ML063620406

Cycle 15 Core Operating Limits Report (COLR) Revision

ML063620406
Person / Time
Site:	Sequoyah
Issue date:	12/20/2006
From:	Morris G Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML063620406 (15)

Text

Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37384-2000 December 20, 2006 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:

In the Matter of )Docket No. 50-328 Tennessee Valley Authority SEQUOYAH NUCLEAR PLANT (SQN) - UNIT 2 CYCLE 15 CORE OPERATING LIMITS REPORT (COLR) REVISION In accordance with the SQN Unit 2 Technical Specification 6.9.l.14.c, enclosed is the Unit 2 Cycle 15 COLR.

Please direct questions concerning this issue to me at (423) 843-7170.

Sincerely, Glenn W. Morris Manager, Site Licensing and Industry Affairs Enclosure cc (Enclosure)

Dr. William D. Travers Regional Administrator, Region II U.S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center 61 Forsyth St'reet, SW, Suite 23T85 Atlanta, Georgia 30323-8931 NRC Senior Resident Inspector Seguoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379-3624 Printedor)recycledpaper

SEQUOYAH UNIT 2 CYCLE 15 CORE OPERATING LIMITS REPORT REVISION 0 December 2006 Prepared by:

Originally Signed by T. D. Beu I 12/07/2006 PWR Fuel Engineering Date Verified by:

Originally Signed by B. S. Catalanotto / 12/07/2006 PWR Fuel Engineering Date Reviewed by:

Originally Signed by C. S. Faulkner I 12/07/2006 PWR Fuel Engineering Manager Date Originally Signed by C. A. Griffin / 12/07/2006 Reactor Engineering Supervisor Date Approved by:

Originally Signed by M. H. Palmer / 12/12/2006 PORC Chairman Date Originally Sigqned by D. A. Kulisek / 12/12/2006 Plant Manager Date Revision 0 Pages affected______

Reason for Revision SEQUOYAH - UNIT 2 Page 1 of 14 Rvso Revision 0

1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for Sequoyah Unit 1 Cycle 15 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 f1(AI) 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(XY))

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 - MVTC (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/kI0 F (BOL limit). With the measured BOL/ARO/HZP MTC more positive than -0.16 x 10-5 Ak/k/0 F (as-measured MTC limit), establish control rod withdrawal limits to ensure the MTC remains less positive than 0 Ak/k/0 F for all times in core l ife.

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

SEQUOYAH - UNIT I Page 2 of 14 Revision 0

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 -

Ak/k/0F.

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 (MWD/MTU) Steps Withdrawn

>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 - AFID (Specification 3/4.2.1) 2.4.1 The axial flux difference (AFD) limits (AFD m') are provided in Figures 2A, 2B, and 2C.

2.5 Heat Flux Hot Channel Factor - Fa (XY.Z) (Specification 3/4.2.2)

F0 (X,Y,Z) shall be limited by the following relationships:

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

Fo RTh' FQ (X,Y,Z)<! *-K(Z) for P*! 0.5 0.5 where P =Thermal Power! Rated Thermal Power 2.5.1 F0QRTP 2.39 2.5.2 K(Z) is provided in Figure 3.

SEQUOYAH- - UNIT 1 Page 3 of 14 Revision 0

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

2.5.3 NSLOPE A = 1.13 where NSLOPE F= Negative AFD limit adjustment required to compensate for each 1%that F0 (X,Y,Z) exceeds BQDES.

2.5.4 PSLOPE AD= 1.73 where PSLOPE AD= Positive AFD limit adjustment required to compensate for each 1% that F0 (X,Y,Z) exceeds BQD ES.

2.5.5 NSLOPE 2(Al)= 1.38 where NSLOPE 2(Al) = Adjustment to negative OPAT f2(AI) limit required to compensate for each 1%that F0 (X,Y,Z) exceeds BCDES.

2.5.6 PSLOPE 2(Al) = 2.02 where PSLOPE 2(Al) -Adjustment to positive OPAT f2(Al) limit required to compensate for each 1% that F0 (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 F0 (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 mnelt 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 imit generation described in the references in Specification 6.9.1.14.

2.5.10 The increase in Fom (X,Y,Z) for compliance with the 4.2.2.2.e Surveillance Requirements is defined as follows:

For all cycle burnups 2.0%

SEQUOYAH - UNIT I Page 4 of 14 Rvso Revision 0

2.6 Nuclear Enthalpy Rise Hot Channel Factor - FAH MXY) (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:

FAHRM (X,Y) :: BHNOM(X,Y) where FAHRM (X,Y) = FAH (X,Y) MA[M / AXIAL(X,Y)

FAH (XY) is the measured radial peak at location X,Y.

MPM 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 KXY) 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.

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 SEQUOYAH- - UNIT 1 Page 5 of 14 Rvso Revision 0

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% 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) margin for compliance with the 4.2.3.2.d.1 Surveillance Requirement.

3.0 REACTOR CORE PROTECTIVE LIMITS 3.1 Trip Reset Term [F (A[) 1for Overtemnperature Delta T-Trip (Specification 2.2.1)

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

3.1.1 QTNL =-20%

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

3.1.2 QTPL =+5%.

where QTPL = 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 QT NS = 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= 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 6 of 14 Rvso Revision 0

3.2. Trip Reset Term [ f2AI) 1for 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 = 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 = 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 = 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 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 I Page 7 of 14 Rvso Revision 0

Table 1 COLR Methodology Topical Reports

1. BAW-1 0180-A, Revision 1, "NEMO - Nodal Expansion Method Optimized," March 1993.

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

2. BAW-1 01 69P-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-1 01 63P-A, Revision 0, "Core Operating Limit Methodology for Westing house-Desig ned PWRs," June 1989.

(Methodology for Specifications 2.2.1 - Reactor Trip System 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-1 0168P-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-110227P-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)

SEQUQYAH- - UNIT 1 Page 8 of 14 Revision 0

Table 2 Maximum Allowable Peaking Limits MAP(X,Y,Z)

AXIAL(X,Y) ELEVATION (ft) MAP(X,Y,Z) AXIAL(X,Y) ELEVATION (ft) MAP(X,Y,Z) 1.1 2 1.9540 1.9 2 2.8169 4 1.9494 4 3.1537 6 1.9431 6 3.0026 8 1.9337 8 2.8465 10 1.9147 10 2.6987 1.2 2 2.1780 >1.9 2 2.5377 4 2.1682 4 2.8412 6 2.1543 6 2.7051 8 2.1317 8 2.5644 10 2.0855 10 2.4313 1.3 2 2.4025 2.2 2 2.6873 4 2.3875 4 3.3150 6 2.3672 6 3.1 660 8 2.3029 8 3.0227 10 2.1902 10 2.7136 1.4 2 2.6264 2.6 2 2.6965 4 2.6047 4 3.5807 6 2.5629 6 3.5514 8 2.4204 8 3.3102 10 2.2893 10 2.9726 1.5 2 2.8525 3.0 2 2.9517 4 2.8119 4 3.8016 6 2.6771 6 4.1225 8 2.5251 8 3.6877 10 2.3839 10 3.3466 1.7 2 2.7765 3.5 2 3.1 500 4 3.0191 4 4.1097 6 2.8610 6 4.1197 8 2.7036 8 3.7296 10 2.5528 10 3.4811 SEQUOYAH- - UNIT 1 Page 9 of 14 Rvso Revision 0

(0.605,231) 220 200 180 a

0 160 0) 140 a) 120 Co 100 M

80 0

60 40 20 0

0 0.2 0.4 0.6 0.81 (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 <231 steps withdrawn, inclusive.

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

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

Ifthe LEFM becomes inoperable, then prior to the next NIS calibration, the maximumn 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 I Page 10 of 14 Revision 0 Rvso

1201 111 1 110 +_ +___+-ý--ý __

(-13,100) (7,100) 90 Uj~naccp Rb inaccepta l OL 80 Acept ble M 70 ion-E -ý

- L

.~60 __

2 50 (2,0 (U (-40,50) F T7 7 (2,0 4- 40____ __

0

~30__ _

10 t -I--tf t - I-

-50 -40 -30 -20 -10 0 10 20 30 40 50 Flux Difference (delta 1)%

FIGURE 2A Axial Flux Difference Limits As A Function of Thermal Power For Burnup Range of 0 EFPD to 254+10 EFPD This figure isvalid for operation at a rated thermal power of 3455 MWt when the LEFMV is in operation.

Ifthe LEFMV becomes inoperable, then prior to the next NIS calibration, the maximum allowable power

~level must be reduced by 1.3% in power, and the AFID limit lines must be made more restrictive by 1%

~in AFID until the LEFMV is returned to operation.

SEQUOYAH - UNIT I Page 11 of 14 Revision 0

1201 1 1 11 1 1 1 110 +_ +___+ __ - -ý

(-10,100) (7,100) 100 -1f- - -ý - -

U_ ptbýnacrepa _c l

0. 90 __ _

a.o 80 ceptable E 70 -jpeain-

.~60 __ __IL_

40 + __

20 10 -- tt __ l

-- ___ -t 0

-50 -40 -30 -20 -10 0 10 20 30 40 50 Flux Difference (delta 1)%

FIGURE 2B Axial Flux Difference Limits As A Function of Thermal Power For Burnup Range of 254+10 EFPD to 431+10 EFPD

[This figure isvalid for operation at a rated thermal power of 3455 MWt when the LEFMV isin operation.

~Ifthe LEFMV 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 AFID until the LEFMV is returned to operation.

SEQUOYAH - UNIT 1 Page 12 of 14 Revision 0

120 110 100 90 0- 80 70 60 0~

50 40 30 20

-50 -40 -30 -20 -10 0 10 20 30 40 50 Flux Difference (delta 1)%

FIGURE 2C Axial Flux Difference Limits As A Function of Thermal Power For Burnup Range of 431+10 EFPD to EOC This figure is valid for operation at a rated thermal power of 3455 MWt when the LEFM is in operation.

Ifthe 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 AFO limit lines must be made more restrictive by 1%

in AFD until the LEFM is returned to operation.

SEQUOYAH - UNIT I Page 13 of 14 Rvso Revision 0

1.2 1.0 i i 0.8 I I-Core Heig ~ht K(Z) 0.000 1.000 N0.6 6.285 1 .000 ____ __

7.995 0.966 9.705 0.920 12.000 0.858 0.4 0.2 0.0 0 2 4 6 8 10 12 Core Height (Feet)

FIGURE 3 K(Z) - Normalized FQ(X,Y,Z4 as a Function of Core Height SEQUQYAH - UNIT I Page 14 of 14 Revision 0