NOC-AE-03001518, Cycle 12 Core Operating Limits Report

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Cycle 12 Core Operating Limits Report
ML031180494
Person / Time
Site: South Texas STP Nuclear Operating Company icon.png
Issue date: 04/21/2003
From: Leazar D
South Texas
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-03001518
Download: ML031180494 (16)
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Text

Nuclear Operating Company South TcsPrzcdEkr/c GCcrmaftlngStlbon PO AM289 Widmfi rcT77483 April 21, 2003 NOC-AE-03001518 10CFR50.36 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Unit 1 Docket No. STN 50498 Unit 1 Cycle 12 Core Operating Limits Report In accordance with Technical Specification 6.9.1.6.d, the attached Core Operating Limits Report is submitted for South Texas Project Unit 1 Cycle 12.

If there are any questions concerning this report, please contact Scott Head at (361) 972-7136 or me at (361) 972-7795.

30'f~i David A. Leazar Director, Nuclear Fuel & Analysis kaw

Attachment:

Unit 1 Cycle 12 Core Operating Limits Report O:\QUALITY ANDLICENSING\Wp\N1\Nrc-ap\Misc-03\0300 1518.doc STI: 31594218 AtD l

,U

NOC-AE-03001518 Page 2 cc:

(paper copy) (electronic copy)

Ellis W. Merschoff A. H. Gutterman, Esquire Regional Administrator, Region IV Morgan, Lewis & Bockius LLP U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 L. D. Blaylock Arlington, Texas 76011-8064 City Public Service U. S. Nuclear Regulatory Commission Mohan C. Thadani Attention: Document Control Desk U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike R. L. Balcom Rockville, MD 20852 Texas Genco, LP Richard A. Ratliff A. Ramirez Bureau of Radiation Control City of Austin Texas Department of Health 1100 West 49th Street C. A. Johnson Austin, TX 78756-3189 AEP Texas Central Company Cornelius F. O'Keefe Jon C. Wood U. S. Nuclear Regulatory Commission Matthews & Branscomb P. 0. Box 289, Mail Code: MN1 16 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 O:\QUALITY ANDLICENSING\Wp\NI\Nrc-ap\Misc-03\0300 151 8.doc STI: 31594218

Nuclear Operating Company

- N N SOUTH TEXAS PROJECT UNIT 1 CYCLE 12 CORE OPERATING LIMITS REPORT April 2003 1

SOUTH TExAs UNIT 1 CYCLE 12 APRIL 2003 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report for STPEGS Unit 1 Cycle 12 has been prepared in accordance with the requirements of Technical Specification 6.9.1.6. The core operating limits have been developed using the NRC-approved methodologies specified in Technical Specification 6.9.1.6.

The Technical Specifications affected by this report are:

1) 2.1 SAFETY LIMITS
2) 2.2 LIMITING SAFETY SYSTEM SETTINGS
3) 3/4.1.1.1 SHUTDOWN MARGIN
4) 3/4.1.1.3 MODERATOR TEMPERATURE COEFFICIENT LIMITS
5) 3/4.1.3.5 SHUTDOWN ROD INSERTION LIMITS
6) 3/4.1.3.6 CONTROL ROD INSERTION LIMITS
7) 3/4.2.1 AFD LIMITS
8) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR
9) 3/4.2.3 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR
10) 3/4.2.5 DNB PARAMETERS 2.0 OPERATING LIMITS The cycle-specific parameter limits for the specifications listed in Section 1.0 are presented below.

2.1 SAFETY LIMITS (Specification 2.1):

2.1.1 The combination of THERMAL POWER, pressurizer pressure, and the highest operating loop coolant temperature (Tavg) shall not exceed the limits shown in Figure 1.

2.2 LI1\ITING SAFETY SYSTEM SETTINGS (Specification 2.2):

2.2.1 The Loop design flow for Reactor Coolant Flow-Low is 98,000 gpm.

2.2.2 The Over-temperature AT and Over-power AT setpoint parameter values are listed below:

Core Operating Limits Report Page 2

  • TAme SOUTH TEXAS UNIT I CYCLE 12 APRIL 2003 Over-temperature AT Setpoint Parameter Values rl measured reactor vessel AT lead/lag time constant, tl = 8 sec T2 measured reactor vessel AT lead/lag time constant, T2 = 3 sec T3 measured reactor vessel AT lag time constant, x3 = 0 sec T4 measured reactor vessel average temperature lead/lag time constant, ¶4 = 28 sec x5 measured reactor vessel average temperature lead/lag time constant, x5 = 4 sec T6 measured reactor vessel average temperature lag time constant, x6 = 0 sec KI Overtemperature AT reactor trip setpoint, Kl = 1.14 K2 Overtemperature AT reactor trip setpoint Tavg coefficient, K2 = 0.028/1F K3 Overtemperature AT reactor trip setpoint pressure coefficient, K3 = 0.001 43/psig Ty Nominal full power Tavg, T'
  • 592.0 IF Pt Nominal RCS pressure, P' = 2235 psig fQ(AJ) is a function of the indicated difference between top and bottom detectors of the power-range neutron ion chambers; with gains to be selected based on measured instrument response during plant startup tests such that:

(1) For q, - q, between -70% and +8%, f1(AI) = 0, where q, and q, are percent RATED THERMAL POWER in the top and bottom halves of the core respectively, and q, + q. is total THERMAL POWER in percent of RATED THERMAL POWER; (2) For each percent that the magnitude of q, - q, exceeds -70%, the AT Trip Setpoint shall be automatically reduced by 0.0% of its value at RATED THERMAL POWER.

(3) For each percent that the magnitude of q, - q, exceeds +8%, the AT Trip Setpoint shall be automatically reduced by 2.65% of its value at RATED THERMAL POWER.

Over-power AT Setpoint Parameter Values rl measured reactor vessel AT lead/lag time constant, rl = 8 sec T2 measured reactor vessel AT lead/lag time constant, T2 = 3 sec T3 measured reactor vessel AT lag time constant, T3 = 0 sec T6 measured reactor vessel average temperature lag time constant, T6 = 0 sec T7 Time constant utilized in the rate-lag compensator for Tavg, ¶7 = 10 sec K4 Overpower AT reactor trip setpoint, K4 = 1.08 K5 Overpower AT reactor trip setpoint Tavg rate/lag coefficient, K5 = 0.02/0 F for increasing average temperature, and K5 = 0 for decreasing average temperature K6 Overpower AT reactor trip setpoint Tavg heatup coefficient K6 = 0.002/ 0 F for T > T" and, K6 = 0 for T < T" T" Indicated full power Tavg, T" < 592.0 IF f2 (AI) = 0 for all (Al) 2.3 SHUTDOWN MARGIN (Specification 3.1.1.1):

The SHUTDOWN MARGIN shall be:

2.3.1 Greater than 1.3% Ap for MODES I and 2*

  • See Special Test Exception 3.10.1 2.3.2 Greater than the limits in Figure 2 for MODES 3 and 4.

2.3.3 Greater than the limits in Figure 3 for MODE 5.

Core Operating Limits Report Page 3

SOUTH TEXAS UNIT 1 CYCLE 12 APRIL 2003 2.4 MODERATOR TEMPERATURE COEFFICIENT (Specification 3.1.1.3):

2.4.1 The BOL, ARO, MTC shall be less positive than the limits shown in Figure 4.

2.4.2 The EOL, ARO, HFP, MTC shall be less negative than -62.72 pcm/0 F.

2.4.3 The 300 ppm, ARO, HFP, MTC shall be less negative than -53.72 pcm/0 F (300 ppm Surveillance Limit).

Where: BOL stands for Beginning-of-Cycle Life, EOL stands for End-of-Cycle Life, ARO stands for All Rods Out, HFP stands for Hot Full Power (100% RATED THERMAL POWER),

HFP vessel average temperature is 592 'F.

2.4.4 The Revised Predicted near-EOL 300 ppm MTC shall be calculated using the algorithm from T.S. 6.9.1.6.b.10:

Revised Predicted MTC = Predicted MTC + AFD Correction - 3 pcm/0 F If the Revised Predicted MTC is less negative than the S.R. 4.1.1.3b limit and all of the benchmark data contained in the surveillance procedure are met, then an MTC measurement in accordance with S.R. 4.1.1.3b is not required.

2.5 ROD INSERTION LIMITS (Specification 3.1.3.5 and 3.1.3.6):

2.5.1 All banks shall have the same Full Out Position (FOP) of at least 249 steps withdrawn but not exceeding 259 steps withdrawn.

2.5.2 The Control Banks shall be limited in physical insertion as specified in Figure 5.

2.5.3 Individual Shutdown bank rods are fully withdrawn when the Bank Demand Indication is at the FOP and the Rod Group Height Limiting Condition for Operation is satisfied (T.S. 3.1.3.1).

2.6 AXIAL FLUX DHIERENCE (Specification 3.2.1):

2.6.1 AFD limits as required by Technical Specification 3.2.1 are determined by CAOC Operations with an AED target band of +5, -10%.

2.6.2 The AFD shall be maintained within the ACCEPTABLE OPERATION portion of Figure 6, as required by Technical Specifications.

2.7 HEAT FLUX HOT CHANNEL FACTOR (Specification 3.2.2):

2.7.1 FPQ= 2.55.

2.7.2 K(Z) is provided in Figure 7.

2.7.3 The FXY limits for RATED THERMAL POWER (FTP) within specific core planes shall be:

2.7.3.1 Less than or equal to 2.102 for all core planes containing Bank "D" control rods, and 2.7.3.2 Less than or equal to the appropriate core height-dependent value from Table I for all unrodded core planes.

2.7.3.3 PFxy = 0.2.

Core Operating Limits Report Page 4

SOUTH TEXAS UNIT I CYCLE 12 APRIL 2003 These Fxy limits were used to confirm that the heat flux hot channel factor FQ(Z) will be limited by Technical Specification 3.2.2 assuming the most-limiting axial power distributions expected to result for the insertion and removal of Control Banks C and D during operation, including the accompanying variations in the axial xenon and power distributions, as described in WCAP-83 85.

Therefore, these Fxy limits provide assurance that the initial conditions assumed in the LOCA analysis are met, along with the ECCS acceptance criteria of 10 CFR 50.46.

2.8 ENTEALPY RISE HOT CHANNEL FACTOR (Specification 3.2.3):

2.8.1 FW^RH = 1.5571 2.8.2 PFm = 0.3 2.9 DNB PARAMETERS (Specification 3.2.5):

2.9.1 The following DNB-related parameters shall be maintained within the following limits)

a. Reactor Coolant System Tavg,
  • 595 'F3,
b. Pressurizer Pressure, > 2200 psig4 ,
c. Minimum Measured Reactor Coolant System Flow > 403,000 gpm 5 .

3.0 REFERENCES

3.1 Letter from T. D. Croyle (Westinghouse) to D. F. Hoppes (STPNOC), "Unit 1 Cycle 12 Final Reload Evaluation," NF-TG-03-36, Rev. 1 (ST-UB-NOC-03002361, Rev. 1), March 18, 2003.

3.2 NUREG-1346, Technical Specifications, South Texas Project Unit Nos. I and 2.

3.3 STPNOC Calculation ZC-7035, Rev. 1, "Loop Uncertainty Calculation for RCS Tavg Instrumentation,"

October 19, 1998.

3.4 STPNOC Calculation ZC-7032, Rev. 3, "Loop Uncertainty Calculation for Narrow Range Pressurizer Pressure Monitoring Instrumentation," June 27, 2001.

3.5 Letter from T.D. Croyle (Westinghouse) to D.F. Hoppes (STPNOC), Unit 1 Cycle 12 Shutdown Margin Limits" NF-TG-03-50, Rev. 1 (ST-UB-NOC-03002375, Rev. 1), April 11, 2003 1 Applies to all fuel in the Unit 1 Cycle 12 core.

2 A discussion of the processes to be used to take these readings is provided in the basis for Technical Specification 3.2.5.

3 Includes a 1.9 'F measurement uncertainty per Reference 3.3.

4 Limit not applicable during either a Thermal Power ramp in excess of 5% of RTP per minute or a Thermal Power step in excess of 10% RTP. Includes a 10.7 psi measurement uncertainty as read on the QDPS display per Reference 3.4.

5 Includes a 2.8% flow measurement uncertainty.

Core Operating Limits Report Page 5

oUT SoUTH TEXAS UNIT 1 CYCLE 12 APRIL 2003 Figure 1 Reactor Core Safety Limits - Four Loops in Operation 680 660 640 i; 620 U

E*

U 600 580 560 540 0 20 40 60 80 100 120 140 Rated Thermal Power (%)

Core Operating Limits Report Page 6

C) 0 a°

  • 00 Q 0

7.0.

2 6.0-CD IACCEPTABLEREG CD0 o4.0.

30 CD 2.0 1.0NACCEPTABLE REGION 0 400 800 1200 1600 2000 2400 2 RCS Critical Boron Concentration (ppmn)

(for ARI minus most reactive stuck rod)

uI 0

0

'0 (0

I aq VA Cn 0

V;

0 0

10 8.0 7.0 f-t P 6.0 II III uC ww WI r'J

5. IACCEPTABLE RGO M L~~~

C. 5.0 CL

-o o' 4.0 50)0 Cn

=W' ITJ r"- w V g: 3.0 I I I I I I I I Mw

~~0 0

0 Ul 2.0 I-

-- I I _

IUNACCEPTABLE REGION 1.0 I I I II-T-I-II1I I (650, 130) - l l I i i 0.0 - l l I I I III _ I Pd qQ0 0 400 800 1200 1600 2000 2400 ow C.

0D 0.

00 RCS Critical Boron Concentration (ppm)

(for ARI minus the most reactive stuck rod)

~.

SOUTH TEXAS UNIT 1 CYCLE 12 APRIL 2003 Figure 4 MTC versus Power Level 7.0 6.0

__ - __IUnacceptable OperationJ _-

5.0 - - I I

.- :S fl - -

C; 4.0 0 Acceptable Operation]

M c~) 3.0 E 2.0 hi

-L c.

0 1.0 T-IX I sl To W) 0.0 To

-1.0

-2.0

-3.0 0 20 40 60 80 100 Rated Thermal Power (%)

Core Operating Limits Report Page 9

N AE SouTH TEXAS UNiT I CYCLE 12 APRIL 2003 Figure 5 Control Rod Insertion Limits* versus Power Level (23, 259) 122 Step Overlap (79, 259) 122 Step Overlap (22, 257) 120 Step Overlap (78, 257) 120 Step Overlap 260 -_ (21, 255) 118 Step Overlap (77, 255) 118 Step Overlap (21, 253) 116 Step Overlap i i I i II II IVILI i11i iIIIII V (77, 253). 116 Step Overlap PIAn _%

/-4LU (20, (19.

251) 249) 114 112 Step Overlap Sten OveTlan II II i I H 4 iH (76, 251) 114 Step Overlap (75 24,41012V St-n Ov-rl 220 200 180 00, T OO,174) 1_%

&J160 Ln E 140

.12

._ OF 0

120 8

01 V 100 I=

9 80 OF 60 40 20 OOF I

(29, 0

0 10 20 30 40 50 60 70 80 90 100 Rated Thermal Power (%)

'Control Bank A is already withdrawn to Full Out Position Fully withdrawn region shall be the condition where shutdown and control banks are at a position within the interval of 249 and :'59 steps withdrawn, inclusive Core Operating Limits Report Page 10

a.-E SOUTH TEXAS UNIT I CYCLE 12 APRIL 2003 Figure 6 AFD Limits versus Rated Thermal Power 120 100 I-.

c 80 N0 F-60 V

c)

Pc4 40 20 0

-50 -30 -10 10 30 50 Axial Flux Difference (A I)

Core Operating Limits Report Page I I

MWNAr-SOUTH TEXAS UNIT I CYCLE 12 APRIL-2003 SOUTH TEXAS UNIT 1 CYCLE 12 APRIL2003 Figure 7 K(Z) - Normalized FQ(Z) versus Core Height 1.2 1.0 N

Te .8 0

LL

._D

.6 ca 0~

(5 10 N

Core Elevation (ft) FQ K(Z)

.4 0.0 2.55 1.0 7.0 2.55 1.0 z

0 14.0 2.359 0.925

.2 0

0.0 7.0 14.0 Core Height (ft)

Core Operating Limits Report Page 12

,X-eo-,,

SONAr-SOUTH TEXAS UNIT I CYCLE 12 APRIL 2003 SOUTH TEXAS UNIT 1 CYCLE 12 APRIL 2003 Table 1 (Part 1 of 2)

Unrodded Fxy for Each Core Height For Cycle Burnups Less Than 10500 MWD/MTU Core Height Axial Unrodded Core Height Axial Unrodded (Ft.) Point Fxy (Ft.) Point Fxy 14.0 1 4.143 6.8 37 1.895 13.8 2 3.614 6.6 38 1.888 13.6 3 3.086 6.4 39 1.883 13.4 4 2.557 6.2 40 1.878 13.2 5 2.248 6.0 41 1.876 13.0 6 2.006 5.8 42 1.874 12.8 7 2.025 5.6 43 1.873 12.6 8 2.020 5.4 44 1.874 12.4 9 2.012 5.2 45 1.877 12.2 10 1.988 5.0 46 1.884 12.0 11 1.970 4.8 47 1.893 11.8 12 1.960 4.6 48 1.903 11.6 13 1.961 4.4 49 1.911 11.4 14 1.967 4.2 50 1.916 11.2 15 1.972 4.0 51 1.920 11.0 16 1.975 3.8 52 1.916 10.8 17 1.976 3.6 53 1.910 10.6 18 1.977 3.4 54 1.908 10.4 19 1.976 3.2 55 1.908 10.2 20 1.978 3.0 56 1.904 10.0 21 1.981 2.8 57 1.896 9.8 22 1.984 2.6 58 1.881 9.6 23 1.988 2.4 59 1.862 9.4 24 1.993 2.2 60 1.833 9.2 25 2.001 2.0 61 1.798 9.0 26 2.009 1.8 62 1.765 8.8 27 2.017 1.6 63 1.736 8.6 28 2.024 1.4 64 1.745 8.4 29 2.032 1.2 65 1.751 8.2 30 2.038 1.0 66 1.775 8.0 31 2.041 0.8 67 1.935 7.8 32 2.033 0.6 68 2.217 7.6 33 2.000 0.4 69 2.562 7.4 34 1.965 0.2 70 2.906 7.2 35 1.935 0.0 71 3.250 7.0 36 1.909 Core Operating Limits Report Page 13

WN~r- SOUTH TEXAS UT-Jr I CYCLE 12 APRiL 2003 SourH TEXAS UNIT I CYCLE 12 APRm 2003 Table 1 (Part 2 of 2)

Unrodded FXy for Each Core Height For Cycle Burnups Greater Than or Equal to 10500 MWD/MTU Core Height Axial Unrodded Core Height Axial Unrodded (Ft.) Point Fxy (Ft.) Point Fxy 14.0 1 4.915 6.8 37 2.146 13.8 2 4.258 6.6 38 2.142 13.6 3 3.601 6.4 39 2.128 13.4 4 2.945 6.2 40 2.115 13.2 5 2.541 6.0 41 2.101 13.0 6 2.217 5.8 42 2.089 12.8 7 2.182 5.6 43 2.078 12.6 8 2.133 5.4 44 2.067 12.4 9 2.097 5.2 45 2.056 12.2 10 2.062 5.0 46 2.046 12.0 I11 2.027 4.8 47 2.035 11.8 12 2.021 4.6 48 2.024 11.6 13 2.017 4.4 49 2.011 11.4 14 2.020 4.2 50 1.998 11.2 15 2.027 4.0 51 1.983 11.0 16 2.035 3.8 52 1.970 10.8 17 2.040 3.6 53 1.958 10.6 18 2.044 3.4 54 1.946 10.4 19 2.046 3.2 55 1.933 10.2 20 2.051 3.0 56 1.917 10.0 21 2.057 2.8 57 1.900 9.8 22 2.065 2.6 58 1.876 9.6 23 2.072 2.4 59 1.847 9.4 24 2.077 2.2 60 1.826 9.2 25 2.082 2.0 61 1.820 9.0 26 2.085 1.8 62 1.818 8.8 27 2.087 1.6 63 1.821 8.6 28 2.090 1.4 64 1.834 8.4 29 2.094 1.2 65 1.879 8.2 30 2.100 1.0 66 1.963 8.0 31 2.108 0.8 67 2.152 7.8 32 2.116 0.6 68 2.460 7.6 33 2.124 0.4 69 2.826 7.4 34 2.132 0.2 70 3.193 7.2 35 2.140 0.0 71 3.559 7.0 36 2.146 Core Operating Limits Report Page 14

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