ML021290436
| ML021290436 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 05/08/2002 |
| From: | James Smith Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML021290436 (14) | |
Text
May 8, 2002 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 12 CORE OPERATING LIMITS REPORT (COLR)
In accordance with the SQN Unit 2 Technical Specifications 6.9.1.14.c, enclosed is the Unit 2 Cycle 12 COLR.
This letter is being sent in accordance with NRC RIS 2001-05.
Please direct questions concerning this issue to me at (423) 843-7170 or J. D. Smith at (423) 843-6672.
Sincerely, Original signed by James D. Smith Site Licensing Supervisor Enclosure
ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 CYCLE 12 CORE OPERATING LIMITS REPORT REVISION 0 (L36 020405 801)
L36 020405 801 SEQUOYAH NUCLEAR PLANT UNIT 2, CYCLE 12 REVISION 0 April 2002 Prepared:
_Terry R. Moffett___________________________________________/_________ 4/5/02___________
Nuclear Fuel Date Reviewed:
Gary Bair___________________________________________/_______________ 4/19/02__
Reactor Engineering Supervisor Date Ed Freeman_____________________________________________/___________4/22/02________
Operations Manager Date Ed Freeman_______________________________________________/_________4/25/02_________
PORC Chairman Date Revision __0__
Pages affected _____
Reason for Revision ___________________________________________________________________
1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for Sequoyah Unit 2 Cycle 12 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 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.
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
< 4,000 > 225 to < 231
> 4,000 to < 14,000 > 222 to < 231
> 14,000 > 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
The following parameters are required for core monitoring per the Surveillance Requirements of Specification 3/4.2.2:
2.5.3 NSLOPEAFD = 1.12 where NSLOPEAFD = Negative AFD limit adjustment required to compensate for each 1% that FQ (X,Y,Z) exceeds BQDES.
2.5.4 PSLOPEAFD = 1.36 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)
= 1.29 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)
= 1.51 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.
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 < 4933 MWd/MTU 2.0%
For cycle burnups > 4933 MWd/MTU to < 6589 MWd/MTU 2.2%
For cycle burnups > 6589 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.
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).
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).
Table 1 Maximum Allowable Peaking Limits MAP(X,Y,Z)
ELEVATION (ft)
AXIAL (X,Y)
MAP (X,Y,Z) 2 1.1 1.921 4
1.917 6
1.911 8
1.901 10 1.882 2
1.2 2.145 4
2.135 6
2.122 8
2.099 10 2.055 2
1.3 2.373 4
2.357 6
2.336 8
2.299 10 2.175 2
1.4 2.599 4
2.577 6
2.549 8
2.419 10 2.280 2
1.5 2.826 4
2.795 6
2.676 8
2.524 10 2.378 2
1.7 3.152 4
3.017 6
2.859 8
2.701 10 2.552 2
1.9 3.302 4
3.152 6
3.001 8
2.845 10 2.696
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) %
FIGURE 2 Axial Flux Difference Limits As A Function of Rated Thermal Power Unacceptable Operation Unacceptable Operation Acceptable Operation
(-40,50)
(-13,100)
(7,100)
(28,50)
% of Rated Thermal Power This figure is valid for:
- operation at a rated thermal power of 3411 MWt
- operation at a rated thermal power of 3455 MWt when the LEFM is in operation If the LEFM becomes inoperable after rated thermal power is increased to 3455 MWt, 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.
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 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 K(Z) - Normalized FQ(X, Y, Z) as a Function of Core Height FIGURE 3