ML14105A386

Peach Bottom, Units 2 and 3 - Attachment 9: WCAP-17649-NP, Rev. 2, ASME Code Stress Report (Enclosure B.3)

ML14105A386
Person / Time
Site:	Peach Bottom
Issue date:	04/11/2014
From:	Srivastava H Westinghouse
To:	Office of Nuclear Reactor Regulation
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ML14105A383	List: ML14105A384 ML14105A385 ML14105A386 ML14105A387 ML14105A388
References
CAW-14-3939, CAW-14-3940, CAW-14-3941, CAW-14-3942, CAW-14-3944 WCAP-17649-NP, Rev 2
Download: ML14105A386 (124)

Text

Attachment 9Peach Bottom Atomic Power Station Units 2 and 3NRC Docket Nos. 50-277 and 50-278WCAP-17649, Rev 2, ASME Code Stress Report Westinghouse Non-Proprietary Class 3WCAP-17649-NP ApRevision 2Peach Bottom Units 2 and 3ASME Code Stress Report(Enclosure B.3)Westinghouse iril 2014 WESTINGHOUSE NON-PROPRIETARY CLASS 3WCAP-17649-NP Revision 2Peach Bottom Units 2 and 3 ASME Code Stress ReportHari Srivastava*,

PEPrincipal

Engineer, BWR Engineering April 2014Verifier:

Approved:

Yan Han*, PEPrincipal

Engineer, BWR Engineering Sanjaybir S. Bakshi*,

ManagerBWR Engineering

• Electronically approved records are authenticated in the electronic document management system.Westinghouse Electric Company LLC1000 Westinghouse DriveCranberry

Township, PA 16066, USA© 2014 Westinghouse Electric Company LLCAll Rights ReservedWCAP-I 7649-NP.docx-040714 TABLE OF CONTENTSLIST OF TABLES .......................................................................................................................................

iiiLIST O F FIGU RES .....................................................................................................................................

ivEXECUTIVE SUM M ARY ...........................................................................................................................

v1 IN TRO DUCTION ........................................................................................................................

1-12 SUM M ARY AN D CON CLU SION S ........................................................................................

2-12.1 AN ALYSIS ......................................................................................................................

2-12.2 DESIGN M ARG IN S .......................................................................................................

2-12.3 INTERFACE LO AD S .....................................................................................................

2-23 AN ALY SIS IN PUT ......................................................................................................................

3-13.1 LOA DS ............................................................................................................................

3-13.1.1 Gravity .............................................................................................................

3-13.1.2 Pressure Loads .................................................................................................

3-13.1.3 Seism ic Loads ..................................................................................................

3-23.2 LOA D COM BIN ATION S ...............................................................................................

3-23.3 ACCEPTAN CE CRITERIA

............................................................................................

3-43.4 M ATERIAL PRO PERTIES .............................................................................................

3-54 AN ALY SIS AN D RESULTS ...................................................................................................

4-14.1 AN ALY SIS M ATRIX ......................................................................................................

4-14.2 AN ALY SIS ......................................................................................................................

4-14.2.1 Analysis M odel ................................................................................................

4-14.2.2 Boundary Conditions

.......................................................................................

4-24.2.3 Load Application

.............................................................................................

4-24.2.4 Load Com bination Approach

...........................................................................

4-24.2.5 Com ponent Stresses

.........................................................................................

4-34.2.6 W eld Stresses

.................................................................................................

4-274.2.7 Interface Loads ..............................................................................................

4-295 DESIGN M ARG IN S ....................................................................................................................

5-15.1 STRESS LIM ITS .............................................................................................................

5-15.2 FATIGUE U SAG E ...........................................................................................................

5-16 RE FERE N CES .............................................................................................................................

6-1WCAP- 17649-NP April 2014Revision 2

iiiLIST OF TABLESTable 2-1 Minimum Design Margins -Components (Service Level A) ..................................................

2-5Table 2-2 Minimum Design Margins -Welds (Service Level A) .............................................................

2-7Table 2-3 Minimum Design Margins -Components (Service Level B) ............................................

2-I1Table 2-4 Minimum Design Margins -Welds (Service Level B) ...........................................................

2-13Table 2-5 Minimum Design Margins -Components (Service Level C) ................................................

2-17Table 2-6 Minimum Design Margins -Welds (Service Level C) ...........................................................

2-19Table 2-7 Minimum Design Margins -Components (Service Level D) ................................................

2-23Table 2-8 Minimum Design Margins -Welds (Service Level D) ...........................................................

2-25Table 2-9 R eaction L oads .......................................................................................................................

2-29Table 3-1 Dryer Pressure Loads (Reference

6) .........................................................................................

3-1Table 3-2 TSV Loads on the Outer Hood (Reference

8) ..........................................................................

3-2Table 3-3 Load Com binations (Reference

9) ............................................................................................

3-3Table 3-4 Stress Lim its (R eference

2) .......................................................................................................

3-4Table 3-5 M aterial Properties (Reference

11) ...........................................................................................

3-5Table 4-1 A nalysis M atrix .........................................................................................................................

4-1Table 4-2 PB2 Dryer with Mast, Load Cases 2-14, Maximum Component Stresses

...............................

4-8Table 4-3 PB2 Dryer with Mast, Load Combinations, Maximum Component Stresses

.........................

4-11Table 4-4 PB2 Dryer without Mast, Load Cases 2-14, Maximum Component Stresses

........................

4-14Table 4-5 PB2 Dryer without Mast, Load Combinations, Maximum Component Stresses

...................

4-17Table 4-6 PB3 Dryer, Load Cases 2-14, Maximum Component Stresses

...............................................

4-20Table 4-7 PB3 Dryer, Load Combinations, Maximum Component Stresses

..........................................

4-23Table 4-8 All Dryers, Service Levels, Maximum Component Stresses

..................................................

4-26Table 4-9 Maximum Component Stresses After Removing Elements at Maximum Stress Locations..4-27 Table 4-10 PB2 Dryer with Mast, Load Cases 2-14, Maximum Weld Stresses

......................................

4-30Table 4-11 PB2 Dryer with Mast, Load Combinations, Maximum Weld Stresses

.................................

4-36Table 4-12 PB2 Dryer without Mast, Load Cases 2-14, Maximum Weld Stresses

.................................

4-42Table 4-13 PB2 Dryer without Mast, Load Combinations, Maximum Weld Stresses

............................

4-48Table 4-14 PB3 Dryer, Load Cases 2-14, Maximum Weld Stresses

.......................................................

4-54Table 4-15 PB3 Dryer, Load Combinations, Maximum Weld Stresses

..................................................

4-60Table 4-16 All Dryers, Service Levels, Maximum Weld Stresses

..........................................................

4-66Table 4-17 Maximum Weld Stresses After Removing Elements at Maximum Stress Locations

..........

4-68WCAP- 17649-NP April 2014February 2014Revision 2

ivLIST OF FIGURESFigure 2-1 PB2 Dryer with Instrumentation Mast: Analysis Model -Outline ..........................................

2-3Figure 2-2 PB2 Dryer with Instrumentation Mast: Analysis Model -Finite Element Mesh ....................

2-4Figure 3-1 Seism ic R esponse Spectra .......................................................................................................

3-6Figure 4-1 Boundary Conditions for Analyses with No Dryer Lift-Off

.................................................

4-70Figure 4-2 Boundary Conditions for Dryer Lift-Off Analysis

................................................................

4-71Figure 4-3 Differential Pressure Loads -DPN, DPu, DPE, MSLBDpI and MSLBDP2 .................

.............. 4-72Figure 4-4 TSV Loads -TSV A, TSVF .....................................................................................................

4-73Figure 4-5 Surface Stress, M iddle Hood: DW + DPN .............................................................................

4-74Figure 4-6 Surface Stress, Outer Hood: DW + DPN ...............................................................................

4-75Figure 4-7 Surface Stress, Vane Bank Top Steps: DW + DPN ................................................................

4-76Figure 4-8 Surface Stresses, Vane Bank Top Side Plates: DW + DPN ....................................................

4-77Figure 4-9 Surface Stresses, Outer Hoods: DW + TSV-a ......................................................................

4-78Figure 4-10 Middle Hood Stresses, MSLBDP2 Pressure Load ................................................................

4-79Trademark Note:ANSYS, ANSYS Workbench, CFX, AUTODYN, and any and all ANSYS, Inc. product and servicenames are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries located in theUnited States or other countries.

Windows 7 operating system is either a registered trademark or trademark of Microsoft Corporation in theUnited States and/or other countries.

WCAP- 17649-NPApril 2014February 2014Revision 2

VEXECUTIVE SUMMARYExelon is planning an extended power uprate (EPU) at Peach Bottom Atomic Power Station (PBAPS)Units 2 and 3 and plans to replace the existing stream dryers with replacement dryers at both units.Evaluation is performed to show compliance of the replacement dryers with the structural requirements ofASME B&PV Code,Section III, Division 1, Subsection NG. The evaluation shows that the dryers meetthe stress and fatigue usage limits of the ASME Code for the EPU duty cycles covering normal operation (Service Level A), upset conditions (Service Level B), emergency conditions (Service Level C), andfaulted conditions (Service Level D).WCAP- 17649-NPApril 2014Revision 2

1-11 INTRODUCTION In 2002, after increasing power to 117 percent of the original licensed thermal power, a steam dryer in aboiling water reactor (BWR) had a series of structural failures.

Various industry experts evaluated anddetermined the root cause of the failures was fluctuating acoustic pressure loads on the steam dryer. Thefluctuation resulted from resonances produced by steam flow in the main steam lines (MSLs) acrosssafety valve and relief valve inlets. The failures in the steam dryer led to changes in Regulatory Guide1.20 (Reference 1), requiring plants to evaluate their steam dryers before any planned increase in powerlevel.Exelon is planning extended power uprate (EPU) at PTable 2-6 Minimum Design Margins -Welds(Service Level C)each Bottom Atomic Power Station (PBAPS) Units 2 (PB2) and 3 (PB3) and plans toreplace the existing stream dryers with replacement dryers at both units. The process used to qualify thereplacement dryers for EPU operation involves scale model testing and multiple acoustic and structural analyses.

High cycle fatigue calculations are performed using special purpose computer codes tocalculate the acoustic loads together with finite element structural analyses using commercially available computer codes. The finite element models used for the acoustic analyses are also used in analyses toqualify the dryers for the ASME Code requirements.

The purpose of this report is to document analyses performed to show compliance of the replacement dryers with the structural requirements of ASME B&PV Code,Section III, Division 1, Subsection NG(Reference 2). Evaluations are performed for the PB2 replacement dryer with and withoutinstrumentation mast assembly and for the PB3 replacement dryer. The evaluations show that the dryersmeet the stress and fatigue usage limits of the ASME Code for the EPU duty cycles covering normaloperation (Service Level A), upset conditions (Service Level B), emergency conditions (Service Level C),and faulted conditions (Service Level D).In Revision 1, there were many changes, as shown below. Therefore, no revision bars were used.* Due to dryer design changes, the affected Tables in Section 2 and Section 4 are completely revised.

Because of the design changes, Figure 2-1 and Figure 2-2 are revised.* FIV stresses include the vane passing frequency (VPF) stress due to recirculation pump operation.

• Figure 4-5 to Figure 4-10 are revised to provide new stress distributions.

0 Text in the report is revised accordingly to show these changes.In Revision 2, the following changes have been made.The allowable stress limits for welds in Table 2-6, Column 4 (Service Level C) are corrected asper the ASME Code. Reference 2.The allowable stress limits for welds in Table 2-8, Column 4 (Service Level D) are corrected asper the ASME Code. Reference 13.* A sentence is added in Section 2.1, at the end of the second paragraph.

WCAP-17649-NP April 2014Revision 2

2-12 SUMMARY AND CONCLUSIONS 2.1 ANALYSISThe dryers were analyzed with finite element code, Version 11.0 (Reference 3), running underthe Microsoft Windows' 7 operating system, using 3600 analysis models. The analysis model for the PB2dryer with the instrumentation mast is shown in Figure 2-1and Figure 2-2. The analysis model for thePB2 dryer without the mast is similar except for removal of finite elements representing the mastassembly.

The analysis model for the PB3 dryer is similar except for removal of finite elementsrepresenting the mast assembly and the hold-down rods, and changes in the lifting lug bracket model.Analyses were performed for deadweight, differential pressures, seismic loads, Turbine Stop Valve (TSV)acoustic and flow reversal loads, and Main Steam Line Break (MSLB) differential pressure loads.Stresses for Flow Induced Vibration (FIV) loads, and recirculation pump Vane Passing Frequency (VPF)loads were based on the stress limits used to qualify the dryers for FIV/VPF loads (Reference 4). Stressesfor MSLB acoustic loads were assumed to equal the maximum stresses calculated in separate analyses forthe MSLB loads (Reference 5). Thermal loads were not considered because the dryer operates underisothermal conditions and the structural design does not have materials with different expansion coefficients.

The secondary stresses are negligible and therefore, an explicit check for primary plus secondary stressintensity range (Pm + Pb + Q) against 3Sin required by NG-3222.2 for Service Levels A and B is notperformed.

The dryers were supported in vertical and circumferential directions at the support lugs for analyses, except analyses for MSLB differential pressure loads that produce a dryer lift-off.

For lift-off

analyses, the models were supported at the top of the dryer hold-down rods (PB2) or lifting rods (PB3) in thevertical direction and at the support lugs in the circumferential direction.

Surface loads were applied as pressure, gravity load was applied as equivalent static acceleration, andOBE and SSE loads were analyzed by response spectrum analyses.

2.2 DESIGN MARGINSComponent and weld stresses for the three dryer configurations (PB2 dryer with and withoutinstrumentation mast, and PB3 dryer) for the specified load combinations, including the FIV/VPF andMSLB acoustic load stresses, are listed in Table 4-2 through Table 4-17. Maximum stresses extracted from these tables are compared with the ASME Code (Section III, Subsection NG) stress limits in Table2-1 through Table 2-8 to calculate design margins applicable to all the dryer configurations.

Positive design margins are calculated for the specified load combinations with conservative assumptions, which include:* Use of seismic response spectra for [ ]a.c damping for OBE and SSEWCAP- 7649-NP April 2014Revision 2

2-2Except for two welds, assumption of all the components and welds to have FIVNPF stressesequal to the ASME Code alternating endurance stress limits. For two of the welds, it wasnecessary to assume somewhat lower FIV/VPF stresses.

However, the assumed FIV/VPFstresses were 40% larger than the weld stresses calculated in Reference 4.Assumption of the components and welds to have MSLB-acoustic stresses equal to the largeststress calculated in MSLB analyses.

Addition of maximum stresses from different loads in a load combination while ignoringdifferences in locations of maximum stresses for the different types of loads.Use of maximum local mid-wall and surface stresses for comparison to membrane and membrane+ bending stress limits without averaging or linearizing the stresses across sections.

Classifying stresses from pressure loads at constrained plate boundaries as primary stresses (withlower stress limits) rather than secondary stresses (with higher stress limits) as classified byASME Code Section III, Subsection NG, Table NG-3217-1.

Fatigue usage for ASME loads and concurrent FIV/VPF loads is insignificant

[ ]a~C compared tothe ASME Code usage limit of 1.0. FIV/VPF loads independent of the ASME loads are shown to be wellbelow the ASME Code endurance limit in Reference 4.2.3 INTERFACE LOADSTable 2-9 lists interface loads for use in evaluation of dryer support brackets and hold-down rods. Theloads in the table are for a single support lug and a single hold-down bracket.WCAP- 17649-NPApril 2014Revision 2

2-3titI2IFigure 2-1 PB2 Dryer with Instrumentation Mast: Analysis Model -OutlineWCAP-1 7649-NP April 2014WCAP-1t7649-NP Apris 2014Revision 2

2-4'LIIIFigure 2-2 PB2 Dryer with Instrumentation Mast: Analysis Model -Finite Element MeshWCAP- 17649-NPApril 2014Revision 2

2-52-1 Minimum Design Margins -Components (Service Level A)a,cWCAP- 17649-NPApril 2014Revision 2

2-6Table 2-1 Minimum Design Margins -Components (Service Level A) (cont.) 1--WCAP- 17649-NPApril 2014Revision 2

2-7-11Table 2-2 Minimum Design Margins -Welds (Service Level A)a,cWCAP- 17649-NPApril 2014Revision 2

2-8Table 2-2 Minimum Design Margins -Welds (Service Level A) (cont.)L_a,cWCAP-17649-NP April 2014Revision 2

2-9..Table 2-2 Minimum Design Margins -Welds (Service Level A) (cont.)I-acWCAP-17649-NP April 2014Revision 2

2-104 Table 2-2 Minimum Design Margins -Welds (Service Level A) (cont.)I-WCAP- 17649-NPApril 2014Revision 2

2-11.4 Table 2-3 Minimum Design Margins -Components (Service Level B)ILa,cWCAP-17649-NP April 2014Revision 2

2-124Table 2-3 Minimum Design Margins -Components (Service Level B) (cont.)4a,cWCAP- 17649-NPApril 2014Revision 2

2-13Table 2-4 Minimum Design Margins -Welds (Service Level B)a,cWCAP- 17649-NP April 2014WCAP- I17649-NP April 2014Revision 2

2-14_ Table 2-4 Mininum Design Margins -Welds (Service Level B) (cont.)a,cWCAP-1 7649-NP April 2014WCAP- 17649-NPApril 2014Revision 2

2-15_1Table 2-4 Minimum Design Margins -Welds (Service Level B) (cont.)-ta,cWCAP- 17649-NPApril 2014Revision 2

2-16L Table 2-4 Minimum Design Margins -Welds (Service Level B) (cont.)2-16a,cWCAP- 17649-NPApril 2014Revision 2

2-17Table 2-5 Minimum Design Margins -Components (Service Level C)a,cWCAP- 17649-NP April 2014Revision 2

2-184 Table 2-5 Minimum Design Margins -Components (Service Level C) (cont.)1-a,cWCAP- 17649-NPApril 2014Revision 2

2-19_4able 2-6 Minimum Design Margins -Welds (Service Level C)4a,cWCAP- 17649-NPApril 2014Revision 2

2-20Table 2-6 Mminium Design Margins -Welds (Service Level C) (cont.)-4acWCAP- 17649-NPApril 2014Revision 2

2-21._Table 2-6 Minimum Design Margins -Welds (Service Level C) (cont.)axcWCAP- 17649-NPApril 2014Revision 2

2-22.Table 2-6 Minimum Design Margins -Welds (Service Level C) (cont.)419 .CWCAP- 17649-NPApril 2014Revision 2

2-23Table 2-7 Minimum Design Margins -Components (Service Level D)2a,cWCAP- 17649-NPApril 2014Revision 2

2-24TIable 2-7 Minimum Design Margins -Components (Service Level D) (cont.)-ka,cWCAP- 17649-NPApril 2014Revision 2

2-25lable 2-8 Minimum Design Margins -Welds (Service Level D)I-a,cWCAP-17649-NP April 2014Revision 2

2-26_LTable 2-8 Minimum Design Margins -Welds (Service Level D) (cont.)4a,cWCAP- 17649-NPApril 2014Revision 2

2-27__Table 2-8 Minimum Design Margins -Welds (Service Level D) (cont.)-4axcWCAP- 17649-NPApril 2014Revision 2

2-28L Table 2-8 Minimum Design Margins -Welds (Service Level D) (cont.)-1axcWCAP- 17649-NPApril 2014Revision 2

2-294Table 2-9 Reaction Loads4a,cWCAP- 17649-NPApril 2014Revision 2

3-13 ANALYSIS INPUT3.1 LOADSSpecified loads are Deadweight, Differential Pressures (DP) from a pressure drop across the dryer vanebanks, and TSV and MSLB loads on the outer hoods. Thermal loads are not considered because the dryeroperates in isothermal environment and the structural design does not involve materials with different thermal expansion coefficienis.

3.1.1 GravityThe dryer weight is included in the analysis models by specifying component dimensions and materialdensities.

3.1.2 Pressure LoadsNormal Operation, Upset Condition, and Emergency Condition pressure differences across the dryer(Reference

6) are listed in Table 3-1 as DPN, DPu, and DPE, respectively.

Pressures following MSLB arelisted as MSLBDPI and MSLBDP2.Reactor Thermal Cycles Diagram (Reference

7) identifies

[ ]aIC start-up cycles and [ ]a'C operational scrams. Because potential pressure reductions during the scram events are not defined, the start-up andscram cycles were added [ ]a"' and enveloped by using [ ]a,c load cycles forfatigue usage calculations.

TSV loads (Reference

8) on the outer hoods are listed in Table 3-2. Acoustic load TSVA is shown aspressure distribution relative to the center line of the affected steam line. The reverse flow impingement load following the valve closure is listed as TSVF. TSVF, not to be combined with TSVA, acts on theouter hood area corresponding to projection of the steam nozzle on the outer hood.For fatigue usage calculations, TSV stress cycles are specified (Reference 9).FIV/VPF loads and MSLB acoustic loads are described and analyzed separately (Reference 4 andReference 5). Stresses from these analyses were enveloped and combined with stresses calculated inpresent analyses as described in Section 4.Table 3-1 Dryer Pressure Loads (Reference 6)DPN, Normal Operation

pressure, psid [ ]a,cDPu, Upset Condition

pressure, psid [ ]a,cDPE, Emergency Condition

pressure, psid [ ]acMSLBDPI, MSLB outside containment, rated power and core flow condition, psid [ laxMSLBDP2, MSLB outside containment, low power / high core flow condition, psid°" [ ]J'CNote: (I) Limit load analysis was performed to justify higher pressure (Reference 12)WCAP- 17649-NPApril 2014Revision 2

3-2-+Table 3-2 TSV Loads on the Outer Hood (Reference 8)4a,c3.1.3 Seismic LoadsSpecific N-S and E-W response spectra for [ damping (Reference

10) are shown in Figure 3-1.These spectra were enveloped and used as horizontal OBE and SSE loads. Two-thirds of the enveloped spectra in the figure were used for Vertical seismic loads (Reference 9).For fatigue usage calculations,

[ ]axc OBE stress cycles are used (Reference 9).3.2 LOAD COMBINATIONS Table 3-3 lists the specific load combinations (Reference 9). When combining seismic loads:1. Stresses from N-S and vertical excitations are to be combined using absolute summation.

2. Stresses from E-W and vertical excitations are to be combined using absolute summation.

3. The larger of the N-S-vertical seismic stresses and E-W-vertical seismic stresses are to be usedwith stresses from other loads to obtain stresses for specific load combinations.

WCAP- 17649-NPApril 2014Revision 2

3-3Table 3-3 Load Combinations (Reference 9)Load Service Acceptance Criteria Operating Condition Load Combination (Service Level)A Normal A Normal Operation DW + DPN + FIVB-I Upset B Turbine Stop Valve Closure DW + DPN + ((TSVA)2 + (FlV)2)"2(Acoustic Load)B-2 Upset B Turbine Stop Valve Closure DW + DPN + TSVF(Flow Reversal Load)B-3 Upset B Normal Operation plus OBE DW + DPN + ((OBE)2 +plus FIVB-6 U pset B DW, Differential Pressure DW + DPu + FIV(Upset) plus FIVC-I Emergency C DW, Differential Pressure DW +/- DPE + FIV(Emergency) plus FIVD-3 Faulted D Normal plus FIV plus SSE DW + DPN + ((MSLBA,)

2 + (SSE)2 + (FIV)2)I,2 plus DBAD-4 Faulted D Normal plus FIV plus SSE DW + DPN + ((MSLBA2)2 + (SSE)2 + (FIV)2)12

__________plus DBAD-5 Faulted D Normal plus SSE plus DBA DW + MSLBDpI + SSED-6 Faulted D Normal plus DBA DW + MSLBDP2Legend:DW Deadweight

(+ weight of entrapped water for dynamic analysis)

DPN Differential pressure

-normal operation DPu Differential pressure

-upset condition DPE Differential pressure

-emergency condition FIV Flow induced vibration loads (plus Vane Passing Frequency (VPF) loads)TSVA Acoustic load caused by closure of Turbine Stop Valve.TSVF Flow impingement load caused by closure of Turbine Stop Valve.OBE OBE inertia load (anchor displacement loads are negligible)

SSE SSE inertia load (anchor displacement loads are negligible)

DBA Design Basis AccidentMSLBAI Acoustic rarefaction wave load due to MSLB outside the containment, rated power andcore flow condition MSLBA2 Acoustic rarefaction wave load due to MSLB outside the containment, low power / highcore flow condition MSLBDPI Differential Pressure load due to MSLB outside the containment, rated power and coreflow condition MSLBDP2 Differential Pressure load due to MSLB outside the containment, low power / high coreflow condition WCAP- 17649-NPApril 2014Revision 2

3-43.3 ACCEPTANCE CRITERIAThe steam dryer is not an ASME B&PV Code component.

However, it is evaluated as an InternalStructure according to the design rules of ASME B&PV Code,Section III, Division 1, Subsection NG(Reference 2). The applicable design rules are summarized in Table 3-4. The TSV pressure loads(Reference

8) in the analysis far exceed the normal operation

([ ]a"C) and upset condition

([i ]a,]) pressure loads (Reference

6) generally used for defining design pressure.

Therefore, whenapplying the Service Level B stress limits to the TSV pressure loads, the stress limits were based on 110%of Sm values, according to Paragraph NG-3223 of the Code.Table 3-4 Stress Limits (Reference 2)Service level Stress category Stress limitService levels A & B(1) Pm SmPm + Pb 1.55SmShear stress 0.6 SnBearing stress Sy, (1.5 S, away from free edge)I fatigue usage 1.0Service level C Pm 1.5 SmPm + Pb 2.25SmShear stress 0.9 Sn,Bearing stress 1.5 S,, (2.25 Sy away from free edge)Service level D Pm Min(2.4 Sm, 0.7 Sj)Pm + Pb Min(3.6 Sm, 1.05 Sj)Shear stress 1.2 SmBearing stress 2.0 Sy, (3.0 Sy away from free edge)Legend:Pm Primary membrane stress intensity Pb Primary bending stress intensity Sm Stress intensity limitSY Yield strengthSý Ultimate strengthNote (I) TSV pressure exceeds the specified normal operation (I la'c) and upset condition pressure (Iconsidered as design pressure and was evaluated using stress intensity value of 110% Sm according toParagraph NG-3223 of Reference 2.WCAP- 17649-NPApril 2014Revision 2

3-53.4 MATERIAL PROPERTIES Dryer structural components are made from SA-240 type 316L. Table 3-5 lists the material properties (Reference

11) used in the analysis.

Table 3-5 Material Properties (Reference 11)Material property 70OF 551OFSm, Stress intensity limit, psi 16,700 14,400SY, Yield strength, psi 25,000 16,000S.. Ultimate

strength, psi 70,000 61,700E, Young's modulus, psi 28.3 x 106 25.42 x 106WCAP-17649-NP April 2014Revision 2

3-6a,cFigure 3-1 Seismic Response SpectraWCAP- 17649-NPApril 2014Revision 2

4-14 ANALYSIS AND RESULTS4.1 ANALYSIS MATRIXFinite element analyses were performed for the PB2 dryer, PB2 dryer with instrumentation mast, and thePB3 dryer. In each case, analyses were performed for deadweight (DW), differential pressures (DPN,DPu, DPE, MSLBDPI, MSLBDP2), seismic loads (OBE, SSE), and TSV loads (TSVA, TSVF). Thehydrodynamic mass of the skirt was included in analyses for dynamic loads. FIV/VPF and MSLBA(MSLBAI and MSLB A2) loads are developed and analyzed separately (Reference 4 and Reference 5).Maximum stresses from these analyses were enveloped and combined with the results of present analyses.

Table 4-1 lists the load cases included in the present analyses.

a,cT4.able 4-1 Analysis Matrix4-4.2 ANALYSIS4.2.1 Analysis ModelAnalysis models include the dryer skirt and drain channels,

gussets, center plate and center ring, draintroughs and trough stiffeners, vane bank end plates, top plates, side plates, bank-to-bank attachment plates, and perforated plates, hoods, and upper girder assembly, all modeled with shell elements, dryersupport ring modeled with solid elements, and lifting rods, hold-down rods, and vane bank tie rodsmodeled with beam elements.

Dryer vanes are modeled as solid elements with weight equal to the vanebank weight. The hydrodynamic mass is modeled by adjusting density of the under-water elements of theWCAP- 17649-NPApril 2014Revision 2

4-2skirt. The analysis model for the PB2 dryer with instrumentation mast is shown in Figure 2-1 and Figure2-2. Analysis models for the PB2 dryer without instrumentation mast and the PB3 dryer are similar,except for the absence of the mast assembly in both of these models, and the absence of hold-down rodsand different lifting lug bracket design in the PB3 dryer model.4.2.2 Boundary Conditions Dryers were supported in vertical and circumferential directions at the dryer support lugs for all theanalyses, except for the analyses for MSLBDPI and MSLBDP2 loads, which produce a dryer lift off. Forlift-off

analyses, the dryers were supported at the top of the lifting rods or hold-down rods in the verticaldirection and at the support lugs in the circumferential direction.

Boundary conditions are shown in Figure 4-1 and Figure 4-2.4.2.3 Load Application For static analyses, pressure was applied as a surface load and gravity load was applied as Ig equivalent static acceleration.

OBE and SSE loads were analyzed in response spectrum analyses.

TSV loads are specified in Table 3-2 as a pressure distribution and impingement load on the hood relativeto one of the four Main Steam Line (MSL) nozzles.

For the analysis, the specified acoustic load pressuredistribution was assumed to apply at all the four MSLs in order to envelop the effects of acoustic wavepropagation through the steam circuit.

For consistency, the flow impingement load was also assumed toapply to all the four MSLs.Figure 4-3 and Figure 4-4 show the pressure load application.

4.2.4 Load Combination ApproachAnalyses were performed for the 14 load cases listed in Table 4-1. Relatively large middle hooddisplacements were calculated for Load Cases 7 ([ ]ac) and 8 ([ ]ac) becauseof the large pressures acting on the thin hood plates. With the small bending stiffness compared to the in-plane stiffness of the hoods, large transverse displacements would be accompanied by in-plane tensileforces resisting the deformations.

The stress-stiffening option of ANSYS software was used to accountfor this coupling between the in-plane and out-of-plane deformations of the hoods.Results of Load Cases 2, 3, 4, 5, 6, 7, and 8 were used directly for Load Combinations A, B-l, B-2, B-6,C-I, D-5, and D-6, respectively, in Table 3-3. OBE and SSE results for use in load combinations B-3,D-3, D-4, and D-5 were obtained from the response spectrum analyses of Load Cases 9 through 14 usingthe following approach:

1. Modal responses for each of the Load Cases 9 through 14 were combined using the Square Rootof the Sum of the Squares (SRSS) approach to obtain OBEx, OBEy, OBEz, SSEx, SSEy, andSSEz responses, where Z is the vertical direction.

2. Vertical and horizontal direction responses were combined using absolute addition to obtain:WCAP- 1 7649-NP April 2014Revision 2

4-3I]a.c3. Maximum stress intensities for each dryer component were extracted for OBExz, OBEyz, SSExz,and SSEyz. These values were compared, ignoring differences in their locations in thecomponents, to obtain maximum component seismic stress intensities as:]a~cOBE stresses were combined with the maximum normal operation stresses (Load Case 2) and maximumFIV/VPF stresses to obtain stresses for Load Combination B-3 using the following relationship:

]a,cSSE stresses were combined with the maximum normal operation stresses (Load Case 2), maximumFIV/VPF stresses, and maximum MSLBA (MSLBAI and MSLBA2) stresses to obtain enveloping stressesfor Load Combinations D-3 and D-4 using the following relationship:

[ ]acSSE stresses were combined with the maximum (DW+MSLBDPI) stresses (Load Case 7) to obtain stressesfor Load Combination D-5 using the following relationship:

[ ]acIt was not possible to SRSS the TSVA and FIV/VPF stresses because TSVA + DW + DPN loads wereanalyzed together (Load Case 3). Therefore, FIV/VPF stresses were added absolutely to the results forLoad Case 3 to obtain stresses for Load Combination B-I.The above approach of combining maximum stresses from different load cases to obtain maximumstresses for a Load Combination conservatively ignores the differences in the locations of maximumstresses for the different load cases.4.2.5 Component StressesMaximum stresses in the dryer components are highly localized at nodes at intersections of weld linesbetween multiple components.

Usually, such local stresses are used for fatigue calculations, and stressesaway from these nodes are averaged and linearized across component sections and used for stress limitcomparisons.

However, the complex geometry of the dryer, large stress gradients, and differences inlocations of maximum stresses for different loads make it difficult to select sections for stress averaging.

Therefore, the following conservative approach was used for design margin calculations.

1. ANSYS post-processor was used to extract maximum mid-wall and surface stresses for eachcomponent modeled with shell elements including the elements at the weld lines, and theWCAP-17649-NP April 2014Revision 2

4-4maximum stresses anywhere in the components modeled with solid elements including theelements at the weld lines.2. Maximum mid-wall and surface stresses from different loads in load combinations werecombined as described in Section 4.2.4, conservatively ignoring differences in their locations inthe components.

3. FIV/VPF loads are developed and analyzed separately (Reference 4). Component stresses inthese analyses are limited to the ASME Code limit ([ ]a.c psi) adjusted for elastic modulusratio [ ]aTc, and divided by a safetyfactor of S > 1"',c or [ For the ASME Code analysis, thesestresses were enveloped by conservatively assuming maximum FIV/VPF stress in eachcomponent to equal the stress limit of [ ]ax psi, corresponding to a safety factor of 1. Thatis, all the components in the dryer were assumed to have a maximum surface stress, ofp ]a,c si.4. Maximum MSLBA (MSLBAI and MSLBA2) surface stress of[ ] psi has been calculated inMSLBA analyses of the three dryer configurations (Reference 5). The high MSLBA stresses arein the outer hood region. Much lower stresses occur in other regions of the dryer. However,these maximum stresses were conservatively assumed to apply as surface stresses for all thecomponents in the dryers.5. As pressure loading produces primarily bending stresses with small membrane

stresses, mid-wallstresses were enveloped by assuming a mid-wall FIV/VPF stress of [ ]", psi and amid-wall MSLBA stress of [ ]", psi for all the components in the dryers.6. The enveloping FIV/VPF and MSLBA stresses described in Steps (3-5) were added to themaximum component stresses calculated in Step (2) as described in Section 4.2.4. The resulting mid-wall stresses were compared with membrane stress limits without any averaging, and surfacestresses were compared with membrane

+ bending stress limits without any linearizing.

7. In a few cases, maximum surface stresses described in Step (6) exceeded the membrane plusbending stress limit. Stress distributions in these cases were investigated in greater detail asdescribed in Section 4.2.5.4.The approach described above was used for each of the three dryer analysis models. Analysis results forthe three dryers are discussed in terms of the following components:

WCAP- 17649-NP April 2014Revision 2

4-5TroughsGussets center plateVB (Vane Bank) end platesVB top side platesOuter hoodsCenter cover plateSupport ringSkirt slotsHorizontal railsGussets (thin section)Gussets center ringVB top platesInner hoodsVB to VB vertical platesUpper girdersDrain channelSkirt beltsSlot beltsGussets (thick section)Trough stiffeners VB top stepsMiddle hoodsVB to VB top platesUpper girders center ringSkirtDrain channel belts4.2.5.1 PB2 Dryer with Instrumentation MastMaximum mid-wall and surface stresses for components of the PB2 dryer with instrumentation mast arelisted in Table 4-2 for load cases 2 through 8 and for OBE and SSE with directional earthquake stressescombined and maximized as described in Section 4.2.4.Maximum stresses listed in Table 4-2 are combined following the approach described above to obtainmid-wall and surface stresses for various load combinations.

These stresses are listed in Table 4-3. Inlisting the stresses, maximums of the stresses for Load Combinations D-3 and D-4 are reported in acommon column.4.2.5.2 PB2 Dryer without Instrumentation MastMaximum mid-wall and surface stresses for components of the PB2 dryer without instrumentation mastare listed in Table 4-4 for load cases 2 through 8 and for OBE and SSE with directional earthquake stresses combined and maximized as described in Section 4.2.4.Maximum stresses listed in Table 4-4 are combined following the approach described above to obtainmid-wall and surface stresses for various load combinations.

These stresses are listed in Table 4-5. Inlisting the stresses, maximums of the stresses for Load Combinations D-3 and D-4 are reported in acommon column.4.2.5.3 PB3 DryerMaximum mid-wall and surface stresses for the PB3 dryer components are listed in Table 4-6 for loadcases 2 through 8 and for OBE and SSE with directional earthquake stresses combined and maximized asdescribed in Section 4.2.4.Maximum stresses listed in Table 4-6 are combined following the approach described above to obtainmid-wall and surface stresses for various load combinations.

These stresses are listed in Table 4-7. Inlisting the stresses, maximums of the stresses for Load Combinations D-3 and D-4 are reported in acommon column.WCAP- 1 7649-NP April 2014WCAP- 17649-NPApril 2014Revision 2

4-64.2.5.4 All DryersStresses listed in Table 4-3, Table 4-5, and Table 4-7 for the three dryer configurations were compared toextract maximum stresses for the 10 load combinations (reported with combined maximum values forLoad Combinations D-3 and D-4), which were further compared to obtain maximum stresses for the fourASME Code Service Levels. These stresses are listed in Table 4-8 together with the membrane andmembrane

+ bending stress limits for the four Service Levels.The conservatively calculated maximum stresses are within the ASME Code limit with two exceptions:

I1. Service Levels A and BService Level A and B surface stresses for Middle Hood, Outer Hood, Vane Bank (VB) TopSteps, and VB Top Side plates are close to or exceed the ASME Code primary stress limits. Thestresses listed in the stress tables generally occur at multi-plate junctions as a result ofdeformation constraints.

These stresses are highly localized and decrease to acceptable valueswithin a small distance from the constraint location.

This is illustrated in the surface stress plotsfor the PB2 dryer with instrumentation mast for DW+DPN loads in Figure 4-5 (Middle hood),Figure 4-6 (Outer hood), Figure 4-7 (VB top steps), and Figure 4-8 (VB top side plates).

Asshown in the top plot in each figure, maximum stresses are localized at intersections of multipleplates rather than in the main plate regions of the plates or along the welds. Removing elementsat the constraint node decreases the stresses by [ ]a or more as shown in the bottom plot ofeach figure. (The maximum stresses in figures are smaller than the corresponding stresses in thestress tables. This is because it was necessary to include multiple plates in the figures to showthat the maximum stresses occur at their junctions.

The angles between the plates result insmaller nodal stress averages compared to the stress tables, which were based on stressdistributions in individual plates).Thus, the listed maximum stresses are local stresses that produce fatigue usage but do notsignificantly contribute to membrane and bending stresses.

Therefore, stresses for codecomparison can be obtained by removing elements at the maximum stress locations whilemaintaining the conservatism.

Accordingly, elements attached to the node corresponding to themaximum stress locations were removed and maximum stresses were extracted from the rest ofthe stress distributions.

This was done only for components and Load Combinations producing local stresses in excess of the stress limits. The resulting stresses are listed in Table 4-9 andreported for design margin results (Table 2-l and Table 2-3). Note that the approach of removinglocal peak stresses does not affect the maximum stress for the TSV acoustic pressure load becausethe maximum stresses occur away from welds as shown in Figure 4-9. Otherwise, the stresseslisted in the table after removing the maximum stress elements are still local peaks stresses ratherthan section-averaged stresses and provide conservative estimates of design margins.2. Service Level DThe Middle hood surface stress of [ ]a,c psi exceeds the ASME Code Service Level DPm+Pb limit of [ ]ac psi for elastic analysis.

Figure 4-10 shows that the overstress condition occurs in the middle hood for the MSLBDP2 pressure load.WCAP- 17649-NP April 2014Revision 2

4-7With the stress limit for elastic analysis

exceeded, collapse analyses were performed (Reference

12) for the middle hood assuming elastic-perfectly plastic behavior and a yield stressof [ ]j.x psi following Appendix F of the ASME Code (Reference 13). A quarter-model of the hood was analyzed with symmetry boundary conditions applied at the symmetry(vertical) boundaries.

Analyses were performed with the upper and lower edges of the hood 1)fixed against displacements, and 2) fixed against displacements and rotations.

Increasing pressure load was applied until collapse was indicated by rapid increase in displacements and lackof convergence.

Collapse pressures of [ ] psi and [ ] psi were calculated for the case with upper andlower edges of the hood fixed only against displacements, and the case with the edges fixedagainst displacements and rotations, respectively.

Using the ASME design limit of 0.9 x collapsepressure (Reference

13) with the lower value of collapse pressure gives a pressure limit of]a"c psi, which provides adequate design margin for the MSLBDP2 pressure of[ ]8'C psi..WCAP- 17649-NPApril 2014Revision 2

4-8T___able 4-2 PB2 Dryer with Mast, Load Cases 2-14, Maximum Component Stresses4-4a,cWCAP- 17649-NPApril 2014Revision 2

4-9Table 4-2 PB2 Dryer with Mast, Load Cases 2-14, Maximum Component Stresses (cont.)-Ia,cWCAP- 17649-NPApril 2014Revision 2

4-10T__able 4-2 PB2 Dryer with Mast, Load Cases 2-14, Maximum Component Stresses (cont.)-1a,cWCAP- 1 7649-NPApril 2014Revision 2

4-11Table 4-3 PB2 Dryer with Mast, Load Combinations, Maximuni Component Stresses4a,cWCAP- 17649-NPApril 2014Revision 2

4-12T__able 4-3 PB2 Dryer with Mast, Load Combinations, Maximum Component Stresses (cont.)-4a,cWCAP- 17649-NPApril 2014Revision 2

4-13T__able 4-3 PB2 Dryer with Mast, Load Combinations, Maximum Component Stresses (cont.) 4a,cWCAP- 17649-NPApril 2014Revision 2

4-14jTable 4-4 PB2 Dryer without Mast, Load Cases 2-14, Maximum Component Stresses-1a,cWCAP- 17649-NPApril 2014Revision 2

4-15j Table 4-4 PB2 Dryer without Mast, Load Cases 2-14, Maximum Component Stresses (cont.)-Ia,cWCAP- 17649-NPApril 2014Revision 2

4-16T__able 4-4 PB2 Dryer without Mast, Load Cases 2-14, Maximum Component Stresses (cont.)4a,cWCAP- 17649-NPApril 2014Revision 2

4-17Table 4-5 PB2 Dryer without Mast, Load Combinations, Maximum Component Stresses-1a,cWCAP-17649-NP April 2014Revision 2

4-18LTable 4-5 PB2 Dryer without Mast, Load Combinations, Maximum Component Stresses (cont.)-4a,cWCAP- 17649-NPApril 2014Revision 2

4-19Table 4-5 PB2 Dryer without Mast, Load Combinations, Maximum Component Stresses (cont.)a,cWCAP- 17649-NPApril 2014Revision 2

4-20lTable 4-6 PB3 Dryer, Load Cases 2-14, Maximum Component Stresses-ia,cWCAP- 17649-NPApril 2014Revision 2

4-21L Table 4-6 PB3 Dryer, Load Cases 2-14, Maximum Component Stresses (cont.)-ia,cWCAP-17649-NP April 2014Revision 2

4-22Table 4-6 PB3 Dryer, Load Cases 2-14, Maximum Component Stresses (cont.)Ia,cWCAP- 17649-NPApril 2014Revision 2

4-23Table 4-7 PB3 Dryer, Load Combinations, Maximum Component Stresses acWCAP- 17649-NPApril 2014Revision 2

4-24Table 4-7 PB3 Dryer, Load Combinations, Maximum Component Stresses (cont.)-Ia,cWCAP- I7649-NPApril 2014Revision 2

4-25Table 4-7 PB3 Dryer, Load Combinations, Maximum Component Stresses (cont.)a,cWCAP-17649-NP April 2014Revision 2

4-26I Table 4-8 All Dryers, Service Levels, Maximum Component Stresses4-26a,cWCAP- 17649-NPApril 2014Revision 2

4-27Table 4-9 Maximum Component Stresses After Removing Elements at Maximum Stress Locations a,c4.2.6 Weld StressesWeld stresses were calculated using the same approach as used for component stress calculations in thatmaximum weld stresses for individual loads were extracted and combined according to specific loadcombinations without taking credit for differences in locations of maximum stresses, and local maximumstresses were used for stress comparison without averaging over potential failure lengths.Different FIV/VPF stresses were used in weld calculations compared to the component stresses.

TheASME alternating stress limit of [ ]a,, psi used as FIV/VPF stress in the dryer components wasdivided by the minimum Stress Concentration factor f = 1.4 used in FIV/VPF analyses (Reference

4) toobtain the corresponding weld stress limit of [ ]a, psi. The maximum stress ofI ],*" psi calculated in MSLBA (MSLBAI and MSLBA2) analyses (Reference

5) would envelop theweld as well as component stresses.

With these considerations, FIV/VPF and MSLBA surface stresses atall welds were assumed to be ]a.C psi and [ ]ac psi, respectively, and FIV/VPF and MSLBAmid-wall stresses at all welds were assumed to be [ ],c psi and [ ]a,c psi,respectively.

Weld stresses for the individual load cases for the PB2 dryer with mast, the PB2 dryer without mast, andthe PB3 dryer are shown in Table 4-10, Table 4-12, and Table 4-14, respectively.

Corresponding stressesfor the various load combinations are shown in Table 4-11, Table 4-13, and Table 4-15, respectively.

Themaximum weld stresses for the four Service Levels, which are obtained by comparing the three dryerstresses for each Service Level's load combination, are listed in Table 4-16 together with the ASME Codestress limits for weld quality factors of n = 0.75 and 0.9. All the welds are full penetration welds to beexamined with root and final PT (n = 0.75), except for the Middle Hood vertical welds, which are to beexamined with progressive PT (n = 0.90).The conservatively calculated local maximum stresses are within the stress limits for most of the welds.Exceptions in which the stresses exceed the stress limits are identified in Table 4-16. As discussed inWCAP- 17649-NP April 2014Revision 2

4-28Section 4.2.5.4, the reported stresses are local stresses from deformation constraints at multiple-plate junctions.

Although used in calculating fatigue usage with appropriate weld strength reduction factorf([ ],C for full penetration welds), they do not contribute significantly to membrane and bendingstresses.

Therefore, elements at maximum stress locations were removed and maximum stresses wereextracted from the rest of the stress distributions.

This was done only for welds and Load Combinations producing local stresses in excess of the stress limits. The resulting stresses are listed in Table 4-17. Witha few exceptions, the highest stresses for different Service Levels in Table 4-17 are directly used fordesign margin results (Table 2-2, Table 2-4, Table 2-6 and Table 2-8). For long welds, maximum stressesoccur at mid-length locations in addition to the ends. The high stresses at mid-length locations are notaffected by removing a few high-stress elements and exceed the stress limits for the welds listed in thefollowing table. Approaches used to resolve them are discussed in the following paragraph.

Maximum surface stress, psiWeld / load combination (After removing elements at the peak(All elements) maximum stress nodes)BI: DW+DPN+TSVA+FIV vb-top step to outer hoods [ [ ]a,couter hood to outer hood [ I[ ]acB3: DW+DPN+OBE+FIV vb-vb vert plate to middle hood [ ]a.c [ ]a.cMaximum stresses for the vane bank top step to outer hood welds ([ ]a,,C psi) and the outer hood toouter hood welds ([ ]a,c psi) exceed the ASME stress limit of [ ],, psi. However, thestresses result from the TSVA loads (Load Combination B 1) assumed to originate from two adjacent MainSteam Lines, producing a [ ],,c psi to [ ]a,c psi pressure load. This exceeds the normal operation and upsetcondition pressures of [ ]J"' psi and [ ]a', psi, respectively.

Therefore, the TSVA pressure can beconsidered much larger than the design pressure, for which the Code specifies 10% higher Service LevelB stress limits. These higher limits are used to calculate design margins for these two weld/load combination stresses.

In addition, it was necessary to assume FIV/VPF weld stresses of [ ],* psi (outer hood to outer hood)and [ ]" psi (vb-vb vert plate to middle hood welds) instead of the [ ]a*c psi FIV/VPF stress usedfor the remaining welds and load combinations in order to meet the stress limits. The following tableshows the weld stress calculated with these assumptions, and used for design margin calculations (Table2-4). Note that the FIV/VPF stresses are not directly additive for two of the welds, but are added usingSRSS because the controlling load combinations involve OBE.The corresponding FIV/VPF stresses calculated for these welds in Reference 4 are [ ]a,c psi,]a*c psi, and [ ]"' psi instead of [ ],', psi, [ ]ja psi, and [ ]a'c psi assumed in thepresent evaluation for the outer hood to outer hood welds, vb-vb vertical plate to middle hood welds, andvb top step to outer hood welds, respectively.

WCAP- 17649-NP April 2014Revision 2

4-29Maximum weld surfaceWeld / load combination Assumed FIV stress, psi strs, csstress, psivb-top step to outer hoods [ ]a.c [ ]a.couter hood to outer hood [ ]afc [ ]a,Cvb-vb vert plate to middle hood [ ] [ ]3,c4.2.7 Interface LoadsTable 2-9 lists the maximum reaction loads imposed by the dryer on the dryer support lugs and the lifting-rod hold-down brackets.

The loads were calculated considering static equilibrium of pressure loads,seismic loads based on ZPA, and dryer weight. It was considered acceptable to use ZPA because thefrequency of the structural components in the dryer is -[ ]'.c Hz, which is close to the response spectraZPA (Figure 3-1). The loads are the maximum loads on a support bracket, a hold-down rod (PB2), or alifting rod (PB3).WCAP- 17649-NPApril 2014Revision 2

4-30Table 4-10 PB2 Dryer with Mast, Load Cases 2-14, Maximum Weld Stresses-ta,cWCAP- 17649-NPApril 2014Revision 2

4-31..Table 4-10 PB2 Dryer with Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)4a,cWCAP- 17649-NPApril 2014Revision 2

4-32-Table 4-10 PB2 Dryer with Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)-4-a,cWCAP- 17649-NPApril 2014Revision 2

4-33L Table 4-10 PB2 Dryer with Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)4a,cWCAP-17649-NP April 2014Revision 2

4-34_LTable 4-10 PB2 Dryer with Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)4a,cWCAP- 17649-NPApril 2014Revision 2

4-35Table 4-10 PB2 Dryer with Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)-4a,cWCAP- 17649-NPApril 2014Revision 2

4-36_LTable 4-11 PB2 Dryer with Mast, Load Combinations, Maximum Weld Stresses4a,cWCAP- 17649-NPApril 2014Revision 2

4-37Table 4-11 PB2 Dryer with Mast, Load Combinations, Maximum Weld Stresses (cont.)a,cWCAP- 17649-NP April 2014Revision 2

4-38_Table 4-11 PB2 Dryer with Mast, Load Combinations, Maximum Weld Stresses (cont.)a,cWCAP-17649-NP April 2014Revision 2

4-39_LTable 4-11 PB2 Dryer with Mast, Load Combinations, Maximum Weld Stresses (cont.)a,cWCAP- 17649-NP April 2014Revision 2

4-40Table 4-11 PB2 Dryer with Mast, Load Combinations, Maximum Weld Stresses (cont.)4a,cWCAP- 17649-NPApril 2014Revision 2

4-41.__Table 4-11 PB2 Dryer with Mast, Load Combinations, Maximum Weld Stresses (cont.)4a,cWCAP- 17649-NPApril 2014Revision 2

4-42Table 4-12 PB2 Dryer without Mast, Load Cases 2-14, Maximum Weld Stresses4axcWCAP- 17649-NPApril 2014Revision 2

4-43Table 4-12 PB2 Dryer without Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)4-a,cWCAP-17649-NP April 2014Revision 2

4-44__Table 4-12 PB2 Dryer without Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)41a,cWCAP-17649-NP April 2014Revision 2

4-45]-Table 4-12 PB2 Dryer without Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)4a,cWCAP- 17649-NPApril 2014Revision 2

4-46_Table 4-12 PB2 Dryer without Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)a,cWCAP- 17649-NPApril 2014Revision 2

4-47_Lable 4-12 PB2 Dryer without Mast, Load Cases 2-14, Maximum Weld Stresses (cont.)a,cWCAP- 17649-NP April 2014WCAP- I17649-NP Apris 2014Revision 2

4-48Table 4-13 PB2 Dryer without Mast, Load Combinations, Maximum Weld Stressesa,cWCAP- 17649-NP April 2014Revision 2

4-49Table 4-13 PB2 Dryer without Mast, Load Combinations, Maximum Weld Stresses (cont.)Ia,cWCAP- I 7649-NPApril 2014Revision 2

4-50I-Table 4-13 PB2 Dryer without Mast, Load Combinations, Maximum Weld Stresses (cont.)4a,cWCAP-17649-NP April 2014Revision 2

4-51]-Table 4-13 PB2 Dryer without Mast, Load Combinations, Maximum Weld Stresses (cont.)-La,cWCAP- 17649-NPApril 2014Revision 2

4-52--Table 4-13 PB2 Dryer without Mast, Load Combinations, Maximum Weld Stresses (cont.)a,cWCAP- 17649-NPApril 2014Revision 2

4-53_Table 4-13 PB2 Dryer without Mast, Load Combinations, Maximum Weld Stresses (cont.)a,cWCAP- 17649-NPApril 2014Revision 2

4-54Table 4-14 PB3 Dryer, Load Cases 2-14, Maximum Weld Stresses2La,cWCAP- 17649-NPApril 2014Revision 2

4-55._LTable 4-14 PB3 Dryer, Load Cases 2-14, Maximum Weld Stresses (cont.)-La,cWCAP- 17649-NPApril 2014Revision 2

4-56A-Table 4-14 PB3 Dryer, Load Cases 2-14, Maximum Weld Stresses (cont.)-4a,cWCAP-17649-NP April 2014Revision 2

4-57I Table 4-14 PB3 Dryer, Load Cases 2-14, Maximum Weld Stresses (cont.)1a,cWCAP- 17649-NPApril 2014Revision 2

4-58T__able 4-14 PB3 Dryer, Load Cases 2-14, Maxinum Weld Stresses (cont.)4-a,cWCAP-17649-NP April 2014Revision 2

4-59Table 4-14 PB3 Dryer, Load Cases 2-14, Maximum Weld Stresses (cont.)4-a,cWCAP- 17649-NPApril 2014Revision 2

4-60_._able 4-15 PB3 Dryer, Load Combinations, Maximum Weld Stresses-1a,cWCAP- 17649-NPApril 2014Revision 2

4-61..jable 4-15 PB3 Dryer, Load Combinations, Maximum Weld Stresses (cont.)-4a,cWCAP- 17649-NPApril 2014Revision 2

4-62Table 4-15 PB3 Dryer, Load Combinations, Maximum Weld Stresses (cont.)4a,cWCAP-17649-NP April 2014Revision 2

4-63Table 4-15 PB3 Dryer, Load Combinations, Maximum Weld Stresses (cont.)-4a,cWCAP- 17649-NPApril 2014Revision 2

4-64&_Table 4-15 PB3 Dryer, Load Combinations, Maximum Weld Stresses (cont.)--La,cWCAP- 17649-NPApril 2014Revision 2

4-65LTable 4-15 PB3 Dryer, Load Combinations, Maimum Weld Stresses (cont.)4acWCAP- 17649-NPApril 2014Revision 2

4-66Table 4-16 All Dryers, Service Levels, Maximum Weld Stresses44a,cWCAP-17649-NP April 2014Revision 2

4-67_Table 4-16 All Dryers, Service Levels, Maximum Weld Stresses (cont.)a,cWCAP- 17649-NPApril 2014Revision 2

4-68__Table 4-17 Maximum Weld Stresses After Removing Elements at Maximum Stress Locations

-A-a,cWCAP- 17649-NPApril 2014Revision 2

4-69_Table 4-17 Maximum Weld Stresses After Removing Elements at Maximum Stress Locations (cont.)4-17~~~-=

Reoin t(cn.WCAP- 17649-NPApril 2014Revision 2

4-70LCircumferential and verticalsupport at the support lugsFigure 4-1 Boundary Conditions for Analyses with No Dryer Lift-OffWCAP- 17649-NPApril 2014Revision 2

4-71Vertical hold-down at thetop of hold-down rods/Figure 4-2 Boundary Conditions for Dryer Lift-Off AnalysisWCAP- 17649-NPApril 2014Revision 2

4-72Figure 4-3 Differential Pressure Loads -DPN, DPu, DPE, MSLBDpI and MSLBDP2WCAP-1 7649-NP April 2014WCAP- 17649-NPApril 2014Revision 2

4-73Acoustic pressureloadFlowimpingement loadPRES-NORM

-6.784m -6.236--5.689--5.141--4.593--4.046-3.498-2.951-2.403--1.855Pressure, psiPressure, psiFigure 4-4 TSV Loads -TSVA, TSVFWCAP-1 7649-NP April 2014WCAP-1I7649-NP April 2014Revision 2

4-74Stress distribution

-all elements19.451714-3408I 510367978492-101861188113575I15270Surface stressintensity, psi19. 4!-977."I 19352893m 3850I 4808I 5766=3 672376818639Surface stressintensity, psiStress distribution

-after removing highest stress elements at multi-plate junctions Figure 4-5 Surface Stress, Middle Hood: DW + DPNWCAP-17649-NP April 2014Revision 2

4-75MN41.0-111321863258433154036475754886209693Surface stressintensity, psiStress distribution

-all elements41.00,648.7'~186 4-- 5511Surface stressintensity, psiStress distribution

-after removing highest stress elements at multi-niate Junctions Stress distribution

-after removing highest stress elements at multi-plate iunctions Figure 4-6 Surface Stress, Outer Hood: DW + DPNWCAP- 17649-NPApril 2014Revision 2

4-76/O/OP1\'*ý\/N.a7/37.7611492261l 3372m 4484M 5596m 6707=3 7819M 89301 10042Surface stressintensity, psie,,Nt\0000r/Stress distribution

-all elem1'-0p../\//i \NNff37.7681.132519692613M 325739014545M 5189M 5832Surface stressintensity, psi/Stress distribution

-after removing highest stress elements at multi-plate junctions Figure 4-7 Surface Stress, Vane Bank Top Steps: DW + DPNWCAP-1 7649-NP April 2014WCAP- 17649-NPApris 2014Revision 2

4-77Stress distribution 19.029793966495259396926m 7912m 8899SSurface stressintensity, psi-all elements19.0864.EM 2556r-l 29793402M 3825Surface stressintensity, psi-after removing highest stress elements at multi-plate junctions Figure 4-8 Surface Stresses, Vane Bank Top Side Plates: DW + DPNStress distribution WCAP- I 7649-NPApril 2014Revision 2

4-78/I--- 1323-2585-3847511063727634E 88961015811421Surface stressintensity, psiFigure 4-9 Surface Stresses, Outer Hoods: DW + TSV-aWCAP- 17649-NPApril 2014Revision 2

4-7954.0523504646694292381153413830161261842220718Mid-wall stressintensity, psi755. 9'L-- 655012344S18139239332972735521[--I 413164711052904Surface stressintensity, psiFigure 4-10 Middle Hood Stresses, MSLBDP2 Pressure LoadWCAP- 17649-NP April 2014WCAP- I17649-NP April 2014Revision 2

5-15 DESIGN MARGINS5.1 STRESS LIMITSComponent design margins are calculated in Table 2-1, Table 2-3, Table 2-5, and Table 2-7 for ServiceLevels A, B, C, and D, respectively.

Weld design margins are calculated in Table 2-2, Table 2-4, Table2-6, and Table 2-8 for Service Levels A, B, C, and D, respectively.

The dryer components and welds for all the dryer configurations meet the ASME Code stress limits.5.2 FATIGUE USAGEA fatigue strength reduction factor of [ ] is conservatively used for all the full-penetration welds asopposed to a fatigue strength reduction factor of [ ]a.c applicable to the component regions away from thewelds. Therefore, the largest calculated fatigue usage will be at the welds. The maximum Service LevelA and B weld stress of [ ]"' psi (Table 4-16) is calculated considering all the load combinations including the weight, pressure, FIV/VPF, and OBE stresses.

Using a fatigue strength reduction factor of]ac and ignoring that the weight stresses do not cycle, the cyclic stress range will be] as psi, and the stress amplitude will be [ ]`'c psi, from Table 4-16.For fatigue usage calculations, the stress amplitude is multiplied by the modulus ratio(EROOM TEMPERATURE

/ EoPERATION

) = ([ ]ac which gives a stress amplitude ofI ]' psi. ASME Code permits [ ]ac cycles operation at this stressamplitude.

Assuming the stress cycle applies to all the cyclic loads, the fatigue usage will beI ]",] start-up-shutdown cycles + [ ]a,C OBE cycles / [ ]3,C,which is insignificant.

FIV and VPF stresses in absence of cyclic pressure and seismic loads are wellbelow the ASME Code endurance limit. Therefore.,

additional fatigue usage from these loads isnegligible.

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6-16 REFERENCES

1. U. S. Nuclear Regulatory Commission, Regulatory Guide 1.20, Rev. 3, Comprehensive Vibration Assessment Program for Reactor Internals during Preoperational and Initial Startup Testing,March 2007.2. American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, SectionIII, Division 1 -Subsection NG, Core Support Structures, 2007 Edition with 2008 Addenda.3. ANSYS Release 11.0, ANSYS, Incorporated.

4. Westinghouse Document CN-A&SA-12-09, Rev. 2, "Peach Bottom Units 2 & 3 Replacement Steam Dryer Acoustic Structural Analysis."

5. Westinghouse Document CN-A&SA-1 2-23, Rev. 2, "Main Steam Line Break Acoustic Transient Load Definition for Peach Bottom Units 2 and 3."6. Westinghouse Document CN-BWR-ENG-12-009, Rev. 0, "Pressure Drop across Exelon SteamDryers."7. Exelon Document TODI EPU-DIR-T0305A08, "Reactor Thermal Cycles."8. Westinghouse Document CN-BWR-ENG-12-002, Rev. 1, "Valve Closure Loads on the SteamDryer."9. Westinghouse Document 425A69, Rev. 4, "Design Specification, Exelon Replacement SteamDryers for PBAPS 2&3."10. Exelon Document TODI EPU-MOD-RSD-11-0, "Design Parameters for Replacement SteamDryer Design."11. American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section II,2007 Edition with 2008 Addenda.12. SES12-207, Rev. 0, "Exelon Replacement Steam Dryer -Limit Analysis of the Middle Hoods forPeach Bottom 2 RSD."13. American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, SectionII1, Division I -Appendix F, 2007 Edition with 2008 Addenda.WCAP- 17649-NP April 2014Revision 2