South Texas Project, Unit 2, Submittal of Cycle 15 Core ... · South Texas Project Unit 2 Docket No. STN 50-499 Unit 2 Cycle 15 Core Operating Limits Report In accordance with Technical

Nuclear Operating Company

South Texas Pro/ect Electric Generating Station PO. Box 289 Wadsworth, Texas 77483 V

April 26, 20NOC-AE-1 5511 OCFR5O.36STI: 32662919

U. S. Nuclear Regulatory CommissionAttention: Document Control DeskOne White Flint North11555 Rockville PikeRockville, MD 20852-2738

South Texas ProjectUnit 2

Docket No. STN 50-499Unit 2 Cycle 15 Core Operating Limits Report

In accordance with Technical Specification 6.9.1.6.d, STP Nuclear Operating Companysubmits the attached Revision 0 to the Core Operating Limits Report for Unit 2 Cycle15. The report reflects core design changes made during the 2RE14 refueling outage.

There are no commitments in this letter.

If there are any questions concerning this report, please contact Marilyn Kistler at (361)972-8385 or me at (361) 972-7743.

Roland F. DunnManager,Nuclear Fuels & Analysis

mk

Attachment: Unit 2 Cycle 15 Core Operating Limits Report, Rev. 0

NOC-AE-10002551Page 2 of 2

cc:(paper copy) (electronic copy)

Regional Administrator, Region IVU. S. Nuclear Regulatory Commission612 East Lamar Blvd, Suite 400Arlington, Texas 76011-4125

Mohan C. ThadaniSenior Project ManagerU.S. Nuclear Regulatory CommissionOne White Flint North (MS 8B1A)11555 Rockville PikeRockville, MD 20852

Senior Resident InspectorU. S. Nuclear Regulatory CommissionP. 0. Box 289, Mail Code: MN1 16Wadsworth, TX 77483

C. M. CanadyCity of AustinElectric Utility Department721 Barton Springs RoadAustin, TX 78704

A. H. Gutterman, EsquireMorgan, Lewis & Bockius LLP

Mohan C. ThadaniU. S. Nuclear Regulatory Commission

Kevin HowellCatherine CallawayJim von SuskilNRG South Texas LP

Ed AlarconJ. J. NesrstaR. K. TempleKevin PolioCity Public Service

Jon C. WoodCox Smith Matthews

C. MeleCity of Austin

Richard A. RatliffTexas Department of State HealthServices

Alice RogersTexas Department of State HealthServices

M Mir"Nuclear Operating Company1W V -

SOUTH TEXAS PROJECT

Unit 2 Cycle 15

CORE OPERATING LIMITS REPORT

Revision 0

Core Operating Limits Report Page I of 16

dLWA Unit 2 Cycle 15Nuclear Operating Company Core Operating Limits Report Rev. 0

Page2 of 16

1.0 CORE OPERATING LIMITS REPORT

This Core Operating Limits Report for STPEGS Unit 2 Cycle 15 has been prepared in accordance withthe requirements of Technical Specification 6.9.1.6. The core operating limits have been developed usingthe 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 SETTINGS3) 3/4.1.1.1 SHUTDOWN MARGIN4) 3/4.1.1.3 MODERATOR TEMPERATURE COEFFICIENT LIMITS5) 3/4.1.3.5 SHUTDOWN ROD INSERTION LIMITS6) 3/4.1.3.6 CONTROL ROD INSERTION LIMITS7) 3/4.2.1 AFD LIMITS8) 3/4.2.2 HEAT FLUX HOT CHANNEL FACTOR9) 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 highestoperating loop coolant temperature (Tavg) shall not exceed the limits shown in Figure 1.

2.2 LIMITING SAFETY SYSTEM SETTINGS (Specification 2.2):

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

Unit 2 Cycle 15Nuclear Operating Company Core Operating Limits Report Rev. 0

Page 3 of 16

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

Over-temperature AT Setpoint Parameter Values

T- measured reactor vessel AT lead/lag time constant, cl = 8 secT2 measured reactor vessel AT lead/lag time constant, c2 = 3 secT3 measured reactor vessel AT lag time constant, c3 = 2 sec"4 measured reactor vessel average temperature lead/lag time constant, -c4 = 28 secz5 measured reactor vessel average temperature lead/lag time constant, r5 = 4 sec

"6 measured reactor vessel average temperature lag time constant, 'C6 = 2 secK1 Overtemperature AT reactor trip setpoint, K, = 1.14

1(2 Overtemperature AT reactor trip setpoint Tavg coefficient, K2 = 0.028/'FK(3 Overtemperature AT reactor trip setpoint pressure coefficient, K3 = 0.001 43/psigT' Nominal full power Tavg, T'_< 592.0 OFP' Nominal RCS pressure, P' = 2235 psig

fi(AI) is a function of the indicated difference between top and bottom detectors of thepower-range neutron ion chambers; with gains to be selected based on measuredinstrument response during plant startup tests such that:

(1) For q, - qb between -70% and +8%, fl(A1) = 0, where q, and qb are percentRATED THERMAL POWER in the top and bottom halves of the corerespectively, and q, + qb is total THERMAL POWER in percent of RATEDTHERMAL POWER;

(2) For each percent that the magnitude of qt - qb exceeds -70%, the AT Trip Setpointshall be automatically reduced by 0.0% of its value at RATED THERMALPOWER; and

(3) For each percent that the magnitude of qt - qb exceeds +8%, the AT Trip Setpointshall be automatically reduced by 2.65% of its value at RATED THERMALPOWER.

Over-power AT Setpoint Parameter Values

"1 measured reactor vessel AT lead/lag time constant, rj = 8 sec

.2 measured reactor vessel AT lead/lag time constant, r2 = 3 secT3 measured reactor vessel AT lag time constant, T3 = 2 sec"6 measured reactor vessel average temperature lag time constant, Tr6 = 2 sec

"7 Time constant utilized in the rate-lag compensator for Tavg, T7 = 10 seeK4 Overpower AT reactor trip setpoint, K4 = 1.08K5 Overpower AT reactor trip setpoint Tavg rate/lag coefficient, K5 = 0.02/°F for

increasing average temperature, and K5 = 0 for decreasing average temperatureK6 Overpower AT reactor trip setpoint Tavg heatup coefficient K6 = 0.002/°F for

T>T",andK 6 = 0 forT__ T"T" Indicated full power Tavg, T"_< 592.0 OFf2(AI) = 0 for all (AI)

• ID• Unit 2 Cycle 15Nuclear Operating Company Core Operating Limits Report Rev. 0

ý NPage 4 of 16

2.3 SHUTDOWN MARGIN (Specification 3.1.1.1):

The SHUTDOWN MARGIN shall be:

2.3.1 Greater than 1.3% Ap for MODES 1 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.

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 -62.6 pcm/°F.

2.4.3 The 300 ppm, ARO, HFP, MTC shall be less negative than -53.6 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 thealgorithm from T.S. 6.9.1.6.b.10:

Revised Predicted MTC = Predicted MTC + AFD Correction - 3 pcm/°F

If the Revised Predicted MTC is less negative than the S.R. 4.1.1.3b limit and all of thebenchmark data contained in the surveillance procedure are met, then an MTCmeasurement 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 either 256 or 259 stepswithdrawn.

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 Indicationis at the FOP and the Rod Group Height Limiting Condition for Operation is satisfied(T.S. 3.1.3.1).

A T M Unit 2 Cycle 15Nuclear Operating Company Core Operating Limits Report Rev. 0

Page 5 of 16

2.6 AXIAL FLUX DIFFERENCE (Specification 3.2.1):

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

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

2.7 HEAT FLUX HOT CHANNEL FACTOR (Specification 3.2.2):

RTP2.7.1 FQ = 2.55.

2.7.2 K(Z) is provided in Figure 7.

2.7.3 The Fxy limits for RATED THERMAL POWER (FxRyTP) within specific core planesshall be:

2.7.3.1 Less than or equal to 2.102 for all cycle burnups for all core planescontaining Bank "D" control rods, and

2.7.3.2 Less than or equal to the appropriate core height-dependent value fromTable 1 for all unrodded core planes.

2.7.3.3 PFxy = 0.2.

These Fxy limits were used to confirm that the heat flux hot channel factor FQ(Z) will belimited by Technical Specification 3.2.2 assuming the most-limiting axial powerdistributions expected to result for the insertion and removal of Control Banks C and Dduring operation, including the accompanying variations in the axial xenon and powerdistributions, as described in WCAP-8385. Therefore, these Fxy limits provideassurance that the initial conditions assumed in the LOCA analysis are met, along withthe ECCS acceptance criteria of 10 CFR 50.46.

2.7.4 Core Power Distribution Measurement Uncertainty for the Heat Flux Hot ChannelFactor

2.7.4.1 If the Power Distribution Monitoring System(PDMS) is operable, asdefined in the Technical Requirements Manual, the core power distributionmeasurement uncertainty (IJFQ) to be applied to the FQ(Z) and Fxy(Z) usingthe PDMS shall be calculated by:

UFQ = (1.0 + (UQ/IOO))*UE

Where:

UQ = Uncertainty for power peaking factor as defined in Equation 5-19of Reference 3.6

UE = Engineering uncertainty factor of 1.03.

This uncertainty is calculated and applied automatically by the BEACONcomputer code.

Unit 2 Cycle 15Nuclear Operating Company Core Operating Limits Report Rev. 0AF A r-

Page 6 of 16

2.7.4.2 If the moveable detector system is used, the core power distributionmeasurement uncertainty (UFQ) to be applied to the FQ(Z) and Fxy(Z) shallbe calculated by:

UFQ = UQU*IUE

Where:

UQU = Base FQ measurement uncertainty of 1.05.UE = Engineering uncertainty factor of 1.03.

2.8 ENTIIALPY RISE HOT CHANNEL FACTOR (Specification 3.2.3):RTP

2.8.1 FAH = 1.62!

2.8.2 PF• = 0.3

2.8.3 Core Power Distribution Measurement Uncertainty for the Enthalpy Rise Hot ChannelFactor

2.8.3.1 If the Power Distribution Monitoring System (PDMS) is operable, asdefined in the Technical Requirements Manual, the core power distributionmeasurement uncertainty (UFH) to be applied to the F1 using the PDMSshall be calculated by:

UFAJ = 1.0 + (U, /100)

Where:

UtH = Uncertainty for power peaking factor as defined in Equation 5-19of Reference 3.6

This uncertainty is calculated and applied automatically by the BEACONcomputer code.

2.8.3.2 If the moveable detector system is used, the core power distributionmeasurement uncertainty (UFAH) shall be:

UFl = 1.04

Applies to all fuel in the Unit 2 Cycle 15 Core.


Unit 2 Cycle 15

Core Operating Limits Report Rev. 0Page 7 of 16

2.9 DNB PARAMETERS (Specification 3.2.5):

2.9.1 The following DNB-related parameters shall be maintained within the followinglimits:I

2.9.1.1 Reactor Coolant System Tavg -s 595 'F 2

2.9.1.2 Pressurizer Pressure > 2200 psig 3 ,

2.9.1.3 Minimum Measured Reactor Coolant System Flow > 403,000 gpm4.

3.0 REFERENCES

3.1 Letter from J. M. Ralston (Westinghouse) to D. F. Hoppes (STPNOC), "South Texas ProjectNuclear Operating Company South Texas Project Electric Generating Station Unit 2 Cycle 15Final Reload Evaluation (RE), Revision 1, " ST-UB-NOC-10003069. Rev. 1, April 17, 2010.

3.2 NUREG-1346, Technical Specifications, South Texas Project Unit Nos. 1 and 2.

3.3 STPNOC Calculation ZC-7035, Rev. 2, "Loop Uncertainty Calculation for RCS TavgInstrumentation," Section 10.1.

3.4 STPNOC Calculation ZC-7032, Rev. 4, "Loop Uncertainty Calculation for Narrow RangePressurizer Pressure Monitoring Instrumentation," Section 2.3, Page 9.

3.5 ConditionReport Engineering Evaluation 08-17345-9, Revision 0, "Unit 2 Cycle 15 ReloadSafety Evaluation and Core Operating Limits Report Modes 1, 2, 3, 4, and 5."

3.6 WCAP-12472-P-A, BEACON Core Monitoring and Operations Support System, August 1994.

3.7 5Z529ZB0 1025 Rev. 4, Design Basis Document, Technical Specifications /LCO, Tech SpecSection 3.2.5.c

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

Specification 3.2.5.2 Includes a 1.9 'F measurement uncertainty per Reference 3.3.3 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 9.6 PSI measurement uncertainty as read on QDPS display per Reference 3.4.4 Includes the most limiting flow measurement uncertainty of 2.8% from Reference 3.7.


ýE N Mr

Unit 2 Cycle 15


Figure 1

Reactor Core Safety Limits - Four Loops in Operation

680

660

640

0

U

620

600

580

560

540

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

120 140

.N.. Operating Company

-ENf --Unit 2 Cycle 15


Figure 2

Required Shutdown Margin for Modes 3 & 4

7.0

6.0

5.0

4.0

S3.0

2.0

1.0

0.0

0 400 800 1200 1600RCS Critical Boron Concentration (ppm)

(for ARI minus most reactive stuck rod)

2000 2400

Nuclear Operating Companysol I N-rUnit 2 Cycle 15


Figure 3

Required Shutdown Margin for Mode 5

7.0

6.0

5.0

~4.0

~3.0

2.0

1.0

0.0

0 400 800 1200 1600RCS Critical Boron Concentration (ppm)(for ARI minus most reactive stuck rod)

2000 2400


l N N--

Unit 2 Cycle 15Core Operating Limits Report Rev. 0

Page I11 of 16

Figure 4

MTC versus Power Level

7.0

6.0

5.0

4.0

' 3.0

2.0

o 1.0

0

o.0

-1.0

-2.0

-3.0

U Unacceptable Operation _

Acceptable OperationL

0 10 20 30 40 50 60 70 80 90 100

Rated Thermal Power (%)

flfl Unit 2 Cycle 15Nuclear Operating Company Core Operating Limits Report Rev. 0

Page 12 of 16

Figure 5

Control Rod Insertion Limits* versus Power Level

260 i , , • • l . . . . I I

ItS4]( 23 ,259): 122 Step Overlap-( 22 ,256 ):119 Step Overlap ( 79,259): 122 Step Overlap

( 78,256): 119 Step OverlapI I! i i i ! [ I I I I :I h

240

220

200

180

•" 160

.2 140

S1200

S100

80

60

40

20

0

( 225a -I I I I I I

* Control.... BakAi"led ihrw oFl u oiinFulIwtdaw hllb=tecndto:wee htow:n

, - -,(-. ,74

• Ole0. .O.. . . .. . I I ý ?

00 ankC i__e:

i i i ioe -: : -:

• : : : : : : : • 0:

'9 /0,

i 1 [ i i i :0:

0ei

oe -- - - -

Fully wihdaw shl etecodto:hresudw n

coto ak rea h oiio fete 56o 5 tp: : : :w,, ,drawn.

0 10 20 30 40 50 60 70 80 90 100

Rated Thermal Power (%)

dP-rAWNuclear Operating Company

-EDA-

Unit 2 Cycle 15


Figure 6

AFD Limits versus Power Level

I-

0=

120

110

100

90

80

70

60

50

40

30

20

10

0

(-11190)1 (11,90) - - -(11,490)

Unacceptable Unacceptableeration Operation

AcceptabliOperation

(-31,50) -1(31,50)1

_LL-L]

-50 -40 -30 -20 -10 0 10 20 30 40 50

Axial Flux Difference (% Delta-I)


I- E -B'

Unit 2 Cycle 15


Figure 7

K(Z) - Normalized FQ(Z) versus Core Height

1.2

1.1

1.0

0.9

0.8

J L-1-1 1-1. 1. I I I ITTT 11 1 L-LL-I

NMI

I I . . I I . I II I. . I. I I I I ; . I. i i i ii ii i-iI i li i ! !! Ii l ii i i II

ilill!lll!llll!!Illl!llllllllllllllllillil!ll!llll!llll!lliiiiiiiiI "

I I I . .. ý .. . .I .I . . I . . I II TTi-4~J II II II i -

j ! i I i! ! i i i i i i !I II II II II II Ii . . .I .I . .I . . . . . .I . .I . I

....I........................................................

0.7

• 0.6-

0

0.4-

0.3

0.2

0.1

0.5

I II II I II II II I I I I I I II I I II II II II I I II II II

f 44TER-C CCore Elev. (it) FQ K(0.0 -2.55 1.0 17.0 2.55 1.0

14.0 2.359 0.925 1-=FF

1 10 1 11 11 11 1 1- 1- I-FF

I II II I I II II II II II I I

!1111!1111!1111111111iiiiiiiiiiiiiiiiiii!lliiiiiu 1111111111111111111.............................

III

111!1!11111111jl!lll!111111111!11111!111!1ill!llll!llll!lliiiiiiiiiiiii........................

I ý I I . . .. I I .. I I . II . ... .. . I . i ! i ii i i Ii i i I II II II i II I I

11 !1 !Ill 1111 1! 1111 11 1! 111111 111111111 1111111111 111111 MI 11 11 11 1111 U--u.................

I I I I I II

I I I I I I I I I I I I.....I

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Core Height (ft)


Unit 2 Cycle 15


Table I (Part 1 of 2)

Unrodded Fy for Each Core Height

for Cycle Burnups Less Than 10000 MWD/MTU

Core Height(Ft.)

AxialPoint

UnroddedFxv

Core Height(Ft.)

AxialPoint

UnroddedFxy

14.0013.8013.6013.4013.2013.0012.8012.6012.4012.2012.0011.8011.6011.4011.2011.0010.8010.6010.4010.2010.009.809.609.409.209.008.808.608.408.208.007.807.607.407.207.00

1234567891011121314151617181920212223242526272829303i3233343536

5.7624.7723.7832.7932.3402.1282.0862.0722.0592.0342.0162.0052.0031.9961.9841.9661.9561.9501.9481.9531.9671.9852.0012.0122.0132.0172.0232.0322.0452.0572.0632.0582.0352.0151.9991.990

6.806.606.406.206.005.805.605.405.205.004.804.604.404.204.003.803.603.403.203.002.802.602.402.202.001.801.601.401.20-1.000.800.600.400.200.00

3738394041424344454647484950515253545556575859606162636465666768697071

1.9841.9801.9781.9751.9741.9741.9741.9781.9821.9861.9901.9911.9911.9911.9861.9791.9741.9701.9621.9551.9491.9481.9481.9471.9281.8921.8421.8021.7901.8192.0102.5613.2904.0204.749

NC Dl!M Unit 2 Cycle 15Nuclear Operating Company Core Operating Limits Report Rev. 0

I Page 16 of 16

Table 1 (Part 2 of 2)

Unrodded Fxy for Each Core Height

for Cycle Burnups Greater Than or Equal to 10000 MWD/MTU

Core Height(Ft.)

AxialPoint

UnroddedFxy

Core Height(Ft.)

AxialPoint

UnroddedFxy

14.0013.8013.6013.4013.2013.0012.8012.6012.4012.2012.0011.8011.6011.4011.2011.0010.8010.6010.4010.2010.009.809.609.409.209.008.808.608.408.208.007.807.607.407.207.00

123456789101112131415161718192021222324252627282930313233343536

4.4003.9003.4012.9012.5682.3322.2022.1162.0532.0102.0051.9971.9921.9951.9992.0062.0112.0162.0222.0382.0592.0832.1012.1102.1152.1172.1172.1182.1182.1192.1212.1262.1352.1452.1562.164

6.806.606.406.206.005.805.605.405.205.004.804.604.404.204.003.803.603.403.203.002.802.602.402.202.001.801.601.401.201.000.800.600.400.200.00

3738394041424344454647484950515253545556575859606162636465666768697071

2.1672.1622.1472.1332.1182.1072.0952.0832.0692.0572.0472.0382.0282.0162.0031.9911.9801.9701.9591.944i.9191.8901.8751.8461.8361.8311.8301.8301.8641.9472.2002.6473.1923.7364.280

Documents

South Texas Project, Unit 2, Submittal of Cycle 15 Core ... · South Texas Project Unit 2 Docket No. STN 50-499 Unit 2 Cycle 15 Core Operating Limits Report In accordance with Technical