ML15154A512

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Cycle 21 Core Operating Limits Report, Revision 0
ML15154A512
Person / Time
Site: Sequoyah Tennessee Valley Authority icon.png
Issue date: 05/27/2015
From: John Carlin
Tennessee Valley Authority
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
L36 150506 800
Download: ML15154A512 (18)
v • d • e


Text

Tennessee Valley Authority, Post Office Box 2000, Soddy Daisy, Tennessee 37384-2000 May 27, 2015 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Sequoyah Nuclear Plant, Unit 1 Facility Operating License No. DPR-77 NRC Docket No. 50-327

Subject:

Sequoyah Unit I Cycle 21 Core Operating Limits Report In accordance with Sequoyah Nuclear Plant (SQN) Unit 1 Technical Specification (TS) 6.9.1.14.c, enclosed is the Unit 1 Cycle 21 Core Operating Limits Report (COLR), Revision 0. In accordance with TS 6.9.1.14.c, the COLR is required to be provided to the Nuclear Regulatory Commission within 30 days after the cycle start-up (Mode 2) for each reload cycle. Sequoyah Unit 1 entered Mode 2 on May 15, 2015, for the current reload cycle.

There are no new regulatory commitments in this letter. If you have any questions, please contact Erin Henderson, SQN Site Licensing Manager at (423) 843-7170.

Jo*hn T. CY*ali n /' ,

Site Vice President Sequoyah Nuclear Plant Enclosure Sequoyah Unit 1 Cycle 21 Core Operating Limits Report cc (Enclosure):

NRC Regional Administrator- Region II NRC Senior Resident Inspector - SQN 01

ENCLOSURE SEQUOYAH UNIT 1 CYCLE 21 CORE OPERATING LIMITS REPORT

QA Record L36 150506 800 SEQUOYAH UNIT I CYCLE 21 CORE OPERATING LIMITS REPORT REVISION 0 May 2015 Prepared by:

W. Andrew Whitener, Nulear Fuels Program & Oversight Date Prepared by:

Date Mark D. Porter, PWR Fuel Engineering Date Verified by:

Christine A. Setter, PWR Fuel Engineering Date Reviewed by:

Da-zo/te Kithlee ;A. Cunningham, PWR Fuel Engineering Manager Date Brandon S. Catalanotto, Reactor ER*ineering Supervisor Date Approved by:

PO ai S-7/'20--

Date Plant Manager Dte Revision 0 Pages affected All Reason for Revision: Initial Issue SEQUOYAH-UNIT 1 Page 1 of 16 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 21 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for Sequoyah Unit 1 Cycle 21 has been prepared in accordance with the requirements of Technical Specification (TS) 6.9.1.14.

The TSs affected by this Report are listed below:

TABLE 2.2-1 fl(Al) trip reset function for OTAT Trip (QTNL, QTPL) and rates of trip setpoint decrease per percent Al (QTNS, QTPS)

TABLE 2.2-1 f2(AI) trip reset function for OPAT Trip (QPNL, QPPL) and rates of trip setpoint decrease per percent Al (QPNS, QPPS) 3/4.1.1.3 Moderator Temperature Coefficient (MTC) 3/4.1.3.5 Shutdown Rod Insertion Limit 3/4.1.3.6 Control Rod Insertion Limits 3/4.2.1 Axial Flux Difference (AFD) 3/4.2.2 Heat Flux Hot Channel Factor (FQ(X,Y,Z))

3/4.2.3 Nuclear Enthalpy Rise Hot Channel Factor (FAH(X,Y))

2.0 OPERATING LIMITS The cycle-specific parameter limits for the specifications listed in section 1.0 are presented in the following subsections. These limits have been developed using the NRC approved methodologies specified in TS 6.9.1.14. The versions of the topical reports which describe the methodologies used for this cycle are listed in Table 1.

The following abbreviations are used in this section:

BOL stands for Beginning of Cycle Life ARO stands for All Rods Out HZP stands for Hot Zero THERMAL POWER EOL stands for End of Cycle Life RTP stands for RATED THERMAL POWER SEQUOYAH-UNIT 1 Page 2 of 16 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 21 2.1 ModeratorTemperature Coefficient - MTC (Specification 3/4.1.1.3) 2.1.1 The MTC limits are:

The BOL/ARO/HZP MTC shall be less positive than 0 Ak/k/°F (BOL limit). With the measured value more positive than

-0.05 x 105 Ak/k/OF, establish control rod withdrawal limits to ensure the MTC remains less positive than 0 Ak/k/°F for all times in core life.

The EOL/ARO/RTP MTC shall be less negative than or equal to -4.5 x 10-4 Ak/k/IF.

2.1.2 The 300 ppm surveillance limit is:

The measured 300 ppm/ARO/RTP MTC shall be less negative than or equal to -3.74 x 10-4 Ak/k/°F.

2.2 Shutdown Rod Insertion Limit (Specification 3/4.1.3.5) 2.2.1 The shutdown rods shall be withdrawn to a position as defined below:

Cycle Burnup Steps Withdrawn (MWd/mtU)

>0 > 225 to < 231 2.3 Control Rod Insertion Limits (Specification3/4.1.3.6) 2.3.1 The control rod banks shall be limited in physical insertion as shown in Figure 1.

2.4 Axial Flux Difference - AFD (Specification3/4.2.1) 2.4.1 The axial flux difference (AFD) limits (AFDLimit) are provided in Figure 2.

SEQUOYAH-UNIT 1 Page 3 of 16 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 21 2.5 Heat Flux Hot Channel Factor- FQ(X, YZ) (Specification 3/4.2.2)

FQ(X,Y,Z) shall be limited by the following relationships:

RTP FQ (X.Y.Z)*<

  • K(Z) for P > 0.5 RTP FQ (XY,Z) 0<

.

  • K(Z) for P*5 0.5 THERMAL POWER where P - RATED THERMAL POWER 2.5.1 FoRTP = 2 .6 2 2.5.2 K(Z) is provided in Figure 3.

The following parameters are required for core monitoring per the Surveillance Requirements of Specification 3/4.2.2:

2.5.3 NSLOPEAFD = 1.21 where NSLOPEAFD = Negative AFD limit adjustment required to compensate for each 1% that FQ (X,Y,Z) exceeds BQDES.

2.5.4 PSLOPEAFD = 1.55 where PSLOPEAFD = Positive AFD limit adjustment required to compensate for each 1% that FQ(X,Y,Z) exceeds BQDES.

2.5.5 NSLOPEf2 (AI) = 1.48 where NSLOPEf2(AI)= Adjustment to negative OPAT f2 (AI) limit required to compensate for each 1 % that FQ(X,Y,Z) exceeds BCDES.

2.5.6 PSLOPEf2 (Al) = 2.00 where PSLOPEf2(AI)= Adjustment to positive OPAT f2 (Al) limit required to compensate for each 1% that FQ(X,Y,Z) exceeds BCDES.

SEQUOYAH-UNIT 1 Page 4 of 16 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 21 2.5.7 BQNOM(X,YZ) = Nominal design peaking factor, increased by an allowance for the expected deviation between the nominal design power distribution and the measurement.

2.5.8 BQDES(X,YZ) = Maximum allowable design peaking factor which ensures that the F0 (X,YZ) limit will be preserved for operation within the LCO limits, including allowances for calculational and measurement uncertainties.

2.5.9 BCDES(X,YZ) = Maximum allowable design peaking factor which ensures that the centerline fuel melt limit will be preserved for operation within the LCO limits, including allowances for calculational and measurement uncertainties.

BQNOM(X,Y,Z), BQDES(X,Y,Z), and BCDES(X,Y,Z) databases are provided for input to the plant power distribution analysis codes on a cycle-specific basis and are determined using the methodology for core limit generation described in the references in Specification 6.9.1.14.

2.5.10 The increase in FQM(X,YZ) for compliance with the 4.2.2.2.e Surveillance Requirements is defined as follows.

For all cycle burnups, use 2.0%

SEQUOYAH-UNIT 1 Page 5 of 16 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 21 2.6 Nuclear Enthalpy Rise Hot Channel Factor- FdH(X, V)

(Specification 3/4.2.3)

FAH(X,Y) shall be limited by the following relationship:

FAH(X,Y) - MAP(X,Y,Z) / AXIAL(X,Y) 2.6.1 MAP(X,YZ) is provided in Table 2.

AXIAL(X,Y) is the axial peak from the normalized axial power shape.

The following parameters are required for core monitoring per the Surveillance Requirements of Specification 3/4.2.3:

FAHR M(X,Y) _ BHNOM(X,Y) where FAHR M(X,Y) = FAHM (X,Y) / [MAPM / AXIAL(X,Y)]

FAHM (X,Y) is' the measured radial peak at location X,Y.

MAPM is the value of MAP(X,Y,Z) obtained from Table 2 for the measured peak.

2.6.2 BHNOM(X,Y) = Nominal design radial peaking factor, increased by an allowance for the expected deviation between the nominal design power distribution and the measurement.

2.6.3 BHDES(X,Y) = Maximum allowable design radial peaking factor which ensures that the FAH (X,Y) limit will be preserved for operation within the LCO limits, including allowances for calculational and measurement uncertainties.

2.6.4 BRDES(X,Y) = Maximum allowable design radial peaking factor which ensures that the steady state DNBR limit will be preserved for operation within the LCO limits, including allowances for calculational and measurement uncertainties.

BHNOM(X,Y), BHDES(X,Y) and BRDES(X,Y) databases are provided for input to the plant power distribution analysis computer codes on a cycle-specific basis and are determined using the methodology for core limit generation described in the references in Specification 6.9.1.14.

SEQUOYAH-UNIT 1 Page 6 of 16 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 21 2.6.5 RRH = 3.34 when 0.8 < P < 1.0 RRH = 1.67 when P < 0.8 where RRH = Thermal power reduction required to compensate for each 1% that FAH(X,Y) exceeds its limit.

P = Thermal Power / Rated Thermal Power 2.6.6 TRH = 0.0334 when 0.8 < P < 1.0 TRH = 0.0167 when P < 0.8 Where TRH= Reduction in OTAT K1 setpoint required to compensate for each 1% that FAH(X,Y) exceeds its limit.

P = Thermal Power / Rated Thermal Power 2.6.7 All cycle burnups shall use a 2% increase in FAHM (X,Y) for compliance with the 4.2.3.2.d.1 Surveillance Requirement.

SEQUOYAH-UNIT 1 Page 7 of 16 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 21 3.0 REACTOR CORE PROTECTIVE LIMITS 3.1 Trip Reset Term [fF(AI)] for OvertemperatureDelta-T Trip (Specification2.2.1)

The following parameters are required to specify the power level-dependent fl(AI) trip reset term limits for the Overtemperature Delta-T trip function:

3.1.1 QTNL = -20%

where QTNL = the maximum negative Al setpoint at rated thermal power at which the trip setpoint is not reduced by the axial power distribution.

3.1.2 QTPL = +5%

where QTPL = the maximum positive Al setpoint at rated thermal power at which the trip setpoint is not reduced by the axial power distribution.

3.1.3 QTNS = 2.50%

where QTNS = the percent reduction in Overtemperature Delta-T trip setpoint for each percent that the magnitude of Al exceeds its negative limit at rated thermal power (QTNL).

3.1.4 QTPS = 1.40%

where QTPS = the percent reduction in Overtemperature Delta-T trip setpoint for each percent that the magnitude of Al exceeds its positive limit at rated thermal power (QTPL).

SEQUOYAH-UNIT 1 Page 8 of 16 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 21 3.2 Trip Reset Term ff2 (AI)] for Overpower Delta-T Trip (Specification 2.2.1)

The following parameters are required to specify the power level-dependent f2(AI) trip reset term limits for the Overpower Delta-T trip function:

3.2.1 QPNL = -25%

where QPNL = the maximum negative Al setpoint at rated thermal power at which the trip setpoint is not reduced by the axial power distribution.

3.2.2 QPPL = +25%

where QPPL = the maximum positive Al setpoint at rated thermal power at which the trip setpoint is not reduced by the axial power distribution.

3.2.3 QPNS = 1.70%

where QPNS = the percent reduction in Overpower Delta-T trip setpoint for each percent that the magnitude of Al exceeds its negative limit at rated thermal power (QPNL).

3.2.4 QPPS = 1.70%

where QPPS = the percent reduction in Overpower Delta-T trip setpoint for each percent that the magnitude of Al exceeds its positive limit at rated thermal power (QPPL).

SEQUOYAH-UNIT 1 Page 9 of 16 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 21 Table 1 COLR Methodology Topical Reports

1. BAW-10180-A, Revision 1, "NEMO-Nodal Expansion Method Optimized," March 1993.

(Methodology for Specification 3/4.1.1.3-Moderator Temperature Coefficient)

2. BAW-10169P-A, Revision 0, "RSG Plant Safety Analysis-B&W Safety Analysis Methodology for Recirculating Steam Generator Plants," October 1989.

(Methodology for Specification 3/4.1.1.3-Moderator Temperature Coefficient)

3. BAW-10163P-A, Revision 0, "Core Operating Limit Methodology for Westinghouse-Designed PWRs," June 1989.

(Methodology for Specifications 2.2.1-Reactor Trip Instrumentation Setpoints [f1(AI),

f2(AI) limits], 3/4.1.3.5-Shutdown Rod Insertion Limit, 3/4.1.3.6-Control Rod Insertion Limits, 3/4.2.1-Axial Flux Difference, 3/4.2.2-Heat Flux Hot Channel Factor, 3/4.2.3-Nuclear Enthalpy Rise Hot Channel Factor)

4. EMF-2328(P)(A), "PWR Small Break LOCA Evaluation Model," March 2001.

(Methodology for Specification 3/4.2.2-Heat Flux Hot Channel Factor)

5. BAW-10227P-A, Revision 1, "Evaluation of Advanced Cladding and Structural Material (M5) in PWR Reactor Fuel," June 2003.

(Methodology for Specification 3/4.2.2-Heat Flux Hot Channel Factor)

6. BAW-10186P-A, Revision 2, "Extended Burnup Evaluation," June 2003.

(Methodology for Specification 3/4.2.2-Heat Flux Hot Channel Factor)

7. EMF-2103P-A, Revision 0, "Realistic Large Break LOCA Methodology for Pressurized Water Reactors," April 2003.

(Methodology for Specification 3/4.2.2-Heat Flux Hot Channel Factor)

8. BAW-1 0241 P-A, Revision 1, "BHTP DNB Correlation Applied with LYNXT," July 2005.

(Methodology for Specification 3/4.2.3-Enthalpy Rise Hot Channel Factor)

9. BAW-10199P-A, Revision 0, "The BWU Critical Heat Flux Correlations," August 1996.

(Methodology for Specification 3/4.2.3-Enthalpy Rise Hot Channel Factor)

10. BAW-10189P-A, "CHF Testing and Analysis of the Mark-BW Fuel Assembly Design,"

January 1996.

(Methodology for Specification 3/4.2.3-Enthalpy Rise Hot Channel Factor)

11. BAW-1 01 59P-A, "BWCMV Correlation of Critical Heat Flux in Mixing Vane Grid Fuel Assemblies," August 1990.

(Methodology for Specification 3/4.2.3-Enthalpy Rise Hot Channel Factor)

12. BAW-1 0231 P-A, Revision 1, "COPERNIC Fuel Rod Design Computer Code," January 2004.

(Methodology for Specification 2.2.1-Reactor Trip Instrumentation Setpoints)

SEQUOYAH-UNIT 1 Page 10 of 16 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 21 Table 2 Maximum Allowable Peaking Limits MAP(X,Y,Z) for Operation AXIAL(X,Y) ELEVATION (ft) MAP(X,Y,Z) AXIAL(X,Y) ELEVATION (ft) MAP(X,Y,Z) 1 1.8128 1 2.5969 2 1.8125 2 2.5380 3 1.8122 3 2.4827 4 1.8119 4 2.4411 5 1.8115 5 2.4315 1.1 6 1.8109 1.4 6 2.4800 7 1.8106 7 2.5356 8 1.8104 8 2.4447 9 1.8098 9 2.3555 10 1.8092 10 2.1738 11 1.7599 11 2.0238 1 2.0671 1 2.6723 2 2.0664 2 2.6061 3 2.0656 3 2.5417 4 2.0649 4 2.4913 5 2.0642 5 2.4801 1.2 6 2.0636 1.5 6 2.5380 7 2.0624 7 2.6273 8 2.0615 8 2.5311 9 2.0457 9 2.4447 10 1.9492 10 2.2772 11 1.8589 11 2.0975 1 2.3433 1 2.7308 2 2.3419 2 2.6605 3 2.3412 3 2.5947 4 2.3397 4 2.5371 5 2.3389 5 2.5234 1.3 6 2.3381 1.6 6 2.5906 7 2.3357 7 2.7077 8 2.3130 8 2.6117 9 2.1886 9 2.5240 10' 2.0643 10 2.3758 11 1.9439 11 2.1662 SEQUOYAH-UNIT 1 Page 11 of 16 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 21 Table 2'(continued)

AXIAL(X,Y) ELEVATION (ft) MAP(X,Y,Z) AXIAL(X,Y) ELEVATION (ft) MAP(X,Y,Z) 1 2.7664 1 2.4339 2 2.7083 2 2.4060 3 2.6380 3 2.3856 4 2.5791 4 2.3423 5 2.5639 5 2.3114 1.7 6 2.6359 >1.9 6 2.6006 7 2.7795 7 2.5003 8 2.6870 8 2.4004 9 2.5798 9 2.2989 10 2.4726 10 2.1483 11 2.2304 11 1.9630 1 2.7963 1 2.5057 2 2.7466 2 2.4754 3 2.6775 3 2.4449 4 2.6172 4 2.3591 5 2.6010 5 2.4205 1.8 6 2.6802 2.1 6 2.7643 7 2.8456 7 2.6474 8 2.7552 8 2.5360 9 2.6648 9 2.4400 10 2.5655 10 2.3277 11 2.2931 11 2.0549 1 2.8235 1 2.5380 2 2.7739 2 2.5216 3 2.7125 3 2.4619 4 2.6523 4 2.4294 5 2.6328 5 2.4290 1.9 6 2.7200 2.3 6 2.8222 7 2.9065 7 2.7334 8 2.8193 8 2.6234 9 2.7288 9 2.5186 10 2.6384 10 2.4215 11 2.3482 11 2.1250 SEQUOYAH-UNIT 1 Page 12 of 16 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 21 Table 2 (continued)

AXIAL(X,Y) ELEVATION (ft) MAP(X,Y,Z) AXIAL(X,Y) ELEVATION (ft) MAP(X,Y,Z) 1 2.6440 1 2.2448 2 2.5160 2 2.5535 3 2.5045 3 2.4678 4 2.4488 4 2.3229 5 2.5803 5 2.8913 2.5 6 2.9481 3.1 6 3.1515 7 2.8544 7 3.0181 8 2.7286 8 2.9699 9 2.6450 9 2.8941 10 2.5527 10 2.7819 11 2.1731 11 2.1866 1 2.5554 1 2.0228 2 2.5529 2 2.5172 3 2.5197 3 2.4007 4 2.4375 4 2.2195 5 2.5643 5 3.0496 2.7 6 2.9839 3.3 6 3.2226 7 2.8837 7 3.1446 8 2.7939 8 3.0350 9 2.7040 9 2.9688 10 2.5997 10 2.8533 11 2.1995 11 2.1473 1 2.4223 1 1.7563 2 2.5653 2 2.4566 3 2.5075 3 2.3062 4 2.3955 4 2.0854 5 2.7295 5 3.2045 2.9 6 3.0921 3.5 6 3.2929 7 3.0070 7 3.2627 8 2.8896 8 3.0846 9 2.8058 9 3.0299 10 2.6974 10 2.9117 11 2.2039 11 2.0862 SEQUOYAH-UNIT 1 Page 13 of 16 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 21 231 (Fully Withdrawn Region)*

220 - 1375,225) 200 -7

~(1.0,182) 180 160

  • )* 10 ---- BANI CC 0140-
P 90120 MIO,110)

WIN -'- BAIPIK D

~~,oo 80o

-60 40 20 - o ,)

0 0.2 0.4 0.6 0.8 (Fully Inserted)

Fraction of Rated Thermal Power FIGURE 1 Rod Bank Insertion Limits Versus Thermal Power, Four Loop Operation

  • Fully withdrawn region shall be the condition where shutdown and control banks are at a position within the interval of >225 and <231steps withdrawn, inclusive.

Fully withdrawn shall be the position as defined below, Cycle Burnup (MWd/mtU) Steps Withdrawn

> 0 > 225 to 5 231 This figure is valid for operation at a rated thermal power of 3455 MWth when the LEFM is in operation.

If the LEFM becomes inoperable, then prior to the next NIS calibration, the maximum allowable power level must be reduced by 1.3% in power, and the rod insertion limit lines must be increased by 3 steps withdrawn until the LEFM is returned to operation.

SEQUOYAH-UNIT 1 Page 14 of 16 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 21 120 loo - - ---I"A---

110_______

--( o--t---1 --- - _

100 43~1c ~,(7,1\00)

U ccept ble ___ _ -- _- Unac ceptable 9 peratiqn Op'ation go 880 Accqptable o Op4ration I-50 _ _ _ _ _ _

70

¶jý150) __ _ ___

o 40 -_ ___ ___ 8 L-10 __ _ _

20 -

-50 -40 -30 -20 -10 0 10 20 30 40 50 Flux Difference (AI) %

FIGURE 2 Axial Flux Difference Limits As A Function of Rated Thermal Power For Burnup Range 0 EFPD to EOL This figure is valid for operation at a rated thermal power of 3455 MWth when the LEFM is in operation.

If the LEFM becomes inoperable, then prior to the next NIS calibration, the maximum allowable power level must be reduced by 1.3% in power, and the AFD limit lines must be made more restrictive by 1% in AFD until the LEFM is returned to operation.

SEQUOYAH-UNIT 1 Page 15 of 16 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 21 1.2 1.0 0.8 N0.6 ---- ---- - ------ ------L - V ----------- V ------- I-----

Elevation K(z) 0.000 1.0000 0.4

--- ----- 6.285 1.0000 -;-- - - - -- - - - - - - - - - -

7.995 1.0000 9.705 1.0000 12.000 1.0000 0.2 -- -- -- - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

0.0 0 2 4 6 8 10 12 Core Height (Feet)

FIGURE 3 K(Z) - Normalized FQ(X,Y,Z) as a Function of Core Height SEQUOYAH-UNIT 1 Page 16 of 16 Revision 0

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