SBK-L-10124, Submittal of Revised Core Operating Limits Report for Cycle 14

Submittal of Revised Core Operating Limits Report for Cycle 14

ML101940344
Person / Time
Site:	Seabrook
Issue date:	07/07/2010
From:	O'Keefe M NextEra Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SBK-L-10124
Download: ML101940344 (17)

Text

NEXTera ENERGY7A SEABROK July 7, 2010 Docket No. 50-443 SBK-L-10124 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 - 0001 Seabrook Station Revised Core Operating Limits Report for Cycle 14 Pursuant to Technical Specification 6.8.1.6.c, NextEra Energy Seabrook, LLC has enclosed the latest revision of the Seabrook Station Core Operating Limits Report (COLR) for cycle 14. This revision changed the limits for the nuclear enthalpy rise hot channel factor.

If you have any questions regarding this information, please contact me at (603) 773-7745.

Sincerely, NextEra Energy Seabrook, LLC Michael O'Keefe Licensing Manager cc: S. J. Collins, NRC Region I Administrator G. E. Miller, NRC Project Manager W. J. Raymond, NRC Senior Resident Inspector NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874

ENCLOSURE TO SBK-L-10124 1.0 Core Operating Limits Report (COLR)

This Core Operating Limits Report for Seabrook Station Unit 1, Cycle 14 has been prepared in accordance with the requirements of Technical Specification 6.8.1.6.

The Technical Specifications affected by this report are:

1) 2.2.1 Limiting Safety System Settings

2) 2.1 Safety Limits

3) 3.1.1.1 Shutdown Margin Limit for MODES 1, 2, 3, 4

4) 3.1.1.2 Shutdown Margin Limit for MODE 5

5) 3.1.1.3 Moderator Temperature Coefficient

6) 3.1.2.7 Minimum Boron Concentration for MODES 4, 5, 6

7) 3.1.3.5 Shutdown Rod Insertion Limit

8) 3.1.3.6 Control Rod Insertion Limits

9) 3.2.1 Axial Flux Difference

10) 3.2.2 Heat Flux Hot Channel Factor

11) 3.2.3 Nuclear Enthalpy Rise Hot Channel Factor

12) 3.2.5 DNB Parameters

13) 3.5.1.1 Boron Concentration Limits for MODES 1, 2, 3

14) 3.5.4 Boron Concentration Limits for MODES 1, 2, 3, 4

15) 3.9.1 Boron Concentration Limits for MODE 6 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 Technical Specification 6.8.1.6.

2.1 Limiting Safety System Settings: (Specification 2.2.1) 2.1.1 Cycle Dependent Overtemperature AT Trip Setpoint Parameters and Function Modifier:

2.1.1.1 K1 = 1.210 0

2.1.1.2 K2 = 0.021/ F 2.1.1.3 K3 =0.0011/psig T = Measured RCS Tavg (IF ), and T' = Indicated RCS Tavg at RATED THERMAL POWER (Calibration temperature for AT instrumentation, < 589.1 IF).

P1 = Nominal RCS operating pressure, 2235 psig 6-1.1 SSTR Rev. 121

2.1.1.4 Channel Total Allowance (TA) = N.A.

2.1.1.5 Channel Z = N.A.

2.1.1.6 Channel Sensor Error (S) = N.A.

2.1.1.7 Allowable Value - The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than 0.5% of AT span. Note that 0.5% of AT span is applicable to OTAT input channels AT, Tavg and Pressurizer Pressure; 0.25% of AT span is applicable to Al.

2.1.1.8 f1(AI) is a function of the indicated difference between top and bottom detectors of the power-range neutron ion chambers; with nominal gains to be selected based on measured instrument response during plant startup tests calibrations such that:

(1) For qt - qb between -20% and +8%, f, (AI) > 0; where qt and qb are percent RATED THERMAL POWER in the upper and lower halves of the core, respectively, and qt + qb is the total THERMAL POWER in percent RATED THERMAL POWER; (2) For each percent that the magnitude of qt - qb exceeds -20%, the AT Trip Setpoint shall be automatically reduced by > 2.87% of its value at RATED THERMAL POWER.

(3) For each percent that the magnitude of qt - qb exceeds +8%, the AT Trip Setpoint shall be automatically reduced by > 1.71% of its value at RATED THERMAL POWER.

See Figure 5.

2.1.1.9 r1 = 0 seconds 2.1.1.10 T2 = 0 seconds 2.1.1.11 T3 < 2 seconds 2.1.1.12 r4 -- 28 seconds 2.1.1.13 r:5<4 seconds 2.1.1.14 T6 < 2 seconds 6-1.2 SSTR Rev. 121

2.1.2 Cycle Dependent Overpower AT Trip Setpoint Parameters and Function Modifier:

2.1.2.1 K4 = 1.116 2.1.2.2 K5 = 0.020 / 'F for increasing average temperature and K5 = 0.0 for decreasing average temperature.

2.1.2.3 0.00175 /°F forT>T 11 and K6=0.0 K6 = forT<Tl",

where:

T = Measured Tavg (F ), and T11 = Indicated Tavg at RATED THERMAL POWER (Calibration temperature for AT instrumentation, < 589.1 'F).

2.1.2.4 Channel Total Allowance (TA) = N.A.

2.1.2.5 Channel Z = N.A.

2.1.2.6 Channel Sensor Error (S) = N.A.

2.1.2.7 Allowable Value - The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than 0.5% of AT span. Note that 0.5% of AT span is applicable to OPAT input channels AT and Tavg.

2.1.2.8 f2 (AI) is disabled.

2.1.2.9 TI as defined in 2.1.1.9, above.

2.1.2.10 T2 as defined in 2.1.1.10, above.

2.1.2.11 T3 as defined in 2.1.1.11, above.

2.1.2.12 -r6 as defined in 2.1.1.14, above.

2.1.2.13 T7 > 10 seconds. It is recognized that exactly equal values cannot always be dialed into the numerator and denominator in the protection system hardware, even if the nominal values are the same (10 seconds). Thus given the inequality sign in the COLR (greater than or equal to) the intent of the definition of this time constant applies primarily to the rate time constant (i.e. the Tau value in the numerator). The lag time constant (denominator Tau value) may be less than 10 seconds or less than the value of the numerator Tau value (e.g., if the numerator is set at 10.5, the denominator may be set to 10 or 9.5) and still satisfy the intent of the anticipatory protective feature.

6-1.3 SSTR Rev. 121

2.2 Safety Limits: (Specification 2.1.1) 2.2.1 In Modes 1 and 2, the combination of Thermal Power, reactor coolant system highest loop average temperature and pressurizer pressure shall not exceed the limits in Figure 6.

2.3 Shutdown Margin Limit for MODES 1, 2, 3, and 4: (Specification 3.1.1.1) 2.3.1 The Shutdown Margin shall be greater than or equal to 1.3% AK/K, in MODES 1, 2 and 3.

2.3.2 The Shutdown Margin shall be greater than or equal to 2.3% AK/K, in MODE 4.

2.3.3 The Boric Acid Storage System boron concentration shall be greater than or equal to 7000 ppm.

2.4 Shutdown Margin Limit for MODE 5: (Specification 3.1.1.2) 2.4.1 The Shutdown Margin shall be greater than or equal to 2.3% AK/K.

2.4.2 The RCS boron concentration shall be greater than or equal to 2000 ppm when the reactor coolant loops are in a drained condition.

2.4.3 The Boric Acid Storage System boron concentration shall be greater than or equal to 7000 ppm.

2.5 Moderator Temperature Coefficient: (Specification 3.1.1.3) 2.5.1 The Moderator Temperature Coefficient (MTC) shall be less positive than

+4.083 x 105 AK/K/OF for Beginning of Cycle Life (BOL), All Rods Out (ARO), Hot Zero Thermal Power conditions.

2.5.2 MTC shall be less negative than -5.5 x 10-4 AK/K/°F for End of Cycle Life (EOL),

ARO, Rated Thermal Power conditions.

2.5.3 The 300 ppm ARO, Rated Thermal Power MTC shall be less negative than -4.6 x 10-4 AK/K/°F (300 ppm Surveillance Limit).

2.5.4 The Revised Predicted near-EOL 300 ppm MTC shall be calculated using the algorithm contained in WCAP 13749-P-A:

Revised Predicted MTC = Predicted MTC + AFD Correction - 3 PCM/degree F If the Revised Predicted MTC is less negative than the SR 4.1.1.3.b 300 ppm surveillance limit and all the benchmark data contained in the surveillance procedure are met, then an MTC measurement in accordance with SR 4.1.1.3.b is not required to be performed.

6-1.4 SSTR Rev. 121

2.6 Minimum Boron Concentration for MODES 4, 5, 6 (Specification 3.1.2.7) 2.6.1 The Boric Acid Storage System boron concentration shall be greater than or equal to 7000 ppm.

2.7 Shutdown Rod Insertion Limit: (Specification 3.1.3.5) 2.7.1 The shutdown rods shall be fully withdrawn. The fully withdrawn position is defined as the interval within 225 steps withdrawn to the mechanical fully withdrawn position inclusive.

2.8 Control Rod Insertion Limits: (Specification 3.1.3.6) 2.8.1 The control rod banks shall be limited in physical insertion as specified in Figure 1.

Control Bank A shall be at least 225 steps withdrawn.

2.9 Axial Flux Difference: (Specification 3.2.1) 2.9.1 The indicated AFD must be within the Acceptable Operation Limits specified in Figure 2.

2.10 Heat Flux Hot Channel Factor: (Specification 3.2.2) 2.10.1 FRTPQ = 2 .50 2.10.2 K(Z) is specified in Figure 3.

2.10.3 W(Z) is specified in Table 1.

The W(Z) data is applied over the cycle as follows:

BU < 150 MWD/MTU, linear extrapolation of 150 and 3000 MWD/MTU W(Z) data 150 __BU < 6500 MWD/MTU, quadratic interpolation of 150, 3000, and 10000 MWD/MTU data 6500 < BU <18000 MWD/MTU, quadratic interpolation of 3000, 10000, and 18000 MWD/MTU W(Z) data BU > 18000 MWD/MTU, linear extrapolation of 10000 and 18000 MWD/MTU W(Z) data Note: The FQ(Z) surveillance exclusion zone is specified by Technical Specification 4.2.2.2.g 6-1.5 SSTR Rev. 121

2.10.4 The FMQ(Z) penalty factor is applied over the cycle as follows:

BU >_0 MWD/MTU, FMQ(Z) penalty factor is 1.020 2.11 Nuclear Enthalpy Rise Hot Channel Factor; (Specification 3.2.3) 2.11.1 FNAH* < FNAH(RTP) x ( 1 + PF x ( I - P))

where P = THERMAL POWER / RATED THERMAL POWER.

2.1 1.2.a For FNN measured by the fixed incore detectors:

F NAH(RTP) = 1.584.

N 2.11.2.b For F~A measured by the movable incore detectors:

FN u(RTP) = 1.584.

2.11.3 Power Factor Multiplier for FNAH = PF = 0.3.

2.12 DNB Parameters (Specification 3.2.5) 2.12.1 The Reactor Coolant System Tavg shall be less than or equal to 595.1 degrees F.

2.12.2 The Pressurizer Pressure shall be greater than or equal to 2185 PSIG.

Note: Technical Specification Bases 3/4.2.5, "DNB Parameters" indicates that the limits on DNB-related parameters assure consistency with the normal steady-state envelope of operation assumed in the transient and accident analyses. Operating procedures include allowances for measurement and indication uncertainty so that the limits in the COLR for Tavg and pressurizer pressure are not exceeded. Consistent with the Bases, the values of these DNB parameters are the limiting Tavg and pressurizer pressure assumed in the transient and accident analyses.

2.13 Accumulator Boron Concentration Limits for MODES 1,2,3 (Specification 3.5.1.1) 2.13.1 Each Accumulator shall have a boron concentration between 2300 and 2600 ppm.

6-1.6 SSTR Rev. 121

2.14 Refueling Water Storage Tank Boron Concentration Limits for MODES 1, 2, 3, 4 (Specification 3.5.4) 2.14.1 The RWST shall have a boron concentration between 2400 and 2600 ppm.

2.15 Refueling Boron Concentration Limits for MODE 6 (Specification 3.9.1) 2.15.1 The Refueling Boron Concentration during Cycle 14 shall be greater than or equal to 2180 ppm.

2.15.2 The Boric Acid Storage System boron concentration shall be greater than or equal to 7000 ppm.

6-1.7 SSTR Rev. 121

Figure 1: Control Bank Insertion Limits Versus Thermal Power 225 (17 3,225)-

(0.726,225) 200 Bank B (0.0,188)

T 175 __

. 150 Bank C U) 0)

125 10,100 50 0

25__

0 (0.216,0.0 _ _ _ _ _ _ _ _ _ _

0.0 0.2 0.4 0.6 0.8 1.0 Fraction of Rated Thermal Power 6-1.8 SSTR Rev. 121

Figure 2: Axial Flux Difference Operating Limits Versus Thermal Power Note: %DI = %AI 6-1.9 SSTR Rev. 121

Figure 3: K(Z) Versus Core Height 1.2 (0.0,1.000) (6.0,1.000)]

0.8

.0.6 0.4 0.2 0 - - - , - . -

0 1 2 3 4 5 6 7 8 9 10 11 12 Core Height (Feet) 6-1.10 SSTR Rev. 121

FIGURE 4 DELETED 6-1.11 SSTR Rev. 121

Figure 5: f1(AI) Function 6-1.12 SSTR Rev. 121

Figure 6: Safety Limits 680 660

-* 640 Q>

c-E 620 C6 C-)

C_)

580 560 Fraction of Rated Thermal Power 6-1.13 SSTR Rev. 121

Table 1: W(Z,BU) versus Axial Height (Sheet 1 of 2)

HEIGHT (Z) W(Z,BU) W(Z,BU) W(Z,BU) W(Z,BU)

(Feet) 150 3000 10000 18000 MWD/MTU MWD/MTU MWD/MTU MWD/MTU

<1.0 1.0000 1.0000 1.0000 1.0000 1.2 1.4007 1.4126 1.2878 1.2932 1.4 1.3855 1.3955 1.2789 1.2837 1.6 1.3685 1.3764 1.2682 1.2726 1.8 1.3497 1.3555 1.2562 1.2601 2.0 1.3294 1.3330 1.2431 1.2465 2.2 1.3079 1.3096 1.2290 1.2321 2.4 1.2858 1.2857 1.2145 1.2172 2.6 1.2632 1.2619 1.1997 1.2020 2.8 1.2431 1.2402 1.1843 1.1862 3.0 1.2284 1.2264 1.1738 1.1753 3.2 1.2181 1.2156 1.1686 1.1698 3.4 1.2083 1.2081 1.1644 1.1662 3.6 1.1982 1.2013 1.1597 1.1619 3.8 1.1904 1.1946 1.1545 1.1559 4.0 1.1839 1.1870 1.1488 1.1535 4.2 1.1772 1.1788 1.1436 1.1532 4.4 1.1697 1.1699 1.1378 1.1518 4.6 1.1616 1.1605 1.1316 1.1497 4.8 1.1528 1.1507 1.1248 1.1468 5.0 1.1434 1.1403 1.1175 1.1429 5.2 1.1335 1.1292 1.1099 1.1383 5.4 1.1231 1.1178 1.1017 1.1331 5.6 1.1124 1.1069 1.0926 1.1307 5.8 1.1029 1.0953 1.0907 1.1329 6.0 1.1002 1.0924 1.0948 1.1418 6.2 1.1015 1.0950 1.1068 1.1541 6.4 1.1040 1.0972 1.1171 1.1645 6.6 1.1078 1.1023 1.1265 1.1730 6.8 1.1112 1.1080 1.1350 1.1798 7.0 1.1135 1.1127 1.1423 1.1850 7.2 1.1158 1.1165 1.1485 1.1886 7.4 1.1188 1.1193 1.1534 1.1904 7.6 1.1208 1.1210 1.1570 1.1905 7.8 1.1220 1.1218 1.1595 1.1884 8.0 1.1221 1.1211 1.1600 1.1857 8.2 1.1213 1.1198 1.1601 1.1832 8.4 1.1195 1.1198 1.1634 1.1794 8.6 1.1163 1.1190 1.1662 1.1766 8.8 1.1145 1.1179 1.1693 1.1743 6-1.14 SSTR Rev. 121

Table 1: W(Z,BU) versus Axial Height (Sheet 2 of 2)

HEIGHT (Z) W(Z,BU) W(Z,BU) W(Z,BU) W(Z,BU)

(Feet) 150 3000 10000 18000 MWD/MTU MWD/MTU MWD/MTU MWD/MTU 9.0 1.1152 1.1191 1.1772 1.1701 9.2 1.1230 1.1282 1.1916 1.1677 9.4 1.1506 1.1414 1.2082 1.1781 9.6 1.1770 1.1657 1.2281 1.1998 9.8 1.2017 1.1970 1.2546 1.2237 10.0 1.2275 1.2279 1.2842 1.2458 10.2 1.2484 1.2585 1.3110 1.2665 10.4 1.2574 1.2928 1.3356 1.2854 10.6 1.2750 1.3181 1.3574 1.3102 10.8 1.2950 1.3426 1.3756 1.3291

>1.l.O 1.0000 1.0000 1.0000 1.0000 Note: The FQ(Z) surveillance exclusion zone is specified by Technical Specification 4 .2.2.2.g 6-1.15 SSTR Rev. 121