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| issue date = 04/20/2017
| issue date = 04/20/2017
| title = Cycle 21 Core Operating Limits Report; Revisions 0 and 1
| title = Cycle 21 Core Operating Limits Report; Revisions 0 and 1
| author name = Dunn R F
| author name = Dunn R
| author affiliation = South Texas Project Nuclear Operating Co
| author affiliation = South Texas Project Nuclear Operating Co
| addressee name =  
| addressee name =  
Line 16: Line 16:


=Text=
=Text=
{{#Wiki_filter:NOC-AE-17003464 Page 2 of 2 cc:  (paper copy
{{#Wiki_filter: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 1 RE20 refueling outage. Revision 0 is applicable to Modes 3, 4, and 5 and Revision 1 incorporates revisions to include Modes 1 and 2.
)  Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, TX 76011
There are no commitments in this letter.
-4511 Lisa M. Regner Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (O8H04) 11555 Rockville Pike
If there are any questions regarding this report, please contact Drew Richards at (361) 972-7666 or me at (361) 972-7743.
amr/RFD Attachments:
Roland F. Dunn
: Manager, Nuclear Fuel & Analysis
: 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


Rockville, MD 20852 NRC Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX   77483
NOC-AE-17003464 Page 2 of 2 cc:
(paper copy)
Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, TX 76011-4511 Lisa M. Regner Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (O8H04) 11555 Rockville Pike Rockville, MD 20852 NRC Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 (electronic copy)
Morgan, Lewis & Bockius LLP Steve Frantz, Esquire Paul Bessette U.S. Nuclear Regulatory Commission Lisa M. Regner NRG South Texas LP Mark Walker Jim von Suskil Skip Zahn CPS Energy Kevin Pollo Cris Eugster L. D. Blaylock City of Austin Elaina Ball John Wester Texas Dept. of State Health Services Helen Watkins Robert Free


(electronic copy)
South Texas Project Unit 1 Cycle 21 Core Operating Limits Report; Revision 0


Morgan, Lewis & Bockius LLP Steve Frantz, Esquire Paul Bessette U.S. Nuclear Regulatory Commission Lisa M. Regner
Core Operating Limits Report Page 1 of 8 SOUTH TEXAS PROJECT Unit 1 Cycle 21 CORE OPERATING LIMITS REPORT Revision 0 MODES 3, 4 and 5


NRG South Texas LP Mark Walker Jim von Suskil Skip Zahn CPS Energy Kevin Pollo Cris Eugster L. D. Blaylock City of Austin Elaina Ball John Wester Texas Dept. of State Health Services Helen Watkins Robert Free
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.
 
Attachment 1 South Texas Project Unit 1 Cycle 21 Core Operating Limits Report; Revision 0
 
Core Operating Limits Report Page 1 of 8 
 
SOUTH  TEXAS  PROJECT Unit 1 Cycle 2 1  CORE  OPERATING  LIMITS  REPORT Revision 0 MODES  3,  4  and 5
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:
The Technical Specifications affected by this report are:
: 1) 2.1 SAFETY LIMITS
: 1) 2.1 SAFETY LIMITS
Line 44: Line 45:
: 8) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR
: 8) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR
: 9) 3/4.2.3 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR
: 9) 3/4.2.3 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR
: 10) 3/4.2.5 DNB PARAMETERS
: 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.


===2.0 OPERATING===
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):
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:
The SHUTDOWN MARGIN shall be:
2.3.1 Will be added prior to initial U1C21 Mode 2 entry
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.
2.3.2 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.  


====2.3.3 Greater====
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):
than the limits in Figure 3 for MODE 5.
2.9.1 Will be added prior to initial U1C21 Mode 2 entry.  
 
===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==
==3.0 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).


===3.1 Letter===
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.  
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 Redesig n," NF-TG-09-26 (ST-UB-NOC-17 00 3590), April 6 , 20 17. 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 2Required Shutdown Margin for Modes 3 & 40.01.02.03.04.05.0 6.0 7.0 0 400 800 1200 1600 2000 2400RCS Critical Boron Concentration (ppm)(for ARI minus most reactive stuck rod)Required Shutdown Margin (% Delta Rho)UnacceptableAcceptable ( 0 , 1.30 )( 2400 , 5.15 )( 600 , 1.30 )
Unit 1 Cycle 21 Core Operating Limits Report Rev. 0 Modes 3, 4 and 5 Page 7 of 8    Figure 3Required Shutdown Margin for Mode 50.01.02.03.0 4.05.06.07.0 0 400 800 1200 1600 2000 2400RCS Critical Boron Concentration (ppm)(for ARI minus most reactive stuck rod)Required Shutdown Margin (% Delta Rho)UnacceptableAcceptable ( 0 , 1.30 )( 2400 , 4.50 )( 650 , 1.30 )
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
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 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0
. -------------------------------------------------------------------------------
400 800 1200 1600 2000 2400 RCS Critical Boron Concentration (ppm)
---------------------------------------------------
(for ARI minus most reactive stuck rod)
FIGURE  7  K(Z) - Normalized F Q(Z) versus Core Height
Required Shutdown Margin (% Delta Rho)
Unacceptable Acceptable
( 0, 1.30 )
( 2400, 5.15 )
( 600, 1.30 )


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 7 of 8 Figure 3 Required Shutdown Margin for Mode 5 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0
. ----------------------------------------------------------------------------------------------
400 800 1200 1600 2000 2400 RCS Critical Boron Concentration (ppm)
------------------------------------
(for ARI minus most reactive stuck rod)
TABLE  1 Unrodded FXY for Each Core Height
Required Shutdown Margin (% Delta Rho)
Unacceptable Acceptable
( 0, 1.30 )
( 2400, 4.50 )
( 650, 1.30 )


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


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


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.
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:
The Technical Specifications affected by this report are:
: 1) 2.1 SAFETY LIMITS
: 1) 2.1 SAFETY LIMITS
Line 148: Line 130:
: 8) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR
: 8) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR
: 9) 3/4.2.3 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR
: 9) 3/4.2.3 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR
: 10) 3/4.2.5 DNB PARAMETERS
: 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.


===2.0 OPERATING===
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:
LIMITS The cycle-specific parameter limits for the specifications listed in Section 1.0 are presented 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)


===2.1 SAFETY===
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 4 of 16 2.3 SHUTDOWN MARGIN1 (Specification 3.1.1.1):
LIMITS  (Specification 2.1):
The SHUTDOWN MARGIN shall be:
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
2.3.1 Greater than 1.3% for MODES 1 and 2*  
: 1. 2.2 LIMITING SAFETY SYSTEM SETTINGS  (Specification 2.2):
*See Special Test Exception 3.10.1 2.3.2 Greater than the limits in Figure 2 for MODES 3 and 4.
2.2.1 The Loop design flow for Reactor Coolant Flow
2.3.3 Greater than the limits in Figure 3 for MODE 5.
-Low is 98,000 gpm.
2.4 MODERATOR TEMPERATURE COEFFICIENT (Specification 3.1.1.3):
 
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 K 1 Overtemperature T reactor trip setpoint, K 1 = 1.14 K 2 Overtemperature T reactor trip setpoint Tavg coefficient, K 2 = 0.028/°F K3  Overtemperature T reactor trip setpoint pressure coefficient, K 3 = 0.00143/psi T' Nominal full power Tavg, T' 592.0 °F P' Nominal RCS pressure, P' = 2235 psig f 1 (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 q t - q b between -70% and +8%, f 1 (I)  =  0, where q t and q b are percent RATED THERMAL POWER in the top and bottom halves of the core respectively, a nd q t + q b is total THERMAL POWER in percent of RATED THERMAL POWER; (2) For each percent that q t - q b 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 q t - q b 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 K 4 Overpower T reactor trip setpoint, K 4 = 1.08 K 5 Overpower T reactor trip setpoint Tavg rate/lag coefficient,  K 5 = 0.02/°F for increasing average temperature, and K5  = 0 for decreasing average temperature K 6 Overpower T reactor trip setpoint Tavg heatup coefficient K 6  = 0.002/°F for T > T", and  K 6  =  0 for T  T" T" Indicated full power Tavg, T"  592.0 °F f 2 (I) = 0 for all (I)
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 4 of 16   2.3 SHUTDOWN MARGIN 1 (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.
2.4.1 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  
2.4.2 The EOL, ARO, HFP, MTC shall be less negative than -62.6 pcm/°F.
-62.6 pcm/ F. 2.4.3 The 300 ppm, ARO, HFP, MTC shall be less negative than  
2.4.3 The 300 ppm, ARO, HFP, MTC shall be less negative than -53.6 pcm/°F (300 ppm Surveillance Limit).
-53.6 pcm/ F (300 ppm Surveillance Limit).
Where:
Where: BOL stands for Beginning
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),
-of-Cycle Life, EOL stands for End
HFP vessel average temperature is 592 °F.
-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
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:
-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.
Revised Predicted MTC = Predicted MTC
2.5 ROD INSERTION LIMITS1 (Specification 3.1.3.5 and 3.1.3.6):
+ 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 LIMITS 1  (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.
2.5.1 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.
2.5.2 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.


====2.5.3 Individual====
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 5 of 16 2.6 AXIAL FLUX DIFFERENCE (Specification 3.2.1):
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).
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 FQRTP = 2.55.
2.7.2 K(Z) is provided in Figure 7.
2.7.3 The Fxy limits for RATED THERMAL POWER (Fxy RTP) 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).  


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 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:
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 5 of 16   2.6 AXIAL FLUX DIFFERENCE  (Specification 3.2.1):
UFQ = UQU*UE Where:
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.
UQU = Base FQ measurement uncertainty of 1.05.
2.7 HEAT FLUX HOT CHANNEL FACTOR (Specification 3.2.2):
UE =
2.7.1 F QRTP  = 2.55. 2.7.2 K(Z) is provided in Figure
Engineering uncertainty factor of 1.03.
: 7. 2.7.3 The F xy limits for RATED THERMAL POWER (Fxy RTP)  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
2.8 ENTHALPY RISE HOT CHANNEL FACTOR (Specification 3.2.3):
-dependent value from Table 1 for all unrodded core planes.
2.8.1 FH RTP = 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 FH N
2.7.3.3 PF xy = 0.2. These F xy limits were used to confirm that the heat flux hot channel factor F Q(Z) will be limited by Technical Specification 3.2.2 assuming the most
using the PDMS shall be the greater of:
-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
UFH = 1.04 OR UFH = 1.0 + (UH/100)
-8385. Therefore, these F xy 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 (U FQ) to be applied to the F Q(Z) and F xy(Z) using the PDMS shall be calculated by:
Where:
U FQ = (1.0 + (U Q/100))*U E Where: U Q = Uncertainty for power peaking factor as defined in Equation 5
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.
-19 from the document referenced by Technical Specification  
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


6.9.1.6.b.11 U E = Engineering uncertainty factor of 1.03.
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 7 of 16 2.9 DNB PARAMETERS (Specification 3.2.5):
This uncertainty is calculated and applied automatically by the Power Distribution Monitoring System (PDMS).
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.  
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 (U FQ) to be applied to the F Q(Z) and F xy(Z) shall be calculated by:
U FQ = U QU*U E Where: UQU = Base F Q measurement uncertainty of 1.05.
U E = Engineering uncertainty factor of 1.03.


===2.8 ENTHALPY===
==3.0 REFERENCES==
RISE HOT CHANNEL FACTOR  (Specification 3.2.3):
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.
====2.8.1 FHRTP====
3.3 STPNOC Calculation ZC-7035, Rev. 2, Loop Uncertainty Calculation for RCS Tavg Instrumentation, Section 10.1.
=  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 (U FH) to be applied to the FH N using the PDMS shall be the greater of:
3.4 STPNOC Calculation ZC-7032, Rev. 6, Loop Uncertainty Calculation for Narrow Range Pressurizer Pressure Monitoring Instrumentation, Section 2.3, Page 9.
U FH = 1.04    OR U FH = 1.0 + (UH/100) Where: UH = Uncertainty for power peaking factor as defined in Equation 5
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.
-19 from the document referenced in Technical Specification
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.


6.9.1.6.b.11.
Nuclear Operating Company 680 I c 2, 664_52 )
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 (U FH) shall be: U FH = 1.0 4 Unit 1 Cycle 21 Core Operating Limits Report Rev. 1  Page 7 of 16  2.9 DNB PARAMETERS  (Specification 3.2.5):
-I""--..............
2.9.1 The following DNB
660 640
-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 gpm
,-... 620
: 4.
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20 Unit 1 Cycle 21 Core Operating Limits Report Figure 1 Reactor Core Safety Limits - Four Loops in Operation I I Unacceptable r--..............
~r--....,
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c 96, 638_57 ) I
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40 60 80 100 120 Rated Thermal Power(%)
'\\
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Rev. 1 Page 8of16 c 130, 600_11 ) I c 130, 589_08) I c 130, 563_93 ) I 140


==3.0 REFERENCES==
Nuclear Operating Company 7.0
: 6. 0
: 5. 0 0
0
: 2. 0 ICO, UO )I
: 1. 0
: 0. 0 0
400 Unit 1 Cycle 21 Core Operating Limits Report Figure 2 Required Shutdown Margin for Modes 3 & 4 I Acceptable I
/
v
~
~ v
~v
~'
/
v v
v
/
/
/
/
/'
/';"
/,,
! Unacceptable !
/
IC 600, uo )I 800 1200 1600 RCS Critical Boron Concentration (ppm)
(for ARI minus most reactive stuck rod) 2000
/
v Rev. 1 Page 9of16 c 2400, 5_15 )I
/
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2400


===3.1 Letter===
Nuclear Operating Company 7.0 6.0 5.0 2.0 1c o, uo ) I 1.0 0.0 0
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-17 00 3 573, Rev. 1) dated April 12, 2017. 3.2 NUREG-1346, Technical Specifications, South Texas Project Unit Nos. 1 and 2.
400 Unit 1 Cycle 21 Core Operating Limits Report Figure 3 Required Shutdown Margin for Mode 5 I
I 1 Acceptable 1
/~
/
v v
v
~/
~/
,/ v
_/ v
/ v-
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/r-
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! Unacceptable !
IC 650, uo )
800 1200 1600 RCS Critical Boron Concentration (ppm)
(for ARI minus most reactive stuck rod) 2000 Rev. 1 Page 10of16 1( 2400,4.50)1  
/
/ v
/"'
2400


===3.3 STPNOC===
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 11 of 16
Calculation ZC
-3.0
-7035, Rev. 2, "Loop Uncertainty Calculation for RCS Tavg Instrumentation," Section 10.1.
-2.0
-1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0
10 20 30 40 50 60 70 80 90 100 Moderator Temperature Coefficient (pcm/&deg;F)
Rated Thermal Power (%)
Figure 4 MTC versus Power Level Unacceptable Acceptable


===3.4 STPNOC===
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 12 of 16
Calculation ZC
-7032, Rev.
6, "Loop Uncertainty Calculation for Narrow Range Pressurizer Pressure Monitoring Instrumentation," Section 2.3, Page 9.


===3.5 Letter===
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 13 of 16 0
from J. S Wyble (Westinghouse) to T. J. Jordan (STPNOC), "STP Nuclear Operating Company Units 1 & 2 Power Uprate PCWG Parameters," ST
10 20 30 40 50 60 70 80 90 100 110 120
-WN-NOC-00-000072 dated December 15, 2000, STI 31218644
-50
. 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 f 1 (Calculation," NF
-40
-TG-11-93 (ST-UB-NOC-11003215) dated November 10, 2011.
-30
-20
-10 0
10 20 30 40 50 Rated Thermal Power (%)
Axial Flux Difference (% Delta-I)
Figure 6 AFD Limits versus Power Level Unacceptable Acceptable Unacceptable
( -31, 50 )
( 11, 90 )
( -11, 90 )
( 31, 50 )


===3.7 Document===
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 14 of 16
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. 


Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 11 of 16   -3.0-2.0-1.00.01.02.03.04.05.06.07.0 0 10 20 30 40 50 60 70 80 90 100Moderator Temperature Coefficient (pcm/
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 15 of 16 Table 1 (Part 1 of 2)
&deg;F)Rated Thermal Power (%)Figure 4MTC versus Power LevelUnacceptableAcceptable 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  0 10 20 30 40 50 60 70 80 90100110120-50-40-30-20-10 0 10 20 30 40 50Rated Thermal Power (%)Axial Flux Difference (% Delta
Unrodded Fxy for Each Core Height for Cycle Burnups Less Than 10,000 MWD/MTU Core Height Axial Unrodded Core Height Axial Unrodded (Ft.)
-I)Figure 6AFD Limits versus Power LevelUnacceptableAcceptableUnacceptable ( -31 , 50 )( 11 , 90 )( -11 , 90 )( 31 , 50 )
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 14 of 16 Unit 1 Cycle 21  Core Operating Limits Report Rev. 1  Page 15 of 16     Table 1 (Part 1 of 2)
Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 16 of 16 Table 1 (Part 2 of 2)
Unrodded F xy 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 1.97 2 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 2.13 3 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 1 0.0 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}}
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}}

Latest revision as of 10:22, 9 January 2025

Cycle 21 Core Operating Limits Report; Revisions 0 and 1
ML17110A499
Person / Time
Site: South Texas STP Nuclear Operating Company icon.png
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 1 RE20 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.

amr/RFD Attachments:

Roland F. Dunn

Manager, Nuclear Fuel & Analysis
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)

Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, TX 76011-4511 Lisa M. Regner Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (O8H04) 11555 Rockville Pike Rockville, MD 20852 NRC Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 (electronic copy)

Morgan, Lewis & Bockius LLP Steve Frantz, Esquire Paul Bessette U.S. Nuclear Regulatory Commission Lisa M. Regner NRG South Texas LP Mark Walker Jim von Suskil Skip Zahn CPS Energy Kevin Pollo Cris Eugster L. D. Blaylock City of Austin Elaina Ball John Wester Texas Dept. of State Health Services Helen Watkins Robert Free

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

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

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 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0

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

(for ARI minus most reactive stuck rod)

Required Shutdown Margin (% Delta Rho)

Unacceptable Acceptable

( 0, 1.30 )

( 2400, 5.15 )

( 600, 1.30 )

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 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0

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

(for ARI minus most reactive stuck rod)

Required Shutdown Margin (% Delta Rho)

Unacceptable Acceptable

( 0, 1.30 )

( 2400, 4.50 )

( 650, 1.30 )

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.

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

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

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 FQRTP = 2.55.

2.7.2 K(Z) is provided in Figure 7.

2.7.3 The Fxy limits for RATED THERMAL POWER (Fxy RTP) 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 FH RTP = 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 FH N

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.

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Unit 1 Cycle 21 Core Operating Limits Report Rev. 1 Page 11 of 16

-3.0

-2.0

-1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0

10 20 30 40 50 60 70 80 90 100 Moderator Temperature Coefficient (pcm/°F)

Rated Thermal Power (%)

Figure 4 MTC versus Power Level Unacceptable Acceptable

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 0

10 20 30 40 50 60 70 80 90 100 110 120

-50

-40

-30

-20

-10 0

10 20 30 40 50 Rated Thermal Power (%)

Axial Flux Difference (% Delta-I)

Figure 6 AFD Limits versus Power Level Unacceptable Acceptable Unacceptable

( -31, 50 )

( 11, 90 )

( -11, 90 )

( 31, 50 )

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