View source for NOC-AE-02001238, Supplemental Response to Request for Additional Information Regarding the 2RE08 Steam Generator Tube Voltage-Based Repair Criteria 90-Day Report

{{Adams
| number = ML020390333
| issue date = 01/09/2002
| title = Supplemental Response to Request for Additional Information Regarding the 2RE08 Steam Generator Tube Voltage-Based Repair Criteria 90-Day Report
| author name = Jordan T
| author affiliation = South Texas Project Nuclear Operating Co
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000499
| license number = NPF-080
| contact person = 
| case reference number = NOC-AE-02001238
| document type = Letter type:NOC
| page count = 11
| project = 
| stage = Supplement
}}

=Text=
{{#Wiki_filter: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&deg;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&deg;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&deg;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?
_........                                                                 Ps)gauge        AP        Tn 4
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                                                                                                                                                                                                                                                                                                                                                                                                                                         .
S.....                                                                                                                                                                                                        ....    ....................................
             ........................ I............
                                                                                                 ................IS
                                                                                                '                              . .11. . . .
B L                 a a e @ 2 60..
p i
                                                                                                                                                                                                                                                                                                                          = 0. 4
                                                                                                                                                                                                                                                                                                                                      . t...
p *...................
                                                                                                                                                                                                                                                                                                                                                                                                                                    .............................                   S......
L "                                         SLB Leak Rate @ 2560                                                               .                     .psi                                 0.146 gpm                                                 :
0.100-                                                                                                                                                                                                                                                                                                                                                                                                                                                        .........
I...........
_       _._ -, i- I &#xfd;&#xfd; I'll - 1.
           .                    . Leak . Rate ..                                                      @. 2405                                psi . . 0 . . . . gp                                                      . m   .        .        .        .       .       .       .        .        .          .        .          .          .    .        .        .        .        .       .       ..........
i                                                                                                                                                                                                                                                                                                                                                                                                                                    ................................
0.010:                                                                                                                                                                                                                                                                                                                                                                                                                                            .........................
I                   .-.                                                                               I                                                                                                             ...........
S......................
S..  ............................................                                                                                                                        . . . ............
                                                                             . . . . . .. . . . . . . . . . . .. . .. . . . . . . .. .. . . . . . . .. . . ........................ . .. .. . . .l".......                   ...............................
                           ....... .. .................. .. .. ..... .. .. ... .. .. .... ......] ...........................
          ..............................................       IIILI. II......       ..?. .....
                                                                      ...............              ..................                                        ii ..............
S..........................................................................   .............     .........
i..............
0.001 j                                                      S 0.000 16(O0                                                                         1800                                                                             2000                                                                    2200                                                                           2400                                                                     2600                                     2800                       3000 APavg (psi)}}