ML062330249

Core Operating Limits Report, Braidwood Unit 1 Cycle 13

ML062330249
Person / Time
Site:	Braidwood
Issue date:	08/21/2006
From:	Boerschig G Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BW060080
Download: ML062330249 (16)

Text

____ ___ Exel n Exelor Ge ieratori Comnany, LLC Nuc] ear Braidwood Station August 21, 2006 BW060080 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Unit 1 Facility Operating License No. NPF-72 NRC Docket No. STN 50-456

Subject:

Core Operating Limits Report, Braidwood Unit 1 Cycle 13 The purpose of this letter is to transmit a mid-cycle revision of the Core Operating Limits Report (COLR) for Braidwood Unit 1 Cycle 13, in accordance with Technical Specification 5.6.5, Core Operating Limits Report (COLR). The Braidwood Unit 1 Cycle 13 COLR was recently revised after discovering that the difference between the measured and predicted Axial Offset was greater than 4%. Item 2.6.2 of the COLA and the corresponding Figures were revised with newly updated W(z) data, a cycle dependent function that accounts for power distribution transients encountered during normal operation. The W(z) data was updated based on actual fluxmap data obtained. The most probable cause for the observed axial offset difference was determined to be Crud Induced Power Shift (CIPS) carryover effect from Cycle 12.

If you have any questions regarding this matter, please contact Mr. Dale Ambler, Regulatory Assurance Manager, at (815) 417-2800.

Sincerely, Gregory A. Boerschig Plant Manager Braidwood Station

Attachment:

Core Operating Limits Report, Braidwood Unit 1 Cycle 13, Revision 5

ATFACHMENT 1 Core Operating Limits Report Braidwood Unit 1 Cycle 13 Revision 5

Westinghouse Proprietary Class 2 NF-CB 126 July 20, 2006 Attachment CORE OPERATING LIMITS REPORT (COLR)

FOR BRAIDWOOD UNIT 1 CYCLE 13 Revision 5 (13 Pages)

COLR BRAIDWOOD 1 Revision 5 Page 1 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for Braidwood Station Unit 1 Cycle 13 has been prepared in accordance with the requirements of Technical Specification 5.6.5 (ITS).

The Technical Specifications affected by this report are listed below:

SL 2.1.1 Reactor Core Safety Limits (SL5)

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 (F0(Z))

LCO 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (FNAH)

LCO 3.2.3 AXIAL FLUX DIFFERENCE (AFD)

LCO 3.2.5 Departure from Nucleate Boiling Ratio (DNBR)

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 affected by this report are listed below:

TRM TLCO 3.1.b Boration Flow Paths Operating TRM TLCO 3.1.d Charging Pumps 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 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 BRAIDWOOD 1 Revision 5 Page 2 of 13 CORE OPERATING LIMiTS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 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 (SL5) (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.

680 660 0

D E

620 600 580 2

Fraction of Nominal Power Figure 2.1.1: Reactor Core Limits

COLR BRAIDWOOD 1 Revision 5 Page 3 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 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% Ak/k (LCO5 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.d, 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% Ak/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 +1.695 x i0~Ak/k/°F.

2.3.2 The EOL/ARO/HFP-MTC lower limit shall be -4.6 x 10 Ak/k/°F.

2.3.3 The EOL/ARO/HFP-MTC Surveillance limit at 300 ppm shall be -3.7 x 10~Ak/k/°F.

2.3.4 The EOL/ARO/HFP-MTC Surveillance limit at 60 ppm shall be -4.3 x 10~Ak/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) 225 110 226 111 227 1 12 228 1 13 229 114

COLR BRAIDWOOD I Revision 5 Page 4 of 13 CORE OPERATING LI~1ITS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 Figure 2.5.1:

Control Bank Insertion Umits Versus Percent Rated Thermal Power 224 (27%, 224) (77%, 224) 220 200 180

~160 (100%, 161) 140

~ 120 C

0

~100 0

a-c80 0

40 20 0

0 10 20 30 40 50 60 70 80 90 100 Relative Power (Percent)

COLR BRAIDWOOD 1 Revision 5 Page 5 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 2.6 Heat Flux Hot Channel Fact~rjF~L~fl (LCO 3.2.1) 2.6.1 Total Peaking Factor:

FRTP FQ(Z) 9----xK(Z) forP0.5 FRTP FQ(Z) ~-xK(Z) forP>0.5 where: P = the ratio of THERMAL POWER to RATED THERMAL POWER F~T~= 2.60 K(Z) is provided in Figure 2.6.1.

2.6.2 W(Z) Values:

a) When PDMS is OPERABLE, W(Z) = 1.00000 for all axial points.

b) When PDMS is inoperable, W(Z) is provided in Table 2.6.2.a.

The normal operation W(Z) values have been determined at burnups of 1620, 6000, 14000, and 20000 MWD/MTU.

Table 2.6.2.b shows the FCQ(z) penalty factors that are greater than 2% per 31 Effective Full Power Days (EFPD). These values shall be used to increase the F~Na(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.b.

2.6.3 Uncertainty

The uncertainty, UFO, to be applied to the Heat Flux Hot Channel Factor F0(Z) shall be calculated by the following formula UFQ =UVU*U,,

where:

Uqu = Base F0 measurement uncertainty = 1.05 when PDMS is inoperable (Uqu is defined by PDMS when OPERABLE.)

Ue = Engineering uncertainty factor = 1.03 2.6.4 PDMS Alarms:

F (Z) Warning Setpoint 2% of FQ(Z) Margin 0

F (Z) Alarm Setpoint 0% of F (Z) Margin 0 0

COLR BRAIDWOOD I Revision 5 Page 6 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 Figure 2.6.1 K(Z) Normalized F0(Z) as a Function of Core Height 1.1 (0.0 1.0) (6.0 1.0)

---

-~

--- - -~_ 121 ,0.924)

- ~

0.9 0.8 R 0.7 a

U.

0.6

~o0.5

~+~LOCALimiting

~0.4 Envelope 0.3 0.2 0.1 0

0 1 2 3 4 5 6 7 8 9 101112 BOTTOM Core Height (ft) TOP

COLR BRAIDWOOD 1 Revision 5 Page 7 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 Table 2.6.2.a W(Z) versus Core Height (Top and Bottom 8% Excluded per WCAP-1 0216)

Height 1620 6000 14000 20000 (feet) MWD/MTU MWD/MTU MWD/MTU MWD/MTU 0.00 (core bottom) 1.5085 1.4831 1.4425 1.3276 0.20 1.4710 1.4439 1.4073 1.3128 0.40 1,4538 1.4287 1.3909 1.3059 0.60 1.4373 1.4153 1.3788 1.3029 0.80 1.3949 1.3692 1.3553 1.2987 1.00 1.3748 1.3521 1.3344 1.2923 1.20 1.3647 1.3692 1.3263 1,2831 1.40 1.3659 1.3453 1.3141 1.2739 1.60 1.3486 1.3132 1.2903 1.2604 1.80 1.3248 1.2870 1.2740 1.2496 2.00 1.2985 1.2598 1.2577 1,2368 2.20 1.2688 1.2284 1,2369 1.2204 2.40 1.2435 1.2043 1.2192 1.2063 2.60 1.2249 1.1966 1.2008 1.T880 2.80 1.2095 1.1900 1.1904 1.1720 3.00 1.1979 1.1827 1,1823 1.1596 3.20 1.1862 1.1730 1.1717 1.1543 3.40 1.1759 1.1662 1.1639 1.1610 3.60 1.1640 1.1564 1.1540 1,1677 3.80 1.1545 1.1486 1.1458 1,1741 4.00 1.1484 1.1409 1.1396 1.1796 4.20 1.1413 1.1311 1.1362 1.1890 4.40 1.1354 1.1257 1.1317 1,1992 4.60 1.1272 1.1184 1.1301 1.2079 4.80 1.1193 1.1117 1.1311 1.2139 5.00 1.1122 1.1055 1.1303 1.2170 5.20 1.1043 1.0986 1.1302 1.2188 5.40 1.0998 1.1026 1.1318 1.2246 5.60 1.0932 1.1059 1.1392 1.2434 5.80 1.0898 1.1093 1.1563 1.2610 6.00 1.0983 1.1117 1.1720 1.2740 6.20 1.1065 1.1132 1.1857 1.2830 6.40 1.1178 1.1240 1.1978 1.2905 6.60 1.1299 1.1380 1.2070 1.2923 6.80 1.1404 1.1511 1.2140 1.2930 7.00 1.1495 1.1607 1.2182 1.2909 7.20 1.1572 4.1683 1.2187 1.2838 7.40 1.1634 1.1734 1.2171 1.2744 7.60 1.1680 1.1768 1.2126 1.2590 7.80 1.1734 1.1839 1.2069 1.2467 8.00 1.1783 1.1912 1.2016 1.2357 8.20 1.1811 1.1964 1.1944 1.2230 8.40 1.1862 1.2023 1.1862 1.2123 8.60 1.1887 1.2075 1.1866 1.1982 8.80 1.1928 1.2140 1.1891 1.1919 9.00 1.1941 1.2178 1.1905 1.1863 9.20 1.1982 1.2194 1.1914 1.1791 9.40 1.2075 1.2212 1.1939 1.2193 9.60 1.2182 1.2272 1.1995 1.2658 9.80 1.2273 1.2346 1.2264 1.3079 10.00 1.2310 1.2413 1.2564 1.3455 10.20 1.2299 1,2478 1.2633 1.3802 10.40 1.2304 4.2554 1.3027 1.4093 10.60 1.2343 1.2727 1.3168 1.4328 10.80 1.2388 1.2891 1.3262 1.4522 11.00 1.2496 1.3046 1.3298 1.4646 11.20 1.2422 1.2684 1.3105 1.4782 11.40 1.2553 1.2827 1.3188 1.4790 11.60 1.2902 1.3416 1.3129 1.4618 11.80 1.2962 1.3437 1.3008 1.4496 12.00 (core top) 1.3097 4.3602 1.2909 1.4420 Note: W(Z) values at 20000 MWD/MTU may be applied to cycle bumups greater than 20000 MWD/MTU to prevent W(Z) function extrapolation

COLR BRAIDWOOD 1 Revision 5 Page 8 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 Table 2.6.2.b Penalty Factors in Excess of 2% per 31 EFPD Cycle Bumup Penalty Factor (MWD/MTU) FC0(z) 840 1.0200 1702 1.0374 1874 1.0385 2219 1.0342 3253 1.0200 11184 1.0200 11529 1.0250 11701 1.0270 11874 1.0283 12046 1.0294 12563 1.0322 12736 1.0314 13080 1.0278 13770 1.0200 16873 1.0200 17218 1.0239 17390 1.0248 17563 1.0252 18597 1.0245 19287 1.0200 Notes:

Linear interpolation is adequate for intermediate cycle bumups.

All cycle bumups outside the range of the table shall use a 2% penalty factor for compliance with the 3.2.1.2 Surveillance Requirements.

COLR BRAIDWOOD 1 Revision 5 Page 9 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 2.7 Nuclear Enthalpy Rise Hot Channel Factor (F~(LCO 3.2.2) 2.7.1 F~H F~~[1.0 + PF,~H(1.0 P)]

where: P = the ratio of THERMAL POWER to RATED THERMAL POWER F~

PF~H= 0.3 2.7.2 Uncertainty when PDMS is inoperable The uncertainty, UFOR, to be applied to the Nuclear Enthalpy Rise Hot Channel Factor FN~Hshall be calculated by the following formula:

UF~H= UF~Hm where:

UFA/-Im Base FN~Hmeasurement uncertainty = 1.04 2.7.3 PDMS Alarms:

F~HWarning Setpoint 2% of F~HMargin FN~HAlarm Setpoint 0% of F~HMargin 2.8 AXIAL FLUX DIFFERENCE (AFD) (LCO 3.2.3) 2.8.1 When PDMS is inoperable, the AXIAL FLUX DIFFERENCE (AFD) Acceptable Operation Limits are provided in Figure 2.8.1 or the latest valid PDMS Surveillance Report, whichever is more conservative.

2.8.2 When PDMS is OPERABLE, no AFD Acceptable Operation Limits are applicable.

2.9 Departure from Nucleate Boiling Ratio (DNBR) (LCO 3.2.5) 2.9.1 DNBRAPSL 1.536 The Axial Power Shape Limiting DNBR (DNBRAPSL) is applicable with THERMAL POWER 50% RTP when PDMS is OPERABLE.

2.9.2 PDMS Alarms:

DNBR Warning Setpoint 2% of DNBR Margin DNBR Alarm Setpoint 0% of DNBR Margin

COLR BRAIDWOOD 1 Revision 5 Page 10 of 13 CORE OPERATING LIM1TS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 Figure 2.8.1 Axial Flux Difference Limits as a Function of Rated Thermal Power Axial Flux Difference Limits w ith PDMS Inoperable 120 100 w

0 a- 80

-J w

I 60 w

I-40 20 0

40 20 -10 0 10 20 30 40 50 AXIAL FLUX DIFFERENCE (%)

COLR BRAIDWOOD 1 Revision 5 Page 11 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT 1 CYCLE 13 2.10 Reactor Trip System (RTS) Instrumentation (LCO 3.3.1) Overtemperature AT Setpoint Parameter Values 2.10.1 The Overtemperature AT reactor trip setpoint K1 shall be equal to 1.325.

2.10.2 The Overtemperature AT reactor trip setpoint Tavg coefficient K2 shall be equal to 0.0297 / °F.

2.10.3 The Overtemperature AT reactor trip setpoint pressure coefficient K3 shall be equal to 0.00181 /psi.

2.10.4 The nominal Tavgat RTP (indicated)T shall be less than or equal to 588.0 °F.

2.10.5 The nominal RCS operating pressure (indicated) P shall be equal to 2235 psig.

2.10.6 The measured reactor vessel AT lead/lag time constant t1 shall be equal to 8 sec.

2.10.7 The measured reactor vessel AT lead/lag time constant r2 shall be equal to 3 sec.

2.10.8 The measured reactor vessel AT lag time constant t3 shall be less than or equal to 2 sec.

2.10.9 The measured reactor vessel average temperature lead/lag time constant t4 shall be equal to 33 sec.

2.10.10 The measured reactor vessel average temperature lead/lag time constant t~shall be equal to 4 sec.

2.10.11 The measured reactor vessel average temperature lag time constant r6shall be less than or equal to 2 sec.

2,10.12 The f1 (Al) positive breakpoint shall be +10% Al.

2.10.13 The f1 (Al) negative breakpoint shall be -18% Al.

2.10.14 The f1 (Al) positive slope shall be +3.47% / % Al.

2.10.15 The f1 (Al) negative slope shall be -2.61% / % Al.

COLR BRAIDWOOD 1 Revision 5 Page 12 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT I CYCLE 13 2.11 Reactor Trip System (RTS) Instrumentation (LCO 3.3.1) Overpower AT Setpoint Parameter Values 2.11.1 The Overpower AT reactor trip setpoint K4 shall be equal to 1.072.

2.11.2 The Overpower AT reactor trip setpoint Tavg rate/lag coefficient K5 shall be equal to 0.02 I ~Ffor increasing Tavg, 2.11.3 The Overpower AT reactor trip setpoint Tavg rate/lag coefficient K5 shall be equal to 0 / °Ffor decreasing Tavg, 2.11.4 The Overpower AT reactor trip setpoint Tavq heatup coefficient K6 shall be equal to 0

0.00245/ FwhenT>T.

2.11.5 The Overpower AT reactor trip setpoint Tavg heatup coefficient K6 shall be equal to 0 / F when T T.

2.11.6 The nominal Ta,,g at RTP (indicated) T shall be less than or equal to 588.0 °F 2.11.7 The measured reactor vessel AT lead/lag time constant t1 shall be equal to 8 sec.

2.11.8 The measured reactor vessel AT lead/lag time constant t2 shall be equal to 3 sec.

2.11.9 The measured reactor vessel AT lag time constant t~shall be less than or equal to 2 sec.

2.11.10 The measured reactor vessel average temperature lag time constant t 6

shall be less than or equal to 2 sec.

2.11.11 The measured reactor vessel average temperature rate/lag time constant t~shall be equal to 10 sec.

2.11.12 The f2(Al) positive breakpoint shall be 0 for all Al.

2.11.13 The f2 (Al) negative breakpoint shall be 0 for all Al.

2.11.14 The f2(Al) positive slope shall be 0 for all Al.

2.11.15 The f2 (Al) negative slope shall be 0 for all Al.

COLR BRAIDWOOD 1 Revision 5 Page 13 of 13 CORE OPERATING LIMITS REPORT (COLR) for BRAIDWOOD UNIT I CYCLE 13 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 (T5~9)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 value given in the Table below (LCO 3.9.1). The reported value also bounds the end-of-cycle requirements for the previous cycle.

2.13.2 To maintain keff 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 values given in the Table below.

COLR Conditions Boron Concentration Section (ppm) 2.13.1 Refueling 1711 2.13.2 a) prior to initial criticality 1765 2.13.2 b) all other times in core life 1984