ML030300474

From kanterella
Jump to navigation Jump to search
Cycle 11 End of Life Moderator Temperature Coefficient Limit Report
ML030300474
Person / Time
Site: South Texas STP Nuclear Operating Company icon.png
Issue date: 01/13/2003
From: Leazar D
South Texas
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-03001449
Download: ML030300474 (16)
v • d • e


Text

{{#Wiki_filter:Nuclear Operating Company South Teccs Pimcd EledI"c GencernS Stanfon PO. 2ox28.9 Wadsnuth, Taws 77483 January 13, 2003 NOC-AE-03001449 10CFR50.90 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 50-498 Unit 1 Cycle 11 End of Life Moderator Temperature Coefficient Limit Report

Reference:

Letter, J. J. Sheppard to U.S. Nuclear Regulatory Commission, "End of Life Moderator Temperature Coefficient," dated October 31, 2002 (NOC-AE-02001425) As a condition for approval of the conditional elimination of the most negative end of life moderator temperature coefficient measurement technical specification change as stated in the referenced correspondence, STP committed to submit the following information for the first three uses of this methodology at STP:

1. A summary of the plant data used to confirm that the Benchmark Criteria of Table 3-2 of WCAP-13749-P-A, Safety Evaluation Supporting the Conditional Elimination of the Most Negative EOL Moderator Temperature Coefficient Measurement, have been met; and,
2. The Most Negative EOL Moderator Temperature Coefficient Limit Report (as found in Appendix D of WCAP-13749-P-A).

The information is attached. If there are any questions regarding this information, please contact Mr. Duane Gore at (361) 972-8909. D.A. Leaz

Manager, Nuclear Fuel and Analysis Attachments:
1. Plant Data Used to Confirm Benchmark Requirements
2. Most Negative End of Life Moderator Temperature Coefficient Limit Report for South Texas Unit 1, Cycle 11

, 6dx 0 C Vtemp\\1449 (U1CI 1 EOL MTC NRC Report) doc ST131540686

NOC-AE-03001449 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: MN116 Wadsworth, TX 77483 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP L. D. Blaylock/W. C. Gunst City Public Service Mohan C. Thadani U. S. Nuclear Regulatory Commission R. L. Balcom Texas Genco, LP A. Ramirez City of Austin C. A. Johnson AEP Texas Central Company Jon C. Wood Matthews & Branscomb C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 Plant Data Used to Confirm Benchmark Requirements Page 1 of 5 Plant Data Used to Confirm Benchmark Requirements are Satisfied This attachment presents a comparison of the South Texas Unit 1 Cycle 11 core characteristics with the requirements for use of the Conditional Exemption of the Most Negative EOL Moderator Temperature Coefficient Measurement Methodology and presents plant data that support that the Benchmark Criteria presented in WCAP-13749-P-A are met. The Conditional Exemption of the Most Negative EOL Moderator Temperature Coefficient Measurement Methodology is described in WCAP-13749-P-A. This report was approved by the NRC with two requirements: "* only PHOENIXIANC calculation methods are used for the individual plant analyses relevant to determinations for the EOL MTC plant methodology, and "* the predictive correction is reexamined if changes in core fuel designs or continued MTC calculation/measurement data show significant effect on the predictive correction. The PHOENIXIANC calculation methods were used for the South Texas Unit 1, Cycle 11, core design and relevant analyses. Also, the Unit 1, Cycle 11, core design does not represent a major change in core fuel design. Therefore, the Predictive Correction of -3 pcm/IF remains valid for this cycle. The Unit 1, Cycle 11, core meets both of the above requirements. A description of the data collection and calculations required to complete the Table 3 Worksheet of the Most Negative Moderator Temperature Coefficient Limit Report is presented. Then the following data tables are provided: "* Table 1 - Benchmark Criteria for Application of the 300 ppm MTC Conditional Exemption Methodology (per WCAP-13749-P-A) "* Table 2 - Flux Map Data: Assembly Powers and Core Tilt Criteria "* Table 3 - Core Reactivity Balance Data "* Table 4 - Low Power Physics Test Data (Beginning of Cycle, Hot Zero Power): Isothermal Temperature Coefficient (ITC) "* Table 5 - Low Power Physics Test Data (Beginning of Cycle, Hot Zero Power): Individual Control Bank Worth Page 2 of 5 Table 1 Benchmark Criteria for Application of the 300 ppm MTC Conditional Exemption Methodology (per WCAP-13749-P-A) Criteria Assembly Power (Measured Normal Reaction Rate) Measured Incore Quadrant Power Tilt (Low Power) Measured Incore Quadrant Power Tilt (Full Power) Core Reactivity (Cb) Difference BOL HZP ITC Individual Control Bank Worth Total Control Bank Worth +/-0.1 or 10% +/-4% +/-2% +/- 1000 pcm

  • 2 pcm/°F

+/- 15 % or +/- 100 pcm +/-10% Parameter Page 3 of 5 Table 2 Flux Map Data:Assembly Powers and Core Tilt Criteria Flux Map Number 111001 Assembly Power Measured to Predicted Error %Diff 4.1 Meas - Pred 0.049 % Diff 4.5 111002 Meas - Pred 0.048 % Diff 4.4 111003 Meas - Pred 0.051 % Diff -3.9 111004 Meas - Pred -0.047 % Diff -3.7 111005 Meas - Pred -0.045 % Diff -3.4 111006 Meas - Pred -0.043 % Diff 9.8 111007 Meas - Pred -0.041 % Diff 9.6 111008 Meas - Pred 0.04 % Diff 10.1 111009 Meas - Pred 0.043 % Diff 10.3 111010 Meas - Pred 0.049 % Diff 10.2 111011 Meas - Pred 0.045 % Diff 11.4 111012 _Meas - Pred 0.052 % Diff 11.6 111013 Meas - Pred 0.053 % Diff 7.1 111014 Meas - Pred 0.038 % Diff 7.7 111015 Meas - Pred 0.035 % Diff 7.1 111016 Meas - Pred 0.04 % Diff 7.6 111017 Meas - Pred 0.042 Benchmark Criteria Reouirement I. I- % Diff within +/- 10% OR M-P within +/-0.1 Criteria Satisfied Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes I-I Measured Incore Ouadrant Power Tilt Benchmark Criteria Criteria Power Tilt Requirement Satisfied Max 1.0132 Min 0.98164 Max 1.00361 Min 0.99612 Max 1.00516 Min 0.99206 Max 1.00509 Min 0.99206 Max 1.00385 Min 0.99293 Max 1.00403 Mm 0.99458 Max 1.00151 Min 0.99857 Max 1.00122 Min 0.99871 Max 1.00173 Min 0.99848 Max 1.00787 Mm 0.99456 Max 1.00258 Min 0.99744 Max 1.00191 Min 0.99899 Max 1.00049 Min 0.99972 Max 1.00352 Mm 0.99605 Max 1.00287 Min 0.99874 Max 1.00639 Min 0.99179 Max 1.00767 Min 0.98997 Max 1.00704 [Mln 0.98888 I ________________________ J _______________ .2 Li 4-Maps at < 90% Reactor Power Max Power Tilt < 1.04 And Min Power Tilt >_ 0.96 OR Maps at > 90% Reactor Power Max Power Tilt < 1.02 And Min Power Tilt >_ 0.98 Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes "Yes Yes Yes Yes Yes 111018 % Diff 7.5 Meas - Pred 0.044 Page 4 of 5 Table 3 Core Reactivity Balance Data Core Reactivity Difference (Critical boron) Reactivity Benchmark Criteria Surveillance Deviation Date/Time (pcm) Requirement Satisfied 10/30/01 16:58 69.3 Yes 11/27/01 14:51 -75.6 Yes 12/18/01 15:39 -235.0 Yes 01/15/02 16:30 -275.2 Yes 02/13/02 14:35 -328.3 Yes 03/11/02 16:06 -335.4 Yes 04/10/02 16:03 -385.4 Yes 05/08/02 11:27 -408.7 Reactivity Yes Deviation within 06/03/02 15:47 -370.6 Yes _ 1000 pcm 07/02/02 15:00 -331.5 Yes 07/30/02 16:13 -281.3 Yes 08/27/02 15:01 -265.3 Yes 09/24/02 16:06 -202.8 Yes 10/22/02 15:10 -172.0 Yes 11/27/02 15:23 -35.7 Yes 12/17/02 14:17 -1.4 Yes Page 5 of 5 Table 4 Low Power Physics Test Data (Beginning of Cycle, Hot Zero Power): Isothermal Temperature Coefficient (ITC)

  • Note: 1 pcm = 1 x 105 AK/K Table 5 Low Power Physics Test Data (Beginning of Cycle, Hot Zero Power):

Individual Control Bank Worth Benchmark Criteria Measured Predicted A Error Bank (pcm)* (pcm)* (pcm)* % Error Requirement Satisfied Shutdown Bank A 278.6 272.1 6.5 2.4% Yes Shutdown Bank B 799.6 775.3 24.3 3.1% % Error Yes Shutdown Bank C 413.4 397.3 16.1 4.1% within +/-15% Yes Shutdown Bank D 398.7 389.6 9.1 2.3% Yes Shutdown Bank E 487.0 483.1 3.9 0.8% OR Yes Control Bank A 791.6 776.4 15.2 2.0% Yes Control Bank B 687.2 656.1 31.1 4.7% A Error Yes Control Bank C 862.7 845.4 17.3 2.1% within +/-100 pcm Yes Control Bank D 540.1 516.4 23.7 4.6% Yes Total Control 5258.9 5111.7 147.2 2.9% %Error Yes Bank Worth IIIwithin +/-10%

  • Note: 1 pcm = 1 x 10.5 AK/K Most Negative End of Life Moderator Temperature Coefficient Limit Report for South Texas Unit 1, Cycle 11 Page 1 of 7 Most Negative End of Life Moderator Temperature Coefficient Limit Report for South Texas Unit 1, Cycle 11 (Measured 300 ppm Bumup, as per WCAP-13749-P-A, Appendix D)

PURPOSE: The purpose of this document is to present cycle-specific best estimate data for use in confirming the most negative end of life moderator temperature coefficient (MTC) limit in Technical Specification 3.1.1.3. This document also summarizes the methodology used for determining if a HFP 300 ppm MTC measurement is required. PRECAUTIONS AND LIMITATIONS: The EOL MTC elimination data presented in this document apply to South Texas Unit 1 Cycle 11 only and may not be used for other operating cycles. The following reference is applicable to this document: Fetterman, R. J., Slagle, W. H., Safety Evaluation Supporting the Conditional Exemption of the Most Negative EOL Moderator Temperature Coefficient Measurement, WCAP-13749-P-A, March, 1997. PROCEDURE: All core performance benchmark criteria listed in Table 1 must be met for the current operating cycle. These criteria are confirmed from startup physics test results and routine HFP boron concentration and flux map surveillance performed during the cycle. If all core performance benchmark criteria are met, then the Revised Predicted MTC may be calculated per the algorithm given in Table 2. The required cycle specific data are provided in Table 2 and Figure 1. This methodology is also described in Reference 1. If all core performance benchmark criteria are met, and the Revised Predicted MTC is less negative than COLR Limit 2.3.3, then a measurement is not required. Note that Figure 1 is not entirely linear. However, the deviation is slight enough that linear interpolation between adjacent points from the data at the bottom of the Figure is acceptable. Page 2 of 7 Table 1 Benchmark Criteria for Application of the 300 ppm MTC Conditional Exemption Methodologv Criteria Assembly Power (Measured Normal Reaction Rate) Measured Incore Quadrant Power Tilt (Low Power) Measured Incore Quadrant Power Tilt (Full Power) Core Reactivity (Cb) Difference BOL HZP ITC Individual Control Bank Worth Total Control Bank Worth +/-0.1 or 10% +/-4% +/-2% . 1000 pcm +/- 2 pcm/IF +/- 15 % or +/- 100 pcm +/-10% Parameter Page 3 of 7 Table 2 Algorithm for Determining the Revised Predicted Near-EOL 300 ppm MTC The Revised Predicted MTC = Predicted MTC + AFD Correction - 3 pcm/IF where: Predicted MTC is calculated from Figure 1 at the burnup corresponding to the measurement of 300 ppm at RTP conditions, AFD Correction is the more negative value of: { 0 pcm/IF, ( AAFD

  • AFD Sensitivity) }

AAFD is the measured AFD minus the predicted AFD from an incore flux map taken at or near the bumup corresponding to 300 ppm. AFD Sensitivity = 0.05 pcm / 'F / AAFD Predictive Correction is -3 pcmrdF, as included in the equation for the Revised Predicted MTC. Page 4 of 7 Table 3 Worksheet for Calculating the Predicted Near-EOL 300 ppm MTC Unit: 1, Cycle 11 Date: 12/17/2002 Time: 1525 Reference for Cycle-Specific MTC Data: Letter from T.D. Croyle, Westinghouse, to D.F. Hoppes, STPNOC, [STPEGS] Unit I Cycle 11 Most Negative Moderator Temperature Cofficient Limit Report, dated 19 Nov 2002, ST UB-NOC-02002311. Part A. Predicted MTC A.1 Cycle Average Bumup Corresponding to the HFP ARO equilibrium xenon CB of 300 ppm. A.2 Predicted HFP ARO MTC corresponding to burnup (A.1) Part B. AFD Correction B.1 Bumup of most recent HFP, equilibrium conditions incore flux map B.2 Measured HFP AFD at bumup (B.1) Reference incore flux map: ID: 111018 Date: 12117/02 B.3 Predicted HFP AFD at bumup (B.1) B.4 MTC Sensitivity to AFD B.5 AFD Correction, more negative of { 0pcm/°F, B.4 *(B.2 - B.3)1 Part C. Revised Prediction C.1 Revised Prediction (A.2 + B.5 - 3) C.2 Surveillance Limit (COLR 2.3.3) 15171.8 MWDIMTU -34.96 pcm/°F 15200.9 MWD/MTU -2.02 % AFD -3.07 % AFD 0.05 pcm/°F/AAFD 0 pcm/°F -37.96 pcrn/°F -53.6 pcm/°F If C.1 is less negative than C.2, then the HFP 300 ppm MTC measurement is not required per Specification 4.1.1.3. Page 5 of 7 Figure 1 Predicted HFP FOP 300 ppm MTC vs. Cycle 11 Burnup -33. -34. z 0 U H H P4 0 0 z 0 0 Al L --- -j .1 I .1 -4 I% I I~-+-+- +- + 4 4 4 4 1 I - L - S - I - S - I - I - 4 - 4 - 4 -

4. -

+ - + - I - 4 - I - I - I - 4 4 - 1 - I-I-I-I-.-.-.-.- 1-1 -*t-*-*-* t-  I t I 00 13000 14000 15000 16000 -36.0 120 17000 Cycle Bumup (MWD/MTU) 12000 14000 16000 17000 CYCLE BURNUP (MWD/MTU) Moderator Temperature Coefficients (pcm/0 F) -33.32 -34.43 -35.34 -35.79 -33. -35.C N V \\ Page 6 of 7 Table 4 Data Collection and Calculations Required to Complete the Table 3 Worksheet of the Most Negative Moderator Temperature Coefficient Limit Report Data at the 300 ppm Boron Point "* RCS Boron at 300 ppm at 14:24 on 12/16/02. "* Burnup at 300 ppm: 15171.8 MWD/ITU (A.1) "* Predicted MTC: -34.96 pcm/°F (A.2) Data from Last Flux Map: "* Flux Map Number: 111018 (B.2) "* Reactor Power 100% RTP Note: The monthly flux map was performed at about the same time the unit reached the 300 ppm concentration value. Data from this flux map was used for the AFD Correction. "* Bumup 15200.9 MWD/MTU (B.1) "* Measured Axial Offset (MAO): -2.02% (B.2) Note: The Westinghouse BEACON computer code (similar to the Westinghouse INCORE code) determines Axial Offset (AO), not Axial Flux Difference (AFD). Therefore, the AO must be converted to AFD before use. The relationship between AO and AFD is AFD = Axial Offset

  • Fractional Power

"* Axial Flux Difference Lower Predicted AO (LPAO): -2.91% at 14000 MWD/MTU Higher Predicted AO (HPAO): -3.17% at 16000 MWD/MTU Predicted AO (PAO) = PAO. BIU@MeauedAO °-B/U@LowerPredictedAO xx(HPAO-LPAO )+ LPAO B / U HigheraedjctedAo - B 1 ULwerPredicredAo PAO = (15200.9 - 14000)/(16000 - 14000) * (-3.17% + 2.91%) - 2.91% = -3.07% (B.3) A AFD = (MAO-PAO)

  • 100%

(-2.02% + 3.07%)

  • 100%

= 1.05% Page 7 of 7 Table 4 (cont.) Data Collection and Calculations Required to Complete the Table 3 Worksheet of the Most Negative Moderator Temperature Coefficient Limit Report Determination of the Revised Predicted Moderator Temperature Coefficient (MTC) AFD Sensitivity: 0.05 pcm/°F/ AAFD AFD Correction: 0 pcm/°F (B.5) where: AFD Correction is the more negative of the following: 0 pcrm/F or (AAFD

  • AFD Sensitivity) 0 pcrm/F or (1.05%
  • 0.05 pcm/IF/ AAFD) 0 pcm/°F or 0.053 pcm/°F

.'. 0 pcm/IF Revised Predicted MTC = Predicted MTC + AFD Correction - 3 pcm/IF = -34.96 pcm/°F + 0.0 pcm/IF - 3 pcm/°F = -37.96 pcmI°F (C.1)}}

Retrieved from "https://kanterella.com/w/index.php?title=ML030300474&oldid=5427387"