ML15308A100

11/10/2015, Public Meeting Presentation Slides Extended Power Uprate License Amendment Request NRC Public Meeting

ML15308A100
Person / Time
Site:	Browns Ferry
Issue date:	11/10/2015
From:	Doyle G Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation
Saba F, NRR/DORL, 415-1447
References
Download: ML15308A100 (37)

Text

Browns Ferry Nuclear PlantExtended Power Uprate License Amendment Request NRC Public Meeting Gerry Doyle Director EPUNovember 10,2015 BFN EPU -AgendaBrowns Ferry EPU License Amendment Request IntroductionsExtended Power Uprate (EPU) Overview

Submittal Format and Content/Approach Disposition of Pre-Application Meetings Feedback Electronic Reading Room

Proposed Audit Schedule Acceptance Review Issues

• Replacement Steam Dryers

• Containment Accident Pressure Credit Elimination

• Spent Fuel Pool Criticality Analysis

• Analysis Code MICROBURN-B2 Questions/Comments G Doyle G Doyle D Green D Green D Green D GreenP DonahueP Donahue G Storey/J Kimberlin

G Storey G Doylel 2 BFN EPU -IntroductionsGerry Doyle -Director, Extended Power Uprate (EPU)Pete Donahue -EPU Engineering ManagerDan Green -EPU Licensing ManagerJeff Kimberlin-EPU Operations Support ManagerEd Schrull-Fleet Licensing ManagerGreg Storey-Fleet BWR Fuels Engineering ManagerBrowns Ferry EPU License Amendment Request l 3 BFN EPU -OverviewBrowns Ferry EPU License Amendment Request l 4 BFN EPU -Submittal Format and Content/ApproachBrowns Ferry EPU License Amendment Request l 5New Consolidated License Amendment Request (LAR) SubmittalSupersedes all previous Browns Ferry Nuclear Plant (BFN) Extended Power Uprate (EPU) submittals

-Previous submittals withdrawn

-Addresses current BFN conditionsFormat of RS-001, Review Standard for Extended Power UpratesApplied Lessons Learned

-Previous applicable NRC Requests for Additional Information addressed in new submittalIncludes replacement of Steam DryersIncludes resolution of Containment Accident Pressure issue

-In accordance with SECY 11-0014, Use of Containment Accident Pressure in Analyzing Emergency Core Cooling System and Containment Heat Removal System Pump Performance in Postulated

Accidents , guidanceApplied improved submittal Verification and Validation process

-To ensure completeness and accuracy BFN EPU -Submittal Format and Content/Approach (continued)Browns Ferry EPU License Amendment Request l 6Applied Institute of Nuclear Power Operations (INPO) Operating Experience (OE)

-Significant Event Report (SER) 5-02, Lessons Learned from Power Uprates-INPO 09-005, Power Uprate Implementation Strategies -A Leadership Perspective

-INPO Event Report (IER) 14-20, Integrated Risk -Healthy Technical ConscienceApplied results of Benchmarking

-Benchmarking of recent Boiling Water Reactor (BWR) Licensees

with EPU LARsMonticello, Grand Gulf, Peach Bottom Applied BWR Owners' Group (BWROG) Lessons Learned

-BWROG-TP-043, BWR Owners' Group EPU Committee -

Extended Power Uprate (EPU) Lessons Learned and

Recommendations BFN EPU -Disposition of Pre-application Meetings FeedbackBrowns Ferry EPU License Amendment Request l 7 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 8 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 9 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 10 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 11 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 12 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 13 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 14 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 15 BFN EPU -Electronic Reading Room

• Facilitates NRC reviewAllows file sharing (e.g., calculations) with NRC reviewersFiles may be opened and viewed by NRC reviewers, but copying, printing or downloading files is precluded Will not be used for Requests for Additional Information (RAIs)

-Normal NRC process will be used for RAIs

• URL for reading room portalhttps://bfepurr.certrec.com

• Access to reading room restricted to those NRC personnel granted accessBFN reading room administrator grants specific NRC personnel access to the reading room

-Need NRC reviewer names and email addresses to assign user names and passwords

• ProcessNRC requests information to review (e.g., calculation)Information is obtained and file uploaded by BFN reading room administratorAfter file is uploaded, an email is generated to NRC (Project Manager or reviewer, as determined by NRC), informing them that information is available for reviewIf, after reviewing the reading room file, NRC determines information from file is needed, the Tennessee Valley Authority will submit the required information on the docketBrowns Ferry EPU License Amendment Request l 16 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 17 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 18 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 19 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 20 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 21 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 22 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 23 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 24 BFN EPU -Proposed Audit Schedule

• Regulatory audits allow NRC to more efficiently conduct its review or gain insights on a licensee's programs or processes

• Regulatory audits are conducted with the intent for the NRC to gain understanding, to verify information, and/or to identify information that will require docketing to support the basis of the licensing or regulatory decisionProposed audit schedule to facilitate NRC review of EPU LAR

-Replacement Steam Dryer Design and AnalysesFebruary 8 -12, 2016

-Containment Accident Pressure Credit Elimination AnalysesMarch 14 -18, 2016

-Fuels AnalysesMarch 21 -25, 2016

-Other Audits, as neededBrowns Ferry EPU License Amendment Request l 25 BFN EPU -Acceptance Review Issues

• Replacement Steam DryersAnalysis Methodology

-BFN Replacement Steam Dryer (RSD) acoustic load definition was developed using the GEH Plant Based Load Evaluation Methods

-For BFN, one acoustic load definition was developed that bounds the loading for all three BFN units

-The RSD for the initial unit at EPU conditions will have on-dryer instrumentation such that actual RSD loading can be compared to predicted loadsAcoustic Vibration Suppressors (AVSs)

-AVSs were designed and installed on all three BFN units to reduce the depth of the standpipe cavity and eliminate an excessive resonance source

-Main Steam Line (MSL) strain gauge data, taken after the installation of the AVSs, shows that the acoustic resonance associated with the standpipes has been eliminated

-Stress analyses for the BFN RSDs used MSL acoustic data for each BFN unit taken with the AVSs installedBrowns Ferry EPU License Amendment Request l 26 BFN EPU -Acceptance Review Issues

• Replacement Steam Dryers (continued)Acoustic Side Branches (ASBs)

-BFN does not currently experience any si gnificant resonances associated with the Safety Relief Valve (SRV) standpipes requiring ASB installation at BFNHowever, based on analyses, it is predicted that SRV resonance could occur at the increased steam flow velocities for EPU

-SRV resonance at BFN EPU conditions is addressed in the BFN SDAR (NEDC-33824P, EPU LAR Attachment 40)

-In addition, monitoring of main steam system piping vibration and SRV vibration at EPU conditions will be performed in accordance with the Flow Induced Vibration Analysis and Monitoring Program (EPU LAR Attachment 45)Browns Ferry EPU License Amendment Request l 27 BFN EPU -Acceptance Review Issues

• Containment Accident Pressure Credit EliminationResidual Heat Removal Heat Exchanger Thermal Performance Testing

-EPU Design Fouling Resistance is 0.001521

-EPU Nominal Fouling Resistance (Fire Event) is 0.001097* Preliminary resultsBrowns Ferry EPU License Amendment Request l 28 BFN EPU -Acceptance Review Issues

• Spent Fuel Pool Criticality AnalysisFuel Uprate Safety Analysis Report (FUSAR) (EPU LAR Attachment 8) section 2.8.6.2 addresses spent fuel storage

-Summarizes results of the criticality safety analyses (CSA) of record

-AREVA fuel types that will reside in EPU cores evaluatedBFN CSA reports comply with the requirements of DSS-ISG-2010-01, Staff Guidance Regarding the Nuclear Safety Analysis for Spent Fuel PoolsCSAs included sensitivity studies for parameters potentially affected by EPU-Power density sensitivity+/-50% variation in power density for a fixed void fraction Higher power density resulted in lower in rack k-infinity (k) -Void history sensitivityRange of void histories between 0% and 90% studiedLimiting void history used in the CSAHigh void history not limiting (typically 0% void history limiting)

-Control history sensitivity Uncontrolled history produces the limiting resultNo EPU impactsBrowns Ferry EPU License Amendment Request l 29 BFN EPU -Acceptance Review Issues

• Spent Fuel Pool Criticality Analysis (continued)

-Fuel temperature sensitivity+/-100°F variation in fuel temperature In rack kshown to be insensitive to operating fuel temperature

-Power shape sensitivityNo impact from EPULattices evaluated at the limiting exposure and void history combination

-Pool temperature sensitivity Higher decay heat from EPU operati on could raise pool temperatureEvaluation showed minimum pool temperature limitingConclusions

-Parameters potentially affected by EPU operation studied

-CSA reports of record are applicable and conservative for EPU Browns Ferry EPU License Amendment Request l 30 BFN EPU -Acceptance Review Issues

• Spent Fuel Pool Criticality Analysis (continued)Additional controls to prevent criticality during fuel movement

-Reactor Engineering creates Fuel Assembly Transfer Form (FATF), based on CSA -Fuel moves are verified and tracked to be in accordance with FATF by the followingPerformerConcurrent VerifierA Senior Reactor Operator on the refuel bridgeA Reactor Engineer on the refuel floorSeparate individual at a remote location using installed camera on refueling bridgeA Licensed Operator in the Control Room

-FATF requirements are input into the Bridge and Trolley Tracking System (BATTS) prior to fuel movementBATTS provides alternate indication/alarm when performing fuel movements in the reactor core or spent fuel poolBrowns Ferry EPU License Amendment Request l 31 BFN EPU -Acceptance Review Issues

• Analysis Code MICROBURN-B2AREVA identified an issue with the MICROBURN-B2 analysis

-Related to convergence of the thermal hydraulic solution at low core flows

-Affects the version of the code used to support the BFN EPU LARNature of the issue

-Calculation of the bypass flow at low core flow conditions can oscillate between two values without reaching convergence (maximum iterations reached)Presence of voiding in the upper bypass creates the convergence difficulties

-Code will continue to run with the unconvergedhydraulic solution

-Results in the axial power shape not being correct in MICROBURN-B2

-Problem observed for core flows < 40% of ratedExtent of condition

-Investigations show the thermal hydraulic stability analysis is affectedIncorrect axial power shape affects stability results

-Flow dependent Critical Power Ratio (CPR) and Linear Heat Generation Rate limits include cases below 40% core flowEvaluations show these two analyses are not affected for EPU LAR

-All other analyses in the EPU LAR that involve MICROBURN-B2 are performed at core flows of 50% and higher

-FUSAR and Unit 3 Cycle 19 EPU Representative Reload Report affectedBrowns Ferry EPU License Amendment Request l 32 BFN EPU -Acceptance Review Issues

• Analysis Code MICROBURN-B2 (continued)Effect on FUSAR (ANP-3403P) (EPU LAR Attachment 8)

-Generic Delta Critical Power Ratio (CPR) over Initial Minimum CPR (MCPR) Versus Oscillation Magnitude (DIVOM) line presented in Figure 2.8-3 will still be boundingCalculated points below the line will change slightly

-Small changes to decay ratio values in Tables 2.8-2 and 2.8-3Backup Stability Protection region boundaries remain the same

-Operating limit CPR values presented in Table 2.8-1 will decrease slightlyValues in current FUSAR report are conservativeStability will continue to not set the overall CPR operating limit when the analysis is rerunEffect on Unit 3 Cycle 19 EPU Representative Reload Report (ANP-3404P) (EPU LAR Attachment 20)

-Operating limit CPR values presented in Table 4.3 decrease slightlyValues in current revision of the report are conservativeStability will continue to not set the overall CPR operating limit when the analysis is rerunCorrective actions to prevent recurrence

-Improved convergence scheme in MICROBURN-B2 for low flow cases

-Message will be written to error file if the condition should occurBrowns Ferry EPU License Amendment Request l 33 BFN EPU -Acceptance Review Issues

• Analysis Code MICROBURN-B2 (continued)AREVA identified a second issue during investigation of the MICROBURN-B2 flow convergence problem

-Related to application of the void quality correlation at low core flowsNature of the issue

-Void quality correlation used in the EPU LAR work has a low mass flux cutoff

-Cutoff is used to preclude non-physical results for calculations where very high quality conditions may occur (Anticipated Transient Without Scram with Core Instability)

-Cutoff may not be appropriate for calculations with low to moderate quality conditions Extent of condition

-Similar to the flow convergence i ssue, stability analysis may be affectedDifference in results is on the order of normal cycle to cycle variation in results

-Other events at low flow shown not to be affected by this issue

-FUSAR and Unit 3 Cycle 19 EPU Representative Reload Report affectedCorrective actions to prevent recurrence

-Issue still in discovery

-Corrective actions will be defined when discovery has been completedBrowns Ferry EPU License Amendment Request l 34 BFN EPU -Acceptance Review Issues

• Analysis Code MICROBURN-B2 (continued)Browns Ferry EPU LAR Supplement

-Interim Report, addressing both issues, expected to be submitted by November 9, 2015Supports continuing EPU LAR acceptance reviews

-Revised FUSAR and Unit 3 Cycle 19 EPU Representative Reload Report, addressing both issues, expected to be submitted by December 15, 2015Browns Ferry EPU License Amendment Request l 35 BFN EPU -Acronym ListBrowns Ferry EPU License Amendment Request l 36*ACRS -Advisory Committee on Reactor Safeguards

• ASBs -Acoustic Side Branches

• ATWS -Anticipated Transient Without Scram

• AVSs -Acoustic Vibration Suppressors

• BATTS -Bridge and Trolley Tracking System

• BFN -Browns Ferry Nuclear Plant

• Btu -British Thermal Unit

• BWR -Boiling Water Reactor

• BWROG -BWR Owners' Group

• CAP -Containment Accident Pressure

• CDF -Core Damage Frequency

• CPR -Critical Power Ratio

• CRDA -Control Rod Drop Accident

• CSA -Criticality Safety Analysis

• DIVOM -Delta CPR over Initial MCPR Versus Oscillation Magnitude*ECCS -Emergency Core Cooling System

• EHPMP -Emergency High Pressure Makeup Pump

• EPU -Extended Power Uprate

• F -Farenheit

• FATF -Fuel Assembly Transfer Form

• ft 2-square feet

• FUSAR -Fuel Uprate Safety Analysis Report

• FIV -Flow Induced Vibration

• GDC -General Design Criteria

• hr-hour*HX -Heat Exchanger

• Hz -Hertz*IER -INPO Event Report

• IN -Information Notice

• INPO -Institute of Nuclear Power Operations

• LA -License Amendment

• LAR -License Amendment Request

• LERF -Large Early Release Frequency

• MAPLHGR -Maximum Average Planar Linear Heat Generation Rate

• MCPR -Minimum Critical Power Ratio

• MSL -Main Steam Line

• MWt-Megawatt Thermal

• NPSH -Net Positive Suction Head

• NRC -Nuclear Regulatory Commission

• OE -Operating Experience

• PCMI -Pellet-to-Cladding Mechanical Interaction

• PM -Preventive Maintenance

• PRA -Probabilistic Risk Assessment

• PUSAR -Power Uprate Safety Analysis Report

• RAI -Request for Additional Information

• RHR -Residual Heat Removal

• RSD -Replacement Steam Dryer

• SDAR -Steam Dryer Analysis Report

• SE -Safety Evaluation

• SER -Significant Event Report

• SLO -Single Loop Operation

• SRP -Standard Review Plan

• SRV -Safety Relief Valve

• TIP -Traversing IncoreProbe

• UFSAR -Updated Safety Analysis Report BFN EPU -Questions/CommentsBrowns Ferry EPU License Amendment Request l 37 Browns Ferry Nuclear PlantExtended Power Uprate License Amendment Request NRC Public Meeting Gerry Doyle Director EPUNovember 10,2015 BFN EPU -AgendaBrowns Ferry EPU License Amendment Request IntroductionsExtended Power Uprate (EPU) Overview

Submittal Format and Content/Approach Disposition of Pre-Application Meetings Feedback Electronic Reading Room

Proposed Audit Schedule Acceptance Review Issues

• Replacement Steam Dryers

• Containment Accident Pressure Credit Elimination

• Spent Fuel Pool Criticality Analysis

• Analysis Code MICROBURN-B2 Questions/Comments G Doyle G Doyle D Green D Green D Green D GreenP DonahueP Donahue G Storey/J Kimberlin

G Storey G Doylel 2 BFN EPU -IntroductionsGerry Doyle -Director, Extended Power Uprate (EPU)Pete Donahue -EPU Engineering ManagerDan Green -EPU Licensing ManagerJeff Kimberlin-EPU Operations Support ManagerEd Schrull-Fleet Licensing ManagerGreg Storey-Fleet BWR Fuels Engineering ManagerBrowns Ferry EPU License Amendment Request l 3 BFN EPU -OverviewBrowns Ferry EPU License Amendment Request l 4 BFN EPU -Submittal Format and Content/ApproachBrowns Ferry EPU License Amendment Request l 5New Consolidated License Amendment Request (LAR) SubmittalSupersedes all previous Browns Ferry Nuclear Plant (BFN) Extended Power Uprate (EPU) submittals

-Previous submittals withdrawn

-Addresses current BFN conditionsFormat of RS-001, Review Standard for Extended Power UpratesApplied Lessons Learned

-Previous applicable NRC Requests for Additional Information addressed in new submittalIncludes replacement of Steam DryersIncludes resolution of Containment Accident Pressure issue

-In accordance with SECY 11-0014, Use of Containment Accident Pressure in Analyzing Emergency Core Cooling System and Containment Heat Removal System Pump Performance in Postulated

Accidents , guidanceApplied improved submittal Verification and Validation process

-To ensure completeness and accuracy BFN EPU -Submittal Format and Content/Approach (continued)Browns Ferry EPU License Amendment Request l 6Applied Institute of Nuclear Power Operations (INPO) Operating Experience (OE)

-Significant Event Report (SER) 5-02, Lessons Learned from Power Uprates-INPO 09-005, Power Uprate Implementation Strategies -A Leadership Perspective

-INPO Event Report (IER) 14-20, Integrated Risk -Healthy Technical ConscienceApplied results of Benchmarking

-Benchmarking of recent Boiling Water Reactor (BWR) Licensees

with EPU LARsMonticello, Grand Gulf, Peach Bottom Applied BWR Owners' Group (BWROG) Lessons Learned

-BWROG-TP-043, BWR Owners' Group EPU Committee -

Extended Power Uprate (EPU) Lessons Learned and

Recommendations BFN EPU -Disposition of Pre-application Meetings FeedbackBrowns Ferry EPU License Amendment Request l 7 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 8 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 9 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 10 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 11 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 12 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 13 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 14 BFN EPU -Disposition of Pre-application Meetings Feedback (continued)Browns Ferry EPU License Amendment Request l 15 BFN EPU -Electronic Reading Room

• Facilitates NRC reviewAllows file sharing (e.g., calculations) with NRC reviewersFiles may be opened and viewed by NRC reviewers, but copying, printing or downloading files is precluded Will not be used for Requests for Additional Information (RAIs)

-Normal NRC process will be used for RAIs

• URL for reading room portalhttps://bfepurr.certrec.com

• Access to reading room restricted to those NRC personnel granted accessBFN reading room administrator grants specific NRC personnel access to the reading room

-Need NRC reviewer names and email addresses to assign user names and passwords

• ProcessNRC requests information to review (e.g., calculation)Information is obtained and file uploaded by BFN reading room administratorAfter file is uploaded, an email is generated to NRC (Project Manager or reviewer, as determined by NRC), informing them that information is available for reviewIf, after reviewing the reading room file, NRC determines information from file is needed, the Tennessee Valley Authority will submit the required information on the docketBrowns Ferry EPU License Amendment Request l 16 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 17 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 18 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 19 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 20 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 21 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 22 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 23 BFN EPU -Electronic Reading Room (continued)Browns Ferry EPU License Amendment Request l 24 BFN EPU -Proposed Audit Schedule

• Regulatory audits allow NRC to more efficiently conduct its review or gain insights on a licensee's programs or processes

• Regulatory audits are conducted with the intent for the NRC to gain understanding, to verify information, and/or to identify information that will require docketing to support the basis of the licensing or regulatory decisionProposed audit schedule to facilitate NRC review of EPU LAR

-Replacement Steam Dryer Design and AnalysesFebruary 8 -12, 2016

-Containment Accident Pressure Credit Elimination AnalysesMarch 14 -18, 2016

-Fuels AnalysesMarch 21 -25, 2016

-Other Audits, as neededBrowns Ferry EPU License Amendment Request l 25 BFN EPU -Acceptance Review Issues

• Replacement Steam DryersAnalysis Methodology

-BFN Replacement Steam Dryer (RSD) acoustic load definition was developed using the GEH Plant Based Load Evaluation Methods

-For BFN, one acoustic load definition was developed that bounds the loading for all three BFN units

-The RSD for the initial unit at EPU conditions will have on-dryer instrumentation such that actual RSD loading can be compared to predicted loadsAcoustic Vibration Suppressors (AVSs)

-AVSs were designed and installed on all three BFN units to reduce the depth of the standpipe cavity and eliminate an excessive resonance source

-Main Steam Line (MSL) strain gauge data, taken after the installation of the AVSs, shows that the acoustic resonance associated with the standpipes has been eliminated

-Stress analyses for the BFN RSDs used MSL acoustic data for each BFN unit taken with the AVSs installedBrowns Ferry EPU License Amendment Request l 26 BFN EPU -Acceptance Review Issues

• Replacement Steam Dryers (continued)Acoustic Side Branches (ASBs)

-BFN does not currently experience any si gnificant resonances associated with the Safety Relief Valve (SRV) standpipes requiring ASB installation at BFNHowever, based on analyses, it is predicted that SRV resonance could occur at the increased steam flow velocities for EPU

-SRV resonance at BFN EPU conditions is addressed in the BFN SDAR (NEDC-33824P, EPU LAR Attachment 40)

-In addition, monitoring of main steam system piping vibration and SRV vibration at EPU conditions will be performed in accordance with the Flow Induced Vibration Analysis and Monitoring Program (EPU LAR Attachment 45)Browns Ferry EPU License Amendment Request l 27 BFN EPU -Acceptance Review Issues

• Containment Accident Pressure Credit EliminationResidual Heat Removal Heat Exchanger Thermal Performance Testing

-EPU Design Fouling Resistance is 0.001521

-EPU Nominal Fouling Resistance (Fire Event) is 0.001097* Preliminary resultsBrowns Ferry EPU License Amendment Request l 28 BFN EPU -Acceptance Review Issues

• Spent Fuel Pool Criticality AnalysisFuel Uprate Safety Analysis Report (FUSAR) (EPU LAR Attachment 8) section 2.8.6.2 addresses spent fuel storage

-Summarizes results of the criticality safety analyses (CSA) of record

-AREVA fuel types that will reside in EPU cores evaluatedBFN CSA reports comply with the requirements of DSS-ISG-2010-01, Staff Guidance Regarding the Nuclear Safety Analysis for Spent Fuel PoolsCSAs included sensitivity studies for parameters potentially affected by EPU-Power density sensitivity+/-50% variation in power density for a fixed void fraction Higher power density resulted in lower in rack k-infinity (k) -Void history sensitivityRange of void histories between 0% and 90% studiedLimiting void history used in the CSAHigh void history not limiting (typically 0% void history limiting)

-Control history sensitivity Uncontrolled history produces the limiting resultNo EPU impactsBrowns Ferry EPU License Amendment Request l 29 BFN EPU -Acceptance Review Issues

• Spent Fuel Pool Criticality Analysis (continued)

-Fuel temperature sensitivity+/-100°F variation in fuel temperature In rack kshown to be insensitive to operating fuel temperature

-Power shape sensitivityNo impact from EPULattices evaluated at the limiting exposure and void history combination

-Pool temperature sensitivity Higher decay heat from EPU operati on could raise pool temperatureEvaluation showed minimum pool temperature limitingConclusions

-Parameters potentially affected by EPU operation studied

-CSA reports of record are applicable and conservative for EPU Browns Ferry EPU License Amendment Request l 30 BFN EPU -Acceptance Review Issues

• Spent Fuel Pool Criticality Analysis (continued)Additional controls to prevent criticality during fuel movement

-Reactor Engineering creates Fuel Assembly Transfer Form (FATF), based on CSA -Fuel moves are verified and tracked to be in accordance with FATF by the followingPerformerConcurrent VerifierA Senior Reactor Operator on the refuel bridgeA Reactor Engineer on the refuel floorSeparate individual at a remote location using installed camera on refueling bridgeA Licensed Operator in the Control Room

-FATF requirements are input into the Bridge and Trolley Tracking System (BATTS) prior to fuel movementBATTS provides alternate indication/alarm when performing fuel movements in the reactor core or spent fuel poolBrowns Ferry EPU License Amendment Request l 31 BFN EPU -Acceptance Review Issues

• Analysis Code MICROBURN-B2AREVA identified an issue with the MICROBURN-B2 analysis

-Related to convergence of the thermal hydraulic solution at low core flows

-Affects the version of the code used to support the BFN EPU LARNature of the issue

-Calculation of the bypass flow at low core flow conditions can oscillate between two values without reaching convergence (maximum iterations reached)Presence of voiding in the upper bypass creates the convergence difficulties

-Code will continue to run with the unconvergedhydraulic solution

-Results in the axial power shape not being correct in MICROBURN-B2

-Problem observed for core flows < 40% of ratedExtent of condition

-Investigations show the thermal hydraulic stability analysis is affectedIncorrect axial power shape affects stability results

-Flow dependent Critical Power Ratio (CPR) and Linear Heat Generation Rate limits include cases below 40% core flowEvaluations show these two analyses are not affected for EPU LAR

-All other analyses in the EPU LAR that involve MICROBURN-B2 are performed at core flows of 50% and higher

-FUSAR and Unit 3 Cycle 19 EPU Representative Reload Report affectedBrowns Ferry EPU License Amendment Request l 32 BFN EPU -Acceptance Review Issues

• Analysis Code MICROBURN-B2 (continued)Effect on FUSAR (ANP-3403P) (EPU LAR Attachment 8)

-Generic Delta Critical Power Ratio (CPR) over Initial Minimum CPR (MCPR) Versus Oscillation Magnitude (DIVOM) line presented in Figure 2.8-3 will still be boundingCalculated points below the line will change slightly

-Small changes to decay ratio values in Tables 2.8-2 and 2.8-3Backup Stability Protection region boundaries remain the same

-Operating limit CPR values presented in Table 2.8-1 will decrease slightlyValues in current FUSAR report are conservativeStability will continue to not set the overall CPR operating limit when the analysis is rerunEffect on Unit 3 Cycle 19 EPU Representative Reload Report (ANP-3404P) (EPU LAR Attachment 20)

-Operating limit CPR values presented in Table 4.3 decrease slightlyValues in current revision of the report are conservativeStability will continue to not set the overall CPR operating limit when the analysis is rerunCorrective actions to prevent recurrence

-Improved convergence scheme in MICROBURN-B2 for low flow cases

-Message will be written to error file if the condition should occurBrowns Ferry EPU License Amendment Request l 33 BFN EPU -Acceptance Review Issues

• Analysis Code MICROBURN-B2 (continued)AREVA identified a second issue during investigation of the MICROBURN-B2 flow convergence problem

-Related to application of the void quality correlation at low core flowsNature of the issue

-Void quality correlation used in the EPU LAR work has a low mass flux cutoff

-Cutoff is used to preclude non-physical results for calculations where very high quality conditions may occur (Anticipated Transient Without Scram with Core Instability)

-Cutoff may not be appropriate for calculations with low to moderate quality conditions Extent of condition

-Similar to the flow convergence i ssue, stability analysis may be affectedDifference in results is on the order of normal cycle to cycle variation in results

-Other events at low flow shown not to be affected by this issue

-FUSAR and Unit 3 Cycle 19 EPU Representative Reload Report affectedCorrective actions to prevent recurrence

-Issue still in discovery

-Corrective actions will be defined when discovery has been completedBrowns Ferry EPU License Amendment Request l 34 BFN EPU -Acceptance Review Issues

• Analysis Code MICROBURN-B2 (continued)Browns Ferry EPU LAR Supplement

-Interim Report, addressing both issues, expected to be submitted by November 9, 2015Supports continuing EPU LAR acceptance reviews

-Revised FUSAR and Unit 3 Cycle 19 EPU Representative Reload Report, addressing both issues, expected to be submitted by December 15, 2015Browns Ferry EPU License Amendment Request l 35 BFN EPU -Acronym ListBrowns Ferry EPU License Amendment Request l 36*ACRS -Advisory Committee on Reactor Safeguards

• ASBs -Acoustic Side Branches

• ATWS -Anticipated Transient Without Scram

• AVSs -Acoustic Vibration Suppressors

• BATTS -Bridge and Trolley Tracking System

• BFN -Browns Ferry Nuclear Plant

• Btu -British Thermal Unit

• BWR -Boiling Water Reactor

• BWROG -BWR Owners' Group

• CAP -Containment Accident Pressure

• CDF -Core Damage Frequency

• CPR -Critical Power Ratio

• CRDA -Control Rod Drop Accident

• CSA -Criticality Safety Analysis

• DIVOM -Delta CPR over Initial MCPR Versus Oscillation Magnitude*ECCS -Emergency Core Cooling System

• EHPMP -Emergency High Pressure Makeup Pump

• EPU -Extended Power Uprate

• F -Farenheit

• FATF -Fuel Assembly Transfer Form

• ft 2-square feet

• FUSAR -Fuel Uprate Safety Analysis Report

• FIV -Flow Induced Vibration

• GDC -General Design Criteria

• hr-hour*HX -Heat Exchanger

• Hz -Hertz*IER -INPO Event Report

• IN -Information Notice

• INPO -Institute of Nuclear Power Operations

• LA -License Amendment

• LAR -License Amendment Request

• LERF -Large Early Release Frequency

• MAPLHGR -Maximum Average Planar Linear Heat Generation Rate

• MCPR -Minimum Critical Power Ratio

• MSL -Main Steam Line

• MWt-Megawatt Thermal

• NPSH -Net Positive Suction Head

• NRC -Nuclear Regulatory Commission

• OE -Operating Experience

• PCMI -Pellet-to-Cladding Mechanical Interaction

• PM -Preventive Maintenance

• PRA -Probabilistic Risk Assessment

• PUSAR -Power Uprate Safety Analysis Report

• RAI -Request for Additional Information

• RHR -Residual Heat Removal

• RSD -Replacement Steam Dryer

• SDAR -Steam Dryer Analysis Report

• SE -Safety Evaluation

• SER -Significant Event Report

• SLO -Single Loop Operation

• SRP -Standard Review Plan

• SRV -Safety Relief Valve

• TIP -Traversing IncoreProbe

• UFSAR -Updated Safety Analysis Report BFN EPU -Questions/CommentsBrowns Ferry EPU License Amendment Request l 37