NOC-AE-02001238, Supplemental Response to Request for Additional Information Regarding the 2RE08 Steam Generator Tube Voltage-Based Repair Criteria 90-Day Report
| ML020390333 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 01/09/2002 |
| From: | Jordan T South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-02001238 | |
| Download: ML020390333 (11) | |
Text
Nuclear Operating Company
-NEI--
South Teas Prgoect Electric GneratS Station Po. Box 289 Wadswurth Teas 77483 January 9, 2002 NOC-AE-02001238 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Unit 2 Docket No. STN 50-499 Supplemental Response to Request for Additional Information Regarding the 2RE08 Steam Generator Tube Voltage-Based Repair Criteria 90-Day Report
Reference:
Letter, M. E. Kanavos to NRC, "2RE08 Steam Generator Tube Voltage-Based Repair Criteria 90-Day Report," dated June 28, 2001 (NOC-AE-0100 1108)
Supplemental information in response to an NRC request for additional information regarding the referenced report is attached to this letter. If there are any questions regarding this response, please contact Mr. Chet McIntyre at (361) 972-8597 or me at (361) 972-7902.
T1 s4J.Jord*an Manager, Engineering jtc Attachment STI: 31390917
NOC-AE-02001238 Page 2 of 2 cc:
Ellis W. Merschoff Jon C. Wood Regional Administrator, Region IV Matthews & Branscomb U.S. Nuclear Regulatory Commission 112 East Pecan, Suite 1100 611 Ryan Plaza Drive, Suite 400 San Antonio, Texas 78205-3692 Arlington, Texas 76011-8064 U. S. Nuclear Regulatory Commission Institute of Nuclear Power Attention: Document Control Desk Operations - Records Center Washington, D.C. 20555-0001 700 Galleria Parkway Atlanta, GA 30339-5957 Mohan C. Thadani Richard A. Ratliff U. S. Nuclear Regulatory Commission Bureau of Radiation Control Project Manager Texas Department of Health 1 White Flint North 1100 West 49th Street 11555 Rockville Place Austin, TX 78756-3189 Rockville, MD 20852-2738 Mail Stop: O-7D1 Cornelius F. O'Keefe D. G. Tees/R. L. Balcom U. S. Nuclear Regulatory Commission Reliant Energy, Inc.
P. O. Box 289, Mail Code: MN116 P. 0. Box 1700 Wadsworth, TX 77483 Houston, TX 77251 A. H. Gutterman, Esquire C. A. JohnsonrA. C. Bakken III Morgan, Lewis & Bockius AEP - Central Power and Light Company 1800 M. Street, N.W. P. 0. Box 289, Mail Code: N5012 Washington, DC 20036-5869 Wadsworth, TX 77483 M. T. Hardt/W. C. Gunst A. Ramirez/C. M. Canady City Public Service City of Austin P. 0. Box 1771 Electric Utility Department San Antonio, TX 78296 721 Barton Springs Road Austin, TX 78704
NOC-AE-02001238 ATTACHMENT
NOC-AE-02001238 Attachment Page 1 of 8 South Texas Project Unit 2 EOC-8 In situ Leak Test Data Procedure for Adjusting Measured Leak Rate to Steam Line Break Conditions The leak rates measured during the South Texas Project Unit 2 EOC-8 in situ leak tests were adjusted to steam line break (SLB) conditions using the adjustment methodology presented in Appendix B of Reference 1. The attached EXCEL spreadsheet contains calculations for adjusting the data from one of the tests (SG-D, R24C47-3H). The following is a step-by-step description of the leak rate adjustment process.
Input Data The in situ test for tube R24C47-3H in SG-D contains five data points as shown in rows 6 through 10 of the spreadsheet. The various input data are:
Col. A, B Tube identification Col. C Test identifier Col. D, E Primary and secondary side pressures during the test (psig)
Col. F Primary to secondary differential pressure (psi)
Col. G, H Primary and secondary side temperatures during the test (OF)
Col. I Measured leak rate (gpm at room temperature)
Col. J, K Test condition - Room temperature test and no prior tube expansion Col. L Saturation vapor pressure at primary side temperature Data Adjustment Brief Descriptionof Methodology From Equation B-1I in Reference 1, the ratio of leak rates at two conditions is obtained as:
R = LR2 = crahy (B-11)
LRi Subscript 1 represents the test condition and subscript 2 represents the desired condition to which the test data is to be adjusted.
The a factor accounts for the variation in the crack opening area with pressure differential across the tube wall and is given by Equation B-15 in Reference 1:
(Ap 2 - Ap,)
a= 10 b (B-15) where (Ap = pp - Ps) represents primary-to-secondary pressure differential and b is a constant.
NOC-AE-02001238 Attachment Page 2 of 8 The f3 term accounts for the leak rate dependency on temperature due to the variation in crack opening area because of variation in tube material properties with temperature as well as due to fluid density variation with temperature. It is given by Equation B-21 in Reference 1 (for a room temperature test with Tprimary = Tambient):
_ Ea__ 2 (B-21)
E2 U2 where p is the fluid density, and E and a, respectively, represent flow stress and Young's modulus of the tube material.
The y term accounts for the variation in fluid flow with pressure differential and is given by Equation B-22 in Reference 1. With Cp = 1.0 and possibility of flashing at both conditions, this factor is given by:
(P, 2 - Pf2) r 2"= (P"l -P2Pfd)
- (B-22)
Ap 1 where pf represents fluid saturation pressure at the primary side temperature.
Step-by-Step Descriptionof the Adjustment Process The following is a description of the steps involved in adjusting a leak rate at a given condition to SLB condition.
Step 1: Adjust measured leak rate to the standard SLB primary side temperature (T = 616°F) and secondary side pressure (Ps = 15 psi) while maintaining the same total pressure differential (Ap).
Since the total pressure differential is maintained the same Ap1 = Ap 2= Ap, a = 1. Therefore, Rstd = LR2 LRI =8)6'~td where, P3 is given by Equation B-21, and sd= p P._, Pp= = A p + 15 pp1 _ Pfh
NOC-AE-02001238 Attachment Page 3 of 8 Columns M through AE contain calculations involved in this step.
Col. M, N, O Desired standard conditions: Psecondary = 0 psig, Tprimary = 616°F, Ap same as in the test.
Col. P Does water flash to steam during the test because the secondary side pressure is below the saturation pressure at the primary side temperature?
Col. Q, R Young's modulus at test and desired conditions Col. S, T Flow stress at test and desired conditions Col. U, V Fluid density at test and desired conditions Col. W Saturation pressure at the desired condition Col. X Calculated 03 factor Col. Y, Z Self explanatory Col. AA Calculated y factor. Note that this term cannot be calculated for a test condition where the primary side pressure for the desired condition pp = (Ap +15) falls below the saturation pressure at the desired primary temperature (616°F).
Col. AD Product 03 times y Col. AE Measured leak rate adjusted to the standard SLB primary side temperature (T = 616 0F) and secondary side pressure (Ps = 15 psi) while maintaining the same Ap as in the test Step 2: Calculate b factor in alpha term (Equation B-15)
Step 1 adjusts the measured leak rate to a condition where the secondary pressure is 15 psi and primary side temperature is 616TF while maintaining the same total pressure differential. This leak rate is adjusted to the SLB pressure differential with the following equation:
( ApSLA - AP,,)
b R = cy = YIO where, R is the ratio of the leak rates at the SLB and test measurement total pressure differentials. (The 03 factor is not affected by total pressure differential.)
Three different methods were used to calculate the b factor and the value that yielded the largest leak rate at the desired SLB pressure differential was picked for use in a leak rate correlation.
Method 1 When more than two data points are available, a value for b can be obtained by fitting a linear regression line to the natural log of leak rate versus Ap data. The b value is given by the inverse of the slope value.
Cell G15 in the spreadsheet contains the b value calculated with this method.
NOC-AE-02001238 Attachment Page 4 of 8 Methods 2A and 2B Alternately, a value for b can obtained using only the two data points with Ap values that bound the SLB Ap (Ap 2 < ApSLB <Api):
b = Ap 2 - ApI log(R/y )
Two slightly different methods were used to pick the leak rate values used to calculate the "R" term in the above equation. In one method (Method 2A), measured leak rates adjusted to standard conditions (in Step 1) were used. In the second method (Method 2B), leak rate values at Ap 2 and Ap1 were calculated using the correlation between log (leak rate) vs. Ap developed in Method 1, and their ratio yielded R. The values for b obtained with Methods 2A and 2B are shown in Cells G27 and G34, respectively.
Step 3: Convert leak rate at test pressure differential to SLB pressure differential The measured leak rates adjusted to standard conditions in Step 1 are adjusted to the SLB pressure differential with the following equation:
( Apsis Ap,,)
b-R = ac" = ylO Columns AE to AG show the leak rates adjusted to SLB Ap =2560 psi using the three values for factor b obtained in Step 2. Columns AH to AJ show the corresponding adjusted leak rates at SLB Ap =2405 psi. Note that each test measurement is adjusted to the SLB condition with the exception of measurements that cannot be adjusted to the standard conditions in Step 1 (tests with Ap < Psat at 616TF). The adjusted SLB leak rate value for the test measurement with Ap closest to and higher than the SLB Ap is chosen for use in a leak rate correlation (Test # 3 in Row 8). There are three choices corresponding to the three values for the b factor (values in Cells AE8, AF8 and AG8 for SLB Ap=2560 psi) and the largest of the three values is chosen (Cell AE8).
Reference
- 1. EPRI Report NP-7480-L, "Steam Generator Tubing Outside Diameter Stress Corrosion Cracking at Tube Support Plates - Database for Alternate Repair Criteria, Volume 2: 3/4 Inch Diameter Tubing,"
October 1993
A B C ID I E F F G H I J K L m T N P South Texas Unit-2 InSitu Leak Test Results SG-D R24 C47 TSP 3H Adjustment to Steamline Break Conditions Enter the Desired Conditions Test Data Entry Describe the Test foreEacheTest WI the I__
2[Wa Specimen Is leak rate a Previousl Water Flash Measured room Psat to Steam At Test ID/ Test Pp Ps Ap, Tp Ts- t*eak temperature Y at Tp Desired Conditions Test Test Spec Setup Rate (-Tp) Expanded Seq. # (psig) (psig) ~(gpms - RT) msmt. of a hot with a (psia) Conditions?
test? (yes/no) Bladder?
5 1440 no 0.0002 no no 0 .44 0 1440 616 no South Texas SR24C47 3H I 1440 0 0
1440 75 75 0.08466 no no 0.44 2046 no 2 2046 2046 75 75 0 616 2001 no no 0.44 2530 i6 3 2530 0 2530 75 75 0.2,4024 0 616 no 75 75 no 0.44 2700 4 2700 0 2700 0540074 no 0 616 no 75 75 0.53798 no no 0 .44 0 2849 616 no Hi 5 2849 0 2049 10 11 12_ Regression Line - Log (leak Estimation of "b" Constant rate) vs. Ap (Used for Plotting) 13 Col F Col AE Calculate Log of Method 1 Calculated d Adjusted Linear Regression Leak Rate Leak Rate Leak Total Leak Log(adjusted leak rate-col AG) Total using m & b using m &
Rate Ap b Rate Label versus AP Label 14 Ap 789.8 <-- 'b" constant (psi) Log (leakral Leakrate
-15 (psi) a2 m 0.0012662 4.073 b 1440 -2.2493 0.0056 16 #VALUE! 1440 #VALUE! al b2 2046 1.4820 0.0330 17 0.032854602 2046 1.4834 hl se m 3.684E-05 0.0939 se_b c2 0.9983101 0.0223 se-y 2530 0.8692 0.1351 1i8 0.132505802 2530 0.8778 cl r2 d2 2 df 2700 -0.6539 0.2218 19 0.235415259 2700 -0.6282 dl F 1181.4888 ssreg 0.5850319 0.001 ssresid 2849 -0.4653 0.3425 0..330287014 2849 -0.4811
_1
-- i 22 23 Method 2a Based on Neighboring Datapoints Using As- asured Leak Rate 24 25 "b" constant 26 b = 1068.51 bl an cl 27 28 29 30 Method 2b Based on Two Neighboring Datapoints Leak Rate Estimated from Regressio Fit 31 32 "b" constant 33 b 1051.81 b2 an c2 34 35 36 37-381J
v W x Y I z AA AB AC I S T U 1
Primary Does the Corrected Test yfaccor for Temp For the Pressure Flash at for and Young's Modulus for Flow Stress Density for Temp Psat Desired GreaterThan the desired Pressure Temp. Correction for Temp Correction Correction Temperatur PsatAtthe desired temperatu (fy) at the e Desired conditio re and desired Condition? ns? pressure 1y conditions Test Desired Test Desired Test Desired Desired (gpm - RT) 4 Te=. Temp. Temp. Te.p. Temp. temp. .
5 Temp._
78.92 71.70 62.23 40.85 1738 0.977 no yes undefined undefined 6 31.23 28.52 0.0329 71.70 62.23 40.85 1738 0.977 yes yes 0.397 0.388 7 31.23 28.52 78.92 62.23 40.85 1738 0.977 yes yes 0.565 0.552 0.1325 8 31.23 28.52 78.92 71.70 40.85 1738 0.977 yes yes 0.602 0.587 0.2354 9 31.23 28.52 78.92 71.70 62.23 62.23 40.85 1738 0.977 yes yes 0.629 0.614 0.3303 10 31.23 28.52 78.92 71.70 11
-12 13 15 SLB Leak Rate - Plot Data 16 1600 0.146415 33.3 17 2560 0.146415 18 2560 0.0001 19 20 21 23 SLB Leak Rate - Plot Data 1600 0.095437 21.1 24 2405 0.095437 26 2405 0.0001 27 28 29 30 31 32 33 34 35 36 37 38
AD AE I AF I AG AH I AI I AJ Steamline Break Steamline Break 1 Ap = 2560 psi Ap = 2405 psi Method 1 Method 2a Method 2b Method 1 Method 2a Method 2b 2
Leak Rate Leak Rate Leak Rate Leak Rate Leak Rate 2405 psi Leak Rate Leak Rate 2560 psi 2560 psi 2560 psi 2560 psi Based on 2405 psi 2405 psi Steamline Based on Based on Based on "b" from Based on Based on Break "b" from
'b' Factor 'b' Factor L.S. Fit 'b' Factor 'b' Factor Ref. L.S. Fit Condn. Slope from from Slope from from 3 (Cell G15) Cell G27 Cell G34 (Cell G15) Cell G27 Cell G34 4 (gipm) (gpm -RT) (gpM- RT) (gM- RT) (on- RT) (gpm - RT) (n - RT) 5 6
7 1.47E-01 2.12E-01 1.43E-01 1.46E-01 1.26E-01 9.54E-02 9.66E-02 8 1.45E-01 1.46E-01 1.43E-01 1.43E-01 8.74E-02 9.54E-02 9.50E-02
-- 1.575-01 1.495-01 1.65E-01 55-01 8.88E-0 1.10E-01 1.09E-01 10 1.42E-01 1.29E-01 .61E-01 1.60E-01 7.7 -02 1.07E-01 1.06E-01 11 12 13 Pick these values for inclusion in the leak rate correlation as the total Ap for this case is closest to the desired SLB pressure differential 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
South Texas -2 SG-D R24C47-3H In Situ Leak Test Data (Normalized to Tp= 616TF and ps = 15 psia Reference SLB Conditions) 1.000 .
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0.001 j S 0.000 16(O0 1800 2000 2200 2400 2600 2800 3000 APavg (psi)