ML25351A064
| ML25351A064 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 09/23/2025 |
| From: | Heverly M Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| COLR Nine Mile Point 2, Rev. 9 | |
| Download: ML25351A064 (0) | |
Text
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 1 of 21 CORE OPERATING LIMITS REPORT FOR NINE MILE POINT UNIT 2 CYCLE 20 Prepared By:
Matthew Heverly Preparer, Nuclear Fuels Prepared By:
Kelly McClure Preparer, Nuclear Fuels Reviewed By:
Andrew Kim Reviewer, Nuclear Fuels Reviewed By:
Timothy Norman Reviewer, Engineering Safety Analysis Reviewed By:
Brett Larimore Reviewer, Reactor Engineering Approved By:
Kristin McCoskey Senior Manager, Nuclear Fuels SQR By:
Eric Kelsey Station Qualified Reviewer Heverly, Matthew M Digitally signed by Heverly, Matthew M Date: 2025.09.23 10:36:16 -04'00' 2025.09.23 10:40:40 -04'00' Kim, Andrew Jin Digitally signed by Kim, Andrew Jin Date: 2025.09.23 10:49:52 -04'00' Digitally signed by Norman, Timothy James Date: 2025.09.23 09:51:49 -05'00' Larimore, Brett Dylan Digitally signed by Larimore, Brett Dylan Date: 2025.09.23 11:39:24 -04'00' Digitally signed by McCoskey, Kristin Date: 2025.09.24 08:47:23 -05'00' Digitally signed by Kelsey, Eric A Date: 2025.09.24 15:32:52 -04'00'
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 2 of 21 Table of Contents Section Page Number Summary of Revisions 3
List of Tables / Figures 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 16 7.0 Turbine Bypass Valve Parameters 17 8.0 Modes of Operation 18 9.0 Stability Protection 19 10.0 Power Flow Operating Map 20 11.0 Methodology 20 12.0 References 21
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 3 of 21 Summary of Revisions Revision Description Revision 8 Revision 9 New Issue for Cycle 20 Updated the List of Tables / Figures to reflect the full title.
Table 4-1 has been updated with OLMCPR values to be consistent with newly added Reference 14.
Table 8-3 has been updated to be consistent with newly added Reference 15.
Removed reference to FCMS document numbers in the References section and replaced them with Constellation document numbers.
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 4 of 21 List of Tables / Figures Page Table 3-1 MAPLHGR Versus Average Planar Exposure, GNF2 Fuel 8
Table 3-2 MAPLHGR Versus Average Planar Exposure, GNF3 Fuel 8
Table 3-3 MAPLHGR SLO Multiplier, All Fuel Types 8
Table 4-1 Operating Limit Minimum Critical Power Ratio (OLMCPR), All Fuel Types 10 Table 4-2 Power Dependent MCPR Limits (MCPRP) and Multipliers (KP), All Fuel Types 11 Table 4-3 Flow Dependent MCPR Limits (MCPRF), GNF2 Fuel, All Modes of Operation 12 Table 4-4 Flow Dependent MCPR Limits (MCPRF), GNF3 Fuel, All Modes of Operation 12 Table 4-5 Cycle Specific SLMCPR (MCPR99.9%)
12 Table 5-1 LHGR Limits for UO2 Fuel Rods 13 Table 5-2 LHGR Limits for Gadolinia Rods 13 Table 5-3 Power Dependent LHGR Multipliers (LHGRFACP), GNF2 Fuel, DLO and SLO 14 Table 5-4 Power Dependent LHGR Multipliers (LHGRFACP), GNF3 Fuel, DLO and SLO 14 Table 5-5 Flow Dependent LHGR Multipliers (LHGRFACF), GNF2 Fuel, All Modes of Operation 15 Table 5-6 Flow Dependent LHGR Multipliers (LHGRFACF), GNF3 Fuel, All Modes of Operation 15 Table 6-1 Rod Block Monitor Setpoints 16 Table 6-2 ARTS RWE Validated MCPR Values 16 Table 7-1 Turbine Bypass Valve Response Time 17 Table 8-1 Modes of Operation 18 Table 8-2 EOOS Conditions Included under BASE Option 18 Table 8-3 Power Level Restrictions 18 Table 9-1 BSP Endpoints for Normal Feedwater Temperature 19 Table 9-2 Automated BSP Setpoints 19 Figure 1 Power/Flow Operating Map for MELLLA+ in Dual Loop Operation 20
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 5 of 21 1.0 Terms and Definitions ADS Automatic Depressurization System ADSOOS Automatic Depressurization System Out of Service. ADSOOS is defined as any ADS valve inoperable.
APLHGR Average Planar Linear Heat Generation Rate APRM Average Power Range Monitor ARTS Average Power Range Monitor, Rod Block Monitor, and Technical Specification (ARTS) improvements program BSP Backup Stability Protection COLR Core Operating Limits Report DLO Dual Loop Operation ECCS Emergency Core Cooling System EIS Equipment In Service EOOS Equipment Out of Service EOR End of Rated. The cycle exposure at which reactor power is equal to 100% rated (3988 MWth), recirculation flow equal to 100% rated (108.5 Mlb/hr), and all control blades are fully withdrawn with equilibrium xenon.
EPU Extended Power Uprate GEH General Electric-Hitachi GNF Global Nuclear Fuel HFCL High Flow Control Line HTSP High Power Trip Set Point (regarding RBM)
ICF Increased Core Flow ITSP Intermediate Power Trip Set Point (regarding RBM)
KP Off-rated power dependent OLMCPR multiplier LCO Limiting Condition for Operation LHGR Linear Heat Generation Rate LHGRFACF Off-rated flow dependent LHGR multiplier LHGRFACP Off-rated power dependent LHGR multiplier LOCA Loss of Coolant Accident LTR Licensing Topical Report LTSP Low Power Trip Set Point (regarding RBM)
MAPFACF Off-rated flow dependent MAPLHGR multiplier MAPFACP Off-rated power dependent MAPLHGR multiplier MAPLHGR Maximum Average Planar Linear Heat Generation Rate MCPR Minimum Critical Power Ratio MCPR99.9%
Limiting MCPR value such that 99.9 percent of the fuel in the core is not susceptible to boiling transition. Also known as the cycle-specific SLMCPR.
MCPRF Off-rated flow dependent OLMCPR
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 6 of 21 MCPRP 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 MSROOS Moisture Separator Reheater Out of Service NCL Natural Circulation Line NRC Nuclear Regulatory Commission OLMCPR Operating Limit MCPR OPRM Oscillation Power Range Monitor PLUOOS Power Load Unbalance Out of Service PROOS Pressure Regulator Out of Service RBM Rod Block Monitor RDF Recirculation Drive Flow RPTOOS Recirculation Pump Trip Out of Service; also known as EOC-RPTOOS RTP Rated Thermal Power (3988 MWt)
RWE Rod Withdrawal Error SER Safety Evaluation Report SLMCPR Safety Limit MCPR SLO Single Loop Operation SRVOOS Safety Relief Valve(s) Out of Service TBV Turbine Bypass Valve TBVOOS Turbine Bypass Valve Out of Service. TBVOOS supports 3 of 5 TBVs slow open and 2 of 5 TBVs do not slow open (stuck closed). TBVOOS also supports 5 TBV to not fast open (Reference 10).
TCV Turbine Control Valve TCVFASOOS Turbine Control Valve Fast Acting Solenoid Out of Service TCVOOS Turbine Control Valve Out of Service TS Technical Specification TSV Turbine Stop Valve TSVOOS Turbine Stop Valve Out of Service
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 7 of 21 2.0 General Information This report is prepared in accordance with Technical Specification (TS) 5.6.5 of Reference 1. Power and flow dependent limits are listed for various power and flow levels. For all power, flow, and exposure-dependent tables, linear interpolation should be used to determine intermediate values unless directed otherwise.
This report provides the values of the power distribution limits, control rod withdraw block instrumentation, and stability protection setpoints for Nine Mile Point Unit 2 Cycle 20.
This report provides the following cycle-specific parameter limits for Nine Mile Point Unit 2 Cycle 20 (Reload 19):
Maximum Average Planar Linear Heat Generation Rate (MAPLHGR)
Single Loop Operation (SLO) MAPLHGR multipliers Operating Limit Minimum Critical Power Ratio (OLMCPR)
ARTS MCPR thermal limit adjustments and multipliers Single Loop Operation (SLO) MCPR adjustment Cycle-specific SLMCPRs (MCPR99.9%)
Linear Heat Generation Rate (LHGR)
ARTS LHGR thermal limit multipliers Single Loop Operation (SLO) LHGR multipliers Rod Block Monitor (RBM) Nominal Trip Setpoints, Allowable Values and MCPR Limits Turbine Bypass Valve (TBV) parameters Backup Stability Protection (BSP) parameters The BASE thermal limit values shown in the tables are for normal, equipment in service (EIS), two loop operation. Analysis also supports Increased Core Flow (ICF) for operational flexibility. Additional equipment out of service (EOOS) applicability can be found in Section 8.0, Modes of Operation.
The data presented in this report is valid for all licensed operating domains on the operating map, including (Reference 2):
Maximum Extended Load Line Limit Analysis Plus (MELLLA+) to a minimum core flow of 85% of rated.
ICF up to 105% of rated (rated core flow is 108.5 Mlb/hr).
Extended Power Uprate (EPU) to 3988 MWth.
Coastdown operation down to 40% Rated Thermal Power (RTP)
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 8 of 21 3.0 MAPLHGR Limits Technical Specification Sections 3.2.1, 3.4.1 The MAPLHGR limits obtained from the ECCS analysis are provided in Table 3-1 and Table 3-2 for GNF2 and GNF3 fuel, respectively. The limiting MAPLHGR value for the most limiting lattice of each fuel type as a function of exposure is given. For SLO, a multiplier is used as shown in Table 3-3.
The power and flow dependent LHGR multipliers are sufficient to provide adequate protection for the off-rated conditions from an ECCS-LOCA analysis perspective and there is no need for MAPLHGR multipliers in addition to off-rated LHGR multipliers, per Reference 2 - Section 16.
Table 3-1 MAPLHGR Versus Average Planar Exposure GNF2 Fuel (Reference 2 - Table 9)
Average Planar Exposure [GWd/ST]
MAPLHGR Limit [kW/ft]
0.00 13.78 17.15 13.78 60.78 6.87 63.50 5.50 Table 3-2 MAPLHGR Versus Average Planar Exposure GNF3 Fuel (Reference 2 - Table 10)
Average Planar Exposure [GWd/ST]
MAPLHGR Limit [kW/ft]
0.00 14.36 21.22 13.01 40.82 10.75 57.60 8.00 63.50 6.00 Table 3-3 MAPLHGR SLO Multiplier All Fuel Types (Reference 2 - Table 11)
Fuel Type SLO Multiplier GNF2 0.78 GNF3 0.95
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 9 of 21 4.0 MCPR Limits Technical Specification Sections 3.2.2, 3.3.4.1, 3.4.1, 3.7.5 OLMCPR values listed in Table 4-1 cover all conditions listed in Section 8.0, Modes of Operation.
Additional EOOS information can be found in Section 8.0. ARTS provides for power and flow dependent thermal limits adjustments, which allow for a more reliable administration of the MCPR thermal limit. Per TS 3.2.2, all MCPRs shall be verified in accordance with limits specified in this section.
Control rod scram time verification is also required per TS 3.1.4, Control Rod Scram Times. The applicable MCPR thermal limit set shall be determined with Tau (, a measure of scram time performance throughout the cycle based on the cumulative plant scram time test results (Reference 13). The calculation of Tau shall be performed in accordance with site procedures.
The power dependent MCPR limits (MCPRP) and multipliers (Kp) are provided in Table 4-2 for all fuel types. The flow dependent MCPR limits (MCPRF) are provided in Tables 4-3 and 4-4, Table 4-3 for GNF2 fuel and Table 4-4 for GNF3 fuel.
ARTS power and flow dependent thermal limits have been confirmed for the following modes of operation:
- 1. Base
+ TCVFASOOS + RPTOOS)
- 4. MSROOS
- 5. The combination of PLUOOS, PROOS, TCVFASOOS, RPTOOS, MSROOS, and TBVOOS (PLUOOS + PROOS + TCVFASOOS + RPTOOS + MSROOS + TBVOOS)
The cycle-specific exposure-dependent 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.
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 10 of 21 Table 4-1 Operating Limit Minimum Critical Power Ratio (OLMCPR)
All Fuel Types (Reference 2 - Section 11, Reference 14)
EOOS Combination SCRAM Time Option1 Cycle Exposure 1724 MWd/ST
> 1724 MWd/ST
& < EOR-3782 MWd/ST EOR-3782 MWd/ST BASE DLO A
1.47 1.47 1.50 B
1.41 1.34 1.38 SLO2 A
1.50 1.50 1.53 B
1.45 1.45 1.45 TBVOOS +
RPTOOS DLO A
1.52 1.52 1.55 B
1.41 1.36 1.39 SLO2 A
1.55 1.55 1.58 B
1.45 1.45 1.45 PLUOOS +
PROOS +
TCVFASOOS
+ RPTOOS DLO A
1.47 1.47 1.50 B
1.41 1.34 1.38 SLO2 A
1.50 1.50 1.53 B
1.45 1.45 1.45 MSROOS DLO A
1.51 1.51 1.55 B
1.41 1.37 1.41 SLO2 A
1.54 1.54 1.58 B
1.45 1.45 1.45 PLUOOS +
PROOS +
TCVFASOOS
+ RPTOOS +
MSROOS +
TBVOOS DLO A
1.55 1.56 1.59 B
1.41 1.40 1.43 SLO2 A
1.58 1.59 1.62 B
1.45 1.45 1.46 1 For tau () = 0, use SCRAM Time Option B limits. For () = 1, use SCRAM Time Option A limits. When tau does not equal 0 or 1, use linear interpolation in accordance with site procedure to calculate OLMCPR.
2 For single-loop operation, the MCPR operating limit is 0.03 greater than the analyzed DLO value. However, a minimum SLO value of 1.45 for all fuel types is required to bound the Recirculation Pump Seizure Event (Reference 2).
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 11 of 21 Table 4-2 Power Dependent MCPR Limits (MCPRP) and Multipliers (KP)
All Fuel Types (Reference 2 - Appendix D)
EOOS Combination Core Flow
[% of rated]
Core Thermal Power [% of rated]
0 23 26
>26 30 55 65 85
>85 100 Operating Limit MCPRP Operating Limit MCPR Multiplier (KP)
BASE DLO 50 2.33 2.33 2.32 1.278 1.266 1.188 1.130 1.056 1.000
<50 2.29 2.29 2.28 SLO 50 2.36 2.36 2.35 1.278 1.266 1.188 1.130 1.056 1.000
<50 2.32 2.32 2.31 TBVOOS +
RPTOOS DLO 50 2.67 2.67 2.56 1.278 1.266 1.188 1.130 1.056 1.000
<50 2.54 2.54 2.39 SLO 50 2.70 2.70 2.59 1.278 1.266 1.188 1.130 1.056 1.000
<50 2.57 2.57 2.42 PLUOOS +
PROOS +
TCVFASOOS
+ RPTOOS DLO 50 2.33 2.33 2.33 1.289 1.277 1.198 1.178 1.072 1.056 1.000
<50 2.29 2.29 2.28 SLO 50 2.36 2.36 2.36 1.289 1.277 1.198 1.178 1.072 1.056 1.000
<50 2.32 2.32 2.31 MSROOS DLO 50 2.34 2.34 2.34 1.278 1.266 1.188 1.130 1.056 1.000
<50 2.30 2.30 2.30 SLO 50 2.37 2.37 2.37 1.278 1.266 1.188 1.130 1.056 1.000
<50 2.33 2.33 2.33 PLUOOS +
PROOS +
TCVFASOOS
+ RPTOOS +
MSROOS +
TBVOOS DLO 50 2.67 2.67 2.56 1.289 1.277 1.198 1.178 1.072 1.056 1.000
<50 2.54 2.54 2.39 SLO 50 2.70 2.70 2.59 1.289 1.277 1.198 1.178 1.072 1.056 1.000
<50 2.57 2.57 2.42
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 12 of 21 Table 4-3 Flow Dependent MCPR Limits (MCPRF)
GNF2 Fuel All Modes of Operation (Reference 2 - Appendix D)
Flow [% of rated]
MCPRF Limit DLO SLO 0.0 2.01 2.04 30.0 1.78 1.81 94.2 1.29 1.32 112.0 1.29 1.32 Table 4-4 Flow Dependent MCPR Limits (MCPRF)
GNF3 Fuel All Modes of Operation (Reference 2 - Appendix D)
Flow [% of rated]
MCPRF Limit DLO SLO 0.0 1.82 1.85 30.0 1.61 1.64 89.5 1.20 1.23 105.0 1.20 1.23 Table 4-5 Cycle Specific SLMCPR (MCPR99.9%)
(Reference 2 - Section 11)
Flow Mode MCPR99.9%
< 8500 MWd/ST 8500 MWd/ST DLO 1.11 1.11 SLO 1.11 1.12
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 13 of 21 5.0 LHGR Limits Technical Specification Section 3.2.3 The LHGR limit is the product of the exposure dependent LHGR limit from Table 5-1 or 5-2 and the minimum of the LHGRFACP or the LHGRFACF from Tables 5-3 through 5-6.
The off-rated limits assumed in the ECCS-LOCA analyses are confirmed to be consistent with the cycle-specific off-rated LHGR multipliers calculated for MELLLA+ operation. The off-rated LHGR multipliers provide adequate protection for MELLLA+ operation (Reference 2 - Appendix F).
Table 5-1 LHGR Limits for UO2 Fuel Rods (Reference 3, Reference 5, Reference 12)
Fuel Type LHGR Limit [kW/ft]
GNF2 See Reference 5 Table 2-1 GNF3 See Reference 12 Table A-1 Table 5-2 LHGR Limits for Gadolinia Rods (Reference 3, Reference 5, Reference 12)
Fuel Type LHGR Limit [kW/ft]
GNF2 See Reference 5 Table 2-2 GNF3 See Reference 12 Table A-2
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 14 of 21 Table 5-3 Power Dependent LHGR Multipliers (LHGRFACP)
GNF2 Fuel DLO and SLO (Reference 2 - Appendix D)
EOOS Combination Core Flow
[% of rated]
Core Thermal Power [% of rated]
0 23 26
>26 55 60 85 100 BASE 75 0.613 0.720 0.791 0.922 1.000
<75 0.495 0.495 0.502 TBVOOS + RPTOOS 75 0.613 0.720 0.791 0.922 1.000
<75 0.475 0.475 0.502 PLUOOS + PROOS +
TCVFASOOS +
RPTOOS 75 0.613 0.720 0.740 0.831 1.000
<75 0.495 0.495 0.502 MSROOS 75 0.613 0.720 0.791 0.922 1.000
<75 0.495 0.495 0.502 PLUOOS + PROOS +
TCVFASOOS + RPTOOS +
MSROOS + TBVOOS 75 0.613 0.720 0.740 0.831 1.000
<75 0.475 0.475 0.502 Table 5-4 Power Dependent LHGR Multipliers (LHGRFACP)
GNF3 Fuel DLO and SLO (Reference 2 - Appendix D)
EOOS Combination Core Flow [%
of rated]
Core Thermal Power [% of rated]
0 23 26
>26 30 55 65 85 100 BASE 50 0.430 0.430 0.440 0.630 0.650 0.760 0.980 1.000 1.000
<50 0.430 0.430 0.440 TBVOOS + RPTOOS 50 0.430 0.430 0.440 0.630 0.650 0.760 0.870 0.970 1.000
<50 0.430 0.430 0.440 PLUOOS + PROOS +
TCVFASOOS + RPTOOS 50 0.430 0.430 0.440 0.630 0.650 0.760 0.850 0.960 1.000
<50 0.430 0.430 0.440 MSROOS 50 0.430 0.430 0.440 0.630 0.650 0.760 0.980 1.000 1.000
<50 0.430 0.430 0.440 PLUOOS + PROOS +
TCVFASOOS + RPTOOS +
MSROOS + TBVOOS 50 0.430 0.430 0.440 0.630 0.650 0.760 0.810 0.920 1.000
<50 0.430 0.430 0.440
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 15 of 21 Table 5-5 Flow Dependent LHGR Multipliers (LHGRFACF)
GNF2 Fuel All Modes of Operation (Reference 2 - Appendix D and Table 11)
EOOS Condition Core Flow [% of rated]
0 30 40 52.7 85 112 DLO 0.241 0.580 0.693 1.000 1.000 SLO 0.241 0.580 0.693 0.780 0.780 0.780 Table 5-6 Flow Dependent LHGR Multipliers (LHGRFACF)
GNF3 Fuel All Modes of Operation (Reference 2 - Appendix D and Table 11)
EOOS Condition Core Flow [% of rated]
0 30 74.3 80 105 DLO 0.298 0.561 1.000 1.000 SLO 0.298 0.561 0.950 0.950 0.950
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 16 of 21 6.0 Rod Block Monitor Setpoints Technical Specification Section 3.3.2.1 Per Technical Specifications 3.3.2.1, the RBM instrumentation channels will be operable with the allowable values set to the values shown in Table 6-1. The values given in Table 6-1 are unfiltered; these unfiltered values are applicable since the time filter constant is set to zero. (Reference 7 -
Table 5B). The RBM operability requirements have been evaluated and shown to be sufficient to ensure that the cycle-specific exposure-dependent SLMCPR and cladding 1% plastic strain criteria will not be exceeded in the event of a Rod Withdrawal Error.
The ARTS RWE analysis validated the MCPR values in Table 6-2 below provide the required margin for full withdrawal of any control rod during Cycle 20. The RWE MCPR values have been analyzed at discrete setpoint values and unblocked (continuous withdrawal) conditions.
Table 6-1 Rod Block Monitor Setpoints3 (Reference 2 - Section 10, Reference 8 - Section 3)
Power Level Allowable Value Nominal Trip Setpoint Analytical Limit LTSP 124.6%
124.2%
127.0%
ITSP 119.6%
119.2%
122.0%
HTSP 114.6%
114.2%
117.0%
Table 6-2 ARTS RWE Validated MCPR Values (Reference 2 - Section 10)
Power Level [% of Rated]
<90%
1.76 90%
1.45 3 See Reference 8 for filtered values. NMP2C20 is analyzed for the following RBM set points, which correspond to set D from Reference 8. However, the station may elect to have more restrictive state points listed in Reference 8 Section 3.
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 17 of 21 7.0 Turbine Bypass Valve Parameters Technical Specification Section 3.7.5 Per Technical Specification LCO 3.7.5, whenever the reactor power is at or above 23% RTP the main turbine bypass system shall be operable or the plant must operate with TBVOOS penalties.
The definition of operable is given in Table 7-1 below.
Table 7-1 Turbine Bypass Valve Response Time (Reference 9 - Section 1.6)
Event Response Time [sec]
Maximum delay time before start of bypass valve opening following initial turbine inlet valve movement 0.15 Maximum time after initial turbine inlet valve movement for bypass valve position to reach 80% of full flow (includes the above delay time) 0.30
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 18 of 21 8.0 Modes of Operation The following conditions are supported by the Cycle 20 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 8-1 provides allowed modes of operation with thermal limit sets in the COLR. Table 8-2 provides allowed modes of operation that do not contain explicit thermal limit sets but are included in the BASE option. Table 8-3 outlines power restrictions associated with various EOOS options.
Note that per TS LCO 3.4.1, SLO in the MELLLA and MELLLA+ domains is prohibited (Reference 1). The MELLLA+ domain and the MELLLA domain upper boundary are defined in Figure 1. The MELLLA domain lower boundary is bounded by the 95% load line (Reference 4). Refer to site power-flow map drawings for allowed SLO regions.
Table 8-1 Modes of Operation (Reference 2, Reference 10)
Options4 Allowed Operating Region BASE DLO Yes SLO Yes TBVOOS + RPTOOS5 DLO Yes SLO Yes PLUOOS + PROOS + TCVFASOOS +
RPTOOS DLO Yes SLO Yes MSROOS DLO Yes SLO Yes PLUOOS + PROOS + TCVFASOOS +
RPTOOS + MSROOS +TBVOOS5 DLO Yes SLO Yes Table 8-2 EOOS Conditions Included under BASE Option (Reference 2, Reference 10)
EOOS Condition 2 SRVOOS 1 ADSOOS 1 MSIVOOS 1 TCV/TSVOOS5 Table 8-3 Power Level Restrictions (Reference 2 - Appendix D, Reference 15)
Condition Power Level Restriction [% of rated]
1 MSIVOOS 75 1 TCV/TSVOOS 85 Combination of MSROOS and TBVOOS 92 4 The EOOS Options listed apply to both Scram Time Option A and Option B 5 TCV/TSVOOS not analyzed concurrent with TBVOOS + RPTOOS or PLUOOS + PROOS + TCVFASOOS + RPTOOS
+ MSROOS +TBVOOS
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 19 of 21 9.0 Stability Protection Technical Specification Section 3.3.1.1 The OPRM Amplitude Discriminator Setpoint (SAD) is 1.10 (Reference 2 - Section 15.1). Results have been validated with rated feedwater temperature 420.5°F as described by Reference 2. Per TS 5.6.5.a.4, the Backup Stability Protection (BSP) regions and values are as shown below in Tables 9-1 and 9-2. The manual BSP region boundary endpoints are connected using the Generic Shape Function. A graphical representation of the BSP regions can be found in Reference 2 - Figure 1.
Table 9-1 BSP Endpoints for Normal Feedwater Temperature6,7 (Reference 2 - Table 4)
Endpoint Power
[% of rated]
Flow
[% of rated]
Definition A1 69.8 44.5 Scram Region Boundary, HFCL B1 39.7 29.5 Scram Region Boundary, NCL A2 64.5 50.0 Controlled Entry Region Boundary, HFCL B2 27.5 28.9 Controlled Entry Region Boundary, NCL Note: The BSP Boundary for Normal Feedwater Temperature is defined by the MELLLA boundary line, per Reference 2. See Figure 1 in Reference 2.
Table 9-2 Automated BSP Setpoints6 (Reference 2 - Table 5)
Parameter Symbol Value Slope of Automated BSP APRM flow-biased trip linear segment.
mTRIP 1.26 Automated BSP APRM flow-biased trip setpoint power intercept. Constant Power Line for Trip from zero Drive Flow to Flow Breakpoint value.
PBSP-TRIP 39.5% RTP Automated BSP APRM flow-biased trip setpoint drive flow intercept. Constant Flow Line for Trip.
WBSP-TRIP 39.2% RDF Flow Breakpoint value.
WBSP-BREAK 20.4% RDF 6 Bounding for both DLO and SLO 7 Station may elect to place additional administrative margin on the endpoints provided in Table 9-1
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 20 of 21 10.0 Power Flow Operating Map Per MELLLA+ LTR SER Limitation and Condition 12.5.c, the MELLLA+ Power/Flow operating map is provided as Figure 1.
Figure 1: Power/Flow Operating Map for MELLLA+ in Dual Loop Operation (Reference 6) 11.0 Methodology The analytical methods used to determine the core operating limits shall be those previously reviewed and approved by the Nuclear Regulatory Commission, particularly those described in the following documents:
- 1. General Electric Standard Application for Reactor Fuel (GESTAR II) (Supplement for United States), NEDE-24011-P-A-31-US, November 2020.
Constellation Energy Generation - Nuclear Fuels Document ID: COLR Nine Mile Point 2, Rev. 9 Core Operating Limits Report Page 21 of 21 12.0 References
- 1. Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License, Constellation Document, Docket No. 50-410, Renewed License No. NPF-69.
- 2. Supplemental Reload Licensing Report for Nine Mile Point Unit 2 Reload 19 Cycle 20, Global Nuclear Fuel Document, No. 007N4299, Revision 0, January 2024.
- 3. Fuel Bundle Information Report for Nine Mile Point Unit 2 Reload 19 Cycle 20, Global Nuclear Fuel Document, No. 007N4300, Revision 0, January 2024.
- 4. Nine Mile Point Nuclear Station Unit 2 Cycle 2 Equipment Out of Service Analysis, GE Nuclear Energy Document, No. EAS 18-0390 (Constellation Document No. MISC167105005),
Revision 0, April 1990.
- 5. Revised GNF2 Thermal Mechanical Operating Limits for Nine Mile Point Unit 2 Global Nuclear Fuel Document, No. 005N5546, Revision 1, January 2020.
- 6. Safety Analysis Report for Nine Mile Point Unit 2 Maximum Extended Load Line Limit Analysis Plus, GEH Document, No. NEDC-33576P, Revision 0, October 2013.
- 7. Revise 22A2843AM, Engineering Change Notice for NSSS161405000 Design Spec Data Sheet, Neutron Monitoring System, Constellation Document, No. 007242, Revision 1, April 2008.
- 8. Instrument Limits Calculation Constellation Generation Group Nine Mile Point Nuclear Station Unit 2 Rod Block Monitor (NUMAC ARTS-MELLLA), GEH Document, No. 0000-0053-1006 NMP2 A-M-T506-RBM-Calc-2006 (Constellation Document No.
NSSS168805002), Revision 1, March 2008.
- 9. Nine Mile Point Unit 2 Cycle 20 OPL-3, Constellation TODI, No. NF230480, Revision 0, August 2023.
- 10. GNF3 Fuel Design Cycle-Independent Analyses for Exelon Nine Mile Point Nuclear Station Unit 2, GEH Document, No. 006N6601, Revision 1, January 2022.
- 11. Deleted.
- 12. GNF3 Generic Compliance with NEDE-24011-P-A (GESTAR II), Global Nuclear Fuel Document, No. NEDC-33879P, Revision 4, August 2020.
004N0521-R0, September 2017.
- 14. Nine Mile Point Unit 2 Cycle 20 RWE Evaluation for Evolutions in the RWE Analysis Process, Global Nuclear Fuel Document, No. 009N2736, Revision 0, January 2025
- 15. Nine Mile Point Unit 2 Cycle 20 Power Restriction with Moisture Separator Reheater Out Of Service Global Nuclear Fuel Document, No. 010N2564-R0, August 2025