ML071410331

Calculation 32-9049388-000, North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis.

ML071410331
Person / Time
Site:	North Anna
Issue date:	04/30/2007
From:	Sorensen T, Straka T AREVA NP
To:	Office of Nuclear Reactor Regulation
References
32-9049388-000
Download: ML071410331 (101)

Text

20697-10 (3/30/06)

A CALCULATION

SUMMARY

SHEET (CSS)

AR EVA Document Identifier 32-9049388-000 Title North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis PREPARED BY: REVIEWED BY:

METHOD: Z DETAILED CHECK [] INDEPENDENT CALCULATION NAME Todd Sorensen NAME Tomas Straka SIGNATURE SIGNATURE TITLE ENGINEER I DATE TITLE PRINCIPAL ENGINEER DATE COST REF. TM STATEMENT:

CENTER 41324 PAGE(S) 56 REVIEWER INDEPENDENCE Basel Djazmati NAME 19 PURPOSE AND

SUMMARY

OF RESULTS:

Purpose:

This document is a non-proprietary version of AREVA NP Document 32-9038441-001. The proprietary information removed from 32-9038441-001 is indicated by a pair of square brackets" ( ) ." The geometry and operating condition are Dominion Power proprietary. This document presents the thermal and structural analyses of the North Anna Units 1 & 2 pressurizer safety/relief nozzle with weld overlays. The purpose of this calculation is to qualify the weld overlay design to the requirements of the ASME Code Section III, 1968 Edition through Winter 1968 Addenda and 2001 Edition through 2003 Addenda.

Summary of Results:

The thermal and structural analyses demonstrate that the safety/relief nozzle weld overlay design satisfies the ASME Code primary and primary plus secondary stress requirements as well as the criteria against fatigue failure.

Based on the loads and cycles specified in Reference 8, the conservative fatigue analysis performed in this document indicates that the maximum fatigue usage factor for the Safety/Relief Nozzles Weld Overlay repair design is ( 3 (see Appendix E).

Revision 000 consists of 97 pages including 1-96, 23a THE DOCUMENT CONTAINS ASSUMPTIONS THAT MUST BE VERIFIED PRIOR TO USE ON THE FOLLOWING COMPUTER CODES HAVE BEEN USED IN THIS DOCUMENT: SAFETY-RELATED WORK CODENERSION/REV CODENERSION/REV I" YES ZI NO AREVA NP, Inc., an AREVA and Siemens company Page I of 97

A North Anna Units 1 & 2 Pressurizer Safety/Relief'Nozzle Weld Overlay Analysis DOCUMENT NUMBER PIAMT AREVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRLETARY RECORD OF REVISIONS Revision Number Description Date 000 Original Release 4/2007 Prepared by: I Sorensen Date: 04/2007 Page 2 Reviewed by: i.. Straka Date: 04/2007

North Anna Units I & 2 Pressurizer Safety/Relief'Noizle Weld Overlay Analysis A OCUMMZNU BER M~

A R EVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY TABLE OF CONTENTS I Purpose..11 2 Analytical Methodology-............ ................. 12 3 Key Assumptions.................................................13 4 Design Input....................................................14 4A1 Geometry .. ..................... ................................................................... 14 4.2 Finite Element Model..............................14 4.3 Materials.................................................................................**...................16 4.4 Bounday Conditions............................................16 4.5 Loads ............................................................................. ..................... 18 4.5.1 External Loads.............................................. 19 4.5.2 Design Conditions ..................... 20 4.5 3 Operational Transient Loads ................... 20 5 Calculation ..................................................... 24 5..1 Design Condition.......... ................ 24 5 2 Thermal Analysis................................ 25 5.3 Stress Analysis ................................................ 38 5.4 ASME Code Criteria........................... 38 5.4.1 ASME Code Primary Stress Intensity (SI) Criteria ..................... 38 5.4.2 ASME Code Primary + Secondary SI Range and Fatigue Usage Criteria. ...... 39 6 Results Summary/Conclusions ................................... ..... 55 7 References ............................. 56 8 Computer Output Files.............................................57 Appendix A.......................................................58 Comparison of' Safety Nozzle and Relief Nozzle Models with Maximum Weld Overlay (WOL) Design................................................58 A-i Propose........................ ..................... 59 A-2 Analytical Methodology ..... ...... ....... ....... 59 .

A-3 Design Input.._....... ....................... ". 60 A-3.1 Geometry.........................................60 Prepared by: 1. Sorensen Date: 04/2007 Page 3 Reviewed by: "I.Straka Date: 04/2007

North Anna Units I & 2 Pressurizer Safety/Relief"Nozzle Weld Overlay Analysis DOCUCENT NEMR PL At EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY A-3.2 Finite Element Model ............ ................. 60 A-3 3 Materials ....................... 62 A-3..4 Boundary Conditions ........................................ 62 A-3.5 Loads ..................................... 63 A-4 Calculation. .................................................. 63 A-4.1 Thermal Analysis ......................... 63 A-4.2 Stress Analysis 68 A-4.3 Comparison SI Ranges of Safety and Relief Nozzle Max WOL .............73 A-5 Results Summary/Conclusion.................................................74 Appendix B........................................ . 75 Comparison of' the Relief Nozzle Models with Maximum Weld Overlay (WOL) Design to "As Built" Condition.......................................... 75 B-1 Purpose ............................................... 76 B-2 Analytical Methodology .......................................... 76 B-3 Design Input. ........................... 77 B-3 .1 Geometry............................................... 77 B-3.2 Finite Element Model ........................................ 77 B-3.3 Materials ............................................. 79 B-3.4 Boundary Conditions ........................................ 79 B-3.5 Loads ................................................... '79 B-4 Calculation............................................... 79 B-4.1 Thermal Analysis ........................................... 79 B-4.2 Stress Analysis8.............................................83 B-43 Comparison SI Ranges of"As Built" Condition and Relief Nozzle Max WOL . 85 B-4.4 SI due to External Loads for "As Built" Condition ... 86 B-5 Results Summary/Conclusion .................... ..................... 89 Appendix C... 90 Stress Report for Fracture Analysis of the Safety/Relief Nozzles with Minimum Weld Overlay (WOL) Design . .................... 90 C-i Propose.....................................................91 C-2 Stiess'and Tempetature Evaluation ................................... 91 Appendix D.................................................93 Prepared by: I. Sorensen Date: 04/2007 Page 4 Reviewed by: I. Straka Date: 04/2007

A A Noith Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Ovei lay Analysis DOCUMORNT NUMBER PLANT AREVA 32-9049388-000 Noith Anna Units I & 2 NON-PROPRIEIARY Justification of'Using Insufficient Length of Weld Oveilay............ ....... 93 D-1 Purpose ........................................... 94 D-2 Analitical Methodology ............................ .. 94 D-3 Boundaiy Conditions and External Loads .... 94 D-4 Results and Conclusions....... 95 Prepared by: T. Sorensen Date: 04/2007 Page 5 Reviewed by: I- Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENt NUMBER p PLANT I A R EVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY LIST OF FIGURES Figure 1 Finite Element Model (max. WOL) ................................. 15 Figure 2 Finite Element Model Details of Safe End, Safe End Weld, Nozzle Weld, Buttering Weld, and Weld Overlay (max. WOL)............................... 15 Figure 3 Surfaces fox Thermal Boundary Conditions (Temperature) 17 Figure 4 Surfaces for Structural Boundary Conditions (Pressure) ..... 18 Figure 5 Deformed Shape vs. Un-Deformed Shape (max. WOL).... ............-.. 24 Figure 6 Stress Intensity Contours for Design Conditions (max.. WOL) .. --. 25 Figure 7 Locations for Evaluation of Temperatuie Gradients (max.. WOL).. 27 Figure 8 Temperature and Thermal Gradient of Selected Locations (HUCD, max. WOL).... 28 Figure 9 Temperature and Ihermal Gradient of Selected Locations (LILD, max. WOL)..... 29 Figure 10 Temperature and Ihermal Gradient of'Selected Locations (LLD, max. WOL) ........ 30 Figure 11 Temperature and Thermal Gradient of Selected Locations (LOL, max. WOL) ......... 31 Figure 12 Temperature and Thermal Gradient of Selected Locations (LOP, max. WOL) ........ 32 Figure 13 Temperature and Thermal Gradient of Selected Locations (LOF, max. WOL) ............... 33 Figure 14 Temperature and Thermal Gradient of Selected Locations (RT, max. WOL) .... 34 Figure 15 Temperature and Thermal Gradient of Selected Locations (OPR, max. WOL) ..... 35 Figure 16 Temperature and Thermal Gradient of Selected Locations (IAS, max. WOL). .. 36 Figure 17 Temperature and Theimal Gradient of Selected Locations (PLT, max. WOL) ...... 37 Figure 18 Path Lines for Stress Analysis (Max. WOL).......................... 41 Figure 19 Path Lines for Stress Analysis (Max. WOL) (continuation) ... 42 Figure A-1 Safety Nozzle Model (max. WOL) ............................. 61 Figure A-2 Relief Nozzle Model (max. WOL)................................ 62 Figure A-3 Locations for Evaluation of Tempeiature Gradients (max. WOL).... ........ 65 Figure A-4 Iemperature and Thermal Gradient of Selected Locations for Safety Nozzle .. 66 Figure A-5 Tempetature and Thermal Gradient of Selected Locations for Relief Nozzle ...67 Figure A-6 Path Lines for Stress Analysis for Safety Nozzle (max. WOL) . ...... 70 Figure A-7 Path Lines for Stress Analysis (max. WOL)(continuation) .. ....... 71 Figure B-I "As Built" Relief'Nozzle Model (max, WOL) .................... 78 Figure B-2 Locations for Evaluation of Temperature Gradients (max. WOL) .... . . 81 Prepared by: ". Sorensen Date: 04/2007 Page 6 Reviewed by: i. Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief'Nozzle Weld Overlay Analysis DOCUMIEN NUMBER P1ANT AR EVA 32-9049388-000 North Anna Units 1 & 2 1 NON-PROPRIETARY Figure B-3 Temperature and Thermal Gradient of Selected Locations for "As Built" Relief Nozzle ................................................................................................ 81 Figure B-4 Path Lines for Stress Analysis for "As Built" Relief'Nozzle (max. WOL) . . 84 Figure C-1 Path Lines in Fracture Analysis (min WOL)...........................92 Figure D-1 Stress Intensity Contom foi the Thin Weld Overlay Configuration 96 Prepared by: T. Sorensen Date: 04/2007 Page 7 Reviewed by: T.Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NUMBER PlA.r A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY LIST OF TABLES Table 1 Applicable External Loads (OBE + Thermal Loads) Applied at the Safe End ........... 19 Table 2 Applicable External Loads (OBE + Thermal Loads) for Relief Reducer ............. 19 Table 3 Steam Region Transients fox Safety/Relief Nozzles...... .............. 20 Table 4 Heat Up and Cool Down (HUCD)............... ........ 21 Table 5 Step Load Increase and Decrease (LILD) ......... .. 21 Table 6 Large Step Load Decrease (LLD) ... 22 Table 7 Loss of Load (LOL) 22 22..............

Table 8 Loss of Power (LOP)_.......................................... 22 Table 9 Loss ofFlow (LOF) ......................... 23 Table 10 Reactor Trip (RT)..................................... ... 23 Table 11 Operation of Power Relief (OPR).. ................... 23 Table 12 Inadvertent Auxiliary Spray (IAS) .................... 23 Table 13 Primary Leak lest (PLI)........................... . . 23 Table 14 Temperature Gradients of Interest .............. ...... 26 Table 15 Path Lines for Linearized Stresses (Max. WOL). ...................... . 39 Table 16 Path Lines for Linearized Stresses (Min. WOL) ........ ....... .40 Table 17 Geometric Characteristics of Path Line Cross-Section Max WOL... 43 Table 18 Geometric Characteristics of Path Line Cross-Section Min WOL 43 Table 19 SI at Path Line Ends due to External Loads for Max WOL .......... 44 Table 20 SI at Path Line Ends due to External Loads for Min WOL ............. 45 Table 21 Summary of Maximum Primary + Secondary SI Ranges for Max WOL.. ....... 46 Table 22 Summary of Maximum Primary + Secondary SI Ranges fox Min WOL ......... 47 Table 23 Membrane+Bending SI Range Summary (max WOL).................... 48 Table 24 Membrane+Bending SI Range Summary (min WOL) ... 49 Table 25 Summary of'Maximum Primary + Secondary SI Ranges for Max WOL (Total) ..... 50 Table 26 Summary of Maximum Primary + Secondary SI Ranges for Min WOL (Total) ......... 51 Table 27 CFUF at PATHI Inside Node - Relief/Safety Nozzle, Head ................. 52 Table 28 CFUF at PATH5 Inside Node Nozzle to Safe End Weld, Buttering... ......... 53

Table 29 CFUF at PATH6_A Inside Node - Nozzle Safe End.................... 53 Prepared by: T Sorensen Date: 04/2007 Page 8 Reviewed by: 1. Straka Date: 04/2007

North Anna Units 1& 2 Pressurizer Safety/Relief Nozzle Weld Over lay Analysis DOCUMWNT NUMBER Pi.ANT A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPR TAY Table 30 CFUF at PATH8M B Outside Node - Weld Overlay..... ................. 54 Table 31 CFUF at PATH7 Outside Node - Reducer' and Reducer to Safe End Weld....... 54 Table A-1 Heat Up and Cool Down (HUCD) ................ . . . . . 63 Table A-2 Temperature Gradients of'Interest for Safety Nozzle.........64 Table A-3 Temperature CGadients of Interest for Relief Nozzle............ ___64 Table A-4 Time Points ofInterest for HUCD for Safety Nozzle ................. 68 Table A-5 Path Lines for Linearized Stresses for Safety Nozzle........... _69 Table A-6 Path Lines for Linearized Stresses for Relief Nozzle ......... .... 72 Table A-7. Comparison of Maximum Membrane plus Bending SI Ranges for Safety and Relief Nozzles......................................................................................................73 Table A-8 Coefficients used with Membrane plus Bending SI Ranges for Relief'Nozzle Model 74 Table B-i Heat Up and Cool Down (HUCD).... ..............................

79 Table B-2 Temperature Gradients of Interest for "As Built" Relief'Nozzle ........... ...80 Table B-3 Path Lines for Linearized Stresses for "As Built" Relief'Nozzle..............88 Table B-4 Comparison of Maximum Membrane plus Bending SI Ranges for "As Built" Condition and Relief Nozzles Design_...............................85 Table B-5 Coefficients used with Membrane plus Bending SI Ranges fox Relief Nozzle Model 86 Table B-6 Geometric Characteristics of Path Line Cross-Section Max WOL ............ 86 Table B-7 Geometric Characteristics of Path Line Cross-Section Min WOL ............. 87 Table B-S SI at Path Line Ends due to External Loads for Max WOL ... ........ 87 Table B-9 SI at Path Line Ends due to External Loads for Min WOL ............... ..88 Table C-1 Path Lines for Fracture Analysis (min WOL)... ................... _91 Table C-2 Stress and Temperature Result files fo Friactute Mechanics Evaluation -.. 92 Table D-I Output Files fox Appendix D .................................. 96 Prepared by: 1. Sorensen Date: 04/2007 Page 9 Reviewed by: T Straka Date: 04/2007

A Nobth Anna Units I & 2 Pressutizet Safety/Relief Nozzle Weld Ovei lay Analysis DOCUMENT NUMBER PLANT AREVA 32-9049388-000 Noith Anna Units I & 2 1 NON-PROPRIETARY Page is left blank Prepaxed by: I Sorensen Date: 04/2007 Page 10 Reviewed by: T.Straka Date: 04/2007

A North Anna Units 1 & 2 Pressmizei Safety/Relief'Nozzle Weld Ovei lay Analysis A R E VA 32-9049388-000 Noith Anna Units I & 2 NON-PROPREARY I PURPOSE It is well recognized that the Alloy 600/82/182 dissimilar metal (DM) welds are susceptible to the primary water stress corrosion cracking (PWSCC), especially those in high temperature components such as pressurizer nozzles. Dominion Generation (Dominion) plans to mitigate the pressurizer nozzle Alloy 82/182 dissimilar metal (DM) welds with structural weld overlays (SWOL) for the North Anna Units 1 and 2 during the fall 2007 and spring 2007 outages, respectively.

Since the three safety nozzles have similar dimensions with the relief nozzle at the nozzle-safe end region, except for the reducer/elbow welded to each safe end (Reference 1 and 2), only two designs are created based on the maximum and minimum weld overlay designs of the relief' nozzle (Reference 7) and safety nozzle (Reference 6).. Appendix A of this document shows the comparison between stresses in Safety and Relief' Nozzles and justifies the usage of the Relief Nozzle model foI this analysis. Detailed sizing calculation of the weld overlay has been documented in Reference 3 for the safety and relief nozzles.

The purpose of' this calculation is to qualify the weld overlay design to the requirements specified in Reference 8 and 10. The design is qualified to meet the criteria and fatigue requirements of the ASME Code Section UI, 2001 Edition through 2003 Addenda (Reference 4).

Prepared by: T. Sorensen Date: 04/2007 Page 11 Reviewed by: I. Straka Date: 04/2007

North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Ovei lay Analysis A DOCUMENT NUMBER I IO'r AREVA 32-9049388-000 North Anna Units 1 & 2 INON-PROPRIETARY 2 ANALYTICAL METHODOLOGY The general methodology of the stress analysis consists of-

1) Building 2-D models of the relief nozzle maximum weld overlay and minimum weld overlay and adjacent part of the pressurizer upper head. The model incorpoiates the geometry (of the adjacent upper head, nozzle, safe end, welds, weld overlay, reducer) of the pressurizer relief nozzle (Reference 2 & 7), appropriate materials and boundary conditions.

The 2-D model is converted into a 2-D finite element model with axisymmetric elements that treat the 2-D model as if it were rotated 3600 around the center axis. There axe two finite element models consisting of thermal and structural elements, respectively so as to enable the thermal and structural analysis using ANSYS 10.0 (Reference 5)

2) Applying the design conditions of the pressure and temperature to the structural finite element model and obtaining the deformation and stresses in the model. The deformation field is used to verify the correct behavior of the model and correct modeling of the boundary and load conditions.

3) Applying the theimal loads pertaining to the service level transients (in the form of transient temperatures and cotresponding heat transfei coefficients versus time). Each of' the major service level transients requires a separate run on the thermal finite element model

4) Reviewing the results of the thermal analysis by examining the magnitude of temperature difference between critical locations in the model at all time points.

5) Applying the corresponding mechanical (pressure) and thermal (nodal temperature) loads at each time point identified in step 4 to the structural finite element model. Since the weld overlay configuration contains layers of different materials having different coefficient of expansion, it is possible that one material is in compression and another is in tension due to thermal expansion. The standard method in defining a path is to go from a free surface to a flee surface.. However, using this method and applying the mathematical equations that ANSYS uses to find the membrane and membrane + bending stresses, may average the stresses at the boundary ofthe two materials. Since there is no guidance on how to evaluate sections with multiple materials, in addition to the flee surface to flee surface path, two partial paths (one in each material) are generated at the same location. These paths will be used to check the 3Sm criteria and to obtain the maximum Ke factor.. It is recognized that no continuous and progressive displacement can occur in one of the materials without the other material restraining that displacement. Therefore this approach is veiy conservative..

6) Hand calculating the effects due to nozzle external loads and adding the resulting stresses to the stress results due to pressure and temperature effect..

7) Comparing the results to the ASME Code criteria for acceptability..

8) Documenting stresses and temperatures for the fracture mechanics analysis of the safety/relief nozzle weld overlay design.

Prepared by: T Sorensen Date: 04/2007 Page 12 Reviewed by: i. Straka Date: 04/2007

A Notth Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Oveilay Analysis DOCUMENT NUMEEXPE PN - PTT A R EVA 32-9049388-000 Noith Anna Units 1 & 2 NON-PROPRIETARY 3 KEY ASSUMPTIONS Iheie me no major assumptions. Minor assumptions and engineering judgments are noted in the body of'the calculation wherever applicable..

Prepared by: I.. Sorensen Date: 04/2007 Page 13 Reviewed by: I.. Stiaka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENTNUMMER PLAMI" A R EVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY 4 DESIGN INPUT 4.1 Geometry The detailed dimensions ofthe relief nozzle design are shown in Reference 2. Major dimensions in building the finite element model include: pressurizer upper head inside radius( )to base metal) and base metal thickness [ ); nozzle ID ( ) and OD( ) at nozzle end); piping reducer at the safe end weld ID ( ) and OD [ 3and at the end with piping elbow ID ( )and OD ( ) for relief nozzle Two weld overlay configurations are provided for the safety and reliefnozzles (Reference 6 and

7) in terms of'the overlay size - the minimum and maximum weld overlay. The minimum weld overlay has a thickness off ), measured from the nozzle end outside surface, at the Alloy 82/182 DM weld and is tapered on to the piping elbow covering the weld at the safe end-elbow connection. The maximum weld overlay has a thickness o4 ) at the Alloy 82/182 DM weld and is also tapered on to the piping elbow covering the weld at the safe end-elbow connection..

4.2 Finite Element Model Iwo finite element models are built based on the weld overlay design - one with the minimum overlay size and the other with the maximum overlay size. Both models are developed with ANSYS 10.0 (Reference 5) and documented in the following two computer files:

No computer' output Is Included with this document The proprietary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system..

The file with "-Overlay" in the file name is for the maximum weld overlay configuration and that with "_Overlay_Min" is for the minimum weld overlay configuration, whenever a file name is mentioned. The 2-D models are meshed with the 8-node PLANE183 elements in the structural analysis and all elements awe replaced by the equivalent thermal elements (PLANE77) in the thermal analysis.. The meshed model with the maximum weld overlay is shown in Figures 1 and 2.

Finite element model is built with the cladding attached to the inside surface of the nozzle..

Where in the field instead of the cladding there is a metal sleeve inserted inside ofthe nozzle and welded at the ends. To study the effect of this discrepancy a very small heat transfer coefficient (HTC=( ) was applied on a surface of the nozzle cladding during CD transient.

The small heat trafer represented separation of the cladding from the nozzle The difference in stress results was insignificant (+/-2%maximum)

This study is documented in the following computei files:

No computer output Is Included with this document. The proprietary version of this document (32-9038441-001) contains computer- output files which are attached to the ploplietary version of this document and are available In the AREVA COLD storage system.

Prepared by: I. Sorensen Date: 04/2007 Page 14 Reviewed by: I. Straka Date: 04/2007

A North Anna Units 1 & 2 Pressuiizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NUMBER KAMT A R EVA 32-9049388-000 Nort Anna Units I & 2 I NON-PROPRIETARY Figure I Finite Element Model (max. WOL)

Figure 2 Finite Element Model Details of Safe End, Safe End Weld, Nozzle Weld, Buttering Weld, and Weld Overlay (max. WOL)

Prepared by: I. Sorensen Date: 04/2007 Page 15 Reviewed by: I. Straka Date: 04/2007

North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis A OOOMEMr NUMBER PIANT EVA 32-9049388-000 North Anna Units 1 & 2T NON-PROPRIETARY 4.3 Materials Reference 8 provides the material designations and properties of the various components:

Pressmizer Upper Head -

Safety/Relief Nozzle Nozzle to Upper Head Weld -

Safe End Nozzle to Safe End Weld Buttering Weld Reducer/Elbow Safe End to Pipe Weld Head Internal Cladding Weld Overlay -

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 iatio (jI), density (p). These pertinent properties (thermal & structural) for the materials listed in Reference 8 can be found in Reference 11.

4A Boundary Conditions The model simulates, in 2-D space, a section of the safety nozzle, safe end, related welds, piping reducer, and part of'the adjacent pressurizer upper head.

Thermal Analysis: During operation, the inside surfaces of the Upper Head (INSHEAD), the inside surface of the Nozzle, Nozzle Weld, Safe End Weld, Safe End, and Reducer (INSNOZ) ae in contact with the pressurizer steam temperature. An appropriate heat transfer coefficient (HTC) and bulk temperature (BI) versus time is applied on these surfaces (Figure 3). The pressurizer steam temperature varies with time depending upon the service load condition that is being applied and is discussed further in section 4.5.3.

The outside surfaces of the Uppei Head, Nozzle, Reducer and Weld Overlay (OUIHEAD) are exposed to the ambient emperature in conjunction with a small HIC.. The safety/relief'nozzljis assumed to be insulated[ J Structural Analysis: Phessurizer steam pressure is applied to all surfaces of these components:

INSHEAD, INSNOZ (Figure 3 and 4). The upper end of the reducer (ENDCAP) has a pressure, p*, applied to represent the hydrostatic end load fi-om the piping closure. The exteriors of the pressurizer head are not loaded by pressure.

Pressure p* is calculated as follows:

Prepared by: T.. Sorensen Date: 04/2007 Page 16 Reviewed by: T.Siaaka Date: 04/2007

S North Anna Units 1 & 2 Piessuizer Safety/Relief Nozzle Weld Overlay Analysis AAEVA DO.VA3Nr-N 32-9049388-000 I*M NhAnn North Anna Units I & 2 1NON-PROPRIE-TAY

• _p-d' Where:

J p = actual pressure applied d = ID of the reducer D = OD of the irducei Ihe boundary conditions for the structural analysis are set to have zero displacement in the ch-cumfeiential direction (from the nozzle axis) and also at the plane of symmetry (Figuie 4).

Figure 3 Surfaces for Thennal Boundary Conditions (Temperature)

Prepared by: I. Sorensen Date: 04/2007 Page 17 Reviewed by: T SUaka Date: 04/2007

A Noith Anna Units I & 2 Pressuizer Safety/Relief'Nozzle Weld Overlay Analysis DOCUMENT NUMER PLANT AREVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY r

I.

Figure 4 Surfaces for Structural Boundary Conditions (Pressure) 4.5 Loads Loads applied to the model include temperatures and heat transfer coefficients for the thermal analysis, and internal pressures for the structural analysis., External forces and moments are evaluated by hand calculation and added to the results fiom the finite element analysis..

Prepared by: T.. Sorensen Date: 04/2007 Page 18 Reviewed by: I. Straka Date: 04/2007

North Anna Units Y& 2 Pressui izer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NUMBER PnANT AR EVA 32-9049388-000 North Anna Units &2 NON-PROPRIETARY 4.5.1 External Loads The applicable external loads applied at the safe end are defined in Reference 10 and 12. The Thermal Expansion (TH) and OBE loads ate listed in Table I and ate fulthet evaluated in Section 5.42..A1 for primary + secondary SI Ranges.. Load due to the axial sluinkage of the weld overlay mitigated by subsequent repaii operations on the safety nozzle line and therefore it is not considered in the calculation (Reference 9).

Table I Applicable External Loads (OBE + Thermal Loads) Applied at the Safe End (Table 6-6 of Reference 12)

OBE + Point Axial Fy FZ Shea (' Torsional My Mz Bending (2)

Thermal Number [lbs] [lbs] [lbs] Jibs] [in-lbs] [in-lbs] [in-Ibs] [in-lbs]

1. 640 unit I #775 Piping #915

1. 370

1. 775 Unit 2 #915 Piping #640

1. 370 Vessel Spec nvelo oad od I I I Note "J: Shear is calculated as the SRSS of Fy and Fz Note (2): Bending is calculated as the SRSS of My and Mz.

Table 2 Applicable External Loads (OBE + Thermal Loads) for Relief Reducer OBE + Point Axial Fy Fz Shear (1) Totsional My Mz Bending (

Thermal Number [lbs] fibs] [ibs] [lbs] [in-lbs] [in-lbs] [in-lbs] [in-lbs]

Unit I Piping #370I4 Unit 2 Piping #370 ]

Enveloped LoadsI I I Note "':Shear is calculated as the SRSS of Fy and Fz.

Note (2): Bending is calculated as the SRSS of My and Mz Prepared by: I. Sorensen Date: 04/2007 Page 19 Reviewed by: T. Sthaka Date: 04/2007

1*

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Over lay Analysis F ADOWNWNTNUMM PLANT Y

A R EVA 32-9049388-000 North Anna Units 1 & 21 NON-PROPRETA 4.5.2 Design Conditions North Anna Units 1 & 2 pressurizer is designed to satisfy the applicable ASME Code criteria at the design pressure off )and temperature of ( J(Reference 10), These design conditions ate simulated on the model by applying a uniform and reference temperature of( ]

throughout the model (the temperature is used to determine the material properties and not for thermal expansion) and uniform pressure of [ ) on all inside surfaces of the model.

Equivalent end cap pressure is also applied on the reducer end cross-section 4.5.3 Operational Transient Loads The safety and relief nozzles are located on top of the pressurizer such that the inside surfaces are subjected to, the piessuirizer steam region theimal and pressure conditions.. The applicable Level A (Normal) and Level B (Upset) transients defined in Reference 12 are listed in Table 3 together with the corresponding number of' cycles. Some transients such as steady state fluctuations are insignificant in fatigue evaluation and are neglected.. NB 3226 (e) of ASME Code (Ref.4) does not require evaluation for the first ten cycles of Testing Condition and therefore, Primary Hydro Test is not included in fatigue analysis. Since the Operation of Safety Valves (Safety Nozzle) and the Operation of Power Relief' (Relief Nozzle) transients are identical, only the Operation of Power Relief transient for ( ) is considered for fatigue evaluation. Plant Loading and Unloading transient is not included in Reference 10 for safety and relief nozzles. Safety and relief'nozzles ae located in area close to spray nozzle. It was assumed that steam temperatures and pressures for spray nozzle can be applied for safety and relief nozzles., Since those parameters are constant dining Plant Loading and Unloading transient for spray nozzle; therefore Plant Loading and Unloading transient is a steady state condition for safety and relief nozzles and does not affect present analysis.

Table 3 Steam Region Transients for Safety/Relief Nozzles Abbreviation Tiansient Name Design Cycles HUCD LILD LLD LOL LOP LOF RT OPR

[AS PLT Note lj)

Note (2)

Nate (3)See Reference 8

)

Prepared by: I. Sorensen Date: 04/2007 Page 20 Reviewed by: I. Stnika Date: 04/2007

A Notth Anna Units 1 & 2 Pressutizer Safety/Relief Nozzle Weld Overlay Analysis I...

DOCUMENTNUMBER PLAMT I AR EVA 32-9049388-000 Noith Anna Units 1 & 2 NON-PROPRIETARY The following tables show the time points used in the theimal analysis.

Table 4 Heat Up and Cool Down (HUCD)

Index ITime Stem Ieinp Pressure INSHEAD HIC IINSNOZ HIC

[_u] [OF] [psial [Btul O-t-F]

1 0.0001 2 2.6500 3 2.65001 4 2.9150 5 4.0000 6 4.0001 7 4.4695 8 4.46951 9 4.5845 10 5.0000 11 5.0001 12 7.9150 k 13 9.0000 I I I Table 5 Step Load Increase and Decrease (LILD) steam rNSHIEADInsozm lime stem essue INHED SNOZ HIC Index _ime Iemp HIC

[lii] [OF] [psia] [Btu-Wft2 -OF]

1 0.0001 2 0.0167 3 0.01671 4 0.0500 5 0.05001 6 0.0700 7 0.07001 8 0.0867 9 0.08671 10 0.1117 11 0.11171 12 0.1367 13 0.2000 I I I Prepared by: I, Sorensen Date: 04/2007 Page 21 Reviewed by: I Straka Date: 04/2007

North Anna Units I & 2 Pressutizer Safety/Relief'Nozzle Weld Overlay Analysis DOCUMENMNUMB!X.* PANt A R EVA 32-9049388-000 Noith Anna Units I & 2 1 NON-PROPRIETARY Table 6 Large Step Load Decrease (LLD)

Time Steam s INSHEAD INSNOZ Index lTemp HTC HIC

[11] [OF] [psia] [Btu/h-ft- -F]

1 0.0001 2 0.0167 3 0.01671 4 0.0334 5 0.1084 6 0.10841 7 0.1984 8 0.2000 )

1- i ) _

Table 7 Loss of Load (LOL)

Steam INSHEAD INSNOZ Index l emp HIC HIC

[hu] [OF] [psia] [Bftvb-e-°F]

1 0.0001 2 0.0021 3 0.0064 4 0.0272 5 0.0355 6 0.03551 7 0.2755 8 0.3000 I I I Table 8 Loss of Power (LOP)

Steam INSHEAD INSNOZ Index T emp HTC HIC

[hr] [oF] [psia] [Btu/hr-fe-°F]

I 0.0001 ""

2 0.0167 3 0.0400 4 0.04001 5 0.4900 -

Prepaxvd by: T, Sorensen Date: 04/2007 Page 22 Reviewed by: I Straka Date: 04/2007

A Noith Anna Units 1 & 2 Piessmuizei Safety/Relief Nozzle Weld Overlay Analysis DOCUM4TNUAEqT fLANT A R EVA 32-9049388-000 North Anna Units I & 2 E NON-PROPRIETARY Table 9 Loss of Flow (LOF) lime Steam INSHEAD INSNOZ Index Temp HIC HIC

[hr] [OF] [psia] [Btu/hz-ift-OF]

1 0.0001 ,

2 0.0067 3 0.0358 4 0.03581 5 0.1608 6 0.2000 I-Table 10 Reactor Trip (RT)

Steam INSHEAD INSNOZ Index Temp HIC HIC o[] [*F] [psia] [Btu/hbrt-OF]

1 0.0001 2 0.0022 3 0.0139 4 0.01391 5 0.1439 6 0.2000 . 1 I 1 Table 11 Operation of Power Relief (OPR)

Steam INSHEAD INSNOZ index ie " Psse HIC HIC

[ai] [OF] [psia] [Btu/lr-ft2-OF]

1 0.0001 2 0.1000 3 0.10001 4 0.1001 5 0.1084 6 0.10841 7 0.1085 8 0.2000 _--

.Prepared by: I. Sorensen Date: 04/2007 Page 23 Reviewed by: 'r.Straka Date: 04/2007 See Inserted page 23a

A North Anna Units I & 2 Pressuxizer Safety/Relief Nozzle Weld Overlay Analysis DOCUq4 NUMBER PLAN! I AREVA 32-9049388-000 Noith Anna Units 1 & 2 NON-PROPRIETARY Table 12 Inadvertent Auxiliary Spray (lAS)

Steam Pressure INSHEAD INSNOZ Index i emp HIC HTC

[1u] [OF] [psia] [ ftu20

-f-°]

1 0.0001 2 0.0333 3 0.0363 4 0.0613 5 0.0643 6 0.0977 7 0.1250 8 0.12501 9 1.4288 10 1 .5000 Table 13 Primary Leak Test (PLT)

Prepaied by: T. Sorensen Date: 04/2007 Page 23a Reviewed by: I. Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NUIMBE A AREVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY 5 CALCULATION 5.1 Design Condition Stress analysis of the model under the design pressure pruvides a basis for verification of the expected behavior of the model, the boundary and load conditions and verifies attenuation of' stress effects at legions distant fi'om the nozzle.

Ihe ANSYS outputs for the design conditions are documented in the following files:

No computer output is Included with this document. The propfietary version of this document (32-9038441-001) contains computer output files which arm attached to the proprietary version of this document and are available In the AREVA COLD storage system.

Figure 5 shows a deformed shape of the max WOL model under design pressure along with the un-deformed shape. Ihe stress intensity contours developed in the model under design pressure case are shown in Figure 6 The similar results have been found for min WOL.

r r

11%-ý, Figure 5 Deformed Shape vs. Un-Deformed Shape (max. WOL)

Prepared by: I.. Sorensen Date: 04/2007 Page 24 Reviewed by: T. Straka Date: 04/2007

A Noith Anna Units 1 & 2 Pressurizet Safety/Relief Nozzle Weld Overlay Analysis DOCU NUMBEX PLANT NON-PROPRIETARY A REVA 32-9049388-000 North Anna Units 1 & 2 Figure 6 Stress Intensity Contours for Design Conditions (max. WOL) 5.2 Thermal Analysis The ANSYS input files containing the transient definition, as tabulated in Tables 3 to 13 are:

HUCD tr reve .inp LOP_trrevl..inp LILDtr.revi inp LOF_'tirrvl inp LLD-trevl.inp OPR tziev inp LOLtrrev 1.inp RT tr revl .inp IAS_ttievl .inp PLrht_*revl inp The ANSYS output files are listed as follows:

No computer output is Included with this document. The proprietary vetsion of this document (32-9038441-001) contains computer output files which am attached to the ptoprietary version of this document and are aviflable In the AREVA COLD storage system.

Prepared by: I Sorensen Date: 04/2007 Page 25 Reviewed by: T- Struka Date: 04/2007

ANorth Anna Units I & 2 Pressuizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMETNUMEER PLANT A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY The results of the thermal analyses ate evaluated to identify the maximum and minimum temperature gradients between critical locations in the model and the conesponding time points.

These temperature giadients generate maximum and minimum theimal stresses, which in turn contribute to maximum iange of'stress intensities in the model.

The node numbers corresponding to the two locations for evaluation of'temperature giadient are listed in Table 14 for the maximum and minimum weld overlay models. The locations for the maximum weld overlay model are shown in Figme 7.

Table 14 Temperature Gradients of Interest Gradient Node Numbers Node Numbers Description Designation (ainWOL) (max WOL)

AlA2 1002 2903 1095 3310 Nozzle to head conjunction BIB2 997 872 1060 927 OD change on nozzle Cl C2 953 827 988 806 Nozzle weld with overlay Dl D2 956 731 991 839 Safe end weld with overlay ElE2 182 537 2091 115 Thickness change from overlay

-_ to roducez

• Prepared by: T Sorensen Date: 04/2007 Page 26 Reviewed by: T. Straka Date: 04/2007

I - I

]

Noith Anna Units I & 2 Pressurizer Safety/Relief'Nozzle Weld Overlay Analysis A DOCUNMETNUMBER 11ANT A REVA 32-9049388-000 North Anna Units 1 & 2 -NON-PROPRIETARY Figure 7 Locations for Evaluation of Temperature Gradients (max. WOL)

The temperaturs of'selected nodes versus transient time as well as the temperature gradients are shown in Figures 8 to 17 (for maximum weld overlay model only, since the plots of minimum WOL awe close to those of maximum WOL configuration).. These figures are provided to show the trend and for visual aid only. Specific data is taken fiom computer output files.

Prepared by: I. Sorensen Prepared by: T.Sorensen Date: 04/2007 Page 27 Reviewed by: i. Straka Date: 04/2007

North Anna Units I & 2 Pressutizer Safety/Relief Nozzle Weld Over lay Analysis DOCxMENtNUMEA RLAW NO A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY Figure 8 Temperature and Thermal Gradient of Selected Locations (HUCD, max. WOL)

Prepared by: T. Sorensen Date: 04/2007 Page 28 Reviewed by: I Stwaka Date: 04/2007

A Noith Anna Units I & 2 Piessurizer Safety/Relief Nozzle Weld Overlay Analysis F

DOCUMEmrNUMBMM PLA "

A R EVA 32-9049388-000 North Anna Units I NON-PROPRIETARY r

Figure 9 Temperature and Thermal Gradient of Selected Locations (LILD, max. WOL)

Phepared by: T. Sorensen Date: 04/2007 Page 29 Reviewed by: T. Straka Date: 04/2007

North Anna Units 1 & 2 Pressurizer Safety/Relief'Nozzle Weld Overlay Analysis DOCJMENTMlNUMBER PlANT A REVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY r

Figure 10 Temperature and Thermal Gradient of Selected Locations (LLD, max. WOL)

Prepared by: T.. Sorensen Date: 04/2007 Page 30 Reviewed by: T. Straka Date: 04/2007

A North Anna Units 1 & 2 Pressut izer Safety/Relief Nozzle Weld Overlay Analysis r

DOCUMENT NU AER I PA m AREVA 32-9049388-000 North Anna Units I & 2 1 NON-PROPRIETARY Figure 11 Temperature and Thermal Gradient of Selected Locations (LOL, may- WOL)

Prepared by: I. Sorensen Date: 04/2007 Page 31 Reviewed by: I Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis

]DOCUMMT NT*UIB PLANT NON-PROPMETARY A REVA 32-9049388-000 North Anna Units I & 2 Figure 12 Temperature and Thermal Gradient of Selected Locations (LOP, max. WOL)

Prepared by: 1". Sorensen Date: 04/2007 Page 32 Reviewed by: 1. Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/ReliefNozzle Weld Ovei lay Analysis DOCUJMNTNUMB5R I PLANT AREVA 32-9049388-000 North Anna Units 1 & 2 1 NON-PROPRIETARY r

Figure 13 Temperature and Thermal Gradient of Selected Locations (LOF, max. WOL)

Prepared by: I. Sorensen Date: 04/2007 Page 33 Reviewed by: T.Straka Date: 04/2007

Noith Anna Units 1 & 2 Pressutizex Safety/Relief Nozzle Weld Overlay Analysis A DOCUMEMfFNLRIE'R IANT r AREVA 32-9049388-000 Notth Anna Units 1 & 2 NON-PROPRIETARY Figure 14 Temperature and Thermal Gradient of Selected Locations (RT, max. WOL)

Prepared by: I Sorensen Date: 04/2007 Page 34 Reviewed by: T.Straka Date: 04/2007

North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Oveilay Analysis ADOCI.*C* TN JMEI p"rAN AREVA 32-9049388-000 Anna Units I & 2 NON-PROPRTRY Figure 15 Temperature and Thermal Gradient of Selected Locations (OPR, max. WOL)

Prepa;ed by: I. Sorensen Date: 04/2007 Page 35 Reviewed by: I. Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief'Nozzle Weld Overlay Analysis DOCUrENT NUBER FLAM North Anna Units 1 & 2 NON-PROPRIETARY A REVA 32-9049388-000 t.

i Figure 16 Temperature and Thermal Gradient of Selected Locations (IAS, max. WOL)

Prepared by: T1.Sorensen Date: 04/2007 Page 36 Reviewed by: I Straka Date: 04/2007

A Noith Anna Units I & 2 Pressutizei Safety/Relief Nozzle Weld Ovei lay Analysis DOCUMENT NW4aBER NON-PROPRIETARY A REVA 32-9049388-000 Notth Anna Units 1 & 2 Figure 17 Temperature and Thermal Gradient of Selected Locations (PLT, max. WOL)

Prepared by: I. Sorensen Date: 04/2007 Page 37 Reviewed by: I. Stnaka Date: 04/2007

A North Anna Units I & 2 Pressurizei Safety/Relief Nozzle Weld Over lay Analysis DOCUMENT NUMBE PL.ANT AREVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIErARY 5.3 Stress Analysis Nodal temperatures flom the thermal analysis are loaded into the structural model within ANSYS.

Stress analyses are performed at each of the time points.. Nodal temperatures ame read fiom the previous ANSYS result files ofthe thermal analysis. Internal pressure at each time point is added as the mechanical load. The ANSYS output files flomr the stress analyses ate listed as follows:

No computer output is included with this document, The pruprietary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available in the AREVA COLD storage system.

5.4 ASME Code Criteria The ASME Code qualification involves two basic sets of criteria:

I) Assure that failure does not occur due to application of the design loads.

2) Assure that failure does not occur due to repetitive loadings, In general, the primary stress intensity criteria of the ASME Code (Reference 4) assure that the design is adequate for application of design loads.

The ASME Code criteria for cumulative fatigue usage factor assure that the design is adequate for repetitive loadings.

5.4.1 ASME Code Primary Stress Intensity (SI) Criteria Per NB-3213 .8 of Reference 4, the primary stresses are those normal or shem stresses developed by an imposed loading such as internal pressure and external loadings. A thermal stress is not classified as a primary stress. The classification as well as the limit of ptimmy stress intensity is specified in NB-3221 of Reference 4 for Design Conditions. The limit of'primary stress intensity for Level B (Upset), Level C (Emergency), Level D (Faulted), and Test Condition is specified in NB-3223, NB-3224, NB-3225, and NB-3226 of Reference 4, respectively..

As presented in Reference 3, the primary stress intensity criteria are the basic requirements in calculating the weld overlay size, which is under the assumption that a 360' circumferential flaw has grown completely through the original weld.. Loading conditions in each service level have been considered in the weld overlay sizing calculation. The nozzle to reducer region has been reinforced by the weld overlay since adding materials to the nozzle outside region relieves primary stress burden resulting fioom internal pressure and external loads.. The overlay fuither reduces stress concentration by eliminating the outside surface discontinuity. Therefore, the primary stress intensity requirements for the nozzle, welds with overlay, safe end and reducer have been satisfied for all service level loadings without the need for further evaluation.

Other- related criteria include the minimum required pressure thickness (NB-3324 of Reference

4) and reinforcement area (NB-3330 of Reference :4), which were addressed in the original nozzle/pressurizer designs. Adding weld overlay will increase the nozzle wall thickness and therefore these requirements are satisfied.

Prepared by: I. Sorensen Date: 04/2007 Page 38 Reviewed by: I Straka Date: 04/2007

A North Anna Units I & 2 Pressuiizet Safety/Relief'Nozzle Weld Ovei lay Analysis DOCUMENT NUMBER PL.ANT A R EVA 32-9049388-000 North Anna Units I & 2 NON-PROPREETARY 6.4.2 ASME Code Primary + Secondary Sl Range and Fatigue Usage Criteria As stated previously, the stress analysis for transient conditions is required for a component to satisfy the requirements for repetitive loadings. The following discussion describes the fatigue analysis process employed herein for the design.

Computer rims for each transient time point chosen for stress analysis are contained in the ANSYS output files as listed in Section 5.3. The overall stress profile is then reviewed to determine the critical locations that require detailed stress/fatigue analysis The objective is to assure that

1) the most severely stressed locations are evaluated;

2) the specified region is quantitatively qualified.

Once the specific locations for detailed stress evaluation are established, the related path lines can be defined with ANSYS. A post-processing is then conducted to convert the component stresses along the selected path lines into the SI categories (i.e., membrane, membrane +

bending, total) that correlate to the criteria of the ASME Code (Reference 4).

The path lines selected for primary plus secondary SI range and fatigue failure evaluation are listed in Table 15 and 16 for the maximum and minimum weld overlay model- The path lines for the maximum weld overlay model are shown in Figure 18 and 19. The minimum WOL model uses for path lines similar locations as shown on these figures for max WOL. A review of the results indicates that these paths include the highest stress locations for the model.

Table 15 Path Lines for Linearized Stresses (Max. WOL)

Path Line Node Numbets Location (See Figures 18 & 19) Material*

PATHI 1095 3310 Nozzle to head conjunction Mat # 2 PATH2 1060 927 Nozzle (WOL end location)

PATH3 1050 1926 Nozzle with WOL Mat #2 & 6 PATH4 1035 868 Buttering with WOL Mat #4 & 6 PATH5 988 806 Nozzle weld with WOL Mat #4 & 6 PATH6 992 1862 Safe end with WOL Mat # 5 & 6 PATH7 947 916 Reducer at WOL end Mat # 7 PATHS 2175 1934 Reducer with WOL Mat #7 & 6 PATH9 977 796 Safe end weld with WOL Mat #7 & 6 PATH3_A 1050 878 Same as PATH3 (only nozzle mateiial) Mat # 2 PATH3 B 878 1926 Same as PATH3 (only WOL'material) Mat # 6 PATH4 A 1035 1913 Same as PATH4 (only buttering material) Mat # 4 PATH4 B 1913 868 Same as PATH4 (only WOL material) Mat # 6 PATH5 A 988 857 Same as PATHS (only nozzle weld material) Mat # 4 PATH5 B 857 806 Same as PATH5 (only WOL material) Mat # 6 PATH6 A 992 835 Same as PATH6 (only safe end material) Mat # 5 PATH6 B 835 1862 Same as PATH6 (only WOL material) Mat # 6 PATH8 A 2175 1938 Same as PATH8 (only reducer material) Mat # 7 PATHSB 1938 1934 Same as PATH8 (only WOL material) Mat #6 Prepared by: T.. Sorensen Date: 04/2007 Page 39 Reviewed by: 1.. Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizei Safety/Relief*Nozzle Weld Overlay Analysis ADOCUCENTlJMBR U PL.r A R EVA 32-9049388-000 Noith Anna Units I & 2 NON-PROPRETARY PATH9 A 977 773 Same as PATH9 (only safe end weld material) Mat #7 PATH9 B 773 796 Same as PATH9 (only WOL material) Mat # 6 Table 16 Path Lines for Linearized Stresses (Min. WOL)

Path Line Node Numbers Location (See Figures 18 & 19) Material*

PATHIM 990 2903 Nozzle to head conjunction Mat # 2 PATH2M 997 872 Nozzle (WOL end location)

PATH3M 1032 846 Nozzle with WOL Mat #2 & 6 PATH4M 1065 838 Buttering with WOL Mat # 4 & 6 PATH5M 953 827 Nozzle weld with WOL Mat #4 & 6 PATH6M 957 753 Safe end with WOL Mat # 5 & 6 PATH7M 2270 855 Reducer at WOL end Mat # 7 PATH8M 2271 858 Reducer with WOL Mat #7 & 6 PATH9M 942 1839 Safe end weld with WOL Mat # 7 & 6 PATH3M A 1032 842 Same as PATH3M (only nozzle material) Mat # 2 PATH3M B 842 846 Same as PATH3M (only WOL material) Mat # 6 PATH4M A 1065 765 Same as PATH4M (only buttering material) Mat #4 PATH4M B 765 838 Same as PATH4M (only WOL material) Mat # 6 PATHSM A 953 1871 Same as PATH5M (only nozzle weld material) Mat # 4 PATHSMB 1871 827 Same as PATH5M (only WOL material) Mat # 6 PATH6M A 957 808 Same as PATH6M (only safe end material) Mat # 5 PATH6M B 808 753 Same as PATH6M (only WOL material) Mat # 6 PATH8M A 2271 859 Same as PATH8M (only reducer material) Mat # 7 PATH8M B 859 858 Same as PATH8M (only WOL material) Mat # 6 PATH9M A 942 1890. Same as PATH9M (only safe end weld material) Mat# 7 PATH9M B 1890 1$39 Same as PATH9M (only WOL material) Mat # 6 C 3 The definition of these path lines linearized stress components for these paths are contained in the ANSYS output files:

No computer output is included with this document. The proprietary version of this document (32-9038441-001) contains computer .output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system.

Prepared by: I. Sorensen Date: 04/2007 Page 40 Reviewed by: I. Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief'Nozzle Weld Overlay Analysis DO j W WNTUMBER. ?LANr' AREVA 32-9049388-000 Noith Anna Units 1 & 2 NONPROPRIETARY Figure 18 Path Lines for Stress Analysis (Max. WOL)

Prepared by: I. Sorensen. Date: 04/2007 Page 41 Reviewed by: T.Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis AXXXDUMNI NUMBEM pKIAr APEVA 32-9049388-000 North Anna Units I & 2 NON-PROP1TRY Figure 19 Path Lines for Stress Analysis (Max. WOL) (continuation) 5.4.2.1 Maximum Primary + Secondary SI Range, NB-3222.2 External loads (Thermal Expansion, OBE and Open Valve) that cause periodic stress changes shall also be included in calculating the maximum SI Ranges. The resulting values of this load combination are listed in Table 1 and 2.

Except for the path PAIHI (PAIHIM) where the strss variation due to these external loads is negligible, stress intensity due to external loads is calculated at the couesponding cioss-section that contains the path.. The geometric chmaacteristics of each cross-section for both maximum and minimum WOL ae listed in Table 17 and 18..

Prepared by: T. Sorensen Date: 04/2007 Page 42 Reviewed by: I. Straka Date: 04/2007

North Anna Units 1 & 2 Pressurizet Safety/Relief Nozzle Weld Overlay Analysis DOCUMENTNUMBE1W PLANT I A R EVA 32-9049388-000 North Anna Units 1 & 2 1 NON-PROPRIETARY Table 17 Geometric Characteristics of Path Line Cross-Section Max WOL D d I So. S.. A L Location

[inch] [inch] [inch 4] [inch3] [inch 3] [inch2] [inch]

PATH2 PATH3 PATH4 PATH5 PATH6 PATH7 PATHS PATH9 I I I Note (1): For path lines PATH7 and PATHS for maximum WOL the stress intensity due to axial bending stress from external shear forces would reduce the stress intensity due to transient loads Therefore, the vertical distances floro path line PATH9 to PATH7 and PATH8 are conservatively reduced to zero Table 18 Geometric Characteristics of Path Line Cross-Section Min WOL D d I SOD Sm A L

_______ [inch] [inch] [inch ]4 3

[inch ] [inch3] [inch2] [inch]

PA.THI2M PATH3M PATH4M PATH5M PATH6M PATH7M PATH8M PATH9M Note (1): For path lines PATI7M and PATH8M for minimum WOL the stress intensity due to axial bending stress fiom external shear forces would reduce the stress intensity due to transient loads Therefore, the vertical distances froma path line PATH9M to PATH7M and PAIH8M are conservatively reduced to zero where:

D [inch] - outside diameter of'the WOL or reducer d [inch] - inside diameter of the nozzle, safe end or reducer I= -'(D4 -d4) [inchl] - moment of inertia I

SOD =- [inch3] - section modulus - outside diameter Prepared by: I. Sorensen Date: 04/2007 Page 43 Reviewed by: T Stiaka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/ReliefNozzle Weld Overlay Analysis DOCUMMT NIUMBER P ANT A R EVA 32-9049388-000 North Anna Units I & 2.1 NON-PROPRIETARY SID = d [inch3] - section modulus - inside diameter A = ;4(D2 - d2) [inch2] - cross-section area L [inch] - moment aim - vertical distance fiom the inside node of path line PATH9 (safe end weld loot) to the outside node of'the other path Stress intensity (SI) at the inside and outside nodes of the selected path lines are then calculated and tabulated in Table 19 and 20.

Table 19 S at Path Line Ends due to External Loads for Max WOL Axial Stress Shear Stress M+B 1

Location xE I g1 _Bp OyaxBM Ga=M+B ;Fs I. Mt TS Sf1f I[ksi] [ksi] [ksi] [ksi] [ksi] [ksi] [ksi] [ksi]

Inside Diametei PATH2 PATH3 PATH4 PATH5 PAIH6 PATHP)

PATHS")~

PAIH9 Outside Diameter PAIH2 PAIH3 PATH4.

PAIH5 PAIH6 PATH7()

PATH8(u' PATH9 C I Prepared by: T.Sorensen Date: 04/2007 Page 44 Reviewed by: i.. Straka Date: 04/2007

North Anna Units 1 & 2 Pressurizet Safety/ReliefNozzle Weld Overlay Analysis DOCUMENT NUMBER PLAICE A R EVA 32-9049388-000 North Anna Units 1 & 21 NON-PROPRE-IARY Table 20 SI at Path Line Ends'due to External Loads for Min WOL Axial Stress Shear Stress M+B L ocation (YAxEX VaBE ~a. BM Ga.xM+B ro TsýMt TS S

,.[ksi] Cksi] [ki [ksi] [ksi I ksil Nsi [ksi] ] ksi]

Inside Diameter PATH2M PAIH3M PATH4M PATH5M PAIH6M 1

PATH7M- ° PAIH8MN0)

PAIH9M Outside Diameter PAIH2M PAIH3M PAIH4M PAIH5M PAIH6M PAMH7M') ,

PATH8M')

PATH9M C

The membrane + bending stress intensities due to external loads in Table 19 and 20 we 1

calculated as follows:

F EX E A*- [ksil- axial membrane stress due to external axial force (F.)

0 =BM

=__

[ksi]- axial bending stress due to external bending moment (Mb)

S

°*-Br = Fs. [ksi]- axial bending stress due to external shear force (F.)

Prepa*ed by: I. Sorensen Date: 04/2007 Page 45 Reviewed by: T Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DACC NDUMBrMPLER ?1T A R-EVA 32-9049388-000 North Anna Units I & 27 NON-PROPRIETARY

[ksi]- shear stress due to external shear force (F.)

1 M.M [ksi]- shear stress due to external torsion moment (Mx) 2-S O'a*_m') = 6-_": +

0

'%-Bf + o'*_ [ksi]- axial membiane + bending stress

[ksi]- shear stress due to external forces and moments SW,2 =VCr.XM+B +4 . [ksi]- membrane + bending stress intensity Where F,, Fy, F_,, Mx, My, and M. ae taken from Table 1 for IH + OBE + Open Valve load combination and, 2 2 F, = (Fy +F2.)1 Mb =M+M S = SOD - for outside diameter S = SYD - for inside diameter Because the directions of the principal stresses may vary during the transient, the range of linearized membrane + bending is deteimined by the method prescribed by Paragraph NB-3216.2 of the ASME Code (Reference 4). StressRange program (Reference 13) is used to obtain the linearized membrane + bending stresses.. The StressRange program takes the output flom the ANSYS Path evaluations (all transients), adds a zero stress case,. and determines all possible ranges. It determines first the iange between the component stresses and then from the component stress ranges calculates the maximum stress intensity for each pair of time points.

The computer run containing the iesults of the application of this method ate Relief_ Ovel layPathl Class ineSummaty(M+B)

Relief_Oveilay_Min PathI ClassLine_Summ ary(M+B)

The summary of Max Stress Intensity Ranges is tabulated in Table 21 and 22.

Table 21 Summary of Maximum Primary + Secondary S1 Ranges for Max WOL Inside Node SI Range Outside SI Range

1. [psi] Node # [psi]

PAIHI 1095 *N 3310 PAIH2 '1060 927 PAIH3 1050 1926 PAIH4 1035 868 PATH5 988 k 806 1 Prepared by: T. Sorensen Date: 04/2007 Page 46 Reviewed by: I. Straka Date: 04/2007

A Noith Anna Units 1 & 2 Pressu izer Safety/Relief Nozzle Weld Overlay Analysis DOCw1ET NUMaER PLAM AREVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY PAIH6 992 1862 PATH7 947 916 PAIH8 2175 1934 PATH9 977 796 PATH3 A 1050 878 PATH3 B 878 1926 PATH4 A 1035 1913 PATH4 B 1913 868 PATH5 A 988 857 PATH5 B 857 806 PATH6 A 992 835 PATH6 B 835 1862 PATHS A 2175 1938 PATHS B 1938 1934 PATH9 A 977 773 PATH9_B 773 796 W rable 22 Summary of Maximum Primary + Secondary Sl Ranges for IN ~in WOL Inside Node SI Range Outside SI Range

1. [psi] Node # [psi]

PATHIM 990 2903 PATH2M 997 8'72 PATH3M 1032 846 PATH4M 1065 838 PATH5M 953 827 PATH6M 957 753 PAIH7M 2270 855 PATH8M 2271 858 PATH9M 942 1839 PATH3M A 1032 842 PATH3M B 842 846 PATH4MA 1065 765 PATH4M B 765 838 PATHSMA 953 1871 PATH5MB 1871 827 PATH6MA 957 808 PATH6M B 808 ., _. 753 _. ._

Prepared by: I. Sorensen Date: 04/2007 Page 47 Reviewed by: T. Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis NDOCUM ERT ERANM A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY PATH8M A 2271 859 f PATHSM B 859 858 PATHgM A 942 1890 PATH9MB 1890 L. 1839 Table 23 Membrane+Bending Sl Range Summary (max WOL)

Inside Node Outside Node SI due M+B M+B M+B SI Range 3Sm M+B SI due to SI Range 3Sm Path Name ST Range Coeff5.2 ) Extema plus Limit0) S[ External plus Limii.')

Lad() External [ksi] Range LoadP) External [ksi]

[ksi]

PATHI

[i

[ksi]

Loads

[_

[ksi]

_i_ _

[ksi]

ki,_

Loads PATH2 PATH3 PATH4 PATH5 PATH6 PATH7 PATHS PATH9 PATR3A PATH3 B PATH4_B PATH5-1A PATH5_A PATH5 B PATH6A PATH6B1 PATHSA PATHSB VATH9_B

( )

Note (2): This Coefficient = Coeff App A x CoeffApp.B. See Appendix A and Appendix B for details.

Note (): The external loads are calculated in Table 19 for original design (Reference 2) and in Table B-8 for "As Built" condition (Reference 17). Conservatively the largest numbers fiom both tables are used.

Prepared by: TL Sorensen Date: 04/2007 Page 48 Reviewed by: i. Straka Date: 04/2007

North Anna Units I & 2 Pressurizet Safety/Relief Nozzle Weld Overlay Analysis A R EVA A

D CU M UNN U BE R 32-9049388-000 " North Anna P1 Units 1 & 2 1 NON-PROPRIETARY T - AU Table 24 Membrane+Bending SI Range Summary (min WOL)

Inside Node Outside Node M+B M+B N m eo SI Range 3Sin St due to SI Range Path Name ps sR 3mnt + (2) External plus LiMt SI Range Coeff.0) Extern pl siS SI Range e xs External [ksi]

External SIR eff Cksi Load")

[ksi] Load() I Loads

, [si PATi] Chki]

Loads [ksi] [ksi]

PATH1M

• PATH2M PATH3M PATH4M PATH-M PATH6M PATH7M PATH8M PATH9M PATH3M_A PATH3M_B PATH4M I PATH4M_13 PATH5MA PATH5M B PATH6M A PATH6M_B PATH8M_

PATH8M B PATH9MA PATH9MB I j Note 0: See Appendix A for calculation comparison reliefand safety nozzles.

Note (): The external loads mae calculated in Table 20 for original design (Reference 2) and in Table B-9 for "As Built" condition (Reference 17). Conservatively the latgest numbers from both tables are used.

Since the maximum membrane + bending - SI Ranges are below the 3S,. limit, the ASME Code requirements are met for all locations.

5.4.2.2 Fatigue Usage Factor Criteria (CFUF), NB-3222.4 Fox consideration of fatigue usage, the Peak Stress Intensity Ranges are calculated. These values must include the 'total' localized stresses. The linearized membiane+bending stress intensity range used in fatigue usage factor calculation may not depict all of the potential peak stresses.

Therefore to bound the potential effect of this consideration, the membrane+bending stress intensity range is multiplied by a Fatigue Strength Reduction Factor (FSRF).. In general Prepared by: I Sorensen Date: 04/2007 Page 49 Reviewed by: i- Straka Date: 04/2007

A S NoithDOCUE8 Anna Units I & 2 Pressut izet Safety/Relief Nozzle Weld Overlay Analysis Nt I & 2 T-NON-PROPRIETARY NUMBER A mUnits Nt AIRE*VA 32-9049388-000 North Ann'a Reference 15 is used for guidance on FSRF for geometric discontinuities in this model. The calculation is performed separately for different materials..

Based on review of the SI range results (Table 23, 24, 25 and 26), the following locations produce higher fatigue usage factor:

Nozzle, Head Nozzle to Safe End Weld, Buttering Nozzle Safe End Weld Overlay Reducer These critical locations envelop the remaining paths.

Paths PATH7 and PATHS_B are part of geometiic discontinuity. Therefore the maximum membiane+bending SI ranges are multiplied by conservative FSRF of 2.0 to account for geometric discontinuity. Per reference 15, Chapter 6, it has been reviewed that this value is conservative..

Since the mesh is fine enough and there is no discontinuity at paths PATH5 and PATIH6_A, the

'Iotal' SI ranges and no FSRF is used for the fatigue usage factor calculation in these locations..

For PATHI membrane+bending SI lange produced slightly higher usage factor and was used in this calculation.. For PATHIM usage factor is same as usage factor fiom PATHI.

The computer run containing the iesults of the 'Total' SI ranges are ReliefOverlayPathl .ClassLine Summary(Iotal)

ReliefOverlayMinPathi ClassLineSummaty(Total)

Table 26 Summary of Maximum Primary + Secondary S! Ranges for Max WOL (Total)

Inside Node SI Range Outside SI Range

1. [psi] Node # [psi]

PAIHI 1095 3310 PAIH2 1060 927 PAIH3 1050 1926 PATH4 1035 868 PATH5 988 806 PAIH6 992 1862 PATH7 947 916 PAIHS 2175 1934 PATH9 977 796 "PATH3_A 1050 ) 9.78 .

Prepared by: I Sorensen Date: 04/2007 Page 50 Reviewed by: T.Straka Date: 04/2007

A Noith Anna Units 1 & 2 Phessurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NUMBER I PLANT AREVA 32-9049388-000 Noith Anna Units 1 & 2 NON-PROPRIETARY 1926 PATH3_B PATH3-B 878 878 1926

ý PATH4 A 1035 1913 PATH4_B 1913 868 857 PATH5 A 988 PATH5_B 857 806 PATH6_A 992 835 PATH6 B 835 1862 PATH8 A 2175 1938 PATH8 B 1938 1934 PATH9 A 977 773 PATH9_B 773 hft 796 Table 26 Summary of Maximum Primary + Secondary St Ranges for Min WOL (Total)

Inside Node SI Range Outside SI Range Path Name Node # [psi]

N [psi]

PATHIM 990 2903 PAIH2M 997 872 PAIH3M 1032 846 PATH4M 1065 838 PAIH5M 953 827 PATH6M 957 753 PATH7M 2270 855 PAIH8M 2271 858 PATH9M 942 1839 PATH3MA 1032 842 PATH3MB 842 846 PATH4M A 1065 765 PA¶H4MB 765 838 PATH5M_A 953 1871 PATH5MB 1871 827 PATH6M A 957 808 PATH6M B 808 753 PATH8MA 2271 859 PATHSMB 859 858 PATH9MA 942 1890 PATH9M B 1890 1.j18 839 .

Prepared by: I. Sorensen Date: 04/2007 Page 51 Reviewed by: I., Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief'Nozzle Weld Overlay Analysis DOMENT NMBUA MAMT A R EVA 32-9049388-000 North Anna Units I & 27 NON-PROPRIETARY The membiane+bending stress intensity ranges for fatigue usage factor calculations ate documented in the following ANSYS output files:

No computer output Is included with this document, The propuietary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system.

Ihe total stress intensity ranges for fatigue usage factor calculations aie documented in the following ANSYS output files:

No computer output is included with this document. The proprietary version of this document (32-9038441-001) contains computer output files which are attached to the proprictary version of this document and are available in the AREVA COLD storage system.

Note that only the stiess intensity ranges and the corresponding time points are taken fiomr the output files since stress intensities due to external loads are not included in the ANSYS output.

The stress intensity due to the external loads is added at each node for each SI range. A review of the results indicates that all CFUF values are well below 1.0.

Tables 27 to 31 provide the calculation of the cumulative fatigue usage factor based on the loads and cycles specified in Section 4.5. The values of 'E curve' in the following tables are taken from Figures 1-9.1 and 1-92-1 of'Reference 4.

Table 27 CFUF at PATHI Inside Node - RelleflSafety Nozzle, Head Pirepaxed by: I Sorensen Date: 04/2007 Page 52 Reviewed by: I Straka Date: 04/2007

AR EVA ADOCU&MENT North Anna Units 1 & 2 Pressurize Safety/Relief Nozzle Weld Overlay Analysis 32-9049388-000 M PENM North Anna Units 1 & 2 NON-PROPRIETARY Table 28 CFUF at PATHS Inside Node Nozzle to Safe End Weld, Buttering Material r Coef.=1.0 UTS (sI=

E r* ... . . . - . . ... ..-. ..... .. 4 Range Transients Reqd Total("' Ext I]oad(2 ) PeakO) S)ksi Allowable Usage Index Extreme Cycles SI range, ksi SI, ksi SI range, ksi Cycles Factor I OPR-PLT 50 2 HUCD-OPR 210 3 OPR-IAS 10 f...

4 LOL-OPR 50 C Material Table 29 CFUF at PATH6.A Inside Node - Nozzle Safe End Coef= 1 25 31 Uis (So=-

E ratio= E_,

Range Transients Req'd Total(') Ext. L4oad(2) Peak() S",() ksi Allowable Usage Index Extreme Cycles SI range, ksi SI, ksi SI range, ksi Cycles FactoT I OPR-PLT 2 HUCD-OPR 3 LOL-OPR 4 LOL-LOL 5 LOF-IAS k.. -../

-Prepared by: T.Sorensen Date: 04/2007 Page 53 Reviewed by: T. Straka Date: 04/2007

North Anna Units 1 & 2 Pressuiizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NUMBEN t PtAMF AREVA 32-9049388-000 North Anna Units 1 & 27 NON-PROPRIETARY Table 30 CFUF at PATH8M_B Outside Node - Weld Overlay Material r FSRF= 2.0 UTS (S.)==

E ratio = I-Range Transients Req'd IM+B(') Ext Load')j Peak) S,,,(4) ksi Allowable Usage Index Extreme Cycles. SI range, ksi SI, ksi SI vange, ksi Cycles Factoz 1 HUCD-OPR e' 2 OPR-PLT 3 OPR-IAS 4 LOL-OPR 5 LOL-LOL 6 LOP-RT Table 31 CFUF at PATH7 Outside Node - Reducer and Reducer to Safe End Weld Prepared by: I. Sorensen Date: 04/2007 Page 54 Reviewed by: T Straka Date: 04/2007

A Noith Anna Units 1 & 2 Pressu izer Safety/Relief Nozzle Weld Overlay Analysis DOCUMtNJT NM PANT A R EVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY 6 RESULTS

SUMMARY

ICONCLUSIONS Pei ASME Code (Reference 4), the stress analysis of North Anna Units 1 & 2 pressurizer safety and relief nozzles with weld overlays is summarized in this report. Both maximum and minimum weld overlay configurations (Reference 7) axe modeled and analyzed for the relief nozzle (Reference 2).

Analysis of the primary plus seconday stresses due to repetitive loadings indicates that reducer at the weld overlay conjunction area is subjected to relatively large stress intensities. External loads significantly contribute to the large stress intensity range..

The safety and relief nozzles with the weld overlay satisfy the ASME Code primary and primary plus secondary stress requirements as well as the criteria against fatigue failure. The primary stress criteria are satisfied as described in Section 5.4.1. The primary plus secondary stress criteria and the fatigue analysis are evaluated in Section 5.4.2.

Based on the loads and cycles specified in Reference 8, the conservative fatigue analysis per formed in this document indicates that the maximum fatigue usage factor for the Safety/Relief Nozzles Weld Overlay repair design is( )of operation for the cycles identified in Table 3 compare to the ASME Code allowed maximum value of 1.0.

Ihe results of this analysis cover evaluation of the original design of the pressurizer safety/relief nozzle without weld overlay.

Prepared by: T.Sorensen Date: 04/2007 Page 55 Reviewed by: I. Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCVMENT NUMNUBER PLANT A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY 7 REFERENCES

[1]* AREVA Drawing 02-8016863C-002, "North Anna Pressurizer Safety Nozzle Design."

[2]* AREVA Drawing 02-8016749C-002, "North Anna Pressurizer Relief Nozzle Design."

[3] AREVA Document 32-9034340-003, "North Anna Units I & 2 Pressurizer Weld Overlay Sizing Calculation - Safety/Relief Nozzles ."

[4] ASME Boiler and Pressure Vessel Code, Section 111, 2001 Edition including Addenda through 2003.

[5] "ANSYS" Finite Element Computer Code, Version 10,0, ANSYS, Inc., Canonsburg, PA.

[6]* AREVA Drawing 02-8017177D-000, "North Anna Pressurizer Safety Nozzle Overlay Design ."

[7]* AREVA Drawing 02-8017182D-000, "North Anna Pressurizer Relief Nozzle Overlay Design.."

[8] AREVA Document 51-9031151-002, "North Anna Units 1 & 2 Pressurizer Nozzle Weld Overlays - Technical Requirements."

[9] AREVA Document 38-9045875-000, "Change to Purchase order for load due to axial shrinkage of safety nozzle line."

[10] AREVA Document 38-9034638-002, "Requited Engineering Input for North Anna Pressurizer Weld Overlays, North Anna Power Station Units I & 2."

[11] AREVA Document 51-9038545-002, "Material Properties for North Anna Units 1 & 2 Pressurizer- Nozzles."

[12] AREVA Document 51-9036969-004, "Pressurizer Bounding Iransients for North Anna Units 1 & 2."

[13] AREVA Document 32-50.32987-02, "StressRange Progiram Verification"

[14] Rao, K.. R. (editor), "Companion Guide to the ASME Boiler & Pressurizer Vessel Code";

American Society of Mechanical Engineers; 2002.

[15] John F. Harvey, '.heory and Design of Pressure Vessels," Second Edition, Van Nostran Reinhold, 1991.

[16]** AREVA Drawing 02-8016863C-004, "North Anna Pressurizer Safety Nozzle Design."

[17]** AREVA Drawing 02-8016749C-004, "North Anna Pressurizei Relief Nozzle Design.."

[18]** AREVA Drawing 02-8017177D-001, "North Anna Pessurizer Safety Nozzle Overlay Design."

[19]** AREVA Drawing 02-8017182D-001, "North Anna Pressurizer Relief Nozzle Overlay Design."

[20] ASME Code Case N-740-1 (Draft dated 2-7-2007), "Dissimilar Metal Weld Overlay for Repair of Class 1, 2, and 3 Items,Section XI, Division L."

• References 1, 2, 6, 7 were used in model design in main document,

• • Referencese 16, 17, 18, 19 "As Built" condition used in Appendix B Prepared by: I. Sorensen Date: 04/2007 Page 56 Reviewed by: i. Straka Date: 04/2007

North Anna Units 1 & 2 Pressutizer Safety/Relief Nozzle Weld Overlay Analysis DOCUFMNT NMMffiER A A R EVA 32-9049388-000 North Anna Units I & 2 1 NON-PROPRIETARY 8 COMPUTER OUTPUT FILES No computer output Is Included with this document. The proprietary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system.

Prepared by: I Sorensen Date: 04/2007 Page 57 Reviewed by: I. Stiaka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis P*o JcurIAMBI PANI AREVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY I

APPENDIX A Comparison of Safety Nozzle and Relief Nozzle Models with Maximum Weld Overlay (WOL) Design Prepared by: r. Sorensen Date: 04/2007 Page 58 Reviewed by: I.. Straka Date: 04/2007

A North Anna Units 1 & 2Pressurizer Safety/Relief Nozzle Weld Overlay Analysis ADOCUMENTKR

' PtANT I A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRLEIARY A-I PURPOSE The purpose of' this appendix is to provide comparison of safety and relief nozzles with maximum weld overlay design based on the HUCD results fiom StressRange program (Refeience 13)..The evaluation of the relief nozzle with maximum and minimum weld overlays design is contained in the section 54.2.

A-2 ANALYTICAL METHODOLOGY The general methodology of'the model comparison consists of.

1.. Building 2-D models of the relief nozzle maximum weld overlay and 3-D model of the safety nozzle maximum weld overlay with adjacent parts of the pressurizer upper head..

The models incorporate the geometry (of the adjacent upper head, nozzle, safe end, welds, weld overlay, elbow) of the pressurizer relief and safety nozzles (Reference 1, 2, 6

& 7), appropriate materials and boundary conditions. The models ate converted into finite element models with appropriate elements. There are two finite element models (Safety and Relief) consisting of thermal and structural elements, respectively so as to enable the thermal and structural analysis using ANSYS 10.0 (Reference 5)

2. Applying the thermal loads of'HUCD (Heat up and Cool Down) transient (in the form of' transient temperatures and corresponding heat transfer coefficients versus time).

3. Reviewing the results of the thermal analysis by examining the magnitude of temperature difference between critical locations in the model at all time points. The time points of interest fox the structural analysis ate those when the pressure changes (e.g.., maximum or minimum) and when the maximum temperature gradients occur, i.e., when the maximum thermal stresses develop. Ihe time points of interest also include the points at temperature extremes, and other points of analytical interests.

4. Applying the corresponding mechanical (pressure) and thermal (nodal temperature) loads at each time point identified in step 3 to the structural finite element models. Since the weld overlay configuration contains layers of different materials having different coefficient of expansion, it is possible that one material is in compression and another is in tension due to thermal expansion.. The standard method in defining a path is to go flom a flee surface to a flee surface.. However, using this method and applying the mathematical equations that ANSYS uses to find the membrane and membrane + bending stresses, may average the stresses at the boundary of the two materials. Since there is no guidance on how to evaluate sections with multiple materials, in addition to the flee surface to flee surface path, two partial paths (one in each material) are generated at the same location. These paths will be used to check the 3Smi for comparison of the models.

5. Comparing SI Ranges results for' Safety and Relief nozzles.

Prepared by: T.. Sorensen Date: 04/2007 Page 59 Reviewed by: I Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief'Nozzle Weld Overlay Analysis DOCWMENT NUMBU P"ANT AREVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY A-3 DESIGN INPUT A-3.1 Geometry Geometry of relief nozzle is described in details in section 4.1 of the main calculation. There is no reducer in safety nozzle so the nozzle safe end is directly connected (through the weld) to the piping elbow with ( )

A-3.2 Finite Element Model Both finite element models ate built with the maximum overlay size. Both models are developed with ANSYS 10.0 (Reference 5) and documented in the following two computer files:

No computer output Is Included with this document The proprletary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system.

Finite element model for relief nozzle is described in section 4,2 ofthe main calculation.

The 3-D model for- safety nozzle is meshed with 3-D 20 node Solidl86 structural elements and 3-D 10 node tetrahedral Solidl87 structural elements for stuctumal analysis and all elements are replaced by the equivalent thermal elements (Solid90 and Solid 87) in thermal analysis Prepared by: T Sorensen Date: 04/2007 Page 60 Reviewed by: T.. Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUNMNUMBER Irp aq AREVA 32-9049388-000 Noith Anna Units 1 & 2 NON-PROPRIETARY 3-D model iepresent Notth Anna Safety Nozzle with maximum WOL.

Figure A-I Safety Nozzle Model (max. WOL)

Prepared by: I. Sorensen Date: 04/2007 Page 61 Reviewed by: I. Straka Date: 04/2007

North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis A4DO 938U8 ANUMB-00 P'ANT North Anna Units I a 2T NON-PROPRIErARY A EVA 32-9049388-000 2-D (axisymmetrie) model represent North Anna Relief Nozzle with maximum WOL r

Figure A-2 Relief Nozzle Model (max. WOL)

A-3.3 Materials See section 4.3 main calculation for material properties A-3.4 Boundary Conditions Boundary conditions for-relief nozzle model are shown in section 4.4 of the main calculation, Safety nozzle model boundary conditions describes below.

The model simulates, in 3-D space, a 180-degree section of the safety nozzle, safe end, related welds, piping elbow, and part of the. adjacent pressurizer upper head. The vertical plane

.-:l!

Prepared by: I Sorensen Date: 04/2007 Page 62 Reviewed by: i.. Stiaka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUM*NT NUMBER PlANT I A R EVA 32-9049388-000 North Anna Units 1i&2e NON-PROPRIsETARY containing the vertical central axis ofthe pressuizer and that of the nozzle itself forms the plane of symmetry for the modeled portion. The thermal and structural boundary conditions ate symmetric with respect to this plane.

The 180-degree cross-sectional plane in radial direction on the pressurizer upper head is selected remote from the nozzle opening area such that symmetric thermal and structural boundary conditions may be well established on this plane.

Boundary Conditions for thermal and structural analysis for safety nozzle are the same as the ielief'nozzle conditions.

A-3.5 Loads the operating thermal loads ate defined by the thermal transient conditions as contained in Reference 12. To examine which nozzle design is bounding HUCD transient is used. The definition of'HUCD transient is in Table A-1.

Table A-I Heat Up and Coot Down (HUCD)

Steam INSHEAD Time Pressure INSNOZ HIC Index Temp HIC

[ht] [°F] [psia] [etu/l/hft4-°F]

1 0.0001 2 2.6500 3 2.65001 4 2.9150 5 4.0000 6 4.0001 7 4.4695 8 4.46951 9 4.5845 10 5.0000 11 5.0001 12 7.9150 13 9.0000 A-4 CALCULATION A-4.1 Thermal Analysis The ANSYS output files sae listed as follows:

No computer output is Included with this document. The proprietary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system..

Prepared by: I Sorensen Date: 04/2007 Page 63 Reviewed by: I- Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief'Nozzle Weld Over lay Analysis DOCtfUMNT NUMBER PIANT A R EVA 32-9049388-000 7 North Anna Units I & 2 NON-PROPRIETARY The results of the thermal analyses are evaluated to identify the maximum and minimum temperature gradients between critical locations in the models and the corresponding time points..

These temperature gradients genelate maximum and minimum thermal stresses, which in turn contribute to maximum range of stress intensities in the model..

The node numbers corresponding to the two locations for evaluation of temperature gradient are listed in Table A-2 and A-3 for the maximum weld overlay models. The locations for the maximum weld overlay relief nozzle model are shown in Figure A-3. For safety nozzle model nozzle locations are similar.

Table A-2 Temperature Gradients of Interest for Safety Nozle Gradient Node Numbers Description Designation (max WOL)

Al A2 16595 16673 Nozzle to head conjunction BIB2 16565 16660 OD change on nozzle Cl C2 16685 18332 Nozzle weld with overlay DI D2 17918 18773 Safe end weld with overlay Thickness t lo change firom overlay ElE2 - 21484 21381 to elbow Table A-3 Temperature Gradients of Interest for Relief Nozzle Gradient Node Numbets Description I-Designation (max WOL)

Al A2 1095 3310 Nozzle to head conjunction BI B2 1060 927 OD change on nozzle C1 C2 988 806 Nozzle weld with overlay DI D2 991 839 Safe end weld with overlay El E2 2091 115 Thickness change from overlay

-_ to reducer

Prepared by: I. Sorensen Date: 04/2007 Page 64 Reviewed by: I Straka Date: 04/2007

Noith Anna Units 1& 2 Pressutizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT MER

.MPAKF AREVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY r

Figure A-3 Locations for Evaluation of Temperature Gradients (max. WOL)

The temperatures of selected nodes versus transient time as well as the temperature gradients are shown in Figures A-4 to A-5. These figures ate provided to show the trend and for- visual aid only. Specific data is taken from computer output files.

Prepared by: T.Sorensen Date: 04/2007 Page 65 Reviewed by: 1V Straka Date: 04/2007

I-A ADOCUMEN North Anna Units 1 & 2 P*essmizer Safety/Relief'Nozzle Weld Overlay Analysis NUMBER PIANT AREVA 32-9049388-000 Noith Anna Units 1 & 2 1 NON-PROPRIETARY r

Figure A-4 Temperature and Thermal Gradient of Selected Locations for Safety Nozzle Prepared by: T. Sorensen Date: 04/2007 Page 66 Reviewed by: 1. Straka Date: 04/2007

Notth Anna Units 1 & 2 Piessuiizer Safety/Relief Nozzle Weld Overlay Analysis DoCLm"ETN*,MBB PLAN T AR EVA 32-9049388-000 North Anna Units I & 21 NON-PROPRIETARY Figure A-6 Temperature and Thermal Gradient of Selected Locations for Relief Nozzle Prepared by: T. Sorensen Date: 04/2007 Page 67 Reviewed by: T. Stiaka Date: 04/2007

A ADOCUMET North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis NUMBER P*LnT A R EVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY A-4.2 Stress Analysis Nodal tempeiattues fiom the theimal analysis are loaded into the stiuctural model within ANSYS.

Stress analyses are performed at each of the time points for relief nozzle and only for most critical points foi safety nozzle listed in Table A-4.

Table A-4 Time Points of Interest for HLICD for Safety Nozzle Time Pressme Index im hr psi psia Descmiption 1 0.000100 2- 1.060060 3 1.192555 4 1.457545 5 1.590040 6 1.987525 7 2.120020 8 2.252515 9 2.650000 10 2.650010 11 2.915000 12 4.000100 13 4.469500 14 4.469510 15 4.475259 16 4.584500 17 5.947442 18 7.915000 Nodal temperatures axe read from the previous ANSYS result files of the thermal analysis.

Internal pressure at each time point is added as the mechanical load. The ANSYS output files from the stress analyses are listed as follows:

No computer output is Included with this document. The proprietary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system.

The path lines selected for stress evaluation are listed in Table A-5 and A-6. The Path lines for relief nozzle maximum overlay are shown in Figures 18 and 19. The path lines for the safety nozzle maximum weld overlay model are shown in Figues A-6 and A-7. A review of the results indicates that these paths include the highest stiess locations for the model.

.Prepared by: I. Sorensen Date: 04/2007 Page 68 Reviewed by: l. Straka Date: 04/2007

AA RortA Noth Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis or U-PROPRIETARY NUMBR PE A R EVA 32-9049388-000 North Anna Units 1 & 2 NON Table A-5 Path Lines for Linearized Stresses for Safety Nozzle Path Line Node Numbers Location (See Figures A-6 & A-7) Material*

PATHI 16593 16673 Nozzle to head conjunction Mat #3 PATH2 62581 16660 Nozzle (WOL end location)

PATH3 16557 18341 Nozzle with WOL Mat # 3 & 6 PATH4 16682 78367 Buttering with WOL Mat#4&6 PATH5 16685 78364 Nozzle weld with WOL Mat # 4 & 6 PATH6 17995 18325 Safe end with WOL Mat # 5 & 6 PATH7 18585 18779 Piping elbow at WOL end Mat # 7 PATH8 18586* 18454 Piping elbow with WOL Mat # 7 & 6 PATH9 18787 78497 Safe end weld with WOL Mat #7 & 6 PATH7L 18615 18775 Piping elbow at WOL end, other side Mat # 7 PATH8L 18617 18394 Piping elbow with WOL, other side Mat # 7 & 6 PATH9L 18786 .18383 Safe end weld with WOL, other side Mat #7 & 6 PATH3 A 16557 16647 Same as PATH3 (only nozzle material) Mat # 3 PATH3 13 16647 18341 Same as PATH3 (only WOL material) Mat # 6 PATH4 A 16682 16689 Same as PATH4 (only buttering material) M& #4 PATH4 B 16689 78367 Same as PATH4 (only WOL material) Mat # 6 PATH5 A 16685 16708 Same as PATH5 (only nozzle weld material) Mat # 4 PATH5 B 16708 78364 Same as PATH5 (only WOL material) Mat # 6 PATH6 A 17995 76822 Same as PATH6 (only safe end material) Mat # 5 PATH6 B 76822 18325 Same as PATH6 (only WOL material) Mat # 6 PATH8 A 18586 78530 Same as PATH8 (only elbow material) Mat # 7 PATHS B 78530 18454 Same as PATH8 (only WOL material) Mat # 6 PATH9 A 18787 18227 Same as PATH9 (only safe end weld material) Mat # 7 PATH9 B 18227 78497 Same as PATH9 (only WOL material) Mat # 6 PATH8L A 18617 18374 Same as PATH8L (only elbow material) Mat # 7 PATHSL B 18374 18394 Same as PATH8L (only WOL material) Mat # 6 PATH9lA 18786 18225 Same as PATH9L (only safe end weld Mat #7 material)

PATIH.9L B 18225 18383 Same as PATH9L (only WOL material) Mat # 6 Prepared by: 1 Sorensen Date: 04/2007 Page 69 Reviewed by: T.Straka Date: 04/2007

North Anna Units 1 & 2 Pressui izer Safety/Relief Nozzle Weld Overlay Analysis AREVA 32-9049388-000 Notth Anna Units 1& 2 1 Figure A-6 Path Lines for Stress Analysis for Safety Nozzle (max. WOL)

Prepared by: I. Sorensen Date: 04/2007 Page 70.

Reviewed by: 1. Straka Date: 04/2007

A ADOcUMEWfMR North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis PnA AREVA 32-9049388-000 Noith Anna Units 1 & 2 NON-PROPRETARY r

Figure A-7 Path Lines for Stress Analysis (max. WOL) (continuation)

Prepared by: I Sorensen Date: 04/2007 Page 71 Reviewed by: T.. Straka Date: 04/2007

North Anna Units I & 2 Pressurizer Safety/Relief'Nozzle Weld Ove, lay Analysis DOCUhMNT NUMBER PLANT A R EVA 32-9049388-000 North Anna Units I & 2 1 NON-PROPRIETARY Table A-6 Path Lines for Linearized Stresses for Relief Nozzle Path Line Node Numbers Location (See Figures 18 & 19) Material*

PATH 1 1095 3310 Nozzle to head conjunction Mat # 2 PATH2 1060 927 Nozzle (WOL end location)

PATH3 1050 1926 Nozzle with WOL Mat # 2 & 6 PATH4 1035 868 Buttering with WOL Mat#4&6 PATHS 988 806 Nozzle weld with WOL Mat #4 & 6 PATH6 992 1862 Safe end with WOL Mat # 5 & 6 PATH7 947 916 Reducez at WOL end Mat # 7 PATH8 2175 1934 Reducer with WOL Mat # 7 & 6 PATH9 977 796 Safe end weld with WOL Mat # 7 & 6 PATH3 A 1050 878 Same as PATH3 (only nozzle material) Mat # 2 PATH3 B 878 1926 Same as PATH3 (only WOL material) Mat # 6 PATH4 A 1035 1913 Same as PATH4 (only buttering matefial) Mat # 4 PATH4 B 1913 868 Same as PATH4 (only WOL material) Mat # 6 PATH5 A 988 857 Same as PATH5 (only nozzle weld material) Mat #4 PATH5 B 857 806 Same as PATH5 (only WOL material) " Mat #6 PATH6 A 992 835 Same as PATH6 (only safe end material) Mat # 5 PATH6 B 835 1862 Same as PATH6 (only WOL mateial) Mat # 6 PATH8 A 2175 1938 Same as PATH8 (only reducer material) Mat # 7 C 13 PATH8 B 1938 1934 Same as PATH8 (only WOL material) Mat #6 PATH9 A 977 773 Same as PATH9 (only safe end weld material) Mat # 7 PATH9 B 773 796 Same as PATH9 (only WOL material) Mat # 6 Prepared by: I Sorensen Date: 04/2007 Page 72 i Reviewed by: ITStraka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Over lay Analysis DOCUMETNUMMBER IPANT A R EVA 32-9049388-000 North Anna Units I & 2F NON-PROPRIETARY A-4.3 Comparison Sl Ranges of Safety and Relief Nozzle Max WOL The comparison of safety and relief nozzles with maximum weld overlay design based on the HUCD results fiom StressRange program (Reference 13). These two designs are compared on the predefined path lines (Table A-5 and A-6).

The computer iuns containing the results of the stress range calculations for membrane plus bending stresses ate:

HUCDReliefOvetlay.Path__rsectl ClassLine .Summary(M+B)

HUCDSafetyOverlayPathI Class_LineSwummaxy(M+B)

A zero stress state (ZSS) is included in this run.

Table A-7 Comparison of Maximum Membrane plus Bending Si Ranges for Safety and Relief Nozzles Safety Nozzle Relief Nozzle Path Name Inside Node [psi] Outside Node [psi] Inside Node [psi] Outside Node (psi]

I PATHI 2 PATH2 3 PATH3 4 PATH4 5 PATH5 6 PATH6 7 PATH7 8 PATH8 9 PATH9 10 PATH7L 11 PATHSL 12 PATH9L 13 PATH3 A 14 PATH3 B 15 PATH4 A 16 PATH4 B 17 PATH5 A 18 PATH5 B 19 PATH6 A 20 PATH6 B 21 PATHS A 22 PATH8 B 23 PATH9 A 24 PATH9 B 25 PATH8LA 26 PATH8L B 27 PATH9L A 28 PATH9LB B Prepared by: I.. Sorensen Date: 04/2007 Page 73 Reviewed by: T.Straka Date: 04/2007

A North Anna Units I & 2 Pressuiizet Safety/Relief Nozzle Weld Overlay Analysis DOCUMENI NUMBER '"Am' A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY As shown in Table A-7 stresses produced in both models are very similar. Table A-8 listed coefficients for comparing safety and relief nozzle maximum weld overlay design.

M + B SI Range (Safety Nozzle)

Coefficient =

M + B SI Range (Relief Nozzle)

Table A-8 Coefficients used with Membrane plus Bending S! Ranges for Relief Nozzle Model Path Name Inside Node Outside Node 1 PATH1 1.00 1.00 2 PATH2 1.00 1.00 3 PATH3 1.01 1.00 4 PATH4 1.00 1.00 5 PATH5 1.00 1.00 6 PATH6 1.00 1.08 7 PATH7 1.14 1.00 8 PATH8 1.00 1.00 9 PATHI9 1.00 1.02 10 PATH3 A 1.01 1.00 11 PATH3 B 1.00 1.00 12 PATH4 A 1.00 1.00 13 PATH4 B 1.00 1.00 14 PATH5 A 1.00 1.02 15 PATH5 B 1.00 1.00 16 PATH6 A 1.00 1.03 17 PATH6 B 1.00 1.06 18 PATH8 A 1.30 1.12 19 PATH8 B 1.03 1.00 20 PATH9 A 1.00 1.00 21 PATH9 B 1.05 1.02 A-5 RESULTS

SUMMARY

ICONCLUSION The stress intensity ranges for safety and relief maximum weld overlay design are very similar There are not any significant locations with the higher stress intensity ranges However in some locations the safety nozzle has a slightly higher SI Ranges; therefore the coefficients are calculated and applied to the SI Ranges for relief nozzle in main document. Based on these results, the relief nozzle maximum and minimum weld overlay design is used as bounding design for safety nozzle maximum and minimum overlay design.

Prepared by: T.Sorensen Date: 04/2007 Page 74 Reviewed by: 1. Stnaka Date: 04/2007

I I

i A North Anna Units 1 & 2 Piessutizei Safety/Relief Nozzle Weld Overlay Analysis DOCU*ET NUMBER PLANT A R EVA. 32-9049388-000 North Anna Units I & 2T NON-PROPRIE"ARY i

i APPENDIX B Comparison of the Relief Nozzle Models with Maximum Weld Overlay (WOL) Design to "As Built" Condition Prepared by: r.. Sorensen Date: 04/2007 Page 75 Reviewed by: T.Straka Date: 04/2007

A North Anna-Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Over lay Analysis

'DOC Id E N' N U Mt~d T "LA [ O - R PR T R A R EVA 32-9049388-000 North Anna Units I & 2 NONPROPRIETAY B-1 PURPOSE Dining the process of evaluation of the relief nozzle weld overlay design it was discovered that geometry provided in Reference 2 and 7 was different than "As Built" condition (Reference 17, 19).

Ihe reason for this appendix was not to recalculate whole analysis and establish compensation for differences between "original" and "As Built" design. The purpose of this appendix is to provide comparison of the relief nozzle model with maximum weld overlay design to "AS Built" Condition based on the HUCD results from StressRange program (Reference 13). The evaluation of the relief nozzle with maximum and minimum weld overlays design is contained in the section 5.4 2.

B-2 ANALYTICAL METHODOLOGY Ihe general methodology of the model comparison consists of:

1. Building 2-D model of the relief nozzle maximum weld overlay with adjacent parts of'the pressurizer upper head according to "As Built"-condition (Reference 17). The model incorporate the geometry (of' the adjacent upper- head, nozzle, safe end, welds, weld overlay, elbow) of the pressurizer relief' nozzle (Reference 17 and 19), appropriate materials and boundary conditions.. !he model is converted into finite element model with appropriate elements. There are two finite element models consisting of thermal and structural elements, so as to enable the thermal and stuctural analysis using ANSYS 10 0 (Reference 5)_

2. Applying the thermal loads of HUCD (Heat up and Cool Down) transient (in the form of transient temperatures and corresponding heat transfer coefficients versus time).

3 Reviewing the results of the thermal analysis by examining the magnitude of'temperatme difference between critical locations in the model at all time points.. The time points of interest for the structural analysis ate those when the pressmue changes (e.g., maximum or minimum) and when the maximum temperature gradients occur, i e., when the maximum thermal stresses develop. The time points of' interest also include the points at temperature extremes, and other points of analytical interests 4.. Applying the corresponding mechanical (pressure) and thermal (nodal temperature) loads at each time point identified in step 3 to the structural finite element model.. Since the weld overlay configmation contains layers of different materials having different coefficient of expansion, it is possible that one material is in compression and another is in tension due to thermal expansion. The standard method in defining a path is to go from a flee surface to a free surface. However, using this method and applying the mathematical equations that ANSYS uses to find the membrane and membrane + bending stresses, may average the stresses at the boundary of the two materials. Since there is no guidance on how to evaluate sections with multiple materials, in addition to the free surface to free surface path, two partial paths (one in each material) are generated at the same location. These paths will be used to check the 3Sm for comparison of the models.

5... Comparing SI Ranges results for "As Built" condition and Relief' nozzles model..

.Prepared by: I. Sorensen Date: 04/2007 Page 76 Reviewed by: I. Straka Date: 04/2007

Noith Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NIUMBER LANT AR EVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY B-3 DESIGN INPUT B-3.1 Geometry Geometry of relief nozzle is described in details in section 4.1 of the main calculation. The difference for "As Built" condition is in a shape of the safe end and nozzle weld, Model is built according to References 17 and 19.. There are several negligible differences between dimensions of weld overlay shown in the drawings and dimensions used in the model. Those differences do not affect the results and conclusion ofthis Appendix, B-3.2 Finite Element Model Finite element model is built with the maximum overlay size. Model is developed with ANSYS 10.0 (Reference 5) and documented in the following computer file:

No computer output is Included with this document. The proprietary version of this document (32-9038441-001) contains computer- output fides which are attached to the proprietary version of this document and are available In the AREVA COLD storage system.

The 2-D model is meshed with the PLANE183 elements in the structural analysis and all elements are replaced by the equivalent thermal elements (PLANE77) in the thermal analysis.

The meshed model with maximum overlay is shown in Figure B-1.

Prepared by: T. Sorensen Date: 04/2007 Page 77

.Reviewed by: I. Stiaka Date: 04/2007

A Notth Anna Units 1 & 2 Presstu izei Safety/Relief'Nozzle Weld Overlay Analysis DOCaM.fNT NUMBER PIAXF A  ::EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY r

Figure B-I "As Built" Relief Nozzle Model (max. WOL)

: Prepared by: T Sorensen Date: 04/2007 Page 78 Reviewed by: L Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis AO CUM4TNUMB.. PIA.,T A R EVA 32-9049388-000 North Anna Units 1 & 2 1 NON-PROPRIETARY B-3.3 Materials See section 4 3 main calculation for material properties.

B-3.4 Boundary Conditions Boundary conditions for relief nozzle model are shown in section 4-4 of the main calculation.

Boundary conditions for "As Built" condition are the same as fox relief nozzle.

B-3.5 Loads The operating thermal loads ate defined by the thermal transient conditions as contained in Reference 12. To examine "As Built" condition HIUCD transient is used. The definition of HUCD transient is in Table B-L Table B-1 Heat Up and Cool Down (HUCD)

I line Stam Fressut INHA INSNOZ HI C Index Temp RTCIC

[hr] [OF] [psia] [13tu/ht-fe-OF]

1 o.0001 F""

2 2.6500 3 2.65001 4 2.91f50)0 5 4.0000 6 4.0001 7 4.46955 8 4.46951 0 9 4.58451:

10 5.0000 11 5.0001 12 7.915L09 -

13 9.0000 , ,,

B-4 CALCULATION B-4.1 Thermal Analysis The ANSYS output files axe listed as follows:

No computer output Is Included with this document. The proprietary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system.

-Preparedby: I. Sorensen Date: 04/2007 Page 79 Reviewed by: T. Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Over lay Analysis DOCUMNT NmER PIANT A R EVA 32-9049388-000 Noith Anna Units 1 & 2 NON-PROPRIErARY The results of the theimal analyses are evaluated to identify the maximum and minimum temperature gradients between critical locations in the models and the corresponding time points.

These temperature gradients generate maximum and minimum thermal stresses, which in turn contribute to maximum range of stress intensities in the model. For present study all time points fiom Thermal run were considered.

The node numbers corresponding to the two locations for evaluation of temperature gradient are listed in Table B-2 for "As Built" relief nozzle with the maximum weld overlay Table B-2 Temperature Gradients of Interest for "As Built" Relief Nozie Gradient Node Numbers Description Designation (maxWOL)

Al A2 1197 1190 Nozzle to head conjunction BI B2 1222 1229 on nozzle C1 C2 3047 1353 Nozzle weld with overlay Dl D2 1075 3981 Safe end weld with overlay ElE2 2163 .3143 Thickness change from overlay to elbow Prepared by: T Sorensen Date: 04/2007 Page 80 Reviewed by: I. Straka Date: 04/2007

A Noith Anna Units 1 & 2 Piessutizeir Safety/Relief Nozzle Weld Overlay Analysis DOCU *NTf NUMBER I IM AtEVA 32-9049388-000 Noith Anna Units 1 & 2 NON-PROPRIETARY Figure B-2 Locations for Evaluation of Temperature Gradients (max. WOL)

The temperatures of selected nodes versus transient time as well as the temperature gradients are shown in Figure B-3. These figures are provided to show the trend and for visual aid only..

Specific data is taken fiom computer output files.

Prepared by: 1. Sorensen Date: 04/2007 Page 81 Reviewed by: I. Straka Date: 04/2007

North Anna Units 1 & 2 Pressu izer Safety/Relief Nozzle Weld Overlay Analysis DOCU NUMNEI0ER MAW A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY r

Figure B-3 Temperature and Thermal Gradient of Selected Locations for "As Bulk" Relief Nozzle Prepaied by: I. Sorensen Date: 04/2007 Page 82 Reviewed by: I. Straka Date: 04/2007

A North Anna Units I & 2 Pressu izer Safety/Relief'Nozzle Weld Overlay Analysis DOCUMENT *NLBER PLANT A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIErARY B-4.2 Stress Analysis Nodal tempexatures from the theimal analysis are loaded into the stiuctural model within ANSYS.

Stress analyses are performed at each of'the time points fox the nozzle Nodal temperatures are read fiom the previous ANSYS result files of' the thermal analysis..

Internal piessture at each time point is added as the mechanical load. The ANSYS output files fiorn the stiess analyses are listed as follows:

No computer output Is included with this document. The proprietary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system.

The path lines selected for stress evaluation are listed in Table B-3. The full Path lines awe shown in Figme B4. Partial paths are similar to Figure 19 of the main calculation. A review of the results indicates that these paths include the highest stress locations fox the model.

Table B-3 Path Lines for Linearized Stresses for "As Built" Relief Nozzle Path Line Node Numbers Location (See Figures B-4 & 19) Material*

PATHI 1197 1190 Nozzle to head conjunction Mat # 2 PATH2 1222 1229 Nozzle (WOL end location)

PATH3 1245 4028 Nozzle with WOL Mat #2 & 6 PATH4 1400 1307 Buttering with WOL Mat # 4 & 6 PATH5 1280 1354 Nozzle weld with WOL Mat#4&6 PATH6 1075 3981 Safe end with WOL Mat #5 & 6 PATH7 2378 1136 Reducer at WOL end Mat # 7 PATH8 1149 1302 Reducer with WOL Mat # 7 & 6 PATH9 2963 3962 Safe end weld with WOL Mat # 7 & 6 PATH3 A 1245 2854 Same as PATH3 (only nozzle material) Mat # 2 PATH3 B 2854 4028 Same as PATH3 (only WOL material) Mat # 6 PATH4 A 1400 1359 Same as PATH4 (only buttering material) Mat # 4 PATH4_B 1359 1307 Same asPATH4 (only.WOL material) Mat # 6 PATH5 A 1280 1278 Same as PATH5 (only nozzle weld material) Mat #4 PATHS B 1278 1354 Same as PATH5 (only WOL material) Mat # 6 PATH6 A 1075 2086 Same as PATH6 (only safe end material) Mat # 5 PATH6 B 2086 3981 Same as PATH6 (only WOL material) Mat # 6 PATHS A 1149 2361 Same as PATHS (only reducer material) Mat # 7 PATH8 B 2361 1302 Same as PATHS (only WOL material) Mat# 6 C ii PATH9 A 2963 1270 Same as PATH9 (only safe end weld material) Mat # 7 PATH9 B 1270 3962 Same as PATH9 (only WOL material) Mat # 6

÷ Prepared by: T.Sorensen Date: 04/2007 Page 83 Reviewed by: i Straka Date: 04/2007 )

r A North Anna Units I & 2 Pressutizer Safety/Relief'Nozzle Weld Overlay Analysis DOC NUM A AENT MEk aANT AREVA 32-9049388-000 North Annaunits&2 NON-PROPRIETARY r

.: . ... Figure B-4 Path Lines for.Stress Analysis for "As Built" Relief Nozzle (max. WOL)

Prepared by: I. Sorensen Date: 04/2007 Page 84 Reviewed by: TI.Straka Date: 04/2007

i I-A Noith Anna Units I & 2 Pressmizet Safety/Relief Nozzle Weld Over lay Analysis A

DOCUMENT NUME A I

&PANT A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY B-4.3 Comparison SI Ranges of "As Built" Condition and Relief Nozzle Max WOL The comparison of "As Built" condition relief nozzle and relief nozzles model with maximum weld overlay design based on the HUCD results from StressRange program (Reference 13).

These two designs are compared on the piedefined path lines (Table B-3 and Table 15).

The computer runs containing the results of the stress range calculations for membrane plus bending stiesses are:

No computer output is included with this document. The proprietary version of this document (32-9038441-001) contains computer output flies which are attached to the proprietaty version of this document and are available in the AREVA COLD storage system.

A zero stress state (ZSS) is included in this run-Table B-4 Comparison of Maximum Membrane plus Bending SI Ranges for "As Built" Condition and Relief Nozzles Design "As Built" Relief Nozzle ReliefNozzle Path Name Inside Node [psi] Outside Node [pSi] Inside Node [psi] Outside Node [psi]

I PATHI 2 PATI2 3 PATH3 4 PATH4 5 PATH5 6 PATH6 7 PATH7 8 PATH8 9 PATH9 13 PATH3 A 14 PATH3 B 15 PATH4 A 16 PATH4 B 17 PATHS A 18 PATH5 B 19 PATH6 A 20 PATH6 B 21 PATH8 A 22 PATH8B 23 PATH9 A 24 PATH9 B ,___,

As shown in Table B-4 stresses produced in both models are very similar. Table B-5 listed coefficients fot comparing "As Built" condition relief nozzle model and relief nozzle maximum weld overlay design.

M + B SI Range ("As Built" Relief Nozzle)

Coefficient =

M + B SI Range (Relief Nozzle)

Prepared by: T Sorensen Date: 04/2007 Page 85 Reviewed by: T. Stuaka Date: 04/2007

A Noith Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Over lay Analysis DOCUMENT NUMBER PLANT A R *VA 32-9049388-000 Noith Anna Units 1 & 2 NON-PROPRIETARY Table B-6 Coefficients used with Membrane plus Bending SI Ranges for Relief Nozzle Model Path Name Inside Node Outside Node I PATHI 2 PATH2 3 PATH3 4 PATH4 5 PATH5 r 6 PATH6 7 PATH7 8 PATH8 9 PATH9 10 PATH3 A II PATH3 B 12 PATH4 A 13 PATH4 B 14 PATHS A 15 PATHS B 16 PATH6 A 17 PATH6 B 18 PATH8 A 19 PATHS B 20 PATH9 A 21 PATH9 B r

B-4.4 SI due to External Loads for "As Built" Condition.

SI due to external loads aie calculated for max and min WOL and used in main calculation.

All foimulas ate shown in Section 5.4-2.1 Table B-6 Geometric Characteristics of Path Line Cross-Section Max WOL Location D d l SOD S,1 A2 _

4 3 3 2

[inch] [inch] [inch ] [inch ] [inch ] [inch ] [inch]

PATH2 PATH3 PATH4 PATH5 PATH6 PATH7 PATHS PATH9 .

Note (1): For path lines PATH7 and PATH8 for maximum WOL. the stiess intensity due to axial bending stress from external shear forces would reduce the stress intensity due to transient loads..

Prepared by: 1. Sorensen Date: 04/2007 Page 86 Reviewed by: T.Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NUMBER PLANT AREVA 32-9049388-000 North Anna Units 1 & 2 1 NON-PROPRIETARY Therefore, the vertical distances fiom path line PATIH9 to PATH7 and PATH8 are conservatively reduced to zeto Table B-7 Geometric Characteristics of Path Line Cross-Section Min WOL D d I SOD SID A L Location

[inch] [inch] 1inch ]4 3

[inch ] [inch'] [inch2 ] [inch]

PATH2M PATH3M PATH4M PATH5M PATH6M PATH7M PATH8M PATH9M Note (1): From the dtawings.

Note (2): For path lines PAIH7M and PATH8M for minimum WOL the stress intensity due to axial bending stress form external shear forces would reduce the stress intensity due to transient loads.

Therefore, the vertical distances fium path line PATH9M to PATH7M and PATHM8 ale conservatively reduced to zero.

Table B-8 SI at Path Line Ends due to External Loads for Max WOL Axial Stress Shear Stress M+B Location oa_*x Oa_ I xD_BM I 'axM+B TI.F& rIsMt TS Sint i[ksid [ksi [ksi] [ksiD [ksiI [ksi] [ksi] [ksi]

Inside Diameter PATH2 PATH3 PAIH4 PATH5 PAIH6 r

PAIH7(0' PATH80)

PAIH9 Outside Diameter PATH2 .

PAIH3 I I 0 . f , /

Prepared by: I. Sorensen Date: 04/2007 Page 87 Reviewed by: I. Straka Date: 04/2007

A North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCU-NM NUJMEEI. PLANT AIFEVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY Table B-, Sl at Path Line Ends due to External Loads for Min WOL Axial Stes ha Stress. M+B Location G VXaz-B) UmaBM (UAXM+B TsFs T,_MWSim T2

[ksi] [ksi] [ksi] [ksi] [ksi] [ksi] [ksi] [ksi]

Inside Diameter PATH2M PATH3M PATIH4M PATH5M PAIH6M PATH7M*')

PATHSM(')

PAIH9M Outside Diameter PATH2M PATH3M PAIH4M PATH5M PAIH6M PATH7TM9()

PATHSM'0 PAIH19M(( [ [

Prepared by: I. Sorensen Date: 04/2007 Page 88 Reviewed by: I- Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NUMBER PlNT AR EVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY B-5 RESULTS

SUMMARY

ICONCLUSION The stress intensity ranges for "As Built" condition (References 17, 19) and relief nozzle maximum weld overlay designs (Reference 2, 7) ate very similar.. There axe not any significant locations with the higher stress intensity ranges. However in some locations the "As Built" condition nozzle has a slightly higher SI Ranges; therefore the coefficients awe calculated and applied to the SI Ranges fox relief nozzle in main document.

Based on these results, the relief nozzle maximum and minimum weld overlay design is used as bounding design fox "As Built" ielief/safety nozzles maximum and minimum weld overlay design (References 16, 17, 18, 19)

Prepared by: I. Sorensen Date: 04/2007 Page 89 Reviewed by: L. Straka Date: 04/2007

Noith Anna Units 1 & 2 Pressui izei Safety/Relief Nozzle Weld Overlay Analysis A DI North Anna Units I & 2 NON-PROPRIETARY A REVA 32-9049388-000 N -NPRER OPIATA APPENDIX C Stress Report for Fracture Analysis of the SafetylRelief Nozzles with Minimum Weld Overlay (WOL) Design Prepared by: I, Sorensen Date: 04/2007 Page 90

• Reviewed by: i. Straka Date: 04/2007

A North Anna Units I & 2 Pressurizer Safety/Relief'Nozzle Weld Overlay Analysis ADOCUMENT NUMBER KPANT N A R EVA 32-9049388-000 North Anna Units I & 2 NON-PROPRIETARY C-1 PURPOSE This appendix provides supplemental stress and temperature results along predefmed path lines for a fiacture analysis on the safety/relief'nozzle minimum weld overlay..

C-2 STRESS AND TEMPERATURE EVALUATION The ANSYS Post Processor is used to tabulate the stresses and temperatures along the 0 predetermined paths., Selected path lines for the model with the minimum WOL size are listed in Table C-I and shown in Figure C-I as follows.

For post processor calculation, the definitions of these paths are contained in computer files:

PathsDef minWOL ,txt Table C-1 Path Lines for Fracture Analysis (mln. WOL).

Path Name Output File Node Numbers Path Inside Outside Location (Figure C-i)

FPATH1M 1 3129 1935 Bottom of the buttering and WOL FPATH2M 2 1067 834 Tbp of the buttering and WOL FPATH3M 3 3128 826 Nozzle to safe end weld and WOL FPATH4M 4 2340 734 Safe end weld and WOL Linearized stresses along the path line in the global coordinate system with "Y'axis along the nozzle axis are summmized at thirteen points separated by an equal distance fiom the inside node to the outside node. At each point the axial (longitudinal, Sy) stress and the temperature in the weld or WOL ate given. The path point distances from the inside node are included in the output files listed in Section 8 with "_PathLocs" in their names.. ANSYS post-processing output files are listed in Section 8 and the stress and temperature result files for fracture mechanics ate listed on Table C-2.

In addition, files with "_PathDisc" in their names listed in Section 8 provide path point distances flomr the inside node including the location at the dissimilar material interface for each path (two path points, one just before and one just after the material discontinuity, define the location of the material interface). No post processing is obtained at these path points; this information is provided for reference purposes only..

Prepared by: I. Sorensen Date: 04/2007 Page 91 Reviewed by: r. Straka Date: 04/2007

Noith Anna Units I & 2 Pressurizei Safety/Relief'Nozzle Weld Overlay Analysis ADOC'Y*TIUMEMMMUR A t EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY Figure C-1 Path Unes In Fracture Analysis (min. WOL)

Table C-2 Stress and Temperature Result Flies for Fracture Mechanics Evaluation No computer output is included with this document. The proprietary version of this document (32-9038441-001) contains computer output files which are attached to the proprietary version of this document and are available In the AREVA COLD storage system.

Prepared by: T. Sorensen Date: 04/2007 Page 92 Reviewed by: I. Straka Date: 04/2007

A A Noith Anna Units 1 & 2 Piessmizer Safety/Relief'Nozzle Weld Overlay Analysis DOCtNUMMaE 32-9049388-000 PLANr Noith Anna Units 1 & 2 NON-PROPRIETARY A R EVA 1*

APPENDIX D Justification of Using Insufficient Length of Weld Overlay Prepared by: I. Sorensen Date: 04/2007 Page 93 Reviewed by: I Straka Date: 04/2007

A North Anna Units A E ADOCUMENT NUMBER I & 2 Presstuizei Safety/Relief Nozzle NNPOPM KtAw Weld Overlay Analysis A R EVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY D-1 PURPOSE The purpose of this Appendix is to examine stress distribution in the North Anna Relief'Nozzle components and to justify the deficient length of weld overlay on the nozzle side calculated in Reference 3.

D-2 ANALITICAL METHODOLOGY By Reference 20, the length of the weld overlay should extend at least O.754(Rt,) beyond each end of the observed crack, where R and t&are the outside radius and nominal wall thickness of the pipe prior to depositing the weld overlay. This requirement is intended to provide enough length to attenuate stresses in case of stress concentration due to crack initiation. Because of the existing short length of the Relief Nozzle analyzed in the main body ofthis document, the above requirement was not satisfied and therefore shorter length for the weld overlay was used. The main focus of'this Appendix is to look closely at the stress distribution for the Relief Nozzle thin weld overlay configuration under a conservative assumption of the total loss of buttering and weld between nozzle and safe end.

For this sake the finite element model for the thin weld overlay created in the main body of this document was tested under design pressure and external loads The dead weight loads awe listed in Table 1 of Reference 3. The OBE and Thermal loads are taken fiom Table 6-4 and Table 6-5, Reference 12. All elements pertain to the weld and buttering between the safe end and nozzle body were eliminated. The modified geometry for this analysis is documented in these files NA RNWOLGeo2.out, and relief'overlay minmac which are listed in Table 32 in the main body of'this document. Also, it is important to note that since the model created in the main body of this document uses 2-D axisymmetric elements and since some of the applied external loads are non-axisymmetric, special 2-D harmonic elements were needed to address this issue.

Consequently, all the elements were changed to PLANE 83 element which allows the application of non-axisymmetiic loads on an axisymmettic model. The detailed description of this element is listed in ANSYS Manual, Reference 5 D-3 BOUNDARY CONDITIONS AND EXTERNAL LOADS The geometric boundary conditions for the model remained the same as it is described in the main body of this document. The external loads are conservatively assumed to be applied at the top of the reducer and their, application to the model is described as follows:

First, unit loads are applied on the model, and in the second step, the unit loads are scaled and combined such that they are representative of the different external loads (DW, Design Pressure, Thermal (TH), and OBE). Five different unit load cases are evaluated for the thin weld overlay configuration. 1) Unit, 1 kip, axial load, 2) Unit, 1 kip-in, torsion, 3) Unit, 1 kip, shear, 4) Unit, 1 kip-in, bending, 5) Unit, 1 ksi, pressure. All unit loads are applied at the end of the reducer with an exception of the unit pressure load applied on the internal surfaces..

The unit axial, unit torsion and unit pressure load cases can be represented by the constant term of a harmonic function series in particular the Fourier series, Reference 5. The unit shear and unit bending load cases can be represented by the first harmonic, either symmetric cosine or antisymmetric sine function of the Fourier series Reference 5.. While the unit bending moment Prepared by: 1?. Sorensen Date: 04/2007 Page 94 Reviewed by: I. Stiaka Date: 04/2007

A North Anna Units I & 2 Pressurizei Safety/Relief Nozzle Weld Overlay Analysis DOCUMENT NUMBER PtANT ...

A REVA 32-9049388-000 North Anna Units 1 & 2 NON-PROPRIETARY can be described by a single. harmonic load applied perpendiculat to the cross section, the unit shear uniform lateral load is composed of two harmonic components applied in two perpendicular directions in the plane of the cross section. Since all load cases considered can be exactly represented by either the constant or first harmonic terms of the Fourier series, no Fouriei sefies expansion of the non-axisymmetfic loads is necessary. The ANSYS output of the unit external loads is contained in the output file NA_RNWOLExtLoad2 out..

Due to the axisymmetry of the geometries only two load combinations need to be defined foi each model (DW + Design Pressure + IH + OBE) and (DW + Design Pressure + iH - OBE).

The shear-and bending moment components are combined using the square root of'the sum of'the squares Fs= (F2 + F,2 ) and for moment Mb= (M' + M,) and since the first load combination produces higher- stresses the stress intensity contour plot for this load combination is shown in Figure 1-D It is important to mention that the axial load here considered to be Fy aligned to the axis of axisymmetry y. The stress output for the aforementioned load combinations is contained in output file NARNWOLCombload2.out.

D-4 RESULTS AND CONCLUSIONS It is clear fiom Figure D-1 that the existing length of the Weld Overlay provides enough material to attenuate the stresses (due to design pressure and external loads) effectively. It is important to note that the comparison with ASME Code limits are documented in the main body of this document and this Appendix is intended to only verify the stess attenuation under conservative assumption of losing the entime weld between safe end and nozzle 4-Prepared by: I. Sorensen Date: 04/2007 Page 95 Reviewed by: I.Straka Date: 04/2007

A North Anna Units 1 & 2 Piessurizei Safety/Relief Nozzle Weld Ovex lay Analysis ADOCUMENMUMBERI'T NON-PROPRIETARY ARE VA 32-9049388-000 North Anna Units 1 & 2 1 Figure D-1 Stress Intensity Contour for the Thin Weld Overlay Configuration Table D-1 Output Files for Appendix D No computer output is Included with this document- The proprietary version of this document (32-9038441-001) contains computer output flies which are attached to the proprietary version of this document and are available in the AREVA COLD storage system.

Prepared by: I, Sorensen Date: 04/2007 Page 96 Reviewed by: T.Stiaka Date: 04/2007

Serial No. 06-1007B Docket No. 50-339 Alternative Request CMP-023R1 ATTACHMENT 3 AFFIDAVIT PWOL STRESS ANALYSIS RESULTS FOR ALLOY 600 PRESSURIZER NOZZLE REPAIR NORTH ANNA POWER STATION UNIT 2 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

AFFIDAVIT COMMONWEALTH OF VIRGINIA )

) ss.

CITY OF LYNCHBURG )

1. My name is Gayle F. Elliott. I am Manager, Product Licensing, for AREVA NP Inc. (AREVA NP) and as such I am authorized to execute this Affidavit.

2. I am familiar with the criteria applied by AREVA NP to determine whether certain AREVA NP information is proprietary. I am familiar with the policies established by AREVA NP to ensure the proper application of these criteria.

3. I am familiar with the AREVA NP information contained in the following Calculation Summary Sheets: 32-9038239-000, "North Anna Units 1 & 2, Pressurizer Surge Nozzle Weld Overlay Analysis," dated February 2007, 32-9038441-001, "North Anna Units 1 & 2 Pressurizer Safety/Relief Nozzle Weld Overlay Analysis," dated March 2007, 32-9035736-001, "North Anna Units I & 2 Pressurizer - Spray Nozzle Weld Overlay Analysis," dated March 2007, 32-9035736-002, "North Anna Units I & 2 Pressurizer - Spray Nozzle Weld Overlay Analysis report," dated April 2007, 32-9043013-000, "North Anna Units I & 2 PZR Safety/Relief Nozzle Weld Overlay Crack Growth Evaluation," dated March 2007, 32-9043015-000, "North Anna Units I & 2 PZR Spray Nozzle Weld Overlay Crack Growth Evaluation," dated March 2007, 32-9042735-000, "North Anna 1 & 2 PZR Surge Nozzle Weld Overlay Crack Growth Evaluation,"

dated March 2007, 32-9038670-001, "North Anna Units 1 & 2 Weld Overlay - Piping Evaluation," dated March 2007 and 32-9045275-001, "North Anna Units I & 2, Pressurizer Surge Nozzle Weld Overlay Engineering Evaluation of Insurge/Outsurge Transients," dated April 2007. These Calculation Summary Sheets are referred to herein as "Documents."

Information contained in these Documents has been classified by AREVA NP as proprietary in accordance with the policies established by AREVA NP for the control and protection of proprietary and confidential information.

4. These Documents contains information of a proprietary and confidential nature and is of the type customarily held in confidence by AREVA NP and not made available to the public. Based on my experience, I am aware that other companies regard information of the kind contained in these Documents as proprietary and confidential.

5. These Documents has been made available to the U.S. Nuclear Regulatory Commission in confidence with the request that the information contained in these Documents be withheld from public disclosure. The request for withholding of proprietary information is made in accordance with 10 CFR 2.390. The information for which withholding from disclosure is requested qualifies under 10 CFR 2.390(a)(4) "Trade secrets and commercial or financial information."

6. The following criteria are customarily applied by AREVA NP to determine whether information should be classified as proprietary:

(a) The information reveals details of AREVA NP's research and development plans and programs or their results.

(b) Use of the information by a competitor would permit the competitor to significantly reduce its expenditures, in time or resources, to design, produce, or market a similar product or service.

(c) The information includes test data or analytical techniques concerning a process, methodology, or component, the application of which results in a competitive advantage for AREVA NP.

(d) The information reveals certain distinguishing aspects of a process, methodology, or component, the exclusive use of which provides a competitive advantage for AREVA NP in product optimization or marketability.

(e) The information is vital to a competitive advantage held by AREVA NP, would be helpful to competitors to AREVA NP, and would likely cause substantial harm to the competitive position of AREVA NP.

The information in these Documents is considered proprietary for the reasons set forth in paragraphs 6(b) and 6(c) above.

7. In accordance with AREVA NP's policies governing the protection and control of information, proprietary information contained in these Documents have been made available, on a limited basis, to others outside AREVA NP only as required and under suitable agreement providing for nondisclosure and limited use of the information.

8. AREVA NP policy requires that proprietary information be kept in a secured file or area and distributed on a need-to-know basis.

9. The foregoing statements are true and correct to the best of my knowledge, information, and belief.

SUBSCRIBED before me this day of J, 2007.

Sherry L. McFaden NOTARY PUBLIC, COMMONWEALTH OF VIRGINIA MY COMMISSION EXPIRES: 10/31/2010