ML17333A957

Generators U1R97 2 Volt Interim Plugging Criteria Rept.

ML17333A957
Person / Time
Site:	Cook
Issue date:	07/21/1997
From:	INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
Shared Package
ML17333A955	List: ML17333A954 ML17333A956 ML17333A957
References
AEP:NRC:1166AI, NUDOCS 9707300004
Download: ML17333A957 (52)

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ATTACHMENT 2 TO AEP:NRC:1166AI COOK STEAM GENERATORS U1R97 2 VOLT INTERIM PLUGGING CRITERIA REPORT9707300004 97072k PDR ADOCK 050008i5 P PDR 4D T ATFACHMENT 2 TO AEP:NRC:1166AI Table of Contents 1.0 Introduction 2.0 Summary and Conclusions 3.0 EOC 15 Inspection Results 4.0 Data Base Applied for Safety Evaluation Report Correlation 24 5.0 Leak Rate and Probability of Burst 25 6.0 Bobbin Voltage Distributions 26 7.0 Tube Leak Rate and Burst Probabilities 34 Page 2 of36 A%I'ACHMENT 2 TO AEP:NRC:1166AI 1.0 Introduction This report provides the results of the Cook Unit 1 steam generator tube eddy current inspection as it applies to the voltage-based repair criteria of Generic Letter 95-05.Per the requirements of GL 95-05, with two cycles of operating data available, the highest growth rate was used in calculations performed for the determination of the leak rate and probability of tube burst for the voltage distribution of the population of tube support plate indications that were returned to service for cycle 16.The methodology for these calculations is'based upon WCAP-14277 Revision 1, which has been approved for use.The application of the voltage-based T/S amendment for Unit 1 requires a 100%BC~inspection of all in service tubes and subsequent RPC inspection of TSP indications greater than 2.0 volts for determination of the repair status of the indications.

Plugging of indications greater than 5.6 volts TSP BC response is required regardless of RPC inspection confirmation.

Calculation results of predicted SG tube leak rate and probability of burst during a postulated MSLB at EOC 16 are well below the applicable regulatory requirements.

The results of the calculations are based upon the distribution of indications that were detected at EOC 15, adjusted by the probability of detection of 0.6, and removing the repaired indications.

The results of the calculations determined that the postulated conditions at EOC 16 are well bolow the requirements outlined in GL 95-05.2.0 Summary and Conclusions MSLB leak rate and tube burst probability analyses were performed for the actual EOC 15 BC voltage distributions and for projected EOC 16 distributions for each of the four Unit 1 SGs.The limiting SG at EOC 15 was determined to be SG 11, with the highest number of indications and the highest leak rate for the postulated MSLB.The tube burst probability at EOC 15 was low (1.6 x 10), with 3 trials having at least one tube burst in 500,000 Monte Carlo simulations for SG 11 and SG 14.SG 11 is predicted to be limiting at EOC 16, with the highest number of indications and BC voltage amplitude and leak rate for the postulated MSLB.The tube burst probability at EOC 15 is low and varied between 9.7 x 10 and 2.1 x 10 between the four SGs.MSLB leak rates for the actual EOC 15 and projected EOC 16 distributions are 0.42 and 0.96 gpm in SG 11 and SG 14, respectively.

These calculations demonstrate that the ARC application at EOC 15 (actual distribution) and at EOC 16 (predicted for POD=0.6)will satisfy the criteria for'allowable leakage and burst probability.

A total of 1053 BC indications were reported in all SG's during the EOC 15 inspection.

Of the 1053 indications, 131'were>1.0 volt and all were less than 1.8 volts.-The highest BC voltage recorded was 1.73 volts, so there were no indications above the 2.0 volt ARC repair limit.No indications were RPC inspected, (except the tube removal candidate).

Tubes removed from service were based upon reasons other than ODSCC at Page 3 of 36

'YI'ACHMENT 2 TO AEP!NRC:1166AI the TSP intersections.

As a result, the total number of TSP indications returned to service for cycle 16 was 903.SG 11 was limiting at EOC 15 with 369 indications from the tubes in service during cycle 15.Of the 369, 7 were reported as greater than 1.0 volt and less than the highest reported BC voltage of 1.73.Of the 369 indications, 47 were removed from service for reasons other than ODSCC at the TSP.For the actual EOC 15 BC voltage distribution, the limiting MSLB tube leak rate is calculated to be 0.42 gpm and the limiting tube burst probability is less than 1.6 x 10 for SG 11, substantially lower than the Unit 1 T/S allowable MSLB tube leak limit and the reporting guideline for the tube bur'st probability contained in NRC report"Safety Evaluation by the Office of Nuclear Reactor Regulations related to Amendment No.200 Facility Operating License DPR-5S Indiana Michigan Power Company Donald C.Cook Nuclear Plant, Unit 1 Docket No.50-315".

The results of actual EOC 15 tube leak rate and burstprobability are lower than corresponding predictions of 0.70 gpm (SG 11)and 2.9 x 10 (SG 13)performed at the BOC-15, demonstrating the conservatism of the prediction methodology.

Using the POD=0.6 criteria to calculate the performance of the limiting SG during the next Unit 1 operating cycle, the MSLB tube leak rate is projected to be 0.96 gpm and the limiting tube burst probability is less than 2.2 x 10 for SG 11 at EOC 16.The results are lower than the Unit 1 ARC requirement for allowable tube leakage and the NRC guideline for the tube burst probability; accordingly cycle 16 operation of Unit 1 is considered to be in compliance with requirements of the Cook Unit 1 T/S.3.0 EOC 15 Inspection Results 3.1 As Found Conditions of SGs at EOC 15 In accordance with ARC guidance provided by GL 95-05, the EOC 15 ECT inspection of the SGs consisted of a 100%full length BC examination of all in service tubes for all four steam generators and included BC probe wear.Per GL 95-05 and our ARC SER, it was required that RPC confirmed indications of greater than 2.0 volts BC amplitude shall be plugged and those greater than 5.6 volts BC amplitude shall be plugged regardless of RPC confirmation.

The highest DSI BC voltage reported during this inspection was 1.73 volts and was not RPC inspected, none of the tubes that were in service during cycle 15 required plugging for ODSCC at TSP intersections.

A summary of ECT indication distributions for all SGs is shown in Table 3-1.For those tubes that were in service during cycle 15, Table 3-1 provides the number of field BC indications, POD at 0.6, indications repaired, and the BOC-16 distribution.

Page 4 of 36 ATTACHMENT 2 TO AEP:NRC:1166AI Of the in service tubes at the EOC 15, 1053 indications were identified during the inspection, 150 were removed from service for causes other than ODSCC at TSP intersections, leaving 903 tubes with DSI indications returning to service for cycle 16.~Of the 1053 indications, no tubes required RPC inspection since all the voltage values were less than the 2.0 volt criteria.o 131 indications were greater than 1.0 volt and less than or equal to 1.73 volts.Of those, 26 were repaired for causes other than ODSCC at TSP intersections.

SG 11 has the largest number of field indications and the largest number of field indications greater than 1.0 volt.Therefore, SG 11 is the limiting SG with SG 14 a close second.The largest BC indication was found-'.n SG 12 (shown in the 1.8 volt bin).3.2 Non Destructive Examination Uncertainties The NDE uncertainties applied for both the as-found conditions and projected EOC 16 calculations are those prescribed in GL 95-05.The probe wear, or acquisition error, has a standard deviation of 7.0%with a mean of zero and a cutoff of 15%based upon implementation of a probe wear standard during the acquisition of the ECT data.The analyst variability uncertainty has a standard deviation of 10.3%with a mean of zero, and no cutoff.These NDE uncertainty distributions were included in both sets of calculations that were performed for the Unit 1 SGs (EOC 15 as-found and EOC 16 projections).

3.3 Voltage Growth Assessment An assessment of the voltage growth of the indications due to defect progression was also performed, per GL 95-05.According to section 2.b.2(2)of the GL;voltage growth rates should only be evaluated for those indications which can be identified at two successive inspections.

Additionally, the most limiting growth rate of either previous or current cycle should be used to estimate the growth for the next inspection cycle when both inspections meet the ECT data acquisition requirements in section 3 of GL 95-05.For cycle 16 growth on Unit 1, the growth rates used are composite growth rates for each SG that consist of cycle 14 plus cycle 15 growth.Since cycle 14 data for all SG's consisted of less than 200 indications each, the data was combined with cycle 15 growth to determine a composite SG specific growth rate.The composite growth rates were then used as the estimated cycle 16 growth used in the tube integrity calculations.

The SG specific growth rates used in the cycle 16 Monte Carlo analysis are contained in'Table 3-9.Tables 3-5 through 3-8 provide the voltage growth for the last four operating cycles.Page 5 of 36

'ATl'ACHMENT 2 TO AEP:NRC:1166AI Table 3-1 Summary of Inspection and Repair for Tubes Inservice during Cycle 15 i%~,'i:g Steam Generator 11 Summary of Inspection and Repair of Tubes Steam Generator 12 Summary of Inspection and Repair of Tubes Voltage Bin 0.10 Field POD=0.6 Indications Adjusted 0.0 Indications BOC S6 Repaired Distribution 0.0 Voltage Bin 0.10 Field POD=0.6 Indications Adjusted 1.7 Indications Repaired BOC 16 Distribution 1.7 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 Total>1V 17 62 73 59 42 28 28 13 16 12 369 31 28.3 103.3 121.7 98.3 70.0 46.7 46.7 21.7 26.7 20.0 13.3 10.0 3.3 0.0 1.7 0.0 0.0 0.0 615 52 0 40 28.3 98.3 112.7 92.3 65.0 42.7 45.7 18.7 23.7 20.0 13.3 8.0 2.3 2.3 0.0 1.7 0.0 0.0 0.0 575 48 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 Total>1V 14 25 21 24 21 14 10 169 23 23.3 41.7 35.0 40.0 35.0 23.3 16.7 11.7 15.0 10.0 11.7 8.3 3.3 1.7 1.7 0.0 1.7 0.'0 0.0 282 38 23 21.3 39.7 35.0 35.0 32.0 23.3 14.7 9.7 13.0 8.0 9.7 8.3 2.3 1.7 1.7 0.0 1.7 0.0 0.0 259 33 Steam Generator 13 Summary of Inspection and Repair of Tubes Steam Generator 14 Summary of Inspection and Repair of Tubes Voltage Bin Field POD=0.6 Indications Adjusted Indications BOC 16 Repaired Distribution Voltage Bin Field Indications POD=0.6 Indications BOC 16 Adjusted Repaired Distribution 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 Total>1V 13 18 40 29 17 15 160 1.7 21.7 30.0 66.7 48.3 28.3 25.0 15.0 13.3 1.7 8.3 1.7 1.7 1.7 1.7 0.0 0.0 0.0 0.0 0.0 267 15 20 1.7 20.7 30.0 61.7 47.3 25.3 21.0 12.0 13.3 1.7 6.3 1.7 1.7 1.7 0.7 0.0 0.0 0.0 0.0 0.0 247 12 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 Total>1V 22 56 63 69 34 28 28 14 16 355 30 0.0 36.7 93.3 105.0 115.0 56.7 46.7 46.7 23.3 18.3 26.7 8.3 6.7 1.7 1.7 3.3 1.7 0.0 0.0 0.0 592 50 19 66 0.0 29.7 86.3 96.0 96.0 54.7 41.7 40.7 20.3 16.3 21.7 8.3 6.7 1.7 0.7 33 1.7 0.0 0.0 0.0 526 44*No indications were repaired due to RPC confirmation.

Tubes were repaired for other pluggable defects.Page 6 of 36

ATl'ACHMENT 2 To AEP:NRC:1166AI Table 3-2 Unit 1 1997 Outage TSP ODSCC Indication Distribution for Tubes in Service during Cycle 15 Steam Generator 11 Steam Generator 12 Tube Support Plate Maxirrum Voltage Average Average Voltage Grawth Tube Support Rate Nurser of MaxirrUm Average Indications Voltage Voltage Average GrawS 1H 213 110 1.23 0.70 0.21 0.34 0.00 0.58 0.000 0.50.007 OA4.019 0.36 0.033 0.21 0.020 0.29-0.030 0.00 0.000 1H Total 76 13 13'169 1.73 0.63 1.54 0.60 0.80 OA4 1.15 0.38 0.62 OA3 0.00 0.00 0.00 0.00 0.075 0.000 0.000 Steam Generator 13 Steam Generator 14 Tube Support Rate 1H Number of Maxirrum Indications Voltage 1.25 Average Voltage 0.50 0.51 Average Grawth 4.073 Tube Support Plate 1H 132 Average Voltage 0.62 0.51 Average Grawth 0.050 0.028 10 0.71 0.00 OA5 0.00 0.00 0.38 0.00 0.29 0.00 0.00 0.000 0.000 0.000 Total 19 0.73 0.00 OA6 0.41 0.47 0.38 0.00 OAO 0.002 0.056 0.023 0.000 0.040 Tube Support Plate 1H Corrposite of All Four SGs Maxirram Average Average Voltage Voltage Grawth 1.73 0.58-0.032 1.58 0.53-0.019 Total 121 1.23 0.42-0.025 1.62 0.30 0.020 0.73 0.33 0.004 0.34 0.07-0.008 OA6 0.10 0.010 Page 7 of 36 ATI'T 2 TO AEP:NRC:1166AI Table 3-3 Cook Unit 1 1997 Outage Average Voltage Growth History Composite of All Steam Generator Data Bobbin Voltage Range Average Number of Voltage Indications BOC Average Voltage Growth Average Percent Growth Entire Cycle Per EFPY Entire Cycle Per EFPY Cycle 15 (1995-1997)

-429.06 EFPD Entire Voltage Range eoc 0 75 Volts>0.75 Volts 1053 831 222 0.54 0.42 1.01-0.011 0.012-0.096-0.009 0.010-0.082-2.0%29%-9.5%24%-8 1%Cyc le 14 (1994-19 95)-390.54 EFPD Entire Voltage Range eoc 0 75 Volts 2 0.75 Volts 597 445 152 0.62 0.50 0.94 0.034 0.031 0.050 0.031 0.029 0.047 54 63%53%5.1%5.8%5.0%Cy cle 13 (1992-1 994)-444.2 E FPD Entire Voltage Range eoc 0.75 Volts 2 0.75 Volts Entire Voltage Range eoc 0 75 Volts>0.75 Volts 514 356 158 201 30 171 0.66 0.50 0.95 1.00 0.67 1.07 0.010 0.000 0.030 ycle 12 (1990-0.020 0.080 0.010 0.008 0.000 0.025 1992)-445 E 0.016 0.064 0.008 FPD 1 2%0.0%2.6%1.6%9.6%0.8%1.0%0.0%21%1 3%77%06%Page 8 of 36 AT1'NT 2 TO AEP:NRC:1166AI Table 3-4 Cook Unit 1 1997 Outage Average Voltage Growth during Cycle 15 Bobbin Voltage Range Number of Indications Average Voltage BOC Co Average Voltage Growth Average Percent Growth Entire Cycle Per EFPY Entire Cycle Per EFPY mposite of All Steam Generator Data Entire Voltage Range eoc 0 75 Volts>0.75 Volts 1053 831 222 0.54 0.42 1.01-0.011 0.012-0.096-0.009 0.010-0.082 2.0%2 9%-g 5 2.4%-8.1%Steam Generator 11 Entire Voltage Range V eoc 0.75 Volts 2 0.75 Volts 369 291 78 0.54 0.42 1.00-0.003 0.022-0.096-0.003 0.019-0.082-0.6%5.2%-g 6-P 5%45 8 2%Steam Generator 12 Entire Voltage Range V eoc 0 75 Volts>0.75 Volts 169 112 57 0.63 0.42 1.06-0.052-0.011-0.131-0.044-0.009-0.111 8.3%-2.6%-12.4%-7 P 2 2%-10 5%Steam Generator 13 Entire Voltage Range eoc<0.75 Volts 2 0.75.Volts 160 130 30 0.57 0.46 1.05-0.083-0.051-0.220-0.071-0.043-0.187-14.6%-11.1%21 P 12.4%-g.4 17.8'team Generator 14 Entire Voltage Range eoc 0 75 Volts>0.75 Volts 355 298 57 0.50 0.41 0.97 0.033 0.039 0.003 0.028 0.033 0.002 6.6%g5 0.3%56 8.1%0.3%Page 9 of 36 ATI'ACHMENT 2 TO AEP:NRC:1166AI Table 3-5 Cook'Jnitl Signal Growth Statistics for Cycle 12 ('90 to'92)on EFPY Basis D Delta Volts-0.3-0.2 Steam Generator 11 Steam Generator12 No.of Obs CPDF No.of Obs CPDF 0.021 Steam Generator 13 No.of Obs CPDF-0.1 0.1 0.2 0.3 0.4 Total 23 24 58 0.086 0.483 0.897 27 48 0.063 0.167 0.729 0.875 0.958 16 27 0.037 0.222 0.815 Delta Volts Cumulative Steam Generator 14 No.of Obs CPDF No.of Obs CPDF-0.3-0.2-0.1 0.1 0.2 0.3 0.4 Total 13 22 19 65 0.031 0.077 0.277 0.615 0.908 0.969 0.985 21 55 86 22 198 0.010 0.030 0.136 0.414 0.848 0.960 0.985 Page l0 of 36 ATTACHMENT 2 TO AEP:NRC:1166AI Table 3-6 Cook Unit 1 Signal Growth Statistics for Cycle 13 ('92 to'94)on EFPY Basis a Delta Volts Steam Generator 11 Steam Generator 12 No.of Obs CPDF No.of Obs CPDF Steam Generator 13 No.of Obs CPDF-0.2-0.1 0.1 0.2 0.3 0.4 Total 18 58 59 18 156 0.006 0.122 0.494 0.872 0.987 35 48 103 0.029 0.078 0.417 0.883 0.961 0.990 33 35 84 0.012 0.071 OA64 0.881 0.988 Delta Volts Steam Generator 14'umulative No.of Obs CPDF No.of Obs CPDF-0.2-0.1 0.1 0.2 0.3 0.4 Total 10 71 70 14 171 0.035 0.094 0.509 0.918 38 197 212 49 514 0.021 0.095 0.479 0.891 0.986 0.998 Page I I of 36

'ATI'ACHMENT 2 TO AEP:NRC:1166AI Table 3-7 Cook Unit 1 Signal Growth Statistics for Cycle 14 ('94 to'95)on EFPY Basis Delta Volts-0.3-0.2 Steam Generator 11 Steam Generator 12 No.of Obs CPDF No.of Obs CPDF 0.017 Steam Generator 13 No.of Obs CPDF-0.1 57 0.035 0.322 47 0.066 0.455 32 0.22 0.378 0.1 81 0.729 45 0.826 41 0.833 0.2 0.3 0.4 0.5 0.6 0.7 Total 36 13 199 0.910 0.975 0.985 0.995 12 121 0.926 0.975 0.983 0.992 0.992 13 90 0.978 Delta Volts Steam Generator 14 Cumulative No.of Obs CPDF No.of Obs CPDF Hybrid 0 No.of Obs CPDF-0.3-0.2-0.1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 64 90 19 0.011 0.016 0.059 0.401 0.882 0.984 0.995 0.995 23 200 257 80 23 0.003 0.008 0.047 0.382 0.812 0.946 0.985 0.990 0.997 0.998 57 81 36 13 0.035 0.320 0.725 0.905 0.970 0.980 0.990 0.995 Total 187 597 200¹Growth disrtibution for SG-11 pIus the largest growth observed, which is in SG-12.Page 12 of 36

ATFACHMENT 2 TO AEP:NRC:1166AI Table 3-8 Cook Unit 1 Signal Growth Statistics for Cycle 15 ('95 to'97)on EFPY Basis Delta Volts Steam Generator 11 Steam Generator12 No.of Obs CPDF No.of Obs CPDF Steam Generator 13 No.of Obs CPDF-0.5-0.4-0.3-0.2-0.1 0.1 0.2 0.3 0.4 0.5 0.6 Total 38 147 106 34 16 369 0.005 0.014 0.024 0.054 0.157 0.556 0.843 0.935 0.978 0.989 0.997 12 20 67 54 169 0.012 0.036 0.036 0.107 0.225'.621 0.941 0.982 32 71 29 160 0.013 0.019 0.044 0.113 0.313 0.756 0.938 0.988 Delta Volts Steam Generator 14 Cumulative No.of Obs CPDF No.of Obs CPDF-0.5-0.4-0.3-0.2-0.1 0.1 0.2 0.3 0.4 0.5 0.6 Total 22 109 144 47 15 355 0.006 0.006 0.008 0.028 0.090 0.397 0.803 0.935 0.977 0.994 41 112 394 333 96 36 10 1053 0.008 0.015 0.024 0.063 0.169 0.543, 0.859 0.951 0.985 0.994 0.999 Page 13 of 36 ATTACHMENT 2 TO AEP:NRC:1166AI Table 3-9 Cook Unit 1 Voltage Growth Statistics for Cycle 16 ('97 to'98)used in Monte Carlo Analysis O Delta Volts Steam Generator 11 Steam Generator 12 Steam Generator 13 No.of Obs CPDF No.of Obs CPDF No.of Obs CPDF-0.5-0.4-0.3-0.2-0.1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Total 45 204 187 70 29 568 0.0035 0.0088 0.0158 0.0352 0.1144 0.4736 0.8028 0.9261 0.9771 0.9877 0.9965 14 26 114 99 19 290 0.0069 0.0207 0.0207 0.0690 0.1586 0.5517 0.8931 0.9586 0.9931 0.9966 0.9966 34 103 70 21 250 0.008 0.012 0.0280 0.0720 0.2080 0.6200 0.9000 0.9840 Delta Volts Steam Generator 14 Cumulative No.of Obs CPDF No.of Obs CPDF-0.5-0.4-0.3-0.2-0.1 30 0.0037 0.0037 0.0092 0.0240 0.0793 44 135 0.0049 0.0097 0.0164 0.0431 0.1249 0.1 173 0.3985 234 0.8303 594 590 0.4851 0.8429 0.2 66 0.9520 176 0.9497 0.3 0.4 0.5 0.6 0.7 Total 17 542 0.9834 0.9945 59 13 1650 0.9854 0.9933 0.9988 1.0000 Page l4 of 36 P

ATI'ACHMENT 2 TO AEP:NRC:1166AI Fi ure3-1 As Found DSI Population D.C.Cook SG 11 04/97 1R97 80 70--60-rn 50.f3 40 O s z 30 20 10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 Bobbin Volts Fi ure3-2 As Found Dsf Popufatfon O.C.Cook SG 12 04/97 1R97 80 70 10-0 0.1 0.2 0.5 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.5 1.4 1.5 1.6 1.7 1.8 1.9 2.0 Bobbin Volts Page l5 of 36 ATI'ACHMENT 2 TO AEP:NRC:1166AI Fi ure 3-3 As Found DSI Population D.C.Cook SG13 04/97 1R97 80 70-60 50 c O ,6 40'5 E 3O 20 10 0 0.1 0.2 0.3 0.4 0.6 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.6 1.6 1.7 1.8 1.9 2.0 Bobbin Volts Fi ure 3-4 As Found DSl Population D.C.Cook SG 14 04/97 1R97 70 10 0 0.1 0.2 0.3 0.4 O.S 0.8 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1A 1.S 1.8 1.7 1.8 1.9 2.0 Bobbin Volts Page 16 of 36 ATTACHMENT 2 TO AEP:NRC:1166Ai Fi ure 3-5 As Found DSI Population D.C.Cook AII SG's 04/97 1R97.I1 100-50-~---0*0.1 0.2 0.8 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.2 1.4 1.5 1.6 1.7 1.8 1.9 2.0 Bobbin Volts Page l7 of 36

ATI'ACHMENT 2 TO AEP:NRC:1166AI Fi ure 3-6 Returned to Service DSls D.C.Cook SG11 04/97 1R97 45 40 35 30-25 20 15 10 0 0.1 0.2 0.3 OA 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 Bobbin Volts Figure 3-7 Returned to Service DSis D.C.Cook SG 12 04/97 1R97 55 45 40 3O 20-15 10 0 0.1 0.2 04 OA 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1A 1A 1.5 1.6 1.7 1.8 1.9 2.0 Bobbin Volts Page l8 of 36

~.AVl'ACHMENT 2 TO AEP:NRC:1166AI Fi ure 3-8 Returned to Service DSls D.C.Cook SG13 04/97 1R97 65 60-55 50 45 co 40 35 30 s s 25-R 20 15 10 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1A 1.5 1.6 1.7 1.8 1.9 2.0 Bobbin Volts 65 60 55 50 45 ee 40 35 o 30>25 20 15 10 Fi ure 3-9 Returned to Service DSls D.C.Cook SG14 04/97 1R97 0 0.1 0.2 0.3 OA O.S 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.$1A 1.5 1.6 1.7 1.8 1.9 2.0 Bobbin Volts Page 19 of 36

'ATTACHMENT 2 TO AEP:NRC:1166AI Fi ure 3-10 Roturnod to Sorvico DSls D.C.Cook All SGs 04/97 1R97 0 0.1 0.2 0.8 0.4 0.5 0.8 0.7 0.8 0.9 1.0 1.1 1.2 1.8 1A 1.$1.8 1.7 1.8 1.9 2.0 Bobbin Volts Page 20 of 36

ATTACHMENT 2 TO AEP:NRC:1166AI Fi ure 3-11 DSI Growth D.C.Cook SG 11 04/97 1R97 Ol 0 too i 0 I, 7F (1 Voltage Bin 0.6 0.9 Fi ure 3-12 DSI Growth D.C.Cook SG 12 04/97 1R97 250 t9 100 50-*--0-Voltage Bin 0.6 0.9 Page 21 of36 ATI'ACHMENT 2 TO AEP:NRC:1166AI Fi ure 3-13 DSI Growth D.C.Cook SG 13 04/97 1R97 100-0 0 Voltage Bin 0.6 Fi ure 3-14 DSI Growth D.C.Cook SG 14 04/97 1R97 100.0 Voltage Bin 0.6 0.9 Page 22 of 36 ATTACHMENT 2 TO AEP:NRC:1166AI Fi ure 3-15 DSI Growth D.C.Cook All SG's 04/97 1R97 8 400 200~~-~II'0 Voltage Bin 0.6 0.9 P ge23of36

ATTACHMENT 2 TO AEP:NRC:1166AI 4.0 Database Applied for Safety Evaluation Report Correlation The database used for the correlation's that are applied in the analyses of this report are consistent with GL 95-05 and the NRC SER applicable to the Cook Unit 1 EOC 15 inspection.

The database used for the calculation reported in this document is the database submitted to the NRC on March 27, 1996 by DLCO.This database was interpreted as the latest"approved" industry database.Additionally, this database contains French plant data and for leakage, does not meet GL 95-05 requirements for a correlation (p value is greater than 5%), thus producing conservative leak rate results.For the MSLB leak rate correlation, the methodology used is that described in Revision 1 of WCAP-14277, for calculating the SG tube leakage from the faulted SG during a postulated MSLB event.The model consists of two major components:

(1)a model predicting the probability that a given indication will leak as a function of voltage and (2)a model predicting leak rate as a function of voltage, given that leakage occurs.This methodology is consistent with the guidance in GL 95-05.Correlation's have been developed for the evaluation of ODSCC indications at TSP locations in SGs of nuclear power plants which relate BC voltage amplitudes, free span burst pressure, probability of leakage and associated leak rates.The methodology used in the calculation of these parameters, is consistent with NRC criteria and guidelin'es of GL 95-05.The analysis process starts with the receipt of BC voltage from the site ECT inspection team.The site data consists of electronic files which include row, column, TSP identification number, and BC voltage.The data is sorted by BC voltage into"voltage bins" consisting of number of indications in discrete voltage ranges in increments of 0.1 volt, constitutes one major component of input for the subsequent voltage distribution, leak and burst probability calculations.

The reference to"volts" in this report invariably applies to"voltage bins," when cited to one significant digit after the decimal, i.e.1.8 volts.The true value of an indication would be cited to two significant digits aAer the decimal, i.e., 1.71 volts.The calculation consists of determining the initial conditions, the BC indication population distribution, projecting the indication growth over the operating period, and then evaluating the tube leak and burst probabilities at the end of the operating period.Since indication growth is considered proportional to the operating time, the limiting tube conditions occur at the end of any given time period or cycle.Page 24 of 36 ATl'ACHMENT 2 TO AEP:NRC:1166AI 5.0 Leak Rate and Probability of Burst A Monte Carlo simulation was used to predict the EOC 16 voltage distributions and to calculate the MSLB leak rates and tube burst probabilities for both the actual EOC 15 voltage distribution and the predicted EOC 16 voltage distribution.

These methods are consistent with the requirements of the Cook Unit 1 NRC SER and the generic methods report of WCAP-14277.

Based on the NRC SER recommended leak rate data base, the leak rate in the March 27, 1996 DLCO letter to the NRC which provided supplemental tube pull data supporting the alternate'ube plugging criteria, does not satisfy the requirement for applying the MSLB leak rate verses BC voltage correlation.

The NRC requirement is that the p value obtained from the regression for the slope parameter be less that 5%.For the NRC recommended data, the p value of 6.5%and leak rate versus voltage correlation is not applied.The MSLB leak rate correlation applied is based on an average of all leak rate data jndependent of voltage.The analysis is similar to that of draft NUREG-1477 except for the uncertainty treatment.

For the case of the burst pressure versus voltage correlation, the database contained in the aforementioned DLCO letter meets all GL 95-05 requirements and was used in cycle 16 calculations.

Material properties were also considered as part of the calculations and were obtained from a December 13, 1996 Westinghouse letter and advance copy of WCAP 14277'evision 1 (AEP-96-183).

Table 5-1 Effect of Additional Data on the 7/8" Tube Burst Pressure vs.Bobbin Amplitude Correlation P~=ai+a~log(Volts)

Parameter+Error N (data pairs)p Value for o,2 Reference 0'f Database 8.278-2.584 81.8%0.9034 80 1.3x10 75 lue to which all d Notes: (1)This is the fl lized rior to erf here ression anal sis.This aff ow stress va ata was norma p p orming t g y ects the coefficient and standard error values.The corresponding values for a flow stress of 75.0 ksi can be obtained from the above values by multiplying by 1.0904.Page 25 of 36 ATTACHMENT 2 TO AEP:NRC:1166AI Table 5-2 7/8" Tube Probability of Leak Correlation Pr(Leak)=(l+e~'+~'g}'arameter V V22 DoF Deviance Pearson SD Database'6.2269 7.7739 2.2911-2.6004 3.2955 107 28.90 59.4%Notes: (I)Parameters V;;are elements of the covariancc matrix of the coenicients, pi, of the regression equation.(2)Degrees of freedom.Table 5-3 Leak Rate Database for 7/8" Tube ARC Applications Parameter Sample Size Sample p Sample cz p Value Leak Rate (Iph)Database 27 13.32 20.84 Log (Leak Rate)'atabase 27 0.5696 0.8188 6.4%Notes: (I)It has been previously shown that a log-normal distribution can be used to describe the population of leak rates.6.0 Bobbin Voltage Distributions The number of BC voltage indications used to predict tube leak rate and burst probability is obtained by adjusting the number of reported indications to account for non-detected cracks which could potentially leak or rupture under MSLB conditions during the next cycle.This is accomplished by using a probability of detection factor.Adjustments are also made for indications either removed from or returned to service.The calculation of projected bobbin voltage frequency distribution is based on a net total number of indications returned to service and is defined as: Page 26 of 36 ATTACHMENT 2 TO AEP:NRC:1166AI Ni NTeeRTR-Nrepeir d+Nde ie ed POD ep ugge Where: Ntot RT/S=Number of BC indications returned to service for the next cycle.N;POD Nrepaired Ndeplugged

=Number of BC indications reported from last cycle inservice tubes.=Probability of Detection.

Number of N;which were repaired (plugged)after the last cycle.=Number of previously plugged tubes were deplugged and returned to service.GL 95-05 requires the application of a POD=0.6 to define the BOC distribution for the EOC voltage projections, unless an alternate POD is approved by the NRC.6.1 Cycle Operating Time The operating periods used in the previous and current voltage projection calculations are: Cycle 12=455 EFPD Cycle 13=444.2 EFPD Cycle 14=390.54 EFPD Cycle 15=429.06 EFPD Cycle 16 (projected)

482 EFPD equals 1.32 EFPY.6.2 Calculation of Voltage Distributions BC voltage projections start with a cycle initial voltage distribution which is projected to the corresponding.

cycle final voltage distribution, based on the growth rates for each of the Unit 1 SG's during the previous two operating periods, as represented by their cumulative probability distribution functions.

The 1995-1997 (cycle 15)growth rates were combined with those of the 1994-1995 (cycle 14)operation and are used to predict the EOC 16 bobbin voltage distributions.

Growth rates were based upon steam generator specific voltage growth from cycle 14 and 15, in order to meet GL 95-05 requirements.

The simulation for determining EOC voltages is consistent with the methods presented in the aforementioned AEP-96-183.

For each SG, the initial BC voltage distribution of indications being returned to service for the next cycle (BOC-16)is derived-from the actual EOC 15 inspection results adjusted for tubes that are either (a)taken out of service by plugging, or (b)have been recovered for cycle 16 by deplugging of tubes plugged in previous outages on the basis of prior repair criteria.Note: No tubes were deplugged and returned to service for the BOC-16.The cycle 16 bobbin Page 27 of 36

ATFACHMENT 2 TO AEP:NRC:1166AI voltage population, summarized on Table 3-1, shows EOC 15 bobbin voltage indications; the subsequent plugged indications (which were in service for cycle 15 and then taken out of service, albeit not for reasons of ODSCC at TSP);and also shows the BOC-16 indications corresponding to PODs of 0.6 and the EPRI lower 95%confidence limit.6.3 Predicted EOC 16 Voltage Distributions Calculation of the predicted EOC 16 BC voltage distributions was performed for all SGs with two different detection factors represented by: POD=0.6, in accordance with NRC direction.

POD=EPRI, a voltage based probability developed by EPRI Using the methodology previously described, analyses were performed to predict the performance of the Unit 1 SGs at EOC 16, based on the BOC-16 summarized in Table 3-1 and the estimated cycle 16 growth distribution.

The EPRI developed voltage dependent POD is based on expert opinion and multiple analysts'valuations for the plants with 3I4" diameter tubes.The EPRI POD is applied for sensitivity analysis and for comparison with POD=0,6.The BOC-16 ARC voltage distributions are summarized on Table 6-1, for POD=0.6, and for the EPRI POD which is the order of decreasing detection uncertainty.

The POD=0.6 is sufficiently small to conservatively account for both undetected and new indications formed during the next operating cycle.Since the net adjustment from the POD is applied to obtain the BOC distribution, the number of indications does not further increase over the operating cycle.As anticipated, the limiting SG is SG 11 with 344 indications predicted for POD=0.6.For each generator, the BOC 16 actual and the EOC 16 predicted bobbin voltage frequency distributions are shown on Figures 6-1, 6-2, 6-3 and 6-4 respectively.

The maximum bobbin voltage predicted for EOC 16 is 2.4 volts for POD=0.6 in SG 14.6.4 Comparison of Predicted and Actual EOC 15 Voltage Distribution The actual EOC 15 bobbin voltage distributions and the corresponding predictions, summarized on Table 6-1 provide a comparison of detection probability factors represented by the two PODs used in the EOC 15 predictions.

As expected, using the POD of 0.6 provides a conservative estimate for the larger ()1.0 volt)indications in each steam generator compared to the EPRI POD.The EPRI POD provides a better estimate in the number of large indications expected at the next cycle because of the higher individual POD of the large indications.

Page 28 of36 I ATTACHMENT 2 TO AEP:NRC:1166AI The frequency table generated by the Monte Carlo analysis was used to determine the number of indications at EOC 16.Figures 6-1, 6-2, 6-3 and 6-4 represent the projected number of indications per voltage bin for the EOC 16.Table 6-2 summarizes the estimated distributions at EOC 16 for each steam generator.

These distributions are considered as a conservative estimate for the projected population of indications at EOC 16.Page 29 of 36

ATTACHMENT 2 TO AEP:NRC:1166AI Table 6-1 EOC 15 Actual and Pro ected Indications Steam Voltage Actual Generator 11 Projected With Steam Voltage Actual Generator 12 Projected With Bin EOC-15 POO~0.6 POO>EPRI Bin E0G.15 POD~0.6 POO~EPRI 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 Total>1V 17 62 73 59 42 28 28 13 16 12 369 31 0.1 1.7 6.1 20.5 39.4 46.1 45.7 42.0 36.0 29.0 23.1 17.0 12.0 8.2 5.5 3.7 2.5 1.7 0.7 0.1 0.7 0.0 0.3 344 77 0.1 3.1 8.5 23.4 41.4 46.0 43.0 37.4 30.5 24.1 18.3 1 3.2 9.3 6.3 4.1 2.7 1.8 1.2 0.8 0.3 0.0 0.7 0.3 0.0 317 59 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 Total>1V 14 25 21 24 21 14 10 169 0.1 2.6 8.1 14.8 1 8.5 21.6 23.5 22.8 20.6 1 7.9 14.5 8.5 6.7 5.5 4.4 3.2 2.2 1.4 0.8 0.1 0.7 0.0 0.3 210 59 0.2 4.7 11.6 1 8.0 20.4 21.7 21.9 20.1 17.3 14.5 1 1.5 8.7 6.5 5.2 4.3 3.4 2.5 1.7 0.5 0.0 0.7 0.3 0.0 196 46 Ste am Generator 13 F-tg~%" S tea m Generator 14 Voltage Actual tn Projected With Voltage Aclual In Projected With 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 Total>1V 13 18 40 29 15 160 0.0 0.9 4.1 1 0.4 17.7 21.9 22.2 19.2 14.8 1 1.3 8.9 7.0 5.4 3.9 2.6 1.6 0.9 0.1 0.7 0.0 0.3 0.0 154 31 0.0 1.7 5.6 12.1 18.8 21.8 20.9 17.2 1 2.7 9.3 7.0 5.5 4.2 3.0 2.0 1.2 0.5 0.0 0.7 0.3 0.0 0.0 145 24 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 Total>1V 22 56 63 69 34 28 28 14 16 355 30 0.0 1.5 1 1.2 23.7 32.7 40.5 43.4 39.1 31.9 25.3 1 9.3 14.3 1 0.4 7.3 5.0 3.3 2.0 1.2 0.5 0.0 0.7 0.3 314 64 0.1 2.4 1 5.2 28.1 35.4 40.4 40.6 34.8 27.1 20.5 15.2 7.9 5.5 3.7 2.4 1.5 0.9 0.1 0.7 0.0 0.3 294 49 Page 30 of 36 ATl'ACHMENT 2 TO AEP:NRC:1166AI Table 6-2 EOC 16 Projected Indications Voltage Bin Steam Generator 12 14 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 Total>1V 0.00 7.17 39.18 79.00 90.65 81.97 66.33 52.58 40.85 31.62 25.06 19.50 14.35 9.93 6.50 4.11 2.54 1.55 0.93 0.54 0.30 0.16 0.09 0.04 0.02 575 86 0.48 7.11 23.15 33.25 33.94 32.92 28.53 21.95 16.40 13.12 11.23 9.71 8.02 6.14 4.36 2.95 1.97 1.31 0.87 0.56 0.35 0.21 0.12 0.07 0.04 259 48 0.53 7.53 20.68 38.38 49.08 39.53 28.26 20.17 14.23 9.66 6.41 4.32 2.94 2.00 1.32 0.82 0.47 0.25 0.12 0.05 0.02 0.01 0.00 0.00 0.00 247 19 0.00 6.62 35.17 70.05 85.05 79.31 62.21 48.49 37.41 28.32 21.75 16.53 11.87 8.02 5.27 3.48 2.34 1.56 1.00 0.61 0.36 0.20 0.10 0.05 0.03 526 73 Page 31 of 36 ATI'ACHMENT 2 TO AEP:NRC:1166AI Figure 6-1 SG 11 EOC 16 100-, 90'0 f--c 70*----C 50 i=----o 9)I 40 t-30 t-20 4-10 t-0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1,7 1.8 1.9 2 2.1 2.2 23 2.4 2.5 2.6 2.7 2.8 2.9 3 Bobbin Voltage Figure 6-2 SG 12 EOC16 90'0 CO 0 9)9'a C 70'2 6 50" 0 40 40 30 E 20 10 f~~-0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 Bobbin Voltage Page 32 of 36 ATTACHMENT 2 TO AEP:NRC:1166AI Figure 6-3 SG 13 EOC 16 100 90 t 50 4-c 70 o 60 0 40 30 0.1 02 0.3 0.4 0.5 0,6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 Bobbin Voltago Figure 6-4 SG 14 EOC 16 100 90~80~---~-'0 60-L-5 50-0 40-E'2 30 20 0,1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0,9 1 1,1 1,2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 Bobbin Voltage Page 33 of 36

7 ATTACHMENT 2 TO AEP:NRC:1166AI 7.0 Tube Leak Rate and Tube Burst Probabilities Correlation's have been developed for the evaluation of ODSCC indications at TSP locations in steam generators of nuclear power plants which relate bobbin voltage amplitudes (either measured or calculated), free span burst pressure, probability of leakage and associated leak rates.The methodology used in the calculation of these parameters is consistent with NRC criteria and the guidelines of GL 95-05.7.1 Predicted and Actual Leak Rate and Tube Burst Probability for EOC 15 Using the methodology previously described, analyses were performed to calculate EOC 15 MSLB tube leak rate and probability of burst for the actual bobbin voltage distribution at EOC,15 (with no growth projections applied)previously presented in this report.The results of Monte Carlo calculations performed for the actual voltage distributions are compared to the prior prediction reported in our Cook Unit 1 1995 Interim Plugging Criteria Report (December 1995), as shown on Table 7-1.Comparison of the EOC 15 actual to the corresponding predictions indicates that: i a)SG 11 was predicted to be the most limiting steam generator for cycle 15.b)Based on actual ECT bobbin measurements at EOC 15, SG 11 has slightly more total (615 vs.592)indications than SG 14.c)The SG 11 tube leak rate (0.42 gpm)during a postulated MSLB at EOC 15 is lower than predicted for the required POD=0.6 for SG 14 (0.59 gpm).Even though leak rates are not significant at such low values.The MSLB leak rate of 0.42 gpm calculated from the actual EOC 15 voltage distribution is well below the Unit 1 allowable limit of less than 8.4 gpm.d)The EOC 15 probability of burst prediction of 1.9 x 10 is conservative compared to the that based on actual ECT bobbin measurements (1.6 x 10)and well below the reporting threshold of 1.0 x 10.e)The EOC 15 predictions based on POD=0.6 are higher when compared to the results based on EOC 15 actual conditions.

This shows the conservatism that is built into the prediction models.Table 7-1 includes the EOC 15 predicted values from the Cook Unit 1 1995 IPC 90 day report that used the current NRC approved data and exclusion criteria.Page 34 of 36 ATTACHMENT 2 TO AEP:NRC:1166AI 7.2 Leak Rate and Tube Burst Probability for EOC 16 Using the methodology previously described, calculations have been conducted to predict the performance of the limiting SG in Unit 1, with the BC voltage distributions predicted for EOC 16.Results of the EOC 16 predictions, summarized on Table 7-1, indicate that there are not major differences between the four SGs during the postulated MSLB conditions, since the tube leak rate and burst probability calculation results are so low.As shown on Table 7-1, the maximum difference in predicted EOC 16 MSLB tube leakage between the four SGs is 0.72 gpm, with the POD=0.6 as the most conservative.

The corresponding range in number of single tube bursts, for all four steam generators varies from 1 to 5.1, in 500,000 Monte Carlo simulations and they are not as meaningful since the burst probabilities are so small.The limiting SG for cycle 16 for Unit 1 is expected to be SG 11.With the NRC endorsed POD=0.6, the predicted EOC 16 MSLB leak rate for SG 11 is calculated as 0.96 gpm, whereas, SG 12 produces 0.47 gpm, SG 13 produces 0.24 gpm and SG 14 produces 0.86 gpm.The highest probability of burst occurs in both SG 11 and SG 14 at 1.2 x 10.These results are well below the Cook Unit 1 allowable MSLB limit of 8.4 gpm and the reporting guideline for tube burst probability of 1.0 x 10.Page 35 of 36 gf ATTACHMENT 2 TO'AEP:NRC:1166AI Table 7-1 D C Cook Unit 1 1997 RFO Summary of MSLB Tube Leak Rate and Burst Probability Steam Genarator POD Number of Indications Max Voits POB¹tubes MSLB Leak Rate EOC-15 Predicted 0.6 EPRI 344 2.4 317.2.3 1.9E-05 1 1.9E-05 1 0.7 0.57 12 0.6 210 2.4 2.3E-05 1.7 0.5 12 EPRI 196 2.3 2.5E-05 2 0.39 13 13 14 0.6 EPRI 0.6 154 145 314 2.1 2.0 2.2 2.9E-05 2.7 0.24 2.5E-05 2 0.19 2.7E-05 2.3 0.59 14 EPRI 294 EOC-1 2.2 5 Actua 1.9E-05 1 0.47 NA 371 1.8 1.6E-05 3 0.42 12 13 NA NA 169 160 1.9 1.7 9.7E-06 1 6.0E-06 0 0.25 0.11 14 NA 358 1.8 1.6E-05 3 0.40 EOC-16 Predict ed 0.6 EPRI 575 2.2 566 2.1E-05 5 0.96 1.3E-05 2 0.76 12 0.6 259 23 1.2E-05 1.7 0.47 12 EPRI 253 1.9 1.3E-05 2 0.33 13 0.6 247 2.1 9.7E-06 1 0.24 13 EPRI 252 1.6 1.6E-05 3 0.18 14 0.6 526 2.5 2.1E-05 5.1 0.86 14 EPRI 521 1.8 1.5E-05 2.7 0.67 1 Voltages include ECT uncertainties from Monte Carlo analyses and exceed measured voltages.Page 36 of 36 ATTACHMENT 3 TO AEP:NRC:1166AI COOK STEAM GENERATORS U1R97 TUBE SAMPLE RESULTS ATTACHMENT 3 TO AEP:NRC:1166AI TUBE SAMPLE RESULTS During U1R97, tube R8C19 was removed from steam generator 12 to below the fourth TSP.Non destructive testing has been completed, however, destructive examination of the tube specimen remains in progress.Concerning the non destructive examination, macrophotography of the tubesheet and support plate regions has been performed as well as stereovisual examination in the support plate region.No unusual conditions or unexpected conditions were noted during these examinations.

Helium leak testing ha~also been completed with no detectable leakage observed.Eddy current testing has been completed.

While comparisons between field and laboratory results have not been finalized, general results indicate a favorable correlation.

Destructive examinations remain in progress.Leakrate testing, simulating normal and main steam line, break pressures has been completed with no indication of through wall leakage.Burst testing has been completed with the second TSP intersection specimen bursting at 9356'psi.Due to mechanical and procedural test problems, the automatic burst pressure measurement on the first TSP intersection was not recorded.Visual observation of a mechanical pressure gauge noted the minimum burst pressure exceeded 7000 psi.Examinations to date point to a combination of OD originated intergranular attack and axially oriented stress corrosion cracking randomly spaced around the tube circumference.

Page 1 of 1 ATTACHMENT 4 TO AEP:NRC:1166AI ACRONYM LISTING 0

f ATTACHMENT 4 TO AEP:NRC:1166AI ARC APC AVB BC BOC Blo'PDF CFR DLCO DSI ECT EFPD EFPY ECT EOC FTI GL GPD GPM HEJ LRT MSLB NDD NDE NOP NQI ODSCC'EM POD PTI PWSCC RG RPC RR RRT RT RTS SER SG TEH TS T/S TSC TSH TSP TTS UEZ URT UUE U1R9X ACRONYM LISTING nction indication king Page 1 of 1 Alternate repair criteria Alternate plugging criteria Anti-vibration bar Bobbin coil Beginning of cycle Bottom of roll transition Cumulative probability distribution fu Code of Federal Regulations Duquesne Light Company Distorted support signal with possible Eddy current testing Effective full power day Effective full power year Eddy current testing End-of-cycle Framatome Technologies Incorporated Generic letter Gallons per day Gallons per minute Hybrid expansion joint Lower roll transition Main steam line break No detectable degradation Non destructive examination Normal operating pressure Non-quantifiable indication Outside diameter stress corrosion crac Original equipment manufacturer Probability of detection Parent tube indication Primary water stress corrosion cracking Regulatory guide Rotating pancake coil Reroll Reroll roll transition Roll transition Return to service Safety evaluation report Steam generator Tube end hot Tubesheet Technical specifications Tubesheet cold Tubesheet hot Tube support plate Top-of-tubesheet Upper expansion zone Upper roll transition Upper expansion Unit 1 refueling outage in 199X P'C'g