L-2025-069, Cycle 35 Core Operating Limits Report
| ML25099A215 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 04/09/2025 |
| From: | Mack K Florida Power & Light Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-2025-069 | |
| Download: ML25099A215 (1) | |
Text
F=PL..
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-00001 Re:
Florida Power & Light Company Turkey Point Nuclear Plant, Unit 4 Docket Nos. 50-250 April 9, 2025 Subsequent Renewed Facility Operating License DPR-41 Turkey Point Unit 4 Cycle 35 Core Operating Limits Report L-2025-069 10 CFR 50.36 Pursuant to Turkey Point Technical Specification (TS) 5.6.3, Florida Power & Light Company (FPL) is submitting the Unit 4 Core Operating Limits Report (COLR) for operating cycle 35.
This letter contains no new regulatory commitments.
If you have any questions regarding this submittal, please contact Maribel Valdez, Fleet Licensing Manager, at 561-904-5164.
Sincerely, Kenneth A. Mack Director, Licensing and Regulatory Compliance Florida Power & Light Company
Attachment:
Turkey Point Unit 4 Cycle 35 Core Operating Limits Report cc:
Regional Administrator, Region II, USNRC Project Manager, Turkey Point Nuclear Generating Station, USNRC Resident Inspector, Turkey Point Nuclear Generating Station, USNRC Florida Power & Light Company 9760 SW 344th Street, Homestead, FL 33035
Turkey Point Nuclear Plant Docket Nos. 50-250 and 50-251 Turkey Point Unit 4 Cycle 35 Core Operating Limits Report (23 pages follow)
L-2025-069 Attachment
APPENDIX 14B TURKEY POINT PLANT UNIT 4 Core Operating Limits Report (COLR) 148-i Revised 10/11/2019
TABLE OF CONTENTS Section 1.0
SUMMARY
............................................................................................................ 146-1 Appendix A Turkey Point Unit 4 Cycle 35................................................................................. 14B-A 1 I<§>
Core Operating Limits Report (COLR) 14B-ii Revised 10/03/2025
This page intentionally left blank.
148-iii Revised 10/11/2019
1.0
SUMMARY
The Core Operating Limits Report (COLR) for Unit 4 Cycle 35 is provided in Appendix A 14B-1 Revised 10/03/2025
Table 14.B-1 DELETED f@v 14B-2 Revised 10/11/2019
Table 148-2 DELETED 148-3 Revised 10/11/2019
Table 148-3 DELETED 14B-4 Revised 10/11/2019
Figure 148-1 DELETED 14B-5 Revised 10/11/2019
Figure 148-2 DELETED 148-6 Revised 10/11/2019
Appendix A Turkey Point Unit 4 Cycle 35 Core Operating Limits Report (COLR) 14B-A1 Revised 10/03/2025
1.0 Introduction Turkey Point Unit 4 Cycle 35 Core Operating Limits Report This Core Operating Limits Report for Turkey Point Unit 4 Cycle 35 has been prepared in accordance with the requirements of Technical Specification 5.6.3.
The Technical Specifications (TS) affected by this report are listed below with the section and page for each one of the TS addressed in this COLR document.
Section Technical Specification Page 2.1 2.1.1 Reactor Core Sls 14B-A3 2.2 3.3.1 Reactor Trip System (RTS) Instrumentation 14B-A3-14B-A4 2.3 3.1.1 Shutdown Margin (SOM) Limit for MODES 1, 2, 3, 4 14B-A4 3.1.4 14B-A4 3.1.5 14B-A4 3.1.6 14B-A4 3.1.8 14B-A4 2.4 3.1.1 Shutdown Margin (SOM) Limit for MODE 5 14B-A4 2.5 3.1.3 Moderator Temperature Coefficient (MTC) 14B-A5 2.6 3.1.3 MTC Surveillance at EOC 14B-A5 2.7 3.1.7 Rod Position Indication 14B-A5 2.8 3.1.6 Control Bank Insertion Limits 14B-A5a 2.9 3.2.3 Axial Flux Difference (AFD) 14B-A5a 2.10 3.2.1 Heat Flux Hot Channel Factor (Fo(Z))
14B-A6 2.11 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (FN"H) 14B-A6c 2.12 3.4.1 RCS Pressure, Temperature, and Flow Departure 14B-A6c from Nucleate Boiling (DNB) Limits 2.13 3.1.5 Shutdown Bank Insertion Limits 14B-A6c 2.14 3.9.1 Boron Concentration MODE 6 14B-A6c 2.15 Peaking Factor Limit Report 14B-A6c Figure Description A1 Reactor Core Safety Limit - Three Loops in Operation 14B-A7 A2 Required Shutdown Margin vs Reactor Coolant Boron Concentration 14B-A8 A3 Turkey Point Unit 4 Cycle 35 Rod Insertion Limits vs Thermal Power 14B-A9 A4 Axial Flux Difference as a Function of Rated Thermal Power 14B-A10 14B-A2 Revised 10/03/2025
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2.0 OPERATING LIMITS Turkey Point Unit 4 Cycle 35 Core Operating Limits Report The cycle-specific parameter limits for the specifications listed in the Introduction are presented below and listed by Technical Specification (TS). These limits have been developed using the NRG-approved methodologies specified in TS 5.6.3.
2.1 Reactor Core SLs (TS 2.1.1)
Figure A1(page 14B-A7)
In Modes 1 and 2, the combination of Thermal Power, reactor coolant system highest loop average temperature and pressurizer pressure shall not exceed the limits in Figure A 1.
2.2 Reactor Trip System (RTS) Instrumentation (TS 3.3.1)
NOTE 1 on TS Table 3.3.1-1 Overtemperature LiT
't1 = Os, 't2 = Os
't3 = 2s K1 = 1.31 K2 = 0.023/°F
't4 = 25s, 'ts = 3s
'ts= 2s T'::;; 583.0 °F K3 = 0.00116/psi Lead/Lag compensator on measured Li T Lag compensator on measured Li T Time constants utilized in the lead-lag compensator for Tav9 Lag compensator on measured T avg Indicated Loop Tavg at RATED THERMAL POWER P' ~ 2235 psig Nominal RCS operating pressure f1(AI) = 0 for qt - qb between - 18% and + 7%.
For each percent that the magnitude of qt - qb exceeds -18%,
the AT Trip Setpoint shall be automatically reduced by 3.51% of its value at RATED THERMAL POWER; and For each percent that the magnitude of qt - qb exceeds +7%, the AT Trip Setpoint shall be automatically reduced by 2.37% of its value at RATED THERMAL POWER.
Where q, and qb are percent RATED THERMAL POWER in the top and bottom halves of the core respectively, and q, + qb is total THERMAL POWER in percent of RATED THERMAL POWER.
14B-A3 Revised 10/03/2025
Turkey Point Unit 4 Cycle 35 Core Operating Limits Report NOTE 2 on TS Table 3.3.1-1 Overpower ~T K4 = 1.09 Ks~ 0.0/°F Ks= 0.0/°F
't7 ~ 0 s Ks = 0.0016/°F Ks= 0.0 T" ::;; 583.0°F f2 (Lil)= 0 For increasing average temperature For decreasing average temperature Time constants utilized in the lead-lag compensator for Tav9 For T > T" For T :s; T" Indicated Loop Tav9 at RATED THERMAL POWER For all ~I 2.3 Shutdown Margin Limit for MODES 1, 2, 3 and 4 (TS 3.1.1, TS 3.1.4, TS 3.1.5, TS 3.1.6, TS 3.1.8)
Figure A2 (page 14B-A8) 2.4 Shutdown Margin Limit for MODE 5 (TS 3.1.1)
?, 1.70 % Lik/k 14B-A4 Revised 10/03/2025
Turkey Point Unit 4 Cycle 35 Core Operating Limits Report 2.5 Moderator temperature coefficient (MTC) (TS 3.1.3)
- 5, + 5.0 X 10-5 Lik/k/°F From 70% RTP to 100% RTP the MTC decreasing linearly from :5, + 5.0 x 1 o-5 Lik/k/°F to :5. o.o x 10-5 Lik/k/°F Less negative than - 44.0 x 1 o-5 Lik/k/°F 2.6 MTC Surveillance at EOC (TS 3.1.3)
SOL, HZP, ARO and from HZP to 70%
Rated Thermal Power (RTP)
EOL, RTP, ARO Less negative than - 38.0 x 10-5 Lik/k/°F (-38 pcm/°F)
Within 7 EFPD of reaching equilibrium I~
boron concentration of 300 ppm.
The Revised Predicted near - EOL 300 ppm MTC shall be calculated using the algorithm contained in WCAP-13749-P-A:
Revised predicted MTC = Predicted MTC + AFD Correction - 3 pcm/°F If the Revised Predicted MTC is less negative than the SR 3.1.3.2 300 ppm surveillance limit and all the benchmark criteria contained in the surveillance procedure are met, then an MTC measurement in accordance with SR 3.1.3.2 is not required to be performed.
The neutronics methods used with WCAP-13749-P-A are those described in WCAP-16045-P-A, "Qualification of the Two-Dimensional Transport Code PARAGON," August 2004.
The benchmark criteria referenced in SR 3.1.3.2 are contained in WCAP-137 49-P-A In the event that the 300 ppm Surveillance fails to be less negative than the limit, SR 3.1.3.2 need not be ~
repeated if the MTC measured at the equivalent of equilibrium RTP-ARO boron concentration of:::: 60 ppm is less negative than:
-42.8 x 10*5 fik/k/°F (-42.8 pcm/°F) 2.7 Rod Position Indication (TS 3.1.7)
Not Used I~
148-AS Revised 10/03/2025
Turkey Point Unit 4 Cycle 35 Core Operating Limits Report 2.8 Control Bank Insertion Limits (TS 3.1.6)
Figure A3 (page 14B-A9)
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The control rod banks shall be limited in physical insertion as specified in Figure A3 for ARO = 228 steps
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2.9 Axial Flux Difference (AFD) (TS 3.2.3)
Figure A4 (page 14B-A10) withdrawn.
or, within a + /- 2% or + /- 3% target band about the target flux difference during Base Load operation.
PT= Reactor power at which predicted Fa would exceed its limit (consistent with SR 3.2.1.2).
14B-A5a Revised 10/03/2025
Turkey Point Unit 4 Cycle 35 Core Operating Limits Report 2.10 Heat Flux Hot Channel Factor Fo(Z) (TS 3.2.1)
FoL(Z) is the Fo limit at RATED THERMAL POWER and shall be limited by the following relationships:
[F0 ]M(Z)S [F~f x[K(Z)] for P > 0.5 L
[F0 ]M(Z)S [:~ x[K(Z)] for P :5. 0.5 where:
p =
Thermal Power Rated The1*mal Power
[F0]M= The Measured Value,
[Fo]L = 2.40 K(z) = 1.0 For O' 2. z 2. 12' where z is core height in ft
NO TES------------------------------------------------------
- 1. [Fo]P = Predicted Fo, as predicted by approved physics calculations.
- 2. Pr= Reactor power level at which [Fo]P would exceed its limits, [Fo]L/[Fo]P.
- 3. Fi(Z) is the normalized axial power distribution from thimble j at core elevation (Z)
- 4. PRs = minimum value of the ratio of [F6Z)]/[Fo(Z)]RB Meas.
- 5. [Fo(Z)]RB Meas. =[Fxy(Z)]Map Meas. X Fz(Z) X 1.09
- 6. lF6 (Z)J = [F6] x K(Z).
SR3.2.1.1 Fo(Z) shall be evaluated to determine if Fo(Z) is within its limit as follows:
- a.
Increase the measured Fo(Z) component of the power distribution map by 3% to account for manufacturing tolerances and further increasing the value by 5% to account for measurement uncertainties.
- b.
Verify F~(Z) 2. F6(Z)
Where F~ (Z) is the measured Fo(Z) increased by the allowance for manufacturing tolerances and measurement uncertainty and F6 (Z) is the Fo limit.
- c.
With the relationship specified in b. above not being satisfied:
- 1)
Calculate the percent F~(Z) exceeds its limit by the following expression:
((
FtZ)
]-1]x100forP~0.5
[Fa] xK(Z)/P
((
~~CZ)
]-1 ]x 100 for P < 0.5
[Fa] xK(Z)/0.5
- 2)
The following action shall be taken:
a)
Comply with the requirements of Specification 3.2.1 for F~(Z) exceeding its limit by the percent calculated above.
14B-A6 Revised 10/03/2025
SR3.2.1.2 Turkey Point Unit 4 Cycle 35 Core Operating Limits Report MIDSMIDS Operation is permitted at power above PT where PT equals the ratio of [Fo]L divided by [Fo]P if the following Augmented Surveillance (Movable lncore Detection System, MIDS) requirements are satisfied.
- a.
The axial power distribution shall be measured by MIDS when required such that the limit of
[Fo]L/p times K(Z) is not exceeded.
- b.
MIDS shall be operable when the thermal power exceeds PT with:
Base Load
- 1.
At least two thimbles available for which Ri and cri as defined in TS 3.2.1 Bases have been determined.
- 2.
At least two movable detectors available for mapping Fi(Z).
- 3.
The continued accuracy and representativeness of the selected thimbles shall be verified by using the most recent flux map to update the R for each selected thimble. The flux map must be updated at least once per 31 effective full power days.
where:
R = Total peaking factor from a full flux map ratioed to the axial peaking factor in a selected thimble.
j = The thimble location selected for monitoring.
Base Load operation is permitted at powers above PT if the following requirements are satisfied:
- a.
Either of the following preconditions for Base Load operation must be satisfied.
- 1.
For entering Base Load operation with power less than PT, a)
Maintain THERMAL POWER between PT/1.05 and PT for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, b)
Maintain the AFD (Delta-I) within a+/- 2% or+/- 3% target band for at least 23 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br /> per 24-hour period.
c)
After 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> have elapsed after entering base load operation take a full core flux map to determine F~ (Z) unless a valid full core flux map was taken within the time period specified in SR 3.2.1.1.
d)
Calculate PBL per Section b.3 (see next page).
- 2.
For entering Base Load operation with power greater than PT, a)
Maintain THERMAL POWER between PT and the power limit determined in MIDS operation for at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and maintain Augmented Surveillance requirements of MIDS operation during this period.
b)
Maintain the AFD (Delta-I) within a+/- 2% or+/- 3% target band for at least 23 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br /> per 24-hour period, c)
Once within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after entering base load operation take a full core flux map to determine F~ (Z) unless a valid full core flux map was taken within the time period specified in SR 3.2.1.1.
d)
Calculate PBL per Section b.3 (see below).
14B-A6a Revised 10/03/2025
Turkey Point Unit 4 Cycle 35 Core Operating Limits Report
- b.
Base Load operation is permitted provided:
- 1.
THERMAL POWER is maintained between PT and PsL or between PT and 100%
(whichever is most limiting).
- 2.
AFD (Delta-I) is maintained within a +/- 2% or+/- 3% target band.
- 3.
Full core flux maps are taken at least once per 31 effective full power days.
PsL and PT are defined as:
P
[Fof xK(Z)
BL -
M Fo(Z)xW(Z)BLx1.09 PT= [Fo]L/[Fo]P where: F~ (z) is the measured Fo(z) with no allowance for manufacturing tolerances or measurement uncertainty. For the purpose of this Specification
[F~(Z)] shall be obtained between elevations bounded by 10% and 90% of the active core height. [Fo]L is the Fo limit. K(Z) is given in the COLR Section 2.10.
W(z)sL is the cycle dependent function that accounts for limited power distribution transients encountered during base load operation. The W(Z)sL function is given as per Peaking Factor Limit Report, COLR Section 2.15. The 9% uncertainty factor accounts for manufacturing tolerance, measurement error, rod bow and any burnup and power dependent peaking factor increases.
- c.
During Base Load operation, if the THERMAL Power is decreased below PT, then the preconditions for Base Load operation in a. above shall be satisfied before re-entering Base Load operation.
Radial Burndown Radial Burndown operation is permitted at powers above PT if the following Radial Burndown condition is satisfied:
- a.
Radial Burndown operation is restricted to use at powers between PT and PRs or PT and 1.00 (whichever is most limiting). The maximum relative power permitted under Radial Burndown operation, PRs, is equal to minimum value of the ratio of [F6Z)]/[Fo(Z)]Rs Meas.
where: [Fo(Z)]RB Meas. =[Fxy(Z)]Map Meas. x Fz(Z) x 1.09 and
[F6 Z] is equal to [F6] x K(Z).
- b. A full core flux map to determine [Fxy(Z)]Map Meas. shall be taken in accordance with in the SFCP for SR 3.2.1.1. For the purpose of the specification, [Fxy(Z)]Map Meas. shall be obtained between the elevations bounded by 10% and 90% of the active core height.
- c. The function Fz(Z), provided in the Peaking Factor Limit Report (COLR Section 2.15), is determined analytically and accounts for the most perturbed axial power shapes which can occur under axial power distribution control. The uncertainty factor of 9% accounts for manufacturing tolerances, measurement error, rod bow, and any burnup dependent peaking factor increases.
- d. Radial Burndown operation may be utilized at powers between PT and PRs, or PT and 1.00 (whichever is most limiting) provided that the AFD (Delta-I) is within +/- 5% of the target axial offset.
14B-A6b Revised 10/03/2025
Turkey Point Unit 4 Cycle 35 Core Operating Limits Report 2.11 Nuclear Enthalpy Rise Hot Channel Factor (FNt.H) (TS 3.2.2)
FNt.H,::: Ft.HRTP [1.0 + PFt.H(1-P)]
Where:
F llHRTP = 1.650 PF llH = 0.3 F t.HRTP = F t.H limit at RTP PFt.H = Power Factor Multiplier for Ft.H p =
Thermal Power Rated Thermal Power 2.12 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits (TS 3.4.1)
RCS Tavg.:5. 585.0 °F Pressurizer Pressure?. 2204 psig RCS total flow rate =:: 270,000 gpm 2.13 Shutdown Bank Insertion Limits (TS 3.1.5)
The Shutdown Banks shall be limited in physical insertion to ARO position.
2.14 Boron Concentration MODE 6 (TS 3.9.1)
The boron concentration of the Reactor Coolant System (RCS), the refueling canal, and the refueling cavity shall be maintained to ensure that the more restrictive of the following reactivity conditions is met; either:
- a.
A Keff of:,; 0.95, or
- b.
A boron concentration of;,: 2350 ppm.
2.15 Peaking Factors Limit Report The W(z) function(s) for Base Load Operation corresponding to a+/- 2% band about the target flux difference and/or a+/- 3% band about the target flux difference, the Load-Follow function Fz(z) and the augmented surveillance turnon power fraction Pr shall be provided to the U.S. Nuclear Regulatory Commission, whenever Pr is< 1.0. In the event, the option of Base Load Operation will not be exercised, the submission of the W(z) function is not required. Should these values (i.e., W(z), Fz(z) and Pr) change requiring a new submittal or an amended submittal to the Peaking Factor Limit Report, the Peaking Factor Limit Report shall be provided to the NRC Document Control desk with copies to the Regional Administrator and the Resident Inspector within 30 days of their implementation, unless otherwise approved by the Commission.
The analytical methods used to generate the Peaking Factor limits shall be those previously reviewed and approved by the NRC. If changes to these methods are deemed necessary they will be evaluated in accordance with 10 CFR 50.59 and submitted to the NRG for review and approval prior to their use if the change is determined to require NRC approval in accordance with 1 O CFR 50.59 or if such the change would require a change to the Technical Specifications.
14B-A6c Revised 10/03/2025
66(1 MO 640 0,0 Figure A1 Reactor Core Safety Limit - Three Loops in Operation Unacceptable Operation 0.2 0.4 0,0 0.8 1.0 12 Core Power (fraction of 2644 MWt) 14B-A7 Revised 07/21/2016
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250 Figure A2 Required Shutdown Margin vs Reactor Coolant Boron Concentration
!750,1.ool MODE 4 with no RCP in operation MODES 1, 2, 3, and 4 with at least one RCP in operation 500 750 1000 1250 1500 1750 2000 2250 2500 RCS BORON CONCENTRATION (PPM) 14B-A8 Revised 10/03/2025
230 220 210 200 190 180 170 160 c 150 I.'!! 140 "C
s:: j 130 (I) g-120 C 110
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- t
~ 100 C.
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80 70 60 50 40 30 20 10 0
0 Figure A3 Turkey Point Unit 4 Cycle 35 Rod Insertion Limits vs Thermal Power ARO = 228 Steps Withdrawn, Overlap = 100 Steps 163.5, 2281 Banko
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10 20 30 40 50 60 70 80 90 Percent Reactor Power 100 14B-A9 Revised 10/03/2025
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7 ~
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120 100 80 60 40 20 0
-50 UNAC OPE Figure A4 Axial Flux Difference as a Function of Rated Thermal Power Turkey Point Unit 4 Cycle 35
(-9,100
{+7,100 I
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UI IACCEPTJIJ ~E RATION DPERATJO~
V
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ACCEPTJ BLE
(-30,50)
OPERAT ON
(+20,50)
- ------~
-40
-30
-20 0
10 20 30 40 50 Axial Flux Difference (%)
14B-A10 Revised 10/03/2025 I~