ML051030178
| ML051030178 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 01/17/2005 |
| From: | Florida Power & Light Co |
| To: | NRC/NRR/DLPM |
| Moroney B, NRR/DLPM, 415-3974 | |
| Shared Package | |
| ML051030078 | List: |
| References | |
| TAC MC5538 | |
| Download: ML051030178 (44) | |
Text
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 FLORIDA POWER & LIGHT ST. LUCIE UNIT 2 STEAM GENERATOR INSPECTION STATUS ATTACHMENT E 1
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 AGENDA g Inspection Status g Inspection Findings g Condition Monitoring Results g Completion of Remaining Inspections g Operational Assessment Plans g Summary & Closing 2
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Opening Comments g Conservative Approach to Degradation g Compliance with Technical Specifications & NEI 97-06 g Reasonable Assurance of Tube Integrity g Conservative In Situ Pressure Test History g SL2-15 Inspection results bounded by OA Model g OA Model is conservatively predicting the observed distribution of detected flaws 3
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 St. Lucie Unit 2 S/G 8 CE Model 3410 8 8411 Tubes / SG 8 ~18.3 EFPY @ SL2-15 8 A-600 HTMA Tubing 8 CS Lattice Support System 8 Tubesheet Joint - Explosive 8 Total Tubes Plugged SG A - 671 (8.0%)
SG B - 872 (10.4%)
8 T-Hot ~600oF 4
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Inspection Status g Scope Previously Discussed & Reviewed with Staff g Planned Bobbin Inspection Scope Complete 8100% Bobbin Full Length Row 3> and Straight Length Row 1-2 8Screen Dings <5 volts g Planned Plus Point Probe Scope Complete 4 100% Hot Leg Top-of-Tubesheet +3/-13 8Cold Leg Periphery Tubes for FO Damage 8 35% Row 1-2 U-bends 8100% Wear Scars at Eggcrates & HL Diagonal 8 20% Wear Scars at U-bends & CL Diagonal 8All Tubes with No Tube Expansion 5
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Inspection Status g Plus Point Probe for Dings Complete SGA SGB 8 All Dings Hot Leg Tubesheet to 1st Support 43 24 8 All Dings >5 volts 1st Support to HL Bend 98 77 8 All Dings in HL & CL Square Bends Row 19-140 68 54 8 All Dings >5 volts in Horizontal Run Row 19-140 97 107 8 All Dings in Rows 1-18 U-Bends 140 104 8 20% Dings >5 volts CL Tubesheet to CL Bend 26 23 472 389 g Visual Inspection of Plugs Complete 6
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Inspection Findings - Pluggable Tubes ID Circumferential (1st observation) 1 ID Axial 2 OD Axial Expansion Transition 15 OD Circumferential Expansion Transition 17 OD Axial Supports 877 OD Axial Freespan 0 OD Volumetric 0 Mechanical Wear 1 Preventative 0 g Increase in Diagnostic Plus Point Inspections 8S/G 2A Approximately 300 Remaining 8S/G 2B Approximately 650 Remaining 7
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Inspection Findings g Bobbin data quality excellent (no masking deposits) 4Reporting criteria more conservative than Industry ETSS 4Impact of improved analyst training & testing materials 4Projection of 1100 - 1600 indications 4Observing ~ 2200 indications (confirmed) g New MIZ-70 Higher Speed Test Capability 4+PointTM Inspections of U-bends, Tubesheet & Bobbin I-Codes 4Pull out scan after Bobbin I-Code has tighter helix (<0.25) 4Was 900 rpm at ~10 ips, now 2800 rpm at ~10 ips 4RCL Indications not reported by bobbin probe 4~ 16% of lower hot leg eggcrates supports affected 4Consistent with expectations 4Additional indications will be plugged 8
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Inspection Findings g Recent NRC GL 2004-01 g LAR on Tubesheet Inspection Depth g Depth of 10.1 below expansion transition or top of tubesheet, which ever is lower 4Variation in transition relative to top of tubesheet 4 Additional margin 4Depth of 13 below top of tubesheet inspected 9
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Summary of Indications Below the Expansion Transition RFO Exam Max Max ISPT Date Depth Orientation S/G Row Col Elev Inch %TW AxLen Volts Test Apr-97 ~2" Axial A 34 102 TSH -1.06 99 0.22 0.40 Nov-98 ~2" Axial -- -- -- -- -- -- -- --
Apr-00 2" Axial A 40 116 TSH -0.14 97 0.16 0.47 Nov-01 5" Axial A 39 103 TSH -1.82 66 0.16 0.32 Yes Nov-01 5" Axial A 39 103 TSH -2.05 58 0.2 0.38 Yes Apr-03 8" Axial A 27 107 TSH -0.56 49 0.16 0.47 Apr-03 8" Axial A 29 105 TSH -1.31 43 0.1 0.34 Apr-03 8" Axial A 29 105 TSH -1.89 60 0.18 0.46 Apr-03 8" Axial A 29 105 TSH -1.74 59 0.18 0.47 Apr-03 8" Axial A 29 105 TSH -1.53 51 0.18 0.48 Apr-03 8" Axial A 42 110 TSH -1.43 69 0.25 0.50 Apr-03 8" Axial B 63 103 TSH -0.27 85 0.27 0.23 Yes Apr-03 8" Axial B 63 103 TSH -0.10 55 0.14 0.57 Yes Jan-05 13" Axial A 29 103 TSH -1.43 32 0.18 0.24 Jan-05 13" Axial B 60 108 TSH -0.14 71 0.17 0.60 Jan-05 13" Circ B 49 111 TSH -0.22 58 0.17 0.15 Exam Scope is 100% of HL for all inspections listed 10
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 CONDITION MONITORING Voltage Distribution for DSIs PSL-2 SGA 01/05 SL2-15 1000 1.0 800 0.8 Number of DSIs 600 0.6 CPDF Number of DSIs 400 0.4 SL2-15 CPDF SL2-14 CPDF 200 0.2 Bobbin Exam 97.11 % Complete 0 0.0
<=0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 >2 Bobbin Volts 11
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 CONDITION MONITORING Voltage Distribution for DSIs PSL-2 SGB 01/05 SL2-15 1000 1.0 800 0.8 Number of DSIs 600 0.6 CPDF Number of DSIs 400 0.4 SL2-15 CPDF SL2-14 CPDF 200 0.2 Bobbin Exam 99.99 % Complete 0 0.0
<=0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 >2 Bobbin Volts 12
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Confirmed Bobbin DSI Voltage - Historical Comparisons Bobbin Voltage for Confirming DSI Indications - SG A Bobbin Voltage for Confirming DSI Indications - SG B 1.0 1.0 0.9 0.9 0.8 0.8 0.7 0.7 Cumulative Distribution Cumulative Distribution 0.6 0.6 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 SG A (2003) SG B (2003) 0.1 0.1 SG A (2005) SG B (2005) 0.0 0.0 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 Bobbin Volts Bobbin Volts 13
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Condition Monitoring Results - Circ Indications S/G 2A PSL-2 SG A Circumferential ODSCC at Top of Tubesheet - January 2005 100 Leak Screening 90 Burst Screening TW Structural Limit 80 <0.5 Volts
>=0.5 Volts Maximum Depth, dmax (%TW) 70 60 50 40 30 20 10 0
0 30 60 90 120 150 180 210 240 270 300 330 360 Angle, (degrees) 14
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Condition Monitoring Results - Circ Indications S/G 2B PSL-2 SG B Circumferential ODSCC at Top of Tubesheet - January 2005 100 Leak Screening 90 Burst Screening TW Structural Limit 80 <0.5 Volts
>=0.5 Volts Maximum Depth, dmax (%TW) 70 60 50 40 30 20 10 0
0 30 60 90 120 150 180 210 240 270 300 330 360 Angle, (degrees) 15
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Condition Monitoring Results - ID Circ Indication PSL-2 SG B Circumferential IDSCC at Top of Tubesheet - January 2005 100 Leak Screening 90 Burst Screening TW Structural Limit 80 < 0.5 volt
>= 0.5 volt Maximum Depth, dmax (%TW) 70 60 50 40 30 20 10 0
0 30 60 90 120 150 180 210 240 270 300 330 360 Angle, (degrees) 16
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 CM Results - Axial Indications at TTS PSL-2 SG B Axial IDSCC Below Top of Tubesheet - January 2005 PSL-2 SG A Axial ODSCC at Top of Tubesheet - January 2005 100 100 Leak Screening Leak Screening 90 Burst Screening 90 Burst Screening TW Structural Limit TW Structural Limit
<0.5 Volts <0.5 Volts
>=0.5 Volts 80 80 >=0.5 Volts 70 70 Maximum Depth, dmax (%TW) Maximum Depth, dmax (%TW) 60 60 50 50 40 40 30 30 20 20 10 10 0 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Axial Degradation Length, L (in) Axial Degradation Length, L (in) 17
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 CM Results - Eggcrate Indications Bobbin Detected S/B 2A PSL-2 SG A Axial ODSCC at Eggcrates - January 16, 2005 PSL-2 SG A Axial ODSCC at Eggcrates - April 2003 100 100 Leak Screening Leak Screening Burst Screening 90 Burst Screening 90 TW Structural Limit TW Structural Limit <0.5 Volts
<0.5 Volts >=0.5 Volts 80
>=0.5 Volts 80 70 70 Maximum Depth, dmax (%TW) Maximum Depth, dmax (%TW) 60 60 50 50 40 40 30 30 20 20 10 10 0 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 Axial Degradation Length, L (in) Axial Degradation Length, L (in) 18
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 CM Results - Eggcrate Indications Bobbin Detected S/G 2B PSL-2 SG B Axial ODSCC at Eggcrates - January 16, 2005 PSL-2 SG B Axial ODSCC at Eggcrates - April 2003 100 100 Leak Screening Leak Screening Burst Screening 90 Burst Screening 90 TW Structural Limit TW Structural Limit
<0.5 Volts
<0.5 Volts >=0.5 Volts 80 >=0.5 Volts 80 70 70 Maximum Depth, dmax (%TW) Maximum Depth, dmax (%TW) 60 60 50 50 40 40 30 30 20 20 10 10 0 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 Axial Degradation Length, L (in) Axial Degradation Length, L (in) 19
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 RCL Eggcrate Indications - Initial Sample PSL-2 SG A Axial ODSCC at Eggcrates - January 16, 2005 PSL-2 SG B Axial ODSCC at Eggcrates - January 16, 2005 100 100 Leak Screening Leak Screening 90 Burst Screening Burst Screening 90 TW Structural Limit TW Structural Limit
<0.5 Volts <0.5 Volts
>=0.5 Volts >=0.5 Volts 80 80 RCL Indications RCL Indications 70 70 Maximum Depth, dmax (%TW) Maximum Depth, dmax (%TW) 60 60 50 50 40 40 30 30 20 20 10 10 0 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 Axial Degradation Length, L (in) Axial Degradation Length, L (in) 20
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Condition Monitoring Results - Eggcrate Indications Calculated Lower 5% Burst Pressures (as of Jan 16, 2005) 1.0 SG A DSIs 0.9 SG B DSIs SG A RCLs 0.8 SG B RCLs 0.7 3xNOPD Cumulative Distribution 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 Burst Pressure (psi) 21
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05
+PointTM Voltage Correlation For RCL Indications VOLTAGE MEASUREMENT VARIATION
- INDUCED BY DIFFERENCES IN HELICAL PITCH
- COMPARITIVE DATA FROM RCL FLAWS AT EGGCRATES
- RCL INITIAL SAMPLE WAS RETESTED WITH +PointTM QUALIFIED TECHNIQUE 22
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05
+PointTM Voltage Correlation For RCL Indications DISTRIBUTION OF VOLTAGE MEASUREMENT ERROR F{ y} = NORMAL ( -0.004051, 0.067015)
RCL FLAWS 60%
50%
40%
Percent of obs 30%
20%
10%
0%
<= -.2 (-.2,-.1] (-.1,0] (0,.1] (.1,.2] > .2 ERROR - [VOLTS(STD)-VOLTS(RCL)]
23
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05
+PointTM Voltage Correlation For RCL Indications ERROR VS. NORMAL PLUSPOINT VOLTS RCL FLAWS 0.35 0.25 0.15 ERROR 0.05
-0.05
-0.15
-0.25 0.05 0.15 0.25 0.35 0.45 0.55 0.65 PLUSPOINT VOLTS (NORMAL) 24
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05
+PointTM Voltage Correlation For RCL Indications ERROR VS. RCL VOLTS RCL FLAWS 0.35 0.25 0.15 ERROR 0.05
-0.05
-0.15
-0.25 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 VOLTS - RCL 25
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05
+PointTM Voltage Correlation For RCL Indications VOLTAGE MEASUREMENT VARIATION g STATISTICAL CORRECTION FACTOR [FOR SCREENING]
g VCORR = VRCL + CFACT g CFACT = 0.15 VOLTS (ONE SIDED 95/95) g ISPT GL CONSERVATIVE SCREENING VALUE OF 0.5 VOLTS TO BE REDUCED BY CFACT TO SCREEN RCL INDICATIONS WITH NORMAL PULL OUT SCAN AT 2800 RPM & 10 IPS 26
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISON BETWEEN ICODE AND RCL FLAWS g PLUSPOINT MEASURED DEPTHS g VOLTAGES 27
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISON BETWEEN ICODE AND RCL FLAWS DISTRIBUTION OF MEASURED FLAW DEPTHS RCL FLAWS 100.0% 100.0%
97.5%
100% 94.9%
91.1%
90%
78.5%
80%
70%
Percent of obs 60%
50%
40% 34.2%
30%
20%
10% 3.8%
0%
<= 15 (15,20] (20,25] (25,30] (30,35] (35,40] (40,45] (45,50] > 50 PEAK DEPTH - %TW 28
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISON BETWEEN ICODE AND RCL FLAWS DISTRIBUTION OF PLUSPOINT DEPTHS DSI FLAWS AT EGGCRATES 98.4% 100.0%
100%
90.3%
90%
80% 75.8%
70%
Percent of obs 60%
48.4%
50%
40%
30%
20% 14.5%
10% 3.2%
0%
<= 15 (15,20] (20,25] (25,30] (30,35] (35,40] (40,45] > 45 PEAK DEPTH - %TW 29
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISON BETWEEN ICODE AND RCL FLAWS COMPARISON OF MEASURED DEPTH DISTRIBUTIONS EGGCRATE ICODES VS. RCL FLAWS 1.1 0.9 CUMULATIVE PROBABILITY 0.7 0.5 0.3 0.1 D2005
-0.1 15 20 25 30 35 40 45 50 55 DRCL DEPTH 30
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISON BETWEEN ICODE AND RCL FLAWS DISTRIBUTION OF PLUSPOINT VOLTS RCL FLAWS 100.0% 100.0%
97.5%
100% 93.7%
87.3%
90%
80%
70%
Percent of obs 60%
48.1%
50%
40%
30%
20%
10%
2.5%
0%
<= .1 (.1,.2] (.2,.3] (.3,.4] (.4,.5] (.5,.6] > .6 PLUSPOINT VOLTS 31
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISON BETWEEN ICODE AND RCL FLAWS DISTRIBUTION OF PLUSPOINT VOLTS DSI FLAWS AT EGGCRATES 100.0%
100% 95.2%
88.7%
90%
80%
69.4%
70%
Percent of obs 60%
50%
40%
30.6%
30%
20%
10%
1.6%
0%
<= .1 (.1,.2] (.2,.3] (.3,.4] (.4,.5] > .5 PLUSPOINT VOLTS 32
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISON BETWEEN ICODE AND RCL FLAWS COMPARISON OF VOLTAGE DISTRIBUTIONS EGGCRATE ICODES VS. RCL FLAWS 1.1 1.0 0.9 CUMULATIVE PROBABILITY 0.8 0.7 0.6 0.5 0.4 0.3 V2005 0.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 VRCL PLUSPOINT VOLTS 33
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISONS OF 2003 AND 2005 DATA g PLUSPOINT VOLTAGES g PLUSPOINT DEPTHS g EGGCRATE FLAWS 34
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISONS OF 2003 AND 2005 DATA COMPARISON OF PLUSPOINT VOLTAGE CDF'S EGGCRATE FLAWS 1.1 1.0 0.9 CUMULATIVE PROBABILITY 0.8 0.7 0.6 0.5 0.4 0.3 2003 0.2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 2005 PLUSPOINT VOLTS 35
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 COMPARISONS OF 2003 AND 2005 DATA COMPARISON OF MEASURED DEPTH CDF'S EGGCRATE FLAWS 1.1 0.9 CUMULATIVE PROBABILITY 0.7 0.5 0.3 0.1 2003
-0.1 15 20 25 30 35 40 45 50 55 2005 MEASURED PLUSPOINT DEPTH 36
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Summary of Condition Monitoring g On-going tube degradation is as-expected from previous cycle OA g First observation of circumferential PWSCC at TTS (very shallow and short in length) g Additional eggcrate indications detected during pull out are expected given the more sensitive +PT probe. Voltage and sizes from retest consistent with expectations for Bobbin probe.
g Screening parameter for RCL indications based on RCL voltage has been established at 0.35 volts g Additional axial indications at eggcrates are accounted for in OA multi-cycle model 4Impact of improved training & test materials and RCL indications 37
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Completion of Remaining Inspections g Continue high speed pull out scan after test of Bobbin I-Codes 4 Provides valuable data for validating BOC population for OA Model 4 Helix pitch ensures detection of critical length flaws 4Short & deep indications at eggcrates not observed 4 Detailed +PointTM inspection if RCL screen exceeded 4 Screen Detailed +PointTM results as usual 38
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Operational Assessment g Axial ODSCC has been assessed with a probabilistic multi-cycle model since EOC 12 using Bobbin detection g Multi-cycle model accounts for the following key parameters as required to correctly characterize ODSCC:
g beginning of cycle defects remaining after inspection (i.e.,
undetected population) g initiation of new sites for ODSCC during operation g growth of defects during operation g determination of EOC defect populations and comparison to NEI 97-06 performance criteria g Model is validated through benchmarking over several cycles of St.
Lucie Unit 2 inspection data 39
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Operational Assessment g Because multi-cycle model tracks the undetected defects, the hidden population like those partially characterized by the RCL indications are addressed in the burst and leakage calculations g Predicted depth sizes are in close agreement with NDE results evaluated to date. The predictions were taken from EOC 13 OA results completed in June 2003 without modification to the run-time simulation.
g Observation of RCL indications is predicted with the existing OA model. This is an expected outcome when the better detection performance of the +PT probe is included in the inspection process.
40
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Depth Projections for EOC 15 and Comparison with 2005 Data 1.0 0.9 0.8 0.7 Cumulative Distribution 0.6 0.5 0.4 0.3 0.2 2005 Measured Depths (Jan 16, 2005) 0.1 April 2003 OA Projection for 2005 0.0 0 10 20 30 40 50 60 70 80 90 100 Maximum Depth (%TW) 41
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Depth Projections for EOC 15 Comparison for RCL Indications 1.0 0.9 0.8 0.7 Cumulative Distribution 0.6 0.5 0.4 0.3 0.2 2005 Measured Depths April 2003 OA Projection 0.1 for 2005 0.0 0 10 20 30 40 50 60 70 80 90 100 Maximum Depth (%TW) 42
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Operational Assessment Plans g Preliminary OA will be completed based on existing OA model g Bobbin probe for detection will be evaluated in final OA. It is expected that Bobbin detection performance will remain sufficient to maintain structural and leak integrity for Cycle 15.
g Confirmation of performance will be achieved through benchmarking of NDE results and validation of growth rate through historical data reviews.
43
STEAM GENERATOR INSPECTION STATUS SL2-15 NRC PHONE CALL 1/17/05 Summary & Closing g Conservative Approach to Degradation g Compliance with Technical Specifications & NEI 97-06 g Reasonable Assurance of Tube Integrity g Conservative In Situ Pressure Test History (14 eggcrates) g SL2-15 Inspection results bounded by OA Model g OA Model is conservatively predicting the observed distribution of detected indications 44