ML22297A092
| ML22297A092 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 10/20/2022 |
| From: | Mcclure K Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML22297A090 | List: |
| References | |
| 22-75 | |
| Download: ML22297A092 (27) | |
Text
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 1 of 27 CORE OPERATING LIMITS REPORT FOR PEACH BOTTOM ATOMIC POWER STATION UNIT 2 RELOAD 23, CYCLE 24 Mcclure, Kelly Prepared By: 2022.10.08 Date:00:46:34 -04'00' K. McClure - Cycle Management Heasley, Gregory M.
Reviewed By: 2022.10.08Date: 00:52:13 -04'00' G. Heasley - Reactor Engineering Digitally signed by Staum, Christopher J.
Staum, Christopher J. DN: cn=Staum, Christopher J.
Date: 2022.10.07 23:57:15 -05'00' Reviewed By: Date:
C. Staum - Engineering Safety Analysis Date: 2022.10.08 01:02:50 Stefanczyk, Megan -04'00' Reviewed By: Date:
M. Stefanczyk - Cycle Management Yokopenic, Emily Ann Digitally signed by Yokopenic, Emily Ann Date: 2022.10.08 01:11:01 -04'00' Approved By: Date:
E. Yokopenic - NF Sr. Manager Digitally signed by Holley, Jeffrey W.
Station Qualified DN: cn=Holley, Jeffrey W.
Date: 2022.10.08 01:15:30 -04'00' Reviewer: Date:
J. Holley - SQR
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 2 of 27 Table of Contents Page Revision History 3 List of Tables 4 1.0 Terms and Definitions 5 2.0 General Information 7 3.0 MAPLHGR Limits 8 4.0 MCPR Limits 9 5.0 LHGR Limits 13 6.0 Rod Block Monitor Setpoints 15 7.0 Turbine Bypass Valve Parameters 16 8.0 EOC Recirculation Pump Trip (EOC-RPT) Operability 17 9.0 Stability Protection 18 10.0 Asymmetric Feedwater Temperature Operation (AFTO) 20 11.0 Modes of Operation 24 12.0 Methodology 25 13.0 References 25 Appendix A: Power/Flow Operating Map for MELLLA+ with TPO 27
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 3 of 27 Revision History Revision Description Revision 16 Initial Issuance for Cycle 24 Revision 17 Revised to relax the power level restrictions associated with EOOS conditions
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 4 of 27 List of Tables Page Table 3-1 MAPLHGR Versus Average Planar Exposure 8 Table 3-2 MAPLHGR Single Loop Operation (SLO) Multiplier 8 Table 4-1 Operating Limit Minimum Critical Power Ratio 10 Table 4-2 Power Dependent MCPR(P) Limit Adjustments and Multipliers 11 Table 4-3 Flow Dependent MCPR Limits MCPR(F) 12 Table 4-4 SLO Flow Dependent MCPR Limits MCPR(F) 12 Table 4-5 Cycle Specific SLMCPR (MCPR99.9%) 12 Table 5-1 Linear Heat Generation Rate Limits - UO2 Rods 13 Table 5-2 Linear Heat Generation Rate Limits - Gad Rods 13 Table 5-3 Power Dependent LHGR Multiplier LHGRFAC(P) 14 Table 5-4 Flow Dependent LHGR Multiplier LHGRFAC(F) 14 Table 6-1 Rod Block Monitor Setpoints 15 Table 7-1 Turbine Bypass System Response Time 16 Table 7-2 Minimum Required Bypass Valves to Maintain System Operability 16 Table 8-1 Recirculation Pump Trip Response Time 17 Table 9-1 Automated BSP Setpoints for the Scram Region 18 Table 9-2 Manual BSP Endpoints for Normal Feedwater Temperature 19 Table 9-3 Manual BSP Endpoints for Reduced Feedwater Temperature 19 Table 10-1 AFTO MAPLHGR Reduction Factor 20 Table 10-2 AFTO Operating Limit Minimum Critical Power Ratio 20F < FWT DELTA 55F 21 Table 10-3 AFTO Power Dependent MCPR Limit Adjustments and Multipliers MCPR(P) 22 20F < FWT DELTA 55F Table 10-4 AFTO Flow Dependent MCPR Limits MCPR(F) 20F < FWT DELTA 55F 22 Table 10-5 AFTO Power Dependent LHGR Multiplier LHGRFAC(P) 20F < FWT DELTA 55F 23 Table 10-6 AFTO Flow Dependent LHGR Multiplier LHGRFAC(F) 20F < FWT DELTA 55F 23 Table 11-1 Modes of Operation 24 Table 11-2 EOOS Options Included in 'Base' Conditions 24 Table 11-3 Power Level Restrictions 24
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 5 of 27 1.0 TERMS AND DEFINITIONS ABSP Automated Backup Stability Protection AFTO Asymmetric Feedwater Temperature Operation APRM Average Power Range Monitor ARTS APRM, Rod Block and Technical Specification Improvement Program BASE The BASE condition is for normal, steady state operation. See Section 11 for more details.
BSP Backup Stability Protection DLO Dual Loop Operation DSS-CD Detect and Suppress Solution - Confirmation Density ECCS-LOCA Emergency Core Cooling System - Loss of Coolant Accident EOC End of Cycle EOC-RPT End of Cycle Recirculation Pump Trip EOOS Equipment Out of Service. An analyzed option that assumes certain equipment to be non-operational EOR End of Rated. The cycle exposure at which reactor power is equal to 100% with recirculation system flow equal to 100%, all control rods fully withdrawn, all feedwater heating in service and equilibrium Xenon.
FFWTR Final Feedwater Temperature Reduction FWHOOS Feedwater Heaters Out of Service FWT Feedwater Temperature HFCL High Flow Control Line HTSP Rod Block Monitor High Trip Setpoint ITSP Rod Block Monitor Intermediate Trip Setpoint KP Off-rated power dependent OLMCPR multiplier LHGR Linear Heat Generation Rate LHGRFAC(F) Off-rated flow dependent LHGR multiplier LHGRFAC(P) Off-rated power dependent LHGR multiplier LTSP Rod Block Monitor Low Trip Setpoint MAPLHGR Maximum Average Planar Linear Heat Generation Rate MCPR Minimum Critical Power Ratio MCPR99.9% Limiting MCPR value such that 99.9% of the fuel in the core is not susceptible to boiling transition MCPR(F) Off-rated flow dependent OLMCPR MCPR(P) Off-rated power dependent OLMCPR MELLLA Maximum Extended Load Line Limit Analysis MELLLA+ Maximum Extended Load Line Limit Analysis Plus MSIVOOS Main Steam Isolation Valve Out of Service NCL Natural Circulation Line NRC Nuclear Regulatory Commission OLMCPR Operating Limit Minimum Critical Power Ratio PLUOOS Power Load Unbalance Out of Service PROOS Pressure Regulator Out of Service PR/PLUOOS Pressure Regulator and/or Power Load Unbalance Out of Service RBM Rod Block Monitor RDF Recirculation Drive Flow
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 6 of 27 RPT Recirculation Pump Trip RPTOOS Recirculation Pump Trip Out of Service RTP Rated Thermal Power RWE Rod Withdrawal Error SAD Amplitude Discriminator Setpoint SFTO Symmetric Feedwater Temperature Operation SLMCPR Safety Limit Minimum Critical Power Ratio SLO Single Loop Operation SRVOOS Safety Relief Valve Out of Service Tau () A measure of scream time performance to notch position 36 throughout the cycle TBSOOS Turbine Bypass System Out of Service TBVOOS Turbine Bypass Valve Out of Service TCVSC Turbine Control Valve Slow Closure TCV/TSVOOS Turbine Control Valve and/or Turbine Stop Valve Out of Service TPO Thermal Power Optimization, also known as Measurement Uncertainty Recapture (MUR)
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 7 of 27 2.0 GENERAL INFORMATION This report provides the following cycle-specific parameter limits for Peach Bottom Atomic Power Station Unit 2 CYCLE 24 (RELOAD 23):
- Maximum Average Planar Linear Heat Generation Rate (MAPLHGR)
- Operating Limit Minimum Critical Power Ratio (OLMCPR)
- MCPR99.9%
- Linear Heat Generation Rate (LHGR)
- Turbine Bypass Valve Parameters
- Stability Protection Setpoints
- Asymmetric Feedwater Temperature Operation (AFTO) thermal limit penalties
- Power Level Restrictions These values have been determined using NRC-approved methodology and are established such that all applicable limits of the plant safety analysis are met. SLO, FWHOOS operation, and FFWTR operation are not permitted in the MELLLA+ Region as controlled by station procedures. For the MELLLA+ Region, a specific definition of FWHOOS is provided in Facility Operating License Section 2.C(16). Operation in the MELLLA+ Region with up to a 10°F reduction in feedwater temperature below the design feedwater temperature is permitted.
This report provides cycle-specific OLMCPR, LHGR, and MAPLHGR thermal limits and related information for the following conditions:
- All points in the operating region of the power/flow map including the MELLLA+ Region down to 85.2%
of rated core flow during full power (4016 MWt) operation (Appendix A)
- Increased Core Flow, up to 110% of rated core flow
- End-of-Cycle Power Coastdown to a minimum power level of 40%
- Feedwater Heaters Out of Service (FWHOOS) up to 55° F temperature reduction
- Final Feedwater Temperature Reduction (FFWTR) between End-of-Rated (EOR) and End-of-Cycle (EOC) up to 90° F temperature reduction (4th and 5th stage FWHOOS)
- Asymmetric Feedwater Temperature Operation (AFTO)
- Equipment Out of Service Conditions per Section 11 ARTS provides for power- and flow-dependent thermal limit adjustments and multipliers that allow for a more reliable administration of the MCPR and LHGR thermal limits. The OLMCPR is determined by the cycle-specific reload analyses in Reference 2. Rated LHGR values are obtained from the bundle-specific thermal-mechanical analysis documented in Reference 13. Supporting documentation for the ARTS-based limits is provided in Reference 2. The off-rated limits assumed in the ECCS-LOCA analyses bound the cycle-specific limits calculated for MELLLA+
operation. The Allowable Values documented in Reference 5 for feedwater temperature as a function of thermal power for both FWHOOS and FFWTR are specified in the appropriate Peach Bottom procedures. The Peach Bottom Unit 2 Cycle 24 core is comprised entirely of GNF2 fuel.
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 8 of 27 3.0 MAPLHGR LIMITS 3.1 Technical Specification Section 3.2.1, 3.3.4.2, 3.4.1 and 3.7.6 3.2 Description The limiting MAPLHGR value for the most limiting lattice of GNF2 fuel as a function of average planar exposure is given in Table 3-1. For SLO, a multiplier is used, which is shown in Table 3-2. The impact of AFTO on MAPLHGR is addressed in Section 10.0. The power and flow dependent LHGR multipliers are sufficient to provide adequate protection for the off-rated conditions from an ECCS-LOCA analysis perspective. The MAPLHGR multipliers can either be set to unity or set equal to the LHGR multipliers, which remain compliant with the basis of the ECCS-LOCA analysis with no loss of ECCS-LOCA margin.
TABLE 3-1 MAPLHGR Versus Average Planar Exposure (Reference 2)
Average Planar Exposure MAPLHGR Limit (GWD/ST) (kW/ft) 0.0 13.78 17.52 13.78 60.78 7.50 63.50 6.69 TABLE 3-2 MAPLHGR Single Loop Operation (SLO) Multiplier (Reference 2)
SLO Multiplier 0.73
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 9 of 27 4.0 MCPR LIMITS 4.1 Technical Specification Section 2.1.1.2, 3.2.2, 3.3.4.2, 3.4.1 and 3.7.6 4.2 Description The OLMCPR for GNF2 fuel is provided in Table 4-1. These values are determined by the cycle-specific fuel reload analyses in Reference 2. Control rod scram time verification is required as per Technical Specification 3.1.4, "Control Rod Scram Times". Tau (), a measure of scram time performance to notch position 36 throughout the cycle, is determined based on the cumulative scram time test results. The calculation of Tau shall be performed in accordance with site procedures. Linear interpolation shall be used to calculate the OLMCPR value if Tau is between 0.0 (Tau Option B) and 1.0 (Tau Option A). Table 4-1 is valid for a maximum Feedwater Temperature (FWT) reduction of 90oF (Reference 2).
The ARTS-based power-dependent MCPR limits (MCPR(P)) and multipliers (Kp) are provided in Table 4-
- 2. Table 4-2 is valid for a maximum temperature reduction of 90F for FFWTR operation (bounding for FWHOOS operation) (Reference 2). The flow-dependent MCPR limits (MCPR(F)) are provided in Tables 4-3 and 4-4. Table 4-3 is valid for DLO conditions with SFTO, and Table 4-4 is valid for SLO conditions with SFTO.
The impact of AFTO on MCPR is addressed in Section 10. For PR/PLUOOS + TBSOOS and PR/PLUOOS
+ RPTOOS conditions, the limits are listed in Section 10; these values are bounding for non-AFTO conditions.
The cycle-specific SLMCPRs, known as MCPR99.9% can be found in Table 4-5 for dual loop and single loop operating conditions. The values in Table 4-5 or conservative values were used to calculate the MCPR limits and off-rated limits in this section and Section 10.
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 10 of 27 TABLE 4-1 Operating Limit Minimum Critical Power Ratio (Symmetric Feedwater Heating)
(Reference 2)
SCRAM Cycle Exposure Time < EOR - 3992 > EOR - 3992 EOOS Combination Option(1) MWd/ST MWd/ST B 1.39 1.39 BASE A 1.46 1.47 B 1.42 1.42 BASE SLO A 1.48 1.49 B 1.41 1.41 RPTOOS A 1.58 1.58 B 1.43 1.43 RPTOOS SLO A 1.60 1.60 B 1.39 1.39 PR/PLUOOS A 1.46 1.47 B 1.42 1.42 PR/PLUOOS SLO A 1.48 1.49 B 1.45 1.45 TBSOOS A 1.50 1.53 B 1.47 1.47 TBSOOS SLO A 1.52 1.55 (1) When Tau does not equal 0 or 1, use linear interpolation.
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 11 of 27 TABLE 4-2 Power Dependent MCPR(P) Limit Adjustments and Multipliers (Symmetric Feedwater Heating)
(Reference 2)
Core Core Thermal Power (% of rated)
EOOS Combination Flow (% 0 22.6 26.3 >26.3 40 55 65 85 100 of rated) OLMCPR OLMCPR Multiplier, Kp
< 60 2.67 2.67 2.60 Base 1.392 1.288 1.237 1.130 1.067 1.000
> 60 2.99 2.99 2.83
< 60 2.69 2.69 2.62 Base SLO 1.392 1.288 1.237 1.130 1.067 1.000
> 60 3.01 3.01 2.85
< 60 2.67 2.67 2.60 RPTOOS 1.392 1.288 1.237 1.130 1.067 1.000
> 60 2.99 2.99 2.83
< 60 2.69 2.69 2.62 RPTOOS SLO 1.392 1.288 1.237 1.130 1.067 1.000
> 60 3.01 3.01 2.85
< 60 2.67 2.67 2.60 PR/PLUOOS 1.392 1.288 1.237 1.210 1.147 1.000
> 60 2.99 2.99 2.83
< 60 2.69 2.69 2.62 PR/PLUOOS SLO 1.392 1.288 1.237 1.210 1.147 1.000
> 60 3.01 3.01 2.85
< 60 3.64 3.64 3.25 TBSOOS 1.399 1.323 1.237 1.155 1.079 1.000
> 60 4.15 4.15 3.78
< 60 3.66 3.66 3.27 TBSOOS SLO 1.399 1.323 1.237 1.155 1.079 1.000
> 60 4.17 4.17 3.80
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 12 of 27 TABLE 4-3 Flow Dependent MCPR Limits MCPR(F)
(Symmetric Feedwater Heating)
(Reference 2)
Core Flow MCPR(F)
(% rated) Limit 0.0 1.71 30.0 1.54 80.9 1.25 110.0 1.25 TABLE 4-4 SLO Flow Dependent MCPR Limits MCPR(F)
(Symmetric Feedwater Heating)
(Reference 2)
Core Flow MCPR(F)
(% rated) Limit 0.0 1.73 30.0 1.56 80.9 1.27 110.0 1.27 TABLE 4-5 Cycle Specific SLMCPR (MCPR99.9%)
(Reference 2)
Loop Operation MCPR99.9%
DLO 1.13 SLO 1.13
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 13 of 27 5.0 LHGR LIMITS 5.1 Technical Specification Section 3.2.3, 3.3.4.2, 3.4.1 and 3.7.6 5.2 Description The LHGR values for the GNF2 fuel type are provided in Tables 5-1 and 5-2. The ARTS-based LHGR power-dependent multipliers (LHGRFAC(P)) are provided in Table 5-3. Table 5-3 is valid for a maximum temperature reduction of 90o F for FFWTR operation (bounding for FWHOOS operation)
(Reference 2). The LHGR flow-dependent multipliers (LHGRFAC(F)) are provided in Table 5-4 as a function of the number of recirculation loops in operation. The SLO LHGR multiplier is provided and accounted for in Table 5-4. The power- and flow-dependent LHGR multipliers were obtained from Reference 2. The impact of AFTO on LHGR is addressed in Section 10.0. For PR/PLUOOS + TBSOOS and PR/PLUOOS + RPTOOS conditions, the limits are listed in Section 10.0; these values are bounding for non-AFTO conditions. The power and flow dependent LHGR multipliers are sufficient to provide adequate protection for the off-rated conditions from an ECCS-LOCA analysis perspective.
TABLE 5-1 Linear Heat Generation Rate Limits - UO2 Rods (References 10 and 13)
Fuel Type LHGR Limit GNF2 See Reference 13 TABLE 5-2 Linear Heat Generation Rate Limits - Gad Rods (References 10 and 13)
Fuel Type LHGR Limit GNF2 See Reference 13
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 14 of 27 TABLE 5-3 Power Dependent LHGR Multiplier LHGRFAC(P)
(Symmetric Feedwater Heating)
(Reference 2)
Core Core Thermal Power (% of rated)
EOOS Flow (%
Combination 0 22.6 26.3 >26.3 40 55 65 85 100 of rated)
< 60 0.508 0.508 0.522 Base 0.620 0.696 0.751 0.817 0.930 1.000
> 60 0.508 0.508 0.522
< 60 0.508 0.508 0.522 Base SLO 0.620 0.696 0.751 0.817 0.930 1.000
> 60 0.508 0.508 0.522
< 60 0.508 0.508 0.522 RPTOOS 0.620 0.696 0.751 0.817 0.930 1.000
> 60 0.508 0.508 0.522
< 60 0.508 0.508 0.522 RPTOOS SLO 0.620 0.696 0.751 0.817 0.930 1.000
> 60 0.508 0.508 0.522
< 60 0.508 0.508 0.522 PR/PLUOOS 0.620 0.696 0.751 0.817 0.930 1.000
> 60 0.508 0.508 0.522 PR/PLUOOS < 60 0.508 0.508 0.522 0.620 0.696 0.751 0.817 0.930 1.000 SLO > 60 0.508 0.508 0.522
< 60 0.397 0.397 0.442 TBSOOS 0.620 0.655 0.714 0.817 0.930 1.000
> 60 0.397 0.397 0.417
< 60 0.397 0.397 0.442 TBSOOS SLO 0.620 0.655 0.714 0.817 0.930 1.000
> 60 0.397 0.397 0.417 TABLE 5-4 Flow Dependent LHGR Multiplier LHGRFAC(F)
(Symmetric Feedwater Heating)
(Reference 2)
Core Flow (% of rated)
EOOS Combination 0 30 33.6 70 80 110 Dual Loop 0.506 0.706 0.730 0.973 1.000 1.000 Single Loop 0.506 0.706 0.730 0.730 0.730 0.730
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 15 of 27 6.0 ROD BLOCK MONITOR SETPOINTS 6.1 Technical Specification Section 3.3.2.1 6.2 Description The RBM power-biased Allowable Values and MCPR Limits are provided in Table 6-1 with supporting documentation in References 2, 3, 8 and 9. The SFTO MCPR Limits apply when FWT difference is below 20°F. The AFTO MCPR Limits apply with FWT difference between 20 and 55°F. AFTO conditions are discussed further in Section 10. These values correspond to the OLMCPR values provided in Table 4-1.
TABLE 6-1 Rod Block Monitor Setpoints (References 2, 3, 8 and 9)
Power Level Allowable Value(1) SFTO MCPR Limit AFTO MCPR Limit Low Trip Setpoint < 1.80 (2) < 1.85 (4) 124.0%
(LTSP) < 1.48 (3) < 1.52 (5)
Intermediate Trip Setpoint < 1.80 (2) < 1.85 (4) 119.2%
(ITSP) < 1.48 (3) < 1.52 (5)
High Trip Setpoint < 1.80 (2) < 1.85 (4) 114.2%
(HTSP) < 1.48 (3) < 1.52 (5)
Inoperable (INOP) N/A < 1.80 (2) < 1.85 (4)
< 1.48 (3) < 1.52 (5)
(1) These setpoints (with RBM filter time constant between 0.1 seconds and 0.55 seconds) are based on cycle-specific rated RWE MCPR limits which are bounded by the OLMCPRs listed in Table 4-1.
(2) This is the MCPR limit for SFTO (given THERMAL POWER is >28.4% and < 90%) below which the RBM is required to be OPERABLE (see COLR Reference 2 and TS Table 3.3.2.1-1).
(3) This is the MCPR limit for SFTO (given THERMAL POWER is > 90%) below which the RBM is required to be OPERABLE (see COLR Reference 2 and TS Table 3.3.2.1-1).
(4) This is the MCPR limit for AFTO (given THERMAL POWER is 28.4% and < 90%) below which the RBM is required to be OPERABLE (see COLR References 2 and 8 and TS Table 3.3.2.1-1).
(5) This is the MCPR limit for AFTO (given THERMAL POWER is 90%) below which the RBM is required to be OPERABLE (see COLR References 2 and 8 and TS Table 3.3.2.1-1).
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 16 of 27 7.0 TURBINE BYPASS VALVE PARAMETERS 7.1 Technical Specification Section 3.7.6 7.2 Description The operability requirements for the steam bypass system are governed by Technical Specification 3.7.6. If the requirements cannot be met, the appropriate power and flow dependent limits for Turbine Bypass System Out-of-Service (TBSOOS) must be used. Additionally, the OLMCPR for TBSOOS must be applied. Table 7-1 includes the Turbine Bypass Valve response time parameters. The minimum number of bypass valves to maintain system operability is provided in Table 7-2 per Reference 12.
TABLE 7-1 Turbine Bypass System Response Time (Reference 12)
Maximum delay time before start of bypass valve opening following initial turbine inlet valve movement(1) 0.10 sec Maximum time after initial turbine inlet valve movement(1) for bypass valve position to reach 80% of full flow (includes the 0.30 sec above delay time)
TABLE 7-2 Minimum Required Bypass Valves to Maintain System Operability (Reference 12)
Reactor Power No. of Valves in Service P 22.6% 7 (1) First movement of any TSV or any TCV (whichever occurs first)
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 17 of 27 8.0 EOC RECIRCULATION PUMP TRIP (EOC-RPT) OPERABILITY 8.1 Technical Specification Section 3.3.4.2 8.2 Description The operability requirements for the EOC-RPT are governed by Technical Specification 3.3.4.2. If the requirements cannot be met, the appropriate power and flow dependent limits for EOC Recirculation Pump Trip Out Of Service (RPTOOS) must be used. Additionally, the OLMCPR for RPTOOS must be applied.
Table 8-1 includes the total RPT response time parameter.
TABLE 8-1 Recirculation Pump Trip Response Time (Reference 12)
Total Recirculation Pump Trip Response Time The time from when the turbine valves (turbine control valve or 0.175 sec turbine stop valve) start to close until complete arc suppression of the EOC-RPT circuit breakers as described in Reference 7.
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 18 of 27 9.0 STABILITY PROTECTION 9.1 Technical Specification Section 3.3.1.1, Table 3.3.1.1-1 Function 2.f 9.2 Description Per Reference 2, the Cycle 24 DSS-CD SAD Setpoint was confirmed to be 1.10 for DLO and SLO. The Automated Backup Stability Protection (BSP) Setpoints are provided in Table 9-1. The Manual BSP Endpoints for Normal FWT and Reduced FWT are provided in Tables 9-2 and Table 9-3, respectively. Table 9-3 is intended for feedwater temperatures 10-90oF below nominal.
TABLE 9-1 Automated BSP Setpoints for the Scram Region (Reference 2)
Parameter Symbol Value Slope of ABSP APRM flow-biased trip mTrip 1.62 linear segment.
ABSP APRM flow-biased trip setpoint power intercept.
PBSP-Trip 39.8 %RTP Constant Power Line for Trip from zero Drive Flow to Flow Breakpoint value.
ABSP APRM flow-biased trip setpoint drive flow intercept. Constant Flow Line WBSP-Trip 46.7 %RDF for Trip.
Flow Breakpoint value WBSP-Break 25.0 %RDF
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 19 of 27 TABLE 9-2(1)
Manual BSP Endpoints for Normal Feedwater Temperature (Reference 2)
Endpoint Power (%) Flow (%) Definition A1 72.4 48.2 Scram Region Boundary, HFCL B1 40.0 31.0 Scram Region Boundary, NCL A2 63.5 50.0 Controlled Entry Region Boundary, HFCL B2 27.6 30.1 Controlled Entry Region Boundary, NCL Note: The BSP Boundary for Normal and Reduced Feedwater Temperature is conservatively defined by the MELLLA boundary line, per Reference 2.
TABLE 9-3(1)
Manual BSP Endpoints for Reduced Feedwater Temperature (Reference 2)
Endpoint Power (%) Flow (%) Definition A1 62.4 48.6 Scram Region Boundary, HFCL B1 33.9 30.6 Scram Region Boundary, NCL A2 64.4 51.2 Controlled Entry Region Boundary, HFCL B2 27.6 30.1 Controlled Entry Region Boundary, NCL Note: The BSP Boundary for Normal and Reduced Feedwater Temperature is conservatively defined by the MELLLA boundary line, per Reference 2.
(1) Station may elect to place additional administrative margin on the endpoints provided in Table 9-2 and Table 9-3, per reference 14.
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 20 of 27 10.0 ASYMMETRIC FEEDWATER TEMPERATURE OPERATION (AFTO)
AFTO is the result of the specific configuration of the feedwater lines at Peach Bottom. A reduction in heating in either the A or the C heater strings will result in a temperature mismatch between the feedwater flows entering the opposite sides of the reactor vessel. This temperature mismatch may result in errors in the thermal limit values calculated by the core monitoring system. Thermal limit values for all conditions and events are impacted by these errors excluding SLO conditions. AFTO is defined as operation in a feedwater heater/string configuration that results in a specified threshold difference as described in Reference 8. To simplify the implementation of the AFTO limits, only the maximum AFTO penalties indicated in Table 13 of Reference 8 will be implemented when the threshold asymmetry temperature is exceeded; this will minimize the number of AFTO thermal limit tables in the COLR and core monitoring system.
There is no AFTO penalty for a FWT difference less than or equal to 20oF, for a difference between 20 and 55oF there is a 4% LHGR/MAPLHGR penalty and a 3% MCPR penalty, and thermal limits are unanalyzed for a difference above 55oF. The MCPR penalty for AFTO also applies to RBM Operability MCPR Limits which are addressed in Section 6.0.
10.1 MAPLHGR LIMITS An appropriate penalty must be applied to MAPLHGR limits under AFTO for varying temperature differentials as per Reference 8. The reduction factor listed in Table 10-1 is the maximum penalty for the full range of analyzed FWT mismatches, bounding all smaller temperature deltas.
TABLE 10-1 AFTO MAPLHGR Reduction Factor (Asymmetric Feedwater Heating)
(Reference 8)
AFTO Reduction Factor 20 F < FWT DELTA 55F 0.960
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 21 of 27 10.2 MCPR LIMITS The OLMCPRs during AFTO with a FWT difference greater than 20F are provided in Table 10-2. The ARTS-based MCPR(P) limits and multipliers (Kp) for use during AFTO conditions are provided in Table 10-3. The MCPR(F) limits for AFTO are provided in Table 10-4. The power- and flow-dependent OLMCPR curves were obtained from Reference 2 and were adjusted with a penalty for feedwater temperature difference greater than 20F as per Reference 8. PR/PLUOOS + TBSOOS and PR/PLUOOS + RPTOOS values were obtained by taking the most limiting values of the two EOOS conditions (Reference 11). No MCPR penalties are required for asymmetric temperature differentials less than or equal to 20 F.
TABLE 10-2 AFTO Operating Limit Minimum Critical Power Ratio 20F < FWT DELTA 55F (Asymmetric Feedwater Heating)
(References 2, 8 and 11)
SCRAM Cycle Exposure Time < EOR - 3992 > EOR - 3992 EOOS Combination Option (1) MWd/ST MWd/ST B 1.43 1.43 BASE A 1.50 1.51 B 1.45 1.45 RPTOOS A 1.63 1.63 B 1.43 1.43 PR/PLUOOS A 1.50 1.51 B 1.49 1.49 TBSOOS A 1.55 1.58 B 1.49 1.49 PR/PLUOOS + TBSOOS A N/A N/A B 1.45 1.45 PR/PLUOOS + RPTOOS A N/A N/A (1) When Tau does not equal 0 or 1, use linear interpolation.
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 22 of 27 TABLE 10-3 AFTO Power Dependent MCPR Limit Adjustments And Multipliers MCPR(P) 20F < FWT DELTA 55F (Asymmetric Feedwater Heating)
(References 2, 8 and 11)
Core Core Thermal Power (% of rated)
Flow 0 22.6 26.3 >26.3 40 55 65 85 100 EOOS Combination
(% of rated) OLMCPR OLMCPR Multiplier, Kp
< 60 2.75 2.75 2.68 Base 1.392 1.288 1.237 1.130 1.067 1.000
> 60 3.08 3.08 2.91
< 60 2.75 2.75 2.68 RPTOOS 1.392 1.288 1.237 1.130 1.067 1.000
> 60 3.08 3.08 2.91
< 60 2.75 2.75 2.68 PR/PLUOOS 1.392 1.288 1.237 1.210 1.147 1.000
> 60 3.08 3.08 2.91
< 60 3.75 3.75 3.35 TBSOOS 1.399 1.323 1.237 1.155 1.079 1.000
> 60 4.27 4.27 3.89
< 60 3.75 3.75 3.35 PR/PLUOOS + TBSOOS 1.399 1.323 1.237 1.210 1.147 1.000
> 60 4.27 4.27 3.89
< 60 2.75 2.75 2.68 PR/PLUOOS + RPTOOS 1.392 1.288 1.237 1.210 1.147 1.000
> 60 3.08 3.08 2.91 TABLE 10-4 AFTO Flow Dependent MCPR Limits MCPR(F) 20F < FWT DELTA 55F (Asymmetric Feedwater Heating)
(References 2 and 8)
Flow MCPR(F)
(% rated) Limit 0.0 1.77 30.0 1.59 80.9 1.29 110.0 1.29
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 23 of 27 10.3 LHGR LIMITS The ARTS-based LHGRFAC(P) values for AFTO operation are provided in Table 10-5. The LHGRFAC(F) values for AFTO in DLO are provided in Table 10-6. The power- and flow-dependent LHGR multipliers were obtained from Reference 2 and were adjusted with the appropriate penalties as per Reference 8.
PR/PLUOOS + TBSOOS and PR/PLUOOS + RPTOOS values were obtained by taking the most limiting values of the two EOOS conditions (Reference 11). The maximum feedwater temperature difference allowed without a thermal limit penalty is 20F. Once the temperature difference exceeds 20F the maximum penalties from Reference 8 are applied to the thermal limits. Additionally, no LHGR penalties are required for AFTO while in SLO as previously discussed.
TABLE 10-5 AFTO Power Dependent LHGR Multiplier LHGRFAC(P) 20F < FWT DELTA 55F (Asymmetric Feedwater Heating)
(References 2, 8 and 11)
Core Core Thermal Power (% of rated)
Flow EOOS Combination
(% of 0 22.6 26.3 >26.3 40 55 65 85 100 rated)
< 60 0.488 0.488 0.501 Base 0.595 0.668 0.721 0.784 0.893 0.960
> 60 0.488 0.488 0.501
< 60 0.488 0.488 0.501 RPTOOS 0.595 0.668 0.721 0.784 0.893 0.960
> 60 0.488 0.488 0.501
< 60 0.488 0.488 0.501 PR/PLUOOS 0.595 0.668 0.721 0.784 0.893 0.960
> 60 0.488 0.488 0.501
< 60 0.381 0.381 0.424 TBSOOS 0.595 0.629 0.685 0.784 0.893 0.960
> 60 0.381 0.381 0.400
< 60 0.381 0.381 0.424 PR/PLUOOS + TBSOOS 0.595 0.629 0.685 0.784 0.893 0.960
> 60 0.381 0.381 0.400
< 60 0.488 0.488 0.501 PR/PLUOOS + RPTOOS 0.595 0.668 0.721 0.784 0.893 0.960
> 60 0.488 0.488 0.501 TABLE 10-6 AFTO Flow Dependent LHGR Multiplier LHGRFAC(F) 20F < FWT DELTA 55F (Asymmetric Feedwater Heating)
(References 2 and 8)
Core Flow (% of rated)
EOOS Combination 0 30 33.6 70 80 110 Dual Loop 0.486 0.678 0.701 0.934 0.960 0.960
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 24 of 27 11.0 MODES OF OPERATION The following conditions are supported by the Peach Bottom 2 Cycle 24 licensing analysis; operation in a condition (or conditions) is controlled by station procedures. If a combination of options is not listed, it is not supported.
Table 11-1 provides allowed modes of operation with thermal limit sets in the COLR. Table 11-2 provides allowed modes of operation that do not contain explicit thermal limit sets in the COLR. Table 11-3 provides power level restrictions that support specific operating conditions.
TABLE 11-1 Modes of Operation (Reference 2)
Supported Scram Supported Recirculation Supported EOOS Options Speed Option Loop Operation SFTO/AFTO Base(1,2) A or B DLO or SLO(3) SFTO or AFTO TBSOOS A or B DLO or SLO(3) SFTO or AFTO RPTOOS A or B DLO or SLO(3) SFTO or AFTO PLUOOS A or B DLO or SLO(3) SFTO or AFTO PROOS A or B DLO or SLO(3) SFTO or AFTO PR/PLUOOS + TBSOOS(6) B DLO AFTO(4)
PR/PLUOOS + RPTOOS B DLO AFTO(4)
TABLE 11-2 EOOS Options Included in 'Base' Conditions (Reference 2)
Condition TBVOOS SRVOOS MSIVOOS(5)
TCV/TSVOOS(5)
TABLE 11-3 Power Level Restrictions (References 2 and 15)
Condition Power Level Restriction (% rated) 1 TCVOOS and/or 1 TSVOOS 90 1 TCVOOS and/or 1 TSVOOS + 2 TBVOOS 85 1 TCVOOS and/or 1 TSVOOS + TBSOOS 85 1 MSIVOOS 75 (1) The 'Base' condition includes the options listed in Table 11-2.
(2) The 'Base' condition includes operation with FWHOOS/FFWTR. Operation not permitted in the MELLLA+
Region for reduced FWT conditions as controlled by station procedures.
(3) Operation in SLO not permitted in the MELLLA+ Region as controlled by station procedures.
(4) AFTO limits bound SFTO limits.
(5) Permitted at power levels provided in Table 11-3 and in the applicable station procedure.
(6) TCVSC event is bounded by the PR/PLUOOS + TBSOOS condition per Reference 4.
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 25 of 27 12.0 METHODOLOGY The analytical methods used in determining the core operating limits have been previously reviewed and approved by the NRC, specifically those described in the following document:
- 1. General Electric Standard Application for Reactor Fuel, Global Nuclear Fuel Document No. NEDE-24011-P-A-29, October 2019 and U.S. Supplement NEDE-24011-P-A-29-US, October 2019.
13.0 REFERENCES
- 1. "Subsequent Renewed Facility Operating License ", Exelon Document, Docket No. 50-277, Subsequent Renewed License No. DPR-44.
- 2. "Supplemental Reload Licensing Report for Peach Bottom Unit 2 Reload 23 Cycle 24, GNF Document No.
006N1965, Revision 0, August 2020.
- 3. Removal of Generic ARTS Rated RWE DCPR for Limerick Units 1 and 2, Nine Mile Point Unit 2, and Peach Bottom Units 2 and 3, General Electric Hitachi Nuclear Energy Document No. 005N2836-R0, Revision 0, July 2019.
- 4. Thermal Limits Evaluation for the TCV Slow Closure Event for Peach Bottom, Exelon Technical Evaluation EC 632705, Revision 0, October 2020.
- 5. Clarify Rated Feedwater Temp for Feedwater Temp Reduction Curves, Exelon Technical Evaluation EC 628049, Revision 0, August 2019.
- 6. Safety Analysis Report for Peach Bottom Atomic Power Station, Units 2 and 3, Thermal Power Optimization, General Electric Hitachi Document NEDO-33873, Revision 0, February 2017.
- 7. Determination of Time Required to Initiate Trip Signal to the RPT CKT, Exelon Calculation No. PE-0173, Revision 1A, January 2019.
- 8. Final Evaluation Report Exelon Nuclear Generating Company LLC Peach Bottom Units 2 & 3 TPO with EPU/MELLLA+ PCR E03: Asymmetric Feedwater Temperature Operation for TPO with EPU/MELLLA+,
General Electric Hitachi Nuclear Energy Document No. 001N6733, Revision 2, September 2017. This is searchable in EDMS as PEAM-MUR-PCR-E03, Revision 0.
- 9. Provide Allowable Values (AV) and Nominal Trip Setpoints (NTSP) for Various Setpoint Functions of the NUMAC PRNM System, Exelon Calculation PE-0251, Revision 4, July 31, 2017.
- 10. "Fuel Bundle Information Report for Peach Bottom Unit 2 Reload 23 Cycle 24", Global Nuclear Fuel Document No. 005N1905, Revision 0, August 2020.
- 11. Peach Bottom Atomic Power Station Units 2 and 3 TRACG Implementation for Reload Licensing Transient Analysis, General Electric Hitachi Document 0000-0135-9000-R2, June 2017.
- 13. PRIME-Based GNF2 LHGR Envelopes for Peach Bottom Atomic Power Station Units 2 and 3, Global Nuclear Fuel Document 004N7833-P, Rev. 0, April 2018.
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 26 of 27
- 14. GE Hitachi Boiling Water Reactor Detect and Suppress Solution - Confirmation Density, General Electric Hitachi Document NEDC-33075P-A, Revision 8, November 2013.
- 15. Peach Bottom Atomic Power Station Units 2 and 3 Power Restrictions for GNF2 Fuel with 1 MSIVOOS or 1 TCV and/or TSVOOS, Constellation Owners Acceptance Report 007N1539, Revision 1, October 2022.
Constellation Energy Generation - Nuclear Fuels COLR PEACH BOTTOM 2 Rev. 17 P2C24 Core Operating Limits Report Page 27 of 27 APPENDIX A POWER/FLOW OPERATING MAP FOR MELLLA+ with TPO (Reference 6)
BSP Boundary