | - R Replacement l t off the th existing i ti d degraded d d voltage lt relays l iincluding l di change from 2 relays to 3 relays (2 of 3 logic). |
| | - Raising the existing voltage setpoints. |
| | - Replacement of 4 existing startup auxiliary transformers |
| | - Addition of 2 new startup auxiliary transformers and 230KV breakers including associated relaying, fire protection, etc. |
| | - Upgrade of 4.16KV bus short circuit capability for 10 buses (breakers and bus bracing). |
| | 5 |
| | |
| | Background - Farley Schedule |
| | * January 2015 - Submit Farley License Amendment Request (LAR) |
| | * January 2016 - NRC approval of Farley LAR |
| | * Spring Outage 2016 (U2R24) - Design implementation begins on U2 |
| | * Fall Outage 2016 (U1R27) - Design implementation b i on U1 begins |
| | * Fall Outage 2017 (U2R25) - Design implementation completed on U2 |
| | * Spring Outage 2018 (U1R28) - Design implementation completed on U1 6 |
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| | Background - Hatch Schedule |
| | * December 2015 - Submit Hatch License Amendment Request (LAR) |
| | * December 2016 - NRC approval of Hatch LAR |
| | * Spring Outage 2017 (U2R24) - Design implementation begins on U2 |
| | * Spring Outage 2018 (U1R28) - Design implementation b i on U1 begins |
| | * Spring Outage 2019 (U2R25) - Design implementation completed on U2 |
| | * Spring Outage 2020 (U1R29) - Design implementation completed on U1 7 |
| | |
| | Definitions & Acronyms |
| | * DVR - Degraded Voltage Relaying |
| | * MEV - Minimum Expectedp Voltage g - The steadyy state voltage level at the 4.16kV buses that is expected when the 230kV switchyard is at the minimum voltage based on contingency studies defined by the FSARFSAR. |
| | * MRV - Minimum Required Voltage - The steady state voltage level at a Class 1E 4.16kV bus that is required for its safety-related loads to accomplish their safety functions. The safety-related motors shall be able to start successfully with the pre pre-start start steady-state steady state bus voltage at the MRV. |
| | 8 |
| | |
| | Design Criteria - Voltage |
| | * The DVR shall be set such that offsite power will be automatically disconnected and transferred to onsite power during an extended degraded grid condition (any voltage dip having a longer duration than expected for normal or accident operations). |
| | * The DVR on the Class 1E 4.16KV bus will be set so that, including tolerances, voltage dropout value will be above the MRV value. |
| | * The Th DVR voltagelt resett value, l i l di including tolerances, will be set below the MEV. |
| | 9 |
| | |
| | Design Criteria - Time Delay |
| | * The DVR minimum time delay will be set such that, with tolerances, it will delay actuation to prevent a spurious trip due to motor starting or other momentary transient events. |
| | * The DVR maximum time delay will be set such that, with tolerances, it will: |
| | - be less than the maximum time allowed for the diesel generator to start and obtain rated speed and voltage. |
| | - prevent loss of Class 1E functions when the voltage is inadequate by actuation prior to a trip of loads on overload. |
| | 10 |
| | |
| | Voltage Setpoint Methodology |
| | * Part 1 - Using maximum expected non-accident bus loading, determine minimum acceptable steady-state voltage for normal operation. |
| | * Part 2 - Using maximum expected accident loading, determine the minimum pre-start voltage that provides acceptable Class 1E motor starting (e.g. during LOCA block motor starting) |
| | * Part 3 - Using maximum expected accident loading, determine the minimum steady-state voltage that provides acceptable Class 1E motor operation and starting for individual motors. |
| | * The maximum voltage of Parts 1-3 determines the MRV (i.e. analytical limit). |
| | 11 |
| | |
| | DVR Voltage Setpoint Example Setting to detect inadequate LOCA starting Setting for voltage prior to start normal steady state requirement Setting for LOCA steady state requirement Colored bar represents the DVR voltage setting uncertainty & reset requirement 12 |
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| | DVR Voltage Setpoint Example Limiting Part Setting to detect inadequate LOCA starting Setting for voltage prior to start normal steady state requirement Setting for LOCA steady state requirement Colored bar represents the DVR voltage setting uncertainty & reset requirement 13 |
| | |
| | DVR Time Delay Setpoint Example |
| | * Minimum Delay: |
| | - At MEV, LOCA block motor starting voltage transient lasts for 7 seconds (i.e. recovers above the DVR voltage reset value). |
| | - The duration of all other motor starting or fault transient events is less than 7 seconds. |
| | * Maximum Delay: |
| | - Upon a LOCA, the diesel must start and be at normal voltage and frequency (i(i.e. |
| | e ready for loading) at 15 seconds seconds. |
| | - With inadequate voltage, motors cannot stall for greater than 12 seconds without tripping on overload. |
| | * C Considering id i DVR time i d delay l uncertainty,i the h setting i |
| | must be between 7 and 12 seconds. |
| | 14 |
| | |
| | LAR Submittal Content |
| | * Calculations (portions) demonstrating the use of the methodology and the setpoint results. |
| | - Criteria, methodology and assumptions |
| | - Steady-state and starting cases for the MEV and the DVR setting part of the analysis p y showing g voltages g for each Class 1E bus and its required loads. |
| | - Setpoint uncertainty calculations |
| | - Basis for setpoints |
| | * List of the most limiting components for each study case. |
| | 15 |
| | |
| | Comments or Questions? |
| 16}} | | 16}} |
Letter Sequence Request |
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MONTHYEARML14108A0052014-04-23023 April 2014 April 23, 2014, Public Meeting Presentation Slides, Southern Nuclear Company, SNC Degraded Grid Design Criteria. Project stage: Request ML14120A2252014-04-23023 April 2014 April 23, 2014, Category 1 Public Meeting, J.M. Farley Presentation Slides, Residual Heat Removal Autoclosure Interlock Deletion. Project stage: Request ML14122A0372014-05-0808 May 2014 April 23, 2014 Summary of Meeting with Southern Nuclear Operating Company to Discuss Grid Design Criteria Project stage: Meeting ML14108A3762014-05-0808 May 2014 Summary of Meeting with Southern Nuclear Operating Company to Discuss Deletion of the Residual Heat Removal Autoclosure Interlock Project stage: Meeting 2014-04-23
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Category:Meeting Briefing Package/Handouts
MONTHYEARML24260A0792024-09-23023 September 2024 9/23/2024 Pre-Submittal Meeting - Joseph M. Farley Nuclear Plant, Units 1 and 2, LAR to Change UFSAR for Exception to RG 1.183, Revision 0, Table 3 - Footnote 11 (EPID L-2024-LRM-0108) - Meeting Slides ML24192A2262024-07-11011 July 2024 Mtg to Exchange Technical Information Regarding Farley, Units 1 & 2, Proposed License Amendment Request to Increase TS 3.6.5 Containment Temperature Limit Completion Using Risk-Informed Process for Evaluation (EPID L-2024-LRM-0086) - Slides ML24190A1082024-07-0808 July 2024 NRC Slides-07/11/2024 Mtg to Exchange Technical Information Regarding Joseph M. Farley Nuclear Plant, Units 1 & 2, Proposed License Amendment Request to Increase TS 3.6.5 Containment Temperature Limit Completion Using Risk-Informed Process ML24134A1062024-05-13013 May 2024 2023 Annual Assessment Meeting Presentation Slides ML24088A1662024-04-0303 April 2024 SNC Slides - Pre-Submittal Meeting on April 3, 2024 - Farley LAR Changing TS 3.6.5 Containment Air Temperature Using RIPE ML23361A0812024-01-0808 January 2024 SNC Slides - Pre-Submittal Public Meeting on January 8, 2024 Related to Fleet QATR ML23139A2462023-05-19019 May 2023 Annual Assessment Public Meeting Slides (May 23, 2023) ML22080A0192022-03-18018 March 2022 Annual Assessment Meeting Presentation ML21306A0242021-11-30030 November 2021 SNC Pre-Submittal Meeting for LAR to Relocate Augmented Piping Inspection Program Details from TSs to a Licensee Controlled Document for Farley Nuclear Plant, Units 1 & 2; and Vogtle Electric Generating Plant, Units 1 & 2 (EPID L-2021-LRM-0 ML21280A0012021-10-31031 October 2021 Pre-Submittal Meeting Presentation from SNC to Discuss a Future LAR Regarding Change TS to Increase Containment Peak Pressure to Address Several NSALs ML21173A0632021-06-24024 June 2021 Pre-Application SNC Presentation Slides - Removal of Encapsulations from Recirculation Suction Valves ML21057A0182021-02-26026 February 2021 Pre-Submittal Meeting Revise Technical Specification 3.2.1 Heat Flux Hot Channel Factor (Fq(Z)) (EPID L-2021-LRM-0023) (Slides) ML21036A1172021-02-0505 February 2021 SNC Slides - Pre-Submittal Meeting on February 16, 2021 - Beacon LAR ML20318A1032020-11-12012 November 2020 SNC ERO Staffing LAR RAI Responses ML20217L4312020-08-13013 August 2020 Edwin I Hatch, Units 1 and 2; and Vogtle Electric Plant, Units 1, 2, 3, and 4 - Meeting Slides a License Amendment Request for the Emergency Plan (EPID Nos L-2020-LLA-0150 and L-2020-LLA-051 ML20101K6582020-04-10010 April 2020 Annual Assessment ML20022A0262020-01-22022 January 2020 NEI Presentation Status Update for Ropte Short Term Action Plan: Removed Planned Unavailability for Mitigating Systems Performance Index ML19149A4222019-05-29029 May 2019 Summary of Public Meeting Concerning Annual Assessment of the Farley Nuclear Plant, Units 1 and 2, Docket Nos. 05000348 and 05000361 ML19057A4762019-03-0707 March 2019 Presentation Slides Related to Pre-Application Public Meeting Regarding to Technical Specification 3.3.1 and 3.3.2 (L-2019-LRM-0010) ML19025A0242019-01-25025 January 2019 SNC License Amendment Request for Proposed Changes to Emergency Response Organization Staffing and Augmentation NL-18-1412, Presentation Material for the Measurement Uncertainty Recovery and Spent Fuel Pool Criticality Analysis Pre-Submittal Meeting2018-11-0808 November 2018 Presentation Material for the Measurement Uncertainty Recovery and Spent Fuel Pool Criticality Analysis Pre-Submittal Meeting ML18311A1822018-11-0707 November 2018 November 13, 2018, Joseph M. Farley Nuclear Power Plant, Public Meeting Slides Regarding Spent Fuel Pool Criticality Analyses and Measurement Uncertainty Recovery (Mur) Pre-Application Meeting ML18290B0942018-10-16016 October 2018 October 16, 2018, Public Meeting Presentation Slides Related to July 27, 2018, License Amendment Request to Implement NEI 06-09, Revision 0-A, Risk-Informed Technical Specifications Initiative 4b. ML18234A4712018-08-23023 August 2018 NRC-Pre Submittal Meeting TSTF-51 for Hatch and TSTF-51 and -471 for Farley - August 23, 2018 ML18136A8902018-05-16016 May 2018 May 21, 2018 Slides for Public Teleconference Regarding Changes to Hatch, Farley, and Vogtle TS 5.2.2.g ML18065A0202018-03-12012 March 2018 March 12, 2018, Public Meeting Presentation ML18065A0222018-03-0606 March 2018 March 12, 2018, Public Meeting - Draft 4b Application ML18065A0252018-03-0606 March 2018 Joseph M Farley March 12, 2018, Public Meeting - Draft 4b Application Enclosures NL-16-0388, September 22, 2016, Public Meeting Presentation Slides2016-09-22022 September 2016 September 22, 2016, Public Meeting Presentation Slides ML16260A1162016-09-22022 September 2016 September 22, 2016, Public Meeting Presentation Slides ML15106A2042015-04-22022 April 2015 April 22, 2015, Meeting with Southern Nuclear Company, Slide Presentation ML14115A4052014-04-25025 April 2014 2013 End of Cycle Farley Public Meeting Summary Memo ML14108A0052014-04-23023 April 2014 April 23, 2014, Public Meeting Presentation Slides, Southern Nuclear Company, SNC Degraded Grid Design Criteria. ML14120A2252014-04-23023 April 2014 April 23, 2014, Category 1 Public Meeting, J.M. Farley Presentation Slides, Residual Heat Removal Autoclosure Interlock Deletion. ML14135A1732014-02-26026 February 2014 May 16, 2014, J.M. Farley Category 1 Meeting Handout, Duration for Completion of the Flood Hazard Re-evaluation. ML13079A1502013-03-20020 March 2013 Summary of Public Meeting with Joseph M. Farley ML13078A2472013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 2 (3/20) ML13078A2552013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 10 ML13078A2542013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 9 ML13078A2532013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 8 ML13078A2522013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 6 ML13078A2512013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 5 (3/19) ML13078A2502013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 4 ML13078A2482013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 3 (3/19) ML13078A2462013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 2 (3/19) ML13078A2452013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 1 (3/19) ML1016705482010-06-0808 June 2010 Farley Nuclear Plant, NRC Screening Criteria Response ML1009805922010-04-0808 April 2010 Summary of Public Meeting to Discuss Nrc'S Reactor Oversight Process and Nrc'S Annual Assessment of Plant Safety Performance for Period of January 1, 2009 - December 31, 2009 - Joseph M. Farley Nuclear Plant ML0909210352009-03-19019 March 2009 Annual Assessment Meeting Presentation ML0814900902008-05-22022 May 2008 List of Attendees - Joseph M. Farley Nuclear Plant, Annual Public Assessment Meeting 2024-09-23
[Table view] Category:Slides and Viewgraphs
MONTHYEARML24260A0792024-09-23023 September 2024 9/23/2024 Pre-Submittal Meeting - Joseph M. Farley Nuclear Plant, Units 1 and 2, LAR to Change UFSAR for Exception to RG 1.183, Revision 0, Table 3 - Footnote 11 (EPID L-2024-LRM-0108) - Meeting Slides ML24192A2262024-07-11011 July 2024 Mtg to Exchange Technical Information Regarding Farley, Units 1 & 2, Proposed License Amendment Request to Increase TS 3.6.5 Containment Temperature Limit Completion Using Risk-Informed Process for Evaluation (EPID L-2024-LRM-0086) - Slides ML24190A1082024-07-0808 July 2024 NRC Slides-07/11/2024 Mtg to Exchange Technical Information Regarding Joseph M. Farley Nuclear Plant, Units 1 & 2, Proposed License Amendment Request to Increase TS 3.6.5 Containment Temperature Limit Completion Using Risk-Informed Process ML24134A1062024-05-13013 May 2024 2023 Annual Assessment Meeting Presentation Slides ML24088A1662024-04-0303 April 2024 SNC Slides - Pre-Submittal Meeting on April 3, 2024 - Farley LAR Changing TS 3.6.5 Containment Air Temperature Using RIPE ML23361A0812024-01-0808 January 2024 SNC Slides - Pre-Submittal Public Meeting on January 8, 2024 Related to Fleet QATR ML23139A2462023-05-19019 May 2023 Annual Assessment Public Meeting Slides (May 23, 2023) ML22080A0192022-03-18018 March 2022 Annual Assessment Meeting Presentation ML21306A0242021-11-30030 November 2021 SNC Pre-Submittal Meeting for LAR to Relocate Augmented Piping Inspection Program Details from TSs to a Licensee Controlled Document for Farley Nuclear Plant, Units 1 & 2; and Vogtle Electric Generating Plant, Units 1 & 2 (EPID L-2021-LRM-0 ML21280A0012021-10-31031 October 2021 Pre-Submittal Meeting Presentation from SNC to Discuss a Future LAR Regarding Change TS to Increase Containment Peak Pressure to Address Several NSALs ML21173A0632021-06-24024 June 2021 Pre-Application SNC Presentation Slides - Removal of Encapsulations from Recirculation Suction Valves ML21083A2872021-03-24024 March 2021 Pre-Submittal Meeting - Quality Assurance Topical Report Revision to Allow Application of Remote Assessment Techniques During Exigent Conditions ML21057A0182021-02-26026 February 2021 Pre-Submittal Meeting Revise Technical Specification 3.2.1 Heat Flux Hot Channel Factor (Fq(Z)) (EPID L-2021-LRM-0023) (Slides) ML21036A1172021-02-0505 February 2021 SNC Slides - Pre-Submittal Meeting on February 16, 2021 - Beacon LAR ML20318A1032020-11-12012 November 2020 SNC ERO Staffing LAR RAI Responses ML20101K6582020-04-10010 April 2020 Annual Assessment ML20022A0262020-01-22022 January 2020 NEI Presentation Status Update for Ropte Short Term Action Plan: Removed Planned Unavailability for Mitigating Systems Performance Index ML19149A4222019-05-29029 May 2019 Summary of Public Meeting Concerning Annual Assessment of the Farley Nuclear Plant, Units 1 and 2, Docket Nos. 05000348 and 05000361 ML19057A4762019-03-0707 March 2019 Presentation Slides Related to Pre-Application Public Meeting Regarding to Technical Specification 3.3.1 and 3.3.2 (L-2019-LRM-0010) ML19025A0242019-01-25025 January 2019 SNC License Amendment Request for Proposed Changes to Emergency Response Organization Staffing and Augmentation NL-18-1412, Presentation Material for the Measurement Uncertainty Recovery and Spent Fuel Pool Criticality Analysis Pre-Submittal Meeting2018-11-0808 November 2018 Presentation Material for the Measurement Uncertainty Recovery and Spent Fuel Pool Criticality Analysis Pre-Submittal Meeting ML18290B0942018-10-16016 October 2018 October 16, 2018, Public Meeting Presentation Slides Related to July 27, 2018, License Amendment Request to Implement NEI 06-09, Revision 0-A, Risk-Informed Technical Specifications Initiative 4b. ML18065A0202018-03-12012 March 2018 March 12, 2018, Public Meeting Presentation ML18065A0252018-03-0606 March 2018 Joseph M Farley March 12, 2018, Public Meeting - Draft 4b Application Enclosures ML18065A0222018-03-0606 March 2018 March 12, 2018, Public Meeting - Draft 4b Application ML16260A1162016-09-22022 September 2016 September 22, 2016, Public Meeting Presentation Slides NL-16-0388, September 22, 2016, Public Meeting Presentation Slides2016-09-22022 September 2016 September 22, 2016, Public Meeting Presentation Slides ML15106A2042015-04-22022 April 2015 April 22, 2015, Meeting with Southern Nuclear Company, Slide Presentation ML14115A4052014-04-25025 April 2014 2013 End of Cycle Farley Public Meeting Summary Memo ML14108A0052014-04-23023 April 2014 April 23, 2014, Public Meeting Presentation Slides, Southern Nuclear Company, SNC Degraded Grid Design Criteria. ML14120A2252014-04-23023 April 2014 April 23, 2014, Category 1 Public Meeting, J.M. Farley Presentation Slides, Residual Heat Removal Autoclosure Interlock Deletion. ML14108A0042014-04-18018 April 2014 April 23, 2014, Category 1 Public Meeting, J.M. Farley Presentation Slides, Residual Heat Removal Autoclosure Interlock Deletion ML13079A1502013-03-20020 March 2013 Summary of Public Meeting with Joseph M. Farley ML13078A2462013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 2 (3/19) ML13078A2552013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 10 ML13078A2542013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 9 ML13078A2532013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 8 ML13078A2522013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 6 ML13078A2512013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 5 (3/19) ML13078A2502013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 4 ML13078A2482013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 3 (3/19) ML13078A2452013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. Farley Nuclear Plant NFPA 805 Fire Modeling LAR Submittal - Session 1 (3/19) ML13078A2472013-03-19019 March 2013 03/21/2013 Licensee Meeting Slides Re Joseph M. 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SNC Degraded Grid Design Criteria April 23, 2014 1
Agenda
Background
- New SNC Degraded Grid Relaying Design Criteria
Purpose Review the design criteria being used by Southern Nuclear for the new degraded grid voltage protective relaying at Hatch Nuclear Plant and Farley Nuclear plant.
These criteria draw from previous industry guidance and our own experience, experience but are not intended as a commitment to any particular existing guidance document.
Obtain NRC feedback on the criteria to help ensure that the implemented solutions meet NRC expectations for automatic protection for potential degraded grid events and resolve NRC findings from the related CDBIs.
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Background
For a potential degraded grid event, previous designs:
y
- Relied on manual actions byy the transmission system and plant operators to prevent an occurrence.
- Some required Class 1E loads were not automatically protected t t d from f a sustained t i d voltage lt inadequacy.
i d There are currently two submittals on the docket docket, one for Plant Farley and one for Plant Hatch, that include a schedule for the degraded grid modification projects. The LAR submittals b itt l revise i each h plants l t operatingti lilicense tto include completion dates, by unit, for the modifications.
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Background - Scope of Modifications
- Replacement of the existing degraded voltage relays
- Raising the existing voltage setpoints.
- R Replacement l t off the th existing i ti d degraded d d voltage lt relays l iincluding l di change from 2 relays to 3 relays (2 of 3 logic).
- Raising the existing voltage setpoints.
- Replacement of 4 existing startup auxiliary transformers
- Addition of 2 new startup auxiliary transformers and 230KV breakers including associated relaying, fire protection, etc.
- Upgrade of 4.16KV bus short circuit capability for 10 buses (breakers and bus bracing).
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Background - Farley Schedule
- January 2015 - Submit Farley License Amendment Request (LAR)
- January 2016 - NRC approval of Farley LAR
- Spring Outage 2016 (U2R24) - Design implementation begins on U2
- Fall Outage 2016 (U1R27) - Design implementation b i on U1 begins
- Fall Outage 2017 (U2R25) - Design implementation completed on U2
- Spring Outage 2018 (U1R28) - Design implementation completed on U1 6
Background - Hatch Schedule
- December 2015 - Submit Hatch License Amendment Request (LAR)
- December 2016 - NRC approval of Hatch LAR
- Spring Outage 2017 (U2R24) - Design implementation begins on U2
- Spring Outage 2018 (U1R28) - Design implementation b i on U1 begins
- Spring Outage 2019 (U2R25) - Design implementation completed on U2
- Spring Outage 2020 (U1R29) - Design implementation completed on U1 7
Definitions & Acronyms
- DVR - Degraded Voltage Relaying
- MEV - Minimum Expectedp Voltage g - The steadyy state voltage level at the 4.16kV buses that is expected when the 230kV switchyard is at the minimum voltage based on contingency studies defined by the FSARFSAR.
- MRV - Minimum Required Voltage - The steady state voltage level at a Class 1E 4.16kV bus that is required for its safety-related loads to accomplish their safety functions. The safety-related motors shall be able to start successfully with the pre pre-start start steady-state steady state bus voltage at the MRV.
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Design Criteria - Voltage
- The DVR shall be set such that offsite power will be automatically disconnected and transferred to onsite power during an extended degraded grid condition (any voltage dip having a longer duration than expected for normal or accident operations).
- The DVR on the Class 1E 4.16KV bus will be set so that, including tolerances, voltage dropout value will be above the MRV value.
- The Th DVR voltagelt resett value, l i l di including tolerances, will be set below the MEV.
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Design Criteria - Time Delay
- The DVR minimum time delay will be set such that, with tolerances, it will delay actuation to prevent a spurious trip due to motor starting or other momentary transient events.
- The DVR maximum time delay will be set such that, with tolerances, it will:
- be less than the maximum time allowed for the diesel generator to start and obtain rated speed and voltage.
- prevent loss of Class 1E functions when the voltage is inadequate by actuation prior to a trip of loads on overload.
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Voltage Setpoint Methodology
- Part 1 - Using maximum expected non-accident bus loading, determine minimum acceptable steady-state voltage for normal operation.
- Part 2 - Using maximum expected accident loading, determine the minimum pre-start voltage that provides acceptable Class 1E motor starting (e.g. during LOCA block motor starting)
- Part 3 - Using maximum expected accident loading, determine the minimum steady-state voltage that provides acceptable Class 1E motor operation and starting for individual motors.
- The maximum voltage of Parts 1-3 determines the MRV (i.e. analytical limit).
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DVR Voltage Setpoint Example Setting to detect inadequate LOCA starting Setting for voltage prior to start normal steady state requirement Setting for LOCA steady state requirement Colored bar represents the DVR voltage setting uncertainty & reset requirement 12
DVR Voltage Setpoint Example Limiting Part Setting to detect inadequate LOCA starting Setting for voltage prior to start normal steady state requirement Setting for LOCA steady state requirement Colored bar represents the DVR voltage setting uncertainty & reset requirement 13
DVR Time Delay Setpoint Example
- At MEV, LOCA block motor starting voltage transient lasts for 7 seconds (i.e. recovers above the DVR voltage reset value).
- The duration of all other motor starting or fault transient events is less than 7 seconds.
- Upon a LOCA, the diesel must start and be at normal voltage and frequency (i(i.e.
e ready for loading) at 15 seconds seconds.
- With inadequate voltage, motors cannot stall for greater than 12 seconds without tripping on overload.
- C Considering id i DVR time i d delay l uncertainty,i the h setting i
must be between 7 and 12 seconds.
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LAR Submittal Content
- Calculations (portions) demonstrating the use of the methodology and the setpoint results.
- Criteria, methodology and assumptions
- Steady-state and starting cases for the MEV and the DVR setting part of the analysis p y showing g voltages g for each Class 1E bus and its required loads.
- Setpoint uncertainty calculations
- Basis for setpoints
- List of the most limiting components for each study case.
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Comments or Questions?
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