ML071360373
| ML071360373 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 05/01/2007 |
| From: | Broussard J, White G Dominion Engineering |
| To: | Office of Nuclear Reactor Regulation |
| MAURICIO GUTIERREZ, RES 301-415-1122 | |
| Shared Package | |
| ML071360367 | List: |
| References | |
| Download: ML071360373 (70) | |
Text
11730 Plaza America Dr. #310Reston, VA 20190703.437.1155 www.domeng.com Advanced FEA Crack Growth Calculations for Evaluation of PWR Pressurizer Nozzle Dissimilar Metal Weld Circumferential PWSCC Sponsored by: EPRI Materials Reliability Program Presented To:Expert Review Panel for Advanc ed FEA Crack Growth Calculations Presented By:
Glenn White John Broussard Dominion Engineering, Inc.
Tuesday, May 1, 2007 Meeting on Treatment of Welding Residual Stress DEI Offices Reston, Virginia Advanced FEA Crack Growth Evaluations:WRS Treatment 2May 1, 2007, Meeting TopicsNozzle and weld geometry cases for subject weldsCollected weld repair information for subject weldsApplication of WRS FEA models
-Previous FEA results by DEI (MRP-106)
-FEA work by Battelle and EMC2 (presentation by Dave Rudland, EMC2)
-Discussion of approach to new FEA fo r selected subject weld casesWRS data for piping butt welds in open literatureCandidate WRS profiles
-Axisymmetricprofiles
-Non-axisymmetricprofilesValidation of WRS inputsMeeting wrap-up Advanced FEA Crack Growth Evaluations:WRS Treatment 3May 1, 2007, Meeting Principal Meeting ParticipantsEPRI Project Management / Support
-Craig Harrington, EPRI
-Tim Gilman, Structural Integrity AssociatesProject Team
-Glenn White, Dominion Engineering, Inc.
-John Broussard, Dominion Engineering, Inc.Expert Review Panel
-Warren Bamford, Westinghouse (via phone)
-Pete Riccardella, Structural In tegrity Associates (via phone)
-Doug Killian, AREVA
-Ken Yoon, AREVANRC Participants
-Al Csontos, NRC Research
-Ted Sullivan, NRC NRR
-Simon Sheng, NRC NRR
-Dave Rudland, EMC2 Advanced FEA Crack Growth Evaluations:WRS Treatment 4May 1, 2007, Meeting Nozzle Geometry for Subject Plants SummaryThere are a total of 51 pressurizer DM welds of concern in the group of nine plants:
-35 safety and relief (S&R) nozzles (1 plant has only three S&R nozzles)
-8 surge nozzles (+1 already overlayed)
-8 spray nozzles (+1 examined by PDI process in 2005)
Advanced FEA Crack Growth Evaluations:WRS Treatment 5May 1, 2007, Meeting Nozzle Geometry for Subject Plants Geometry CasesA review of design drawings for the nine plants indicates the following nozzle geometry cases:
-S&R nozzles*Types 1a and 1b: W design without liner, connected to 6 pipe*Types 2a and 2b: W design with liner directly covering DM weld,connected to 6 pipe*Type 3: CE design (no liner), connected to 6 pipe-Spray nozzles*Type 4: W design with liner (does not ext end to most of DM weld), connected to 4 pipe*Type 5: W design with liner directly covering DM weld, connected to 4 pipe*Type 6: W design without liner, connected to 6 pipe*Type 7: CE design (no liner, sleeve not extending to DM weld), connected to 4 pipe-Surge nozzles*Type 8: W design (sleeve directly covers fill-in weld under nozzle-to-safe-end weld), connected to 14 pipe*Type 9: CE design (sleeve not exte nding to DM weld), connected to 12 pipe Advanced FEA Crack Growth Evaluations:WRS Treatment 6May 1, 2007, Meeting Nozzle Geometry for Subject Plants PWR Pressurizers 2 6 4 3 1 7 5 3 2 3 1 Example Westinghouse Design Pressurizer Example CE Design Pressurizer
- 1. Surge Nozzle
- 2. Spray Nozzle
- 3. Safety/Relief Nozzle Advanced FEA Crack Growth Evaluations:WRS Treatment 7May 1, 2007, Meeting Nozzle Geometry for Subject Plants S&R Types 1a and 1b: W design without liner Source: MRP 2007-003 Attachment 1 (White Paper).Wolf Creek Surge Nozzle Materials Advanced FEA Crack Growth Evaluations:WRS Treatment 8May 1, 2007, Meeting Nozzle Geometry for Subject Plants S&R Type 1a: W design without liner (6 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 9May 1, 2007, Meeting Nozzle Geometry for Subject Plants S&R Type 1b: W design without liner (6 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 10May 1, 2007, Meeting Nozzle Geometry for Subject Plants S&R Type 2a: W design with liner (6 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 11May 1, 2007, Meeting Nozzle Geometry for Subject Plants S&R Type 2b: W design with liner (6 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 12May 1, 2007, Meeting Nozzle Geometry for Subject Plants S&R Type 3: CE design Advanced FEA Crack Growth Evaluations:WRS Treatment 13May 1, 2007, Meeting Nozzle Geometry for Subject Plants S&R Type 3: CE design (no liner) (6 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 14May 1, 2007, Meeting Nozzle Geometry for Subject Plants Spray Type 4: W w/liner (not extend to most DM) (4 pipe)Wolf Creek Surge Nozzle Materials Advanced FEA Crack Growth Evaluations:WRS Treatment 15May 1, 2007, Meeting Nozzle Geometry for Subject Plants Spray Type 4: W w/liner (not extend to most DM) (4 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 16May 1, 2007, Meeting Nozzle Geometry for Subject Plants Spray Type 5: W with liner directly covering DM (4 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 17May 1, 2007, Meeting Nozzle Geometry for Subject Plants Spray Type 6: W design without liner (6 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 18May 1, 2007, Meeting Nozzle Geometry for Subject Plants Spray Type 7: CE design Advanced FEA Crack Growth Evaluations:WRS Treatment 19May 1, 2007, Meeting Nozzle Geometry for Subject Plants Spray Type 7: CE (no liner, sleeve not extend) (4 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 20May 1, 2007, Meeting Nozzle Geometry for Subject Plants Surge Type 8: W design (sleeve under fill-in weld)
Source: MRP 2007-003 Attachment 1 (White Paper).Wolf Creek Surge Nozzle Materials Advanced FEA Crack Growth Evaluations:WRS Treatment 21May 1, 2007, Meeting Nozzle Geometry for Subject Plants Surge Type 8: W design (sleeve under fill-in weld) (14 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 22May 1, 2007, Meeting Nozzle Geometry for Subject Plants Surge Type 9: CE design Advanced FEA Crack Growth Evaluations:WRS Treatment 23May 1, 2007, Meeting Nozzle Geometry for Subject PlantsSurge Type 9: CE design (sleeve not extend) (12 pipe)
Advanced FEA Crack Growth Evaluations:WRS Treatment 24May 1, 2007, Meeting Nozzle Geometry for Subject Plants Basic Weld Dimensions 0 2 4
6 8 10 12 1401 A - Re (7.75x5.17)02 A - SA (7.75x5.17) 03 A - SB (7.75x5.17)04 A - SC (7.75x5.17)05 E - Re (7.75x5.17)06 E - SA (7.75x5.17)07 E - SB (7.75x5.17)08 E - SC (7.75x5.17)09 H - Re (7.75x5.17)10 H - SA (7.75x5.17) 11 H - SB (7.75x5.17)12 H - SC (7.75x5.17)WC1 J - Re (7.75x5.17)WC1a J - Re/Sa (7.75x5.17)WC2 J - SA (7.75x5.17)WC3 J - SB (7.75x5.17)WC4 J - SC (7.75x5.17)13 F - Re (8x5.19)14 F - SA (8x5.19)15 F - SB (8x5.19)16 F - SC (8x5.19)17 B - Re (7.75x5.62)18 B - SA (7.75x5.62) 19 B - SB (7.75x5.62)20 B - SC (7.75x5.62)21 G - Re (7.75x5.62)22 G - SA (7.75x5.62) 23 G - SB (7.75x5.62)24 G - SC (7.75x5.62)25 C - Re (7.75x5.62)26 C - SA (7.75x5.62) 27 C - SB (7.75x5.62)28 C - SC (7.75x5.62)29 D - Re (8x4.937)30 D - SA (8x4.937) 31 D - SB (8x4.937)32 D - SC (8x4.937)33 I - Re (8x4.937)34 I - SA (8x4.937)35 I - SB (8x4.937)36 A - Sp (5.81x4.01) 37 E - Sp (5.81x4.01)WC5 J - Sp (5.81x4.01)38 B - Sp (5.81x4.25)39 G - Sp (5.81x4.25)40 C - Sp (5.81x4.25)41 F - Sp (8x5.695)42 D - Sp (5.188x3.062)43 I - Sp (5.188x3.25)44 A - Su (15x11.844) 45 E - Su (15x11.844)46 H - Su (15x11.844)WC6 J - Su (15x11.844)47 B - Su (15x11.844)48 G - Su (15x11.844)49 C - Su (15x11.875)50 D - Su (13.063x10.125)51 I - Su (13.063x10.125) 0 50 100 150 200 250 300 350 400 0.0 0 0.7 51.502.25 3.0 0 3.7 54.505.256.00 6.7 5 7.508.259.00 9.7 5 1 0.5011.2512.0012.7 5 13.5 014.2515.0015.7 5 16.5 017.2518.0018.75 19.5 0 20.2 521.0021.75 22.5 0 23.2 5 24.0 024.7525.5 0 26.2 5 27.0 027.7528.5 0 29.2 5 30.0 0 3 0.7531.5 032.2 5 33.0 0 3 3.7534.5 035.2 5 36.0 0 36.7 5 37.5038.2 539.0 0 39.7 5 40.5041.2 542.0 0 42.7 5 43.5044.2545.0 045.7 5 46.5047.2548.0 048.7 5 49.5 050.2551.0051.7 5 52.5 053.2554.0054.7 5 55.5 0 56.2 557.0057.75 58.5 0 59.2 560.00ID (in)OD (in)t (in)ID/t Advanced FEA Crack Growth Evaluations:WRS Treatment 25May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Summary TableDesign #Piping NPSLiner?DM Weld t (in.)DM Weld R i/tWeld Sep. (in.)Butter WeldRepairsID Weld RepairsOD Weld RepairsDesign #Piping NPSLiner?DM Weld t (in.)DM Weld R i/tWeld Sep. (in.)Butter WeldRepairsID Weld RepairsOD Weld RepairsPlant A1a6"N1.292.02.2NRNRNR1a6"N1.292.02.2NRNRR4Plant E1a6"N1.292.02.2NRNRR1a6"N1.292.02.2NRNRNRPlant H1a6"N1.292.02.2NRNRNR1a6"N1.292.02.2NRRRPlant B2a6"Y1.072.62.6NRNRR12a6"Y1.072.62.6NRNRNRPlant G2a6"Y1.072.62.6NRNRNR2a6"Y1.072.62.6NRNRNRPlant C2b6"Y1.072.62.3NRNRNR2b6"Y1.072.62.3Plant F1b6"N1.411.83.3NRNRNR1b6"N1.411.83.3Plant D36"N1.411.86.8NRNRNR36"N1.411.86.8RNRNRPlant I36"N1.411.86.8N/AN/AN/A36"N1.411.86.8N/AN/AN/APlant J1a6"N1.292.02.2Rx5R1R11a6"N1.292.02.2RR2NRNotes:1. For Designs #2a, #2b, and #5, liner directly covers DM weld.
- 2. For Design #4, liner does not extend to most of DM weld.
- 3. For Designs #4, #5, and #6, sleeve covers but does not contact DM weld.4. For Design #8, sleeve directly covers DM weld.5. For Designs #7 and #9, sleeve does not extend to DM weld.
- 6. NR = No weld repairs reported
- 7. Rn = Repairs reported (n indicates number of defect or repaired areas if reported; "x" indicates repeat weld repair operations)8. N/A = Results for fabrication records review not available9. Weld repair entries for Plants C and F are preliminary.
- 10. All pressurizer nozzle DM welds in Plant H are reported to be Alloy 82, not Alloy 82/182.Safety APlantCodeRelief R R Advanced FEA Crack Growth Evaluations:WRS Treatment 26May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Summary Table (cont'd)Design #Piping NPS Liner?DM Weld t (in.)DM Weld R i/tWeld Sep. (in.)Butter WeldRepairsID Weld RepairsOD Weld RepairsDesign #Piping NPSLiner?DM Weld t (in.)DM Weld R i/tWeld Sep. (in.)Butter WeldRepairsID Weld RepairsOD Weld RepairsPlant A1a6"N1.292.02.2NRR1NR1a6"N1.292.02.2NRNRNRPlant E1a6"N1.292.02.2NRNRNR1a6"N1.292.02.2NRRNRPlant H1a6"N1.292.02.2NRNRNR1a6"N1.292.02.2NRNRNRPlant B2a6"Y1.072.62.6NRNRNR2a6"Y1.072.62.6NRNRNRPlant G2a6"Y1.072.62.6NRNRNR2a6"Y1.072.62.6NRNRNRPlant C2b6"Y1.072.62.32b6"Y1.072.62.3Plant F1b6"N1.411.83.3NRNRNR1b6"N1.411.83.3NRNRNRPlant D36"N1.411.86.8NRNRNR36"N1.411.86.8NRNRNRPlant I36"N1.411.86.8N/AN/AN/APlant J1a6"N1.292.02.2NRR6x2NR1a6"N1.292.02.2NRNRNRNotes:1. For Designs #2a, #2b, and #5, liner directly covers DM weld.2. For Design #4, liner does not extend to most of DM weld.3. For Designs #4, #5, and #6, sleeve covers but does not contact DM weld.
- 6. NR = No weld repairs reported7. Rn = Repairs reported (n indicates number of defect or repaired areas if reported; "x" indicates repeat weld repair operations)8. N/A = Results for fabrication records review not available
- 9. Weld repair entries for Plants C and F are preliminary.
- 10. All pressurizer nozzle DM welds in Plant H are reported to be Alloy 82, not Alloy 82/182.PlantCodeSafety BSafety CNo Safety C RR Advanced FEA Crack Growth Evaluations:WRS Treatment 27May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Summary Table (cont'd)Design #Piping NPS Liner?DM Weld t (in.)DM Weld R i/tWeld Sep. (in.)Butter WeldRepairsID Weld RepairsOD Weld RepairsDesign #Piping NPSLiner?DM Weld t (in.)DM Weld R i/tWeld Sep. (in.)Butter WeldRepairsID Weld RepairsOD Weld RepairsPlant A44"Y0.902.2~2.3NRNRNR814"N1.583.83.4NRR5R3Plant E44"Y0.902.2~2.3RNRR814"N1.583.83.4NRR3NRPlant H814"N1.583.83.4NRNRNRPlant B54"Y0.782.72.2NRNRNR814"N1.583.83.4R1R1x2R2Plant G54"Y0.782.72.2NRNRNR814"N1.583.83.4NRNRNRPlant C54"Y0.782.7~2.2814"N1.563.83.5NRNRNRPlant F66"N1.152.53.6NRNRNRPlant D74"N1.061.43.3NRNRNR912"N1.473.43.0NRNRNRPlant I74"N1.061.43.3N/AN/AN/A912"N1.473.43.0N/AN/AN/APlant J44"Y0.902.2~2.3RNRNR814"N1.583.83.4R2R1NRNotes:1. For Designs #2a, #2b, and #5, liner directly covers DM weld.2. For Design #4, liner does not extend to most of DM weld.3. For Designs #4, #5, and #6, sleeve covers but does not contact DM weld.
- 6. NR = No weld repairs reported7. Rn = Repairs reported (n indicates number of defect or repaired areas if reported; "x" indicates repeat weld repair operations)8. N/A = Results for fabrication records review not available
- 9. Weld repair entries for Plants C and F are preliminary.
- 10. All pressurizer nozzle DM welds in Plant H are reported to be Alloy 82, not Alloy 82/182.PlantCodeSpray (all have thermal sleeve)Surge (all have thermal sleeve)Already PDI examinedAlready structural overlayed R
Advanced FEA Crack Growth Evaluations:WRS Treatment 28May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Weld Repair Summary TableTableLinePlantCodeNozzleTypeNozzleCountDesign#Butteringor WeldLength(in.)Depth(in.)Length(in.)Depth(in.)Length(in.)Depth(in.)Length(in.)Depth(in.)Length(in.)Depth(in.)Length(in.)Depth(in.)1ASafety A11aweldODN/AN/A4N/A~1/2N/A~1/2N/A~1/2N/A~1/22ASafety B21aweldIDN/AN/A11/25/83ERelief31aweldODN/ANN/AN/AN/A 4ESafety C41aweldID<22%N/ANN/AN/AN/A5ID82YN/AN/AN/A6OD82YN/AN/AN/A7FSafety A61bNRNRNRNRNRNRNR8BRelief72aweldOD182N/A10.50.375 9CSafety A82bNRNRNRNRNRNRNR10CSafety B92bNRNRNRNRNRNRNR11CSafety C102bNRNRNRNRNRNRNR12DSafety A113butterN/AN/AYN/AN/AN/A13butterID82YN/AN/A~0.314weldODN/ANN/AN/AN/A15CSpray135NRNRNRNRNRNRNR 16IDN/AN/A51.55/163.750.523/162.55/1625/1617ODN/AN/A32.50.520.513/1618ESurge158weldID<10%82N3N/AN/AN/AN/AN/AN/A19butterN/A82Y1N/AN/A20OD182N/A21.750.8751.51 21ID182N/A11.00.62522ID182N/A140.75Notes:1. For Designs #2a, #2b, and #5, liner directly covers DM weld.2. For Design #4, liner does not extend to most of DM weld.
- 3. For Designs #4, #5, and #6, sleeve covers but does not contact DM weld.4. For Design #8, sleeve directly covers DM weld.5. NR = Information not yet reported (or may not be available)6. N/A = Information not available7. Weld repair entries for Plants C and F are preliminary.PWHTafterRepair?Alloy82 or182# Defect orRepairAreasDefect/RepairArea #6Defect/RepairArea #4Defect/RepairArea #5Defect/RepairArea #1Defect/RepairArea #2Defect/RepairArea #3Safety AH1aweld 5ESpray4ASurge8 12weldweldBSurge8 14 16ID/OD (%circ.)
Advanced FEA Crack Growth Evaluations:WRS Treatment 29May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Weld Repair Summary Table (cont'd)TableLinePlantCodeNozzleTypeNozzleCountDesign#Butteringor WeldLength(in.)Depth(in.)Length(in.)Depth(in.)Length(in.)Depth(in.)Length(in.)Depth(in.)Length(in.)Depth(in.)Length(in.)Depth(in.)WC1N/A82/182YN/AN/AN/AWC2ID+OD82Y21/27/16ID 17/16ODWC3OD182Y113/4 WC4ID82Y33/43/42-1/43/41/23/4WC5OD182Y313/42-1/43/41/23/4WC6OD82N/A11-1/41/2WC7ID82N/A11/21/2WC8butterN/A182YN/AN/A1/8WC9weldID82N/A21-1/411/327/811/32WC1082N/A62-1/23/411/21-1/21/211/22-1/23/42-1/23/4WC1182N/A61-1/21/21-1/413/47/81-1/23/811-1/161/21/2 WC12JSprayWC44butterlip/bondline82YN/AN/AN/AWC13butterOD182Y27/89/161-1/81WC14weldID82Y117/16Notes:1. For Designs #2a, #2b, and #5, liner directly covers DM weld.2. For Design #4, liner does not extend to most of DM weld.3. For Designs #4, #5, and #6, sleeve covers but does not contact DM weld.4. For Design #8, sleeve directly covers DM weld.5. NR = Information not yet reported (or may not be available)
- 6. N/A = Information not available7. Weld repair entries for Plants C and F are preliminary.PWHTafterRepair?Alloy82 or182# Defect orRepairAreasDefect/RepairArea #6Defect/RepairArea #4Defect/RepairArea #5Defect/RepairArea #1Defect/RepairArea #2Defect/RepairArea #3weldJRelief1aWC1 1aJSurge8WC2WC5ID/OD (%circ.)JSafety BWC31aweldIDbutterJSafety A Advanced FEA Crack Growth Evaluations:WRS Treatment 30May 1, 2007, Meeting Nozzle Geometry and Repair History Wolf Creek Repair History Summary Source: MRP 2007-003 Attachment 1 (White Paper).
Advanced FEA Crack Growth Evaluations:WRS Treatment 31May 1, 2007, Meeting Nozzle Geometry for Subject Plants As-Built Dimensional InformationAvailable as-built dimensions are being collected for the subject weldsThis information is being used to investigate as-built DM weld OD and thickness versus design dimensionsSensitivity cases for the crack growth calculations are planned to check sensitivity to as-built dimensions Advanced FEA Crack Growth Evaluations:WRS Treatment 32May 1, 2007, Meeting Welding Residual Stress ASME DistributionsGeneric residual stress models established by testing
-Most results were for thinner wall BWR piping
-Generic models based on nominal fit of test data NUREG-0313, Technical Report on Material Selection and Processing Guidelines for BWR Coolant Pressure Boundary Piping: Final Report"Evaluations of Flaws in Austenitic Piping," Transactions of ASME, J. of Pressure Vessel Technology , v. 108, Aug.
1986, pp. 352-366.
Advanced FEA Crack Growth Evaluations:WRS Treatment 33May 1, 2007, Meeting DEI Welding Residual Stress FEA Previous FEA Results for Butt WeldsWeld stresses originally not explicitly considered in DEI nozzle penetration analysesInitial use of DEI finite element analysis techniques for weld metal residual stresses in BWRVIP-14 (1995)
-Stainless steel BWR shroud horizontal welds
-Vertical shroud welds considered in later workInitial use of DEI FEA model for Ni-alloy butt weld stresses in BWRVIP-59 (1998)
-Welds joined low-alloy steel RPV and stai nless steel shroud to Alloy 600 shroud support components
-Extensive comparisons made to measured re sidual stresses in samples taken from fabricated RPVs Advanced FEA Crack Growth Evaluations:WRS Treatment 34May 1, 2007, Meeting DEI Welding Residual Stress FEA Previous FEA Results for Butt WeldsAnalysis models were then used to investigate PWSCC cracking observed in PWR butt weldmentsPWR Ni-alloy butt weld stress analyses are summarized in two MRP reports
-Elastic-Plastic Finite Element Analysi s: Single and Double-V Hot Leg Nozzle-to-Pipe Welds (MRP-33): Welding Residual and Operating Stresses , EPRI, Palo Alto, CA. TR-1001501
-Materials Reliability Program -Welding Residual and Operating Stresses in PWR Plant Alloy 182 Butt Welds (MRP-106), EPRI, Palo Alto, CA, 1009378*MRP-106 considers MRP-33 cases plus multiple additional nozzle geometries Advanced FEA Crack Growth Evaluations:WRS Treatment 35May 1, 2007, Meeting DEI Welding Residual Stress FEA Analysis MethodologyWelding analysis model is a combined thermal transient plus structural analysis
-Temperatures generated during welding simulated using thermal transient analysis-Structural model analyzed with a series of static load steps by inputting temperatures from the thermal transient analysisWeld beads are simulated using layers of weld material
-Number of weld layers used depends on age (i.e., available computing power) and complexity of analysis model
-Heat generation rate and time for each layer varied to obtain idealized temperatures at the center and at the fusion line of the weldModels have been developed for D (axisymmetric) and 3-D models
-Single-V and Double-V groove butt welds
-Single V groove butt welds with ID repair, both axisymmetric andpartial-arc Advanced FEA Crack Growth Evaluations:WRS Treatment 36May 1, 2007, MeetingVC Summer -2000PWSCC cracks have been discovered in RPV inlet and outlet nozzle to primary coolant pipe butt welds at VC Summer and Ringhals
-Axial cracks in inlet and outlet nozzle butt welds at VC Summer,including one through-wall crack in an outlet nozzle butt weld that led to a leak
-Part-depth axial cracks in outlet nozzle welds at Ringhals3 and 4
-A shallow circumferential crack in outlet nozzle cladding at VC Summer that arrested once the crack penetrated to the low-alloy steel nozzle Through-Wall Axial Flaw at VC Summer Advanced FEA Crack Growth Evaluations:WRS Treatment 37May 1, 2007, MeetingVC Summer -2000 MRP-33The outlet nozzle butt weld at VC Summer had been repaired from the inside surfaceWeld repair on the inside of a nozzle has been shown to produce high residual tensile stresses MXOperating Hoop Stress -As DesignedOperating Hoop Stress -With ID Repair MX Advanced FEA Crack Growth Evaluations:WRS Treatment 38May 1, 2007, Meeting FEA Methodology Pressurizer surge nozzle with ID repairAbout 10 weld pass layers for original weldWeld backgougedfrom the inside surfac e approximately 1/3 wall thicknessBackgougedarea weld repaired from the inside surface using 4 passes Advanced FEA Crack Growth Evaluations:WRS Treatment 39May 1, 2007, Meeting FEA Methodology Example Finite Element Model X Y Z Stainless Steel Pipe Low-Alloy Steel Nozzle Alloy 82/182 Buttering and Butt Weld Advanced FEA Crack Growth Evaluations:WRS Treatment 40May 1, 2007, Meeting FEA Methodology Example Finite Element Model (cont'd)
Advanced FEA Crack Growth Evaluations:WRS Treatment 41May 1, 2007, Meeting FEA Methodology Example 3D Finite Element Model Surge Nozzle ID30 Repair - 60% TW Crack, 6:1 Aspect Ratio 1 Surge Nozzle ID30 Repair - 60% TW Crack, 6:1 Aspect Ratio Advanced FEA Crack Growth Evaluations:WRS Treatment 42May 1, 2007, Meeting DEI Welding Residual Stress FEAAnalysis Results -Surge Nozzle MN MXAxial StressHoop Stress MN MX-60000
-40000
-20000 0
15000 30000 40000 50000 70000 Welding Residual Stress (as designed)
Advanced FEA Crack Growth Evaluations:WRS Treatment 43May 1, 2007, Meeting DEI Welding Residual Stress FEAAnalysis Results -Surge NozzleOperating Stress (as designed)
MN MX MN MXAxial StressHoop Stress
-60000
-40000
-20000 0
15000 30000 40000 50000 70000 Advanced FEA Crack Growth Evaluations:WRS Treatment 44May 1, 2007, Meeting DEI Welding Residual Stress FEAAnalysis Results -Surge NozzleOperating Stress (with ID 360°weld repair)
MX Axial Stress Hoop Stress MX-60000
-40000
-20000 0
15000 30000 40000 50000 70000 Advanced FEA Crack Growth Evaluations:WRS Treatment 45May 1, 2007, Meeting DEI Welding Residual Stress FEAAnalysis Results -Surge Nozzle 1 MN MXAxial StressHoop Stress 1 MN MX-60000
-40000
-20000 0
15000 30000 40000 50000 70000 Operating Stress (with ID 30°weld repair)
Advanced FEA Crack Growth Evaluations:WRS Treatment 46May 1, 2007, Meeting DEI Welding Residual Stress FEAAnalysis Results -Surge Nozzle 1 MN MXAxial StressHoop Stress 1 MX-60000
-40000
-20000 0
15000 30000 40000 50000 70000 Operating Stress (with ID 60°weld repair)
Advanced FEA Crack Growth Evaluations:WRS Treatment 47May 1, 2007, Meeting DEI Welding Residual Stress FEAAnalysis Results -Surge NozzleOperating Stress (with ID 90°weld repair) 1 MXAxial StressHoop Stress 1 MX-60000
-40000
-20000 0
15000 30000 40000 50000 70000 Advanced FEA Crack Growth Evaluations:WRS Treatment 48May 1, 2007, Meeting Welding Residual Stresses FEA vs. Standard Generic Model (Without Weld Repairs)For Pipes < 1" ThicknessFor Pipes > 1" Thickness-80.0-60.0-40.0-20.00.020.0 40.060.080.00.000.200.400.600.801.00Fraction Through Wall (from ID)Welding Residual Hoop Stress (ksi)Generic <1 Inch ThickHP Injection (t=0.8, Di/t =2.7)Instrument (t=0.2, Di/t=5.6)-80.0-60.0
-40.0-20.00.020.040.0 60.080.00.000.200.400.600.801.00Fraction Through Wall (from ID)Welding Residual Hoop Stress (ksi)Generic >1 Inch Thick RPV (t =2.3, Di/t =13.0)PZR Surge (t=1.7, Di/t=6.0)PZR Safety (t=1.6, Di/t=3.1)For Pipes < 1" ThicknessFor Pipes > 1" Thickness-80.0-60.0
-40.0-20.00.020.040.060.00.000.200.400.600.801.00Fraction Through Wall (from ID)Welding Residual Axial Stress (ksi)Generic <1 Inch ThickHP Injection (t=0.8, Di/t =2.7)Instrument (t=0.2, Di/t=5.6)-80.0-60.0
-40.0-20.00.020.040.0 60.080.00.000.200.400.600.801.00Fraction Through Wall (from ID)Welding Residual Axial Stress (ksi)Generic >1 Inch Thick RPV (t =2.3, Di/t =13.0)PZR Surge (t=1.7, Di/t=6.0)PZR Safety (t=1.6, Di/t=3.1)
Generic results generally conservative through mid-wall Advanced FEA Crack Growth Evaluations:WRS Treatment 49May 1, 2007, Meeting Welding Residual Stresses FEA vs. Standard Generic Model (with Weld Repair from ID Surface)Axial Stress-80.0-60.0-40.0-20.00.020.040.060.080.00.000.200.400.600.801.00Fraction Through Wall (from ID)Welding Residual Axial Stress (ksi)Generic >1 Inch Thick RPV (t =2.3, Di/t =13.0)PZR Surge (t=1.7, Di/t=6.0)PZR Safety (t=1.6, Di/t=3.1)
Generic results do not bound FEA re sults for areas with ID repairsHoop Stress-80.0-60.0-40.0-20.0 0.0 20.0 40.0 60.0 80.00.000.200.400.600.801.00Fraction Through Wall (from ID)Welding Residual Hoop Stress (ksi)Generic >1 Inch Thick RPV (t =2.3, Di/t =13.0)PZR Surge (t=1.7, Di/t=6.0)PZR Safety (t=1.6, Di/t=3.1)
Advanced FEA Crack Growth Evaluations:WRS Treatment 50May 1, 2007, Meeting Welding Residual & Operating Stresses With Partial-Arc Weld Repair fr om ID & OD Surface (FEA vs. FEA)-50.0-40.0-30.0-20.0-10.00.010.020.0 30.0 40.0 50.00.000.200.400.600.801.00Fraction Through Wall (from ID)Operating Axial Stress (ksi)As-Designed15° ID Repair15° OD Repair Partial-arc weld repairs from ID and OD produce high restraint and result in through-wall stresses mu ch higher than without weld repairs-10.00.010.020.030.040.050.060.070.080.00.000.200.400.600.801.00Fraction Through Wall (from ID)Operating Hoop Stress (ksi)As-Designed15° ID Repair15° OD Repair Advanced FEA Crack Growth Evaluations:WRS Treatment 51May 1, 2007, Meeting Welding Residual Stress Conclusions of Previous DEI Work for EPRI (MRP-106, etc.)Welding residual stresses are high and a significant contributorto butt weld PWSCC The generic welding residual stress model is conservative for the as-designed case without repairsWeld repairs from the ID surface (360°or partial-arc) significantly increase ID surface stresses
-Generic welding residual stress model does not bound FEA resultsfor cases involving repairs from the ID surfaceDeep partial-arc weld repairs from the OD surf ace have high restraint and may produce similar through-wall stress dist ributions as for cases of ID repairs depending on depth of repair
-Generic welding residual stress model does not bound FEA resultsfor some cases involving partial-arc repairs from the OD surfaceHigh stresses for cases involving partial-ar c repairs are limited to the repaired area
-Expected to produce cracks limite d to the repaired area, not 360° Advanced FEA Crack Growth Evaluations:WRS Treatment 52May 1, 2007, MeetingPiping Butt Weld WRS -Literature Review P. Dong, J. Zhang, and P.J. BouchardP. Dong, J. Zhang, and P.J. Bouchard , "Effects of Repair Weld Length on Residual Stress Distribution,"
Journal of Pressure Vessel Technology , vol. 124, February 2002.
-3D shell element model with 21.3 OD 0.75 thickness, 75% depth repairs
-Short repairs highest peak OD axial stress in repair zone
-Model shows OD repair start-stop region characterized by shar p transition from compressive to tensile axial stresses (as high as 70 ksichange in stress within about 20°)
-Generally good agreement between 3D s hell model and deep hole residual stress measurements Advanced FEA Crack Growth Evaluations:WRS Treatment 53May 1, 2007, MeetingPiping Butt Weld WRS -Literature Review A. Scaramangas et al.A. Scaramangaset al., "Residual Stresses in Cylinder Girth Butt Welds,"
Offshore Technology Conference , OTC 5024, pp.
25-28.-Developed model for predicting surface axial residual stresses as a function of net linear heat input, and validated it with experimental measurements and
literature review
-At higher net linear heat input and lower R/t, the through-thickness axial stress profile adopts a pure
bending shape with yield occurring at the outer and
inner fibers (tourniquet effect)
-At lower net linear heat input, profile is more complex and axial stress at weld root is reduced Advanced FEA Crack Growth Evaluations:WRS Treatment 54May 1, 2007, Meeting OD IDPiping Butt Weld WRS -Literature ReviewT. McGaughyand L. BoylesT. McGaughyand L. Boyles, "Significance of Changes in Residual Stresses and Fracture Toughness due to SMAW Repair of Girth
Welds in Line Pipe,"
Pipeline Technology Conference , Ooostende, Belgium, vol. 2., pp.
16.29-16.36, 1990.
-Experimental study with three different repair types (single pass part-depth, two-pass part-depth, and through-wall)
-Pipe thickness = 0.257 , Pipe outside diameter = 20-8 repair length (between 5 and 7 o'clock positions)
-Through-wall repair produced highest axial residual stress distributions -yield magnitude tensile axial
stresses at weld centerline on ID
-Highest residual axial stresses found on the inner pipe surface of repaired and non-repaired weld samples
-OD residual stresses significantly lower than those on ID Advanced FEA Crack Growth Evaluations:WRS Treatment 55May 1, 2007, MeetingPiping Butt Weld WRS -Literature Review CANDU Feeder Pipe StudiesAECL and National Research Council Canada have studied welding residual stresses in CANDU reactor feeder pipe butt
welds-Detailed studies are proprietary
-CANDU feeder pipes are about 2 to 31/2 NPS diameter
-Neutron diffraction technique has been appl ied to measure through-wall welding residual stress distributions
-Studies examined WRS field with and without presence of repairs
-Work demonstrates that weld start/s tops and presence of repairs lead to asymmetries in WRS
-Work demonstrates that weld repairs generally increase the magnitude of maximum tensile axial residual stress Advanced FEA Crack Growth Evaluations:WRS Treatment 56May 1, 2007, MeetingPiping Butt Weld WRS -Literature Review Other ReferencesW. J. Shack, "Measurement of Throug h-Wall Residual Stresses in Large-Diameter Piping Butt Weldmentsusing Strain-Gauge Techniques,"Proceedings: Second Seminar on Countermeasures for Pipe Crackingin BWRs , EPRI, vol. 2, pp. 8-1 to 8-22, 1983.K. Satoh and T. Terasaki, "Effect of Weld Heat-Input Parameters on Residual Stress Distribution in Butt Joint,"
International Institute of Welding Annual Assembly , ASM, 1978.A. Stacey, J.-Y. Barthelemy, R. H.
Leggatt, and R. A. Ainsworth, "Incorporation of Residual Stresses into the SINTAP Defect Assessment Procedure,"
Engineering Fracture Mechanics , 67 (200), pp. 573-611.R. H. Leggatt,"ResidualStresses at Circumferential Welds in Pipes,"
Welding Institute Research Bulletin , 23/6, pp. 181-188, 06/1982.
Advanced FEA Crack Growth Evaluations:WRS Treatment 57May 1, 2007, MeetingPiping Butt Weld WRS -Literature Review Preliminary ConclusionsPiping Butt Welds Without Repairs:
-Stress measurements show that welding star t/stops can produce variations in axial and hoop stress on the order of or greater t han the material yield strength over circumferential arc lengths of 15°to 20°Piping Butt Welds With Repairs:
-Weld repairs generally increase the magnitude of maximum tensileaxial residual stress-Location of maximum axial tensile stresse s can be in the repair zone or possibly opposite the repair zone depending on the location of the repairrelative to the original weld start/stop location
-Weld cap removal provides little benefit in reducing welding residual stresses, particularly on the weld ID
-Short, deep repairs generally result in gr eater increases in axial tensile residual stresses Advanced FEA Crack Growth Evaluations:WRS Treatment 58May 1, 2007, Meeting Development of WRS Cases ApproachBecause of the uncertainty in the true re sidual stress field in each of the 51 subject welds, a matrix of sensit ivity cases will be considered covering a wide range of WRS patternsRange of welding residual stress profiles
-Axisymmetric (self balance at every circumferential position)
-Non-axisymmetric (self balance over entire cross section)
-Weld fabrication and repair data compiled as i nput to selection of WR S profiles for analysisAs previously planned, the follow ing sources will be applied to develop the WRS cases considered:
-Weld fabrication and repair data from construction for the 51 subject welds
-Previous WRS calculations by DEI and others for PWR piping butt welds
-Limited number of DEI WRS FEA model runs fo r the specific geometry of some of the 51 subject welds considering the weld fabrication information
-WRS data in the open literature including BWR mockup data used to develop the ASME standard WRS distributions Advanced FEA Crack Growth Evaluations:WRS Treatment 59May 1, 2007, Meeting Development of WRS Cases Potential Axisymmetric WRS ProfilesAxisymmetric WRS profile must be self balancing
-Definite integral from ID to OD weighted by radius r must be zero
-If a cubic profile is assumed, then 3 of the 4 coefficients may be specified
-On a preliminary basis, 26 possible profiles have been developedusing the following constraints:*Stress on ID: x,ID= 54, 40, 20 ksi*Depth at which tensile stress becomes compressive:
a/t= 0.145, 0.25, 0.40*Maximum compressive stress: x,min= -12, -22.32, -30 ksi-50-25 0 25 50 7500.10.20.30.40.50.60.70.80.91 a/t x (ksi)a0=54, min=-22.32, x1 @ y1 = 0=0.145a0=54, min=-22.32, x1 @ y1 = 0=0.250a0=54, min=-30.00, x1 @ y1 = 0=0.145a0=54, min=-30.00, x1 @ y1 = 0=0.250a0=54, min=-30.00, x1 @ y1 = 0=0.400a0=54, min=-12.00, x1 @ y1 = 0=0.145a0=54, min=-12.00, x1 @ y1 = 0=0.250a0=54, min=-12.00, x1 @ y1 = 0=0.400 Plot for x,ID=54 ksi cases Advanced FEA Crack Growth Evaluations:WRS Treatment 60May 1, 2007, Meeting Development of WRS Cases Potential Axisymmetric WRS Profiles (cont'd)
Plot for x,ID=40 ksi cases Plot for x,ID=20 ksi cases-50-25 0 25 50 7500.10.20.30.40.50.60.70.80.91 a/t x (ksi)a0=20, min=-22.32, x1 @ y1 = 0=0.145a0=20, min=-22.32, x1 @ y1 = 0=0.250a0=20, min=-22.32, x1 @ y1 = 0=0.400a0=20, min=-30.00, x1 @ y1 = 0=0.145a0=20, min=-30.00, x1 @ y1 = 0=0.250a0=20, min=-30.00, x1 @ y1 = 0=0.400a0=20, min=-12.00, x1 @ y1 = 0=0.145a0=20, min=-12.00, x1 @ y1 = 0=0.250a0=20, min=-12.00, x1 @ y1 = 0=0.400 Advanced FEA Crack Growth Evaluations:WRS Treatment 61May 1, 2007, Meeting Development of WRS Cases Alternative Method to Build Distributions
-0.5 0.0 0.5 1.0 0.00.20.40.60.81.0 normalized residual stressD:\WINMCAD\Apr24a.pltxi0=0.3 rho=0.4xi0=0.15 rho=0.2An alternative method was suggested by David Harris
-Definite integral from ID to OD weighted by radius r must be zero
-Normalize with respect to stress at inside surface
-If a cubic profile is assumed, then 2 additional constraints areneeded for cubic shape:*Specify the value of a/t at which the residual stress passes through zero*Specify the ratio of the stress at the OD to that at the ID ()-Could specify so that there would not be a peak in the curve close to the OD Example distributions for 2 selected cases a/t Advanced FEA Crack Growth Evaluations:WRS Treatment 62May 1, 2007, Meeting Validation of WRS InputsA two-step process to model validation is envisioned:
-Validation of residual stress assumptions based on available stress measurements, model predictions, and the general WRS literature
-Validation of the overall crack growth model based on available destructive examinations results for weld meta l applications and other informationVarious sources of WRS information will be sorted and organized to support range of WRS cases considered in the
calculations:
-Mockup stress measurements
-Stress measurements on removed plant components
-Various FEA models including DEI, SI, EMC2, etc.
-General WRS literature Advanced FEA Crack Growth Evaluations:WRS Treatment 63May 1, 2007, Meeting Validation of WRS Inputs (cont'd)The results of the DEI WRS model have shown reasonable agreement versus measured WRS:
-Measured CRDM nozzle mockup stress
-Measured BWR shroud support weld stress
-Measured CRDM nozzle ovalityDiscussion of sources of data for validation of WRS assumptions Advanced FEA Crack Growth Evaluations:WRS Treatment 64May 1, 2007, Meeting Welding Residual Stress Model Validation General Model BackgroundIndependent welding residual stress models have been developed by many industry and regulatory consultantsDEI model originally developed in 1990 to simulate J-groove attachment welds of pressurizer heater sleeves
-Expanded to include other nozzle penetr ations with J-groove welds since 1991
-Expanded to butt welds in 1995 (stainless steel) and 1997 (Ni base alloys)
-Expanded to various nozzle re pair methodologies since 2002Consistent analysis methodology has been used since initial development of welding residual stress model
-Thermal model simulates weld heating and cooling using idealizedtarget temperatures for weld center and HAZ
-Structural model uses temperatures from t hermal model to simulate thermal expansion followed by weld strengthening with cooling Advanced FEA Crack Growth Evaluations:WRS Treatment 65May 1, 2007, Meeting Welding Residual Stress Model Validation Model BackgroundWelding residual stress calculations have been performed for a variety of Ni base alloy welds J-groove welds for a wide range of nozzle penetration types (e.g., CRDM, heater sleeve, etc.)Piping butt welds for sizes ranging from RPV outlet to 1-inch diameter nozzlesAll major nozzle repair types
-Nozzle left in place (ID inlay, J-groove weld overlay)
-Nozzle partially removed (internally or externally)*ID temper-bead half nozzle weld repair*Outer surface weld pad buildup wi th new J-groove weld attachment Advanced FEA Crack Growth Evaluations:WRS Treatment 66May 1, 2007, Meeting Welding Residual Stress Model Validation Key ReportsPWSCC of Alloy 600 Materials in PWR Primary System Penetrations , EPRI TR-103696, July 1994.
-Describes development of welding residual stress model properties
-Compares model results to measured residual stresses from mockupsEvaluation of Crack Growth in BWR Nickel Base Austenitic Alloys in RPV Internals (BWRVIP-59), EPRI TR-108710.
-Shroud support welds examined (butt weld type geometries)
-Model results compared to measured residual stresses from actualweldsProceedings: 1992 EPRI Workshop on PWSCC of Alloy 600 in PWRs. December 1993. EPRI TR-103345.
-Overview of industry at a time when many models were being developed Advanced FEA Crack Growth Evaluations:WRS Treatment 67May 1, 2007, Meeting Welding Residual Stress Model Validation EPRI TR-103696Comparison with Combustion E ngineering XRD residual stress measurements for pressurizer heater sleeve mockups at inside surface Advanced FEA Crack Growth Evaluations:WRS Treatment 68May 1, 2007, Meeting Welding Residual Stress Model Validation EPRI TR-103696Comparison with EdF hole-drilling strain gauge residual stress measurements for CRDM nozzle mockups at inside surface (39° nozzle, downhill side shown)
Advanced FEA Crack Growth Evaluations:WRS Treatment 69May 1, 2007, Meeting Welding Residual Stress Model Validation Measured OvalityTR-103696 reported two sets of ovality measurements taken from mockups compared to DEI analyses
-47°EdF CRDM: 0.064 inch measured vs 0.052 inch calculated
-Ringhals outer row CRDM: 0.045 inch measured vs 0.049 inch calculatedBMN analyses for South Texas compared against measured ovality for EdF plants
-Measured ovality (average outer penetrat ions): 0.020 inch vs 0.0122 inch calculated Advanced FEA Crack Growth Evaluations:WRS Treatment 70May 1, 2007, Meeting Meeting Wrap-UpSummaryAction items