NOC-AE-17003464, Cycle 21 Core Operating Limits Report; Revisions 0 and 1

Cycle 21 Core Operating Limits Report; Revisions 0 and 1

ML17110A499
Person / Time
Site:	South Texas
Issue date:	04/20/2017
From:	Dunn R South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-17003464, STI: 34479791
Download: ML17110A499 (28)

Text

Soutli Texas Project Electric Generating Station PO. Box 2851 Wadswolfh. Texas 77483 April 20, 2017 NOC-AE-17003464 10 CFR 50.36 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Unit 1 Docket No. STN 50-498 Unit 1 Cycle 21 Core Operating Limits Report; Revisions 0 and 1 In accordance with Technical Specification 6.9.1.6.d, STP Nuclear Operating Company submits the attached Core Operating Limits Reports (COLRs) for Unit 1 Cycle 21. The reports cover the core design changes made during the 1RE20 refueling outage. Revision 0 is applicable to Modes 3, 4, and 5 and Revision 1 incorporates revisions to include Modes 1 and 2.

There are no commitments in this letter.

If there are any questions regarding this report, please contact Drew Richards at (361) 972-7666 or me at (361) 972-7743.

Roland F. Dunn Manager, Nuclear Fuel & Analysis amr/RFD Attachments:

1. South Texas Project Unit 1 Cycle 21 Core Operating Limits Report; Revision 0

2. South Texas Project Unit 1 Cycle 21 Core Operating Limits Report; Revision 1 STI: 34479791

NOC-AE-17003464 Page 2 of 2 cc:

(paper copy) (electronic copy)

Regional Administrator, Region IV Morgan, Lewis & Bockius LLP U.S. Nuclear Regulatory Commission Steve Frantz, Esquire 1600 East Lamar Boulevard Paul Bessette Arlington, TX 76011-4511 U.S. Nuclear Regulatory Commission Lisa M. Regner Lisa M. Regner Senior Project Manager U.S. Nuclear Regulatory Commission NRG South Texas LP One White Flint North (O8H04) Mark Walker 11555 Rockville Pike Jim von Suskil Rockville, MD 20852 Skip Zahn NRC Resident Inspector CPS Energy U. S. Nuclear Regulatory Commission Kevin Pollo P. O. Box 289, Mail Code: MN116 Cris Eugster Wadsworth, TX 77483 L. D. Blaylock City of Austin Elaina Ball John Wester Texas Dept. of State Health Services Helen Watkins Robert Free

Attachment 1 South Texas Project Unit 1 Cycle 21 Core Operating Limits Report; Revision 0

SOUTH TEXAS PROJECT Unit 1 Cycle 21 CORE OPERATING LIMITS REPORT Revision 0 MODES 3, 4 and 5 Core Operating Limits Report Page 1 of 8

Unit 1 Cycle 21 Core Operating Limits Report Rev. 0 Modes 3, 4 and 5 Page 2 of 8 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report for STPEGS Unit 1 Cycle 21 has been prepared in accordance with the requirements of Technical Specification 6.9.1.6. The core operating limits have been developed using the NRC-approved methodologies specified in Technical Specification 6.9.1.6.

The Technical Specifications affected by this report are:

1) 2.1 SAFETY LIMITS

2) 2.2 LIMITING SAFETY SYSTEM SETTINGS

3) 3/4.1.1.1 SHUTDOWN MARGIN

4) 3/4.1.1.3 MODERATOR TEMPERATURE COEFFICIENT LIMITS

5) 3/4.1.3.5 SHUTDOWN ROD INSERTION LIMITS

6) 3/4.1.3.6 CONTROL ROD INSERTION LIMITS

7) 3/4.2.1 AFD LIMITS

8) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR

9) 3/4.2.3 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR

10) 3/4.2.5 DNB PARAMETERS 2.0 OPERATING LIMITS The cycle-specific parameter limits for the specifications listed in Section 1.0 are presented below.

2.1 SAFETY LIMITS (Specification 2.1):

2.1.1 Will be added prior to initial U1C21 Mode 2 entry.

2.2 LIMITING SAFETY SYSTEM SETTINGS (Specification 2.2):

2.2.1 Will be added prior to initial U1C21 Mode 2 entry.

2.2.2 The Over-temperature T and Over-power T setpoint parameter values are listed below:

Over-temperature T Setpoint Parameter Values Will be added prior to initial U1C21 Mode 2 entry.

Over-power T Setpoint Parameter Values Will be added prior to initial U1C21 Mode 2 entry.

Unit 1 Cycle 21 Core Operating Limits Report Rev. 0 Modes 3, 4 and 5 Page 3 of 8 2.3 SHUTDOWN MARGIN (Specification 3.1.1.1):

The SHUTDOWN MARGIN shall be:

2.3.1 Will be added prior to initial U1C21 Mode 2 entry.

2.3.2 Greater than the limits in Figure 2 for MODES 3 and 4.

2.3.3 Greater than the limits in Figure 3 for MODE 5.

2.4 MODERATOR TEMPERATURE COEFFICIENT (Specification 3.1.1.3):

2.4.1 Will be added prior to initial U1C21 Mode 2 entry.

2.4.2 Will be added prior to initial U1C21 Mode 2 entry.

2.4.3 Will be added prior to initial U1C21 Mode 2 entry.

2.4.4 Will be added prior to initial U1C21 Mode 2 entry.

2.5 ROD INSERTION LIMITS (Specification 3.1.3.5 and 3.1.3.6):

2.5.1 Will be added prior to initial U1C21 Mode 2 entry.

2.5.2 Will be added prior to initial U1C21 Mode 2 entry.

2.5.3 Will be added prior to initial U1C21 Mode 2 entry.

2.6 AXIAL FLUX DIFFERENCE (Specification 3.2.1):

2.6.1 Will be added prior to initial U1C21 Mode 2 entry.

2.6.2 Will be added prior to initial U1C21 Mode 2 entry.

2.7 HEAT FLUX HOT CHANNEL FACTOR (Specification 3.2.2):

2.7.1 Will be added prior to initial U1C21 Mode 2 entry.

2.7.2 Will be added prior to initial U1C21 Mode 2 entry.

2.7.3 Will be added prior to initial U1C21 Mode 2 entry.

2.7.4 Will be added prior to initial U1C21 Mode 2 entry.

2.8 ENTHALPY RISE HOT CHANNEL FACTOR (Specification 3.2.3):

2.8.1 Will be added prior to initial U1C21 Mode 2 entry.

2.8.2 Will be added prior to initial U1C21 Mode 2 entry.

2.8.3 Will be added prior to initial U1C21 Mode 2 entry.

Unit 1 Cycle 21 Core Operating Limits Report Rev. 0 Modes 3, 4 and 5 Page 4 of 8 2.9 DNB PARAMETERS (Specification 3.2.5):

2.9.1 Will be added prior to initial U1C21 Mode 2 entry.

3.0 REFERENCES

3.1 Letter from J. M. Ralston (Westinghouse) to R. F. Dunn (STPNOC), "Confirmation of Mode 3, 4, and 5 RSAC Limits for South Texas Unit 1 Cycle 21 Redesign," NF-TG-09-26 (ST-UB-NOC-17003590), April 6, 2017.

3.2 NUREG-1346, Technical Specifications, South Texas Project Unit Nos. 1 and 2.

3.3 Document RSE-U1, Rev. 6, Unit 1 Cycle 21 Reload Safety Evaluation and Core Operating Limits Report. (CR Action 16-454-70).

Unit 1 Cycle 21 Core Operating Limits Report Rev. 0 Modes 3, 4 and 5 Page 5 of 8 FIGURE 1 Reactor Core Safety Limits - Four Loops in Operation Will be added prior to initial U1C21 Mode 2 entry.

Unit 1 Cycle 21 Core Operating Limits Report Rev. 0 Modes 3, 4 and 5 Page 6 of 8 Figure 2 Required Shutdown Margin for Modes 3 & 4 7.0 6.0 Acceptable

( 2400 , 5.15 )

5.0 Required Shutdown Margin (% Delta Rho) 4.0 3.0 2.0

( 0 , 1.30 )

Unacceptable

( 600 , 1.30 )

1.0 0.0 0 400 800 1200 1600 2000 2400 RCS Critical Boron Concentration (ppm)

(for ARI minus most reactive stuck rod)

Unit 1 Cycle 21 Core Operating Limits Report Rev. 0 Modes 3, 4 and 5 Page 7 of 8 Figure 3 Required Shutdown Margin for Mode 5 7.0 6.0 Acceptable 5.0 Required Shutdown Margin (% Delta Rho)

( 2400 , 4.50 )

4.0 3.0 2.0

( 0 , 1.30 )

Unacceptable

( 650 , 1.30 )

1.0 0.0 0 400 800 1200 1600 2000 2400 RCS Critical Boron Concentration (ppm)

(for ARI minus most reactive stuck rod)

Unit 1 Cycle 21 Core Operating Limits Report Rev. 0 Modes 3, 4 and 5 Page 8 of 8 FIGURE 4 MTC versus Power Level Will be added prior to initial U1C21 Mode 2 entry.

FIGURE 5 Control Rod Insertion Limits versus Power Level Will be added prior to initial U1C21 Mode 2 entry.

FIGURE 6 AFD Limits versus Power Level Will be added prior to initial U1C21 Mode 2 entry.

FIGURE 7 K(Z) - Normalized FQ(Z) versus Core Height Will be added prior to initial U1C21 Mode 2 entry.

TABLE 1 Unrodded FXY for Each Core Height Will be added prior to initial U1C21 Mode 2 entry.

Attachment 2 South Texas Project Unit 1 Cycle 21 Core Operating Limits Report; Revision 1

SOUTH TEXAS PROJECT Unit 1 Cycle 21 CORE OPERATING LIMITS REPORT Revision 1 Core Operating Limits Report Page 1 of 16

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 2 of 16 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report for STPEGS Unit 1 Cycle 21 has been prepared in accordance with the requirements of Technical Specification 6.9.1.6. The core operating limits have been developed using the NRC-approved methodologies specified in Technical Specification 6.9.1.6.

The Technical Specifications affected by this report are:

1) 2.1 SAFETY LIMITS

2) 2.2 LIMITING SAFETY SYSTEM SETTINGS

3) 3/4.1.1.1 SHUTDOWN MARGIN

4) 3/4.1.1.3 MODERATOR TEMPERATURE COEFFICIENT LIMITS

5) 3/4.1.3.5 SHUTDOWN ROD INSERTION LIMITS

6) 3/4.1.3.6 CONTROL ROD INSERTION LIMITS

7) 3/4.2.1 AFD LIMITS

8) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR

9) 3/4.2.3 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR

10) 3/4.2.5 DNB PARAMETERS 2.0 OPERATING LIMITS The cycle-specific parameter limits for the specifications listed in Section 1.0 are presented below.

2.1 SAFETY LIMITS (Specification 2.1):

2.1.1 The combination of THERMAL POWER, pressurizer pressure, and the highest operating loop coolant temperature (Tavg) shall not exceed the limits shown in Figure 1.

2.2 LIMITING SAFETY SYSTEM SETTINGS (Specification 2.2):

2.2.1 The Loop design flow for Reactor Coolant Flow-Low is 98,000 gpm.

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 3 of 16 2.2.2 The Over-temperature T and Over-power T setpoint parameter values are listed below:

Over-temperature T Setpoint Parameter Values 1 measured reactor vessel T lead/lag time constant, 1 = 8 sec 2 measured reactor vessel T lead/lag time constant, 2 = 3 sec 3 measured reactor vessel T lag time constant, 3 = 2 sec 4 measured reactor vessel average temperature lead/lag time constant, 4 = 28 sec 5 measured reactor vessel average temperature lead/lag time constant, 5 = 4 sec 6 measured reactor vessel average temperature lag time constant, 6 = 2 sec K1 Overtemperature T reactor trip setpoint, K1 = 1.14 K2 Overtemperature T reactor trip setpoint Tavg coefficient, K2 = 0.028/°F K3 Overtemperature T reactor trip setpoint pressure coefficient, K3 = 0.00143/psi T Nominal full power Tavg, T 592.0 °F P Nominal RCS pressure, P = 2235 psig f1(I) is a function of the indicated difference between top and bottom detectors of the power-range neutron ion chambers; with gains to be selected based on measured instrument response during plant startup tests such that:

(1) For qt - qb between -70% and +8%, f1(I) = 0, where qt and qb are percent RATED THERMAL POWER in the top and bottom halves of the core respectively, and qt + qb is total THERMAL POWER in percent of RATED THERMAL POWER; (2) For each percent that qt - qb is more negative than -70%, the T Trip Setpoint shall be automatically reduced by 0.0% of its value at RATED THERMAL POWER; and (3) For each percent that qt - qb is more positive than +8%, the T Trip Setpoint shall be automatically reduced by 2.65% of its value at RATED THERMAL POWER.

(Reference 3.6 and Section 4.4.1.2 of Reference 3.7)

Over-power T Setpoint Parameter Values 1 measured reactor vessel T lead/lag time constant, 1 = 8 sec 2 measured reactor vessel T lead/lag time constant, 2 = 3 sec 3 measured reactor vessel T lag time constant, 3 = 2 sec 6 measured reactor vessel average temperature lag time constant, 6 = 2 sec 7 Time constant utilized in the rate-lag compensator for Tavg, 7 = 10 sec K4 Overpower T reactor trip setpoint, K4 = 1.08 K5 Overpower T reactor trip setpoint Tavg rate/lag coefficient, K5 = 0.02/°F for increasing average temperature, and K5 = 0 for decreasing average temperature K6 Overpower T reactor trip setpoint Tavg heatup coefficient K6 = 0.002/°F for T > T, and K6 = 0 for T T T Indicated full power Tavg, T 592.0 °F f2(I) = 0 for all (I)

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 4 of 16 2.3 SHUTDOWN MARGIN1 (Specification 3.1.1.1):

The SHUTDOWN MARGIN shall be:

2.3.1 Greater than 1.3% for MODES 1 and 2*

• See Special Test Exception 3.10.1 2.3.2 Greater than the limits in Figure 2 for MODES 3 and 4.

2.3.3 Greater than the limits in Figure 3 for MODE 5.

2.4 MODERATOR TEMPERATURE COEFFICIENT (Specification 3.1.1.3):

2.4.1 The BOL, ARO, MTC shall be less positive than the limits shown in Figure 4.

2.4.2 The EOL, ARO, HFP, MTC shall be less negative than -62.6 pcm/°F.

2.4.3 The 300 ppm, ARO, HFP, MTC shall be less negative than -53.6 pcm/°F (300 ppm Surveillance Limit).

Where: BOL stands for Beginning-of-Cycle Life, EOL stands for End-of-Cycle Life, ARO stands for All Rods Out, HFP stands for Hot Full Power (100% RATED THERMAL POWER),

HFP vessel average temperature is 592 °F.

2.4.4 The Revised Predicted near-EOL 300 ppm MTC shall be calculated using the algorithm from the document referenced by Technical Specification 6.9.1.6.b.10:

Revised Predicted MTC = Predicted MTC + AFD Correction - 3 pcm/°F If the Revised Predicted MTC is less negative than the COLR Section 2.4.3 limit and all of the benchmark data contained in the surveillance procedure are met, then an MTC measurement in accordance with S.R. 4.1.1.3b is not required.

2.5 ROD INSERTION LIMITS1 (Specification 3.1.3.5 and 3.1.3.6):

2.5.1 All banks shall have the same Full Out Position (FOP) of either 256 or 259 steps withdrawn.

2.5.2 The Control Banks shall be limited in physical insertion as specified in Figure 5.

2.5.3 Individual Shutdown bank rods are fully withdrawn when the Bank Demand Indication is at the FOP and the Rod Group Height Limiting Condition for Operation is satisfied (T.S. 3.1.3.1).

1 The Shutdown Margin and Rod Insertion limits account for the removal of RCCA D6 in Shutdown Bank A.

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 5 of 16 2.6 AXIAL FLUX DIFFERENCE (Specification 3.2.1):

2.6.1 AFD limits as required by Technical Specification 3.2.1 are determined by Constant Axial Offset Control (CAOC) Operations with an AFD target band of +5, -10%.

2.6.2 The AFD shall be maintained within the ACCEPTABLE OPERATION portion of Figure 6, as required by Technical Specifications.

2.7 HEAT FLUX HOT CHANNEL FACTOR (Specification 3.2.2):

2.7.1 FRTP Q = 2.55.

2.7.2 K(Z) is provided in Figure 7.

2.7.3 The Fxy limits for RATED THERMAL POWER (FRTP xy ) within specific core planes shall be:

2.7.3.1 Less than or equal to 2.102 for all cycle burnups for all core planes containing Bank "D" control rods, and 2.7.3.2 Less than or equal to the appropriate core height-dependent value from Table 1 for all unrodded core planes.

2.7.3.3 PFxy = 0.2.

These Fxy limits were used to confirm that the heat flux hot channel factor FQ(Z) will be limited by Technical Specification 3.2.2 assuming the most-limiting axial power distributions expected to result for the insertion and removal of Control Banks C and D during operation, including the accompanying variations in the axial xenon and power distributions, as described in WCAP-8385. Therefore, these Fxy limits provide assurance that the initial conditions assumed in the LOCA analysis are met, along with the ECCS acceptance criteria of 10 CFR 50.46.

2.7.4 Core Power Distribution Measurement Uncertainty for the Heat Flux Hot Channel Factor 2.7.4.1 If the Power Distribution Monitoring System (PDMS) is operable, as defined in the Technical Requirements Manual Section 3.3.3.12, the core power distribution measurement uncertainty (UFQ) to be applied to the FQ(Z) and Fxy(Z) using the PDMS shall be calculated by:

UFQ = (1.0 + (UQ/100))*UE Where:

UQ = Uncertainty for power peaking factor as defined in Equation 5-19 from the document referenced by Technical Specification 6.9.1.6.b.11 UE = Engineering uncertainty factor of 1.03.

This uncertainty is calculated and applied automatically by the Power Distribution Monitoring System (PDMS).

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 6 of 16 2.7.4.2 If the moveable detector system is used, the core power distribution measurement uncertainty (UFQ) to be applied to the FQ(Z) and Fxy(Z) shall be calculated by:

UFQ = UQU*UE Where:

UQU = Base FQ measurement uncertainty of 1.05.

UE = Engineering uncertainty factor of 1.03.

2.8 ENTHALPY RISE HOT CHANNEL FACTOR (Specification 3.2.3):

2.8.1 FRTP H = 1.62 2.8.2 PFH = 0.3 2.8.3 Core Power Distribution Measurement Uncertainty for the Enthalpy Rise Hot Channel Factor 2.8.3.1 If the Power Distribution Monitoring System (PDMS) is operable, as defined in the Technical Requirements Manual Section 3.3.3.12, the core power distribution measurement uncertainty (UFH) to be applied to the FNH using the PDMS shall be the greater of:

UFH = 1.04 OR UFH = 1.0 + (UH/100)

Where:

UH = Uncertainty for power peaking factor as defined in Equation 5-19 from the document referenced in Technical Specification 6.9.1.6.b.11.

This uncertainty is calculated and applied automatically by the Power Distribution Monitoring System.

2.8.3.2 If the moveable detector system is used, the core power distribution measurement uncertainty (UFH) shall be:

UFH = 1.04

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 7 of 16 2.9 DNB PARAMETERS (Specification 3.2.5):

2.9.1 The following DNB-related parameters shall be maintained within the following limits: 1 2.9.1.1 Reactor Coolant System Tavg 595 °F 2, 2.9.1.2 Pressurizer Pressure > 2200 psig 3, 2.9.1.3 Minimum Measured Reactor Coolant System Flow > 403,000 gpm4.

3.0 REFERENCES

3.1 Letter from J. M. Ralston (Westinghouse) to R. F. Dunn (STPNOC), "South Texas Project Electric Generating Station Unit 1 Cycle 21 Redesign Final Reload Evaluation" NF-TG-17-7, Rev. 1 (ST-UB-NOC-17003573, Rev. 1) dated April 12, 2017.

3.2 NUREG-1346, Technical Specifications, South Texas Project Unit Nos. 1 and 2.

3.3 STPNOC Calculation ZC-7035, Rev. 2, Loop Uncertainty Calculation for RCS Tavg Instrumentation, Section 10.1.

3.4 STPNOC Calculation ZC-7032, Rev. 6, Loop Uncertainty Calculation for Narrow Range Pressurizer Pressure Monitoring Instrumentation, Section 2.3, Page 9.

3.5 Letter from J. S Wyble (Westinghouse) to T. J. Jordan (STPNOC), STP Nuclear Operating Company Units 1 & 2 Power Uprate PCWG Parameters, ST-WN-NOC-00-000072 dated December 15, 2000, STI 31218644.

3.6 Letter from J. M. Ralston (Westinghouse) to D. F. Hoppes (STPNOC), South Texas Project Electric Generating Station Units 1 and 2 Documentation of the f1(I) Function in OTT Setpoint Calculation, NF-TG-11-93 (ST-UB-NOC-11003215) dated November 10, 2011.

3.7 Document RSE-U1, Rev. 7, Unit 1 Cycle 21 Reload Safety Evaluation and Core Operating Limits Report. (CR Action 16-454-9) 1 A discussion of the processes to be used to take these readings is provided in the basis for Technical Specification 3.2.5.

2 Includes a 1.9 °F measurement uncertainty per Reference 3.3, Page 37.

3 Limit not applicable during either a Thermal Power ramp in excess of 5% of RTP per minute or a Thermal Power step in excess of 10% RTP. Per Technical Specification 3.2.5 Bases, this includes a 10.7 psi measurement uncertainty as read on the QDPS display, which is bounded by the 9.6 psi averaged measurement calculated in Reference 3.4.

4 Includes the flow measurement uncertainty of 2.8% from Reference 3.5.

Nuclear Operating Company Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 8of16 Figure 1 Reactor Core Safety Limits - Four Loops in Operation 680 I c 2, 664_52 )

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I I Unacceptable 660 r--..... .........

I c 2,652 _1 0 )

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I ( 11 2 , 587-35 ) I 580

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! Acceptable  ! ~

560 540 0 20 40 60 80 100 120 140 Rated Thermal Power(%)

Nuclear Operating Company Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 9of16 Figure 2 Required Shutdown Margin for Modes 3 & 4 7.0

6. 0 I Acceptable I c2400 , 5_ 15 )I

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IC600 , uo )I

1. 0 0.0 0 400 800 1200 1600 2000 2400 RCS Critical Boron Concentration (ppm)

(for ARI minus most reactive stuck rod)

Nuclear Operating Company Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 10of16 Figure 3 Required Shutdown Margin for Mode 5 7.0 6.0 I I 1Acceptable 1 5.0 1( 2400 , 4.50) 1

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1.0 0.0 0 400 800 1200 1600 2000 2400 RCS Critical Boron Concentration (ppm)

(for ARI minus most reactive stuck rod)

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 11 of 16 Figure 4 MTC versus Power Level 7.0 6.0 Unacceptable 5.0 Moderator Temperature Coefficient (pcm/°F) 4.0 Acceptable 3.0 2.0 1.0 0.0

-1.0

-2.0

-3.0 0 10 20 30 40 50 60 70 80 90 100 Rated Thermal Power (%)

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 12 of 16

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 13 of 16 Figure 6 AFD Limits versus Power Level 120 110 100

( -11 , 90 ) ( 11 , 90 )

90 80 Unacceptable Unacceptable Rated Thermal Power (%)

70 Acceptable 60 50

( -31 , 50 ) ( 31 , 50 )

40 30 20 10 0

-50 -40 -30 -20 -10 0 10 20 30 40 50 Axial Flux Difference (% Delta-I)

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 14 of 16

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 15 of 16 Table 1 (Part 1 of 2)

Unrodded Fxy for Each Core Height for Cycle Burnups Less Than 10,000 MWD/MTU Core Height Axial Unrodded Core Height Axial Unrodded (Ft.) Point Fxy (Ft.) Point Fxy 14.0 1 7.401 6.8 37 1.982 13.8 2 5.801 6.6 38 2.031 13.6 3 4.200 6.4 39 2.008 13.4 4 2.815 6.2 40 1.953 13.2 5 2.534 6.0 41 1.924 13.0 6 2.276 5.8 42 1.956 12.8 7 2.204 5.6 43 1.967 12.6 8 2.186 5.4 44 1.973 12.4 9 2.120 5.2 45 2.019 12.2 10 2.066 5.0 46 2.083 12.0 11 2.039 4.8 47 2.096 11.8 12 2.048 4.6 48 2.042 11.6 13 2.075 4.4 49 1.975 11.4 14 2.061 4.2 50 1.985 11.2 15 2.017 4.0 51 1.984 11.0 16 1.984 3.8 52 1.973 10.8 17 1.972 3.6 53 1.981 10.6 18 1.964 3.4 54 2.024 10.4 19 1.934 3.2 55 2.050 10.2 20 1.950 3.0 56 1.992 10.0 21 1.994 2.8 57 1.939 9.8 22 2.004 2.6 58 1.943 9.6 23 1.934 2.4 59 1.947 9.4 24 1.913 2.2 60 1.955 9.2 25 1.908 2.0 61 1.988 9.0 26 1.903 1.8 62 2.048 8.8 27 1.909 1.6 63 2.049 8.6 28 1.929 1.4 64 1.957 8.4 29 1.987 1.2 65 1.895 8.2 30 2.038 1.0 66 1.937 8.0 31 1.999 0.8 67 2.254 7.8 32 1.937 0.6 68 3.025 7.6 33 1.934 0.4 69 4.318 7.4 34 1.955 0.2 70 6.145 7.2 35 1.950 0.0 71 9.182 7.0 36 1.940

Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 16 of 16 Table 1 (Part 2 of 2)

Unrodded Fxy for Each Core Height for Cycle Burnups Greater Than or Equal to 10,000 MWD/MTU Core Height Axial Unrodded Core Height Axial Unrodded (Ft.) Point Fxy (Ft.) Point Fxy 14.0 1 6.408 6.8 37 2.210 13.8 2 5.134 6.6 38 2.246 13.6 3 3.860 6.4 39 2.213 13.4 4 2.756 6.2 40 2.155 13.2 5 2.530 6.0 41 2.121 13.0 6 2.280 5.8 42 2.113 12.8 7 2.139 5.6 43 2.101 12.6 8 2.070 5.4 44 2.088 12.4 9 2.002 5.2 45 2.105 12.2 10 1.991 5.0 46 2.139 12.0 11 2.001 4.8 47 2.133 11.8 12 2.029 4.6 48 2.075 11.6 13 2.061 4.4 49 2.027 11.4 14 2.055 4.2 50 2.022 11.2 15 2.029 4.0 51 2.009 11.0 16 2.015 3.8 52 1.993 10.8 17 2.026 3.6 53 1.994 10.6 18 2.033 3.4 54 2.028 10.4 19 2.043 3.2 55 2.050 10.2 20 2.073 3.0 56 1.992 10.0 21 2.119 2.8 57 1.939 9.8 22 2.137 2.6 58 1.925 9.6 23 2.104 2.4 59 1.907 9.4 24 2.076 2.2 60 1.879 9.2 25 2.088 2.0 61 1.889 9.0 26 2.099 1.8 62 1.936 8.8 27 2.110 1.6 63 1.965 8.6 28 2.127 1.4 64 1.943 8.4 29 2.166 1.2 65 1.956 8.2 30 2.201 1.0 66 2.067 8.0 31 2.166 0.8 67 2.434 7.8 32 2.133 0.6 68 3.163 7.6 33 2.134 0.4 69 4.275 7.4 34 2.146 0.2 70 5.814 7.2 35 2.157 0.0 71 8.515 7.0 36 2.169