ML18271A191

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LLC Submittal of Technical Report TR-0916-51502, NuScale Power Module Seismic Analysis, Revision 1
ML18271A191
Person / Time
Site: NuScale
Issue date: 09/28/2018
From: Bergman T
NuScale
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Document Control Desk, Office of New Reactors
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ML18271A190 List:
References
LO-0918-61887
Download: ML18271A191 (216)


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LO-0918-61887 September 28, 2018 Docket No.52-048 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738

SUBJECT:

NuScale Power, LLC Submittal of Technical Report TR-0916-51502, "Nu Scale Power Module Seismic Analysis," Revision 1

REFERENCES:

1. Letter from NuScale Power, LLC to U.S. Nuclear Regulatory Commission, "Submittal of Technical Report 'Nu Scale Power Module Seismic Analysis,"

dated January 10, 2017 (ML17010A433)

2. NuScale Technical Report, "NuScale Power Module Seismic Analysis,"

Revision 0, TR-0916-51502, dated January 2017 (ML17010A434)

In a letter dated January 10, 2017 (Reference 1), NuScale Power, LLC (NuScale) submitted the technical report titled "NuScale Power Module Seismic Analysis," Revision O (Reference 2).

The purpose of this letter is to provide Revision 1 of the Technical Report TR-0716-50439 incorporating changes that resulted from responses submitted to date for the following RAls.

RAI No. 200, RAI 8911 (3.9.2)

RAI No. 202, RAI 9021 (3.9.3)

RAI No. 410, RAI 9310 (3.9.2)

Additional edits have also been made to reflect the removal of seismic Belleville washers from the NuScale Power Module design, change to a 4% composite structural damping, and general updates to address NRC review comments. Changes are identified with revision bars in the margin. is the proprietary version of the report titled "Nu Scale Power Module Seismic Analysis" Revision 1. Enclosure 2 is the non proprietary version of the report titled "NuScale Power Module Seismic Analysis" Revision 1.

NuScale requests that the proprietary Enclosure 1 be withheld from public disclosure in accordance with the requirements of 10 CFR § 2.390. The enclosed affidavit (Enclosure 3) supports this request.

This letter and its enclosures make no regulatory commitments and no revisions to any existing regulatory commitments.

Please feel free to contact Jennie Wike at (541) 360-0539 or at jwike@nuscalepower.com if you have any questions.

Sincerely, NuScale Power, LLC 1100 NE Circle Blvd , Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com

LO-0918-61887 Page 2 of 2 09/28/2018 Distribution: Greg Cranston, NRC, OWFN-8G9A Marieliz Vera, NRC, OWFN-8G9A Samuel Lee, NRC, OWFN-8G9A Enclosure 1: NuScale Power Module Seismic Analysis, TR-0916-51502-P, Revision 1, proprietary version Enclosure 2: NuScale Power Module Seismic Analysis, TR-0716-51502-NP, Revision 1, nonproprietary version Enclosure 3: Affidavit of Thomas A. Bergman, AF-0918-61892 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com

LO-0918-61887 :

NuScale Power Module Seismic Analysis, TR-0916-51502-P, Revision 1, proprietary version NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com

LO-0918-61887 :

NuScale Power Module Seismic Analysis, TR-0716-51502-NP, Revision 1, nonproprietary version NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 NuScale Power Module Seismic Analysis September 2018 Revision 1 Docket: No.52-048 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 www.nuscalepower.com

© Copyright 2018 by NuScale Power, LLC

© Copyright 2018 by NuScale Power, LLC i

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 COPYRIGHT NOTICE This report has been prepared by NuScale Power, LLC and bears a NuScale Power, LLC, copyright notice. No right to disclose, use, or copy any of the information in this report, other than by the U.S.

Nuclear Regulatory Commission (NRC), is authorized without the express, written permission of NuScale Power, LLC.

The NRC is permitted to make the number of copies of the information contained in this report that is necessary for its internal use in connection with generic and plant-specific reviews and approvals, as well as the issuance, denial, amendment, transfer, renewal, modification, suspension, revocation, or violation of a license, permit, order, or regulation subject to the requirements of 10 CFR 2.390 regarding restrictions on public disclosure to the extent such information has been identified as proprietary by NuScale Power, LLC, copyright protection notwithstanding. Regarding nonproprietary versions of these reports, the NRC is permitted to make the number of copies necessary for public viewing in appropriate docket files in public document rooms in Washington, DC, and elsewhere as may be required by NRC regulations. Copies made by the NRC must include this copyright notice and contain the proprietary marking if the original was identified as proprietary.

© Copyright 2018 by NuScale Power, LLC ii

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Department of Energy Acknowledgement and Disclaimer This material is based upon work supported by the Department of Energy under Award Number DE-NE0000633 and DE-NE0008742.

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

© Copyright 2018 by NuScale Power, LLC iii

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 CONTENTS Abstract ....................................................................................................................................... 1 Executive Summary .................................................................................................................... 2 1.0 Introduction ..................................................................................................................... 3 1.1 Purpose ................................................................................................................. 3 1.2 Scope .................................................................................................................... 3 1.3 Abbreviations ......................................................................................................... 5 2.0 Background ..................................................................................................................... 7 2.1 Layout of the NuScale Power Module and Reactor Building ................................. 7 2.2 Load Path for Core Support ................................................................................ 13 2.3 Seismic Design Basis .......................................................................................... 16 2.4 Regulatory Requirements .................................................................................... 16 3.0 Seismic Analysis and Design Methodology for the NuScale Power Module .......... 17 3.1 Summary of Analysis Steps ................................................................................. 21 4.0 Detailed Three-Dimensional ANSYS models of the NuScale Power Module and Single Bay Pool ...................................................................................................... 30 4.1 Seismic Model Methodology................................................................................ 30 5.0 Detailed Three-Dimensional ANSYS models of the NuScale Power Module ........... 81 5.1 Three-Dimensional ANSYS models of NuScale Power Module and Entire Pool ..................................................................................................................... 81 5.2 Three-Dimensional ANSYS model of Lower NPM and Reactor Flange Tool ...................................................................................................................... 83 5.3 Acceleration Boundary Conditions ...................................................................... 87 6.0 Equivalent Beam Models of the NuScale Power Module........................................... 91 6.1 Dry NuScale Power Module Simplified Beam Model........................................... 92 6.2 Tuning................................................................................................................ 105 6.3 Combined Model ............................................................................................... 108 6.4 Wet NuScale Power Module Simplified Beam Model ........................................ 109 6.5 Confirmatory Analyses for the NuScale Power Module Beam Models .............. 111 6.6 Methodologies to Account for Fluid-Structure Interaction .................................. 133 7.0 Seismic Analysis Methods for Structures, Systems, and Components that Comprise the NuScale Power Module ....................................................................... 147 7.1 Time History Analysis Method ........................................................................... 147

© Copyright 2018 by NuScale Power, LLC iv

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 7.2 Response Spectrum Analysis Method ............................................................... 147 7.3 Equivalent Static Load Method .......................................................................... 147 7.4 Uncertainties in the NuScale Power Module Subsystem Model........................ 147 8.0 Three-Dimensional Seismic Model Analysis ............................................................ 149 8.1 Transient Analysis ............................................................................................. 150 8.2 Modal Analysis .................................................................................................. 150 8.3 Static Analysis ................................................................................................... 158 8.4 Dynamic Analysis Methodology ......................................................................... 161 9.0 Conclusion ................................................................................................................... 173 10.0 References ................................................................................................................... 174 10.1 Referenced Documents ..................................................................................... 174 Appendix A. Locations for Displacements, ISRS, Forces, and Moments ........................ 175 Appendix B. Representative In-Structure Response Spectra ........................................... 182 TABLES Table 1-1 Components supported by the NuScale Power Module ........................................ 4 Table 1-2 Abbreviations ......................................................................................................... 5 Table 1-3 Definitions .............................................................................................................. 6 Table 4-1 Mass adjustment for the containment vessel ...................................................... 37 Table 4-2 Containment vessel head and TSS mass adjustment distribution ...................... 38 Table 4-3 Density adjustment calculation for top of TSS ..................................................... 38 Table 4-4 ANSYS Material Properties for Acoustic Fluid Elements Assigned to the Pool Water ........................................................................................................... 40 Table 4-5 Mass adjustment for the reactor pressure vessel ................................................ 43 Table 4-6 Density adjustment calculation for the control rod drive mechanism support frame ...................................................................................................... 43 Table 4-7 Mass adjustment summary for the lower reactor vessel internals ....................... 46 Table 4-8 Density adjustment calculation for reflector ......................................................... 46 Table 4-9 Fuel beam element properties ............................................................................. 47 Table 4-10 Fuel assembly modal results validation ............................................................... 50 Table 4-11 Mass adjustment summary for the upper RVI ..................................................... 59 Table 4-12 Valve, insulation, and piping fluid mass summary ............................................... 68 Table 4-13 Distribution of cable masses ............................................................................... 69 Table 4-14 Reactor coolant system volumes and fluid masses............................................. 71 Table 4-15 Steam generator secondary fluid mass calculation ............................................. 73 Table 4-16 Steam generator mass summary ........................................................................ 73 Table 4-17 Elevations, span lengths, and annulus dimensions used in setting up the Fourier Nodes constraint equations..................................................................... 79 Table 5-1 Offset to convert SASSI coordinates to ANSYS coordinates .............................. 89 Table 6-1 Containment vessel mass and torsional mass moment of inertia ....................... 95

© Copyright 2018 by NuScale Power, LLC v

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-2 Vertical masses and spring stiffnesses................................................................ 98 Table 6-3 Reactor pressure vessel horizontal masses and torsional mass moments of inertia ............................................................................................................. 103 Table 6-4 Reactor vessel internals spring-mass properties............................................... 107 Table 6-5 Dry model boundary conditions ......................................................................... 112 Table 6-6 Wet model boundary conditions ........................................................................ 113 Table 6-7 Dry model major modes .................................................................................... 114 Table 6-8 Wet model major modes.................................................................................... 122 Table 6-9 ANSYS dry beam model static analysis results................................................. 123 Table 6-10 ANSYS wet simplified beam model static analysis results ................................ 123 Table 6-11 SAP2000 wet simplified beam model static analysis results ............................. 123 Table 6-12 Maximum reaction force comparison (dry condition) ......................................... 130 Table 6-13 Maximum reaction force comparison (wet condition) ........................................ 133 Table 6-14 Fluid cells for defining Fritz mass matrices........................................................ 136 Table 6-15 Hydrodynamic mass M1..................................................................................... 144 Table 6-16 Hydrodynamic mass M2,.................................................................................... 144 Table 6-17 Hydrodynamic mass Mh..................................................................................... 145 Table 6-18 Hydrodynamic mass MA .................................................................................... 145 Table 6-19 Hydrodynamic mass MB .................................................................................... 146 Table 6-20 Hydrodynamic mass MC .................................................................................... 146 Table 8-1 Modal analysis results for the single-bay dry NPM model (no pool water) ........ 151 Table 8-2 Modal analysis results for the single bay wet NPM model ................................ 153 Table 8-3 List of node locations for time-history and response spectra generation .......... 164 Table 8-4 List of representative component interfaces for force and moment generation ......................................................................................................... 166 Table 8-5 List of component sections for force and moment generation ........................... 167 Table 8-6 Maximum seismic forces on NuScale Power Module supports ......................... 170 Table 8-7 Maximum seismic reactions at RPV Upper Supports (cylindrical coordinates) ....................................................................................................... 171 Table 8-8 Maximum Seismic Reactions at Fuel Assembly Supports................................. 171 Table 8-9 Maximum uplift displacements .......................................................................... 172 FIGURES Figure 2-1 NuScale Reactor Building conceptual design........................................................ 8 Figure 2-2 NuScale Reactor Building cut-away view .............................................................. 9 Figure 2-3 NuScale Power Modules located in respective operating bays ........................... 10 Figure 2-4 Reactor Building at 62 ft. elevation (pool floor elevation) .................................... 11 Figure 2-5 NuScale Power Module general arrangement..................................................... 12 Figure 2-6 Core support assembly ....................................................................................... 14 Figure 2-7 Load path for vertical core support (left), horizontal core support (right) ............. 15 Figure 3-1 Overview of seismic design methodology ........................................................... 19 Figure 3-2 Overview of various finite element models .......................................................... 20 Figure 3-3 Integrated seismic model including NPM, RP and RXB ...................................... 23 Figure 3-4 CNV top head vertical acceleration comparison.................................................. 24 Figure 3-5 RPV top head vertical acceleration comparison .................................................. 25 Figure 3-6 UCP vertical acceleration comparison................................................................. 25 Figure 3-7 LCP vertical acceleration comparison ................................................................. 26

© Copyright 2018 by NuScale Power, LLC vi

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 3-8 CNV skirt vertical reaction force comparison....................................................... 26 Figure 4-1 NuScale Power Module single bay, three-dimensional model geometry and mesh ............................................................................................................. 33 Figure 4-2 Containment vessel geometry and mesh ............................................................ 35 Figure 4-3 Pool bay geometry and mesh and combined containment vessel-pool bay mesh .................................................................................................................... 36 Figure 4-4 Reactor pressure vessel geometry and mesh ..................................................... 42 Figure 4-5 Lower reactor vessel internals geometry and mesh ............................................ 45 Figure 4-6 Fuel core model (with real element shapes) and its connections to LRVI ........... 48 Figure 4-7 Fuel beam model ................................................................................................. 49 Figure 4-8 Lower reactor vessel core support blocks and core support attachment ............ 51 Figure 4-9 Upper support blocks to RPV shell contact meshes............................................ 54 Figure 4-10 Lower RVI to Reflector contact meshes .............................................................. 55 Figure 4-11 Upper Riser Geometry ........................................................................................ 57 Figure 4-12 Upper reactor vessel internals geometry and mesh ............................................ 58 Figure 4-13 Constraint equations between URVI and LRVI ................................................... 61 Figure 4-14 Connections between upper RVI and RPV (top section view) ............................ 62 Figure 4-15 Connections between upper RVI and RPV (side view) ....................................... 63 Figure 4-16 Constraint equations between the upper RVI and RPV ...................................... 64 Figure 4-17 Connection between URVI and baffle plate of RPV submodel ............................ 65 Figure 4-18 Control rod drive mechanism beam model mesh (true section shapes shown) and control rod drive mechanism assembly on reactor pressure vessel head ......................................................................................................... 66 Figure 4-19 Containment vessel and reactor pressure vessel section diagrams ................... 70 Figure 4-20 Reactor coolant system volume region locations ................................................ 72 Figure 4-21 Mass elements (red dots) representing SG mass ............................................... 74 Figure 4-22 Control rod drive system support names and span lengths ................................ 75 Figure 4-23 Fourier node locations and couplings .................................................................. 78 Figure 4-24 Fourier nodes regions diagram............................................................................ 80 Figure 5-1 NPM numbering convention ................................................................................ 81 Figure 5-2 NPM 1 entire pool model ..................................................................................... 82 Figure 5-3 NPM 6 entire pool model ..................................................................................... 82 Figure 5-4 Cutaway view showing NPM cavities and rigid floor representation ................... 83 Figure 5-5 Lower RPV, Lower Riser, and Core Support inside the RFT (fuel not shown) ................................................................................................................. 84 Figure 5-6 Reactor Flange Tool Location .............................................................................. 85 Figure 5-7 Refueling Configuration for Seismic Analysis. ..................................................... 85 Figure 5-8 RPV to RFT Support Interface............................................................................. 86 Figure 5-9 SASSI model surface geometry and coordinate system ..................................... 88 Figure 5-10 ANSYS NPM 1 surface geometry and coordinate system .................................. 88 Figure 6-1 Dry NPM simplified beam model (real element shapes also shown) .................. 92 Figure 6-2 Containment vessel submodel finite element model (with real element shapes) ................................................................................................................ 93 Figure 6-3 Containment vessel submodel diagram with nodal elevations ............................ 94 Figure 6-4 Containment vessel lug diagram top view ........................................................... 96 Figure 6-5 Reactor pressure vessel support ledge top view ................................................. 97

© Copyright 2018 by NuScale Power, LLC vii

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 6-6 Containment vessel skirt representation and vertical masses and springs diagram ............................................................................................................... 99 Figure 6-7 RPV beam submodel FEM (with real element shapes) ..................................... 100 Figure 6-8 Reactor pressure vessel beam submodel diagram with nodal elevations ......... 101 Figure 6-9 Reactor pressure vessel three-dimensional submodel for tuning and torsional mass moments of inertia ..................................................................... 102 Figure 6-10 Reactor pressure vessel support skirt top view (not in scale) ........................... 105 Figure 6-11 Spring-mass elements in reactor pressure vessel submodel ............................ 107 Figure 6-12 Connection of containment vessel and reactor pressure vessel submodels ......................................................................................................... 108 Figure 6-13 Wet NuScale Power Module simplified beam model (with real element shapes) .............................................................................................................. 109 Figure 6-14 Wet NuScale Power Module simplified beam model boundary conditions ........ 110 Figure 6-15 SAP2000 wet NuScale Power Module beam model ......................................... 111 Figure 6-16 Dry model, 1st Significant Vertical Mode ............................................................ 115 Figure 6-17 Dry model, 2nd Significant Vertical Mode ........................................................... 116 Figure 6-18 Dry model, 3rd Significant Vertical Mode ............................................................ 117 Figure 6-19 Wet model, 1st Significant Vertical Mode ........................................................... 118 Figure 6-20 Wet model, 2nd Significant Vertical Mode .......................................................... 119 Figure 6-21 Wet model, 3rd Significant Vertical Mode ........................................................... 120 Figure 6-22 Wet model, 4th Significant Vertical Mode ........................................................... 121 Figure 6-23 Dry model reaction force amplitudes (loads in east-west direction) .................. 124 Figure 6-24 Dry model reaction force amplitudes (loads in north-south direction) ............... 125 Figure 6-25 Dry model reaction force amplitudes (loads in vertical direction) ...................... 125 Figure 6-26 Wet model skirt east-west reaction force amplitudes (loads in east-west direction) ............................................................................................................ 126 Figure 6-27 Wet model north lug east-west reaction force amplitudes (loads in east-west direction) ................................................................................................... 127 Figure 6-28 Wet model east lug east-west reaction force amplitudes (loads in east-west direction) ................................................................................................... 127 Figure 6-29 Wet model skirt north-south reaction force amplitudes (loads in north-south direction) .................................................................................................. 128 Figure 6-30 Wet model east lug north-south reaction force amplitudes (loads in north-south direction) .................................................................................................. 128 Figure 6-31 Wet model skirt vertical reaction force amplitudes (loads in vertical direction) ............................................................................................................ 129 Figure 6-32 Selected time history reaction force from simplified beam and three-dimensional model (dry condition) ..................................................................... 130 Figure 6-33 Selected time history reaction forces from wet simplified beam and three-dimensional model ............................................................................................ 132 Figure 6-34 Hydrodynamic mass M1 versus height above pool floor .................................... 137 Figure 6-35 Hydrodynamic mass M2 versus height above pool floor .................................... 138 Figure 6-36 Hydrodynamic mass Mh versus height above pool floor .................................... 139 Figure 6-37 Lumped mass model used to represent off-diagonal Fritz stiffness matrix........ 140 Figure 6-38 Unit acceleration to the NuScale Power Module, xNPM 0.0, xRXB = 0.0 ...... 141 Figure 6-39 Unit acceleration applied to the reactor building, xNPM = 0.0, xRXB 0.0 ....... 142 Figure 8-1 Wet model, 1st Significant Horizontal Mode in E-W Direction ............................ 155

© Copyright 2018 by NuScale Power, LLC viii

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 8-2 Wet model, 1st Significant Horizontal Mode in N-S Direction ............................. 156 Figure 8-3 Wet model, 2nd Significant Horizontal Mode in N-S Direction ............................ 157 Figure 8-4 Pool pressure effects due to gravity for the single bay pool model. .................. 159 Figure 8-5 Pool pressure effects due to gravity for NPM 1 entire pool model .................... 160 Figure 8-6 Pool pressure effects due to gravity for NPM 6 entire pool model .................... 160 Figure 8-7 Reactor Building coordinate system and NuScale Power Module numbering convention ....................................................................................... 161 Figure 8-8 Reactor Building and NuScale Power Module coordinate systems................... 162 Figure 8-9 NuScale Power Module coordinate systems for post-processing ..................... 163 Figure 8-10 Design ISRS, CNV Top Head, Z-Direction (North-South), 4% Damping ........... 168 Figure A-1 Locations on the containment vessel ................................................................ 175 Figure A-2 Locations on reactor pressure vessel and control rod drive mechanism support .............................................................................................................. 176 Figure A-3 Locations on lower core plate ............................................................................ 177 Figure A-4 Locations on upper core plate ........................................................................... 177 Figure A-5 Additional locations on the containment vessel ................................................. 178 Figure A-6 Additional locations on the reactor pressure vessel .......................................... 179 Figure A-7 Locations on lower reactor vessel internals....................................................... 180 Figure A-8 Locations on upper reactor vessel internals ...................................................... 181 Figure B-1 Design ISRS, CNV skirt, location 1, X-direction (east-west) ............................. 182 Figure B-2 Design ISRS, CNV skirt, location 1, Z-direction (north-south) ........................... 182 Figure B-3 Design ISRS, CNV skirt, location 1, Y-direction (vertical) ................................. 183 Figure B-4 Design ISRS, containment vessel lug +X, location 4, X-direction (east-west) .................................................................................................................. 183 Figure B-5 Design ISRS, containment vessel lug +X, location 4, Z-direction (north-south) ................................................................................................................ 184 Figure B-6 Design ISRS, containment vessel lug +X, location 4, Y-direction (vertical)....... 184 Figure B-7 Design ISRS, containment vessel lug -X, location 5, X-direction (east-west) .................................................................................................................. 185 Figure B-8 Design ISRS, containment vessel lug -X, location 5, Z-direction (north-south) ................................................................................................................ 185 Figure B-9 Design ISRS, containment vessel lug -X, location 5, Y-direction (vertical) ....... 186 Figure B-10 Design ISRS, containment vessel lug -Z, location 6, X-direction (east-west) .................................................................................................................. 186 Figure B-11 Design ISRS, containment vessel lug -Z, location 6, Z-direction (north-south) ................................................................................................................ 187 Figure B-12 Design ISRS, containment vessel lug -Z, location 6, Y-direction (vertical) ........ 187 Figure B-13 Design ISRS, containment vessel top head, location 8, X-direction (east-west) .................................................................................................................. 188 Figure B-14 Design ISRS, containment vessel top head, location 8, Z-direction (north-south) ................................................................................................................ 188 Figure B-15 Design ISRS, containment vessel top head, location 8, Y-direction (vertical) ............................................................................................................. 189

© Copyright 2018 by NuScale Power, LLC ix

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-16 Design ISRS, reactor pressure vessel top head, location 14, X-direction (east-west) ......................................................................................................... 189 Figure B-17 Design ISRS, reactor pressure vessel top head, location 14, Z-direction (north-south) ...................................................................................................... 190 Figure B-18 Design ISRS, reactor pressure vessel top head, location 14, Y-direction (vertical) ............................................................................................................. 190 Figure B-19 Design ISRS, top of lower core plate, location 16, X-direction (east-west) ....... 191 Figure B-20 Design ISRS, top of lower core plate, location 16, Z-direction (north-south) ................................................................................................................ 191 Figure B-21 Design ISRS, top of lower core plate, location 16, Y-direction (vertical) ........... 192 Figure B-22 Design ISRS, bottom of upper core plate, location 17, X-direction (east-west) .................................................................................................................. 192 Figure B-23 Design ISRS, bottom of upper core plate, location 17, Z-direction (north-south) ................................................................................................................ 193 Figure B-24 Design ISRS, bottom of upper core plate, location 17, Y-direction (vertical) ............................................................................................................. 193 Figure B-25 Design ISRS, steam generator section top, location 32, X-direction (east-west) .................................................................................................................. 194 Figure B-26 Design ISRS, steam generator section top, location 32, Z-direction (north-south) ................................................................................................................ 194 Figure B-27 Design ISRS, steam generator section top, location 32, Y-direction (vertical) ............................................................................................................. 195 Figure B-28 Design ISRS, steam generator section bottom, location 33, X-direction (east-west) ......................................................................................................... 195 Figure B-29 Design ISRS, steam generator section bottom, location 33, Z-direction (north-south) ...................................................................................................... 196 Figure B-30 Design ISRS, steam generator section bottom, location 33, Y-direction (vertical) ............................................................................................................. 196 Figure B-31 RFT Model ISRS, top of lower core plate, location 16, X-Direction (east-west) .................................................................................................................. 197 Figure B-32 RFT Model ISRS, top of lower core plate, location 16, Z-Direction (north-south) ................................................................................................................ 197 Figure B-33 RFT Model ISRS, top of lower core plate, location 16, Y-Direction (vertical) ............................................................................................................. 198 Figure B-34 RFT Model ISRS, bottom of upper core plate, location 17, X-Direction (east-west) ......................................................................................................... 198 Figure B-35 RFT Model ISRS, bottom of upper core plate, location 17, Z-Direction (north-south) ...................................................................................................... 199 Figure B-36 RFT Model ISRS, bottom of upper core plate, location 17, Y-Direction (vertical) ............................................................................................................. 199

© Copyright 2018 by NuScale Power, LLC x

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Abstract This report describes the methodologies and structural models that are used to analyze the dynamic structural response due to seismic loads acting on the NuScale Power Module (NPM).

It also provides the dynamic analysis methodology and presents final analysis results. The detailed dynamic model for the NPM is coupled with the dynamic model of the Reactor Building (RXB) to consider effects of fluid-structure interaction due to pool water found between the NPM and pool floor and walls. The performance of the dynamic analysis yields loads, in-structure response spectra, and in-structure time histories, which are used as the basis for the mechanical design of Seismic Category I structures, systems, and components (SSC) that comprise or are supported by the NPM.

The content of this technical report provides additional information to substantiate the statements made in the NuScale Final Safety Analysis Report, thereby facilitating a comprehensive review by the U.S. Nuclear Regulatory Commission of the NuScale Power Module design.

© Copyright 2018 by NuScale Power, LLC 1

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Executive Summary Seismic analysis of the NuScale Power Module (NPM) and the structures, systems, and components (SSC) supported therein requires a complete system model to represent the dynamic coupling of the reactor pressure vessel (RPV), containment vessel (CNV), reactor internals and core support, reactor core, surrounding pool water, and SSC supported by the NPM. The dynamic analysis of the complete NPM system is performed using time history dynamic analysis methods and a three dimensional (3D) ANSYS finite element model. The skirt of the NPM containment vessel is not restrained to preclude liftoff from the pool floor; therefore, nonlinear contact elements are used to represent this effect. The NPM system model includes acoustic elements to represent the effects of fluid-structure interaction (FSI) due to pool water found between the CNV and pool floor and walls.

To account for possible dynamic coupling of the NPMs and the Reactor Building (RXB) system, a model of each of the NPMs is included in the RXB system model.

The RXB system model, with representation of the NPMs, is then analyzed for soil-structure interaction (SSI) in the frequency domain using the computer code SASSI. Results from the RXB seismic system analysis include in-structure time histories at each NPM support location and the pool walls and floor surrounding the NPM. In-structure response spectra (ISRS) are also calculated. The RXB analysis is repeated for a number of SSI analysis cases.

A detailed dynamic analysis of the NPM subsystem is performed using 3D NPM system models using ANSYS. In addition, the NPM models provide in-structure time histories or response spectra for qualification of equipment supported on the NPM and time histories for seismic qualification of fuel assemblies.

© Copyright 2018 by NuScale Power, LLC 2

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 1.0 Introduction 1.1 Purpose This report describes the methodologies and structural models that are used for the seismic analyses of the NuScale Power Module (NPM) and presents the analysis results. In-structure responses determined by using the methodologies and models are used as inputs for the dynamic response analysis of subsystems and components supported by the NPM. Loads and displacement time histories determined using these models are used in conjunction with other loads for the design of the containment vessel (CNV), reactor pressure vessel (RPV), core support, and internal structures.

Seismic analysis of the NPM and structures, systems, and components (SSC) supported thereon requires a complete system model to represent the dynamic coupling of the RPV, the CNV, reactor internals and core support, the reactor core, surrounding pool water, and supported SSC. The dynamic analysis of the complete model is performed using time history dynamic analysis methods and a 3D ANSYS finite element model.

The NPM system model also includes acoustic elements to represent the effects of fluid-structure interaction (FSI) due to pool water between the CNV and the pool floor and walls. Additionally, FSI of the water contained in the annular gap between reactor internals and RPV is accounted for by using the Fourier node method.

The seismic analysis of the lower RPV, lower reactor vessel internals (LRVI) and fuel in the reactor flange tool (RFT) includes a simplified representation of the displaced pool water mass. The mass of the displaced fluid is accounted for by increasing the density of the RPV, RFT, and the portion of the LRVI above the lower RPV by the density of water.

1.2 Scope The SSC within the scope of this document are limited to those that comprise the NPM, which is the self-contained nuclear steam supply system within the NuScale Nuclear Power Plant. The NPM is comprised of a reactor core, a pressurizer (PZR), and two steam generators (SGs) integrated within an RPV and housed in a compact steel CNV.

Other components integral to the NPM are the reactor vessel internals (RVI), control rod drive mechanisms (CRDMs), piping, valves, and instrumentation and controls.

The NPM seismic analysis provides time histories of core support motions that are used as seismic input for fuel qualification. The interface between the NPM and the reactor building (lug and skirt reaction forces) is also included in this report. The methodologies for seismic qualification of the fuel itself are provided in TR-0816-51127, NuFuel-HTP2 Fuel and Control Rod Assembly Designs.

Seismic input for the NPM model is obtained from the RXB soil-structure interaction (SSI) analysis results. Methodologies used for the RXB soil-structure interaction analysis are addressed in NuScale Final Safety Analysis Report (FSAR) Section 3.7.2; however, a brief discussion is included as background information.

The seismic analysis methodology applies to the NPM and SSC supported by the NPM, and includes the following (Table 1-1):

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 1-1 Components supported by the NuScale Power Module Reactor pressure vessel Upper reactor vessel internals Containment vessel Lower reactor vessel internals Containment vessel supports Piping and valves Steam generators Control rod drive system Pressurizer heater assemblies Instrumentation and controls Top support structure The methodology described in this section is also used to determine core plate motion time histories required for seismic analysis of the fuel.

The NPM seismic analysis applies to the NPM while situated in the operating bays and while secured in the reactor flange tool. Refueling transitions, such as the NPM suspended by the building crane including the containment flange tool (CFT), are not seismically evaluated, based on the short time durations in these configurations. For a twelve module NuScale power plant, the time in refueling transition configurations is less than ten days per year (assuming a two year fuel cycle per NPM, the refueling of six modules per year, and an estimated 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> of crane movement per NPM refueling, plus approximately 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> in the CFT, where the module is suspended by the crane, and the fuel is protected within the RPV). This 'time in refueling transition' is less than the refueling outage durations for the U.S. nuclear operating fleet. The operating fleet does not perform seismic evaluation of the reactor components and nuclear fuel during refueling operations based on their short duration of time in the refueling phases.

Operating experience outage details as tabulated for the U.S. nuclear operating fleet (calendar year 2000 through 2017), document average refueling durations (excluding extended outages) of 40.2 days for all Pressurized Water Reactors, 34.6 days for all Boiling Water Reactors, and 38.5 days for all nuclear plants.

COL Items 9.1-5 and 9.1-7 governing the handling of heavy loads ensure the durations are controlled in these refueling configurations.

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 1.3 Abbreviations Note: if the NRC and NuScale acronyms or abbreviations differ, the project acronyms and abbreviations shall be followed.

Table 1-2 Abbreviations Term Definition APDL ANSYS parametric design language ASCE American Society of Civil Engineers CNV containment vessel CRA control rod assembly CRDM control rod drive mechanism CRDS control rod drive system CSA core support assembly CSDRS certified seismic design response spectra DHRS decay heat removal system DOF degree of freedom FSAR Final Safety Analysis Report FSI fluid-structure interaction FW feedwater IEEE Institute of Electrical and Electronics Engineers ISRS in-structure response spectra LCP lower core plate LWR light water reactor NPM NuScale Power Module NRC U.S. Nuclear Regulatory Commission PZR pressurizer RCPB reactor coolant pressure boundary RCS reactor coolant system RG Regulatory Guide RP reactor pool RPV reactor pressure vessel RVI reactor vessel internals RXB reactor building SG steam generator SRP Standard Review Plan SSC structures, systems, and components SSI soil-structure interaction TSS top support structure UCP upper core plate 3D three-dimensional

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 1-3 Definitions Term Definition Operating basis earthquake The vibratory ground motion for which those features of the nuclear power plant necessary for continued operation without undue risk to the health and safety of the public will remain functional. The operating basis earthquake ground motion is only associated with plant shutdown and inspection unless specifically selected by the applicant as a design input.

Safe shutdown earthquake The vibratory ground motion for which certain structures, systems, and components must be designed to remain functional.

Submodel The finite element model of a specific component (CNV, RPV, lower RVI, upper RVI, or CRDMs) in the NPM full model. Each submodel is created separately using either ANSYS Workbench or APDL code, and written out as a coded database file (.cdb). The submodels in this report are not the geometry regions with highest stresses that need a refined mesh as used in the submodeling technique described in the ANSYS manual.

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 2.0 Background This NPM seismic analysis is provided as a Technical Report in support of U.S Nuclear Regulatory Commission (NRC) review of the NuScale Design Certification Application.

This section summarizes related information relevant to the understanding of the analyses described in this report.

2.1 Layout of the NuScale Power Module and Reactor Building Figure 2-1 presents a conceptual layout of the NuScale Reactor Building (RXB). The RXB is located above and below grade and is considered a deeply embedded structure.

The RXB houses the NPMs and systems and components required for plant operation and shutdown. The RXB is a rectangular configuration approximately 350 ft. long and 150 ft. wide, with a height approximately 81 ft. above nominal plant grade level. The bottom of the RXB foundation is approximately 86 ft. below grade except for the areas under the elevator pit and the refueling pool, which are approximately 92 ft. below grade.

A cut-away view of the RXB is shown in Figure 2-2 with major equipment and areas identified.

Each NPM is located in the common reactor pool (RP) within its own three-walled bay, with the open side toward the center of the pool, as shown in Figure 2-3 and Figure 2-4.

The bays are arranged into two rows, with six bays per row, along the north and south walls of the reactor pool. A central channel is provided between the bays to allow for movement of the NPMs between the bays and the refueling pool. The bays are approximately 20 ft. wide by 20 ft. long by 100 ft. tall with a normal RP water depth of approximately 69 ft., which corresponds to an elevation of approximately 6 ft. below grade). The NPMs, reactor pool, and spent fuel pool are below grade.

The NPM consists of a reactor core, two helical-coil SGs, and a PZR integrated within the RPV as shown in Figure 2-5. The reactor core is located below the SGs inside the RPV. The RPV is enclosed in a cylindrical CNV.

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 2-1 NuScale Reactor Building conceptual design

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 2-2 NuScale Reactor Building cut-away view

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 2-3 NuScale Power Modules located in respective operating bays

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 2-4 Reactor Building at 62 ft. elevation (pool floor elevation)

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 2-5 NuScale Power Module general arrangement

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 2.2 Load Path for Core Support Vertical and horizontal support of the reactor core is provided by the upper and lower core plates. The core plates are supported by the core barrel and lower RPV shown on Figure 2-6. Load is transferred from the lower core plate and core barrel to the RPV through four core support blocks located on the interior of the RPV bottom head. The upper core plate loads are transferred to the inner walls of the RPV through four upper support blocks.

Horizontal displacements of the core are also resisted by the contact of peripheral fuel assemblies with the reflector. The reflector is supported by the core barrel and load is transferred through the core support blocks.

The primary load path for core support is illustrated on Figure 2-7. For horizontal seismic loads acting upon the lower core plate, the primary load path from the RPV to the RXB is through the RPV/CNV alignment feature located between the bottom of the RPV and the CNV. The horizontal load in this load path is primarily transferred to the pool floor through the CNV skirt. Horizontal loads from the upper core plate are carried through the CNV skirt as are the loads from the lower core plate, with a secondary load path through the supports of the RPV and CNV support lugs located approximately 45 feet above the pool floor. The CNV support lugs provide horizontal restraint.

Vertical loads from the core are carried from the core barrel and lower RPV upward to the connection of the upper RPV and CNV (CNV-RPV support ledge in Figure 2-7). The load is then transferred downward to the CNV support skirt. To allow for free vertical thermal expansion of the RPV and internals, no vertical load is transferred through the alignment feature at the bottom of the RPV.

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NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1

((2(a),(c) Figure 2-6 Core support assembly © Copyright 2018 by NuScale Power, LLC 14

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 2-7 Load path for vertical core support (left), horizontal core support (right) © Copyright 2018 by NuScale Power, LLC 15

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 2.3 Seismic Design Basis The seismic design basis for the NPM is the certified seismic design response spectra (CSDRS) for 5 percent damping. The CSDRS is site-independent and is defined as an enveloped outcrop motion in the free field, applied at the foundation level of the building. The NPM is analyzed using time history methods and an input artificial time history compatible with the CSDRS at 5 percent damping. The artificial time histories (two horizontal components and vertical component) used for analysis of the NPM are generated based on the Capitola station recordings of the 1989 Loma Prieta earthquake. The seismic design basis for the NPM is a site characterized by a subsurface profile consisting of a half-space of hard rock having a shear wave velocity of 5000 ft/sec. This soil profile is referred to as soil case 7. The seismic design basis for the RXB includes a set of additional generic soil/rock profiles. Uncertainty in the soil profile, building stiffness, and other parameters is accounted for by concrete cracking assumptions and other parameters used in the time history SSI analysis of the building system. Uncertainty in the NPM model input and assumptions is accounted for by multiple analyses using +/-30 percent variation of stiffness, equivalent to approximately a +/-15 percent variation of the frequencies (see Section 7.4). For seismic subsystems supported by the NPM, additional uncertainty is included by broadening of the ISRS or equivalent methods when time history analysis results are used. If time histories, rather than ISRS, are used for a subsystem analysis, soil profiles are analyzed using the CSDRS compatible time history input. The envelope of responses (loads, accelerations and displacements) is used for design. 2.4 Regulatory Requirements Seismic analysis methods are developed in accordance with guidance given in U.S. Nuclear Regulatory Commission (NRC) NUREG-0800, Standard Review Plan for Review of Safety Analysis Reports for Nuclear Power Plants, Section 3.7.1, Seismic Design Parameters, Revision 4, December 2014; Section 3.7.2, Seismic System Analysis, Revision 4, September 2013; and Section 3.9.2, Dynamic Testing and Analysis of Systems, Structures, and Components, Revision 3, March 2007. Additional guidance is derived from the Interim Staff Guidance on Ensuring Hazard-Consistent Seismic Input for Site Response and Soil Structure Interaction Analyses, DC/COL-ISG-017, and the Interim Staff Guidance on Seismic Issues Associated with High Frequency Ground Motion in Design Certification and Combined License Applications, DC/COL-ISG-001. © Copyright 2018 by NuScale Power, LLC 16

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 3.0 Seismic Analysis and Design Methodology for the NuScale Power Module The NuScale Power Plant includes up to twelve NPMs that contribute to the overall mass of the RXB, and thus affect the dynamic characteristics of the reactor building. Additionally, the NuScale design includes a water-filled RP which occupies the center of the RXB and spans almost the entire length of the building (see Figure 2-2). The pool includes bays that house and support the partially immersed NPMs. In this configuration, the effects of fluid-structure interaction (FSI) become significant, both for the NPM and the RXB. Although the NPM is considered a seismic subsystem of the NuScale Power Plant, it cannot be completely decoupled from the RXB for analysis. Therefore, seismic analysis of the NPM and SSC supported therein requires a detailed system model to represent the dynamic coupling of the RPV, CNV, reactor internals and core support, reactor core, surrounding pool water, and SSC supported by the NPM. Dynamic analysis of the complete NPM system is performed using time history dynamic analysis methods and a 3-D ANSYS finite element model. Since the skirt of the CNV is not restrained to preclude liftoff from the pool floor, nonlinear contact elements are used to represent this effect. The NPM system model also includes acoustic elements to represent the effects of FSI due to pool water between the CNV and pool floor and walls. A simplified model (i.e., beam model) was used to represent the NPMs in the model of the RXB. Analysis of the RXB was then performed to generate inputs for use in the analysis of a detailed 3D model of the NPM. The specific steps used in this approach are as follows: a) creation of a detailed 3D ANSYS model of the NPM and surrounding water located within the reactor bay (See Sections 3.1.1 and 4.0) b) creation of a simplified model of the NPM in ANSYS and SAP2000, that is dynamically equivalent to the detailed 3D model created in step (a) (See Section 7.0) c) creation of a RXB model in SAP2000 that includes the simplified NPM models from step (b) (See Section 3.1.3) d) creation of a SASSI model and performance of SSI analysis (See Section 3.1.4) e) performance of seismic analysis of the detailed 3D ANSYS model of the NPM and the entire pool (See Sections 3.1.5 and 5.0) f) development of NPM seismic loads, including in-structure time histories and broadened in-structure response spectra (See Section 3.1.6 and results in Section 8.0) g) performance of seismic stress analyses of NPM components (See Sections 3.1.7 and 7.0) © Copyright 2018 by NuScale Power, LLC 17

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 The process described above is depicted as a flowchart in Figure 3-1. There are numerous finite element models used throughout the seismic design process. A description of the basic features of the models within the scope of this document is included in Section 4.0 through 6.0. Figure 3-2 shows examples of the types of finite element models used in the various analyses. These illustrations are only intended to illustrate the level of detail and mesh size of the models. © Copyright 2018 by NuScale Power, LLC 18

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 3-1 Overview of seismic design methodology © Copyright 2018 by NuScale Power, LLC 19

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                            }}2(a),(c)

Figure 3-2 Overview of various finite element models © Copyright 2018 by NuScale Power, LLC 20

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 3.1 Summary of Analysis Steps Each of the steps outlined in Section 3.0 are discussed below in more detail. 3.1.1 Detailed 3D Model of the NuScale Power Module in ANSYS The initial step of the seismic design process is creation of a detailed 3D finite element NPM model, including the fluid volume representing a single RP bay (i.e. single bay model). In this step, the dynamic properties of the model are calculated by performing modal, harmonic and benchmark transient analyses. The analytical results are then used as a basis for the development of a simplified NPM beam model that is dynamically similar to the detailed 3D model. From modal analysis, the major modal frequencies and associated effective masses are determined. From the harmonic analysis, reaction force vs. frequency plots are generated at the NPM supports. From the benchmark transient analyses, a set of reaction force vs. time plots are generated at the NPM supports. The analyses described can also be performed for submodels (e.g., CNV only, RPV only) that are extracted from the complete detailed 3D finite element model. These submodels facilitate the independent creation of separate simplified models that can then be combined, thus simplifying the tuning process described in Section 3.1.2. The detailed 3D model of the NPM is further described in Section 4.0. In addition to aiding the creation of a simplified model of the NPM, the detailed 3D finite element model provides the initial finite element model that is later expanded to include the entire RP (see Section 3.1.5).The NPM seismic analysis with the reactor pool and a single NPM considers the vibration wave energy dissipation at the interfaces of the reactor pool and reactor building (the RXB is not included in the 3D NPM seismic model). The wave energy dissipation is simulated using an absorption interface of the fluid body in ANSYS. However, due to the complexity of the reactor building, pool water, and module interaction, a detailed study of the FSI interaction is required to quantify the absorption coefficient for the energy dissipation. This is achieved through modeling the reactor building, pool water and modules together in an integrated ANSYS model, Figure 3-3, independent from the seismic model used in SASSI. For this purpose, harmonic analyses are performed for the following two cases, with the module located in the NPM1 bay, and the responses compared:

1) A combined model that includes the reactor module, reactor pool water, and RXB. The FSI is simulated between the reactor pool water and the RXB. The model is shown in Figure 3-3, and only used for the absorption coefficient.
2) A combined model that includes the reactor module and reactor pool water without RXB. This standard 3D NPM seismic model is shown in Figure 5-2.

For the first case, the boundary conditions are the same as the harmonic runs for the standard 3D NPM seismic model (case 2). A vertical excitation of 1g acceleration is applied to the soil-structure interaction (SSI) interface, shown in red in Figure 3-3(a). The horizontal directions of the SSI interface are constrained. During harmonic motion, a certain amount of energy is dissipated into the RXB floor at the FSI interface. The vertical acceleration response at the CNV top head, the RPV top head, and the © Copyright 2018 by NuScale Power, LLC 21

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 UCP/LCP, and the vertical reaction force at the CNV skirt, are extracted from the harmonic analysis. For the second case, there is no RXB included. A vertical excitation of 1g acceleration is applied to the RP FSI interface and the CNV skirt directly. In this way, the energy is not dissipated into the RXB floor because the floor is not included in the model. In order to simulate the dissipated energy (equivalent to that for the first situation discussed above) at the FSI interface when the RXB floor is not included, an absorption coefficient (alpha), selected by trial, is applied to the RP bottom surface using the ANSYS SF ATTN command. The horizontal directions of the RP FSI interface and the shear direction of CNV lugs are constrained. The vertical acceleration response at the CNV top head, the RPV top head, and the upper and lower core plates (UCP/LCP), and the vertical reaction force at the CNV skirt, are extracted from the harmonic analysis, and the best-estimated absorption coefficient (alpha) is identified. It is shown that an absorption coefficient of 0.75 produces the best match between the model without RXB and the model with RXB. Figure 3-4 through Figure 3-8 present the comparison results. © Copyright 2018 by NuScale Power, LLC 22

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                             }}2(a),(c)

Figure 3-3 Integrated seismic model including NPM, RP and RXB © Copyright 2018 by NuScale Power, LLC 23

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Note that the absorption coefficient is quantified only between the pool water and the floor (vertical direction) because the dynamic behavior is simpler in the vertical direction than other directions. It is not feasible to use a single absorption coefficient to represent the energy dissipation due to FSI in the other interfaces (horizontal directions) because of the complexity of the structures, and the scattering of the modal frequencies. When the absorption coefficient is applied to the seismic model (where the reactor building is not explicitly included), the seismic response in the vertical direction is reduced. Figure 3-4 CNV top head vertical acceleration comparison © Copyright 2018 by NuScale Power, LLC 24

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 3-5 RPV top head vertical acceleration comparison Figure 3-6 UCP vertical acceleration comparison © Copyright 2018 by NuScale Power, LLC 25

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 3-7 LCP vertical acceleration comparison Figure 3-8 CNV skirt vertical reaction force comparison © Copyright 2018 by NuScale Power, LLC 26

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 3.1.2 Creation of a Simplified Model of the NuScale Power Module in ANSYS and SAP2000 This step creates linear beam models of the NPM in ANSYS and SAP2000 that have dynamically equivalent behaviors as the 3D model, but with fewer elements and nodes. This step does not perform the seismic analysis of the NPM, but develops a model for future analysis. Multiple analyses including modal, harmonic, and time history transient analyses are performed to tune the models to match the dynamic response of the detailed 3D model. Tuning is an iterative process in which analysis is performed on the simplified model and the results are compared to those of the detailed 3D model. Modifications expected to improve the comparison are then made to the simplified model and the analyses and comparisons are repeated. Modifications that are made to the model may include adjustments to the mass distribution and stiffnesses. This process is repeated until the results of the simplified model replicate those of the detailed 3D model. The simplified model of the NPM is further described in Section 6.0. 3.1.3 Creation of the Reactor Building Model in SAP2000 This step develops a detailed finite element structural analysis model of the RXB using the SAP2000 computer program. The simplified NPM SAP2000 model is inserted into each of the twelve reactor bays in the RXB model. This model is converted to the SASSI RXB model for the SSI analyses in a later step. This is a limited scope analysis because it only uses one soil case and one time history. The details and methodology used for the RXB SAP2000 model are discussed in the NuScale FSAR Section 3.8.4. 3.1.4 Creation and Analysis of a Reactor Building Model in SASSI The SAP2000 RXB model created in step 3.1.3 is converted to a SASSI model. The SASSI RXB model is then evaluated for SSI by analysis performed in the frequency domain. The results of this analysis are used for seismic analysis of the RXB; however, because only a simplified representation of the NPM is included, final seismic analysis of the NPM is not performed with this model. Results from this analysis are only used as inputs for seismic analysis of the detailed 3D model of the NPM, as described in a later step, and to compare the reaction forces at the NPM support locations to the detailed 3D model, ensuring a conservative design. Results from the RXB seismic analysis include in-structure acceleration time histories at each NPM support, at centerline nodes of the CNV, and various locations on the RP walls and floor. In-structure response spectra are also calculated for the RXB model at the NPM skirt and lugs. The RXB analysis is repeated for multiple SSI analysis cases. The details and methodology used for the RXB SASSI model are discussed in the NuScale FSAR Section 3.7.2. 3.1.5 Creation and Analysis of Detailed Three-Dimensional NuScale Power Module Models in ANSYS (Entire Pool Model) Detailed 3D finite element models of the NPM and RP fluid are created and used to perform seismic analysis. The 3D model created in the initial step of the seismic design process (see Section 3.1.1) is used and modified to include the entire RP volume (i.e., entire pool model). Multiple versions of the model are created to analyze the bounding © Copyright 2018 by NuScale Power, LLC 27

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 NPM locations within the RXB. The detailed 3D models of the NPM are further described in Sections 4.0 and 5.0. Seismic analyses of the models are performed by applying time history accelerations from the Reactor Building SSI analysis to the NPM support locations, and time history accelerations to the RP fluid surfaces in contact with the RP floor and walls. At acoustic fluid element surfaces, possible boundary conditions for transient dynamic analysis include either specified pressure or specified normal acceleration time histories. Acceleration time histories are applied on fluid boundaries at the reactor pool walls and floor and at fluid surfaces where NPMs are not explicitly modeled. Zero pressure is specified on the top surface of the pool. An absorption coefficient is specified at the pool floor (Section 3.1.1). In the detailed 3D models, only one of the twelve NPMs is modeled. To account for the effect of NPMs that are not explicitly modeled, CNV centerline time history accelerations are applied to the surfaces of the fluid that would be in contact with the missing NPMs. Contact between the CNV skirt and pool floor is generated using a rigid surface below the NPM in the operating bay. The rigid surface is defined as a square of 50 feet, coincident with and centered on the base of the CNV skirt (Figure 5-4). Nonlinear contact is established via the rigid surface representing target elements on the floor, and contact elements on the bottom surface of the CNV skirt support ring. Multiple seismic analyses, described in Section 8.0, are performed for each model. Results generated during the analysis include maximum reaction and internal forces and relative displacements at various locations within the NPM. The NPM model also stores results for the creation of ISRS and time histories (displacement and reaction force). 3.1.6 Generation of In-Structure Time Histories and Response Spectra Further processing of the results obtained from the seismic analyses of the detailed 3D NPM models is performed in order to produce inputs for downstream analyses. At various in-structure locations, one vertical and two horizontal sets of time history displacements and accelerations are generated using the seismic analysis results from the detailed 3D NPM model, each set representing the effect of three components of statistically independent earthquake motions applied simultaneously. ISRS are generated by post-processing the analysis results in ANSYS. ISRS are developed in accordance with Regulatory Guide (RG) 1.122 (Reference 10.1.6). Two horizontal and a vertical response spectra are computed from the time history motions of the supporting structure at elevations of interest. Because the mathematical model of the supporting structural system (i.e., RXB) is subjected simultaneously to the action of three statistically independent spatial components of an earthquake, the three computed in-structure time histories used to compute the three ISRS account for all components of seismic input ground motion. Design spectra are generated by broadening and enveloping ISRS computed for applicable soil and rock profiles and concrete conditions. Design response spectra are provided for 2, 3, 4, 5, 7 and 10 percent damping. © Copyright 2018 by NuScale Power, LLC 28

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 3.1.7 Seismic Analysis of NuScale Power Module Components The final step in the seismic design of the NPM is to perform stress analysis of the NPM components using inputs developed in previous steps. As appropriate to each component, seismic analysis methods and procedures satisfy relevant sections of American Society of Civil Engineers (ASCE) 4-98 (Reference 10.1.7), ASCE 43-05 (Reference 10.1.8), ASME Boiler and Pressure Vessel Code (Reference 10.1.5) or IEEE-344-2004 (Reference 10.1.4). Additional guidance for analysis of the NPM is provided in Section 7.0. © Copyright 2018 by NuScale Power, LLC 29

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 4.0 Detailed Three-Dimensional ANSYS models of the NuScale Power Module and Single Bay Pool This section describes 3D finite element models of the NuScale Power Module (NPM) that are used for seismic analysis. These models use time history motions from the reactor building (RXB) analysis as inputs to the NPM support locations and pool walls and floor. The NPM models store results for creation of ISRS, time histories (acceleration), and maximum reaction and internal forces at various locations within the NPM. This information allows for analysis of the CNV, the RPV, the RVIs, the valves, the SGs, CRDMs, fuel, and other components within the NPM. Four 3D ANSYS finite element models of the NPM are developed, which include the following variants:

  • NPM with single pool bay
  • NPM at location NPM1 with entire pool
  • NPM at location NPM6 with entire pool
  • Partial NPM in the reactor flange tool (RFT)

The first of these four variants is described in Section 4.1 and consists of submodels for a single CNV and nearby pool water within the reactor bay, the RPV, upper RVI, lower RVI, and CRDMs. The next two variants are described in Section 5.1 and consist of the same submodels as the first variant but with the pool water extended to the entire pool. The NPMs in operating bays 1 and 6 are representative of the other NPMs because the forces at the CNV lug supports in bays 1 and 6 bound those of the other NPM locations, and the CNV support skirt reaction forces closely match the highest values. Therefore, the 3D models including the entire pool are developed for the NPM in operating bay 1 and in operating bay 6 in order to represent the response of all NPMs. The last variant is described in Section 5.2, and encompasses only a subset of the NPM model, namely the lower RPV, core support assembly with fuel, lower internals, and a representation of the RFT. 4.1 Seismic Model Methodology The NPM is modeled primarily using solid elements, solid shell elements, beam elements, and acoustic fluid elements (for the RP). Pipe elements, matrix elements, surface elements, mass elements, contact/target elements, and spring elements are also used. A full 360-degree model is used because this model does not have symmetric boundary conditions that would justify using a partial symmetric model (half-model or quarter-model). The NPM seismic model in a single pool bay as shown in Figure 4-1 is created from five submodels: CNV and NPM pool bay, RPV, lower RVI, upper RVI, and CRDMs. The five submodels are combined into a single model. The details of the submodels and the combined model are described in the following sections. The coordinate system of the models is shown in Figure 4-2. © Copyright 2018 by NuScale Power, LLC 30

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 The term submodel does not refer to the term substructure as used by the ANSYS structural analysis program. The term submodel refers to assemblies or components that are separately defined in the ANSYS input. To form a single model, the submodels are connected by constraint equations, contact elements, or coupled degrees of freedom. These connections between the submodels are often accomplished using pilot nodes. Pilot nodes are manually created within ANSYS Mechanical as remote points. Faces of geometry or individual nodes are selected and the remote point is scoped to the faces or nodes. Scoping refers to the geometry over which a boundary condition is applied. ANSYS uses multipoint constraint equations to generate a connection between the remote point and the meshed face to which the remote point is scoped. Those multipoint constraint equations comprise the function and input for the pilot nodes. The remote points connecting the submodels have options that specify them as deformable, meaning that the geometry to which each remote point is scoped is free to deform. A TARGE170 element is used at the remote point location, and CONTA174 elements at the scoped faces. For the TARGE170 element, six degrees of freedom (DOF) are used in the multipoint constraint. The CONTA174 elements are constrained in the translational DOFs only. This deformable option is chosen because if the boundary conditions on the RPV were specified as rigid, the combined model would be constrained unrealistically. The remote points considered here are used to transmit loads between each submodel only, and are abstractions that do not add stiffness to the submodels. ANSYS also uses the term submodeling to describe a finite element technique that can be used to obtain more accurate results in a particular region of a model, by using a more refined model of the particular region. This use of the term submodel is not the meaning intended in this report. In the ANSYS documentation, substructuring refers to procedures that condense a group of finite elements into one element represented by a single mass, stiffness and damping matrix. The single-matrix element is called a superelement. The ANSYS substructuring technique, ANSYS superelements, and the concept of master nodes are not used in this report. The CRDM support frame and CRDM submodel described in this report are generated by the ANSYS computer code. The ANSYS CRDM submodel is translated from a CRDM stress analysis model developed by the CRDM vendor using their proprietary structural computer code. Modal analyses were performed to verify the equivalence of the ANSYS models to the CRDM vendor models. The piping, valves, manways, instruments, PZR heaters, and other small internal components such as bolts are not explicitly modeled. These minor features do not affect the gross structural behavior of the model and removing them allows for simplified meshing techniques to be used. The piping is flexible relative to the vessels, so it does not drive the response of the CNV or RPV. © Copyright 2018 by NuScale Power, LLC 31

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 A mesh sensitivity study for the model described in the following sections was conducted. The mesh was increased from approximately ((

        }}2(a),(c) elements. A modal analysis and a harmonic analysis were conducted using the refined model.

For the major components, the modal response of the structure with the refined mesh is within 10% of the response of the coarse mesh, with the exception of the coarse mesh mode at (( }}2(a),(c). This upper riser internals mode is not as significant for the refined model, as this mode has separated into four modes ((

                                             }}2(a),(c) of lesser significance. The mass participation for the

(( }}2(a),(c) mode was (( }}2(a),(c) while the sum of the mass participation for the four separated modes is (( }}2(a),(c). The sum of the responses of the four separated modes is similar to the single mode response in magnitude and these modes are within 10% of the single mode. Therefore, the mesh used for the NPM seismic model as described in the following sections is acceptable. Potential uplift of the NPM is captured through nonlinear contact with the rigid floor surface (Figure 5-4). © Copyright 2018 by NuScale Power, LLC 32

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                      }}2(a),(c)

Figure 4-1 NuScale Power Module single bay, three-dimensional model geometry and mesh © Copyright 2018 by NuScale Power, LLC 33

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 4.1.1 Containment Vessel and Pool Bay Submodel 4.1.1.1 Containment Vessel and Pool Geometry, Mesh and Mass This section describes the CNV and NPM pool bay submodel, including the top support structure (TSS). The CNV and TSS geometry is based on the CNV and NPM drawings. The computer aided design model used to generate the drawings was defeatured and simplified in order to reduce the element count of the mesh, specifically by merging the cladding with the base metal and removing small features. Merging the cladding with the base material is justified because the modulus of elasticity of each is almost identical. Figure 4-2 shows the simplified CNV geometry. The pool model footprint dimensions are based on the bay size for a single NPM. The top of the pool is 69 ft above the base of the CNV. Figure 4-3 shows the pool bay geometry. The CNV is meshed using 8-node solid shell elements and 8-node solid elements. The solid shell elements are used at any shell section where there is one element through the thickness. This element was chosen for its efficient computation time and its ability to accurately model thin to moderately thick shells without multiple elements. The solid elements are used at intersection regions of shells and where there is more than one element through the thickness. The use of solid shell elements (similar to shell elements) allows for a coarser mesh to decrease computation time; however, the mesh is refined around the CNV lateral lugs and the lower lateral RPV support in order to capture the deformation in these highly strained regions. The TSS is meshed using beam elements. The CNV and TSS mesh is shown in Figure 4-2. © Copyright 2018 by NuScale Power, LLC 34

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                         }}2(a),(c)

Figure 4-2 Containment vessel geometry and mesh The pool bay is meshed using 8-node acoustic elements (FLUID30) with the tetrahedral and pyramid options. A coarse mesh is used in order to reduce computation time. The mesh size of the pool was validated to give correct hydrostatic pressures (see Section 8.3). The pool mesh is shown in Figure 4-3 along with the CNV-pool combined mesh. © Copyright 2018 by NuScale Power, LLC 35

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                               }}2(a),(c)

Figure 4-3 Pool bay geometry and mesh and combined containment vessel-pool bay mesh The CNV and pool bay are meshed as a single part in order to have one conformal mesh between the two. Due to removed components, defeaturing, and coarse meshing of the CNV, some of the CNV mass is not accounted for in the elements. To compensate for this, distributed masses were added to the CNV and applied to the appropriate surfaces. The value of each mass is the difference between the actual mass (including valves, piping, bolts, etc.) and the meshed mass of various sections. The CNV mass adjustment summary is shown in Table 4-1. A depiction of the CNV sections is shown in Figure 4-19. See Table 4-2 for how additional masses in this region are distributed between the CNV head and the TSS. The additional masses are accounted for by increasing the density of the top members of the TSS, per the Table 4-3 density adjustment calculation. © Copyright 2018 by NuScale Power, LLC 36

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 4-1 Mass adjustment for the containment vessel Piping Total Mass Section Lifting Lugs Cable Fluid Mesh Mass Adjustment CNV Section Mass and Bolting Mass Mass (lbm) Added to (lbm) Mass (lbm) (lbm) (lbm) Section (lbm) Top Head and TSS (( }}2(a),(c) PZR Shell (( - }}2(a),(c) Lug Shell (( }}2(a),(c) Ledge Shell (( }}2(a),(c) Straight Shell 1 (( }}2(a),(c) Flange (( }}2(a),(c) Straight Shell 2 (( }}2(a),(c) Transition Shell (( }}2(a),(c) Straight Shell 3 (( }}2(a),(c) Bottom Head (( }}2(a),(c) TOTAL (( }}2(a),(c) TOTAL (( CNV MASS (lbm):

                                                                                      }}2(a),(c)

© Copyright 2018 by NuScale Power, LLC 37

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 4-2 Containment vessel head and TSS mass adjustment distribution Location of additional mass, and method of applying mass [in brackets] Additional Component Lifting Lugs CNV Head Top of TSS [split into 4 point [surface elements [density increase] masses] w/ mass] (lbm) (lbm) (lbm) Section mass minus mesh mass (( }}2(a),(c) Lifting lugs (( }}2(a),(c) Cables: NPM bay wall to TSS (( }}2(a),(c) Cables: TSS to CNV head (( }}2(a),(c) Cables: below CNV head (( }}2(a),(c) Chemical and volume control system piping water (( }}2(a),(c) FW piping water (( - }}2(a),(c) MS piping water (( }}2(a),(c) Total (( }}2(a),(c) Total (( }}2(a),(c) Table 4-3 Density adjustment calculation for top of TSS Density Adjustment for top of TSS Initial density (lbm/in3) (( }}2(a),(c) Initial mass (lbm) (( }}2(a),(c) Mass to add (lbm) (( }}2(a),(c) Final mass (lbm) (( }}2(a),(c) Adjusted density (lbm/in3) (( }}2(a),(c) (initial density) (final mass/initial mass) 4.1.1.2 Containment Vessel and Pool Boundary Conditions Acceleration time histories are applied to the CNV skirt and CNV lateral lugs using pilot nodes. The CNV lateral lugs act in their lateral shear directions only. The CNV skirt is treated as a pinned connection. The CNV skirt is treated as a linear pinned connection in this single bay model, to tune the simplified beam model described in Section 6.0. In the entire RP models described in Section 5.1, the CNV skirt is treated as a non-linear pinned connection with the ability to uplift. © Copyright 2018 by NuScale Power, LLC 38

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Fluid-structure interaction (FSI) between the CNV and the pool water is accounted for at interfacing surfaces between the CNV and pool bodies. The three concrete pool walls and pool floor are modeled by applying no boundary conditions to these surfaces, with the exception of the pool floor that has an absorption coefficient specified (Section 3.1.1). The default boundary condition for the external faces of the acoustic body is to reflect acoustic pressure waves, which is the desired behavior for the concrete walls. The side of the NPM bay that is open to the rest of the pool is modeled as a reflective rigid wall. The pressure reflection at this interface is explicitly modeled with the rest of the pool, as described in Section 5.0. The entire pool model is used for transient analysis, described in Section 5.3. The top surface of the pool is assigned an acoustic pressure of zero psi because this is the free surface. 4.1.1.3 Containment Vessel and Pool Materials The CNV is assigned material properties of SA-508 Grade 3 Class 2 steel for the upper CNV and SA-182 FXM-19 steel for the lower CNV. The elastic moduli are taken at the CNV operating temperature of 100 degrees F. The densities are taken at the as-built temperature of 70 degrees F. The material property values are derived from the 2013 ASME Boiler and Pressure Vessel Code, Section II. The TSS is assigned the elastic modulus of low carbon steel. The elastic modulus is taken at the CNV operating temperature of 100 degrees F. The initial density of this material is arbitrary since it is adjusted as part of the mass correction. The assigned material properties of the acoustic fluid elements used to represent pool water at 100 degrees F are shown in Table 4-4: © Copyright 2018 by NuScale Power, LLC 39

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 4-4 ANSYS Material Properties for Acoustic Fluid Elements Assigned to the Pool Water ANSYS Material Property Value Units Property Label 0.9292E-04 (lbf - sec2)/in4 Mass density DENS (0.035876) (lbm/in3) Dynamic viscosity VISC 0.000000 (lbf - sec)/in2 Sonic velocity SONC 60042.00 in/sec Bulk viscosity BVIS 0.000000 (lbf - sec)/in2 Not applicable to structural analysis; Thermal conductivity KXX zero value is assigned Not applicable to structural analysis; Specific heat C zero value is assigned Not applicable to structural analysis; Heat coefficient CVH zero value is assigned 4.1.2 Reactor Pressure Vessel Submodel 4.1.2.1 Reactor Pressure Vessel Geometry, Mesh and Mass The RPV geometry is based on the RPV drawings. The computer-aided design model used to generate the drawings was defeatured and simplified in order to reduce the element count of the mesh. Figure 4-4 shows the simplified RPV geometry. The steam generator assembly is comprised of two interwoven helical steam generators that feed two individual steam lines. The support structures are shared between each steam generator. The steam generator assembly spans the annulus between the reactor pressure vessel and the upper riser. The steam generator tubes are supported by 8 locations of 21 tube support bar assemblies. The tube support bar assemblies are long with a relatively small cross section. These tube support bar assemblies hang from the T-shaped upper tube support bars on the integral steam plenum plate. The bottom ends of the tube support bar assemblies are supported by the lower tube support cantilevers. The lower tube supports only provide circumferential restraint for large displacements of the tube support bars and do not provide restraint in other directions. The steam generator tubes rest on the tube support bar assemblies, providing radial and vertical support but potentially allowing the tubes to slide axially along the tube length. The tubes are constrained at the feed and steam plenum tubesheets. The tube support bar assemblies are interconnected in the circumferential direction via the overhanging tabs from adjacent supports. This coupling effectively ties the tube support assemblies together in the circumferential direction. © Copyright 2018 by NuScale Power, LLC 40

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 The tube support bar assemblies also interface with each other radially outward between the upper riser and the RPV shell. This allows loads to be transmitted radially outward from the riser to the shell. The upper riser is coupled to the RPV shell to model this behavior. See Section 4.1.4.2 for further details on the upper riser to reactor vessel coupling. The stiffness of the steam generator assembly in the other directions is inherently flexible compared to the RPV and therefore, not modeled. The comparative stiffness of the reactor pressure vessel, including the steam generator properties beyond its mass contribution, and the radial coupling of the upper riser to RPV shell, do not have a significant effect on the results presented in this report. The aspects of the steam generator assembly that are physically modeled are the lower tube support cantilevers and upper tube support bars on the integral steam plenum plate. The lower tube support cantilevers are attached to the reactor pressure vessel. The tip of the lower tube support cantilever is near, but not welded or bolted to, the upper riser, and does not provide for load transfer from the upper riser to the RPV. The upper tube support bars are modeled as rectangular beams, integrally meshed directly to the integral steam plenum plate. The RPV is meshed using 8-node solid shell elements and 8-node solid elements. The solid shell elements are used at any shell section where there is one element through the thickness. The solid elements are used at intersection regions of shells and where there is more than one element through the thickness. The RPV mesh is shown in Figure 4-4. © Copyright 2018 by NuScale Power, LLC 41

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                            }}2(a),(c)

Figure 4-4 Reactor pressure vessel geometry and mesh The RPV has its mass adjusted in a similar manner as the CNV. The RPV mass adjustment summary is shown in Table 4-4. A depiction of the RPV sections is shown in Figure 4-19. The cable mass in the vicinity of the CRDM supports is accounted for by increasing the density of the CRDM support structure. See Table 4-5 for the density adjustment calculation. © Copyright 2018 by NuScale Power, LLC 42

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 4-5 Mass adjustment for the reactor pressure vessel Piping Total Mass Bolting Cable Section Fluid Mesh Mass Adjustment RPV Section Mass Mass Mass (lbm) Mass (lbm) Added to (lbm) (lbm) (lbm) Section (lbm) CRDM Support (( - }}2(a),(c) Top head (( }}2(a),(c) Straight shell 1 (( }}2(a),(c) Steam shell (( }}2(a),(c) Upper Support shell (( }}2(a),(c) Straight shell 2 (( }}2(a),(c) Feed shell (( }}2(a),(c) Transition shell (( }}2(a),(c) Straight shell 3 (( }}2(a),(c) Flange (( }}2(a),(c) Straight shell 4 (( }}2(a),(c) Bottom head (( }}2(a),(c) TOTAL (( }}2(a),(c) TOTAL RPV (( MASS (lbm):

                                                                                            }}2(a),(c)

Table 4-6 Density adjustment calculation for the control rod drive mechanism support frame Density Adjustment for CRDM Support Initial density (lbm/in3) (( }}2(a),(c) Initial mass (lbm) (( }}2(a),(c) Mass to add (lbm) (( }}2(a),(c) Final mass (lbm) (( }}2(a),(c) Adjusted density (lbm/in3) (( }}2(a),(c) (initial density) (final mass/initial mass) © Copyright 2018 by NuScale Power, LLC 43

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 4.1.2.2 Reactor Pressure Vessel Boundary Conditions At the bottom of the RPV, the pilot node associated with the mating surface of the male RPV alignment feature, and the pilot node associated with the mating surface of the female CNV alignment feature, are constrained to displace equally in the horizontal directions using the CE command in APDL. This is because the nominal design is a (( }}2(a),(c) between the RPV and CNV alignment features in the cold condition. These nodes are not coupled in the vertical direction because the CNV alignment feature is designed to allow thermal expansion of the RPV alignment feature in the vertical direction without restraining motion. The boundary conditions at the RPV Supports are governed by the nature of the connection with the CNV Ledges. The bolts which connect the RPV support slots to the CNV ledges are tensioned to accommodate thermal expansion of the RPV in the radial direction. Cylindrical coordinate systems are employed in order to capture this behavior using the CE command. Constraint equations are applied between the pilot nodes of the RPV supports and the CNV ledges in only the circumferential and vertical direction, because the rotation of the RPV about its vertical axis is not possible due to the four bolted connections securing it to the CNV ledges. By coupling the displacement of the pilot nodes of the RPV supports to the displacement of the pilot nodes of the CNV ledges in the circumferential direction, the connection is effectively modeled. Likewise, the bolted connection at each of the four CNV ledges generates the need to couple the pilot nodes associated with the slots of the RPV supports and the holes of the CNV ledges in the vertical direction (i.e., there is no uplift). The CRDM support frame is modeled with beam elements as shown in Figure 4-18. The cross-sections of these beam elements are either a rectangle (representation of the support plates) or hollow rectangles (other beams in the CRDM support frame). An actual representation of the seismic support plates is not needed at the level of detail of the NPM seismic model. The connection to the RPV head is facilitated by six degree of freedom (DOF) target/contact pairs (bonded) to the proximal surfaces of the RPV head solid elements. 4.1.2.3 Reactor Pressure Vessel Materials The RPV is assigned material properties of SA-508 Grade 3 Class 2 steel, except for the upper RPV support, which is SA-533 Grade B Class 2. The elastic modulus values are taken at the average reactor coolant system (RCS) temperature of 550 degrees F. The density is taken at the as-built temperature of 70 degrees F because the model is built with room temperature nominal dimensions. 4.1.3 Lower Reactor Vessel Internals Submodel 4.1.3.1 Lower Reactor Vessel Internals Geometry, Mesh and Mass The lower RVI geometry is based on the lower riser and core support drawings. The computer-aided design model used to generate the drawings was defeatured and © Copyright 2018 by NuScale Power, LLC 44

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 simplified in order to reduce the element count of the mesh. Figure 4-5 shows the simplified lower RVI geometry. The lower RVI is meshed using 8-node solid shell elements and 8-node solid elements. The solid shell elements are used at any shell section where there is one element through the thickness. The solid elements are used at intersection regions of shells and where there is more than one element through the thickness. The reflector blocks are modeled as separate from the rest of the lower RVI. A cutaway view of the lower RVI mesh is shown in Figure 4-5 (fuel assembly beam elements not shown). ((

                                                                                                  }}2(a),(c)

Figure 4-5 Lower reactor vessel internals geometry and mesh The lower RVI has its mass adjusted in a similar manner as the vessels. The lower RVI mass adjustment summary is shown in Table 4-7. The core support mass is the sum of the following three RVI components: the Core Support, Surveillance Capsules, and Core Entrance Flow Plate. The negative mass adjustment associated with the core support was incorporated by reducing the density of the reflector material as shown in Table 4-8. © Copyright 2018 by NuScale Power, LLC 45

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 The meshed mass is higher than the actual mass because the cooling channels in the reflector are not modeled (they are filled in) in the ANSYS model. Table 4-7 Mass adjustment summary for the lower reactor vessel internals Mesh Mass Mass Adjustment Lower RVI Section Mass (lbm) (lbm) (lbm) Lower riser (( }}2(a),(c) Core support (( }}2(a),(c) TOTAL (( }}2(a),(c) TOTAL Lower RVI MASS (( }}2(a),(c) (lbm): Table 4-8 Density adjustment calculation for reflector Density Adjustment for Reflector Initial density (lbm/in3) (( }}2(a),(c) Initial mass (lbm) (( }}2(a),(c) Mass to add (lbm) (( }}2(a),(c) Final mass (lbm) (( }}2(a),(c) Adjusted density (lbm/in3) (( }}2(a),(c) (initial density) (final mass/initial mass) 4.1.3.2 Fuel Modeling Within the lower RVI submodel is a model to represent the fuel assemblies. The model uses properties provided directly by the fuel vendor. The fuel model consists of beam and spring elements. The diagram of a single fuel assembly beam model is shown in Figure 4-7. To account for all 37 fuel assemblies, the stiffnesses of the beams and springs and the displaced water mass and holddown preload were multiplied by 37. The final values are listed in Table 4-9. The total mass does not include the fluid mass. The fluid mass determined in Table 4-14 is added separately to the NPM full model. The spring stiffness values are not calculated. The values are tuned based on a benchmark of the fuel beam model to experimentally measured frequency values for a single fuel assembly. The combined mass and stiffness for a single fuel assembly is attached to the upper and lower core plates of the lower RVI submodel (fixed at the base and laterally/fully rotationally coupled on the top of the fuel assembly, as shown in Figure 4-6. © Copyright 2018 by NuScale Power, LLC 46

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 4-9 Fuel beam element properties Area, Combined Stiffness & Elevations of Fuel Beam Element Fuel Beam Area, A [in2] (( }}2(a),(c) Fuel Beam Moment of inertia, Iyy, Izz [in4] (( }}2(a),(c) Fuel Beam Polar moment of inertia, J [in4] (( }}2(a),(c) Fuel Beam Thickness (square), Txx, Tzz [in] (( }}2(a),(c) Fuel Beam Youngs Modulus, E [psi] (( }}2(a),(c) Fuel Beam Density, [lbf-s2/in4] (( }}2(a),(c) BN(1) upper surface elevation, y1 [in] (( }}2(a),(c) Lower HMP(2) grid elevation, y2 [in] (( }}2(a),(c) HTP(3) 1 grid elevation, y3 [in] (( }}2(a),(c) HTP 2 grid elevation, y4 [in] (( }}2(a),(c) HTP 3 grid elevation, y5 [in] (( }}2(a),(c) HTP 4 grid elevation, y6 [in] (( }}2(a),(c) TN(4) lower surface elevation, y7 [in] (( }}2(a),(c) Lower nozzle spring stiffness, K,LEG(5)[in-lbf/rad] (( }}2(a),(c) Fuel spring stiffness, K,ISG(6)[in-lbf/rad] (( }}2(a),(c) Upper nozzle spring stiffness, K,UEG(7)[in-lbf/rad] (( }}2(a),(c) Holddown Spring Stiffness, KHDS(8) [lbf/in] (( }}2(a),(c) Adjusted Holddown Spring Preload, F [lbf] (( }}2(a),(c) Point Mass for Displaced Water, mnode [lbf-s2/in] (( }}2(a),(c) (Note: Each fuel assembly model has 3 point masses.) Note: (1) BN: Bottom Nozzle. (2) HMP: HMP is a spacer grid product name. (3) HTP1-4: HTP is a spacer grid product name. The numbers 1 through 4 represent the spacer grid location, with 1 being the lowermost location, 2 and 3 being intermediate locations, and 4 being the uppermost location. (4) TN: Top Nozzle. (5) LEG: Lower End Grid (HMP). (6) ISG: Intermediate Spacer Grid (HTP). (7) UEG: Upper End Grid (HTP). (8) HDS: Holddown Spring © Copyright 2018 by NuScale Power, LLC 47

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                }}2(a),(c)

Figure 4-6 Fuel core model (with real element shapes) and its connections to LRVI © Copyright 2018 by NuScale Power, LLC 48

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                    }}2(a),(c)

Figure 4-7 Fuel beam model © Copyright 2018 by NuScale Power, LLC 49

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 A modal analysis of the lower RVI was performed to verify the modes of the fuel assembly match the modes calculated by the fuel vendor. The entire lower RVI model except the fuel assembly was restrained for this analysis. The modal results are shown in Table 4-10. Table 4-10 Fuel assembly modal results validation Frequency (Hz) Mode NuScale Results Fuel Vendor Results 1 (( }}2(a),(c) 2 (( }}2(a),(c) 3 (( }}2(a),(c) Vertical (( }}2(a),(c) 4.1.3.3 Lower Reactor Vessel Internals Boundary Conditions In separate submodels for the Lower RVI and the RPV, pilot nodes are created using the detailed methodology described in Section 4.1.2.2. The four lower core plate tabs on the lower RVI are coupled to the four lower core support blocks of the RPV submodel in the circumferential and vertical directions using these pilot nodes. There are no nonlinear effects, such as gaps, in the connection between the lower RVI core plate tabs and the core support blocks on the RPV, as the actual connection consists of socket head cap screws and shear pins (Figure 4-8) that provide a circumferential and vertical restraint. The interfacing slotted holes on the lower core plate permit relative thermal growth of the core support and lower RPV. The radial direction restraint is therefore released in the NPM seismic model. © Copyright 2018 by NuScale Power, LLC 50

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                    }}2(a),(c)

Figure 4-8 Lower reactor vessel core support blocks and core support attachment The upper core support blocks of the lower RVI are connected to the inner walls of the core region of the RPV submodel. This is done by coupling remote points scoped to the inside of the RPV and to the faces of the upper support blocks in the radial direction. The surfaces to which the remote points are scoped are shown in Figure 4-9. The reflector blocks are connected to the inner surface of the core support barrel using a no-separation contact. No-separation contact means contact detection points that are either initially inside the pinball region or that once they involve contact, always attach to the target surface along the normal direction to the contact surface (sliding is permitted). © Copyright 2018 by NuScale Power, LLC 51

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 No friction coefficient is assigned to the elements. The no-separation contact is assigned using element types CONTA174 and TARGE170. These elements do not represent compression-only one-way springs. The no-separation contact surfaces are indicated in Figure 4-5. The contact surface meshes are shown in Figure 4-10. Nonlinear effects are not considered for the radial gaps in the boundary conditions because the radial gaps are small (i.e. the gap between reflector blocks and core barrel is 0.125 inch). Therefore, they are modeled as linear supports that cause the components to move together (in the radial direction) during a seismic event. For these contact surfaces, the effect of additional energy dissipation due to Coulomb friction is neglected. The primary load path for resisting external seismic loads is through the contact forces normal to the interfaces. By setting the coefficient of friction to zero, Coulomb friction is not used to provide additional resistance to external seismic loads through a secondary load path, which can relieve forces acting on the primary load path. The exclusion of frictional resistance results in a conservative assessment of the normal seismic forces acting on the interface. The natural frequency of the system is a characteristic of the linear system. Frictional forces render the dynamic response nonlinear and act to perturb the dynamic response. When friction is included, the response is not characterized by modal analysis or changes in component natural frequency. The effect of friction in perturbing the dynamic response is addressed by the inclusion of uncertainty in the analysis of the NPM dynamic response for a range of stiffness values. The inclusion of uncertainty in the dynamic analysis encompasses numerous causes of uncertainty, including the effect of neglecting friction at these interfaces. Internal boundary between upper support blocks and the lower RPV shell: The upper support blocks radially coupled remote point scoped surfaces and the RPV shell no-separation contact surfaces are shown on Figure 4-9. Neglecting friction, the contact forces act only in the radial direction. The components slide vertically and circumferentially relative to each other due to relative deflections of the lower RPV and the lower RVI shells. Transfer of load across this interface is assumed to occur through radial forces alone. Therefore, the primary load path and resistance provided by this interface is in the radial direction. Additional resistance due to frictional circumferential forces is neglected. In the vertical direction the primary load path is through the core barrel. The secondary support path due to vertical friction at the core support blocks is neglected. Large dissipative Coulomb friction forces are expected. Energy dissipation due to Coulomb friction forces is neglected by setting the coefficient of friction to zero. © Copyright 2018 by NuScale Power, LLC 52

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Internal boundary between lower RVI and reflector: The lower RVI to reflector no-separation contact surfaces are shown on Figure 4-10. Neglecting friction, the contact forces act only in the radial direction, therefore, the primary load path provided by this interface is in the radial direction. The reflector blocks and core barrel are physically separated by a water filled annular gap. The fluid filled gap is nominally 0.125 inch thick. Coulomb friction does not act on the interface between the reflector and core barrel unless the gap closes due to relative displacements. Viscous forces acting due to the fluid do not cause significant damping and are conservatively neglected. For horizontal seismic loads, the primary load path for forces acting on the reflector blocks is through alignment pins between each stacked block and between the lowest block and lower core plate. Additionally, the outer rim of the top of each of the first five reflector blocks is raised to form an inset that provides a horizontal load path between the blocks. A secondary load path for horizontal loads is through the action of inertial and viscous forces resulting from fluid within the annular gap. For vertical loads, the primary load path is between stacked blocks and the lower core plate. The reflector blocks are connected to the lower core plate and to each other using frictionless contact, to account for potential uplift. In order to prevent rigid body motion of the reflector blocks, rotation about the vertical axis is coupled between remote points scoped to the edges of the bottom of each block and to the lower core plate. These rotational constraints model the effect of the reflector block alignment pins. Forces due to Coulomb friction occur only if deflection is sufficient to close the vertical gap above the reflector blocks and below the upper core plate and do not provide a primary load path for resisting vertical seismic load. © Copyright 2018 by NuScale Power, LLC 53

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                              }}2(a),(c)

Figure 4-9 Upper support blocks to RPV shell contact meshes © Copyright 2018 by NuScale Power, LLC 54

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                      }}2(a),(c)

Figure 4-10 Lower RVI to Reflector contact meshes 4.1.3.4 Lower Reactor Vessel Internals Materials The lower RVI is assigned material properties of Type 304 stainless steel. The elastic modulus is taken at the average RCS temperature of 550 degrees F. The density is taken at the as-built temperature of 70 degrees F. 4.1.4 Upper Reactor Vessel Internals Submodel 4.1.4.1 Upper Reactor Vessel Internals Geometry, Mesh and Mass The upper RVI geometry is based on the upper riser drawings. The upper RVI assembly is primarily composed of the upper riser shell. The upper riser shell is a long cylindrical structure that is approximately ((

                             }}2(a),(c) The bottom of the upper riser shell is attached to a cone that connects the upper riser to the lower riser. The upper riser shell is bolted to the pressurizer baffle plate by the upper riser hanger ring. The upper riser hanger ring is a

(( }}2(a),(c) plate. The upper riser hanger braces connect the upper riser shell to the upper riser hanger ring. Within the upper riser shell are five control rod drive shaft supports. These supports guide the CRDM shafts from the CRDMs to the fuel and provide guidance and support for the in-core instrumentation. As a secondary role, these supports also stiffen the © Copyright 2018 by NuScale Power, LLC 55

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 upper riser shell. The members of these supports are approximately ((

                              }}2(a),(c) tall.

The upper riser bellows are between the upper riser shell and the upper riser cone section. The bellows allow for vertical thermal growth while limiting relative horizontal deflections between the upper riser and the lower riser. While the geometry of the bellows has not been modeled, its effect has been captured by coupling the upper riser and lower riser in the horizontal directions while the vertical directions are not coupled. The in-core instrumentation guide tubes, riser backing strips, and the RCS injection piping from the CVCS are not modeled. None of these structures significantly affect the stiffness of the upper riser assembly and therefore do not affect the analysis results. The upper riser geometry and general dimensions are shown in Figure 4-11. The CAD model used to generate the drawings was defeatured and simplified in order to reduce the element count of the mesh. Figure 4-12 shows the simplified upper RVI geometry. The upper RVI submodel is composed of the upper riser shell, upper control rod drive shaft supports, upper riser hanger ring, and upper riser hanger braces. The upper riser shell and upper riser hanger ring are meshed with SOLSH190 elements while the upper control rod drive shaft supports and upper riser hanger braces are meshed with SOLID185 elements. Figure 4-12 presents the mesh of the upper riser. SOLID185 elements are shown in red and SOLSH190 elements are shown in blue. The upper RVI has its mass adjusted in a similar manner as the lower RVI. The upper RVI mass adjustment summary is shown in Table 4-11. See Section 4.1.8.2 for additional details on mass elements added to the model. © Copyright 2018 by NuScale Power, LLC 56

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                    }}2(a),(c)

Figure 4-11 Upper Riser Geometry © Copyright 2018 by NuScale Power, LLC 57

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                          }}2(a),(c)

Figure 4-12 Upper reactor vessel internals geometry and mesh © Copyright 2018 by NuScale Power, LLC 58

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 4-11 Mass adjustment summary for the upper RVI Mesh Mass Mass Adjustment Upper RVI Section Mass (lbm) (lbm) (lbm) Upper riser (total) (( }}2(a),(c) TOTAL Upper RVI MASS (( }}2(a),(c) (lbm): 4.1.4.2 Upper Reactor Vessel Internals Boundary Conditions The physical connection between the upper RVI and the lower RVI is made by bellows. In the seismic model, the cone of the upper RVI is coupled to the cone of the lower RVI submodel in the horizontal directions only, as shown in Figure 4-13. The bellows are not modeled using a spring in the axial direction. Instead, in order to account for the bellows, the upper and lower risers are decoupled in the vertical direction. The primary function of the bellows assembly is to decouple the vertical load path from the lower riser to the upper riser in order to accommodate thermal expansion. The specific function of the bellows (i.e., the convolutions portion) is to prevent bypass flow between the cold and hot legs during operation. The bellows vertical expansion structure does not provide any structural function. The bellows exerts a force on the lower riser under normal operating conditions. The magnitude of the force between the risers is a combination of the mass of the upper riser beneath the bellows and the displacement of the bellows with respect to its equivalent spring constant. The total force (considering the bellows stiffness, preload, and the mass of the upper riser section beneath the bellows) exerted on the lower riser by the bellows is insignificant for the seismic model. The physical connections between the upper riser and the RPV are shown in Figure 4-14 and Figure 4-15. In the entire pool model, radial coupling is provided between the upper riser and the RPV using constraint equations, as shown in Figure 4-16. These represent the radial load transfer that occurs due to the stack-up of SG tube supports between the upper riser and RPV. The load transfer occurs along the height of the SG at the 8 support locations around the circumference. The stiffness in the circumferential direction of the SG tube support bar assemblies and the SG tubes does not affect the results of the model. As a confirmatory analysis for this assumption, the stiffness of the SG tube support bar assemblies on two adjacent planes of supports that are (( }}2(a),(c) apart (as shown in Figure 4-14) was compared to the stiffness of the RPV by treating each as a simply supported beam. The other two planes of support are oriented mostly in the direction of bending, and these supports will transfer radial loads that are appropriately modeled. The calculations, performed using beam formulas from Reference 10.1.12, show that the stiffness of the tube supports in the circumferential direction is four orders of magnitude © Copyright 2018 by NuScale Power, LLC 59

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 lower than the RPV. The tubes are only completely constrained at the feed and steam plenum tubesheets. In this configuration the tubes act only to transfer force between the tubesheets and the tube supports, and from one tube support to the next. During bending of the RPV with the SG, the tubes move in unison with the supports. Therefore, the modeling choice to neglect the stiffness of the SG tubes in the circumferential direction is justified. The connections between the upper RVI and the baffle plate are shown in Figure 4-17. The upper riser ring hole locations on the upper RVI are coupled to pin locations on the baffle plate of the RPV submodel. This is done by coupling the translational degrees of freedom on the eight pairs of pilot nodes, as shown in Figure 4-17. © Copyright 2018 by NuScale Power, LLC 60

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                    }}2(a),(c)

Figure 4-13 Constraint equations between URVI and LRVI © Copyright 2018 by NuScale Power, LLC 61

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                        }}2(a),(c)

Figure 4-14 Connections between upper RVI and RPV (top section view) © Copyright 2018 by NuScale Power, LLC 62

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                        }}2(a),(c)

Figure 4-15 Connections between upper RVI and RPV (side view) © Copyright 2018 by NuScale Power, LLC 63

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                         }}2(a),(c)

Figure 4-16 Constraint equations between the upper RVI and RPV © Copyright 2018 by NuScale Power, LLC 64

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                             }}2(a),(c)

Figure 4-17 Connection between URVI and baffle plate of RPV submodel 4.1.4.3 Upper Reactor Vessel Internals Materials The upper RVI is assigned material properties of Type 304 stainless steel. The elastic modulus is taken at the average RCS temperature of 550 degrees F. The density is taken at the as-built temperature of 70 degrees F. 4.1.5 Control Rod Drive Mechanism Submodel For the CRDM submodel, minor modifications were made to the mass and to couple the external coil stack beams to the pressure housing pipe elements. The CRDM submodel is imported 16 times into the combined model and connected to the RPV head, as shown in Figure 4-18. The CRDM is meshed using 2-node pipe elements, 2-node beam elements and structural mass elements. Additional masses were added to account for the control rod drive shafts and control rod assemblies (CRAs). The vertical masses of the drive shafts © Copyright 2018 by NuScale Power, LLC 65

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 (( }}2(a),(c) for the CRA are included in the CRDM submodel (these values are divided by 16 before being added to CRDM submodel). The portion of the horizontal drive shaft masses that lie within the CRDM geometry are also included in the CRDM submodel. See Section 4.1.8.3 for a calculation of these masses. The CRDM mesh is shown in Figure 4-18 with true section shapes displayed on the right two images in the figure. ((

                                                                                                    }}2(a),(c)

Figure 4-18 Control rod drive mechanism beam model mesh (true section shapes shown) and control rod drive mechanism assembly on reactor pressure vessel head © Copyright 2018 by NuScale Power, LLC 66

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 4.1.5.1 Control Rod Drive Mechanism Boundary Conditions A CRDM is constrained to the RPV head by beam elements representing the CRDM nozzles. The nozzle elements share the two nodes through the thickness of the RPV head, and connect to the bottom of the CRDM by six DOF target/contact pairs (always bonded) to the proximal surfaces of the RPV head solid elements. This couples the translational degrees of freedom, as well as rotation about the two horizontal axes. CRDM rotation about the vertical axis is constrained. The mid-heights of the CRDMs are coupled laterally to the CRDM support frame. Nonlinear effects are not included in the linear analysis. The radial gaps between the CRDM latch housings (( }}2(a),(c) and the seismic support plates (( }} 2(a),(c) are sized nominally to provide a tight fit in the cold assembly condition. The tops of the CRDMs are coupled laterally to the inside of the CNV top head opening, and the gaps are closed by the seismic support frame bolts. 4.1.5.2 Control Rod Drive Mechanism Support Structure Materials The mid-height of the CRDM is coupled laterally to the CRDM support structure frame on the top of the RPV. Material properties for the frame and support plates (connecting the frame to the CRDMs) are assigned as Type 304 stainless steel. The elastic modulus is taken at the average CNV gas temperature of 300 degrees F. The density is taken at the as-built temperature of 70 degrees F. 4.1.5.3 Control Rod Drive Mechanism Materials The CRDM submodel uses several sets of material properties whose values were assigned at temperatures between 450 degrees F and 600 degrees F. An additional set of material properties for SA-508 Grade 3 Class 2 was added to represent the CRDM nozzle material at 550 degrees F. 4.1.6 Piping Fluid Mass Summary The masses of the piping fluid applied to the previously described submodels are summarized in Table 4-12. The fluid masses apply to multiple submodels. Reactor component cooling water system fluid is neglected; however, as its volume is small, and its calculated mass is negligible. See Section 4.1.8.2 for computation of steam and feedwater (FW) densities. Feedwater density is also applied to chemical and volume control system piping fluid density. The decay heat removal system (DHRS) water density is taken at 60 degrees F and atmospheric pressure (62.4 lbm/ft3, or 0.0361 lbm/in3). © Copyright 2018 by NuScale Power, LLC 67

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 4-12 Valve, insulation, and piping fluid mass summary Piping Fluid Section Mass is Piping Fluid Section Mass (lbm) Applied To 1/2 on CNV ledge DHRS passive condenser (( }}2(a),(c) shell; 1/2 on CNV water straight shell 1 1/2 on CNV PZR DHRS piping water (( }}2(a),(c) shell; 1/2 on CNV lug shell 1/2 on CNV top Chemical and volume head and TSS; 1/4 control system Piping (( }}2(a),(c) on RPV top head; Water 1/4 on RPV feed shell 1/2 on CNV top FW piping water (( }}2(a),(c) head and TSS; 1/2 on RPV feed shell 1/2 on CNV top MS piping water (vapor) (( }}2(a),(c) head and TSS; 1/2 on RPV steam shell All on RPV feed FW plenum water (( }}2(a),(c) shell All on RPV steam MS plenum water (vapor) (( }}2(a),(c) shell Total (( }}2(a),(c) 4.1.7 Cable, Conduit, and Sensor Mass Summary The masses of electrical cables, conduit, and sensors are included in the model. They are discussed in this section since they apply to multiple submodels. The cable mass, including conduit and sensors, is broken up into three sections: NPM bay wall to TSS, TSS to CNV head, and below the CNV head. The bay wall to TSS mass is located entirely on the top of the TSS. The TSS to CNV head mass is split evenly between the top of the TSS and the CNV head. The mass below the CNV head is assumed to have a triangular distribution that is maximum at the top (CNV Head) and tapers down until it reaches just below the RPV flange. These masses are distributed on the CNV head and along the RPV sections. For a detailed breakdown of the masses and the equation for the triangular distribution, see Table 4-13. The cable mass in the gap between CNV head and CRDM support is distributed equally between the CNV head and CRDM support. See Figure 4-19 for a description of the section names. © Copyright 2018 by NuScale Power, LLC 68

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 4-13 Distribution of cable masses NPM Bay TSS to Top of Section Below CNV Head Vessel Section Name Wall to TSS CNV Head Elevation (in) (lbm) (lbm) (lbm) CNV Top head and TSS (( }}2(a),(c) (Gap between CNV CNV to head and CRDM (( }}2(a),(c) RPV support) RPV CRDM support (( }}2(a),(c) RPV Top head (( }}2(a),(c) RPV Straight shell 1 (( }}2(a),(c) RPV Steam shell (( }}2(a),(c) RPV Upper support shell (( - }}2(a),(c) RPV Straight shell 2 (( }}2(a),(c) RPV Feed shell (( }}2(a),(c) RPV Transition shell (( }}2(a),(c) RPV Straight shell 3 (( - }}2(a),(c) RPV Flange (( }}2(a),(c) RPV Straight shell 4 (( - }}2(a),(c) RPV Bottom head (( }}2(a),(c) Total: (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 69

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                         }}2(a),(c)

Figure 4-19 Containment vessel and reactor pressure vessel section diagrams 4.1.8 Combined Model The five submodels are imported into the combined NPM model. The combined model contains directional masses that are applied to the applicable surfaces of the NPM model. These masses include the RCS fluid mass, SG mass, control rod drive shaft mass, and CRA mass. Each has the horizontal and vertical masses applied to different surfaces. The total mass is divided by the number of nodes in the named selection, and a point mass is applied to each node in the named selection. The directional masses are explained in detail in Sections 4.1.8.1 through 4.1.8.4. © Copyright 2018 by NuScale Power, LLC 70

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 4.1.8.1 Reactor Coolant System Fluid Mass The RCS volumes are summarized in Table 4-14. The reference volumes already account for space displaced by SG tubes and fuel assemblies, and therefore are not adjusted further. The annular volumes are taken from the Fluid Coupling (Section 4.1.8.5) for consistency within this model. The total RCS volume in this model is (( }}2(a),(c). The volume region locations of Table 4-14 are depicted in Figure 4-20. The masses are calculated by multiplying the volume of each region by the water density at the approximate average RCS temperature of 550 degrees F and pressure of 1850 psia, except for the PZR volumes. The two PZR regions use the density of liquid water and steam at saturation (for 1850 psia and 625 degrees F). The RCS volumes and masses are summarized in Table 4-14. The mass of the fluid within the lower RVI is accounted for as follows. The horizontal fluid masses are listed as Core + reflector channels, Lower riser, and Riser transition in Table 4-14 and are applied to the inner surfaces of the reflector blocks, the inner surfaces of the lower riser, and the inner surface of the riser transition, respectively. The vertical component of these fluid masses is contained within the Main RCS Total (no PZR) mass in Table 4-14. Half of this mass is applied to the inside surface of the lower reactor pressure vessel (RPV) head, and half is applied to the bottom of the pressurizer baffle plate. Table 4-14 Reactor coolant system volumes and fluid masses Region Volume (in3) Density (lbm/in3) Mass (lbm) Lower plenum (( }}2(a),(c) Core + reflector channels (( }}2(a),(c) Lower riser (( }}2(a),(c) Riser transition (( }}2(a),(c) Upper riser (( }}2(a),(c) Upper riser supports (( }}2(a),(c) PZR liquid (65%) (( }}2(a),(c) PZR vapor (35%) (( }}2(a),(c) Annular volume SG (( }}2(a),(c) Annular volume lower (( }}2(a),(c) TOTAL (( }}2(a),(c) Main RCS Total (no PZR) (( }}2(a),(c) PZR Total (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 71

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure 4-20 Reactor coolant system volume region locations © Copyright 2018 by NuScale Power, LLC 72

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 4.1.8.2 Steam Generator Mass The SG has a mass of (( }}2(a),(c). Half of the horizontal mass is applied to the riser, and half is applied to the inner surfaces of the RPV. The vertical mass is applied to the upper SG supports only. This represents the floating vertical connection at the bottom cantilever interface. See Figure 4-21 for the locations of the distributed mass. The SG ISRS presented in Appendix B envelops both steam generators. The actual configuration of the helical tube columns of the two SGs form an intertwined bundle of tubes around the upper riser assembly, with a total of four feed plena and four steam plena located 90 degrees apart around the RPV (shown in Figure 2-5). Therefore, the simplified SG modeling detail in the NPM seismic model is adequate for the overall NPM seismic response analysis. Subsequent component qualification remains unaffected. The mass of the SG includes the tube mass, tube support mass, and secondary fluid mass (see Table 4-17). The mass of the cantilevers and upper support bars are included in the RPV mass adjustment (Section 4.1.2). The secondary fluid mass is calculated below. The secondary fluid SG fluid mass is calculated in Table 4-15. The liquid and vapor temperatures are for 100 percent reactor power. Table 4-15 Steam generator secondary fluid mass calculation Volume fraction of Section Temperature (°F) liquid and vapor Liquid (( }}2(a),(c) Vapor (( }}2(a),(c) Total volume (in3) (( }}2(a),(c) Table 4-16 Steam generator mass summary Component Mass (lbm) Tubes + supports (( }}2(a),(c) Internal fluid (( }}2(a),(c) TOTAL (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 73

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                 }}2(a),(c)

Figure 4-21 Mass elements (red dots) representing SG mass © Copyright 2018 by NuScale Power, LLC 74

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 4.1.8.3 Control Rod Drive Shaft Mass The control rod drive shaft horizontal masses are applied to the various lateral supports along the height of the shafts. The total control rod drive shaft mass is ((

                                         }}2(a),(c) per shaft. The mass each support carries is ((
               }}2(a),(c) times the ratio of the support span to total height. See Figure 4-22 for a diagram of the support elevations and spans. The vertical mass of the control rod drive shaft is applied in the CRDM submodel (see Section 4.1.5). The top two horizontal masses are also applied within the CRDM submodel. The remaining horizontal masses are applied in the combined NPM submodel.

((

                                                                                                       }}2(a),(c)

Figure 4-22 Control rod drive system support names and span lengths © Copyright 2018 by NuScale Power, LLC 75

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 The radial gap between the control rod drive shaft alignment cone (( }}2(a),(c) and CRA hub (( }}2(a),(c) is closely controlled to provide a tight fit. The lowest CRA card is located only (( }}2(a),(c) above the top of the upper core plate (direct load path), and provides for an even closer fit to the control rods (( }}2(a),(c). Therefore, gaps are not modeled. 4.1.8.4 Control Rod Assembly Mass The mass of the control rod assemblies (CRA) is also applied directionally. Half of the horizontal mass is applied to the CRA guide tube support plate, and the other half is applied to the upper core plate. In the normal operating position, the CRA are all out of the core, and the rodlets contact the guide tube support cards. The hub on top of the CRAs contact the control rod drive shaft alignment cones, structurally connected to the top of the lower riser by the CRA guide tube support plate. The load path for lateral seismic loads is through the upper core plate on the bottom and to the support plate on top of the lower riser, that are included in the model (the guide tubes and support cards are not modeled). In the vertical direction, the control rod drive shaft with attached CRA is supported during normal reactor operation (all rods out of the core) by the stationary grippers on top of the RPV (in the CRDM submodel), ignoring any friction on CRA and drive shaft supports. The vertical mass is combined with the control rod drive shaft mass in the CRDM submodel. Each CRA has a mass of ((

        }}2(a),(c).

4.1.8.5 Fluid Coupling The fluid coupling in the annular region between the RPV and the RVI is accounted for by a method called Fourier Nodes. This method accounts for the mass of the fluid as well as the fluid-structure interaction between the RPV and RVI. It. reduces the computational effort without explicitly modeling acoustic elements (such as in the NPM pool bay). This method creates a set of constraint equations connecting the inner and outer surfaces of the annulus at several elevations along the annulus (23 locations for this model), as shown in Figure 4-23. At each elevation, two nodes are created at the center of the module as the Fourier nodes (identical location); one for RVI and the other for RPV. Each Fourier node is coupled to the wall inner surface in the radial direction at 16 locations along the circumference using the CE command. The ANSYS element type MATRIX27 with symmetric element matrices (keyopt(2)=0) is used for fluid coupling. For each element, 78 matrix constants are entered to the mass matrix, as shown in Equation 4-1 below. In Equation 4-1, Fxna and Fzna are the reaction forces at Fourier Node a which is coupled to the inner cylinder in the x-axis and z-axis, and Fxnb and Fznb are the reaction forces at Fourier Node b which is coupled to the outer cylinder in the x-axis and z-axis, respectively. For the beam mode, the hydrodynamic masses M11, M12, M21, and M22 are expressed in Equation 4-2, which is from Reference 10.1.11 © Copyright 2018 by NuScale Power, LLC 76

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 0 0 0 0 0 0 0 0 0 0 Equation 4-1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

      =                                      0   0    0    0   0 0   0    0    0   0 0    0   0 0    0    0 0    0 0

1 + Equation 4-2

         =

1 2

         =       =

1 1 +

         =

1 where

             = hydrodynamic mass ( = 1  2)
             = fluid density
             = axial length of the discretized segment
             = radius of the inner cylinder shell
             = radius of the outer cylinder shell
             =

Only the first coupled mode (M=1, beam mode) between the RPV and RVI is considered because shell modes do not have a significant impact on the overall response of the NPM. This is justified since the overall seismic inertial loading and response of the NPM is dominated by beam modes. Modal participation associated with local shell modes (determined without considering shell mode fluid coupling) is not significant. The frequency of shell modes such as the n=8 mode of the lower riser are above the range of significant seismic input and response is not sensitive to frequency changes due to fluid coupling. Therefore it was not necessary to include fluid coupling effects upon shell modes. For calculation of the mass, the outer radius of the SG region of the annulus was reduced to adjust for the volume taken up by the SG (the last two rows of region 4, and © Copyright 2018 by NuScale Power, LLC 77

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 all of region 5, Table 4-17 and Figure 4-24). The adjusted volume is reduced by 34 percent, which is 1 minus the ratio of the RCS volume of the SG region ((

        }}2(a),(c) to the total volume of this region without consideration of the SG displacement

(( }}2(a),(c). Values for all five of these vectors are summarized in Table 4-17. Region location is shown in Figure 4-24. The geometric dimensions were obtained from the RPV and RVI geometry. ((

                                                                                                  }}2(a),(c)

Figure 4-23 Fourier node locations and couplings © Copyright 2018 by NuScale Power, LLC 78

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 4-17 Elevations, span lengths, and annulus dimensions used in setting up the Fourier Nodes constraint equations Span Adjusted Node Elev, RVI OR, a RPV IR, Volume with Region Length, len RPV IR, elev (in) (in) b (in) Adjustment (in3) (in) bb (in) 53.920 23.200 (( }}2(a),(c) 77.120 23.200 (( }}2(a),(c) 1 100.320 23.200 (( }}2(a),(c) 123.520 23.200 (( }}2(a),(c) 146.720 23.200 (( }}2(a),(c) 168.070 19.500 (( }}2(a),(c) 187.570 19.500 (( }}2(a),(c) 2 207.070 19.500 (( }}2(a),(c) 226.570 19.500 (( }}2(a),(c) 243.493 14.345 (( }}2(a),(c) 3 257.838 14.345 (( }}2(a),(c) 275.759 21.498 (( }}2(a),(c) 297.256 21.498 (( }}2(a),(c) 4 318.754 21.498 (( }}2(a),(c) 340.251 21.498 (( }}2(a),(c) 364.508 27.016 (( }}2(a),(c) 391.524 27.016 (( }}2(a),(c) 418.541 27.016 (( }}2(a),(c) 445.557 27.016 (( }}2(a),(c) 5 472.573 27.016 (( }}2(a),(c) 499.589 27.016 (( }}2(a),(c) 526.606 27.016 (( }}2(a),(c) 553.622 27.016 (( }}2(a),(c) TOTAL (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 79

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                       }}2(a),(c)

Figure 4-24 Fourier nodes regions diagram © Copyright 2018 by NuScale Power, LLC 80

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 5.0 Detailed Three-Dimensional ANSYS models of the NuScale Power Module 5.1 Three-Dimensional ANSYS models of NuScale Power Module and Entire Pool Additional NPM models that include modeling of the entire RP are provided. These models are used for transient analysis, as they more accurately capture effects of acoustic wave reflection and standing waves than the single bay model. One model has an NPM in location 1, and the second has an NPM in location 6. The forces at the CNV support skirt and lug supports in bays 1 and 6 closely represent those of the other NPM locations. The NPM numbering scheme is shown in Figure 5-1. The remaining NPM locations that do not have an NPM explicitly modeled have an empty cavity in the approximate shape of the NPM to correctly represent acoustic boundary conditions. To account for the effect of NPMs that are not explicitly modeled, CNV centerline time history accelerations are applied to the surfaces of the fluid that would be in contact with the missing NPMs. Figure 5-1 NPM numbering convention The NPM 1 entire pool model is shown in Figure 5-2, and the NPM 6 entire pool model is shown in Figure 5-3. Both models use the default rigid reflective behavior for all external pool surfaces, including the cavities at NPM locations without explicit NPM models. The top surface of the pool is assigned a pressure of zero psi. A cutaway view of the NPM cavities is shown in Figure 5-4. The center wall at the X end of the pool was simplified to have a uniform thickness of 6 ft along its entire length (the step down to 5 ft was removed). © Copyright 2018 by NuScale Power, LLC 81

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                       }}2(a),(c)

Figure 5-2 NPM 1 entire pool model ((

                                                          }}2(a),(c)

Figure 5-3 NPM 6 entire pool model © Copyright 2018 by NuScale Power, LLC 82

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                }}2(a),(c)

Figure 5-4 Cutaway view showing NPM cavities and rigid floor representation 5.2 Three-Dimensional ANSYS model of Lower NPM and Reactor Flange Tool The refueling position examined is the lower RPV, lower riser, core support structure, and fuel (Figure 5-5) on the reactor flange tool support with other components of the module removed. This position is the only refueling configuration in which the fuel is open to the reactor pool. While in the containment flange tool (CFT) and while being lifted by the crane, the fuel remains isolated inside the RPV. See Figure 5-6 for the location of the RFT. The model consists of the lower RPV, lower riser, core barrel, fuel, and RFT support, see Figure 5-7. The RPV model documented in Section 4.1.2 has been modified to incorporate the refueling ledge at the bottom of the RPV, see Figure 5-8. The LRVI submodel is consistent with the model documented in Section 4.1.3. The mass of the displaced pool water is accounted for by increasing the density of the RPV, RFT, and the portion of the LRVI above the lower RPV by the density of water at 70°F and 14.6 psia. The fluid-structure interaction of the water contained by the lower RPV is represented using the Fourier node method described in Section 4.1.8.5. © Copyright 2018 by NuScale Power, LLC 83

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                }}2(a),(c)

Figure 5-5 Lower RPV, Lower Riser, and Core Support inside the RFT (fuel not shown) © Copyright 2018 by NuScale Power, LLC 84

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                              }}2(a),(c)

Figure 5-6 Reactor Flange Tool Location ((

                                                                                              }}2(a),(c)

Figure 5-7 Refueling Configuration for Seismic Analysis. © Copyright 2018 by NuScale Power, LLC 85

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                               }}2(a),(c)

Figure 5-8 RPV to RFT Support Interface Acceleration time histories on top of the base mat at the reactor flange tool location are applied to the bottom of the RFT model. The cracked and uncracked cases are considered for nominal stiffness, as well as the cracked case with reduced stiffness. The Y-direction (vertical) time history acceleration files are modified to remove gravity from the input. This is done by subtracting 386.089 in/sec2 from each time step, such that the only value remaining is the seismic portion of the input. Additionally, the frequency range used to apply damping is adjusted according to the modal results obtained for this configuration. Alpha-beta damping is used for the analysis, and a 4 percent damping value is applied to the frequency range of (( }}2(a),(c)

  © Copyright 2018 by NuScale Power, LLC 86

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 5.3 Acceleration Boundary Conditions The SASSI time history acceleration data was applied to the ANSYS mesh at each node of the pool walls and floor and the CNV cavities for the NPM models with the entire pool (Section 5.1). The data manipulation process is described in the list below and in more detail in the following sections:

1. Store the 3D surface representation of the nodes and faces of the SASSI data.
2. Read the acceleration time history data for each node.
3. Store the 3D surface representation of the nodes and faces of the ANSYS model.
4. Interpolate the data at the ANSYS nodes and generate tables for each node of the pool walls from the SASSI surface.
5. Create tables of CNV accelerations versus elevation tables for the 11 empty cavities.
6. Create NPM lug and base skirt acceleration tables.

The lateral seismic accelerations are applied to a remote point that is centered on, and scoped to, the bottom of the CNV skirt support ring. This models the actual configuration, in which the CNV skirt engages with the passive support ring on the pool floor in the lateral directions. The vertical seismic acceleration is applied to a separate remote point, to allow for seismic uplift displacement of the CNV skirt from the rigid floor. 5.3.1 Coordinate Systems The SASSI model and the ANSYS model use different coordinate systems as shown in Figure 5-9 and Figure 5-10. Both coordinates have the positive X direction in the East building direction. The SASSI model has positive Z in the vertical direction and the ANSYS model has positive Y in the vertical direction. The origins of the models are also different. To convert coordinates from the SASSI system to the ANSYS system, first the coordinate is rotated -90 degrees about the X axis and then translated by an offset vector. Since the origin of the ANSYS models is always at the pool floor on the centerline of the subject NPM, the offset is different for different NPMs. Table 5-1 shows the offsets for NPMs 1 and 6. © Copyright 2018 by NuScale Power, LLC 87

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                               }}2(a),(c)

Figure 5-9 SASSI model surface geometry and coordinate system ((

                                                                                }}2(a),(c)

Figure 5-10 ANSYS NPM 1 surface geometry and coordinate system © Copyright 2018 by NuScale Power, LLC 88

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 5-1 Offset to convert SASSI coordinates to ANSYS coordinates NPM X Offset (in) Y1 Offset (in) Z1 Offset (in) NPM 1 (( }}2(a),(c) NPM 6 (( }}2(a),(c) 1

Direction labels are in the ANSYS model coordinate system, +Y is vertical up and +Z is South 5.3.2 SASSI Model Geometry The SASSI acceleration data is stored at nodes. The majority of those nodes are part of the pool walls. The remaining nodes represent the centerline of the CNV and the lug locations where the CNV connects to the bay walls.

The truncated SASSI data output does not contain all of the nodes located on the floor of the pool and on the wall that divides the refueling area and the dry dock. Therefore, the face information for those surfaces is incomplete due to the missing nodes. To construct the nodes, a Delaunay triangulation is used to connect the floor nodes and to connect the refueling area wall nodes. 5.3.3 Surface to Surface Interpolation With the surface geometry of the SASSI data and the ANSYS data, accelerations are interpolated from the SASSI surface to the ANSYS surface. There are four scripts for doing the surface interpolation for the entire pool NPM 1, entire pool NPM 6, single bay NPM 1, and the single bay NPM 6 cases. The surface interpolation script first reads the SASSI surface geometry file, rotates it -90 degrees about the X axis, and adds the appropriate offset as defined in Table 5-1. This puts the SASSI surface in the same coordinate system as the ANSYS surface. Next, the script reads the ANSYS surface geometry file. The surface interpolation is carried out for each node on the ANSYS surface. Interpolation is carried out using Equation 7 in Reference 10.1.10 for generalized Barycentric interpolation. This type of interpolation is linear along the edges of the face and is smooth within the face. The interpolation process returns weights for the nodes that form the SASSI face. The interpolated value is the weighted sum of the data from the face nodes. The interpolation script is repeated three times for each direction. First the acceleration data is read for each SASSI node. If the direction corresponds to the North-South direction, the SASSI data is multiplied by -1 to account for the difference in direction between the SASSI Y axis and the ANSYS Z axis. If the direction is vertical, an upward acceleration equal to gravity is added. The interpolation is carried out using the stored interpolation face and weights and ANSYS tables provided for each ANSYS node. © Copyright 2018 by NuScale Power, LLC 89

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 The single bay cases require an extra step to interpolate the nodes of the artificial wall placed over the open side of the bay. The nodes on the artificial wall are moved to coincide with the North bay wall before interpolation and moved back after interpolation. 5.3.4 Containment Vessel Acceleration Representation In the entire pool model, the 11 NPMs that are not modeled are replaced with acceleration tables. These tables are two dimensional, time and elevation. The nodal acceleration data for each NPM is written to a text file compatible with ANSYS. A 1000 second steady state period is added to the beginning of the acceleration data to match the pool wall accelerations. If the acceleration direction corresponds to the North-South direction, the SASSI data is multiplied by -1 to account for the difference in direction between the SASSI Y axis and the ANSYS Z axis. If the direction is vertical, an upward acceleration equal to gravity is added. Skirt accelerations are calculated from the acceleration data for each SASSI node. The accelerations are averaged and then output as a table for the single ANSYS node representing the skirt. The accelerations are also output as tables for the corresponding ANSYS lug nodes. © Copyright 2018 by NuScale Power, LLC 90

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.0 Equivalent Beam Models of the NuScale Power Module These models provide linear simplified beam models of the NPM that have dynamic characteristics equivalent to the detailed 3D ANSYS model (single bay). The ANSYS model was created first and tuned to match the detailed 3D model. Then the tuned ANSYS model was converted to a SAP2000 model for use in the RXB model. These models were not used for final stress analysis as the geometry is simplistic and the meshing coarse to achieve faster computation time. The simplified NPM beam models consist of linear beam, spring, and mass elements only. Components such as the RPV, CNV, CNV support skirt, TSS and CRDMs are represented by massless hollow beam elements. The equivalent inner and outer diameters of the components are calculated matching cross-section areas and mass moments of inertia. Lumped masses are included to represent the mass properties of the components. Beam elements are created to attach the CNV centerline to the RXB wall at the lateral support lug elevation. Both the CNV and the RPV are represented by distinct beam models that are coupled together using stiff spring elements. However, the RVI are not explicitly modeled using beam elements and are instead considered by lumping the RVI mass onto the RPV beam model. Certain modes that are visible in the harmonic response of the detailed RPV 3D model are associated primarily with the RVI or other subcomponents of the RPV. The responses associated with these modes are difficult to capture using a beam model that does not include a separate set of beams to explicitly model the components. Therefore, the response is alternatively captured by employing a set of tuned point masses and springs to model significant missing modes. The tuning process is first performed using a dry model (i.e., without accounting for the RP) and the results are compared to the dry detailed 3D model. This is done to initiate the tuning process. After the dry simplified model is tuned, it is compared to the detailed 3D model that includes the acoustic elements (i.e., accounts for FSI). To capture the FSI response of the NPM using a simplified beam model, a system of beam, spring, and mass elements was employed to couple the NPM to the bay walls of the RXB model at ten elevations. The detailed methodology used to develop this approach is further described in Section 6.6.4. In the simplified models, the mass properties are defined in the lateral directions. The tuning of the model, as first discussed in Section 3.1.2, is focused on replicating the lateral response of the NPM. The vertical response is captured by a set of tuned point masses and springs that comprise the primary vertical modes from the detailed 3D model. Although the detailed 3D models use nonlinear boundary conditions to capture the behavior of the CNV skirt, the use of linear boundary conditions for the simplified model is justified if the vertical lift-off of the skirt as calculated by the detailed 3D model analysis is negligible (less than 1/8 inch). The NPM beam model was created using beam elements, mass elements, and spring elements. A dry simplified beam model (without pool water but including the enclosed fluids) was developed first to serve as a starting model for construction of the equivalent © Copyright 2018 by NuScale Power, LLC 91

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ANSYS beam model. The dry simplified beam model is composed of two dry submodels, the CNV submodel and the RPV submodel, which are generated and tuned. After these two dry submodels were finalized, they were combined and tuned to be the dry NPM simplified beam model. Mass and spring elements were added to the dry model to create a fluid-structure interaction (FSI) response equivalent to the 3D model. 6.1 Dry NuScale Power Module Simplified Beam Model The dry NPM beam model, shown in Figure 6-1, is composed of two submodels. The CNV submodel includes the CNV, CNV wall lugs, RPV support ledges, TSS, and a CNV skirt connection. The RPV submodel includes the RPV, RPV-CNV support skirts, CRDMs, and a representation of RVIs and coolant mass inside the RPV. Detailed descriptions of the CNV and RPV submodels are included in Section 6.1. The combination of CNV and RPV submodels is presented in Section 6.3. ((

                                                                                    }}2(a),(c)

Figure 6-1 Dry NPM simplified beam model (real element shapes also shown) © Copyright 2018 by NuScale Power, LLC 92

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.1.1 Containment Vessel Submodel The CNV submodel is illustrated in Figure 6-2 and Figure 6-3. ANSYS elements with the circular tube section option are used for the CNV. The TSS is modeled using the hollow rectangle option. A total of 26 sections are defined along the longitudinal direction. The OD and ID of each section are selected based on the CNV drawings. The beam elements are assigned as massless. Point masses are added to the CNV nodes. Only horizontal masses are assigned to these mass elements, while vertical masses are assigned separately at the CNV bottom using spring-mass element combinations as presented in Section 6.1.4. The mass values are listed in Table 6-1. Note that some mass elements whose mass is lumped to adjacent mass elements, have a zero mass value. Torsional mass moments of inertia (Izz) are also assigned to point mass elements. The value at each mass element is listed in Table 6-1. These values are determined from the 3D model by slicing the model horizontally and extracting the Izz property for each section. ((

                                                                              }}2(a),(c)

Figure 6-2 Containment vessel submodel finite element model (with real element shapes) © Copyright 2018 by NuScale Power, LLC 93

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                               }}2(a),(c)

Figure 6-3 Containment vessel submodel diagram with nodal elevations © Copyright 2018 by NuScale Power, LLC 94

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-1 Containment vessel mass and torsional mass moment of inertia Mass Izz Node (lbfs2/in) (lbfs2in) 102 (( }}2(a),(c) 105 (( }}2(a),(c) 107 (( }}2(a),(c) 110 (( }}2(a),(c) 112 (( }}2(a),(c) 114 (( }}2(a),(c) 116 (( }}2(a),(c) 120 (( }}2(a),(c) 124 (( }}2(a),(c) 126 (( }}2(a),(c) 127 (( }}2(a),(c) 6.1.2 Containment Vessel Lugs, Reactor Pressure Vessel Support Ledges, and TSS The CNV lugs are modeled using beam and spring elements as shown in Figure 6-4. The CNV shell is represented by three horizontal beams connecting to node 118. Three lugs are represented by three other horizontal beams. The diameters of these 6 beam elements are the same arbitrary value. Each lug and shell is connected using 6 springs (3 translational and 3 rotational). In order to have the same structural response as the 3D model, the stiffness of these 6 springs is calculated by matching the static analysis. At the exterior end of the lugs, a spring in the shear direction is applied. The purpose of these springs is to be consistent with the SASSI model, which requires spring elements at a support for obtaining reaction forces. In order to minimize the impact of structural response caused by these springs, their stiffness is assigned with a high value, 1e12 lb/in. The boundary conditions on the lugs (constraint or displacement for analyses in Section 6.5) are applied on nodes 10, 20, and 30. © Copyright 2018 by NuScale Power, LLC 95

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                           }}2(a),(c)

Figure 6-4 Containment vessel lug diagram top view The RPV support ledge is modeled using beam elements as shown in Figure 6-5. The diameters of these beam elements are the same arbitrary value. The RPV support ledge is connected to the RPV support beam element nodes 128 through 131 as described in Section 6.1.6. The TSS is created using beam and mass elements. © Copyright 2018 by NuScale Power, LLC 96

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                }}2(a),(c)

Figure 6-5 Reactor pressure vessel support ledge top view 6.1.3 Containment Vessel Skirt Representation Beam and translational spring elements are added at the CNV bottom to represent the distribution of loads at the CNV skirt. 8 beam elements are used, as shown in Figure 6-6. The 8 beam elements are connected to CNV bottom (node 101) by three translational springs. At the exterior ends of the beam elements, three translational springs are added to the model. These springs are used in the simplified beam model because of the SASSI model requirement as described in Section 6.1.2. 6.1.4 Vertical Masses and Springs Vertical response is captured by a set of tuned point masses and springs that comprise the primary vertical modes from the 3D model. These spring-mass combinations are shown in Figure 6-6. For the dry condition, the springs and masses are tuned to the 3D model frequencies and effective masses. To get the proper frequency, the equation below is solved for each spring stiffness (k). © Copyright 2018 by NuScale Power, LLC 97

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 1 Equation 6-1

                       =

2 where,

             = frequency (Hz),
             = spring stiffness (lbf/in), and
             = effective mass of the 3D model with respect to each of the major modes (lbm).

The tuning approaches for the missing horizontal (Section 6.2) and vertical effective masses are different. The horizontal part of the wet model (Figure 6-13) is made by first tuning a dry model; then the water (springs and lumped masses) is added based on a Fritz mass approximation. Some fine tuning is done using harmonic analysis; however there are no significant changes to the Fritz masses model. The horizontal effective mass is greater than structural mass alone due to the added fluid model. For the vertical wet condition, the effective mass used in Equation 6-1 is not derived from the 3D model, because the water mass is involved in the NPM response, and the water mass included at each major mode is unknown. Therefore, for the wet simplified beam model, harmonic analysis is used. The mass values for the wet simplified beam model are determined iteratively in the harmonic analysis to match the skirt vertical reaction force amplitudes from the 3D model results. The masses and spring stiffnesses are listed in Table 6-2. For the dry model only three spring-mass combinations are used. For the wet model in Section 6.4, four spring-mass combinations are used. Table 6-2 Vertical masses and spring stiffnesses Mass Spring Stiffness Frequency Spring Mass (lbfs2/in) (lbf/in) (Hz) Stiffness Number Number Dry Wet Dry Wet Dry Wet 645 (( }}2(a),(c) 615 (( }}2(a),(c) (( }}2(a),(c) 646 (( }}2(a),(c) 616 (( }}2(a),(c) (( }}2(a),(c) 647 (( }}2(a),(c) 617 (( }}2(a),(c) (( }}2(a),(c) 2(a),(c) 2(a),(c) 648 (( }} 618 (( }} (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 98

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                               }}2(a),(c)

Figure 6-6 Containment vessel skirt representation and vertical masses and springs diagram 6.1.5 Reactor Pressure Vessel Submodel The RPV submodel is illustrated in Figure 6-7 and Figure 6-8. Circular tube section is used for the RPV. A total of 24 sections are defined along the longitudinal direction. The OD and ID of each section are from RPV drawings. The beam elements are assigned as massless. Masses are assigned by point mass elements. The masses include everything inside the RPV. Only horizontal masses are assigned in these mass elements, while vertical masses are assigned in the CNV submodel for the whole NPM vertical response as described in Section 6.1.4. The mass values are listed in Table 6-3. Torsional mass moment of inertia is also assigned in mass elements. The value at each mass element is listed in Table 6-3. These values are determined from the 3D model shown in Figure 6-9 by slicing the model horizontally and extracting the properties for each section. © Copyright 2018 by NuScale Power, LLC 99

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                       }}2(a),(c)

Figure 6-7 RPV beam submodel FEM (with real element shapes) © Copyright 2018 by NuScale Power, LLC 100

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                      }}2(a)(c)

Figure 6-8 Reactor pressure vessel beam submodel diagram with nodal elevations © Copyright 2018 by NuScale Power, LLC 101

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                             }}2(a),(c)

Figure 6-9 Reactor pressure vessel three-dimensional submodel for tuning and torsional mass moments of inertia © Copyright 2018 by NuScale Power, LLC 102

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-3 Reactor pressure vessel horizontal masses and torsional mass moments of inertia Initial Mass Final Final Izz Additional Mass Node Mass Tuning Mass Mass (lbfs2in) Sources (lbm) (lbm) (lbm) (lbfs2/in) 201 (( 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 103

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 As detailed in Tuning Section 6.2, the missing mass of the RVI (not captured in the spring-mass elements shown in Figure 6-11) is proportioned to the RPV upper and lower RVI support elevation nodes. Masses of RPV attachments that are not explicitly modeled in the underlying 3D vessel model (Figure 6-9), such as cables, are indicated for individual nodes and considered for their contribution to the torsional mass moment of inertia. 6.1.6 Reactor Pressure Vessel Supports The RPV support skirts are modeled using four elements, as shown in Figure 6-10. An arbitrary small value is assigned as the cross section area of these four beams. High values of moment of inertia, shear modulus, and torsional constant are assigned to these four beams representing rigid elements in these directions. At the end of each beam, three translational springs are applied. For these springs, one end is on the RPV support skirts (nodes 226 through 229) and the other end is on the CNV (nodes 128 through 131). The nodes in each spring are radially separated by 0.19 inches, determined from the 3D model to represent joint sliding in the radial direction. The RPV skirt joint is slotted to allow unrestrained thermal expansion between the CNV and RPV in the radial direction. For the other two directions (circumferential and vertical), the translational springs are connected to the RPV support ledge (on the CNV). Thus, these spring stiffnesses are calculated. Their stiffness is determined from static analysis on the 3D model. Since in SAP2000 spring elements can only be defined in the global coordinate system (CS), the 45 degrees horizontal springs (local CS) are replaced by the springs in the global CS. © Copyright 2018 by NuScale Power, LLC 104

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                               }}2(a),(c)

Figure 6-10 Reactor pressure vessel support skirt top view (not in scale) 6.1.7 Control Rod Drive Mechanism The CRDMs above the CRDM support (elements between nodes 223 and 225 in Figure 6-8) are modeled using elements with arbitrary section. The cross section area, moment of inertia, and torsional constant are determined for 16 CRDMs by multiplying a single CRDM value by 16. 6.2 Tuning Because the RPV submodel is a simplified model that does not include structures inside the RPV (only masses are included), it requires tuning to represent the 3D model. The purpose of tuning is to match the 3D model harmonic response. Tuning is accomplished by changing the elastic modulus material properties to influence the overall response and by adding spring-mass systems to capture missing modes. Certain modes that are visible in the harmonic response of the RPV 3D model are associated primarily with the RVI, the reactor coolant, or other subcomponents of the RPV. The responses associated with these modes are difficult to capture using a beam model that does not include a separate set of beams to explicitly model the components. Therefore, the response is alternatively captured by employing a set of tuned point © Copyright 2018 by NuScale Power, LLC 105

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 masses and springs to model the three most significant missing modes. The spring-mass element combination is shown in Figure 6-11. If a mode is determined to be missing from the harmonic response of the dry RPV beam model, the modal analysis results from the RPV 3D model are reviewed to determine which subcomponents are associated with that frequency. To determine the properties of the spring-mass combination, the mass (m) is first assumed to be the total mass of the components identified as being associated with the missing response, and the stiffness (k) is solved for using Equation 6-1, where the frequency (f) is that of the missing modal response. The spring-mass elements (one for the X-direction and one for the Y-direction) are then initially added to the RPV beam model at an elevation near the center of mass of the associated components. Once the initial spring-mass element properties are added to the model, a harmonic analysis is run and the results compared to those of the 3D model. Adjustments to the mass, frequency, and elevation of the spring-mass elements and to the elastic modulus of the RPV beam model are then made to match the harmonic response results. The final properties of the three spring-mass elements that were used in the beam model are listed in Table 6-4. Additionally, the remaining mass of the RVI that was not included in the three spring-mass elements was placed at the RPV upper or lower RVI support elevations proportionally, so that the static load (initial value for the harmonic response) of the beam model matched that of the 3D model. © Copyright 2018 by NuScale Power, LLC 106

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                         }}2(a),(c)

Figure 6-11 Spring-mass elements in reactor pressure vessel submodel Table 6-4 Reactor vessel internals spring-mass properties Frequency Mass Spring Stiffness Elevation Component (Hz) (lbfs2/in) (lbf/in) (in) Description (( }}2(a),(c) fuel (( }}2(a),(c) lower riser CRDMs/upper (( }}2(a),(c) riser © Copyright 2018 by NuScale Power, LLC 107

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.3 Combined Model The connection of CNV and RPV submodels is illustrated in Figure 6-12. The RPV alignment feature is connected to the CNV bottom head by two horizontal springs. The CRDM top is also connected to the CNV head by two horizontal springs. The stiffness of these four springs is the same, and is tuned by iteration to make the best match of harmonic response of the simplified beam model to the 3D model. The RPV support skirt and ledge are connected by translational springs as described in Section 6.1.6. ((

                                                                                              }}2(a),(c)

Figure 6-12 Connection of containment vessel and reactor pressure vessel submodels © Copyright 2018 by NuScale Power, LLC 108

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.4 Wet NuScale Power Module Simplified Beam Model The wet NPM simplified beam model is generated by adding mass and spring elements to the dry NPM model to create an FSI response equivalent to the 3D model, as shown in Figure 6-13 where the pool water elements are displayed in blue. ((

                                                                                          }}2(a),(c)

Figure 6-13 Wet NuScale Power Module simplified beam model (with real element shapes) The red nodes and the nodal numbers shown in Figure 6-14 are the nodes where boundary conditions are applied. Other than the lug nodes (10, 20, and 30 described in Section 6.1.2) and beam and translational spring elements (611 through 618 described in Section 6.1.3) the wall nodes are represented by the 4-series-nodes and the 5-series-nodes, where 1 through 10 represent various elevations. The 5-series-nodes are fixed in the analyses presented in Section 6.5. The 4-series-nodes are applied with the loads listed in Table 6-6 components Pool open side and Pool walls and floor. These nodes are at the center of the walls. © Copyright 2018 by NuScale Power, LLC 109

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 In the linear transient analysis, the wall input data are at the edges of the walls (the twelve green squares in three elevations in Figure 6-14). The average of data from two adjacent corners for each elevation (the nine purple triangles in Figure 6-14) is first calculated. Then the input data for each 4-series-node is calculated by ANSYS using linear interpolation from these nine centerline data points. ((

                                                                                                 }}2(a),(c)

Figure 6-14 Wet NuScale Power Module simplified beam model boundary conditions 6.4.1 SAP2000 Model The wet NPM simplified beam ANSYS model is converted to a SAP2000 model, as shown in Figure 6-15. The SAP2000 input data, including elements, materials, nodal locations, loads, boundary conditions and other analysis options are equivalent to the © Copyright 2018 by NuScale Power, LLC 110

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ANSYS input data. The dynamic equivalency of the models is demonstrated by the confirmatory analyses described in Section 6.5. ((

                                                                          }}2(a),(c)

Figure 6-15 SAP2000 wet NuScale Power Module beam model 6.5 Confirmatory Analyses for the NuScale Power Module Beam Models The analyses performed and their boundary conditions are listed in Table 6-5 and Table 6-6 for the dry and wet NPM beam models, respectively. © Copyright 2018 by NuScale Power, LLC 111

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-5 Dry model boundary conditions ANALYSIS Component Modal Static Harmonic Linear Transient Beam and constrained the 8 same as constrained the 8 nodes applied translational time history translational nodes (representing modal (representing skirt base) displacements on all three axes spring skirt base) translational analysis translational displacements on all simultaneously at the 8 beam and element base displacements on all three axes translational spring element ends three axes Lugs constrained lug same as applied lug horizontal shear applied lug horizontal shear direction horizontal shear modal direction translational time history translational time history direction translational analysis displacements displacements displacements Damping N/A N/A 4% modal damping rate is used for 4% Rayleigh damping with frequency tuning. range 5.8 to 35.6 Hz is used for tuning. Whole body N/A whole body 1g N/A whole body 1g gravity applied on acceleration acceleration vertical axis applied on 3 axes separately © Copyright 2018 by NuScale Power, LLC 112

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-6 Wet model boundary conditions ANALYSIS Component Modal Static Harmonic Linear Transient Beam and constrained the 8 same as modal constrained the 8 nodes applied translational time history translational nodes (representing analysis (representing skirt base) translational displacements on all three axes spring skirt base) translational displacements on all three axes simultaneously at the 8 beam and element base displacements on all translational spring element ends three axes Lugs constrained lug same as modal applied lug horizontal shear direction applied lug horizontal shear direction horizontal shear analysis translational time history translational time history displacements direction translational displacements displacements Pool open Constrained the "cell" Constrained the Applied normal component of Applied normal component of side nodes translational "cell" nodes displacements. The open side uses accelerations. The open side uses the displacements on all translational the displacements from the opposite accelerations from the opposite wall three axes displacements wall (north wall). Displacements for (north wall). Accelerations for each on all three axes each surface only vary in the vertical surface only vary in the vertical direction. direction. An average value is used An average value is used for a given for a given elevation for each wall. elevation for each wall. Pool walls Constrained the "cell" Constrained the Applied normal component of Applied normal component of and floor nodes translational "cell" nodes displacements. Both horizontal accelerations. Both horizontal directions displacements on all translational directions applied simultaneously. No applied simultaneously. No vertical three axes displacements vertical acceleration for floor. acceleration for floor. on all three axes Damping N/A N/A 4% modal damping rate is used for 4% Rayleigh damping with frequency tuning. range 5.8 to 35.6 Hz is used for tuning. Whole body N/A whole body 1g N/A whole body 1g gravity applied on vertical acceleration acceleration axis applied on 3 axes separately © Copyright 2018 by NuScale Power, LLC 113

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.5.1 Modal Analysis The modal analysis results from the dry simplified beam model are summarized in Table 6-7. These results are compared to the 3D model results in Table 6-7. The wet NPM simplified beam model modal analysis results and SAP2000 results are summarized in Table 6-8. Table 6-7 Dry model major modes ANSYS SIMPLIFIED BEAM ANSYS 3D MODEL MODEL X-Freq. X-Eff. Mass X-Freq. X-Eff. Mass (Hz) (lbfs2/in) (Hz) (lbfs2/in) ((

                                                                                  }}2(a),(c)

ANSYS SIMPLIFIED BEAM ANSYS 3D MODEL MODEL Y-Freq. Y-Eff. Mass Z-Freq. Z-Eff. Mass (Hz) (lbfs2/in) (Hz) (lbfs2/in) ((

                                                                               }}2(a),(c)

ANSYS SIMPLIFIED BEAM ANSYS 3D MODEL MODEL Z-Freq. Z-Eff. Mass Y-Freq. Y-Eff. Mass (Hz) (lbfs2/in) (Hz) (lbfs2/in) ((

                                                                                  }}2(a),(c)

© Copyright 2018 by NuScale Power, LLC 114

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.5.1.1 Vertical modes The dominant mode in the vertical direction is (( }}2(a),(c) for the dry model (See Table 6-7 and Figure 6-16) and (( }}2(a),(c) (See Figure 6-19) for the wet model. The dominant vertical modes consist of vertical translation of the RPV and RVI with relatively small translation of the CNV. The predominant vertical deflection occurs where the RPV upper support segments are connected to the CNV ledges. For the wet model, the mode at (( }}2(a),(c) (See Figure 6-20) is of lesser significance and consists of coupled vertical motion of the fluid, CNV, RPV and RVI. Higher modes near (( }}2(a),(c) (dry model shown on Figure 6-17 and Figure 6-18; wet model shown on Figure 6-21 and Figure 6-22) consist primarily of the vertical response of the top support structure and CNV. ((

                                                                                                      }}2(a),(c)

Figure 6-16 Dry model, 1st Significant Vertical Mode © Copyright 2018 by NuScale Power, LLC 115

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                  }}2(a),(c)

Figure 6-17 Dry model, 2nd Significant Vertical Mode © Copyright 2018 by NuScale Power, LLC 116

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                  }}2(a),(c)

Figure 6-18 Dry model, 3rd Significant Vertical Mode © Copyright 2018 by NuScale Power, LLC 117

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                  }}2(a),(c)

Figure 6-19 Wet model, 1st Significant Vertical Mode © Copyright 2018 by NuScale Power, LLC 118

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                  }}2(a),(c)

Figure 6-20 Wet model, 2nd Significant Vertical Mode © Copyright 2018 by NuScale Power, LLC 119

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                  }}2(a),(c)

Figure 6-21 Wet model, 3rd Significant Vertical Mode © Copyright 2018 by NuScale Power, LLC 120

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                  }}2(a),(c)

Figure 6-22 Wet model, 4th Significant Vertical Mode © Copyright 2018 by NuScale Power, LLC 121

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-8 Wet model major modes SAP2000 Simplified beam ANSYS Simplified beam Model ANSYS 3D Model Model X-Freq. X-Eff. Mass X-Freq. X-Eff. Mass X-Freq. (Hz) (lbfs2/in) (Hz) (lbfs2/in) (Hz) ((

                                                                                }}2(a),(c)

SAP2000 Simplified beam ANSYS Simplified beam Model ANSYS 3D Model Model Y-Freq. Y-Eff. Mass Y-Freq. Y-Eff. Mass Z-Freq. (Hz) (lbfs2/in) (Hz) (lbfs2/in) (Hz) ((

                                                                                }}2(a),(c)

SAP2000 Simplified beam ANSYS Simplified beam Model ANSYS 3D Model Model Z-Freq. Z-Eff. Mass Z-Freq. Z-Eff. Mass Y-Freq. (Hz) (lbfs2/in) (Hz) (lbfs2/in) (Hz) ((

                                                                                     }}2(a),(c)

© Copyright 2018 by NuScale Power, LLC 122

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.5.2 Static Analysis A static analysis was performed after the modal analysis. This analysis applied a 1g acceleration on each axis separately. The dry and wet model results are summarized in Table 6-9 and Table 6-10 respectively. The SAP2000 wet model results are listed in Table 6-11. Note that the skirt load represents the sum of 8 beam and translational spring element end reaction forces. Table 6-9 ANSYS dry beam model static analysis results Load Case 1g Acc. in X-axis 1g Acc. in Y-axis 1g Acc. in Z-axis Fx Fy Fx Fy Fz Support (lbf) (lbf) (lbf) (lbf) (lbf) East Lug (( }}2(a),(c) West Lug (( }}2(a),(c) North Lug (( }}2(a),(c) Skirt (( }}2(a),(c) Table 6-10 ANSYS wet simplified beam model static analysis results Load Case 1g Acc. in X-axis 1g Acc. in Y-axis 1g Acc. in Z-axis Fx Fy Fx Fy Fz Support (lbf) (lbf) (lbf) (lbf) (lbf) East Lug (( }}2(a),(c) West Lug (( }}2(a),(c) North Lug (( }}2(a),(c) Skirt (( }}2(a),(c) Table 6-11 SAP2000 wet simplified beam model static analysis results Load Case 1g Acc. in X-axis 1g Acc. in Y-axis 1g Acc. in Z-axis Fx Fy Fx Fy Fz Support (lbf) (lbf) (lbf) (lbf) (lbf) East Lug (( }}2(a),(c) West Lug (( }}2(a),(c) North Lug (( }}2(a),(c) Skirt (( }}2(a),(c) 6.5.3 Harmonic Analysis Harmonic analysis was performed after the post-processing of the modal and static analyses. Full harmonic analysis was performed for the purpose of tuning the simplified beam models. The frequency range for the harmonic analysis starts from 0 to 100 Hz at an increment of 0.1 Hz. Three sets of harmonic analyses were performed for three axes separately. © Copyright 2018 by NuScale Power, LLC 123

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.5.3.1 Dry Condition The dry simplified beam model harmonic analysis results are plotted in Figure 6-23 through Figure 6-25. The 3D model harmonic analysis results are also shown in the plots for comparison. In Figure 6-23, the major frequencies match the values calculated from modal analysis in Table 6-7. The simplified beam model curves match the 3D model results. The difference of peak amplitudes of simplified beam and 3D results ((

        }}2(a),(c). The vertical results in Figure 6-25 show a good match of the simplified beam to 3D model. Therefore, this dry NPM simplified beam model is considered acceptable.

((

                                                                                                  }}2(a),(c)

Figure 6-23 Dry model reaction force amplitudes (loads in east-west direction) © Copyright 2018 by NuScale Power, LLC 124

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                 }}2(a),(c)

Figure 6-24 Dry model reaction force amplitudes (loads in north-south direction) ((

                                                                                                 }}2(a),(c)

Figure 6-25 Dry model reaction force amplitudes (loads in vertical direction) © Copyright 2018 by NuScale Power, LLC 125

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.5.3.2 Wet Condition The wet model results are shown in Figure 6-26 through Figure 6-31. Results from the ANSYS 3D model, ANSYS simplified beam model, and SAP2000 simplified beam model are compared in these figures. In the case of an acceleration load applied in the East-West direction (Figure 6-26 through Figure 6-27), the peak amplitude occurs at (( }}2(a),(c) on the North lug. The ANSYS simplified beam model Rayleigh-damping results under-predict the amplitude from the 3D Rayleigh-damping model by about 12.5 percent. In the vertical loading case (Figure 6-31), the ANSYS simplified beam Rayleigh-damping results under-predict the amplitude from the 3D Rayleigh-damping model results by about 23 percent. These differences are considered acceptable, because it is difficult to use the simple beam and mass elements in the simplified beam model to match the FSI dynamic responses in the 3D model exactly. By comparing the analyses using structural damping (S), the ANSYS and SAP2000 models yield similar results. The maximum difference of (( }}2(a),(c) between these two models occurs at (( }}2(a),(c) in Figure 6-27 and is considered acceptable. ((

                                                                                                       }}2(a),(c)

Figure 6-26 Wet model skirt east-west reaction force amplitudes (loads in east-west direction) © Copyright 2018 by NuScale Power, LLC 126

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                }}2(a),(c)

Figure 6-27 Wet model north lug east-west reaction force amplitudes (loads in east-west direction) ((

                                                                                                }}2(a),(c)

Figure 6-28 Wet model east lug east-west reaction force amplitudes (loads in east-west direction) © Copyright 2018 by NuScale Power, LLC 127

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                }}2(a),(c)

Figure 6-29 Wet model skirt north-south reaction force amplitudes (loads in north-south direction) ((

                                                                                                }}2(a),(c)

Figure 6-30 Wet model east lug north-south reaction force amplitudes (loads in north-south direction) © Copyright 2018 by NuScale Power, LLC 128

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                      }}2(a),(c)

Figure 6-31 Wet model skirt vertical reaction force amplitudes (loads in vertical direction) For the dry condition, time history reaction force plots are illustrated in Figure 6-32. Table 6-12 compares the peak reaction forces of the simplified beam model to the 3D model. The beam model results match 3D results well. The maximum difference of the two models is about ((

        }}2(a),(c). Note that the difference in the Table 6-12 is calculated by the following equation:

3

             . % =

3 Equation 6-2 © Copyright 2018 by NuScale Power, LLC 129

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                                }}2(a),(c)

Figure 6-32 Selected time history reaction force from simplified beam and three-dimensional model (dry condition) Table 6-12 Maximum reaction force comparison (dry condition) Model East Wall North West Wall Skirt E-W Skirt N-S Skirt vertical dir. Lug Wall Lug Lug dir. dir. (lbf) (lbf) (lbf) (lbf) (lbf) (lbf) 3D Model (( }}2(a),(c) Beam Model (( }}2(a),(c) Diff. (%) (( }}2(a),(c) For the wet condition, time history reaction force plots are illustrated in Figure 6-33. Table 6-13 compares the peak reaction forces of the simplified beam model to the 3D model. The simplified beam model lug reaction forces match the 3D results well. The maximum difference of the two models is about (( }}2(a),(c). The skirt reaction, however, differs as much as (( }}2(a),(c) in the East-West direction (along the refueling pool axis). Although the harmonic response of the simplified beam model matches the 3D model well, the dynamic response at the skirt in the transient analysis cannot be accurately predicted by the simplified beam model. This difference is acceptable because the reaction forces are generally smaller in the skirt than in the lug supports, and the beam model reaction force exceeds the 3D model © Copyright 2018 by NuScale Power, LLC 130

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 reaction force. In addition, the structural RXB-NPM coupling is less significant for the skirt-basemat configuration. © Copyright 2018 by NuScale Power, LLC 131

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                            }}2(a),(c)

Figure 6-33 Selected time history reaction forces from wet simplified beam and three-dimensional model © Copyright 2018 by NuScale Power, LLC 132

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-13 Maximum reaction force comparison (wet condition) East Wall North Wall West Wall Skirt E-W Skirt N-S Skirt vertical dir. Model Lug Lug Lug dir. dir. (lbf) (lbf) (lbf) (lbf) (lbf) (lbf) 3D Model (( }}2(a),(c) Beam (( }}2(a),(c) model Diff. (%) (( }}2(a),(c) 6.6 Methodologies to Account for Fluid-Structure Interaction Different methods are employed to model FSI depending on the type of model used and the type of analysis performed. These methods are described below in Sections 6.6.1 through 6.6.4. 6.6.1 Pool Sloshing Sloshing does not have a significant effect upon wall motions. The maximum sloshing height is estimated to be less than 25 inches. The corresponding maximum pressure amplitude is approximately 0.9 psi. Furthermore, the frequency of sloshing is much lower than the fundamental frequency of the NPM. Therefore sloshing is assumed to have an insignificant effect on the seismic response of the NPM. 6.6.2 Representation of Fluid-Structure Interaction using Acoustic Elements The detailed 3D NPM ANSYS models use acoustic elements to model the RP and the interfaces involved in the FSI between the NPM, RP fluid, RP walls, and floor. The typical applications for these elements include sound wave propagation and analysis of submerged structures. For these elements, the governing equation for acoustics (3D wave equation) is discretized while considering the coupling of acoustic pressure and structural displacements at the interface. The element nodes have four degrees of freedom, displacements in the nodal x, y and z directions, and pressure. The displacements are applicable only at nodes on the interface. Acceleration effects are included. 6.6.3 Representation of Fluid-Structure Interaction using Fourier Nodes and Mass Matrices An alternative method used to account for FSI in the detailed 3D NPM ANSYS models is referred to as Fourier nodes. This method accounts for the mass of the fluid as well as the FSI without explicitly modeling acoustic elements. It significantly reduces the computational effort. The Fourier nodes method was used to model the fluid coupling in the annular region between the RPV and the RVI. © Copyright 2018 by NuScale Power, LLC 133

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 6.6.4 Representation of Fluid-Structure Interaction using Fritz Mass For the simplified NPM models, another method of accounting for FSI that is compatible with all three software programs, ANSYS, SAP2000, and SASSI, was used. The analysis provided in, The Effect of Liquids on Dynamic Motion of Immersed Solids, by R. J. Fritz (Reference 10.1.9) was used to develop this method. In the paper, dynamic analysis of solid bodies that are immersed in fluid is performed and the forces due to the presence of the fluid are determined. The case of two long concentric cylinders is considered and a system of equations is developed (Equations 14 and 15 from Reference 10.1.9) to determine the reaction forces on the two cylinders, which can be written as a mass matrix. The Fritz form of the mass matrix,

                                                        +          
                                      =                                                    Equation 6-3
                                         +          + +

In the Fritz mass matrix: M1 = mass of water displaced by the NPM, i.e., volume of water displaced by the immersed CNV. This represents inertial force acting on the NPM due to a constant acceleration of both the NPM and pool walls resulting in a uniform pressure gradient in the fluid. It characterizes the buoyancy effect on the NPM. M2 = mass of water that would fill the bay without the NPM present. This mass is adjusted for free surface effect as described below. Mh = mass of water that represents the inertia from the squeeze of water displaced by relative motion of the pool walls and NPM.

                       = acceleration of the NPM (in/s2)
                       = acceleration of the RP wall (in/s2)

FNPM = reaction force acting on the NPM (lbf) FRXB = reaction force acting on the RP wall (lbf) 6.6.5 Assumptions and Limitations of Fritz Mass 6.6.5.1 Fluid Compressibility The analysis presented by Fritz assumes an incompressible fluid. Application of the Fritz Mass method requires that the flow channel length be small compared to the wavelength for propagating disturbances (less than 10 percent), in order to avoid the possibility of standing-wave effects. For the horizontal direction the flow channel length is approximately 20 feet. Given that the wave velocity is 5000 ft/sec, the Fritz theory is valid for frequencies up to ((5000 ft/sec)/20ft)/10) = 25 Hz. The participation of modes © Copyright 2018 by NuScale Power, LLC 134

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 greater than this frequency is small. Therefore, acoustic modes in the horizontal direction are uncoupled to the fundamental modes of the NPM and the effect of standing waves is small. The Fritz model was not used in the vertical direction where the acoustic mode around 18 Hz is close to the module vertical frequency. For the vertical direction, response was evaluated using the 3D finite element model that uses acoustic elements. 6.6.5.2 Geometry of Fluid Annulus Reference 10.1.9 discusses the application of the Fritz Mass to a circular annulus with two-dimensional flow. It is also shown that the method is applicable to geometries other than circular annuli. Section 6.6.6 describes the approach used to calculate mass matrices of the Fritz formulation for the actual geometry of the NPM and pool walls. The Fritz formulation provides a representation of fluid forces applicable to beam vibration modes of the NPM. Shell modes of vibration of the NPM have smaller participation for seismic loading and are therefore neglected. 6.6.5.3 Fluid Damping Fluid damping is neglected in the Fritz Mass analysis because fluid damping is much less than the structural damping. 6.6.6 Evaluation of Fritz Mass Due to Pool Water in the NuScale Power Module Bay The Fritz Mass matrix as described in Reference 10.1.9 applies to the annular space between two bodies with two dimensional flow. The bodies in Reference 10.1.9 have constant cross section in the third dimension. The annulus between the pool walls and the NPM is not circular and varies with height. The top surface of the pool is a zero pressure boundary. The result is three-dimensional flow requiring the approximate representation described below. The fluid forces acting on the NPM are represented by dividing the fluid annulus into a set of ten discrete cells of height as shown in Table 6-14. The inertia of the fluid in each cell is represented by the Fritz Mass matrix with masses M1, M2 and Mh as presented in Sections 6.6.6.1, 6.6.6.2, and 6.6.6.3, respectively. © Copyright 2018 by NuScale Power, LLC 135

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-14 Fluid cells for defining Fritz mass matrices Bottom Elevation Top Elevation Cell Number Height (inches) (inches) (inches) 1 0 100.5 100.5 2 100.5 175.5 75 3 175.5 250.5 75 4 250.5 325.5 75 5 325.5 400.5 75 6 400.5 475.5 75 7 475.5 550.5 75 8 550.5 625.5 75 9 625.5 700.5 75 10 700.5 828 127.5 6.6.6.1 Hydrodynamic Mass, M1 Due to varying radius of the containment, the mass matrix M1 varies with height above the pool floor. The mass M1 is calculated by evaluating the displaced water volume for the cell multiplied by the density of water. Figure 6-34 shows the Mass M1 versus height. Values vary because the radius of the containment varies and because the cell heights are not uniform. © Copyright 2018 by NuScale Power, LLC 136

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                        }}2(a),(c)

Figure 6-34 Hydrodynamic mass M1 versus height above pool floor 6.6.6.2 Hydrodynamic Mass, M2 The mass M2 represents the mass of water that would fill the bay without the NPM present; however, this assumes that flow is confined at the top and bottom of the annulus. Flow is confined only at the pool floor while the top surface is not confined; therefore, the mass M2 was calculated by applying a 1.0 g acceleration to the 3D acoustic model at both the pool walls and floor. The fluid force on the wall, equal to M2 x1.0g, is evaluated by integration of the wall pressures. Figure 6-35 shows the resulting mass M2 at each elevation. The figure shows the mass, calculated by taking the mass of water that would fill the bay without the NPM present, as the curve labeled confined on the figure. ((

                                                  }}2(a),(c).

© Copyright 2018 by NuScale Power, LLC 137

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                       }}2(a),(c)

Figure 6-35 Hydrodynamic mass M2 versus height above pool floor 6.6.6.3 Hydrodynamic Mass, Mh The 3D acoustic model was subjected to a pool wall acceleration of 1.0 g while the NPM was held fixed. The force on the wall obtained by integration of fluid pressures is equal to FRXB=(M1+M2+Mh)x1.0g. Since M1 and M2 are evaluated as above, Mh=(FRXB/1.0g)-M1-M2. Figure 6-36 shows the resulting mass Mh at each elevation. ((

                                                               }}2(a),(c).

© Copyright 2018 by NuScale Power, LLC 138

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                          }}2(a),(c)

Figure 6-36 Hydrodynamic mass Mh versus height above pool floor 6.6.7 Lumped Mass Representation of Fritz Mass Matrix The Fritz Mass matrix includes off-diagonal terms that represent inertial coupling between pool walls and the NPM. The off diagonal mass matrix cannot be entered directly into SAP2000. This section describes the approach used to replace the off-diagonal mass matrix with a system of equivalent lumped masses, beams and springs. © Copyright 2018 by NuScale Power, LLC 139

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 The lumped mass model used to replace the off-diagonal mass matrix is shown in Figure 6-37 for a cell located in an X-Y plane. The model consists of: ((

        }}2(a),(c). Only inertial resistance is represented by the model; the lumped mass model provides no stiffness or damping forces acting on the NPM or RXB as a result of motion in either of the horizontal directions.

((

                                                                                              }}2(a),(c)

Figure 6-37 Lumped mass model used to represent off-diagonal Fritz stiffness matrix The mass matrix for this system can be determined by applying a unit acceleration to the NPM with the RXB fixed and vice versa. © Copyright 2018 by NuScale Power, LLC 140

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 First, as shown in Figure 6-38, apply a unit acceleration to the NPM, 0.0,

                 = 0.0. Considering only horizontal reactions:

((

                                                                                           }}2(a),(c)

Figure 6-38 Unit acceleration to the NuScale Power Module, 0.0, = 0.0 © Copyright 2018 by NuScale Power, LLC 141

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Next, as shown in Figure 6-39 apply a unit acceleration to the RXB, 0.0,

                  = 0.0. Considering only horizontal reactions:

((

                                                                                             }}2(a),(c)

Figure 6-39 Unit acceleration applied to the reactor building, = 0.0, 0.0 © Copyright 2018 by NuScale Power, LLC 142

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Now the mass matrix can be constructed for this model: ((

                                                                                                 }}2(a),(c)

The Fritz Mass matrix is positive definite; however some of the terms in the lumped mass model are negative lumped mass and are to be subtracted from the structural mass of the NPM or RXB walls. The mass MC is always positive. The mass MA is positive except near the free surface. When the mass is negative, it is subtracted from the adjacent lumped structural mass element. The mass MB is generally negative and must be subtracted from the mass of the concrete wall if the computer code does not allow combination of negative values for lumped masses. Table 6-15 through Table 6-20 summarize the masses M1, M2, Mh, MA, MB and MC for each of the ten fluid cells listed in Table 6-14. Masses are provided separately for each of the four model boundaries of the 3D detailed NPM model. North corresponds to the RP wall, east and west to the RP bay walls and south corresponds to region that is open to the entire RP, (i.e., the cut boundary of the 3D model). © Copyright 2018 by NuScale Power, LLC 143

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-15 Hydrodynamic mass M1 Mass M1 (lbm) Elev. No West East North South 1 (( }}2(a),(c) 2 (( }}2(a),(c) 3 (( }}2(a),(c) 4 (( }}2(a),(c) 5 (( }}2(a),(c) 6 (( }}2(a),(c) 7 (( }}2(a),(c) 8 (( }}2(a),(c) 9 (( }}2(a),(c) 10 (( }}2(a),(c) Sum (( }}2(a),(c) Total (( }}2(a),(c) Table 6-16 Hydrodynamic mass M2, Mass M2 (lbm) Elev. No West East North South 1 (( }}2(a),(c) 2 (( }}2(a),(c) 3 (( }}2(a),(c) 4 (( }}2(a),(c) 5 (( }}2(a),(c) 6 (( }}2(a),(c) 7 (( }}2(a),(c) 8 (( }}2(a),(c) 9 (( }}2(a),(c) 10 (( }}2(a),(c) Sum (( }}2(a),(c) Total (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 144

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-17 Hydrodynamic mass Mh Mass Mh (lbm) Elev. No West East North South 1 (( }}2(a),(c) 2 (( }}2(a),(c) 3 (( }}2(a),(c) 4 (( }}2(a),(c) 5 (( }}2(a),(c) 6 (( }}2(a),(c) 7 (( }}2(a),(c) 8 (( }}2(a),(c) 9 (( }}2(a),(c) 10 (( }}2(a),(c) Sum (( }}2(a),(c) Total (( }}2(a),(c) Table 6-18 Hydrodynamic mass MA Mass MA=(Mh-M1)/2 (lbm) Elev. No West East North South 1 (( }}2(a),(c) 2 (( }}2(a),(c) 3 (( }}2(a),(c) 4 (( }}2(a),(c) 5 (( }}2(a),(c) 6 (( }}2(a),(c) 7 (( }}2(a),(c) 8 (( }}2(a),(c) 9 (( }}2(a),(c) 10 (( }}2(a),(c) Sum (( }}2(a),(c) Total (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 145

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 6-19 Hydrodynamic mass MB Mass MB=M2-M1-Mh (lbm) Elev. No West East North South 1 (( }}2(a),(c) 2 (( }}2(a),(c) 3 (( }}2(a),(c) 4 (( }}2(a),(c) 5 (( }}2(a),(c) 6 (( }}2(a),(c) 7 (( }}2(a),(c) 8 (( }}2(a),(c) 9 (( }}2(a),(c) 10 (( - }}2(a),(c) Sum (( }}2(a),(c) Total (( }}2(a),(c) Table 6-20 Hydrodynamic mass MC Mass MC=(Mh+M1)/2 (lbm) Elev. No West East North South 1 (( }}2(a),(c) 2 (( }}2(a),(c) 3 (( }}2(a),(c) 4 (( }}2(a),(c) 5 (( }}2(a),(c) 6 (( }}2(a),(c) 7 (( }}2(a),(c) 8 (( }}2(a),(c) 9 (( }}2(a),(c) 10 (( }}2(a),(c) Sum (( }}2(a),(c) Total (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 146

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 7.0 Seismic Analysis Methods for Structures, Systems, and Components that Comprise the NuScale Power Module The NPM 3D model described in Section 5.0 was used to determine seismic inputs for the SSC that are integral to or attached to the NPM. Structures, systems, and components supported by the NPM can be analyzed by any of the dynamic analysis methods from NuScale FSAR Section 3.7. 7.1 Time History Analysis Method For analysis of complex Structures, systems, and components within the NPM a more detailed structural model can be used with in-structure time histories obtained from the NPM 3D analyses. Qualification of fuel assemblies uses this approach. 7.2 Response Spectrum Analysis Method The response spectrum method can be used for design of the SSC that are supported by the NPM where appropriate in accordance with Standard Review Plan (SRP) 3.7.2, SRP 3.7.3 and guidelines in ASCE 4. From time history analyses of the NPM 3D model, time histories at locations of equipment supports within the NPM were calculated. The in-structure floor response spectra provided in this report were generated using the guidance provided in RG 1.122, Rev. 1 (Reference 10.1.6). Analysis of piping supported by the NPM at multiple locations can be performed using the Uniform Support Motion (USM) approach. However, the USM method can result in considerable overestimation of seismic responses. Therefore, an alternate method that may be used is the independent support motion (ISM) method. The ISM method is generally used for piping systems that are supported by more than one structure, but may be used for piping systems with multiple supports located in a single structure, if appropriate. 7.3 Equivalent Static Load Method Where applicable, the equivalent static load method can be used for equipment supported on or within the NPM. The input is the ISRS at the support point and the equivalent force is in accordance with Section 4.5 of Reference 10.1.7. The ISRS is the broadened spectrum obtained from time history analysis of the NPM subsystem after broadening and enveloping the SSI cases. 7.4 Uncertainties in the NuScale Power Module Subsystem Model Uncertainty in the input and assumptions used in the finite element models of the NPM is accounted for by considering multiple analyses using +/-30 percent variations of the stiffness properties of the model, equivalent to +/-15 percent variations of the frequencies © Copyright 2018 by NuScale Power, LLC 147

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 of the models responses. A +/-30 percent variation of stiffness is achieved by modification of the NPM materials Youngs and shear moduli and the stiffnesses of non-rigid springs. © Copyright 2018 by NuScale Power, LLC 148

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 8.0 Three-Dimensional Seismic Model Analysis This section analyzes the NPM for seismic loading using the non-linear 3D ANSYS finite element models. Seismic time history data from the RXB are used as inputs to the model. Outputs of the model include ISRS, time history data, relative displacements, and forces and moments within the NPM. The results were obtained using the entire pool seismic models described in Section 5.1 and for the lower reactor vessel in the reactor flange tool in Section 5.2. Results are included for both NPM 1 in the entire pool, and NPM 6 in the entire pool models, as well as the lower RPV in the RFT (limited to ISRS results). The scope of this calculation includes analyzing the NPM for various seismic inputs, and generating time histories, relative displacements, ISRS, and forces and moments. The inputs include seismic time history data from the RXB seismic analysis for certified seismic design response spectra (CSDRS) input. The NPM model in the entire pool is analyzed for the following:

  • one seed input location (Capitola)
  • one soil type (Soil 7)
  • two RXB concrete conditions (cracked and uncracked)
  • two modules (NPM 1 and NPM 6)
  • one case nominal NPM stiffness for the uncracked case, and two NPM stiffness conditions for the cracked case ( [1] NPM stiffness adjustment = 1/1.3=77% of nominal stiffness and [2] nominal stiffness; i.e. no adjustment to NPM stiffness)

This gives 6 runs in total for the NPM models. The six runs are:

1. NPM 1 and entire pool, Cracked Concrete Properties, Nominal NPM stiffness
2. NPM 1 and entire pool, Cracked Concrete Properties, 77% of Nominal NPM stiffness
3. NPM 1 and entire pool, Uncracked Concrete Properties, Nominal NPM stiffness
4. NPM 6 and entire pool, Cracked Concrete Properties, Nominal NPM stiffness
5. NPM 6 and entire pool, Cracked Concrete Properties, 77% of Nominal NPM stiffness
6. NPM 6 and entire pool, Uncracked Concrete Properties, Nominal NPM stiffness The analysis cases were performed using inputs derived from the SASSI analysis of the RXB with soil profile 7 (Hard rock) and a CSDRS compatible control motion based on the Capitola recording.

Outputs from the post-processing include:

  • time-history displacement and acceleration data for 33 points within the NPM

© Copyright 2018 by NuScale Power, LLC 149

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1

  • broadened ISRS for the same 33 points within the NPM
  • maximum forces and moments at 83 interfaces between NPM components
  • maximum forces and moments within 22 NPM component sections
  • maximum forces at 4 NPM support locations For each location, direction, and damping value, the response spectra were calculated for the six seismic analysis runs. Using each set of six response spectra, an envelope spectrum was constructed by finding the maximum of the six response values at each spectral frequency point. The envelope of the six spectra was then broadened by +/-15%

to produce the design ISRS (see example Figure 8-10 for the 4% damping curve in Figure B-14). 8.1 Transient Analysis The input file (and subsequent APDL files that it executes) are set up to run CSDRS inputs. The input files load the combined model as explained previously. The file has an option to reduce or increase stiffness of the NPM material properties and springs when not running the nominal stiffness cases. The commands in the file create a rigid floor and apply contact between the floor pilot node and the CNV skirt pilot node. This captures any uplift of the NPM. The file then sets up the transient solution options, applies the table loads, and solves. Alpha-beta damping is used for the analysis, and a 4 percent damping value is applied to the frequency range of (( }}2(a),(c). This frequency range covers the major modes in Table 8-2, and the range is adjusted for the soft and stiff models. The composite 4 percent structural damping is used, as it is the lowest specified damping value for the SSE event for welded steel or bolted steel structures with friction connections in Regulatory Guide 1.61, Table 1. The RG 1.61 Revision emphasizes the distinction between slip-critical and bearing-bolted connections. The major difference between these types of joints is that in a slip-critical connection bolt forces are large enough to prevent joint sliding versus bearing-bolted type joints where the joint may slide and the bolts are loaded in shear. Conservatively, the lower damping value (4%) is used instead of 7% for the bearing-bolted connections. A static time step with no loads is applied to ensure the model is in equilibrium before the transient starts. The initial time step for the static step is 1,000 seconds. A fixed time step of 0.001 seconds is used during the remaining transient portion of the solution. For CSDRS runs, the transient run time is truncated to 24 seconds, plus the additional 1,000 second initial step, for a total of 1,024 seconds. This is acceptable since the main earthquake response for all provided seeds occurs in the first 24 seconds. 8.2 Modal Analysis Modal analyses were run with and without the pool water (wet or dry, respectively). The Block Lanczos solver was used for the dry analysis, and the unsymmetric matrix © Copyright 2018 by NuScale Power, LLC 150

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 solver used for the wet analysis. The total mass (static) of the model is ((

                                      }}2(a),(c) is the pool bay water mass. The sum of the percentage of modal mass to total mass in the horizontal directions exceeds 100% because of the effect of the confined hydrodynamic mass (see Section 6.6.5.2). Note that the bending modes of the major vessels include shell deformation.

Dry model modal results above a mass participation cutoff of 0.1% are shown in Table 8-1 and wet model modal results are shown in Table 8-2. Table 8-1 Modal analysis results for the single-bay dry NPM model (no pool water) ANSYS 3D DRY MODEL X-Freq. X-Eff. Mass Major NPM subcomponent Modal mass to Type of mode (Hz) (lbf -s2/in) responding at frequency total mass (%) ((

                                                                                                      }}2(a),(c)

ANSYS 3D DRY MODEL Y-Freq. Y-Eff. Mass Major NPM subcomponent Modal mass to Type of mode (Hz) (lbf -s2/in) responding at frequency total mass (%) ((

                                                                                                      }}2(a),(c)

© Copyright 2018 by NuScale Power, LLC 151

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ANSYS 3D DRY MODEL Z-Freq. Z-Eff. Mass Major NPM subcomponent Modal mass to Type of mode (Hz) (lbf -s2/in) responding at frequency total mass (%) ((

                                                                                            }}2(a),(c)

© Copyright 2018 by NuScale Power, LLC 152

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 8-2 Modal analysis results for the single bay wet NPM model ANSYS 3D WET MODEL X-Freq. X-Eff. Mass Major NPM subcomponent Modal mass to Type of mode (Hz) 2 (lbf -s /in) responding at frequency total mass (%) ((

                                                                                                }}2(a),(c)

ANSYS 3D WET MODEL Y-Freq. Y-Eff. Mass Major NPM subcomponent Modal mass to Type of mode (Hz) (lbf -s2/in) responding at frequency total mass (%) ((

                                                                                              }}2(a),(c)

© Copyright 2018 by NuScale Power, LLC 153

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ANSYS 3D WET MODEL Z-Freq. Z-Eff. Mass Major NPM subcomponent Modal mass to Type of mode (Hz) 2 (lbf -s /in) responding at frequency total mass (%) ((

                                                                                                             }}2(a),(c) 8.2.1    Horizontal Modes The dominant modes in the horizontal direction for the wet model are ((
                                                      }}2(a),(c), see Figure 8-1 and ((
                                        }}2(a),(c), see Figure 8-2, both representing the first NPM bending mode in the respective directions, plus ((
                         }}2(a),(c), see Figure 8-3, representing the first RPV bending mode.

© Copyright 2018 by NuScale Power, LLC 154

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                }}2(a),(c)

Figure 8-1 Wet model, 1st Significant Horizontal Mode in E-W Direction © Copyright 2018 by NuScale Power, LLC 155

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                }}2(a),(c)

Figure 8-2 Wet model, 1st Significant Horizontal Mode in N-S Direction © Copyright 2018 by NuScale Power, LLC 156

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                }}2(a),(c)

Figure 8-3 Wet model, 2nd Significant Horizontal Mode in N-S Direction © Copyright 2018 by NuScale Power, LLC 157

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 8.3 Static Analysis A static analysis was performed in the CNV submodels to ensure that the appropriate pressure was developing in the pool water under acceleration (gravity in this case). Results are obtained from a transient analysis; however, time integration effects were turned off. The resulting pressure at the bottom of the pool is 29.71 psi (see Figure 8-5 through Figure 8-7). This matches (within 0.1 percent) the predicted theoretical value:

                                        /
          =  = 0.0359                    386.09     828in = 29.73 psi.

© Copyright 2018 by NuScale Power, LLC 158

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                               }}2(a),(c)

Figure 8-4 Pool pressure effects due to gravity for the single bay pool model. © Copyright 2018 by NuScale Power, LLC 159

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                          }}2(a),(c)

Figure 8-5 Pool pressure effects due to gravity for NPM 1 entire pool model ((

                                                                                            }}2(a),(c)

Figure 8-6 Pool pressure effects due to gravity for NPM 6 entire pool model © Copyright 2018 by NuScale Power, LLC 160

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 8.4 Dynamic Analysis Methodology 8.4.1 Pre-processing Coordinate Systems and NuScale Power Module Numbering Two coordinate systems are used in this calculation during pre-processing: the Cartesian RXB coordinate system, and the Cartesian NPM coordinate system. The seismic inputs are received in RXB coordinates and transformed into NPM coordinates in order to be applied to the NPM model. In general, the NPM coordinate system is used in this section unless otherwise specified. The NPMs are numbered 1 through 12. Figure 8-8 shows the RXB coordinate system along with the NPM numbering convention. Figure 8-7 Reactor Building coordinate system and NuScale Power Module numbering convention The RXB coordinate system is shown compared to the NPM coordinate system in Figure 8-8. Five NPM coordinate systems are used during post-processing of the seismic force and moment outputs. This is done to provide results in the most convenient coordinates for downstream analysis. The coordinate systems include the main Cartesian NPM coordinate system (coordinate system 0), a 45 degrees rotated Cartesian NPM coordinate system (coordinate system 100), a 33.7° rotated Cartesian NPM coordinate © Copyright 2018 by NuScale Power, LLC 161

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 system (coordinate system 200), a 15° rotated Cartesian NPM coordinate system (coordinate system 300), and a -15° rotated Cartesian NPM coordinate system (coordinate system 400). These coordinate systems are depicted in Figure 8-9. The origin of the post-processing coordinate systems is the center of the CNV skirt at the floor elevation. Figure 8-8 Reactor Building and NuScale Power Module coordinate systems © Copyright 2018 by NuScale Power, LLC 162

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                               }}2(a),(c)

Figure 8-9 NuScale Power Module coordinate systems for post-processing 8.4.2 NuScale Power Module Seismic Model Locations The NPM finite element models used in this dynamic analysis are from Section 4.0. See Section 5.1 for detailed description of the seismic model of NPM 1 in the entire pool, and NPM 6 in the entire pool. Interface, section, and support locations are selected to provide analysis results. Details related to the locations and parameters are provided in the following subsections. © Copyright 2018 by NuScale Power, LLC 163

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 8.4.2.1 Forces and Moments for Component Interfaces, Component Sections, and Supports A total of 53 interface, section and support locations are selected to provide response spectra and relative displacements (shown in Table 8-3). Appendix A provides figures identifying the representative locations. Note that location IDs 34 through 41 have relative displacements generated between the support slot and the corresponding ledge hole (no ISRS are provided). Twelve nodes on the reflector blocks and lower core plate (location IDs 42 through 53) are used to determine the amount of relative displacement (uplift) from the lower core plate and between each block interface (no ISRS provided). Table 8-3 List of node locations for time-history and response spectra generation Location ID Description X (in) Y (in) Z (in) Figure 1 (( }}2(a),(c) Figure A-1 2 (( }}2(a),(c) Figure A-1 2(a),(c) 3 (( }} Figure A-1 2(a),(c) 4 (( }} Figure A-1 2(a),(c) 5 (( }} Figure A-1 2(a),(c) 6 (( }} Figure A-1 7 (( }}2(a),(c) Figure A-1 2(a),(c) 8 (( }} Figure A-1 2(a),(c) 9 (( }} Figure A-1 2(a),(c) 10 (( }} Figure A-2 2(a),(c) 11 (( }} Figure A-2 2(a),(c) 12 (( }} Figure A-2 2(a),(c) 13 (( }} Figure A-2 14 (( }}2(a),(c) Figure A-2 2(a),(c) 15 (( }} Figure A-2 2(a),(c) 16 (( }} Figure A-3 2(a),(c) 17 (( }} Figure A-4 2(a),(c) 18 (( }} Figure A-7 2(a),(c) 19 (( }} Figure A-8 2(a),(c) 20 (( }} Figure A-8 21 (( }}2(a),(c) Figure A-2 2(a),(c) 22 (( }} Figure A-2 2(a),(c) 23 (( }} Figure A-2 2(a),(c) 24 (( }} Figure A-8 2(a),(c) 25 (( }} Figure A-8 2(a),(c) 26 (( }} Figure A-8 27 (( }}2(a),(c) Figure A-8 2(a),(c) 28 (( }} Figure A-8 © Copyright 2018 by NuScale Power, LLC 164

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Location ID Description X (in) Y (in) Z (in) Figure 2(a),(c) 29 (( }} Figure A-8 2(a),(c) 30 (( }} Figure A-7 (( 31 }}2(a),(c) Figure A-7 32 (( }}2(a),(c) Figure A-2 2(a),(c) 33 (( }} Figure A-2 2(a),(c) 34 (( }} Figure A-2 2(a),(c) 35 (( }} Figure A-2 2(a),(c) 36 (( }} Figure A-2 37 (( }}2(a),(c) Figure A-2 2(a),(c) 38 (( }} Figure A-1 2(a),(c) 39 (( }} Figure A-1 2(a),(c) 40 (( }} Figure A-1 2(a),(c) 41 (( }} Figure A-1 42 (( }}2(a),(c) Figure A-7 43 (( }}2(a),(c) Figure A-7 44 (( }}2(a),(c) Figure A-7 45 (( }}2(a),(c) Figure A-7 46 (( }}2(a),(c) Figure A-7 47 (( }}2(a),(c) Figure A-7 48 (( }}2(a),(c) Figure A-7 49 (( }}2(a),(c) Figure A-7 50 (( }}2(a),(c) Figure A-7 51 (( }}2(a),(c) Figure A-7 52 (( }}2(a),(c) Figure A-7 53 (( }}2(a),(c) Figure A-7 8.4.2.2 Displacements, Accelerations, Rotations, and Relative Displacements For each of the node points listed in Table 8-3, the displacements, accelerations, and rotations are extracted from the model at every time step for each direction in the global coordinate system. 8.4.2.3 Forces and Moments at Component Interfaces The 3D NPM model is a global model that is used to compute internal load distributions, reaction forces and accelerations that are used to define the seismic loading applied for refined stress analysis of individual components using local finite-element analysis or classical methods. For this purpose, the resultant internal force and moment acting upon cross sections across shell structures or upon interfaces are evaluated as follows: © Copyright 2018 by NuScale Power, LLC 165

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1

1. Nodal forces and moments associated with elements adjacent to a cross section or interface are calculated for all time points.
2. Elements on one side of the cross section-cut or interface are selected for following steps. The associated nodes on the cross section or interface are selected.
3. Forces and moments acting on the selected set of nodes from the selected elements are summed about a point at the centerline of the cross section or interface. Only forces and moments acting on the selected nodes and elements contribute to the resultant. For each time point, the resultant three force components and three moment components are stored.
4. For each force and moment component direction, the maximum absolute value is determined. Maximum forces and moments are summarized in a seismic loading specification for use in subsequent analysis. Note that the maximum values may occur at different times and from different NPM seismic analysis runs. Time histories of each force and moment component may be used for detailed analysis when necessary.

Forces and moments were generated for 83 interfaces between NPM components. Seven representative component interface locations are listed in Table 8-4. For the RPV upper support interfaces, remote points at the interface representing the center of the bolts are used instead of the center coordinates of the bolt hole surfaces. Table 8-4 List of representative component interfaces for force and moment generation Component Coordinate Name X (in) Y (in) Z (in) Figure Interface ID System 1 (( }}2(a),(c) Figure A-5 4 (( }}2(a),(c) Figure A-6 5 (( }}2(a),(c) Figure A-6 6 (( }}2(a),(c) Figure A-6 7 (( }}2(a),(c) Figure A-6 18 (( }}2(a),(c) Figure A-7 19 (( }}2(a),(c) Figure A-7 8.4.2.4 Forces and Moments within Component Sections Forces and moments were generated for 22 internal sections of NPM components, including various elevations of the RPV, CNV, and RVI. Resultant forces and moments acting on internal components are evaluated as described in Section 8.4.2.3. The Section locations are listed in Table 8-5. Appendix A provides figures identifying the representative locations. © Copyright 2018 by NuScale Power, LLC 166

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 8-5 List of component sections for force and moment generation Component Name Elevation, Y (in) Figure Section ID 1 (( }}2(a),(c) Figure A-5 2 (( }}2(a),(c) Figure A-5 3 (( }}2(a),(c) Figure A-5 4 (( }}2(a),(c) Figure A-5 5 (( }}2(a),(c) Figure A-5 6 (( }}2(a),(c) Figure A-5 7 (( }}2(a),(c) Figure A-5 8 (( }}2(a),(c) Figure A-5 9 (( }}2(a),(c) Figure A-6 10 (( }}2(a),(c) Figure A-6 11 (( }}2(a),(c) Figure A-6 12 (( }}2(a),(c) Figure A-6 13 (( }}2(a),(c) Figure A-6 14 (( }}2(a),(c) Figure A-6 15 (( }}2(a),(c) Figure A-6 16 (( }}2(a),(c) Figure A-6 17 (( }}2(a),(c) Figure A-6 18 (( }}2(a),(c) Figure A-6 19 (( }}2(a),(c) Figure A-7 20 (( }}2(a),(c) Figure A-7 21 (( }}2(a),(c) Figure A-7 22 (( }}2(a),(c) Figure A-7 The FSUM command is used by selecting the elements and nodes that compose a full cross section at each component section or interface. The nodal force contributions of the selected elements (on one side of the section) are summed and stored. The nodal moment contributions of the selected elements are summed about the geometric center of the nodes that compose the cross section and stored. The nodes in the geometric center of the cross-sections are named for data retrieval. 8.4.2.5 In-Structure Response Spectra For each of the locations listed in Table 8-3, the displacements were extracted for each direction in the global Cartesian coordinate system. For response spectrum generation, six different damping ratios were considered: 2, 3, 4, 5, 7 and 10 percent. ISRS was generated from the seismic model result files, and broadened ISRS with a 15 percent frequency shift calculated for the enveloping ISRS. A typical broadened ISRS is shown in Figure 8-10. © Copyright 2018 by NuScale Power, LLC 167

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                }}2(a),(c)

Figure 8-10 Design ISRS, CNV Top Head, Z-Direction (North-South), 4% Damping 8.4.2.6 Maximum Relative Displacements The module vertical displacement was recorded at the CNV skirt (Table 8-3 Location 1) relative to the pool floor from the seismic model result files. Additional relative displacement between the 1st reflector block and the top of the lower core plate (Table 8-3 Locations 42 and 43) is recorded The relative vertical displacement is the uplift of the module or reflector blocks during seismic events. The maximum uplift displacement and occurring time were recorded for each case. 8.4.3 NuScale Power Module Seismic Analysis Results Displacement and acceleration time-histories, maximum relative displacements, and broadened response spectra were generated for 33 locations in the NPM model. An additional set of relative displacements were generated for 8 more nodes on the RPV upper support to determine how much radial sliding occurs between each support segment slot and the hole on the ledge it with which it interfaces. Twelve nodes on the reflector blocks and lower core plate are used to determine the amount of relative © Copyright 2018 by NuScale Power, LLC 168

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 displacement (uplift) from the lower core plate and between each block interface Node locations are listed in Table 8-3. See Appendix A for figures. The maximum forces and moments for the representative component interfaces listed in Table 8-4 are provided in Table 8-7 and Table 8-8. Maximum reaction forces were generated for four NPM support locations (CNV skirt and three CNV shear lugs) corresponding to nodes 1, 4, 5, and 6 of Table 8-3, at the top of the lower core plate, and at the bottom of the upper core plate for the fuel assemblies (nodes 18 and 19 of Table 8-3). The NPM support location forces are provided and compared to the reaction forces produced by the SASSI RXB model (Section 3.1.4) in Table 8-6. There were no reaction moments at the support locations. Bounding and enveloped ISRS plots were generated for the nodes listed in Table 8-3. One set of ISRS plots was generated bounding the CSDRS runs. Due to the large number of plots, representative plots are presented in Appendix B. © Copyright 2018 by NuScale Power, LLC 169

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 8-6 Maximum seismic forces on NuScale Power Module supports Maximum force (lbf) East-West Vertical North-South Location ID Description 3D Detailed SASSI RXB 3D Detailed SASSI RXB 3D Detailed SASSI RXB model model model model model model 1 CNV Skirt (1) (( }}2(a),(c) 4 CNV East Lug (( }}2(a),(c) 5 CNV West Lug (( }}2(a),(c) 6 CNV North Lug (( }}2(a),(c) Notes: (1) The NPM seismic model does not consider eccentricity of the vertical force at the CNV skirt that should be considered in the design. The CNV skirt outer radius, which is 70.6 in., can be conservatively used as the maximum eccentricity. © Copyright 2018 by NuScale Power, LLC 170

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Table 8-7 Maximum seismic reactions at RPV Upper Supports (cylindrical coordinates) Maximum force (lbf) ID Description FR FY F Radial Vertical Circumferential 4 RPV upper support - segment -X+Z (( }}2(a),(c) 5 RPV upper support - segment +X+Z (( }}2(a),(c) 6 RPV upper support - segment +X-Z (( }}2(a),(c) 7 RPV upper support - segment -X-Z (( }}2(a),(c) Table 8-8 Maximum Seismic Reactions at Fuel Assembly Supports Maximum force (lbf) Maximum Moment (in-lbf) Coor-ID Description FX FZ dinate FY East- North- MX MY MZ System Vertical West South 18 Fuel Assemblies, Lower Core Plate (( }}2(a),(c) 19 Fuel Assemblies, Upper Core Plate (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 171

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Maximum uplift displacements were calculated for each of the six runs. The maximum uplift for the CNV skirt occurred in the run representing the Capitola time history, soil type 7, with cracked concrete, on the NPM in operating bay 1 with a reduced stiffness. Reflector block uplift is calculated with respect to the top of the lower core plate. The maximum uplift for the reflector blocks occurred in the run representing the Capitola time history, soil type 7, with cracked concrete, on the NPM in operating bay 1 with a nominal stiffness. The displacements and time are provided in Table 8-9. Table 8-9 Maximum uplift displacements Component Max. Uplift Occurring Time (s) Displacement (in) CNV Skirt (( }}2(a),(c) 1st Reflector Block (( }}2(a),(c) © Copyright 2018 by NuScale Power, LLC 172

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 9.0 Conclusion Given the complexity of the NuScale Power Module and its connected subsystems, the dynamic analysis of the NPM required a complete system model to represent the dynamic coupling of the RPV, the CNV, reactor internals and core support, the reactor core, surrounding pool water, and SSC supported by the NPM. Dynamic analysis of the complete NPM system was performed using time history dynamic analysis methods and a three-dimensional ANSYS finite element model, as well as a model of the lower RPV in the RFT. The detailed NPM system model included acoustic elements to properly represent the effects of fluid-structure interaction due to the pool water between the CNV and pool floor and walls. To account for the dynamic coupling of the NPMs and the RXB system, a model of each of the NPMs was included in the RXB system model. The complete RXB system model, with representation of the NPMs, was analyzed for SSI in the frequency domain using computer code SASSI. Results from the RXB seismic system analysis were in-structure time histories at each NPM support location and the pool walls and floor surrounding the NPM. In-structure response spectra were also calculated and representative ISRS plots presented in Appendix B. The NPM dynamic analysis produced in-structure time histories and in-structure response spectra to be used for qualification of equipment supported on the NPM, and time histories at the core support locations for seismic qualification of fuel assemblies. © Copyright 2018 by NuScale Power, LLC 173

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 10.0 References 10.1 Referenced Documents 10.1.1 Not Used. 10.1.2 US NRC, Interim Staff Guidance on Seismic Issues Associated with High Frequency Ground Motion in Design Certification and Combined License Applications, DC/COL-ISG-001. 10.1.3 NUREG-0800, Standard Review Plan for Review of Safety Analysis Reports for Nuclear Power Plants, Section 3.7.3, Seismic Subsystem Analysis, Revision 4, September, 2013. 10.1.4 IEEE Standard 344-2004, IEEE Recommended Practice for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations. 10.1.5 ASME Boiler and Pressure Vessel Code, Section III, Rules for Construction of Nuclear Facility Components, 2013 Edition with no addenda. 10.1.6 US NRC Regulatory Guide 1.122,Development of Floor Design Response Spectra for Seismic Design of Floor-Supported Equipment or Components, Revision 1, February 1978. 10.1.7 American Society of Civil Engineers, Seismic Analysis of Safety-Related Nuclear Structures, ASCE 4, 1998. 10.1.8 American Society of Civil Engineers, Seismic Design Criteria for Structures, Systems, and Components in Nuclear Facilities, ASCE/SEI 43, 2005. 10.1.9 R.J. Fritz, The Effect of Liquids on Dynamic Motion of Immersed Solids, Journal of Engineering for Industry, February, 1972. 10.1.10 Meyer, M. et al. Generalized Barycentric Coordinates on Irregular Polygons. Pages 13-22. Journal of Graphic Tools, Volume 7 Issue 1, November 2002. 10.1.11 Matthew D. Snyder, Method for Hydrodynamic Coupling of Concentric Cylindrical Shells and Beams, 2004 International ANSYS Conference, Pittsburgh, PA, May 24-26, 2004. 10.1.12 Manual of Steel Construction: Load and Resistance Factor Design, Volume 1, Second Edition. © Copyright 2018 by NuScale Power, LLC 174

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Appendix A. Locations for Displacements, ISRS, Forces, and Moments ((

                                                                                          }}2(a),(c)

Figure A-1 Locations on the containment vessel © Copyright 2018 by NuScale Power, LLC 175

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                 }}2(a),(c)

Figure A-2 Locations on reactor pressure vessel and control rod drive mechanism support © Copyright 2018 by NuScale Power, LLC 176

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                       }}2(a),(c)

Figure A-3 Locations on lower core plate ((

                                                                                       }}2(a),(c)

Figure A-4 Locations on upper core plate © Copyright 2018 by NuScale Power, LLC 177

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                               }}2(a),(c)

Figure A-5 Additional locations on the containment vessel © Copyright 2018 by NuScale Power, LLC 178

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                                  }}2(a),(c)

Figure A-6 Additional locations on the reactor pressure vessel © Copyright 2018 by NuScale Power, LLC 179

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                            }}2(a),(c)

Figure A-7 Locations on lower reactor vessel internals © Copyright 2018 by NuScale Power, LLC 180

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 ((

                                                                                            }}2(a),(c)

Figure A-8 Locations on upper reactor vessel internals © Copyright 2018 by NuScale Power, LLC 181

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Appendix B. Representative In-Structure Response Spectra The representative full model ISRS plots are provided in Figure B-1 to Figure B-30, and Figure B-31 to Figure B-36 for the RFT model. All figures are plotted in the NPM coordinate system. Figure B-1 Design ISRS, CNV skirt, location 1, X-direction (east-west) Figure B-2 Design ISRS, CNV skirt, location 1, Z-direction (north-south) © Copyright 2018 by NuScale Power, LLC 182

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-3 Design ISRS, CNV skirt, location 1, Y-direction (vertical) Figure B-4 Design ISRS, containment vessel lug +X, location 4, X-direction (east-west) © Copyright 2018 by NuScale Power, LLC 183

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-5 Design ISRS, containment vessel lug +X, location 4, Z-direction (north-south) Figure B-6 Design ISRS, containment vessel lug +X, location 4, Y-direction (vertical) © Copyright 2018 by NuScale Power, LLC 184

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-7 Design ISRS, containment vessel lug -X, location 5, X-direction (east-west) Figure B-8 Design ISRS, containment vessel lug -X, location 5, Z-direction (north-south) © Copyright 2018 by NuScale Power, LLC 185

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-9 Design ISRS, containment vessel lug -X, location 5, Y-direction (vertical) Figure B-10 Design ISRS, containment vessel lug -Z, location 6, X-direction (east-west) © Copyright 2018 by NuScale Power, LLC 186

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-11 Design ISRS, containment vessel lug -Z, location 6, Z-direction (north-south) Figure B-12 Design ISRS, containment vessel lug -Z, location 6, Y-direction (vertical) © Copyright 2018 by NuScale Power, LLC 187

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-13 Design ISRS, containment vessel top head, location 8, X-direction (east-west) Figure B-14 Design ISRS, containment vessel top head, location 8, Z-direction (north-south) © Copyright 2018 by NuScale Power, LLC 188

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-15 Design ISRS, containment vessel top head, location 8, Y-direction (vertical) Figure B-16 Design ISRS, reactor pressure vessel top head, location 14, X-direction (east-west) © Copyright 2018 by NuScale Power, LLC 189

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-17 Design ISRS, reactor pressure vessel top head, location 14, Z-direction (north-south) Figure B-18 Design ISRS, reactor pressure vessel top head, location 14, Y-direction (vertical) © Copyright 2018 by NuScale Power, LLC 190

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-19 Design ISRS, top of lower core plate, location 16, X-direction (east-west) Figure B-20 Design ISRS, top of lower core plate, location 16, Z-direction (north-south) © Copyright 2018 by NuScale Power, LLC 191

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-21 Design ISRS, top of lower core plate, location 16, Y-direction (vertical) Figure B-22 Design ISRS, bottom of upper core plate, location 17, X-direction (east-west) © Copyright 2018 by NuScale Power, LLC 192

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-23 Design ISRS, bottom of upper core plate, location 17, Z-direction (north-south) Figure B-24 Design ISRS, bottom of upper core plate, location 17, Y-direction (vertical) © Copyright 2018 by NuScale Power, LLC 193

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-25 Design ISRS, steam generator section top, location 32, X-direction (east-west) Figure B-26 Design ISRS, steam generator section top, location 32, Z-direction (north-south) © Copyright 2018 by NuScale Power, LLC 194

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-27 Design ISRS, steam generator section top, location 32, Y-direction (vertical) Figure B-28 Design ISRS, steam generator section bottom, location 33, X-direction (east-west) © Copyright 2018 by NuScale Power, LLC 195

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-29 Design ISRS, steam generator section bottom, location 33, Z-direction (north-south) Figure B-30 Design ISRS, steam generator section bottom, location 33, Y-direction (vertical) © Copyright 2018 by NuScale Power, LLC 196

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-31 RFT Model ISRS, top of lower core plate, location 16, X-Direction (east-west) Figure B-32 RFT Model ISRS, top of lower core plate, location 16, Z-Direction (north-south) © Copyright 2018 by NuScale Power, LLC 197

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-33 RFT Model ISRS, top of lower core plate, location 16, Y-Direction (vertical) Figure B-34 RFT Model ISRS, bottom of upper core plate, location 17, X-Direction (east-west) © Copyright 2018 by NuScale Power, LLC 198

NuScale Power Module Seismic Analysis TR-0916-51502-NP Rev. 1 Figure B-35 RFT Model ISRS, bottom of upper core plate, location 17, Z-Direction (north-south) Figure B-36 RFT Model ISRS, bottom of upper core plate, location 17, Y-Direction (vertical) © Copyright 2018 by NuScale Power, LLC 199

LO-0918-61887 : Affidavit of Thomas A. Bergman, AF-0918-61892 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvallis, Oregon 97330 Office 541.360-0500 Fax 541.207.3928 www.nuscalepower.com

NuScale Power, LLC AFFIDAVIT of Thomas A. Bergman I, Thomas A. Bergman, state as follows: (1) I am the Vice President of Regulatory Affairs of NuScale Power, LLC (NuScale), and as such, I have been specifically delegated the function of reviewing the information described in this Affidavit that NuScale seeks to have withheld from public disclosure, and am authorized to apply for its withholding on behalf of NuScale. (2) I am knowledgeable of the criteria and procedures used by NuScale in designating information as a trade secret, privileged, or as confidential commercial or financial information. This request to withhold information from public disclosure is driven by one or more of the following: (a) The information requested to be withheld reveals distinguishing aspects of a process (or component, structure, tool, method, etc.) whose use by NuScale competitors, without a license from NuScale, would constitute a competitive economic disadvantage to NuScale. (b) The information requested to be withheld consists of supporting data, including test data, relative to a process (or component, structure, tool, method, etc.), and the application of the data secures a competitive economic advantage, as described more fully in paragraph 3 of this Affidavit. (c) Use by a competitor of the information requested to be withheld would reduce the competitors expenditure of resources, or improve its competitive position, in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product. (d) The information requested to be withheld reveals cost or price information, production capabilities, budget levels, or commercial strategies of NuScale. (e) The information requested to be withheld consists of patentable ideas. (3) Public disclosure of the information sought to be withheld is likely to cause substantial harm to NuScales competitive position and foreclose or reduce the availability of profit-making opportunities. The accompanying technical report reveals distinguishing aspects about the method and analyses by which NuScale evaluates its power module seismic response. NuScale has performed significant research and evaluation to develop a basis for the subject method and analyses and has invested significant resources, including the expenditure of a considerable sum of money. The precise financial value of the information is difficult to quantify, but it is a key element of the design basis for a NuScale plant and, therefore, has substantial value to NuScale. If the information were disclosed to the public, NuScale's competitors would have access to the information without purchasing the right to use it or having been required to undertake a similar expenditure of resources. Such disclosure would constitute a misappropriation of NuScale's intellectual property, and would deprive NuScale of the opportunity to exercise its competitive advantage to seek an adequate return on its investment. (4) The information sought to be withheld is in the enclosed technical report titled NuScale Power Module Seismic Analysis, Revision 1. The enclosure contains the designation Proprietary" at the top of each page containing proprietary information. The information considered by NuScale to be proprietary is identified within double braces, "(( }}" in the document. (5) The basis for proposing that the information be withheld is that NuScale treats the information as a trade secret, privileged, or as confidential commercial or financial information. NuScale relies upon AF-0918-61892 Page 1 of 2

the exemption from disclosure set forth in the Freedom of Information Act ("FOIA"), 5 USC § 552(b)(4), as well as exemptions applicable to the NRC under 10 CFR §§ 2.390(a)(4) and 9.17(a)(4). (6) Pursuant to the provIsIons set forth in 10 CFR § 2.390(b)(4), the following is provided for consideration by the Commission in determining whether the information sought to be withheld from public disclosure should be withheld: (a) The information sought to be withheld is owned and has been held in confidence by NuScale . (b) The information is of a sort customarily held in confidence by NuScale and, to the best of my knowledge and belief, consistently has been held in confidence by NuScale. The procedure for approval of external release of such information typically requires review by the staff manager, project manager, chief technology officer or other equivalent authority, or the manager of the cognizant marketing function (or his delegate), for technical content, competitive effect, and determination of the accuracy of the proprietary designation. Disclosures outside NuScale are limited to regulatory bodies, customers and potential customers and their agents, suppliers, licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or contractual agreements to maintain confidentiality. (c) The information is being transmitted to and received by the NRC in confidence. (d) No public disclosure of the information has been made, and it is not available in public sources. All disclosures to third parties, including any required transmittals to NRC, have been made, or must be made, pursuant to regulatory provisions or contractual agreements that provide for maintenance of the information in confidence. (e) Public disclosure of the information is likely to cause substantial harm to the competitive position of NuScale, taking into account the value of the information to Nu Scale, the amount of effort and money expended by NuScale in developing the information, and the difficulty others would have in acquiring or duplicating the information. The information sought to be withheld is part of NuScale's technology that provides NuScale with a competitive advantage over other firms in the industry. NuScale has invested significant human and financial capital in developing this technology and Nu Scale believes it would be difficult for others to duplicate the technology without access to the information sought to be withheld. I declare under penalty of perjury that the foregoing is true and correct. Executed on September 28, 2017. AF-0918-61892 Page 2 of 2}}