ML18059A107
| ML18059A107 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 03/16/2018 |
| From: | Tennessee Valley Authority |
| To: | Farideh Saba Plant Licensing Branch II |
| Saba F DORL/LPL2-2 301-415-1447 | |
| References | |
| Download: ML18059A107 (20) | |
Text
Browns Ferry Nuclear Plant Maximum Extended Load Line Limit Analysis Plus License Amendment Request Pete Donahue March 16, 2018
Browns Ferry Nuclear Plant (BFN) MELLLA+ LAR Agenda Browns Ferry MELLLA+ License Amendment Request
Introductions
Background
LAR Overview Electronic Reading Room MELLLA+ Analyses Comparison - BFN to Brunswick Tennessee Valley Authority Scope Analyses GEH Scope Analyses AREVA/Framatome Scope Analyses Questions/Comments P. Donahue B. Baker D. Green D. Green M. Dick/G. Storey P. Donahue l 2
Background
Browns Ferry MELLLA+ License Amendment Request l 3 Extended Power Uprate (EPU) power levels restrict flow window Maximum Extended Load Line Limit Analysis (MELLLA) rod line extrapolated to EPU power Licensed flow window reduced: 99% - 105% core flow at rated EPU power Administrative margin would limit operating flow window: 100% - 104% range MELLLA Plus (MELLLA+) raises the maximum allowed rod line Licensed flow window: 85% - 105% core flow at rated EPU power
BFN MELLLA+ LAR Background (continued)
Browns Ferry MELLLA+ License Amendment Request l 4 Expands nominal core flow window at EPU conditions Reduction in number of near end of cycle down-powers Fewer control rod manipulations required to manage reactivity Provides improved core instability algorithm - Detect and Suppress Solution - Confirmation Density (DSS-CD)
Increases station capacity factor during the operating cycle Month
BFN MELLLA+LAR Background (continued)
Browns Ferry MELLLA+ License Amendment Request l 5
BFN MELLLA+ LAR LAR Overview Browns Ferry MELLLA+ License Amendment Request Renewed Facility Operating License and Technical Specifications (TS) Changes New License Condition to prohibit operation at reduced Feedwater (FW) temperature in MELLLA+ operating domain TS 3.3.1.1, Reactor Protection System (RPS) Instrumentation -
Actions changed to reflect implementation of DSS-CD stability solution
Deleted Surveillance Requirement associated with verifying OPRM is not bypassed due to implementation of DSS-CD stability solution
Revised Oscillation Power Range Monitor (OPRM) Upscale Applicability to reflect implementation of DSS-CD stability solution
Revised Allowable Value for APRM Flow Biased Simulated Thermal Power - High Function TS 3.4.1, Recirculation Loops Operating - Added Note and Actions to prohibit single loop operation in the MELLLA+ operating domain TS 5.6.5, Core Operating Limits Report (COLR) - Revised to reflect implementation of DSS-CD stability solution TS 5.6.7, OPRM Report - Added to reflect implementation of DSS-CD stability solution l 6
BFN MELLLA+ LAR LAR Overview (continued)
Browns Ferry MELLLA+ License Amendment Request General Electric - Hitachi (GEH) MELLLA+ Safety Analysis Report (M+SAR)
Provides results of safety analyses and evaluations performed that support operation under MELLLA+ conditions
Technical evaluations supporting proposed MELLLA+ operation are based on Nuclear Regulatory Commission (NRC)-approved MELLLA+ Licensing Topical Report (NEDC-33006P-A), including associated Limitations and Conditions
Addresses Limitations and Conditions of the NRC-approved Interim Methods Licensing Topical Report (NEDC-33173P-A) and NRC-approved DSS-CD Licensing Topical Report (NEDC-33075P-A)
For certain fuel analyses, the technical evaluations are provided in the AREVA MELLLA+
Safety Analysis Report (AMSAR) and fuel analysis related reports
Addresses the addition of the DSS-CD stability algorithm, including setpoints, diversity, armed region, and backup stability protection (Includes information to address Brunswick Requests for Additional Information (RAIs) SRXB-RAI-1, -2, and -3)
Includes demonstration that Containment Accident Pressure (CAP) credit is not required to ensure adequate Net Positive Suction Head (NPSH) for Emergency Core Cooling System (ECCS) pumps under MELLLA+ conditions (Included to address Pre-application Meeting feedback and Brunswick RAIs) l 7
BFN MELLLA+ LAR LAR Overview (continued)
Browns Ferry MELLLA+ License Amendment Request
Provides Anticipated Transient Without Scram with Instability (ATWS-I) Analysis GEH explicitly analyzed ATRIUM 10XM fuel for ATWS-I
Treatment of uncertainties associated with modeling AREVA fuel follows the conservative approach used for Brunswick
Demonstrates that coolable geometry is maintained (Brunswick LAR includes similar approach)
Addresses NRC concerns with Minimum Stable Film Boiling Correlation (Tmin)
ATWS-I results provided using the current Tmin correlation in TRACG (i.e.,
modified Shumway)
Sensitivity analysis results using the homogeneous nucleation Tmin model are also provided, including an assessment that coolable geometry is maintained (Included to address Brunswick RAI SRXB-RAI-7) l 8
BFN MELLLA+ LAR LAR Overview (continued)
Browns Ferry MELLLA+ License Amendment Request Note: AREVA nuclear reactor operations was recently renamed Framatome - for the purposes of this presentation, AREVA should be considered synonymous with Framatome AMSAR and Fuel Analysis Related Reports
Similar to Power Uprate Safety Analysis Report/Fuel Uprate Safety Analysis Report approach of BFN EPU LAR
Supplements the M+SAR and summarizes the results of fuel related safety analyses and evaluations performed to support proposed operation under MELLLA+ conditions (Brunswick LAR includes both GEH and AREVA/Framatome scope evaluations in a single document)
Includes Appendices addressing applicable Limitations and Conditions of associated MELLLA+ and Interim Methods Licensing Topical Reports
MELLLA+ LAR also includes AREVA/Framatome fuel analysis related reports No new AREVA/Framatome methods required for MELLLA+ analyses and evaluations Reports updated to consider EPU and MELLLA+ conditions AREVA/Framatome fuel analysis related reports similar to recent BFN fuel transition LARs and BFN EPU LAR
Transition cycle design report Basis of representative Reload Report analyses EPU transition core re-depleted at MELLLA+ conditions (Included to address BFN transition cores)
Equilibrium cycle ATRIUM 10XM design report Basis of AMSAR fuel related analyses EPU equilibrium core re-depleted at MELLLA+ conditions (Brunswick LAR includes similar report) l 9
BFN MELLLA+ LAR LAR Overview (continued)
Browns Ferry MELLLA+ License Amendment Request AREVA/Framatome fuel analysis related reports similar to recent BFN fuel transition LARs and BFN EPU LAR
Reload Analysis Report (transition cycle based)
Full representative reload evaluation (Brunswick LAR includes similar report which addresses ATRIUM 10XM fuel, BFN report addresses ATRIUM 10 and ATRIUM 10XM fuel)
(Brunswick report includes reference to disposition of events table, BFN report includes disposition of events table)
Fuel rod thermal mechanical report Demonstrates application of RODEX4 to BFN at MELLLA+ conditions (Included to address potential RAIs - Brunswick RAI SNPB-RAI-1)
Fuel thermal hydraulic report Demonstrates continued acceptability of thermal hydraulic performance of ATRIUM 10XM and legacy ATRIUM 10 fuel at MELLLA+ conditions (Included to address BFN transition cores)
Safety Limit Minimum Critical Power Ratio (SLMCPR) Report Performed for representative transition core using SAFLIM3D (Brunswick addresses this topic in their integrated M+SAR)
Methods applicability report Plant specific demonstration of AREVA/Framatome methods applicability at MELLLA+ conditions Update to prior supplements of ANP-2860, Browns Ferry Unit 1 - Summary of Responses to Request for Additional Information, Extension to use ATRIUM 10XM Fuel for Extended Power Uprate Also provides data to support removal of SLMCPR adder required by Limitation and Condition 9.5 of the GEH Methods Licensing Topical Report (NEDC-33173P-A, Applicability of GE Methods to Expanded Operating Domains)
(Brunswick includes similar report, BFN report updated to address Brunswick RAI SRXB-RAI-12 (SLMCPR adder))
l 10
BFN MELLLA+ LAR LAR Overview (continued)
Browns Ferry MELLLA+ License Amendment Request AREVA/Framatome fuel analysis related reports similar to recent BFN fuel transition LARs and BFN EPU LAR (continued)
Loss of Coolant Accident (LOCA)
New break spectrum analysis at MELLLA+ conditions ATRIUM 10XM fuel based Break spectrum and ATRIUM 10XM fuel Maximum Average Planar Linear Heat Generation Rate (MAPLHGR) reports included in LAR (Brunswick LAR includes similar report, BFN report provide more results based on past BFN LOCA break spectrum reports provided to NRC)
Legacy ATRIUM 10 LOCA approach (same approach as used for EPU)
LOCA system response from the MELLLA+ based ATRIUM 10XM analysis will be used to drive ATRIUM 10 hot channel heatup ATRIUM 10XM break spectrum is applicable because the two fuel types are closely matched thermal hydraulically MAPLHGR report for ATRIUM 10 provided (Included to address BFN transition cores)
Treatment of 10 CFR 50.46c Issues Same approach as included in BFN EPU LAR Update 10 CFR 50.46c evaluation presented in ANP-3409, Fuel-Related Emergent Regulatory Issues, for MELLLA+ conditions (Included consistent with BFN EPU LAR)
Treatment of Reactivity Initiated Accidents (RIAs)
RIA will be evaluated with NRC-approved methodology 230 Calorie limit will be imposed for fuel fragmentation For BFN EPU LAR, an additional conservative RIA evaluation was presented in ANP-3409, Fuel-Related Emergent Regulatory Issues Similar evaluation performed for MELLLA+ and updated for latest draft criteria (Included to address potential RAIs - Brunswick RAI SNPB-RAI-2) l 11
Browns Ferry MELLLA+ License Amendment Request Differences Between BFN Units Potentially Impacting MELLLA+ Analyses During the NRC acceptance review of the Brunswick MELLLA+ LAR, this information was requested Describes differences between BFN units that could impact MELLLA+
analyses and evaluations Includes discussion of how these differences were addressed in the BFN MELLLA+ analyses and evaluations
e.g., use of bounding or representative values in analyses or performing separate analyses for different configurations (Included to address Brunswick MELLLA+ LAR Acceptance Review issue) l 12 BFN MELLLA+ LAR LAR Overview (continued)
BFN MELLLA+ LAR LAR Overview (continued)
Browns Ferry MELLLA+ License Amendment Request Basis for FW Temperature Reduction Input Parameter Values for BFN MELLLA+ Anticipated Transient Without Scram with Instability (ATWS-I)
Analysis
During NRC audit of Brunswick MELLLA+ LAR analyses, NRC requested this information from Brunswick
Provides detailed basis for FW temperature reduction rate used in analysis BFN plant trip data utilized (Included to address Brunswick RAI SRXB-RAI-8)
BFN-specific responses to issues identified in Brunswick RAIs
Including a comparison of steady state modeling and benchmarking results of the BFN equilibrium core from the AREVA/Framatome computer code MICROBURN-B2 and the GEH computer code PANAC11 (MELLLA+ LAR Attachments 34 and 35)
(Included to address Brunswick RAI SRXB-RAI-11)
Remainder of applicable Brunswick RAIs not already included in other BFN MELLLA+
LAR Attachments SRXB-RAI-4, -5, -6, -7, -9, and -10 SNPB-RAI-3, -4, and -7 (MELLLA+ LAR Supplement 1)
(Included to address Brunswick RAIs) l 13
BFN MELLLA+ LAR Electronic Reading Room Facilitates NRC review
Allows file sharing (e.g., calculations) with NRC reviewers
Files may be opened and viewed by NRC reviewers, but copying, printing or downloading files is precluded
Will not be used for docketed submittals or RAIs Normal NRC process will be used for docketed submittals and RAIs URL for reading room portal (same as BFN EPU reading room portal)
https://bfepurr.certrec.com Access to reading room restricted to those NRC personnel granted access Process
NRC requests information to review (e.g., calculation)
Information is obtained and file uploaded by BFN reading room administrator
After file is uploaded, an email is generated to NRC (Project Manager and reviewer) informing them that information is available for review
If, after reviewing the reading room file, NRC determines information from file is needed, TVA will submit the required information on the docket Browns Ferry MELLLA+ License Amendment Request l 14
BFN MELLLA+ LAR MELLLA+ Analyses Comparison - BFN to Brunswick Browns Ferry MELLLA+ License Amendment Request Tennessee Valley Authority Scope Analyses High Energy Line Break (HELB)
Standard approach used by GEH for dispositioning Reactor Water Cleanup (RWCU) HELBs under MELLLA+ conditions is to take advantage of the stations existing Final Feedwater Temperature Reduction (FFWTR) and/or Feedwater Heater Out of Service (FWHOOS) HELB analyses MELLLA+ core inlet subcooling at statepoint of 77.6% power/ 55% core flow not bounded by EPU power with FFWTR in the MELLLA domain.
As a result, RWCU HELB analyses needed to reflect EPU under MELLLA+
conditions were performed and results summarized in M+SAR (Brunswick existing HELB analyses bound MELLLA+ conditions, no new HELB analyses required)
Containment Accident Pressure Credit Containment Accident Pressure (CAP) credit is not required to ensure adequate Net Positive Suction Head (NPSH) for Emergency Core Cooling System (ECCS) pumps under MELLLA+ conditions Consistent with Current Licensing Basis established with BFN EPU Only ATWS event suppression pool temperature response affected by MELLLA+
Large NPSH margin Supporting analyses described in M+SAR (Brunswick LAR maintained Current Licensing Basis, which required credit for CAP) l 15
BFN MELLLA+ LAR MELLLA+ Analyses Comparison - BFN to Brunswick Browns Ferry MELLLA+ License Amendment Request GEH Scope Analyses
AREVA/Framatome provided the following thermal hydraulic data to BFN for transmittal to GEH/GNF Channel seal resistance Core support plate resistance Specific core and bundle-specific thermal-hydraulic results for four radial peaking factors and three axial power shapes at 100/100 and 54.3/37.3 power/flow conditions Core pressure drop and bypass flow fractions for various power/flow and axial profiles GNF used this data to create the ISCOR basedeck for ATRIUM 10XM used by GEH/GNF for analysis (Brunswick created the ISCOR basedeck for ATRIUM 10XM and provided it to GEH/GNF for analysis) l 16
BFN MELLLA+ LAR MELLLA+ Analyses Comparison - BFN to Brunswick Browns Ferry MELLLA+ License Amendment Request AREVA/Framatome Scope Analyses BFN used minimum core flow for LOCA analysis For BFN LOCA analysis, as discussed in the AMSAR, no credit taken for any setdown in thermal limits
Minimum core flow of 55% evaluated (In Brunswick LOCA analysis, LOCA calculations in MELLLA+ region were performed and justified at a transition point rather than the minimum core flow of 55%, based on crediting off-rated thermal limits - both approaches comply with Limitation and Condition 12.10.a)
BFN statistical data for SRVs supported 3% drift value assumption for all valves, with one SRV out-of-service, as bounding BFN, based on statistical work, provided AREVA/Framatome with the 95/95 setpoints for the ATWS evaluation
ATWS calculations demonstrated that assuming 3% drift on all valves, with one SRV out-of-service, bounded the data provided by BFN
ATWS pressure limits were met (Brunswick statistical data for SRV did not support 3% drift for all valves; Brunswick provided AREVA/Framatome with a different set of drift values for SRVs, consistent with plant-specific performance) l 17
BFN MELLLA+ LAR MELLLA+ Analyses Comparison - BFN to Brunswick Browns Ferry MELLLA+ License Amendment Request AREVA/Framatome Scope Analyses (continued)
BFN Representative Reload Safety Analysis Report based on ACE critical power correlation equivalent to ACE Revision 1 BFN current licensing basis ACE critical power correlation is ACE Revision 0 plus ANP-3140 (which is the plant-specific correction to ACE Revision 0)
ANP-3140 is equivalent to the ACE supplement that resulted in ACE Revision 1 (Brunswick Unit 1 Cycle 19 MELLLA+ Reload Analysis Report was based on critical power correlation ACE Revision 0) l 18
BFN MELLLA+ LAR Acronym List Browns Ferry MELLLA+ License Amendment Request l 19 LOCA - Loss of Coolant Accident MAPLHGR - Maximum Average Planar Linear Heat Generation Rate MELLLA - Maximum Extended Load Line Limit Analysis MELLLA+ - MELLLA Plus M+SAR - MELLLA+ Safety Analysis Report (GEH)
NPSH - Net Positive Suction Head NRC - Nuclear Regulatory Commission OLTP - Original Licensed Thermal Power OPRM - Oscillation Power Range Monitor RAIs - Requests for Additional Information RIAs - Reactivity Initiated Accidents RPS - Reactor Protection System RWCU - Reactor Water Cleanup SLMCPR - Safety Limit Minimum Critical Power Ratio SPU - Stretch Power Uprate SRV - Safety Relief Valve Tmin - Minimum Stable Film Boiling Correlation TS - Technical Specifications AMSAR - AREVA MELLLA+ Safety Analysis Report ATWS - Anticipated Transient Without Scram ATWS-I - ATWS with Instability BFN - Browns Ferry Nuclear Plant CAP - Containment Accident Pressure COLR - Core Operating Limits Report DSS-CD - Detect and Suppress Solution -
Confirmation Density ECCS - Emergency Core Cooling System ELLLA - Extended Load Line Limit Analysis EPU - Extended Power Uprate FFTWR - Final Feedwater Temperature Reduction FWHOOS - Feedwater Heater Out of Service FW - Feedwater GEH - General Electric - Hitachi GNF - Global Nuclear Fuels HELB - High Energy Line Break ICF - Increased Core Flow LAR - License Amendment Request
BFN MELLLA+ LAR Questions/Comments Browns Ferry MELLLA+ License Amendment Request l 20