BYRON 2026-0007, Cycle 27 Core Operating Limits Report
| ML26043A428 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 02/12/2026 |
| From: | Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML26043A426 | List: |
| References | |
| BYRON 2026-0007, 10.101, 5A.101 | |
| Download: ML26043A428 (0) | |
Text
CORE OPERATING LIMITS REPORT (COLR)
FOR BYRON UNIT 1 CYCLE 27 CONSTELLATION TRACKING ID:
COLR BYRON UNIT 1 REVISION 20
COLR BYRON 1 Revision 20 Page 1 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for Byron Station Unit 1 Cycle 27 has been prepared in accordance with the requirements of Technical Specification 5.6.5 (ITS).
The Technical Specification Safety Limits and Limiting Conditions for Operation (LCOs) affected by this report are listed below:
SL 2.1.1 Reactor Core Safety Limits (SLs)
LCO 3.1.1 SHUTDOWN MARGIN (SDM)
LCO 3.1.3 Moderator Temperature Coefficient (MTC)
LCO 3.1.4 Rod Group Alignment Limits LCO 3.1.5 Shutdown Bank Insertion Limits LCO 3.1.6 Control Bank Insertion Limits LCO 3.1.8 PHYSICS TESTS Exceptions - MODE 2 LCO 3.2.1 Heat Flux Hot Channel Factor (FQ(Z))
LCO 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (FN'H)
LCO 3.2.3 AXIAL FLUX DIFFERENCE (AFD)
LCO 3.3.1 Reactor Trip System (RTS) Instrumentation LCO 3.3.9 Boron Dilution Protection System (BDPS)
LCO 3.4.1 Reactor Coolant System (RCS) Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits LCO 3.9.1 Boron Concentration The portions of the Technical Requirements Manual (TRM) affected by this report are listed below:
TRM TLCO 3.1.b Boration Flow Paths - Operating TRM TLCO 3.1.f Borated Water Sources - Operating TRM TLCO 3.1.g Position Indication System - Shutdown TRM TLCO 3.1.h Shutdown Margin (SDM) - MODE 1 and MODE 2 with keff t 1.0 TRM TLCO 3.1.i Shutdown Margin (SDM) - MODE 5 TRM TLCO 3.1.j Shutdown and Control Rods TRM TLCO 3.1.k Position Indication System - Shutdown (Special Test Exception)
COLR BYRON 1 Revision 20 Page 2 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 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 are applicable for the entire cycle unless otherwise identified. These limits have been developed using the NRC-approved methodologies specified in Technical Specification 5.6.5.
2.1 Reactor Core Safety Limits (SLs) (SL 2.1.1) 2.1.1 In MODES 1 and 2, the combination of Thermal Power, Reactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure shall not exceed the limits specified in Figure 2.1.1.
Figure 2.1.1: Reactor Core Limits
COLR BYRON 1 Revision 20 Page 3 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 2.2 SHUTDOWN MARGIN (SDM)
The SDM limit for MODES 1, 2, 3, and 4 is:
2.2.1 The SDM shall be greater than or equal to 1.3% 'k/k (LCOs 3.1.1, 3.1.4, 3.1.5, 3.1.6, 3.1.8, 3.3.9; TRM TLCOs 3.1.b, 3.1.f, 3.1.h, and 3.1.j).
The SDM limit for MODE 5 is:
2.2.2 SDM shall be greater than or equal to 1.3% 'k/k (LCO 3.1.1, LCO 3.3.9; TRM TLCOs 3.1.i and 3.1.j).
2.3 Moderator Temperature Coefficient (MTC) (LCO 3.1.3)
The Moderator Temperature Coefficient (MTC) limits are:
2.3.1 The BOL/ARO/HZP-MTC upper limit shall be +2.915 x 10-5 'k/k/°F.
2.3.2 The EOL/ARO/HFP-MTC lower limit shall be -4.6 x 10-4 'k/k/°F.
2.3.3 The EOL/ARO/HFP-MTC Surveillance limit at 300 ppm shall be -3.7 x 10-4 'k/k/°F.
2.3.4 The EOL/ARO/HFP-MTC Surveillance limit at 60 ppm shall be -4.3 x 10-4 'k/k/°F.
where: 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 HFP stands for Hot Full Thermal Power 2.4 Shutdown Bank Insertion Limits (LCO 3.1.5) 2.4.1 All shutdown banks shall be fully withdrawn to at least 224 steps.
2.5 Control Bank Insertion Limits (LCO 3.1.6) 2.5.1 The control banks, with Bank A greater than or equal to 224 steps, shall be limited in physical insertion as shown in Figure 2.5.1.
2.5.2 Each control bank shall be considered fully withdrawn from the core at greater than or equal to 224 steps.
2.5.3 The control banks shall be operated in sequence by withdrawal of Bank A, Bank B, Bank C and Bank D. The control banks shall be sequenced in reverse order upon insertion.
2.5.4 Each control bank not fully withdrawn from the core shall be operated with the following overlap limits as a function of park position:
Park Position (step)
Overlap Limit (step) 231 115
COLR BYRON 1 Revision 20 Page 4 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 Figure 2.5.1:
Control Bank Insertion Limits Versus Percent Rated Thermal Power 224 220 (27%, 224)
(77%, 224) 200 180 160 140 (100%, 161) 120 100 80 60 40 20 0
0 10 20 30 40 50 60 70 80 90 100 R e l a t i v e P o w e r ( P e r c e n t )
The bank position is given as follows:
Control Bank D: (161/70) * (P-100) + 161 (for 30 P 100)
Where P is defined as the core power (in percent).
BANK B (0%, 163)
BANK C BANK D (0%, 47)
(30%, 0)
Rod Bank Position (Steps Withdrawn)
COLR BYRON 1 Revision 20 Page 5 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 2.6 Heat Flux Hot Channel Factor (FQ(Z)) (LCO 3.2.1) 2.6.1 Total Peaking Factor:
RTP FQ(Z) d Q
0.5 xK(Z) for P d 0.5 FQ(Z) d RTP Q
P xK(Z) for P ! 0.5 where: P = the ratio of THERMAL POWER to RATED THERMAL POWER FQRTP = 2.60 1.1 K(Z) is provided in Figure 2.6.1.
Figure 2.6.1 K(Z) - Normalized FQ(Z) as a Function of Core Height (0.0, 1.0)
(6.0, 1.0)
(12.0,1.0) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0
0 1
2 3
4 5
6 7
8 9
10 11 12 BOTTOM Core Height (ft)
TOP LOCA Limiting Envelope K(Z) Normalized FQ(Z)
F F
COLR BYRON 1 Revision 20 Page 6 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 2.6.2 W(Z) Values:
W(Z) is provided as:
1)
Table 2.6.2.a are the normal operation W(Z) values that correspond to the NORMAL AXIAL FLUX DIFFERENCE (AFD) Acceptable Operation Limits provided in Figure 2.8.1.a. The Normal AFD Acceptable Operation Limits may be invoked at any time and must be used with the corresponding W(Z) values.
2)
Table 2.6.2.b are the Expanded normal operation W(Z) values that correspond to the EXPANDED AXIAL FLUX DIFFERENCE (AFD) Acceptable Operation Limits provided in Figure 2.8.1.b. The Expanded AFD Acceptable Operation Limits may be invoked at any time and must be used with the corresponding W(Z) values.
2.6.3 Table 2.6.2.c shows the FQC(Z) penalty factors that are greater than 2% per the allowable surveillance frequency. These values shall be used to increase the FQW(Z) as per Surveillance Requirement 3.2.1.2. A 2% penalty factor shall be used at all cycle burnups that are outside the range of Table 2.6.2.c.
Table 2.6.2.d contains the required operating space reduction values for THERMAL POWER and AXIAL FLUX DIFFERENCE (AFD) when FQW(Z) is not within its limits. These values are used in conjunction with Technical Specification LCO 3.2.1 Required Actions B.1 and B.2.
Uncertainty:
The uncertainty, UFQ, to be applied to the Heat Flux Hot Channel Factor FQ(Z) shall be calculated by the following formula UFQ = Uqu
- Ue where:
Uqu = Base F4 measurement uncertainty = 1.05 Ue = Engineering uncertainty factor = 1.03
COLR BYRON 1 Revision 20 Page 7 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 Table 2.6.2.a W(Z) versus Core Height for Normal AFD Acceptable Operation Limits in Figure 2.8.1.a (Top and Bottom 8% Excluded per Byron SR 3.2.1.2 Bases)
Height 150 5000 14000 20000 (feet)
MWD/MTU MWD/MTU MWD/MTU MWD/MTU 0.00 (core bottom) 1.2833 1.3976 1.2316 1.1912 0.20 1.2751 1.3849 1.2254 1.1823 0.40 1.2746 1.3794 1.2312 1.1881 0.60 1.2786 1.3783 1.2381 1.1952 0.80 1.2877 1.3808 1.2520 1.2111 1.00 1.2866 1.3723 1.2558 1.2172 1.20 1.2762 1.3559 1.2494 1.2118 1.40 1.2615 1.3351 1.2390 1.2024 1.60 1.2462 1.3130 1.2284 1.1933 1.80 1.2297 1.2891 1.2168 1.1837 2.00 1.2117 1.2636 1.2038 1.1729 2.20 1.1926 1.2371 1.1896 1.1613 2.40 1.1734 1.2105 1.1753 1.1493 2.60 1.1544 1.1843 1.1630 1.1374 2.80 1.1345 1.1584 1.1522 1.1255 3.00 1.1218 1.1360 1.1405 1.1140 3.20 1.1189 1.1234 1.1335 1.1099 3.40 1.1188 1.1214 1.1335 1.1139 3.60 1.1191 1.1201 1.1385 1.1269 3.80 1.1190 1.1183 1.1436 1.1405 4.00 1.1182 1.1162 1.1482 1.1531 4.20 1.1178 1.1134 1.1524 1.1653 4.40 1.1190 1.1102 1.1560 1.1764 4.60 1.1195 1.1081 1.1589 1.1863 4.80 1.1196 1.1088 1.1607 1.1947 5.00 1.1190 1.1103 1.1616 1.2016 5.20 1.1192 1.1108 1.1612 1.2064 5.40 1.1217 1.1107 1.1596 1.2094 5.60 1.1244 1.1097 1.1577 1.2128 5.80 1.1265 1.1119 1.1575 1.2197 6.00 1.1353 1.1176 1.1615 1.2321 6.20 1.1512 1.1226 1.1732 1.2470 6.40 1.1650 1.1265 1.1826 1.2584 6.60 1.1775 1.1300 1.1920 1.2670 6.80 1.1886 1.1387 1.2001 1.2728 7.00 1.1979 1.1507 1.2057 1.2756 7.20 1.2054 1.1613 1.2094 1.2753 7.40 1.2109 1.1703 1.2107 1.2719 7.60 1.2144 1.1779 1.2099 1.2657 7.80 1.2145 1.1821 1.2066 1.2549 8.00 1.2159 1.1888 1.2013 1.2459 8.20 1.2229 1.2011 1.1961 1.2418 8.40 1.2279 1.2119 1.1927 1.2358 8.60 1.2355 1.2256 1.1895 1.2329 8.80 1.2440 1.2409 1.1922 1.2280 9.00 1.2552 1.2586 1.2014 1.2250 9.20 1.2681 1.2775 1.2138 1.2308 9.40 1.2750 1.2909 1.2279 1.2410 9.60 1.2900 1.3066 1.2376 1.2592 9.80 1.3144 1.3323 1.2458 1.2809 10.00 1.3415 1.3660 1.2536 1.3011 10.20 1.3664 1.3998 1.2606 1.3190 10.40 1.3895 1.4286 1.2687 1.3338 10.60 1.4111 1.4531 1.2750 1.3460 10.80 1.4210 1.4756 1.2770 1.3534 11.00 1.4258 1.5003 1.2779 1.3587 11.20 1.4152 1.5140 1.2767 1.3604 11.40 1.3548 1.4683 1.2616 1.3454 11.60 1.3054 1.4215 1.2422 1.3247 11.80 1.3000 1.4141 1.2380 1.3109 12.00 (core top) 1.2924 1.4036 1.2282 1.2912 Note: W(Z) values at 20000 MWD/MTU may be applied to cycle burnups greater than 20000 MWD/MTU to prevent W(Z) function extrapolation
COLR BYRON 1 Revision 20 Page 8 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 Table 2.6.2.b W(Z) versus Core Height for Expanded AFD Acceptable Operation Limits in Figure 2.8.1.b (Top and Bottom 8% Excluded per Byron SR 3.2.1.2 Bases)
Height 150 5000 14000 20000 (feet)
MWD/MTU MWD/MTU MWD/MTU MWD/MTU 0.00 (core bottom) 1.3681 1.4883 1.3373 1.3325 0.20 1.3589 1.4741 1.3295 1.2909 0.40 1.3589 1.4675 1.3346 1.2834 0.60 1.3612 1.4657 1.3408 1.2860 0.80 1.3699 1.4671 1.3544 1.3038 1.00 1.3677 1.4571 1.3570 1.3053 1.20 1.3558 1.4389 1.3488 1.3000 1.40 1.3392 1.4161 1.3362 1.2902 1.60 1.3219 1.3917 1.3231 1.2773 1.80 1.3030 1.3654 1.3087 1.2619 2.00 1.2823 1.3372 1.2927 1.2457 2.20 1.2604 1.3078 1.2752 1.2300 2.40 1.2379 1.2782 1.2571 1.2151 2.60 1.2152 1.2489 1.2387 1.1997 2.80 1.1952 1.2191 1.2194 1.1846 3.00 1.1855 1.1959 1.2034 1.1808 3.20 1.1831 1.1809 1.1923 1.1821 3.40 1.1788 1.1704 1.1859 1.1827 3.60 1.1741 1.1663 1.1863 1.1841 3.80 1.1689 1.1617 1.1878 1.1911 4.00 1.1626 1.1575 1.1891 1.1999 4.20 1.1563 1.1547 1.1897 1.2069 4.40 1.1518 1.1509 1.1895 1.2129 4.60 1.1481 1.1466 1.1883 1.2174 4.80 1.1439 1.1416 1.1860 1.2200 5.00 1.1390 1.1358 1.1823 1.2225 5.20 1.1333 1.1294 1.1775 1.2245 5.40 1.1275 1.1222 1.1712 1.2242 5.60 1.1257 1.1131 1.1622 1.2254 5.80 1.1278 1.1123 1.1662 1.2364 6.00 1.1347 1.1178 1.1800 1.2525 6.20 1.1433 1.1226 1.1935 1.2662 6.40 1.1523 1.1263 1.2047 1.2769 6.60 1.1609 1.1335 1.2136 1.2846 6.80 1.1694 1.1417 1.2202 1.2891 7.00 1.1785 1.1507 1.2243 1.2903 7.20 1.1875 1.1607 1.2257 1.2882 7.40 1.1948 1.1697 1.2246 1.2829 7.60 1.2007 1.1771 1.2211 1.2746 7.80 1.2049 1.1820 1.2134 1.2615 8.00 1.2073 1.1891 1.2077 1.2503 8.20 1.2081 1.2004 1.2073 1.2440 8.40 1.2072 1.2113 1.2052 1.2357 8.60 1.2035 1.2251 1.2058 1.2309 8.80 1.2036 1.2407 1.2107 1.2230 9.00 1.2127 1.2588 1.2234 1.2202 9.20 1.2315 1.2777 1.2376 1.2300 9.40 1.2569 1.2912 1.2468 1.2396 9.60 1.2815 1.3069 1.2560 1.2564 9.80 1.3041 1.3325 1.2623 1.2772 10.00 1.3252 1.3664 1.2651 1.2969 10.20 1.3440 1.3999 1.2698 1.3142 10.40 1.3608 1.4285 1.2810 1.3285 10.60 1.3761 1.4528 1.2930 1.3402 10.80 1.3796 1.4751 1.3021 1.3472 11.00 1.3815 1.4996 1.3084 1.3522 11.20 1.3738 1.5131 1.3103 1.3536 11.40 1.3169 1.4671 1.2998 1.3383 11.60 1.2704 1.4202 1.2829 1.3175 11.80 1.2666 1.4126 1.2717 1.3034 12.00 (core top) 1.2614 1.4018 1.2559 1.2835 Note: W(Z) values at 20000 MWD/MTU may be applied to cycle burnups greater than 20000 MWD/MTU to prevent W(Z) function extrapolation
COLR BYRON 1 Revision 20 Page 9 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 Table 2.6.2.c Penalty Factors in Excess of 2%
Cycle Burnup Penalty Factor (MWD/MTU) 0 1.0200 150 1.0650 700 1.0950 1100 1.0950 2500 1.0500 3475 1.0300 4140 1.0200 6135 1.0200 6350 1.0300 6900 1.0400 7500 1.0390 7900 1.0350 8574 1.0200 9460 1.0200 9650 1.0230 10125 1.0200 18770 1.0200 19300 1.0275 20000 1.0260 24160 1.0260 Notes:
Linear interpolation is adequate for intermediate cycle burnups.
All cycle burnups outside the range of Table 2.6.2.c shall use a 2% penalty factor for compliance with the 3.2.1.2 Surveillance Requirements.
Table 2.6.2.d Required Operating Space Reduction When FQW(Z) Exceeds Its Limits Required FQW(Z)
Margin Improvement THERMAL POWER Reduction (% RTP)
Negative AFD Band Reduction (% AFD)
Positive AFD Band Reduction (% AFD) 1%
3%
1%
1%
> 1% AND 2%
6%
2%
2%
> 2% AND 3%
9%
3%
3%
> 3%
50%
N/A N/A FQC(Z)
COLR BYRON 1 Revision 20 Page 10 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 2.7 Nuclear Enthalpy Rise Hot Channel Factor (FN'H) (LCO 3.2.2) 2.7.1 FN'H d FRTP'H[1.0 + PF'H(1.0 - P)]
where: P = the ratio of THERMAL POWER to RATED THERMAL POWER (RTP)
FRTP'H = 1.63 PF'H = 0.3
2.7.2 Uncertainty
The uncertainty, UFH, to be applied to the Nuclear Enthalpy Rise Hot Channel Factor FNH shall be calculated by the following formula:
UFH = UFHm where:
UFHm = Base FNH measurement uncertainty = 1.04 2.8 AXIAL FLUX DIFFERENCE (AFD) (LCO 3.2.3) 2.8.1 The AXIAL FLUX DIFFERENCE (AFD) Acceptable Operation Limits are provided in the Figures described below.
a)
Figure 2.8.1.a is the Normal AFD Acceptable Operation Limits associated with the W(Z) values in Table 2.6.2.a. These limits may be modified in accordance with Table 2.6.2.d if LCO 3.2.1 Required Actions B.1 and B.2 must be taken. Prior to changing to Figure 2.8.1.a, confirm that the plant is within the specified AFD envelope.
b)
Figure 2.8.1.b is the Expanded AFD Acceptable Operation Limits associated with the W(Z) values in Table 2.6.2.b. These limits may be modified in accordance with Table 2.6.2.d if LCO 3.2.1 Required Actions B.1 and B.2 must be taken.
2.9 DELETED
COLR BYRON 1 Revision 20 Page 11 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 Figure 2.8.1.a:
Normal Axial Flux Difference Limits as a Function of Rated Thermal Power EŽ & >
h KŽ h
KŽ
KŽ
y/> &>hy /&& Z E
Ž Zd d, ZD> WKt Z
COLR BYRON 1 Revision 20 Page 12 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 Figure 2.8.1.b:
Expanded Axial Flux Difference Limits as a Function of Rated Thermal Power
& >
h KŽ h
KŽ
KŽ
y/> &>hy /&& Z E
Ž Zd d, ZD> WKt Z
COLR BYRON 1 Revision 20 Page 13 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 2.10 Reactor Trip System (RTS) Instrumentation (LCO 3.3.1) - Overtemperature 'T Setpoint Parameter Values 2.10.1 The Overtemperature 'T reactor trip setpoint K1 shall be equal to 1.325.
2.10.2 The Overtemperature 'T reactor trip setpoint Tavg coefficient K2 shall be equal to 0.0297 / °F.
2.10.3 The Overtemperature 'T reactor trip setpoint pressure coefficient K3 shall be equal to 0.00135 / psi.
2.10.4 The nominal Tavg at RTP (indicated) Tc shall be less than or equal to 588.0 °F.
2.10.5 The nominal RCS operating pressure (indicated) Pc shall be equal to 2235 psig.
2.10.6 The measured reactor vessel 'T lead/lag time constant W1 shall be equal to 8 sec.
2.10.7 The measured reactor vessel 'T lead/lag time constant W2 shall be equal to 3 sec.
2.10.8 The measured reactor vessel 'T lag time constant W3 shall be less than or equal to 2 sec.
2.10.9 The measured reactor vessel average temperature lead/lag time constant W4 shall be equal to 33 sec.
2.10.10 The measured reactor vessel average temperature lead/lag time constant W5 shall be equal to 4 sec.
2.10.11 The measured reactor vessel average temperature lag time constant W6 shall be less than or equal to 2 sec.
2.10.12 The f1 ('I) positive breakpoint shall be +10% 'I.
2.10.13 The f1 ('I) negative breakpoint shall be -18% 'I.
2.10.14 The f1 ('I) positive slope shall be +3.47% / % 'I.
2.10.15 The f1 ('I) negative slope shall be -2.61% / % 'I.
COLR BYRON 1 Revision 20 Page 14 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 2.11 Reactor Trip System (RTS) Instrumentation (LCO 3.3.1) - Overpower 'T Setpoint Parameter Values 2.11.1 The Overpower 'T reactor trip setpoint K4 shall be equal to 1.072.
2.11.2 The Overpower 'T reactor trip setpoint Tavg rate/lag coefficient K5 shall be equal to 0.02 / °F for increasing Tavg.
2.11.3 The Overpower 'T reactor trip setpoint Tavg rate/lag coefficient K5 shall be equal to 0 / °F for decreasing Tavg.
2.11.4 The Overpower 'T reactor trip setpoint Tavg heatup coefficient K6 shall be equal to 0.00245 / °F when T ! Ts.
2.11.5 The Overpower 'T reactor trip setpoint Tavg heatup coefficient K6 shall be equal to 0 / °F when T d Ts.
2.11.6 The nominal Tavg at RTP (indicated) Ts shall be less than or equal to 588.0 °F.
2.11.7 The measured reactor vessel 'T lead/lag time constant W1 shall be equal to 8 sec.
2.11.8 The measured reactor vessel 'T lead/lag time constant W2 shall be equal to 3 sec.
2.11.9 The measured reactor vessel 'T lag time constant W3 shall be less than or equal to 2 sec.
2.11.10 The measured reactor vessel average temperature lag time constant W6 shall be less than or equal to 2 sec.
2.11.11 The measured reactor vessel average temperature rate/lag time constant W7 shall be equal to 10 sec.
2.11.12 The f2 ('I) positive breakpoint shall be 0 for all 'I.
2.11.13 The f2 ('I) negative breakpoint shall be 0 for all 'I.
2.11.14 The f2 ('I) positive slope shall be 0 for all 'I.
2.11.15 The f2 ('I) negative slope shall be 0 for all 'I.
COLR BYRON 1 Revision 20 Page 15 of 15 CORE OPERATING LIMITS REPORT (COLR) for BYRON UNIT 1 CYCLE 27 2.12 Reactor Coolant System (RCS) Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits (LCO 3.4.1) 2.12.1 The pressurizer pressure shall be greater than or equal to 2209 psig.
2.12.2 The RCS average temperature (Tavg) shall be less than or equal to 593.1 °F.
2.12.3 The RCS total flow rate shall be greater than or equal to 386,000 gpm.
2.13 Boron Concentration 2.13.1 The refueling boron concentration shall be greater than or equal to the applicable value given in the Table below (LCO 3.9.1). The reported prior to initial criticality value also bounds the end-of-cycle requirements for the previous cycle.
2.13.2 To maintain keff d 0.987 with all shutdown and control rods fully withdrawn in MODES 3, 4, or 5 (TRM TLCO 3.1.g Required Action B.2 and TRM TLCO 3.1.k.2), the Reactor Coolant System boron concentration shall be greater than or equal to the applicable value given in the Table below.
COLR Section Conditions Boron Concentration (ppm) 2.13.1 a) prior to initial criticality 1726 b) for cycle burnups t 0 MWD/MTU and < 16000 MWD/MTU 1885 c) for cycle burnups t 16000 MWD/MTU 1475 2.13.2 a) prior to initial criticality 1775 b) for cycle burnups t 0 MWD/MTU and < 16000 MWD/MTU 2104 c) for cycle burnups t 16000 MWD/MTU 1597