ML023400535

Cycle 10 Core Operating Limits Report

ML023400535
Person / Time
Site:	South Texas
Issue date:	12/02/2002
From:	Leazar D South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-02001433
Download: ML023400535 (13)

Text

Nuclear Operating Company South Txas Prolect Electric Generating Station P Box 289 adMmrth T7ws 77483 A

December 2, 2002 NOC-AE-02001433 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 2 Docket No. STN 50-499 Unit 2 Cycle 10 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 2 Cycle 10. This report does not reflect the end of life moderator temperature coefficient amendment (Amendments 144/132), issued on November 26, 2002, because it was completed prior to the amendment date.

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

David A. Leazar

Director, Nuclear Fuel & Analysis kaw

Attachment:

Unit 2 Cycle 10 Core Operating Limits Report cc:

Licensing Library RMS (w/o attachment)

O:\\Wp\\Nl\\Nrc-wk\\Misc-02\\02001433.doc STI:31528174

NOC-AE-02001433 Page 2 cc:

(paper copy)

(electronic copy)

Ellis W. Merschoff Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 Richard A. Ratliff Bureau of Radiation Control Texas Department of Health 1100 West 49th Street Austin, TX 78756-3189 Cornelius F. O'Keefe U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN1 16 Wadsworth, TX 77483 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP M. T. Hardt/W. C. Gunst City Public Service Mohan C. Thadani U. S. Nuclear Regulatory Commission R. L. Balcom Reliant Energy, Inc.

A. Ramirez City of Austin C. A. Johnson AEP - Central Power and Light Company Jon C. Wood Matthews & Branscomb C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704

3/5-;LL(p 4/

Nuclear Operating Company SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION UNIT 2 CYCLE 10 CORE OPERATING LIMITS REPORT Revision 0 November 2002 Core Operating Limits Report Page I

SOUTH TEXAS UNr 2 CYCLE 10 NOVEMBER 2002 1.0 CORE OPERATINGLIMITS REPORT This Core Operating Limits Report for STPEGS Unit 2 Cycle 10 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 SETITINGS

3) 3/4.1.13 MODERATOR TEMPERATURE COEFFICIENT LIMITS

4) 3/4.1.3.5 SHUTDOWN ROD INSERTION LIMITS

5) 3/4.1.3.6 CONTROL ROD INSERTION LIMITS

6) 3/4.2.1 AFD LIMITS

7) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR

8) 314.23 NUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR

9) 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 (Ta,)

shall not exceed the limits shown in Figure 1.

2.2 LIMITING SAFETY SYSTEM SEITINGS (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.

Over-temperature AT Setpoint Parameter Values Tj measured reactor vessel AT lead/lag time constafht, ri = 8 sec T2 measured reactor vessel AT lead/lag time constant, -2 = 3 sec T3 measured reactor vessel AT lag time constant, r3 = 0 sec T4 measured reactor vessel average temperature lead/lag time constant, T4 = 28 sec "tr 5

measured reactor vessel average temperature lead/lag time constant, T5 = 4 sec T6 measured reactor vessel average temperature lag time constant, "t6 = 0 sec K,

Overtemperature AT reactor trip setpoint, K, = 1.14 K2 Overtemperature AT reactor trip setpoint Ta, coefficient, K2 = 0.028PF K3 Overtemperature AT reactor trip setpoint pressure coefficient, K3 = 0.00143/psig To Nominal full power T.,,, T' < 592.0 'F P'

Nominal RCS pressure, P' = 2235 psig f,(AI) 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; (Continued on next page)

Core Operating Limits Report Page 2

SOUTH TEXAS UNrr 2 CYCLE 10 NOVEMBER 2002 (1)

For q, - qb between -70% and +8%, fl(AI) = 0, where q, and qb are percent RATED THERMAL POWER in the top and bottom halves of the core respectively, and q, + qb is total THERMAL POWER in percent of RATED THERMAL POWER; (2)

For each percent that the magnitude of qt - qb exceeds -70%, the AT Trip Setpoint shall be automatically reduced by 0.0% of its value at RATED THERMAL POWER; and (3)

For each percent that the magnitude of q, - qb 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

'T measured reactor vessel AT lead/lag time constant, cl = 8 sec "T2 measured reactor vessel AT lead/lag time constant, t2 = 3 sec T3 measured reactor vessel AT lag time constant, r3 = 0 sec 16 measured reactor vessel average temperature lag time constant, r6 = 0 sec "17 Time constant utilized in the rate-lag compensator for T,,,, ¶-7 = 10 sec K4 Overpower AT reactor trip setpoint, K4 = 1.08 K5 Overpower AT reactor trip setpoint T,,, rate/lag coefficient, K5 = 0.02/F for increasing average temperature, and K5 = 0 for decreasing average temperature K6 Overpower AT reactor trip setpoint T., heatup coefficient K6 = 0.002/'F for T > T", and K6 = 0 for T < T" T"

Indicated full power T.., T" < 592.0 'F f2(AI)

= 0 for all (Al) 2.3 MODERATOR TEMPERATURE COEFFICIENT (Specification 3.1.1.3):

2.3.1 The BOL, ARO, MTC shall be less positive than the limits shown in Figure 2.

2.3.2 The EOL, ARO, HFP, MTC shall be less negative than -61.2 pcmPF.

2.3.3 The 300 ppm, ARO, HFP, MTC shall be less negative than -53.6 pcm/"F (300 ppm Surveillance Limit).

where:

B OL 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 2A ROD INSERTION LIMITS (Specification 3.1.3.5 and 3.1.3.6):

2.4.1 All banks shall have the same Full Out Position (FOP) of at least 250 steps withdrawn but not exceeding 259 steps withdrawn.

2.4.2 The Control Banks shall be limited in physical insertion as specified in Figure 3.

2.4.3 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).

2.5 AXIAL FLUX DIFFERENCE (Specification 3.2.1):

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

2.5.2 The AFD shall be maintained within the ACCEPTABLE OPERATION portion of Figure 4, as required by Technical Specifications.

Core Operating Limits Report Page 3

SOUTH TEXAS UNIT2 CYCLE 10 NOVEMBER 2002 2.6 HEAT FLUX HOT CHANNEL FACTOR (Specification 3.2.2):

2.6.1 FQRTP = 2.55.

2.6.2 K(Z) is provided in Figure 5.

2.6.3 The F5y limits for RATED THERMAL POWER (FRjT) within specific core planes shall be:

2.6.3.1 Less than or equal to 2.102 for all cycle burnups for all core planes containing Bank "D" control rods, and 2.6.3.2 Less than or equal to the appropriate core height-dependent value from Table 1 for all unrodded core planes.

2.6.3.3 PF1y = 0.2.

These Fy 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-8385. Therefore, these F5r 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.

2.7 ENTHALPY RISE HOT CHANNEL FACTOR (Specification 3.2.3):

2.7.1 FARTP = 1.557' 2.7.2 PFAH = 0.3 2.8 DNB PARAMETERS (Specification 3.2.5):

2.8.1 The following DNB-related parameters shall be maintained within the following limits:2

a.

Reactor Coolant System T,,,, _< 595 'F 3,

b.

Pressurizer Pressure, > 2200 psig4,

c.

Minimum Measured Reactor Coolant System Flow5 > 403,000 gpm.

3.0 REFERENCES

3.1 Letter from T. D. Croyle (Westinghouse) to D. F. Hoppes (STPNOC), "Unit 2 Cycle 10 Final Reload Evaluation," NF-TG-02-86 (ST-UB-NOC-02002294), October 1, 2002.

3.2 NUREG-1346, Technical Specifications, South Texas Project Unit Nos. 1 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.

I Applies to all fuel in the Unit 2 Cycle 10 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 19 *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 QDPS display per Reference 3.4.

5 Includes a 2.8% flow measurement uncertainty.

Core Operating Limits Report Page 4 I

I I ý I

Figure 1 Reactor Core Safety Limits - Four Loops in Operation 680 660 640 O 620 U 600 580 560 540 140 Core Operating Limits Report 0

20 40 60 80 100 120 Rated Thermal Power (%)

SOi-nH TEXAS UNrT 2 CYCLE 10 NOVEMBER 2002 Page 5

-NM--

Sotrrx TEXAS UNIT 2 CYCLE 10 NOVEMBER 2002 Figure 2 MTC versus Power Level 0

C.)

U "C) 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0

-1.0

-2.0

-3.0 0

20 40 60 80 100 Rated Thermal Power (%)

Core Operating Limits Report Unacceptable Operation Acceptable Operation SOUT TEXAS UNrr 2 CYCL.E 10 NOVEMBER 2002 Page 6

SouTH TEXAS UNrr 2 CYCLE 10 NOVEMBER 2002 Figure 3 Control Rod Insertion Limits* versus Power Level 260 240 220 200 180 S16 0

c 140

- 120 0

r 100 80 60 (79,259). 122 Step Overlap (79, 258). 121 Step Overlap (78,256): 119 Step Overlap (77.254): 117 Step Overlap (76.252). 115 Step Overlap (75, 250) 113 Step Overlap I

a I

I I

I I

I I!

I

-- I' 4 0 ~

-I '

1 1I II' 1 1 1 1t1A l 1 1 1 1l l

1l l

1I 11

A.

t I I I I I I I 1z I I I I Ii I I I I I I 40-20 0

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

"Control Bank A is already withdrawn to Full Out Position. F611y withdrawn region shall be the condition where shutdown and control banks are at a posiuon within the interval of 250 and :259 steps withdrawn, inclusive.

Page 7 Core Operating Linits Report

SOUTH ThXAS UNrr 2 CYCLE 10 NoVEMBER 2002 Figure 4 AFD LimIits wrsus Rated Thermal Power

(.31.50)

(11.50)

I

/-1.0 (3150

-30

-10 10 Axial Flux Difference (A I) 30 50 Core Operating Limits Report Page 8 120 100 S80 c;

60 S40 20 0

-50

VIC SOUTH TEXAS UNrrT2 CYCLE 10 NOVEMBER 2002 Figure 5 K(Z) - Normalized FQ(Z) versus Core Height 7

Core Height (ft)

Core Operating Limits Report 7-7-=7 1.2 1

0.8 0.6 E, O U.

0.6 o

0.2

• 0 Core Elevation (ft) F0 K(Z) 0.0 2.55 1.0 7.0 2.55 1.0 14.0 2.359 0.925 0

14 Page 9 i

I

SOUTH TEXAS UNIT2 CYCLE 10 NOVEMBER 2002 Table I (Part I of 2)

Unrodded F.y for Each Core Height for Cycle Burnups Less Than 9000 MWD/MTU Core Height Axial S(Ft.)

Point 14.00 13.80 13.60 13.40 13.20 13.00 12.80 12.60 12.40 12.20 12.00 11.80 11.60 11.40 11.20 11.00 10.80 10.60 10.40 10.20 10.00 9.80 9.60 9.40 9.20 9.00 8.80 8.60 8.40 8.20 8.00 7.80 7.60 7.40 7.20 7.00 1

2 3

4 5

6 7

8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Unrodded F.

5.689 4.773 3.857 2.941 2.493 2.193 2.172 2.123 2.087 2.058 2.033 2.018 2.017 2.018 2.016 2.011 2.005 2.000 1.995 1.992 1.989 1.987 1.986 1.984 1.983 1.983 1.986 1.989 1.995 2.004 2.015 2.028 2.028 2.014 1.990 1.971 Core Height Axial (Ft.).

Point 6.80 6.60 6.40 6.20 6.00 5.80 5.60 5.40 5.20 5.00 4.80 4.60 4.40 4.20 4.00 3.80 3.60 3.40 3.20 3.00 2.80 2.60 2.40 2.20 2.00 1.80 1.60 1.40 1.20 1.00 0.80 0.60 0.40 0.20 0.00 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Core Operating Limits Report Unrodded F...

1.955 1.937 1.921 1.967 1.893 1.878 1.867 1.856 1.853 1.856 1.860 1.865 1.871 1.881 1.892 1.898 1.901 1.899 1.897 1.901 1.907 1.914 1.917 1.921 1.917 1.911 1.904 1.908 1.950 2.039 2.260 2.641 3.094 3.547 4.001 Page 10

SOUTH TEXAS UNrr 2 CYCLE 10 NOVEMBER 2002 Table I (Part 2 of 2)

Unrodded Fxy for Each Core Height for Cycle Burnups Greater Than or Equai to 9000 MWDIMTU Core Height Axial (Ft.)

Point 14.00 13.80 13.60 13.40 13.20 13.00 12.80 12.60 12.40 12.20 12.00 11.80 11.60 11.40 11.20 11.00 10.80 10.60 10.40 10.20 10.00 9.80 9.60 9.40 9.20 9.00 8.80 8.60 8.40 8.20 8.00 7.80 7.60 7.40 7.20 7.00 1

2 3

4 5

6 7

8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Unrodded F..

4.440 3.949 3.400 2.827 2.474 2.189 2.171 2.140 2.114 2.088 2.065 2.055 2.054 2.058 2.063 2.070 2.071 2.071 2.070 2.072 2.076 2.082 2.083 2.081 2.077 2.071 2.061 2.051 2.044 2.038 2.032 2.031 2.034 2.042 2.053 2.065 Core Height Axial (Ft.)

Point 6.80 6.60 6.40 6.20 6.00 5.80 5.60 5A0 5.20 5.00 4.80 4.60 4.40 4.20 4.00 3.80 3.60 3.40 3.20 3.00 2.80 2.60 2.40 2.20 2.00 1.80 1.60 1.40 1.20 1.00 0.80 0.60 0.40 0.20 0.00 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Core Operating Limits Report Unrodded Fu 2.075 2.085 2.096 2.094 2.088 2.077 2.066 2.054 2.044 2.035 2.027 2.021 2.010 1.998 1.983 1.970 1.959 1.949 1.934 1.917 1.895 1.870 1.844 1.813 1.798 1.786 1.779 1.778 1.806 "1.870 2.031 2.295 2.590 2.828 2.885 Page 11