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. #310 Reston, VA 20190 703.437.1155 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 Advanced 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 2
May 1, 2007, Meeting Topics Nozzle and weld geometry cases for subject welds Collected weld repair information for subject welds Application 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 for selected subject weld cases WRS data for piping butt welds in open literature Candidate WRS profiles
- Axisymmetric profiles
- Non-axisymmetric profiles Validation of WRS inputs Meeting wrap-up
Advanced FEA Crack Growth Evaluations: WRS Treatment 3
May 1, 2007, Meeting Principal Meeting Participants EPRI Project Management / Support
- Craig Harrington, EPRI
- Tim Gilman, Structural Integrity Associates Project Team
- Glenn White, Dominion Engineering, Inc.
- John Broussard, Dominion Engineering, Inc.
Expert Review Panel
- Warren Bamford, Westinghouse (via phone)
- Pete Riccardella, Structural Integrity Associates (via phone)
- Doug Killian, AREVA
- Ken Yoon, AREVA NRC Participants
- Al Csontos, NRC Research
- Ted Sullivan, NRC NRR
- Simon Sheng, NRC NRR
- Dave Rudland, EMC2
Advanced FEA Crack Growth Evaluations: WRS Treatment 4
May 1, 2007, Meeting Nozzle Geometry for Subject Plants Summary There 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 5
May 1, 2007, Meeting Nozzle Geometry for Subject Plants Geometry Cases A 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 extend 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 extending to DM weld), connected to 12 pipe
Advanced FEA Crack Growth Evaluations: WRS Treatment 6
May 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 7
May 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 8
May 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 9
May 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 10 May 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 11 May 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 12 May 1, 2007, Meeting Nozzle Geometry for Subject Plants S&R Type 3: CE design
Advanced FEA Crack Growth Evaluations: WRS Treatment 13 May 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 14 May 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 15 May 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 16 May 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 17 May 1, 2007, Meeting Nozzle Geometry for Subject Plants Spray Type 6: W design without liner (6 pipe)
Advanced FEA Crack Growth Evaluations: WRS Treatment 18 May 1, 2007, Meeting Nozzle Geometry for Subject Plants Spray Type 7: CE design
Advanced FEA Crack Growth Evaluations: WRS Treatment 19 May 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 20 May 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 21 May 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 22 May 1, 2007, Meeting Nozzle Geometry for Subject Plants Surge Type 9: CE design
Advanced FEA Crack Growth Evaluations: WRS Treatment 23 May 1, 2007, Meeting Nozzle Geometry for Subject Plants Surge Type 9: CE design (sleeve not extend) (12 pipe)
Advanced FEA Crack Growth Evaluations: WRS Treatment 24 May 1, 2007, Meeting Nozzle Geometry for Subject Plants Basic Weld Dimensions 0
2 4
6 8
10 12 14 01 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 0.00 0.75 1.50 2.25 3.00 3.75 4.50 5.25 6.00 6.75 7.50 8.25 9.00 9.75 10.50 11.25 12.00 12.75 13.50 14.25 15.00 15.75 16.50 17.25 18.00 18.75 19.50 20.25 21.00 21.75 22.50 23.25 24.00 24.75 25.50 26.25 27.00 27.75 28.50 29.25 30.00 30.75 31.50 32.25 33.00 33.75 34.50 35.25 36.00 36.75 37.50 38.25 39.00 39.75 40.50 41.25 42.00 42.75 43.50 44.25 45.00 45.75 46.50 47.25 48.00 48.75 49.50 50.25 51.00 51.75 52.50 53.25 54.00 54.75 55.50 56.25 57.00 57.75 58.50 59.25 60.00 ID (in)
OD (in) t (in)
ID/t
Advanced FEA Crack Growth Evaluations: WRS Treatment 25 May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Summary Table Design #
Piping NPS Liner?
DM Weld t (in.)
(in.)
Butter Weld Repairs ID Weld Repairs OD Weld Repairs Design #
Piping NPS Liner?
DM Weld t (in.)
(in.)
Butter Weld Repairs ID Weld Repairs OD Weld Repairs Plant A 1a 6"
N 1.29 2.0 2.2 NR NR NR 1a 6"
N 1.29 2.0 2.2 NR NR R4 Plant E 1a 6"
N 1.29 2.0 2.2 NR NR R
1a 6"
N 1.29 2.0 2.2 NR NR NR Plant H 1a 6"
N 1.29 2.0 2.2 NR NR NR 1a 6"
N 1.29 2.0 2.2 NR R
R Plant B 2a 6"
Y 1.07 2.6 2.6 NR NR R1 2a 6"
Y 1.07 2.6 2.6 NR NR NR Plant G 2a 6"
Y 1.07 2.6 2.6 NR NR NR 2a 6"
Y 1.07 2.6 2.6 NR NR NR Plant C 2b 6"
Y 1.07 2.6 2.3 NR NR NR 2b 6"
Y 1.07 2.6 2.3 Plant F 1b 6"
N 1.41 1.8 3.3 NR NR NR 1b 6"
N 1.41 1.8 3.3 Plant D 3
6" N
1.41 1.8 6.8 NR NR NR 3
6" N
1.41 1.8 6.8 R
NR NR Plant I 3
6" N
1.41 1.8 6.8 N/A N/A N/A 3
6" N
1.41 1.8 6.8 N/A N/A N/A Plant J 1a 6"
N 1.29 2.0 2.2 Rx5 R1 R1 1a 6"
N 1.29 2.0 2.2 R
R2 NR Notes:
- 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.
- 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 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.
Safety A Plant Code Relief R
R
Advanced FEA Crack Growth Evaluations: WRS Treatment 26 May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Summary Table (contd)
Design #
Piping NPS Liner?
DM Weld t (in.)
(in.)
Butter Weld Repairs ID Weld Repairs OD Weld Repairs Design #
Piping NPS Liner?
DM Weld t (in.)
(in.)
Butter Weld Repairs ID Weld Repairs OD Weld Repairs Plant A 1a 6"
N 1.29 2.0 2.2 NR R1 NR 1a 6"
N 1.29 2.0 2.2 NR NR NR Plant E 1a 6"
N 1.29 2.0 2.2 NR NR NR 1a 6"
N 1.29 2.0 2.2 NR R
NR Plant H 1a 6"
N 1.29 2.0 2.2 NR NR NR 1a 6"
N 1.29 2.0 2.2 NR NR NR Plant B 2a 6"
Y 1.07 2.6 2.6 NR NR NR 2a 6"
Y 1.07 2.6 2.6 NR NR NR Plant G 2a 6"
Y 1.07 2.6 2.6 NR NR NR 2a 6"
Y 1.07 2.6 2.6 NR NR NR Plant C 2b 6"
Y 1.07 2.6 2.3 2b 6"
Y 1.07 2.6 2.3 Plant F 1b 6"
N 1.41 1.8 3.3 NR NR NR 1b 6"
N 1.41 1.8 3.3 NR NR NR Plant D 3
6" N
1.41 1.8 6.8 NR NR NR 3
6" N
1.41 1.8 6.8 NR NR NR Plant I 3
6" N
1.41 1.8 6.8 N/A N/A N/A Plant J 1a 6"
N 1.29 2.0 2.2 NR R6x2 NR 1a 6"
N 1.29 2.0 2.2 NR NR NR Notes:
- 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.
- 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 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.
Plant Code Safety B Safety C No Safety C R
R
Advanced FEA Crack Growth Evaluations: WRS Treatment 27 May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Summary Table (contd)
Design #
Piping NPS Liner?
DM Weld t (in.)
(in.)
Butter Weld Repairs ID Weld Repairs OD Weld Repairs Design #
Piping NPS Liner?
DM Weld t (in.)
(in.)
Butter Weld Repairs ID Weld Repairs OD Weld Repairs Plant A 4
4" Y
0.90 2.2
~2.3 NR NR NR 8
14" N
1.58 3.8 3.4 NR R5 R3 Plant E 4
4" Y
0.90 2.2
~2.3 R
NR R
8 14" N
1.58 3.8 3.4 NR R3 NR Plant H 8
14" N
1.58 3.8 3.4 NR NR NR Plant B 5
4" Y
0.78 2.7 2.2 NR NR NR 8
14" N
1.58 3.8 3.4 R1 R1x2 R2 Plant G 5
4" Y
0.78 2.7 2.2 NR NR NR 8
14" N
1.58 3.8 3.4 NR NR NR Plant C 5
4" Y
0.78 2.7
~2.2 8
14" N
1.56 3.8 3.5 NR NR NR Plant F 6
6" N
1.15 2.5 3.6 NR NR NR Plant D 7
4" N
1.06 1.4 3.3 NR NR NR 9
12" N
1.47 3.4 3.0 NR NR NR Plant I 7
4" N
1.06 1.4 3.3 N/A N/A N/A 9
12" N
1.47 3.4 3.0 N/A N/A N/A Plant J 4
4" Y
0.90 2.2
~2.3 R
NR NR 8
14" N
1.58 3.8 3.4 R2 R1 NR Notes:
- 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.
- 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 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.
Plant Code Spray (all have thermal sleeve)
Surge (all have thermal sleeve)
Already PDI examined Already structural overlayed R
Advanced FEA Crack Growth Evaluations: WRS Treatment 28 May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Weld Repair Summary Table Table Line Plant Code Nozzle Type Nozzle Count Design Buttering or Weld Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
1 A
Safety A 1
N/A
~1/2 N/A
~1/2 N/A
~1/2 N/A
~1/2 2
A Safety B 2
1a weld ID N/A N/A 1
1/2 5/8 3
E Relief 3
N/A N/A N/A 4
E Safety C 4
1a weld ID<22%
N/A N
N/A N/A N/A 5
ID 82 Y
N/A N/A N/A 6
OD 82 Y
N/A N/A N/A 7
F Safety A 6
1b NR NR NR NR NR NR NR 8
B Relief 7
0.5 0.375 9
C Safety A 8
2b NR NR NR NR NR NR NR 10 C
Safety B 9
2b NR NR NR NR NR NR NR 11 C
Safety C 10 2b NR NR NR NR NR NR NR 12 D
Safety A 11 3
butter N/A N/A Y
N/A N/A N/A 13 butter ID 82 Y
N/A N/A
N/A N/A N/A 15 C
Spray 13 5
NR NR NR NR NR NR NR 16 ID N/A N/A 5
1.5 5/16 3.75 0.5 2
3/16 2.5 5/16 2
5/16 17 OD N/A N/A 3
2.5 0.5 2
0.5 1
3/16 18 E
Surge 15 8
weld ID<10%
82 N
3 N/A N/A N/A N/A N/A N/A 19 butter N/A 82 Y
1 N/A N/A 20 OD 182 N/A 2
1.75 0.875 1.5 1
21 ID 182 N/A 1
1.0 0.625 22 ID 182 N/A 1
4 0.75 Notes:
- 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.
- 5. NR = Information not yet reported (or may not be available)
- 6. N/A = Information not available
- 7. Weld repair entries for Plants C and F are preliminary.
PWHT after Repair?
Alloy 82 or 182
- Defect or Repair Areas Defect/Repair Area #6 Defect/Repair Area #4 Defect/Repair Area #5 Defect/Repair Area #1 Defect/Repair Area #2 Defect/Repair Area #3 Safety A H
1a weld 5
E Spray 4
A Surge 8
12 weld weld B
Surge 8
14 16 ID/OD
(%
circ.)
Advanced FEA Crack Growth Evaluations: WRS Treatment 29 May 1, 2007, Meeting Nozzle Geometry and Repair History PRELIMINARY Weld Repair Summary Table (contd)
Table Line Plant Code Nozzle Type Nozzle Count Design Buttering or Weld Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
Length (in.)
Depth (in.)
WC1 N/A 82/182 Y
N/A N/A N/A WC2 ID+OD 82 Y
2 1/2 7/16ID 1
7/16OD WC3 OD 182 Y
1 1
3/4 WC4 ID 82 Y
3 3/4 3/4 2-1/4 3/4 1/2 3/4 WC5 OD 182 Y
3 1
3/4 2-1/4 3/4 1/2 3/4 WC6 OD 82 N/A 1
1-1/4 1/2 WC7 ID 82 N/A 1
1/2 1/2 WC8 butter N/A 182 Y
N/A N/A 1/8 WC9 weld ID 82 N/A 2
1-1/4 11/32 7/8 11/32 WC10 82 N/A 6
2-1/2 3/4 1
1/2 1-1/2 1/2 1
1/2 2-1/2 3/4 2-1/2 3/4 WC11 82 N/A 6
1-1/2 1/2 1-1/4 1
3/4 7/8 1-1/2 3/8 1
1-1/16 1/2 1/2 WC12 J
Spray WC4 4
butter lip/bondline 82 Y
N/A N/A N/A WC13 butter OD 182 Y
2 7/8 9/16 1-1/8 1
WC14 weld ID 82 Y
1 1
7/16 Notes:
- 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.
- 5. NR = Information not yet reported (or may not be available)
- 6. N/A = Information not available
- 7. Weld repair entries for Plants C and F are preliminary.
PWHT after Repair?
Alloy 82 or 182
- Defect or Repair Areas Defect/Repair Area #6 Defect/Repair Area #4 Defect/Repair Area #5 Defect/Repair Area #1 Defect/Repair Area #2 Defect/Repair Area #3 weld J
Relief 1a WC1 1a J
Surge 8
WC2 WC5 ID/OD
(%
circ.)
J Safety B WC3 1a weld ID butter J
Safety A
Advanced FEA Crack Growth Evaluations: WRS Treatment 30 May 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 31 May 1, 2007, Meeting Nozzle Geometry for Subject Plants As-Built Dimensional Information Available as-built dimensions are being collected for the subject welds This information is being used to investigate as-built DM weld OD and thickness versus design dimensions Sensitivity cases for the crack growth calculations are planned to check sensitivity to as-built dimensions
Advanced FEA Crack Growth Evaluations: WRS Treatment 32 May 1, 2007, Meeting Welding Residual Stress ASME Distributions Generic 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 33 May 1, 2007, Meeting DEI Welding Residual Stress FEA Previous FEA Results for Butt Welds Weld stresses originally not explicitly considered in DEI nozzle penetration analyses Initial 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 work Initial use of DEI FEA model for Ni-alloy butt weld stresses in BWRVIP-59 (1998)
- Welds joined low-alloy steel RPV and stainless steel shroud to Alloy 600 shroud support components
- Extensive comparisons made to measured residual stresses in samples taken from fabricated RPVs
Advanced FEA Crack Growth Evaluations: WRS Treatment 34 May 1, 2007, Meeting DEI Welding Residual Stress FEA Previous FEA Results for Butt Welds Analysis models were then used to investigate PWSCC cracking observed in PWR butt weldments PWR Ni-alloy butt weld stress analyses are summarized in two MRP reports
- Elastic-Plastic Finite Element Analysis: 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 35 May 1, 2007, Meeting DEI Welding Residual Stress FEA Analysis Methodology Welding 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 analysis Weld 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 weld Models 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 and partial-arc
Advanced FEA Crack Growth Evaluations: WRS Treatment 36 May 1, 2007, Meeting VC Summer - 2000 PWSCC 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 Ringhals 3 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 37 May 1, 2007, Meeting VC Summer - 2000 MRP-33 The outlet nozzle butt weld at VC Summer had been repaired from the inside surface Weld repair on the inside of a nozzle has been shown to produce high residual tensile stresses MX Operating Hoop Stress - As Designed Operating Hoop Stress - With ID Repair MX
Advanced FEA Crack Growth Evaluations: WRS Treatment 38 May 1, 2007, Meeting FEA Methodology Pressurizer surge nozzle with ID repair About 10 weld pass layers for original weld Weld backgouged from the inside surface approximately 1/3 wall thickness Backgouged area weld repaired from the inside surface using 4 passes
Advanced FEA Crack Growth Evaluations: WRS Treatment 39 May 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 40 May 1, 2007, Meeting FEA Methodology Example Finite Element Model (contd)
Advanced FEA Crack Growth Evaluations: WRS Treatment 41 May 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 42 May 1, 2007, Meeting DEI Welding Residual Stress FEA Analysis Results - Surge Nozzle MN MX Axial Stress Hoop Stress MN MX
-60000
-40000
-20000 0
15000 30000 40000 50000 70000 Welding Residual Stress (as designed)
Advanced FEA Crack Growth Evaluations: WRS Treatment 43 May 1, 2007, Meeting DEI Welding Residual Stress FEA Analysis Results - Surge Nozzle Operating Stress (as designed)
MN MX MN MX Axial Stress Hoop Stress
-60000
-40000
-20000 0
15000 30000 40000 50000 70000
Advanced FEA Crack Growth Evaluations: WRS Treatment 44 May 1, 2007, Meeting DEI Welding Residual Stress FEA Analysis Results - Surge Nozzle Operating 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 45 May 1, 2007, Meeting DEI Welding Residual Stress FEA Analysis Results - Surge Nozzle 1
MN MX Axial Stress Hoop 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 46 May 1, 2007, Meeting DEI Welding Residual Stress FEA Analysis Results - Surge Nozzle 1
MN MX Axial Stress Hoop 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 47 May 1, 2007, Meeting DEI Welding Residual Stress FEA Analysis Results - Surge Nozzle Operating Stress (with ID 90° weld repair) 1 MX Axial Stress Hoop Stress 1
MX
-60000
-40000
-20000 0
15000 30000 40000 50000 70000
Advanced FEA Crack Growth Evaluations: WRS Treatment 48 May 1, 2007, Meeting Welding Residual Stresses FEA vs. Standard Generic Model (Without Weld Repairs)
For Pipes < 1" Thickness For Pipes > 1" Thickness
-80.0
-60.0
-40.0
-20.0 0.0 20.0 40.0 60.0 80.0 0.00 0.20 0.40 0.60 0.80 1.00 Fraction Through Wall (from ID)
Welding Residual Hoop Stress (ksi)
Generic <1 Inch Thick HP Injection (t=0.8, Di/t =2.7)
Instrument (t=0.2, Di/t=5.6)
-80.0
-60.0
-40.0
-20.0 0.0 20.0 40.0 60.0 80.0 0.00 0.20 0.40 0.60 0.80 1.00 Fraction 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" Thickness For Pipes > 1" Thickness
-80.0
-60.0
-40.0
-20.0 0.0 20.0 40.0 60.0 0.00 0.20 0.40 0.60 0.80 1.00 Fraction Through Wall (from ID)
Welding Residual Axial Stress (ksi)
Generic <1 Inch Thick HP Injection (t=0.8, Di/t =2.7)
Instrument (t=0.2, Di/t=5.6)
-80.0
-60.0
-40.0
-20.0 0.0 20.0 40.0 60.0 80.0 0.00 0.20 0.40 0.60 0.80 1.00 Fraction 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 49 May 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
-20.0 0.0 20.0 40.0 60.0 80.0 0.00 0.20 0.40 0.60 0.80 1.00 Fraction 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 results for areas with ID repairs Hoop Stress
-80.0
-60.0
-40.0
-20.0 0.0 20.0 40.0 60.0 80.0 0.00 0.20 0.40 0.60 0.80 1.00 Fraction 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 50 May 1, 2007, Meeting Welding Residual & Operating Stresses With Partial-Arc Weld Repair from ID & OD Surface (FEA vs. FEA)
-50.0
-40.0
-30.0
-20.0
-10.0 0.0 10.0 20.0 30.0 40.0 50.0 0.00 0.20 0.40 0.60 0.80 1.00 Fraction Through Wall (from ID)
Operating Axial Stress (ksi)
As-Designed 15° ID Repair 15° OD Repair Partial-arc weld repairs from ID and OD produce high restraint and result in through-wall stresses much higher than without weld repairs
-10.0 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 0.00 0.20 0.40 0.60 0.80 1.00 Fraction Through Wall (from ID)
Operating Hoop Stress (ksi)
As-Designed 15° ID Repair 15° OD Repair
Advanced FEA Crack Growth Evaluations: WRS Treatment 51 May 1, 2007, Meeting Welding Residual Stress Conclusions of Previous DEI Work for EPRI (MRP-106, etc.)
Welding residual stresses are high and a significant contributor to butt weld PWSCC The generic welding residual stress model is conservative for the as-designed case without repairs Weld repairs from the ID surface (360° or partial-arc) significantly increase ID surface stresses
- Generic welding residual stress model does not bound FEA results for cases involving repairs from the ID surface Deep partial-arc weld repairs from the OD surface have high restraint and may produce similar through-wall stress distributions as for cases of ID repairs depending on depth of repair
- Generic welding residual stress model does not bound FEA results for some cases involving partial-arc repairs from the OD surface High stresses for cases involving partial-arc repairs are limited to the repaired area
- Expected to produce cracks limited to the repaired area, not 360°
Advanced FEA Crack Growth Evaluations: WRS Treatment 52 May 1, 2007, Meeting Piping Butt Weld WRS - Literature Review P. Dong, J. Zhang, and P.J. Bouchard P. 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 x 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 sharp transition from compressive to tensile axial stresses (as high as 70 ksi change in stress within about 20°)
- Generally good agreement between 3D shell model and deep hole residual stress measurements
Advanced FEA Crack Growth Evaluations: WRS Treatment 53 May 1, 2007, Meeting Piping Butt Weld WRS - Literature Review A. Scaramangas et al.
A. Scaramangas et 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 54 May 1, 2007, Meeting OD ID Piping Butt Weld WRS - Literature Review T. McGaughy and L. Boyles T. McGaughy and 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 oclock 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 55 May 1, 2007, Meeting Piping Butt Weld WRS - Literature Review CANDU Feeder Pipe Studies AECL 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 applied to measure through-wall welding residual stress distributions
- Studies examined WRS field with and without presence of repairs
- Work demonstrates that weld start/stops 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 56 May 1, 2007, Meeting Piping Butt Weld WRS - Literature Review Other References W. J. Shack, Measurement of Through-Wall Residual Stresses in Large-Diameter Piping Butt Weldments using Strain-Gauge Techniques, Proceedings: Second Seminar on Countermeasures for Pipe Cracking in 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,Residual Stresses at Circumferential Welds in Pipes, Welding Institute Research Bulletin, 23/6, pp. 181-188, 06/1982.
Advanced FEA Crack Growth Evaluations: WRS Treatment 57 May 1, 2007, Meeting Piping Butt Weld WRS - Literature Review Preliminary Conclusions Piping Butt Welds Without Repairs:
- Stress measurements show that welding start/stops can produce variations in axial and hoop stress on the order of or greater than 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 tensile axial residual stress
- Location of maximum axial tensile stresses can be in the repair zone or possibly opposite the repair zone depending on the location of the repair relative 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 greater increases in axial tensile residual stresses
Advanced FEA Crack Growth Evaluations: WRS Treatment 58 May 1, 2007, Meeting Development of WRS Cases Approach Because of the uncertainty in the true residual stress field in each of the 51 subject welds, a matrix of sensitivity cases will be considered covering a wide range of WRS patterns Range 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 input to selection of WRS profiles for analysis As previously planned, the following 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 for 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 59 May 1, 2007, Meeting Development of WRS Cases Potential Axisymmetric WRS Profiles Axisymmetric 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 developed using 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 75 0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
a /t x (ksi) a0=54, min=-22.32, x1 @ y1 = 0=0.145 a0=54, min=-22.32, x1 @ y1 = 0=0.250 a0=54, min=-30.00, x1 @ y1 = 0=0.145 a0=54, min=-30.00, x1 @ y1 = 0=0.250 a0=54, min=-30.00, x1 @ y1 = 0=0.400 a0=54, min=-12.00, x1 @ y1 = 0=0.145 a0=54, min=-12.00, x1 @ y1 = 0=0.250 a0=54, min=-12.00, x1 @ y1 = 0=0.400 Plot for x,ID =
54 ksi cases
Advanced FEA Crack Growth Evaluations: WRS Treatment 60 May 1, 2007, Meeting Development of WRS Cases Potential Axisymmetric WRS Profiles (contd)
Plot for x,ID =
40 ksi cases Plot for x,ID =
20 ksi cases
-50
-25 0
25 50 75 0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
a /t x (ksi) a0=20, min=-22.32, x1 @ y1 = 0=0.145 a0=20, min=-22.32, x1 @ y1 = 0=0.250 a0=20, min=-22.32, x1 @ y1 = 0=0.400 a0=20, min=-30.00, x1 @ y1 = 0=0.145 a0=20, min=-30.00, x1 @ y1 = 0=0.250 a0=20, min=-30.00, x1 @ y1 = 0=0.400 a0=20, min=-12.00, x1 @ y1 = 0=0.145 a0=20, min=-12.00, x1 @ y1 = 0=0.250 a0=20, min=-12.00, x1 @ y1 = 0=0.400
Advanced FEA Crack Growth Evaluations: WRS Treatment 61 May 1, 2007, Meeting Development of WRS Cases Alternative Method to Build Distributions
-0.5 0.0 0.5 1.0 0.0 0.2 0.4 0.6 0.8 1.0 normalized residual stress D:\\WINMCAD\\Apr24a.plt xi0=0.3 rho=0.4 xi0=0.15 rho=0.2 An 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 are needed 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 62 May 1, 2007, Meeting Validation of WRS Inputs A 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 metal applications and other information Various 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 63 May 1, 2007, Meeting Validation of WRS Inputs (contd)
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 ovality Discussion of sources of data for validation of WRS assumptions
Advanced FEA Crack Growth Evaluations: WRS Treatment 64 May 1, 2007, Meeting Welding Residual Stress Model Validation General Model Background Independent welding residual stress models have been developed by many industry and regulatory consultants DEI model originally developed in 1990 to simulate J-groove attachment welds of pressurizer heater sleeves
- Expanded to include other nozzle penetrations with J-groove welds since 1991
- Expanded to butt welds in 1995 (stainless steel) and 1997 (Ni base alloys)
- Expanded to various nozzle repair methodologies since 2002 Consistent analysis methodology has been used since initial development of welding residual stress model
- Thermal model simulates weld heating and cooling using idealized target temperatures for weld center and HAZ
- Structural model uses temperatures from thermal model to simulate thermal expansion followed by weld strengthening with cooling
Advanced FEA Crack Growth Evaluations: WRS Treatment 65 May 1, 2007, Meeting Welding Residual Stress Model Validation Model Background Welding 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 nozzles All 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 with new J-groove weld attachment
Advanced FEA Crack Growth Evaluations: WRS Treatment 66 May 1, 2007, Meeting Welding Residual Stress Model Validation Key Reports PWSCC 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 mockups Evaluation 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 actual welds Proceedings: 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 67 May 1, 2007, Meeting Welding Residual Stress Model Validation EPRI TR-103696 Comparison with Combustion Engineering XRD residual stress measurements for pressurizer heater sleeve mockups at inside surface
Advanced FEA Crack Growth Evaluations: WRS Treatment 68 May 1, 2007, Meeting Welding Residual Stress Model Validation EPRI TR-103696 Comparison 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 69 May 1, 2007, Meeting Welding Residual Stress Model Validation Measured Ovality TR-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 calculated BMN analyses for South Texas compared against measured ovality for EdF plants
- Measured ovality (average outer penetrations): 0.020 inch vs 0.0122 inch calculated
Advanced FEA Crack Growth Evaluations: WRS Treatment 70 May 1, 2007, Meeting Meeting Wrap-Up Summary Action items