ML25079A245
| ML25079A245 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 03/20/2025 |
| From: | Komm D Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| Download: ML25079A245 (1) | |
Text
Post Office Box 2000, Decatur, Alabama 35609-2000 March 20, 2025 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 2 Facility Operating License No. DPR-54 NRC Docket No. 50-260
Subject:
Browns Ferry Nuclear Plant, Unit 2 Core Operating Limits Report for Cycle 24 Operation, Revision 0 In accordance with the requirements of Technical Specification (TS) 5.6.5.d, the Tennessee Valley Authority is submitting the Browns Ferry Nuclear Plant (BFN), Unit 2, Cycle 24, Core Operating Limits Report (COLR). Revision 0 of the Unit 2 COLR includes all Modes of operation (Modes 1 through 5).
There are no new regulatory commitments in this letter. If you have any questions, please contact D. J. Renn, Nuclear Site Compliance Manager, at (256) 729-2636.
Respectfully, Daniel A. Komm Site Vice President
Enclosure:
Core Operating Limits Report, (120% OLTP, MELLLA+), for Cycle 24 Operation, TVA-COLR-BF2C24, Revision 0 cc: (w/ Enclosure)
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Project Manager - Browns Ferry Nuclear Plant
Enclosure Tennessee Valley Authority Browns Ferry Nuclear Plant Unit 2 Core Operating Limits Report, (120% OLTP, MELLLA+), for Unit 2 Cycle 24 Operation, TVA-COLR-BF2C24, Revision 0 (See Attached)
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page ii Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 Table of Contents Total Number of Pages = 52 (including review cover sheet)
List of Tables.................................................................................................................................iii List of Figures.............................................................................................................................. iv Revision Log.................................................................................................................................v Nomenclature............................................................................................................................... vi References..................................................................................................................................viii 1
Introduction..........................................................................................................................1 1.1 Purpose.........................................................................................................................1 1.2 Scope............................................................................................................................1 1.3 Fuel Loading..................................................................................................................2 1.4 Acceptability..................................................................................................................2 2
MCPR99.9% Safety Limit........................................................................................................3 3
APLHGR..............................................................................................................................4 3.1 Rated Power and Flow Limit: APLHGRRATED.................................................................4 3.2 Off-Rated Power Dependent Limit: APLHGRP..............................................................4 3.2.1 Startup without Feedwater Heaters.......................................................................4 3.3 Off-Rated Flow Dependent Limit: APLHGRF.................................................................4 3.4 Single Loop Operation Limit: APLHGRSLO.....................................................................4 3.5 Equipment Out-Of-Service Corrections.........................................................................6 4
LHGR Limits.........................................................................................................................7 4.1 Rated Power and Flow Limit: LHGRRATED......................................................................7 4.2 Off-Rated Power Dependent Limit: LHGRP...................................................................7 4.2.1 Startup without Feedwater Heaters.......................................................................7 4.3 Off-Rated Flow Dependent Limit: LHGRF......................................................................8 4.4 Equipment Out-Of-Service Corrections.........................................................................8 5
OLMCPR Limits.................................................................................................................12 5.1 Flow Dependent MCPR Limit: MCPRF.......................................................................12 5.2 Power Dependent MCPR Limit: MCPRP....................................................................12 5.2.1 Startup without Feedwater Heaters.....................................................................12 5.2.2 Scram Speed Dependent Limits (TSSS vs. NSS vs. OSS).................................13 5.2.3 Exposure Dependent Limits................................................................................13 5.2.4 Equipment Out-Of-Service (EOOS) Options.......................................................14 5.2.5 Single-Loop-Operation (SLO) Limits...................................................................14 5.2.6 Flow Flags...........................................................................................................14 6
Thermal-Hydraulic Stability Protection...............................................................................35 7
APRM Flow Biased Rod Block Trip Settings......................................................................37 8
Rod Block Monitor (RBM) Trip Setpoints and Operability..................................................38 9
Shutdown Margin Limit.......................................................................................................40 Appendix A:
MBSP Maps...................................................................................................... A-1
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page iii Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 List of Tables Nuclear Fuel Types
.................................................................................................................2 MCPR99.9%.....................................................................................................................................3 APLHGRRATED for ATRIUM 10XM and ATRIUM 11 Fuel..............................................................5 Startup Feedwater Temperature Basis.........................................................................................7 LHGRRATED for ATRIUM 10XM and ATRIUM 11 Fuel...................................................................9 LHGRFACP for ATRIUM 10XM and ATRIUM 11 Fuel...............................................................10 LHGRFACF for ATRIUM 10XM and ATRIUM 11 Fuel................................................................11 Nominal Scram Time Basis.........................................................................................................13 MCPRF for ATRIUM 10XM and ATRIUM 11 Fuel.......................................................................15 TLO MCPRP Limits for OSS, BOC to NEOC...............................................................................16 TLO MCPRP Limits for NSS, BOC to NEOC...............................................................................17 TLO MCPRP Limits for TSSS, BOC to NEOC.............................................................................20 TLO MCPRP Limits for OSS, NEOC to EOCLB..........................................................................23 TLO MCPRP Limits for NSS, NEOC to EOCLB..........................................................................24 TLO MCPRP Limits for TSSS, NEOC to EOCLB........................................................................27 TLO MCPRP Limits for OSS, EOCLB to End of Coast..............................................................30 TLO MCPRP Limits for NSS, EOCLB to End of Coast...............................................................31 TLO MCPRP Limits for TSSS, EOCLB to End of Coast.............................................................33 ABSP Setpoints for the Scram Region.......................................................................................35 Analyzed MBSP Endpoints: Nominal Feedwater Temperature..................................................36 Analyzed MBSP Endpoints: Reduced Feedwater Temperature.................................................36 Analytical RBM Trip Setpoints
...............................................................................................38 RBM Setpoint Applicability..........................................................................................................38 Control Rod Withdrawal Error Results........................................................................................39
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page iv Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 List of Figures MBSP Boundaries for Nominal Feedwater Temperature.......................................................... A-1 MBSP Boundaries for Reduced Feedwater Temperature........................................................ A-2
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page v Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 Revision Log Number Page Description 0
All New document.
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page vi Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 Nomenclature ABSP Automatic Backup Stability Protection APLHGR Average Planar Linear Heat Generation Rate APRM Average Power Range Monitor BOC Beginning of Cycle BSP Backup Stability Protection BWR Boiling Water Reactor CAVEX Core Average Exposure CMSS Core Monitoring System Software COLR Core Operating Limits Report CPR Critical Power Ratio CRWE Control Rod Withdrawal Error CSDM Cold Shutdown Margin DSS-CD Detect and Suppress Solution - Confirmation Density EOC End of Cycle EOCLB End of Cycle Licensing Basis EOOS Equipment Out-of-Service EPU Extended Power Uprate (120% Original Licensed Thermal Power)
FFWTR Final Feedwater Temperature Reduction FHOOS Feedwater Heaters Out-Of-Service Framatome Vendor (AREVA, Siemens)
GNF Vendor (General Electric, Global Nuclear Fuels)
GWd Giga Watt Day HTSP High Trip Setpoint ICA Interim Corrective Action ICF Increased Core Flow (beyond rated)
IS In-Service LCO License Condition of Operation LHGR Linear Heat Generation Rate LHGRFAC LHGR Multiplier (Power or Flow dependent)
LPRM Local Power Range Monitor MAPFAC Maximum Planar Linear Heat Generation Rate multiplier MAPLHGR Maximum Planar Linear Heat Generation Rate MBSP Manual Backup Stability Protection MCPR Minimum Critical Power Ratio MELLLA Maximum Extended Load Line Limit Analysis MELLLA+
Maximum Extended Load Line Limit Analysis Plus MTU Metric Ton Uranium MWd/MTU Mega Watt Day per Metric Ton Uranium
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page vii Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 NEOC Near End of Cycle NFT Nuclear Fuel Type NRC United States Nuclear Regulatory Commission NSS Nominal Scram Speed NTSP Nominal Trip Setpoint OLMCPR Operating Limit, Minimum Critical Power Ratio OLTP Original Licensed Thermal Power OOS Out-Of-Service OPRM Oscillation Power Range Monitor OSS Optimum Scram Speed PBDA Period Based Detection Algorithm Pbypass Power below which TSV Position and TCV Fast Closure Scrams are Bypassed PLU Power Load Unbalance PLUOOS PLU Out-of-Service PRNM Power Range Neutron Monitor RBM Rod Block Monitor RCPOOS Recirculation Pump Out-Of-Service (SLO)
RDF Rated Drive Flow RPS Reactor Protection System RPT Recirculation Pump Trip RPTOOS Recirculation Pump Trip Out-Of-Service RTP Rated Thermal Power SDM Shutdown Margin SLMCPR MCPR Safety Limit SLO Single Loop Operation (RCPOOS)
SRVOOS Safety Relief Valve Out-Of-Service STP Average Power Range Monitor Simulated Thermal Power TBV Turbine Bypass Valve TBVIS Turbine Bypass Valve In-Service TBVOOS Turbine Bypass Valves Out-of-Service TCV Turbine Control Valve TIP Traversing In-core Probe TIPOOS Traversing In-core Probe Out-of-Service TLO Two Loop Operation TSP Trip Setpoint TSSS Technical Specification Scram Speed TSV Turbine Stop Valve TVA Tennessee Valley Authority
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page viii Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 References 1.
ANP-4128, Revision 1, Browns Ferry Unit 2 Cycle 24 Reload Analysis, Framatome Inc., December 2024. [L32 250106 800]
2.
ANP-3860P, Revision 3, Mechanical Design Report for Browns Ferry ATRIUM 11 Fuel Assemblies, Framatome Inc., December 2024. [L86 250106 001]
3.
ANP-3150P, Revision 4, Mechanical Design Report for Browns Ferry ATRIUM 10XM Fuel Assemblies, AREVA Inc., November 2017. [L86 190311 001]
4.
ANP-4111P, Revision 0, Browns Ferry Unit 2 Cycle 24 Plant Parameters Document, Framatome Inc., June 2024. [L32 241015 800]
- 5.
BFE-4897, Revision 0, Browns Ferry Unit 2 Cycle 24 In-Core Shuffle, Tennessee Valley Authority, December 2024. [L32 241119 800]
Methodology References
- 6.
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.
- 7.
XN-NF-85-67(P)(A) Revision 1, Generic Mechanical Design for Exxon Nuclear Jet Pump BWR Reload Fuel, Exxon Nuclear Company, September 1986.
8.
EMF-85-74(P) Revision 0 Supplement 1(P)(A) and Supplement 2(P)(A), RODEX2A (BWR) Fuel Rod Thermal-Mechanical Evaluation Model, Siemens Power Corporation, February 1998.
9.
ANF-89-98(P)(A) Revision 1 and Supplement 1, Generic Mechanical Design Criteria for BWR Fuel Designs, Advanced Nuclear Fuels Corporation, May 1995.
- 10.
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.
- 11.
XN-NF-80-19(P)(A) Volume 4 Revision 1, Exxon Nuclear Methodology for Boiling Water Reactors: Application of the ENC Methodology to BWR Reloads, Exxon Nuclear Company, June 1986.
12.
EMF-2158(P)(A) Revision 0, Siemens Power Corporation Methodology for Boiling Water Reactors: Evaluation and Validation of CASMO-4/MICROBURN-B2, Siemens Power Corporation, October 1999.
- 13.
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.
14.
ANP-10307PA, Revision 0, AREVA MCPR Safety Limit Methodology for Boiling Water Reactors, AREVA NP Inc., June 2011.
15.
EMF-2361(P)(A) Revision 0, EXEM BWR-2000 ECCS Evaluation Model, Framatome ANP Inc., May 2001, as supplemented by the site specific approval in NRC safety evaluation dated February 15, 2013, and July 31, 2014.
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page ix Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 16.
EMF-2292(P)(A) Revision 0, ATRIUM'-10: Appendix K Spray Heat Transfer Coefficients, Siemens Power Corporation, September 2000.
17.
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.
- 18.
BAW-10247PA, Revision 0, Realistic Thermal-Mechanical Fuel Rod Methodology for Boiling Water Reactors, AREVA NP, February 2008.
19.
ANP-10298P-A, Revision 1, ACE/ATRIUM 10XM Critical Power Correlation, AREVA Inc., March 2014.
20.
NEDC-33075P-A, Revision 8, GE Hitachi Boiling Water Reactor Detect and Suppress Solution - Confirmation Density, GE Hitachi, November 2013.
- 21.
BAW-10247P-A Supplement 2P-A Revision 0, Realistic Thermal-Mechanical Fuel Rod Methodology for Boiling Water Reactors Supplement 2: Mechanical Methods, Framatome Inc., August 2018.
22.
ANP-10300P-A Revision 1, AURORA-B: An Evaluation Model for Boiling Water Reactors; Application to Transient and Accident Scenarios, Framatome Inc.,
January 2018.
23.
ANP-10332P-A Revision 0, AURORA-B: An Evaluation Model for Boiling Water Reactors; Application to Loss of Coolant Accident Scenarios, Framatome Inc.,
March 2019.
24.
ANP-10333P-A Revision 0, AURORA-B: An Evaluation Model for Boiling Water Reactors; Application to Control Rod Drop Accident (CRDA), Framatome Inc.,
March 2018 (as supplemented by Section 6.4 of ANP-3908P Revision 4, Applicability of Framatome BWR Methods to Browns Ferry with ATRIUM 11 Fuel, Framatome Inc., June 2022) 25.
ANP-10335P-A Revision 0, ACE/ATRIUM 11 Critical Power Correlation, Framatome Inc., May 2018.
26.
ANP-10340P-A Revision 0, Incorporation of Chromia Doped Fuel Properties in AREVA Approved Methods, Framatome Inc., May 2018.
27.
ANP-3907P Revision 0, Application of BEO-III Methodology with the Confirmation Density Algorithm at Browns Ferry, Framatome Inc., April 2021.
Setpoint References 28.
EDQ2092900118, R41, Setpoint and Scaling Calculations for Neutron Monitoring System & Recirculation Flow Loops, Calculation File, Tennessee Valley Authority, October 2024.
29.
Task T0500, Revision 0, Neutron Monitoring System w/RBM, Project Task Report, GE Hitachi Nuclear Energy, June 2017.
30.
Task T0506, Revision 0, TS Instrument Setpoints, Project Task Report, Tennessee Valley Authority, August 2017.
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page x Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 31.
NEDC-33006P-A, Revision 3, General Electric Boiling Water Reactor Maximum Extended Load Line Limit Analysis Plus, GE Energy Nuclear, June 2009.
32.
NEDC-33075P-A, Revision 8, GE Hitachi Boiling Water Reactor Detect and Suppress Solution - Confirmation Density, GE Hitachi, November 2013.
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 1 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 1
Introduction In anticipation of cycle startup, it is necessary to describe the expected limits of operation.
1.1 Purpose The primary purpose of this document is to satisfy requirements identified by unit technical specification section 5.6.5. This document may be provided, upon final approval, to the NRC.
1.2 Scope This document will discuss the following areas:
3/4 Minimum Critical Power Ratio Safety Limit (MCPR99.9%)
(Technical Specifications 2.1.1.2, 3.2.2, and 5.6.5.a(3))
Applicability: Mode 1, 23% RTP (Technical Specifications definition of RTP) 3/4 Average Planar Linear Heat Generation Rate (APLHGR) Limit (Technical Specifications 3.2.1 and 3.7.5)
Applicability: Mode 1, 23% RTP (Technical Specifications definition of RTP) 3/4 Linear Heat Generation Rate (LHGR) Limit (Technical Specification 3.2.3, 3.3.4.1, and 3.7.5)
Applicability: Mode 1, 23% RTP (Technical Specifications definition of RTP) 3/4 Minimum Critical Power Ratio Operating Limit (OLMCPR)
(Technical Specifications 3.2.2, 3.3.4.1, 3.7.5 and Table 3.3.2.1-1)
Applicability: Mode 1, 23% RTP (Technical Specifications definition of RTP) 3/4 Thermal-Hydraulic Stability Protection (Technical Specification Table 3.3.1.1)
Applicability: Mode 1, (as specified in Technical Specifications Table 3.3.1.1-1) 3/4 Average Power Range Monitor (APRM) Flow Biased Rod Block Trip Setting (Technical Requirements Manual Section 5.3.1 and Table 3.3.4-1)
Applicability: Mode 1, (as specified in Technical Requirements Manuals Table 3.3.4-1) 3/4 Rod Block Monitor (RBM) Trip Setpoints and Operability (Technical Specification Table 3.3.2.1-1)
Applicability: Mode 1, % RTP as specified in Table 3.3.2.1-1 (TS definition of RTP) 3/4 Shutdown Margin (SDM) Limit (Technical Specification 3.1.1)
Applicability: All Modes
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 2 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 1.3 Fuel Loading The core will contain fresh ATRIUM 11 and exposed ATRIUM 10XM and ATRIUM 11. Nuclear fuel types used in the core loading are shown in Table 1.1. The core shuffle and final loading were explicitly evaluated for BOC cold shutdown margin performance as documented per Reference 5.
Table 1.1 Nuclear Fuel Types
- Fuel Description Original Cycle Number of Assemblies Nuclear Fuel Type Fuel Names (Range)
ATRIUM 10XM XMLC-4058B-15GV80-FBJ 22 28 24 FBJ331-FBJ546 ATRIUM 10XM XMLC-4015B-15GV80-FBJ 22 68 25 FBJ547-FBJ638 ATRIUM 11 AT11-3974B-14GV100-FBK 23 84 26 FBK649-FBK732 ATRIUM 11 AT11-3971B-14GV100-FBK 23 160 27 FBK733-FBK892 ATRIUM 11 AT11-4175B-13GV80-FBK 23 88 28 FBK893-FBK980 ATRIUM 11 AT11-3998B-14GV100-FBL 24 160 29 FBL001-FBL160 ATRIUM 11 AT11-3998B-14GV100a-FBL 24 104 30 FBL161-FBL264 ATRIUM 11 AT11-4180B-11GV90-FBL 24 72 31 FBL265-FBL336 1.4 Acceptability Limits discussed in this document were generated based on NRC approved methodologies per References 6 through 27.
- The table identifies the expected fuel type breakdown in anticipation of final core loading. The final composition of the core depends upon uncertainties during the outage such as discovering a failed fuel bundle, or other bundle damage. Minor core loading changes, due to unforeseen events, will conform to the safety and monitoring requirements identified in this document.
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 3 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 2 MCPR99.9% Safety Limit (Technical Specifications 2.1.1.2, and 3.2.2)
SLMCPR of Technical Specification 2.1.1.2 has been changed by approval of Traveler TSTF-564, Revision 2. Now, the SLMCPR of Technical Specification 2.1.1.2 represents the MCPR95/95, relative to the critical power correlations being used. Values in TS 2.1.1.2 would only potentially change if there is a change to critical power correlation being used or system measurement uncertainty.
Values provided in Table 2.1, per Reference 1, represent the integral MCPR99.9% considering all forms of uncertainties, and cycle specific fuel designs, core loading, and projected cycle operation.
Table 2.1 MCPR99.9%
SLMCPR BOC to NEOC NEOC to EOCLB EOCLB to End of Coast TLO 1.08 1.08 1.08 SLO 1.09 1.09 1.09
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 4 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 3 APLHGR (Technical Specifications 3.2.1 & 3.7.5)
The APLHGR limit is determined by adjusting the rated power APLHGR limit for off-rated power, off-rated flow, and SLO conditions. The most limiting of these is then used as follows:
APLHGR limit = MIN ( APLHGRP, APLHGRF, APLHGRSLO )
where:
APLHGRP off-rated power APLHGR limit
[APLHGRRATED
- MAPFACP]
APLHGRF off-rated flow APLHGR limit
[APLHGRRATED
- MAPFACF]
[APLHGRRATED
- SLO Multiplier]
3.1 Rated Power and Flow Limit: APLHGRRATED The rated conditions APLHGR for all fuel are identified per Reference 1. The rated conditions APLHGR for ATRIUM 10XM and ATRIUM 11 fuel are shown in Table 3.1.
3.2 Off-Rated Power Dependent Limit: APLHGRP Reference 1 does not specify a power dependent APLHGR. Therefore, MAPFACP is set to a value of 1.0.
3.2.1 Startup without Feedwater Heaters There is a range of operation during startup when the feedwater heaters are not placed into service until after the unit has reached a significant operating power level. No additional power dependent limitation is required.
3.3 Off-Rated Flow Dependent Limit: APLHGRF Reference 1 does not specify a flow dependent APLHGR. Therefore, MAPFACF is set to a value of 1.0.
3.4 Single Loop Operation Limit: APLHGRSLO The single loop operation multiplier for ATRIUM 10XM and ATRIUM 11 fuel is 0.85, per Reference 1.
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 5 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 Table 3.1 APLHGRRATED for ATRIUM 10XM and ATRIUM 11 Fuel
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 6 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 3.5 Equipment Out-Of-Service Corrections The limits shown in Table 3.1 are applicable for operation with all equipment In-Service as well as the following Equipment Out-Of-Service (EOOS) options; including combinations of the options. Base case and each EOOS condition are supported with 1 SRVOOS, up to 18 TIP channels out-of-service, and up to 50% of the LPRMs out-of-service. Base case, FHOOS, PLUOOS, combined FHOOS and PLUOOS, and RCPOOS analyses support 1 TBVOOS. For RCPOOS, use the APLHGRSLO multiplier in Section 3.4.
In-Service All Equipment In-Service RPTOOS EOC-Recirculation Pump Trip Out-Of-Service TBVOOS Turbine Bypass Valve(s) Out-Of-Service PLUOOS Power Load Unbalance Out-Of-Service FHOOS (or FFWTR)
Feedwater Heaters Out-Of-Service or Final Feedwater Temperature Reduction RCPOOS One Recirculation Pump Out-Of-Service
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 7 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 4 LHGR Limits (Technical Specification 3.2.3, 3.3.4.1, & 3.7.5)
The LHGR limit is determined by adjusting the rated power LHGR limit for off-rated power and off-rated flow conditions. The most limiting of these is then used as follows:
LHGR limit = MIN ( LHGRP, LHGRF )
where:
LHGRP off-rated power LHGR limit
[LHGRRATED
- LHGRFACP]
LHGRF off-rated flow LHGR limit
[LHGRRATED
- LHGRFACF]
4.1 Rated Power and Flow Limit: LHGRRATED The rated conditions LHGR for all fuel are identified per Reference 1. The rated conditions LHGR for ATRIUM 10XM and ATRIUM 11 are shown in Table 4.2. The LHGR limits are consistent with References 2 & 3.
4.2 Off-Rated Power Dependent Limit: LHGRP LHGR limits are adjusted for off-rated power conditions using the LHGRFACP multiplier provided in Reference 1. The multiplier is split into two sub cases: TBVIS and TBVOOS. The TBVIS case assumes 1 TBVOOS. The base case multipliers are shown in Table 4.3.
4.2.1 Startup without Feedwater Heaters There is a range of operation during startup when the feedwater heaters are not placed into service until after the unit has reached a significant operating power level. Additional limits are shown in Table 4.3, based on temperature conditions identified in Table 4.1. The reduced feedwater temperatures are not applicable above 50 % of rated power.
Table 4.1 Startup Feedwater Temperature Basis Power Temperature
(% Rated)
(°F) 23 150.0 30 157.0 40 167.0 50 177.0
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 8 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 4.3 Off-Rated Flow Dependent Limit: LHGRF LHGR limits are adjusted for off-rated flow conditions using the LHGRFACF multiplier provided in Reference 1. Multipliers are shown in Table 4.4.
4.4 Equipment Out-Of-Service Corrections The limits shown in Table 4.2 are applicable for operation with all equipment In-Service as well as the following Equipment Out-Of-Service (EOOS) options; including combinations of the options. Base case and each EOOS condition are supported with 1 SRVOOS, up to 18 TIP channels out-of-service, and up to 50% of the LPRMs out-of-service. Base case, FHOOS, PLUOOS, combined FHOOS and PLUOOS, and RCPOOS analyses support 1 TBVOOS.
In-Service All equipment In-Service RPTOOS EOC-Recirculation Pump Trip Out-Of-Service TBVOOS Turbine Bypass Valve(s) Out-Of-Service PLUOOS Power Load Unbalance Out-Of-Service FHOOS (or FFWTR)
Feedwater Heaters Out-Of-Service or Final Feedwater Temperature Reduction RCPOOS One Recirculation Pump Out-Of-Service Off-rated power corrections shown in Table 4.3 are dependent on operation of the Turbine Bypass Valve system. For this reason, separate limits are to be applied for TBVIS or TBVOOS operation. The TBVIS case assumes 1 TBVOOS. The limits have no dependency on RPTOOS, PLUOOS, FHOOS/FFWTR, or SLO.
Off-rated flow corrections shown in Table 4.4 are bounding for all EOOS conditions.
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 9 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 Table 4.2 LHGRRATED for ATRIUM 10XM and ATRIUM 11 Fuel
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 10 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 Table 4.3 LHGRFACP for ATRIUM 10XM and ATRIUM 11 Fuel*
TBVIS limits assume 1 TBVOOS and are applicable for all EOOS scenarios presented in Section 4.4 except those that include TBVOOS.
TBVOOS limits are applicable for all EOOS scenarios presented in Section 4.4. Startup FHOOS temperatures are presented in Table 4.1.
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page 11 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 Table 4.4 LHGRFACF for ATRIUM 10XM and ATRIUM 11 Fuel
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TVA-COLR-BF2C24, Revision 0 5 OLMCPR Limits (Technical Specification 3.2.2, 3.3.4.1, & 3.7.5)
OLMCPR is calculated to be the most limiting of the flow or power dependent values OLMCPR limit = MAX ( MCPRF, MCPRP )
where:
MCPRF core flow-dependent MCPR limit MCPRP power-(and flow flag) dependent MCPR limit 5.1 Flow Dependent MCPR Limit: MCPRF MCPRF limits are dependent upon core flow (% of Rated), and the max core flow limit, (Rated or Increased Core Flow, ICF). MCPRF limits are shown in Table 5.2, per Reference 1. Limits are valid for all EOOS combinations. No adjustment is required for SLO conditions.
5.2 Power Dependent MCPR Limit: MCPRP MCPRP limits are dependent upon:
Core Power (% of Rated) for a specified flow flag bin.
Technical Specification Scram Speed (TSSS), Nominal Scram Speed (NSS), or Optimum Scram Speed (OSS)
Cycle Operating Exposure (NEOC, EOCLB, and End of Coast)
Equipment Out-Of-Service Options
Two or Single Recirculation Loop Operation (TLO vs. SLO)
The TLO MCPRP limits are provided in Table 5.3 through Table 5.11, where each table contains a specified scram speed and exposure range. The CMSS determines MCPRP limits, from these tables, based on linear interpolation between the specified powers.
5.2.1 Startup without Feedwater Heaters There is a range of operation during startup when the feedwater heaters are not placed into service until after the unit has reached a significant operating power level. Table 5.3 through Table 5.11 also contain TLO MCPRP limits based on temperature conditions identified in Table 4.1. The reduced feedwater temperatures are not applicable above 50 % of rated power.
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TVA-COLR-BF2C24, Revision 0 5.2.2 Scram Speed Dependent Limits (TSSS vs. NSS vs. OSS)
MCPRP limits are provided for three different sets of assumed scram speeds. The Technical Specification Scram Speed (TSSS) MCPRP limits are applicable at all times, as long as the scram time surveillance demonstrates the times in Technical Specification Table 3.1.4-1 are met. Both Nominal Scram Speeds (NSS) and/or Optimum Scram Speeds (OSS) may be used, as long as the scram time surveillance demonstrates Table 5.1 times are applicable.
(seconds)
(seconds) 46 0.380 0.350 36 0.960 0.930 26 1.590 1.560 6
2.900 2.800 In demonstrating compliance with the NSS and/or OSS scram time basis, surveillance requirements from Technical Specification 3.1.4 apply; accepting the definition of SLOW rods should conform to scram speeds shown in Table 5.1. If conformance is not demonstrated, TSSS based MCPRP limits are applied.
On initial cycle startup, TSSS limits are used until the successful completion of scram timing confirms NSS and/or OSS based limits are applicable.
5.2.3 Exposure Dependent Limits Exposures are tracked on a Core Average Exposure basis (CAVEX, not Cycle Exposure).
Higher exposure MCPRP limits are NOT always more limiting. Per Reference 1, MCPRP limits are provided for the following exposure ranges:
BOC to NEOC NEOC corresponds to 30,599.7 MWd / MTU NEOC to EOCLB EOCLB corresponds to 34,001.2 MWd / MTU EOCLB to End of Coast End of Coast 35,698.7 MWd / MTU The EOCLB exposure point is not the true end of cycle exposure. Instead, it corresponds to a licensing exposure window exceeding expected end-of-full-power-life.
- Reference 1 analysis results are based on information identified in Reference 4.
Drop out times consistent with method used to perform actual timing measurements (i.e., including pickup/dropout effects).
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TVA-COLR-BF2C24, Revision 0 The End of Coast exposure point represents a licensing exposure point exceeding the expected end of cycle exposure including cycle extension options.
5.2.4 Equipment Out-Of-Service (EOOS) Options Base case and each EOOS condition are supported with 1 SRVOOS, up to 18 TIP channels out-of-service, and up to 50% of the LPRMs out-of-service. Base case, FHOOS, PLUOOS, combined FHOOS and PLUOOS, and RCPOOS analyses support 1 TBVOOS. EOOS options covered by MCPRP limits are given by the following:
In-Service All equipment In-Service RPTOOS EOC-Recirculation Pump Trip Out-Of-Service TBVOOS Turbine Bypass Valve(s) Out-Of-Service RPTOOS+TBVOOS Combined RPTOOS and TBVOOS PLUOOS Power Load Unbalance Out-Of-Service PLUOOS+RPTOOS Combined PLUOOS and RPTOOS PLUOOS+TBVOOS Combined PLUOOS and TBVOOS PLUOOS+TBVOOS+RPTOOS Combined PLUOOS, RPTOOS, and TBVOOS FHOOS (or FFWTR)
Feedwater Heaters Out-Of-Service (or Final Feedwater Temperature Reduction)
RCPOOS One Recirculation Pump Out-Of-Service For exposure ranges up to NEOC and EOCLB, additional combinations of MCPRP limits are also provided including FHOOS. The End of Coast exposure range assumes application of FFWTR. FHOOS based MCPRP limits for the End of Coast exposure are redundant because the temperature set down assumption is identical with FFWTR.
5.2.5 Single-Loop-Operation (SLO) Limits When operating with one recirculation pump out-of-service (RCPOOS/SLO), MCPRp limits are constructed differently from the normal operating RCP conditions. The limiting event for RCPOOS is a pump seizure scenario, which sets the upper bound for allowed core power and flow. This event is not impacted by scram time assumptions. Specific SLO MCPRP limits are obtained by the addition of a 0.01 adder to the corresponding TLO MCPRP limit. RCPOOS limits are only valid up to 43.75% rated core power, 50% rated core flow, and an active recirculation drive flow of 17.73 Mlbm/hr.
5.2.6 Flow Flags A flow flag is a point on the core flow axis of the power/flow map defining core flow bins where limits are applicable. For the cycle, a 90% core flow flag is employed. Hence, there are 2 core flow bins generated. While not every flow flag bin pair has a benefit, there are two MCPRP values for each exposure bin, and each power level. It should be noted that values for a bin pair may be equal. Below Pbypass (26% rated power), a flow flag of 50% is utilized.
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TVA-COLR-BF2C24, Revision 0 Table 5.2 MCPRF for ATRIUM 10XM and ATRIUM 11 Fuel
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TVA-COLR-BF2C24, Revision 0 Table 5.3 TLO MCPRP Limits for OSS, BOC to NEOC FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.4 TLO MCPRP Limits for NSS, BOC to NEOC FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.4 TLO MCPRP Limits for NSS, BOC to NEOC (Continued)
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.4 TLO MCPRP Limits for NSS, BOC to NEOC (Continued)
TBVIS limits assume 1 TBVOOS and are applicable for all EOOS scenarios presented in Section 5.2.4 except those that include TBVOOS.
TBVOOS limits are applicable for all EOOS scenarios presented in Section 5.2.4. Startup FHOOS temperatures are presented in Table 4.1.
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.5 TLO MCPRP Limits for TSSS, BOC to NEOC FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.5 TLO MCPRP Limits for TSSS, BOC to NEOC (Continued)
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.5 TLO MCPRP Limits for TSSS, BOC to NEOC (Continued)
TBVIS limits assume 1 TBVOOS and are applicable for all EOOS scenarios presented in Section 5.2.4 except those that include TBVOOS.
TBVOOS limits are applicable for all EOOS scenarios presented in Section 5.2.4. Startup FHOOS temperatures are presented in Table 4.1.
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.6 TLO MCPRP Limits for OSS, NEOC to EOCLB FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.7 TLO MCPRP Limits for NSS, NEOC to EOCLB FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.7 TLO MCPRP Limits for NSS, NEOC to EOCLB (Continued)
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.7 TLO MCPRP Limits for NSS, NEOC to EOCLB (Continued)
TBVIS limits assume 1 TBVOOS and are applicable for all EOOS scenarios presented in Section 5.2.4 except those that include TBVOOS.
TBVOOS limits are applicable for all EOOS scenarios presented in Section 5.2.4. Startup FHOOS temperatures are presented in Table 4.1.
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.8 TLO MCPRP Limits for TSSS, NEOC to EOCLB FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.8 TLO MCPRP Limits for TSSS, NEOC to EOCLB (Continued)
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.8 TLO MCPRP Limits for TSSS, NEOC to EOCLB (Continued)
TBVIS limits assume 1 TBVOOS and are applicable for all EOOS scenarios presented in Section 5.2.4 except those that include TBVOOS.
TBVOOS limits are applicable for all EOOS scenarios presented in Section 5.2.4. Startup FHOOS temperatures are presented in Table 4.1.
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.9 TLO MCPRP Limits for OSS, EOCLB to End of Coast*
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.10 TLO MCPRP Limits for NSS, EOCLB to End of Coast*
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.10 TLO MCPRP Limits for NSS, EOCLB to End of Coast (Continued)
TBVIS limits assume 1 TBVOOS and are applicable for all EOOS scenarios presented in Section 5.2.4 except those that include TBVOOS.
TBVOOS limits are applicable for all EOOS scenarios presented in Section 5.2.4. Startup FHOOS temperatures are presented in Table 4.1.
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.11 TLO MCPRP Limits for TSSS, EOCLB to End of Coast*
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 Table 5.11 TLO MCPRP Limits for TSSS, EOCLB to End of Coast (Continued)
TBVIS limits assume 1 TBVOOS and are applicable for all EOOS scenarios presented in Section 5.2.4 except those that include TBVOOS.
TBVOOS limits are applicable for all EOOS scenarios presented in Section 5.2.4. Startup FHOOS temperatures are presented in Table 4.1.
FHOOS / FFWTR and SLO conditions are not allowed when operating in the MELLLA+ operating domain.
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TVA-COLR-BF2C24, Revision 0 6
Thermal-Hydraulic Stability Protection (Technical Specification 3.3.1.1)
Technical Specification Table 3.3.1.1-1, Function 2f, identifies the function.
Instrument setpoints are established, such that the reactor will be tripped before an oscillation can grow to the point where the SLMCPR is exceeded. With application of Reference 31, the DSS-CD stability solution as originally per Reference 20 is now used in a hybrid manner, per Reference 27. The DSS-CD SAD setpoint is 1.10 for TLO and SLO.
New analyses have been developed based on Reference 27. With the implementation of the MELLLA+ operating domain expansion, an ABSP trip is required when the OPRM is out-of-service. The ABSP trip settings define a region of the power to flow map within which an automatic reactor scram occurs. The ABSP trip settings are provided in Table 6.1. If both the OPRM and ABSP are out-of-service, operation within the MELLLA+ domain is not allowed and the MBSP Regions provide stability protection. Table 6.2 and Table 6.3 provide the endpoints for the MBSP regions for nominal and reduced feedwater temperature conditions. These endpoints are connected using the generic shape function of Reference 20 and have been graphed in Appendix A.
Table 6.1 ABSP Setpoints for the Scram Region Parameter Symbol Setting Value (unit)
Comments Slope for Trip mTRIP 2.00 (% RTP/% RDF)
Slope of ABSP APRM Flow-Biased Trip Linear Segment Constant Power Line for Trip PBSP-TRIP 35.0 (% RTP)
ABSP APRM Flow-Biased Trip Setpoint Power Intercept. Constant Power Line for Trip from Zero Drive Flow to Flow Breakpoint Value Constant Flow Line for Trip WBSP-TRIP 49 (% RDF)
ABSP APRM Flow-Biased Trip Setpoint Drive Flow Intercept.
Constant Flow Line for Trip (see Note 1 below)
Flow Breakpoint WBSP-BREAK 30.0 (% RDF)
Flow Breakpoint Value 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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TVA-COLR-BF2C24, Revision 0 Table 6.2 Analyzed MBSP Endpoints: Nominal Feedwater Temperature Endpoint Power
(% Rated)
Core Flow
(% Rated)
Definition A1 75.9 52.7 Scram Region (Region I)
Boundary Intercept on MELLLA+ Line B1 35.5 29.0 Scram Region (Region I)
Boundary Intercept on Natural Circulation Line (NCL)
A2 66.1 52.0 Controlled Entry Region (Region II) Boundary Intercept on MELLLA Line B2 25.5 29.0 Controlled Entry Region (Region II) Boundary Intercept on Natural Circulation Line (NCL)
Table 6.3 Analyzed MBSP Endpoints: Reduced Feedwater Temperature Endpoint Power
(% Rated)
Core Flow
(% Rated)
Definition A1 64.9 50.5 Scram Region (Region I)
Boundary Intercept on MELLLA Line B1 29.4 29.0 Scram Region (Region I)
Boundary Intercept on Natural Circulation Line (NCL)
A2 68.3 54.9 Controlled Entry Region (Region II) Boundary Intercept on MELLLA Line B2 24.5 29.0 Controlled Entry Region (Region II) Boundary Intercept on Natural Circulation Line (NCL)
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TVA-COLR-BF2C24, Revision 0 7 APRM Flow Biased Rod Block Trip Settings (Technical Requirements Manual Section 5.3.1 and Table 3.3.4-1)
The APRM rod block trip setting is based upon References 28 & 30, and is defined by the following:
for two loop operation:
SRB d (0.61Wd + 63.3)
Allowable Value SRB d (0.61Wd + 62.0)
Nominal Trip Setpoint (NTSP) where:
SRB
=
Rod Block setting in percent of rated thermal power (3952 MWt)
Wd
=
Recirculation drive flow rate in percent of rated (100% drive flow required to achieve 100% core power and flow) and for single loop operation:
SRB d (0.55(Wd-'W) + 60.5)
Allowable Value SRB d (0.55(Wd-'W) + 58.5)
Nominal Trip Setpoint (NTSP) where:
SRB
=
Rod Block setting in percent of rated thermal power (3952 MWt)
Wd
=
Recirculation drive flow rate in percent of rated (100% drive flow required to achieve 100% core power and flow)
'W
=
Difference between two-loop and single-loop effective recirculation flow at the same core flow ('W=0.0 for two-loop operation)
The APRM rod block trip setting is clamped at a maximum allowable value of 115%
(corresponding to a NTSP of 113%).
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TVA-COLR-BF2C24, Revision 0 8
Rod Block Monitor (RBM) Trip Setpoints and Operability (Technical Specification Table 3.3.2.1-1)
The RBM trip setpoints and applicable power ranges, based on References 28 & 29, are shown in Table 8.1. Setpoints are based on an HTSP, unfiltered analytical limit of 114%. Unfiltered setpoints are consistent with a nominal RBM filter setting of 0.0 seconds; filtered setpoints are consistent with a nominal RBM filter setting less than 0.5 seconds. Cycle specific CRWE analyses of OLMCPR are documented in Reference 1, superseding values reported in References 28, 29, and 30.
Table 8.1 Analytical RBM Trip Setpoints
Nominal Trip Setpoint (NTSP)
LPSP 27%
25%
IPSP 62%
60%
HPSP 82%
80%
LTSP - unfiltered
- filtered 121.7%
120.7%
120.0%
119.0%
ITSP
- unfiltered
- filtered 116.7%
115.7%
115.0%
114.0%
HTSP - unfiltered
- filtered 111.7%
110.9%
110.0%
109.2%
DTSP 90%
92%
As a result of cycle specific CRWE analyses, RBM setpoints in Technical Specification Table 3.3.2.1-1 are applicable as shown in Table 8.2. Cycle specific setpoint analysis results are shown in Table 8.3, per Reference 1.
Table 8.2 RBM Setpoint Applicability Thermal Power
(% Rated)
Applicable MCPR Notes from Table 3.3.2.1-1 Comment 27% and < 90%
< 1.58 (a), (b), (f), (h) two loop operation
< 1.60 (a), (b), (f), (h) single loop operation 90%
< 1.38 (g) two loop operation
- Values are considered maximums. Using lower values, due to RBM system hardware/software limitations, is conservative, and acceptable.
MCPR values shown correspond with, (support), values identified in Table 1.1.
Greater than 90% rated power is not attainable in single loop operation.
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TVA-COLR-BF2C24, Revision 0 Table 8.3 Control Rod Withdrawal Error Results RBM CRWE HTSP Analytical Limit OLMCPR Unfiltered 107 1.23 111 1.29 114 1.32 117 1.36 Results, compared against the base case OLMCPR results of Table 5.7, indicate Table 2.1 MCPR99.9 remains protected for RBM inoperable conditions (i.e., 114% unblocked).
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TVA-COLR-BF2C24, Revision 0 9
Shutdown Margin Limit (Technical Specification 3.1.1)
Assuming the strongest OPERABLE control blade is fully withdrawn, and all other OPERABLE control blades are fully inserted, the core shall be sub-critical and meet the following minimum shutdown margin:
SDM 0.38% dk/k
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page A-1 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 Appendix A: MBSP Maps Figure A.1 MBSP Boundaries for Nominal Feedwater Temperature (Operation in the MELLLA+ Region Prohibited for Feedwater Temperature greater than 10 degrees F below the Nominal Feedwater Temperature) 0 10 20 30 40 50 60 70 80 90 100 110 0
10 20 30 40 50 60 70 80 90 100 110 120 Core Power (% Rated: 100% = 3952MWt)
Core Flow (% Rated: 100% = 102.5 Mlb/hr)
MELLLA+ Region Manual Scram Region I BSP Boundary MELLLA Region ICF Region Controlled Entry Region II Min. Flow Control Min. Power Line 20% Pump Speed Line Natural Circulation MELLLA Upper Boundary 87.5% Rod Line
ECM: L32 241120 800 Reactor Engineering and Fuels - BWRFE 1101 Market Street, Chattanooga TN 37402 Date: January 7, 2025 Browns Ferry Unit 2 Cycle 24 Page A-2 Core Operating Limits Report, (120% OLTP, MELLLA+)
TVA-COLR-BF2C24, Revision 0 Figure A.2 MBSP Boundaries for Reduced Feedwater Temperature (Operation in the MELLLA+ Region Prohibited for a Reduced Feedwater Temperature greater than 10 degrees F below the Nominal Feedwater Temperature) 0 10 20 30 40 50 60 70 80 90 100 110 0
10 20 30 40 50 60 70 80 90 100 110 120 Core Power (% Rated: 100% = 3952MWt)
Core Flow (% Rated: 100% = 102.5 Mlb/hr)
MELLLA+ Region Manual Scram Region I BSP Boundary MELLLA Region ICF Region Controlled Entry Region II Min. Flow Control Min. Power Line 20% Pump Speed Line Natural Circulation 87.5% Rod Line MELLLA Upper Boundary