ML093490964

From kanterella
Jump to navigation Jump to search
Cycle 17 Core Operating Limits Report
ML093490964
Person / Time
Site: Sequoyah Tennessee Valley Authority icon.png
Issue date: 12/14/2009
From: Krich R
Tennessee Valley Authority
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML093490964 (14)
v • d • e


Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402-2801 December 14, 2009 10 CFR 50.4 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Sequoyah Nuclear Plant, Unit 2 Facility Operating License No. DPR-79 NRC Docket No. 50-328

Subject:

Sequoyah Nuclear Plant Unit 2 Cycle 17 Core Operating Limits Report In accordance with Sequoyah Nuclear Plant (SQN) Unit 2 Technical Specification 6.9.1.14.c, enclosed is the Unit 2 Cycle 17 Core Operating Limits Report.

If you have any questions about this change, please contact me at (423) 751-3628 or Beth A. Wetzel at (423) 843-7170.

Respectfully, M. Krich Vice President Nuclear Licensing Enclosure cc (Enclosure):

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Sequoyah Nuclear Plant Printed on recycled paper

ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 CYCLE 17 CORE OPERATING LIMITS REPORT

QA RECORD L36 091114 805 SEQUOYAH UNIT 2 CYCLE 17 CORE OPERATING LIMITS REPORT REVISION 0 November 2009 Prepared by:

/ I/., o. /./

,-- - L& ._ t" / 0/I//,.'oo 9

PWR Fuel Engineering Date Verified by:

PWR Fuel Engineering bate Reviewed by:

PWR Fuel Engineering ManagW Date Reactor Engineering Supervisor Date Approved by:. , (..

Revision 0 Pages affected All Reason for Revision: Initial Issue SEQUOYAH - UNIT 2 Page 1 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 2 CYCLE 17 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for Sequoyah Unit 2 Cycle 17 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(Al) 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 (F0 (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 BOLJARO/HZP MTC shall be less positive than 0 Ak/k/°F (BOL limit). With the measured BOL/ARO/HZP MTC more positive than -0.08 x.10-5 Ak/k/°F (as-measured MTC limit), establish control rod withdrawal limits to ensure the MTC remains less positive than 0 Ak/kF 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/°F.

SEQUOYAH - UNIT 2 Page 2 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 2 CYCLE 17 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 314.1.3.5) 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 - AFD (Specification 3/4.2.1) 2.4.1 The axial flux difference (AFD) limits (AFDumit) are provided in Figure 2.

2.5 Heat Flux Hot Channel Factor - Fq(XY (Specification 3/4.2.2)

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

FQRTP Fa (X,Y,Z)_*

  • K(Z) for P > 0.5 P

FORTP Fo (X,Y,Z)* -

  • K(Z) for P *0.5 0.5 where P = Thermal Power / Rated Thermal Power 2.5.1 FoaTP = 2.62 2.5.2 K(Z) is provided in Figure 3.

SEQUOYAH - UNIT 2 Page 3 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 2 CYCLE 17 The following parameters are required for core monitoring per the Surveillance Requirements of Specification 3/4.2.2:

2,5.3 NSLOPEAFD = 1.18 where NSLOPEAFD = Negative AFD limit adjustment required to compensate for each 1% that Fa (X,Y,Z) exceeds BQDES.

2,5.4 PSLOPEAM = 2.33 where PSLOPEAFD = Positive AFD limit adjustment required to compensate for each 1% that F0 (X,Y,Z) exceeds BODES.

f2Ws) 2.5.5 NSLOPE = 1.45 where NSLOPE 12('I) Adjustment to negative OPAT f2(AI) limit required to compensate for each 1% that FQ (X,Y,Z) exceeds BCDES.

2.5.6 PSLOPE = 1.89 where PSLOPE t2(AI)= Adjustment to positive OPAT f2(AI) limit required to compensate for each 1% that Fa (X,Y,Z) exceeds BCDES.

25.7 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.

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 cycle burnups 0 to 4052 MWd/mtU, use 2.0%

For cycle burnups 4052 to 7788 MWd/mtU, use 3.4%

For cycle burnups > 7788 MWd/mtU, use 2.0%

SEQUOYAH - UNIT 2 Page 4 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 2 CYCLE 17 2.6 ' Nuclear Enthalpv Rise Hot Channel Factor - FAH,,,Xi (Specification 3/4.2.3)

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

FA (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) = FAHM (X,Y) / [ MAP' / 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.

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 2 Page 5 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 2 CYCLE 17 2.6.6 TRH = 0.0334 when 0.8 < P < 1.0 TRH = 0.0167 when P < 0.8 where TRH = Reduction in OTAT Ki 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 [rf(AI) 1for Overtemlperature Delta T-Trip (Specification 2.2.1)

The following parameters are required to specify the power level-dependent f1 (Al) 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 setpoint 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 QTNS = 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 2 Page 6 of 12 Revision 0

COLR FOR SEOUOYAH UNIT 2 CYCLE 17 3.2 Trip Reset Term r fM(AD) I for Overnower 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 2 Page 7 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 2 CYCLE 17 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-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 System Instrumentation Setpoints [fl(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 01 68P-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-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, "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 2 Page 8 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 2 CYCLE 17 Table 2 Maximum Allowable Peaking Limits MAP(X,Y,Z)

AXIAL(X,Y) ELEVATION (ft) NAP(X,Y,Z) AXIAL(X,Y) ELEVATION (ft) XAP(X,Y,Z) 2 1.9796 2 2.8084 4 1.9750 4 2.9772 1.. 6 1.9675 1.9 6 2.9986 8 1.9561 8 2.8424 10 1.9346 10 2.6948 2 2.1787 2 2.5301 4 2.1683 4 2.6821 1.2 6 2.1890 >1.9 6 2.7014 8 2.1626 8 2.5607 10 2.0894 10 2.4278 2 2.4200 2 2.6742 4 2.4024 4 3.3050 1.3 6 2.4119 2.2 6 3.1569 8 2.3100 8 3.0147 10 2.1923 10 2.7071 2 2.6650 2 2.6810 4 2.6238 4 3.5687 1.4 6 2.5696 2.6 6 3.5402 8 2.4224 8 3.3006 10 2.2895 10 2.9649 2 2.7164 2 2.9366 4 2.7476 4 3.7887 1.5 6 2.6782 3.0 6 4.1090 8 2.5262 8 3.6762 10 2.3832 10 3.3366 2 2.7673 2 2.9665 4 2.9138 4 4.0948 1.7 6 2.8590 3.5 6 4.1053 8 2.7018 8 3.7168 10 2.5502 10 3.4708 SEQUOYAH - UNIT 2 Page 9 of 12 Revision 0

COLR FOR SEOUOYAH UNIT 2 CYCLE 17 (0.605,231)

Mflill Withfriaw n PaI.A%*,*

220 - ,--575,22" 200 -_ _1 .. _ _

-.,- __ __ (1.0,182 180 -

160 --. . . ..

O 0.

140 --

c 120 U) (0,110)

V, 100 __ -- -- --

In 80 4pAK 0 __

M~ 60____ __ __

40 _ _______ _

20 (o 9, 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 <231 steps withdrawn, inclusive.

Fully withdrawn shall be the position as defined below, Cycle Burupu (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.

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 2 Page 10 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 2 CYCLE 17 120 I i 110 ---- I-loo 90 80 -

I--

HAcclptabie

-p-\01 -o-E 80 Operati-on - -

-- 70 E

"8 0-- -

50 30

- I___ I "28 40 . ... . . ... .....

30 1020 J

71 T

I

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

FIGURE 2 Axial Flux Difference Limits As A Function of Thermal Power For Burnup Range 0 EFPD to EOC This figure is valid for operation at a rated thermal power of 3455 MWt 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 2 Page 11 of 12 Revision 0

COLR FOR SEQUOYAH UNIT 2 CYCLE 17 1.2 1.0-0.8 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 ------ ------------ ------ ------ .. ...--......

0.01 0 2" 10 12 Core Height (Feet)

FIGURE 3 K(Z) - Normalized FQ(X,Y,Z) as a Function of Core Height SEQUOYAH -UNIT 2 Page 12 of 12 Revision 0

Retrieved from "https://kanterella.com/w/index.php?title=ML093490964&oldid=2560416"