ML043290060
| ML043290060 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/23/2004 |
| From: | Pace P Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML043290060 (13) | |
Text
November 23, 2004 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:
In the Matter of
)
Docket No. 50-327 Tennessee Valley Authority
)
SEQUOYAH NUCLEAR PLANT (SQN) - UNIT 1 CYCLE 14 CORE OPERATING LIMITS REPORT (COLR)
In accordance with SQN Unit 1 Technical Specification 6.9.1.14.c, enclosed is the Unit 1 Cycle 14 COLR.
If you have any questions concerning this matter, please call me at (423) 843-7170 or J. D. Smith at (423) 843-6672.
Sincerely, Original signed by Jim Smith for:
P. L. Pace Manager, Site Licensing and Industry Affairs Enclosure
SEQUOYAH - UNIT 1 Revision 0 ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 1 CYCLE 14 CORE OPERATING LIMITS REPORT REVISION 0
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 1 of 11 CORE OPERATING LIMITS REPORT REVISION 0 October 2004 Prepared by:
Signed by T. D. Beu
/
10/27/2004 Engineering Specialist, Core Design, Nuclear Fuel Date Verified by:
Signed by Terry R. Moffett
/
10/27/2004 Nuclear Engineer, Core Design, Nuclear Fuel Date Approved by:
Signed by James F. Lemons
/
10/27/2004 Manager, Core Design, Nuclear Fuel Date Reviewed by:
Signed by Kathryn W. Allen
/
10/27/2004 Reactor Engineering Supervisor Date Signed by Marie Gillman PORC # 6213
/
10/29/2004 PORC Chairman Date Signed by D. L. Kulisek
/
11/02/2004 Plant Manager Date Revision 0 Pages affected _____
Reason for Revision __________________________________________________________________
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 2 of 11 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for Sequoyah Unit 1 Cycle 14 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 (I) trip reset function for OTT Trip (QTNL, QTPL) and rates of trip setpoint decrease per percent I (QTNS, QTPS)
TABLE 2.2-1 f2 (I) trip reset function for OPT Trip (QPNL, QPPL) and rates of trip setpoint decrease per percent I (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 (FH (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 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 k/k/°F (BOL limit). With the measured BOL/ARO/HZP MTC more positive than -0.04 x 10-5 k/k/°F (as-measured MTC limit),
establish control rod withdrawal limits to ensure the MTC remains less positive than 0 k/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 k/k/°F.
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 3 of 11 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 k/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 (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 (AFDLimit) are provided in Figure 2.
2.5 Heat Flux Hot Channel Factor - FQ (X,Y,Z) (Specification 3/4.2.2)
FQ (X,Y,Z) shall be limited by the following relationships:
FQ RTP FQ (X,Y,Z) ______
- K(Z) for P > 0.5 P
FQ RTP FQ (X,Y,Z) ______
- K(Z) for P 0.5 0.5 THERMAL POWER where P = ______________________
RATED THERMAL POWER 2.5.1 FQ RTP = 2.50 2.5.2 K(Z) is provided in Figure 3
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 4 of 11 The following parameters are required for core monitoring per the Surveillance Requirements of Specification 3/4.2.2:
2.5.3 NSLOPEAFD = 1.09 where NSLOPEAFD = Negative AFD limit adjustment required to compensate for each 1% that FQ (X,Y,Z) exceeds BQDES.
2.5.4 PSLOPEAFD = 1.61 where PSLOPEAFD = Positive AFD limit adjustment required to compensate for each 1% that FQ (X,Y,Z) exceeds BQDES.
2.5.5 NSLOPE f2(I) = 1.46 where NSLOPE f2(I) = Adjustment to negative OPT f2(I) limit required to compensate for each 1% that FQ (X,Y,Z) exceeds BCDES.
2.5.6 PSLOPE f2(I) = 1.62 where PSLOPE f2(I) =
Adjustment to positive OPT f2(I) 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.
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 5 of 11 2.5.10 The increase in FQ M (X,Y,Z) for compliance with the 4.2.2.2.e Surveillance Requirements is defined as follows:
For cycle burnups < 6000 MWd/MTU 2.0%
For cycle burnups > 6000 MWd/MTU to < 9000 MWd/MTU 2.7%
For cycle burnups > 9000 MWd/MTU 2.0%
2.6 Nuclear Enthalpy Rise Hot Channel Factor - FH (X,Y) (Specification 3/4.2.3)
FH (X,Y) shall be limited by the following relationship:
FH (X,Y) < MAP(X,Y,Z) / AXIAL(X,Y) 2.6.1 MAP(X,Y,Z) is provided in Table 1.
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:
FHRM (X,Y) < BHNOM(X,Y) where FHRM (X,Y) = FH (X,Y) / MAPM / AXIAL(X,Y)
FH (X,Y) is the measured radial peak at location X,Y.
MAPM is the value of MAP(X,Y,Z) obtained from Table 1 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 FH (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.
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 6 of 11 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 FH(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 OTT K1 setpoint required to compensate for each 1% FH(X,Y) exceeds its limit.
2.6.7 All cycle burnups shall use a 2% increase in FH M (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 [ f1(I) ] for Overtemperature Delta T-Trip (Specification 2.2.1)
The following parameters are required to specify the power level-dependent f1(I) trip reset term limits for the Overtemperature Delta-T trip function:
3.1.1 QTNL = -20%
where QTNL = the maximum negative I 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 I 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 I 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 I exceeds its positive limit at rated thermal power (QTPL).
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 7 of 11 3.2 Trip Reset Term [ f2(I) ] for Overpower Delta-T Trip (Specification 2.2.1)
The following parameters are required to specify the power level-dependent f2(I) trip reset term limits for the Overpower Delta-T trip function:
3.2.1 QPNL = -25%
where QPNL = the maximum negative I 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 I 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 I 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 I exceeds its positive limit at rated thermal power (QPPL).
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 8 of 11 Table 1 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
4 6
8 10 1.9540 1.9494 1.9431 1.9337 1.9147 1.9 2
4 6
8 10 2.8169 3.1537 3.0026 2.8465 2.6987 1.2 2
4 6
8 10 2.1780 2.1682 2.1543 2.1317 2.0855
>1.9 2
4 6
8 10 2.5377 2.8412 2.7051 2.5644 2.4313 1.3 2
4 6
8 10 2.4025 2.3875 2.3672 2.3029 2.1902 2.2 2
4 6
8 10 2.6873 3.3150 3.1660 3.0227 2.7136 1.4 2
4 6
8 10 2.6264 2.6047 2.5629 2.4204 2.2893 2.6 2
4 6
8 10 2.6965 3.5807 3.5514 3.3102 2.9726 1.5 2
4 6
8 10 2.8525 2.8119 2.6771 2.5251 2.3839 3.0 2
4 6
8 10 2.9517 3.8016 4.1225 3.6877 3.3466 1.7 2
4 6
8 10 2.7765 3.0191 2.8610 2.7036 2.5528 3.5 2
4 6
8 10 3.1500 4.1097 4.1197 3.7296 3.4811
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 9 of 11 0
20 40 60 80 100 120 140 160 180 200 220 0
0.2 0.4 0.6 0.8 1
Fraction of Rated Thermal Power Rod Bank Step Position BANK C BANK D (0.605,231)
(0.575,225)
(Fully Withdraw n Region) *
(1.0,182)
(0,110)
(0.09,0)
FIGURE 1 Rod Bank Insertion Limits Versus Thermal Power, Four Loop Operation (Fully Inserted)
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.
- 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
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 10 of 11 0
10 20 30 40 50 60 70 80 90 100 110 120
-50
-40
-30
-20
-10 0
10 20 30 40 50 Flux Difference (delta I) %
% of Rated Thermal Power FIGURE 2 Axial Flux Difference Limits As A Function of Rated Thermal Power Unacceptable Operation Unacceptable Operation Acceptable Operation
(-40,50)
(-12,100)
(7,100)
(28,50)
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.
COLR FOR SEQUOYAH UNIT 1 CYCLE 14 SEQUOYAH - UNIT 1 Revision 0 Page 11 of 11 0.0 0.2 0.4 0.6 0.8 1.0 1.2 0
2 4
6 8
10 12 Core Height (Feet)
K(Z) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Total Peaking, FQ FIGURE 3 K(Z) - Normalized FQ(X,Y,Z) as a Function of Core Height Core Height K(Z) FQ 0.000 1.000 2.500 6.285 1.000 2.500 7.995 0.966 2.415 9.705 0.920 2.300 12.000 0.858 2.145