NOC-AE-03001449, Cycle 11 End of Life Moderator Temperature Coefficient Limit Report
| ML030300474 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| 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) | |
Text
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 EvaluationSupporting the ConditionalEliminationof the Most Negative EOL ModeratorTemperature 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 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/W. C. Gunst 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. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704
Attachment 1 Plant Data Used to Confirm Benchmark Requirements
Attachment 1 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
Attachment 1 Page 2 of 5 Table 1 Benchmark Criteria for Application of the 300 ppm MTC Conditional Exemption Methodology (per WCAP-13749-P-A)
Parameter Criteria Assembly Power (Measured Normal Reaction Rate) +/-0.1 or 10%
Measured Incore Quadrant Power Tilt (Low Power) +/-4%
Measured Incore Quadrant Power Tilt (Full Power) +/-2%
Core Reactivity (Cb) Difference +/- 1000 pcm BOL HZP ITC *2 pcm/°F Individual Control Bank Worth +/- 15 % or +/- 100 pcm Total Control Bank Worth +/-10%
Attachment 1 Page 3 of 5 Table 2 Flux Map Data:Assembly Powers and Core Tilt Criteria I-I Assembly Power Measured Incore Ouadrant Power Tilt Benchmark Criteria Benchmark Criteria Flux Map Measured to Predicted Criteria Criteria Number Error Reouirement Satisfied Power Tilt Requirement Satisfied I. I-
%Diff 4.1 Max 1.0132 111001 Yes Yes Meas - Pred 0.049 Min 0.98164
%Diff 4.5 Max 1.00361 111002 Yes Yes Meas - Pred 0.048 Min 0.99612
%Diff 4.4 Max 1.00516 111003 Yes Yes Meas - Pred 0.051 Min 0.99206
% Diff -3.9 Max 1.00509 111004 Yes Yes Meas - Pred -0.047 Min 0.99206
% Diff -3.7 Max 1.00385 111005 Yes Yes Meas - Pred -0.045 Min 0.99293
% Diff -3.4 Max 1.00403 111006 Yes Yes Meas - Pred -0.043 Mm 0.99458 Maps at < 90%
Reactor Power
% Diff 9.8 Max 1.00151 Max Power 111007 Yes Yes Meas - Pred -0.041 Min 0.99857 Tilt < 1.04 And
%Diff 9.6 Max 1.00122 111008 Yes Min Power Yes Meas - Pred 0.04 Min 0.99871 Tilt >_0.96
% Diff within
%Diff 10.1 +/- 10% Max 1.00173 111009 Yes Yes Meas - Pred 0.043 Min 0.99848 OR OR
%Diff 10.3 Max 1.00787 111010 Yes Yes Meas - Pred 0.049 M-P within Mm 0.99456
+/-0.1 Maps at > 90%
% Diff 10.2 Max 1.00258 111011 Yes Reactor Power Yes Meas - Pred 0.045 Min 0.99744 Max Power
%Diff 11.4 Max 1.00191 Tilt < 1.02 111012 Yes And Yes
_Meas - Pred 0.052 Min 0.99899 Min Power
%Diff 11.6 Max 1.00049 Tilt >_0.98 111013 Yes Yes Meas - Pred 0.053 Min 0.99972
%Diff 7.1 Max 1.00352 111014 Yes "Yes Meas - Pred 0.038 Mm 0.99605
% Diff 7.7 Max 1.00287 111015 Yes Yes Meas - Pred 0.035 Min 0.99874
%Diff 7.1 Max 1.00639 111016 Yes Yes Meas - Pred 0.04 Min 0.99179
%Diff 7.6 Max 1.00767 111017 Yes Yes Meas - Pred 0.042 Min 0.98997
%Diff 7.5 Max 1.00704 111018 Yes Yes Meas - Pred 0.044 [Mln 0.98888
___________ I ________________________ J _______________ .2 Li 4-
Attachment 1 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 Deviation within Yes 06/03/02 15:47 -370.6 _ 1000 pcm Yes 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
Attachment 1 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
Attachment 2 Most Negative End of Life Moderator Temperature Coefficient Limit Report for South Texas Unit 1, Cycle 11
Attachment 2 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 ConditionalExemption of the Most Negative EOL ModeratorTemperature 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.
Attachment 2 Page 2 of 7 Table 1 Benchmark Criteria for Application of the 300 ppm MTC Conditional Exemption Methodologv Parameter Criteria Assembly Power (Measured Normal Reaction Rate) +/-0.1 or 10%
Measured Incore Quadrant Power Tilt (Low Power) +/-4%
Measured Incore Quadrant Power Tilt (Full Power) +/-2%
Core Reactivity (Cb) Difference . 1000 pcm BOL HZP ITC +/- 2 pcm/IF Individual Control Bank Worth +/- 15 % or +/- 100 pcm Total Control Bank Worth +/-10%
Attachment 2 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.
Attachment 2 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 ModeratorTemperature 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. 15171.8 MWDIMTU A.2 Predicted HFP ARO MTC corresponding to burnup (A.1) -34.96 pcm/°F Part B. AFD Correction B.1 Bumup of most recent HFP, equilibrium conditions incore flux map 15200.9 MWD/MTU B.2 Measured HFP AFD at bumup (B.1)
Reference incore flux map:
ID: 111018 Date: 12117/02 -2.02 % AFD B.3 Predicted HFP AFD at bumup (B.1) -3.07 % AFD B.4 MTC Sensitivity to AFD 0.05 pcm/°F/AAFD B.5 AFD Correction, more negative of
{ 0pcm/°F, B.4 *(B.2 - B.3)1 0 pcm/°F Part C. Revised Prediction C.1 Revised Prediction (A.2 + B.5 - 3) -37.96 pcrn/°F C.2 Surveillance Limit (COLR 2.3.3) -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.
Attachment 2 Page 5 of 7 Figure 1 Predicted HFP FOP 300 ppm MTC vs. Cycle 11 Burnup
-33. 0 z
0
-33.
U H
N H -34. Al L---
V j- . - -4 .1 - - - +- + 4 4 4 4 I .11 I% I I~-+-+-
P4 - - - - - - - - -
0 0
-35.C - -- - - - - - - - - - - - -
0 z
I - L- S- I - S- I - I - 4- 4- 4- 4. - + - + - - I - 4 - I - I - - I - - 4 1-
\
I-I-I- -- I-.-.-.-.- - -.
1-1 - -*t-*-*-* --------
t- I -
t I
-36.0 120 00 13000 14000 15000 16000 17000 CYCLE BURNUP (MWD/MTU)
Cycle Bumup Moderator Temperature Coefficients (MWD/MTU) (pcm/0 F) 12000 -33.32 14000 -34.43 16000 -35.34 17000 -35.79
Attachment 2 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 concentrationvalue. Datafrom this flux map was usedfor the AFD Correction.
"* Bumup 15200.9 MWD/MTU (B.1)
"* Measured Axial Offset (MAO): -2.02% (B.2)
Note: The Westinghouse BEACON computer code (similarto the Westinghouse INCORE code) determines Axial Offset (AO), not Axial Flux Difference (AFD). Therefore, the AO must be converted to AFD before use. The relationshipbetween 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%
Attachment 2 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)