ML14259A312
| ML14259A312 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 09/15/2014 |
| From: | AREVA |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML14259A323 | List: |
| References | |
| DCL-14-084 32-9219781-002, 32-9219813-002 | |
| Download: ML14259A312 (59) | |
Text
Controlled Document A .AREV.A Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary
4.4 Welding
Parameters The welding parameters used in the modeling of the welding processes are shown in Table 4-3. Table 4-3: Welding Parameters Welding Parameter Value Groove weld heat input calculated from typical welding parameters for a manual metal arc or manual gas shielded tungsten arc weld Current [ ] Voltage [ ] Travel Speed [ ] Arc Efficiency [ ] Bead Size [ ] Maximum lnterpass Temperature [ ] Overlay weld heat input Heat Input [7] [ ] Arc Efficiency (typical) [ ] Bead Size, typically
[ ] [ ] Maximum lnterpass Temperature
[7] [ ] 4.5 Boundary Conditions
4.5.1 Thermal
Analysis The thermal model is loaded by a volumetric heat source applied to each weld pass. To enforce thermal continuity with adjacent components, adiabatic boundary conditions are applied at the nozzle end (where it attaches to the vessel) and at the end of the piping section modeled. Thus no heat transfer occurs through the two ends of the model shown in Figure 6. Heat loss at the inner and outer surfaces is simulated using a heat transfer coefficient of [ ] BTU/hr-ft 2-°F per the Reference
[1] WRS procedure to model natural convection to an air environment.
Radiative boundary conditions are not considered since radiation losses from the molten weld pool are included in the weld efficiency. Page 11 -/
Controlled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary
4.5.2 Structural
Analysis The temperature history from the thermal analysis is used as the thermal load in the structural analysis.
A traction free boundary condition is maintained on all external surfaces of the finite element model. The finite element model is constrained against rigid body translation and rotation by eliminating axial displacements at the nozzle end. 5.0 FINITE ELEMENT RESULTS/
SUMMARY
Following the completion of the SWOL simulation, two operating load cycles were applied to the finite element model to obtain a stable state of residual stress after shakedown.
This stress state is referred to as shutdown at 70°F. The axial and hoop stress contours at shutdown are shown in Figure 10. Following shutdown, an additional half cycle of operating loads were applied to the finite element model to obtain the sustained stresses under steady state condition at 653°F. Figure 11 shows the axial and hoop stress contours at steady state. PWSCC is only a concern when the conditions of high temperature, corrodant, and high tensile stress state in a susceptible material are met simultaneously.
Alloy 82/182 is a material that is susceptible to PWSCC. The operating temperature of the pressurizer safety/relief nozzle design is conducive to PWSCC. Figure 14 shows the steady state axial and hoop stress distributions along a path line ("IDSURF1
") at the DMW inner surface. Figure 15 shows the steady state axial and hoop stress distributions along a path line ("IDSURF2")
at the inner surface of the liner weld and safe end. These path lines (shown in Figure 12 includes the surfaces of the nozzle, the butter, the repair weld, the DMW, liner weld and the safe end. It is seen that the axial and hoop stresses are all compressive along the inner surface of the DMW region, thus showing the effectiveness of the SWOL as a preemptive measure to reduce the PWSCC susceptibility of the DMW. The through-wall axial and hoop stress distributions, along three path lines in the DMW region and one path line in the SSW, at shutdown are shown in Figure 16 and Figure 17, respectively. These path lines are defined in Figure 13. These axial and hoop stress distributions at shutdown are part of the sources of stress to be used in fatigue crack growth evaluations.
They are tabulated in Appendix A. The through-wall axial and hoop stress distributions at steady state are given in Figure 18 and Figure 19 respectively, using the same path lines defined in Figure 13. These axial and hoop stress distributions at steady state are part of the required stress input to the PWSCC crack growth evaluations.
They are also tabulated in Appendix A. Page 12 ControUed Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary
6.0 REFERENCES
- 1. AREVA NP Document 32-2500013-001, "Technical Basis for Numerical Simulation of Welding Residual Stresses" 2. "ANSYS" Finite Element Computer Code, Version 10.0, ANSYS Inc., Canonsburg, PA 3. AREVA NP Drawing 02-8018401C-001, "Diablo Canyon Unit 2 Pressurizer Safety/ReliefNozzle Existing Configuration" 4. AREVA NP Drawing 02-8019311D-001, "Diablo Canyon Pressurizer Safety/ReliefNozzle Weld Overlay Design Input" 5. AREVA NP Document 08-9042937-003, "Pressurizer Nozzle Weld Overlays at Pacific Gas and Electric Diablo Canyon Nuclear Power Plant, Unit 2 -Certified Design Specification" 6. AREVA NP Document 32-2500012-002, "Materials Database for Weld Residual Stress Finite Element Analyses." 7. ARE VA NP Document 55-WP3-8-F430L TBSCa3-005, "Welding Procedure Specification." Page 13 Controlled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary
7.0 COMPUTER
OUTPUT The computer output files that support the fracture mechanics analysis are listed in Table 7-1. Table 7-1: Computer Output Files for Fracture Mechanics Analysis*
File Name Date Description SrvSD2 AXIAL.out 5/31/2007 Axial stress along all four path lines at shutdown (70°F) SrvSD2 _ Hoop.out 5/31/2007 Hoop stress along all four path lines at shutdown (70°F) SrvSD2 Locs.out 5/31/2007 Path coordinates for all four path lines at shutdown (70°F) SrvHU3 AXIAL.out 5/31/2007 Axial stress along all four path lines at steady state (653°F) SrvHU3 _ Hoop.out 5/31/2007 Hoop stress along all four path lines at steady state (653°F) SrvHU3 Locs.out 5/31/2007 Path coordinates for all four path lines at steady state (653°F) Verification Case for elements Plane 55 and V m3 2-Modified.
vrt 5/30/2007 Plane 182 through axisymmetric analysis of thermal stresses in an infmitely long cylinder.
Verification Case for element Plane 182 through Vm38-Modified.vrt 5/30/2007 axisymmetric analysis of elastic plastic problem of an infmitely long cylinder under pressure.
- Note: The computer output from Revision 000 of this document is unchanged and remains applicable to Revision 002. It is therefore not attached to Revision 002. The list of computer output is provided for information only. Page 14 Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary
8.0 FIGURES
SECTION Figure 1: Welding of the stainless steel safe end to the pressurizer safety/relief nozzle using Alloy 82/182 weld metal I .. -......................
.. Figure 2: Removal of weld material from the inner surface of the DMW and replacement of the cavity with Alloy 182 weldment to simulate a weld repair .................. _______ ..... Figure 3: Welding of the liner to the inside surface of the nozzle I ... ..._ ' Page 15 Controlled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure 4: Welding of the stainless steel pipe to the safe end using stainless steel weld metal Figure 5: Welding of an Alloy 52M SWOL onto the outer surface, covering the nozzle, the DMW, and the stainless steel weld ............. --.....,..
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.. ....... **---*-****** *--Page 16 Controlled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure 6: Finite element mesh for the safety/relief nozzle design and SWOL OM We l d w i th Rep a ir S t a i n l ess Steel Weld Page 17 Cant oiled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure 7: Weld passes employed in the DMW Figure 8: Weld passes employed for the weld repair and in the stainless steel weld Figure 9: Weld passes employed in the SWOL and liner weld Page 18 Controned Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure 10: Axial and hoop stress contours at shutdown (70°F) obtained by applying two operating load cycles following the completion of the SWOL Page 19 Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure 11: Axial and hoop stress contours at steady state (653°F) obtained by applying two-and-a-half operating load cycles following the completion of the SWOL Page 20 Cont r o H ed Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure 12: Path lines for axial_and hoop stress distributions along the ID surfaces Figure 13: Path lines for the through-wall axial WRS distribution in the DMW region and the stainless steel weld Page 21 Controlled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure 14: Axial and hoop stress distributions along the DMW ID surface at steady state (653°F) Figure 15: Axial and hoop stress distributions along the liner weld ID surface at steady state (653°F) Page 22 Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure 16: Through-wall axial stress distributions at shutdown (70°F) obtained by applying two operating load cycles following the completion of the SWOL Figure 17: Through-wall hoop stress distributions at shutdown (70°F) obtained by applying two operating load cycles following the completion of the SWOL Page 23 ControHed Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure 18: Through-wall axial stress distributions at steady state (653°F) obtained by applying two-and-a-half operating load cycles following the completion of the SWOL shutdown Figure 19: Through-wall hoop stress distributions at steady state (653°F) obtained by applying two-and-a-half operating load cycles following the completion of the SWOL Page 24 Controlled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary APPENDIX A: AXIAL AND HOOP STRESS TABLES Figure 13 shows the path lines along which the stress results are obtained.
The axial and hoop WRS distribution at the completion of the SWOL at shutdown and steady state operating conditions are listed in Table A-1 and Table A-2 respectively.
Table A-1: Through-wall axial and hoop stress distributions at shutdown (70°F) Along Path Line "FR1" Distance Along Path Line from the AxiaiWRS HoopWRS ID (in.) (psi) Along Path Line "FR3" Distance Along Path (psi) Line from the Axial WRS Hoop WRS ID (in.) (psi) (psi)
Path Line "FR2" Distance Along Path Line from Axial HoopWRS the ID (in.) WRS (psi)
Path Line "FR4" Distance Along Path (psi) Line from Axial Hoop WRS the ID (in.) WRS (psi) (psi)
Page A-1 Controlled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Table A-2: Through-wall axial and hoop stress distributions at steady state (653°F) Along Path Line "FR1" Path Line "FR2" Distance Distance Along Path Along Path Line from the Axial WRS HoopWRS Line from Axial HoopWRS ID (in.) (psi) (psi) the ID (in.) WRS (psi) (psi) Along Path Line "FR3" Path Line "FR4" Distance Distance Along Path Along Path Line from the AxiaiWRS HoopWRS Line from Axial HoopWRS ID (in.) (psi) (psi) the ID (in.) WRS (psi) (psi) Page A-2 ControUed Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary APPENDIX 8: VERIFICATION OF THE FINITE ELEMENT PROGRAM The following two verification cases were run to verify that the finite element program ANSYS [2] executes properly.
The two cases were selected to verify the elements used in the current analysis (plane 55 and plane 182) for the scope of the simulations used in this document, thermal stress analysis in an infinitely long cylinder and elastic plastic structural analysis in a cylinder.
For the thermal stress analysis case, the standard ANSYS verification case (vm32) is setup to verify plane 55 (thermal) and plane 42 (structural).
This case was modified to replace plane 42 structural element with plane 182. For the elastic plastic case, the ANSYS verification test case was setup to handle plane 42, this case was modified to verify the plane 182 element instead of the plane 42 structural element. The results of the verification cases are presented below: -------------------
VM32-Modified RESULTS COMPARISON
I TARGET I ANSYS I RATIO THERMAL ANALYSIS:
T (C) X=.1875 in T (C) X=.2788 in T (C) X=0.625 in -1.00000 -1.00000 1.000 -0.67037 -0.67039 1.000 0.00000 0.00000 0.000 PRINTOUT RESUMED BY /GOP STATIC ANALYSIS:
A_STS psi X=.187 420.42 429.99 1.023 T _STS psi X=.187 420.42 429.61 1.022 A_STS psi X=.625 -194.58 -205.15 1.054 T _STS psi X=.625 -194.58 -205.08 1.054 -------------------
VM38-Modified RESULTS COMPARISON
I TARGET I ANSYS I RATIO FULLY ELASTIC, PLANE182 RESULTS: SIGR LFT _END psi -9984. -10075. 1.009 SIGT LFT _END psi 18645. 18785. 1.008 SIGR RT _END psi -468. -478. 1.021 SIGT RT _END psi 9128. 9131. 1.000 FULLY PLASTIC, PLANE182 RESULTS: SIGEFF L 30000. 31239. 1.041 SIGEFF R 30000. 30442. 1.015 This is modifie.d from ANSYS VM38 case to verity the PLANE 182 Element solving a problem of Long Cylinder under plastic Pressure Load Page B-1 Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary APPENDIX C: STRESS FOR EVALUATING NDE INDICATIONS C.1 Purposes The purpose of this appendix is to summarize residual stresses to support flaw evaluations of indications detected or assumed to exist based on the results of the 2013 seventeenth refueling outage (2R17) inservice inspection that are considered rejectable in the overlaid Pressurizer (PZR) Safety Nozzles of Diablo Canyon Power Plant (DCPP) Unit 2. The indications are reported in Reference
[C1]. Results are provided along path lines that are located in close proximity to the found indications in the Safety/Relief nozzle. C.2 Methodology This revision provided only post processing of the database that was developed in the previous revision of the document.
Path lines for obtaining the residual stresses were selected to best match the locations and sizes of the flaw indications as described in Reference
[C1]. It should be noted that since the finite element is discrete and it does not exactly match the sketches of the Safety Nozzles provided in Reference
[C1], the selected path lines location and sizes are only a best estimate representation of the indications locations and sizes. For every reportable indications two path lines were selected, an interfacial (horizontal path line) and a vertical path line. The interfacial path line is used to sample stresses to be used for evaluating a laminar flaw. Thus radial and shear stresses are of interest for the interfacial path line. The vertical path line is used to sample stresses to be used for evaluation any planar projection of the indications.
Axial, hoop stresses, or both axial and hoop stresses may be used for evaluating the planar extent of the indications.
The path lines investigated in this appendix are illustrated in Figure C-1 through Figure C-3. Since only Safety Nozzle "A" indication has planar component vertical path line of only Safety Nozzle "A" will be required for further analysis.
Stresses along vertical path lines B, C1 and C2 are included for information only. Figure C-1: Safety Nozzle A Path lines Safety Nozzle A ---Interfacial Pathline Page C-1 Cant oiled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Figure C-2: Safety Nozzle B Path lines Safety Nozzle B Interfacial Path line Figure C-3: Safety Nozzle C Path lines Safety Nozzle C Vertical Path line Safety Nozzle C Vertical Path line 2 Safety Nozzle C Horizontal Path line 2 Page C-2 Controiled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary C.3 Results Axial (SY), hoop (SZ), radial (SX), and shear (SXY) stresses are read from the database and the result files that were archived with the previous revisions of this document.
To ensure that the stress sampling results in the most bounding stresses for the path lines located near the interface of the overlay and the original material (nozzle), the post processing for interfacial path lines was processed while selecting either the overlay material, the nozzle material, or both materials.
C.3.1 Interfacial Pathlines Results As mentioned above, the interfacial path lines are of interest for evaluating laminar flaws. Thus, only the radial and shear stresses are of interests.
As discussed before, for all interfacial path lines (except for Safety Nozzle C Interfacial Pathline 2, which is located entirely in the overlay), three post processing runs were performed by either selecting all materials, overlay material, or nozzle material.
The results are documented in output files "SafetyRellief_pathsALL.out", "SafetyRellief_pathsOL.out", "SafetyRellief_pathsBASE.out".
The results from the output files are manipulated in file "Results.xlsm" to select most bounding stresses.
The minimum and maximum values of the radial and shear stresses are tabulated in Table C-1. Table C-1: Bounding Radial and Shear Stresses for Interfacial Path lines Nozzle Path line Radial Stress (psi) Shear Stress (psi) Minimum Maximum Minimum Maximum Safety Nozzle A [ ] [ ] [ ] [ ]
Safety Nozzle B [ ] [ ] [ ] [ ]
Safety Nozzle C (1) [ ] [ ] [ ] [ ]
Safety Nozzle C (2) [ ] [ ] [ ] [ ]
C.3.2 Vertical Path lines Results Vertical path lines are required for analyzing the planar flaws. Only axial and hoop stresses are of interest in the analysis.
The post processing was performed by selecting all materials. The results are documented in output files "SafetyRellief_pathsALL.out".
The hoop and axial stresses are tabulated below in Table C-2. Since only Safety Nozzle "A" indication has planar component only Path line "A" stresses will be required for further analysis.
Stresses along path line B, C1 and C2 are for information only. Page C-3 Controlled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary Table C-2: Through-wall axial and hoop stresses for vertical path lines at shutdown (70°F) Along Path Line "A" Along Path Line "B" (For information only) Distance Distance Along Path HoopWRS AxiaiWRS Along Path Hoop Axial WRS Line from the (psi) (psi) Line from WRS (psi) (psi) ID (in.) the ID (in.) Along Path Line "C1" Along Path Line "C2" (For information only) (For information only) Distance Distance Along Path HoopWRS Axial WRS Along Path Hoop AxiaiWRS Line from the (psi) (psi) Line from WRS (psi) (psi) ID (in.) the ID (in.) Page C-4 Controlled Document A AREVA Document No. 32-9219813-002 Diablo Canyon Unit 2 Pressurizer Safety/Relief Nozzle Weld Overlay Residual Stress Analysis-NonProprietary C.4 Computer Usage C.4.1 Software and Hardware ANSYS Version 14.0 [C2] was used in this calculation.
Verification test cases were performed and documented herein.
- Computer program tested: ANSYS Version 14.0, verification tests vm32mod2D.vrt and vm38mod2D.
vrt.
- Error notices for ANSYS Version 14.0 were reviewed and none apply for this analysis.
- Computer hardware used: The computer hardware used in the analysis is DELL (Service Tag # 5VKW5S1).
The hardware platform is Intel CoreŽ i7-2640M CPU @ 2.8 GHz, 8 GB RAM and operating system is Microsoft Windows 7 Enterprise x 64 Edition, Version 2009, and Service Pack 1.
- Name of person running the test: Silvester Noronha
- Date of test: 11-05-2013
- Acceptability:
For ANSYS 14.0 cases vm32mod2D, vm38mod2D, obtained from Reference
[1] are run to verify that the answers are correct. The files vm32mod2D.vrt and vm38mod2D.vrt contain output from the test cases. Review of the output shows that the answers are identical to those contained in Reference
[1]. C.4.2 Computer Files All ANSYS input/output files are collected and listed in Table C-3. All computer runs and post processing along with post processing macros are documented in the ColdStor storage path "\cold\Generai
-Access\32\32
-9000000\32-9049062-003\official".
ANSYS verification input/output files are also listed. Table C-3: Computer Files Name Size Date/Time Modified Checksum ........ w .......................... ...................................................
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PostProcessSafetyAll.inp 4168 Nov 04 2013 11:05:26 16117 PostProcessSafetyBase.inp 4171 Nov 04 2013 14:38:55 13367 PostProcessSafetyOL.inp 4165 Nov 04 2013 14:38:40 64989 SafetyRellief_pathsALL.out 12056 Nov 04 2013 13:40:51 33139 SafetyRellief_pathsBASE.out 12059 Nov 04 2013 14:41:17 34886 SafetyRellief_pathsOL.out 12053 Nov 04 2013 14:40:03 57649 Results.xlsm 52148 Nov 14 2 013 16:38:08 09536 vm32mod2 D. inp 3551 Jan 05 2009 10:09:26 30336 vm32mod2D.vrt 624 Nov 05 2013 09:55:59 17780 vm38mod2D.inp 2458 Jan 07 2009 11:28:06 51869 vm38mod2D.vrt 650 Nov 05 2013 09:56:31 36343 C.5 References C.1. AREVA Document 38-9200149-001, (DCPP Unit 2 DIT-50540188-04-00), "DCPP Unit 2 Pressurizer Nozzle NDE Data" C.2. ANSYS Finite Element Computer Code, Version 14.0, ANSYS Inc., Canonsburg, PA Page C-5 Controlled Document 0402-01-F01 (Rev. 018, 01/30/2014)
A AREVA CALCULATION
SUMMARY
SHEET (CSS) Document No. 32 -9219781 -002 ---------------------===----------------
Safety Related: IZJYes D No Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Title Proprietary PURPOSE AND
SUMMARY
OF RESULTS: PURPOSE: The purpose of this calculation is to qualify the Diablo Canyon Unit 2 spray nozzle weld overlay design to the requirements specified in Reference
[1]. The analysis was performed using computer program ANSYS version 11.0 and StressRange version 2.0.
SUMMARY
OF RESULTS: The calculation demonstrates that the design of the Pressurizer spray nozzle weld overlay for Diablo Canyon Unit 2 meets the stress and fatigue requirements of the ASME Code (References
[14]). Based on the loads and cycles specified in References
[2] and [4], the conservative fatigue analysis indicates that Pressurizer spray nozzle weld overlay design has the maximum usage factor of [ ] for specified number of cycles per Reference
[2] compared to the ASME Code allowed maximum value of 1.0. This document is the Non-Proprietary document for 32-9049112-005.
Proprietary information is contained within bold square brackets"[
]". Westinghouse proprietary information is contained within blue boxes. The complete document has 110 pages, which includes pages 1, 1 a, 1 b, and 2 through 108. THE FOLLOWING COMPUTER CODES HAVE BEEN USED IN THIS DOCUMENT:
CODENERSION/REV ANSYS 11.0 (Rev. 000) StressRange 2.0 (Rev. 000) ANSYS 14.0 (Rev. 002) CODENERSION/REV Operating System: Win 7 THE DOCUMENT CONTAINS ASSUMPTIONS THAT SHALL BE VERIFIED PRIOR TO USE DYes l2Sl No Page 1 of 110 Controlled Document A AREV.A 0402-01-F01 (Rev. 018, 01/30/2014)
Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Review Method: IZJ Design Review (Detailed Check) D Alternate Calculation Signature Block P/R/A Name and Title and (printed or typed) Signature LP/LR Date Samer H Mahmoud p Principal Engineer Tom Riordan 12SEP2014 Engineer III R Tim M Wiger --p;1. ?0--;?r A Y-01 Engineering Manger \.../ I Note: P/RIA designates Preparet (P), Reviewer (R), Approver (A); LPILR designates Lead Preparer (LP), Lead Reviewer (LR) Pages/Sections Prepared/Reviewed/Approved All. All. All. Project Manager Approval of Customer References (N/A if not applicable)
Name Title (printed or typed) (printed or typed) Signature Date N/A N/A N/A N/A Mentoring Information (not required per 0402-01) Name Title Mentor to: (printed or typed) (printed or typed) (P/R) Signature Date N/A N/A N/A N/A N/A Page 1A A AREVA *Controlled Document 0402-01-F01 (Rev. 018, 01 /30/2014)
Document No. 32-9219781-002 Diablo Canyon Unit 2 -Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Record of Revision Revision Pages/Sections/Paragraphs No. Changed Brief Description I Change Authorization 000 All Original Release. 000 All Non-Proprietary document for 32-9049112-003 001 CSS, page 1 Updated the purpose and summary. 001 Throughout Proprietary markings of material names removed. 001 Non-Proprietary document for 32-9049112-004.
001 Throughout Added Westinghouse proprietary indicators.
002 Throughout Updated proprietary markings Non-Proprietary document for 32-9049112-005.
Page 1 B Controlled Document A AREV.A Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Table of Contents Page SIGNATURE BLOCK .............................................................
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...... lA RECORD OF REVISION .....................................................................................................
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9 3 KEY ASS U MPTION ....................
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1 0 4 DES I GN INPU T ...................................
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10 4.1 G E OI\1ETRY ...........................................
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10 5 FINITE E L E fEN T MODEL ..................................................
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13 5.2 BOUNDARY CONDITIO N AND L OADS .......................................................................
17 5.2.1 Therma l Boundary ............
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... 17 5.2.2 Stn 1 ctu:ml Bou n dacy ...................................
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1 7 6 EXTERNAL LO .. i\D*S ...........
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20 6.1 APPL I CABL.E. LOAD*S ......................................................................
................................ 20 6.1.1 Nozzle Cross Sections ........................
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............... 22 6.1.2 Stress Due To Externa l Loads Calculation
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26 8 THERJviAL ANALYS I S ..........................................................................
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29 9 STRUCTURA.L A N ALYSIS ............................
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73 10.1 AS1>fE Code Primary-Str*ess Intensity (SI) Criteria .................
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73 l 0.2 ASME Code Primary + Secondary Stress Intensity (SI) Criteria ................
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76 10.2.3 Ivlaximum P rimary+ Secondary Str.ess. In t ens ity R a n ge ...........................................
76 10.2.4 Pr i mary+ Seco n dary (P+Q) Stress Intensity R ange Qualification (NB 3222.2) ..... 76 Page 2 ControUed Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2 -Pressurizer Spray Nozzle Weld Overlay Structural Analysis -Non Proprietary Table of Contents (continued)
Page 10.2_5 Simp]ifi e d Elastic-Pl a stic Analysis (NB-3228.5) ...................................................... 78 10.2.6 Fatigue Usage Factor Calculation
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.... 82 1 1 RESULTS S U MMARY /CONSLUSION
................ *--------------*----------------------**-----------*** __________ 91 12 SOFTVlARE VE RI FICATION _______________________________________________________________________________________________
92 13 COMPUTER OUTPUT FILES __________________ ........ ___ .................... ____ ... _____________ ... ___________ . _ ... _______ 93 14 REF E.RE.NCE ____________________________________________________________ 97 APPENDi.X A-Stresses used for Fract u re Mecha n ics Analysis--
*-----------------
98 APPENDIX B-Additional Stresses Used For Fracture Mechanics Analysis ...................
....... 100 Page 3 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2 -Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary List of Tables Page Table 5-l Table ofMaterials
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13 Table 5-2 Pressurize!" Upper Head Mate:rial PI"operties
......................................................
..........
14 Table 5-3 Spray Nozzle and Nozzle to Head Weld Mate:rial Properties
.......................
...............
1 5 Table 5-4 Safe End Material Properties
................
---*---------------------*****************
- ----****----****-15 Table 5-5 Sale End to Nozzle \\7 eld. Buttei"ing 1\.faterial Properties
...........................
................
.. 15 Table 5-6 Thermal Sleeve, Liner , Cladding andl Safe End to Pipe \'leld 1\.faterial Properties
...... 16 Table 5-7 Pipe Material Properties--
-*****************************:*********************-**
-**********-*-******--------**---*****
16 Tabl e 5-8 \Veld Overlay Matei"ial Properties
..............
..........
.................
.......................................
16 Table 6-1 External Loads ... *--*--****----**------------**----*-------*
- -***-----**-***-*-*-**-----*--*--**-***--*-***
- ----------------
20 Table 6-2 External Summary-*****--***--*-----------*---------------*-------****-----------*****--***-------*----
-*-----21 Table 6-3 Nozzle CI"oss Sectional Chai"actei"is.tics
........................................................................
22 Table 6-4 Summary of the Stress Components-OBE .........................
........................................
23 Table 6-5 Summary of the Stress Components-Thermal Expansion
..................
.......................
24 Table 6-6 Summary* of the Stress Components-OBE + Therm1J!l Expansion
.........................
.... 24 Table 6-7 Stress Intensity Summary-OBE ..........
..................
................................
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24 Table 6-8 Stress Intensity Summary*-Tnenna l Expansion
...................................................
....... 25 Table 6-9 St:ress Intensity Summary-OBE + Thermal Expansion
.............................................
25 Table 8-1 Transietlts
*--
**-----------*****---**----****---
*------------------***
29 Table 8-2 Summary of Ana]yzed Transients----------------------
32 Table 8-3 Heat-up Early Spray
.... * .........................
....................................................... 33 Table 8-4 Heat-up Late Spray Transient
.....................
..................................................................
34 Table 8-5 Cool-Down Early Spray with Temp , erature Drop of 405°F ..................................
....... 35 Table 8-6 Late Spray with Temperature DI"op of 405°F ....................................
....... 36 Table 8-7 Coo]-Down Early Spray with Temperature Drop of320°F .................................
........ 37 Table 8-8 Cool-Down Late Spray \vith Temperatu:re Drop of320°F ........................................
... 38 Table 8-9 Unit Loading & Unit Unloading at of Full Po*wer T r.ansients
................................
39 Table 8-10 Large Step Decrease in Load! Transient..
.....................
...............................................
39 Table 8-11 Step Load Increase of 101}'0 of Full Po\ver Transient
...................................
............... 40 Table 8-12 Step Load Decrease of 10%, of Full Power Transient
..................
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................. 41 Page4 Contro U ed Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary List of Tables (continued)
Page Table 8-13 Bor on Concentration Equa l i za tion Transient
............................................................
42 Table 8-14 Loss of Load Transient
...............................................................................................
42 Tabl e 8-15 Loss ofPm.ver Transient.
...................................
......................................................... 43 Table 8-16 Los s of Flow Transient.
..............................................................................................
44 Table 8-17 Reac tor Trip Transient
...............................................................................................
45 Table 8-18 Inadvertent Auxiliary Spray Transient.
......................
................................................ 46 Tabl e 8-19 Turbine Roll Test TrruLsienL
......................................................................................
46 Table 8-20 Nodes of Interest for Evaluation of Temperature Gradients
...........................
........... 48 Table 8-21 Temperature Gradients ofinterest
...............
..................
............................................. 48 Table 9-1 Time Points ofJinter*est-HU-ES ..................................................................................
67 Table 9-2 Time Poin ts ofJinter.est-HU-LS ..................................................
................................ 68 Table 9-3 Time Points ofJinterest-CD-ES405 ---------****************************-******--***************-****----******
68 Table 9-4 Time Points oflnter.est-CD-LS:}05
................................
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......................... 69 Table 9-5 Time Points ofinterest-CD-ES320 .................................
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....... 69 Table 9-6 Time Points ofinterest-CD-LS J20 .....................................
...............................
........ 70 Table 9-7 Time Points ofinterest-PLPU ....................................
- ............................................... 70 Table 9-8 Time Points ofinterest-LSL .....................................
..................................................
70 Table 9-9 Time Points of Inter-est-SLI -----------*****---
*************----------------------**--******
71 Table 9-10 T ime P oints ofinterest.-
LOL *****-----***-----***----------------*-**************----*************-*****---**
- 71 Table 9-11 Time Points ofinter e st-SLD -----------------------------------------*-**--******--*-***----------------*-----**
71 Table 9-12 Tim e P oints ofJinterest-BCE ********-******-*****--******--*************
- --------------------------------
71 Table 9-13 Time P oints ofinterest-LOP ....................................................................................
71 Table 9-14 Time Po ints oflnterest-LOF -------**************************************-----------****-------*-----------*****
72 Table 9-15 Time Poin ts ofinterest-RT ....................................................................................... 72 Table 9-16 Time P oints ofJinterest-JIA ......................................................................
................. 72 Table 9-17 Time Points of Interest-TRT .................
...................................................................
72 Table 10-1 Path D*ermition ............................................................................................................
74 Table 10-2 Summary ofrYfaxnnum Primary+ Sec.on dary SI Ranges forM+ B Stcess*es ........... 77 Tabl e 10-3-Loa d Step Combinations for th e l.ocations.
that Exceed 3Sm Limit. .........................
78 Table 10-4 SI Range s of Maximum Primary+ Secondary M en1bra ne Plus Ben di ng Stress Ex cludi ng Thermal Bending Stresses ....................
....................................
- -***************:*****************
79 Page 5 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary List of Tables (continued)
Page Table 10-5 General JVf , embrane Stress for Critical Locations
..................
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81 Table 10-6 Allowable Ranges ofThermal Stresses ....... *-*************--------------------**-------------*---------
--* 81 Table 10-7 Minimum St£ength Ratio ...........
...................................
.............................................. 82 Table 1 0-8 St£ess Category and FSRF in Fatigue Evaluation****-*******--******---******---****-----***
- --*-***** 83 Table 1 0-9 Nozzle Usage Factor. ..................................................................................................
8.4 T able 1 0-10 DM \Veldt Usage Factor. ................................................................................
........... 85 Ta ble 1 0-11 Safe End Usage Factor ...............
............
........................................................
.......... 86 Ta ble 1 0-12 E and Sm at Ave£age Temperature for Table 10-11 Fatigue Evaluation
.................
8:7 T able 10-13 Safe End to Pipe \Veld Us age Factor .....................
...............................
................... 88 Ta ble 10-14 W*eld Overlay Usage Facto£*************
- --****************-***--******--*****-***-
- -*****--*-****---
89 Table 10-15 Pipe Usa ge Factor. ....................................
..............................................................
.. 90 Table 11-1 Summaty ofResuhs ............................
................
....................
..............................
..... 91 T able 12-1 ANSYS \'*e£iflication Files ............
.................... : ..........................
............................... 92 Tabl e 12-2 StressRauge P£ogram v2.0 Verification F il es ..................................................
.......... 92 Tabl e 13-1 Compute:r Output and Input Files .....................................
...................
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.......... 93 T able A-1 Path Desc£iiption
..............................................
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.. 98 Table B-1 Additional Paths in Appendix B ..........................................................
- ....................
100 Table B-2 Appendix B ANSYS files .........................................................................................
105 Page 6 ControUed Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressur i zer Spray Nozzle Weld Overlay Structural Analys i s-Non Propr i etary L i s t of F igur es Page Figure 5-1 Expanded 2-D Axisymmetric lvfodel of the Spray Nozzle *with 11 Figure 5-2 Finite Element Model-Mesh---------*----
12 Figure 5-3 Thermal Boundary Conditious
_______________________________________
_______________________________________
"* ____ 18 Figure 5-4 Stn1ctural Boundary*
Conditions
________ ;-*---------
1 9 Figure 6-1 Po i nt of External Loads*--------------*-**--*---------*
*-------------------------------
---*---------*
2 1 Figuce 7-1 Deformed Shape vs. Un-defonned Outline ________________________________
_______________________________
__ 26 Figure 7-2 Stress I ntensity Contoucs at Design Condition------------------------------------
27 Figure 7-3 Contact P:ressure at Design Condition
____________________
_______________________
_________________________
_____ 28 Figure 8-1 Heat-Up and Cool-Down Early and Late Tran.<.iients with Sp:ray Actuations-
31 Figure 8-2 Location Num b ers for Evaluation of Temperature Gradients
_____________________________________
49 Figure 8-3 Heat-Up Early Sp:ray Transi*ent ___________________________________________________
________________________________ 50 Figure 8-4 Heat-Up Late Spray Transient--------
*-*---------*-----*----------**-------------
***
51 Figt1ce 8-5 Cool-Do\vn Eady Sp:ray \Vith Temperatu:re Drop of 105°F ------------------------------------
52 Figure 8-6 Cool-Do\vn Late Spray with Tempe:rature Drop of 40:5°F ---------*---------
*53 F iguce 8-7 Cool-Do\vn Eady Spray with Temperatuf<e Drop of320,oF --------*---------------*
-*--*-**------*54 Figuce 8-8 Cool-Dowu Late Spray with Temperature Drop of320°F -*-----***-*
***55 Figt1ce 8-9 Unit Loading & Unit UnlQading at of Fun Powe:r Transients
___________________ , __________
56 Figtl£e 8-10 Large St*ep De*creas*e in Load* Transient-
-*-*-------
57 Figure 8-11 Step Load Increase of 100,'o of Full Transient-----
58 Figttre 8-12 Step Load D , ecrease of of Full Power Transient
______________________
_________________
________ 59 Figure 8-13 Boron Concentration Equaliza t ion Transient
... ------------------------------------
60 Figttre 8-14 Loss of Load Transi.eu t. __ . __________ . _____ .. __________ . ___ .. __ . ___ . _ ... __ ...... _ ... __ .. __ ... _____ .. _. ____ ... __ . __ ... 61 Figure 8-15 Loss of Power Transient.
___________________________________
___________________________________
____________________ 62 Figure 8-16 Loss of Flow Transient
________________________________
____________
____________________
______________
________________
63 Figure 8-1 7 Reactor *Trip Transient-
- ------------------------------------*------------*--*-------------***** 64 Figuce 8-18 Inadvertent Auxiliary Sp:ray Tcans1.ent
__________________________________________________
____________________ 65 FigJife 8-19 Turbine Roll Test Transient-----
*-***-***-*
-:***------**--*-----
*-------*----------66 FigJtce 10-l Stress Paths through the Spcay Nozzle J\.1odel ________________________________
____________
______________ 75 Figure A-1 Paths Defined for Fractu:re Mechanics Evaluation
..............
....... ------****-----*-
... 99 Figu r e B-1 Additional Paths For Fracture Mechanics
.............
.................................................
102 Figure B-2 Stress Plots during HU-ES ..........................
................................................. .........
103 Figu r e B-3 Stress Plots during CD-ES 05 ..................
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104 Page 7 Contro U ed Document A .AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary 1 PURPOSE
1.1 INTRODUCTION
Primary water stress corrosion cracking (PWSCC) of Alloy 600/82/182 materials is a well documented phenomenon in the nuclear power industry.
High temperature components, such as those associated with the pressurizer , have risk for PWSCC. Pacific Gas and Electric (PG&E) plans to mitigate the Diablo Canyon Unit 2 pressurizer nozzle Alloy 82/182 dissimilar metal (DM) welds with full structural weld overlays (SWOL) during the spring 2008 2R14 refueling outage for Unit 2. The planned mitigation using SWOL is a preemptive measure to reduce susceptibility of the DM weld and the adjacent pipe to safe end welds to PWSCC. 1.2 SCOPE The spray nozzle is located on the top of the pressurizer upper head. The nozzle provides a conduit for spray line sprays. The weld overlay is designed to cover both the Alloy 82/182 DM weld and the austenitic stainless weld between the nozzle safe end and the pipe. Application of weld overlays alters the local stress distribution.
A detailed finite element analysis (FEA) is therefore conducted to investigate stress conditions . under various operational transients.
The results are summarized in this report to certify that criteria per ASME Code Section ill for Class 1 components (Reference
[14]) are satisfied for the spray nozzle with weld overlays.
The analysis is focused on the overlaid region for requirements on both stress distribution and fatigue failure criterion.
The main scope of the analysis includes the spray line piping , the stainless steel weld between the safe end and the piping , the safe end , the DM weld between the safe end and the nozzle , the spray nozzle , SWOL , and the pressurizer upper head. In addition , post-processing of thermal and stn1ctural results is performed to provide data for fracture analysis of the spray nozzle (see APPENDIX A). It should be noted that the original nozzle configuration without the Weld Overlay is not analyzed in this calculation.
The application of the SWOL will increase the secondary stress due to thermal gradients and added discontinuities at the SWOL to pipe , and SWOL to nozzle _ junctures.
The cumulative fatigue usage factors calculated in this document assume the spray nozzle SWOL has been in place since the plant conception.
Therefore, the usage factors calculated will be higher than the actual usage factors based on summing spray nozzle's usage prior to SWOL and usage with the SWOL. Page 8 Controlled Document A A.REVA. Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary 2 ANALYTICAL METHODOLOGY The general methodology of model developtnent and stress analysis consists of: 1) Only the minitnum SWOL will be modeled and evaluated.
Based on past experience, the stresses due to transients had minor differences between the maximum SWOL and minin1um SWOL, and the minimum SWOL stresses due to external loads control over the maximum SWOL. Therefore, it is reasonable to evaluate the minimum SWOL only. 2) Building a two-dimensional model of the spray nozzle weld overlay geometry.
The model incorporates the geon1etry (of the adjacent upper head, spray nozzle, spray nozzle safe end , welds, weld overlay and a part of the pipe welded to the spray nozzle safe end), appropriate materials, and boundary conditions.
The 2-D solid n1odel is converted into a 2-D ftnite element model. There are two finite element n1odels consisting of thermal and structural elements, respectively, to enable the thermal and structural analysis.
- 3) Applying the design conditions of pressure and temperature (as temperature affects the material properties only) to the structural fnrite element model and obtaining the deformation and stresses in the model. The deformation fteld is used to verify the correct behavior of the model and correct modeling of boundary and load conditions.
- 4) Applying the thermal loads resultit1g from the plant operating transients (in the fom1 of transient temperatures and corresponding heat transfer coefficients versus time). Evaluatit1g the results of the thermal analysis by examinit1g the magnitude of temperature differences between key locations of the model. The time points of the maximum temperature gradient are those at which the maximum thermal stresses develop. 5) Applying the corresponding pressure and thermal loads (nodal temperature) at each time point identified in step 3 and other time points of analytical interest on the structural finite element model and obtaining the stress results. 6) Hand calculatit1g the effects due to the nozzle exten1al loads and adding the resulting stresses to the stress results due to the pressure and temperature effect. 7) Comparing the results to the ASME Code for acceptability.
- 8) Docun1enting stresses and tetnperatures for the fracture n1echanics analysis of the spray nozzle weld overlay design. Page 9 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary 3 KEY ASSUMPTION There are no major assumptions for this calculation.
Minor assumptions are noted where applicable.
4 DESIGN INPUT 4.1 GEOMETRY Some of the major dimensions (References
[ 11] and [ 12]) are: Page 10 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2 -Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary 5 FINITE ELEMENT MODEL The 2D axisymmetric finite element model is built based on the weld overlay minimum design. The model simulates, in two-dimensional space, the spray nozzle, safe end, weld overlay, part of the pipe, thennal sleeve and pressurizer upper head. The finite element analyses in this document are performed using ANSYS 11.0 (Reference
[13]). The model was developed in ANSYS WORKBENCH 11.0 and is shown in Figure 5-l. The element type chosen is the structural element PLANE183 (2-D 8-Node Structural Solid). This eletnent is converted to the thermal element type PLANE77 (2-D 8-Node Thermal Solid) for the thermal analysis.
The contact surfaces between the liner and nozzle are modeled by using contact elements TARGE169 (2-D Target Segtnent) and CONTA172 (2-D 3-Node Surface-to-Surface Contact).
The modeled portion of pressurizer head is sufficient for attenuation of the stresses and thermal gradients.
The thermal sleeve is attached by[ ]and it is non-structural weld (Reference
[I] and [12]). Therefore, the thermal sleeve is not included in structural runs. Nevertheless, the thermal sleeve is contained in the thermal runs for temperature distribution.
Pipe Weld Overlay Liner/Safe End Weld Safe End/Pipe Weld DMWeld Safe End Spray Nozzle Thermal Sleeve Weld Upper Head Figure 5-1 Expanded 2-D Axisymmetric Model of the Spray Nozzle with SWOL Page 11 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary r--Figure 5-2 Finite Element Model -Mesh r---1 I I I I I I I I I I I I Page 12 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2 -Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary
5.1 MATERIALS
Reference
[I] and Reference
[2] provide the material designations of various components as listed below. Per reference
[I], the material properties for the structural analysis shall be in accordance with ASME Code I965 Edition including Addenda through Summer I966 (Reference
[ 6]) for existing material and ASME Code 200 I Edition including Addenda through 2003 (Reference
[ 5]) for weld filler material.
Since not all materials and material properties for existing components are provided by Reference
[6], later Addenda or Editions of the ASME Code (Reference
[7], [8] and [9]) were used to determine the remaining material properties.
Table 5-1 Table of Materials Location Material Pressurizer Upper Head SA 533 , Grade A, Class 2 Spray Nozzle SA 508, Class 2 Nozzle to Pressurizer Weld Safe End SA 182, F316L Safe End to Nozzle Weld Buttering Weld Alloy 82/182 (equivalent to Alloy 600, SB 166) Liner to Safe End Weld 1 Thermal Sleeve to Safe End Weld Thermal Sleeve Liner Cladding 2 SA 213, TP304 Safe End to Pipe Weld 2 Liner to Cladding Weld 3 Pipe SA 376, Grade TP316 Weld Overlay Alloy 52M (equivalent to Alloy 690, SB 166) Reference
[I], par. 4.2.2 specifies material (Alloy 82 and ER309L) for the "Barrier Layer." This very thin layer (0.065in., Reference
[11]) is not modeled in detail in this analysis and is covered by the weld overlay filler material.
The effect on the results is negligible.
1 Material for these welds is specified in Reference
[3]. 2 Reference
[1 ], par. 4.1.5 and 4.1. 7 specify that the cladding material properties should be equivalent to ER309 weld filler material and the existing pipe to safe end weld is E308 austenitic stainless steel. This mate1ial is used for welding components with similar chemical composition such as Type 304 (18Cr-8Ni) material. Therefore material SA-213 , TP304 is considered representative of this weld material.
3 The liner to cladding mate1ial is specified as SS308L per [3]. This material has similar chemical composition such as Type 304 (18Cr-8Ni) material, and material SA-213 , TP304 is considered representative of this weld mate1ial.
Page 13 ControUed Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary The analysis herein uses the thermal properties
-mean coefficient of thermal expansion (a), specific heat (C), thermal conductivity (k) and the mechanical properties
-modulus of elasticity (E), Poisson's ratio (f.l), density (p). The pertinent properties (thermal & structural) for these materials are listed in the following tables. The units of the properties are: Young's Modulus Poisson's Ratio Density E p [10 6 psi] [unitless]
[lb/in 3] Coefficient of Thermal Expansion
- a. [ 10-6 in/in-°F] Thermal Conductivity Specific Heat Design Stress Intensity Yield Strength Tensile Strength k (Btu/hr-in-°F]
C (Btu/lb-°F]
Sm [ksi] Sy [ksi] Su [ksi] (Cis a calculated value: C = k/(p *thermal diffusivity) where them1al diffusivity is taken from the same source as "k") Table 5-2 Pressurizer Upper Head Material Properties SA-533, Grade A, Class 2 (C, Mn, Mo) Temp I E I 1-1 I p I a I k I C I Sm I Sy I Su I Reference I [6] typical [10) [6) [9] I calculated I [8] [8] [8] Page 14 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Table 5-3 Spray Nozzle and Nozzle to Head Weld Material Properties I Reference I [6] I typical I [1 0] I [6] [9] I calculated I [7] [7] [7] Table 5-4 Safe End Material Properties I Reference I [6] typical [1 0] [6] [9] I calculated I [6] [6] [6] Table 5-5 Safe End to Nozzle Weld, Buttering, Liner/Safe End Weld and Thermal Sleeve to Safe End Weld Material Properties Alloy 600,58-166 (Ni-Cr-Fe)
Temp l E l 1J I p I a I k I C I Sm I Sy *1 Su I Reference I [6] typical [1 0] [6] [9] I calculated I [7] [7] [7] Page 15 Controlled Document A AREV.A Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Table 5-6 Thermal Sleeve, Liner, Cladding and Safe End to Pipe Weld Material Properties I Reference I [6] typical (10] (6] (9] I calculated I (6] (6] (6] Table 5-7 Pipe Material Properties SA-376, TP316 (16Cr-13Ni-3Mo)
Temp I E I 1J I p I a I
- k I C I Sm I Sy I Su I Reference I [6] I typical (10] [6] [9] I calculated I [6] [6] [6] Table 5-8 Weld Overlay Material Properties Alloy 690, SB-166 (58Ni-29Cr-9Fe)
Temp I E I 1J I p I a 1* k I C I Sm I Sy I Su I Reference I [5] I typical [10] [5] [5] I calculated I * (5] [5] [5] Page 16 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary
5.2 BOUNDARY
CONDITION AND LOADS 5.2.1 Thermal Boundary During operation without spray events , the inside surface of the upper heacl the inside bore surfaces of the spray nozzle , pipe, safe end weld , a part of the safe end , and the inside & outside surfaces of the thermal sleeve are in contact with the pressurizer fluid at steam temperature.
During spray events , the inside surfaces of the pipe, safe end welcl a part of the safe end , and thermal sleeve are in contact with the spray fluid at spray temperature. An appropriate heat transfer coefficient (HTC) and bulk temperature versus time are applied on these surfaces , which are in contact with the pressurizer steam or spray fluid (Figure 5-3). Thermal coupling was applied on the surfaces between the safe end and thermal sleeve in the thermal sleeve weld vicinity and between the liner and nozzle (Figure 5-3). The outside surfaces of the upper head , spray nozzle , pipe and weld overlay are exposed to the ambient temperature in conjunction with a small HTC. Ambient temperature o( }s used for all time points in the thermal analysis.
The spray nozzle is assumed to be insulated.
A very small HTC o1( ]s used. 5.2.2 Structural Boundary Pressurizer pressure is applied to all inside surfaces which are in contact with steam or fluid. The exteriors of the pressurizer upper head are not loaded by pressure.
The upper end of the pipe has an end cap pressure p* applied to represent the hydrostatic end load from the piping closure. Pressure p* is calculated as follows:[ J Where p is internal pressure , d is inside diameter of the pipe and D is outside diameter of the p1pe. The displacements of the pressurizer upper head in the circumferential direction are set to be zero (see Figure 5-4). Page 17 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Figure 5-3 Thermal Boundary Conditions Page 18 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Figure 5-4 Structural Boundary Conditions Page 19 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary
- s EXTERNAL LOADS 6.1 APPLICABLE LOADS Per Reference
[1], the external forces and moments acting on the spray nozzle safe end weld location (Figure 6-1) are listed in Table 6-1. These loads are defined in the local coordinate system with the "x" axis oriented along the nozzle axis of symmetry in the nozzle to pipe direction per Reference
[3]. The "y" and z" axes are the horizontal components.
The stresses due to OBE and thermal loads are evaluated using hand calculation and they are added to the ANSYS results where appropriate for AS:rvtE evaluation in Section 10. Per Reference
[2], the OBE loads have 400 cycles (20 events with 20 cycles each). The thennal expansion loads are considered during the maximum temperature variance in the pressurizer , which corresponds to the heatup-cooldown transient.
Much smaller temperature variance occurs during other transients and the loads during these variations are much smaller. Therefore , the thermal expansion is assumed to have same number of cycles as the cooldown transients for 250 cycles. The following Table 6-2 lists the loads used for the SI calculation for the evaluated locations.
The total shear force (Fs) and total bending moment (Mb) by combined as the SRSS method. 1 Pressure load is not used since it is accounted in stress analysis model. 2 The DW , SSE and Pipe Rupture loads are not evaluate in this document , since the document qualifies only Primary plus Secondary stress intensity range (see Section 10.1 ); these loads are listed for information pmpose only. Dead weight loads act at all time points of all transients. and therefore do not contribute to the SI Ranges. Page 20
Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Table 6-2 External Loads Summarv --Figure 6-1 Point of External Loads Note: The path's numbering starts fron1 the number "2". TI1e pathline Path l" is no t defmed. Page 21 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary
6.1.1 Nozzle
Cross Sections The cross sectional characteristics are calculated for the path locations as shown in Figure 6-1. These paths correspondent with paths defmed in Section 1 0.2.1 for the stress linearization.
The nozzle geometric dimensions are specified in References
[ 11] and [ 12] and some dimensions are also taken directly from the FE model. Table 6-3 Nozzle Cross Sectional Characteristics Section Modulus Path line r [in] R [in] L [in] I [in'i A [in 2] S [in 3] -Sinside I Soutsid\.-
Path2 Path3 Path4 Path5 Path6 Path? Path8 1 Path9 1 Path10 1 --Where: R -outside radius (for the nozzle, WOL or pipe) r -inside radius (for the nozzle , WOL or pipe) L -moment arm I= Jr (R 4 -r 4) -tnoment of inertia 4 A= 1r(R 2 -r 2) -cross-section area at an appropriate location s outside = I I R ' s ins i de = I I r -section modulus The radii (R, r) are taken at the inside and outside nodes of the paths. Since some of the paths are in slope , the longer moment ann (L) between the safe end weld-root and the further node of the path is conservatively taken into calculation.
1 For paths PathS , Path9 and PathlO , the stress intensity due to axial bending stress from external shear forces would reduce the stress intensity due to transient loads. Therefore. the moment anns for these locations are consetvatively reduced to zero. Page 22 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary
6.1.2 Stress
Intensity Due To External Loads Calculation The stress con1ponents and membrane + bending stress intensities due to external loads and loads combination for inside and outside nodes are calculated based on following fonnulas and they are listed in Table 6-4 through Table 6-9. The resulting stress intensities will be used along with the transient SI Ranges in the AS:ME Code Primary plus Secondary Membrane +Bending SI Range qualification in Section 10.2 ab =Mb IS abs = Fs *LIS r T = M s 1(2. s) axial membrane stress due to an external axial force Fx axial bending stress due to an external moment Mb axial bending stress due to an external shear force Fs shear stress due to an external torsion Mx shear stress due to an external shear force Fs (]"X =(]"ax + (J"b + (J"bS SUm Of axial StreSSeS sutn of shear stresses membrane + bending stress intensity Table 6-4 Summary of the Stress Components
-OBE Shear Inside Outside Path line Oax Ts I abs [ksi] I I <Jbs [ksi] I [ksi] [ksi] ab [ksi] TT [ksi) ub [ksi] Path2 Path3 Path4 Path5 Path6 Path? Path8 Path9 Path10 -rT[ksi] -Page 23 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Table 6-5 Summary of the Stress Components-Thermal Expansion O"ax Shear Inside Outside Path line [ksi] Ts ab [ksi] I O"bs [ksi] I I Obs [ksi] I rT[ksiL. [ksi] Tr [ksi] ab [ksi] Path2 Path3 Path4 Path5 Path6 Path7 PathS Path9 Path10 ---Table 6-6 Summary of the Stress Components
-OBE + Thermal Expansion Shear Inside Outside Path line O"ax [ksi] Ts I <Ybs [ksi] I I O"bs [ksi] I [ksi] ab [ksi] r 1 [ksi] ab [ksi] rr[ksi] *--Path2 -Path3 -Path4 -Path5 -Path6 -Path? -PathS -Path9 -Path10 ---Table 6-7 Stress Intensity Summary -OBE Pathline Inside Outside ax[ksi] I T [ksi] I aiNr[ksi]
ax [ksi] I T [ksi] I 0"1NT (ksi) -Path2 I ---* I ... -------I -*-.... I -----Path3 -Path4 -Path5 -Path6 -Path? -PathS -Path9 -Path10 ---Page 24 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary
- Table 6-8 Stress Intensity Summary-Thermal Expansion Path line Inside I Outside --ax[ksi] I T [ksi] I aiNr[ksi]
I ax [ksi] I T [ksi] I aiNT[ksi]_
Path2 -Path3 -Path4 -Path5 -Path6 -Path? -PathS -Path9 -Path10 --Table 6-9 Stress Intensity Summary-OBE +Thermal Expansion Path line Inside I Outside """. ax[ksi] I T [ksi] I a*Nr[ksi]
I ax [ksi] I T [ksi] I OJNT[ksi]_
Path2 -Path3 -Path4 -Path5 -Path6 -Path? -Path8 -Path9 -Path10 -Page 25 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary 7 DESIGN CONDITION It is assumed that the pressurizer assembly was designed to satisfy the ASJvffi Code Criteria at a pressure of 2485 psig and temperature of 680°F. These design conditions were simulated by setting a uniform temperature of 680°F throughout the n1odel (this temperature is only used to define material properties and not thermal expansion) and a uniform pressure of 2485psig.
The pressure loading is described in detail in Section 5.2.2 . The ANSYS computer output is documented in file "min DC. out". Stress analysis of the model under design pressure case served two important purposes.
It provides a basis for verification of the correct behavior of the model as well as boundary conditions.
Attenuation of stress effects at regions distant from the nozzle is also verified. Figure 7-1 shows the deformed shape of the model under the design pressure along with the outline of the un-deformed shape. The stress intensity contours developed in the model under design pressure is shown in Figure 7-2. The contact pressure between the liner and nozzle is shown on Figure 7-3. Figure 7-1 Deformed Shape vs. Un-deformed Outline Page 26 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Figure 7-2 Stress Intensity Contours at Design Condition Page 27
- Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Figure 7-3 Contact Pressure at Design Condition Page 28 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary 8 THERMAL ANALYSIS The operating thermal loads are defmed by the thermal transient conditions as contained in Reference
[2] and Reference
[4]. The applicable transient data from references are shown in Table 8-1. Table 8-1 Transients ASME Code Transient Name Cycles Spray Actuation 1 Condition Heat Up 250 1200 spray actuations at a Ll T of -320°F arbitrarily, duration of 60 sec. 1200 spray actuations at a L\T of -320°F Cool Down 250 arbitrarily plus an additional 200 spray acuation with a Ll T of -405° F after the pressurizer pressure is below 400 psia, duration of 60 sec. -Unit Loading at 5% of 18,300 rn Full Power/Min E .... Unit Unloading at 5% of 0 18,300 Full Power/Min Spray actuation occurs once during each <( a:; Large Step Decrease in 250 transient cycle at the pressurizer full steady-> Load With Steam Dump state pressure and temperature.
LlT = -125°F, Q) ....J Step Load Increase of duration of 60 sec. Q) 2,500 0 10% of Full Power Q) Step Load Decrease of 2,500 (/) 1 0% of Full Power Steady State Fluctuation
--Spray actuation occurs once during each Boron Concentration 32,000 transient cycle at the pressurizer full steady-Equalization state pressure and temperature.
L\T = -125°F, duration of 60 min. Page 29 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Table 8-1 Transients (Continuing)
ASME Code Transient Name Cycles Spray Actuation Condition Spray actuation occurs once during each Loss of Load 100 transient cycle at the pressurizer full steady--state pressure and temperature. = -125°F, 1i) duration of 60 sec. en a. 2. Loss of Power 50 co a> Loss of Flow 100 -> G.> -' G.> Reactor Trip 500 0 Spray actuation occurs once during each G.> (/) Inadvertent Auxiliary transient cycle at the pressurizer full steady-Spray 12 state pressure and temperature. T = -360°F, duration of 300 sec. Turbine Roll Test 10 t; Leak Test at 2485psig 60 Q) Hydro Test 1 10 During the heat-up and cool-down transients, the timing for the 1200 spray actuations at a 11 T of 320°F is arbitrary.
Therefore, the transients are developed as "Early Spray" (ES) and "Late Spray" (LS) to investigate all limiting cases of spray occurrences.
For cool-down transient , there are the additional 200 spray actuations with 11 T of 405°F when the pressurizer pressure is below 400psia. Therefore , the cool-down is developed as early spray and late spray with temperature drop of 320°F and 405°F to investigate all limiting cases of spray occurrences.
The applicable heat-up and cool-down transients are shown on Figure 8-1. Unit Loading and Unit Unloading (PLPU) are combined together to form one composite transient.
Each transient consists 18 , 300 spray actuations with drop 11T of 125°F, and therefore the composite transient consists 36 , 600 spray actuations.
The spray actuation during Unit Loading!Unloding, Large Step Degrease in Load, Step Load Increase/Decrease of 10% full power and Loss of Load transients starts from the same temperature of 652. 7°F and the same pressure of 2250psia with the same temperature rate and same 60 second duration.
Therefore, this spray actuation transient is developed only one time for PLPU and the stresses resulting from this transient bound all spray actuations of rest transients.
The total number of cycles of spray actuations is sum of cycles for PLPU and all bounded transients.
Therefore, the transient PLPU is considered to occur 41,950 times.
- 1 Per NB-3226( e), the first 10 hydro test cycles need no be considered for the fatigue evaluation.
Page 30 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary According to Reference
[4], there is small temperature fluctuation during the Steady State Fluctuation transient for the spray nozzle. Per Reference
[2], the pressure fluctuation is +/-25 psi. These small variations of temperature and pressure create negligible stresses compared to the other transients.
Therefore, the steady state fluctuation transient is not contained in spray nozzle analysis.
The leak test comes on at steady state heat-up condition with pressure spikes to 2485 psig momentarily.
Therefore, this transient is modeled by adding a timepoint with pressure of 2485 psig during heat-up steady state condition.
Figure 8-1 Heat-Up and Cool-Down Early and Late Transients with Spray Actuations Page 31 -
Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary Table 8-2 Summary of Analyzed Transients Designation Transient Name Design Cycles HU-ES Heat-up Early Spray HU-LS Heat-up Late Spray+ Leak Test at 2485psig CD-ES320 Cool-down Early Spray with two of 320°F spray actuations.
CD-LS-320 Cool-down Late Spray with two T of 320°F spray actuations.
250 1'2 CD-ES405 Cool-down Early Spray with a T of 320°F and a T of 405°F spray actuations.
CD-LS405 Cool-down Late Spray with a of 320°F and a of 405°F spray actuations.
PLPU Plant Loading and Plant Unloading 41,950 3 LSL Large Step Decrease in Load 250 SLI Step Load Increase 2,500 SLD Step Load Decrease 2,500 BCE Boron Concentration Equalization 32,000 LOL Loss of Load 100 LOP Loss of Power 50 LOF Loss of Flow 100 RT Reactor Trip 500 lA Inadvertent Auxiliary Spray 12 TRT Turbine Roll Test 10 The boundary conditions for thermal analysis are described in detail in Section 5 .2.1 . The thermal loading was applied to the finite element n1odel in the form of temperatures and HTC versus time on the appropriate surfaces (see Section 5.2.1 , Figure 5-3). The following transient tables (Table 8-3 through Table 8-19) are based on the data from Reference
[4] and list the pressure, HTC and temperature values for the tune points used in the thermal analysis.
Some time-points are omitted from transients that are listed in Reference
[4] to simplify the transient definition.
The differences between original transients and modified transients are negligible, and they have negligible effect to the results. 1 Number of spray occunences is desctibed in detail in Table 8-1. 2 Leak test with 60 design cycles is applied at the end of the heat-up transient at steady state condition.
Therefore , the leak test is considered as internal cycle of the heat-up transient.
3 PLPU transient bounds the spray actuations of the others transients as described in text in this section and it results . 41,950 number of cycles for PLPU. Page 32 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary T bl 8 3 H a e -eat-up E I S anv pray T rans1en t --I"' ------I"' . ----'--,.--'------------------------------.... --Page 33 Cant oiled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2 -Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary
-4H TabeS eat-up Late S ray Transient
-.... -.. Page 34 Controlled Document A AREVA Document No. 32-9219781-002 Diablo Canyon Unit 2-Pressurizer Spray Nozzle Weld Overlay Structural Analysis-Non Proprietary 8-5 Cool-Down Earlv Snrav witl Iemperature Drop of 405°F . --. . ---Page 35