ML22049B324

Amendment 29 to Updated Final Safety Analysis Report, Appendix N, Unit 1 Cycle 14 Reload Analysis (July 2020) - Redacted

ML22049B324
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Site:	Browns Ferry
Issue date:	10/04/2021
From:	Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation
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BFN-29 L94 200810 802 framatome Browns Ferry Unit 1 Cycle 14 ANP-3856 Revision 0 Reload Analysis July 2020

© 2020 Framatome Inc.

0414-12-F04 (Rev. 004, 04/27/2020)

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BFN-29 ANP-3856 Revision 0 Copyright © 2020 Framatome Inc.

All Rights Reserved ATRIUM and POWERPLEX are trademarks or registered trademarks of Framatome or its affiliates, in the USA or other countries.

0414-12-F04 (Rev. 004, 04/27/2020)

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page i Nature of Changes Section(s) or Item Page(s) Description and Justification

1. All This is the initial release.

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page ii Contents

1.0 INTRODUCTION

............................................................................................... 1-1 2.0 DISPOSITION OF EVENTS .............................................................................. 2-1 3.0 MECHANICAL DESIGN ANALYSIS .................................................................. 3-1 4.0 THERMAL-HYDRAULIC DESIGN ANALYSIS .................................................. 4-1 4.1 Thermal-Hydraulic Design and Compatibility .......................................... 4-1 4.2 Safety Limit MCPR Analysis ................................................................... 4-1 4.3 Core Hydrodynamic Stability................................................................... 4-2 4.3.1 Stability DSS-CD Solution ............................................................ 4-2 4.3.2 DSS-CD Backup Stability Protection ............................................ 4-2 4.4 Voiding in the Channel Bypass Region ................................................... 4-3 5.0 ANTICIPATED OPERATIONAL OCCURRENCES ........................................... 5-1 5.1 System Transients .................................................................................. 5-1 5.1.1 Load Rejection No Bypass (LRNB) .............................................. 5-3 5.1.2 Turbine Trip No Bypass (TTNB) ................................................... 5-3 5.1.3 Feedwater Controller Failure (FWCF) .......................................... 5-4 5.1.4 Loss of Feedwater Heating .......................................................... 5-5 5.1.5 Control Rod Withdrawal Error ...................................................... 5-5 5.2 Slow Flow Runup Analysis ...................................................................... 5-6 5.3 Equipment Out-of-Service Scenarios ...................................................... 5-7 5.3.1 TBVOOS ...................................................................................... 5-7 5.3.2 FHOOS ........................................................................................ 5-7 5.3.3 PLUOOS ...................................................................................... 5-8 5.3.4 Combined TBVOOS and FHOOS ................................................ 5-8 5.3.5 Combined TBVOOS and PLUOOS .............................................. 5-8 5.3.6 Combined FHOOS and PLUOOS ................................................ 5-9 5.3.7 Combined TBVOOS, FHOOS, and PLUOOS .............................. 5-9 5.3.8 Reduced Feedwater Temperature at Startup ............................... 5-9 5.3.9 Recirculation Pump Out-of-Service ............................................ 5-10 5.4 Licensing Power Shape ........................................................................ 5-10 6.0 POSTULATED ACCIDENTS ............................................................................. 6-1 6.1 Loss-of-Coolant-Accident (LOCA) .......................................................... 6-1 6.2 Control Rod Drop Accident (CRDA) ........................................................ 6-1 6.3 Fuel and Equipment Handling Accident .................................................. 6-2 N.1-4

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page iii 6.4 Fuel Loading Error (Infrequent Event) .................................................... 6-2 6.4.1 Mislocated Fuel Bundle ................................................................ 6-2 6.4.2 Misoriented Fuel Bundle .............................................................. 6-3 7.0 SPECIAL ANALYSES ....................................................................................... 7-1 7.1 ASME Overpressurization Analysis ........................................................ 7-1 7.2 ATWS Event Evaluation.......................................................................... 7-2 7.2.1 ATWS Overpressurization Analysis ............................................. 7-2 7.2.2 Long-Term Evaluation .................................................................. 7-2 7.3 Standby Liquid Control System............................................................... 7-3 7.4 Fuel Criticality ......................................................................................... 7-3 8.0 OPERATING LIMITS AND COLR INPUT .......................................................... 8-1 8.1 MCPR Limits ........................................................................................... 8-1 8.2 LHGR Limits ........................................................................................... 8-1 8.3 MAPLHGR Limits .................................................................................... 8-2

9.0 REFERENCES

.................................................................................................. 9-1 N.1-5

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page iv Tables Table 1.1 EOD and EOOS Operating Conditions ...................................................... 1-2 Table 4.1 Plant-Related Uncertainties for Safety Limit MCPR Analyses ................... 4-4 Table 4.2 Results Summary for Safety Limit MCPR Analyses .................................. 4-5 Table 4.3 DSS-CD BSP Endpoints for Nominal Feedwater Temperature ................. 4-6 Table 4.4 DSS-CD BSP Endpoints for Reduced Feedwater Temperature ................ 4-6 Table 4.5 ABSP Setpoints for the Scram Region ...................................................... 4-7 Table 4.6 Nominal Feedwater Temperature Boundary Points ................................... 4-8 Table 4.7 Reduced Feedwater Temperature Boundary Points.................................. 4-9 Table 5.1 Exposure Basis for Transient Analysis .................................................... 5-12 Table 5.2 Scram Speed Insertion Times ................................................................. 5-13 Table 5.3 Base Case LRNB Transient CPR Results ............................................. 5-14 Table 5.4 Base Case FWCF Transient CPR Results ............................................ 5-15 Table 5.5 Loss of Feedwater Heating Transient Analysis Results........................... 5-17 Table 5.6 Control Rod Withdrawal Error CPR Results .......................................... 5-17 Table 5.7 RBM Operability Requirements ............................................................... 5-18 Table 5.8 Flow-Dependent MCPR Results .............................................................. 5-18 Table 5.9 RCPOOS Pump Seizure Results............................................................. 5-18 Table 5.10 LHGRFACp Transient Results................................................................. 5-19 Table 5.11 Licensing Basis Core Average Axial Power Profile................................. 5-20 Table 7.1 ASME Overpressurization Analysis Results .............................................. 7-4 Table 7.2 ATWS Overpressurization Analysis Results .............................................. 7-5 Table 8.1 TLO MCPRp Limits for OSS Insertion Times ............................................. 8-3 Table 8.2 TLO MCPRp Limits for NSS Insertion Times ............................................. 8-4 Table 8.3 TLO MCPRp Limits for TSSS Insertion Times ........................................... 8-6 Table 8.4 TLO MCPRp Limits for Reduced Feedwater Temperature at Startup NSS Insertion Times.................................................................................. 8-8 Table 8.5 TLO MCPRp Limits for Reduced Feedwater Temperature at Startup TSSS Insertion Times.............................................................................. 8-10 Table 8.6 SLO MCPRp Limits for All Scram Speeds ............................................... 8-12 Table 8.7 MCPRf Limits ........................................................................................... 8-13 Table 8.8 Steady-State LHGR Limits ...................................................................... 8-13 N.1-6

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page v Table 8.9 LHGRFACp Multipliers ............................................................................. 8-14 Table 8.10 LHGRFACf Multipliers.............................................................................. 8-15 Table 8.11 MAPLHGR Limits .................................................................................... 8-15 N.1-7

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page vi Figures Figure 1.1 Power / Flow Map - EPU / MELLLA+ ........................................................ 1-3 Figure 5.1 EOCLB LRNB at 100P / 105F - TSSS Key Parameters ......................... 5-21 Figure 5.2 EOCLB LRNB at 100P / 105F - TSSS Sensed Water Level ................... 5-22 Figure 5.3 EOCLB LRNB at 100P / 105F - TSSS Vessel Pressures ....................... 5-23 Figure 5.4 EOCLB FWCF at 100P / 105F - TSSS Key Parameters......................... 5-24 Figure 5.5 EOCLB FWCF at 100P / 105F - TSSS Sensed Water Level .................. 5-25 Figure 5.6 EOCLB FWCF at 100P / 105F - TSSS Vessel Pressures ..................... 5-26 Figure 7.1 MSIV Closure Overpressurization Event at 102P / 105F - Key Parameters ................................................................................................ 7-6 Figure 7.2 MSIV Closure Overpressurization Event at 102P / 105F - Sensed Water Level ............................................................................................... 7-7 Figure 7.3 MSIV Closure Overpressurization Event at 102P / 105F - Vessel Pressures .................................................................................................. 7-8 Figure 7.4 MSIV Closure Overpressurization Event at 102P / 105F - Safety /

Relief Valve Flow Rates ............................................................................ 7-9 Figure 7.5 PRFO ATWS Overpressurization Event at 100P / 85F - Key Parameters .............................................................................................. 7-10 Figure 7.6 PRFO ATWS Overpressurization Event at 100P / 85F - Sensed Water Level ............................................................................................. 7-11 Figure 7.7 PRFO ATWS Overpressurization Event at 100P / 85F - Vessel Pressures ................................................................................................ 7-12 Figure 7.8 PRFO ATWS Overpressurization Event at 100P / 85F - Safety /

Relief Valve Flow Rates .......................................................................... 7-13 N.1-8

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page vii Nomenclature 2PT two pump trip ABSP automated backup stability AOT abnormal operational transient APLHGR average planar linear heat generation rate APRM average power range monitor ARO all control rods out ASME American Society of Mechanical Engineers AST alternate source term ATWS anticipated transient without scram ATWS-RPT anticipated transient without scram recirculation pump trip BFE1-14 Browns Ferry Unit 1 Cycle 14 BLEU blended low enriched uranium BOC beginning-of-cycle BPWS banked position withdrawal sequence BSP backup stability protection BWR boiling water reactor BWROG Boiling Water Reactor Owners Group CDA confirmation density algorithm CFR Code of Federal Regulations CGU commercial grade uranium COLR core operating limits report CPR critical power ratio CRDA control rod drop accident CRWE control rod withdrawal error DSS-CD detect and suppress solution - confirmation density EFPD effective full-power days EFPH effective full-power hours EOC end-of-cycle EOCLB end-of-cycle licensing basis EOC-RPT end-of-cycle recirculation pump trip EOC-RPT-OOS end-of-cycle recirculation pump trip out-of-service EOD extended operating domain EOFP end of full power EOOS equipment out-of-service EPU extended power uprate defined as 120 % OLTP FFTR final feedwater temperature reduction FHOOS feedwater heaters out-of-service FSAR final safety analysis report FW feedwater FWCF feedwater controller failure N.1-9

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page viii Nomenclature (Continued)

GSF generic shape function HPCI high pressure coolant injection ICF increased core flow LFWH loss of feedwater heating LHGR linear heat generation rate LHGRFACf flow-dependent linear heat generation rate multipliers LHGRFACp power-dependent linear heat generation rate multipliers LOCA loss-of-coolant accident LPRM local power range monitor LRNB generator load rejection with no bypass MAPFAC maximum average planar multipliers MAPLHGR maximum average planar linear heat generation rate MCPR minimum critical power ratio MCPRf flow-dependent minimum critical power ratio MCPRp power-dependent minimum critical power ratio MELLLA maximum extended load line limit analysis MELLLA+ maximum extended load line limit analysis plus MSIV main steam isolation valve MSRV main steam relief valve MSRVOOS main steam relief valve out-of-service NCL natural circulation line NEOC near end-of-cycle NSS nominal scram speed NRC Nuclear Regulatory Commission, U.S.

OLMCPR operating limit minimum critical power ratio OLTP original licensed thermal power OPRM oscillation power range monitor OSS optimum scram speed Pbypass power below which direct scram on TSV / TCV closure is bypassed PCT peak cladding temperature PLU power load unbalance PLUOOS power load unbalance out-of-service PRFO pressure regulator failure open RBM (control) rod block monitor RCPOOS recirculation pump out-of-service RDF rated drive flow RHR residual heat removal N.1-10

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page ix Nomenclature (Continued)

RPT recirculation pump trip RTP rated thermal power SAD amplitude discriminator setpoint SLC standby liquid control SLMCPR safety limit minimum critical power ratio SLO single-loop operation STP simulated thermal power TBV turbine bypass valve TBVIS turbine bypass valves in service TBVOOS turbine bypass valves out-of-service TCV turbine control valve TIP traversing incore probe TIPOOS traversing incore probe out-of-service TLO two-loop operation TSSS technical specifications scram speed TSV turbine stop valve TTNB turbine trip with no bypass TVA Tennessee Valley Authority CPR change in critical power ratio N.1-11

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 1-1

1.0 INTRODUCTION

Reload licensing analyses results generated by Framatome Inc. (Framatome) are presented in support of cycle operation with MELLLA+. The analyses reported in this document were performed using methodologies previously approved for generic application to boiling water reactors. The U. S. Nuclear Regulatory Commission (NRC) technical limitations and conditions associated with the application of the approved methodologies have been satisfied by these analyses.

The Browns Ferry Unit 1 Cycle 14 (BFE1-14) core consists of a total of 764 fuel assemblies including 316 fresh ATRIUM 10XM assemblies and 448 irradiated ATRIUM 10XM assemblies.

Licensing analyses support the core design presented in Reference 1.

Reload licensing analyses were performed for potentially limiting events and analyses identified in Section 2.0. Results of analyses are used to establish the Technical Specifications / COLR limits and ensure design and licensing criteria are met. Design and safety analyses are based on both operational assumptions and plant parameters provided by the utility. The results of the reload licensing analyses support operation for the power / flow map presented in Figure 1.1 and also support operation with the equipment out-of-service (EOOS) scenarios presented in Table 1.1.

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 1-2 Table 1.1 EOD and EOOS Operating Conditions Extended Operating Domain (EOD) Conditions Increased core flow (ICF)

Maximum extended load line limit analysis plus (MELLLA+)

Combined final feedwater temperature reduction (FFTR) / coastdown Equipment Out-of-Service (EOOS) Conditions*

Turbine bypass valves out-of-service (TBVOOS)

Feedwater heaters out-of-service (FHOOS)

Power load unbalance out-of-service (PLUOOS)

Combined TBVOOS and FHOOS Combined TBVOOS and PLUOOS Combined FHOOS and PLUOOS Combined TBVOOS, FHOOS, and PLUOOS Recirculation Pump out-of-service (RCPOOS),

• Base case and each EOOS condition is supported in combination with 1 MSRVOOS, EOC-RPT-OOS, up to 2 traversing incore probe (TIP) machines out-of-service (TIPOOS) or the equivalent number of TIP channels (per operating requirements defined in Section 4.2), and up to 50 % of the LPRMs out-of-service.

Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

RCPOOS is the EOOS implying single loop operation. RCPOOS thermal limit sets are provided for the EOOS conditions specified in Table 8.6. Operation in SLO is only supported up to a maximum core flow of 50 % of rated, a maximum power level of 43.75 % of rated, and an active recirculation drive flow of 17.73 Mlb/hr.

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 1-3 Core Power(% Rated: 100%= 3952MWJ 110 100 MELLLA+ Region 90 80 70 60 100.7% Rod Line ICF Region 50 MELLLA Region 87.5% Rod Line 40 30 Min. Flow Control 20 Natural Min. Power Line Circulation 10 20% Pump Speed Line 0

0 10 20 30 40 50 60 70 80 90 100 110 120 Core Flow(% Rated: 100%=102.5 MLbmlhr)

Figure 1.1 Power / Flow Map - EPU / MELLLA+

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 2-1 2.0 DISPOSITION OF EVENTS A review of FSAR events was performed to support the first application of EPU (120 % OLTP) power with ATRIUM 10XM fuel (Reference 2). The goal of Reference 2 was to identify potentially limiting events and analyses requiring evaluation either on a cycle-specific basis or generically. When changes to plant configurations are implemented, it warrants a review of the Reference 2 conclusions.

The fresh ATRIUM 10XM reload consists of 316 commercial grade uranium (CGU) fuel assemblies. The irradiated ATRIUM 10XM is a mix of CGU fuel assemblies and blended low-enriched uranium (BLEU) fuel assemblies. BLEU fuel was previously addressed in Reference 3.

Reference 3 remains applicable for BFE1-14. The calculation plan for BFE1-14 reload licensing analyses (Reference 4) was based on these dispositions.

Parameter differences between the initial Browns Ferry ATRIUM 10XM licensing analyses and the BFE1-14 MELLLA+ reload were reviewed to determine if the conclusions remain applicable.

The affected analyses were included in the Reference 4 calculation plan and addressed as part of the reload analyses.

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 3-1 3.0 MECHANICAL DESIGN ANALYSIS NRC approved exposure limits for ATRIUM 10XM are presented in References 5, 6, and 7. The maximum exposure limits for the reload fuel are:

54.0 GWd/MTU average assembly exposure 62.0 GWd/MTU rod average exposure (full-length fuel rods)

Fuel cycle design analyses (Reference 1) verified all fuel assemblies remain within licensed burnup limits.

The maximum calculated rod oxide thicknesses are presented in Tables 3-2 and 3-3 of Reference 7 for ATRIUM 10XM fuel. The calculated oxide thickness complies with the limit provided in Section 3.2.7 of Reference 8.

LHGR limits are presented in Section 8.0.

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 4-1 4.0 THERMAL-HYDRAULIC DESIGN ANALYSIS 4.1 Thermal-Hydraulic Design and Compatibility Results of thermal-hydraulic characterization and compatibility analyses are presented in Reference 9. Analysis results demonstrate the thermal-hydraulic design and compatibility criteria are satisfied for the equilibrium core consisting of ATRIUM 10XM.

4.2 Safety Limit MCPR Analysis The safety limit MCPR (SLMCPR) is defined as the minimum value of the critical power ratio (CPR) ensuring less than 0.1 % of the fuel rods are expected to experience boiling transition during normal operation or an abnormal operational transient (AOT). The SLMCPR for all fuel was determined using the methodology described in Reference 10. The analysis was performed with a power distribution conservatively representing expected reactor operation throughout the cycle.

The SLMCPR analysis used the ACE/ATRIUM 10XM critical power correlation (References 11 and 12).

In the Framatome methodology, the effects of channel bow on the critical power performance are accounted for in the SLMCPR analysis. Reference 10 discusses the application of a realistic channel bow model. For BFE1-14, the channel bow model uncertainty has been augmented for those channels experiencing fluence gradients outside the bounds of the measurement database.

Plant-related uncertainties used in the SLMCPR analysis are presented in Table 4.1. The radial power uncertainty used in the analysis includes the effects of up to 40 % of the TIP channels out-of-service, up to 50 % of the LPRMs out-of-service, and a 2500 EFPH LPRM calibration interval.

Analysis results support a two-loop operation (TLO) SLMCPR of 1.06 and a single-loop operation (SLO) SLMCPR of 1.08. Analysis results, including the SLMCPR and the percentage of rods expected to experience boiling transition, are summarized in Table 4.2.

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 4-2 4.3 Core Hydrodynamic Stability 4.3.1 Stability DSS-CD Solution Browns Ferry has implemented the stability DSS-CD solution using the Oscillation Power Range Monitor (OPRM) as described in Reference 13. Plant-specific analyses for the DSS-CD Solution are provided in Reference 14. The Detect and Suppress function of the DSS-CD solution based on the OPRM system relies on the Confirmation Density Algorithm (CDA) which constitutes the licensing basis. The Backup Stability Protection (BSP) solution may be used by the plant in the event the OPRM system is declared inoperable.

The CDA enabled through the OPRM system and the BSP solution described in Reference 14 is the stability licensing basis for Browns Ferry operation in the MELLLA+ region. The applicability of the DSS-CD solution and the Amplitude Discriminator Setpoint (SAD) of the CDA were confirmed by TVA for the Unit 1 Cycle 14 core. TVA utilized the extended applicability checklists provided in Reference 13 to document the DSS-CD solution applicability to Unit 1 Cycle 14. The SAD value provided in Reference 14 was confirmed by TVA to apply to Unit 1 Cycle 14 using the process provided in Reference 14.

4.3.2 DSS-CD Backup Stability Protection Reference 13 describes two BSP options based on selected elements from three distinct constituents: BSP Manual Regions, BSP Boundary, and Automated BSP (ABSP) setpoints.

The Manual BSP region boundaries were calculated for Browns Ferry Unit 1 Cycle 14 using STAIF (Reference 15) for nominal and reduced feedwater temperature operation (both FFTR and FHOOS). The endpoints of the regions are defined in Table 4.3 and Table 4.4 for nominal and reduced feedwater temperature, respectively. The Manual BSP region boundary endpoints are connected using the Generic Shape Function (GSF) and are provided with Table 4.6 and Table 4.7 for nominal and reduced feedwater temperature, respectively. The BSP Boundary for nominal and reduced feedwater temperature is defined by the MELLLA boundary line, per Reference 16. The ABSP Average Power Range Monitor (APRM) Simulated Thermal Power (STP) setpoints associated with the ABSP Scram Region are listed in Table 4.5. These ABSP setpoints are applicable to nominal and reduced feedwater temperature operation.

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 4-3 4.4 Voiding in the Channel Bypass Region To demonstrate compliance with the NRCs 5 % maximum bypass voiding around the LPRMs requirement (see Section 5.1.1.5.1 of the Reference 17 Safety Evaluation), the bypass void level has been evaluated throughout the cycle. The maximum bypass void value at the LPRM D level and at the axial elevation equivalent to the top of the TIP tube have been confirmed to remain below this limit for the Cycle 14 design.

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 4-4 Table 4.1 Plant-Related Uncertainties for Safety Limit MCPR Analyses Parameter Uncertainty Feedwater flow rate 1.8 %

Feedwater temperature 0.8 %

Core pressure 0.7 %

Total core flow rate TLO 2.5 %

SLO 6.0 %

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 4-5 Table 4.2 Results Summary for Safety Limit MCPR Analyses Minimum Percentage of Supported Rods in Boiling SLMCPR Transition TLO - 1.06 0.0935 SLO - 1.08 0.0877 N.1-21

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 4-6 Table 4.3 DSS-CD BSP Endpoints for Nominal Feedwater Temperature Power Flow Endpoint (%) (%) Definition Scram Region (Region I)

A1 75.9 52.7 Boundary Intercept on MELLLA+ Line Scram Region (Region I)

B1 35.5 29.0 Boundary Intercept on NCL Controlled Entry Region A2 66.1 52.0 (Region II) Boundary Intercept on MELLLA Line Controlled Entry Region B2 25.5 29.0 (Region II) Boundary Intercept on NCL Table 4.4 DSS-CD BSP Endpoints for Reduced Feedwater Temperature Power Flow Endpoint (%) (%) Definition Scram Region (Region I)

A1 64.9 50.5 Boundary Intercept on MELLLA Line Scram Region (Region I)

B1 29.4 29.0 Boundary Intercept on NCL Controlled Entry Region A2 68.3 54.9 (Region II) Boundary Intercept on MELLLA Line Controlled Entry Region B2 24.5 29.0 (Region II) Boundary Intercept on NCL N.1-22

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 4-7 Table 4.5 ABSP Setpoints for the Scram Region Parameter Symbol Setting Value (Unit) Comments Slope for Slope of ABSP APRM flow-mTRIP 2.00 (% RTP / % RDF)

Trip biased trip linear segment.

ABSP APRM flow-biased trip Constant setpoint power intercept.

Power Line PBSP-TRIP 35.0 (% RTP) Constant Power Line for Trip for Trip from zero Drive Flow to Flow Breakpoint value.

ABSP APRM flow-biased trip Constant setpoint drive flow intercept.

Flow Line for WBSP-TRIP 49 (% RDF)

Constant Flow Line for Trip.

Trip (see Note 1)

Flow WBSP-BREAK 30.0 (% RDF) Flow Breakpoint value Breakpoint Note 1: WBSP-TRIP can be set to 49.0 % RDF or any higher value up to the intersection of the ABSP sloped line with the APRM flow-biased STP scram line.

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BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 4-8 Table 4.6 Nominal Feedwater Temperature Boundary Points Scram Region Exit Region Flow (% rated) Power (% rated) Flow (% rated) Power (% rated) 52.70 75.90 52.00 66.10 51.52 71.76 50.85 61.62 50.33 67.98 49.70 57.57 49.15 64.52 48.55 53.92 47.96 61.35 47.40 50.63 46.78 58.45 46.25 47.64 45.59 55.79 45.10 44.94 44.41 53.36 43.95 42.50 43.22 51.13 42.80 40.28 42.04 49.08 41.65 38.27 40.85 47.20 40.50 36.45 39.67 45.49 39.35 34.79 38.48 43.92 38.20 33.29 37.30 42.48 37.05 31.94 36.11 41.17 35.90 30.70 34.93 39.98 34.75 29.59 33.74 38.89 33.60 28.59 32.56 37.90 32.45 27.68 31.37 37.02 31.30 26.87 30.19 36.22 30.15 26.15 29.00 35.50 29.00 25.50 N.1-24

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 4-9 Table 4.7 Reduced Feedwater Temperature Boundary Points Scram Region Exit Region Flow (% rated) Power (% rated) Flow (% rated) Power (% rated) 50.50 64.90 54.90 68.30 49.43 61.22 53.61 63.33 48.35 57.86 52.31 58.87 47.28 54.79 51.02 54.86 46.20 51.99 49.72 51.26 45.13 49.43 48.43 48.01 44.05 47.09 47.13 45.09 42.98 44.95 45.84 42.46 41.90 43.00 44.54 40.08 40.83 41.20 43.25 37.93 39.75 39.56 41.95 35.99 38.68 38.07 40.66 34.23 37.60 36.70 39.36 32.65 36.53 35.45 38.07 31.21 35.45 34.31 36.77 29.92 34.38 33.27 35.48 28.76 33.30 32.33 34.18 27.71 32.23 31.48 32.89 26.77 31.15 30.71 31.59 25.92 30.08 30.02 30.30 25.17 29.00 29.40 29.00 24.50 N.1-25

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-1 5.0 ANTICIPATED OPERATIONAL OCCURRENCES This section describes the analyses performed to determine the power- and flow-dependent MCPR operating limits (MCPRf and MCPRp) for base case operation.

CASMO-4/MICROBURN-B2 (Reference 18), COTRANSA2 (Reference 19), XCOBRA (Reference 20), and XCOBRA-T (Reference 21) are the major codes used in the thermal limits analyses as described in the Framatome THERMEX methodology report (Reference 20) and neutronics methodology report (Reference 18). COTRANSA2 is a system transient simulation code which includes an axial one-dimensional neutronics model capturing the effects of axial power shifts associated with the system transients. XCOBRA is used in steady-state analyses.

XCOBRA-T is a transient thermal-hydraulics code used in the analysis of thermal margins for the limiting fuel assembly. The ACE/ATRIUM 10XM critical power correlation (References 11 and 12) is used to evaluate the thermal margin for the ATRIUM 10XM fuel. Fuel pellet-to-cladding gap conductance values are based on RODEX2 (Reference 22) calculations for the BFE1-14 core.

5.1 System Transients The reactor plant parameters for the system transient analyses were provided by the utility.

Analyses have been performed to determine MCPRp limits protecting operation throughout the power / flow domain depicted in Figure 1.1.

At Browns Ferry, direct scram on turbine stop valve (TSV) position and turbine control valve (TCV) fast closure are bypassed at power levels less than 26 % of rated (Pbypass). Below Pbypass scram occurs when either the high pressure or high neutron flux scram setpoint is reached.

MCPR limits are monitored at power levels greater than or equal to 23 % of rated, which is the lowest power analyzed for this report, consistent with Reference 23.

The limiting exposure for rated power pressurization transients is typically at end of full power (EOFP) when the control rods are fully withdrawn. To provide additional margin to the operating limits earlier in the cycle, analyses were also performed to establish operating limits at a near end-of-cycle (NEOC) core average exposure. Analyses were performed at cycle exposures prior to NEOC to ensure the operating limits provide the necessary protection. The end-of-cycle licensing basis (EOCLB) analysis was performed at EOFP + 15 EFPD. Analyses were also performed to support extended cycle operation with FFTR and power coastdown. The licensing N.1-26

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-2 basis exposures used to develop the neutronics inputs to the transient analyses are presented in Table 5.1.

All pressurization transients assumed one of the lowest setpoint main steam relief valves (MSRV) is inoperable. The basis supports operation with 1 MSRV out-of-service.

Reductions in feedwater temperature of less than 15 °F from the nominal feedwater temperature and variations of +/-10 psi in dome pressure are considered base case operation not an EOOS condition. Although the base case operating condition assumes a maximum reduction of 15 °F from the nominal feedwater temperature, the Browns Ferry Operating License does not allow operation at 100 % power in the MELLLA+ domain with final feedwater temperature less than 384.5 °F. Analyses were performed to determine the limiting conditions in the allowable ranges.

FFTR is used to extend rated power operation by decreasing the feedwater temperature. The amount of feedwater temperature reduction is a function of power with the maximum decrease of 70 °F (55 °F + 15 °F bias) at rated power. Analyses were performed to support combined FFTR / Coastdown operation to the core average exposure provided in Table 5.1. The analyses were performed with the limiting feedwater and dome pressure conditions in the allowable ranges. Operation with FFTR is not allowed in the MELLLA+ operating domain.

System pressurization transient results are sensitive to scram speed assumptions. To take advantage of average scram speeds faster than those associated with the Technical Specifications requirements, scram speed-dependent MCPRp limits are provided. The analytically adjusted timing for optimum scram speed (OSS) insertion times, nominal scram speed (NSS) insertion times, and the Technical Specifications scram speed (TSSS) insertion times used in the analyses are presented in Table 5.2 compared to the surveillance testing timing. The OSS and NSS MCPRp limits can only be applied if the scram speed test results meet the required insertion times. System transient analyses were performed to establish MCPRp limits for OSS, NSS, and TSSS insertion times.

The Technical Specifications (Reference 23) allow for operation with up to 13 slow and 1 stuck control rod. One additional control rod is assumed to fail to scram. Conservative adjustments to the OSS, NSS, and TSSS scram speeds were made to the analysis inputs to appropriately account for these effects on scram reactivity. For cases below 26 % power, the results are relatively insensitive to scram reactivity and only TSSS analyses are performed. At 26 % power N.1-27

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-3 (Pbypass), analyses were performed both with and without bypass of the direct scram function resulting in an operating limits step change.

5.1.1 Load Rejection No Bypass (LRNB)

Load rejection causes a fast closure of the TCV. The TCV closure creates a pressure compression wave traveling through the steam lines into the vessel causing a rapid pressurization. The increase in pressure causes a decrease in core voids which in turn causes a rapid increase in power. Fast closure of the TCV also causes a reactor scram and recirculation pump trip (RPT). Turbine bypass system operation, which also mitigates the consequences of the event, is not credited. The excursion of the core power due to void collapse is terminated primarily by the reactor scram and revoiding of the core.

LRNB analyses assume the power load unbalance (PLU) is inoperable for power levels less than 50 % of rated. The LRNB sequence of events is different than the standard event when the PLU is inoperable. Instead of a fast closure, the TCVs close in servo mode and there is no direct scram on TCV closure. The power and pressure excursion continues until the high pressure scram occurs.

LRNB analyses were performed for a range of power / flow conditions to support generation of the thermal limits. Base case limiting LRNB transient analysis results used to generate the NEOC and EOCLB operating limits are shown in Table 5.3. Responses of various reactor and plant parameters during the LRNB event initiated at 100 % of rated power and 105 % of rated core flow with TSSS insertion times are shown in Figure 5.1 - Figure 5.3.

5.1.2 Turbine Trip No Bypass (TTNB)

A turbine trip event can be initiated as a result of several different signals. The initiating signal causes the TSV to close in order to prevent damage to the turbine. The TSV closure creates a pressure compression wave traveling through the steam lines into the vessel causing a rapid pressurization. The increase in pressure causes a decrease in core voids which in turn causes a rapid increase in power. Closure of the TSV also causes a reactor scram and an RPT which helps mitigate the pressurization effects. Turbine bypass system operation, which also mitigates the consequences of the event, is not credited. The excursion of the core power due to void collapse is terminated primarily by the reactor scram and revoiding of the core.

N.1-28

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-4 In addition to closing the TSV, a signal is also sent to close the TCV in fast mode. The consequences of a fast closure of the TCV are very similar to those resulting from a TSV closure.

The main difference is the time required to close the valves. While the TCV full stroke closure time is greater than the TSV (0.150 second compared to 0.100 second), the initial position of the TCV is dependent on the initial steam flow. At rated power and lower, the initial position of the TCV is such that the closure time is less than the TSV. However, the TCV closure characteristics are nonlinear such that the resulting core pressurization and CPR may not always bound those of the slower TSV closure.

Analyses were performed demonstrating the TTNB event is equivalent to or bound by the LRNB event; therefore, the thermal limits established for LRNB will also protect against the TTNB event.

5.1.3 Feedwater Controller Failure (FWCF)

The increase in feedwater flow due to a failure of the feedwater control system to maximum demand results in an increase in the water level and a decrease in the coolant temperature at the core inlet. The increase in core inlet subcooling causes an increase in core power. As the feedwater flow continues at maximum demand, the water level continues to rise and eventually reaches the high water level trip setpoint. The initial water level is conservatively assumed to be at the low level normal operating range to delay the high-level trip and maximize the core inlet subcooling resulting from the FWCF. The high water level trip causes the TSVs to close in order to prevent damage to the turbine from excessive liquid inventory in the steam line. Valve closure creates a pressure compression wave traveling back to the core, causing void collapse and a subsequent rapid power excursion. The closure of the TSVs also initiates a reactor scram and an RPT. In addition to the TSV closure, the TCVs also close in the fast closure mode. Because of the partially closed initial position of the control valves, they will typically close faster than the stop valves and control the pressurization portion of the event. However, TCV closure characteristics are nonlinear such that the resulting core pressurization and CPR results may not always bound those of the slower TSV closure at rated power (steam flow increases above rated before fast TCV closure). The limiting of TCV or TSV closure, for the initial operating conditions, was used in the FWCF analyses based on sensitivity analyses. The turbine bypass valves (TBV) are assumed operable and provide some pressure relief. The core power excursion is mitigated in part by pressure relief, but the primary mechanisms for termination of the event are reactor scram and revoiding of the core.

N.1-29

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-5 FWCF analyses were performed for a range of power / flow conditions to support generation of the thermal limits. Analyses performed at power levels equal to and greater than 65 % assume a maximum feedwater runout of 22.79 Mlbm/hr. For power levels equal to above Pbypass (26 %

power) up to 65 %, analyses assumed a maximum feedwater runout of 19.82 Mlbm/hr. For below Pbypass, a maximum feedwater runout of 16.68 Mlbm/hr was assumed. A discussion of this input is provided in Comment 25 of Reference 24.

Table 5.4 presents the base case limiting FWCF transient analysis results used to generate the NEOC and EOCLB operating limits. Figure 5.4 - Figure 5.6 show the responses of various reactor and plant parameters during the FWCF event initiated at 100 % of rated power and 105

% of rated core flow with TSSS insertion times.

5.1.4 Loss of Feedwater Heating The loss of feedwater heating (LFWH) event analysis supports an assumed 100 °F decrease in the feedwater temperature. The result is an increase in core inlet subcooling which reduces voids thereby increasing core power and shifting the axial power distribution towards the bottom of the core. As a result of the axial power shift and increased core power, voids begin to build up in the bottom region of the core acting as negative feedback to the increased subcooling effect.

The negative feedback moderates the core power increase. Although there is a substantial increase in core thermal power during the event, the increase in steam flow is much less because a large part of the added power is used to overcome the increase in inlet subcooling.

The increase in steam flow is accommodated by the pressure control system via the TCVs or TBVs, so no pressurization occurs. A cycle-specific analysis was performed in accordance with the Reference 25 methodology to determine the change in MCPR for the event. The LFWH results are presented in Table 5.5.

5.1.5 Control Rod Withdrawal Error The control rod withdrawal error (CRWE) transient is an inadvertent reactor operator initiated withdrawal of a control rod. This withdrawal increases local power and core thermal power which lowers the core MCPR. The CRWE transient is typically terminated by control rod blocks initiated by the rod block monitor (RBM). The CRWE event was analyzed assuming no Xenon and allowing credible instrumentation out-of-service in the RBM system. The analysis further assumes the plant could be operating in either an A or B sequence control rod pattern. The rated power CRWE results are shown in Table 5.6 for the analytical unfiltered RBM high power N.1-30

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-6 setpoint values of 107 % to 117 %. Analysis results indicate standard filtered RBM setpoint reductions are supported. Analyses demonstrate the 1 % strain and centerline melt criteria are met. LHGR limits and associated multipliers are presented in Section 8.2. Recommended operability requirements supporting unblocked CRWE operation are shown in Table 5.7 based on the SLMCPR values presented in Section 4.2.

5.2 Slow Flow Runup Analysis Flow-dependent MCPR limits and LHGR multipliers (LHGRFACf) are established to support operation at off-rated core flow conditions. Limits are based on the CPR and heat flux changes experienced by the fuel during slow flow excursions. The slow flow excursion event assumes recirculation flow control system failure such that core flow increases slowly to the maximum flow physically attainable by the equipment (107 % of rated core flow). An uncontrolled increase in flow creates the potential for a significant increase in core power and heat flux. A conservatively steep flow runup path was used in the analysis. Evaluations were performed to support operation in all the EOOS scenarios.

A steady-state hydraulic model, using bounding statepoint assumptions, is used to calculate the change in CPR during a two-loop flow runup to the maximum flow rate. The MCPRf limit is set so an increase in core power, resulting from the maximum increase in core flow, assures the TLO SLMCPR is not violated. Calculations were performed over a range of initial flow rates to determine the corresponding MCPR values causing the limiting assembly to be at the SLMCPR for the high flow condition at the end of the flow excursion.

Analysis results are presented in Table 5.8. MCPRf limits providing the required protection are presented in Table 8.7. MCPRf limits are applicable for all exposures.

Flow runup analyses were performed to determine LHGRFACf multipliers. The analysis assumes recirculation flow increases slowly along the limiting rod line to the maximum flow physically attainable by the equipment. A series of flow excursion analyses were performed at several exposures throughout the cycle starting from different initial power / flow conditions.

Xenon is assumed to remain constant during the event. LHGRFACf multipliers are established to provide protection against fuel centerline melt and overstraining of the cladding during a flow runup. LHGRFACf multipliers are presented in Table 8.10.

N.1-31

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-7 The maximum flow during a flow excursion in SLO is much less than the maximum flow during TLO. Therefore, the MCPRf limits and LHGRFACf multipliers for TLO are applicable for SLO.

5.3 Equipment Out-of-Service Scenarios The EOOS scenarios supported are shown in Table 1.1. As noted in Table 1.1, base case and each EOOS condition is supported in combination with 1 MSRVOOS, EOC-RPT-OOS, up to 2 TIP machines out-of-service or the equivalent number of TIP channels (per operating requirements defined in Section 4.2), and up to 50 % of the LPRMs out-of-service.

When EOC-RPT is inoperable, no credit is assumed for RPT on TSV position or TCV fast closure. The function of the EOC-RPT feature is to reduce the severity of the core power excursion caused by the pressurization transient. The RPT accomplishes this by helping revoid the core thereby reducing the magnitude of the reactivity insertion resulting from the pressurization transient. Failure of the RPT feature can result in higher operating limits.

Analyses were performed for LRNB and FWCF events assuming EOC-RPT-OOS.

The analyses presented in this section also include these EOOS conditions protected by the base case limits. No further discussion for these EOOS conditions is presented in this section.

Base thermal limits presented in Section 8.0 are applicable with or without function of the EOC-RPT.

Table 5.10 presents the limiting LHGRFACp transient analysis results for each EOOS scenario used to generate the operating limits for all scram insertion times.

5.3.1 TBVOOS The effect of operation with TBVOOS is a reduction in the system pressure relief capacity which makes the pressurization events more severe. While the base case LRNB and TTNB events are analyzed assuming the TBVs out-of-service, operation with TBVOOS has an adverse effect on the FWCF event. Analyses of the FWCF event with TBVOOS were performed to establish the TBVOOS operating limits.

5.3.2 FHOOS The FHOOS scenario assumes a feedwater temperature reduction of 70 °F (55 °F + 15 °F bias) at rated power and steam flow. The effect of reduced feedwater temperature is an increase in core inlet subcooling changing the axial power shape and core void fraction. Additionally, steam N.1-32

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-8 flow for a given power level decreases because more power is required to increase coolant enthalpy to saturated conditions. Generally, LRNB and TTNB events are less severe with FHOOS conditions due to the decrease in steam flow relative to nominal conditions. FWCF events with FHOOS conditions are generally worse due to a larger change in inlet subcooling and core power prior to the pressurization phase of the event.

Separate FHOOS limits are not needed for operation beyond the EOCLB exposure since a feedwater (FW) temperature reduction is included to attain the additional cycle extension to the FFTR / coastdown exposure, i.e., FFTR is equivalent to FHOOS since both are based on the same feedwater temperature reduction.

5.3.3 PLUOOS The PLU device in normal operation is assumed to not function below 50 % power. PLUOOS is assumed to mean the PLU device does not function for any power level and does not initiate fast TCV closure. The following PLUOOS scenario was assumed for the load reject event.

• Initially, the TCVs remain in pressure / speed control mode. There is no direct scram or EOC-RPT on valve motion.

• Loss of load results in increasing turbine speed. Depending on initial power, a turbine overspeed condition may be reached to initiate a turbine trip resulting in scram and EOC-RPT.

• Without a turbine trip signal, scram occurs on either high flux or high dome pressure to terminate the event.

Analyses were performed for LRNB events assuming PLUOOS.

5.3.4 Combined TBVOOS and FHOOS FWCF analyses with both TBVOOS and FHOOS were performed. Operating limits for this combined EOOS scenario were established using these FWCF results and results previously discussed. Separate TBVOOS and FHOOS combined limits are not needed for operation beyond the EOCLB exposure since a FW temperature reduction is included to attain the additional cycle extension to the FFTR / coastdown exposure.

5.3.5 Combined TBVOOS and PLUOOS Limits were established to support operation with both TBVOOS and PLUOOS. No additional analyses are required to construct MCPRp operating limits for TBVOOS and PLUOOS since N.1-33

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-9 TBVOOS and PLUOOS are independent EOOS conditions (TBVOOS only impacts FWCF events; PLUOOS only impacts LRNB events).

5.3.6 Combined FHOOS and PLUOOS LRNB analyses with both FHOOS and PLUOOS were performed. Operating limits for this combined EOOS scenario were established using these LRNB results and results previously discussed. Separate FHOOS and PLUOOS combined limits are not needed for operation beyond the EOCLB exposure since a FW temperature reduction is included to attain the additional cycle extension to the FFTR / coastdown exposure.

5.3.7 Combined TBVOOS, FHOOS, and PLUOOS Limits were established to support operation with TBVOOS, FHOOS, and PLUOOS. No additional analyses are required to construct MCPRp operating limits for TBVOOS, FHOOS, and PLUOOS since TBVOOS and PLUOOS are independent EOOS conditions (TBVOOS only impacts FWCF events; PLUOOS only impacts LRNB events). Separate TBVOOS, FHOOS, and PLUOOS combined limits are not needed for operation beyond the EOCLB exposure since a FW temperature reduction is included to attain the additional cycle extension to the FFTR / coastdown exposure.

5.3.8 Reduced Feedwater Temperature at Startup During reactor startup, it is beneficial to reduce feedwater temperature to avoid excessive wear on reactor equipment. The desired feedwater temperature is less than the temperature assumed in the FHOOS licensing analyses performed each cycle. Therefore, previously defined EOOS scenarios are not adequate to cover operation during startup with the desired reduction in feedwater temperature.

Analyses were performed to support all cycle exposures with or without EOC-RPT-OOS.

Analyses were also performed to support all cycle exposures with TBVOOS in combination with or without EOC-RPT-OOS. The analyses consider both NSS (above Pbypass cases) and TSSS. In addition, these analyses inherently cover all remaining non-PLUOOS equipment out-of-service scenarios defined in Table 1.1. Two separate startup feedwater temperatures are evaluated as provided in Item 6.6.1 of Reference 24. Limits for startup feedwater temperatures are presented in Table 8.4, Table 8.5, and Table 8.9.

N.1-34

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-10 The reduced feedwater temperatures are not applicable above 50 % of rated power. The startup feedwater temperatures cannot be less than the values defined in Item 6.6.1 of Reference 24. If this requirement is met, reactor startup is restricted to the 85 % rod line or less.

5.3.9 Recirculation Pump Out-of-Service Recirculation pump out-of-service (RCPOOS) is the EOOS implying single loop operation. The pump seizure event assumes the reactor is operating with one recirculation pump inactive and an instantaneous seizure of the pump motor shaft of the active recirculation pump occurs. Flow through the active loop is rapidly reduced due to the large hydraulic resistance introduced by the stopped rotor causing core thermal power to decrease and reactor water level to swell. The sudden decrease in core coolant flow while the reactor is at power results in a degradation of core heat transfer which could result in fuel damage. The high water level setpoint is not reached; therefore, no reactor scram occurs.

Analysis assumptions have been constructed to seek a balance between operating flexibility and margin to thermal limits. Maximum core power is restricted to 43.75 % of rated and core flow is restricted to 50 % of rated; active recirculation drive flow is assumed < 17.73 Mlb/hr. The results for the SLO pump seizure event are provided in Table 5.9.

For RCPOOS, the TLO transient CPRs and LHGRFAC multipliers remain applicable.

Therefore, when developing the thermal limits, the only impacts on the LHGR and MAPLHGR limits is the application of a MAPLHGR multiplier discussed in Section 8.3. The same situation is true for the EOOS scenarios. The TLO EOOS LHGRFAC multipliers remain applicable.

5.4 Licensing Power Shape The licensing axial power profile used by Framatome for the plant transient analyses bounds the projected end of full power axial power profile. The conservative licensing axial power profile generated at the EOCLB core average exposure of 34,078.5 MWd/MTU is given in Table 5.11.

Operation is considered to be in compliance when:

• The integrated normalized power generated in the bottom 7 nodes from the projected EOFP solution at the state conditions provided in Table 5.11 is greater than the integrated normalized power generated in the bottom 7 nodes in the licensing basis axial power profile, and the individual normalized power from the projected EOFP solution is greater than the corresponding normalized power from the licensing basis axial power profile for at least 6 of the 7 bottom nodes.

N.1-35

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-11

• The projected EOFP condition occurs at a core average exposure less than or equal to EOCLB.

If the criteria cannot be fully met, the licensing basis may nevertheless remain valid but further assessment will be required.

The licensing basis power profile in Table 5.11 was calculated using the MICROBURN-B2 code.

Compliance analyses must also be performed using MICROBURN-B2 or POWERPLEX-XD.

Note the power profile comparison should be done without incorporating instrument updates to the axial profile because the updated power is not used in the core monitoring system to accumulate assembly burnups.

N.1-36

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-12 Table 5.1 Exposure Basis for Transient Analysis Core Average Exposure (MWd/MTU) Comments 15,758.8 Beginning of cycle 30,758.8 Break point for exposure-dependent MCPRp limits (NEOC) 34,078.5 Design basis rod patterns to EOFP + 15 EFPD (EOCLB) 35,767.8 Maximum licensing core exposure -

including FFTR /Coastdown 33,756.8 Cycle 13 EOC (short window) 34,282.4 Cycle 13 EOC (nominal window) 34,606.8 Cycle 13 EOC (long window)

N.1-37

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-13 Table 5.2 Scram Speed Insertion Times Surveillance Timing Control Analytically Adjusted Timing Rod TSSS NSS OSS Position TSSS NSS OSS (seconds) (seconds) (seconds) (notch) (seconds) (seconds) (seconds) 48

--- 0.000 0.000 0.000 0.000 0.000 (full out)

--- 0.200 0.200 48 0.200 0.200 0.200 0.45 0.420 0.380 46 0.460 0.421 0.392 1.08 0.980 0.875 36 1.090 0.991 0.887 1.84 1.600 1.465 26 1.860 1.620 1.487 3.36 2.900 2.900 6 3.500 3.040 3.040 0

--- --- --- 4.000 3.500 3.500 (full in)

N.1-38

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-14 Table 5.3 Base Case LRNB Transient CPR Results*

Power

(% rated) NEOC EOCLB TSSS Insertion Times 50.0 0.76 0.76 40.0 0.84 0.84 NSS Insertion Times 50.0 0.75 0.75 40.0 0.83 0.83 OSS Insertion Times 50.0 0.75 0.75 40.0 0.83 0.83

• Based on previous EPU analyses and as discussed in Table A.2 of Reference 4, the LRNB event at high core power and 26 % power is bound by the FWCF event.

N.1-39

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-15 Table 5.4 Base Case FWCF Transient CPR Results Power

(% rated) NEOC EOCLB TSSS Insertion Times 100.0 0.36 0.37 90.0 0.40 0.41 77.6 0.45 0.45 65.0 0.53 0.53 60.0 0.53 0.53 55.0 0.57 0.57 50.0 0.64 0.64 40.0 0.83 0.83 26.0 1.35 1.35 26.0 at > 50 % F below Pbypass 1.60 1.60 26.0 at 50 % F below Pbypass 1.47 1.47 23.0 at > 50 % F below Pbypass 1.78 1.78 23.0 at 50 % F below Pbypass 1.64 1.64 NSS Insertion Times 100.0 0.35 0.36 90.0 0.39 0.39 77.6 0.44 0.44 65.0 0.50 0.50 60.0 0.51 0.51 55.0 0.55 0.55 50.0 0.62 0.62 40.0 0.80 0.80 26.0 1.33 1.33 N.1-40

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-16 Table 5.4 Base Case FWCF Transient CPR Results (Continued)

Power

(% rated) NEOC EOCLB OSS Insertion Times 100.0 0.34 0.35 90.0 0.38 0.38 77.6 0.43 0.44 65.0 0.49 0.49 60.0 0.49 0.50 55.0 0.52 0.53 50.0 0.59 0.59 40.0 0.78 0.78 26.0 1.30 1.30 N.1-41

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-17 Table 5.5 Loss of Feedwater Heating Transient Analysis Results Power

(% rated) CPR 100 0.12 90 0.13 80 0.14 70 0.15 60 0.16 50 0.18 40 0.21 30 0.25 23 0.31 Table 5.6 Control Rod Withdrawal Error CPR Results Analytical RBM Setpoint (without filter) CRWE

(%) CPR MCPR*

107 0.20 1.26 111 0.24 1.30 114 0.25 1.31 117 0.27 1.33

• For rated power and a 1.06 SLMCPR.

N.1-42

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-18 Table 5.7 RBM Operability Requirements Thermal Power Applicable

(% rated) MCPR 1.65 TLO 27 % and < 90 % 1.68 SLO 90 % 1.36 TLO Table 5.8 Flow-Dependent MCPR Results Core Flow

(% rated) MCPR 30 1.36 40 1.32 50 1.33 60 1.33 70 1.28 80 1.21 90 1.17 100 1.13 107 1.06 Table 5.9 RCPOOS Pump Seizure Results State point Power / Flow

(% rated) CPR 43.75 / 50 1.01 N.1-43

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-19 Table 5.10 LHGRFACp Transient Results*

PLUOOS TBVOOS Power Base and and

(% rated) Case FHOOS PLUOOS FHOOS TBVOOS FHOOS 100.0 1.00 1.00 1.00 1.00 0.99 1.00 90.0 0.99 0.98 1.00 1.00 0.96 0.96 77.6 0.97 0.97 1.00 1.00 0.92 0.94 65.0 0.93 0.95 0.99 1.00 0.89 0.90 60.0 0.94 0.93 0.98 0.97 0.88 0.90 55.0 0.92 0.91 0.94 0.94 0.85 0.88 50.0 0.91 0.89 0.91 0.89 0.85 0.86 40.0 0.88 0.82 0.88 0.82 0.83 0.80 26.0 0.68 0.64 0.68 0.64 0.66 0.62 26.0 at > 50 % F below Pbypass 0.50 0.46 0.50 0.46 0.43 0.40 23.0 at > 50 % F below Pbypass 0.46 0.44 0.46 0.44 0.40 0.37 26.0 at 50 % F below Pbypass 0.53 0.51 0.53 0.51 0.54 0.51 23.0 at 50 % F below Pbypass 0.50 0.49 0.50 0.49 0.48 0.46 Power SFHOOS1 SFHOOS1 SFHOOS2 SFHOOS2

(% rated) TBVIS TBVOOS TBVIS TBVOOS 50.0 0.79 0.79 0.81 0.79 40.0 0.73 0.71 0.70 0.69 26.0 0.54 0.53 0.53 0.52 26.0 at > 50 % F below Pbypass 0.42 0.37 0.42 0.37 23.0 at > 50 % F below Pbypass 0.38 0.33 0.38 0.33 26.0 at 50 % F below Pbypass 0.46 0.46 0.45 0.45 23.0 at 50 % F below Pbypass 0.43 0.41 0.43 0.42

• Results support operation with or without EOC-RPT-OOS and are presented for all cycle exposures and scram insertion times.

N.1-44

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-20 Table 5.11 Licensing Basis Core Average Axial Power Profile State Conditions for Power Shape Evaluation Power, MWt 3952.0 Core pressure, psia 1050.0 Inlet subcooling, Btu/lbm 25.5 Flow, Mlb/hr 107.6 Control state ARO Core average exposure 34,078.5 (EOCLB), MWd/MTU Licensing Axial Power Profile (Normalized)

Node Power Top 25 0.300 24 0.767 23 0.978 22 1.120 21 1.265 20 1.347 19 1.382 18 1.410 17 1.404 16 1.377 15 1.360 14 1.301 13 1.390 12 1.354 11 1.281 10 1.205 9 1.109 8 0.986 7 0.853 6 0.737 5 0.623 4 0.526 3 0.457 2 0.360 Bottom 1 0.107 Sum of Bottom 7 Nodes = 3.663 N.1-45

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-21 400.0 Relative Core Power Relative Heat Flux Relative Total Core Flow Relative Steam Flow 300.0 Relative Feed Flow 200.0 0

ry 0

C aD U

100.0 n ------- -

0.0

` J U

-100.0 0.0 1.0 2.0 3.0 4.0 5.0 Time (seconds)

Figure 5.1 EOCLB LRNB at 100P / 105F - TSSS Key Parameters N.1-46

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-22 38.0 O

N N 34.5 N

E cc 33.0 30.0 O

J N

28.5 27.0 1 1 0.0 1.0 2.0 3.0 4.0 5.0 Time (seconds)

Figure 5.2 EOCLB LRNB at 100P / 105F - TSSS Sensed Water Level N.1-47

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-23 1300.0 1250.0 1200.0

/

/

/

1100.0 1050.0 Vessel Lower Plenum Steam Dome 1000.0 I 0.0 1.0 2.0 3.0 4.0 5.0 Time (seconds)

Figure 5.3 EOCLB LRNB at 100P / 105F - TSSS Vessel Pressures N.1-48

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-24 400.0 Relative Core Power Relative Heat Flux Relative Total Core Flow Relative Steam Flow 300.0 Relative Feed Flow T) 200.0 O

_____ i ~

\

\

II 0.0 V

J I

-100.0 i i 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Time (seconds)

Figure 5.4 EOCLB FWCF at 100P / 105F - TSSS Key Parameters N.1-49

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-25 70.0 C

J n

CD N

60.0 C

N E

L C

0 50.0 U

N Q

U)

N n

L 40.0 N

a~

J L

a>

6 30.0 N

E N

U) 20.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Time (seconds)

Figure 5.5 EOCLB FWCF at 100P / 105F - TSSS Sensed Water Level N.1-50

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 5-26 1300.0 Vessel Lower Plenum Steam Dome 1250.0 1

1~

1 ~

I 1200.0 1 ~

I 0 I 1 EO I a

1 I `

I I ~

I \~

r1 \

1100.0 I ~

I ~

I I \~

I 1050.0 I '

1000.0 0.0 5.0 10.0 15.0 20.0 25.0 30.3 Time (seconds)

Figure 5.6 EOCLB FWCF at 100P / 105F - TSSS Vessel Pressures N.1-51

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 6-1 6.0 POSTULATED ACCIDENTS 6.1 Loss-of-Coolant-Accident (LOCA)

The results of the ATRIUM 10XM LOCA analysis are presented in References 26 and 27 as supplemented by Reference 28. The ATRIUM 10XM PCT is 2052 °F. The peak local metal water reaction is 2.06 % and the maximum core wide metal-water reaction (for hydrogen generation) for a full ATRIUM 10XM core is < 1.0 %.

The cycle-specific ATRIUM 10XM reload fuel PCT is bounded by the limiting neutronic design used in Reference 27. When compared to the acceptance criteria of less than 17 % local cladding oxidation thickness, the local metal-water reaction result remains acceptable.

Analyses and results support the EOD and EOOS conditions listed in Table 1.1. Note TBVOOS, EOC-RPT-OOS, PLUOOS, and TIPOOS/LPRM out-of-service have no direct influence on the LOCA events.

6.2 Control Rod Drop Accident (CRDA)

Plant startup utilizes a bank position withdrawal sequence (BPWS) including rod worth minimization strategies. The CRDA evaluation was performed for both A and B sequence startups consistent with the withdrawal sequences specified by TVA. The approved Framatome generic CRDA methodology is described in Reference 29. Subsequent calculations have shown the methodology is applicable to fuel modeled with the CASMO-4/MICROBURN-B2 code system and is applicable to ATRIUM 10XM.

Maximum deposited fuel rod enthalpy is less than both the current core coolability limit of 280 cal/g and the 230 cal/g limit identified in Standard Review Plan 4.2, Revision 3, Appendix B, Section C, Item 1. Fuel rods conservatively estimated to exceed the existing fuel damage threshold of 170 cal/g are within the UFSAR basis (850 rods). The CRDA analysis results are summarized below.

Maximum dropped control rod worth, mk 8.85 o

Core average Doppler coefficient, k/k/ F -10.5 x 10-6 Effective delayed neutron fraction 0.0052 Four-bundle local peaking factor 1.449 N.1-52

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 6-2 Maximum deposited fuel rod enthalpy, cal/g 164.2 Maximum number of assemblies exceeding 170 cal/g 0 Number of rods failed 0 6.3 Fuel and Equipment Handling Accident The fuel handling accident radiological analysis implementing the alternate source term (AST) as approved in Reference 30 was performed with consideration of ATRIUM-10 core source terms. The ATRIUM 10XM source terms have been dispositioned relative to those in the AST analysis of record and found to support the same conclusions. Fuel assembly and reactor core isotopic inventories used as input to design basis radiological accident analyses are applicable to all three units (Reference 30). The number of failed fuel rods for the ATRIUM-10 fuel as previously provided to TVA in Reference 31 for use in the AST analysis is unchanged. The number of failed fuel rods for the ATRIUM 10XM fuel is 163 which remains bounded by the analysis of record. No other aspect of utilizing the ATRIUM-10 and ATRIUM 10XM fuel affects the current analysis; therefore, the AST fuel handling accident analysis remains applicable.

6.4 Fuel Loading Error (Infrequent Event)

There are two types of fuel loading errors possible in a BWR - the mislocation of a fuel assembly in a core position prescribed to be loaded with another fuel assembly and the misorientation of a fuel assembly with respect to the control blade. As described in Reference 32, the fuel loading error is characterized as an infrequent event. The acceptance criteria is the offsite dose consequences due to the event shall not exceed a small fraction of the 10 CFR 50.67 limits.

6.4.1 Mislocated Fuel Bundle Framatome has performed a bounding fuel mislocation error analysis and has demonstrated continued applicability of the bounding results. The analysis considered the impact of a mislocated assembly against potential fuel rod failure mechanisms due to increased LHGR and reduced CPR. Based on the analyses the offsite dose criteria (a small fraction of 10 CFR 50.67) is conservatively satisfied. A dose consequence evaluation is not necessary since no rod approaches the fuel centerline melt or 1 % strain limits and less than 0.1 % of the fuel rods are expected to experience boiling transition.

N.1-53

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 6-3 6.4.2 Misoriented Fuel Bundle Framatome has performed a bounding fuel assembly misorientation analysis. The analysis was performed assuming the limiting assembly was loaded in the worst orientation (rotated 180 °),

while simultaneously producing sufficient power to be on the MCPR operating limit as if it were oriented correctly. The analysis demonstrates the small fraction of 10 CFR 50.67 offsite dose criteria is conservatively satisfied. A dose consequence evaluation is not necessary since no rod approaches fuel centerline melt or 1 % strain limits and less than 0.1 % of the fuel rods are expected to experience boiling transition.

N.1-54

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-1 7.0 SPECIAL ANALYSES 7.1 ASME Overpressurization Analysis This section describes the maximum overpressurization analyses performed to demonstrate compliance with the ASME Boiler and Pressure Vessel Code. The analysis shows the safety / relief valves have sufficient capacity and performance to prevent the reactor vessel pressure from reaching the safety limit of 110 % of the design pressure.

Main steam isolation valve (MSIV) closure, TSV closure, and TCV closure (without bypass) analyses were performed with the Framatome plant simulator code COTRANSA2 (Reference 19) for 102 % power and both 85 % and 105 % flow at the highest cycle exposure.

The MSIV closure event is similar to the other steam line valve closure events in that the valve closure results in a rapid pressurization of the core. The increase in pressure causes a decrease in voids which in turn causes a rapid increase in power. The TBVs do not impact the system response and are not modeled in the analysis. The following assumptions were made in the analysis.

• The most critical active component (direct scram on valve position or motion) was assumed to fail. However, scram on high neutron flux and high dome pressure is available.

• To support operation with 1 MSRVOOS, the plant configuration analyzed assumed one of the lowest setpoint MSRVs was inoperable.

• TSSS insertion times were used.

• The initial dome pressure was set at the maximum allowed by the Technical Specifications plus an additional 5 psi bias, 1070 psia (1055 psig).

• A fast MSIV closure time of 3.0 seconds was used.

• The analytical limit ATWS-RPT setpoint and function were assumed.

Results of the MSIV closure, TCV closure, and TSV closure overpressurization analyses are presented in Table 7.1. Various reactor plant parameters during the limiting MSIV closure event are presented in Figure 7.1 - Figure 7.4. The maximum pressure of 1350 psig occurs in the lower plenum. The maximum dome pressure for the same event is 1317 psig. The results demonstrate the maximum vessel pressure limit of 1375 psig and dome pressure limit of 1325 psig are not exceeded for any analyses.

The peak pressure results include adjustments to address the NRC concerns associated with the void-quality correlation, exposure-dependent thermal conductivity, and Doppler effects.

N.1-55

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-2 7.2 ATWS Event Evaluation 7.2.1 ATWS Overpressurization Analysis This section describes analyses performed to demonstrate the peak vessel pressure for the limiting anticipated transient without scram (ATWS) event is less than the ASME Service Level C limit of 120 % of the design pressure (1500 psig). Overpressurization analyses were performed at 100 % power at both 85 % and 105 % flow over the cycle exposure range for both the MSIV closure event and the pressure regulator failure open (PRFO) event. The PRFO event assumes a step decrease in pressure demand such that the pressure control system opens the TCVs and TBVs. Steam flow demand is assumed to increase to 125 % demand (equivalent to 131.3 % of rated steam flow) allowing a maximum TCV flow of 105 % and a maximum bypass system flow of 21.3 %. The system pressure decreases until the low pressure setpoint is reached resulting in the closure of the MSIVs. The subsequent pressurization wave collapses core voids, thereby increasing core power.

The following assumptions were made in the analyses.

• The analytical limit ATWS-RPT setpoint and function were assumed.

• To support operation with 1 MSRVOOS, the plant configuration analyzed assumed one of the lowest setpoint MSRVs was inoperable.

• All scram functions were disabled.

• The initial dome pressure was set to the nominal pressure of 1050 psia.

• A nominal MSIV closure time of 4.0 seconds was used for both events.

Analyses results are presented in Table 7.2. The response of various reactor plant parameters during the limiting PRFO event are shown in Figure 7.5 - Figure 7.8. The maximum lower plenum pressure is 1485 psig and the maximum dome pressure is 1466 psig. The results demonstrate the ATWS maximum vessel pressure limit of 1500 psig is not exceeded.

The peak pressure results include adjustments to address the NRC concerns associated with the void-quality correlation, exposure-dependent thermal conductivity, and Doppler effects.

7.2.2 Long-Term Evaluation Fuel design differences may impact the power and pressure excursion experienced during the ATWS event. This in turn may impact the amount of steam discharged to the suppression pool and containment.

N.1-56

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-3 An evaluation of ATRIUM 10XM fuel at EPU conditions was presented in Section 7.2.2 of Reference 33. This conclusion is applicable for the BFE1-14 core design.

7.3 Standby Liquid Control System In the event the control rod scram function becomes incapable of rendering the core in a shutdown state, the standby liquid control (SLC) system is required to be capable of bringing the reactor from full power to a cold shutdown condition at any time in the core life. The Browns Ferry Unit 1 SLC system is required to be able to inject 720 ppm natural boron equivalent at 70 °F into the reactor coolant. Framatome has performed an analysis demonstrating the SLC system meets the required shutdown capability for the cycle. The analysis was performed at a coolant temperature of 366 °F with a boron concentration equivalent to 720 ppm at 68 °F*. The temperature of 366 °F corresponds to the low pressure permissive for the RHR shutdown cooling suction valves and represents the maximum reactivity condition with soluble boron in the coolant. The analysis shows the core to be subcritical throughout the cycle by at least 2.35 % k/k based on the short Cycle 13 EOC.

7.4 Fuel Criticality The spent fuel pool criticality analysis for ATRIUM-10 and ATRIUM 10XM fuel are presented in References 34 and 35, respectively. The ATRIUM-10 and ATRIUM 10XM fuel assemblies identified for the cycle meet the spent fuel storage requirements. ATRIUM-10 and ATRIUM 10XM fuel assemblies will not be stored in the new fuel storage vault.

• TVA Browns Ferry SLC licensing basis documents indicate a minimum of 720 ppm boron at a temperature of 70 °F. The Framatome cold analysis basis of 68 °F represents a negligible difference and the results are adequate to protect the 70 °F licensing basis for the plant.

N.1-57

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-4 Table 7.1 ASME Overpressurization Analysis Results*

Maximum Peak Peak Vessel Maximum Neutron Heat Pressure Dome Flux Flux Lower-Plenum Pressure Event (% rated) (% rated) (psig) (psig)

MSIV closure 273 129 1350 1317 (102P / 105F)

TSV closure without bypass 436 139 1344 1311 (102P / 105F)

TCV closure without bypass 435 139 1344 1311 (102P / 105F)

Pressure

--- --- 1375 1325 Limit

• The peak pressure results include adjustments to address the NRC concerns associated with the void-quality correlation, exposure-dependent thermal conductivity, and Doppler effects.

N.1-58

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-5 Table 7.2 ATWS Overpressurization Analysis Results*

Maximum Peak Peak Vessel Maximum Neutron Heat Pressure Dome Flux Flux Lower-Plenum Pressure Event (% rated) (% rated) (psig) (psig)

MSIV closure 277 134 1480 1462 (100P / 85F)

PRFO 250 139 1485 1466 (100P / 85F)

Pressure

--- --- 1500 1500 Limit

• The peak pressure results include adjustments to address the NRC concerns associated with the void-quality correlation, exposure-dependent thermal conductivity, and Doppler effects.

N.1-59

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-6 300.0 Relative Core Power Relative Heat Flux Relative Total Core Flow Relative Steam Flow Relative Feed Flow 200.0 0

0' O 100.0 U

Q) `

n ---- --------

~

I4 P7 0.0 100.0 i I 0.0 2.0 4.0 6.0 8.0 10.0 1 2.0 Time (seconds)

Figure 7.1 MSIV Closure Overpressurization Event at 102P / 105F - Key Parameters N.1-60

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-7 Sensed Water Level With Respect to Instrument Zero (in.)

Figure 7.2 MSIV Closure Overpressurization Event at 102P / 105F - Sensed Water Level N.1-61

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-8 1400.0 Vessel Lower Plenum Steam Dome 1350.0 1300.0 I ~

0 V) 1250.0 w

I ~

U) 1200.0 t ~

n f \~

1150.0

(

/

/

1100.0 r

/

1050.0 0.0 2.0 4.0 6.0 8.0 10.0 1 2.0 Time (seconds)

Figure 7.3 MSIV Closure Overpressurization Event at 102P / 105F - Vessel Pressures N.1-62

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-9 1500.0 Low Setpt (3)

---

- Med Sett 4 High Setpt (5) 1250.0

~I I I

~ I v ~ I I

j 750.0 I I I

Q) I I v 'I ry 0 500.0 I

I I

I Q) t I I I I

.0C

~ I II I 250.0 {

d I I~ I I

I R I 0.0 I 0.0 2.0 4.0 6.0 8.0 10,0 1 2.0 Time (seconds)

Figure 7.4 MSIV Closure Overpressurization Event at 102P / 105F - Safety / Relief Valve Flow Rates N.1-63

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-10 250.0 Relative Core Power Relative Heat Flux Relative Total Core Flow 200.0 Relative Steam Flow Relative Feed Flow 150.0 N

0 rY 1 ~

° 100.0 U

N r

50.0 I~lh~I

- - ------------------------ ----*-------1'---1 0.0 I I IIIII~ ,~`v

-50.0 0.0 10.0 20.0 30.0 40.0 50.0 Time (seconds)

Figure 7.5 PRFO ATWS Overpressurization Event at 100P / 85F - Key Parameters N.1-64

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-11 Sensed Water Level With Respect to Instrument Zero (in.)

Figure 7.6 PRFO ATWS Overpressurization Event at 100P / 85F - Sensed Water Level N.1-65

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-12 1600.0 Vessel Lower Plenum Steam Dome 1400.0 0

a qU) 1200.0 V) v n

1000.0 806.0 i I 0.0 10.0 20.0 30.0 40.0 50.0 Time (seconds)

Figure 7.7 PRFO ATWS Overpressurization Event at 100P / 85F - Vessel Pressures N.1-66

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 7-13 1600.0

---

Low Setpt (3)

Med Setpt (4)

High Setpt (5) 800.0 4MO 0.0 10.0 20.0 3a.0 40.0 50.0 Time (seconds)

Figure 7.8 PRFO ATWS Overpressurization Event at 100P / 85F - Safety / Relief Valve Flow Rates N.1-67

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-1 8.0 OPERATING LIMITS AND COLR INPUT 8.1 MCPR Limits Determination of MCPR limits are based on analyses of the limiting AOTs. MCPR operating limits are established such that less than 0.1 % of the fuel rods in the core are expected to experience boiling transition during an AOT initiated from rated or off-rated conditions and are based on the Technical Specifications TLO SLMCPR of 1.06 and SLO SLMCPR of 1.08.

Exposure-dependent MCPR limits were established to support operation from BOC to NEOC, BOC to EOCLB, and BOC to end of combined FFTR / Coastdown (COAST). MCPR limits are established to support base case operation and the EOOS scenarios presented in Table 1.1.

TLO MCPRp limits are presented for base case operation and the EOOS conditions in Table 8.1 - Table 8.5. Limits are presented for OSS (Table 8.1), NSS (Table 8.2), and TSSS (Table 8.3) insertion times for the exposure ranges considered. Table 8.4 and Table 8.5 present the TLO MCPRp limits for the reduced feedwater temperature at startup conditions.

MCPRp limits for SLO are presented in Table 8.6. They are developed by a combination of the SLO pump seizure results provided in Table 5.9 and the corresponding TLO limits plus 0.02 which accounts for the difference in the TLO and SLO SLMCPR.

MCPRf limits protect against fuel failures during a postulated slow flow excursion. The MCPRf limits presented in Table 8.7 are applicable for all cycle exposures and EOOS conditions identified in Table 1.1.

8.2 LHGR Limits The LHGR limits are presented in Table 8.8. Power- and flow-dependent multipliers (LHGRFACp and LHGRFACf) are applied directly to the LHGR limits to protect against fuel melting and overstraining of the cladding during an AOT.

The LHGRFACp multipliers are determined using the RODEX4 thermal-mechanical methodology (Reference 36). LHGRFACp multipliers were established to support operation at all cycle exposures for all scram insertion times and for the EOOS conditions identified in Table 1.1 with and without TBVOOS. LHGRFACp limits are presented in Table 8.9.

N.1-68

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-2 LHGRFACf multipliers are established to provide protection against fuel centerline melt and overstraining of the cladding during a postulated slow flow excursion. LHGRFACf limits are presented in Table 8.10. LHGRFACf multipliers are applicable for all cycle exposures and EOOS conditions identified in Table 1.1.

8.3 MAPLHGR Limits MAPLHGR limits are discussed in Reference 27. The TLO limits are presented in Table 8.11.

For SLO, a multiplier of 0.85 must be applied to the TLO MAPLHGR limits. Power- and flow-dependent MAPFAC set-downs are not required; therefore, MAPFAC = 1.0.

N.1-69

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-3 Table 8.1 TLO MCPRp Limits for OSS Insertion Times*

Operating Power BOC to BOC to BOC to Condition (% of rated) NEOC EOCLB End of COAST 100.0 1.40 1.41 1.42 90.0 1.44 1.44 1.47 77.6 1.49 1.50 1.52 65.0 1.55 1.55 1.59

> 50.0 1.65 1.65 1.72 Base case 50.0 1.81 1.81 1.81 operation 40.0 1.89 1.89 1.92 26.0 2.36 2.36 2.49 26.0 at > 50 % F 2.66 2.66 2.78 23.0 at > 50 % F 2.84 2.84 2.97 26.0 at 50 % F 2.53 2.53 2.64 23.0 at 50 % F 2.70 2.70 2.83 100.0 1.42 1.42 ---

90.0 1.46 1.47 ---

77.6 1.52 1.52 ---

65.0 1.58 1.59 ---

> 50.0 1.72 1.72 ---

50.0 1.81 1.81 ---

FHOOS 40.0 1.92 1.92 ---

26.0 2.49 2.49 ---

26.0 at > 50 % F 2.78 2.78 ---

23.0 at > 50 % F 2.97 2.97 ---

26.0 at 50 % F 2.64 2.64 ---

23.0 at 50 % F 2.83 2.83 ---

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

BOC to End of COAST limits also support operation with FFTR / FHOOS which bounds operation with feedwater heaters in-service.

Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-70

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-4 Table 8.2 TLO MCPRp Limits for NSS Insertion Times*

Operating Power BOC to BOC to BOC to Condition (% of rated) NEOC EOCLB End of COAST 100.0 1.41 1.42 1.44 90.0 1.45 1.45 1.48 77.6 1.50 1.50 1.53 65.0 1.56 1.56 1.61

> 50.0 1.68 1.68 1.74 Base case 50.0 1.81 1.81 1.81 operation 40.0 1.89 1.89 1.95 26.0 2.39 2.39 2.52 26.0 at > 50 % F 2.66 2.66 2.78 23.0 at > 50 % F 2.84 2.84 2.97 26.0 at 50 % F 2.53 2.53 2.64 23.0 at 50 % F 2.70 2.70 2.83 100.0 1.45 1.46 1.48 90.0 1.48 1.49 1.52 77.6 1.53 1.54 1.57 65.0 1.59 1.60 1.64

> 50.0 1.68 1.68 1.76 50.0 1.81 1.81 1.82 TBVOOS 40.0 1.89 1.89 1.96 26.0 2.39 2.39 2.53 26.0 at > 50 % F 3.21 3.21 3.33 23.0 at > 50 % F 3.46 3.46 3.62 26.0 at 50 % F 2.88 2.88 3.04 23.0 at 50 % F 3.18 3.18 3.35 100.0 1.43 1.44 ---

90.0 1.47 1.48 ---

77.6 1.52 1.53 ---

65.0 1.61 1.61 ---

> 50.0 1.74 1.74 ---

50.0 1.81 1.81 ---

FHOOS 40.0 1.95 1.95 ---

26.0 2.52 2.52 ---

26.0 at > 50 % F 2.78 2.78 ---

23.0 at > 50 % F 2.97 2.97 ---

26.0 at 50 % F 2.64 2.64 ---

23.0 at 50 % F 2.83 2.83 ---

100.0 1.41 1.42 1.44 90.0 1.45 1.45 1.48 77.6 1.50 1.50 1.53 65.0 1.74 1.74 1.74

> 50.0 --- --- ---

50.0 1.82 1.82 1.82 PLUOOS 40.0 1.89 1.89 1.95 26.0 2.39 2.39 2.52 26.0 at > 50 % F 2.66 2.66 2.78 23.0 at > 50 % F 2.84 2.84 2.97 26.0 at 50 % F 2.53 2.53 2.64 23.0 at 50 % F 2.70 2.70 2.83

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

BOC to End of COAST limits also support operation with FFTR / FHOOS which bounds operation with feedwater heaters in-service.

Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-71

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-5 Table 8.2 TLO MCPRp Limits for NSS Insertion Times*

(Continued)

Operating Power BOC to BOC to BOC to Condition (% of rated) NEOC EOCLB End of COAST 100.0 1.47 1.48 ---

90.0 1.51 1.52 ---

77.6 1.57 1.57 ---

65.0 1.64 1.64 ---

> 50.0 1.76 1.76 ---

TBVOOS 50.0 1.82 1.82 ---

and FHOOS 40.0 1.96 1.96 ---

26.0 2.53 2.53 ---

26.0 at > 50 % F 3.33 3.33 ---

23.0 at > 50 % F 3.62 3.62 ---

26.0 at 50 % F 3.04 3.04 ---

23.0 at 50 % F 3.35 3.35 ---

100.0 1.45 1.46 1.48 90.0 1.48 1.49 1.52 77.6 1.53 1.54 1.57 65.0 1.74 1.74 1.75

> 50.0 --- --- ---

TBVOOS 50.0 1.82 1.82 1.82 and PLUOOS 40.0 1.89 1.89 1.96 26.0 2.39 2.39 2.53 26.0 at > 50 % F 3.21 3.21 3.33 23.0 at > 50 % F 3.46 3.46 3.62 26.0 at 50 % F 2.88 2.88 3.04 23.0 at 50 % F 3.18 3.18 3.35 100.0 1.43 1.44 ---

90.0 1.47 1.48 ---

77.6 1.52 1.53 ---

65.0 1.74 1.74 ---

> 50.0 --- --- ---

FHOOS 50.0 1.82 1.82 ---

and PLUOOS 40.0 1.95 1.95 ---

26.0 2.52 2.52 ---

26.0 at > 50 % F 2.78 2.78 ---

23.0 at > 50 % F 2.97 2.97 ---

26.0 at 50 % F 2.64 2.64 ---

23.0 at 50 % F 2.83 2.83 ---

100.0 1.47 1.48 ---

90.0 1.51 1.52 ---

77.6 1.57 1.57 ---

65.0 1.75 1.75 ---

> 50.0 --- --- ---

TBVOOS, 50.0 1.82 1.82 ---

FHOOS, 40.0 1.96 1.96 ---

and PLUOOS 26.0 2.53 2.53 ---

26.0 at > 50 % F 3.33 3.33 ---

23.0 at > 50 % F 3.62 3.62 ---

26.0 at 50 % F 3.04 3.04 ---

23.0 at 50 % F 3.35 3.35 ---

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

BOC to End of COAST limits also support operation with FFTR / FHOOS which bounds operation with feedwater heaters in-service.

Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-72

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-6 Table 8.3 TLO MCPRp Limits for TSSS Insertion Times*

Operating Power BOC to BOC to BOC to Condition (% of rated) NEOC EOCLB End of COAST 100.0 1.42 1.43 1.46 90.0 1.46 1.47 1.50 77.6 1.51 1.51 1.57 65.0 1.59 1.59 1.65

> 50.0 1.70 1.70 1.78 Base case 50.0 1.82 1.82 1.83 operation 40.0 1.90 1.90 1.98 26.0 2.41 2.41 2.55 26.0 at > 50 % F 2.66 2.66 2.79 23.0 at > 50 % F 2.84 2.84 2.98 26.0 at 50 % F 2.53 2.53 2.65 23.0 at 50 % F 2.70 2.70 2.84 100.0 1.46 1.47 1.50 90.0 1.49 1.50 1.54 77.6 1.54 1.55 1.60 65.0 1.61 1.61 1.68

> 50.0 1.71 1.71 1.80 50.0 1.82 1.82 1.84 TBVOOS 40.0 1.90 1.90 2.00 26.0 2.41 2.41 2.56 26.0 at > 50 % F 3.21 3.21 3.34 23.0 at > 50 % F 3.46 3.46 3.63 26.0 at 50 % F 2.88 2.88 3.05 23.0 at 50 % F 3.18 3.18 3.36 100.0 1.46 1.46 ---

90.0 1.50 1.50 ---

77.6 1.57 1.57 ---

65.0 1.65 1.65 ---

> 50.0 1.78 1.78 ---

50.0 1.83 1.83 ---

FHOOS 40.0 1.98 1.98 ---

26.0 2.55 2.55 ---

26.0 at > 50 % F 2.79 2.79 ---

23.0 at > 50 % F 2.98 2.98 ---

26.0 at 50 % F 2.65 2.65 ---

23.0 at 50 % F 2.84 2.84 ---

100.0 1.42 1.43 1.46 90.0 1.46 1.47 1.50 77.6 1.51 1.51 1.57 65.0 1.74 1.74 1.75

> 50.0 --- --- ---

50.0 1.83 1.83 1.83 PLUOOS 40.0 1.90 1.90 1.90 26.0 2.41 2.41 2.55 26.0 at > 50 % F 2.66 2.66 2.79 23.0 at > 50 % F 2.84 2.84 2.98 26.0 at 50 % F 2.53 2.53 2.65 23.0 at 50 % F 2.70 2.70 2.84

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

BOC to End of COAST limits also support operation with FFTR / FHOOS which bounds operation with feedwater heaters in-service.

Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-73

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-7 Table 8.3 TLO MCPRp Limits for TSSS Insertion Times*

(Continued)

Operating Power BOC to BOC to BOC to Condition (% of rated) NEOC EOCLB End of COAST 100.0 1.50 1.50 ---

90.0 1.53 1.54 ---

77.6 1.60 1.60 ---

65.0 1.68 1.68 ---

> 50.0 1.80 1.80 ---

TBVOOS 50.0 1.84 1.84 ---

and FHOOS 40.0 2.00 2.00 ---

26.0 2.56 2.56 ---

26.0 at > 50 % F 3.34 3.34 ---

23.0 at > 50 % F 3.63 3.63 ---

26.0 at 50 % F 3.05 3.05 ---

23.0 at 50 % F 3.36 3.36 ---

100.0 1.46 1.47 1.50 90.0 1.49 1.50 1.54 77.6 1.54 1.55 1.60 65.0 1.74 1.74 1.76

> 50.0 --- --- ---

TBVOOS 50.0 1.83 1.83 1.84 and PLUOOS 40.0 1.90 1.90 2.00 26.0 2.41 2.41 2.56 26.0 at > 50 % F 3.21 3.21 3.34 23.0 at > 50 % F 3.46 3.46 3.63 26.0 at 50 % F 2.88 2.88 3.05 23.0 at 50 % F 3.18 3.18 3.36 100.0 1.46 1.46 ---

90.0 1.50 1.50 ---

77.6 1.57 1.57 ---

65.0 1.75 1.75 ---

> 50.0 --- --- ---

FHOOS 50.0 1.83 1.83 ---

and PLUOOS 40.0 1.98 1.98 ---

26.0 2.55 2.55 ---

26.0 at > 50 % F 2.79 2.79 ---

23.0 at > 50 % F 2.98 2.98 ---

26.0 at 50 % F 2.65 2.65 ---

23.0 at 50 % F 2.84 2.84 ---

100.0 1.50 1.50 ---

90.0 1.53 1.54 ---

77.6 1.60 1.60 ---

65.0 1.76 1.76 ---

> 50.0 --- --- ---

TBVOOS, 50.0 1.84 1.84 ---

FHOOS, 40.0 2.00 2.00 ---

and PLUOOS 26.0 2.56 2.56 ---

26.0 at > 50 % F 3.34 3.34 ---

23.0 at > 50 % F 3.63 3.63 ---

26.0 at 50 % F 3.05 3.05 ---

23.0 at 50 % F 3.36 3.36 ---

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

BOC to End of COAST limits also support operation with FFTR / FHOOS which bounds operation with feedwater heaters in-service.

Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-74

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-8 Table 8.4 TLO MCPRp Limits for Reduced Feedwater Temperature at Startup NSS Insertion Times*

Operating Power BOC to BOC to BOC to Condition (% of rated) NEOC EOCLB End of COAST 100.0 1.43 1.44 1.44 90.0 1.47 1.48 1.48 77.6 1.52 1.53 1.53 65.0 1.74 1.74 1.74

> 50.0 --- --- ---

Startup 50.0 1.89 1.89 1.89 FHOOS 1 TBVIS 40.0 2.14 2.14 2.14 26.0 2.82 2.82 2.82 26.0 at > 50 % F 3.06 3.06 3.06 23.0 at > 50 % F 3.31 3.31 3.31 26.0 at 50 % F 2.91 2.91 2.91 23.0 at 50 % F 3.14 3.14 3.14 100.0 1.47 1.48 1.48 90.0 1.51 1.52 1.52 77.6 1.57 1.57 1.57 65.0 1.75 1.75 1.75

> 50.0 --- --- ---

Startup 50.0 1.90 1.90 1.90 FHOOS 1 TBVOOS 40.0 2.15 2.15 2.15 26.0 2.83 2.83 2.83 26.0 at > 50 % F 3.57 3.57 3.57 23.0 at > 50 % F 3.87 3.87 3.87 26.0 at 50 % F 3.27 3.27 3.27 23.0 at 50 % F 3.61 3.61 3.61

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

TBVIS limits are applicable for all EOOS scenarios presented in Table 1.1 except those including TBVOOS. TBVOOS limits are applicable for all EOOS scenarios presented in Table 1.1. Startup FHOOS 1 temperatures are presented as FW Set 1 in Item 6.6.1 of Reference 24. Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-75

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-9 Table 8.4 TLO MCPRp Limits for Reduced Feedwater Temperature at Startup NSS Insertion Times* (Continued)

Operating Power BOC to BOC to BOC to Condition (% of rated) NEOC EOCLB End of COAST 100.0 1.43 1.44 1.44 90.0 1.47 1.48 1.48 77.6 1.52 1.53 1.53 65.0 1.74 1.74 1.74

> 50.0 --- --- ---

Startup 50.0 1.90 1.90 1.90 FHOOS 2 TBVIS 40.0 2.16 2.16 2.16 26.0 2.85 2.85 2.85 26.0 at > 50 % F 3.08 3.08 3.08 23.0 at > 50 % F 3.32 3.32 3.32 26.0 at 50 % F 2.92 2.92 2.92 23.0 at 50 % F 3.17 3.17 3.17 100.0 1.47 1.48 1.48 90.0 1.51 1.52 1.52 77.6 1.57 1.57 1.57 65.0 1.75 1.75 1.75

> 50.0 --- --- ---

Startup 50.0 1.91 1.91 1.91 FHOOS 2 TBVOOS 40.0 2.17 2.17 2.17 26.0 2.86 2.86 2.86 26.0 at > 50 % F 3.58 3.58 3.58 23.0 at > 50 % F 3.89 3.89 3.89 26.0 at 50 % F 3.28 3.28 3.28 23.0 at 50 % F 3.63 3.63 3.63

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

TBVIS limits are applicable for all EOOS scenarios presented in Table 1.1 except those including TBVOOS. TBVOOS limits are applicable for all EOOS scenarios presented in Table 1.1. Startup FHOOS 2 temperatures are presented as FW Set 2 in Item 6.6.1 of Reference 24. Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-76

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-10 Table 8.5 TLO MCPRp Limits for Reduced Feedwater Temperature at Startup TSSS Insertion Times*

Operating Power BOC to BOC to BOC to Condition (% of rated) NEOC EOCLB End of COAST 100.0 1.46 1.46 1.46 90.0 1.50 1.50 1.50 77.6 1.57 1.57 1.57 65.0 1.75 1.75 1.75

> 50.0 --- --- ---

Startup 50.0 1.93 1.93 1.93 FHOOS 1 TBVIS 40.0 2.18 2.18 2.18 26.0 2.86 2.86 2.86 26.0 at > 50 % F 3.07 3.07 3.07 23.0 at > 50 % F 3.32 3.32 3.32 26.0 at 50 % F 2.92 2.92 2.92 23.0 at 50 % F 3.15 3.15 3.15 100.0 1.50 1.50 1.50 90.0 1.53 1.54 1.54 77.6 1.60 1.60 1.60 65.0 1.76 1.76 1.76

> 50.0 --- --- ---

Startup 50.0 1.94 1.94 1.94 FHOOS 1 TBVOOS 40.0 2.19 2.19 2.19 26.0 2.87 2.87 2.87 26.0 at > 50 % F 3.58 3.58 3.58 23.0 at > 50 % F 3.88 3.88 3.88 26.0 at 50 % F 3.28 3.28 3.28 23.0 at 50 % F 3.62 3.62 3.62

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

TBVIS limits are applicable for all EOOS scenarios presented in Table 1.1 except those including TBVOOS. TBVOOS limits are applicable for all EOOS scenarios presented in Table 1.1. Startup FHOOS 1 temperatures are presented as FW Set 1 in Item 6.6.1 of Reference 24. Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-77

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-11 Table 8.5 TLO MCPRp Limits for Reduced Feedwater Temperature at Startup TSSS Insertion Times* (Continued)

Operating Power BOC to BOC to BOC to Condition (% of rated) NEOC EOCLB End of COAST 100.0 1.46 1.46 1.46 90.0 1.50 1.50 1.50 77.6 1.57 1.57 1.57 65.0 1.75 1.75 1.75

> 50.0 --- --- ---

Startup 50.0 1.94 1.94 1.94 FHOOS 2 TBVIS 40.0 2.20 2.20 2.20 26.0 2.89 2.89 2.89 26.0 at > 50 % F 3.09 3.09 3.09 23.0 at > 50 % F 3.33 3.33 3.33 26.0 at 50 % F 2.93 2.93 2.93 23.0 at 50 % F 3.18 3.18 3.18 100.0 1.50 1.50 1.50 90.0 1.53 1.54 1.54 77.6 1.60 1.60 1.60 65.0 1.76 1.76 1.76

> 50.0 --- --- ---

Startup 50.0 1.95 1.95 1.95 FHOOS 2 TBVOOS 40.0 2.21 2.21 2.21 26.0 2.90 2.90 2.90 26.0 at > 50 % F 3.59 3.59 3.59 23.0 at > 50 % F 3.90 3.90 3.90 26.0 at 50 % F 3.29 3.29 3.29 23.0 at 50 % F 3.64 3.64 3.64

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

TBVIS limits are applicable for all EOOS scenarios presented in Table 1.1 except those including TBVOOS. TBVOOS limits are applicable for all EOOS scenarios presented in Table 1.1. Startup FHOOS 2 temperatures are presented as FW Set 2 in Item 6.6.1 of Reference 24. Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-78

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-12 Table 8.6 SLO MCPRp Limits for All Scram Speeds*

BOC to Operating Power End of Condition (% of rated) COAST 100.0 2.09 43.75 2.09 40.0 2.09 RCPOOS 26.0 2.57 FHOOS 26.0 at > 50 % F 2.81 23.0 at > 50 % F 3.00 26.0 at 50 % F 2.67 23.0 at 50 % F 2.86 100.0 2.09 43.75 2.09 40.0 2.09 RCPOOS TBVOOS 26.0 2.58 PLUOOS 26.0 at > 50 % F 3.36 FHOOS 23.0 at > 50 % F 3.65 26.0 at 50 % F 3.07 23.0 at 50 % F 3.38 100.0 2.12 43.75 2.12 40.0 2.21 RCPOOS 26.0 2.89 TBVOOS FHOOS1 26.0 at > 50 % F 3.60 23.0 at > 50 % F 3.90 26.0 at 50 % F 3.30 23.0 at 50 % F 3.64 100.0 2.14 43.75 2.14 40.0 2.23 RCPOOS 26.0 2.92 TBVOOS FHOOS2 26.0 at > 50 % F 3.61 23.0 at > 50 % F 3.92 26.0 at 50 % F 3.31 23.0 at 50 % F 3.66

• Thermal limits are developed by combining the SLO pump seizure event with the corresponding TLO limit set plus 0.02, which accounts for the difference in TLO and SLO SLMCPR. RCPOOS thermal limits are only valid up to 43.75 % core power, 50 % core flow, and an active recirculation drive flow of 17.73 Mlb/hr.

Note feedwater heaters out-of-service / FFTR and single-loop operation conditions are not allowed when operating in the MELLLA+ operating domain.

N.1-79

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-13 Table 8.7 MCPRf Limits Core Flow

(% of rated) MCPRf 30.0 1.58 84.0 1.34 107.0 1.34 Table 8.8 Steady-State LHGR Limits Peak Pellet Exposure LHGR (GWd/MTU) (kW/ft) 0.0 14.1 18.9 14.1 74.4 7.4 N.1-80

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-14 Table 8.9 LHGRFACp Multipliers*

Base case operation EOOS Power (TBVIS) TBVOOS Condition (% rated) LHGRFACp LHGRFACp 100.0 1.00 0.99 26.0 0.61 0.59 Nominal operation 26.0 at > 50 % F 0.43 0.37

§ and FHOOS 23.0 at > 50 % F 0.41 0.34 26.0 at 50 % F 0.48 0.48 23.0 at 50 % F 0.46 0.43 100.0 1.00 0.99 26.0 0.51 0.50

§ 26.0 at > 50 % F 0.39 0.34 Startup FHOOS 1 23.0 at > 50 % F 0.35 0.30 26.0 at 50 % F 0.43 0.43 23.0 at 50 % F 0.40 0.38 100.0 1.00 0.99 26.0 0.50 0.49

§ 26.0 at > 50 % F 0.39 0.34 Startup FHOOS 2 23.0 at > 50 % F 0.35 0.30 26.0 at 50 % F 0.42 0.42 23.0 at 50 % F 0.40 0.38

• Limits support operation with or without EOC-RPT-OOS and any combination of 1 MSRVOOS, up to 2 TIPOOS (or the equivalent number of TIP channels), and up to 50 % of the LPRMs out-of-service.

Base case supports single-loop operation.

Limits are applicable for all the EOOS scenarios presented in Table 1.1 except those including TBVOOS.

Limits are applicable for all the EOOS scenarios presented in Table 1.1 including those with TBVOOS.

§ Nominal operation and FHOOS represents the feedwater temperatures shown in Figure 2.2 of Reference 24. Startup FHOOS 1 and Startup FHOOS 2 temperatures are presented as FW Set 1 and FW Set 2, respectively, in Item 6.6.1 of Reference 24.

N.1-81

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 8-15 Table 8.10 LHGRFACf Multipliers Core Flow

(% of rated) LHGRFACf 0.0 0.61 30.0 0.61 78.1 1.00 107.0 1.00 Table 8.11 MAPLHGR Limits Average Planar Exposure MAPLHGR (GWd/MTU) (kW/ft) 0.0 13.0 15.0 13.0 67.0 7.6 N.1-82

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 9-1

9.0 REFERENCES

1. ANP-3837P Revision 1, Browns Ferry Unit 1 Cycle 14 Fuel Cycle Design Report, Framatome Inc., April 2020.

2. FS1-0035055 Revision 1.0, Browns Ferry Disposition of Events at EPU Conditions, Framatome Inc., January 2018.

3. 12-9214860-000, Engineering Self-Assessment for ATRIUM 10XM Fuel Containing BLEU, AREVA NP, November 2013.

4. FS1-0048034 Revision 1.0, Browns Ferry Unit 1 Cycle 14 Calculation Plan, Framatome Inc., February 2020.

5. ANP-3150P Revision 4, Mechanical Design Report for Browns Ferry ATRIUM 10XM Fuel Assemblies, AREVA Inc., November 2017.

6. ANP-3796P Revision 0, ATRIUM 10XM Fuel Rod Thermal-Mechanical Evaluation for Browns Ferry Unit 1 Cycle 13 - MELLLA+, Framatome Inc., August 2019.

7. ANP-3847P Revision 0, ATRIUM 10XM Fuel Rod Thermal-Mechanical Evaluation for Browns Ferry Unit 1 Cycle 14, Framatome Inc., May 2020.

8. ANP-3159P Revision 0, ATRIUM 10XM Fuel Rod Thermal-Mechanical Evaluation for Browns Ferry Unit 2 Cycle 19 Reload BFE2-19, AREVA NP, October 2012.

9. ANP-3602P Revision 1, Browns Ferry Thermal-Hydraulic Design Report for ATRIUM 10XM Fuel Assemblies at EPU MELLLA+, Framatome Inc., June 2019.

10. ANP-10307PA Revision 0, AREVA MCPR Safety Limit Methodology for Boiling Water Reactors, AREVA NP, June 2011.

11. ANP-10298PA Revision 0, ACE/ATRIUM 10XM Critical Power Correlation, AREVA NP, March 2010.

12. ANP-3140(P) Revision 0, Browns Ferry Units 1, 2, and 3 Improved K-factor Model for ACE/ATRIUM 10XM Critical Power Correlation, AREVA NP, August 2012.

13. NEDO-33075-A Revision 8, GE Hitachi Nuclear Energy, GE Hitachi Boiling Water Reactor, Detect and Suppress Solution - Confirmation Density, November 2013.

14. NEDO-33877 Revision 0, Safety Analysis Report for Browns Ferry Nuclear Plant Units 1, 2, and 3 Maximum Extended Load Line Limit Analysis Plus, February 2018. (ADAMS Accession Number ML18079B140)

15. EMF-CC-074(P)(A) Volume 4 Revision 0, BWR Stability Analysis: Assessment of STAIF with Input from MICROBURN-B2, Siemens Power Corporation, August 2000.

N.1-83

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 9-2

16. 004N5430 Revision 2, Browns Ferry Units 1, 2 and 3 - Backup Stability Protection Region Endpoint Determination Procedure and ABSP Setpoints Confirmation, GE Hitachi Nuclear Energy, April 2018 (FS1-0038489 Revision 1.0).

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20. XN-NF-80-19(P)(A) Volume 3 Revision 2, Exxon Nuclear Methodology for Boiling Water Reactors, THERMEX: Thermal Limits Methodology Summary Description, Exxon Nuclear Company, January 1987.

21. XN-NF-84-105(P)(A) Volume 1 and Volume 1 Supplements 1 and 2, XCOBRA-T: A Computer Code for BWR Transient Thermal-Hydraulic Core Analysis, Exxon Nuclear Company, February 1987.

22. XN-NF-81-58(P)(A) Revision 2 and Supplements 1 and 2, RODEX2 Fuel Rod Thermal-Mechanical Response Evaluation Model, Exxon Nuclear Company, March 1984.

23. Technical Specification Requirements for Browns Ferry Nuclear Plant Unit 1, Tennessee Valley Authority, as amended.

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25. ANF-1358(P)(A) Revision 3, The Loss of Feedwater Heating Transient in Boiling Water Reactors, Framatome ANP, September 2005.

26. ANP-3546P Revision 0, Browns Ferry Units 1, 2, and 3 LOCA Break Spectrum Analysis for ATRIUM 10XM Fuel (EPU MELLLA+), AREVA Inc., March 2017.

27. ANP-3547P Revision 2, Browns Ferry Units 1, 2, and 3 LOCA-ECCS Analysis MAPLHGR Limits for ATRIUM 10XM Fuel (EPU MELLLA+), Framatome Inc., January 2020.

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29. XN-NF-80-19(P)(A) Volume 1 and Supplements 1 and 2, Exxon Nuclear Methodology for Boiling Water Reactors - Neutronic Methods for Design and Analysis, Exxon Nuclear Company, March 1983.

N.1-84

BFN-29 Framatome Inc. ANP-3856 Revision 0 Browns Ferry Unit 1 Cycle 14 Reload Analysis Page 9-3

30. Letter, EA Brown (NRC) to KW Singer (TVA), Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Issuance of Amendments Regarding Full-Scope Implementation of Alternative Source Term (TAC Nos. MB5733, MB5734, MB5735, MC0156, MC0157 and MC0158)

(TS-405), September 27, 2004.

31. Letter, TA Galioto (FANP) to JF Lemons (TVA), Fuel Handling Accident Assumptions for Browns Ferry, TAG:02:012, January 23, 2002.

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34. ANP-2945(P) Revision 1, Browns Ferry Nuclear Plant Units 1, 2, and 3 Spent Fuel Storage Pool Criticality Safety Analysis, AREVA NP, July 2011.

35. ANP-3160(P) Revision 1, Browns Ferry Nuclear Plant Units 1, 2, and 3 Spent Fuel Storage Pool Criticality Safety Analysis for ATRIUM' 10XM Fuel, AREVA Inc.,

December 2015.

36. BAW-10247PA Revision 0, Realistic Thermal-Mechanical Fuel Rod Methodology for Boiling Water Reactors, AREVA NP, February 2008.

N.1-85