ML12104A268

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Cycle 19, Core Operating Limits Report
ML12104A268
Person / Time
Site: Sequoyah Tennessee Valley Authority icon.png
Issue date: 04/10/2012
From: James Shea
Tennessee Valley Authority
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML12104A268 (14)
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Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 April 10, 2012 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 Nuclear Plant, Unit 1, Cycle 19, Core Operating Limits Report The purpose of this letter is to submit the Sequoyah Nuclear Plant (SQN), Unit 1, Cycle 19, Core Operating Limits Report (COLR), Revision 0, as required by SQN Technical Specification (TS) 6.9.1.14.c. 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 cycle start-up (i.e., Mode 2) for each reload cycle. SQN, Unit 1, entered Mode 2 on March 31, 2012, for the current reload cycle. Therefore, to fulfill this requirement the Tennessee Valley Authority issubmitting the enclosed COLR prior to April 30, 2012.

There are no new regulatory commitments in this letter. If you have any questions, please contact Geoff Cook at (423) 843-7170.

Respe ly, Shea a ger, Corporate Nuclear Licensing Enclosure Unit 1 Cycle 19 Core Operating Limits Report cc (Enclosure):

NRC Regional Administrator - Region II NRC Senior Resident Inspector - SQN Printed on recycled paper

ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT I CYCLE 19 CORE OPERATING LIMITS REPORT

QA Record L36 120319 800 SEQUOYAH UNIT 1 CYCLE 19 CORE OPERATING LIMITS REPORT REVISION 0 March 2012 Prepared by:

1-k-(hIT.,U -ý C.A. Seifert, PWŽ-Fuel Engineering

/

7-7 /z zDate Date Verified by: /

M.D. Porter, PWR FueT'C'ngineering Dat Reviewed by.

Date D.M. Brown, PWR Fuel Engineering Manager Date

, W.I 'Stackler-r eactor Engineerin~g-upervisor Approved by:

PORG Chairman U Date Plant Kanager Date Revision 0 Pages affected All Reason for Revision: Initial Issue SEQUOYAH-UNIT I Page I of 12 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 19 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for Sequoyah Unit 1 Cycle 19 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 fi(Al) trip reset function for OTAT Trip (QTNL, QTPL) and rates of trip setpoint decrease per percent Al (QTNS, QTPS) f2(AI) trip reset function for OPAT Trip (QPNL, QPPL) and rates of trip setpoint TABLE 2.2-1 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 2.1 Moderator Temperature 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/lF (BOL limit). With the measured value more positive than -0.18 x10 5 Ak/kIF (as-measured MTC limit),

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/kf0F.

SEQUOYAH-UNIT 1 Page 2 of 12 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 19 2.1.2 The 300 ppm surveillance limit is:

The measured 300 ppm/ARO/RTP MTC should be less negative than or equal to

-3.75 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 (Specification 3/4.1.3.6) 2.3.1 The control rod banks shall be limited in physical insertion as shown in Figure 1.

2.4 Axial Flux Difference - AFD (Specification 3/4.2.1) 2.4.1 The axial flux difference (AFD) limits (AFD m) are provided in Figure 2.

2.5 Heat Flux Hot Channel Factor - F0 (X.Y.Z) (Specification 3/4.2.2)

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

FQRTP FQ (X,Y,Z)_ *K(Z) for P > 0.5 P

FQRTP FQ(X,Y,Z)<- *K(Z) forP_<0.5 0.5 THERMAL POWER where P =

RATED THERMAL POWER 2.5.1 FQRTP = 2.62 2.5.2 K(Z) is provided in Figure 3 SEQUOYAH-UNIT 1 Page 3 of 12 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 19 The following parameters are required for core monitoring per the Surveillance Requirements of Specification 3/4.2.2:

2.5.3 NSLOPEAFD = 1.32 where NSLOPEAFD = Negative AFD limit adjustment required to compensate for each 1% that FQ (X,Y,Z) exceeds BQDES.

2.5.4 PSLOPEAFD = 1.94

=

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

2.5.5 NSLOPEr(AI) = 1.40 where NSLOPEr2(Al) = Adjustment to negative OPAT f2(AI) limit required to compensate for each 1% that FQ(X,Y,Z) exceeds BCDES.

2.5.6 PSLOPE2(A') = 2.36 where PSLOPE'(AI) - Adjustment to positive OPAT f2 (AI) limit required to compensate for each 1% that FQ(X,Y,Z) exceeds BCDES.

2.5.7 BQNOM(X,Y,Z) = 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,Y,Z) = Maximum allowable design peaking factor which ensures that the FQ (X,Y,Z) limit will be preserved for operation within the LCO limits, including allowances for calculational and measurement uncertainties.

2.5.9 BCDES(X,Y,Z) = 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) data bases 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.

SEQUOYAH-UNIT 1 Page 4 of 12 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 19 2.5.10 The increase in FQM(X,Y,Z) for compliance with the 4.2.2.2.e Surveillance Requirements is defined as follows:

For cycle burnups 0 to 4497 MWd/mtU, use 2.0%

For cycle burnups > 4497 to 7969 MWd/mtU, use 3.1%

For cycle burnups > 7969 to 13767 MWd/mtU, use 2.0%

For cycle burnups > 13767 to 13846 MWd/mtU, use 2.02 %

For cycle burnups > 13846 MWd/mtU, use 2.0%

2.6 Nuclear Enthalpy Rise Hot Channel Factor - FAH(XY) (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,Y,Z) 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) data bases 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 5 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 19 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 whenP<0.8 where TRH = Reduction in OTAT K1 setpoint required to compensate for each 1%

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.

3.0 REACTOR CORE PROTECTIVE LIMITS 3.1 Trig, Reset Term [f_(AI)l for Overtemperature Delta-T Trip (Specification 2.2.1)

The following parameters are required to specify the power level-dependent f1(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-AI exceeds its positive limit at rated thermal power (QTPL).

SEQUOYAH-UNIT 1 Page 6 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 19 3.2 Trip Reset Term [f_(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 7 of 12 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 19 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. BAW-10168P-A, Revision 3, "RSG LOCA-BWNT Loss of Coolant Accident Evaluation Model for Recirculating Steam Generator Plants," December 1996.

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

5. BAW-1 0227P-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, "Realistic Large Break LOCA Methodology for Pressurized Water Reactors," April 2003.

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

SEQUOYAH-UNIT I Page 8 of 12 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 19 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) 2 1.9343 2 2.8143 4 1.9300 4 2.9856 1.1 6 1.9234 1.9 6 3.0073 8 1.9115 8 2.8509 10 1.8894 10 2.7048 2 2.1663 2 2.4405 4 2.1558 4 2.4405 1.2 6 2.1410 >1.9 6 2.7376 8 2.1153 8 2.5906 10 2.0582 10 2.3456 2 2.4023 2 2.5881 4 2.3825 4 2.5881 1.3 6 2.3599 2.2 6 2.9899 8 2.3100 8 2.7800 10 2.1760 10 2.5367 2 2.6453 2 2.6111 4 2.6136 4 2.6111 1.4 6 2.5610 2.6 6 3.2947 8 2.4199 8 3.2055 10 2.2787 10 2.8049 2 2.7189 2 2.9142 4 2.8181 4 2.9142 1.5 6 2.6735 3.0 6 4.0216 8 2.5280 8 3.6527 10 2.3749 10 3.1711 2 2.7720 2 2.9618 4 2.9219 4 2.9618 1.7 6 2.8641 3.5 6 4.2351 8 2.7064 8 3.7452 10 2.5539 10 3.3214 SEQUOYAH-UNIT 1 Page 9 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 19 220 - .57* 2-25 -

200 -_ _L (1.0,182) 180 - -

160 -- -__ __

o60

  • _.BANKC
= 140 W40

(.. 120 _ ___

20 (0,110) 1001 FG 80 Bn BANK D 80 FatoofRtdThermal orLo Power, prto

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

Fully withdr'awn shall be the position as defined below, Cycle Burnup (MWd/mtU) Steps Withdrawn 00 >225 to _<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 10 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 1 CYCLE 19 120 110 100 90 0 80 D.

70 E

I- 60 0, 50 40 30 20 10 0

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

FIGURE 2 Axial Flux Difference Limits As A Function of Thermal Power For Burnup Range of 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 11 of 12 Revision 0

COLR FOR SEQUOYAH UNIT I CYCLE 19 1.2 1.0 0.8 Elevation K(z)

(ft) 100 0.000 100 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 12 of 12 Revision 0

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